WorldWideScience

Sample records for incentives cellulosic ethanol

  1. [Insights into engineering of cellulosic ethanol].

    Science.gov (United States)

    Yue, Guojun; Wu, Guoqing; Lin, Xin

    2014-06-01

    For energy security, air pollution concerns, coupled with the desire to sustain the agricultural sector and revitalize the rural economy, many countries have applied ethanol as oxygenate or fuel to supplement or replace gasoline in transportation sector. Because of abundant feedstock resources and effective reduction of green-house-gas emissions, the cellulosic ethanol has attracted great attention. With a couple of pioneers beginning to produce this biofuel from biomass in commercial quantities around the world, it is necessary to solve engineering problems and complete the economic assessment in 2015-2016, gradually enter the commercialization stage. To avoid "competing for food with humans and competing for land with food", the 1st generation fuel ethanol will gradually transit to the 2nd generation cellulosic ethanol. Based on the overview of cellulosic ethanol industrialization from domestic and abroad in recent years, the main engineering application problems encountered in pretreatment, enzymes and enzymatic hydrolysis, pentose/hexose co-fermentation strains and processes, equipment were discussed from chemical engineering and biotechnology perspective. The development direction of cellulosic ethanol technology in China was addressed.

  2. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

    Bensah, Edem Cudjoe; Kemausuor, Francis; Miezah, Kodwo

    2015-01-01

    A major challenge to commercial production of cellulosic ethanol pertains to the cost-effective breakdown of the complex and recalcitrant structure of lignocellulose into its components via pretreatment, the cost of enzymes for hydrolysis and fermentation, and the conversion rate of C5 sugars...... to ethanol, among others. While the industrialized and some emerging countries are gradually breaking grounds in cellulosic ethanol, most African countries have made little effort in research and development even though the continent is rich in lignocellulosic biomass. The paper estimates residues from...... widely available crops and municipal waste and determines their respective theoretical ethanol potential (around 22 billion litres annually). It further reviews stages involved in the production of cellulosic ethanol, focussing on processing methods that can be adapted to current situation in most...

  3. Pavlovian conditioning with ethanol: sign-tracking (autoshaping), conditioned incentive, and ethanol self-administration.

    Science.gov (United States)

    Krank, Marvin D

    2003-10-01

    Conditioned incentive theories of addictive behavior propose that cues signaling a drug's reinforcing effects activate a central motivational state. Incentive motivation enhances drug-taking and drug-seeking behavior. We investigated the behavioral response to cues associated with ethanol and their interaction with operant self-administration of ethanol. In two experiments, rats received operant training to press a lever for a sweetened ethanol solution. After operant training, the animals were given Pavlovian pairings of a brief and localized cue light with the sweetened ethanol solution (no lever present). Lever pressing for ethanol was then re-established, and the behavioral effects of the cue light were tested during an ethanol self-administration session. The conditioned responses resulting from pairing cue lights with the opportunity to ingest ethanol had three main effects: (1) induction of operant behavior reinforced by ethanol, (2) stimulation of ethanol-seeking behavior (magazine entries), and (3) signal-directed behavior (i.e., autoshaping, or sign-tracking). Signal-directed behavior interacted with the other two effects in a manner predicted by the location of the cue light. These conditioned responses interact with operant responding for ethanol reinforcement. These findings demonstrate the importance of Pavlovian conditioning effects on ethanol self-administration and are consistent with conditioned incentive theories of addictive behavior.

  4. Method for producing ethanol and co-products from cellulosic biomass

    Science.gov (United States)

    Nguyen, Quang A

    2013-10-01

    The present invention generally relates to processes for production of ethanol from cellulosic biomass. The present invention also relates to production of various co-products of preparation of ethanol from cellulosic biomass. The present invention further relates to improvements in one or more aspects of preparation of ethanol from cellulosic biomass including, for example, improved methods for cleaning biomass feedstocks, improved acid impregnation, and improved steam treatment, or "steam explosion."

  5. Cellulosic ethanol is ready to go

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M. [SunOpta BioProcess Group, Brampton, ON (Canada)

    2006-07-01

    A corporate overview of the SunOpta organization was presented. The organization includes three divisions, notably organic food, industrial minerals, and a bioprocess group. It is a Canadian organization that has experienced over 60 per cent growth per year since 1999. The presentation provided a history of the bioprocess group from 1973 to 2003. The presentation also illustrated the biomass process from wood, straw or corn stover to cellulosic ethanol and acetone and butanol. Several images were presented. The production of xylitol from oat hulls and birch and from ryegrass straw to linerboard was also illustrated. Last, the presentation illustrated the biomass production of cellulose, hemicellulose and lignin extraction as well as the ammonia pretreatment of cellulosics. The presentation also listed several current and future developments such as an expansion plan and implementation of cellulosic ethanol. Economic success was defined as requiring proximity to market; high percentage concentration to distillation; and co-located within existing infrastructure. figs.

  6. Production of ethanol from cellulose (sawdust)

    OpenAIRE

    Otulugbu, Kingsley

    2012-01-01

    The production of ethanol from food such as corn, cassava etc. is the most predominate way of producing ethanol. This has led to a shortage in food, inbalance in food chain, increased food price and indirect land use. This thesis thus explores using another feed for the production of ethanol- hence ethanol from cellulose. Sawdust was used to carry out the experiment from the production of ethanol and two methods were considered: SHF (Separate Hydrolysis and Fermentation) and SSF (Simultaneous...

  7. Evaluation of ethanol productivity from cellulose by Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Kurose, N; Yagyu, J; Miyazaki, T; Uchida, M; Hanai, S; Obayashi, A

    1986-01-01

    Clostridium thermocellum, a thermophilic anaerobe, directly converts cellulose to EtOH. To estimate its EtOH production from cellulose, we used a new method based on material balance by which the efficiencies of the enzymes that convert cellulose to ethanol were calculated. Using this method, the maximum efficiency of ethanol production of two strains of C. thermocellum was estimated to be 0.05, with 0.67 as the theoretical maximum. 3 references.

  8. Implications of Industrial Processing Strategy on Cellulosic Ethanol Production at High Solids Concentrations

    DEFF Research Database (Denmark)

    Cannella, David

    The production of cellulosic ethanol is a biochemical process of not edible biomasses which contain the cellulose. The process involves the use of enzymes to hydrolyze the cellulose in fermentable sugars to finally produce ethanol via fermentative microorganisms (i.e. yeasts). These biomasses...... are the leftover of agricultural productions (straws), not edible crops (giant reed) or wood, thus the ethanol so produced is also called second generation (or 2G ethanol), which differs from the first generation produced from starch (sugar beets mostly). In the industrial production of cellulosic ethanol high...... solids strategy resulted critical for its cost effectiveness: high concentration of initial biomass it will lead to high concentration of the final product (ethanol), thus more convenient to isolate. This thesis investigate the implementation of a high solids loading concept into cellulosic ethanol...

  9. Experimental study on the liquefaction of cellulose in supercritical ethanol

    Science.gov (United States)

    Peng, Jinxing; Liu, Xinyuan; Bao, Zhenbo

    2018-03-01

    Cellulose is the major composition of solid waste for producing biofuel; cellulose liquefaction is helpful for realizing biomass supercritical liquefaction process. This paper is taking supercritical ethanol as the medium, liquefied cellulose with the intermittence installation of high press cauldron. Experiments have studied technical condition and the technology parameter of cellulose liquefaction in supercritical ethanol, and the pyrolysis mechanism was analysed based on the pyrolysis product. Results show that cellulose can be liquefied, can get good effect through appropriate technology condition. Under not catalyst, highest liquefaction rate of cellulose can reach 73.5%. The composition of the pyrolysis product was determined by GC-MS.

  10. Adsorption of Saccharomyces cerevisiae onto cellulose and ecteola-cellulose films for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Lueng, K.L.; Joshi, S.; Yamazaki, H.

    1983-05-01

    Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Umodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 hours of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour. (Refs. 4).

  11. Grain and cellulosic ethanol: History, economics, and energy policy

    International Nuclear Information System (INIS)

    Solomon, Barry D.; Barnes, Justin R.; Halvorsen, Kathleen E.

    2007-01-01

    The United States (US) and Brazil have been the two leading producers of fuel ethanol since the 1970s. National policies have supported the production and use of ethanol from corn and sugarcane. US support in particular has included exemption from federal gasoline excise taxes, whole or partial exemption from road use (sales) taxes in nine states, a federal production tax credit, and a federal blender's credit. In the last decade the subsidization of grain-based ethanol has been increasingly criticized as economically inefficient and of questionable social benefit. In addition, much greater production of ethanol from corn may conflict with food production needs. A promising development is the acceleration of the technical readiness of cellulosic alcohol fuels, which can be produced from the woody parts of trees and plants, perennial grasses, or residues. This technology is now being commercialized and has greater long-term potential than grain ethanol. Cellulosic ethanol is projected to be much more cost-effective, environmentally beneficial, and have a greater energy output to input ratio than grain ethanol. The technology is being developed in North America, Brazil, Japan and Europe. In this paper, we will review the historical evolution of US federal and state energy policy support for and the currently attractive economics of the production and use of ethanol from biomass. The various energy and economic policies will be reviewed and assessed for their potential effects on cellulosic ethanol development relative to gasoline in the US. (author)

  12. Cellulosic ethanol. Potential, technology and development status

    Energy Technology Data Exchange (ETDEWEB)

    Rarbach, M. [Sued-Chemie AG, Muenchen (Germany)

    2012-07-01

    In times of rising oil prices and a growing energy demand, sustainable alternative energy sources are needed. Cellulosic ethanol is a sustainable biofuel, made from lignocellulosic feedstock such as agricultural residues (corn stover, cereal straw, bagasse) or dedicated energy crops. Its production is almost carbon neutral, doesn't compete with food or feed production and induces no land use changes. It constitutes a new energy source using an already existing renewable feedstock without needing any further production capacity and can thus play a major role on the way to more sustainability in transport and the chemical industry and reducing the dependence on the import of fossil resources. The potential for cellulosic ethanol is huge: In the US, the annual production of agricultural residues (cereal straw and corn stover) reached almost 384 million tons in 2009 and Brazil alone produced more than 670 million tons of sugar cane in 2009 yielding more than 100 million tons of bagasse (dry basis). And alone in the European Union, almost 300 million tons of crop straw are produced annually. The last years have seen success in the development and deployment in the field of cellulosic ethanol production. The main challenge thereby remains to demonstrate that the technology is economically feasible for the up-scaling to industrial scale. Clariant has developed the sunliquid {sup registered} process, a proprietary cellulosic ethanol technology that reaches highest greenhouse gas (GHG) emission savings while cutting production costs to a minimum. The sunliquid {sup registered} process for cellulosic ethanol matches the ambitious targets for economically and ecologically sustainable production and greenhouse gas reduction. It was developed using an integrated design concept. Highly optimized, feedstock and process specific biocatalysts and microorganisms ensure a highly efficient process with improved yields and feedstock-driven production costs. Integrated, on

  13. Maximizing cellulosic ethanol potentials by minimizing wastewater generation and energy consumption: Competing with corn ethanol.

    Science.gov (United States)

    Liu, Gang; Bao, Jie

    2017-12-01

    Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63GJ and wastewater generation to 7.71tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83GJ and 8.33tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Long-run effects of falling cellulosic ethanol production costs on the US agricultural economy

    International Nuclear Information System (INIS)

    Campiche, Jody L; Bryant, Henry L; Richardson, James W

    2010-01-01

    Renewable energy production has been expanding at a rapid pace. New advances in cellulosic ethanol technologies have the potential to displace the use of petroleum as a transportation fuel, and could have significant effects on both the agricultural economy and the environment. In this letter, the effects of falling cellulosic ethanol production costs on the mix of ethanol feedstocks employed and on the US agricultural economy are examined. Results indicate that, as expected, cellulosic ethanol production increases by a substantial amount as conversion technology improves. Corn production increases initially following the introduction of cellulosic technology, because producers enjoy new revenue from sales of corn stover. After cellulosic ethanol production becomes substantially cheaper, however, acres are shifted from corn production to all other agricultural commodities. Essentially, this new technology could facilitate the exploitation of a previously under-employed resource (corn stover), resulting in an improvement in overall welfare. In the most optimistic scenario considered, 68% of US ethanol is derived from cellulosic sources, coarse grain production is reduced by about 2%, and the prices of all food commodities are reduced modestly.

  15. High-resolution techno-ecological modelling of a bioenergy landscape to identify climate mitigation opportunities in cellulosic ethanol production

    Science.gov (United States)

    Field, John L.; Evans, Samuel G.; Marx, Ernie; Easter, Mark; Adler, Paul R.; Dinh, Thai; Willson, Bryan; Paustian, Keith

    2018-03-01

    Although dedicated energy crops will probably be an important feedstock for future cellulosic bioenergy production, it is unknown how they can best be integrated into existing agricultural systems. Here we use the DayCent ecosystem model to simulate various scenarios for growing switchgrass in the heterogeneous landscape that surrounds a commercial-scale cellulosic ethanol biorefinery in southwestern Kansas, and quantify the associated fuel production costs and lifecycle greenhouse gas (GHG) emissions. We show that the GHG footprint of ethanol production can be reduced by up to 22 g of CO2 equivalent per megajoule (CO2e MJ-1) through careful optimization of the soils cultivated and corresponding fertilizer application rates (the US Renewable Fuel Standard requires a 56 gCO2e MJ-1 lifecycle emissions reduction for `cellulosic' biofuels compared with conventional gasoline). This improved climate performance is realizable at modest additional costs, less than the current value of low-carbon fuel incentives. We also demonstrate that existing subsidized switchgrass plantings within this landscape probably achieve suboptimal GHG mitigation, as would landscape designs that strictly minimize the biomass collection radius or target certain marginal lands.

  16. Assessing Resource Intensity and Renewability of Cellulosic Ethanol Technologies using Eco-LCA

    Science.gov (United States)

    Recognizing the contributions of natural resources and the lack of their comprehensive accounting in life cycle assessment (LCA) of cellulosic ethanol, an in-depth analysis of the contribution of natural resources in the life cycle of cellulosic ethanol derived from five differen...

  17. Overview of technical barriers and implementation of cellulosic ethanol in the U.S

    International Nuclear Information System (INIS)

    Kim, Tae Hoon; Kim, Tae Hyun

    2014-01-01

    There is mounting concern about the buildup of carbon dioxide (CO 2 ) and other so-called greenhouse gases in the atmosphere. In general, bioethanol production requires minimal fossil fuel input in the conversion step, and ethanol is considered a promising alternative fuel to petroleum-derived products. It is anticipated that ethanol production with second-generation biomass, i.e. lignocellulosic materials, will be possible on a large scale in the near future. Latest efforts have been focused on overcoming technical challenges in bioconversion, particularly pretreatment, and finding the solutions required to implement biorefinery on a large scale. This paper introduces and reviews the current status of research, and of the ethanol industry in the U.S. In addition, other important concepts in biofuels, cellulosic ethanol, and biorefinery in general are reviewed, and the key technical issues in bioconversion of cellulosic ethanol, such as pretreatment and factors affecting bioconversion of biomass are also discussed. - Highlights: • The current status of research, and of the ethanol industry in the U.S. • Important concepts in biofuels, cellulosic ethanol, and biorefinery. • The key technical issues in bioconversion of cellulosic ethanol. • Pretreatment and factors affecting bioconversion of biomass

  18. Characteristics of the products of hydrothermal liquefaction combined with cellulosic bio-ethanol process

    International Nuclear Information System (INIS)

    Li, Rundong; Xie, Yinghui; Yang, Tianhua; Li, Bingshuo; Zhang, Yang; Kai, Xingping

    2016-01-01

    The integration utilization of fermentation residues from cellulosic bio-ethanol has attracted a great deal of attention to balance the total cost of bio-ethanol production while simultaneously dealing with bio-ethanol wastewater. A process of hydrothermal liquefaction (HTL) of intact materials from cellulosic bio-ethanol in a batch reactor was proposed. The effects of the reaction temperature and time on the liquefaction characteristics were examined. The optimum condition for liquefaction fermentation residues was 370 °C (21.25 MPa) and 30 min with a bio-oil yield of 40.79 wt%. GC-MS results indicated that the major chemical species in the bio-oil were phenols, ketones, long-chain hydrocarbons and fatty acids. Supercritical conditions (375 °C, 23.50 MPa) was favored for the low-molecular-weight species formation compared to subcritical conditions (370 °C, 21.25 MPa), as some long-chain species decreased. This work thus can provide a novel idea for bio-oil production from HTL of cellulosic bio-ethanol fermentation residues. - Highlights: • Bio-oil production via HTL combined with cellulosic bio-ethanol process was proposed. • Optimum condition for HTL of materials from cellulosic bio-ethanol was 370 °C and 30 min. • Bio-oil contained higher content of hydrocarbons and lower contents of organic acids.

  19. Ethanol production from cellulose, lactose and xylose using yeasts and enzymes. Gewinnung von Ethanol aus Cellulose, Lactose, und Xylose mit Hilfe von Hefen und Enzymen

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, U

    1986-07-03

    Experiments with mixtures of whey and corn showed that more than 85% of the lactose was degraded into ethanol. The applicability of cellulose was investigated by means of potatoes. Cellulase is inhibited by glucose, which is a fermentation intermediate, as well as by the end product ethanol. A cellulase inhibitor in potatoes was detected and stabilized; this inhibitor could be degraded into neutral components by a suitable enzyme. Saccharification and fermentation experiments showed that the cellulose fraction of potatoes can be reduced efficiently. The effects of non-enzymatic pretreatment on enzymatic degradation of cellulose, combined with fermentation of the degradation products, are illustrated by the example of cellulose treated with acid and alkaline substances. A continuous fermentation system was developed from which the ethanol is withdrawn in vapour form. The system made better use of the cellulase activity and increased the efficiency of a xylose-fermenting yeast. The new method is compared with batch experiments in order to assess its efficiency. The advantages of the continuous process are proved for two yeasts of the species Pachysolu and Pichia. Specific fermentation rates up to 0.08 g/(g x h) and fermentation yields up to 0.42 g ethanol/g xylose were achieved with Pichia stipitis.

  20. 75 FR 42745 - Production Incentives for Cellulosic Biofuels: Notice of Program Intent

    Science.gov (United States)

    2010-07-22

    ... Cellulosic Biofuels: Notice of Program Intent AGENCY: Office of Energy Efficiency and Renewable Energy...). Through this notice, biofuels producers and other interested parties are invited to submit pre-auction..., ``Production Incentives for Cellulosic Biofuels; Reverse Auction Procedures and Standards,'' (74 FR 52867...

  1. The Role of Cellulosic Ethanol in Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Neilson, Jr.

    2007-10-01

    Petroleum provides essentially all of the energy used today in the transportation sector. To reduce this dependence on fossil energy, other fuels are beginning to be used, notably ethanol and biodiesel. Almost all fuel ethanol is produced by the conversion of corn grain to starch with subsequent fermentation to ethanol. In 2006, almost 5 billion gallons of fuel ethanol were produced, which used 17% of domestic corn production. The DOE has a goal to displace 30% of motor gasoline demand or 60 billion gallons per year by 2030. To achieve this goal, production of ethanol from lignocellulosic sources (e.g., agricultural residues, forest residues, and dedicated energy crops) is needed. This paper will describe the production of cellulosic ethanol as well as the issues and benefits associated with its production.

  2. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

    Gallagher, M. E.; Hockaday, W. C.; Snapp, S.; McSwiney, C.; Baldock, J.

    2010-12-01

    Corn grain biofuel crops produce the highest yields when the cropping ecosystem is not nitrogen (N)-limited, achieved by application of fertilizer. There are environmental consequences for excessive fertilizer application to crops, including greenhouse gas emissions, hypoxic “dead zones,” and health problems from N runoff into groundwater. The increase in corn acreage in response to demand for alternative fuels (i.e. ethanol) could exacerbate these problems, and divert food supplies to fuel production. A potential substitute for grain ethanol that could reduce some of these impacts is cellulosic ethanol. Cellulosic ethanol feedstocks include grasses (switchgrass), hardwoods, and crop residues (e.g. corn stover, wheat straw). It has been assumed that these feedstocks will require similar N fertilization rates to grain biofuel crops to maximize yields, but carbohydrate yield versus N application has not previously been monitored. We report the biochemical stocks (carbohydrate, protein, and lignin in Mg ha-1) of a corn ecosystem grown under varying N levels. We measured biochemical yield in Mg ha-1 within the grain, leaf and stem, and reproductive parts of corn plants grown at seven N fertilization rates (0-202 kg N ha-1), to evaluate the quantity and quality of these feedstocks across a N fertilization gradient. The N fertilization rate study was performed at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. Biochemical stocks were measured using 13C nuclear magnetic resonance spectroscopy (NMR), combined with a molecular mixing model (Baldock et al. 2004). Carbohydrate and lignin are the main biochemicals of interest in ethanol production since carbohydrate is the ethanol feedstock, and lignin hinders the carbohydrate to ethanol conversion process. We show that corn residue carbohydrate yields respond only weakly to N fertilization compared to grain. Grain carbohydrate yields plateau in response to fertilization at

  3. The operable modeling of simultaneous saccharification and fermentation of ethanol production from cellulose.

    Science.gov (United States)

    Shen, Jiacheng; Agblevor, Foster A

    2010-03-01

    An operable batch model of simultaneous saccharification and fermentation (SSF) for ethanol production from cellulose has been developed. The model includes four ordinary differential equations that describe the changes of cellobiose, glucose, yeast, and ethanol concentrations with respect to time. These equations were used to simulate the experimental data of the four main components in the SSF process of ethanol production from microcrystalline cellulose (Avicel PH101). The model parameters at 95% confidence intervals were determined by a MATLAB program based on the batch experimental data of the SSF. Both experimental data and model simulations showed that the cell growth was the rate-controlling step at the initial period in a series of reactions of cellulose to ethanol, and later, the conversion of cellulose to cellobiose controlled the process. The batch model was extended to the continuous and fed-batch operating models. For the continuous operation in the SSF, the ethanol productivities increased with increasing dilution rate, until a maximum value was attained, and rapidly decreased as the dilution rate approached the washout point. The model also predicted a relatively high ethanol mass for the fed-batch operation than the batch operation.

  4. Analysis of ethanol production potential from cellulosic feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Stone, J E

    1982-03-01

    This report provides a comprehensive and scientific overview of results emerging from research on ethanol producton from cellulosic materials and indicates those areas which appear to warrant additional support. Many published economic analyses of production costs are examined, but the emphasis of the report is on research and on its potential for reducing the cost of ethanol production. The author concludes that the uncertainty surrounding the cost of producing ethanol from cellulosic feedstocks via enzymatic hydrolysis will not be resolved until a pilot plant has been built of sufficient size to produce realistic engineering data. He gives five reasons why Canada should build such a pilot plant: Canada's apparent leadership in developing a steam pre-treatment process, the desirability of encouraging developments and building a cadre of experts in biotechnology, the absence of a pilot plant in Canada where the various organisms and biochemical processes involved in ethanol production and by-product utilization can be developed on a reasonably large scale, Canadian expertise in lignin chemistry which might be used to capitalize upon the reactive lignin residue, and research in progress at National Research Council and elsewhere on the conversion of C/sub 5/ sugars to ethanol. 37 refs., 2 figs., 4 tabs.

  5. Nanofibrillated Cellulose (NFC: A High-Value Co-Product that Improves the Economics of Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Qiong Song

    2014-02-01

    Full Text Available Cellulosic ethanol is a sustainable alternative to petroleum as a transportation fuel, which could be made biologically from agricultural and forestry residues, municipal waste, or herbaceous and woody crops. Instead of putting efforts on steps overcoming the natural resistance of plants to biological breakdown, our study proposes a unique pathway to improve the outcome of the process by co-producing high-value nanofibrillated cellulose (NFC, offering a new economic leverage for cellulosic ethanol to compete with fossil fuels in the near future. In this study, glucose has been produced by commercial enzymes while the residual solids are converted into NFC via sonification. Here, we report the morphology of fibers changed through the process and yield of glucose in the enzymatic hydrolysis step.

  6. Physical Energy Accounting in California: A Case Study of Cellulosic Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, Katie; Fridley, David

    2008-07-17

    California's target for greenhouse gas reduction in part relies on the development of viable low-carbon fuel alternatives to gasoline. It is often assumed that cellulosic ethanol--ethanol made from the structural parts of a plant and not from the food parts--will be one of these alternatives. This study examines the physical viability of a switchgrass-based cellulosic ethanol industry in California from the point of view of the physical requirements of land, water, energy and other material use. Starting from a scenario in which existing irrigated pastureland and fiber-crop land is converted to switchgrass production, the analysis determines the total acreage and water supply available and the resulting total biofuel feedstock output under different assumed yields. The number and location of cellulosic ethanol biorefineries that can be supported is also determined, assuming that the distance from field to biorefinery would be minimized. The biorefinery energy input requirement, available energy from the fraction of biomass not converted to ethanol, and energy output is calculated at various levels of ethanol yields, making different assumptions about process efficiencies. The analysis shows that there is insufficient biomass (after cellulose separation and fermentation into ethanol) to provide all the process energy needed to run the biorefinery; hence, the purchase of external energy such as natural gas is required to produce ethanol from switchgrass. The higher the yield of ethanol, the more external energy is needed, so that the net gains due to improved process efficiency may not be positive. On 2.7 million acres of land planted in switchgrass in this scenario, the switchgrass outputproduces enough ethanol to substitute for only 1.2 to 4.0percent of California's gasoline consumption in 2007.

  7. Biomass Supply Chain and Conversion Economics of Cellulosic Ethanol

    Science.gov (United States)

    Gonzalez, Ronalds W.

    2011-12-01

    Cellulosic biomass is a potential and competitive source for bioenergy production, reasons for such acclamation include: biomass is one the few energy sources that can actually be utilized to produce several types of energy (motor fuel, electricity, heat) and cellulosic biomass is renewable and relatively found everywhere. Despite these positive advantages, issues regarding cellulosic biomass availability, supply chain, conversion process and economics need a more comprehensive understanding in order to identify the near short term routes in biomass to bioenergy production. Cellulosic biomass accounts for around 35% to 45% of cost share in cellulosic ethanol production, in addition, different feedstock have very different production rate, (dry ton/acre/year), availability across the year, and chemical composition that affect process yield and conversion costs as well. In the other hand, existing and brand new conversion technologies for cellulosic ethanol production offer different advantages, risks and financial returns. Ethanol yield, financial returns, delivered cost and supply chain logistic for combinations of feedstock and conversion technology are investigated in six studies. In the first study, biomass productivity, supply chain and delivered cost of fast growing Eucalyptus is simulated in economic and supply chain models to supply a hypothetic ethanol biorefinery. Finding suggests that Eucalyptus can be a potential hardwood grown specifically for energy. Delivered cost is highly sensitive to biomass productivity, percentage of covered area. Evaluated at different financial expectations, delivered cost can be competitive compared to current forest feedstock supply. In the second study, Eucalyptus biomass conversion into cellulosic ethanol is simulated in the dilute acid pretreatment, analysis of conversion costs, cost share, CAPEX and ethanol yield are examined. In the third study, biomass supply and delivered cost of loblolly pine is simulated in economic

  8. Integrated production of nano-fibrillated cellulose and cellulosic biofuel (ethanol) by enzymatic fractionation of wood fibers

    Science.gov (United States)

    Junyong Zhu; Ronald Sabo; Xiaolin Luo

    2011-01-01

    This study demonstrates the feasibility of integrating the production of nano-fibrillated cellulose (NFC), a potentially highly valuable biomaterial, with sugar/biofuel (ethanol) from wood fibers. Commercial cellulase enzymes were used to fractionate the less recalcitrant amorphous cellulose from a bleached Kraft eucalyptus pulp, resulting in a highly crystalline and...

  9. The feasibility of producing adequate feedstock for year–round cellulosic ethanol production in an intensive agricultural fuelshed

    Science.gov (United States)

    Uden, Daniel R.; Mitchell, Rob B.; Allen, Craig R.; Guan, Qingfeng; McCoy, Tim D.

    2013-01-01

    To date, cellulosic ethanol production has not been commercialized in the United States. However, government mandates aimed at increasing second-generation biofuel production could spur exploratory development in the cellulosic ethanol industry. We conducted an in-depth analysis of the fuelshed surrounding a starch-based ethanol plant near York, Nebraska that has the potential for cellulosic ethanol production. To assess the feasibility of supplying adequate biomass for year-round cellulosic ethanol production from residual maize (Zea mays) stover and bioenergy switchgrass (Panicum virgatum) within a 40-km road network service area of the existing ethanol plant, we identified ∼14,000 ha of marginally productive cropland within the service area suitable for conversion from annual rowcrops to switchgrass and ∼132,000 ha of maize-enrolled cropland from which maize stover could be collected. Annual maize stover and switchgrass biomass supplies within the 40-km service area could range between 429,000 and 752,000 metric tons (mT). Approximately 140–250 million liters (l) of cellulosic ethanol could be produced, rivaling the current 208 million l annual starch-based ethanol production capacity of the plant. We conclude that sufficient quantities of biomass could be produced from maize stover and switchgrass near the plant to support year-round cellulosic ethanol production at current feedstock yields, sustainable removal rates and bioconversion efficiencies. Modifying existing starch-based ethanol plants in intensive agricultural fuelsheds could increase ethanol output, return marginally productive cropland to perennial vegetation, and remove maize stover from productive cropland to meet feedstock demand.

  10. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui [Chonnam National University, Bio-Energy Research Institute, Gwangju (Korea, Republic of)

    2010-10-15

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

  11. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    International Nuclear Information System (INIS)

    Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui

    2010-10-01

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

  12. Impacts of facility size and location decisions on ethanol production cost

    International Nuclear Information System (INIS)

    Kocoloski, Matt; Michael Griffin, W.; Scott Matthews, H.

    2011-01-01

    Cellulosic ethanol has been identified as a promising alternative to fossil fuels to provide energy for the transportation sector. One of the obstacles cellulosic ethanol must overcome in order to contribute to transportation energy demand is the infrastructure required to produce and distribute the fuel. Given a nascent cellulosic ethanol industry, locating cellulosic ethanol refineries and creating the accompanying infrastructure is essentially a greenfield problem that may benefit greatly from quantitative analysis. This study models cellulosic ethanol infrastructure investment using a mixed integer program (MIP) that locates ethanol refineries and connects these refineries to the biomass supplies and ethanol demands in a way that minimizes the total cost. For the single- and multi-state regions examined in this study, larger facilities can decrease ethanol costs by $0.20-0.30 per gallon, and placing these facilities in locations that minimize feedstock and product transportation costs can decrease ethanol costs by up to $0.25 per gallon compared to uninformed placement that could result from influences such as local subsidies to encourage economic development. To best benefit society, policies should allow for incentives that encourage these low-cost production scenarios and avoid politically motivated siting of plants. - Research highlights: → Mixed-integer programming can be used to model ethanol infrastructure investment. → Large cellulosic ethanol facilities can decrease production cost by $0.20/gallon. → Optimized facility placement can save $0.25/gallon.

  13. Immobilization of Cold-Active Cellulase from Antarctic Bacterium and Its Use for Kelp Cellulose Ethanol Fermentation

    Directory of Open Access Journals (Sweden)

    Yi Bin Wang

    2015-01-01

    Full Text Available Immobilization is an effective way to solve the problem associated with the application of cold-active cellulase in industrial processes. In this study, a cold-active cellulase from the Antarctic psychrophilic bacterium Pseudoalteromonas sp. NJ64 was obtained, immobilized, and analyzed for optimal immobilization conditions. Then it was used in kelp cellulose ethanol fermentation, achieving a higher purity level of kelp cellulose ethanol. The enzymatic activity of this cold-active cellulase was 49.7 U/mL. The optimal immobilization process conditions were as follows: sodium alginate, 30 g/L; calcium chloride, 5 g/L; glutaraldehyde, 0.4%; and cross-linking time, 5 h. Under these conditions, the activity recovery rate was 51.58%. The optimum reaction temperature was at 40 °C, the optimum initial pH was 9.0, and the relative enzyme activity was 58.37% after being recovered seven times. A higher purity level of kelp cellulose ethanol has reached (37.37%. Immobilized cold-active cellulase can effectively hydrolyze the cellulose of kelp residue, which is a valuable component of cellulose bio-ethanol production and will have broad implications in the development of the ethanol industry in China.

  14. Process Design of Wastewater Treatment for the NREL Cellulosic Ethanol Model

    Energy Technology Data Exchange (ETDEWEB)

    Steinwinder, T.; Gill, E.; Gerhardt, M.

    2011-09-01

    This report describes a preliminary process design for treating the wastewater from NREL's cellulosic ethanol production process to quality levels required for recycle. In this report Brown and Caldwell report on three main tasks: 1) characterization of the effluent from NREL's ammonia-conditioned hydrolyzate fermentation process; 2) development of the wastewater treatment process design; and 3) development of a capital and operational cost estimate for the treatment concept option. This wastewater treatment design was incorporated into NREL's cellulosic ethanol process design update published in May 2011 (NREL/TP-5100-47764).

  15. USE OF IONIC LIQUIDS FOR IMPROVEMENT OF CELLULOSIC ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Qijun Wang

    2011-02-01

    Full Text Available Cellulosic ethanol production has drawn much attention in recent years. However, there remain significant technical challenges before such production can be considered as economically feasible at an industrial scale. Among them, the efficient conversion of carbohydrates in lignocellulosic biomass into fermentable sugars is one of the most challenging technical difficulties in cellulosic ethanol production. Use of ionic liquids has opened new avenues to solve this problem by two different pathways. One is pretreatment of lignocellulosic biomass using ionic liquids to increase its enzymatic hydrolysis efficiency. The other is to transform the hydrolysis process of lignocellulosic biomass from a heterogeneous reaction system to a homogeneous one by dissolving it into ionic liquids, thus improving its hydrolysis efficiency.

  16. Fair Oaks Dairy Farms Cellulosic Ethanol Technology Review Summary

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Wold; Robert Divers

    2011-06-23

    At Fair Oaks Dairy, dried manure solids (''DMS'') are currently used as a low value compost. United Power was engaged to evaluate the feasibility of processing these DMS into ethanol utilizing commercially available cellulosic biofuels conversion platforms. The Fair Oaks Dairy group is transitioning their traditional ''manure to methane'' mesophilic anaerobic digester platform to an integrated bio-refinery centered upon thermophilic digestion. Presently, the Digested Manure Solids (DMS) are used as a low value soil amendment (compost). United Power evaluated the feasibility of processing DMS into higher value ethanol utilizing commercially available cellulosic biofuels conversion platforms. DMS was analyzed and over 100 potential technology providers were reviewed and evaluated. DMS contains enough carbon to be suitable as a biomass feedstock for conversion into ethanol by gasification technology, or as part of a conversion process that would include combined heat and power. In the first process, 100% of the feedstock is converted into ethanol. In the second process, the feedstock is combusted to provide heat to generate electrical power supporting other processes. Of the 100 technology vendors evaluated, a short list of nine technology providers was developed. From this, two vendors were selected as finalists (one was an enzymatic platform and one was a gasification platform). Their selection was based upon the technical feasibility of their systems, engineering expertise, experience in commercial or pilot scale operations, the ability or willingness to integrate the system into the Fair Oaks Biorefinery, the know-how or experience in producing bio-ethanol, and a clear path to commercial development.

  17. Bioconversion of cellulose to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B; Mandenius, C F; Mattiasson, B; Nilsson, B; Axelsson, J P; Hagander, P

    1985-06-20

    Enzymatic hydrolysis of steam pretreated sallow gives highest yields of soluble sugars when hemicellulose is degraded already in the pretreatment step. The steam pretreatment equipment is rebuilt so that 75 g (dry matter) material instead of 7 g can be treated each time. The cellulose production has been increased 123% by the utilization of aqueous two-phase systems as compared to regular growth medium. The cellulase activity per gram of cellulose has been increased from 42 FPU in regular growth medium to 156 FPU in aqueous two-phase systems. Crude dextran can be used for enzyme production. Enzyme recovery up to 75% has been achieved by combining aqueous two-phase technique with membrane technique. Using the enzyme glucose isomerase in combination with S. cerevisiae theoretical yields in pentose fermentations have been achieved, with a product concentration of 60 g/L and a productivity of 2 g/L x h. Yeast and enzyme can be recirculated using membrane technique. Computer simulation shows that the rate equation for enzymatic hydrolysis with respect to inhibiting sugar concentrations can be used to interpolate with respect to sugar concentrations. Computer simulations show that hydrolysis experiments should focus on high substrate concentrations (>10%) using fed-batch technique and enzyme concentrations in the range of 2-8% in relation to substrate dry matter. The combined 'flow injection analysis', FIA, and enzyme reactor probe has been adapted to enzymatic saccarifications of sodium hydroxide pretreated sallow. The gas membrane sensor for ethanol has been utilized in simultaneous saccharification and fermentation of sodium hydroxide pretreated sallow. A literature study concerning pervaporation for ethanol up-grading has been made.(Author).

  18. Direct conversion of straw to ethanol by Fusarium oxysporum: effect of cellulose crystallinity

    Energy Technology Data Exchange (ETDEWEB)

    Christakopoulos, P.; Koullas, D.P.; Kekos, D.; Koukios, E.G.; Macris, B.J. (Ethnikon Metsovion Polytechneion, Athens (Greece))

    1991-03-01

    Wheat straw was successfully fermented to ethanol by Fusarium oxysporum F3 in a one-step process. Cellulose crystallinity was found to be a major factor in the bioconversion process. Ethanol yields increased linearly with decreasing crystallinity index. Approximately 80% of straw carbohydrates were converted directly to ethanol with a yield of 0.28 g ethanol/g{sup -1} of straw when the crystallinity index was reduced to 23.6%. (author).

  19. Direct ethanol production from cellulosic materials at high temperature using the thermotolerant yeast Kluyveromyces marxianus displaying cellulolytic enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Yanase, Shuhei; Yamada, Ryosuke; Ogino, Chiaki; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering; Hasunuma, Tomohisa; Tanaka, Tsutomu; Fukuda, Hideki [Kobe Univ. (Japan). Organization of Advanced Science and Technology

    2010-09-15

    To exploit cellulosic materials for fuel ethanol production, a microorganism capable of high temperature and simultaneous saccharification-fermentation has been required. However, a major drawback is the optimum temperature for the saccharification and fermentation. Most ethanol-fermenting microbes have an optimum temperature for ethanol fermentation ranging between 28 C and 37 C, while the activity of cellulolytic enzymes is highest at around 50 C and significantly decreases with a decrease in temperature. Therefore, in the present study, a thermotolerant yeast, Kluyveromyces marxianus, which has high growth and fermentation at elevated temperatures, was used as a producer of ethanol from cellulose. The strain was genetically engineered to display Trichoderma reesei endoglucanase and Aspergillus aculeatus {beta}-glucosidase on the cell surface, which successfully converts a cellulosic {beta}-glucan to ethanol directly at 48 C with a yield of 4.24 g/l from 10 g/l within 12 h. The yield (in grams of ethanol produced per gram of {beta}-glucan consumed) was 0.47 g/g, which corresponds to 92.2% of the theoretical yield. This indicates that high-temperature cellulose fermentation to ethanol can be efficiently accomplished using a recombinant K. marxianus strain displaying thermostable cellulolytic enzymes on the cell surface. (orig.)

  20. Use of Byproduct from Cellulosic Ethanol Production as an Additive for Concrete: A Possible Win-win Strategy?

    Directory of Open Access Journals (Sweden)

    Xiangwei Hao

    2015-08-01

    Full Text Available Technologists are facing increasing demands to achieve ecologically sustainable industrial practices. Currently the concrete industry is a significant contributor to greenhouse gas emissions. On the other hand, the scaling up of cellulosic ethanol technology has not been a very easy task. In this context, the integration of “greener” concrete with cellulosic ethanol technology may open up promising possibilities. The solid byproducts from cellulosic ethanol production process have been demonstrated to increase the strength of concrete structures when used as a partial cement replacement. Such a delicate integration can also lead to reduction in both carbon footprint and product cost. The possible commercialization of the integrated technologies would provide win-win benefits for both industries.

  1. The commercial performance of cellulosic ethanol supply-chains in Europe

    Directory of Open Access Journals (Sweden)

    Shah Nilay

    2009-02-01

    Full Text Available Abstract Background The production of fuel-grade ethanol from lignocellulosic biomass resources has the potential to increase biofuel production capacity whilst minimising the negative environmental impacts. These benefits will only be realised if lignocellulosic ethanol production can compete on price with conventional fossil fuels and if it can be produced commercially at scale. This paper focuses on lignocellulosic ethanol production in Europe. The hypothesis is that the eventual cost of production will be determined not only by the performance of the conversion process but by the performance of the entire supply-chain from feedstock production to consumption. To test this, a model for supply-chain cost comparison is developed, the components of representative ethanol supply-chains are described, the factors that are most important in determining the cost and profitability of ethanol production are identified, and a detailed sensitivity analysis is conducted. Results The most important cost determinants are the cost of feedstocks, primarily determined by location and existing markets, and the value obtained for ethanol, primarily determined by the oil price and policy incentives. Both of these factors are highly uncertain. The best performing chains (ethanol produced from softwood and sold as a low percentage blend with gasoline could ultimately be cost competitive with gasoline without requiring subsidy, but production from straw would generally be less competitive. Conclusion Supply-chain design will play a critical role in determining commercial viability. The importance of feedstock supply highlights the need for location-specific assessments of feedstock availability and price. Similarly, the role of subsidies and policy incentives in creating and sustaining the ethanol market highlights the importance of political engagement and the need to include political risks in investment appraisal. For the supply-chains described here, and with

  2. Cellulosic ethanol production via consolidated bioprocessing by a novel thermophilic anaerobic bacterium isolated from a Himalayan hot spring.

    Science.gov (United States)

    Singh, Nisha; Mathur, Anshu S; Tuli, Deepak K; Gupta, Ravi P; Barrow, Colin J; Puri, Munish

    2017-01-01

    Cellulose-degrading thermophilic anaerobic bacterium as a suitable host for consolidated bioprocessing (CBP) has been proposed as an economically suited platform for the production of second-generation biofuels. To recognize the overall objective of CBP, fermentation using co-culture of different cellulolytic and sugar-fermenting thermophilic anaerobic bacteria has been widely studied as an approach to achieving improved ethanol production. We assessed monoculture and co-culture fermentation of novel thermophilic anaerobic bacterium for ethanol production from real substrates under controlled conditions. In this study, Clostridium sp. DBT-IOC-C19, a cellulose-degrading thermophilic anaerobic bacterium, was isolated from the cellulolytic enrichment cultures obtained from a Himalayan hot spring. Strain DBT-IOC-C19 exhibited a broad substrate spectrum and presented single-step conversion of various cellulosic and hemicellulosic substrates to ethanol, acetate, and lactate with ethanol being the major fermentation product. Additionally, the effect of varying cellulose concentrations on the fermentation performance of the strain was studied, indicating a maximum cellulose utilization ability of 10 g L -1 cellulose. Avicel degradation kinetics of the strain DBT-IOC-C19 displayed 94.6% degradation at 5 g L -1 and 82.74% degradation at 10 g L -1 avicel concentration within 96 h of fermentation. In a comparative study with Clostridium thermocellum DSM 1313, the ethanol and total product concentrations were higher by the newly isolated strain on pretreated rice straw at an equivalent substrate loading. Three different co-culture combinations were used on various substrates that presented two-fold yield improvement than the monoculture during batch fermentation. This study demonstrated the direct fermentation ability of the novel thermophilic anaerobic bacteria on various cellulosic and hemicellulosic substrates into ethanol without the aid of any exogenous enzymes

  3. A whole cell biocatalyst for cellulosic ethanol production from dilute acid-pretreated corn stover hydrolyzates

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seunghyun; Karim, Muhammad Nazmul [Texas Tech Univ., Lubbock, TX (United States). Dept. of Chemical Engineering

    2011-08-15

    In this research, a recombinant whole cell biocatalyst was developed by expressing three cellulases from Clostridium cellulolyticum - endoglucanase (Cel5A), exoglucanase (Cel9E), and {beta}-glucosidase - on the surface of the Escherichia coli LY01. The modified strain is identified as LY01/pRE1H-AEB. The cellulases were displayed on the surface of the cell by fusing with an anchor protein, PgsA. The developed whole cell biocatalyst was used for single-step ethanol fermentation using the phosphoric acid-swollen cellulose (PASC) and the dilute acid-pretreated corn stover. Ethanol production was 3.59 {+-} 0.15 g/L using 10 g/L of PASC, which corresponds to a theoretical yield of 95.4 {+-} 0.15%. Ethanol production was 0.30 {+-} 0.02 g/L when 1 g/L equivalent of glucose in the cellulosic fraction of the dilute sulfuric acid-pretreated corn stover (PCS) was fermented for 84 h. A total of 0.71 {+-} 0.12 g/L ethanol was produced in 48 h when the PCS was fermented in the simultaneous saccharification and co-fermentation mode using the hemicellulosic (1 g/L of total soluble sugar) and as well as the cellulosic (1 g/L of glucose equivalent) parts of PCS. In a control experiment, 0.48 g/L ethanol was obtained from 1 g/L of hemicellulosic PCS. It was concluded that the whole cell biocatalyst could convert both cellulosic and hemicellulosic substrates into ethanol in a single reactor. The developed C. cellulolyticum-E. coli whole cell biocatalyst also overcame the incompatible temperature problem of the frequently reported fungal-yeast systems. (orig.)

  4. Synergetic effect of yeast cell-surface expression of cellulase and expansin-like protein on direct ethanol production from cellulose

    Science.gov (United States)

    2013-01-01

    Background Numerous studies have examined the direct fermentation of cellulosic materials by cellulase-expressing yeast; however, ethanol productivity in these systems has not yet reached an industrial level. Certain microorganisms, such as the cellulolytic fungus Trichoderma reesei, produce expansin-like proteins, which have a cellulose-loosening effect that may increase the breakdown of cellulose. Here, to improve the direct conversion of cellulose to ethanol, yeast Saccharomyces cerevisiae co-displaying cellulase and expansin-like protein on the cell surface were constructed and examined for direct ethanol fermentation performance. Results The cellulase and expansin-like protein co-expressing strain showed 246 mU/g-wet cell of phosphoric acid swollen cellulose (PASC) degradation activity, which corresponded to 2.9-fold higher activity than that of a cellulase-expressing strain. This result clearly demonstrated that yeast cell-surface expressed cellulase and expansin-like protein act synergistically to breakdown cellulose. In fermentation experiments examining direct ethanol production from PASC, the cellulase and expansin-like protein co-expressing strain produced 3.4 g/L ethanol after 96 h of fermentation, a concentration that was 1.4-fold higher than that achieved by the cellulase-expressing strain (2.5 g/L). Conclusions The PASC degradation and fermentation ability of an engineered yeast strain was markedly improved by co-expressing cellulase and expansin-like protein on the cell surface. To our knowledge, this is the first report to demonstrate the synergetic effect of co-expressing cellulase and expansin-like protein on a yeast cell surface, which may be a promising strategy for constructing direct ethanol fermenting yeast from cellulose. PMID:23835302

  5. Process development studies on the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.; Blanch, H.W.

    1978-12-01

    Progress is reported in the following areas: raw materials and process evaluation, enzyme fermentation studies, ethanol fermentation studies, hydrolysis reactor development, and utilization of hemi-cellulose sugars. (MHR)

  6. Simultaneous cell growth and ethanol production from cellulose by an engineered yeast consortium displaying a functional mini-cellulosome

    Directory of Open Access Journals (Sweden)

    Madan Bhawna

    2011-11-01

    Full Text Available Abstract Background The recalcitrant nature of cellulosic materials and the high cost of enzymes required for efficient hydrolysis are the major impeding steps to their practical usage for ethanol production. Ideally, a recombinant microorganism, possessing the capability to utilize cellulose for simultaneous growth and ethanol production, is of great interest. We have reported recently the use of a yeast consortium for the functional presentation of a mini-cellulosome structure onto the yeast surface by exploiting the specific interaction of different cohesin-dockerin pairs. In this study, we engineered a yeast consortium capable of displaying a functional mini-cellulosome for the simultaneous growth and ethanol production on phosphoric acid swollen cellulose (PASC. Results A yeast consortium composed of four different populations was engineered to display a functional mini-cellulosome containing an endoglucanase, an exoglucanase and a β-glucosidase. The resulting consortium was demonstrated to utilize PASC for growth and ethanol production. The final ethanol production of 1.25 g/L corresponded to 87% of the theoretical value and was 3-fold higher than a similar yeast consortium secreting only the three cellulases. Quantitative PCR was used to enumerate the dynamics of each individual yeast population for the two consortia. Results indicated that the slight difference in cell growth cannot explain the 3-fold increase in PASC hydrolysis and ethanol production. Instead, the substantial increase in ethanol production is consistent with the reported synergistic effect on cellulose hydrolysis using the displayed mini-cellulosome. Conclusions This report represents a significant step towards the goal of cellulosic ethanol production. This engineered yeast consortium displaying a functional mini-cellulosome demonstrated not only the ability to grow on the released sugars from PASC but also a 3-fold higher ethanol production than a similar yeast

  7. Impact of pretreatment and downstream processing technologies on economics and energy in cellulosic ethanol production

    Directory of Open Access Journals (Sweden)

    Murthy Ganti S

    2011-09-01

    Full Text Available Abstract Background While advantages of biofuel have been widely reported, studies also highlight the challenges in large scale production of biofuel. Cost of ethanol and process energy use in cellulosic ethanol plants are dependent on technologies used for conversion of feedstock. Process modeling can aid in identifying techno-economic bottlenecks in a production process. A comprehensive techno-economic analysis was performed for conversion of cellulosic feedstock to ethanol using some of the common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. Detailed process models incorporating feedstock handling, pretreatment, simultaneous saccharification and co-fermentation, ethanol recovery and downstream processing were developed using SuperPro Designer. Tall Fescue (Festuca arundinacea Schreb was used as a model feedstock. Results Projected ethanol yields were 252.62, 255.80, 255.27 and 230.23 L/dry metric ton biomass for conversion process using dilute acid, dilute alkali, hot water and steam explosion pretreatment technologies respectively. Price of feedstock and cellulose enzymes were assumed as $50/metric ton and 0.517/kg broth (10% protein in broth, 600 FPU/g protein respectively. Capital cost of ethanol plants processing 250,000 metric tons of feedstock/year was $1.92, $1.73, $1.72 and $1.70/L ethanol for process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Ethanol production cost of $0.83, $0.88, $0.81 and $0.85/L ethanol was estimated for production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment respectively. Water use in the production process using dilute acid, dilute alkali, hot water and steam explosion pretreatment was estimated 5.96, 6.07, 5.84 and 4.36 kg/L ethanol respectively. Conclusions Ethanol price and energy use were highly dependent on process conditions used in the ethanol production plant. Potential for

  8. Cellulosic ethanol: status and innovation

    Energy Technology Data Exchange (ETDEWEB)

    Lynd, Lee R.; Liang, Xiaoyu; Biddy, Mary J.; Allee, Andrew; Cai, Hao; Foust, Thomas; Himmel, Michael E.; Laser, Mark S.; Wang, Michael; Wyman, Charles E.

    2017-06-01

    Although the purchase price of cellulosic feedstocks is competitive with petroleum on an energy basis, the cost of lignocellulose conversion to ethanol using today’s technology is high. Cost reductions can be pursued via either in-paradigm or new-paradigm innovation. As an example of new-paradigm innovation, consolidated bioprocessing using thermophilic bacteria combined with milling during fermentation (cotreatment) is analyzed. Acknowledging the nascent state of this approach, our analysis indicates potential for radically improved cost competitiveness and feasibility at smaller scale compared to current technology, arising from (a) R&D-driven advances (consolidated bioprocessing with cotreatment in lieu of thermochemical pretreatment and added fungal cellulase), and (b) configurational changes (fuel pellet coproduction instead of electricity, gas boiler(s) in lieu of a solid fuel boiler).

  9. An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production.

    Science.gov (United States)

    Mathew, Anil Kuruvilla; Parameshwaran, Binod; Sukumaran, Rajeev Kumar; Pandey, Ashok

    2016-01-01

    The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Breaking into the Cellulosic Ethanol Market: Capacity and Storage Strategies

    OpenAIRE

    Darby, Paul M.; Mark, Tyler B.; Salassi, Michael E.

    2010-01-01

    This paper examines the possibilities of breaking into the cellulosic ethanol market in south Louisiana via strategic feedstock choices and the leveraging of the area’s competitive advantages. A small plant strategy is devised whereby the first-mover problem might be solved, and several scenarios are tested using Net Present Value analysis.

  11. The Potential of Cellulosic Ethanol Production from Grasses in Thailand

    Directory of Open Access Journals (Sweden)

    Jinaporn Wongwatanapaiboon

    2012-01-01

    Full Text Available The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85–38.51, 31.13–42.61, and 3.10–5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500–600 mg/g grasses (70–80% yield were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF. The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35°C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values.

  12. Integrated energy, environmental and financial analysis of ethanol production from cellulosic switchgrass

    International Nuclear Information System (INIS)

    Felix, Erika; Tilley, David R.

    2009-01-01

    Ethanol production from cellulosic sources such as switchgrass (Panicum virgatum L.) requires the use of natural resources, fossil fuels, electricity, and human-derived goods and services. We used emergy accounting to integrate the ultimate amount of environmental, fossil fuel, and human-derived energy required to produce ethanol from switchgrass. Emergy is the total amount of energy of one form required directly and indirectly to make another form of energy. Forty-four percent of required emergy came from the environment either directly or embodied in purchased goods, 30% came from fossil fuels either directly or embodied in purchased goods, and 25% came from human-derived services indirectly. Ethanol production per petroleum use (emergy/emergy) was 4.0-to-1 under our Baseline Scenario, but dropped to 0.5-to-1 under a scenario that assumed higher input prices, lower conversion efficiencies and less waste recycling. At least 75% of total emergy was from non-renewable sources. Energy 'hidden' in indirect paths such as goods and services was 65% of the total. Cellulosic-ethanol is not a primary fuel source that substitutes for petroleum because its production relies heavily on non-renewable energy and purchased inputs. It is a means for converting natural resources to liquid fuel. (author)

  13. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    International Nuclear Information System (INIS)

    Bae, Hyeun Jong; Wi, Seung Gon; Lee, Yoon Gyo; Kim, Ho Myung; Kim, Su Bae

    2011-10-01

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. The 2nd year Research scope includes: 1) Optimization of pre-treatment conditions for enzymatic hydrolysis of lignocellulosic biomass and 2) Demonstration of enzymatic hydrolysis by recombinant enzymes. To optimize the pretreatment, we applied two processes: a wet process (wet milling + popping), and dry process (popping + dry milling). Out of these, the wet process presented the best glucose yield with a 93.1% conversion, while the dry process yielded 69.6%, and the unpretreated process yielded <20%. The recombinant cellulolytic enzymes showed very high specific activity, about 80-1000 times on CMC and 13-70 times on filter paper at pH 3.5 and 55 .deg. C

  14. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    Science.gov (United States)

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-08

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The production of cellulosic ethanol using SMR. A prefeasibility study for the Italian scenario

    International Nuclear Information System (INIS)

    Locatelli, Giorgio; Mancini, Mauro

    2011-01-01

    Small Medium Reactors (SMR) can play an important role in the global nuclear renaissance coupling the production of Electrical Energy (EE) with by-products useful to increase their economic attractiveness and enhance the public acceptability. Light Water Reactors (LWR) have an average thermal efficiency of about 33%-35%, therefore two third of the thermal energy produced by the nuclear reaction is usually wasted. Nowadays there are industries able to use this thermal energy in an efficient way. Among the other the production of cellulosic ethanol seems one of the most attractive for the coupling with a nuclear power plant. This industry can exploit two by-products of a nuclear reactor: the wide area around the plant (the so called Emergency Planning Zone - EPZ) and the residual thermal energy post turbines. Cellulosic ethanol is a bio-fuel produced from non-edible parts of plants or wood. It is produced from lignocellulose the material composing much of the mass of plants. Production of ethanol (that can be used as a fuel) from lignocellulose can avoid the usage of food grain or precious vegetables usable for the human nutrition, but requires an enormous amount of heat in the production process. A SMR can be the ideal source of this thermal energy. The paper presents a prefeasibility study with the economic and strategic assessment of coupling an SMR and a cellulosic ethanol plant in the north of Italy. After an introduction on the ethanol production the papers describe the market of this product and the production process. Then it provides the cost estimation of coupling the SMR with the production plant. The results point out as this combination can be very attractive to enhance the production of ethanol since is really cost competitive and does not produce any green house gases (GHG). (author)

  16. Improvement of ethanol production from crystalline cellulose via optimizing cellulase ratios in cellulolytic Saccharomyces cerevisiae.

    Science.gov (United States)

    Liu, Zhuo; Inokuma, Kentaro; Ho, Shih-Hsin; den Haan, Riaan; van Zyl, Willem H; Hasunuma, Tomohisa; Kondo, Akihiko

    2017-06-01

    Crystalline cellulose is one of the major contributors to the recalcitrance of lignocellulose to degradation, necessitating high dosages of cellulase to digest, thereby impeding the economic feasibility of cellulosic biofuels. Several recombinant cellulolytic yeast strains have been developed to reduce the cost of enzyme addition, but few of these strains are able to efficiently degrade crystalline cellulose due to their low cellulolytic activities. Here, by combining the cellulase ratio optimization with a novel screening strategy, we successfully improved the cellulolytic activity of a Saccharomyces cerevisiae strain displaying four different synergistic cellulases on the cell surface. The optimized strain exhibited an ethanol yield from Avicel of 57% of the theoretical maximum, and a 60% increase of ethanol titer from rice straw. To our knowledge, this work is the first optimization of the degradation of crystalline cellulose by tuning the cellulase ratio in a cellulase cell-surface display system. This work provides key insights in engineering the cellulase cocktail in a consolidated bioprocessing yeast strain. Biotechnol. Bioeng. 2017;114: 1201-1207. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. An energy analysis of ethanol from cellulosic feedstock. Corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Lin; Van der Voet, Ester; Huppes, Gjalt [Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA, Leiden (Netherlands)

    2009-10-15

    The shift from fossil resources to renewables for energy and materials production has been the driving force for research on energy analysis and environmental impact assessment of bio-based production. This study presents a detailed energy analysis of corn stover based ethanol production using advanced cellulosic technologies. The method used differs from that in LCA and from major studies on the subject as published in Science in two respects. First, it accounts for all the co-products together and so mainly avoids the allocation problems which plague all LCA studies explicitly and other studies implicitly. Second, the system boundaries only involve the content of the energy products used in the system but not the production processes of these energy products, like refining and electricity production. We normalized the six Science studies to this unified method. The resulting values of the total energy product use in both agricultural production and biomass conversion to ethanol are lower than these literature values. LCA-type of values including energy conversion would systematically be higher, in our case study around 45%. The net energy value of cellulosic ethanol production is substantially higher than the ones of the corn-based technologies, and it is similar to incineration and gasification for electricity production. The detailed analysis of energy inputs indicates opportunities to optimize the system. This form of energy analysis helps establishing models for the analysis of more complex systems such as biorefineries. (author)

  18. Mapping grasslands suitable for cellulosic biofuels in the Greater Platte River Basin, United States

    Science.gov (United States)

    Wylie, Bruce K.; Gu, Yingxin

    2012-01-01

    Biofuels are an important component in the development of alternative energy supplies, which is needed to achieve national energy independence and security in the United States. The most common biofuel product today in the United States is corn-based ethanol; however, its development is limited because of concerns about global food shortages, livestock and food price increases, and water demand increases for irrigation and ethanol production. Corn-based ethanol also potentially contributes to soil erosion, and pesticides and fertilizers affect water quality. Studies indicate that future potential production of cellulosic ethanol is likely to be much greater than grain- or starch-based ethanol. As a result, economics and policy incentives could, in the near future, encourage expansion of cellulosic biofuels production from grasses, forest woody biomass, and agricultural and municipal wastes. If production expands, cultivation of cellulosic feedstock crops, such as switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus species), is expected to increase dramatically. The main objective of this study is to identify grasslands in the Great Plains that are potentially suitable for cellulosic feedstock (such as switchgrass) production. Producing ethanol from noncropland holdings (such as grassland) will minimize the effects of biofuel developments on global food supplies. Our pilot study area is the Greater Platte River Basin, which includes a broad range of plant productivity from semiarid grasslands in the west to the fertile corn belt in the east. The Greater Platte River Basin was the subject of related U.S. Geological Survey (USGS) integrated research projects.

  19. [Pretreatment of oil palm residues by dilute alkali for cellulosic ethanol production].

    Science.gov (United States)

    Zhang, Haiyan; Zhou, Yujie; Li, Jinping; Dai, Lingmei; Liu, Dehua; Zhang, Jian'an; Choo, Yuen May; Loh, Soh Kheang

    2013-04-01

    In the study, we used oil palm residues (empty fruit bunch, EFB) as raw material to produce cellulosic ethanol by pretreatment, enzymatic hydrolysis and fermentation. Firstly, the pretreatment of EFB with alkali, alkali/hydrogen peroxide and the effects on the components and enzymatic hydrolysis of cellulose were studied. The results show that dilute alkali was the suitable pretreatment method and the conditions were first to soak the substrate with 1% sodium hydroxide with a solid-liquid ratio of 1:10 at 40 degrees C for 24 h, and then subjected to 121 degrees C for 30 min. Under the conditions, EFB solid recovery was 74.09%, and glucan, xylan and lignin content were 44.08%, 25.74% and 13.89%, respectively. After separated with alkali solution, the pretreated EFB was washed and hydrolyzed for 72 h with 5% substrate concentration and 30 FPU/g dry mass (DM) enzyme loading, and the conversion of glucan and xylan reached 84.44% and 89.28%, respectively. We further investigated the effects of substrate concentration and enzyme loading on enzymatic hydrolysis and ethanol batch simultaneous saccharification and fermentation (SSF). The results show that when enzyme loading was 30 FPU/g DM and substrate concentration was increased from 5% to 25%, ethanol concentration were 9.76 g/L and 35.25 g/L after 72 h fermentation with Saccharomyces cerevisiae (inoculum size 5%, V/V), which was 79.09% and 56.96% of ethanol theory yield.

  20. Process and utility water requirements for cellulosic ethanol production processes via fermentation pathway

    Science.gov (United States)

    The increasing need of additional water resources for energy production is a growing concern for future economic development. In technology development for ethanol production from cellulosic feedstocks, a detailed assessment of the quantity and quality of water required, and the ...

  1. Enzymatic hydrolysis of pretreated cellulosic wastes by the cellulase complex of Myceliophthora thermophila D-14 to produce ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Roy, S K; Sadhukhan, R; Raha, S K; Chakrabarty, S L [Bose Institute, Calcutta (India). Dept. of Microbiology

    1991-06-01

    Pretreatment of different cellulosic wastes and their subsequent saccharification by thermostable cellulase from a thermophilic fungus Myceliophthora thermophila D-14 was investigated. Alkali treatment was found to be most effective. Carboxymethyl cellulose and untreated materials were used as controls. Significant inhibition of the cellulase activity was observed in the presence of glucose, but with ethanol no such effect was detected. The conversion of sugar to ethanol varied from 21-50% depending on the nature of substrate used. 14 refs., 2 figs., 4 tabs.

  2. Next-generation cellulosic ethanol technologies and their contribution to a sustainable Africa.

    Science.gov (United States)

    van Zyl, W H; Chimphango, A F A; den Haan, R; Görgens, J F; Chirwa, P W C

    2011-04-06

    The world is currently heavily dependent on oil, especially in the transport sector. However, rising oil prices, concern about environmental impact and supply instability are among the factors that have led to greater interest in renewable fuel and green chemistry alternatives. Lignocellulose is the only foreseeable renewable feedstock for sustainable production of transport fuels. The main technological impediment to more widespread utilization of lignocellulose for production of fuels and chemicals in the past has been the lack of low-cost technologies to overcome the recalcitrance of its structure. Both biological and thermochemical second-generation conversion technologies are currently coming online for the commercial production of cellulosic ethanol concomitantly with heat and electricity production. The latest advances in biological conversion of lignocellulosics to ethanol with a focus on consolidated bioprocessing are highlighted. Furthermore, integration of cellulosic ethanol production into existing bio-based industries also using thermochemical processes to optimize energy balances is discussed. Biofuels have played a pivotal yet suboptimal role in supplementing Africa's energy requirements in the past. Capitalizing on sub-Saharan Africa's total biomass potential and using second-generation technologies merit a fresh look at the potential role of bioethanol production towards developing a sustainable Africa while addressing food security, human needs and local wealth creation.

  3. Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda

    Energy Technology Data Exchange (ETDEWEB)

    Houghton, John [Dept. of Energy (DOE), Washington DC (United States); Weatherwax, Sharlene [Dept. of Energy (DOE), Washington DC (United States); Ferrell, John [Dept. of Energy (DOE), Washington DC (United States)

    2006-06-07

    The Biomass to Biofuels Workshop, held December 7–9, 2005, was convened by the Department of Energy’s Office of Biological and Environmental Research in the Office of Science; and the Office of the Biomass Program in the Office of Energy Efficiency and Renewable Energy. The purpose was to define barriers and challenges to a rapid expansion of cellulosic-ethanol production and determine ways to speed solutions through concerted application of modern biology tools as part of a joint research agenda. Although the focus was ethanol, the science applies to additional fuels that include biodiesel and other bioproducts or coproducts having critical roles in any deployment scheme.

  4. Optical Sensor based Chemical Modification as a Porous Cellulose Acetate Film and Its Application for Ethanol Sensor

    Science.gov (United States)

    Mulijani, S.; Iswantini, D.; Wicaksono, R.; Notriawan, D.

    2018-03-01

    A new approach to design and construction of an optical ethanol sensor has been developed by immobilizing a direct dye at a porous cellulosic polymer fllm. This sensor was fabricated by binding Nile Red to a cellulose acetate membrane that had previously been subjected to an exhaustive base hydrolysis. The prepared optical ethanol sensor was enhanced by adding pluronic as a porogen in the membrane. The addition of pluronic surfactant into cellulose acetate membrane increased the hydrophilic and porous properties of membrane. Advantageous features of the design include simple and easy of fabrication. Variable affecting sensor performance of dye concentration have been fully evaluated and optimized. The rapid response results from the porous structure of the polymeric support, which minimizes barriers to mass transport. Signal of optical sensor based on reaction of dye nile red over the membrane with ethanol and will produce the purple colored product. Result was obtained that maximum intensity of dye nile red reacted with alcohol is at 630-640 nm. Linear regression equation (r2), limit of detection, and limit of quantitation of membrane with 2% dye was 0.9625, 0.29%, and 0.97%. Performance of optical sensor was also evaluated through methanol, ethanol and propanol. This study was purposed to measure the polarity and selectivity of optic sensor toward the alcohol derivatives. Fluorescence intensity of optic sensor membrane for methanol 5%, ethanol 5% and propanol 5% was 15113.56, 16573.75 and 18495.97 respectively.

  5. Modelling ethanol production from cellulose: separate hydrolysis and fermentation versus simultaneous saccharification and fermentation

    NARCIS (Netherlands)

    Drissen, R.E.T.; Maas, R.H.W.; Tramper, J.; Beeftink, H.H.

    2009-01-01

    In ethanol production from cellulose, enzymatic hydrolysis, and fermentative conversion may be performed sequentially (separate hydrolysis and fermentation, SHF) or in a single reaction vessel (simultaneous saccharification and fermentation, SSF). Opting for either is essentially a trade-off between

  6. Cellulosic ethanol production from agricultural residues in Nigeria

    International Nuclear Information System (INIS)

    Iye, Edward; Bilsborrow, Paul

    2013-01-01

    Nigeria′s Biofuels Policy introduced in 2007 mandates a 10% blend (E10) of bioethanol with gasoline. This study investigates the potential for the development of a cellulosic ethanol industry based on the availability of agricultural residues and models the number of commercial processing facilities that could be sited in the six Geo-political zones. The potential for cellulosic ethanol production from agricultural residues in Nigeria is 7556 km 3 per annum exceeding the mandate of 10% renewable fuel required and providing the potential for 12 large- and 11 medium-scale processing facilities based on the use of a single feedstock. Cassava and yam peelings provided in excess of 80% of the process residues available with enough feedstock to supply 10 large-scale facilities with a fairly even distribution across the zones. Sorghum straw, millet straw and maize stalks represented 75% of the potential resource available from field residues with the potential to supply 2 large- and 7 medium-scale processing facilities, all of which would be located in the north of the country. When a multi-feedstock approach is used, this provides the potential for either 29 large- or 58 medium-scale facilities based on outputs of 250 and 125 km 3 per annum respectively. - Highlights: • Nigeria′s Biofuels Policy mandates a 10% blend of bioethanol with gasoline. • Total bioethanol production from agricultural residues was 7556 km 3 per annum. • Process residues offer the greatest potential accounting for 62% of production. • Nigeria has the potential for 12 large- and 11 medium scale commercial. • The use of mixed feedstocks significantly increases the potential for production

  7. Value Chain Structures that Define European Cellulosic Ethanol Production

    DEFF Research Database (Denmark)

    Gregg, Jay Sterling; Bolwig, Simon; Hansen, Teis

    2017-01-01

    production plants across Europe from a global value chain (GVC) perspective. We find that most CE production plants in the EU focus largely on intellectual property and are therefore only at the pilot or demonstration scale. Crescentino, the largest CE production facility in Europe, is also more interested...... petroleum markets and higher financial risks. We argue that, to increase CE production, policies should consider value chains, promote the wider bio-economy of products and focus on economies of scope. Whereas the EU and its member states have ethanol quotas and blending targets, a more effective policy......Production of cellulosic ethanol (CE) has not yet reached the scale envisaged by the literature and industry. This study explores CE production in Europe to improve understanding of the motivations and barriers associated with this situation. To do this, we conduct a case study-based analysis of CE...

  8. Bioethanol Production From Cellulose by Candida tropicalis, as An Alternative Microbial Agent to Produce Ethanol from Lignocellulosic Biomass

    Directory of Open Access Journals (Sweden)

    Hermansyah

    2016-04-01

    Full Text Available Abstract: Candida tropicalis isolated from Tuak is a potentially useful microorganism for the ethanol production from lignocellulosic biomass and it can be alterbative agent replacing Saccharomyces cerevisae for fermentation process. Although C.tropicalis could not convert all carbohydrates content of lignocellulosic into bioethanol, however it is able to grow on medium in the presence of either xylose or arabinose as carbon source. Our result showed that fermentation of 10 % (w/v cellulosic as sole carbon source produced 2.88% (v/v ethanol by C.tropicalis. This ethanol production was lower than usage of 10% (w/v dextrose as sole carbon source medium which producing 5.51% (v/v ethanol. Based upon our expreiment indicated that C.tropicalis is able to conduct two main process in converting of cellulosic material- to ethanol which is hydrolysis the degradation of cellulose into glucose, and fermentation the process the conversion glucose into bioethanol. Keywords : Candida tropicalis, bioethanol, fermentation, cellulosic Abstrak (Indonesian: Candida tropicalis yang diisiolasi dari Tuak adalah agen yang berpotensi dalam produksi etanol dari biomasa lignoselulosa dan dapat dijadikan agen alternatif menggantikan Saccharomyces cerevisiae pada proses fernentasi. Walaupun C.tropicalis tidak dapat mengkonversi semua kandungan karbohidrat lignoselulosamenjadi etanol, akan tetapi C.tropicalis mampu tumbuh pada media dengan xilosa atau arabinosa sebagaisumber karbon. Hasil kami menunjukkan bahwa dengan mengguankan C.tropicalis fermentasi 10% (w/v selulosa sebagai satu-satunya sumber karbon menghasilkan 2,88% (v/v etanol, Produksi etanol ini lebih rendah jika menggunakan 10% (w/v dekstrosa sebagai satu satunya sumber karbon yang menghasilkan 5,51% (v/v etanol. Berdasarkan percobaan menunjukkan bahwa C.tropicalis mampu melakukan dua proses utama dalam mengkonversi material selulosa menjadi etanol yaitu hidrolisis degradasi selulosa menjadi glukosa, dan

  9. Combined enzyme mediated fermentation of cellulose and xylose to ethanol by Schizosaccharomyces pombe, cellulase, [beta]-glucosidase, and xylose isomerase

    Science.gov (United States)

    Lastick, S.M.; Mohagheghi, A.; Tucker, M.P.; Grohmann, K.

    1994-12-13

    A process for producing ethanol from mixed sugar streams from pretreated biomass comprising xylose and cellulose using enzymes to convert these substrates to fermentable sugars; selecting and isolating a yeast Schizosaccharomyces pombe ATCC No. 2476, having the ability to ferment these sugars as they are being formed to produce ethanol; loading the substrates with the fermentation mix composed of yeast, enzymes and substrates; fermenting the loaded substrates and enzymes under anaerobic conditions at a pH range of between about 5.0 to about 6.0 and at a temperature range of between about 35 C to about 40 C until the fermentation is completed, the xylose being isomerized to xylulose, the cellulose being converted to glucose, and these sugars being concurrently converted to ethanol by yeast through means of the anaerobic fermentation; and recovering the ethanol. 2 figures.

  10. Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

    Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

  11. Comparing oxidative and dilute acid wet explosion pretreatment of Cocksfoot grass at high dry matter concentration for cellulosic ethanol production

    DEFF Research Database (Denmark)

    Njoku, Stephen Ikechukwu; Uellendahl, Hinrich; Ahring, Birgitte Kiær

    2013-01-01

    into cellulose monomeric C6 sugars was achieved for WEx condition AC-E (180°C, 15 min, and 0.2% sulfuric acid). For that condition, the highest ethanol yield of 197 g/kg DM (97% of theoretical maximum value) was achieved for SSF process by Saccharomyces cerevisiae. However, the highest concentration...... of hemicellulose C5 sugars was found for WEx pretreatment condition O2-A (160°C, 15 min, and 6 bar O2) which means that the highest potential ethanol yield was found at this moderate pretreatment condition with oxygen added. Increasing the pretreatment temperature to 180–190°C with addition of oxygen or dilute...... was investigated for cellulosic ethanol production. The biomass raw materials were pretreated using wet explosion (WEx) at 25% dry matter concentration with addition of oxygen or dilute sulfuric acid. The enzymatic hydrolysis of cellulose was significantly improved after pretreatment. The highest conversion...

  12. Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

    Science.gov (United States)

    Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

    2016-03-01

    Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

  13. Enhancing ethanol production from cellulosic sugars using Scheffersomyces (Pichia) stipitis.

    Science.gov (United States)

    Okonkwo, C C; Azam, M M; Ezeji, T C; Qureshi, N

    2016-07-01

    Studies were performed on the effect of CaCO3 and CaCl2 supplementation to fermentation medium for ethanol production from xylose, glucose, or their mixtures using Scheffersomyces (Pichia) stipitis. Both of these chemicals were found to improve maximum ethanol concentration and ethanol productivity. Use of xylose alone resulted in the production of 20.68 ± 0.44 g L(-1) ethanol with a productivity of 0.17 ± 0.00 g L(-1) h(-1), while xylose plus 3 g L(-1) CaCO3 resulted in the production of 24.68 ± 0.75 g L(-1) ethanol with a productivity of 0.21 ± 0.01 g L(-1) h(-1). Use of xylose plus glucose in combination with 3 g L(-1) CaCO3 resulted in the production of 47.37 ± 0.55 g L(-1) ethanol (aerobic culture), thus resulting in an ethanol productivity of 0.39 ± 0.00 g L(-1) h(-1). These values are 229 % of that achieved in xylose medium. Supplementation of xylose and glucose medium with 0.40 g L(-1) CaCl2 resulted in the production of 44.84 ± 0.28 g L(-1) ethanol with a productivity of 0.37 ± 0.02 g L(-1) h(-1). Use of glucose plus 3 g L(-1) CaCO3 resulted in the production of 57.39 ± 1.41 g L(-1) ethanol under micro-aerophilic conditions. These results indicate that supplementation of cellulosic sugars in the fermentation medium with CaCO3 and CaCl2 would improve economics of ethanol production from agricultural residues.

  14. Value Chain Structures that Define European Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Jay Sterling Gregg

    2017-01-01

    Full Text Available Production of cellulosic ethanol (CE has not yet reached the scale envisaged by the literature and industry. This study explores CE production in Europe to improve understanding of the motivations and barriers associated with this situation. To do this, we conduct a case study-based analysis of CE production plants across Europe from a global value chain (GVC perspective. We find that most CE production plants in the EU focus largely on intellectual property and are therefore only at the pilot or demonstration scale. Crescentino, the largest CE production facility in Europe, is also more interested in technology licensing than producing ethanol. Demonstration-scale plants tend to have a larger variety of feedstocks, whereas forestry-based plants have more diversity of outputs. As scale increases, the diversity of feedstocks and outputs diminishes, and firms struggle with feedstock provisioning, global petroleum markets and higher financial risks. We argue that, to increase CE production, policies should consider value chains, promote the wider bio-economy of products and focus on economies of scope. Whereas the EU and its member states have ethanol quotas and blending targets, a more effective policy would be to seek to reduce the risks involved in financing capital projects, secure feedstock provisioning and support a diversity of end products.

  15. Modification of Corn Starch Ethanol Refinery to Efficiently Accept Various High-Impact Cellulosic Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Derr, Dan [Logos Technologies, Fairfax, VA (United States)

    2013-12-30

    The goal of the Corn-to-Cellulosic Migration (CCM) pilot facility was to demonstrate the implementation of advanced technologies and methods for conversion of non-food, cellulosic feedstocks into ethanol, assess the economics of the facility and evaluate potential environmental benefits for biomass to fuels conversion. The CCM project was comprised of design, build, and operate phases for the CCM pilot facility as well as research & development, and modeling components. The CCM pilot facility was designed to process 1 tonne per day of non-food biomass and biologically convert that biomass to ethanol at a rate of 70 gallons per tonne. The plant demonstrated throughputs in excess of 1 tonne per day for an extended run of 1400 hours. Although target yields were not fully achieved, the continuous operation validated the design and operability of the plant. These designs will permit the design of larger scale operations at existing corn milling operations or for greenfield plants. EdeniQ, a partner in the project and the owner of the pilot plant, continues to operate and evaluate other feedstocks.

  16. Availability of crop cellulosics for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, R.D.

    1982-10-01

    Past estimates of cellulosic resources available from Canadian agriculture totalled over 23 million tonnes of cereal grain straw and corn stover residues surplus to soil and animal requirements. A new much reduced estimate, based on four detailed regional studies that also include previously unassessed resources such as chaff, oilseed hulls, and food processing wastes, is suggested. Eleven million tonnes are currently available from all residue sources for energy conversion by different processes. Only five million tonnes are identified as potentially usable in ethanol production plants were they to be constructed. Additional resource opportunities may become available in future from currently underutilized land, especially saline soils, novel processing techniques of conventional grains and forages, innovative cropping systems that may increase the yield of agricultural biomass, and new food/feed/fuel (i.e. multi-purpose) crops such as kochia, milkweed, and Jerusalem artichoke. 27 refs., 1 fig., 1 tab.

  17. Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

    Directory of Open Access Journals (Sweden)

    Li Yongchao

    2012-01-01

    Full Text Available Abstract Background The model bacterium Clostridium cellulolyticum efficiently degrades crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels production. Therefore genetic engineering will likely be required to improve the ethanol yield. Plasmid transformation, random mutagenesis and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism, hindering genetic engineering. Results The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh and L-malate dehydrogenase (Ccel_0137; mdh genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain, resulting in a substantial shift in fermentation toward ethanol production. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products, corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant's tricarboxylic acid pathway. Conclusions The efficient intron-based gene inactivation system produced the first non-random, targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox

  18. Influence of the crystalline structure of cellulose on the production of ethanol from lignocellulose biomass

    Science.gov (United States)

    Smuga-Kogut, Małgorzata; Zgórska, Kazimiera; Szymanowska-Powałowska, Daria

    2016-01-01

    In recent years, much attention has been devoted to the possibility of using lignocellulosic biomass for energy. Bioethanol is a promising substitute for conventional fossil fuels and can be produced from straw and wood biomass. Therefore, the aim of this paper was to investigate the effect of 1-ethyl-3-methylimidazolium pretreatment on the structure of cellulose and the acquisition of reducing sugars and bioethanol from cellulosic materials. Material used in the study was rye straw and microcrystalline cellulose subjected to ionic liquid 1-ethyl-3-methylimidazolium pretreatment. The morphology of cellulose fibres in rye straw and microcrystalline cellulose was imaged prior to and after ionic liquid pretreatment. Solutions of ionic liquid-treated and untreated cellulosic materials were subjected to enzymatic hydrolysis in order to obtain reducing sugars, which constituted a substrate for alcoholic fermentation. An influence of the ionic liquid on the cellulose structure, accumulation of reducing sugars in the process of hydrolysis of this material, and an increase in ethanol amount after fermentation was observed. The ionic liquid did not affect cellulolytic enzymes negatively and did not inhibit yeast activity. The amount of reducing sugars and ethyl alcohol was higher in samples purified with 1-ethyl-3-methy-limidazolium acetate. A change in the supramolecular structure of cellulose induced by the ionic liquid was also observed.

  19. Opportunity for profitable investments in cellulosic biofuels

    International Nuclear Information System (INIS)

    Babcock, Bruce A.; Marette, Stephan; Treguer, David

    2011-01-01

    Research efforts to allow large-scale conversion of cellulose into biofuels are being undertaken in the US and EU. These efforts are designed to increase logistic and conversion efficiencies, enhancing the economic competitiveness of cellulosic biofuels. However, not enough attention has been paid to the future market conditions for cellulosic biofuels, which will determine whether the necessary private investment will be available to allow a cellulosic biofuels industry to emerge. We examine the future market for cellulosic biofuels, differentiating between cellulosic ethanol and 'drop-in' cellulosic biofuels that can be transported with petroleum fuels and have equivalent energy values. We show that emergence of a cellulosic ethanol industry is unlikely without costly government subsidies, in part because of strong competition from conventional ethanol and limits on ethanol blending. If production costs of drop-in cellulosic biofuels fall enough to become competitive, then their expansion will not necessarily cause feedstock prices to rise. As long as local supplies of feedstocks that have no or low-valued alternative uses exist, then expansion will not cause prices to rise significantly. If cellulosic feedstocks come from dedicated biomass crops, then the supply curves will have a steeper slope because of competition for land. (author)

  20. Enhanced cellulase recovery without β-glucosidase supplementation for cellulosic ethanol production using an engineered strain and surfactant.

    Science.gov (United States)

    Huang, Renliang; Guo, Hong; Su, Rongxin; Qi, Wei; He, Zhimin

    2017-03-01

    Recycling cellulases by substrate adsorption is a promising strategy for reducing the enzyme cost of cellulosic ethanol production. However, β-glucosidase has no carbohydrate-binding module (CBM). Thus, additional enzymes are required in each cycle to achieve a high ethanol yield. In this study, we report a new method of recycling cellulases without β-glucosidase supplementation using lignocellulosic substrate, an engineered strain expressing β-glucosidase and Tween 80. The cellulases and Tween 80 were added to an aqueous suspension of diluted sulfuric acid/ammonia-treated corncobs in a simultaneous saccharification and fermentation (SSF) process for ethanol production. Subsequently, the addition of fresh pretreated corncobs to the fermentation liquor and remaining solid residue provided substrates with absorbed cellulases for the next SSF cycle. This method provided excellent ethanol production in three successive SSF cycles without requiring the addition of new cellulases. For a 10% (w/v) solid loading, a cellulase dosage of 30 filter paper units (FPU)/g cellulose, 0.5% Tween 80, and 2 g/L of the engineered strain, approximately 90% of the initial ethanol concentration from the first SSF process was obtained in the next two SSF processes, with a total ethanol production of 306.27 g/kg corncobs and an enzyme productivity of 0.044 g/FPU. Tween 80 played an important role in enhancing cellulase recovery. This new enzyme recycling method is more efficient and practical than other reported methods. Biotechnol. Bioeng. 2017;114: 543-551. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. The ethanol pathway from Thermoanaerobacterium saccharolyticum improves ethanol production in Clostridium thermocellum.

    Science.gov (United States)

    Hon, Shuen; Olson, Daniel G; Holwerda, Evert K; Lanahan, Anthony A; Murphy, Sean J L; Maloney, Marybeth I; Zheng, Tianyong; Papanek, Beth; Guss, Adam M; Lynd, Lee R

    2017-07-01

    Clostridium thermocellum ferments cellulose, is a promising candidate for ethanol production from cellulosic biomass, and has been the focus of studies aimed at improving ethanol yield. Thermoanaerobacterium saccharolyticum ferments hemicellulose, but not cellulose, and has been engineered to produce ethanol at high yield and titer. Recent research has led to the identification of four genes in T. saccharolyticum involved in ethanol production: adhE, nfnA, nfnB and adhA. We introduced these genes into C. thermocellum and observed significant improvements to ethanol yield, titer, and productivity. The four genes alone, however, were insufficient to achieve in C. thermocellum the ethanol yields and titers observed in engineered T. saccharolyticum strains, even when combined with gene deletions targeting hydrogen production. This suggests that other parts of T. saccharolyticum metabolism may also be necessary to reproduce the high ethanol yield and titer phenotype in C. thermocellum. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  2. Techno-Economic Analysis of Biochemical Scenarios for Production of Cellulosic Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, F. K.; Fortman, J.; Anex, R.; Kothandaraman, G.; Hsu, D.; Aden, A.; Dutta, A.

    2010-06-01

    A techno-economic analysis on the production of cellulosic ethanol by fermentation was conducted to understand the viability of liquid biofuel production processes within the next 5-8 years. Initially, 35 technologies were reviewed, then a two-step down selection was performed to choose scenarios to be evaluated in a more detailed economic analysis. The lignocellulosic ethanol process was selected because it is well studied and portions of the process have been tested at pilot scales. Seven process variations were selected and examined in detail. Process designs were constrained to public data published in 2007 or earlier, without projecting for future process improvements. Economic analysis was performed for an 'nth plant' (mature technology) to obtain total investment and product value (PV). Sensitivity analysis was performed on PV to assess the impact of variations in process and economic parameters. Results show that the modeled dilute acid pretreatment process without any downstream process variation had the lowest PV of $3.40/gal of ethanol ($5.15/gallon of gasoline equivalent) in 2007 dollars. Sensitivity analysis shows that PV is most sensitive to feedstock and enzyme costs.

  3. Lifecycle greenhouse gas implications of US national scenarios for cellulosic ethanol production

    Science.gov (United States)

    Scown, Corinne D.; Nazaroff, William W.; Mishra, Umakant; Strogen, Bret; Lobscheid, Agnes B.; Masanet, Eric; Santero, Nicholas J.; Horvath, Arpad; McKone, Thomas E.

    2012-03-01

    The Energy Independence and Security Act of 2007 set an annual US national production goal of 39.7 billion l of cellulosic ethanol by 2020. This paper explores the possibility of meeting that target by growing and processing Miscanthus × giganteus. We define and assess six production scenarios in which active cropland and/or Conservation Reserve Program land are used to grow to Miscanthus. The crop and biorefinery locations are chosen with consideration of economic, land-use, water management and greenhouse gas (GHG) emissions reduction objectives. Using lifecycle assessment, the net GHG footprint of each scenario is evaluated, providing insight into the climate costs and benefits associated with each scenario’s objectives. Assuming that indirect land-use change is successfully minimized or mitigated, the results suggest two major drivers for overall GHG impact of cellulosic ethanol from Miscanthus: (a) net soil carbon sequestration or emissions during Miscanthus cultivation and (b) GHG offset credits for electricity exported by biorefineries to the grid. Without these factors, the GHG intensity of bioethanol from Miscanthus is calculated to be 11-13 g CO2-equivalent per MJ of fuel, which is 80-90% lower than gasoline. Including soil carbon sequestration and the power-offset credit results in net GHG sequestration up to 26 g CO2-equivalent per MJ of fuel.

  4. Lifecycle greenhouse gas implications of US national scenarios for cellulosic ethanol production

    International Nuclear Information System (INIS)

    Scown, Corinne D; Nazaroff, William W; Strogen, Bret; Santero, Nicholas J; Horvath, Arpad; Mishra, Umakant; Lobscheid, Agnes B; Masanet, Eric; McKone, Thomas E

    2012-01-01

    The Energy Independence and Security Act of 2007 set an annual US national production goal of 39.7 billion l of cellulosic ethanol by 2020. This paper explores the possibility of meeting that target by growing and processing Miscanthus × giganteus. We define and assess six production scenarios in which active cropland and/or Conservation Reserve Program land are used to grow to Miscanthus. The crop and biorefinery locations are chosen with consideration of economic, land-use, water management and greenhouse gas (GHG) emissions reduction objectives. Using lifecycle assessment, the net GHG footprint of each scenario is evaluated, providing insight into the climate costs and benefits associated with each scenario’s objectives. Assuming that indirect land-use change is successfully minimized or mitigated, the results suggest two major drivers for overall GHG impact of cellulosic ethanol from Miscanthus: (a) net soil carbon sequestration or emissions during Miscanthus cultivation and (b) GHG offset credits for electricity exported by biorefineries to the grid. Without these factors, the GHG intensity of bioethanol from Miscanthus is calculated to be 11–13 g CO 2 -equivalent per MJ of fuel, which is 80–90% lower than gasoline. Including soil carbon sequestration and the power-offset credit results in net GHG sequestration up to 26 g CO 2 -equivalent per MJ of fuel. (letter)

  5. Ethanol production from paper sludge using Kluyveromyces marxianus

    International Nuclear Information System (INIS)

    Madrid, Lina Maria; Quintero Diaz, Juan Carlos

    2011-01-01

    Recycled paper sludge is a promising raw material for ethanol production. In this study, we first evaluated the effects of ethanol concentration, solids load, and cellulose crystallinity on the enzymatic hydrolysis of cellulose to produce reducing sugars. We then evaluated the production of ethanol by either saccharification and simultaneous fermentation (SSF) or separated hydrolysis and fermentation (SHF) using the yeast Kluyveromyces marxianus ATCC 36907. We found that cellulose hydrolysis decreased as ethanol concentrations increased; at 40 g/L ethanol, the reducing sugar production was decreased by 79 %. Hydrolysis also decreased as solids load increased; at 9 % of solids, the cellulose conversion was 76 % of the stoichiometric production. The ethanol yield and cellulose conversion rate were higher with SSF as opposed to SHF processes at 72 h of treatment.

  6. Characterization of persistent colors and decolorization of effluent from biologically treated cellulosic ethanol production wastewater.

    Science.gov (United States)

    Shan, Lili; Liu, Junfeng; Yu, Yanling; Ambuchi, John J; Feng, Yujie

    2016-05-01

    The high chroma of cellulosic ethanol production wastewater poses a serious environmental concern; however, color-causing compounds are still not fully clear. The characteristics of the color compounds and decolorization of biologically treated effluent by electro-catalytic oxidation were investigated in this study. Excitation-emission matrix (EEM), fourier transform infrared spectrometer (FTIR), UV-Vis spectra, and ultrafiltration (UF) fractionation were used to analyze color compounds. High chroma of wastewater largely comes from humic materials, which exhibited great fluorescence proportion (67.1 %) in the biologically treated effluent. Additionally, the color compounds were mainly distributed in the molecular weight fractions with 3-10 and 10-30 kDa, which contributed 53.5 and 34.6 % of the wastewater color, respectively. Further decolorization of biologically treated effluent by electro-catalytic oxidation was investigated, and 98.3 % of color removal accompanied with 97.3 % reduction of humic acid-like matter was achieved after 180 min. The results presented herein will facilitate the development of a well decolorization for cellulosic ethanol production wastewater and better understanding of the biological fermentation.

  7. Combined enzyme hydrolysis of cellulose and yeast fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Savarese, J J; Young, S D

    1978-08-01

    The conversion of cellulose, especially waste cellulosics, into utilizable materials, especially liquid fuel, is a most valuable outcome of cellulase technology pioneered at the US Army Laboratories, Natick, Mass. A process design has been proposed by Wilke for the conversion of cellulosic materials to ethanol and single-cell protein (SCP). The estimated ethanol production cost by this process is at the moment slightly more expensive than ethanol derived from petroleum. This paper deals with a process design improvement which will lower production cost for ethanol obtained via a Wilke or similar type system. We report a process by which the cellulase-catalyzed hydrolysis of cellulose to glucose is coupled with the yeast fermentation of the glucose produced to ethanol and SCP. Both processes take place in the same fermentor thus eliminating the need for the separation of glucose and a second reactor.

  8. Production of liquid transport fuel from cellulose material (wood). III Laboratory preparation of wood sugars and fermentation to ethanol and yeast

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, D A; Harwood, V D

    1977-10-25

    A laboratory procedure is described for hydrolyzing cellulose material to sugars by the use of hot sulfuric acid. The procedure has been used routinely for assessing raw materials. Raw materials used were radiata pine (fresh wood and decayed thinnings), pine needles, sawdust from old dumps, newspaper, cardboard, beech wood, and coconut wood. The neutralized sugar-liquors produced, supplemented with fertilizer grade nutrients, were fermented with bakers' yeast and gave near optimal conversion of hexoses to ethanol and of pentoses to protein biomass. From 100 g radiata pine (wood: bark mix 85:15) 25 ml (20 g) of ethanol and 2 g yeast biomass were routinely produced, although fermentation rates were lower than with pure sugars. The results, however, clearly showed that, by a hot dilute sulfure acid hydrolysis followed by a yeast fermentation process, cellulose resources avaliable in New Zealand are suitable for conversion to ethanol. 5 table, 1 figure.

  9. Final report (September, 1999--February, 2002) [Public outreach and information dissemination - cellulosic and corn-based ethanol outreach project

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Jeremy; Werner, Carol

    2002-08-01

    EESI's ''Ethanol, Climate Protection, Oil Reduction'' (ECO) electr[on]ic newsletter reaches out to the environmental and agricultural communities, state/local government officials and other interested parties, and provides a forum for dialogue about ''the potential benefits of ethanol--and particularly the expanded opportunities provided by cellulosic ethanol--with a special focus on climate protection.'' Each issue features expert commentary, excerpts from recent studies about ethanol, a summary of current government activity on ethanol, and ''notable quotables.'' The newsletter is distributed primarily via email and is also posted on EESI's web site. EESI also conducts outreach on the benefits of ethanol and other biofuels by attending and speaking at conferences, meetings and workshops around the country. The 16 issues of the newsletter published through December 2001 are included as attachments.

  10. Robust cellulosic ethanol production from SPORL-pretreated lodgepole pine using an adapted strain Saccharomyces cervisiae without detoxification

    Science.gov (United States)

    S. Tian; X.L. Luo; X.S. Yang; J.Y. Zhu

    2010-01-01

    This study reports an ethanol yield of 270 L/ton wood from lodgepole pine pretreated with sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) using an adapted strain, Saccharomyces cerevisiae Y5, without detoxification. The enzymatic hydrolysate produced from pretreated cellulosic solids substrate was combined with pretreatment hydrolysate before...

  11. Emotional reactivity to incentive downshift as a correlated response to selection of high and low alcohol preferring mice and an influencing factor on ethanol intake.

    Science.gov (United States)

    Matson, Liana M; Grahame, Nicholas J

    2015-11-01

    Losing a job or significant other are examples of incentive loss that result in negative emotional reactions. The occurrence of negative life events is associated with increased drinking (Keyes, Hatzenbuehler, & Hasin, 2011). Further, certain genotypes are more likely to drink alcohol in response to stressful negative life events (Blomeyer et al., 2008; Covault et al., 2007). Shared genetic factors may contribute to alcohol drinking and emotional reactivity, but this relationship is not currently well understood. We used an incentive downshift paradigm to address whether emotional reactivity is elevated in mice predisposed to drink alcohol. We also investigated if ethanol drinking is influenced in High Alcohol Preferring mice that had been exposed to an incentive downshift. Incentive downshift procedures have been widely utilized to model emotional reactivity, and involve shifting a high reward group to a low reward and comparing the shifted group to a consistently rewarded control group. Here, we show that replicate lines of selectively bred High Alcohol Preferring mice exhibited larger successive negative contrast effects than their corresponding replicate Low Alcohol Preferring lines, providing strong evidence for a genetic association between alcohol drinking and susceptibility to the emotional effects of negative contrast. These mice can be used to study the shared neurological and genetic underpinnings of emotional reactivity and alcohol preference. Unexpectedly, an incentive downshift suppressed ethanol drinking immediately following an incentive downshift. This could be due to a specific effect of negative contrast on ethanol consumption or a suppressive effect on consummatory behavior in general. These data suggest that either alcohol intake does not provide the anticipated negative reinforcement, or that a single test was insufficient for animals to learn to drink following incentive downshift. However, the emotional intensity following incentive

  12. On the conflicting findings of Role of Cellulose-Crystallinity in Enzume Hydrolysis of Biomass

    Science.gov (United States)

    Umesh Agarwal; Sally Ralph

    2014-01-01

    In the field of conversion of biomass to ethanol, an important area of research is the enzymatic hydrolysis of cellulose. Once cellulose is converted to glucose, it can be easily fermented to ethanol. As the cellulosic ethanol technology stands now, costly pretreatments and high dosages of cellulases are needed to achieve complete hydrolysis of the cellulose fraction...

  13. Cellulose utilization: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Bassham, J A

    1975-01-01

    To summarize, the conversion of cellulose to ethanol via hydrolysis to glucose followed by fermentation appears to be highly efficient in terms of energy conservation, yield, and quality of product, especially when reasonably high quality cellulosic waste is available.

  14. Lampung natural zeolite filled cellulose acetate membrane for pervaporation of ethanol-water mixtures

    Science.gov (United States)

    Iryani, D. A.; Wulandari, N. F.; Cindradewi, AW; Ginting, S. Br; Ernawati, E.; Hasanudin, U.

    2018-03-01

    Pervaporation of ethanol–water can be cost-competitive in the production of renewable biomass ethanol. For the purpose of improving the pervaporation performance of polymeric membranes, we prepared cellulose acetate (CA) filled Lampung Natural Zeolite (LNZ) membranes by incorporating LNZ into CA for pervaporation separation of ethanol-water mixtures. The characteristics and performance of these filled membranes in the varied ratio of CA:LNZ (30:0, 30:5, 30:10, 30: 20, 20:20 and 40:10) wt% were investigated. The prepared membranes were characterized for pervaporation membrane performance such as %water content and membrane swelling degree. Further, the permeation flux and selectivity of membrane were also observed. The results of investigation show that water content of membrane tends to increase with increase of LNZ content. However, the swelling degree of membrane decrease compared than that of CA control membrane. The permeation flux and the selectivity of membranes tend to increase continuously. The CA membrane with ratio of CA:LNZ 30:20 shows the highest selectivity of 80.42 with a permeation flux of 0.986 kg/(m2 h) and ethanol concentration of 99.08 wt%.

  15. Recent updates on lignocellulosic biomass derived ethanol - A review

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2016-03-01

    Full Text Available Lignocellulosic (or cellulosic biomass derived ethanol is the most promising near/long term fuel candidate. In addition, cellulosic biomass derived ethanol may serve a precursor to other fuels and chemicals that are currently derived from unsustainable sources and/or are proposed to be derived from cellulosic biomass. However, the processing cost for second generation ethanol is still high to make the process commercially profitable and replicable. In this review, recent trends in cellulosic biomass ethanol derived via biochemical route are reviewed with main focus on current research efforts that are being undertaken to realize high product yields/titers and bring the overall cost down.

  16. Conversion of bagasse cellulose into ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Cuzens, J.E.

    1997-11-19

    The study conducted by Arkenol was designed to test the conversion of feedstocks such as sugar cane bagasse, sorghum, napier grass and rice straw into fermentable sugars, and then ferment these sugars using natural yeasts and genetically engineered Zymomonis mobilis bacteria (ZM). The study did convert various cellulosic feedstocks into fermentable sugars utilizing the patented Arkenol Concentrated Acid Hydrolysis Process and equipment at the Arkenol Technology Center in Orange, California. The sugars produced using this process were in the concentration range of 12--15%, much higher than the sugar concentrations the genetically engineered ZM bacteria had been developed for. As a result, while the ZM bacteria fermented the produced sugars without initial inhibition, the completion of high sugar concentration fermentations was slower and at lower yield than predicted by the National Renewable Energy Laboratory (NREL). Natural yeasts performed as expected by Arkenol, similar to the results obtained over the last four years of testing. Overall, at sugar concentrations in the 10--13% range, yeast produced 850090% theoretical ethanol yields and ZM bacteria produced 82--87% theoretical yields in 96 hour fermentations. Additional commercialization work revealed the ability to centrifugally separate and recycle the ZM bacteria after fermentation, slight additional benefits from mixed culture ZM bacteria fermentations, and successful utilization of defined media for ZM bacteria fermentation nutrients in lieu of natural media.

  17. High-Octane Mid-Level Ethanol Blend Market Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Caley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Newes, Emily [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brooker, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); McCormick, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Peterson, Steve [Lexidyne, LLC, Colorado Springs, CO (United States); Leiby, Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martinez, Rocio Uria [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Oladosu, Gbadebo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brown, Maxwell L. [Colorado School of Mines, Golden, CO (United States)

    2015-12-01

    The United States government has been promoting increased use of biofuels, including ethanol from non-food feedstocks, through policies contained in the Energy Independence and Security Act of 2007. The objective is to enhance energy security, reduce greenhouse gas (GHG) emissions, and provide economic benefits. However, the United States has reached the ethanol blend wall, where more ethanol is produced domestically than can be blended into standard gasoline. Nearly all ethanol is blended at 10 volume percent (vol%) in gasoline. At the same time, the introduction of more stringent standards for fuel economy and GHG tailpipe emissions is driving research to increase the efficiency of spark ignition (SI) engines. Advanced strategies for increasing SI engine efficiency are enabled by higher octane number (more highly knock-resistant) fuels. Ethanol has a research octane number (RON) of 109, compared to typical U.S. regular gasoline at 91-93. Accordingly, high RON ethanol blends containing 20 vol% to 40 vol% ethanol are being extensively studied as fuels that enable design of more efficient engines. These blends are referred to as high-octane fuel (HOF) in this report. HOF could enable dramatic growth in the U.S. ethanol industry, with consequent energy security and GHG emission benefits, while also supporting introduction of more efficient vehicles. HOF could provide the additional ethanol demand necessary for more widespread deployment of cellulosic ethanol. However, the potential of HOF can be realized only if it is adopted by the motor fuel marketplace. This study assesses the feasibility, economics, and logistics of this adoption by the four required participants--drivers, vehicle manufacturers, fuel retailers, and fuel producers. It first assesses the benefits that could motivate these participants to adopt HOF. Then it focuses on the drawbacks and barriers that these participants could face when adopting HOF and proposes strategies--including incentives and

  18. Fulton Cellulosic Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Sumait, Necy [BlueFire Ethanol, Irvine, CA (United States); Cuzens, John [BlueFire Ethanol, Irvine, CA (United States); Klann, Richard [BlueFire Ethanol, Irvine, CA (United States)

    2015-07-24

    Final report on work performed by BlueFire on the deployment of acid hydrolysis technology to convert cellulosic waste materials into renewable fuels, power and chemicals in a production facility to be located in Fulton, Mississippi.

  19. Cellulase and alcohol dehydrogenase immobilized in Langmuir and Langmuir-Blodgett films and their molecular-level effects upon contact with cellulose and ethanol.

    Science.gov (United States)

    Rodrigues, Dilmer; Camilo, Fernanda Ferraz; Caseli, Luciano

    2014-02-25

    The key challenges for producing devices based on nanostructured films with control over the molecular architecture are to preserve the catalytic activity of the immobilized biomolecules and to provide a reliable method for determining the intermolecular interactions and the accommodation of molecules at very small scales. In this work, the enzymes cellulase and alcohol dehydrogenase (ADH) were coimmobilized with dipalmitoylphosphatidylcholine (DPPC) as Langmuir-Blodgett (LB) films, and their biological activities were assayed by accommodating the structure formed in contact with cellulose. For this purpose, the polysaccharide was dissolved in an ionic liquid, 1-buthyl-3-methylimidazolium chloride (BMImCl), and dropped on the top of the hybrid cellulase-ADH-DPPC LB film. The interactions between cellulose and ethanol, which are the catalytic substrates of the enzymes as well as important elements in the production of second-generation fuels, were then investigated using polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS). Investigation of the secondary structures of the enzymes was performed using PM-IRRAS, through which the presence of ethanol and cellulose was observed to highly affect the structures of ADH and cellulase, respectively. The detection of products formed from the catalyzed reactions as well as the changes of secondary structure of the enzymes immobilization could be carried out, which opens the possibility to produce a means for producing second-generation ethanol using nanoscale arrangements.

  20. Evaluation of mountain beetle-infested lodgepole pine for cellulosic ethanol production by sulfite pretreatment to overcome recalcitrance of lignocellulose

    Science.gov (United States)

    X. Luo; R. Gleisner; S. Tian; J. Negron; W. Zhu; E. Horn; X. J. Pan; J. Y. Zhu

    2010-01-01

    The potentials of deteriorated mountain pine beetle (Dendroctonus ponderosae)-killed lodgepole pine (Pinus contorta) trees for cellulosic ethanol production were evaluated using the sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) process. The trees were harvested from two sites in the United States Arapaho-Roosevelt National Forest, Colorado....

  1. Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongchao [ORNL; Tschaplinski, Timothy J [ORNL; Engle, Nancy L [ORNL; Hamilton, Choo Yieng [ORNL; Rodriguez, Jr., Miguel [ORNL; Liao, James C [ORNL; Schadt, Christopher Warren [ORNL; Guss, Adam M [ORNL; Yang, Yunfeng [ORNL; Graham, David E [ORNL

    2012-01-01

    Background: The model bacterium Clostridium cellulolyticum efficiently hydrolyzes crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels. Therefore genetic engineering will likely be required to improve the ethanol yield. Random mutagenesis, plasmid transformation, and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism. Results: The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh) and L-malate dehydrogenase (Ccel_0137; mdh) genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products (by molarity), corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four-times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant s TCA pathway. Conclusions: The efficient intron-based gene inactivation system produced the first gene-targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox for this bacterium, markerless targeted mutagenesis enables functional genomic research in C. cellulolyticum and rapid genetic engineering to

  2. Robust cellulosic ethanol production from SPORL-pretreated lodgepole pine using an adapted strain Saccharomyces cerevisiae without detoxification.

    Science.gov (United States)

    Tian, S; Luo, X L; Yang, X S; Zhu, J Y

    2010-11-01

    This study reports an ethanol yield of 270L/ton wood from lodgepole pine pretreated with sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) using an adapted strain, Saccharomyces cerevisiae Y5, without detoxification. The enzymatic hydrolysate produced from pretreated cellulosic solids substrate was combined with pretreatment hydrolysate before fermentation. Detoxification of the pretreatment hydrolysate using overliming or XAD-4 resin before being combined with enzymatic hydrolysate improved ethanol productivity in the first 4h of fermentation and overall fermentation efficiency. However, detoxification did not improve final ethanol yield because of sugar losses. The Y5 strain showed excellent ethanol productivities of 2.0 and 0.8g/L/h averaged over a period of 4 and 24h, respectively, in the undetoxified run. The furan metabolization rates of the Y5 strain were significantly higher for the undetoxified run than those for the detoxidfied runs, suggesting it can tolerate even higher furan concentrations than those studied. Preliminary mass and energy balances were conducted. SPORL produced an excellent monomeric sugar recovery value of about 85% theoretical and a net energy output of 4.05GJ/ton wood with an ethanol energy production efficiency of 178% before distillation.

  3. Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification and Fermentation by Xylanase

    Directory of Open Access Journals (Sweden)

    M Samsuri

    2010-10-01

    Full Text Available Bagasse is a solid residue from sugar cane process, which is not many use it for some product which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternative energy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesia could be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanase enzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, and 24,2% lignin. Xylanase enzyme and Saccharomyces cerevisiae was used to hydrolyse and fermentation in SSF process. Variation in this research use pH (4, 4,5, and 5, for increasing ethanol quantity, SSF process was done by added chloride acid (HCl with concentration 0.5% and 1% (v/v and also pre-treatment with white rot fungi such as Lentinus edodes (L.edodes as long 4 weeks. The SSF process was done with 24, 48, 72, and 96 hour's incubation time for fermentation. Variation of pH 4, 4,5, and 5 can produce ethanol with concentrations 2,357 g/L, 2,451 g/L, 2,709 g/L. The added chloride acid (HCl with concentration 0.5% and 1% (v/v and L. edodes can increase ethanol yield, The highest ethanol concentration with added chloride acid (HCl concentration 0.5% and 1% consecutively is 2,967 g/L, 3,249 g/L. The highest ethanol concentration with pre-treatment by L. edodes is 3,202 g/L.

  4. Oxidative production of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth by Gluconobacter oxydans.

    Science.gov (United States)

    Zhang, Hongsen; Han, Xushen; Wei, Chengxiang; Bao, Jie

    2017-01-01

    An oxidative production process of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth was designed, experimentally investigated, and evaluated. Dry dilute acid pretreated and biodetoxified corn stover was simultaneously saccharified and fermented into 59.80g/L of ethanol (no xylose utilization). 65.39g/L of xylose was obtained in the distillation stillage without any concentrating step after ethanol was distillated. Then the xylose was completely converted into 66.42g/L of xylonic acid by Gluconobacter oxydans. The rigorous Aspen Plus modeling shows that the wastewater generation and energy consumption was significantly reduced comparing to the previous xylonic acid production process using xylose in pretreatment liquid. This study provided a practical process option for xylonic acid production from lignocellulose feedstock with significant reduction of wastewater and energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Refining sweet sorghum to ethanol and sugar: economic trade-offs in the context of North China.

    Science.gov (United States)

    Gnansounou, E; Dauriat, A; Wyman, C E

    2005-06-01

    Reducing the use of non-renewable fossil energy reserves together with improving the environment are two important reasons that drive interest in the use of bioethanol as an automotive fuel. Conversion of sugar and starch to ethanol has been proven at an industrial scale in Brazil and the United States, respectively, and this alcohol has been able to compete with conventional gasoline due to various incentives. In this paper, we examined making ethanol from the sugar extracted from the juice of sweet sorghum and/or from the hemicellulose and cellulose in the residual sorghum bagasse versus selling the sugar from the juice or burning the bagasse to make electricity in four scenarios in the context of North China. In general terms, the production of ethanol from the hemicellulose and cellulose in bagasse was more favorable than burning it to make power, but the relative merits of making ethanol or sugar from the juice was very sensitive to the price of sugar in China. This result was confirmed by both process economics and analysis of opportunity costs. Thus, a flexible plant capable of making both sugar and fuel-ethanol from the juice is recommended. Overall, ethanol production from sorghum bagasse appears very favorable, but other agricultural residues such as corn stover and rice hulls would likely provide a more attractive feedstock for making ethanol in the medium and long term due to their extensive availability in North China and their independence from other markets. Furthermore, the process for residue conversion was based on particular design assumptions, and other technologies could enhance competitiveness while considerations such as perceived risk could impede applications.

  6. Separate hydrolysis and fermentation (SHF) of Prosopis juliflora, a woody substrate, for the production of cellulosic ethanol by Saccharomyces cerevisiae and Pichia stipitis-NCIM 3498.

    Science.gov (United States)

    Gupta, Rishi; Sharma, Krishna Kant; Kuhad, Ramesh Chander

    2009-02-01

    Prosopis juliflora (Mesquite) is a raw material for long-term sustainable production of cellulosics ethanol. In this study, we used acid pretreatment, delignification and enzymatic hydrolysis to evaluate the pretreatment to produce more sugar, to be fermented to ethanol. Dilute H(2)SO(4) (3.0%,v/v) treatment resulted in hydrolysis of hemicelluloses from lignocellulosic complex to pentose sugars along with other byproducts such as furfural, hydroxymethyl furfural (HMF), phenolics and acetic acid. The acid pretreated substrate was delignified to the extent of 93.2% by the combined action of sodium sulphite (5.0%,w/v) and sodium chlorite (3.0%,w/v). The remaining cellulosic residue was enzymatically hydrolyzed in 0.05 M citrate phosphate buffer (pH 5.0) using 3.0 U of filter paper cellulase (FPase) and 9.0 U of beta-glucosidase per mL of citrate phosphate buffer. The maximum enzymatic saccharification of cellulosic material (82.8%) was achieved after 28 h incubation at 50 degrees C. The fermentation of both acid and enzymatic hydrolysates, containing 18.24 g/L and 37.47 g/L sugars, with Pichia stipitis and Saccharomyces cerevisiae produced 7.13 g/L and 18.52 g/L of ethanol with corresponding yield of 0.39 g/g and 0.49 g/g, respectively.

  7. Scale up of ethanol production using pulp mill wastewater sludge by cellulase and saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Kunchada Sangasintu; Petchporn Chawakitchareon

    2010-01-01

    This study aimed to evaluate the potential use of pulp mill wastewater sludge as substrate in ethanol production. The simultaneous saccharification and fermentation process was conducted by using Saccharomyces cerevisiae TISTR 5339 under optimum proportion of cellulase and pulp mill wastewater sludge. The ethanol production from cellulosic materials in simultaneous saccharification and fermentation needs cooperation between cellulase and yeast. The cellulase hydrolyzes cellulose to sugar while yeast utilizes sugar to produce ethanol. The pulp mill wastewater sludge has an average content of 73.3 % hemi cellulose, 67.1 % alpha cellulose, 4.7 % beta cellulose and 1.4 % gamma cellulose. The experimental results indicated that the volume of the ethanol tend to increase with time, providing the maximum ethanol yield of 0.69 g/g on the 7"t"h day, the last day of the experiment. The ethanol production was scaled up in 5 L fermentor under optimum proportion and increased the fermentation period. It was found that the ethanol production gave the maximum ethanol yield of 1.14 g/g on the 9"t"h day of the totally 13 days experimentation. These results showed that the cellulose from pulp mill wastewater sludge was as effective substrate for ethanol production and alternative energy for the future. (author)

  8. Overall process considerations for using dilute acid cellulose hydrolysis technology to produce ethanol from biomass

    International Nuclear Information System (INIS)

    Elander, R.; Ibsen, K.; Hayward, T.; Nagle, N.; Torget, R.

    1997-01-01

    Recent advances in reactors, designed for the dilute acid thermochemical treatment of biomass, have resulted in the development of process alternatives in which both cellulose and hemicellulose are hydrolyzed to soluble sugars in high yields. The optimal extent of cellulose hydrolysis will depend on both the performance and economics of the thermochemical treatment operation, and on subsequent unit operations in the bioethanol production process. Examples of subsequent unit operation interactions include the extent to which cellulase enzymes are used to hydrolyze any remaining cellulose, kinetics and conditions of a largely soluble mixed sugar cofermentation, and the extent to which removal of compounds that inhabit fermenting microorganisms is required. In addition, a number of process operation and economic considerations affect the ultimate economic viability of this type of biomass hydrolysis process. These considerations include reactor design issues to accommodate the kinetic parameters of the various hydrolysis and sugar degradation reactions, liquid volume requirements to achieve acceptable sugar yields, sugar concentrations that result from such a process and their impact on subsequent fermentation volumes and ethanol recovery operations, potential co-product opportunities that result from solubilized lignin, and process steam requirements. Several potential whole-process configurations are presented and key process and economic issues for each are discussed. (author)

  9. Analysis of federal and state policies and environmental issues for bioethanol production facilities.

    Science.gov (United States)

    McGee, Chandra; Chan Hilton, Amy B

    2011-03-01

    The purpose of this work was to investigate incentives and barriers to fuel ethanol production from biomass in the U.S. during the past decade (2000-2010). In particular, we examine the results of policies and economic conditions during this period by way of cellulosic ethanol activity in four selected states with the potential to produce different types of feedstocks (i.e., sugar, starch, and cellulosic crops) for ethanol production (Florida, California, Hawaii, and Iowa). Two of the four states, Iowa and California, currently have commercial ethanol production facilities in operation using corn feedstocks. While several companies have proposed commercial scale facilities in Florida and Hawaii, none are operating to date. Federal and state policies and incentives, potential for feedstock production and conversion to ethanol and associated potential environmental impacts, and environmental regulatory conditions among the states were investigated. Additionally, an analysis of proposed and operational ethanol production facilities provided evidence that a combination of these policies and incentives along with the ability to address environmental issues and regulatory environment and positive economic conditions all impact ethanol production. The 2000-2010 decade saw the rise of the promise of cellulosic ethanol. Federal and state policies were enacted to increase ethanol production. Since the initial push for development, expansion of cellulosic ethanol production has not happened as quickly as predicted. Government and private funding supported the development of ethanol production facilities, which peaked and then declined by the end of the decade. Although there are technical issues that remain to be solved to more efficiently convert cellulosic material to ethanol while reducing environmental impacts, the largest barriers to increasing ethanol production appear to be related to government policies, economics, and logistical issues. The numerous federal and state

  10. Evaluation of Ethanol Production Activity by Engineered Saccharomyces cerevisiae Fermenting Cellobiose through the Phosphorolytic Pathway in Simultaneous Saccharification and Fermentation of Cellulose.

    Science.gov (United States)

    Lee, Won-Heong; Jin, Yong-Su

    2017-09-28

    In simultaneous saccharification and fermentation (SSF) for production of cellulosic biofuels, engineered Saccharomyces cerevisiae capable of fermenting cellobiose has provided several benefits, such as lower enzyme costs and faster fermentation rate compared with wild-type S. cerevisiae fermenting glucose. In this study, the effects of an alternative intracellular cellobiose utilization pathway-a phosphorolytic pathway based on a mutant cellodextrin transporter (CDT-1 (F213L)) and cellobiose phosphorylase (SdCBP)-was investigated by comparing with a hydrolytic pathway based on the same transporter and an intracellular β-glucosidase (GH1-1) for their SSF performances under various conditions. Whereas the phosphorolytic and hydrolytic cellobiose-fermenting S. cerevisiae strains performed similarly under the anoxic SSF conditions, the hydrolytic S. cerevisiae performed slightly better than the phosphorolytic S. cerevisiae under the microaerobic SSF conditions. Nonetheless, the phosphorolytic S. cerevisiae expressing the mutant CDT-1 showed better ethanol production than the glucose-fermenting S. cerevisiae with an extracellular β-glucosidase, regardless of SSF conditions. These results clearly prove that introduction of the intracellular cellobiose metabolic pathway into yeast can be effective on cellulosic ethanol production in SSF. They also demonstrate that enhancement of cellobiose transport activity in engineered yeast is the most important factor affecting the efficiency of SSF of cellulose.

  11. Chemical Pretreatment Methods for the Production of Cellulosic Ethanol: Technologies and Innovations

    Directory of Open Access Journals (Sweden)

    Edem Cudjoe Bensah

    2013-01-01

    Full Text Available Pretreatment of lignocellulose has received considerable research globally due to its influence on the technical, economic and environmental sustainability of cellulosic ethanol production. Some of the most promising pretreatment methods require the application of chemicals such as acids, alkali, salts, oxidants, and solvents. Thus, advances in research have enabled the development and integration of chemical-based pretreatment into proprietary ethanol production technologies in several pilot and demonstration plants globally, with potential to scale-up to commercial levels. This paper reviews known and emerging chemical pretreatment methods, highlighting recent findings and process innovations developed to offset inherent challenges via a range of interventions, notably, the combination of chemical pretreatment with other methods to improve carbohydrate preservation, reduce formation of degradation products, achieve high sugar yields at mild reaction conditions, reduce solvent loads and enzyme dose, reduce waste generation, and improve recovery of biomass components in pure forms. The use of chemicals such as ionic liquids, NMMO, and sulphite are promising once challenges in solvent recovery are overcome. For developing countries, alkali-based methods are relatively easy to deploy in decentralized, low-tech systems owing to advantages such as the requirement of simple reactors and the ease of operation.

  12. Ethanol extract grapefruit peel ( Citrus maxima Murr.) gel formulations with gelling agent durian seed gum and carboxy methyl cellulose

    OpenAIRE

    Nazliniwaty; Karsono; Zebua, Nilsya Febrika; Nerdy

    2017-01-01

    This research aims to investigate the best gel formula of grapefruit ethanol extracts (Citrus maxima Murr.) with gelling agent combination durian seed gum and carboxy methyl cellulose (CMC). Durian seed gum was isolated with centrifuge and then combined with CMC-Na in five formulas. Evaluation material of topical gel that is its homogeneity, pH, stability testing, and irritation of the volunteers. All formula gel preparations its ...

  13. Fuel ethanol discussion paper

    International Nuclear Information System (INIS)

    1992-01-01

    In recognition of the potential benefits of ethanol and the merits of encouraging value-added agricultural development, a committee was formed to develop options for the role of the Ontario Ministry of Agriculture and Food in the further development of the ethanol industry in Ontario. A consultation with interested parties produced a discussion paper which begins with an outline of the role of ethanol as an alternative fuel. Ethanol issues which require industry consideration are presented, including the function of ethanol as a gasoline oxygenate or octane enhancer, environmental impacts, energy impacts, agricultural impacts, trade and fiscal implications, and regulation. The ethanol industry and distribution systems in Ontario are then described. The current industry consists of one ethanol plant and over 30 retail stations. The key issue for expanding the industry is the economics of producing ethanol. At present, production of ethanol in the short term depends on tax incentives amounting to 23.2 cents/l. In the longer term, a significant reduction in feedstock costs and a significant improvement in processing technology, or equally significant gasoline price increases, will be needed to create a sustainable ethanol industry that does not need incentives. Possible roles for the Ministry are identified, such as support for ethanol research and development, financial support for construction of ethanol plants, and active encouragement of market demand for ethanol-blended gasolines

  14. Metabolic engineering of a haploid strain derived from a triploid industrial yeast for producing cellulosic ethanol.

    Science.gov (United States)

    Kim, Soo Rin; Skerker, Jeffrey M; Kong, In Iok; Kim, Heejin; Maurer, Matthew J; Zhang, Guo-Chang; Peng, Dairong; Wei, Na; Arkin, Adam P; Jin, Yong-Su

    2017-03-01

    Many desired phenotypes for producing cellulosic biofuels are often observed in industrial Saccharomyces cerevisiae strains. However, many industrial yeast strains are polyploid and have low spore viability, making it difficult to use these strains for metabolic engineering applications. We selected the polyploid industrial strain S. cerevisiae ATCC 4124 exhibiting rapid glucose fermentation capability, high ethanol productivity, strong heat and inhibitor tolerance in order to construct an optimal yeast strain for producing cellulosic ethanol. Here, we focused on developing a general approach and high-throughput screening method to isolate stable haploid segregants derived from a polyploid parent, such as triploid ATCC 4124 with a poor spore viability. Specifically, we deleted the HO genes, performed random sporulation, and screened the resulting segregants based on growth rate, mating type, and ploidy. Only one stable haploid derivative (4124-S60) was isolated, while 14 other segregants with a stable mating type were aneuploid. The 4124-S60 strain inherited only a subset of desirable traits present in the parent strain, same as other aneuploids, suggesting that glucose fermentation and specific ethanol productivity are likely to be genetically complex traits and/or they might depend on ploidy. Nonetheless, the 4124-60 strain did inherit the ability to tolerate fermentation inhibitors. When additional genetic perturbations known to improve xylose fermentation were introduced into the 4124-60 strain, the resulting engineered strain (IIK1) was able to ferment a Miscanthus hydrolysate better than a previously engineered laboratory strain (SR8), built by making the same genetic changes. However, the IIK1 strain showed higher glycerol and xylitol yields than the SR8 strain. In order to decrease glycerol and xylitol production, an NADH-dependent acetate reduction pathway was introduced into the IIK1 strain. By consuming 2.4g/L of acetate, the resulting strain (IIK1A

  15. Cellulose conversion of corn pericarp without pretreatment.

    Science.gov (United States)

    Kim, Daehwan; Orrego, David; Ximenes, Eduardo A; Ladisch, Michael R

    2017-12-01

    We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5mg/g and gave 98% cellulose conversion in 72h. However, for double the amount of enzyme from Trichoderma reesei, which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Ethanol production in China: Potential and technologies

    International Nuclear Information System (INIS)

    Li, Shi-Zhong; Chan-Halbrendt, Catherine

    2009-01-01

    Rising oil demand in China has resulted in surging oil imports and mounting environmental pollution. It is projected that by 2030 the demand for fossil fuel oil will be 250 million tons. Ethanol seems to be an attractive renewable alternative to fossil fuel. This study assesses China's ethanol supply potential by examining potential non-food crops as feedstock; emerging conversion technologies; and cost competitiveness. Results of this study show that sweet sorghum among all the non-food feedstocks has the greatest potential. It grows well on the available marginal lands and the ASSF technology when commercialized will shorten the fermentation time which will lower the costs. Other emerging technologies such as improved saccharification and fermentation; and cellulosic technologies will make China more competitive in ethanol production in the future. Based on the estimated available marginal lands for energy crop production and conversion yields of the potential feedstocks, the most likely and optimistic production levels are 19 and 50 million tons of ethanol by 2020. In order to achieve those levels, the roadmap for China is to: select the non-food feedstock most suitable to grow on the available marginal land; provide funding to support the high priority conversion technologies identified by the scientists; provide monetary incentives to new and poor farmers to grow the feedstocks to revitalize rural economy; less market regulation and gradual reduction of subsidies to producers for industry efficiency; and educate consumers on the impact of fossil fuel on the environment to reduce consumption. Since the share of ethanol in the overall fuel demand is small, the impact of ethanol on lowering pollution and enhancing fuel security will be minimal. (author)

  17. Structural differences of xylans affect their interaction with cellulose

    NARCIS (Netherlands)

    Kabel, M.A.; Borne, van den H.; Vincken, J.P.; Voragen, A.G.J.; Schols, H.A.

    2007-01-01

    The affinity of xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different xylans to cellulose. Therefore, the adsorption of various xylans to

  18. ETHANOL ORGANOSOLV PRETREATMENT OF BAMBOO FOR EFFICIENT ENZYMATIC SACCHARIFICATION

    Directory of Open Access Journals (Sweden)

    Zhiqiang Li,

    2012-06-01

    Full Text Available Bamboo is a potential lignocellulosic biomass for the production of bioethanol because of its high cellulose and hemicelluloses content. In this research, ethanol organosolv pretreatment with dilute sulfuric acid as the catalyst was studied in order to enhance enzymatic saccharification of moso bamboo. The addition of 2% (w/w bamboo dilute sulfuric acid in 75% ethanol had a particularly strong effect on fractionation of bamboo. It yielded a solids fraction containing 83.4% cellulose in the treated substrate. The cellulose conversion to glucose yield reached 77.1 to 83.4% after enzymatic hydrolysis of the solids fraction for 48 h at an enzyme loading of 15 FPU cellulase/g cellulose and 30 IU β-glucosidase/g cellulose. The enzymatic hydrolysis rate was significantly accelerated as the ethanol organosolv pretreatment time increased, reaching the highest enzymatic glucose yield of 83.4% after 48 h at 50 °C. The concentrations of fermentation inhibitors such as HMF (5-hydroxy-2-methyl furfural and furfural were 0.96 g/L and 4.38 g/L in the spent liquor after the ethanol organosolv pretreatment, which were slightly lower than the concentrations quantified during H2SO4-water treatment. Spent liquor was diluted with water, and more than 87.2% of lignin in raw bamboo was recovered as ethanol organosolv lignin through the filtration process.

  19. Novel heat–integrated and intensified biorefinery process for cellulosic ethanol production from lignocellulosic biomass

    International Nuclear Information System (INIS)

    Nhien, Le Cao; Long, Nguyen Van Duc; Lee, Moonyong

    2017-01-01

    Highlights: • A compact biorefinery design was proposed for cellulosic ethanol purification. • Actual fermentation broth from lignocellulosic biomass was considered. • Process integration and intensification achieves competitive biorefinery context. • The response surface method optimizes the complex column structure effectively. • The proposed process could save up to 47.6% of total annual cost. - Abstract: Biofuels have the most potential as an alternative to fossil fuels and overcoming global warming, which has become one of the most serious environmental issues over the past few decades. As the world confronts food shortages due to an increase in world population, the development of biofuels from inedible lignocellulosic feedstock may be more sustainable in the long term. Inspired by the NREL conventional process, this paper proposes a novel heat–integrated and intensified biorefinery design for cellulosic ethanol production from lignocellulosic biomass. For the preconcentration section, heat pump assisted distillation and double–effect heat integration were evaluated, while a combination of heat–integrated technique and intensified technique, extractive dividing wall column (EDWC), was applied to enhance the process energy and cost efficiency for the purification section. A biosolvent, glycerol, which can be produced from biodiesel production, was used as the extracting solvent in an EDWC to obtain a high degree of integration in a biorefinery context. All configuration alternatives were simulated rigorously using Aspen Plus were based on the energy requirements, total annual costs (TAC), and total carbon dioxide emissions (TCE). In addition, the structure of the EDWC was optimized using the reliable response surface method, which was carried out using Minitab statistical software. The simulation results showed that the proposed heat–integrated and intensified process can save up to 47.6% and 56.9% of the TAC and TCE for the purification

  20. Fed-batch culture for the direct conversion of cellulosic substrates to acetic acid/ethanol by Fusarium oxysporum

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.K.R.; Singh, A.; Schuegerl, K. (Hannover Univ. (Germany). Inst. fuer Technische Chemie)

    1991-01-01

    The production of acetic acid/ethanol and hydrolytic enzymes from potato waste (cellulosic waste from potato starch industries) by Fusarium oxysporum 841 was improved considerably by using fed-batch culture. In this, two types of feed policies were adopted consisting of different substrate concentrations and feeding times. In fed-batch culture, the enzymes tested, namely avicelase, CMCase, cellobiase and xylanase, showed significant improvements over batch fermentations with regard to enzyme titres and productivities. The maximum concentration, yield and productivity of acetic acid were 22.5 g litre{sup -1}, 0.38 g (g {sub strate}){sup -1} and 0.09 g litre{sup -1} h{sup -1}, respectively, and these values for ethanol were 5.7 g litre{sup -1}, 0.1 g (g substrate){sup -1} and 0.03 g litre{sup -1}h{sup -1}, respectively. (author).

  1. Cellulosic ethanol

    DEFF Research Database (Denmark)

    Lindedam, Jane; Bruun, Sander; Jørgensen, Henning

    2010-01-01

    Background Variations in sugar yield due to genotypic qualities of feedstock are largely undescribed for pilot-scale ethanol processing. Our objectives were to compare glucose and xylose yield (conversion and total sugar yield) from straw of five winter wheat cultivars at three enzyme loadings (2.......5, 5 and 10 FPU g-1 dm pretreated straw) and to compare particle size distribution of cultivars after pilot-scale hydrothermal pretreatment. Results Significant interactions between enzyme loading and cultivars show that breeding for cultivars with high sugar yields under modest enzyme loading could...... be warranted. At an enzyme loading of 5 FPU g-1 dm pretreated straw, a significant difference in sugar yields of 17% was found between the highest and lowest yielding cultivars. Sugar yield from separately hydrolyzed particle-size fractions of each cultivar showed that finer particles had 11% to 21% higher...

  2. The environmental benefits of cellulosic energy crops at a landscape scale

    International Nuclear Information System (INIS)

    Graham, R.L.; Liu, W.; English, B.C.

    1995-01-01

    The objective of this paper is to present a broad overview of the potential environmental impacts of biomass energy from energy crops--particularly the cellulosic energy crops current under development. For this discussion, the term energy crop refers to a crop grown primarily to create feedstock for either making biofuels such as ethanol or burning in a heat or electricity generation facility. Cellulosic energy crops are designed to be used in cellulose-based ethanol conversion processes (as opposed to starch or sugar-based ethanol conversion processes). As more cellulose can be produced per hectare of land than can sugar or starch, the cellulose-based ethanol conversion process is a more efficient sue of land for ethanol production. Assessing the environmental impacts of biomass energy from energy crops is complex because the environmental impact of using biomass for energy must be considered in the context of alternative energy options while the environmental impact of producing biomass from energy crops must be considered in the context of alternative land-uses. Using biomass-derived energy can reduce greenhouse gas emissions or increase them; growing biomass energy crops can enhance soil fertility or degrade it. Without knowing the context of the biomass energy, one can say little about its specific environmental impacts. The primary focus of this paper is an evaluation of the environmental impacts of growing cellulosic energy crops especially at the landscape or regional scale. However, to set the stage for this discussion, the authors begin by comparing the environmental advantages and disadvantages of biomass-derived energy relative to other energy alternatives such as coal, hydropower, nuclear power, oil/gasoline, natural gas and photovoltaics

  3. Valorization of lignin and cellulose in acid-steam-exploded corn stover by a moderate alkaline ethanol post-treatment based on an integrated biorefinery concept.

    Science.gov (United States)

    Yang, Sheng; Zhang, Yue; Yue, Wen; Wang, Wei; Wang, Yun-Yan; Yuan, Tong-Qi; Sun, Run-Cang

    2016-01-01

    Due to the unsustainable consumption of fossil resources, great efforts have been made to convert lignocellulose into bioethanol and commodity organic compounds through biological methods. The conversion of cellulose is impeded by the compactness of plant cell wall matrix and crystalline structure of the native cellulose. Therefore, appropriate pretreatment and even post-treatment are indispensable to overcome this problem. Additionally, an adequate utilization of coproduct lignin will be important for improving the economic viability of modern biorefinery industries. The effectiveness of moderate alkaline ethanol post-treatment on the bioconversion efficiency of cellulose in the acid-steam-exploded corn stover was investigated in this study. Results showed that an increase of the alcoholic sodium hydroxide (NaOH) concentration from 0.05 to 4% led to a decrease in the lignin content in the post-treated samples from 32.8 to 10.7%, while the cellulose digestibility consequently increased. The cellulose conversion of the 4% alcoholic NaOH integrally treated corn stover reached up to 99.3% after 72 h, which was significantly higher than that of the acid steam exploded corn stover without post-treatment (57.3%). In addition to the decrease in lignin content, an expansion of cellulose I lattice induced by the 4% alcoholic NaOH post-treatment played a significant role in promoting the enzymatic hydrolysis of corn stover. More importantly, the lignin fraction (AL) released during the 4% alcoholic NaOH post-treatment and the lignin-rich residue (EHR) remained after the enzymatic hydrolysis of the 4% alcoholic NaOH post-treated acid-steam-exploded corn stover were employed to synthesize lignin-phenol-formaldehyde (LPF) resins. The plywoods prepared with the resins exhibit satisfactory performances. An alkaline ethanol system with an appropriate NaOH concentration could improve the removal of lignin and modification of the crystalline structure of cellulose in acid

  4. Enzymatic hydrolysis and fermentation of agricultural residues to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Mes-Hartree, M.; Hogan, C.M.; Saddler, J.N.

    1984-01-01

    A combined enzymatic hydrolysis and fermentation process was used to convert steam-treated wheat and barley straw to ethanol. Maximum conversion efficiencies were obtained when the substrates were steamed for 90 s. These substrates could yield over 0.4 g ethanol/g cellulose following a combined enzymatic hydrolysis and fermentation process procedure using culture filtrates derived from Trichoderma harzianum E58. When culture filtrates from Trichoderma reesei C30 and T. reesei QM9414 were used, the ethanol yields obtained were 0.32 and 0.12 g ethanol/g cellulose utilized, respectively. The lower ethanol yields obtained with these strains were attributed to the lower amounts of ..beta..-glucosidase detected in the T. reesei culture filtrates.

  5. A novel marine bacterium Isoptericola sp. JS-C42 with the ability to saccharifying the plant biomasses for the aid in cellulosic ethanol production

    Directory of Open Access Journals (Sweden)

    Velayudhan Satheeja Santhi

    2014-06-01

    Full Text Available The ever growing demands for food products such as starch and sugar produces; there is a need to find the sources for saccharification for cellulosic bioethanol production. This study provides the first evidence of the lignocellulolytic and saccharifying ability of a marine bacterium namely Isoptericola sp. JS-C42, a Gram positive actinobacterium with the cocci cells embedded on mycelia isolated from the Arabian Sea, India. It exhibited highest filter paper unit effect, endoglucanase, exoglucanase, cellobiohydrolase, β-glucosidase, xylanase and ligninase effect. The hydrolytic potential of the enzymes displayed the efficient saccharification capability of steam pretreated biomass. It was also found to degrade the paddy, sorghum, Acacia mangium and Ficus religiosa into simple reducing sugars by its efficient lignocellulose enzyme complex with limited consumption of sugars. Production of ethanol was also achieved with the Saccharomyces cerevisiae. Overall, it offers a great potential for the cellulosic ethanol production in an economically reliable and eco-friendly point-of-care.

  6. A novel marine bacterium Isoptericola sp. JS-C42 with the ability to saccharifying the plant biomasses for the aid in cellulosic ethanol production.

    Science.gov (United States)

    Santhi, Velayudhan Satheeja; Gupta, Ashutosh; Saranya, Somasundaram; Jebakumar, Solomon Robinson David

    2014-06-01

    The ever growing demands for food products such as starch and sugar produces; there is a need to find the sources for saccharification for cellulosic bioethanol production. This study provides the first evidence of the lignocellulolytic and saccharifying ability of a marine bacterium namely Isoptericola sp. JS-C42, a Gram positive actinobacterium with the cocci cells embedded on mycelia isolated from the Arabian Sea, India. It exhibited highest filter paper unit effect, endoglucanase, exoglucanase, cellobiohydrolase, β-glucosidase, xylanase and ligninase effect. The hydrolytic potential of the enzymes displayed the efficient saccharification capability of steam pretreated biomass. It was also found to degrade the paddy, sorghum, Acacia mangium and Ficus religiosa into simple reducing sugars by its efficient lignocellulose enzyme complex with limited consumption of sugars. Production of ethanol was also achieved with the Saccharomyces cerevisiae . Overall, it offers a great potential for the cellulosic ethanol production in an economically reliable and eco-friendly point-of-care.

  7. NREL 2012 Achievement of Ethanol Cost Targets: Biochemical Ethanol Fermentation via Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Tao, L.; Schell, D.; Davis, R.; Tan, E.; Elander, R.; Bratis, A.

    2014-04-01

    For the DOE Bioenergy Technologies Office, the annual State of Technology (SOT) assessment is an essential activity for quantifying the benefits of biochemical platform research. This assessment has historically allowed the impact of research progress achieved through targeted Bioenergy Technologies Office funding to be quantified in terms of economic improvements within the context of a fully integrated cellulosic ethanol production process. As such, progress toward the ultimate 2012 goal of demonstrating cost-competitive cellulosic ethanol technology can be tracked. With an assumed feedstock cost for corn stover of $58.50/ton this target has historically been set at $1.41/gal ethanol for conversion costs only (exclusive of feedstock) and $2.15/gal total production cost (inclusive of feedstock) or minimum ethanol selling price (MESP). This year, fully integrated cellulosic ethanol production data generated by National Renewable Energy Laboratory (NREL) researchers in their Integrated Biorefinery Research Facility (IBRF) successfully demonstrated performance commensurate with both the FY 2012 SOT MESP target of $2.15/gal (2007$, $58.50/ton feedstock cost) and the conversion target of $1.41/gal through core research and process improvements in pretreatment, enzymatic hydrolysis, and fermentation.

  8. Expanded ethanol production: Implications for agriculture, water demand, and water quality

    International Nuclear Information System (INIS)

    De La Torre Ugarte, Daniel G.; He, Lixia; Jensen, Kimberly L.; English, Burton C.

    2010-01-01

    Feedstock production for large scale development of the U.S. ethanol industry and introduction of cellulose-to-ethanol technology will require extensive changes in land use and field management. Hence, this production will likely have significant impact on water demand and quality. This study compares two 'what if' scenarios for attaining a 227.1 hm 3 of ethanol by 2030 and 3.8 hm 3 of biodiesel by 2012. In the first scenario cellulose-to-ethanol technology is introduced in 2012, while in the second scenario the technology is delayed until 2015. Results show that the timing of introduction of cellulose-to-ethanol technology will affect the water use and water quality related input use in primarily in the eastern part of the nation. Results also suggest policy emphasis on reduced and no-till practices needs to be complementary to increased crop residue use. (author)

  9. Development of an alcohol dehydrogenase biosensor for ethanol determination with toluidine blue O covalently attached to a cellulose acetate modified electrode.

    Science.gov (United States)

    Alpat, Senol; Telefoncu, Azmi

    2010-01-01

    In this work, a novel voltammetric ethanol biosensor was constructed using alcohol dehydrogenase (ADH). Firstly, alcohol dehydrogenase was immobilized on the surface of a glassy carbon electrode modified by cellulose acetate (CA) bonded to toluidine blue O (TBO). Secondly, the surface was covered by a glutaraldehyde/bovine serum albumin (BSA) cross-linking procedure to provide a new voltammetric sensor for the ethanol determination. In order to fabricate the biosensor, a new electrode matrix containing insoluble Toluidine Blue O (TBO) was obtained from the process, and enzyme/coenzyme was combined on the biosensor surface. The influence of various experimental conditions was examined for the characterization of the optimum analytical performance. The developed biosensor exhibited sensitive and selective determination of ethanol and showed a linear response between 1 × 10(-5) M and 4 × 10(-4) M ethanol. A detection limit calculated as three times the signal-to-noise ratio was 5.0 × 10(-6) M. At the end of the 20(th) day, the biosensor still retained 50% of its initial activity.

  10. Development of an Alcohol Dehydrogenase Biosensor for Ethanol Determination with Toluidine Blue O Covalently Attached to a Cellulose Acetate Modified Electrode

    Directory of Open Access Journals (Sweden)

    Azmi Telefoncu

    2010-01-01

    Full Text Available In this work, a novel voltammetric ethanol biosensor was constructed using alcohol dehydrogenase (ADH. Firstly, alcohol dehydrogenase was immobilized on the surface of a glassy carbon electrode modified by cellulose acetate (CA bonded to toluidine blue O (TBO. Secondly, the surface was covered by a glutaraldehyde/bovine serum albumin (BSA cross-linking procedure to provide a new voltammetric sensor for the ethanol determination. In order to fabricate the biosensor, a new electrode matrix containing insoluble Toluidine Blue O (TBO was obtained from the process, and enzyme/coenzyme was combined on the biosensor surface. The influence of various experimental conditions was examined for the characterization of the optimum analytical performance. The developed biosensor exhibited sensitive and selective determination of ethanol and showed a linear response between 1 × 10−5 M and 4 × 10−4 M ethanol. A detection limit calculated as three times the signal-to-noise ratio was 5.0 × 10−6 M. At the end of the 20th day, the biosensor still retained 50% of its initial activity.

  11. Ammonia fiber expansion (AFEX) pretreatment, enzymatic hydrolysis, and fermentation on empty palm fruit bunch fiber (EPFBF) for cellulosic ethanol production.

    Science.gov (United States)

    Lau, Ming J; Lau, Ming W; Gunawan, Christa; Dale, Bruce E

    2010-11-01

    Empty palm fruit bunch fiber (EPFBF), a readily available cellulosic biomass from palm processing facilities, is investigated as a potential carbohydrate source for cellulosic ethanol production. This feedstock was pretreated using ammonia fiber expansion (AFEX) and enzymatically hydrolyzed. The best tested AFEX conditions were at 135 °C, 45 min retention time, water to dry biomass loading of 1:1 (weight ratio), and ammonia to dry biomass loading of 1:1 (weight ratio). The particle size of the pretreated biomass was reduced post-AFEX. The optimized enzyme formulation consists of Accellerase (84 μL/g biomass), Multifect Xylanase (31 μL/g biomass), and Multifect Pectinase (24 μL/g biomass). This mixture achieved close to 90% of the total maximum yield within 72 h of enzymatic hydrolysis. Fermentation on the water extract of this biomass affirms that nutrients solely from the pretreated EPFBF can support yeast growth for complete glucose fermentation. These results suggest that AFEX-treated EPFBF can be used for cellulosic biofuels production because biomass recalcitrance has been overcome without reducing the fermentability of the pretreated materials.

  12. An Investigation of Cellulose Digesting Bacteria in the Camel Feces Microbiome

    Science.gov (United States)

    Man, V.; Leung, F. C.

    2015-12-01

    Research Question: Is there a bacteria in camel feces that digests cellulose material and can be used for waste to energy projects? Fossil fuels are the current main resource of energy in the modern world. However, as the demand for fuel increases, biofuels have been proposed as an alternative energy source that is a more sustainable form of liquid fuel generation from living things or waste, commonly known as biofuels and ethanol. The Camelus dromedarius', also known as Arabian camel, diet consist of grass, grains, wheat and oats as well desert vegetation in their natural habitat. However, as the Arabian camel lacks the enzymes to degrade cellulose, it is hypothesized that cellulose digestion is performed by microbial symbionts in camel microbiota. Fecal samples were collected from the Camelus dromedarius in United Arab Emirates and diluted 10-7 times. The diluted sample was then streaked onto a Sodium Carboxymethyl Cellulose plate, and inoculated onto CMC and Azure-B plates. Afterwards, Congo Red was used for staining in order to identify clearance zones of single colonies that may potentially be used as a qualitative assays for cellulose digestion. Then the colonies undergo polymerase chain reaction amplification to produce amplified RNA fragments. The 16S ribosomal RNA gene is identified based on BLAST result using Sanger Sequencing. Amongst the three identified microbes: Bacillus, Staphylococcus and Escherichia coli, both Bacillus and Staphylococcus are cellulose-digesting microbes, and through the fermentation of lignocellulosic, biomasses can be converted into cellulosic ethanol (Biofuel). According to the Improvements in Life Cycle Energy Efficiency and Greenhouse Gas Emissions of Corn-Ethanol by Adam J. Liska, ""Ethanol reduces greenhouse gas emissions by 40-50% when compared directly to gasoline." The determination of bacterial communities that are capable of efficiently and effectively digesting cellulose materials requires that the bacteria be first

  13. Influence of sugarcane bagasse variability on sugar recovery for cellulosic ethanol production.

    Science.gov (United States)

    Andrade, Liliane Pires; Crespim, Elaine; de Oliveira, Nilton; de Campos, Rafael Carinha; Teodoro, Juliana Conceição; Galvão, Célia Maria Araújo; Maciel Filho, Rubens

    2017-10-01

    In the context of cellulosic ethanol production, special attention must be given to the raw material, as it affects final product yield. As observed for sugarcane, bagasse variations may derive from several elements, for instance edaphoclimatic factors, seasonality, maturation stage and harvesting techniques. Therefore, in the present work, to investigate the impact of raw material characteristics on process performance, sugarcane bagasse from four harvests from October/2010 to October/2011 was pretreated by steam explosion and had its soluble and insoluble solids contents measured, following enzymatic hydrolysis to assess glucan conversion. As confirmed by ANOVA, glucose concentration was related to the solids content in the reactor, whereas glucan conversion was related to the enzymatic load. Variations in raw material composition were indeed observed to significantly interfere in the final sugar recovery, probably due to the increase in the impurities observed as a result of the type of harvest performed in 2011. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Ethanol production from biomass. Voorlopig nauwelijks ethanolproduktie uit biomassa

    Energy Technology Data Exchange (ETDEWEB)

    Van der Knijff, A; Wildschut, L R [Haskoning Koninklijk Ingenieurs- en Architectenbureau, Nijmegen (Netherlands); Williams, A [Technische Univ. Twente, Enschede (Netherlands)

    1991-04-01

    Fluid fuels, for instance ethanol and methanol, can be produced from agricultural materials and from waste materials. For 37 waste flows (among which scrap from the oil- and fat industry, waste potatoes, withdrawn vegetables, waste wood, straw, roadside grass, vegetables-, fruits- and garden wastes and beet tails) possibilities to produce fuels have been considered. In general, sacchariferous and farinaceous wastes, which could be used for ethanol production, are used for other purposes. Therefore ethanol production from these materials is expensive. Cellulose wastes (for instance straw, wood wastes and paper sludge) can be suitable in the future for ethanol production. But first a cheap method to decompose and hydrolize cellulose has to be developed. 2 figs., 2 ills., 3 refs.

  15. Current Pretreatment Technologies for the Development of Cellulosic Ethanol and Biorefineries.

    Science.gov (United States)

    Silveira, Marcos Henrique Luciano; Morais, Ana Rita C; da Costa Lopes, Andre M; Olekszyszen, Drielly Nayara; Bogel-Łukasik, Rafał; Andreaus, Jürgen; Pereira Ramos, Luiz

    2015-10-26

    Lignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin-carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Cellulose- and xylan-degrading thermophilic anaerobic bacteria from biocompost.

    Science.gov (United States)

    Sizova, M V; Izquierdo, J A; Panikov, N S; Lynd, L R

    2011-04-01

    Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to a Clostridium clariflavum strain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation.

  17. Optimizing fermentation process miscanthus-to-ethanol biorefinery scale under uncertain conditions

    International Nuclear Information System (INIS)

    Bomberg, Matthew; Sanchez, Daniel L; Lipman, Timothy E

    2014-01-01

    Ethanol produced from cellulosic feedstocks has garnered significant interest for greenhouse gas abatement and energy security promotion. One outstanding question in the development of a mature cellulosic ethanol industry is the optimal scale of biorefining activities. This question is important for companies and entrepreneurs seeking to construct and operate cellulosic ethanol biorefineries as it determines the size of investment needed and the amount of feedstock for which they must contract. The question also has important implications for the nature and location of lifecycle environmental impacts from cellulosic ethanol. We use an optimization framework similar to previous studies, but add richer details by treating many of these critical parameters as random variables and incorporating a stochastic sub-model for land conversion. We then use Monte Carlo simulation to obtain a probability distribution for the optimal scale of a biorefinery using a fermentation process and miscanthus feedstock. We find a bimodal distribution with a high peak at around 10–30 MMgal yr −1 (representing circumstances where a relatively low percentage of farmers elect to participate in miscanthus cultivation) and a lower and flatter peak between 150 and 250 MMgal yr −1 (representing more typically assumed land-conversion conditions). This distribution leads to useful insights; in particular, the asymmetry of the distribution—with significantly more mass on the low side—indicates that developers of cellulosic ethanol biorefineries may wish to exercise caution in scale-up. (letters)

  18. Optimizing fermentation process miscanthus-to-ethanol biorefinery scale under uncertain conditions

    Science.gov (United States)

    Bomberg, Matthew; Sanchez, Daniel L.; Lipman, Timothy E.

    2014-05-01

    Ethanol produced from cellulosic feedstocks has garnered significant interest for greenhouse gas abatement and energy security promotion. One outstanding question in the development of a mature cellulosic ethanol industry is the optimal scale of biorefining activities. This question is important for companies and entrepreneurs seeking to construct and operate cellulosic ethanol biorefineries as it determines the size of investment needed and the amount of feedstock for which they must contract. The question also has important implications for the nature and location of lifecycle environmental impacts from cellulosic ethanol. We use an optimization framework similar to previous studies, but add richer details by treating many of these critical parameters as random variables and incorporating a stochastic sub-model for land conversion. We then use Monte Carlo simulation to obtain a probability distribution for the optimal scale of a biorefinery using a fermentation process and miscanthus feedstock. We find a bimodal distribution with a high peak at around 10-30 MMgal yr-1 (representing circumstances where a relatively low percentage of farmers elect to participate in miscanthus cultivation) and a lower and flatter peak between 150 and 250 MMgal yr-1 (representing more typically assumed land-conversion conditions). This distribution leads to useful insights; in particular, the asymmetry of the distribution—with significantly more mass on the low side—indicates that developers of cellulosic ethanol biorefineries may wish to exercise caution in scale-up.

  19. A biorefinery concept for simultaneous recovery of cellulosic ethanol and phenolic compounds from oil palm fronds: Process optimization

    International Nuclear Information System (INIS)

    Ofori-Boateng, Cynthia; Lee, Keat Teong; Saad, Bahruddin

    2014-01-01

    Highlights: • Biorefinery concept for simultaneous recovery of cellulose and phenolic compounds. • Sono-assisted organosolv/H 2 O 2 pretreatment was used to isolate palm fronds cellulose. • Optimum conditions for pretreatment: 60 °C, 40 min, 1:20 g/ml, 3% NaOH concentration. • Optimum conditions yielded 55.3% cellulose, 20.1 g/l glucose and 0.769 g/g ethanol. • Pretreatment liquor contained 4.691 mg GAE/g phenolics. - Abstract: In this study, process optimization of an ultrasonic-assisted organosolv/liquid oxidative pretreatment (SOP) of oil palm fronds (OPFs) for the simultaneous recovery of cellulose, bioethanol and biochemicals (i.e. phenolic compounds) in a biorefinery concept was carried out. The effects of time (30–60 min.), temperature (40–80 °C), NaOH concentration (1–5%) and sample:solvent ratio (1:10–1:50 g/ml) on cellulose content, bioethanol yield and total phenolics contents (TPC) after SOP were investigated. At optimum conditions of pretreatment (i.e. 60 °C, 40 min, 3% w/v aq. NaOH and 1:20 g/ml sample to solvent ratio), the recovered cellulose (55.30%) which served as substrate for enzymatic hydrolysis and subsequent fermentation yielded about 20.1 g/l glucose, 11.3 g/l xylose and 9.3 g/l bioethanol (yield of 0.769 g/g). The pretreatment liquor (mostly regarded as wastes) obtained at the optimum pretreatment conditions contained about 4.691 mg gallic acid equivalent (GAE)/g OPFs of TPC, 0.297 mg vanillic acid (VA)/g OPFs, 1.591 mg gallic acid (GA)/g OPFs and 0.331 mg quercetin (QU)/g OPFs. The pretreatment liquor was again analyzed to possess high antiradical scavenging activity (about 97.2%) compared to the synthetic antioxidant, 3,5-di-tert-butyl-4-hydroxytoluene (BHT) (80.7%) at 100 ppm. Thus one sustainable way of managing wastes in biorefinery is the recovery of multi-bioproducts (e.g. bioethanol and biochemicals) during the pretreatment process

  20. Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production

    Energy Technology Data Exchange (ETDEWEB)

    Donal F. Day

    2009-03-31

    The work conducted in this project is an extension of the developments itemized in DE-FG-36-04GO14236. This program is designed to help the development of a biorefinery based around a raw sugar mill, which in Louisiana is an underutilized asset. Some technical questions were answered regarding the addition of a biomass to ethanol facility to existing sugar mills. The focus of this work is on developing technology to produce ethanol and valuable by-products from bagasse. Three major areas are addressed, feedstock storage, potential by-products and the technology for producing ethanol from dilute ammonia pre-treated bagasse. Sugar mills normally store bagasse in a simple pile. During the off season there is a natural degradation of the bagasse, due to the composting action of microorganisms in the pile. This has serious implications if bagasse must be stored to operate a bagasse/biorefinery for a 300+ day operating cycle. Deterioration of the fermentables in bagasse was found to be 6.5% per month, on pile storage. This indicates that long term storage of adequate amounts of bagasse for year-round operation is probably not feasible. Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of

  1. Improving ethanol productivity through self-cycling fermentation of yeast: a proof of concept.

    Science.gov (United States)

    Wang, Jie; Chae, Michael; Sauvageau, Dominic; Bressler, David C

    2017-01-01

    The cellulosic ethanol industry has developed efficient strategies for converting sugars obtained from various cellulosic feedstocks to bioethanol. However, any further major improvements in ethanol productivity will require development of novel and innovative fermentation strategies that enhance incumbent technologies in a cost-effective manner. The present study investigates the feasibility of applying self-cycling fermentation (SCF) to cellulosic ethanol production to elevate productivity. SCF is a semi-continuous cycling process that employs the following strategy: once the onset of stationary phase is detected, half of the broth volume is automatically harvested and replaced with fresh medium to initiate the next cycle. SCF has been shown to increase product yield and/or productivity in many types of microbial cultivation. To test whether this cycling process could increase productivity during ethanol fermentations, we mimicked the process by manually cycling the fermentation for five cycles in shake flasks, and then compared the results to batch operation. Mimicking SCF for five cycles resulted in regular patterns with regards to glucose consumption, ethanol titer, pH, and biomass production. Compared to batch fermentation, our cycling strategy displayed improved ethanol volumetric productivity (the titer of ethanol produced in a given cycle per corresponding cycle time) and specific productivity (the amount of ethanol produced per cellular biomass) by 43.1 ± 11.6 and 42.7 ± 9.8%, respectively. Five successive cycles contributed to an improvement of overall productivity (the aggregate amount of ethanol produced at the end of a given cycle per total processing time) and the estimated annual ethanol productivity (the amount of ethanol produced per year) by 64.4 ± 3.3 and 33.1 ± 7.2%, respectively. This study provides proof of concept that applying SCF to ethanol production could significantly increase productivities, which will help strengthen the

  2. Single-step ethanol production from lignocellulose using novel extremely thermophilic bacteria.

    Science.gov (United States)

    Svetlitchnyi, Vitali A; Kensch, Oliver; Falkenhan, Doris A; Korseska, Svenja G; Lippert, Nadine; Prinz, Melanie; Sassi, Jamaleddine; Schickor, Anke; Curvers, Simon

    2013-02-28

    Consolidated bioprocessing (CBP) of lignocellulosic biomass to ethanol using thermophilic bacteria provides a promising solution for efficient lignocellulose conversion without the need for additional cellulolytic enzymes. Most studies on the thermophilic CBP concentrate on co-cultivation of the thermophilic cellulolytic bacterium Clostridium thermocellum with non-cellulolytic thermophilic anaerobes at temperatures of 55°C-60°C. We have specifically screened for cellulolytic bacteria growing at temperatures >70°C to enable direct conversion of lignocellulosic materials into ethanol. Seven new strains of extremely thermophilic anaerobic cellulolytic bacteria of the genus Caldicellulosiruptor and eight new strains of extremely thermophilic xylanolytic/saccharolytic bacteria of the genus Thermoanaerobacter isolated from environmental samples exhibited fast growth at 72°C, extensive lignocellulose degradation and high yield ethanol production on cellulose and pretreated lignocellulosic biomass. Monocultures of Caldicellulosiruptor strains degraded up to 89-97% of the cellulose and hemicellulose polymers in pretreated biomass and produced up to 72 mM ethanol on cellulose without addition of exogenous enzymes. In dual co-cultures of Caldicellulosiruptor strains with Thermoanaerobacter strains the ethanol concentrations rose 2- to 8.2-fold compared to cellulolytic monocultures. A co-culture of Caldicellulosiruptor DIB 087C and Thermoanaerobacter DIB 097X was particularly effective in the conversion of cellulose to ethanol, ethanol comprising 34.8 mol% of the total organic products. In contrast, a co-culture of Caldicellulosiruptor saccharolyticus DSM 8903 and Thermoanaerobacter mathranii subsp. mathranii DSM 11426 produced only low amounts of ethanol. The newly discovered Caldicellulosiruptor sp. strain DIB 004C was capable of producing unexpectedly large amounts of ethanol from lignocellulose in fermentors. The established co-cultures of new Caldicellulosiruptor

  3. The preparation and ethanol fermentation of high-concentration sugars from steam-explosion corn stover.

    Science.gov (United States)

    Xie, Hui; Wang, Fengqin; Yin, Shuangyao; Ren, Tianbao; Song, Andong

    2015-05-01

    In the field of biofuel ethanol, high-concentration- reducing sugars made from cellulosic materials lay the foundation for high-concentration ethanol fermentation. In this study, corn stover was pre-treated in a process combining chemical methods and steam explosion; the cellulosic hydrolyzed sugars obtained by fed-batch saccharification were then used as the carbon source for high-concentration ethanol fermentation. Saccharomyces cerevisiae 1308, Angel yeast, and Issatchenkia orientalis were shake-cultured with Pachysolen tannophilus P-01 for fermentation. Results implied that the ethanol yields from the three types of mixed strains were 4.85 g/100 mL, 4.57 g/100 mL, and 5.02 g/100 mL (separately) at yield rates of 91.6, 89.3, and 92.2%, respectively. Therefore, it was inferred that shock-fermentation using mixed strains achieved a higher ethanol yield at a greater rate in a shorter fermentation period. This study provided a theoretical basis and technical guidance for the fermentation of industrial high-concentrated cellulosic ethanol.

  4. Cultivar variation and selection potential relevant to the production of cellulosic ethanol from wheat straw

    DEFF Research Database (Denmark)

    Lindedam, Jane; Andersen, Sven Bode; DeMartini, J.

    2012-01-01

    Optimizing cellulosic ethanol yield depends strongly on understanding the biological variation of feedstocks. Our objective was to study variation in capacity for producing fermentable sugars from straw of winter wheat cultivars with a high-throughput pretreatment and hydrolysis well......-plate technique. This technique enabled us to estimate cultivar-related and environmental correlations between sugar yield, chemical composition, agronomic qualities, and distribution of botanical plant parts of wheat straw cultivars. Straws from 20 cultivars were collected in duplicates on two sites in Denmark....... Following hydrothermal pretreatment (180 °C for 17.6 min) and co-hydrolysis, sugar release and sugar conversion were measured. Up to 26% difference in sugar release between cultivars was observed. Sugar release showed negative cultivar correlation with lignin and ash content, whereas sugar release showed...

  5. Ethanol production from rape straw: Part of an oilseed rape biorefinery

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia

    The aim of this study was 1) present an oilseed rape whole crop biorefinery; 2) to investigate the best available experimental conditions for production of cellulosic ethanol from rape straw, and included the processes of thermo-chemical pretreatment, enzymatic hydrolysis, and C6 fermentation......, and 3) to couple cellulosic ethanol production to production of cellulolytic enzymes that are needed for cellulosic ethanol production, inside a rape straw biorefinery. For the first is based less on available experiments, and more on literature review. The second and third study conclusions were drawn...... rapeseed biodiesel plant of Europe to an oilseed rape whole-crop biorefinery by 2020 is envisioned and discussed. The description and discussion of this biorefinery is based partly on literature review, and partly on own experimental data, especially on pretreatment of rape straw, and production...

  6. Co-production of bio-ethanol, electricity and heat from biomass residues

    Energy Technology Data Exchange (ETDEWEB)

    Reith, J.H.; Den Uil, H.; Van Veen, H. [ECN Biomass, Petten (Netherlands); De Laat, W.T.A.M.; Niessen, J.J. [Royal Nedalco, Bergen op Zoom (Netherlands); De Jong, E.; Elbersen, H.W.; Weusthuis, R. [Agrotechnological Research Institute ATO, BU Renewable Resources, Wageningen (Netherlands); Van Dijken, J.P.; Raamsdonk, L. [Delft University of Technology, Delft (Netherlands)

    2002-07-01

    The use of lignocellulose biomass residues as a feedstock offers good perspectives for large scale production of fuel ethanol at competitive costs. An evaluation was performed to assess the international status of lignocellulose-to-bioethanol technology and the economical and ecological system performance, to identify RandD approaches for further development. Deriving fermentable sugars from the hemicellulose and cellulose fractions of lignocellulose materials via suitable pretreatment and enzymatic cellulose hydrolysis is a critical RandD issue. Further development of pretreatment via mild, low temperature alkaline extraction or weak acid hydrolysis using CO2, dissolved in pressurized hot water ('carbonic acid process') shows good perspectives. Enzymatic cellulose hydrolysis with the currently available industrial cellulases accounts for 36-45% of ethanol production costs. At least a 10-fold increase of cellulase cost-effectiveness is required. Despite substantial RandD efforts, no suitable fermentation system is currently available for the fermentation of pentoses (mainly xylose) from the hemicellulose fraction. Several strains of anaerobic, thermophilic bacteria are able to convert all (hemi)cellulose components into ethanol. Follow-up RandD will focus on isolation of suitable strain(s) from this group. The system evaluation shows a 40-55% energetic efficiency (LHV basis) for conversion of lignocellulose feedstocks to ethanol. Thermal conversion of non-fermentable residues (mainly lignin) in a Biomass-Integrated-Gasifier/Combined Cycle (BIG/CC) system can provide the total steam and electricity requirement for the production process and an electricity surplus for export to the grid, giving a total system efficiency of 56-68%. Water consumption in the process (28-54 liter water/liter ethanol) is much higher than in current ethanol production (lo-15 l/l ethanol). The large amount of process water (used in the pretreatment and cellulose hydrolysis

  7. Competitiveness of Brazilian sugarcane ethanol compared to US corn ethanol

    International Nuclear Information System (INIS)

    Crago, Christine L.; Khanna, Madhu; Barton, Jason; Giuliani, Eduardo; Amaral, Weber

    2010-01-01

    Corn ethanol produced in the US and sugarcane ethanol produced in Brazil are the world's leading sources of biofuel. Current US biofuel policies create both incentives and constraints for the import of ethanol from Brazil and together with the cost competitiveness and greenhouse gas intensity of sugarcane ethanol compared to corn ethanol will determine the extent of these imports. This study analyzes the supply-side determinants of cost competitiveness and compares the greenhouse gas intensity of corn ethanol and sugarcane ethanol delivered to US ports. We find that while the cost of sugarcane ethanol production in Brazil is lower than that of corn ethanol in the US, the inclusion of transportation costs for the former and co-product credits for the latter changes their relative competitiveness. We also find that the relative cost of ethanol in the US and Brazil is highly sensitive to the prevailing exchange rate and prices of feedstocks. At an exchange rate of US1=R2.15 the cost of corn ethanol is 15% lower than the delivered cost of sugarcane ethanol at a US port. Sugarcane ethanol has lower GHG emissions than corn ethanol but a price of over $113 per ton of CO 2 is needed to affect competitiveness. (author)

  8. Alcohol for cellulosic material using plural ferments

    Energy Technology Data Exchange (ETDEWEB)

    Hoge, W H

    1977-02-22

    A process is described for producing ethanol (EtOH) from cellulosic materials by first hydrolyzing the material to sugars and then converting the sugars to alcohol by digestion and fermentation. Thus, fibrous cellulosic material obtained from municipal waste slurry was sterilized by autoclaving, followed by inoculation with Trichoderma viride cellulase and Saccharomyces cerevisiae. From 100 g of raw material, 25 mL of 95% EtOH was produced by this method.

  9. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  10. Liquid fuel resources and prospects for ligno-cellulosic ethanol: An Egyptian case study

    Directory of Open Access Journals (Sweden)

    Shadia R. Tewfik

    2013-12-01

    Full Text Available Fossil fuels (oil, natural gas and coal presently represent about 90% of the world’s total commercial primary energy demand. Yet, they are depletable sources of energy. Growth in the production of easily accessible oil, the main source of high energy liquid transportation fuels, will not match the projected rate of demand growth, especially in developing countries. In the transport sector, today, the only alternative to non-sustainable fossil fuels is biofuels that are produced from biomass, a stored environmentally neutral solar energy. These fuels are compatible with current vehicles and blendable with conventional fuels. Moreover, they share the long-established distribution infrastructure with little, if any, modification of equipment. The main biofuels presently in commercial production are bioethanol and biodiesel. Industrial countries started production of the 1st generation bioethanol and biodiesel from food products (grains and edible oil since a few decades and these fuels are currently available at petrol stations. Second generation bioethanol from ligno-cellulosic materials is on the research, pilot and/or demonstration stage. This paper discusses the current situation regarding liquid fuels in Egypt which are experiencing imbalance between total production and demand for gasoline and diesel fuels. The quantified need for nonconventional sources is presented. Based on a thorough assessment of current and prospective generated agriculture residues as distributed over the political areas, mapping of the number and capacity of plants to be installed for production of bioethanol from available residues namely rice straw, sugar cane residues and cotton stalks has been developed. Annual capacities of 3000, 10,000 and 20,000 tons ethanol/year until year 2021 have been proposed. Capital and operating requirements and economic indicators have been estimated. It has been concluded that at current price of ethanol of about $0.6/kg, the

  11. Ethanol production from residual wood chips of cellulose industry: acid pretreatment investigation, hemicellulosic hydrolysate fermentation, and remaining solid fraction fermentation by SSF process.

    Science.gov (United States)

    Silva, Neumara Luci Conceição; Betancur, Gabriel Jaime Vargas; Vasquez, Mariana Peñuela; Gomes, Edelvio de Barros; Pereira, Nei

    2011-04-01

    Current research indicates the ethanol fuel production from lignocellulosic materials, such as residual wood chips from the cellulose industry, as new emerging technology. This work aimed at evaluating the ethanol production from hemicellulose of eucalyptus chips by diluted acid pretreatment and the subsequent fermentation of the generated hydrolysate by a flocculating strain of Pichia stipitis. The remaining solid fraction generated after pretreatment was subjected to enzymatic hydrolysis, which was carried out simultaneously with glucose fermentation [saccharification and fermentation (SSF) process] using a strain of Saccharomyces cerevisiae. The acid pretreatment was evaluated using a central composite design for sulfuric acid concentration (1.0-4.0 v/v) and solid to liquid ratio (1:2-1:4, grams to milliliter) as independent variables. A maximum xylose concentration of 50 g/L was obtained in the hemicellulosic hydrolysate. The fermentation of hemicellulosic hydrolysate and the SSF process were performed in bioreactors and the final ethanol concentrations of 15.3 g/L and 28.7 g/L were obtained, respectively.

  12. An Investigation of Cellulose Digesting Bacteria in the Panda Gut Microbiome

    Science.gov (United States)

    Lu, M.; Leung, F. C.

    2014-12-01

    The Giant Panda (Ailuropoda melanoleuca) diet consists primarily of bamboo leaves, stems and shoots. However, the Giant Panda lacks genes for the enzymes needed to digest cellulose, the core component of bamboo. Thus, it is hypothesized that the cellulolytic digestion necessary for maintaining the Giant Panda diet is carried out by microbial symbionts in the panda gut microbiota. Fecal microbiota is used as surrogate index for gut microbiota since the Giant Panda is listed by the World Conservation Union as a Threatened Species. Two bacterial isolates with potential cellulolytic activity were isolated from Giant Panda fecal samples and cultured on selective media CMC (carboxymethyl cellulose) agar and CMC-Congo Red agar using various methods of inoculation. After incubation, clearance zones around colonies were observed and used as qualitative assays for cellulose digestion. Polymerase chain reaction amplification of the 16S rRNA gene was completed and species identification was done based on the BLAST result of 16S rRNA sequence obtained using Sanger sequencing. Once the cellulase activity is confirmed, genomic DNA of the bacteria will be extracted and used for whole genome shotgun sequencing. Illumina next generation sequencing platform will be adopted as it yields high-throughput information, providing a better understanding of cellulose digestion and the molecular genetic pathways to renewable sources of biofuels. Researchers have identified multiple cellulose-digesting microbes in the Giant Panda gut, but few have applied such bacteria in converting cellulose into glucose to create biofuel. Cellulosic ethanol, a biofuel, is produced through the fermentation of lignocellulosic biomasses. This anaerobic process is aided by cellulose-digesting enzymes. Certain microbes, such as those present in the Giant Panda gut, can produce enzymes that cleave the glycosidic bonds of cellulose (C6H10O5) into glucose molecules (C6H12O6), which can then be fermented into ethanol

  13. One-pot bioethanol production from cellulose by co-culture of Acremonium cellulolyticus and Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Park Enoch Y

    2012-08-01

    Full Text Available Abstract Background While the ethanol production from biomass by consolidated bioprocess (CBP is considered to be the most ideal process, simultaneous saccharification and fermentation (SSF is the most appropriate strategy in practice. In this study, one-pot bioethanol production, including cellulase production, saccharification of cellulose, and ethanol production, was investigated for the conversion of biomass to biofuel by co-culture of two different microorganisms such as a hyper cellulase producer, Acremonium cellulolyticus C-1 and an ethanol producer Saccharomyces cerevisiae. Furthermore, the operational conditions of the one-pot process were evaluated for maximizing ethanol concentration from cellulose in a single reactor. Results Ethanol production from cellulose was carried out in one-pot bioethanol production process. A. cellulolyticus C-1 and S. cerevisiae were co-cultured in a single reactor. Cellulase producing-medium supplemented with 2.5 g/l of yeast extract was used for productions of both cellulase and ethanol. Cellulase production was achieved by A. cellulolyticus C-1 using Solka-Floc (SF as a cellulase-inducing substrate. Subsequently, ethanol was produced with addition of both 10%(v/v of S. cerevisiae inoculum and SF at the culture time of 60 h. Dissolved oxygen levels were adjusted at higher than 20% during cellulase producing phase and at lower than 10% during ethanol producing phase. Cellulase activity remained 8–12 FPU/ml throughout the one-pot process. When 50–300 g SF/l was used in 500 ml Erlenmeyer flask scale, the ethanol concentration and yield based on initial SF were as 8.7–46.3 g/l and 0.15–0.18 (g ethanol/g SF, respectively. In 3-l fermentor with 50–300 g SF/l, the ethanol concentration and yield were 9.5–35.1 g/l with their yields of 0.12–0.19 (g/g respectively, demonstrating that the one-pot bioethanol production is a reproducible process in a scale-up bioconversion of cellulose to ethanol

  14. Utilization of cellulosic materials through enzymic hydrolysis. 11. Preliminary assessment of an integrated processing scheme

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C R; Cysewski, G R; Yang, R D

    1976-01-01

    An integrated processing scheme is described for the conversion of a cellulose waste (newsprint) to sugars by enzymic hydrolysis and then to ethanol and yeast by fermentation. The unconverted solids are burned to produce process energy requirements and surplus electric power. With the preliminary design at an estimate total capital investment of $33.4 x 10/sup 6/, 95% ethanol may be produced FOB (free on board) the plant for approx.61 cents/gal, assuming zero cost for cellulosic feed; taking into account interest rates and taxes and a cellulose feed cost of $20/ton the figure becomes $1.67/gal.

  15. Pretreatment of Reed by Wet Oxidation and Subsequent Utilization of the Pretreated Fibers for Ethanol Production

    DEFF Research Database (Denmark)

    Szijarto, Nora; Kádár, Zsófia; Varga, Eniko

    2009-01-01

    lignocelluloses usually do. In the present study, wet oxidation was investigated as the pretreatment method to enhance the enzymatic digestibility of reed cellulose to soluble sugars and thus improve the convertibility of reed to ethanol. The most effective treatment increased the digestibility of reed cellulose...... of cellulose to glucose was 82.4%. Simultaneous saccharification and fermentation of pretreated solids resulted in a final ethanol concentration as high as 8.7 g/L, yielding 73% of the theoretical....

  16. The potential of lignocellulosic ethanol production in the Mediterranean Basin

    Energy Technology Data Exchange (ETDEWEB)

    Faraco, Vincenza [Department of Organic Chemistry and Biochemistry, University of Naples ' ' Federico II' ' , Naples (Italy); School of Biotechnological Sciences, University of Naples ' ' Federico II' ' , Naples (Italy); Hadar, Yitzhak [Department of Microbiology and Plant Pathology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot (Israel)

    2011-01-15

    This review provides an overview of the potential of bioethanol fuel production from lignocellulosic residues in the Mediterranean Basin. Residues from cereal crops, olive trees, and tomato and grape processing are abundant lignocellulosic wastes in France, Italy, Spain, Turkey and Egypt, where their use as raw materials for ethanol production could give rise to a potential production capacity of 13 Mtoe of ethanol. Due to the lack of sufficient amounts of agricultural residues in all of the other Mediterranean countries, use of the cellulosic content of municipal solid waste (MSW) as feedstock for ethanol fuel production is also proposed. A maximum potential production capacity of 30 Mtoe of ethanol could be achieved from 50% of the 180 million tons of waste currently produced annually in the Mediterranean Basin, the management of which has become a subject of serious concern. However, to make large-scale ethanol production from agricultural residues and MSW a medium-term feasible goal in the Mediterranean Basin, huge efforts are needed to achieve the required progress in cellulose ethanol technologies and to overcome several foreseeable constraints. (author)

  17. Electron beam processing of sugar cane bagasse to cellulose hydrolysis

    International Nuclear Information System (INIS)

    Ribeiro, Marcia A.; Cardoso, Vanessa M.; Mori, Manoel N.; Duarte, Celina L.

    2009-01-01

    Sugarcane bagasse has been considered as a substrate for single cell protein, animal feed, and renewable energy production. Sugarcane bagasse generally contain up to 45% glucose polymer cellulose, 40% hemicelluloses, and 20% lignin. Pure cellulose is readily depolymerised by radiation, but in biomass, the cellulose is intimately bonded with lignin, that protect it from radiation effects. The objective of this study is the evaluation of the electron beam irradiation as a pre-treatment to enzymatic hydrolysis of cellulose in order to facilitate its fermentation and improves the production of ethanol biofuel. Samples of sugarcane bagasse were obtained in sugar/ethanol Iracema Mill sited in Piracicaba, Brazil, and were irradiated using Radiation Dynamics Electron Beam Accelerator with 1.5 MeV energy and 37kW, in batch systems. The applied absorbed doses of the fist sampling, Bagasse A, were 20 kGy, 50 kGy, 100 kGy and 200 kGy. After the evaluation the preliminary obtained results, it was applied lower absorbed doses in the second assay: 5 kGy, 10 kGy, 20 kGy, 30 kGy, 50 kGy, 70 kGy, 100 kGy and 150 kGy. The electron beam processing took to changes in the sugarcane bagasse structure and composition, lignin and cellulose cleavage. The yield of enzymatic hydrolyzes of cellulose increase about 40 % with 30 kGy of absorbed dose. (author)

  18. Bio ethanol production from oil palm empty fruit bunches

    International Nuclear Information System (INIS)

    Loh Soh Kheang; Muhammad Asyraf Kasim; Nasrin Abu Bakar

    2010-01-01

    Full text: The oil palm industry has an abundance of oil palm biomass. The type of biomass generated includes empty fruit bunches (EFB), oil palm trunk (OPT), kernel, shell and fronds. Generally, ligno celluloses biomass derived from oil palm has great potential to be converted into various forms of renewable energy. In this study, EFB in pulverized form was used as a feedstock for bio ethanol production. EFB contains lignin, hemicelluloses and cellulose which can be converted into fermentable sugar and bio ethanol. The EFB was initially pre-treated with 1% NaOH followed by acid hydrolysis with 0.7% sulfuric acid and enzyme prior to fermentation process with Saccharomyces cerevisea. The various process parameters for bio ethanol production was optimized i.e. pH, temperature, rate of agitation and initial feedstock concentration. The fermentation of EFB hydrolysate was at pH 4, 30 degree Celsius and 100 rpm within 72 hours of incubation yielded 10.48 g/L of bio ethanol from 50 g/L of EFB. The bio ethanol production in a 6-L bioreactor showed 36% conversion of fermentable sugar from EFB into bio ethanol. (author)

  19. Modeling and analysing storage systems in agricultural biomass supply chain for cellulosic ethanol production

    International Nuclear Information System (INIS)

    Ebadian, Mahmood; Sowlati, Taraneh; Sokhansanj, Shahab; Townley-Smith, Lawrence; Stumborg, Mark

    2013-01-01

    Highlights: ► Studied the agricultural biomass supply chain for cellulosic ethanol production. ► Evaluated the impact of storage systems on different supply chain actors. ► Developed a combined simulation/optimization model to evaluate storage systems. ► Compared two satellite storage systems with roadside storage in terms of costs and emitted CO 2 . ► SS would lead to a more cost-efficient supply chain compared to roadside storage. -- Abstract: In this paper, a combined simulation/optimization model is developed to better understand and evaluate the impact of the storage systems on the costs incurred by each actor in the agricultural biomass supply chain including farmers, hauling contractors and the cellulosic ethanol plant. The optimization model prescribes the optimum number and location of farms and storages. It also determines the supply radius, the number of farms required to secure the annual supply of biomass and also the assignment of farms to storage locations. Given the specific design of the supply chain determined by the optimization model, the simulation model determines the number of required machines for each operation, their daily working schedule and utilization rates, along with the capacities of storages. To evaluate the impact of the storage systems on the delivered costs, three storage systems are molded and compared: roadside storage (RS) system and two satellite storage (SS) systems including SS with fixed hauling distance (SF) and SS with variable hauling distance (SV). In all storage systems, it is assumed the loading equipment is dedicated to storage locations. The obtained results from a real case study provide detailed cost figures for each storage system since the developed model analyses the supply chain on an hourly basis and considers time-dependence and stochasticity of the supply chain. Comparison of the storage systems shows SV would outperform SF and RS by reducing the total delivered cost by 8% and 6%, respectively

  20. Determining the potential of inedible weed biomass for bio-energy and ethanol production

    Directory of Open Access Journals (Sweden)

    Siripong Premjet

    2013-02-01

    Full Text Available Surveys of indigenous weeds in six provinces located in the low northern part of Thailand were undertaken to determine the potential of weed biomass for bio-energy and bio-ethanol. The results reveal that most of the weed samples had low moisture contents and high lower heating values (LHVs. The LHVs at the highest level, ranging from 17.7 to 18.9 Mg/kg, and at the second highest level, ranging from 16.4 to 17.6 Mg/kg, were obtained from 11 and 31 weed species, respectively. It was found that most of the collected weed samples contained high cellulose and low lignin contents. Additionally, an estimate of the theoretical ethanol yields based on the amount of cellulose and hemicellulose in each weed species indicated that a high ethanol yield resulted from weed biomasses with high cellulose and hemicellulose contents. Among the collected weed species, the highest level of ethanol yield, ranging from 478.9 to 548.5 L/ton (substrate, was achieved from 11 weed species. It was demonstrated that most of the collected weed species tested have the potential for thermal conversion and can be used as substrates for ethanol production.

  1. The Canadian Petroleum Products Institute : position on ethanol

    International Nuclear Information System (INIS)

    2002-01-01

    A brief overview of the Canadian Petroleum Products Institute (CPPI), an industry association which represents Canadian Petroleum Refiners and Marketers is provided. It is not against nor for the use of ethanol as a fuel. Ethanol blends are marketed by some CPPI members. It is mentioned that consumers accept ethanol fuels when the price is competitive with the price of non-ethanol fuel. Mandating the use of ethanol in fuels is not an issue supported by the CPPI. A subsidy is required in order for ethanol to be an economically attractive option, and the consumers would be forced to bear subsidy costs if the use of ethanol in fuels were to be mandated. The technology is still some years away for ethanol from cellulose to be an attractive option. It is difficult to finance new plants, and 50 million of the 240 million litres of ethanol blended has to be imported. The advantages of ethanol as a fuel are marginal and not cost effective. Some changes to the gasoline distribution system would be required, as ethanol must be added near the consumer, and it may not be appropriate for some older vehicles and some off-road equipment. The gasoline industry's flexibility would be reduced by provincial mandates. Several questions have not yet been answered, such as what is the real purpose of mandating ethanol in motor fuels? when will new technology be available? The CPPI makes four recommendations: (1) the development of a clear understanding of and the articulation of the objectives of a new ethanol policy, (2) support the development of new cellulose based technology, (3) take a prudent and gradual approach to development of a new policy, and (4) CPPI does not believe that an ethanol mandate is in the best interests of all Canadians

  2. On the determination of crystallinity and cellulose content in plant fibres

    DEFF Research Database (Denmark)

    Thygesen, Anders; Oddershede, Jette; Lilholt, Hans

    2005-01-01

    A comparative study of cellulose crystallinity based on the sample crystallinity and the cellulose content in plant fibres was performed for samples of different origin. Strong acid hydrolysis was found superior to agricultural fibre analysis and comprehensive plant fibre analysis for a consistent...... determination of the cellulose content. Crystallinity determinations were based on X-ray powder diffraction methods using side-loaded samples in reflection (Bragg-Brentano) mode. Rietveld refinements based on the recently published crystal structure of cellulose I beta followed by integration of the crystalline...... and 60 - 70 g/ 100 g cellulose in wood based fibres. These findings are significant in relation to strong fibre composites and bio-ethanol production....

  3. Mutant alcohol dehydrogenase leads to improved ethanol tolerance in Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D [ORNL; Guss, Adam M [ORNL; Karpinets, Tatiana V [ORNL; Parks, Jerry M [ORNL; Smolin, Nikolai [ORNL; Yang, Shihui [ORNL; Land, Miriam L [ORNL; Klingeman, Dawn Marie [ORNL; Bhandiwad, Ashwini [Thayer School of Engineering at Dartmouth; Rodriguez, Jr., Miguel [ORNL; Raman, Babu [Dow Chemical Company, The; Shao, Xiongjun [Thayer School of Engineering at Dartmouth; Mielenz, Jonathan R [ORNL; Smith, Jeremy C [ORNL; Keller, Martin [ORNL; Lynd, Lee R [Thayer School of Engineering at Dartmouth

    2011-01-01

    Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. Biochemical assays confirm a complete loss of NADH-dependent activity with concomitant acquisition of NADPH-dependent activity, which likely affects electron flow in the mutant. The simplicity of the genetic basis for the ethanol-tolerant phenotype observed here informs rational engineering of mutant microbial strains for cellulosic ethanol production.

  4. Valuing climate protection through willingness to pay for biomass ethanol

    International Nuclear Information System (INIS)

    Solomon, Barry D.; Johnson, Nicholas H.

    2009-01-01

    This study uses a multi-part, split-sample contingent valuation method (CVM) and fair share (FS) survey to better understand the public's valuation of mitigating global climate change through its willingness to pay for biomass or 'cellulosic' ethanol. In addition to a basic CVM question, a related scenario was developed that asked half of the survey respondents to state their fair share cost to lessen a potential food shortage in the next decade, also through the expanded use of cellulosic ethanol. Three alternative biomass feedstocks were assessed: farming residues, forestry residues and paper mill wastes, and municipal solid wastes. Overall a slightly larger proportion of respondents were WTP extra for cellulosic ethanol in the basic CVM scenario than in the FS scenario, though no significant differences were found in the WTP for the different feedstocks. Bid curve lognormal regression results for the two models were similar, supporting the idea that asking a FS rather than a conventional WTP question may be justifiable in some circumstances, such as in cases of a national emergency. (author)

  5. Upper Midwestern U.S. consumers and ethanol: Knowledge, beliefs and consumption

    International Nuclear Information System (INIS)

    Johnson, Dana M.; Halvorsen, Kathleen E.; Solomen, Barry D.

    2011-01-01

    This study uses multivariate statistical methods to explore the beliefs of upper Midwestern U.S. residents about global climate change, and possible consumer responses to determine their willingness to pay more for cellulosic ethanol from multiple feedstocks. A mail survey was sent to residents of Michigan, Minnesota, and Wisconsin to determine baseline knowledge, attitudes and beliefs on several aspects of these issues, with a focus on the emerging market for cellulosic ethanol. First, survey responses were compiled and principal components analysis was used to reduce the dimensionality of the data. This resulted in seven factors and a theoretical framework to help understand consumers' beliefs about climate change and possible energy policy responses. Second, these results were combined with insights from previous studies that were used as input for further research hypotheses and multivariate analyses. The factor scores from principal components analysis along with the some of the key control variables (i.e., gender, income, and rural/urban) served as independent variables in three revised multiple regression models of consumer's willingness to pay (WTP) their fair share of any additional cost of cellulosic ethanol, as reported in an earlier study. Four explanatory variables were found to be significant determinants of WTP in every model: environment, energy consumption, and climate change; concerns about climate change impacts; inability to stop climate change; and gasoline prices and consumption. These results suggest strong public support and consumer WTP for cellulosic ethanol production in the region.

  6. An oil palm-based biorefinery concept for cellulosic ethanol and phytochemicals production: Sustainability evaluation using exergetic life cycle assessment

    International Nuclear Information System (INIS)

    Ofori-Boateng, Cynthia; Lee, Keat Teong

    2014-01-01

    In this study, thermo-environmental sustainability of an oil palm-based biorefinery concept for the co-production of cellulosic ethanol and phytochemicals from oil palm fronds (OPFs) was evaluated based on exergetic life cycle assessment (ExLCA). For the production of 1 tonne bioethanol, the exergy content of oil palm seeds was upgraded from 236 MJ to 77,999 MJ during the farming process for OPFs production. Again, the high exergy content of the OPFs was degraded by about 62.02% and 98.36% when they were converted into cellulosic ethanol and phenolic compounds respectively. With a total exergy destruction of about 958,606 MJ (internal) and 120,491 MJ (external or exergy of wastes), the biorefinery recorded an overall exergy efficiency and thermodynamic sustainability index (TSI) of about 59.05% and 2.44 per tonne of OPFs' bioethanol respectively. Due to the use of fossil fuels, pesticides, fertilizers and other toxic chemicals during the production, the global warming potential (GWP = 2265.69 kg CO 2 eq.), acidification potential (AP = 355.34 kg SO 2 eq.) and human toxicity potential (HTP = 142.79 kg DCB eq.) were the most significant environmental impact categories for a tonne of bioethanol produced in the biorefinery. The simultaneous saccharification and fermentation (SSF) unit emerged as the most exergetically efficient (89.66%), thermodynamically sustainable (TSI = 9.67) and environmentally friendly (6.59% of total GWP) production system. -- Highlights: • Thermo-environmental sustainability of palm-based biorefinery was assessed. • OPFs' exergy content was degraded when converted into bioethanol and phytochemicals. • Exergy efficiency (59.05%) and TSI (2.44) were recorded for the biorefinery • Global warming potential of 2265.6 kg CO 2 eq. was recorded for the whole biorefinery

  7. Acid hydrolysis of sisal cellulose: studies aiming at nano fibers and bio ethanol preparation

    International Nuclear Information System (INIS)

    Paula, Mauricio P. de; Lacerda, Talita M.; Zambon, Marcia D.; Frollini, Elisabete

    2009-01-01

    The hydrolysis of cellulose can result in nanofibers and also is an important stage in the bioethanol production process. In order to evaluate the influence of acid (sulfuric) concentration, temperature, and native cellulose (sisal) pretreatment on cellulose hydrolysis, the acid concentration was varied between 5% and 30% (v/v) in the temperature range from 60 to 100 deg C using native and alkali-treated (mercerized) sisal cellulose. The following techniques were used to evaluate the residual (non-hydrolysed) cellulose characteristics: viscometry, average degree of polymerization (DP), X-ray diffraction, crystallinity index, and Scanning Electron Microscopy. The sugar cane liquor was analyzed in terms of sugar composition, using High Performance Liquid Chromatography (HPLC). The results showed that increasing the concentration of sulfuric acid and temperature afforded residual cellulose with lower molecular weight and, up to specific acid concentrations, higher crystallinity indexes, when compared to the original cellulose values, and increased the glucose (the bioethanol precursor ) production of the liquor, which was favored for mercerized cellulose. (author)

  8. Ethanol production of banana shell and cassava starch

    International Nuclear Information System (INIS)

    Monsalve G, John F; Medina de Perez, Victoria Isabel; Ruiz colorado, Angela Adriana

    2006-01-01

    In this work the acid hydrolysis of the starch was evaluated in cassava and the cellulose shell banana and its later fermentation to ethanol, the means of fermentation were adjusted for the microorganisms saccharomyces cerevisiae nrrl y-2034 and zymomonas mobilis cp4. The banana shell has been characterized, which possesses a content of starch, cellulose and hemicelluloses that represent more than 80% of the shell deserve the study of this as source of carbon. The acid hydrolysis of the banana shell yield 20g/l reducing sugar was obtained as maximum concentration. For the cassava with 170 g/l of starch to ph 0.8 in 5 hours complete conversion is achieved to you reducing sugars and any inhibitory effect is not noticed on the part of the cultivations carried out with banana shell and cassava by the cyanide presence in the cassava and for the formation of toxic compounds in the acid hydrolysis the cellulose in banana shell. For the fermentation carried out with saccharomyces cerevisiae a concentration of ethanol of 7.92± 0.31% it is achieved and a considerable production of ethanol is not appreciated (smaller than 0.1 g/l) for none of the means fermented with zymomonas mobilis

  9. Wet oxidation pretreatment of rape straw for ethanol production

    International Nuclear Information System (INIS)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole slurry (Filter cake + filtrate) in SSF were also tested. Except ethanol yields, pretreatment methods were evaluated based on achieved glucose yields, amount of water used, recovery of cellulose, hemicellulose, and lignin. The highest ethanol yield obtained was 67% after fermenting the whole slurry produced by WO at 205 °C for 3 min with 12 bar of oxygen gas pressure and featured with presoaking in water. At these conditions after pre-treatment, cellulose and hemicellulose was recovered quantitatively (100%) together with 86% of the lignin. WO treatments of 2–3 min at 205–210 °C with 12 bar of oxygen gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid formation in SSF. -- Highlights: ► Wet Oxidation pretreatment on rape straw for sugar and ethanol production. ► Variables were reaction time, temperature, and oxygen gas pressure. ► Also, other configurations for increase of water and energy efficiency. ► Short Wet oxidation pretreatment (2–3 min) produced highest ethanol yield. ► After these pretreatment conditions recovery of lignin in solids was 86%.

  10. Production of ethanol from hemicellulose fraction of cocksfoot grass using pichia stipitis

    DEFF Research Database (Denmark)

    Njoku, Stephen Ikechukwu; Iversen, Jens Asmus; Uellendahl, Hinrich

    2013-01-01

    liquid hydrolysate to ethanol is essential for economically feasible cellulosic ethanol processes. Fermentation of the separated hemicellulose liquid hydrolysates obtained after the WEx pretreatment was done by Pichia stipitis CBS 6054 (Scheffersomyces stipitis). Results: The fermentation of the WEx...

  11. Feasibility Study for Co-Locating and Integrating Ethanol Production Plants from Corn Starch and Lignocellulosic Feedstocks (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.; Ibsen, K.; McAloon, A.; Yee, W.

    2005-01-01

    Analysis of the feasibility of co-locating corn-grain-to-ethanol and lignocellulosic ethanol plants and potential savings from combining utilities, ethanol purification, product processing, and fermentation. Although none of the scenarios identified could produce ethanol at lower cost than a straight grain ethanol plant, several were lower cost than a straight cellulosic ethanol plant.

  12. Microbial fuel cell treatment of ethanol fermentation process water

    Science.gov (United States)

    Borole, Abhijeet P [Knoxville, TN

    2012-06-05

    The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

  13. Influence of spatially dependent, modeled soil carbon emission factors on life-cycle greenhouse gas emissions of corn and cellulosic ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhangcai [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Dunn, Jennifer B. [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue Argonne IL 60439 USA; Kwon, Hoyoung [Environment and Production Technology Division, International Food Policy Research Institute, 2033 K St. NW Washington DC 20006 USA; Mueller, Steffen [Energy Resources Center, University of Illinois at Chicago, 1309 South Halsted Street Chicago IL 60607 USA; Wander, Michelle M. [Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 South Goodwin Avenue Urbana IL 61801 USA

    2016-03-03

    Converting land to biofuel feedstock production incurs changes in soil organic carbon (SOC) that can influence biofuel life-cycle greenhouse gas (GHG) emissions. Estimates of these land use change (LUC) and life-cycle GHG emissions affect biofuels’ attractiveness and eligibility under a number of renewable fuel policies in the U.S. and abroad. Modeling was used to refine the spatial resolution and depth-extent of domestic estimates of SOC change for land (cropland, cropland pasture, grasslands, and forests) conversion scenarios to biofuel crops (corn, corn stover, switchgrass, Miscanthus, poplar, and willow). In most regions, conversions from cropland and cropland pasture to biofuel crops led to neutral or small levels of SOC sequestration, while conversion of grassland and forest generally caused net SOC loss. Results of SOC change were incorporated into the Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model to assess their influence on life-cycle GHG emissions for the biofuels considered. Total LUC GHG emissions (g CO2eq MJ-1) were 2.1–9.3 for corn, -0.7 for corn stover, -3.4–12.9 for switchgrass, and -20.1–-6.2 for Miscanthus; these varied with SOC modeling assumptions applied. Extending soil depth from 30 to 100cm affected spatially-explicit SOC change and overall LUC GHG emissions; however the influence on LUC GHG emissions estimates were less significant in corn and corn stover than cellulosic feedstocks. Total life-cycle GHG emissions (g CO2eq MJ-1, 100cm) were estimated to be 59–66 for corn ethanol, 14 for stover ethanol, 18-26 for switchgrass ethanol, and -0.6–-7 for Miscanthus ethanol.

  14. Enhancement of both salivary protein-enological tannin interactions and astringency perception by ethanol.

    Science.gov (United States)

    Obreque-Slíer, Elías; Peña-Neira, Alvaro; López-Solís, Remigio

    2010-03-24

    Red wine astringency has been associated with interactions of tannins with salivary proteins. Tannins are active protein precipitants. Not much evidence exists demonstrating contribution of other wine components to astringency. We aimed to investigate an eventual role of ethanol both in astringency and salivary protein-enological tannin interactions. A trained sensory panel scored perceived astringency. Salivary protein-tannin interactions were assessed by observing both tannin-dependent changes in salivary protein diffusion on cellulose membranes and tannin-induced salivary protein precipitation. Proanthocyanidins and gallotannins in aqueous and hydroalcoholic solutions were assayed. A biphasic mode of diffusion on cellulose membranes displayed by salivary proteins was unaffected after dilution with water or enological concentrations of ethanol. At those concentrations ethanol was not astringent. In aqueous solution, tannins provoked both restriction of salivary protein diffusion, protein precipitation, and astringency. Those effects were exacerbated by 13% ethanol. In summary, enological concentrations of ethanol exacerbate astringency and salivary protein-tannin interactions.

  15. Consolidated Bio-Processing of Cellulosic Biomass for Efficient Biofuel Production Using Yeast Consortium

    Science.gov (United States)

    Goyal, Garima

    Fossil fuels have been the major source for liquid transportation fuels for ages. However, decline in oil reserves and environmental concerns have raised a lot of interest in alternative and renewable energy sources. One promising alternative is the conversion of plant biomass into ethanol. The primary biomass feed stocks currently being used for the ethanol industry have been food based biomass (corn and sugar cane). However, interest has recently shifted to replace these traditional feed-stocks with more abundant, non-food based cellulosic biomass such as agriculture wastes (corn stover) or crops (switch grass). The use of cellulosic biomass as feed stock for the production of ethanol via bio-chemical routes presents many technical challenges not faced with the use of corn or sugar-cane as feed-stock. Recently, a new process called consolidated Bio-processing (CBP) has been proposed. This process combines simultaneous saccharification of lignocellulose with fermentation of the resulting sugars into a single process step mediated by a single microorganism or microbial consortium. Although there is no natural microorganism that possesses all properties of lignocellulose utilization and ethanol production desired for CBP, some bacteria and fungi exhibit some of the essential traits. The yeast Saccharomyces cerevisiae is the most attractive host organism for the usage of this strategy due to its high ethanol productivity at close to theoretical yields (0.51g ethanol/g glucose consumed), high osmo- and ethanol- tolerance, natural robustness in industrial processes, and ease of genetic manipulation. Introduction of the cellulosome, found naturally in microorganisms, has shown new directions to deal with recalcitrant biomass. In this case enzymes work in synergy in order to hydrolyze biomass more effectively than in case of free enzymes. A microbial consortium has been successfully developed, which ensures the functional assembly of minicellulosome on the yeast surface

  16. Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions

    International Nuclear Information System (INIS)

    C. Saricks; D. Santini; M. Wang

    1999-01-01

    We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our analysis includes petroleum use, energy use, and emissions associated with chemicals manufacturing, farming of corn and biomass, ethanol production, and ethanol combustion for ethanol; and petroleum use, energy use, and emissions associated with petroleum recovery, petroleum refining, and gasoline combustion for gasoline. For corn-based ethanol, the key factors in determining energy and emissions impacts include energy and chemical usage intensity of corn farming, energy intensity of the ethanol plant, and the method used to estimate energy and emissions credits for co-products of corn ethanol. The key factors in determining the impacts of cellulosic ethanol are energy and chemical usage intensity of biomass farming, ethanol yield per dry ton of biomass, and electricity credits in cellulosic ethanol plants. The results of our fuel-cycle analysis for fuel ethanol are listed below. Note that, in the first half of this summary, the reductions cited are per-vehicle-mile traveled using the specified ethanol/gasoline blend instead of conventional (not reformulated) gasoline. The second half of the summary presents estimated changes per gallon of ethanol used in ethanol blends. GHG emissions are global warming potential (GWP)-weighted, carbon dioxide (CO2)-equivalent emissions of CO2, methane (CH4), and nitrous oxide (N2O)

  17. Fuel ethanol production from wet oxidised corn stover by S. cerevisiae

    DEFF Research Database (Denmark)

    Qiang, zhang; Thomsen, Anne Belinda

    2012-01-01

    of 74.6% were obtained after pretreatment. 86.5% of cellulose was remained in the solid cake. After 24h hydrolysis at 50°C using cellulase (Cellubrix L), the achieved conversion of cellulose to glucose was 64.8%. Ethanol production was evaluated from dried solid cake and the hydrolysate was employed...

  18. Utilization of agricultural wastes for production of ethanol. Progress report, October 1979-May 1980

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.

    1980-05-01

    The project proposes to develop methods to utilize agricultural wastes, especially cottonseed hulls and peanut shells to produce ethanol. Initial steps will involve development of methods to break down cellulose to a usable form of substrates for chemical or biological digestion. The process of ethanol production will consist of (a) preparatory step to separate fibrous (cellulose) and non-fibrous (non-cellulosic compounds). The non-cellulosic residues which may include grains, fats or other substrates for alcoholic fermentation. The fibrous residues will be first pre-treated to digest cellulose with acid, alkali, and sulfur dioxide gas or other solvents. (b) The altered cellulose will be digested by suitable micro-organisms and cellulose enzymes before alcoholic fermentation. The digester and fermentative unit will be specially designed to develop a prototype for pilot plant for a continuous process. The first phase of the project will be devoted toward screening of a suitable method for cellulose modification, separation of fibrous and non-fibrous residues, the micro-organism and enzyme preparations. Work is in progress on: the effects of various microorganisms on the degree of saccharification; the effects of higher concentrations of acids, alkali, and EDTA on efficiency of microbial degradation; and the effects of chemicals on enzymatic digestion.

  19. The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases

    Energy Technology Data Exchange (ETDEWEB)

    Stipanovic, Arthur J [SUNY College of Environmental Science and Forestry

    2014-11-17

    Consistent with the US-DOE and USDA “Roadmap” objective of producing ethanol and chemicals from cellulosic feedstocks more efficiently, a three year research project entitled “The Effect of Cellulose Crystal Structure and Solid-State Morphology on the Activity of Cellulases” was initiated in early 2003 under DOE sponsorship (Project Number DE-FG02-02ER15356). A three year continuation was awarded in June 2005 for the period September 15, 2005 through September 14, 2008. The original goal of this project was to determine the effect of cellulose crystal structure, including allomorphic crystalline form (Cellulose I, II, III, IV and sub-allomorphs), relative degree of crystallinity and crystallite size, on the activity of different types of genetically engineered cellulase enzymes to provide insight into the mechanism and kinetics of cellulose digestion by “pure” enzymes rather than complex mixtures. We expected that such information would ultimately help enhance the accessibility of cellulose to enzymatic conversion processes thereby creating a more cost-effective commercial process yielding sugars for fermentation into ethanol and other chemical products. Perhaps the most significant finding of the initial project phase was that conversion of native bacterial cellulose (Cellulose I; BC-I) to the Cellulose II (BC-II) crystal form by aqueous NaOH “pretreatment” provided an increase in cellulase conversion rate approaching 2-4 fold depending on enzyme concentration and temperature, even when initial % crystallinity values were similar for both allomorphs.

  20. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  1. The bioconversion of mountain pine beetle-killed lodgepole pine to fuel ethanol using the organosolv process.

    Science.gov (United States)

    Pan, Xuejun; Xie, Dan; Yu, Richard W; Saddler, Jack N

    2008-09-01

    Lodgepole pine (Pinus contorta) killed by mountain pine beetle (Dendroctonus ponderosae) (BLP) was compared with healthy lodgepole pine (HLP) for bioconversion to ethanol and high-value co-products. The BLP and HLP chips were pretreated using an ethanol organosolv process at a variety of severities. It was shown that the BLP was easier to pretreat and delignify than were the HLP chips. The resulting pretreated BLP substrate had a lower residual lignin, lower degree of polymerization of cellulose, lower cellulose crystallinity, smaller fiber size and thereby a better enzymatic hydrolysability than did the HLP substrates. However, under the same conditions, the BLP showed lower substrate yield and cellulose recovery than did the HLP, which likely resulted from the excessive hydrolysis and subsequent decomposition of the cellulose and hemicellulose during the pretreatment. The BLP wood yielded more ethanol organosolv lignin than was obtained with the HLP material. The HLP lignin had a lower molecular weight and narrower distribution than did the BLP lignin. It appears that the beetle killed LP is more receptive to organosolv pretreatment other than a slightly lower recovery of carbohydrates.

  2. Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

    KAUST Repository

    Puspasari, Tiara

    2018-05-01

    with a good compatibility. The cellulose–PDMS membranes demonstrate attractive performance in ethanol-water pervaporation as compared to the commercial PDMS membrane, and allow nanofiltration of a wide range of solvents with different polarity. The cellulose-PEI membranes exhibit anomalous performance improvement in nanofiltration as compared to the corresponding pure membranes. This study has opened up many great opportunities for cellulose to continuously contribute to sustainable and economical membrane processes.

  3. Cellulose gels produced in room temperature ionic liquids by ionizing radiation

    International Nuclear Information System (INIS)

    Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa

    2014-01-01

    Cellulose-based gels were produced in room temperature ionic liquids (RTILs) by ionizing radiation. Cellulose was dissolved at the initial concentration of 20 wt% in 1-ethyl-3-methylimidazolium (EMI)-acetate or N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEMA)-formate with a water content of 18 wt%, and irradiated with γ-rays under aerated condition to produce new cellulose gels. The gel fractions of the cellulose gels obtained in EMI-acetate and DEMA-formate at a dose of 10 kGy were 13% and 19%, respectively. The formation of gel fractions was found to depend on the initial concentration of cellulose, water content, and irradiation temperature. The obtained gel readily absorbed water, methanol, ethanol, dichloromethane, N,N-dimethylacetamide, and RTILs. - Highlights: • Cellulose gels were produced in room temperature ionic liquids (RTILs). • Water plays a crucial role in the cross-linking reaction. • Cellulose gels swollen with RTILs show good electronic conductivity (3.0 mS cm −1 )

  4. Internal and External Barriers Impacting Non-Food Cellulosic Biofuel Projects in the United States

    Directory of Open Access Journals (Sweden)

    Jeremy Withers

    2015-05-01

    Full Text Available Escalating demand, along with EPAct 2005, has led the United States government to assume a twofold leadership approach of energy security and environmental practices. This has initiated several important issues pertaining to cellulosic biofuel production. However, little is known about what is needed for the U.S. to lead long-term renewable energy security, how the US will develop and implement leading environmental energy practices, what supply capabilities and refining technologies are available to produce renewable fuels, and how funding can be used to adopt available technologies. This article examines geographical aspects, operational status, and barriers tending to prevent the successful commercialization of non-food cellulosic ethanol projects in the U.S. from secondary sources. Outcomes of this research can be used to further understand inhibitors that impact the production and commercialization of ethanol from non-food cellulosic sources.

  5. Production of Biofuels from Selected Cellulosic Waste materials

    Directory of Open Access Journals (Sweden)

    Jathwa Abdul Kareem Ibrahim

    2017-08-01

    Full Text Available In this study four types of cellulose-rich municipal solid wastes (residuals of orange, banana peel, corn residues, and saw dust were used as raw materials. These cellulosic substrates usually have a lot of lignin content which prevents the process of saccharification by microorganisms. Thus pretreatment methods of enzymatic, acid or base with enzymatic treatment and dilute acid followed by autoclaving were necessary to dignify these wastes and to obtain higher reducing sugar yields and hence higher ethanol production. Dilute HCl acid of 1% followed by autoclaving at 121℃ for 30 min proved to give good result where significant amounts of reducing sugars were obtained at the end of the saccharification process. Orange peel proved to give the highest glucose concentration of an average of 6000 mg/l on day 4 of the saccharification process. Fermentation was carried out for the hydrolyzed samples using Saccharomyces cerevisiae yeast. The amount of ethanol produced after fermentation was found to be the highest for orange peel having a value of 1300 mg/l after 96h of incubation. As science is proceeding, engineered microorganisms could help to produce sustainable fuels from cellulose-rich municipal solid wastes in the future.

  6. Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions; TOPICAL

    International Nuclear Information System (INIS)

    C. Saricks; D. Santini; M. Wang

    1999-01-01

    We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our analysis includes petroleum use, energy use, and emissions associated with chemicals manufacturing, farming of corn and biomass, ethanol production, and ethanol combustion for ethanol; and petroleum use, energy use, and emissions associated with petroleum recovery, petroleum refining, and gasoline combustion for gasoline. For corn-based ethanol, the key factors in determining energy and emissions impacts include energy and chemical usage intensity of corn farming, energy intensity of the ethanol plant, and the method used to estimate energy and emissions credits for co-products of corn ethanol. The key factors in determining the impacts of cellulosic ethanol are energy and chemical usage intensity of biomass farming, ethanol yield per dry ton of biomass, and electricity credits in cellulosic ethanol plants. The results of our fuel-cycle analysis for fuel ethanol are listed below. Note that, in the first half of this summary, the reductions cited are per-vehicle-mile traveled using the specified ethanol/gasoline blend instead of conventional (not reformulated) gasoline. The second half of the summary presents estimated changes per gallon of ethanol used in ethanol blends. GHG emissions are global warming potential (GWP)-weighted, carbon dioxide (CO2)-equivalent emissions of CO2, methane (CH4), and nitrous oxide (N2O)

  7. Ethanol production from wet oxidized corn straw by simultaneous saccharification and fermentation

    DEFF Research Database (Denmark)

    Zhang, Q.; Yin, Y.; Thygesen, Anders

    2010-01-01

    remained in the solid fraction and recovery of cellulose was 95.87% after pretreatment. After 24 h hydrolysis at 50°C using cellulase, the achieved conversion of cellulose to glucose was about 67.6%. After 142 h of SSF with substrate concentration of 8%, ethanol yield of 79.0% of the theoretical...

  8. A novel biochemical route for fuels and chemicals production from cellulosic biomass.

    Directory of Open Access Journals (Sweden)

    Zhiliang Fan

    Full Text Available The conventional biochemical platform featuring enzymatic hydrolysis involves five key steps: pretreatment, cellulase production, enzymatic hydrolysis, fermentation, and product recovery. Sugars are produced as reactive intermediates for subsequent fermentation to fuels and chemicals. Herein, an alternative biochemical route is proposed. Pretreatment, enzymatic hydrolysis and cellulase production is consolidated into one single step, referred to as consolidated aerobic processing, and sugar aldonates are produced as the reactive intermediates for biofuels production by fermentation. In this study, we demonstrate the viability of consolidation of the enzymatic hydrolysis and cellulase production steps in the new route using Neurospora crassa as the model microorganism and the conversion of cellulose to ethanol as the model system. We intended to prove the two hypotheses: 1 cellulose can be directed to produce cellobionate by reducing β-glucosidase production and by enhancing cellobiose dehydrogenase production; and 2 both of the two hydrolysis products of cellobionate--glucose and gluconate--can be used as carbon sources for ethanol and other chemical production. Our results showed that knocking out multiple copies of β-glucosidase genes led to cellobionate production from cellulose, without jeopardizing the cellulose hydrolysis rate. Simulating cellobiose dehydrogenase over-expression by addition of exogenous cellobiose dehydrogenase led to more cellobionate production. Both of the two hydrolysis products of cellobionate: glucose and gluconate can be used by Escherichia coli KO 11 for efficient ethanol production. They were utilized simultaneously in glucose and gluconate co-fermentation. Gluconate was used even faster than glucose. The results support the viability of the two hypotheses that lay the foundation for the proposed new route.

  9. A novel biochemical route for fuels and chemicals production from cellulosic biomass.

    Science.gov (United States)

    Fan, Zhiliang; Wu, Weihua; Hildebrand, Amanda; Kasuga, Takao; Zhang, Ruifu; Xiong, Xiaochao

    2012-01-01

    The conventional biochemical platform featuring enzymatic hydrolysis involves five key steps: pretreatment, cellulase production, enzymatic hydrolysis, fermentation, and product recovery. Sugars are produced as reactive intermediates for subsequent fermentation to fuels and chemicals. Herein, an alternative biochemical route is proposed. Pretreatment, enzymatic hydrolysis and cellulase production is consolidated into one single step, referred to as consolidated aerobic processing, and sugar aldonates are produced as the reactive intermediates for biofuels production by fermentation. In this study, we demonstrate the viability of consolidation of the enzymatic hydrolysis and cellulase production steps in the new route using Neurospora crassa as the model microorganism and the conversion of cellulose to ethanol as the model system. We intended to prove the two hypotheses: 1) cellulose can be directed to produce cellobionate by reducing β-glucosidase production and by enhancing cellobiose dehydrogenase production; and 2) both of the two hydrolysis products of cellobionate--glucose and gluconate--can be used as carbon sources for ethanol and other chemical production. Our results showed that knocking out multiple copies of β-glucosidase genes led to cellobionate production from cellulose, without jeopardizing the cellulose hydrolysis rate. Simulating cellobiose dehydrogenase over-expression by addition of exogenous cellobiose dehydrogenase led to more cellobionate production. Both of the two hydrolysis products of cellobionate: glucose and gluconate can be used by Escherichia coli KO 11 for efficient ethanol production. They were utilized simultaneously in glucose and gluconate co-fermentation. Gluconate was used even faster than glucose. The results support the viability of the two hypotheses that lay the foundation for the proposed new route.

  10. Production of ethanol from sugars and lignocellulosic biomass by Thermoanaerobacter J1 isolated from a hot spring in Iceland.

    Science.gov (United States)

    Jessen, Jan Eric; Orlygsson, Johann

    2012-01-01

    Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production by Thermoanaerobacter strain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined. The strain showed a broad substrate spectrum, and high ethanol yields were observed on glucose (1.70 mol/mol) and xylose (1.25 mol/mol). Ethanol yields were, however, dramatically lowered by adding thiosulfate or by cocultivating strain J1 with a hydrogenotrophic methanogen with acetate becoming the major end product. Ethanol production from 4.5 g/L of lignocellulosic biomass hydrolysates (grass, hemp stem, wheat straw, newspaper, and cellulose) pretreated with acid or alkali and the enzymes Celluclast and Novozymes 188 was investigated. The highest ethanol yields were obtained on cellulose (7.5 mM·g(-1)) but the lowest on straw (0.8 mM·g(-1)). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The largest increase was on straw hydrolysates where ethanol production increased from 0.8 mM·g(-1) to 3.3 mM·g(-1) using alkali-pretreated biomass. The highest ethanol yields on lignocellulosic hydrolysates were observed with hemp hydrolysates pretreated with acid, 4.2 mM·g(-1).

  11. Establishing an ethanol production business

    International Nuclear Information System (INIS)

    1993-01-01

    Many Saskatchewan communities are interested in the potential benefits of establishing an ethanol production facility. A guide is presented to outline areas that communities should consider when contemplating the development of an ethanol production facility. Political issues affecting the ethanol industry are discussed including environmental impacts, United States legislation, Canadian legislation, and government incentives. Key success factors in starting a business, project management, marketing, financing, production, physical requirements, and licensing and regulation are considered. Factors which must be taken into consideration by the project manager and team include markets for ethanol and co-products, competent business management staff, equity partners for financing, production and co-product utilization technologies, integration with another facility such as a feedlot or gluten plant, use of outside consultants, and feedstock, water, energy, labour, environmental and site size requirements. 2 figs., 2 tabs

  12. Surface Photochemistry: Benzophenone as a Probe for the Study of Modified Cellulose Fibres

    Directory of Open Access Journals (Sweden)

    L. F. Vieira Ferreira

    2007-01-01

    Full Text Available This work reports the use of benzophenone, a very well characterized probe, to study new hosts (i.e., modified celluloses grafted with alkyl chains bearing 12 carbon atoms by surface esterification. Laser-induced room temperature luminescence of air-equilibrated or argon-purged solid powdered samples of benzophenone adsorbed onto the two modified celluloses, which will be named C12-1500 and C12-1700, revealed the existence of a vibrationally structured phosphorescence emission of benzophenone in the case where ethanol was used for sample preparation, while a nonstructured emission of benzophenone exists when water was used instead of ethanol. The decay times of the benzophenone emission vary greatly with the solvent used for sample preparation and do not change with the alkylation degree in the range of 1500–1700 micromoles of alkyl chains per gram of cellulose. When water was used as a solvent for sample preparation, the shortest lifetime for the benzophenone emission was observed; this result is similar to the case of benzophenone adsorbed onto the “normal” microcrystalline cellulose surface, with this latter case previously reported by Vieira Ferreira et al. in 1995. This is due to the more efficient hydrogen abstraction reaction from the glycoside rings of cellulose when compared with hydrogen abstraction from the alkyl chains of the modified celluloses. Triplet-triplet transient absorption of benzophenone was obtained in both cases and is the predominant absorption immediately after laser pulse, while benzophenone ketyl radical formation occurs in a microsecond time scale both for normal and modified celluloses.

  13. Ethanol from wood. Cellulase enzyme production

    Energy Technology Data Exchange (ETDEWEB)

    Szengyel, Zsolt

    2000-03-01

    Conversion of biomass to liquid fuels, such as ethanol, has been investigated during the past decades. First due to the oil crisis of the 1970s and lately because of concerns about greenhouse effect, ethanol has been found to be a suitable substitute for gasoline in transportation. Although ethanol is produced in large quantities from corn starch, the conversion of lignocellulosic biomass to ethanol is rather problematic. However, cellulosic raw materials are important as they are available in large quantities from agriculture and forestry. One of the most extensively investigated processes is the enzymatic process, in which fungal cellulolytic enzymes are used to convert the cellulose content of the biomass to glucose, which is then fermented to ethanol. In order to make the raw material accessible to biological attack, it has to be pretreated first. The most successful method, which has been evaluated for various lignocellulosic materials, is the steam pretreatment. In this thesis the utilization of steam pretreated willow (hardwood) and spruce (softwood) was examined for enzyme production using a filamentous fungus T. reesei RUT C30. Various carbon sources originating from the steam pretreated materials have been investigated. The replacement of the solid carbon source with a liquid carbon source, as well as the effect of pH, was studied. The effect of toxic compounds generated during pretreatment was also examined. Comparative study of softwood and hardwood showed that steam pretreated hardwood is a better carbon source than softwood. The hydrolytic potential of enzyme solutions produced on wood derived carbon sources was better compared to commercial cellulases. Also enzyme solutions produced on steam pretreated spruce showed less sensitivity towards toxic compounds formed during steam pretreatment.

  14. Net-Immobilization of β-glucosidase on Nonwoven Fabrics to Lower the Cost of “Cellulosic Ethanol” and Increase Cellulose Conversions

    Science.gov (United States)

    Zhu, Xing; He, Bin; Zhao, Changwen; Fan, Rong; Zhang, Lihua; Wang, Guan; Ma, Yuhong; Yang, Wantai

    2016-03-01

    The main limitation preventing the use of enzymatic cellulosic ethanol in industrial production is its higher cost which is mainly due to the elevated price of β-glucosidase (BG). Herein, we report on a simple strategy for the in-situ encapsulation of BG for repeated cellulosic ethanol production. In this strategy, BG was net-immobilized into a poly(ethylene glycol) (PEG) net-cloth layer on a PP nonwoven fabric by way of the visible light-induced surface controlled/living graft cross-linking polymerization. The visible light and mild reaction conditions could ensure the activity retention of BG during immobilization, while the non-swelling uniform net-mesh formed by living cross-linking polymerization could prevent the leakage of BG effectively (at the immobilization rate of more than 98.6% and the leakage rate of only 0.4%). When the BG-loaded fabric was used in combination with free cellulase (CEL), the results of the catalytic reaction demonstrated that these BG-loaded fabrics could not only give a 40% increase in cellulose conversions but also be reused for more than fifteen batches without losing the activity. These BG-loaded fabrics with characteristics including easy separation, excellent operation stability, a low cost of the polymeric matrix and a simple fabrication process are particularly interesting for a future bio-fuel production strategy.

  15. MICROBIAL FERMENTATION OF ABUNDANT BIOPOLYMERS: CELLULOSE AND CHITIN

    Energy Technology Data Exchange (ETDEWEB)

    Leschine, Susan

    2009-10-31

    Our research has dealt with seven major areas of investigation: i) characterization of cellulolytic members of microbial consortia, with special attention recently given to Clostridium phytofermentans, a bacterium that decomposes cellulose and produces uncommonly large amounts of ethanol, ii) investigations of the chitinase system of Cellulomonas uda; including the purification and characterization of ChiA, the major component of this enzyme system, iii) molecular cloning, sequence and structural analysis of the gene that encodes ChiA in C. uda, iv) biofilm formation by C. uda on nutritive surfaces, v) investigations of the effects of humic substances on cellulose degradation by anaerobic cellulolytic microbes, vi) studies of nitrogen metabolism in cellulolytic anaerobes, and vii) understanding the molecular architecture of the multicomplex cellulase-xylanase system of Clostridium papyrosolvens. Also, progress toward completing the research of more recent projects is briefly summarized. Major accomplishments include: 1. Characterization of Clostridium phytofermentans, a cellulose-fermenting, ethanol-producing bacterium from forest soil. The characterization of a new cellulolytic species isolated from a cellulose-decomposing microbial consortium from forest soil was completed. This bacterium is remarkable for the high concentrations of ethanol produced during cellulose fermentation, typically more than twice the concentration produced by other species of cellulolytic clostridia. 2. Examination of the use of chitin as a source of carbon and nitrogen by cellulolytic microbes. We discovered that many cellulolytic anaerobes and facultative aerobes are able to use chitin as a source of both carbon and nitrogen. This major discovery expands our understanding of the biology of cellulose-fermenting bacteria and may lead to new applications for these microbes. 3. Comparative studies of the cellulase and chitinase systems of Cellulomonas uda. Results of these studies indicate

  16. Calcium carbonate growth in the presence of water soluble cellulose ethers

    International Nuclear Information System (INIS)

    Zhang Fengju; Yang Xinguo; Tian Fei

    2009-01-01

    Calcium carbonate precipitation was performed in the presence of methyl cellulose (MC) and two kinds of hydroxyethyl cellulose (HEC FD-10000, HEC FD-30000). The results demonstrated that the final product morphology and structure of CaCO 3 crystals are highly sensitive to the concentration of the cellulose ethers aqueous solution. By precisely controlling their concentrations, all these three cellulose ethers solutions have the ability of protecting metastable vaterite from thermodynamically transforming into stable calcite. The intermediate products investigation showed to some extent the phase transformation of calcium carbonate in its growing process from metastable vaterite to calcite and indicated that the calcium carbonate crystal growth in HEC solutions occurs through dissolution and reprecipitation process. Calcium carbonate growth in both presence of HEC and ethanol or Mg 2+ was also examined. This work demonstrates the potential of water soluble cellulose ethers in controlling biominerals crystallization and growth. The results are revelatory for biomineralization and fabricating new organic-inorganic hybrids based on cellulose derivatives.

  17. Impact of various storage conditions on enzymatic activity, biomass components and conversion to ethanol yields from sorghum biomass used as a bioenergy crop.

    Science.gov (United States)

    Rigdon, Anne R; Jumpponen, Ari; Vadlani, Praveen V; Maier, Dirk E

    2013-03-01

    With increased mandates for biofuel production in the US, ethanol production from lignocellulosic substrates is burgeoning, highlighting the need for thorough examination of the biofuel production supply chain. This research focused on the impact storage has on biomass, particularly photoperiod-sensitive sorghum biomass. Biomass quality parameters were monitored and included biomass components, cellulose, hemicellulose and lignin, along with extra-cellular enzymatic activity (EEA) responsible for cellulose and hemicellulose degradation and conversion to ethanol yields. Analyses revealed dramatic decreases in uncovered treatments, specifically reduced dry matter content from 88% to 59.9%, cellulose content from 35.3% to 25%, hemicellulose content from 23.7% to 16.0% and ethanol production of 0.20 to 0.02gL(-1) after 6months storage along with almost double EEA activities. In contrast, biomass components, EEA and ethanol yields remained relatively stable in covered treatments, indicating covering of biomass during storage is essential for optimal substrate retention and ethanol yields. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. γ radiolysis of cellulose acetate

    International Nuclear Information System (INIS)

    Ali, S.M.; Clay, P.G.

    1979-01-01

    The major degradative process in γ-irradiated cellulose acetate is chain scission. For the dry powder the G/sub s/ value (number of scissions per 100 eV of energy absorbed) was found to be 7.1. The water-swollen material was found to degrade at the higher rate of G/sub s/ = 9.45. Additions of ethanol and methanol to the water brought about reductions in G/sub s/, whereas dissolved nitrous oxide produced an increase in G/sub s/. The useful life of cellulose acetate reverse osmosis membranes exposed to γ radiation was estimated by observations of the water permeation rate during irradiation. Membrane breakdown occurred at 15 Mrad in pure water, but the dose to breakdown was extended to 83 Mrad in the presence of 4% methanol. 3 figures, 1 table

  19. Thermogravimetric analysis of the behavior of sub-bituminous coal and cellulosic ethanol residue during co-combustion.

    Science.gov (United States)

    Buratti, C; Barbanera, M; Bartocci, P; Fantozzi, F

    2015-06-01

    The influence of the addition of cellulosic ethanol residue (CER) on the combustion of Indonesian sub-bituminous coal was analyzed by non isothermal thermo-gravimetric analysis (TGA). The effect of blends ratio (5%, 10%, 15% and 20%), interaction mechanism, and heating rate (5°C/min, 10°C/min, 15°C/min, 20°C/min) on the combustion process was studied. The results show that the increase of the blending ratio allows to achieve the increase of the combustibility index from 7.49E-08 to 5.26E-07 at the blending ratio of 20%. Two types of non-isothermal kinetic analysis methods (Ozawa-Flynn-Wall and Vyazovkin) were also applied. Results indicate that the activation energy of the blends decreases with increasing the conversion rate. In particular, the blending ratio of 20% confirms to have the better combustion performance, with the average value of the activation energy equal to 41.10 kJ/mol obtained by Ozawa-Flynn-Wall model and 31.17 kJ/mol obtained by Vyazovkin model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Optimization of Deacetylation Process for Regenerated Cellulose Hollow Fiber Membranes

    Directory of Open Access Journals (Sweden)

    Xuezhong He

    2017-01-01

    Full Text Available Cellulose acetate (CA hollow fibers were spun from a CA+ Polyvinylpyrrolidone (PVP/N-methyl-2-pyrrolidone (NMP/H2O dope solution and regenerated by deacetylation. The complete deacetylation time of 0.5 h was found at a high concentration (0.2 M NaOH ethanol (96% solution. The reaction rate of deacetylation with 0.5 M NaOH was faster in a 50% ethanol compared to a 96 vol.% ethanol. The hydrogen bond between CA and tertiary amide group of PVP was confirmed. The deacetylation parameters of NaOH concentration, reaction time, swelling time, and solution were investigated by orthogonal experimental design (OED method. The degree of cross-linking, the residual acetyl content, and the PVP content in the deacetylated membranes were determined by FTIR analysis. The conjoint analysis in the Statistical Product and Service Solutions (SPSS software was used to analyze the OED results, and the importance of the deacetylation parameters was sorted as Solution > Swelling time > Reaction time > Concentration. The optimal deacetylation condition of 96 vol.% ethanol solution, swelling time 24 h, the concentration of NaOH (0.075 M, and the reaction time (2 h were identified. The regenerated cellulose hollow fibers under the optimal deacetylation condition can be further used as precursors for preparation of hollow fiber carbon membranes.

  1. Ethanol Production from Brewers’ Spent Grain Pretreated by Dilute Phosphoric Acid

    DEFF Research Database (Denmark)

    Rojas-Chamorro, José A.; Cara, Cristóbal; Romero, Inmaculada

    2018-01-01

    of both pretreatment and enzymatic hydrolysis together recovered 92% of total sugars in BSG, mainly solubilized in the prehydrolysate (63%). Escherichia coli SL100 fermented this mixed sugar solution containing hemicellulosic sugars and starchy glucose without previous detoxification with an ethanol yield...... in this work allowed 69% of the total sugars in the BSG to be converted to ethanol....... of 0.40 g/g. Considering also the glucose released from the cellulosic structure and converted to ethanol by a simultaneous saccharification and fermentation process, an overall ethanol yield of 17.9 g of ethanol per 100 g of raw BSG was achieved. Thereby, the process configuration proposed...

  2. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K [Idaho National Laboratory; Jacobson, Jacob Jordan [Idaho National Laboratory; Cafferty, Kara Grace [Idaho National Laboratory; Lamers, Patrick [Idaho National Laboratory; Roni, MD S [Idaho National Laboratory

    2015-03-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  3. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K.; Jacobson, Jacob J.; Cafferty, Kara G.; Lamers, Patrick; Roni, Mohammad S.

    2015-07-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  4. Biohydrogen, bioelectricity and bioalcohols from cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nissila, M.

    2013-03-01

    The demand for renewable energy is increasing due to increasing energy demand and global warming associated with increasing use of fossil fuels. Renewable energy can be derived from biological production of energy carriers from cellulosic biomass. These biochemical processes include biomass fermentation to hydrogen, methane and alcohols, and bioelectricity production in microbial fuel cells (MFCs). The objective of this study was to investigate the production of different energy carriers (hydrogen, methane, ethanol, butanol, bioelectricity) through biochemical processes. Hydrogen production potential of a hot spring enrichment culture from different sugars was determined, and hydrogen was produced continuously from xylose. Cellulolytic and hydrogenic cultures were enriched on cellulose, cellulosic pulp materials, and on silage at different process conditions. The enrichment cultures were further characterized. The effect of acid pretreatment on hydrogen production from pulp materials was studied and compared to direct pulp fermentation to hydrogen. Electricity and alcohol(s) were simultaneously produced from xylose in MFCs and the exoelectrogenic and alcohologenic enrichment cultures were characterized. In the end, the energy yields obtained from different biochemical processes were determined and compared. In this study, cultures carrying out simultaneous cellulose hydrolysis and hydrogen fermentation were enriched from different sources at different operational conditions. These cultures were successfully utilized for cellulose to hydrogen fermentation in batch systems. Based on these results further research should be conducted on continuous hydrogen production from cellulosic materials.

  5. Development of efficient, integrated cellulosic biorefineries : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Kwee-Yan; Hecht, Ethan S.; Shaddix, Christopher R.; Buffleben, George M.; Dibble, Dean C.; Lutz, Andrew E.

    2010-09-01

    Cellulosic ethanol, generated from lignocellulosic biomass sources such as grasses and trees, is a promising alternative to conventional starch- and sugar-based ethanol production in terms of potential production quantities, CO{sub 2} impact, and economic competitiveness. In addition, cellulosic ethanol can be generated (at least in principle) without competing with food production. However, approximately 1/3 of the lignocellulosic biomass material (including all of the lignin) cannot be converted to ethanol through biochemical means and must be extracted at some point in the biochemical process. In this project we gathered basic information on the prospects for utilizing this lignin residue material in thermochemical conversion processes to improve the overall energy efficiency or liquid fuel production capacity of cellulosic biorefineries. Two existing pretreatment approaches, soaking in aqueous ammonia (SAA) and the Arkenol (strong sulfuric acid) process, were implemented at Sandia and used to generated suitable quantities of residue material from corn stover and eucalyptus feedstocks for subsequent thermochemical research. A third, novel technique, using ionic liquids (IL) was investigated by Sandia researchers at the Joint Bioenergy Institute (JBEI), but was not successful in isolating sufficient lignin residue. Additional residue material for thermochemical research was supplied from the dilute-acid simultaneous saccharification/fermentation (SSF) pilot-scale process at the National Renewable Energy Laboratory (NREL). The high-temperature volatiles yields of the different residues were measured, as were the char combustion reactivities. The residue chars showed slightly lower reactivity than raw biomass char, except for the SSF residue, which had substantially lower reactivity. Exergy analysis was applied to the NREL standard process design model for thermochemical ethanol production and from a prototypical dedicated biochemical process, with process data

  6. Production of Ethanol from Sugars and Lignocellulosic Biomass by Thermoanaerobacter J1 Isolated from a Hot Spring in Iceland

    Directory of Open Access Journals (Sweden)

    Jan Eric Jessen

    2012-01-01

    Full Text Available Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production by Thermoanaerobacter strain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined. The strain showed a broad substrate spectrum, and high ethanol yields were observed on glucose (1.70 mol/mol and xylose (1.25 mol/mol. Ethanol yields were, however, dramatically lowered by adding thiosulfate or by cocultivating strain J1 with a hydrogenotrophic methanogen with acetate becoming the major end product. Ethanol production from 4.5 g/L of lignocellulosic biomass hydrolysates (grass, hemp stem, wheat straw, newspaper, and cellulose pretreated with acid or alkali and the enzymes Celluclast and Novozymes 188 was investigated. The highest ethanol yields were obtained on cellulose (7.5 mM·g−1 but the lowest on straw (0.8 mM·g−1. Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The largest increase was on straw hydrolysates where ethanol production increased from 0.8 mM·g−1 to 3.3 mM·g−1 using alkali-pretreated biomass. The highest ethanol yields on lignocellulosic hydrolysates were observed with hemp hydrolysates pretreated with acid, 4.2 mM·g−1.

  7. Preliminary studies on 1-vinyl-2-pyrrolidone grafting onto cellulose by pre-irradiation method

    Energy Technology Data Exchange (ETDEWEB)

    Severich, Patrick; Dutra, Rodrigo da Costa; Kodama, Yasko, E-mail: ykodama@ipen.br, E-mail: patrick.severich@ipen.br, E-mail: rodrigo.dutra@ipen.br [Instituto de Pesquisas Energética s e Nucleares (IPEN-CNEN/SP), São Paulo, SP (Brazil)

    2017-07-01

    Cellulose is considered a renewable biopolymer most abundant in nature. Better functional surfaces can be Obtained by modifying cellulose. On the other hand, poly vinyl pyrrolidone, PVP, is a synthetic nontoxic, water-soluble polymer frequently used in an extensive variety of applications including several pharmaceutical applications. Grafting 1-vinyl-2-pyrrolidone, NVP, onto polymeric cellulose can be obtained by ionizing radiation. Ionizing radiation grafting can be affected by several factors as environment, solvent, monomer concentration, temperature of graft reaction. Grafting by ionizing radiation can be performed by three methods, pre-irradiation, oxidation by peroxide and simultaneous irradiation. In this study, it was used pre-irradiation method of cellulose. Paper filter without ash, NVP without purification was used in this study. Paper samples were exposed to electron beam from Dynamitron Accelerator with radiation absorbed dose of 25 kGy. Influence of NVP concentration, temperature of reaction after irradiation on degree of grafting (DG) was studied. Also, cellulose radicals of grafted paper samples was studied by electron paramagnetic resonance using a Bruker X-band ESR at room temperature just after heating reaction. Small decrease of cellulose radicals was observed with increasing reaction temperature. It was observed DG small increase with increasing concentration of monomer in solution of water ethanol 50-50 v:v and rising temperature of reaction. Further tests using simultaneous method of grafting of NVP in cellulose paper, in water:ethanol 75:25 v:v solution, induced by gamma irradiation were performed. It was observed homopolymerization forming PVP with increasing monomer concentration. (author)

  8. Preliminary studies on 1-vinyl-2-pyrrolidone grafting onto cellulose by pre-irradiation method

    International Nuclear Information System (INIS)

    Severich, Patrick; Dutra, Rodrigo da Costa; Kodama, Yasko

    2017-01-01

    Cellulose is considered a renewable biopolymer most abundant in nature. Better functional surfaces can be Obtained by modifying cellulose. On the other hand, poly vinyl pyrrolidone, PVP, is a synthetic nontoxic, water-soluble polymer frequently used in an extensive variety of applications including several pharmaceutical applications. Grafting 1-vinyl-2-pyrrolidone, NVP, onto polymeric cellulose can be obtained by ionizing radiation. Ionizing radiation grafting can be affected by several factors as environment, solvent, monomer concentration, temperature of graft reaction. Grafting by ionizing radiation can be performed by three methods, pre-irradiation, oxidation by peroxide and simultaneous irradiation. In this study, it was used pre-irradiation method of cellulose. Paper filter without ash, NVP without purification was used in this study. Paper samples were exposed to electron beam from Dynamitron Accelerator with radiation absorbed dose of 25 kGy. Influence of NVP concentration, temperature of reaction after irradiation on degree of grafting (DG) was studied. Also, cellulose radicals of grafted paper samples was studied by electron paramagnetic resonance using a Bruker X-band ESR at room temperature just after heating reaction. Small decrease of cellulose radicals was observed with increasing reaction temperature. It was observed DG small increase with increasing concentration of monomer in solution of water ethanol 50-50 v:v and rising temperature of reaction. Further tests using simultaneous method of grafting of NVP in cellulose paper, in water:ethanol 75:25 v:v solution, induced by gamma irradiation were performed. It was observed homopolymerization forming PVP with increasing monomer concentration. (author)

  9. Ethanol production from rape straw: Part of an oilseed rape biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Arvaniti, E.

    2010-12-15

    Agricultural residues from rapeseed biodiesel industry (rapeseed cake, rape straw, crude glycerol), which represent the 82%wt. of the oilseed rape, currently have only low-grade applications in the market. For this, a scenario was built on exploiting qualities of rapeseed biodiesel residues for forming added-value products, and expanding and upgrading an existing biodiesel plant, to an oilseed rape biorefinery by 2020 in European ground. Selection of products was based on a technological feasibility study given the time frame, while priority was given to Low-Value-High-Volume readily marketed products, like production of energy and feed. Products selected except rapeseed biodiesel, were ethanol, biogas, enzymes energy, chemical building blocks, and superior quality animal fodder. The production lines were analyzed and prospects for 2020 were projected on a critical basis. Particular merit was given to two products, ethanol from cellulose, and cellulolytic enzymes from rape straw. Cellulosic ethanol from rape straw was optimized for all production steps, i.e. for thermo-chemical pretreatment, enzyme hydrolysis, and fermentation of C6 sugars. Thermo-chemical pretreatment was studied with Wet oxidation technique at different conditions of temperature, reaction time, and oxygen pressure, but also factors like pre-soaking straw in warm water, or recycling liquid were also studied. Wet oxidation has been extensively tested in the past for different substrates, and gives promising results with indicators that are important for cellulosic ethanol production; C6 sugars recovery, high digestibility for enzymes, and limited formed degradation products. Here, optimal pretreatment conditions for rape straw were first presoaking rape straw at 80 deg. C for 20 minutes, and then wet-oxidize with 12 bar of oxygen at 205 deg. C for 3 minutes. Recovery of cellulose and hemicellulose under these conditions was 105% and 106% respectively, while recovery of lignin was 86%. When this

  10. Ethanol production from rape straw: Part of an oilseed rape biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Arvaniti, E

    2010-12-15

    Agricultural residues from rapeseed biodiesel industry (rapeseed cake, rape straw, crude glycerol), which represent the 82%wt. of the oilseed rape, currently have only low-grade applications in the market. For this, a scenario was built on exploiting qualities of rapeseed biodiesel residues for forming added-value products, and expanding and upgrading an existing biodiesel plant, to an oilseed rape biorefinery by 2020 in European ground. Selection of products was based on a technological feasibility study given the time frame, while priority was given to Low-Value-High-Volume readily marketed products, like production of energy and feed. Products selected except rapeseed biodiesel, were ethanol, biogas, enzymes energy, chemical building blocks, and superior quality animal fodder. The production lines were analyzed and prospects for 2020 were projected on a critical basis. Particular merit was given to two products, ethanol from cellulose, and cellulolytic enzymes from rape straw. Cellulosic ethanol from rape straw was optimized for all production steps, i.e. for thermo-chemical pretreatment, enzyme hydrolysis, and fermentation of C6 sugars. Thermo-chemical pretreatment was studied with Wet oxidation technique at different conditions of temperature, reaction time, and oxygen pressure, but also factors like pre-soaking straw in warm water, or recycling liquid were also studied. Wet oxidation has been extensively tested in the past for different substrates, and gives promising results with indicators that are important for cellulosic ethanol production; C6 sugars recovery, high digestibility for enzymes, and limited formed degradation products. Here, optimal pretreatment conditions for rape straw were first presoaking rape straw at 80 deg. C for 20 minutes, and then wet-oxidize with 12 bar of oxygen at 205 deg. C for 3 minutes. Recovery of cellulose and hemicellulose under these conditions was 105% and 106% respectively, while recovery of lignin was 86%. When this

  11. Lignocellulosic ethanol production by starch-base industrial yeast under PEG detoxification

    Science.gov (United States)

    Liu, Xiumei; Xu, Wenjuan; Mao, Liaoyuan; Zhang, Chao; Yan, Peifang; Xu, Zhanwei; Zhang, Z. Conrad

    2016-02-01

    Cellulosic ethanol production from lignocellulosic biomass offers a sustainable solution for transition from fossil based fuels to renewable alternatives. However, a few long-standing technical challenges remain to be addressed in the development of an economically viable fermentation process from lignocellulose. Such challenges include the needs to improve yeast tolerance to toxic inhibitory compounds and to achieve high fermentation efficiency with minimum detoxification steps after a simple biomass pretreatment. Here we report an in-situ detoxification strategy by PEG exo-protection of an industrial dry yeast (starch-base). The exo-protected yeast cells displayed remarkably boosted vitality with high tolerance to toxic inhibitory compounds, and with largely improved ethanol productivity from crude hydrolysate derived from a pretreated lignocellulose. The PEG chemical exo-protection makes the industrial S. cerevisiae yeast directly applicable for the production of cellulosic ethanol with substantially improved productivity and yield, without of the need to use genetically modified microorganisms.

  12. Process for producing ethanol from plant biomass using the fungus Paecilomyces sp

    Science.gov (United States)

    Wu, J.F.

    1985-08-08

    A process for producing ethanol from plant biomass is disclosed. The process includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the fungus Paecilomyces which has the ability to ferment both cellobiose and xylose to ethanol is then selected and isolated. The substrate is inoculated with this fungus, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. Finally, ethanol is recovered from the fermented substrate. 5 figs., 3 tabs.

  13. Kinetic modeling and dynamic analysis of simultaneous saccharification and fermentation of cellulose to bioethanol

    International Nuclear Information System (INIS)

    Shadbahr, Jalil; Khan, Faisal; Zhang, Yan

    2017-01-01

    Highlights: • Deeper understanding of saccharification and fermentation process. • A new kinetic model for dynamic analysis of the simultaneous saccharification and fermentation. • Testing and validation of kinetic model. - Abstract: Kinetic modeling and dynamic analysis of the simultaneous saccharification and fermentation (SSF) of cellulose to ethanol was carried out in this study to determine the key reaction kinetics parameters and product inhibition features of the process. To obtain the more reliable kinetic parameters which can be applied for a wide range of operating conditions, batch SSF experiments were carried out at three enzyme loadings (10, 15 and 20 FPU/g cellulose) and two levels of initial concentrations of fermentable sugars (glucose and mannose). Results indicated that the maximum ethanol yield and concentration were achieved at high level of sugar concentrations with intermediate enzyme loading (15 FPU/g cellulose). Dynamic analysis of the acquired experimental results revealed that cellulase inhibition by cellobiose plays the most important role at high level of enzyme loading and low level of initial sugar concentrations. The inhibition of glucose becomes significant when high concentrations of sugars were present in the feedstock. Experimental results of SSF process also reveal that an efficient mixing between the phases helps to improve the ethanol yield significantly.

  14. Ionizing Radiation Conversion of Lignocellulosic Biomass from Sugarcane Bagasse to Production Ethanol Biofuel

    International Nuclear Information System (INIS)

    Duarte, C.L.; Mori, M.N.; Oikawa, H.; Finguerut, J.; Galvão, A.; Nagatomi, H.R.; Célia, M.

    2010-01-01

    Sugarcane bagasse has been considered as a substrate for single cell protein, animal feed, and renewable energy production. Sugarcane bagasse generally contain up to 45% glucose polymer cellulose, 40% hemicelluloses, and 20% lignin. Pure cellulose is readily depolymerised by radiation, but in biomass, the cellulose is intimately bonded with lignin, that protect it from radiation effects. The objective of this study is the evaluation of the electron beam irradiation as a pre-treatment to enzymatic hydrolysis of cellulose in order to facilitate its fermentation and improves the production of ethanol biofuel. Samples of sugarcane bagasse were obtained in sugar/ethanol Iracema Mill sited in Piracicaba, Brazil, and were irradiated using Radiation Dynamics Electron Beam Accelerator with 1.5 MeV energy and 37kW, in batch systems. The applied absorbed doses of the fist sampling, Bagasse A, were 20 kGy, 50 kGy, 100 kGy and 200 kGy. After the evaluation the preliminary obtained results, it was applied lower absorbed doses in the second assay: 5 kGy, 10 kGy, 20 kGy, 30 kGy, 50 kGy, 70 kGy, 100 kGy and 150 kGy. The electron beam processing took to changes in the sugarcane bagasse structure and composition, lignin and cellulose cleavage. The yield of enzymatic hydrolyzes of cellulose increase about 75 % with 30 kGy of absorbed dose. (author)

  15. Ethanol production from banana peels using statistically optimized simultaneous saccharification and fermentation process.

    Science.gov (United States)

    Oberoi, Harinder Singh; Vadlani, Praveen V; Saida, Lavudi; Bansal, Sunil; Hughes, Joshua D

    2011-07-01

    Dried and ground banana peel biomass (BP) after hydrothermal sterilization pretreatment was used for ethanol production using simultaneous saccharification and fermentation (SSF). Central composite design (CCD) was used to optimize concentrations of cellulase and pectinase, temperature and time for ethanol production from BP using SSF. Analysis of variance showed a high coefficient of determination (R(2)) value of 0.92 for ethanol production. On the basis of model graphs and numerical optimization, the validation was done in a laboratory batch fermenter with cellulase, pectinase, temperature and time of nine cellulase filter paper unit/gram cellulose (FPU/g-cellulose), 72 international units/gram pectin (IU/g-pectin), 37 °C and 15 h, respectively. The experiment using optimized parameters in batch fermenter not only resulted in higher ethanol concentration than the one predicted by the model equation, but also saved fermentation time. This study demonstrated that both hydrothermal pretreatment and SSF could be successfully carried out in a single vessel, and use of optimized process parameters helped achieve significant ethanol productivity, indicating commercial potential for the process. To the best of our knowledge, ethanol concentration and ethanol productivity of 28.2 g/l and 2.3 g/l/h, respectively from banana peels have not been reported to date. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Feasibility of reusing the black liquor for enzymatic hydrolysis and ethanol fermentation.

    Science.gov (United States)

    Wang, Wen; Chen, Xiaoyan; Tan, Xuesong; Wang, Qiong; Liu, Yunyun; He, Minchao; Yu, Qiang; Qi, Wei; Luo, Yu; Zhuang, Xinshu; Yuan, Zhenhong

    2017-03-01

    The black liquor (BL) generated in the alkaline pretreatment process is usually thought as the environmental pollutant. This study found that the pure alkaline lignin hardly inhibited the enzymatic hydrolysis of cellulose (EHC), which led to the investigation on the feasibility of reusing BL as the buffer via pH adjustment for the subsequent enzymatic hydrolysis and fermentation. The pH value of BL was adjusted from 13.23 to 4.80 with acetic acid, and the alkaline lignin was partially precipitated. It deposited on the surface of cellulose and negatively influenced the EHC via blocking the access of cellulase to cellulose and adsorbing cellulase. The supernatant separated from the acidified BL scarcely affected the EHC, but inhibited the ethanol fermentation. The 4-times diluted supernatant and the last-time waste wash water of the alkali-treated sugarcane bagasse didn't inhibit the EHC and ethanol production. This work gives a clue of saving water for alkaline pretreatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. North America markets for alcohol and alcohol-derived motor fuels and need for tax incentives

    International Nuclear Information System (INIS)

    Haigwood, B.

    1991-01-01

    The U.S. fuel alcohol and ether industry has grown from its infancy in 1979 to approximately 2.9 billion gallons of production capacity in 1991. With the emphasis on clean air, the uncertainties in the Middle East, and fluctuating oil prices, IRI believes the demand for alcohol-derived motor fuels is poised to begin a second phase of expansion. Historically, the two primary alcohol-derived motor fuels sold in the U.S. have been methyl tertiary butyl ether (MTBE) and ethanol. There is also a limited but growing use of methanol as 85% blendstock for gasoline. Since 1978, fuel ethanol has provided the U.S. petroleum industry with an additional source of supply, octane, and profit. Its price was based on the price of wholesale gasoline plus available federal and state tax incentives. These incentives allowed ethanol, with production costs of $1.00 to $1.25 per gallon, to compete with gasoline at prices of 40 to 65 per gallon. Without the federal and state tax incentives, it would not be economically feasible to sell or manufacture fuel ethanol. On the other hand, the largest consumption of methanol has been as a feedstock for the production of MTBE, the world's fastest growing chemical over the past seven years. MTBE prices are based on the cost of raising the octane level of gasoline, and this commodity does not receive subsidies. Beginning in 1992, IRI predicts the price relationship between ethanol, MTBE, and gasoline will change as U.S. refiners and marketers are required to include oxygenated fuels (alcohol-derived) in their gasoline. In total, over 60 billion gallons of gasoline will need to be reformulated by the year 2000. The increased demand for oxygen will result in a 2.5-billion gallon deficit of MTBE and 1.2-billion gallon deficit of ethanol by the year 2000. 2 tabs

  18. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, December 1, 1978-February 28, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.I.C.; Cooney, C.L.; Demain, A.L.; Gomez, R.F.; Sinskey, A.J.

    1979-02-01

    The ongoing progress of a coordinated research program aimed at optimizing the biodegradation of cellulosic biomass to ethanol and chemical feedstocks is summarized. Growth requirements and genetic manipulations of clostridium thermocellum for selection of high cellulose producers are reported. The enzymatic activity of the cellulase produced by these organisms was studied. The soluble sugars produced from hydrolysis were analyzed. Increasing the tolerance of C. thermocellum to ethanol during liquid fuel production, increasing the rate of product formation, and directing the catabolism to selectively achieve high ethanol concentrations with respect to other products were studied. Alternative substrates for C. thermocellum were evaluated. Studies on the utilization of xylose were performed. Single stage fermentation of cellulose using mixed cultures of C. thermocellum and C. thermosaccharolyticum were studied. The study of the production of chemical feedstocks focused on acrylic acid, acetone/butanol, acetic acid, and lactic acid.

  19. High polymorphism in Est-SSR loci for cellulose synthase and β-amylase of sugarcane varieties (Saccharum spp.) used by the industrial sector for ethanol production.

    Science.gov (United States)

    Augusto, Raphael; Maranho, Rone Charles; Mangolin, Claudete Aparecida; Pires da Silva Machado, Maria de Fátima

    2015-01-01

    High and low polymorphisms in simple sequence repeats of expressed sequence tag (EST-SSR) for specific proteins and enzymes, such as β-amylase, cellulose synthase, xyloglucan endotransglucosylase, fructose 1,6-bisphosphate aldolase, and fructose 1,6-bisphosphatase, were used to illustrate the genetic divergence within and between varieties of sugarcane (Saccharum spp.) and to guide the technological paths to optimize ethanol production from lignocellulose biomass. The varieties RB72454, RB867515, RB92579, and SP813250 on the second stage of cutting, all grown in the state of Paraná (PR), and the varieties RB92579 and SP813250 cultured in the PR state and in Northeastern Brazil, state of Pernambuco (PE), were analyzed using five EST-SSR primers for EstC66, EstC67, EstC68, EstC69, and EstC91 loci. Genetic divergence was evident in the EstC67 and EstC69 loci for β-amylase and cellulose synthase, respectively, among the four sugarcane varieties. An extremely high level of genetic differentiation was also detected in the EstC67 locus from the RB82579 and SP813250 varieties cultured in the PR and PE states. High polymorphism in SSR of the cellulose synthase locus may explain the high variability of substrates used in pretreatment and enzymatic hydrolysis processes, which has been an obstacle to effective industrial adaptations.

  20. Effect of various carbon and nitrogen sources on cellulose synthesis ...

    African Journals Online (AJOL)

    The effect of various carbon and nitrogen sources on cellulose production by Acetobacter lovaniensis HBB5 was examined. In this study, glucose, fructose, sucrose and ethanol as carbon source and yeast extract, casein hydrolysate and ammonium sulphate as nitrogen source were used. Among the carbon sources, ...

  1. Clostridium thermocellum ATCC27405 transcriptomic, metabolomic and proteomic profiles after ethanol stress

    Directory of Open Access Journals (Sweden)

    Yang Shihui

    2012-07-01

    Full Text Available Abstract Background Clostridium thermocellum is a candidate consolidated bioprocessing biocatalyst, which is a microorganism that expresses enzymes for both cellulose hydrolysis and its fermentation to produce fuels such as lignocellulosic ethanol. However, C. thermocellum is relatively sensitive to ethanol compared to ethanologenic microorganisms such as yeast and Zymomonas mobilis that are used in industrial fermentations but do not possess native enzymes for industrial cellulose hydrolysis. Results In this study, C. thermocellum was grown to mid-exponential phase and then treated with ethanol to a final concentration of 3.9 g/L to investigate its physiological and regulatory responses to ethanol stress. Samples were taken pre-shock and 2, 12, 30, 60, 120, and 240 min post-shock, and from untreated control fermentations for systems biology analyses. Cell growth was arrested by ethanol supplementation with intracellular accumulation of carbon sources such as cellobiose, and sugar phosphates, including fructose-6-phosphate and glucose-6-phosphate. The largest response of C. thermocellum to ethanol shock treatment was in genes and proteins related to nitrogen uptake and metabolism, which is likely important for redirecting the cells physiology to overcome inhibition and allow growth to resume. Conclusion This study suggests possible avenues for metabolic engineering and provides comprehensive, integrated systems biology datasets that will be useful for future metabolic modeling and strain development endeavors.

  2. Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, R.E.; Bellamy, W.D.; Su, T.M.

    1978-03-23

    The objective of this research is to demonstrate on a laboratory scale the technical feasibility of the direct microbial conversion of pretreated wood to ethanol. During the first year of this contract, we investigated the feasibility of biologically delignifying wood with C. pruinosum and directly fermenting the pretreated wood to ethanol with a mixed culture. Bench-top fermentations of a thermophilic bacillus growing on glucose and of a mixed culture of thermophilic sporocytophaga (US) and a thermophilic bacillus growing on microcrystalline and amorphous cellulose were evaluated for growth and ethanol production. In the mixed culture fermentation of amorphous and microcrystalline cellulose, the specific rate of substrate depletion was calculated to be 0.087 hr/sup -1/ and 0.0346 hr/sup -1/, respectively. However, defining the growth requirements of C. pruinosum and sporocytophaga (US) proved more difficult than originally anticipated. In order to achieve the program objectives within the contract period, a revised research plan was developed based upon chemical pretreatment and the direct fermentation of pretreated hardwood to ethanol. In place of the biological delignification pretreatment step, we have substituted a chemically supplemented steam pretreatment step to partially delignify wood and to enhance its accessibility to microbial utilization. Clostridium thermocellum, which ferments cellulose directly to ethanol and acetic acid, has replaced the mixed culture fermentation stage for ethanol production. Research on the production of ethanol from xylose by the thermophilic bacillus ZB-B2 is retained as one means of utilizing the hemicellulose fraction of hardwood. Work on the genetic improvement of the ethanol yields of both cultures by suppressing acetic acid production is also retained. The rationale, experimental approach, and economic considerations of this revised research plan are also presented.

  3. TECHNOLOGICAL ADVANCES IN THE OBTAINING OF ETHANOL FROM Sweet sorghum (Sorghum bicolor (L. Moench

    Directory of Open Access Journals (Sweden)

    Sandro Pedroso Cunha

    2010-11-01

    Full Text Available ABSTRACT: Replacing the use of gasoline with ethanol in vehicles reduces by 90% CO2 emissions, this justifies the interest in the use of bioethanol as renewable energy. Besides sugar cane, cassava, maize and sugar beet special emphasis is being given to sorghum (Sorghum bicolor L. Moench to produce ethanol for its productivity and resistance. The sorghum is grown in Rio Grande do Sul with a production of about 70,000 tons / year. Embrapa has a program to develop cultivars of sorghum from the time the Pro-Alcohol and currently 25 new varieties of sorghum are being evaluated. Several factors are relevant in the optimization of production such as increased productivity and reduced costs in the production of ethanol. This study aimed to survey recent data that will assess production parameters of ethanol from sorghum. Factors such as reducing the risk of bacterial contamination, the means conducive to fermentation processes or grain sorghum stalk through the use of pretreatment of the sample, have been of great importance because it is basically turning cellulosic biomass into fermentable sugars. Superior genotypes of sweet sorghum for ethanol production are of utmost importance, as well as better ways to convert sugars into ethanol. Lignin, toxic against microorganisms, prevents the conversion of lignocellulose into ethanol. The conversion of lignocellulosic ethanol compounds based on the hydrolysis of cellulose producing simple sugars and fermenting those sugars into ethanol through microbiology.

  4. Bioconversion of different sizes of microcrystalline cellulose pretreated by microwave irradiation with/without NaOH

    International Nuclear Information System (INIS)

    Peng, Huadong; Chen, Hongzhang; Qu, Yongshui; Li, Hongqiang; Xu, Jian

    2014-01-01

    Highlights: • High concentration of alkali or temperature was necessary in cellulose degradation. • Effects of alkali pretreatment could be enhanced with the addition of microwave irradiation. • The structures diversities of microcrystalline cellulose were eliminated in the fermentation. • The significance of particle size and treat condition varied with reaction time. - Abstract: The process of microwave irradiation (MWI) pretreatment on microcrystalline cellulose (MCC) with different sizes with/without NaOH was investigated on the variation of the ratio of degradated solid residue (R DS ), particle size, crystallinity index (CrI), crystallite size (Sc) and specific surface area (SSA). High concentration of alkali or high temperature was necessary in dissolving or decomposing the cellulose. Appropriate pretreatment severity eliminated the effects of structural diversities in feedstocks, which led to convergence in the ethanol fermentation. After the reaction proceeded to 120 h, the samples could be converted to glucose completely and the highest ethanol yield of the theoretical was 58.91% for all the samples pretreated by the combined treatment of MWI and NaOH. In addition, the statistical analysis implied that when reaction time got to 24 h, particle size and pretreatment condition affected much more significant than other factors

  5. Use of ethanol in public urban transport: BEST (BioEthanol for Sustainable Transport) Project; Uso de etanol no transporte publico urbano: projeto BEST (Bio Ethanol para o Transporte Sustentavel)

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Jose Roberto; Apolinario, Sandra; Pecora, Vanessa [Universidade de Sao Paulo (CENBIO/USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Centro Nacional de Referencia em Biomassa; Velazquez, Silvia [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil)

    2008-07-01

    This paper present the BEST project - Bio Ethanol for Sustainable Transport, that aims to promote the ethanol usage, replacing diesel, in the urban public transport in Brazil and worldwide. Apart from Sao Paulo, leading city in the Americas, another eight cities located in Europe and Asia takes part in the project. One of the Brazilian project's goals is to evaluate ethanol usage as diesel fuel replacement in public transport buses by comparatively following the operational output of the experimental fleet, taking as reference an equivalent diesel bus. The utilized test vehicles will be evaluated and monitored to demonstrate ethanol energetic efficiency and, after the results the BEST project and the European Union will set a blue print for public policies to incentive ethanol usage in the urban public transport. The results will allow identifying technical and economical barriers that will eventually overlap the viability process of this technology in the Brazilian public transport. (author)

  6. Use of ethanol in public urban transport: BEST (BioEthanol for Sustainable Transport) Project; Uso de etanol no transporte publico urbano: projeto BEST (Bio Ethanol para o Transporte Sustentavel)

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Jose Roberto; Apolinario, Sandra; Pecora, Vanessa [Universidade de Sao Paulo (CENBIO/USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Centro Nacional de Referencia em Biomassa; Velazquez, Silvia [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil)

    2008-07-01

    This paper present the BEST project - Bio Ethanol for Sustainable Transport, that aims to promote the ethanol usage, replacing diesel, in the urban public transport in Brazil and worldwide. Apart from Sao Paulo, leading city in the Americas, another eight cities located in Europe and Asia takes part in the project. One of the Brazilian project's goals is to evaluate ethanol usage as diesel fuel replacement in public transport buses by comparatively following the operational output of the experimental fleet, taking as reference an equivalent diesel bus. The utilized test vehicles will be evaluated and monitored to demonstrate ethanol energetic efficiency and, after the results the BEST project and the European Union will set a blue print for public policies to incentive ethanol usage in the urban public transport. The results will allow identifying technical and economical barriers that will eventually overlap the viability process of this technology in the Brazilian public transport. (author)

  7. Improvement of the enzymatic hydrolysis of furfural residues by pretreatment with combined green liquor and ethanol organosolv.

    Science.gov (United States)

    Yu, Hailong; Xing, Yang; Lei, Fuhou; Liu, Zhiping; Liu, Zuguang; Jiang, Jianxin

    2014-09-01

    Furfural residues (FRs) were pretreated with ethanol and a green liquor (GL) catalyst to produce fermentable sugar. Anthraquinone (AQ) was used as an auxiliary reagent to improve delignification and reduce cellulose decomposition. The results showed that 42.7% of lignin was removed and 96.5% of cellulose was recovered from substrates pretreated with 1.0 mL GL/g of dry substrate and 0.4% (w/w) AQ at 140°C for 1h. Compared with raw material, ethanol-GL pretreatment of FRs increased the glucose yield from 69.0% to 85.9% after 96 h hydrolysis with 18 FPU/g-cellulose for cellulase, 27 CBU/g-cellulose for β-glucosidase. The Brauner-Emmett-Teller surface area was reduced during pretreatment, which did not inhibit the enzymatic hydrolysis. Owing to the reduced surface area, the unproductive binding of cellulase to lignin was decreased, thus improving the enzymatic hydrolysis. The degree of polymerization of cellulose from FRs was too low to be a key factor for improving enzymatic hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Evaluation of Potential Fungal Species for the in situ Simultaneous Saccharification and Fermentation (SSF of Cellulosic Material

    Directory of Open Access Journals (Sweden)

    Leeuwen, J.

    2011-01-01

    Full Text Available Three fungal species were evaluated for their abilities to saccharify pure cellulose. The three species chosen represented three major wood-rot molds; brown rot (Gloeophyllum trabeum, white rot (Phanerochaete chrysosporium and soft rot (Trichoderma reesei. After solid state fermentation of the fungi on the filter paper for four days, the saccharified cellulose was then fermented to ethanol by using Saccharomyces cerevisiae. The efficiency of the fungal species in saccharifying the filter paper was compared against a low dose (25 FPU/g cellulose of a commercial cellulase. Total sugar, cellobiose and glucose were monitored during the fermentation period, along with ethanol, acetic acid and lactic acid. Results indicated that the most efficient fungal species in saccharifying the filter paper was T. reesei with 5.13 g/100 g filter paper of ethanol being produced at days 5, followed by P. chrysosporium at 1.79 g/100 g filter paper. No ethanol was detected for the filter paper treated with G. trabeum throughout the five day fermentation stage. Acetic acid was only produced in the sample treated with T. reesei and the commercial enzyme, with concentration 0.95 and 2.57 g/100 g filter paper, respectively at day 5. Lactic acid production was not detected for all the fungal treated filter paper after day 5. Our study indicated that there is potential in utilizing in situ enzymatic saccharification of biomass by using T. reesei and P. chrysosporium that may lead to an economical simultaneous saccharification and fermentation process for the production of fuel ethanol.

  9. Potential of giant reed (Arundo donax L. for second generation ethanol production

    Directory of Open Access Journals (Sweden)

    Claudia Fernanda Lemons e Silva

    2015-01-01

    Conclusions: The fermentability of the pretreated biomass was performed successfully through the conception of simultaneous saccharification and fermentation resulting in approximately 75 L of ethanol per ton of cellulose.

  10. Anhydrous ethanol: A renewable source of energy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Santosh; Singh, Neetu; Prasad, Ram [Department of Chemical Engineering, H. B. Technological Institute, Kanpur 208002 (India)

    2010-09-15

    Anhydrous ethanol is one of the biofuels produced today and it is a subset of renewable energy. It is considered to be an excellent alternative clean-burning fuel to gasoline. Anhydrous ethanol is commercially produced by either catalytic hydration of ethylene or fermentation of biomass. Any biological material that has sugar, starch or cellulose can be used as biomass for producing anhydrous ethanol. Since ethanol-water solution forms a minimum-boiling azeotrope of composition of 89.4 mol% ethanol and 10.6 mol% water at 78.2 C and standard atmospheric pressure, the dilute ethanol-water solutions produced by fermentation process can be continuously rectified to give at best solutions containing 89.4 mol% ethanol at standard atmospheric pressure. Therefore, special process for removal of the remaining water is required for manufacture of anhydrous ethanol. Various processes for producing anhydrous ethanol have been used/suggested. These include: (i) chemical dehydration process, (ii) dehydration by vacuum distillation process, (iii) azeotropic distillation process, (iv) extractive distillation processes, (v) membrane processes, (vi) adsorption processes and (vii) diffusion distillation process. These processes of manufacturing anhydrous ethanol have been improved continuously due to the increasingly strict requirements for quantity and quality of this product. The literature available on these processes is reviewed. These processes are also compared on the basis of energy requirements. (author)

  11. Biotechnological production of ethanol from renewable resources by Neurospora crassa: an alternative to conventional yeast fermentations?

    Science.gov (United States)

    Dogaris, Ioannis; Mamma, Diomi; Kekos, Dimitris

    2013-02-01

    Microbial production of ethanol might be a potential route to replace oil and chemical feedstocks. Bioethanol is by far the most common biofuel in use worldwide. Lignocellulosic biomass is the most promising renewable resource for fuel bioethanol production. Bioconversion of lignocellulosics to ethanol consists of four major unit operations: pretreatment, hydrolysis, fermentation, and product separation/distillation. Conventional bioethanol processes for lignocellulosics apply commercial fungal cellulase enzymes for biomass hydrolysis, followed by yeast fermentation of resulting glucose to ethanol. The fungus Neurospora crassa has been used extensively for genetic, biochemical, and molecular studies as a model organism. However, the strain's potential in biotechnological applications has not been widely investigated and discussed. The fungus N. crassa has the ability to synthesize and secrete all three enzyme types involved in cellulose hydrolysis as well as various enzymes for hemicellulose degradation. In addition, N. crassa has been reported to convert to ethanol hexose and pentose sugars, cellulose polymers, and agro-industrial residues. The combination of these characteristics makes N. crassa a promising alternative candidate for biotechnological production of ethanol from renewable resources. This review consists of an overview of the ethanol process from lignocellulosic biomass, followed by cellulases and hemicellulases production, ethanol fermentations of sugars and lignocellulosics, and industrial application potential of N. crassa.

  12. Ethanol production from Sorghum bicolor using both separate and ...

    African Journals Online (AJOL)

    increase the monomeric sugar during enzymatic hydrolysis and it has been observed that the addition of these surfactants contributed significantly in cellulosic conversion but no effect was shown on hemicellulosic hydrolysis. Fermentability of hydrolyzate was tested using Saccharomyces cerevisiae Ethanol RedTM and it ...

  13. Efficient production of ethanol from waste paper and the biochemical methane potential of stillage eluted from ethanol fermentation.

    Science.gov (United States)

    Nishimura, Hiroto; Tan, Li; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji; Morimura, Shigeru

    2016-02-01

    Waste paper can serve as a feedstock for ethanol production due to being rich in cellulose and not requiring energy-intensive thermophysical pretreatment. In this study, an efficient process was developed to convert waste paper to ethanol. To accelerate enzymatic saccharification, pH of waste paper slurry was adjusted to 4.5-5.0 with H2SO4. Presaccharification and simultaneous saccharification and fermentation (PSSF) with enzyme loading of 40 FPU/g waste paper achieved an ethanol yield of 91.8% and productivity of 0.53g/(Lh) with an ethanol concentration of 32g/L. Fed-batch PSSF was used to decrease enzyme loading to 13 FPU/g waste paper by feeding two separate batches of waste paper slurry. Feeding with 20% w/w waste paper slurry increased ethanol concentration to 41.8g/L while ethanol yield decreased to 83.8%. To improve the ethanol yield, presaccharification was done prior to feeding and resulted in a higher ethanol concentration of 45.3g/L, a yield of 90.8%, and productivity of 0.54g/(Lh). Ethanol fermentation recovered 33.2% of the energy in waste paper as ethanol. The biochemical methane potential of the stillage eluted from ethanol fermentation was 270.5mL/g VTS and 73.0% of the energy in the stillage was recovered as methane. Integrating ethanol fermentation with methane fermentation, recovered a total of 80.4% of the energy in waste paper as ethanol and methane. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, September 1-November 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.I.; Cooney, C.L.; Demain, A.L.; Gomez, R.F.; Sinskey, A.J.

    1978-11-01

    Studies on the accumulation of glucose during the fermentation of cellulose by Clostridium thermocellum are discussed. Production of ethanol and its relationship to growth rate in C. thermocellum is reported. Different biomasses were tested for ethanol yields. These included exploded poplar, sugar cane, bagasse, corn cobs, sweet gum, rice straw, and wheat straw. Thermophilic bacteria were tested to determine relationship of temperature to yield of ethanol. A preliminary report on isolating plaque forming emits derived from C. thermocellum is presented as well as the utilization of carbohydrates in nutrition. A cellulose enzyme is being purified from C. thermocellum. The production of chemical feedstocks by fermentation is reported. Acrylic acid, acetone/butanol, and acetic acid, produced by C. propionicum, C. acetobutylicum, and C. thermoaceticum, are discussed. (DC)

  15. Three-dimensional cellulose sponge: Fabrication, characterization, biomimetic mineralization, and in vitro cell infiltration.

    Science.gov (United States)

    Joshi, Mahesh Kumar; Pant, Hem Raj; Tiwari, Arjun Prasad; Maharjan, Bikendra; Liao, Nina; Kim, Han Joo; Park, Chan Hee; Kim, Cheol Sang

    2016-01-20

    In this study, cellulose based scaffolds were produced by electrospinning of cellulose acetate (CA) solution followed by its saponification with NaOH/ethanol system for 24h. The resulting nonwoven cellulose mat was treated with sodium borohydride (SB) solution. In situ hydrolysis of SB solution into the pores of the membrane produced hydrogen gas resulting a three-dimensional (3D) cellulose sponge. SEM images demonstrated an open porous and loosely packed fibrous mesh compared to the tightly packed single-layered structure of the conventional electrospun membrane. 3D cellulose sponge showed admirable ability to nucleate bioactive calcium phosphate (Ca-P) crystals in simulated body fluid (SBF) solution. SEM-EDX and X-ray diffraction studies revealed that the minerals deposited on the nanofibers have the nonstoichiometric composition similar to that of hydroxyapatite, the mineralized component of the bone. 3D cellulose sponge exhibited the better cell infiltration, spreading and proliferation compared to 2D cellulose mat. Therefore, a facile fabrication of 3D cellulose sponge with improved mineralization represents an innovative strategy for the bone tissue engineering applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Gasoline, diesel, and ethanol biofuels from grasses and plants

    National Research Council Canada - National Science Library

    Gupta, Ram B; Demirbas, Ayhan

    2010-01-01

    ...-generation biofuels obtained from nonfood biomass, such as forest residue, agricultural residue, switchgrass, corn stover, waste wood, and municipal solid wastes. Various technologies are discussed, including cellulosic ethanol, biomass gasification, synthesis of diesel and gasoline, biocrude by hydrothermal liquefaction, bio-oil by fast pyrolysis, and the...

  17. Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

    Science.gov (United States)

    Shrestha, Prachand

    This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

  18. Improved enzymatic saccharification of steam exploded cotton stalk using alkaline extraction and fermentation of cellulosic sugars into ethanol.

    Science.gov (United States)

    Keshav, Praveen K; Naseeruddin, Shaik; Rao, L Venkateswar

    2016-08-01

    Cotton stalk, a widely available and cheap agricultural residue lacking economic alternatives, was subjected to steam explosion in the range 170-200°C for 5min. Steam explosion at 200°C and 5min led to significant hemicellulose solubilization (71.90±0.10%). Alkaline extraction of steam exploded cotton stalk (SECOH) using 3% NaOH at room temperature for 6h led to 85.07±1.43% lignin removal with complete hemicellulose solubilization. Besides, this combined pretreatment allowed a high recovery of the cellulosic fraction from the biomass. Enzymatic saccharification was studied between steam exploded cotton stalk (SECS) and SECOH using different cellulase loadings. SECOH gave a maximum of 785.30±8.28mg/g reducing sugars with saccharification efficiency of 82.13±0.72%. Subsequently, fermentation of SECOH hydrolysate containing sugars (68.20±1.16g/L) with Saccharomyces cerevisiae produced 23.17±0.84g/L ethanol with 0.44g/g yield. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Comparison of Different Pretreatment Strategies for Ethanol Production of West African Biomass

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe; Gonzalez Londono, Jorge Enrique; Schmidt, Jens Ejbye

    2015-01-01

    husks, cocoa pods, maize cobs, maize stalks, rice straw, groundnut straw and oil palm empty fruit bunches. It was found that four biomass’ (plantain peelings, plantain trunks, maize cobs and maize stalks) were most promising for production of cellulosic ethanol with profitable enzymatic conversion......Pretreating lignocellulosic biomass for cellulosic ethanol production in a West African setting requires smaller scale and less capital expenditure compared to current state of the art. In the present study, three low-tech methods applicable for West African conditions, namely Boiling Pretreatment...... (BP), Soaking in Aqueous Ammonia (SAA) and White Rot Fungi pretreatment (WRF), were compared to the high-tech solution of hydrothermal pretreatment (HTT). The pretreatment methods were tested on 11 West African biomasses, i.e. cassava stalks, plantain peelings, plantain trunks, plantain leaves, cocoa...

  20. A New Proposal Of Cellulosic Ethanol To Boost Sugarcane Biorefineries: Techno-economic Evaluation

    OpenAIRE

    Albarelli J.Q.; Ensinas A.V.; Silva M.A.

    2014-01-01

    Commercial simulator Aspen Plus was used to simulate a biorefinery producing ethanol from sugarcane juice and second generation ethanol production using bagasse fine fraction composed of parenchyma cells (P-fraction). Liquid hot water and steam explosion pretreatment technologies were evaluated. The processes were thermal and water integrated and compared to a biorefinery producing ethanol from juice and sugarcane bagasse. The results indicated that after thermal and water integration, the ev...

  1. Stimulating learning-by-doing in advanced biofuels: effectiveness of alternative policies

    International Nuclear Information System (INIS)

    Chen Xiaoguang; Khanna, Madhu; Yeh, Sonia

    2012-01-01

    This letter examines the effectiveness of various biofuel and climate policies in reducing future processing costs of cellulosic biofuels due to learning-by-doing. These policies include a biofuel production mandate alone and supplementing the biofuel mandate with other policies, namely a national low carbon fuel standard, a cellulosic biofuel production tax credit or a carbon price policy. We find that the binding biofuel targets considered here can reduce the unit processing cost of cellulosic ethanol by about 30% to 70% between 2015 and 2035 depending on the assumptions about learning rates and initial costs of biofuel production. The cost in 2035 is more sensitive to the speed with which learning occurs and less sensitive to uncertainty in the initial production cost. With learning rates of 5–10%, cellulosic biofuels will still be at least 40% more expensive than liquid fossil fuels in 2035. The addition of supplementary low carbon/tax credit policies to the mandate that enhance incentives for cellulosic biofuels can achieve similar reductions in these costs several years earlier than the mandate alone; the extent of these incentives differs across policies and different kinds of cellulosic biofuels. (letter)

  2. Lignocellulose pretreatment technologies affect the level of enzymatic cellulose oxidation by LPMO

    DEFF Research Database (Denmark)

    Rodríguez-Zúñiga, Ursula Fabiola; Cannella, David; de Campos Giordano, Roberto

    2015-01-01

    of the cellulose oxidizing enzyme lytic polysaccharide monooxygenase (LPMO). The highest activity of LPMO was observed for the hydrothermally pretreated biomasses, which also contained the highest level of lignin. All hydrolysis were done at high dry matter levels, using a commercial enzyme preparation containing......Sugarcane bagasse, corn stover, and wheat straw are among the most available resources for production of cellulosic ethanol. For these biomasses we study the influence of pre-treatment methods on the chemical composition, as well as on the subsequent reactions of enzymatic hydrolysis and oxidation...

  3. Cellulosic-based ethanol and the contribution from agriculture and forestry

    Science.gov (United States)

    Robert D. Perlack; Bryce J. Stokes; John Ferrell; Mary Bohman; Kenneth E. Skog; Dennis P. Dykstra; Patricia K. Lebow; Patrick D. Miles

    2008-01-01

    The cellulosic feedstocks (see chapter 2) needed to produce 20 billion gallons per year (BGY) of second-generation and other renewable fuels can come from a wide variety of cropland and forestland sources, including imports. The impact of producing these biofuels on U.S. agriculture and forestry will very much depend on the relative proportions of cropland- and...

  4. The correlation between cellulose allomorphs (I and II) and conversion after removal of hemicellulose and lignin of lignocellulose.

    Science.gov (United States)

    Song, Yanliang; Zhang, Jingzhi; Zhang, Xu; Tan, Tianwei

    2015-10-01

    H2SO4, NaOH and H3PO4 were applied to decompose lignocellulose samples (giant reeds, pennisetum and cotton stalks) to investigate the correlation between cellulose allomorphs (cellulose I and II) and conversion of cellulose. The effect of removal of hemicellulose and lignin on the surface morphology, crystallinity index (CrI), cellulose allomorphs (cellulose I and II), and enzymatic hydrolysis under different pretreatments was also studied. CrI caused by H3PO4 pretreatment reached 11.19%, 24.93% and 8.15% for the three samples, respectively. Corn stalk showed highest conversion of cellulose among three samples, irrespective of the pretreatment used. This accounted for the widely use of corn stalk as the renewable crop substrate to synthesize biofuels like ethanol. CrI of cellulose I (CrI-I) negatively affects cellulose conversion but CrI of cellulose II (CrI-II) positively affects cellulose conversion. It contributes to make the strategy to transform cellulose I to cellulose II and enhancing enzymatic hydrolysis of lignocellulose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Process for fermentation of ethanol. Verfahren zur Aethanolfermentation

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, M S; Crawford, S D

    1980-06-19

    The invention concerns an improved process for the manufacture of ethanol from cellulose and substrates containing cellulate with cellulase enzymes and yeast (Candida brassicae ATCC 32196). The cellulase and the micro-organisms producing the alcohol are caused to react simultaneously on the same substrate. The yeast is active below and above 40/sup 0/C.

  6. DEVELOPMENT OF MICROORGANISMS FOR CELLULOSE-BIOFUEL CONSOLIDATED BIOPROCESSINGS: METABOLIC ENGINEERS' TRICKS

    Directory of Open Access Journals (Sweden)

    Roberto Mazzoli

    2012-10-01

    By starting from the description of natural enzyme systems for plant biomass degradation and natural metabolic pathways for some of the most valuable product (i.e. butanol, ethanol, and hydrogen biosynthesis, this review describes state-of-the-art bottlenecks and solutions for the development of recombinant microbial strains for cellulosic biofuel CBP by metabolic engineering. Complexed cellulases (i.e. cellulosomes benefit from stronger proximity effects and show enhanced synergy on insoluble substrates (i.e. crystalline cellulose with respect to free enzymes. For this reason, special attention was held on strategies involving cellulosome/designer cellulosome-bearing recombinant microorganisms.

  7. Simultaneous saccharification and co-fermentation of paper sludge to ethanol by Saccharomyces cerevisiae RWB222--Part I: kinetic modeling and parameters.

    Science.gov (United States)

    Zhang, Jiayi; Shao, Xiongjun; Townsend, Oliver V; Lynd, Lee R

    2009-12-01

    A kinetic model was developed to predict batch simultaneous saccharification and co-fermentation (SSCF) of paper sludge by the xylose-utilizing yeast Saccharomyces cerevisiae RWB222 and the commercial cellulase preparation Spezyme CP. The model accounts for cellulose and xylan enzymatic hydrolysis and competitive uptake of glucose and xylose. Experimental results show that glucan and xylan enzymatic hydrolysis are highly correlated, and that the low concentrations of xylose encountered during SSCF do not have a significant inhibitory effect on enzymatic hydrolysis. Ethanol is found to not only inhibit the specific growth rate, but also to accelerate cell death. Glucose and xylose uptake rates were found to be competitively inhibitory, but this did not have a large impact during SSCF because the sugar concentrations are low. The model was used to evaluate which constants had the greatest impact on ethanol titer for a fixed substrate loading, enzyme loading, and fermentation time. The cellulose adsorption capacity and cellulose hydrolysis rate constants were found to have the greatest impact among enzymatic hydrolysis related constants, and ethanol yield and maximum ethanol tolerance had the greatest impact among fermentation related constants.

  8. Detoxification and fermentation of pyrolytic sugar for ethanol production.

    Science.gov (United States)

    Wang, Hui; Livingston, Darrell; Srinivasan, Radhakrishnan; Li, Qi; Steele, Philip; Yu, Fei

    2012-11-01

    The sugars present in bio-oil produced by fast pyrolysis can potentially be fermented by microbial organisms to produce cellulosic ethanol. This study shows the potential for microbial digestion of the aqueous fraction of bio-oil in an enrichment medium to consume glucose and produce ethanol. In addition to glucose, inhibitors such as furans and phenols are present in the bio-oil. A pure glucose enrichment medium of 20 g/l was used as a standard to compare with glucose and aqueous fraction mixtures for digestion. Thirty percent by volume of aqueous fraction in media was the maximum additive amount that could be consumed and converted to ethanol. Inhibitors were removed by extraction, activated carbon, air stripping, and microbial methods. After economic analysis, the cost of ethanol using an inexpensive fermentation medium in a large scale plant is approximately $14 per gallon.

  9. Removal of the Fermentation Inhibitor, Furfural, Using Activated Carbon in Cellulosic-Ethanol Production

    KAUST Repository

    Zhang, Kuang; Agrawal, Manoj; Harper, Justin; Chen, Rachel; Koros, William J.

    2011-01-01

    Ethanol can be produced from lignocellulosic biomass through fermentation; however, some byproducts from lignocellulosics, such as furfural compounds, are highly inhibitory to the fermentation and can substantially reduce the efficiency of ethanol

  10. Biofuel excision and the viability of ethanol production in the Green Triangle, Australia

    International Nuclear Information System (INIS)

    Rodriguez, Luis C.; May, Barrie; Herr, Alexander; Farine, Damien; O'Connell, Deborah

    2011-01-01

    The promotion and use of renewable energy sources are established priorities worldwide as a way to reduce emissions of Greenhouse Gases and promote energy security. Australia is committed to reach a target of 350 ML of biofuels per year by 2010, and incentives targeted to producers and consumers have been placed. These incentives include zero excise until 2011 for the ethanol produced in Australia and gradual increase of the taxation rates reaching the full excise of 0.125 AUD per litre by 2015. This paper analyses the viability of the second generation ethanol industry in the Green Triangle, one of the most promising Australian regions for biomass production, by comparing the energy adjusted pump prices of petrol and the produced ethanol under different taxation rates and forecasted oil prices. Major findings suggest that under the current conditions of zero fuel excise and oil prices around 80US$ per barrel ethanol production is viable using biomass with a plant gate cost of up to 74 AUD per ton. Moreover, the forecasted increase in oil prices have a higher impact on the price of petrol than the increased ethanol excise on the pump price of the biofuel. Thus, by 2016 feedstock with a plant gate cost of up to 190 AUD per ton might be used for ethanol production, representing a flow of 1.7 million tons of biomass per year potentially mitigating 1.2 million tons of CO 2 by replacing fossil fuels with ethanol. - Research highlights: →We assessed the potential for ethanol production in the Green Triangle. → Despite of increased ethanol taxation, higher oil prices promote ethanol production. → Currently, ethanol from biomass with a plant gate cost of up to 74 AUD/ton is viable. →Forecasted oil prices suggest biomass of 190 AUD/ton might be used by 2016.

  11. PEI detoxification of pretreated spruce for high solids ethanol fermentation

    DEFF Research Database (Denmark)

    Cannella, David; Sveding, Per Viktor; Jørgensen, Henning

    2014-01-01

    .e. spruce) this has been difficult to reach. The main reason behind this difference is the higher recalcitrance of woody substrates which require harsher pretreatment conditions, thus generating higher amounts of inhibitory compounds, ultimately lowering fermentation performances. In this work we studied...... ethanol production from spruce performing the whole process, from pretreatment to hydrolysis and fermentation, at 30% dry matter (equivalent to similar to 20% WIS). Hydrolysis and fermentation was performed in a horizontal free fall mixing reactor enabling efficient mixing at high solids loadings....... In batch simultaneous saccharification and fermentation (SSF), up to 76% cellulose to ethanol conversion was achieved resulting in a concentration of 51 g/kg of ethanol. Key to obtaining this high ethanol yield at these conditions was the use of a detoxification technology based on applying a soluble...

  12. Composition of corn dry-grind ethanol by-products: DDGS, wet cake, and thin stillage.

    Science.gov (United States)

    Kim, Youngmi; Mosier, Nathan S; Hendrickson, Rick; Ezeji, Thaddeus; Blaschek, Hans; Dien, Bruce; Cotta, Michael; Dale, Bruce; Ladisch, Michael R

    2008-08-01

    DDGS and wet distillers' grains are the major co-products of the dry grind ethanol facilities. As they are mainly used as animal feed, a typical compositional analysis of the DDGS and wet distillers' grains mainly focuses on defining the feedstock's nutritional characteristics. With an increasing demand for fuel ethanol, the DDGS and wet distillers' grains are viewed as a potential bridge feedstock for ethanol production from other cellulosic biomass. The introduction of DDGS or wet distillers' grains as an additional feed to the existing dry grind plants for increased ethanol yield requires a different approach to the compositional analysis of the material. Rather than focusing on its nutritional value, this new approach aims at determining more detailed chemical composition, especially on polymeric sugars such as cellulose, starch and xylan, which release fermentable sugars upon enzymatic hydrolysis. In this paper we present a detailed and complete compositional analysis procedure suggested for DDGS and wet distillers' grains, as well as the resulting compositions completed by three different research groups. Polymeric sugars, crude protein, crude oil and ash contents of DDGS and wet distillers' grains were accurately and reproducibly determined by the compositional analysis procedure described in this paper.

  13. Ethanol annual report FY 1990

    Energy Technology Data Exchange (ETDEWEB)

    Texeira, R.H.; Goodman, B.J. (eds.)

    1991-01-01

    This report summarizes the research progress and accomplishments of the US Department of Energy (DOE) Ethanol from Biomass Program, field managed by the Solar Energy Research Institute, during FY 1990. The report includes an overview of the entire program and summaries of individual research projects. These projects are grouped into the following subject areas: technoeconomic analysis; pretreatment; cellulose conversion; xylose fermentation; and lignin conversion. Individual papers have been indexed separately for inclusion on the data base.

  14. Ethanol production from alfalfa fiber fractions by saccharification and fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Sreenath, H.K. [University of Wisconsin, Madison, WI (United States). Dept. of Biological Systems Engineering; USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Koegel, R.G. [US Department of Agriculture, Madison, WI (United States). Dairy Forage Research Center; Moldes, A.B. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Universidade de Vigo, Ourense (Spain); Jeffries, T.W. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Straub, R.J. [University of Wisconsin, Madison, WI (United States). Dept. of Biological Systems Engineering

    2001-07-01

    This work describes ethanol production from alfalfa fiber using separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) with and without liquid hot water (LHW) pretreatment. Candida shehatae FPL-702 produced 5 and 6.4 g/l ethanol with a yield of 0.25 and 0.16 g ethanol/g sugar respectively by SHF and SSF from alfalfa fiber without pretreatment. With LHW pretreatment using SSF, C. shehatae FPL-702 produced 18.0 g/l ethanol, a yield of 0.45 g ethanol/g sugar from cellulosic solids or 'raffinate'. Using SHF, it produced 9.6 g/l ethanol, a yield of 0.47 g ethanol/g sugar from raffinate. However, the soluble extract fraction containing hemicelluloses was poorly fermented in both SHF and SSF due to the presence of inhibitors. Addition of dilute acid during LHW pretreatment of alfalfa fiber resulted in fractions that were poorly saccharified and fermented. These results show that unpretreated alfalfa fiber produced a lower ethanol yield. Although LHW pretreatment can increase ethanol production from raffinate fiber fractions, it does not increase production from the hemicellulosic and pectin fractions. (author)

  15. Electron beam application as pre treatment of sugar cane bagasse to enzymatic hydrolysis of cellulose

    International Nuclear Information System (INIS)

    Cardoso, Vanessa Miguel

    2008-01-01

    Due to increasing worldwide shortage of food and energy sources, sugarcane bagasse has been considered as a substrate for single cell protein, animal feed, and renewable energy production. Sugarcane bagasse generally contain up to 45% glucose polymer cellulose, much of which is in a crystalline structure, 40% hemicelluloses, an amorphous polymer usually composed of xylose, arabinose, galactose, glucose, and mannose and 20% lignin, which cannot be easily separated into readily usable components due to their recalcitrant nature. Pure cellulose is readily depolymerised by radiation, but in biomass the cellulose is intimately bonded with lignin, that protect it from radiation effects. The objective of this study was the evaluation of the electron beam irradiation efficiency as a pre-treatment to enzymatic hydrolysis of cellulose in order to facilitate its fermentation and improves the production of ethanol biofuel. Samples of sugarcane bagasse were obtained in sugar/ethanol Mill sited in Piracicaba, Brazil, and were irradiated using Radiation Dynamics Electron Beam Accelerator with 1,5 MeV energy and 37 kW, in batch systems. The applied absorbed doses of the fist sampling, Bagasse A, were 20 kGy, 50 kGy, 10 0 kGy and 200 kGy. After the evaluation the preliminary obtained results, it was applied lower absorbed doses in the second assay: 5 kGy, 10 kGy, 20 kGy, 30 kGy, 50 kGy, 70 kGy, 100 kGy and 150 kGy. The electron beam processing took to changes in the sugarcane bagasse structure and composition, lignin and cellulose cleavage. The yield of enzymatic hydrolyzes of cellulose in. (author)

  16. Enzymatic hydrolysis of cellulose dissolved in N-methyl morpholine oxide/water solutions.

    Science.gov (United States)

    Ramakrishnan, S; Collier, J; Oyetunji, R; Stutts, B; Burnett, R

    2010-07-01

    In situ hydrolysis of cellulose (dissolving pulp) in N-methyl morpholine oxide (NMMO) solutions by commercially available Accellerase1000 is carried out. The yield of reducing sugars is followed as a function of time at three different temperatures and four different enzyme loadings to study the effect of system parameters on enzymatic hydrolysis. Initial results show that rates of hydrolysis of cellulose and yields of reducing sugars in the presence of NMMO-water is superior initially (ratio of initial reaction rates approximately 4) and comparable to that of regenerated cellulose (for times greater than 5h) when suspended in aqueous solutions. The usage of Accellerase1000 results predominantly in the formation of glucose with minimal amounts of cellobiose. This study proves the ability of cellulases to remain active in NMMO to carry out an in situ saccharification of cellulose thus eliminating the need to recover regenerated cellulose. Thus this work will form the basis for developing a continuous process for conversion of biomass to hydrogen, ethanol and other hydrocarbons. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Transcriptome profiling of Zymomonas mobilis under ethanol stress

    Directory of Open Access Journals (Sweden)

    He Ming-xiong

    2012-10-01

    Full Text Available Abstract Background High tolerance to ethanol is a desirable characteristics for ethanologenic strains used in industrial ethanol fermentation. A deeper understanding of the molecular mechanisms underlying ethanologenic strains tolerance of ethanol stress may guide the design of rational strategies to increase process performance in industrial alcoholic production. Many extensive studies have been performed in Saccharomyces cerevisiae and Escherichia coli. However, the physiological basis and genetic mechanisms involved in ethanol tolerance for Zymomonas mobilis are poorly understood on genomic level. To identify the genes required for tolerance to ethanol, microarray technology was used to investigate the transcriptome profiling of the ethanologenic Z. mobilis in response to ethanol stress. Results We successfully identified 127 genes which were differentially expressed in response to ethanol. Ethanol up- or down-regulated genes related to cell wall/membrane biogenesis, metabolism, and transcription. These genes were classified as being involved in a wide range of cellular processes including carbohydrate metabolism, cell wall/membrane biogenesis, respiratory chain, terpenoid biosynthesis, DNA replication, DNA recombination, DNA repair, transport, transcriptional regulation, some universal stress response, etc. Conclusion In this study, genome-wide transcriptional responses to ethanol were investigated for the first time in Z. mobilis using microarray analysis.Our results revealed that ethanol had effects on multiple aspects of cellular metabolism at the transcriptional level and that membrane might play important roles in response to ethanol. Although the molecular mechanism involved in tolerance and adaptation of ethanologenic strains to ethanol is still unclear, this research has provided insights into molecular response to ethanol in Z. mobilis. These data will also be helpful to construct more ethanol resistant strains for cellulosic

  18. Recent trends in global production and utilization of bio-ethanol fuel

    International Nuclear Information System (INIS)

    Balat, Mustafa; Balat, Havva

    2009-01-01

    Bio-fuels are important because they replace petroleum fuels. A number of environmental and economic benefits are claimed for bio-fuels. Bio-ethanol is by far the most widely used bio-fuel for transportation worldwide. Production of bio-ethanol from biomass is one way to reduce both consumption of crude oil and environmental pollution. Using bio-ethanol blended gasoline fuel for automobiles can significantly reduce petroleum use and exhaust greenhouse gas emission. Bio-ethanol can be produced from different kinds of raw materials. These raw materials are classified into three categories of agricultural raw materials: simple sugars, starch and lignocellulose. Bio-ethanol from sugar cane, produced under the proper conditions, is essentially a clean fuel and has several clear advantages over petroleum-derived gasoline in reducing greenhouse gas emissions and improving air quality in metropolitan areas. Conversion technologies for producing bio-ethanol from cellulosic biomass resources such as forest materials, agricultural residues and urban wastes are under development and have not yet been demonstrated commercially.

  19. Development of Biocomposites with Antioxidant Activity Based on Red Onion Extract and Acetate Cellulose

    Directory of Open Access Journals (Sweden)

    Carol López de Dicastillo

    2015-08-01

    Full Text Available Antioxidant biocomposites have been successfully developed from cellulose acetate, eco-friendly triethyl citrate plasticizer and onion extract as a source of natural antioxidants. First, an onion extraction process was optimized to obtain the extract with highest antioxidant power. Extracts under absolute ethanol and ethanol 85% were the extracts with the highest antioxidant activity, which were the characterized through different methods, DPPH (2,2-diphenyl-1-picrylhydrazyl and ABTS (2,2ʹ-azinobis(3-ethylbenzothiazoline-6-sulphonate, that measure radical scavenger activity, and polyphenolic and flavonoid content. Afterwards, the extract was incorporated in cellulose acetate as polymer matrix owing to develop an active material intended to oxidative sensitive food products packaging. Different concentrations of onion extract and plasticizer were statistically studied by using response surface methodology in order to analyze the influence of both factors on the release of active compounds and therefore the antioxidant activity of these materials.

  20. Greenprint on ethanol production in Saskatchewan

    International Nuclear Information System (INIS)

    2002-04-01

    Investment in Saskatchewan's ethanol industry is being actively promoted by the provincial government. This document represents the provincial strategy in support of the ethanol industry, which will result in significant environmental benefits for the province and the residents through the increased use of ethanol as an additive to conventional gasoline. The big advantage offered by ethanol is a more complete fuel combustion, thereby reducing emissions of greenhouse gases by as much as 30 per cent. The production costs of ethanol have decreased in the last twenty years by 50 per cent. The competitiveness of ethanol should increase due to ongoing research and development progress being made. The agricultural sector should benefit through the creation of meaningful jobs in the sector, as well as offering new marketing opportunities to the grain producers of the province and the wood-product companies. A renewable resource, ethanol reduces carbon dioxide exhaust emissions bu up to 20 per cent, reduces the smog-creating compounds up to 15 per cent, and achieves a net reduction of up to 10 per cent in carbon dioxide emissions. The abundance of raw materials and resources required for the production of ethanol, Saskatchewan possesses an obvious advantage for becoming a world leader in the field. The government of Saskatchewan has developed its strategy, outlined in this document. It calls for tax incentives, the mandating of ethanol blend, opening up markets, working with communities. The industry size, economic impact, export potential, and future opportunities were briefly discussed in the last section of the document. 1 tab., 3 figs

  1. Removal of the Fermentation Inhibitor, Furfural, Using Activated Carbon in Cellulosic-Ethanol Production

    KAUST Repository

    Zhang, Kuang

    2011-12-21

    Ethanol can be produced from lignocellulosic biomass through fermentation; however, some byproducts from lignocellulosics, such as furfural compounds, are highly inhibitory to the fermentation and can substantially reduce the efficiency of ethanol production. In this study, commercial and polymer-derived activated carbons were utilized to selectively remove the model fermentation inhibitor, furfural, from water solution during bioethanol production. The oxygen functional groups on the carbon surface were found to influence the selectivity of sorbents between inhibitors and sugars during the separation. After inhibitors were selectively removed from the broth, the cell growth and ethanol production efficiency was recovered noticeably in the fermentation. A sorption/desorption cycle was designed, and the sorbents were regenerated in a fixed-bed column system using ethanol-containing standard solution. Dynamic mass balance was obtained after running four or five cycles, and regeneration results were stable even after twenty cycles. © 2011 American Chemical Society.

  2. Engineering microorganisms to increase ethanol production by metabolic redirection

    Science.gov (United States)

    Deng, Yu; Olson, Daniel G.; van Dijken, Johannes Pieter; Shaw, IV, Arthur J.; Argyros, Aaron; Barrett, Trisha; Caiazza, Nicky; Herring, Christopher D.; Rogers, Stephen R.; Agbogbo, Frank

    2017-10-31

    The present invention provides for the manipulation of carbon flux in a recombinant host cell to increase the formation of desirable products. The invention relates to cellulose-digesting organisms that have been genetically modified to allow the production of ethanol at a high yield by redirecting carbon flux at key steps of central metabolism.

  3. Getting to Yes or Bailing on No: The Site Selection Process of Ethanol Plants in Wisconsin

    Science.gov (United States)

    Tigges, Leann M.; Noble, Molly

    2012-01-01

    Prior studies of ethanol location rest on the assumption that ethanol producers are economic free agents--evaluating sites as if all counties are contenders for their business, weighing the availability of feedstocks along with their infrastructure needs, operating without ties to localities, and being subject to enticement from policy incentives.…

  4. A New Proposal of Cellulosic Ethanol to Boost Sugarcane Biorefineries: Techno-Economic Evaluation

    Directory of Open Access Journals (Sweden)

    Juliana Q. Albarelli

    2014-01-01

    Full Text Available Commercial simulator Aspen Plus was used to simulate a biorefinery producing ethanol from sugarcane juice and second generation ethanol production using bagasse fine fraction composed of parenchyma cells (P-fraction. Liquid hot water and steam explosion pretreatment technologies were evaluated. The processes were thermal and water integrated and compared to a biorefinery producing ethanol from juice and sugarcane bagasse. The results indicated that after thermal and water integration, the evaluated processes were self-sufficient in energy demand, being able to sell the surplus electricity to the grid, and presented water intake inside the environmental limit for São Paulo State, Brazil. The processes that evaluated the use of the bagasse fine fraction presented higher economic results compared with the use of the entire bagasse. Even though, due to the high enzyme costs, the payback calculated for the biorefineries were higher than 8 years for all cases that considered second generation ethanol and the net present value for the investment was negative. The reduction on the enzyme load, in a way that the conversion rates could be maintained, is the limiting factor to make second generation ethanol competitive with the most immediate uses of bagasse: fuel for the cogeneration system to surplus electricity production.

  5. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  6. Microbiology and physiology of anaerobic fermentations of cellulose. Progress report, September 1, 1979-May 15, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Peck, H.D. Jr.; Ljungdahl, L.G.

    1980-01-01

    Reseach progress is reported for the period September, 1979 to May, 1980. Studies on the mesophilic and thermophilic microorganisms fermenting cellulose to various products (ethanol, acetate, CO/sub 2/, H/sub 2/, and methane) are summarized. (ACR)

  7. Performance of CSTR-EGSB-SBR system for treating sulfate-rich cellulosic ethanol wastewater and microbial community analysis.

    Science.gov (United States)

    Shan, Lili; Zhang, Zhaohan; Yu, Yanling; Ambuchi, John Justo; Feng, Yujie

    2017-06-01

    Performance and microbial community composition were evaluated in a two-phase anaerobic and aerobic system treating sulfate-rich cellulosic ethanol wastewater (CEW). The system was operated at five different chemical oxygen demand (COD)/SO 4 2- ratios (63.8, 26.3, 17.8, 13.7, and 10.7). Stable performance was obtained for total COD removal efficiency (94.5%), sulfate removal (89.3%), and methane production rate (11.5 L/day) at an organic loading rate of 32.4 kg COD/(m 3 ·day). The acidogenic reactor made a positive contribution to net VFAs production (2318.1 mg/L) and sulfate removal (60.9%). Acidogenic bacteria (Megasphaera, Parabacteroides, unclassified Ruminococcaceae spp., and Prevotella) and sulfate-reducing bacteria (Butyrivibrio, Megasphaera) were rich in the acidogenic reactor. In the methanogenic reactor, high diversity of microorganisms corresponded with a COD removal contribution of 83.2%. Moreover, methanogens (Methanosaeta) were predominant, suggesting that these organisms played an important role in the acetotrophic methanogenesis pathway. The dominant aerobic bacteria (Truepera) appeared to have been responsible for the COD removal of the SBR. These results indicate that dividing the sulfate reduction process could effectively minimize sulfide toxicity, which is important for the successful operation of system treating sulfate-rich CEW.

  8. The greenhouse gas emissions performance of cellulosic ethanol supply chains in Europe

    Directory of Open Access Journals (Sweden)

    Bauen Ausilio

    2009-08-01

    Full Text Available Abstract Background Calculating the greenhouse gas savings that may be attributed to biofuels is problematic because production systems are inherently complex and methods used to quantify savings are subjective. Differing approaches and interpretations have fuelled a debate about the environmental merit of biofuels, and consequently about the level of policy support that can be justified. This paper estimates and compares emissions from plausible supply chains for lignocellulosic ethanol production, exemplified using data specific to the UK and Sweden. The common elements that give rise to the greatest greenhouse gas emissions are identified and the sensitivity of total emissions to variations in these elements is estimated. The implications of including consequential impacts including indirect land-use change, and the effects of selecting alternative allocation methods on the interpretation of results are discussed. Results We find that the most important factors affecting supply chain emissions are the emissions embodied in biomass production, the use of electricity in the conversion process and potentially consequential impacts: indirect land-use change and fertiliser replacement. The large quantity of electricity consumed during enzyme manufacture suggests that enzymatic conversion processes may give rise to greater greenhouse gas emissions than the dilute acid conversion process, even though the dilute acid process has a somewhat lower ethanol yield. Conclusion The lignocellulosic ethanol supply chains considered here all lead to greenhouse gas savings relative to gasoline An important caveat to this is that if lignocellulosic ethanol production uses feedstocks that lead to indirect land-use change, or other significant consequential impacts, the benefit may be greatly reduced. Co-locating ethanol, electricity generation and enzyme production in a single facility may improve performance, particularly if this allows the number of energy

  9. Composition of sugar cane, energy cane, and sweet sorghum suitable for ethanol production at Louisiana sugar mills.

    Science.gov (United States)

    Kim, Misook; Day, Donal F

    2011-07-01

    A challenge facing the biofuel industry is to develop an economically viable and sustainable biorefinery. The existing potential biorefineries in Louisiana, raw sugar mills, operate only 3 months of the year. For year-round operation, they must adopt other feedstocks, besides sugar cane, as supplemental feedstocks. Energy cane and sweet sorghum have different harvest times, but can be processed for bio-ethanol using the same equipment. Juice of energy cane contains 9.8% fermentable sugars and that of sweet sorghum, 11.8%. Chemical composition of sugar cane bagasse was determined to be 42% cellulose, 25% hemicellulose, and 20% lignin, and that of energy cane was 43% cellulose, 24% hemicellulose, and 22% lignin. Sweet sorghum was 45% cellulose, 27% hemicellulose, and 21% lignin. Theoretical ethanol yields would be 3,609 kg per ha from sugar cane, 12,938 kg per ha from energy cane, and 5,804 kg per ha from sweet sorghum.

  10. Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and β-glucosidase.

    Science.gov (United States)

    Apiwatanapiwat, Waraporn; Murata, Yoshinori; Kosugi, Akihiko; Yamada, Ryosuke; Kondo, Akihiko; Arai, Takamitsu; Rugthaworn, Prapassorn; Mori, Yutaka

    2011-04-01

    In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying α-amylase (α-AM), glucoamylase, endoglucanase, cellobiohydrase, and β-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley β-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes.

  11. Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and {beta}-glucosidase

    Energy Technology Data Exchange (ETDEWEB)

    Apiwatanapiwat, Waraporn; Rugthaworn, Prapassorn [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Kasetsart Univ., Bangkok (Thailand). Nanotechnology and Biotechnology Div.; Murata, Yoshinori; Kosugi, Akihiko; Arai, Takamitsu; Mori, Yutaka [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Yamada, Ryosuke; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

    2011-04-15

    In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying {alpha}-amylase ({alpha}-AM), glucoamylase, endoglucanase, cellobiohydrase, and {beta}-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley {beta}-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes. (orig.)

  12. Potential of thin stillage as a low-cost nutrient source for direct cellulose fermentation by Clostridium thermocellum

    Directory of Open Access Journals (Sweden)

    Rumana Islam

    2015-11-01

    Full Text Available Utilization of thin stillage (TS, derived from grain-based ethanol production, was investigated as an alternative source for microbial growth nutrients during direct conversion of cellulose by Clostridium thermocellum DSM 1237. Fermentation end-products synthesized by C. thermocellum grown on media prepared with various concentrations (50-400 g/L of TS were compared to those synthesized by C. thermocellum grown on reagent grade chemical (reference medium. Cell-growth in TS media, monitored with the aid of quantitative polymerase chain reactions (qPCR technique, showed prolonged growth with increasing TS concentration. Final fermentation end-product concentrations from TS media were comparable with those from the reference medium despite lower growth-rates. The volumetric H2 production generated by C. thermocellum grown with medium containing a low concentration (50 g/L of TS matched the volumetric H2 production by C. thermocellum grown in the reference medium, while higher concentrations (200 g/L of TS resulted in greater synthesis of ethanol. Supplementation of TS-media with Mg++ enhanced ethanol production, while hydrogen production remained unchanged. These results suggest that TS, an attractive source of low-cost nutrients, is capable of supporting the growth of C. thermocellum and that high concentrations of TS favor synthesis of ethanol over hydrogen from cellulose.

  13. Can Hawaii Meet Its Renewable Fuel Target? Case Study of Banagrass-Based Cellulosic Ethanol

    Directory of Open Access Journals (Sweden)

    Chinh Tran

    2016-08-01

    Full Text Available Banagrass is a biomass crop candidate for ethanol production in the State of Hawaii. This study examines: (i whether enough banagrass can be produced to meet Hawaii’s renewable fuel target of 20% highway fuel demand produced with renewable sources by 2020 and (ii at what cost. This study proposes to locate suitable land areas for banagrass production and ethanol processing, focusing on the two largest islands in the state of Hawaii—Hawaii and Maui. The results suggest that the 20% target is not achievable by using all suitable land resources for banagrass production on both Hawaii and Maui. A total of about 74,224,160 gallons, accounting for 16.04% of the state’s highway fuel demand, can be potentially produced at a cost of $6.28/gallon. Lower ethanol cost is found when using a smaller production scale. The lowest cost of $3.31/gallon is found at a production processing capacity of about 9 million gallons per year (MGY, which meets about 2% of state demand. This cost is still higher than the average imported ethanol price of $3/gallon. Sensitivity analysis finds that it is possible to produce banagrass-based ethanol on Hawaii Island at a cost below the average imported ethanol price if banagrass yield increases of at least 35.56%.

  14. Ethanol production from Dekkera bruxellensis in synthetic media with pentose

    Directory of Open Access Journals (Sweden)

    Carolina B. Codato

    Full Text Available Abstract Ethanol is obtained in Brazil from the fermentation of sugarcane, molasses or a mixture of these. Alternatively, it can also be obtained from products composed of cellulose and hemicellulose, called “second generation ethanol - 2G”. The yeast Saccharomyces cerevisiae, commonly applied in industrial ethanol production, is not efficient in the conversion of pentoses, which is present in high amounts in lignocellulosic materials. This study aimed to evaluate the ability of a yeast strain of Dekkera bruxellensis in producing ethanol from synthetic media, containing xylose or arabinose, xylose and glucose as the sole carbon sources. The results indicated that D. bruxellensis was capable of producing ethanol from xylose and arabinose, with ethanol concentration similar for both carbon sources, 1.9 g L-1. For the fermentations performed with xylose and glucose, there was an increase in the concentration of ethanol to 5.9 g L-1, lower than the standard yeast Pichia stipitis (9.3 g L-1, but with similar maximum yield in ethanol (0.9 g g TOC-1. This proves that the yeast D. bruxellensis produced lower amounts of ethanol when compared with P. stipitis, but showed that is capable of fermenting xylose and can be a promising alternative for ethanol conversion from hydrolysates containing glucose and xylose as carbon source.

  15. Beyond commonplace biofuels: Social aspects of ethanol

    International Nuclear Information System (INIS)

    Ribeiro, Barbara Esteves

    2013-01-01

    Biofuels policies and projects may lead to environmental, economic and social impacts. A number of studies point out the need to deliver comprehensive sustainability assessments regarding biofuels, with some presenting analytical frameworks that claim to be exhaustive. However, what is often found in the literature is an overexploitation of environmental and economic concerns, by contrast to a limited appraisal of the social aspects of biofuels. Building on a systematic review of the peer-reviewed literature, this paper discusses the social constraints and strengths of ethanol, with regard to the product's lifecycle stages and the actors involved. Its objective is to contribute to the development of social frameworks to be used in assessing the impact of ethanol. Main findings indicate that ethanol developments can increase the levels of social vulnerability, although there is little evidence in the literature regarding the positive and negative social impacts of 1st-generation ethanol and potential impacts of cellulosic ethanol. Further work is needed on the formulation of social criteria and indicators for a comprehensive sustainability assessment of this biofuel. Policy makers need to internalise the social dimension of ethanol in decision-making to prevent public opposition and irreversible social costs in the future. - Highlights: ► The literature lacks evidence on the social impacts of ethanol. ► Further work is needed on social criteria and indicators for assessment. ► Ethanol developments can increase the levels of social vulnerability. ► Decision-making should internalise the social dimension of biofuels sustainability

  16. Electrospinning cellulose based nanofibers for sensor applications

    Science.gov (United States)

    Nartker, Steven

    2009-12-01

    Bacterial pathogens have recently become a serious threat to the food and water supply. A biosensor based on an electrochemical immunoassay has been developed for detecting food borne pathogens, such as Escherichia coli (E. coli) O157:H7. These sensors consist of several materials including, cellulose, cellulose nitrate, polyaniline and glass fibers. The current sensors have not been optimized in terms of microscale architecture and materials. The major problem associated with the current sensors is the limited concentration range of pathogens that provides a linear response on the concentration conductivity chart. Electrospinning is a process that can be used to create a patterned fiber mat design that will increase the linear range and lower the detection limit of these sensors by improving the microscale architecture. Using the electrospinning process to produce novel mats of cellulose nitrate will offer improved surface area, and the cellulose nitrate can be treated to further improve chemical interactions required for sensor activity. The macro and micro architecture of the sensor is critical to the performance of the sensors. Electrospinning technology can be used to create patterned architectures of nanofibers that will enhance sensor performance. To date electrospinning of cellulose nitrate has not been performed and optimization of the electrospinning process will provide novel materials suitable for applications such as filtration and sensing. The goal of this research is to identify and elucidate the primary materials and process factors necessary to produce cellulose nitrate nanofibers using the electrospinning process that will improve the performance of biosensors. Cellulose nitrate is readily dissolved in common organic solvents such as acetone, tetrahydrofuran (THF) and N,N dimethylformamide (DMF). These solvents can be mixed with other latent solvents such as ethanol and other alcohols to provide a solvent system with good electrospinning behavior

  17. Xylose isomerase improves growth and ethanol production rates from biomass sugars for both Saccharomyces pastorianus and Saccharomyces cerevisiae.

    Science.gov (United States)

    Miller, Kristen P; Gowtham, Yogender Kumar; Henson, J Michael; Harcum, Sarah W

    2012-01-01

    The demand for biofuel ethanol made from clean, renewable nonfood sources is growing. Cellulosic biomass, such as switch grass (Panicum virgatum L.), is an alternative feedstock for ethanol production; however, cellulosic feedstock hydrolysates contain high levels of xylose, which needs to be converted to ethanol to meet economic feasibility. In this study, the effects of xylose isomerase on cell growth and ethanol production from biomass sugars representative of switch grass were investigated using low cell density cultures. The lager yeast species Saccharomyces pastorianus was grown with immobilized xylose isomerase in the fermentation step to determine the impact of the glucose and xylose concentrations on the ethanol production rates. Ethanol production rates were improved due to xylose isomerase; however, the positive effect was not due solely to the conversion of xylose to xylulose. Xylose isomerase also has glucose isomerase activity, so to better understand the impact of the xylose isomerase on S. pastorianus, growth and ethanol production were examined in cultures provided fructose as the sole carbon. It was observed that growth and ethanol production rates were higher for the fructose cultures with xylose isomerase even in the absence of xylose. To determine whether the positive effects of xylose isomerase extended to other yeast species, a side-by-side comparison of S. pastorianus and Saccharomyces cerevisiae was conducted. These comparisons demonstrated that the xylose isomerase increased ethanol productivity for both the yeast species by increasing the glucose consumption rate. These results suggest that xylose isomerase can contribute to improved ethanol productivity, even without significant xylose conversion. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  18. Technological trends, global market, and challenges of bio-ethanol production.

    Science.gov (United States)

    Mussatto, Solange I; Dragone, Giuliano; Guimarães, Pedro M R; Silva, João Paulo A; Carneiro, Lívia M; Roberto, Inês C; Vicente, António; Domingues, Lucília; Teixeira, José A

    2010-01-01

    Ethanol use as a fuel additive or directly as a fuel source has grown in popularity due to governmental regulations and in some cases economic incentives based on environmental concerns as well as a desire to reduce oil dependency. As a consequence, several countries are interested in developing their internal market for use of this biofuel. Currently, almost all bio-ethanol is produced from grain or sugarcane. However, as this kind of feedstock is essentially food, other efficient and economically viable technologies for ethanol production have been evaluated. This article reviews some current and promising technologies for ethanol production considering aspects related to the raw materials, processes, and engineered strains development. The main producer and consumer nations and future perspectives for the ethanol market are also presented. Finally, technological trends to expand this market are discussed focusing on promising strategies like the use of microalgae and continuous systems with immobilized cells. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Enzymatic digestibility and ethanol fermentability of AFEX-treated starch-rich lignocellulosics such as corn silage and whole corn plant

    Directory of Open Access Journals (Sweden)

    Thelen Kurt D

    2010-06-01

    Full Text Available Abstract Background Corn grain is an important renewable source for bioethanol production in the USA. Corn ethanol is currently produced by steam liquefaction of starch-rich grains followed by enzymatic saccharification and fermentation. Corn stover (the non-grain parts of the plant is a potential feedstock to produce cellulosic ethanol in second-generation biorefineries. At present, corn grain is harvested by removing the grain from the living plant while leaving the stover behind on the field. Alternatively, whole corn plants can be harvested to cohydrolyze both starch and cellulose after a suitable thermochemical pretreatment to produce fermentable monomeric sugars. In this study, we used physiologically immature corn silage (CS and matured whole corn plants (WCP as feedstocks to produce ethanol using ammonia fiber expansion (AFEX pretreatment followed by enzymatic hydrolysis (at low enzyme loadings and cofermentation (for both glucose and xylose using a cellulase-amylase-based cocktail and a recombinant Saccharomyces cerevisiae 424A (LNH-ST strain, respectively. The effect on hydrolysis yields of AFEX pretreatment conditions and a starch/cellulose-degrading enzyme addition sequence for both substrates was also studied. Results AFEX-pretreated starch-rich substrates (for example, corn grain, soluble starch had a 1.5-3-fold higher enzymatic hydrolysis yield compared with the untreated substrates. Sequential addition of cellulases after hydrolysis of starch within WCP resulted in 15-20% higher hydrolysis yield compared with simultaneous addition of hydrolytic enzymes. AFEX-pretreated CS gave 70% glucan conversion after 72 h of hydrolysis for 6% glucan loading (at 8 mg total enzyme loading per gram glucan. Microbial inoculation of CS before ensilation yielded a 10-15% lower glucose hydrolysis yield for the pretreated substrate, due to loss in starch content. Ethanol fermentation of AFEX-treated (at 6% w/w glucan loading CS hydrolyzate (resulting

  20. Enzymatic digestibility and ethanol fermentability of AFEX-treated starch-rich lignocellulosics such as corn silage and whole corn plant

    Science.gov (United States)

    2010-01-01

    Background Corn grain is an important renewable source for bioethanol production in the USA. Corn ethanol is currently produced by steam liquefaction of starch-rich grains followed by enzymatic saccharification and fermentation. Corn stover (the non-grain parts of the plant) is a potential feedstock to produce cellulosic ethanol in second-generation biorefineries. At present, corn grain is harvested by removing the grain from the living plant while leaving the stover behind on the field. Alternatively, whole corn plants can be harvested to cohydrolyze both starch and cellulose after a suitable thermochemical pretreatment to produce fermentable monomeric sugars. In this study, we used physiologically immature corn silage (CS) and matured whole corn plants (WCP) as feedstocks to produce ethanol using ammonia fiber expansion (AFEX) pretreatment followed by enzymatic hydrolysis (at low enzyme loadings) and cofermentation (for both glucose and xylose) using a cellulase-amylase-based cocktail and a recombinant Saccharomyces cerevisiae 424A (LNH-ST) strain, respectively. The effect on hydrolysis yields of AFEX pretreatment conditions and a starch/cellulose-degrading enzyme addition sequence for both substrates was also studied. Results AFEX-pretreated starch-rich substrates (for example, corn grain, soluble starch) had a 1.5-3-fold higher enzymatic hydrolysis yield compared with the untreated substrates. Sequential addition of cellulases after hydrolysis of starch within WCP resulted in 15-20% higher hydrolysis yield compared with simultaneous addition of hydrolytic enzymes. AFEX-pretreated CS gave 70% glucan conversion after 72 h of hydrolysis for 6% glucan loading (at 8 mg total enzyme loading per gram glucan). Microbial inoculation of CS before ensilation yielded a 10-15% lower glucose hydrolysis yield for the pretreated substrate, due to loss in starch content. Ethanol fermentation of AFEX-treated (at 6% w/w glucan loading) CS hydrolyzate (resulting in 28 g/L ethanol

  1. Microscopic Analysis of Corn Fiber Using Corn Starch- and Cellulose-Specific Molecular Probes

    Energy Technology Data Exchange (ETDEWEB)

    Porter, S. E.; Donohoe, B. S.; Beery, K. E.; Xu, Q.; Ding, S.-Y.; Vinzant, T. B.; Abbas, C. A.; Himmel, M. E.

    2007-09-01

    Ethanol is the primary liquid transportation fuel produced from renewable feedstocks in the United States today. The majority of corn grain, the primary feedstock for ethanol production, has been historically processed in wet mills yielding products such as gluten feed, gluten meal, starch, and germ. Starch extracted from the grain is used to produce ethanol in saccharification and fermentation steps; however the extraction of starch is not 100% efficient. To better understand starch extraction during the wet milling process, we have developed fluorescent probes that can be used to visually localize starch and cellulose in samples using confocal microscopy. These probes are based on the binding specificities of two types of carbohydrate binding modules (CBMs), which are small substrate-specific protein domains derived from carbohydrate degrading enzymes. CBMs were fused, using molecular cloning techniques, to a green fluorescent protein (GFP) or to the red fluorescent protein DsRed (RFP). Using these engineered probes, we found that the binding of the starch-specific probe correlates with starch content in corn fiber samples. We also demonstrate that there is starch internally localized in the endosperm that may contribute to the high starch content in corn fiber. We also surprisingly found that the cellulose-specific probe did not bind to most corn fiber samples, but only to corn fiber that had been hydrolyzed using a thermochemical process that removes the residual starch and much of the hemicellulose. Our findings should be of interest to those working to increase the efficiency of the corn grain to ethanol process.

  2. Improved ethanol production at high temperature by consolidated bioprocessing using Saccharomyces cerevisiae strain engineered with artificial zinc finger protein.

    Science.gov (United States)

    Khatun, M Mahfuza; Yu, Xinshui; Kondo, Akihiko; Bai, Fengwu; Zhao, Xinqing

    2017-12-01

    In this work, the consolidated bioprocessing (CBP) yeast Saccharomyces cerevisiae MNII/cocδBEC3 was transformed by an artificial zinc finger protein (AZFP) library to improve its thermal tolerance, and the strain MNII-AZFP with superior growth at 42°C was selected. Improved degradation of acid swollen cellulose by 45.9% led to an increase in ethanol production, when compared to the control strain. Moreover, the fermentation of Jerusalem artichoke stalk (JAS) by MNII-AZFP was shortened by 12h at 42°C with a concomitant improvement in ethanol production. Comparative transcriptomics analysis suggested that the AZFP in the mutant exerted beneficial effect by modulating the expression of multiple functional genes. These results provide a feasible strategy for efficient ethanol production from JAS and other cellulosic biomass through CBP based-fermentation at elevated temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Perspectives on fuel ethanol consumption and trade

    International Nuclear Information System (INIS)

    Walter, Arnaldo; Dolzan, Paulo; Piacente, Erik; Borges da Cunha, Kamyla; Rosillo-Calle, Frank

    2008-01-01

    Since the year 2000 or so there has been a rapid growth on fuel ethanol production and consumption, particularly in US and Brazil. Ethanol trade represented about 10% of world consumption in 2005, Brazil being the main exporter. The most important consumer markets - US and European Union (EU) - have trade regimes that constrained the comparative advantages of the most efficient producers, such as Brazil. This paper evaluates the fuel ethanol market up to 2030 together with the potential for international biotrade. Based on forecasts of gasoline consumption and on targets and mandates of fuel ethanol use, it is estimated that demand could reach 272 Gl in 2030, displacing 10% of the estimated demand of gasoline (Scenario 1), or even 566 Gl in the same year, displacing about 20% of the gasoline demand (Scenario 2). The analysis considers fuel ethanol consumption and production in US, EU-25, Japan, China, Brazil and the rest of the world (ROW-BR). Without significant production of ethanol from cellulosic materials in this period, displacing 10% of the gasoline demand in 2030, at reasonable cost, can only be accomplished by fostering fuel ethanol production in developing countries and enhancing ethanol trade. If the US and EU-25 reach their full production potential (based on conventional routes), the minimum amount that could be traded in 2030 would be about 34 Gl. Displacing 20% of the gasoline demand by 2030 will require the combined development of second-generation technologies and large-scale international trade in ethanol fuel. Without second-generation technologies, Scenario 2 could become a reality only with large-scale production of ethanol from sugarcane in developing countries, e.g., Brazil and ROW-BR could be able to export at least 14.5 Gl in 2010, 73.9 Gl in 2020 and 71.8 Gl in 2030. (author)

  4. Bioconversion of paper sludge with low cellulosic content to ethanol ...

    African Journals Online (AJOL)

    The purpose of the present work was to evaluate the possibility of converting paper sludge into ethanol using xylose-fermenting yeast SHY07-1 in separate hydrolysis and fermentation. In the enzymatic hydrolysis step, sludge on 2% (w/v, expressed in terms of total carbohydrate mass) substrate consistency was incubated ...

  5. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, March 1-August 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D. I.C.

    1980-09-01

    Progress is reported in this coordinated research program to effect the microbiological degradation of cellulosic biomass by anaerobic microorganisms possessing cellulolytic enzymes. Three main areas of research are discussed: increasing enzyme levels through genetics, mutations, and genetic manipulation; the direct conversion of cellulosic biomass to liquid fuel (ethanol); and the production of chemical feedstocks from biomass (acrylic acid, acetone/butanol, and acetic acid). (DMC)

  6. The impact of lignocellulosic ethanol yields in polygeneration with district heating – A case study

    International Nuclear Information System (INIS)

    Starfelt, Fredrik; Daianova, Lilia; Yan, Jinyue; Thorin, Eva; Dotzauer, Erik

    2012-01-01

    Highlights: ► We model a system with ethanol, power and district heating production. ► Different ethanol yields are investigated from an overall system perspective. ► Yields of ethanol production have less importance for the profitability of the plant. -- Abstract: The development towards high energy efficiency and low environmental impact from human interactions has led to changes at many levels of society. As a result of the introduction of penalties on carbon dioxide emissions and other economic instruments, the energy industry is striving to improve energy efficiency and climate mitigation by switching from fossil fuels to renewable fuels. Biomass-based combined heat and power (CHP) plants connected to district heating networks have a need to find uses for the excess heat they produce in summer when the heat demand is low. On the other hand, the transport sector makes a substantial contribution to the increasing CO 2 emissions, which have to be reduced. One promising alternative to address these challenging issues is the integration of vehicle fuel production with biomass-based CHP plants. This paper presents the configuration and operating profits in terms of electricity, heat and ethanol fuel from cellulosic biomass. A case study of a commercial small scale CHP plant was conducted using simulation and modeling tools. The results clearly show that electricity production can be increased when CHP production is integrated with cellulosic ethanol production. The findings also show that the economic benefits of the energy system can be realized with near-term commercially available technology, and that the benefits do not rely solely on ethanol yields.

  7. Simultaneous co-fermentation of mixed sugars: a promising strategy for producing cellulosic ethanol.

    Science.gov (United States)

    Kim, Soo Rin; Ha, Suk-Jin; Wei, Na; Oh, Eun Joong; Jin, Yong-Su

    2012-05-01

    The lack of microbial strains capable of fermenting all sugars prevalent in plant cell wall hydrolyzates to ethanol is a major challenge. Although naturally existing or engineered microorganisms can ferment mixed sugars (glucose, xylose and galactose) in these hydrolyzates sequentially, the preferential utilization of glucose to non-glucose sugars often results in lower overall yield and productivity of ethanol. Therefore, numerous metabolic engineering approaches have been attempted to construct optimal microorganisms capable of co-fermenting mixed sugars simultaneously. Here, we present recent findings and breakthroughs in engineering yeast for improved ethanol production from mixed sugars. In particular, this review discusses new sugar transporters, various strategies for simultaneous co-fermentation of mixed sugars, and potential applications of co-fermentation for producing fuels and chemicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Wet oxidation treatment of organic household waste enriched with wheat straw for simultaneous saccharification and fermentation into ethanol

    DEFF Research Database (Denmark)

    Lissens, G.; Klinke, H.B.; Verstraete, W.

    2004-01-01

    Organic municipal solid waste enriched with wheat straw was subjected to wet-oxidation as a pre-treatment for subsequent enzymatic conversion and fermentation into bio-ethanol. The effect of tempera (185-195degrees C), oxygen pressure (3-12) and sodium carbonate (0-2 g l(-1)) addition on enzymatic...... in the treated waste could be converted into respectively hexose and pentose sugars compared to 46% for cellulose and 36% for hemicellulose in the raw waste. For all wet oxidation conditions tested, total carbohydrate recoveries were high (> 89%) and 44-66% of the original lignin could be converted into non......-toxic carboxylic acids mainly (2.2-4.5 % on DS basis). Simultaneous saccharification and fermentation (SSF) of the treated waste at 10% DS by Saccharomyces cerevisae yielded average ethanol concentrations of 16.5 to 22 g l(-1) for enzyme loadings of 5 and 25 FPU g(-1) DS, respectively. The cellulose to ethanol...

  9. Dilute acid pretreatment of rye straw and bermudagrass for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Ye Sun; Jay J Cheng [North Carolina State Univ., Dept. of Biological and Agricultural Engineering, Raleigh, NC (United States)

    2005-09-01

    Ethanol production from lignocellulosic materials provides an alternative energy production system. Rye and bermudagrass that are used in hog farms for nutrient uptake from swine wastewater have the potential for fuel ethanol production because they have a relative high cellulose and hemicellulose content. Dilute sulfuric acid pretreatment of rye straw and bermudagrass before enzymatic hydrolysis of cellulose was investigated in this study. The biomass at a solid loading rate of 10% was pretreated at 121 deg C with different sulfuric acid concentrations (0.6, 0.9, 1.2 and 1.5%, w/w) and residence times (30, 60, and 90 min). Total reducing sugars, arabinose, galactose, glucose, and xylose in the prehydrolyzate were analyzed. In addition, the solid residues were hydrolyzed by cellulases to investigate the enzymatic digestibility. With the increasing acid concentration and residence time, the amount of arabinose and galactose in the filtrates increased. The glucose concentration in the prehydrolyzate of rye straw was not significantly influenced by the sulfuric acid concentration and residence time, but it increased in the prehydrolyzate of bermudagrass with the increase of pretreatment severity. The xylose concentration in the filtrates increased with the increase of sulfuric acid concentration and residence time. Most of the arabinan, galactan and xylan in the biomass were hydrolyzed during the acid pretreatment. Cellulose remaining in the pretreated feedstock was highly digestible by cellulases from Trichoderma reesei. (Author)

  10. Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa

    Energy Technology Data Exchange (ETDEWEB)

    Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris [National Technical Univ. of Athens, Zografou (Greece). Biotechnology Lab.

    2012-07-15

    Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and {beta}-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively. (orig.)

  11. Evaluation of wheat stillage for ethanol production by recombinant Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Davis, L.; Peiris, P. [University of Western Sydney, Penrith (Australia). School of Science, Food and Horticulture; Young-Jae Jeon; Svenson, C.; Rogers, P. [University of New South Wales, Sydney (Australia). School of Biotechnology and Biomolecular Sciences; Pearce, J. [Manildra Group, Bomaderry (Australia)

    2005-07-01

    Stillage is the main residue from the starch-to-ethanol fermentation process.Carbohydrates (hemicellulose and cellulose) comprise approximately 50% (w/w)of the total components of stillage. Conversion of the hemicellulose and cellulose to fermentable sugars and then to ethanol has the potential to significantly increase the efficiency of the process. The hydrolysis of stillage to fermentable sugars was optimised using 2% (v/v) H{sub 2}SO{sub 4} at 100{sup o}C for 5.5 h and produced 18 g/L xylose, 11.5 g/L arabinose and 6.5 g/L glucose from 120 g/L stillage. Further hydrolysis using enzymes increased the release of glucose by 61%. Furfural, acetate and lactate were the main inhibitors present in the acid hydrolysate of stillage. The lignin-derived inhibitors hydroxymethylfuraldehyde, hydroxybenzaldehyde, vanillin and syringaldehyde were not detected. Neutralisation of the hydrolysate with lime to pH 5 decreased the concentration of furfural by 50%. Fermentation of hydrolysate supplemented with glucose 10 g/L, by recombinant Zymomonas mobilis ZM4(pZB5), produced 11 g/L of ethanol after 70 h, with residual xylose 12 g/L. Supplementation of the hydrolysate with 5 g/L yeast extract and 40 g/L glucose produced 28 g/L ethanol with 2.6 g/L residual xylose after 18 h. Arabinose was not utilised by this particular recombinant strain. From the results, Z. mobilis ZM4(pZB5) may be a suitable candidate for the fermentation of both glucose and xylose in stillage acid hydrolysates. (author)

  12. Forage crops as substrate for animal feed and ethanol production in ...

    African Journals Online (AJOL)

    The results indicate the effect of harvesting time on their composition, including the contents of cellulose, lignin, and crude protein, thus affecting the ethanol yield and quality of animal feed. Ruzi grass, harvested 45 days after being planted, was shown to be the most suitable substrate for animal feed due to its highest crude ...

  13. The cellulose resource matrix.

    Science.gov (United States)

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  14. Superabsorbent nanocomposite synthesis of cellulose from rice husk grafted poly(acrylate acid-co-acrylamide)/bentonite

    Science.gov (United States)

    Helmiyati; Abbas, G. H.; Kurniawan, S.

    2017-04-01

    Superabsorbent nanocomposite synthesis of cellulose rice husk as the backbone with free radical polymerization method in copolymerization grafted with acrylic acid and acrylamide monomer. The cellulose was isolated from rice husk with mixture of toluene and ethanol and then hemicellulose and lignin were removed by using potassium hydroxide 4% and hydrogen peroxide 2%. The obtained cellulose rendement was 37.85%. The functional group of lignin analyzed by FTIR spectra was disappeared at wavenumber 1724 cm-1. Crystal size of the obtained isolated cellulose analyzed by XRD diffraction pattern was 34.6 nm, indicated the nanocrystal structure. Copolymerization was performed at temperature of 70°C with flow nitrogen gas. Initiator and crosslinking agent used were potassium persulfate and N‧N-methylene-bis-acrylamide. The swelling capacity of water and urea showed the results was quite satisfactory, the maximum swelling capacity in urea and water were 611.700 g/g and 451.303 g/g, respectively, and can be applied in agriculture to absorb water and urea fertilizer.

  15. Microaerobic conversion of xylose to ethanol in recombinant Saccharomyces cerevisiae SX6(MUT) expressing cofactor-balanced xylose metabolic enzymes and deficient in ALD6.

    Science.gov (United States)

    Jo, Sung-Eun; Seong, Yeong-Je; Lee, Hyun-Soo; Lee, Soo Min; Kim, Soo-Jung; Park, Kyungmoon; Park, Yong-Cheol

    2016-06-10

    Xylose is a major monosugar in cellulosic biomass and should be utilized for cost-effective ethanol production. In this study, xylose-converting ability of recombinant Saccharomyces cerevisiae SX6(MUT) expressing NADH-preferring xylose reductase mutant (R276H) and other xylose-metabolic enzymes, and deficient in aldehyde dehydrogenase 6 (Ald6p) were characterized at microaerobic conditions using various sugar mixtures. The reduction of air supply from 0.5vvm to 0.1vvm increased specific ethanol production rate by 75% and did not affect specific xylose consumption rate. In batch fermentations using various concentrations of xylose (50-104g/L), higher xylose concentration enhanced xylose consumption rate and ethanol productivity but reduced ethanol yield, owing to the accumulation of xylitol and glycerol from xylose. SX6(MUT) consumed monosugars in pitch pine hydrolysates and produced 23.1g/L ethanol from 58.7g/L sugars with 0.39g/g ethanol yield, which was 14% higher than the host strain of S. cerevisiae D452-2 without the xylose assimilating enzymes. In conclusion, S. cerevisiae SX6(MUT) was characterized to possess high xylose-consuming ability in microaerobic conditions and a potential for ethanol production from cellulosic biomass. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Cost estimate for the production of ethanol from spent sulphite liquors and wood residues

    International Nuclear Information System (INIS)

    Nguyen, Q.

    1990-03-01

    A Lotus 1-2-3 spreadsheet model for estimating the production cost of 95 wt % ethanol from spent sulfite liquors (SSL) and from a wood hydrolysis front-end is described. The most economically attractive process is the fermentation of softwood SSL (SSSL) by the yeast Saccharomyces cerevisiae, yielding a production cost estimate of $0.47/liter. The cost of producing ethanol from cellulosic waste (clarifier sludge) via acid hydrolysis is approximately $0.55/liter, still below the market price of ca $0.60/liter for industrial ethanol. Neither the fermentation of hardwood SSL nor the conversion of sawdust to ethanol, using current technology, are economically viable. However, these processes can become commercially viable if acetic acid-tolerant xylose-fermenting yeasts can be found. 17 refs., 12 figs., 16 tabs

  17. Accounting for all sugars produced during integrated production of ethanol from lignocellulosic biomass.

    Science.gov (United States)

    Schell, Daniel J; Dowe, Nancy; Chapeaux, Alexandre; Nelson, Robert S; Jennings, Edward W

    2016-04-01

    Accurate mass balance and conversion data from integrated operation is needed to fully elucidate the economics of biofuel production processes. This study explored integrated conversion of corn stover to ethanol and highlights techniques for accurate yield calculations. Acid pretreated corn stover (PCS) produced in a pilot-scale reactor was enzymatically hydrolyzed and the resulting sugars were fermented to ethanol by the glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. The calculations presented here account for high solids operation and oligomeric sugars produced during pretreatment, enzymatic hydrolysis, and fermentation, which, if not accounted for, leads to overestimating ethanol yields. The calculations are illustrated for enzymatic hydrolysis and fermentation of PCS at 17.5% and 20.0% total solids achieving 80.1% and 77.9% conversion of cellulose and xylan to ethanol and ethanol titers of 63g/L and 69g/L, respectively. These procedures will be employed in the future and the resulting information used for techno-economic analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Production of ethanol 3G from Kappaphycus alvarezii: evaluation of different process strategies.

    Science.gov (United States)

    Hargreaves, Paulo Iiboshi; Barcelos, Carolina Araújo; da Costa, Antonio Carlos Augusto; Pereira, Nei

    2013-04-01

    This study evaluated the potential of Kappaphycus alvarezii as feedstock for ethanol production, i.e. ethanol 3G. First, aquatic biomass was subjected to a diluted acid pretreatment. This acid pretreatment generated two streams--a galactose-containing liquid fraction and a cellulose-containing solid fraction, which were investigated to determine their fermentability with the following strategies: a single-stream process (simultaneous saccharification and co-fermentation (SSCF) of both fractions altogether), which achieved 64.3 g L(-1) of ethanol, and a two-stream process (fractions were fermented separately), which resulted in 38 g L(-1) of ethanol from the liquid fraction and 53.0 g L(-1) from the simultaneous saccharification and fermentation (SSF) of the solid fraction. Based on the average fermentable carbohydrate concentration, it was possible to obtain 105 L of ethanol per ton of dry seaweed. These preliminaries results indicate that the use of the macro-algae K. alvarezii has a good potential feedstock for bioethanol production. Copyright © 2013. Published by Elsevier Ltd.

  19. The attribution of incentive salience to Pavlovian alcohol cues: a shift from goal-tracking to sign-tracking.

    Science.gov (United States)

    Srey, Chandra S; Maddux, Jean-Marie N; Chaudhri, Nadia

    2015-01-01

    Environmental stimuli that are reliably paired with alcohol may acquire incentive salience, a property that can operate in the use and abuse of alcohol. Here we investigated the incentive salience of Pavlovian alcohol cues using a preclinical animal model. Male, Long-Evans rats (Harlan) with unrestricted access to food and water were acclimated to drinking 15% ethanol (v/v) in their home-cages. Rats then received Pavlovian autoshaping training in which the 10 s presentation of a retractable lever served as the conditioned stimulus (CS) and 15% ethanol served as the unconditioned stimulus (US) (0.2 ml/CS; 12 CS presentations/session; 27 sessions). Next, in an operant test of conditioned reinforcement, nose pokes into an active aperture delivered presentations of the lever-CS, whereas nose pokes into an inactive aperture had no consequences. Across initial autoshaping sessions, goal-tracking behavior, as measured by entries into the fluid port where ethanol was delivered, developed rapidly. However, with extended training goal-tracking diminished, and sign-tracking responses, as measured by lever-CS activations, emerged. Control rats that received explicitly unpaired CS and US presentations did not show goal-tracking or sign-tracking responses. In the test for conditioned reinforcement, rats with CS-US pairings during autoshaping training made more active relative to inactive nose pokes, whereas rats in the unpaired control group did not. Moreover, active nose pokes were positively correlated with sign-tracking behavior during autoshaping. Extended training may produce a shift in the learned properties of Pavlovian alcohol cues, such that after initially predicting alcohol availability they acquire robust incentive salience.

  20. Environmental aspects of ethanol-based fuels from Brassica carinata. A case study of second generation ethanol

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, Sara; Moreira, M'a Teresa; Feijoo, Gumersindo; Gasol, Carles M.; Gabarrell, Xavier; Rieradevall, Joan

    2009-01-01

    One of the main challenges faced by mankind in the 21st century is to meet the increasing demand for energy requirements by means of a more sustainable energy supply. In countries that are net fossil fuel importers, expectation about the benefit of using alternative fuels on reducing oil imports is the primary driving force behind efforts to promote its production and use. Spain is scarce in domestic energy sources and more than 50% of the energy used is fossil fuel based. The promotion of renewable energies use is one of the principal vectors in the Spanish energy policy. Selected herbaceous crops such as Brassica carinata are currently under study as potential energy sources. Its biomass can be considered as potential feedstock to ethanol conversion by an enzymatic process due to the characteristics of its composition, rich in cellulose and hemicellulose. This paper aims to analyse the environmental performance of two ethanol-based fuel applications (E10 and E85) in a passenger car (E10 fuel: a mixture of 10% ethanol and 90% gasoline by volume; E85 fuel: a mixture of 85% ethanol and 15% gasoline by volume) as well as their comparison with conventional gasoline as transport fuel. Two types of functional units are applied in this study: ethanol production oriented and travelling distance oriented functional units in order to reflect the availability or not of ethanol supply. E85 seems to be the best alternative when ethanol production based functional unit is considered in terms of greenhouse gas (GHG) emissions and E10 in terms of non-renewable energy resources use. Nevertheless, E85 offers the best environmental performance when travelling distance oriented functional unit is assumed in both impacts. In both functional unit perspectives, the use of ethanol-based fuels reduces the global warming and fossil fuels consumption. However, the contributions to other impact indicators (e.g. acidification, eutrophication and photochemical oxidants formation) were lower

  1. The BEST project - BioEthanol for the Sustainable Transportation - a contribution to the environment of the metropolis; O projeto BEST - BioEtanol para o Transporte Sustentavel - uma contribuicao ao meio ambiente das metropoles

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Velazquez, Silvia Maria Stortini; Santos, Sandra Maria Apolinario; Moreira, Jose Roberto; Melo, Euler Hoffmann; Coelho, Suani Teixeira [Centro Nacional de Referencia em Biomassa (CENBIO), Sao Paulo, SP (Brazil)], E-mail: silvia@iee.usp.br

    2010-07-01

    The BEST Project - Bio Ethanol for the Sustainable Transportation was an initiative of the European Union, coordinated by the Stockholm City Hall, at Sweden. This project gave incentives the use of ethanol, replacing the Diesel fuel, at the public transportation in Brazil and in the world. The used vehicles in the tests were monitored and evaluated to demonstrate the efficiency and environmental energy of the ethanol, and after the results, the BEST project and the European Union gave recommendations for the formulation of public politics of incentives to the use of technology.

  2. Genome-Wide Association Study Reveals Novel Genes Associated with Culm Cellulose Content in Bread Wheat (Triticum aestivum, L.

    Directory of Open Access Journals (Sweden)

    Simerjeet Kaur

    2017-11-01

    Full Text Available Plant cell wall formation is a complex, coordinated and developmentally regulated process. Cellulose is the most dominant constituent of plant cell walls. Because of its paracrystalline structure, cellulose is the main determinant of mechanical strength of plant tissues. As the most abundant polysaccharide on earth, it is also the focus of cellulosic biofuel industry. To reduce culm lodging in wheat and for improved ethanol production, delineation of the variation for stem cellulose content could prove useful. We present results on the analysis of the stem cellulose content of 288 diverse wheat accessions and its genome-wide association study (GWAS. Cellulose concentration ranged from 35 to 52% (w/w. Cellulose content was normally distributed in the accessions around a mean and median of 45% (w/w. Genome-wide marker-trait association study using 21,073 SNPs helped identify nine SNPs that were associated (p < 1E-05 with cellulose content. Four strongly associated (p < 8.17E-05 SNP markers were linked to wheat unigenes, which included β-tubulin, Auxin-induced protein 5NG4, and a putative transmembrane protein of unknown function. These genes may be directly or indirectly involved in the formation of cellulose in wheat culms. GWAS results from this study have the potential for genetic manipulation of cellulose content in bread wheat and other small grain cereals to enhance culm strength and improve biofuel production.

  3. Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa.

    Science.gov (United States)

    Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris

    2012-07-01

    Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 °C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and β-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively.

  4. Value-added biotransformation of cellulosic sugars by engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Lane, Stephan; Dong, Jia; Jin, Yong-Su

    2018-07-01

    The substantial research efforts into lignocellulosic biofuels have generated an abundance of valuable knowledge and technologies for metabolic engineering. In particular, these investments have led to a vast growth in proficiency of engineering the yeast Saccharomyces cerevisiae for consuming lignocellulosic sugars, enabling the simultaneous assimilation of multiple carbon sources, and producing a large variety of value-added products by introduction of heterologous metabolic pathways. While microbial conversion of cellulosic sugars into large-volume low-value biofuels is not currently economically feasible, there may still be opportunities to produce other value-added chemicals as regulation of cellulosic sugar metabolism is quite different from glucose metabolism. This review summarizes these recent advances with an emphasis on employing engineered yeast for the bioconversion of lignocellulosic sugars into a variety of non-ethanol value-added products. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Comparison of various pretreatments for ethanol production enhancement from solid residue after rumen fluid digestion of rice straw.

    Science.gov (United States)

    Zhang, Haibo; Zhang, Panyue; Ye, Jie; Wu, Yan; Liu, Jianbo; Fang, Wei; Xu, Dong; Wang, Bei; Yan, Li; Zeng, Guangming

    2018-01-01

    The rumen digested residue of rice straw contains high residual carbohydrates, which makes it a potential cellulosic ethanol feedstock. This study evaluated the feasibility and effectiveness of applying microwave assisted alkali (MAP), ultrasound assisted alkali (UAP), and ball milling pretreatment (BMP) to enhance ethanol production from two digested residues (2.5%-DR and 10%-DR) after rumen fluid digestion of rice straw at 2.5% and 10.0% solid content. Results revealed that 2.5%-DR and 10%-DR had a cellulose content of 36.4% and 41.7%, respectively. MAP and UAP improved enzymatic hydrolysis of digested residue by removing the lignin and hemicellulose, while BMP by decreasing the particle size and crystallinity. BMP was concluded as the suitable pretreatment, resulting in an ethanol yield of 116.65 and 147.42mgg -1 for 2.5%-DR and 10%-DR, respectively. The integrated system including BMP for digested residue at 2.5% solid content achieved a maximum energy output of 7010kJkg -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The tendency to sign-track predicts cue-induced reinstatement during nicotine self-administration, and is enhanced by nicotine but not ethanol

    Science.gov (United States)

    Versaggi, Cassandra L.; King, Christopher P.; Meyer, Paul J.

    2016-01-01

    Rationale Some individuals are particularly responsive to reward-associated stimuli (“cues”), including the effects of these cues on craving and relapse to drug-seeking behavior. In the cases of nicotine and alcohol, cues may acquire these abilities via the incentive-enhancing properties of the drug. Objectives To determine the interaction between cue-responsivity and nicotine reinforcement, we studied the patterns of nicotine self-administration in rats categorized based on their tendency to approach a food predictive cue (“sign-trackers”) or a reward-delivery location (“goal-trackers”). In a second experiment, we determined whether nicotine and ethanol altered the incentive value of a food cue. Methods Rats were classified as sign- or goal-trackers during a Pavlovian conditioned approach paradigm. Rats then self-administered intravenous nicotine (0.03 mg/kg infusions) followed by extinction and cue induced reinstatement tests. We also tested the effects of nicotine (0.4 mg/kg base s.c.) or ethanol (0.7 g/kg i.p.) on the approach to, and reinforcing efficacy of, a food cue. Results Sign-trackers showed greater reinstatement in response to a nicotine cue. Further, nicotine enhanced sign-tracking but not goal-tracking to a food cue, and also enhanced responding for the food cue during the conditioned reinforcement test. Conversely, ethanol reduced sign-tracking and increased goal-tracking, but had no effect on conditioned reinforcement. Conclusions Our studies demonstrate that the tendency to attribute incentive value to a food cue predicts enhanced cue-induced reinstatement. Additionally, the incentive value of food cues is differentially modulated by nicotine and ethanol, which may be related to the reinforcing effects of these drugs. PMID:27282365

  7. The tendency to sign-track predicts cue-induced reinstatement during nicotine self-administration, and is enhanced by nicotine but not ethanol.

    Science.gov (United States)

    Versaggi, Cassandra L; King, Christopher P; Meyer, Paul J

    2016-08-01

    Some individuals are particularly responsive to reward-associated stimuli ("cues"), including the effects of these cues on craving and relapse to drug-seeking behavior. In the cases of nicotine and alcohol, cues may acquire these abilities via the incentive-enhancing properties of the drug. To determine the interaction between cue-responsivity and nicotine reinforcement, we studied the patterns of nicotine self-administration in rats categorized based on their tendency to approach a food-predictive cue ("sign-trackers") or a reward-delivery location ("goal-trackers"). In a second experiment, we determined whether nicotine and ethanol altered the incentive value of a food cue. Rats were classified as sign- or goal-trackers during a Pavlovian conditioned approach paradigm. Rats then self-administered intravenous nicotine (0.03 mg/kg infusions) followed by extinction and cue-induced reinstatement tests. We also tested the effects of nicotine (0.4 mg/kg base s.c.) or ethanol (0.7 g/kg i.p.) on the approach to, and reinforcing efficacy of, a food cue. Sign-trackers showed greater reinstatement in response to a nicotine cue. Further, nicotine enhanced sign-tracking but not goal-tracking to a food cue and also enhanced responding for the food cue during the conditioned reinforcement test. Conversely, ethanol reduced sign-tracking and increased goal-tracking, but had no effect on conditioned reinforcement. Our studies demonstrate that the tendency to attribute incentive value to a food cue predicts enhanced cue-induced reinstatement. Additionally, the incentive value of food cues is differentially modulated by nicotine and ethanol, which may be related to the reinforcing effects of these drugs.

  8. Evaluation of processing technology for Triarrhena sacchariflora (Maxim. Nakai for ethanol production.

    Directory of Open Access Journals (Sweden)

    Fengqin Gao

    Full Text Available The effects of dilute H2SO4 concentration, forage:sulfuric acid ratio, digestion time, and digestion temperature were evaluated to determine effects on ethanol yield of Triarrhena sacchariflora (Maxim. Nakai. Twenty single factor experiments were conducted to evaluate H2SO4 concentration (0.5, 1.0, 1.5, 2.0, and 2.5%, w/w, forage:sulfuric acid ratio (1:6, 1:8, 1:10, 1:12, and 1:14, g/ml, digestion time (15, 30, 45, 60, and 90, min, digestion temperature (80, 100, 110, 120, and 125 °C for 3 replicates of the 5 levels of each factor. Based on results of the single factor experiments, an incomplete factorial was designed to evaluate ethanol yield from the best combinations of single factors. Finally, the best combination was tested by enzymatic hydrolysis and fermentation experiment in selected combinations according to pretreatment results. Percentage cellulose, hemicellulose, and lignin contents of forage residue after pretreatment, and glucose and xylose concentrations of the filtrate were analyzed prior to enzymatic hydrolysis, and percentage crystallinity was observed in untreated grass and pretreated residue. In addition, the solid residues were then hydrolysed and fermented by cellulase and yeast, the concentrations of glucose and ethanol being monitored for 96 h. Results showed that the order of the effect of main effect factors was as follows: digestion temperature > dilute H2SO4 concentration > digestion time > forage:sulfuric acid ratio. The best process parameters evaluated were sulfuric acid concentration of 1.5%, forage:sulfuric acid ratio of 1:6, digestion time of 15 min, and digestion temperature of 120°C. With this combination of factors, 80% of the cellulose was hydrolysed in 96 h, and 78% converted to ethanol. The findings identified that hemicelluloses were the key deconstruction barrier for pretreatment of Triarrhena sacchariflora (Maxim. Nakai for ethanol production. The results of this research provide evidence of

  9. Evaluation of processing technology for Triarrhena sacchariflora (Maxim.) Nakai for ethanol production.

    Science.gov (United States)

    Gao, Fengqin; Yang, Fuyu; Zhou, He; Sun, Qizhong; Zhang, Yunwei; Brown, Michael A

    2014-01-01

    The effects of dilute H2SO4 concentration, forage:sulfuric acid ratio, digestion time, and digestion temperature were evaluated to determine effects on ethanol yield of Triarrhena sacchariflora (Maxim.) Nakai. Twenty single factor experiments were conducted to evaluate H2SO4 concentration (0.5, 1.0, 1.5, 2.0, and 2.5%, w/w), forage:sulfuric acid ratio (1:6, 1:8, 1:10, 1:12, and 1:14, g/ml), digestion time (15, 30, 45, 60, and 90, min), digestion temperature (80, 100, 110, 120, and 125 °C) for 3 replicates of the 5 levels of each factor. Based on results of the single factor experiments, an incomplete factorial was designed to evaluate ethanol yield from the best combinations of single factors. Finally, the best combination was tested by enzymatic hydrolysis and fermentation experiment in selected combinations according to pretreatment results. Percentage cellulose, hemicellulose, and lignin contents of forage residue after pretreatment, and glucose and xylose concentrations of the filtrate were analyzed prior to enzymatic hydrolysis, and percentage crystallinity was observed in untreated grass and pretreated residue. In addition, the solid residues were then hydrolysed and fermented by cellulase and yeast, the concentrations of glucose and ethanol being monitored for 96 h. Results showed that the order of the effect of main effect factors was as follows: digestion temperature > dilute H2SO4 concentration > digestion time > forage:sulfuric acid ratio. The best process parameters evaluated were sulfuric acid concentration of 1.5%, forage:sulfuric acid ratio of 1:6, digestion time of 15 min, and digestion temperature of 120°C. With this combination of factors, 80% of the cellulose was hydrolysed in 96 h, and 78% converted to ethanol. The findings identified that hemicelluloses were the key deconstruction barrier for pretreatment of Triarrhena sacchariflora (Maxim.) Nakai for ethanol production. The results of this research provide evidence of appropriate

  10. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    KAUST Repository

    Zhang, Bo

    2016-08-16

    This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission of ethanol blended gasoline mixtures in future engines. The optimal fuel blend (lowest CO2 emitting fuel) is identified. A range of gasoline fuels is studied, containing different ethanol volume percentages (E0–E40), research octane numbers (RON, 92–105), and octane sensitivities (8.5–15.5). Sugarcane-based and cellulosic ethanol-blended gasolines are shown to be effective in reducing lifecycle CO2 emission, while corn-based ethanol is not as effective. A refinery simulation of production emission was utilized, and combined with vehicle fuel consumption modeling to determine the lifecycle CO2 emissions associated with ethanol-blended gasoline in turbocharged engines. The critical parameters studied, and related to blended fuel lifecycle CO2 emissions, are ethanol content, research octane number, and octane sensitivity. The lowest-emitting blended fuel had an ethanol content of 32 vol%, RON of 105, and octane sensitivity of 15.5; resulting in a CO2 reduction of 7.1%, compared to the reference gasoline fuel and engine technology. The advantage of ethanol addition is greatest on a per unit basis at low concentrations. Finally, this study shows that engine-downsizing technology can yield an additional CO2 reduction of up to 25.5% in a two-stage downsized turbocharged engine burning the optimum sugarcane-based fuel blend. The social cost savings in the USA, from the CO2 reduction, is estimated to be as much as $187 billion/year. © 2016 Elsevier Ltd

  11. Evaluation of environmental impacts of cellulosic ethanol using life cycle assessment with technological advances over time

    International Nuclear Information System (INIS)

    Pawelzik, Paul F.; Zhang, Qiong

    2012-01-01

    Life Cycle Assessment (LCA) has been used in quantifying the environmental impacts of materials, processes, products, or systems across their entire lifespan from creation to disposal. To evaluate the environmental impact of advancing technology, Life Cycle Assessment with Technological Advances over Time (LCA-TAT) incorporates technology improvements within the traditional LCA framework. In this paper, the LCA-TAT is applied to quantify the environmental impacts of ethanol production using cellulosic biomass as a feedstock through the simultaneous saccharification and co-fermentation (SSCF) process as it improves over time. The data for the SSCF process are taken from the Aspen Plus ® simulation developed by the National Renewable Energy Lab (NREL). The Environmental Fate and Risk Assessment Tool (EFRAT) is used to calculate the fugitive emissions and SimaPro 7.1 software is used to quantify the environmental impacts of processes. The impact indicators of the processes are calculated using the Eco-indicator 95 method; impact categories analyzed include ozone layer depletion, heavy metals, carcinogens, summer smog, winter smog, pesticides, greenhouse effect, acidification, and eutrophication. Based on the LCA-TAT results, it is found that removal of the continuous ion exchange step within the pretreatment area increases the environmental impact of the process. The main contributor to the increase in the environmental impact of the process is the heavy metal indicator. In addition, a sensitivity analysis is performed to identify major inputs and outputs that affect environmental impacts of the overall process. Based on this analysis it is observed that an increase in waste production and acid use have the greatest effect on the environmental impacts of the SSCF process. Comparing economic analysis with projected technological advances performed by NREL, the improvement in environmental impact was not matched by a concomitant improvement in economic performance. In

  12. Optimization of microwave pretreatment on wheat straw for ethanol production

    DEFF Research Database (Denmark)

    Xu, Jian; Chen, Hongzhang; Kádár, Zsófia

    2011-01-01

    An orthogonal design (L9(34)) was used to optimize the microwave pretreatment on wheat straw for ethanol production. The orthogonal analysis was done based on the results obtained from the nine pretreatments. The effect of four factors including the ratio of biomass to NaOH solution, pretreatment...... time, microwave power, and the concentration of NaOH solution with three different levels on the chemical composition, cellulose/hemicellulose recoveries and ethanol concentration was investigated. According to the orthogonal analysis, pretreatment with the ratio of biomass to liquid at 80 g kg−1......, the NaOH concentration of 10 kg m−3, the microwave power of 1000 W for 15 min was confirmed to be the optimal condition. The ethanol yield was 148.93 g kg−1 wheat straw at this condition, much higher than that from the untreated material which was only 26.78 g kg−1....

  13. Forage Quality and Composition Measurements as Predictors of Ethanol Yield from Maize (Zea mays L.) Stover

    Science.gov (United States)

    Improvement of biofeedstock quality for cellulosic ethanol production will be facilitated by inexpensive and rapid methods of evaluation, such as those already employed in the field of ruminant nutrition. Our objective was to evaluate whether forage quality and compositional measurements could be u...

  14. Development of microorganisms for cellulose-biofuel consolidated bioprocessings: metabolic engineers’ tricks

    Directory of Open Access Journals (Sweden)

    Roberto Mazzoli

    2012-10-01

    Full Text Available Cellulose waste biomass is the most abundant and attractive substrate for "biorefinery strategies" that are aimed to produce high-value products (e.g. solvents, fuels, building blocks by economically and environmentally sustainable fermentation processes. However, cellulose is highly recalcitrant to biodegradation and its conversion by biotechnological strategies currently requires economically inefficient multistep industrial processes. The need for dedicated cellulase production continues to be a major constraint to cost-effective processing of cellulosic biomass.Research efforts have been aimed at developing recombinant microorganisms with suitable characteristics for single step biomass fermentation (consolidated bioprocessing, CBP. Two paradigms have been applied for such, so far unsuccessful, attempts: a “native cellulolytic strategies”, aimed at conferring high-value product properties to natural cellulolytic microorganisms; b “recombinant cellulolytic strategies”, aimed to confer cellulolytic ability to microorganisms exhibiting high product yields and titers.By starting from the description of natural enzyme systems for plant biomass degradation and natural metabolic pathways for some of the most valuable product (i.e. butanol, ethanol, and hydrogen biosynthesis, this review describes state-of-the-art bottlenecks and solutions for the development of recombinant microbial strains for cellulosic biofuel CBP by metabolic engineering. Complexed cellulases (i.e. cellulosomes benefit from stronger proximity effects and show enhanced synergy on insoluble substrates (i.e. crystalline cellulose with respect to free enzymes. For this reason, special attention was held on strategies involving cellulosome/designer cellulosome-bearing recombinant microorganisms.

  15. Energy analysis of ethanol production from sweet sorghum

    Energy Technology Data Exchange (ETDEWEB)

    Worley, J.W. (Georgia Univ., Athens, GA (United States). Dept. of Agricultural Engineering); Vaughan, D.H.; Cundiff, J.S. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Agricultural Engineering)

    1992-01-01

    The Piedmont System is a collection of equipment for efficiently removing the juice from sweet sorghum stalks for the production of ethanol. The concept is to separate the whole stalks into pith and rind-leaf fractions, pass only the pith fraction through a screw press, and thus achieve an improvement in juice-expression efficiency and press capacity. An energy analysis was done for two options of this proposed harvesting/processing system: (Option 1) The juice is evaporated to syrup and used throughout the year to produce ethanol, and the by-products are used as cattle feed. (Option 2) The juice is fermented as it is harvested, and the by-products (along with other cellulosic materials) are used as feedstock for the remainder of the year. Energy ratios (energy output/energy input) of 0.9, 1.1 and 0.8 were found for sweet sorghum Option 1, sweet sorghum Option 2, and corn, respectively, as feedstocks for ethanol. If only liquid fuels are considered, the ratios are increased to 3.5, 7.9 and 4.5. (author).

  16. Identification and characterization of an anaerobic ethanol-producing cellulolytic bacterial consortium from Great Basin hot springs with agricultural residues and energy crops.

    Science.gov (United States)

    Zhao, Chao; Deng, Yunjin; Wang, Xingna; Li, Qiuzhe; Huang, Yifan; Liu, Bin

    2014-09-01

    In order to obtain the cellulolytic bacterial consortia, sediments from Great Basin hot springs (Nevada, USA) were sampled and enriched with cellulosic biomass as the sole carbon source. The bacterial composition of the resulting anaerobic ethanol-producing celluloytic bacterial consortium, named SV79, was analyzed. With methods of the full-length 16S rRNA librarybased analysis and denaturing gradient gel electrophoresis, 21 bacteria belonging to eight genera were detected from this consortium. Clones with closest relation to the genera Acetivibrio, Clostridium, Cellulosilyticum, Ruminococcus, and Sporomusa were predominant. The cellulase activities and ethanol productions of consortium SV79 using different agricultural residues (sugarcane bagasse and spent mushroom substrate) and energy crops (Spartina anglica, Miscanthus floridulus, and Pennisetum sinese Roxb) were studied. During cultivation, consortium SV79 produced the maximum filter paper activity (FPase, 9.41 U/ml), carboxymethylcellulase activity (CMCase, 6.35 U/ml), and xylanase activity (4.28 U/ml) with sugarcane bagasse, spent mushroom substrate, and S. anglica, respectively. The ethanol production using M. floridulus as substrate was up to 2.63 mM ethanol/g using gas chromatography analysis. It has high potential to be a new candidate for producing ethanol with cellulosic biomass under anoxic conditions in natural environments.

  17. fA cellular automaton model of crystalline cellulose hydrolysis by cellulases

    Directory of Open Access Journals (Sweden)

    Little Bryce A

    2011-10-01

    Full Text Available Abstract Background Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model. Results The Cellulase 4D model was developed de novo taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from Trichoderma reesei cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall

  18. The attribution of incentive salience to Pavlovian alcohol cues: a shift from goal-tracking to sign-tracking

    Directory of Open Access Journals (Sweden)

    Chandra S. Srey

    2015-03-01

    Full Text Available Environmental stimuli that are reliably paired with alcohol may acquire incentive salience, a property that can operate in the use and abuse of alcohol. Here we investigated the incentive salience of Pavlovian alcohol cues using a preclinical animal model. Male, Long-Evans rats (Harlan with unrestricted access to food and water were acclimated to drinking 15% ethanol (v/v in their home-cages. Rats then received Pavlovian autoshaping training in which the 10 second presentation of a retractable lever served as the conditioned stimulus (CS and 15% ethanol served as the unconditioned stimulus (US (0.2 ml/CS; 12 CS presentations/session; 27 sessions. Next, in an operant test of conditioned reinforcement, nose pokes into an active aperture delivered presentations of the lever-CS, whereas nose pokes into an inactive aperture had no consequences. Across initial autoshaping sessions, goal-tracking behavior, as measured by entries into the fluid port where ethanol was delivered, developed rapidly. However, with extended training goal-tracking diminished, and sign-tracking responses, as measured by lever-CS activations, emerged. Control rats that received explicitly unpaired CS and US presentations did not show goal-tracking or sign-tracking responses. In the test for conditioned reinforcement, rats with CS-US pairings during autoshaping training made more active relative to inactive nose pokes, whereas rats in the unpaired control group did not. Moreover, active nose pokes were positively correlated with sign-tracking behavior during autoshaping. Extended training may produce a shift in the learned properties of Pavlovian alcohol cues, such that after initially predicting alcohol availability they acquire robust incentive salience.

  19. Ethanol production from sunflower meal biomass by simultaneous saccharification and fermentation (SSF) with Kluyveromyces marxianus ATCC 36907.

    Science.gov (United States)

    Camargo, Danielle; Gomes, Simone D; Sene, Luciane

    2014-11-01

    The lignocellulosic materials are considered promising renewable resources for ethanol production, but improvements in the processes should be studied to reduce operating costs. Thus, the appropriate enzyme loading for cellulose saccharification is critical for process economics. This study aimed at evaluating the concentration of cellulase and β-glucosidase in the production of bioethanol by simultaneous saccharification and fermentation (SSF) of sunflower meal biomass. The sunflower biomass was pretreated with 6% H2SO4 (w/v), at 121 °C, for 20 min, for hemicellulose removal and delignificated with 1% NaOH. SSF was performed with Kluyveromyces marxianus ATCC 36907, at 38 °C, 150 rpm, for 72 h, with different enzyme concentrations (Cellulase Complex NS22086-10, 15 and 20 FPU/gsubstrate and β-Glucosidase NS22118, with a cellulase to β-glucosidase ratio of 1.5:1; 2:1 and 3:1). The best condition for ethanol production was cellulase 20 FPU/gsubstrate and β-glucosidase 13.3 CBU/gsubstrate, resulting in 27.88 g/L ethanol, yield of 0.47 g/g and productivity of 0.38 g/L h. Under this condition the highest enzymatic conversion of cellulose to glucose was attained (87.06%).

  20. Dynamic modeling and analyses of simultaneous saccharification and fermentation process to produce bio-ethanol from rice straw.

    Science.gov (United States)

    Ko, Jordon; Su, Wen-Jun; Chien, I-Lung; Chang, Der-Ming; Chou, Sheng-Hsin; Zhan, Rui-Yu

    2010-02-01

    The rice straw, an agricultural waste from Asians' main provision, was collected as feedstock to convert cellulose into ethanol through the enzymatic hydrolysis and followed by the fermentation process. When the two process steps are performed sequentially, it is referred to as separate hydrolysis and fermentation (SHF). The steps can also be performed simultaneously, i.e., simultaneous saccharification and fermentation (SSF). In this research, the kinetic model parameters of the cellulose saccharification process step using the rice straw as feedstock is obtained from real experimental data of cellulase hydrolysis. Furthermore, this model can be combined with a fermentation model at high glucose and ethanol concentrations to form a SSF model. The fermentation model is based on cybernetic approach from a paper in the literature with an extension of including both the glucose and ethanol inhibition terms to approach more to the actual plants. Dynamic effects of the operating variables in the enzymatic hydrolysis and the fermentation models will be analyzed. The operation of the SSF process will be compared to the SHF process. It is shown that the SSF process is better in reducing the processing time when the product (ethanol) concentration is high. The means to improve the productivity of the overall SSF process, by properly using aeration during the batch operation will also be discussed.

  1. Industrial-scale steam explosion pretreatment of sugarcane straw for enzymatic hydrolysis of cellulose for production of second generation ethanol and value-added products.

    Science.gov (United States)

    Oliveira, Fernando M V; Pinheiro, Irapuan O; Souto-Maior, Ana M; Martin, Carlos; Gonçalves, Adilson R; Rocha, George J M

    2013-02-01

    Steam explosion at 180, 190 and 200°C for 15min was applied to sugarcane straw in an industrial sugar/ethanol reactor (2.5m(3)). The pretreated straw was delignificated by sodium hydroxide and hydrolyzed with cellulases, or submitted directly to enzymatic hydrolysis after the pretreatment. The pretreatments led to remarkable hemicellulose solubilization, with the maximum (92.7%) for pretreatment performed at 200°C. Alkaline treatment of the pretreated materials led to lignin solubilization of 86.7% at 180°C, and only to 81.3% in the material pretreated at 200°C. All pretreatment conditions led to high hydrolysis conversion of cellulose, with the maximum (80.0%) achieved at 200°C. Delignification increase the enzymatic conversion (from 58.8% in the cellulignin to 85.1% in the delignificated pulp) of the material pretreated at 180°C, but for the material pretreated at 190°C, the improvement was less remarkable, while for the pretreated at 200°C the hydrolysis conversion decreased after the alkaline treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Cellulose synthase complex organization and cellulose microfibril structure.

    Science.gov (United States)

    Turner, Simon; Kumar, Manoj

    2018-02-13

    Cellulose consists of linear chains of β-1,4-linked glucose units, which are synthesized by the cellulose synthase complex (CSC). In plants, these chains associate in an ordered manner to form the cellulose microfibrils. Both the CSC and the local environment in which the individual chains coalesce to form the cellulose microfibril determine the structure and the unique physical properties of the microfibril. There are several recent reviews that cover many aspects of cellulose biosynthesis, which include trafficking of the complex to the plasma membrane and the relationship between the movement of the CSC and the underlying cortical microtubules (Bringmann et al. 2012 Trends Plant Sci. 17 , 666-674 (doi:10.1016/j.tplants.2012.06.003); Kumar & Turner 2015 Phytochemistry 112 , 91-99 (doi:10.1016/j.phytochem.2014.07.009); Schneider et al. 2016 Curr. Opin. Plant Biol. 34 , 9-16 (doi:10.1016/j.pbi.2016.07.007)). In this review, we will focus on recent advances in cellulose biosynthesis in plants, with an emphasis on our current understanding of the structure of individual catalytic subunits together with the local membrane environment where cellulose synthesis occurs. We will attempt to relate this information to our current knowledge of the structure of the cellulose microfibril and propose a model in which variations in the structure of the CSC have important implications for the structure of the cellulose microfibril produced.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'. © 2017 The Author(s).

  3. IMPROVEMENT OF BIOFUEL ETHANOL RECOVERY USING THE PERVAPORATION SEPARATION TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    Nilufer Durmaz Hilmioglu [Kocaeli University Chemical Engineering Department Veziroglu Campus, Kocaeli (Turkey)

    2008-09-30

    The climatic impact of carbon dioxide emissions from the burning of fossil fuels have become a major problem. The production of renewable biofuels from biomass has received increasing attention. Because of the economic and environmental benefits of fuel ethanol's use it is considered one of the most important renewable fuels. In ethanol fermentations inhibition of the microorganism by ethanol limits the amount of substrate in the feed that can be converted. In a process high feed concentrations are desirable to minimize the flows. Such high feed concentrations can be realized in integrated processes in which ethanol is recovered by pervaporation from the fermentation broth as it is formed. The hybrid process is an attractive process to increase ethanol production economics and to decrease environmental pollution. The separaiton of alcohol from mixtures with ethanol produced by fermentation is usually carried out by distillation and the energy consumption is very high when azeotropic concentration is reached, which corresponds to 5% water in ethanol/water mixture. The pervaporation process provides an economical alternative to the existing distillation technique. A continous recovery of alcohol could be achieved by using the pervaporation process during fermentation, making the process more energy efficient. In this work, for the purposes of membrane material development for pervaporation; zeolite filled and unfilled cellulose acetate membranes were prepared. Zeolite types were 4A, 13X. The effect of incorporation of nano-sized zeolites prepared in a colloidal form in membranes was also investigated. From the sorption tests it is concluded that, ethanol/water azeotropy can be breaked by pervaporation.

  4. Energy and greenhouse gas emission effects of corn and cellulosic ethanol with technology improvements and land use changes

    International Nuclear Information System (INIS)

    Wang, Michael Q.; Han, Jeongwoo; Haq, Zia; Tyner, Wallace E.; Wu, May; Elgowainy, Amgad

    2011-01-01

    Use of ethanol as a transportation fuel in the United States has grown from 76 dam 3 in 1980 to over 40.1 hm 3 in 2009 - and virtually all of it has been produced from corn. It has been debated whether using corn ethanol results in any energy and greenhouse gas benefits. This issue has been especially critical in the past several years, when indirect effects, such as indirect land use changes, associated with U.S. corn ethanol production are considered in evaluation. In the past three years, modeling of direct and indirect land use changes related to the production of corn ethanol has advanced significantly. Meanwhile, technology improvements in key stages of the ethanol life cycle (such as corn farming and ethanol production) have been made. With updated simulation results of direct and indirect land use changes and observed technology improvements in the past several years, we conducted a life-cycle analysis of ethanol and show that at present and in the near future, using corn ethanol reduces greenhouse gas emission by more than 20%, relative to those of petroleum gasoline. On the other hand, second-generation ethanol could achieve much higher reductions in greenhouse gas emissions. In a broader sense, sound evaluation of U.S. biofuel policies should account for both unanticipated consequences and technology potentials. We maintain that the usefulness of such evaluations is to provide insight into how to prevent unanticipated consequences and how to promote efficient technologies with policy intervention.

  5. Correlation between anatomical characteristics of ethanol organosolv pretreated Buddleja davidii and its enzymatic conversion to glucose.

    Science.gov (United States)

    Hallac, Bassem B; Ray, Michael; Murphy, Richard J; Ragauskas, Arthur J

    2010-12-01

    Buddleja davidii is a unique biomass that has many attractive agroenergy features, especially its wide range of growth habitat. The anatomical characteristics of B. davidii were investigated before and after ethanol organosolv pretreatment (one of the leading pretreatment technologies) in order to further understand the alterations that occur to the cellular structure of the biomass which can then be correlated with its enzymatic digestibility. Results showed that the ethanol organosolv pretreatment of B. davidii selectively removes lignin from the middle lamella (ML), which does not significantly disrupt the crystalline structure of cellulose. The removal of ML lignin is a major factor in enhancing enzymatic cellulose-to-glucose hydrolysis. The pretreatment also causes cell deformation, resulting in cracks and breaks in the cell wall. These observations, together with characterization analysis of the cell wall polymer material, lend support to the hypothesis that the physical distribution of lignin in the biomass matrix is an important structural feature affecting biomass enzymatic digestibility. © 2010 Wiley Periodicals, Inc.

  6. Production of ethanol from cassava pulp via fermentation with a surface-engineered yeast strain displaying glucoamylase

    Energy Technology Data Exchange (ETDEWEB)

    Kosugi, Akihiko; Murata, Yoshinori; Arai, Takamitsu; Mori, Yutaka [Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686 (Japan); Kondo, Akihiko [Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Nada-ku, Kobe, 657-8501 (Japan); Ueda, Mitsuyoshi [Department of Applied Biochemistry, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Vaithanomsat, Pilanee; Thanapase, Warunee [Nanotechnology and Biotechnology Division, Kasetsart Agricultural and Agro-Industrial Product Improvement Institute (KAPI), Kasetsart University, 50 Chatuchak, Ladyao, Bangkok 10900 (Thailand)

    2009-05-15

    Cassava (Manihot esculenta Crantz) pulp, produced in large amounts as a by-product of starch manufacturing, is a major biomass resource in Southeast Asian countries. It contains abundant starch (approximately 60%) and cellulose fiber (approximately 20%). To effectively utilize the cassava pulp, an attempt was made to convert its components to ethanol using a sake-brewing yeast displaying glucoamylase on the cell surface. Saccharomyces cerevisiae Kyokai no. 7 (strain K7) displaying Rhizopus oryzae glucoamylase, designated strain K7G, was constructed using the C-terminal-half region of {alpha}-agglutinin. A sample of cassava pulp was pretreated with a hydrothermal reaction (140 C for 1 h), followed by treatment with a Trichoderma reesei cellulase to hydrolyze the cellulose in the sample. The K7G strain fermented starch and glucose in pretreated samples without addition of amylolytic enzymes, and produced ethanol in 91% and 80% of theoretical yield from 5% and 10% cassava pulp, respectively. (author)

  7. Application of Box-Behnken Design in Optimization of Glucose Production from Oil Palm Empty Fruit Bunch Cellulose

    Directory of Open Access Journals (Sweden)

    Satriani Aga Pasma

    2013-01-01

    Full Text Available Oil palm empty fruit bunch fiber (OPEFB is a lignocellulosic waste from palm oil mills. It contains mainly cellulose from which glucose can be derived to serve as raw materials for valuable chemicals such as succinic acid. A three-level Box-Behnken design combined with the canonical and ridge analysis was employed to optimize the process parameters for glucose production from OPEFB cellulose using enzymatic hydrolysis. Organosolv pretreatment was used to extract cellulose from OPEFB using ethanol and water as the solvents. The extracted cellulose was characterized by thermogravimetric analysis, FTIR spectroscopy, and field emission scanning electron microscopy. Hydrolysis parameters including amount of enzyme, amount of cellulose, and reaction time were investigated. The experimental results were fitted with a second-order polynomial equation by a multiple regression analysis and found that more than 97% of the variations could be predicted by the models. Using the ridge analysis, the optimal conditions reaction time found for the production of glucose was 76 hours and 30 min, whereas the optimum amount of enzyme and cellulose was 0.5 mL and 0.9 g, respectively. Under these optimal conditions, the corresponding response value predicted for glucose concentration was 169.34 g/L, which was confirmed by validation experiments.

  8. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Rydzak, Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Garcia, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Stevenson, David M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Sladek, Margaret [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Klingeman, Dawn M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Holwerda, Evert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Dartmouth College, Hanover, NH (United States). Thayer School of Engineering; Amador-Noguez, Daniel [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Guss, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center

    2017-05-01

    Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. And while recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H2), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine and α-ketoglutarate levels indicative of nitrogen-rich conditions. Here, we propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine/α-ketoglutarate levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.

  9. Enzymatic hydrolysis and ethanol fermentation of high dry matter wet-exploded wheat straw at low enzyme loading

    DEFF Research Database (Denmark)

    Georgieva, T.I.; Hou, Xiaoru; Hilstrøm, Troels

    2008-01-01

    was the most efficient in enhancing overall convertibility of the raw material to sugars and minimizing generation of furfural as a by-product. For scale-up of the process, high dry matter (DM) concentrations of 15-20% will be necessary. However, high DM hydrolysis and fermentation are limited by high...... and a low enzyme loading of 10 FPU/g cellulose in an industrial acceptable time frame of 96 h. Cellulose and hemicellulose conversion from enzymatic hydrolysis were 70 and 68%, respectively, and an overall ethanol yield from SSF was 68%....

  10. Conversion of paper sludge to ethanol, II: process design and economic analysis.

    Science.gov (United States)

    Fan, Zhiliang; Lynd, Lee R

    2007-01-01

    Process design and economics are considered for conversion of paper sludge to ethanol. A particular site, a bleached kraft mill operated in Gorham, NH by Fraser Papers (15 tons dry sludge processed per day), is considered. In addition, profitability is examined for a larger plant (50 dry tons per day) and sensitivity analysis is carried out with respect to capacity, tipping fee, and ethanol price. Conversion based on simultaneous saccharification and fermentation with intermittent feeding is examined, with ethanol recovery provided by distillation and molecular sieve adsorption. It was found that the Fraser plant achieves positive cash flow with or without xylose conversion and mineral recovery. Sensitivity analysis indicates economics are very sensitive to ethanol selling price and scale; significant but less sensitive to the tipping fee, and rather insensitive to the prices of cellulase and power. Internal rates of return exceeding 15% are projected for larger plants at most combinations of scale, tipping fee, and ethanol price. Our analysis lends support to the proposition that paper sludge is a leading point-of-entry and proving ground for emergent industrial processes featuring enzymatic hydrolysis of cellulosic biomass.

  11. Co-production of electricity and ethanol, process economics of value prior combustion

    International Nuclear Information System (INIS)

    Treasure, T.; Gonzalez, R.; Venditti, R.; Pu, Y.; Jameel, H.; Kelley, S.; Prestemon, Jeffrey

    2012-01-01

    Highlights: ► Economics of producing cellulosic ethanol and bio-power in the same facility using an autohydrolysis process. ► Feedstock considerably affect the economics of the biorefinery facility. ► Lower moisture content improves financial performance of the bio-power business. - Abstract: A process economic analysis of co-producing bioethanol and electricity (value prior to combustion) from mixed southern hardwood and southern yellow pine is presented. Bioethanol is produced by extracting carbohydrates from wood via autohydrolysis, membrane separation of byproducts, enzymatic hydrolysis of extracted oligomers and fermentation to ethanol. The residual solids after autohydrolysis are pressed and burned in a power boiler to generate steam and electricity. A base case scenario of biomass combustion to produce electricity is presented as a reference to understand the basics of bio-power generation economics. For the base case, minimum electricity revenue of $70–$96/MWh must be realized to achieve a 6–12% internal rate of return. In the alternative co-production cases, the ethanol facility is treated as a separate business entity that purchases power and steam from the biomass power plant. Minimum ethanol revenue required to achieve a 12% internal rate of return was estimated to be $0.84–$1.05/l for hardwood and $0.74–$0.85/l for softwood. Based on current market conditions and an assumed future ethanol selling price of $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.

  12. Cellulose is not just cellulose

    DEFF Research Database (Denmark)

    Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja Salomon

    2012-01-01

    are not regions where free cellulose ends are more abundant than in the bulk cell wall. In more severe cases cracks between fibrils form at dislocations and it is possible that the increased accessibility that these cracks give is the reason why hydrolysis of cellulose starts at these locations. If acid...... or enzymatic hydrolysis of plant cell walls is carried out simultaneously with the application of shear stress, plant cells such as fibers or tracheids break at their dislocations. At present it is not known whether specific carbohydrate binding modules (CBMs) and/or cellulases preferentially access cellulose...

  13. National Geo-Database for Biofuel Simulations and Regional Analysis of Biorefinery Siting Based on Cellulosic Feedstock Grown on Marginal Lands

    Energy Technology Data Exchange (ETDEWEB)

    Izaurralde, Roberto C.; Zhang, Xuesong; Sahajpal, Ritvik; Manowitz, David H.

    2012-04-01

    The goal of this project undertaken by GLBRC (Great Lakes Bioenergy Research Center) Area 4 (Sustainability) modelers is to develop a national capability to model feedstock supply, ethanol production, and biogeochemical impacts of cellulosic biofuels. The results of this project contribute to sustainability goals of the GLBRC; i.e. to contribute to developing a sustainable bioenergy economy: one that is profitable to farmers and refiners, acceptable to society, and environmentally sound. A sustainable bioenergy economy will also contribute, in a fundamental way, to meeting national objectives on energy security and climate mitigation. The specific objectives of this study are to: (1) develop a spatially explicit national geodatabase for conducting biofuel simulation studies and (4) locate possible sites for the establishment of cellulosic ethanol biorefineries. To address the first objective, we developed SENGBEM (Spatially Explicit National Geodatabase for Biofuel and Environmental Modeling), a 60-m resolution geodatabase of the conterminous USA containing data on: (1) climate, (2) soils, (3) topography, (4) hydrography, (5) land cover/ land use (LCLU), and (6) ancillary data (e.g., road networks, federal and state lands, national and state parks, etc.). A unique feature of SENGBEM is its 2008-2010 crop rotation data, a crucially important component for simulating productivity and biogeochemical cycles as well as land-use changes associated with biofuel cropping. ARRA support for this project and to the PNNL Joint Global Change Research Institute enabled us to create an advanced computing infrastructure to execute millions of simulations, conduct post-processing calculations, store input and output data, and visualize results. These computing resources included two components installed at the Research Data Center of the University of Maryland. The first resource was 'deltac': an 8-core Linux server, dedicated to county-level and state-level simulations

  14. Compositional and structural changes in Phoenix canariensis and Opuntia ficus-indica with pretreatment: Effects on enzymatic hydrolysis and second generation ethanol production.

    Science.gov (United States)

    Udeh, Benard Anayo; Erkurt, Emrah Ahmet

    2017-01-01

    Two different plants namely Phoenix canariensis and Opuntia ficus-indica were used as substrate for reducing sugar generation and ethanol production. Dilute acid, alkaline and steam explosion were used as pretreatment methods in order to depolymerize lignin and/or hemicellulose and recover cellulose. By using alkaline pretreatment with 2.5% NaOH 71.08% for P. canariensis and 74.61% for O. ficus-indica lignin removal and 81.84% for P. canariensis and 72.66% for O. ficus-indica cellulose recovery yields were obtained. Pretreated materials were hydrolyzed by cellulase with high efficiency (87.0% and 84.5% cellulose conversion yields for P. canariensis and O. ficus-indica) and used as substrate for fermentation. Maximum ethanol production of 15.75g/L and 14.71g/L were achieved from P. canariensis and O. ficus-indica respectively. Structural differences were observed by XRD, FTIR and SEM for untreated, pretreated, hydrolyzed and fermented samples and were highly correlated with compositional analysis results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Steam explosion treatment for ethanol production from branches pruned from pear trees by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Sasaki, Chizuru; Okumura, Ryosuke; Asada, Chikako; Nakamura, Yoshitoshi

    2014-01-01

    This study investigated the production of ethanol from unutilized branches pruned from pear trees by steam explosion pretreatment. Steam pressures of 25, 35, and 45 atm were applied for 5 min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after steam explosion at 25, 35, and 45 tm, respectively. These values corresponded to 34.9, 34.3, and 27.1 g of glucose per 100 g of dry steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100 g/L of water- and methanol-washed residues from 35 atm-exploded pear branches was used as substrate.

  16. Co-fermentation using Recombinant Saccharomyces cerevisiae Yeast Strains Hyper-secreting Different Cellulases for the Production of Cellulosic Bioethanol.

    Science.gov (United States)

    Lee, Cho-Ryong; Sung, Bong Hyun; Lim, Kwang-Mook; Kim, Mi-Jin; Sohn, Min Jeong; Bae, Jung-Hoon; Sohn, Jung-Hoon

    2017-06-30

    To realize the economical production of ethanol and other bio-based chemicals from lignocellulosic biomass by consolidated bioprocessing (CBP), various cellulases from different sources were tested to improve the level of cellulase secretion in the yeast Saccharomyces cerevisiae by screening an optimal translational fusion partner (TFP) as both a secretion signal and fusion partner. Among them, four indispensable cellulases for cellulose hydrolysis, including Chaetomium thermophilum cellobiohydrolase (CtCBH1), Chrysosporium lucknowense cellobiohydrolase (ClCBH2), Trichoderma reesei endoglucanase (TrEGL2), and Saccharomycopsis fibuligera β-glucosidase (SfBGL1), were identified to be highly secreted in active form in yeast. Despite variability in the enzyme levels produced, each recombinant yeast could secrete approximately 0.6-2.0 g/L of cellulases into the fermentation broth. The synergistic effect of the mixed culture of the four strains expressing the essential cellulases with the insoluble substrate Avicel and several types of cellulosic biomass was demonstrated to be effective. Co-fermentation of these yeast strains produced approximately 14 g/L ethanol from the pre-treated rice straw containing 35 g/L glucan with 3-fold higher productivity than that of wild type yeast using a reduced amount of commercial cellulases. This process will contribute to the cost-effective production of bioenergy such as bioethanol and biochemicals from cellulosic biomass.

  17. Ethanol production using whole plant biomass of Jerusalem artichoke by Kluyveromyces marxianus CBS1555.

    Science.gov (United States)

    Kim, Seonghun; Park, Jang Min; Kim, Chul Ho

    2013-03-01

    Jerusalem artichoke is a low-requirement sugar crop containing cellulose and hemicellulose in the stalk and a high content of inulin in the tuber. However, the lignocellulosic component in Jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. In this study, Jerusalem artichoke stalk was pretreated sequentially with dilute acid and alkali, and then hydrolyzed enzymatically. During enzymatic hydrolysis, approximately 88 % of the glucan and xylan were converted to glucose and xylose, respectively. Batch and fed-batch simultaneous saccharification and fermentation of both pretreated stalk and tuber by Kluyveromyces marxianus CBS1555 were effectively performed, yielding 29.1 and 70.2 g/L ethanol, respectively. In fed-batch fermentation, ethanol productivity was 0.255 g ethanol per gram of dry Jerusalem artichoke biomass, or 0.361 g ethanol per gram of glucose, with a 0.924 g/L/h ethanol productivity. These results show that combining the tuber and the stalk hydrolysate is a useful strategy for whole biomass utilization in effective bioethanol fermentation from Jerusalem artichoke.

  18. HPLC mapping of second generation ethanol production with lignocelluloses wastes and diluted sulfuric hydrolysis

    Directory of Open Access Journals (Sweden)

    Diogo José Horst

    2014-09-01

    Full Text Available Wood wastes are potential material for second generation ethanol production within the concept of residual forest bio-refinery. Current paper reports on ethanol production employing an HPLC method for monitoring the chemical content dispersed in the hydrolysate liquor after fermented. The proton-exchange technique was the analytical method employed. Twelve types of wood chips were used as biomass, including Hymenolobium petraeum, Tabebuia cassinoides, Myroxylon peruiferum, Nectandra lanceolata, Ocotea catharinensis, Cedrelinga catenaeformis, Cedrela fissilis Vell, Ocotea porosa, Laurus nobilis, Balfourodendron riedelianum, Pinus Elliotti and Brosimum spp. The influence of diluted sulfuric hydrolysis on the yeast Saccharomyces cerevisiae during the fermentation assay was also investigated. Standard compounds mapped in the analysis comprised fructose, lactic acid, acetic acid, glycerol, glucose and ethanol. The yeast showed ethanol productivity between 0.75 and 1.91 g L-1 h-1, respectively, without the addition of supplementary nutrients or detoxification. The use of these materials for the bioconversion of cellulose into ethanol has been proved. Current analysis contributes towards the production of biofuels by wastes recovery and by process monitoring and optimization.

  19. Fermentation of biomass sugars to ethanol using native industrial yeast strains.

    Science.gov (United States)

    Yuan, Dawei; Rao, Kripa; Relue, Patricia; Varanasi, Sasidhar

    2011-02-01

    In this paper, the feasibility of a technology for fermenting sugar mixtures representative of cellulosic biomass hydrolyzates with native industrial yeast strains is demonstrated. This paper explores the isomerization of xylose to xylulose using a bi-layered enzyme pellet system capable of sustaining a micro-environmental pH gradient. This ability allows for considerable flexibility in conducting the isomerization and fermentation steps. With this method, the isomerization and fermentation could be conducted sequentially, in fed-batch, or simultaneously to maximize utilization of both C5 and C6 sugars and ethanol yield. This system takes advantage of a pH-dependent complexation of xylulose with a supplemented additive to achieve up to 86% isomerization of xylose at fermentation conditions. Commercially-proven Saccharomyces cerevisiae strains from the corn-ethanol industry were used and shown to be very effective in implementation of the technology for ethanol production. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Process and technoeconomic analysis of leading pretreatment technologies for lignocellulosic ethanol production using switchgrass.

    Science.gov (United States)

    Tao, Ling; Aden, Andy; Elander, Richard T; Pallapolu, Venkata Ramesh; Lee, Y Y; Garlock, Rebecca J; Balan, Venkatesh; Dale, Bruce E; Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R; Falls, Matthew; Holtzapple, Mark T; Sierra, Rocio; Shi, Jian; Ebrik, Mirvat A; Redmond, Tim; Yang, Bin; Wyman, Charles E; Hames, Bonnie; Thomas, Steve; Warner, Ryan E

    2011-12-01

    Six biomass pretreatment processes to convert switchgrass to fermentable sugars and ultimately to cellulosic ethanol are compared on a consistent basis in this technoeconomic analysis. The six pretreatment processes are ammonia fiber expansion (AFEX), dilute acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide-impregnated steam explosion (SO(2)). Each pretreatment process is modeled in the framework of an existing biochemical design model so that systematic variations of process-related changes are consistently captured. The pretreatment area process design and simulation are based on the research data generated within the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) 3 project. Overall ethanol production, total capital investment, and minimum ethanol selling price (MESP) are reported along with selected sensitivity analysis. The results show limited differentiation between the projected economic performances of the pretreatment options, except for processes that exhibit significantly lower monomer sugar and resulting ethanol yields. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Pretreatment and Fractionation of Wheat Straw for Production of Fuel Ethanol and Value-added Co-products in a Biorefinery

    Directory of Open Access Journals (Sweden)

    Xiu Zhang

    2014-08-01

    Full Text Available An integrated process has been developed for a wheat straw biorefinery. In this process, wheat straw was pretreated by soaking in aqueous ammonia (SAA, which extensively removed lignin but preserved high percentages of the carbohydrate fractions for subsequent bioconversion. The pretreatment conditions included 15 wt% NH4OH, 1:10 solid:liquid ratio, 65 oC and 15 hours. Under these conditions, 48% of the original lignin was removed, whereas 98%, 83% and 78% of the original glucan, xylan, and arabinan, respectively, were preserved. The pretreated material was subsequently hydrolyzed with a commercial hemicellulase to produce a solution rich in xylose and low in glucose plus a cellulose-enriched solid residue. The xylose-rich solution then was used for production of value-added products. Xylitol and astaxanthin were selected to demonstrate the fermentability of the xylose-rich hydrolysate. Candida mogii and Phaffia rhodozyma were used for xylitol and astaxanthin fermentation, respectively. The cellulose-enriched residue obtained after the enzymatic hydrolysis of the pretreated straw was used for ethanol production in a fed-batch simultaneous saccharification and fermentation (SSF process. In this process, a commercial cellulase was used for hydrolysis of the glucan in the residue and Saccharomyces cerevisiae, which is the most efficient commercial ethanol-producing organism, was used for ethanol production. Final ethanol concentration of 57 g/l was obtained at 27 wt% total solid loading.

  2. Efficient chemical and enzymatic saccharification of the lignocellulosic residue from Agave tequilana bagasse to produce ethanol by Pichia caribbica.

    Science.gov (United States)

    Saucedo-Luna, Jaime; Castro-Montoya, Agustin Jaime; Martinez-Pacheco, Mauro Manuel; Sosa-Aguirre, Carlos Ruben; Campos-Garcia, Jesus

    2011-06-01

    Bagasse of Agave tequilana (BAT) is the residual lignocellulosic waste that remains from tequila production. In this study we characterized the chemical composition of BAT, which was further saccharified and fermented to produce ethanol. BAT was constituted by cellulose (42%), hemicellulose (20%), lignin (15%), and other (23%). Saccharification of BAT was carried out at 147 °C with 2% sulfuric acid for 15 min, yielding 25.8 g/l of fermentable sugars, corresponding to 36.1% of saccharificable material (cellulose and hemicellulose contents, w/w). The remaining lignocellulosic material was further hydrolyzed by commercial enzymes, ~8.2% of BAT load was incubated for 72 h at 40 °C rendering 41 g/l of fermentable sugars corresponding to 73.6% of the saccharificable material (w/w). Mathematic surface response analysis of the acid and enzymatic BAT hydrolysis was used for process optimization. The results showed a satisfactory correlation (R (2) = 0.90) between the obtained and predicted responses. The native yeast Pichia caribbica UM-5 was used to ferment sugar liquors from both acid and enzymatic hydrolysis to ethanol yielding 50 and 87%, respectively. The final optimized process generated 8.99 g ethanol/50 g of BAT, corresponding to an overall 56.75% of theoretical ethanol (w/w). Thus, BAT may be employed as a lignocellulosic raw material for bioethanol production and can contribute to BAT residue elimination from environment.

  3. Goal- and signal-directed incentive: conditioned approach, seeking, and consumption established with unsweetened alcohol in rats.

    Science.gov (United States)

    Krank, Marvin D; O'Neill, Susan; Squarey, Kyna; Jacob, Jackie

    2008-02-01

    Many theories of addictive behavior propose that cues signaling drug administration influence the likelihood of drug-taking and drug-seeking behavior. We investigated the behavioral impact of cues associated with unsweetened ethanol and their interaction with responding maintained by ethanol self-administration. Our goal was to establish the influence of such cues on ethanol seeking. The experiment used a matching contingency and saccharin-fading procedure to establish equal levels of responding to two spatially distinct levers using unsweetened 10% ethanol solution. After ethanol self-administration was established, a brief cue light located alternately over each lever location was either paired or unpaired (control) with the opportunity to consume the same ethanol solution. Finally, self-administration was re-established, and the effect of the cue was measured in a transfer design. The reaction to lights paired with the opportunity to ingest unsweetened ethanol had three main effects: (1) induction of operant behavior reinforced by ethanol, (2) stimulation of ethanol-seeking behavior (drinker entries), and (3) cue-directed approach and contact behavior (i.e. autoshaping or sign-tracking). Cue-directed behavior to the light interacted with choice behavior in a manner predicted by the location of the cue light, enhancing responding only when the approach response did not interfere with the operant response. These findings replicate and extend the effects of Pavlovian conditioning on ethanol-seeking and support-conditioned incentive theories of addictive behavior. Signals for ethanol influence spatial choice behavior and may be relevant to attentional bias shown to alcohol-associated stimuli in humans.

  4. Wet oxidation pretreatment of rape straw for ethanol production

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via...... Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole...... gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid...

  5. The Effect of Incentives and Meta-incentives on the Evolution of Cooperation.

    Directory of Open Access Journals (Sweden)

    Isamu Okada

    2015-05-01

    Full Text Available Although positive incentives for cooperators and/or negative incentives for free-riders in social dilemmas play an important role in maintaining cooperation, there is still the outstanding issue of who should pay the cost of incentives. The second-order free-rider problem, in which players who do not provide the incentives dominate in a game, is a well-known academic challenge. In order to meet this challenge, we devise and analyze a meta-incentive game that integrates positive incentives (rewards and negative incentives (punishments with second-order incentives, which are incentives for other players' incentives. The critical assumption of our model is that players who tend to provide incentives to other players for their cooperative or non-cooperative behavior also tend to provide incentives to their incentive behaviors. In this paper, we solve the replicator dynamics for a simple version of the game and analytically categorize the game types into four groups. We find that the second-order free-rider problem is completely resolved without any third-order or higher (meta incentive under the assumption. To do so, a second-order costly incentive, which is given individually (peer-to-peer after playing donation games, is needed. The paper concludes that (1 second-order incentives for first-order reward are necessary for cooperative regimes, (2 a system without first-order rewards cannot maintain a cooperative regime, (3 a system with first-order rewards and no incentives for rewards is the worst because it never reaches cooperation, and (4 a system with rewards for incentives is more likely to be a cooperative regime than a system with punishments for incentives when the cost-effect ratio of incentives is sufficiently large. This solution is general and strong in the sense that the game does not need any centralized institution or proactive system for incentives.

  6. The Effect of Incentives and Meta-incentives on the Evolution of Cooperation.

    Science.gov (United States)

    Okada, Isamu; Yamamoto, Hitoshi; Toriumi, Fujio; Sasaki, Tatsuya

    2015-05-01

    Although positive incentives for cooperators and/or negative incentives for free-riders in social dilemmas play an important role in maintaining cooperation, there is still the outstanding issue of who should pay the cost of incentives. The second-order free-rider problem, in which players who do not provide the incentives dominate in a game, is a well-known academic challenge. In order to meet this challenge, we devise and analyze a meta-incentive game that integrates positive incentives (rewards) and negative incentives (punishments) with second-order incentives, which are incentives for other players' incentives. The critical assumption of our model is that players who tend to provide incentives to other players for their cooperative or non-cooperative behavior also tend to provide incentives to their incentive behaviors. In this paper, we solve the replicator dynamics for a simple version of the game and analytically categorize the game types into four groups. We find that the second-order free-rider problem is completely resolved without any third-order or higher (meta) incentive under the assumption. To do so, a second-order costly incentive, which is given individually (peer-to-peer) after playing donation games, is needed. The paper concludes that (1) second-order incentives for first-order reward are necessary for cooperative regimes, (2) a system without first-order rewards cannot maintain a cooperative regime, (3) a system with first-order rewards and no incentives for rewards is the worst because it never reaches cooperation, and (4) a system with rewards for incentives is more likely to be a cooperative regime than a system with punishments for incentives when the cost-effect ratio of incentives is sufficiently large. This solution is general and strong in the sense that the game does not need any centralized institution or proactive system for incentives.

  7. High pressure HC1 conversion of cellulose to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Antonoplis, Robert Alexander [Univ. of California, Berkeley, CA (United States); Blanch, Harvey W. [Univ. of California, Berkeley, CA (United States); Wilke, Charles R. [Univ. of California, Berkeley, CA (United States)

    1981-08-01

    The production of ethanol from glucose by means of fermentation represents a potential long-range alternative to oil for use as a transportation fuel. Today's rising oil prices and the dwindling world supply of oil have made other fuels, such as ethanol, attractive alternatives. It has been shown that automobiles can operate, with minor alterations, on a 10% ethanol-gasoline mixture popularly known as gasohol. Wood has long been known as a potential source of glucose. Glucose may be obtained from wood following acid hydrolysis. In this research, it was found that saturating wood particles with HCl gas under pressure was an effective pretreatment before subjecting the wood to dilute acid hydrolysis. The pretreatment is necessary because of the tight lattice structure of cellulose, which inhibits dilute acid hydrolysis. HCl gas makes the cellulose more susceptible to hydrolysis and the glucose yield is doubled when dilute acid hydrolysis is preceded by HCl saturation at high pressure. The saturation was most effectively performed in a fluidized bed reactor, with pure HCl gas fluidizing equal volumes of ground wood and inert particles. The fluidized bed effectively dissipated the large amount of heat released upon HCl absorption into the wood. Batch reaction times of one hour at 314.7 p.s.i.a. gave glucose yields of 80% and xylose yields of 95% after dilute acid hydrolysis. A non-catalytic gas-solid reaction model, with gas diffusing through the solid limiting the reaction rate, was found to describe the HCl-wood reaction in the fluidized bed. HCl was found to form a stable adduct with the lignin residue in the wood, in a ratio of 3.33 moles per mole of lignin monomer. This resulted in a loss of 0.1453 lb. of HCl per pound of wood. The adduct was broken upon the addition of water. A process design and economic evaluation for a plant to produce 214 tons per day of glucose from air-dried ground Populus tristi gave an estimated glucose cost of 15.14 cents per pound

  8. The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation

    Science.gov (United States)

    Jae-Won Lee; Rita C.L.B. Rodrigues; Hyun Joo Kim; In-Gyu Choi; Thomas W. Jeffries

    2010-01-01

    High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 23 full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment...

  9. Converting Eucalyptus biomass into ethanol: Financial and sensitivity analysis in a co-current dilute acid process. Part II

    International Nuclear Information System (INIS)

    Gonzalez, R.; Treasure, T.; Phillips, R.; Jameel, H.; Saloni, D.; Wright, J.; Abt, R.

    2011-01-01

    The technical and financial performance of high yield Eucalyptus biomass in a co-current dilute acid pretreatment followed by enzymatic hydrolysis process was simulated using WinGEMS registered and Excel registered . Average ethanol yield per dry Mg of Eucalyptus biomass was approximately 347.6 L of ethanol (with average carbohydrate content in the biomass around 66.1%) at a cost of 0.49 L -1 of ethanol, cash cost of ∝0.46 L -1 and CAPEX of 1.03 L -1 of ethanol. The main cost drivers are: biomass, enzyme, tax, fuel (gasoline), depreciation and labor. Profitability of the process is very sensitive to biomass cost, carbohydrate content (%) in biomass and enzyme cost. Biomass delivered cost was simulated and financially evaluated in Part I; here in Part II the conversion of this raw material into cellulosic ethanol using the dilute acid process is evaluated. (author)

  10. Uncertainty in techno-economic estimates of cellulosic ethanol production due to experimental measurement uncertainty

    Directory of Open Access Journals (Sweden)

    Vicari Kristin J

    2012-04-01

    Full Text Available Abstract Background Cost-effective production of lignocellulosic biofuels remains a major financial and technical challenge at the industrial scale. A critical tool in biofuels process development is the techno-economic (TE model, which calculates biofuel production costs using a process model and an economic model. The process model solves mass and energy balances for each unit, and the economic model estimates capital and operating costs from the process model based on economic assumptions. The process model inputs include experimental data on the feedstock composition and intermediate product yields for each unit. These experimental yield data are calculated from primary measurements. Uncertainty in these primary measurements is propagated to the calculated yields, to the process model, and ultimately to the economic model. Thus, outputs of the TE model have a minimum uncertainty associated with the uncertainty in the primary measurements. Results We calculate the uncertainty in the Minimum Ethanol Selling Price (MESP estimate for lignocellulosic ethanol production via a biochemical conversion process: dilute sulfuric acid pretreatment of corn stover followed by enzymatic hydrolysis and co-fermentation of the resulting sugars to ethanol. We perform a sensitivity analysis on the TE model and identify the feedstock composition and conversion yields from three unit operations (xylose from pretreatment, glucose from enzymatic hydrolysis, and ethanol from fermentation as the most important variables. The uncertainty in the pretreatment xylose yield arises from multiple measurements, whereas the glucose and ethanol yields from enzymatic hydrolysis and fermentation, respectively, are dominated by a single measurement: the fraction of insoluble solids (fIS in the biomass slurries. Conclusions We calculate a $0.15/gal uncertainty in MESP from the TE model due to uncertainties in primary measurements. This result sets a lower bound on the error bars of

  11. Ethanol Production from Enzymatically Treated Dried Food Waste Using Enzymes Produced On-Site

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2015-01-01

    Full Text Available The environmental crisis and the need to find renewable fuel alternatives have made production of biofuels an important priority. At the same time, the increasing production of food waste is an important environmental issue. For this reason, production of ethanol from food waste is an interesting approach. Volumes of food waste are reduced and ethanol production does not compete with food production. In this work, we evaluated the possibility of using source-separated household food waste for the production of ethanol. To minimize the cost of ethanol production, the hydrolytic enzymes that are necessary for cellulose hydrolysis were produced in-house using the thermophillic fungus Myceliophthora thermophila. At the initial stage of the study, production of these thermophilic enzymes was studied and optimized, resulting in an activity of 0.28 FPU/mL in the extracellular broth. These enzymes were used to saccharify household food waste at a high dry material consistency of 30% w/w, followed by fermentation. Ethanol production reached 19.27 g/L with a volumetric productivity of 0.92 g/L·h, whereas only 5.98 g/L of ethanol was produced with a volumetric productivity of 0.28 g/L·h when no enzymatic saccharification was used.

  12. Pilot plant studies of the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1977-01-31

    Progress is reported in several areas of research. The following cellulosic raw materials were selected for study: wheat, barley, and rice straws, rice hulls, sorghum, corn stover, cotton gin trash, newsprint, ground wood, and masonite steam-treated Douglas fir and redwood. Samples were collected, prepared, and analyzed for hexosans, pentosans, lignin, ash, and protein. Results of acid extraction and enzymatic hydrolysis are discussed. Yields of glucose, polyglucose, xylose, and arabinose are reported. Progress in process design and economic studies, as well as pilot plant process development and design studies, is summarized. (JGB)

  13. Properties of cellulose derivatives produced from radiation-Modified cellulose pulps

    International Nuclear Information System (INIS)

    Iller, Edward; Stupinska, Halina; Starostka, Pawel

    2007-01-01

    The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared

  14. An Update on Ethanol Production and Utilization in Thailand, 2014

    Energy Technology Data Exchange (ETDEWEB)

    Bloyd, Cary N.; Foster, Nikolas A.F.

    2014-09-01

    In spite of the recent political turmoil, Thailand has continued to develop its ethanol based alternative fuel supply and demand infrastructure. Its support of production and sales of ethanol contributed to more than doubling the production over the past five years alone. In April 2014, average consumption stood at 3.18 million liter per day- more than a third on its way to its domestic consumption goal of 9 million liters per day by 2021. Strong government incentives and the phasing out of non-blended gasoline contributed substantially. Concurrently, exports dropped significantly to their lowest level since 2011, increasing the pressure on Thai policy makers to best balance energy independency goals with other priorities, such as Thailand’s trade balance and environmental aspirations. Utilization of second generation biofuels might have the potential to further expand Thailand’s growing ethanol market. Thailand has also dramatically increased its higher ethanol blend vehicle fleet, with all new vehicles sold in the Thai market now being E20 capable and the number of E85 vehicles increasing three fold in the last year from 100,000 in 2013 to 300,000 in 2014.

  15. Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

    International Nuclear Information System (INIS)

    Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

    2011-01-01

    The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13 C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

  16. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum.

    Science.gov (United States)

    Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

    2017-05-01

    Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

  17. Bacterial laminarinase for application in ethanol production from brown algae Sargassum sp. using halotolerant yeast

    Directory of Open Access Journals (Sweden)

    C.M.T. Perez

    2018-03-01

    Full Text Available Macroalgae are known to have many industrial applications, with current research targeting the potential of macroalgal biomass as feedstock in production of biofuels. Marine algal biomass is rich in storage carbohydrates, laminarin, and cellulose, which can be converted to fermentable sugars using appropriate enzymes, for fermentation to ethanol. This study focused on ethanol production from macroalgae using only enzymatic treatment for saccharification of algal biomass. This involved the isolation and identification of cellulase and laminarinase-producing microorganisms from mangrove area in the Philippines and production of partially purified enzymes for algal biomass saccharification. Results showed that the partially purified laminarinase produced from Bacillus sp. was capable of hydrolyzing the laminarin present in the macroalage. Fermentation of the algal hydrolysate yielded only small amount of ethanol due to lack of other pre-treatment methods, however, it was observed that higher ethanol was produced in saccharification treatments using a combination of cellulase and laminarinase which implies a possible synergistic effect between the two enzymes.

  18. Improved ethanol yield and reduced Minimum Ethanol Selling Price (MESP by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 1 Experimental

    Directory of Open Access Journals (Sweden)

    Chen Xiaowen

    2012-08-01

    Full Text Available Abstract Background Historically, acid pretreatment technology for the production of bio-ethanol from corn stover has required severe conditions to overcome biomass recalcitrance. However, the high usage of acid and steam at severe pretreatment conditions hinders the economic feasibility of the ethanol production from biomass. In addition, the amount of acetate and furfural produced during harsh pretreatment is in the range that strongly inhibits cell growth and impedes ethanol fermentation. The current work addresses these issues through pretreatment with lower acid concentrations and temperatures incorporated with deacetylation and mechanical refining. Results The results showed that deacetylation with 0.1 M NaOH before acid pretreatment improved the monomeric xylose yield in pretreatment by up to 20% while keeping the furfural yield under 2%. Deacetylation also improved the glucose yield by 10% and the xylose yield by 20% during low solids enzymatic hydrolysis. Mechanical refining using a PFI mill further improved sugar yields during both low- and high-solids enzymatic hydrolysis. Mechanical refining also allowed enzyme loadings to be reduced while maintaining high yields. Deacetylation and mechanical refining are shown to assist in achieving 90% cellulose yield in high-solids (20% enzymatic hydrolysis. When fermentations were performed under pH control to evaluate the effect of deacetylation and mechanical refining on the ethanol yields, glucose and xylose utilizations over 90% and ethanol yields over 90% were achieved. Overall ethanol yields were calculated based on experimental results for the base case and modified cases. One modified case that integrated deacetylation, mechanical refining, and washing was estimated to produce 88 gallons of ethanol per ton of biomass. Conclusion The current work developed a novel bio-ethanol process that features pretreatment with lower acid concentrations and temperatures incorporated with deacetylation

  19. Recovery of cellulase activity after ethanol stripping in a novel pilot-scale unit

    DEFF Research Database (Denmark)

    Skovgaard, Pernille Anastasia; Christensen, Børge Holm; Felby, Claus

    2014-01-01

    Recycling of enzymes has a potential interest during cellulosic bioethanol production as purchasing enzymes is one of the largest expenses in the process. By recycling enzymes after distillation, loss of sugars and ethanol are avoided, but depending on the distillation temperature......, there is a potential risk of enzyme degradation. Studies of the rate of enzyme denaturation based on estimation of the denaturation constant K D was performed using a novel distillation setup allowing stripping of ethanol at 50–65 °C. Experiments were performed in a pilot-scale stripper, where the effect...... of temperature (55–65 °C) and exposure to gas–liquid and liquid–heat transmission interfaces were tested on a mesophilic and thermostable enzyme mixture in fiber beer and buffer. Lab-scale tests were included in addition to the pilot-scale experiments to study the effect of shear, ethanol concentration, and PEG...

  20. Effects of alternative energy sources on bacterial cellulose characteristics produced by Komagataeibacter medellinensis.

    Science.gov (United States)

    Molina-Ramírez, Carlos; Enciso, Carla; Torres-Taborda, Mabel; Zuluaga, Robin; Gañán, Piedad; Rojas, Orlando J; Castro, Cristina

    2018-05-27

    Bacterial cellulose (BC) was produced by Komagataeibacter medellinensis using Hestrin and Schramm modified medium in the presence of alternative energy sources (AES), such as ethanol and acetic acid, to explore the effect of AES on the characteristics and properties of the resulting BC. In this study, the physicochemical and structural characteristics of the obtained BC were determined using Fourier-transform infrared spectroscopy, X-ray diffraction spectrometry, thermogravimetric analysis, and mechanical testing analysis. Ethanol and acetic acid (at 0.1 wt%) were proven to improve the BC yield by K. medellinensis by 279% and 222%, respectively. However, the crystallinity index (%), the degree of polymerization, and maximum rate of degradation temperatures decreased by 9.2%, 36%, and 4.96%, respectively, by the addition of ethanol and by 7.2%, 27%, and 4.21%, respectively, by the addition of acetic acid. The significance of this work, lies on the fact that there is not any report about how BC properties change when substances like ethanol or acetic acid are added to culture medium, and which is the mechanism that provokes those changes, that in our case we could demonstrate the relationship of a higher BC production rate (provoked by ethanol and acetic acid adding) and changes in BC properties. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. A lignocellulosic ethanol strategy via nonenzymatic sugar production: process synthesis and analysis.

    Science.gov (United States)

    Han, Jeehoon; Luterbacher, Jeremy S; Alonso, David Martin; Dumesic, James A; Maravelias, Christos T

    2015-04-01

    The work develops a strategy for the production of ethanol from lignocellulosic biomass. In this strategy, the cellulose and hemicellulose fractions are simultaneously converted to sugars using a γ-valerolactone (GVL) solvent containing a dilute acid catalyst. To effectively recover GVL for reuse as solvent and biomass-derived lignin for heat and power generation, separation subsystems, including a novel CO2-based extraction for the separation of sugars from GVL, lignin and humins have been designed. The sugars are co-fermented by yeast to produce ethanol. Furthermore, heat integration to reduce utility requirements is performed. It is shown that this strategy leads to high ethanol yields and the total energy requirements could be satisfied by burning the lignin. The integrated strategy using corn stover feedstock leads to a minimum selling price of $5 per gallon of gasoline equivalent, which suggests that it is a promising alternative to current biofuels production approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Simultaneous saccharification and fermentation of alkaline-pretreated corn stover to ethanol using a recombinant yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jing; Xia, Liming [Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2009-10-15

    Bio-ethanol converted from cheap and abundant lignocellulosic materials is a potential renewable resource to replace depleting fossil fuels. Simultaneous saccharification and fermentation (SSF) of alkaline-pretreated corn stover for the production of ethanol was investigated using a recombinant yeast strain Saccharomyces cerevisiae ZU-10. Low cellobiase activity in Trichoderma reesei cellulase resulted in cellobiose accumulation. Supplementing the simultaneous saccharification and fermentation system with cellobiase greatly reduced feedback inhibition caused by cellobiose to the cellulase reaction, thereby increased the ethanol yield. 12 h of enzymatic prehydrolysis at 50 C prior to simultaneous saccharification and fermentation was found to have a negative effect on the overall ethanol yield. Glucose and xylose produced from alkaline-pretreated corn stover could be co-fermented to ethanol effectively by S. cerevisiae ZU-10. An ethanol concentration of 27.8 g/L and the corresponding ethanol yield on carbohydrate in substrate of 0.350 g/g were achieved within 72 h at 33 C with 80 g/L of substrate and enzyme loadings of 20 filter paper activity units (FPU)/g substrate and 10 cellobiase units (CBU)/g substrate. The results are meaningful in co-conversion of cellulose and hemicellulose fraction of lignocellulosic materials to fuel ethanol. (author)

  3. IMPROVED BIOREFINERY FOR THE PRODUCTION OF ETHANOL, CHEMICALS, ANIMAL FEED AND BIOMATERIALS FROM SUGAR CANE

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Donal F. Day

    2009-01-29

    The Audubon Sugar Institute (ASI) of Louisiana State University’s Agricultural Center (LSU AgCenter) and MBI International (MBI) sought to develop technologies that will lead to the development of a sugar-cane biorefinery, capable of supplying fuel ethanol from bagasse. Technology development focused on the conversion of bagasse, cane-leaf matter (CLM) and molasses into high value-added products that included ethanol, specialty chemicals, biomaterials and animal feed; i.e. a sugar cane-based biorefinery. The key to lignocellulosic biomass utilization is an economically feasible method (pretreatment) for separating the cellulose and the hemicellulose from the physical protection provided by lignin. An effective pretreatment disrupts physical barriers, cellulose crystallinity, and the association of lignin and hemicellulose with cellulose so that hydrolytic enzymes can access the biomass macrostructure (Teymouri et al. 2004, Laureano-Perez, 2005). We chose to focus on alkaline pretreatment methods for, and in particular, the Ammonia Fiber Expansion (AFEX) process owned by MBI. During the first two years of this program a laboratory process was established for the pretreatment of bagasse and CLM using the AFEX process. There was significant improvement of both rate and yield of glucose and xylose upon enzymatic hydrolysis of AFEX-treated bagasse and CLM compared with untreated material. Because of reactor size limitation, several other alkaline pretreatment methods were also co-investigated. They included, dilute ammonia, lime and hydroxy-hypochlorite treatments. Scale-up focused on using a dilute ammonia process as a substitute for AFEX, allowing development at a larger scale. The pretreatment of bagasse by an ammonia process, followed by saccharification and fermentation produced ethanol from bagasse. Simultaneous saccharification and fermentation (SSF) allowed two operations in the same vessel. The addition of sugarcane molasses to the hydrolysate

  4. INFLUENCE OF CELLULOSE POLYMERIZATION DEGREE AND CRYSTALLINITY ON KINETICS OF CELLULOSE DEGRADATION

    OpenAIRE

    Edita Jasiukaitytė-Grojzdek,; Matjaž Kunaver,; Ida Poljanšek

    2012-01-01

    Cellulose was treated in ethylene glycol with p-toluene sulfonic acid monohydrate as a catalyst at different temperatures. At the highest treatment temperature (150 °C) liquefaction of wood pulp cellulose was achieved and was dependant on cellulose polymerization degree (DP). Furthermore, the rate of amorphous cellulose weight loss was found to increase with cellulose degree of polymerization, while the rate of crystalline cellulose weight loss was reciprocal to the size of the crystallites. ...

  5. Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

    Science.gov (United States)

    Huang, Yu; Wei, Xiaoyang; Zhou, Shiguang; Liu, Mingyong; Tu, Yuanyuan; Li, Ao; Chen, Peng; Wang, Yanting; Zhang, Xuewen; Tai, Hongzhong; Peng, Liangcai; Xia, Tao

    2015-04-01

    In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Direct ethanol production from barley beta-glucan by sake yeast displaying Aspergillus oryzae beta-glucosidase and endoglucanase.

    Science.gov (United States)

    Kotaka, Atsushi; Bando, Hiroki; Kaya, Masahiko; Kato-Murai, Michiko; Kuroda, Kouichi; Sahara, Hiroshi; Hata, Yoji; Kondo, Akihiko; Ueda, Mitsuyoshi

    2008-06-01

    Three beta-glucosidase- and two endoglucanase-encoding genes were cloned from Aspergillus oryzae, and their gene products were displayed on the cell surface of the sake yeast, Saccharomyces cerevisiae GRI-117-UK. GRI-117-UK/pUDB7 displaying beta-glucosidase AO090009000356 showed the highest activity against various substrates and efficiently produced ethanol from cellobiose. On the other hand, GRI-117-UK/pUDCB displaying endoglucanase AO090010000314 efficiently degraded barley beta-glucan to glucose and smaller cellooligosaccharides. GRI-117-UK/pUDB7CB codisplaying both beta-glucosidase AO090009000356 and endoglucanase AO090010000314 was constructed. When direct ethanol fermentation from 20 g/l barley beta-glucan as a model substrate was performed with the codisplaying strain, the ethanol concentration reached 7.94 g/l after 24 h of fermentation. The conversion ratio of ethanol from beta-glucan was 69.6% of the theoretical ethanol concentration produced from 20 g/l barley beta-glucan. These results showed that sake yeast displaying A. oryzae cellulolytic enzymes can be used to produce ethanol from cellulosic materials. Our constructs have higher ethanol production potential than the laboratory constructs previously reported.

  7. Cellulose-Hemicellulose Interactions at Elevated Temperatures Increase Cellulose Recalcitrance to Biological Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Himmel, Michael E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kumar, Rajeev [University of California, Riverside; Oak Ridge National Laboratory; ; Smith, Micholas Dean [Oak Ridge National Laboratory; University of Tennessee; Petridis, Loukas [Oak Ridge National Laboratory; University of Tennessee; Ong, Rebecca G. [Michigan Technological University; Cai, Charles M. [University of California, Riverside; Oak Ridge National Laboratory; Balan, Venkatesh [University of Houston; Dale, Bruce E. [Michigan State University; Ragauskas, Arthur J. [Oak Ridge National Laboratory; University of Tennessee; Smith, Jeremy C. [Oak Ridge National Laboratory; University of Tennessee; Wyman, Charles E. [University of California, Riverside; Oak Ridge National Laboratory

    2018-01-23

    It has been previously shown that cellulose-lignin droplets' strong interactions, resulting from lignin coalescence and redisposition on cellulose surface during thermochemical pretreatments, increase cellulose recalcitrance to biological conversion, especially at commercially viable low enzyme loadings. However, information on the impact of cellulose-hemicellulose interactions on cellulose recalcitrance following relevant pretreatment conditions are scarce. Here, to investigate the effects of plausible hemicellulose precipitation and re-association with cellulose on cellulose conversion, different pretreatments were applied to pure Avicel(R) PH101 cellulose alone and Avicel mixed with model hemicellulose compounds followed by enzymatic hydrolysis of resulting solids at both low and high enzyme loadings. Solids produced by pretreatment of Avicel mixed with hemicelluloses (AMH) were found to contain about 2 to 14.6% of exogenous, precipitated hemicelluloses and showed a remarkably much lower digestibility (up to 60%) than their respective controls. However, the exogenous hemicellulosic residues that associated with Avicel following high temperature pretreatments resulted in greater losses in cellulose conversion than those formed at low temperatures, suggesting that temperature plays a strong role in the strength of cellulose-hemicellulose association. Molecular dynamics simulations of hemicellulosic xylan and cellulose were found to further support this temperature effect as the xylan-cellulose interactions were found to substantially increase at elevated temperatures. Furthermore, exogenous, precipitated hemicelluloses in pretreated AMH solids resulted in a larger drop in cellulose conversion than the delignified lignocellulosic biomass containing comparably much higher natural hemicellulose amounts. Increased cellulase loadings or supplementation of cellulase with xylanases enhanced cellulose conversion for most pretreated AMH solids; however, this approach

  8. Immobilization of Saccharomyces Cerevisiae in Rice Hulls for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Edita Martini

    2011-05-01

    Full Text Available The whole cell immobilization in ethanol fermentation can be done by using natural carriers or through synthetic carriers. All of these methods have the same purpose of retaining high cell concentrations within a certain defined region of space which leads to higher ethanol productivity. Lignocellulosic plant substance represents one of highly potential sources in ethanol production. Some studies have found that cellulosic substances substances can also be used as a natural carrier in cell immobilization by re-circulating pre-culture medium into a reactor. In this experiment, rice hulls without any treatment were used to immobilize Saccharomyces cerevisiae through semi solid state incubation combined with re-circulating pre-culture medium. The scanning electron microscopy (SEM pictures of the carrier show that the yeast cells are absorbed and embedded to the rice hull pore. In liquid batch fermentation system with an initial sugar concentration of 50 g/L, nearly 100% total sugar was consumed after 48 hours. This resulted in an ethanol yield of 0.32 g ethanol/g glucose, which is 62.7% of the theoretical value. Ethanol productivity of 0.59 g/(L.h is 2.3 fold higher than that of free cells which is 0.26 g/(L.h. An effort to reuse the immobilized cells in liquid fermentation system showed poor results due to cell desorption in the first batch which led to high sugar concentration inhibitory effect in the second batch fermentation. This might be solved by using semi solid fermentation process in the future work.

  9. 稀碱预处理棕榈残渣制备纤维乙醇%Pretreatment of oil palm residues by dilute alkali for cellulosic ethanol production

    Institute of Scientific and Technical Information of China (English)

    张海燕; 周玉杰; 李晋平; 戴玲妹; 刘德华; 张建安; Yuen May Choo; Soh Kheang Loh

    2013-01-01

    In the study, we used oil palm residues (empty fruit bunch, EFB) as raw material to produce cellulosic ethanol by pretreatment, enzymatic hydrolysis and fermentation. Firstly, the pretreatment of EFB with alkali, alkali/hydrogen peroxide and the effects on the components and enzymatic hydrolysis of cellulose were studied. The results show that dilute alkali was the suitable pretreatment method and the conditions were first to soak the substrate with 1% sodium hydroxide with a solid-liquid ratio of 1:10 at 40 ℃ for 24 h, and then subjected to 121 ℃ for 30 min. Under the conditions, EFB solid recovery was 74.09%, and glucan, xylan and lignin content were 44.08%, 25.74% and 13.89%, respectively. After separated with alkali solution, the pretreated EFB was washed and hydrolyzed for 72 h with 5% substrate concentration and 30 FPU/g dry mass (DM) enzyme loading, and the conversion of glucan and xylan reached 84.44% and 89.28%, respectively. We further investigated the effects of substrate concentration and enzyme loading on enzymatic hydrolysis and ethanol batch simultaneous saccharification and fermentation (SSF). The results show that when enzyme loading was 30 FPU/g DM and substrate concentration was increased from 5% to 25%, ethanol concentration were 9.76 g/L and 35.25 g/L after 72 h fermentation with Saccharomyces cerevisiae (inoculum size 5%, V/V), which was 79.09% and 56.96% of ethanol theory yield.%以棕榈残渣(Empty fruit bunch,EFB)为原料,通过预处理、酶解、发酵等过程制备纤维乙醇.首先对比了碱、碱/过氧化氢等预处理条件对棕榈残渣组成及酶解的影响,结果表明稀碱预处理效果较好.适宜的稀碱预处理条件为:NaOH浓度为1%,固液比为1∶10,在40℃浸泡24 h后于121℃下保温30 min,在该条件下,EFB的固体回收率为74.09%,纤维素、半纤维素和木质素的含量分别为44.08%、25.74%和13.89%.对该条件下预处理后的固体样品,以底物浓度5

  10. SO{sub 2}-ethanol-water (SEW) fractionation of lignocellulosics

    Energy Technology Data Exchange (ETDEWEB)

    Iakovlev, M.

    2011-10-15

    This study deals with SO{sub 2}-ethanol-water (SEW) fractionation as a potential method for a Lignocellulosic Biorefinery to achieve high yield separation of the three important components of biomass; cellulose, hemicelluloses and lignin. Representatives of all principal biomass species were successfully treated by SEW fractionation at similar rates. The kinetics of delignification, polysaccharides removal and cellulose hydrolysis at different temperatures and SO{sub 2} concentrations are described and interpreted from the viewpoint of acid-catalysed degradation of the biomass polymers. The fractionation pattern is compared to that of commercial acid sulfite cooking. The kinetics of delignification, hemicelluloses removal and cellulose hydrolysis during SEW fractionation each follow a two phase behaviour. The delignification is first order in lignin and SO{sub 2}. The observed lignin sulfonation and delignification patterns can be explained using Haegglund's consecutive fast sulfonation-slow hydrolysis scheme. During the initial phase of fractionation, the hemicelluloses removal and cellulose hydrolysis rates are related to the delignification rate, while in the following bulk phase the former two processes proceed independently from the latter. It is proposed that during the initial phase the hemicelluloses are removed together with lignin in the form of lignocarbohydrate complexes, while cellulose is protected by lignin from hydrolytic attack leading to a lower hydrolysis rate. Most hemicellulose side units as well as acetyl groups are cleaved during the first phase, while the glucomannan and xylan backbone polymers are removed at a considerably lower rate in the second (bulk) phase following first order kinetics in the residual polysaccharides. The observed polysaccharides dissolution behaviour can be interpreted in terms of low glucomannan stabilisation by crystallisation on cellulose at the applied conditions. Minimal cellulose dissolution occurs during

  11. Synthesis and characterization of amorphous cellulose from triacetate of cellulose

    International Nuclear Information System (INIS)

    Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

    2014-01-01

    It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

  12. Assessment of Bermudagrass and Bunch Grasses as Feedstock for Conversion to Ethanol

    Science.gov (United States)

    Anderson, William F.; Dien, Bruce S.; Brandon, Sarah K.; Peterson, Joy Doran

    Research is needed to allow more efficient processing of lignocellulose from abundant plant biomass resources for production to fuel ethanol at lower costs. Potential dedicated feedstock species vary in degrees of recalcitrance to ethanol processing. The standard dilute acid hydrolysis pretreatment followed by simultaneous sacharification and fermentation (SSF) was performed on leaf and stem material from three grasses: giant reed (Arundo donax L.), napiergrass (Pennisetum purpureum Schumach.), and bermudagrass (Cynodon spp). In a separate study, napiergrass, and bermudagrass whole samples were pretreated with esterase and cellulose before fermentation. Conversion via SSF was greatest with two bermudagrass cultivars (140 and 122 mg g-1 of biomass) followed by leaves of two napiergrass genotypes (107 and 97 mg g-1) and two giant reed clones (109 and 85 mg g-1). Variability existed among bermudagrass cultivars for conversion to ethanol after esterase and cellulase treatments, with Tifton 85 (289 mg g) and Coastcross II (284 mg g-1) being superior to Coastal (247 mg g-1) and Tifton 44 (245 mg g-1). Results suggest that ethanol yields vary significantly for feedstocks by species and within species and that genetic breeding for improved feedstocks should be possible.

  13. Raw materials evaluation and process development studies for conversion of biomass to sugars and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.; Yang, R.D.; Sciamanna, A.S.; Freitas, R.P.

    1978-06-01

    A range of cellulosic raw materials in the form of agricultural crop residue was analyzed for chemical composition and assessed for potential yields of sugars through chemical pretreatment and enzymatic hydrolysis of these materials. Corn stover was used as a representative raw material for a preliminary process design and economic assessment of the production of sugars and ethanol. With the process as presently developed, 23 gallons of ethanol can be obtained per ton of corn stover at a processing cost of about $1.80 per gallon exclusive of by-product credits. The analysis shows the cost of ethanol to be highly dependent upon (1) the cost of the biomass, (2) the extent of conversion to glucose, (3) enzyme recovery and production cost and (4) potential utilization of xylose. Significant cost reduction appears possible through further research in these directions.

  14. Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

    Science.gov (United States)

    Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

    2012-01-01

    This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

  15. Radiation modification of cellulose pulps. Preparation of cellulose derivatives

    International Nuclear Information System (INIS)

    Iller, E.; Zimek, Z.; Stupinska, H.; Mikolajczyk, W; Starostka, P.

    2005-01-01

    One of the most common methods of cellulose pulp modification (activation) applied in the production process of cellulose derivatives is the treatment of the pulp with NaOH solutions leading to the formation of alkalicellulose. The product then undergoes a prolonged process of maturation by its storage under specific conditions. The goal of the process is lowering of the molecular weight of cellulose down to the level resulting from various technological requirements. The process is time-consuming and costly; besides, it requires usage of large-capacity technological vessels and produces considerable amounts of liquid waste. Therefore, many attempts have been made to limit or altogether eliminate the highly disadvantageous stage of cellulose treatment with lye. One of the alternatives proposed so far is the radiation treatment of the cellulose pulp. In the pulp exposed to an electron beam, the bonds between molecules of D-antihydroglucopiranoses loosen and the local crystalline lattice becomes destroyed. This facilitates the access of chemical reagents to the inner structure of the cellulose and, in consequence, eliminates the need for the prolonged maturation of alkalicellulose, thus reducing the consumption of chemicals by the whole process. Research aimed at the application of radiation treatment of cellulose pulp for the production of cellulose derivatives has been conducted by a number of scientific institutions including the Institute of Nuclear Chemistry and Technology, Institute of Biopolymers and Chemical Fibres, and Pulp and Paper Research Institute. For the investigations and assessment of the molecular, hypermolecular, morphologic properties and the chemical reactivity, cellulose pulps used for chemical processing, namely Alicell, Borregaard and Ketchikan, as well as paper pulps made from pine and birch wood were selected. The selected cellulose pulps were exposed to an electron beam with an energy of 10 MeV generated in a linear electron accelerator

  16. Modeling energy production of solar thermal systems and wind turbines for installation at corn ethanol plants

    Science.gov (United States)

    Ehrke, Elizabeth

    Nearly every aspect of human existence relies on energy in some way. Most of this energy is currently derived from fossil fuel resources. Increasing energy demands coupled with environmental and national security concerns have facilitated the move towards renewable energy sources. Biofuels like corn ethanol are one of the ways the U.S. has significantly reduced petroleum consumption. However, the large energy requirement of corn ethanol limits the net benefit of the fuel. Using renewable energy sources to produce ethanol can greatly improve its economic and environmental benefits. The main purpose of this study was to model the useful energy received from a solar thermal array and a wind turbine at various locations to determine the feasibility of applying these technologies at ethanol plants around the country. The model calculates thermal energy received from a solar collector array and electricity generated by a wind turbine utilizing various input data to characterize the equipment. Project cost and energy rate inputs are used to evaluate the profitability of the solar array or wind turbine. The current state of the wind and solar markets were examined to give an accurate representation of the economics of each industry. Eighteen ethanol plant locations were evaluated for the viability of a solar thermal array and/or wind turbine. All ethanol plant locations have long payback periods for solar thermal arrays, but high natural gas prices significantly reduce this timeframe. Government incentives will be necessary for the economic feasibility of solar thermal arrays. Wind turbines can be very profitable for ethanol plants in the Midwest due to large wind resources. The profitability of wind power is sensitive to regional energy prices. However, government incentives for wind power do not significantly change the economic feasibility of a wind turbine. This model can be used by current or future ethanol facilities to investigate or begin the planning process for a

  17. Monetary value of the environmental and health externalities associated with production of ethanol from biomass feedstocks

    International Nuclear Information System (INIS)

    Kusiima, Jamil M.; Powers, Susan E.

    2010-01-01

    This research is aimed at monetizing the life cycle environmental and health externalities associated with production of ethanol from corn, corn stover, switchgrass, and forest residue. The results of this study reveal current average external costs for the production of 1 l of ethanol ranged from $0.07 for forest residue to $0.57 for ethanol production from corn. Among the various feedstocks, the external costs of PM 10 , NO X , and PM 2.5 are among the greatest contributors to these costs. The combustion of fossil fuels in upstream fertilizer and energy production processes is the primary source of these emissions and their costs, especially for corn ethanol. The combined costs of emissions associated with the production and use of nitrogen fertilizer also contribute substantially to the net external costs. For cellulosic ethanol production, the combustion of waste lignin to generate heat and power helps to keep the external costs lower than corn ethanol. Credits both for the biogenic carbon combustion and displacement of grid electricity by exporting excess electricity substantially negate many of the emissions and external costs. External costs associated with greenhouse gas emissions were not significant. However, adding estimates of indirect GHG emissions from land use changes would nearly double corn ethanol cost estimates.

  18. The Effect of Incentives and Meta-incentives on the Evolution of Cooperation

    OpenAIRE

    Okada, Isamu; Yamamoto, Hitoshi; Toriumi, Fujio; Sasaki, Tatsuya

    2015-01-01

    Although positive incentives for cooperators and/or negative incentives for free-riders in social dilemmas play an important role in maintaining cooperation, there is still the outstanding issue of who should pay the cost of incentives. The second-order free-rider problem, in which players who do not provide the incentives dominate in a game, is a well-known academic challenge. In order to meet this challenge, we devise and analyze a meta-incentive game that integrates positive incentives (re...

  19. Process development studies on the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1978-02-01

    Progress is reported on studies on the NO--O/sub 2/ pretreatment of wheat straw prior to enzymatic hydrolysis. Studies of the conversion of xylose to ethanol by Fusarium oxysporum were continued. Progress is also reported on pilot plant process development and design studies on continuous cellulase production, enzyme recovery, batch cellulase enzyme production from Trichoderma viride, and kinetic modelling of the enzymatic hydrolysis of 5 percent newsprint. (JGB)

  20. Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels.

    Science.gov (United States)

    Hill, Jason; Nelson, Erik; Tilman, David; Polasky, Stephen; Tiffany, Douglas

    2006-07-25

    Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.

  1. Irregular incentives

    International Nuclear Information System (INIS)

    Cicchetti, M.A.

    1993-01-01

    Public utility regulation lacks a formal proxy for the economic profits that can be earned in an effectively competitive market if a firm is efficient or innovative. After all, public utility regulation operated on cost-plus basis. If a utility is efficient or innovative and lowers its costs, its typical reward is to have its rates reduced. This is a perverse incentive to motivate a utility to produce at the most efficient level. In addition, since regulation operates on this cost-plus basis, a utility can increase its net income, all other things being equal, by overinvesting in (or open-quotes gold-platingclose quotes) its system, another perverse incentive. Recognizing these flaws of regulation, academicians, utility executives, regulators, and legislators have tried over the last several years to implement incentive regulation plans that correct such perverse incentives. However, under many of the earnings-sharing or price-regulation incentive plans, the rewards for efficient production are not tied directly to measures under a company's control. In fact, such plans could prove highly detrimental to ratepayers and competitors of the regulated company and its affiliates. An incentive regulation plan that ties an appropriate reward for efficient production to specific efficiency gains is a better proxy of an effectively competitive environment. What's more, it is superior to an incentive plan that rewards circumstances beyond the company's control or self-serving manipulation. This is particularly true if no earnings cap is associated with the reward for efficiency. Rewards for efficient production should be tied to specific actions. A suitable incentive plan does not preclude appropriately derived flexible prices for certain products or services where warranted

  2. Assessment of cellulose purification methods from the residue of enzymatic hydrolysis of sugarcane bagasse for the production of cellulose nanocrystals

    International Nuclear Information System (INIS)

    Camargo, Lais Angelice de; Farinas, Cristiane Sanchez; Marconcini, José Manoel; Mattoso, Luiz Henrique Capparelli; Pereira, Sandra Cerqueira

    2016-01-01

    Full text: Over the years, there is a growing trend in the reuse of residues from the agricultural industries due to social, environmental and economic demands. The production of Brazilian sugarcane in the 2014/15 season was more than 640 million tons, estimating that one third of this total is bagasse [1]. After enzymatic hydrolysis of bagasse in order to give the 2G ethanol, remains a solid fibrous residue which can be repurposed in other processes. This study evaluated four methods for the purification of the resulting solid fibrous residue from the enzymatic hydrolysis process of bagasse, with the intention of obtaining cellulose. Measurements of the crystallinity index (CI) of the cellulose contained in the samples were determined using X-ray Diffraction (XRD). The enzymatic hydrolysis of generates a fibrous solid residue with contents of lignin and cellulose. This residue was subjected to four purification methods: I) 100 mL of NaOH (5%, w/w) at 55 °C was added to 5 g of residue and 43 mL of H 2 O 2 (35%, v/v) under stirring for 1.5 hours; II) the same procedure was repeated on the resulting material from I; III) 105 mL of solution 10:1 (ν/ν) of CH 3 COOH and HNO 3 at 60 °C was added to 5 g of residue under stirring for 30 minutes; IV) reaction with a solution composed of 1 ml of CH 3 COOH and 2.5 g of NaClO 2 at 70 °C under stirring for 1 hour and after that time, the procedure was repeated twice and then the solution was kept under stirring for further 3 hours. The crystallinity indexes found for the purification procedures were: I) 81.7%; II) 83.2%; III) 52.1% e IV) 77.2%. The best result was found for the material subjected to the method II. This process (II) generated a material composed of high content of crystalline cellulose. References: [1] CONAB (National Supply Company), 2015. (author)

  3. The food v. fuel debate. A nuanced view of incentive structures

    International Nuclear Information System (INIS)

    Srinivasan, Sunderasan

    2009-01-01

    The rapid rise in crude oil prices and the geo-political uncertainty associated with ensuring uninterrupted supplies have compelled researchers, economists and politicians to look for indigenous substitutes. Liquid biofuels - ethanol and biodiesel - are widely recognized, technically feasible alternatives. Even as the jury is out to determine the environmental footprint of biofuels, the surrounding frenzy has often led to the announcement of unsustainable support prices for feedstock and unviable procurement prices for the finished product. This paper makes a detailed assessment of incentive structures facing the agriculturists, refiners and the consumers. Data from the Indian market are employed to illustrate. (author)

  4. Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis

    Science.gov (United States)

    Jijiao Zeng; Zhaohui Tong; Letian Wang; J.Y. Zhu; Lonnie Ingram

    2014-01-01

    The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation...

  5. Pilot plant studies of the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1977-09-30

    Work for the period July 1 to September 30, 1977 is summarized briefly. Results of the following studies are reported: analysis and evaluation of potential raw materials--chemical analysis of the Kudzu plant and effect of NO/sub x/ pretreatments on the hydrolysis of wheat straw; utilization of hemicellulose sugars; process design and economic studies--hydrolysis process and ethanol fermentation; pilot plant process development and design studies--enhanced cellulase production and continuous hydrolysis. (JGB)

  6. Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

    Science.gov (United States)

    Slavens, Shelyn Gehle

    Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

  7. Cellulose accessibility limits the effectiveness of minimum cellulase loading on the efficient hydrolysis of pretreated lignocellulosic substrates

    Directory of Open Access Journals (Sweden)

    Saddler Jack N

    2011-02-01

    Full Text Available Abstract A range of lignocellulosic feedstocks (including agricultural, softwood and hardwood substrates were pretreated with either sulfur dioxide-catalyzed steam or an ethanol organosolv procedure to try to establish a reliable assessment of the factors governing the minimum protein loading that could be used to achieve efficient hydrolysis. A statistical design approach was first used to define what might constitute the minimum protein loading (cellulases and β-glucosidase that could be used to achieve efficient saccharification (defined as at least 70% glucan conversion of the pretreated substrates after 72 hours of hydrolysis. The likely substrate factors that limit cellulose availability/accessibility were assessed, and then compared with the optimized minimum amounts of protein used to obtain effective hydrolysis. The optimized minimum protein loadings to achieve efficient hydrolysis of seven pretreated substrates ranged between 18 and 63 mg protein per gram of glucan. Within the similarly pretreated group of lignocellulosic feedstocks, the agricultural residues (corn stover and corn fiber required significantly lower protein loadings to achieve efficient hydrolysis than did the pretreated woody biomass (poplar, douglas fir and lodgepole pine. Regardless of the substantial differences in the source, structure and chemical composition of the feedstocks, and the difference in the pretreatment technology used, the protein loading required to achieve efficient hydrolysis of lignocellulosic substrates was strongly dependent on the accessibility of the cellulosic component of each of the substrates. We found that cellulose-rich substrates with highly accessible cellulose, as assessed by the Simons' stain method, required a lower protein loading per gram of glucan to obtain efficient hydrolysis compared with substrates containing less accessible cellulose. These results suggest that the rate-limiting step during hydrolysis is not the catalytic

  8. Characterization of ethyl cellulose polymer.

    Science.gov (United States)

    Mahnaj, Tazin; Ahmed, Salah U; Plakogiannis, Fotios M

    2013-01-01

    Ethyl cellulose (EC) polymer was characterized for its property before considering the interactions with the plasicizer. Ethocel Std.10 FP Premium from Dow chemical company USA was tested for its solubility, morphology and thermal properties. Seven percentage of EC solution in ethanol was found to be the right viscosity used to prepare the film. The EC polymer and EC film without any plasticizers showed almost identical thermal behavior, but in X-ray diffraction showed different arrangements of crystallites and amorphous region. Dynamic mechanical analysis of film showed that without a plasticizer, EC film was not flexible and had very low elongation with high applied force. The aim of the work was to avoid using the commercially available EC dispersions Surelease® and Aquacoat®; both already have additives on it. Instead, Ethocel EC polymer (powder) was characterized in our laboratory in order to find out the properties of polymer before considering the interactions of the polymer with various plasticizers.

  9. Ethanol production from Sorghum bicolor using both separate and simultaneous saccharification and fermentation in batch and fed batch systems

    DEFF Research Database (Denmark)

    Mehmood, Sajid; Gulfraz, M.; Rana, N. F.

    2009-01-01

    The objective of this work was to find the best combination of different experimental conditions during pre-treatment, enzymatic saccharification, detoxification of inhibitors and fermentation of Sorghum bicolor straw for ethanol production. The optimization of pre-treatment using different...... were used in order to increase the monomeric sugar during enzymatic hydrolysis and it has been observed that the addition of these surfactants contributed significantly in cellulosic conversion but no effect was shown on hemicellulosic hydrolysis. Fermentability of hydrolyzate was tested using...... Saccharomyces cerevisiae Ethanol Red (TM) and it was observed that simultaneous saccharification and fermentation ( SSF) with both batch and fed batch resulted in better ethanol yield as compared to separate hydrolysis and fermentation ( SHF). Detoxification of furan during SHF facilitated reduction...

  10. Energy assessment of second generation (2G) ethanol production from wheat straw in Indian scenario.

    Science.gov (United States)

    Mishra, Archana; Kumar, Akash; Ghosh, Sanjoy

    2018-03-01

    Impact of second-generation ethanol (2G) use in transportation sector mainly depends upon energy efficiency of entire production process. The objective of present study was to determine energy efficiency of a potential lignocellulosic feedstock; wheat straw and its conversion into cellulosic ethanol in Indian scenario. Energy efficiency was determined by calculating Net energy ratio (NER), i.e. ratio of output energy obtained by ethanol and input energy used in ethanol production. Energy consumption and generation at each step is calculated briefly (11,837.35 MJ/ha during Indian dwarf irrigated variety of wheat crop production and 7.1148 MJ/kg straw during ethanol production stage). Total energy consumption is calculated as 8.2988 MJ/kg straw whereas energy generation from ethanol is 15.082 MJ/kg straw; resulting into NER > 1. Major portion of agricultural energy input is contributed by diesel and fertilisers whereas refining process of wheat straw feedstock to ethanol and by-products require mainly in the form of steam and electricity. On an average, 1671.8 kg water free ethanol, 930 kg lignin rich biomass (for combustion), and 561 kg C5-molasses (for fodder) per hectare are produced. Findings of this study, net energy ratio (1.81) and figure of merit (14.8028 MJ/nil kg carbon) proves wheat straw as highest energy efficient lignocellulosic feedstock for the country.

  11. Incentive Compatibility

    OpenAIRE

    Ledyard, John O.

    1987-01-01

    Incentive compatibility is described and discussed. A summary of the current state of understanding is provided. Key words are: incentive compatibility, game theory, implementation, mechanism, Bayes, Nash, and revelation.

  12. Process analysis and optimization of simultaneous saccharification and co-fermentation of ethylenediamine-pretreated corn stover for ethanol production.

    Science.gov (United States)

    Qin, Lei; Zhao, Xiong; Li, Wen-Chao; Zhu, Jia-Qing; Liu, Li; Li, Bing-Zhi; Yuan, Ying-Jin

    2018-01-01

    Improving ethanol concentration and reducing enzyme dosage are main challenges in bioethanol refinery from lignocellulosic biomass. Ethylenediamine (EDA) pretreatment is a novel method to improve enzymatic digestibility of lignocellulose. In this study, simultaneous saccharification and co-fermentation (SSCF) process using EDA-pretreated corn stover was analyzed and optimized to verify the constraint factors on ethanol production. Highest ethanol concentration was achieved with the following optimized SSCF conditions at 6% glucan loading: 12-h pre-hydrolysis, 34 °C, pH 5.4, and inoculum size of 5 g dry cell/L. As glucan loading increased from 6 to 9%, ethanol concentration increased from 33.8 to 48.0 g/L, while ethanol yield reduced by 7%. Mass balance of SSCF showed that the reduction of ethanol yield with the increasing solid loading was mainly due to the decrease of glucan enzymatic conversion and xylose metabolism of the strain. Tween 20 and BSA increased ethanol concentration through enhancing enzymatic efficiency. The solid-recycled SSCF process reduced enzyme dosage by 40% (from 20 to 12 mg protein/g glucan) to achieve the similar ethanol concentration (~ 40 g/L) comparing to conventional SSCF. Here, we established an efficient SSCF procedure using EDA-pretreated biomass. Glucose enzymatic yield and yeast viability were regarded as the key factors affecting ethanol production at high solid loading. The extensive analysis of SSCF would be constructive to overcome the bottlenecks and improve ethanol production in cellulosic ethanol refinery.

  13. Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells

    Directory of Open Access Journals (Sweden)

    Chukwuemeka P. Azubuike

    2012-09-01

    Full Text Available α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow properties were investigated. α–Cellulose (GCN was extracted from groundnut shell (an agricultural waste product using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN. The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA, using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α-cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.

  14. The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6

    OpenAIRE

    Endler, Anne; Schneider, Rene; Kesten, Christopher; Lampugnani, Edwin R.; Persson, Staffan

    2016-01-01

    Cellulose is a cell wall constituent that is essential for plant growth and development, and an important raw material for a range of industrial applications. Cellulose is synthesized at the plasma membrane by massive cellulose synthase (CesA) complexes that track along cortical microtubules in elongating cells of Arabidopsis through the activity of the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1). In a recent study we identified another family of proteins that also are associated with the ...

  15. Characterization of purified bacterial cellulose focused on its use on paper restoration.

    Science.gov (United States)

    Santos, Sara M; Carbajo, José M; Quintana, Ester; Ibarra, David; Gomez, Nuria; Ladero, Miguel; Eugenio, M Eugenia; Villar, Juan C

    2015-02-13

    Bacterial cellulose (BC) synthesized by Gluconacetobacter sucrofermentans CECT 7291 seems to be a good option for the restoration of degraded paper. In this work BC layers are cultivated and purified by two different methods: an alkaline treatment when the culture media contains ethanol and a thermal treatment if the media is free from ethanol. The main goal of these tests was the characterization of BC layers measured in terms of tear and burst indexes, optical properties, SEM, X-ray diffraction, FTIR, degree of polymerization, static and dynamic contact angles, and mercury intrusion porosimetry. The BC layers were also evaluated in the same terms after an aging treatment. Results showed that BC has got high crystallinity index, low internal porosity, good mechanical properties and high stability over time, especially when purified by the alkaline treatment. These features make BC an adequate candidate for degraded paper reinforcement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Tax Incentives : Using Tax Incentives to Attract Foreign Direct Investment

    OpenAIRE

    Morisset, Jacques

    2003-01-01

    The increasing mobility of international firms and the gradual elimination of barriers to global capital flows have stimulated competition among governments to attract foreign direct investment, often through tax incentives. This note reviews the debate about the effectiveness of tax incentives, examining two much-contested questions: can tax incentives attract foreign investment? And what...

  17. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Science.gov (United States)

    Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

    2014-01-01

    Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. PMID:25000264

  18. Co-production of bio-ethanol, xylonic acid and slow-release nitrogen fertilizer from low-cost straw pulping solid residue.

    Science.gov (United States)

    Huang, Chen; Ragauskas, Arthur J; Wu, Xinxing; Huang, Yang; Zhou, Xuelian; He, Juan; Huang, Caoxing; Lai, Chenhuan; Li, Xin; Yong, Qiang

    2018-02-01

    A novel bio-refinery sequence yielding varieties of co-products was developed using straw pulping solid residue. This process utilizes neutral sulfite pretreatment which under optimal conditions (160 °C and 3% (w/v) sulfite charge) provides 64.3% delignification while retaining 90% of cellulose and 67.3% of xylan. The pretreated solids exhibited excellent enzymatic digestibility, with saccharification yields of 86.9% and 81.1% for cellulose and xylan, respectively. After pretreatment, the process of semi-simultaneous saccharification and fermentation (S-SSF) and bio-catalysis was investigated. The results revealed that decreased ethanol yields were achieved when solid loading increased from 5% to 30%. An acceptable ethanol yield of 76.8% was obtained at 20% solid loading. After fermentation, bio-catalysis of xylose remaining in fermentation broth resulted in near 100% xylonic acid (XA) yield at varied solid loadings. To complete the co-product portfolio, oxidation ammoniation of the dissolved lignin successfully transformed it into biodegradable slow-release nitrogen fertilizer with excellent agricultural properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Applying Adaptive Agricultural Management & Industrial Ecology Principles to Produce Lower- Carbon Ethanol from California Energy Beets

    Science.gov (United States)

    Alexiades, Anthy Maria

    The life cycle assessment of a proposed beet-to-ethanol pathway demonstrates how agricultural management and industrial ecology principles can be applied to reduce greenhouse gas emissions, minimize agrochemical inputs and waste, provide ecosystem services and yield a lower-carbon fuel from a highly land-use efficient, first-generation feedstock cultivated in California. Beets grown in California have unique potential as a biofuel feedstock. A mature agricultural product with well-developed supply chains, beet-sugar production in California has contracted over recent decades, leaving idle production capacity and forcing growers to seek other crops for use in rotation or find a new market for beets. California's Low Carbon Fuel Standard (LCFS) faces risk of steeply-rising compliance costs, as greenhouse gas reduction targets in the transportation sector were established assuming commercial volumes of lower-carbon fuels from second-generation feedstocks -- such as residues, waste, algae and cellulosic crops -- would be available by 2020. The expected shortfall of cellulosic ethanol has created an immediate need to develop lower-carbon fuels from readily available feedstocks using conventional conversion technologies. The life cycle carbon intensity of this ethanol pathway is less than 28 gCO2e/MJEthanol: a 72% reduction compared to gasoline and 19% lower than the most efficient corn ethanol pathway (34 gCO2e/MJ not including indirect land use change) approved under LCFS. The system relies primarily on waste-to-energy resources; nearly 18 gCO2e/MJ are avoided by using renewable heat and power generated from anaerobic digestion of fermentation stillage and gasification of orchard residues to meet 88% of the facility's steam demand. Co-products displace 2 gCO2e/MJ. Beet cultivation is the largest source of emissions, contributing 15 gCO 2e/MJ. The goal of the study is to explore opportunities to minimize carbon intensity of beet-ethanol and investigate the potential

  20. Aligning ambition and incentives

    DEFF Research Database (Denmark)

    Koch, Alexander; Peyrache, Eloïc

    2011-01-01

    Labor turnover creates longer term career concerns incentives that motivate employees in addition to the short term monetary incentives provided by the current employer. We analyze how these incentives interact, and derive implications for the design of incentive contracts and organizational choice...

  1. Aligning Ambition and Incentives

    DEFF Research Database (Denmark)

    Koch, Alexander; Peyrache, Eloïc

    Labor turnover creates longer term career concerns incentives that motivate employees in addition to the short term monetary incentives provided by the current employer. We analyze how these incentives interact and derive implications for the design of incentive contracts and organizational choice...

  2. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  3. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  4. Do Tax Incentives Affect Business Location? Evidence from State Film Incentives

    OpenAIRE

    Patrick Button

    2015-01-01

    I provide the first estimates of the impacts of recently-popular U.S. state film incentives on filming location, establishment location, and employment in the film industry. Filming in this industry is relatively insensitive to locational characteristics, and these incentives are numerous and strong, so this is a good case study to bound the effects of tax incentives on business location. I compile a detailed database of incentives across U.S. states, matching this with TV series and feature ...

  5. Comparison of cellulosic ethanol yields from midwestern maize and reconstructed tallgrass prairie systems managed for bioenergy

    Science.gov (United States)

    Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-spe...

  6. BIOETHANOL PRODUCTION BY MISCANTHUS AS A LIGNOCELLULOSIC BIOMASS: FOCUS ON HIGH EFFICIENCY CONVERSION TO GLUCOSE AND ETHANOL

    Directory of Open Access Journals (Sweden)

    Minhee Han Mail

    2011-04-01

    Full Text Available Current ethanol production processes using crops such as corn and sugar cane have been well established. However, the utilization of cheaper lignocellulosic biomass could make bioethanol more competitive with fossil fuels while avoiding the ethical concerns associated with using potential food resources. In this study, Miscanthus, a lignocellulosic biomass, was pretreated using NaOH to produce bioethanol. The pretreatment and enzymatic hydrolysis conditions were evaluated by response surface methodology (RSM. The optimal conditions were found to be 145.29 °C, 28.97 min, and 1.49 M for temperature, reaction time, and NaOH concentration, respectively. Enzymatic digestibility of pretreated Miscanthus was examined at various enzyme loadings (10 to 70 FPU/g cellulose of cellulase and 30 CbU/g of β-glucosidase. Regarding enzymatic digestibility, 50 FPU/g cellulose of cellulase and 30 CbU/g of β-glucosidase were selected as the test concentrations, resulting in a total glucose conversion rate of 83.92%. Fermentation of hydrolyzed Miscanthus using Saccharomyces cerevisiae resulted in an ethanol concentration of 59.20 g/L at 20% pretreated biomass loading. The results presented here constitute a significant contribution to the production of bioethanol from Miscanthus.

  7. Simultaneous saccharification and cofermentation of lignocellulosic residues from commercial furfural production and corn kernels using different nutrient media

    Directory of Open Access Journals (Sweden)

    Cristhian Carrasco

    2011-07-01

    Full Text Available Abstract Background As the supply of starch grain and sugar cane, currently the main feedstocks for bioethanol production, become limited, lignocelluloses will be sought as alternative materials for bioethanol production. Production of cellulosic ethanol is still cost-inefficient because of the low final ethanol concentration and the addition of nutrients. We report the use of simultaneous saccharification and cofermentation (SSCF of lignocellulosic residues from commercial furfural production (furfural residue, FR and corn kernels to compare different nutritional media. The final ethanol concentration, yield, number of live yeast cells, and yeast-cell death ratio were investigated to evaluate the effectiveness of integrating cellulosic and starch ethanol. Results Both the ethanol yield and number of live yeast cells increased with increasing corn-kernel concentration, whereas the yeast-cell death ratio decreased in SSCF of FR and corn kernels. An ethanol concentration of 73.1 g/L at 120 h, which corresponded to a 101.1% ethanol yield based on FR cellulose and corn starch, was obtained in SSCF of 7.5% FR and 14.5% corn kernels with mineral-salt medium. SSCF could simultaneously convert cellulose into ethanol from both corn kernels and FR, and SSCF ethanol yield was similar between the organic and mineral-salt media. Conclusions Starch ethanol promotes cellulosic ethanol by providing important nutrients for fermentative organisms, and in turn cellulosic ethanol promotes starch ethanol by providing cellulosic enzymes that convert the cellulosic polysaccharides in starch materials into additional ethanol. It is feasible to produce ethanol in SSCF of FR and corn kernels with mineral-salt medium. It would be cost-efficient to produce ethanol in SSCF of high concentrations of water-insoluble solids of lignocellulosic materials and corn kernels. Compared with prehydrolysis and fed-batch strategy using lignocellulosic materials, addition of starch

  8. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    International Nuclear Information System (INIS)

    Fu, Jiapeng; Pang, Zengyuan; Yang, Jie; Huang, Fenglin; Cai, Yibing; Wei, Qufu

    2015-01-01

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors

  9. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiapeng, E-mail: firgexiao@sina.cn; Pang, Zengyuan, E-mail: pangzengyuan1212@163.com; Yang, Jie, E-mail: young1993@126.com; Huang, Fenglin, E-mail: flhuang@jiangnan.edu.cn; Cai, Yibing, E-mail: yibingcai@jiangnan.edu.cn; Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn

    2015-09-15

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors.

  10. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara

    2018-04-11

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration of trimethylsilyl cellulose (TMSC), an easily synthesized cellulose derivative. The amorphous hydrophilic feature of the regenerated cellulose enabled fast permeation of water vapour. The pore-free cellulose layer thickness was adjustable by the initial TMSC concentration and acted as an efficient gas barrier. As a result, a 5,000 GPU water vapour transmission rate (WVTR) at the highest ideal selectivity of 1.1 x 106 was achieved by the membranes spin coated from a 7% (w/w) TMSC solution. The membranes maintained a 4,000 GPU WVTR with selectivity of 1.1 x 104 in the mixed-gas experiments, surpassing the performances of the previously reported composite membranes. This study provides a simple way to not only produce high performance membranes but also to advance cellulose as a low-cost and sustainable membrane material for dehumidification applications.

  11. Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

    International Nuclear Information System (INIS)

    Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

    1987-01-01

    Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

  12. Water consumption in the production of ethanol and petroleum gasoline.

    Science.gov (United States)

    Wu, May; Mintz, Marianne; Wang, Michael; Arora, Salil

    2009-11-01

    We assessed current water consumption during liquid fuel production, evaluating major steps of fuel lifecycle for five fuel pathways: bioethanol from corn, bioethanol from cellulosic feedstocks, gasoline from U.S. conventional crude obtained from onshore wells, gasoline from Saudi Arabian crude, and gasoline from Canadian oil sands. Our analysis revealed that the amount of irrigation water used to grow biofuel feedstocks varies significantly from one region to another and that water consumption for biofuel production varies with processing technology. In oil exploration and production, water consumption depends on the source and location of crude, the recovery technology, and the amount of produced water re-injected for oil recovery. Our results also indicate that crop irrigation is the most important factor determining water consumption in the production of corn ethanol. Nearly 70% of U.S. corn used for ethanol is produced in regions where 10-17 liters of water are consumed to produce one liter of ethanol. Ethanol production plants are less water intensive and there is a downward trend in water consumption. Water requirements for switchgrass ethanol production vary from 1.9 to 9.8 liters for each liter of ethanol produced. We found that water is consumed at a rate of 2.8-6.6 liters for each liter of gasoline produced for more than 90% of crude oil obtained from conventional onshore sources in the U.S. and more than half of crude oil imported from Saudi Arabia. For more than 55% of crude oil from Canadian oil sands, about 5.2 liters of water are consumed for each liter of gasoline produced. Our analysis highlighted the vital importance of water management during the feedstock production and conversion stage of the fuel lifecycle.

  13. Water Consumption in the Production of Ethanol and Petroleum Gasoline

    Science.gov (United States)

    Wu, May; Mintz, Marianne; Wang, Michael; Arora, Salil

    2009-11-01

    We assessed current water consumption during liquid fuel production, evaluating major steps of fuel lifecycle for five fuel pathways: bioethanol from corn, bioethanol from cellulosic feedstocks, gasoline from U.S. conventional crude obtained from onshore wells, gasoline from Saudi Arabian crude, and gasoline from Canadian oil sands. Our analysis revealed that the amount of irrigation water used to grow biofuel feedstocks varies significantly from one region to another and that water consumption for biofuel production varies with processing technology. In oil exploration and production, water consumption depends on the source and location of crude, the recovery technology, and the amount of produced water re-injected for oil recovery. Our results also indicate that crop irrigation is the most important factor determining water consumption in the production of corn ethanol. Nearly 70% of U.S. corn used for ethanol is produced in regions where 10-17 liters of water are consumed to produce one liter of ethanol. Ethanol production plants are less water intensive and there is a downward trend in water consumption. Water requirements for switchgrass ethanol production vary from 1.9 to 9.8 liters for each liter of ethanol produced. We found that water is consumed at a rate of 2.8-6.6 liters for each liter of gasoline produced for more than 90% of crude oil obtained from conventional onshore sources in the U.S. and more than half of crude oil imported from Saudi Arabia. For more than 55% of crude oil from Canadian oil sands, about 5.2 liters of water are consumed for each liter of gasoline produced. Our analysis highlighted the vital importance of water management during the feedstock production and conversion stage of the fuel lifecycle.

  14. Life cycle greenhouse gas impacts of ethanol, biomethane and limonene production from citrus waste

    Science.gov (United States)

    Pourbafrani, Mohammad; McKechnie, Jon; MacLean, Heather L.; Saville, Bradley A.

    2013-03-01

    The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA

  15. Life cycle greenhouse gas impacts of ethanol, biomethane and limonene production from citrus waste

    International Nuclear Information System (INIS)

    Pourbafrani, Mohammad; MacLean, Heather L; Saville, Bradley A; McKechnie, Jon

    2013-01-01

    The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA

  16. Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

    NARCIS (Netherlands)

    Boerstoel, H.

    2006-01-01

    The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline

  17. Utilization of household food waste for the production of ethanol at high dry material content.

    Science.gov (United States)

    Matsakas, Leonidas; Kekos, Dimitris; Loizidou, Maria; Christakopoulos, Paul

    2014-01-08

    Environmental issues and shortage of fossil fuels have turned the public interest to the utilization of renewable, environmentally friendly fuels, such as ethanol. In order to minimize the competition between fuels and food production, researchers are focusing their efforts to the utilization of wastes and by-products as raw materials for the production of ethanol. household food wastes are being produced in great quantities in European Union and their handling can be a challenge. Moreover, their disposal can cause severe environmental issues (for example emission of greenhouse gasses). On the other hand, they contain significant amounts of sugars (both soluble and insoluble) and they can be used as raw material for the production of ethanol. Household food wastes were utilized as raw material for the production of ethanol at high dry material consistencies. A distinct liquefaction/saccharification step has been included to the process, which rapidly reduced the viscosity of the high solid content substrate, resulting in better mixing of the fermenting microorganism. This step had a positive effect in both ethanol production and productivity, leading to a significant increase in both values, which was up to 40.81% and 4.46 fold, respectively. Remaining solids (residue) after fermentation at 45% w/v dry material (which contained also the unhydrolyzed fraction of cellulose), were subjected to a hydrothermal pretreatment in order to be utilized as raw material for a subsequent ethanol fermentation. This led to an increase of 13.16% in the ethanol production levels achieving a final ethanol yield of 107.58 g/kg dry material. In conclusion, the ability of utilizing household food waste for the production of ethanol at elevated dry material content has been demonstrated. A separate liquefaction/saccharification process can increase both ethanol production and productivity. Finally, subsequent fermentation of the remaining solids could lead to an increase of the overall

  18. Do new cellulolytic enzyme preparations affect the industrial strategies for high solids lignocellulosic ethanol production?

    DEFF Research Database (Denmark)

    Cannella, David; Jørgensen, Henning

    2014-01-01

    proven essential for economic feasibility at industrial scale. Historically, simultaneous saccharification and fermentation (SSF) was found to give better ethanol yields compared to separate hydrolysis and fermentation (SHF), but data in literature are typically based on operating the process at low dry...... matter conditions. In this work the impact of selected enzyme preparation and processing strategy (SHF, presaccharification and simultaneous saccharification and fermentation—PSSF, and SSF) on final ethanol yield and overall performance was investigated with pretreated wheat straw up to 30% DM...... cellulose to around 94%, revealing that the most relevant products could be accounted for. One observation was the presence of oxidized sugar (gluconic acid) upon enzymatic hydrolysis with the latest enzyme preparation. Experiments showed gluconic acid formation by recently discovered enzymatic class...

  19. Characterization of cellulose nanowhiskers

    International Nuclear Information System (INIS)

    Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia

    2015-01-01

    Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

  20. Utilization of biomass in the U.S. for the production of ethanol fuel as a gasoline replacement. I - Terrestrial resource potential. II - Energy requirements, with emphasis on lignocellulosic conversion

    Science.gov (United States)

    Ferchak, J. D.; Pye, E. K.

    The paper assesses the biomass resource represented by starch derived from feed corn, surplus and distressed grain, and high-yield sugar crops planted on set-aside land in the U.S. It is determined that the quantity of ethanol produced may be sufficient to replace between 5 to 27% of present gasoline requirements. Utilization of novel cellulose conversion technology may in addition provide fermentable sugars from municipal, agricultural and forest wastes, and ultimately from highly productive silvicultural operations. The potential additional yield of ethanol from lignocellulosic biomass appears to be well in excess of liquid fuel requirements of an enhanced-efficiency transport sector at present mileage demands. No conflict with food production would be entailed. A net-energy assessment is made for lignocellulosic biomass feedstocks' conversion to ethanol and an almost 10:1 energy yield/energy cost ratio determined. It is also found that novel cellulose pretreatment and enzymatic conversion methods still under development may significantly improve even that figure, and that both chemical-feedstocks and energy-yielding byproducts such as carbon dioxide, biogas and lignin make ethanol production potentially energy self-sufficient. A final high-efficiency production approach incorporates site-optimized, nonpolluting energy sources such as solar and geothermal.

  1. CELLULOSIC NANOCOMPOSITES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2008-08-01

    Full Text Available Because of their wide abundance, their renewable and environmentally benign nature, and their outstanding mechanical properties, a great deal of attention has been paid recently to cellulosic nanofibrillar structures as components in nanocomposites. A first major challenge has been to find efficient ways to liberate cellulosic fibrils from different source materials, including wood, agricultural residues, or bacterial cellulose. A second major challenge has involved the lack of compatibility of cellulosic surfaces with a variety of plastic materials. The water-swellable nature of cellulose, especially in its non-crystalline regions, also can be a concern in various composite materials. This review of recent work shows that considerable progress has been achieved in addressing these issues and that there is potential to use cellulosic nano-components in a wide range of high-tech applications.

  2. Estimation of economic impacts of cellulosic biofuel production: a comparative analysis of three biofuel pathways: Economic impacts of biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yimin; Goldberg, Marshall; Tan, Eric; Meyer, Pimphan A.

    2016-03-07

    The development of a cellulosic biofuel industry utilizing domestic biomass resources is expected to create opportunities for economic growth resulting from the construction and operation of new biorefineries. We applied an economic input-output model to estimate potential economic impacts, particularly gross job growth, resulting from the construction and operation of biorefineries using three different technology pathways: 1) cellulosic ethanol via biochemical conversion in Iowa, 2) renewable diesel blendstock via biological conversion in Georgia, and 3) renewable diesel and gasoline blendstock via fast pyrolysis in Mississippi. Combining direct, indirect, and induced effects, capital investment associated with the construction of a biorefinery processing 2,000 dry metric tons of biomass per day (DMT/day) could yield between 5,960 and 8,470 full-time equivalent (FTE) jobs during the construction period. Fast pyrolysis biorefineries produce the most jobs on a project level thanks to the highest capital requirement among the three pathways. Normalized for one million dollars of capital investment, the fast pyrolysis biorefineries are estimated to yield slighter more jobs (12.1 jobs) than the renewable diesel (11.8 jobs) and the cellulosic ethanol (11.6 jobs) biorefineries. While operating biorefineries is not labor-intensive, the annual operation of a 2,000 DMT/day biorefinery could support between 720 and 970 jobs when the direct, indirect, and induced effects are considered. The major factor, which results in the variations among the three pathways, is the type of biomass feedstock used for biofuels. The agriculture/forest, services, and trade industries are the primary sectors that will benefit from the ongoing operation of biorefineries.

  3. Rheology of corn stover slurries during fermentation to ethanol

    Science.gov (United States)

    Ghosh, Sanchari; Epps, Brenden; Lynd, Lee

    2017-11-01

    In typical processes that convert cellulosic biomass into ethanol fuel, solubilization of the biomass is carried out by saccharolytic enzymes; however, these enzymes require an expensive pretreatment step to make the biomass accessible for solubilization (and subsequent fermentation). We have proposed a potentially-less-expensive approach using the bacterium Clostridium thermocellum, which can initiate fermentation without pretreatment. Moreover, we have proposed a ``cotreatment'' process, in which fermentation and mechanical milling occur alternately so as to achieve the highest ethanol yield for the least milling energy input. In order to inform the energetic requirements of cotreatment, we experimentally characterized the rheological properties of corn stover slurries at various stages of fermentation. Results show that a corn stover slurry is a yield stress fluid, with shear thinning behavior well described by a power law model. Viscosity decreases dramatically upon fermentation, controlling for variables such as solids concentration and particle size distribution. To the authors' knowledge, this is the first study to characterize the changes in the physical properties of biomass during fermentation by a thermophilic bacterium.

  4. Recent Strategies in Preparation of Cellulose Nanocrystals and Cellulose Nanofibrils Derived from Raw Cellulose Materials

    Directory of Open Access Journals (Sweden)

    Hongxiang Xie

    2018-01-01

    Full Text Available The recent strategies in preparation of cellulose nanocrystals (CNCs and cellulose nanofibrils (CNFs were described. CNCs and CNFs are two types of nanocelluloses (NCs, and they possess various superior properties, such as large specific surface area, high tensile strength and stiffness, low density, and low thermal expansion coefficient. Due to various applications in biomedical engineering, food, sensor, packaging, and so on, there are many studies conducted on CNCs and CNFs. In this review, various methods of preparation of CNCs and CNFs are summarized, including mechanical, chemical, and biological methods. The methods of pretreatment of cellulose are described in view of the benefits to fibrillation.

  5. Enhanced enzymatic hydrolysis and ethanol production from cashew apple bagasse pretreated with alkaline hydrogen peroxide.

    Science.gov (United States)

    da Costa, Jessyca Aline; Marques, José Edvan; Gonçalves, Luciana Rocha Barros; Rocha, Maria Valderez Ponte

    2015-03-01

    The effect of combinations and ratios between different enzymes has been investigated in order to assess the optimal conditions for hydrolysis of cashew apple bagasse pretreated with alkaline hydrogen peroxide (the solids named CAB-AHP). The separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes were evaluated in the ethanol production. The enzymatic hydrolysis conducted with cellulase complex and β-glucosidase in a ratio of 0.61:0.39, enzyme loading of 30FPU/g(CAB-AHP) and 66CBU/g(CAB-AHP), respectively, using 4% cellulose from CAB-AHP, turned out to be the most effective conditions, with glucose and xylose yields of 511.68 mg/g(CAB-AHP) and 237.8 mg/g(CAB-AHP), respectively. Fermentation of the pure hydrolysate by Kluyveromyces marxianus ATCC 36907 led to an ethanol yield of 61.8kg/ton(CAB), corresponding to 15 g/L ethanol and productivity of 3.75 g/( Lh). The ethanol production obtained for SSF process using K. marxianus ATCC 36907 was 18 g/L corresponding to 80% yield and 74.2kg/ton(CAB). Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Photovoltaic Incentive Design Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, T. E.

    2006-12-01

    Investments in customer-owned grid-connected photovoltaic (PV) energy systems are growing at a steady pace. This is due, in part, to the availability of attractive economic incentives offered by public state agencies and utilities. In the United States, these incentives have largely been upfront lump payments tied to the system capacity rating. While capacity-based ''buydowns'' have stimulated the domestic PV market, they have been criticized for subsidizing systems with potentially poor energy performance. As a result, the industry has been forced to consider alternative incentive structures, particularly ones that pay based on long-term measured performance. The industry, however, lacks consensus in the debate over the tradeoffs between upfront incentive payments versus longer-term payments for energy delivery. This handbook is designed for agencies and utilities that offer or intend to offer incentive programs for customer-owned PV systems. Its purpose is to help select, design, and implement incentive programs that best meet programmatic goals. The handbook begins with a discussion of the various available incentive structures and then provides qualitative and quantitative tools necessary to design the most appropriate incentive structure. It concludes with program administration considerations.

  7. Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

    KAUST Repository

    Puspasari, Tiara

    2018-01-01

    (TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome

  8. Robust enzymatic hydrolysis of Formiline-pretreated oil palm empty fruit bunches (EFB) for efficient conversion of polysaccharide to sugars and ethanol.

    Science.gov (United States)

    Cui, Xingkai; Zhao, Xuebing; Zeng, Jing; Loh, Soh Kheang; Choo, Yuen May; Liu, Dehua

    2014-08-01

    Oil palm empty fruit bunch (EFB) was pretreated by Formiline process to overcome biomass recalcitrance and obtain hemicellulosic syrup and lignin. Higher formic acid concentration led to more lignin removal but also higher degree of cellulose formylation. Cellulose digestibility could be well recovered after deformylation with a small amount of lime. After digested by enzyme loading of 15 FPU+10 CBU/g solid for 48 h, the polysaccharide conversion could be over 90%. Simultaneous saccharification and fermentation (SSF) results demonstrated that ethanol concentration reached 83.6 g/L with approximate 85% of theoretic yield when performed at an initial dry solid consistency of 20%. A mass balance showed that via Formiline pretreatment 0.166 kg of ethanol could be produced from 1 kg of dry EFB with co-production of 0.14 kg of high-purity lignin and 5.26 kg hemicellulosic syrup containing 2.8% xylose. Formiline pretreatment thus can be employed as an entry for biorefining of EFB. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A systems approach for the evaluation of ethanol production based on forages

    Energy Technology Data Exchange (ETDEWEB)

    Alvo, P. [McGill Univ., Ste. Anne de Bellevue, PQ (Canada). Macdonald Coll.; Savoie, P. [Agriculture and Agri-Food Canada, Quebec, PQ (Canada). Saine-Foy Research Centre; Tremblay, D. [Laval Univ., Quebec, PQ (Canada). Dept. de Genie Rural; Emond, J.-P.; Turcotte, G. [Laval Univ., Quebec City, PQ (Canada). Dept. de Sciences et Technologie des Aliments

    1996-04-01

    A systems approach is proposed to simultaneously consider the agronomic aspects of forage production and the processing aspects related to the extraction of a glucose or xylose substrate, its fermentation into ethanol and the optimal utilization of co-products (protein meal, fibrous residue). The energy to produce and transport forage on the farm was estimated to be only 375 MJ/t dry matter (DM) when liquid manure was used and 1165 MJ/t DM when mineral fertilizer was used. An additional 126 MJ/t DM would be required to transport it to a processing plant. In contrast, whole-plant corn production using mineral fertilizer required about 3211 MJ/t DM, but it had a potential ethanol yield 3.2 times greater per unit area than perennial forage. A forage system with mechanical juice extraction resulted in 8-20% of the original forage dry matter available in a liquid substrate with subsequent protein meal separation and the fermentation of soluble sugars into ethanol. Another forage system with relatively complete conversion of cellulose and hemicellulose into simple sugars by thermal, acidic and enzymatic treatments was estimated to produce 12-28 times more ethanol per unit area than the mechanically extracted juice. Complete conversion of perennial forages would meet the petroleum industry`s needs more consistently than simple extraction of soluble components. (Author)

  10. Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

    African Journals Online (AJOL)

    The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

  11. Incentives, health promotion and equality.

    Science.gov (United States)

    Voigt, Kristin

    2012-07-01

    The use of incentives to encourage individuals to adopt 'healthier' behaviours is an increasingly popular instrument in health policy. Much of the literature has been critical of 'negative' incentives, often due to concerns about equality; 'positive' incentives, however, have largely been welcomed as an instrument for the improvement of population health and possibly the reduction of health inequalities. The aim of this paper is to provide a more systematic assessment of the use of incentives from the perspective of equality. The paper begins with an overview of existing and proposed incentive schemes. I then suggest that the distinction between 'positive' and 'negative' incentives - or 'carrots' and 'sticks' - is of limited use in distinguishing those incentive schemes that raise concerns of equality from those that do not. The paper assesses incentive schemes with respect to two important considerations of equality: equality of access and equality of outcomes. While our assessment of incentive schemes will, ultimately, depend on various empirical facts, the paper aims to advance the debate by identifying some of the empirical questions we need to ask. The paper concludes by considering a number of trade-offs and caveats relevant to the assessment of incentive schemes.

  12. From the Cover: Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels

    Science.gov (United States)

    Hill, Jason; Nelson, Erik; Tilman, David; Polasky, Stephen; Tiffany, Douglas

    2006-07-01

    Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels. corn | soybean | life-cycle accounting | agriculture | fossil fuel

  13. Potentiality of Yeasts in the Direct Conversion of Starchy Materials to Ethanol and Its Relevance in the New Millennium

    Science.gov (United States)

    Reddy, L. V. A.; Reddy, O. V. S.; Basappa, S. C.

    In recent years, the use of renewable and abundantly available starchy and cellulosic materials for industrial production of ethanol is gaining importance, in view of the fact, that ethanol is one of the most prospective future motor fuels, that can be expected to replace fossil fuels, which are fast depleting in the world scenario. Although, the starch and the starchy substrates could be converted successfully to ethanol on industrial scales by the use of commercial amylolytic enzymes and yeast fermentation, the cost of production is rather very high. This is mainly due to the non-enzymatic and enzymatic conversion (gelatinization, liquefaction and saccharification) of starch to sugars, which costs around 20 % of the cost of production of ethanol from starch. In this context, the use of amylolytic yeasts, that can directly convert starch to ethanol by a single step, are potentially suited to reduce the cost of production of ethanol from starch. Research advances made in this direction have shown encouraging results, both in terms of identifying the potentially suited yeasts for the purpose and also their economic ethanol yields. This chapter focuses on the types of starch and starchy substrates and their digestion to fermentable sugars, optimization of fermentation conditions to ethanol from starch, factors that affect starch fermentation, potential amylolytic yeasts which can directly convert starch to ethanol, genetic improvement of these yeasts for better conversion efficiency and their future economic prospects in the new millennium.

  14. A case study of agricultural residue availability and cost for a cellulosic ethanol conversion facility in the Henan province of China

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Erin [ORNL; Wu, Yun [ORNL

    2012-05-01

    A preliminary analysis of the availability and cost of corn stover and wheat straw for the area surrounding a demonstration biorefinery in the Henan Province of China was performed as a case study of potential cooperative analyses of bioenergy feedstocks between researchers and industry in the US and China. Though limited in scope, the purpose of this analysis is to provide insight into some of the issues and challenges of estimating feedstock availability in China and how this relates to analyses of feedstocks in the U.S. Completing this analysis also highlighted the importance of improving communication between U.S. researchers and Chinese collaborators. Understanding the units and terms used in the data provided by Tianguan proved to be a significant challenge. This was further complicated by language barriers between collaborators in the U.S. and China. The Tianguan demonstration biorefinery has a current capacity of 3k tons (1 million gallons) of cellulosic ethanol per year with plans to scale up to 10k tons (3.34 million gallons) per year. Using data provided by Tianguan staff in summer of 2011, the costs and availability of corn stover and wheat straw were estimated. Currently, there are sufficient volumes of wheat straw and corn stover that are considered 'waste' and would likely be available for bioenergy in the 20-km (12-mile) region surrounding the demonstration biorefinery at a low cost. However, as the industry grows, competition for feedstock will grow and prices are likely to rise as producers demand additional compensation to fully recover costs.

  15. Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept.

    Science.gov (United States)

    Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar; Angelidaki, Irini

    2016-01-01

    The aim of this study was to develop integrated biofuel (cellulosic bioethanol) and biochemical (succinic acid) production from industrial hemp (Cannabis sativa L.) in a biorefinery concept. Two types of pretreatments were studied (dilute-acid and alkaline oxidative method). High cellulose recovery (>95%) as well as significant hemicelluloses solubilization (49-59%) after acid-based method and lignin solubilization (35-41%) after alkaline H2O2 method were registered. Alkaline pretreatment showed to be superior over the acid-based method with respect to the rate of enzymatic hydrolysis and ethanol productivity. With respect to succinic acid production, the highest productivity was obtained after liquid fraction fermentation originated from steam treatment with 1.5% of acid. The mass balance calculations clearly showed that 149kg of EtOH and 115kg of succinic acid can be obtained per 1ton of dry hemp. Results obtained in this study clearly document the potential of industrial hemp for a biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A sustained release system using porous cellulose spheres modified by grafting as matrices

    International Nuclear Information System (INIS)

    Hosoi, Fumio; Makuuchi, Keizo; Saito, Kenji; Koishi, Masumi.

    1987-01-01

    Polymer-coated spheres, obtained by the graft polymerization of methyl methacrylate (MMA) onto porous spheres based on cellulose by the pre-irradiation method, were used as matrices for the drug sustained release system for salicylic acid. The adsorption of salicylic acid was carried out by dipping the grafted spheres in a 50% aqueous ethanol solution containing salicylic acid. The amount of salicylic acid adsorbed (Q) increased proportionately with the percent graft of MMA (G) to the power of 2.9. Adsorption mechanism of salicylic acid could be expressed in term of Langmuir's adsorption isotherm. The ratio of constants for adsorption and desorption (k) and the saturated amount of salicylic acid adsorbed (Q 0 ) were expressed as k = k 1 G and Q 0 = k 2 G 2.4 , respectively. These results indicate that the number of adsorption sites increased proportionately with the nth power of G as a results of the interaction of grafted poly (methyl methacrylate)(PMMA) and cellulose. Similar results were obtained with grafting of MMA, MMA-styrene (St), and MMA-methacrylic acid (MAc) in the presence of salicylic acid. (author)

  17. Brittle Culm1, a COBRA-Like Protein, Functions in Cellulose Assembly through Binding Cellulose Microfibrils

    Science.gov (United States)

    Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

    2013-01-01

    Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity. PMID:23990797

  18. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Directory of Open Access Journals (Sweden)

    Lifeng Liu

    Full Text Available Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1, a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  19. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Science.gov (United States)

    Liu, Lifeng; Shang-Guan, Keke; Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

    2013-01-01

    Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  20. Incentive delegation and collusion

    NARCIS (Netherlands)

    Mukherjee, A.

    2000-01-01

    In an infinitely repeated duopoly the implications of strategic incentive delegation are shown. Whether incentive delegation makes consumers or producers better-off depends on the nature of competition. WeThe presence or absence of incentive delegation may affect the interests of the consumers and

  1. A constraint-based model of Scheffersomyces stipitis for improved ethanol production

    Directory of Open Access Journals (Sweden)

    Liu Ting

    2012-09-01

    Full Text Available Abstract Background As one of the best xylose utilization microorganisms, Scheffersomyces stipitis exhibits great potential for the efficient lignocellulosic biomass fermentation. Therefore, a comprehensive understanding of its unique physiological and metabolic characteristics is required to further improve its performance on cellulosic ethanol production. Results A constraint-based genome-scale metabolic model for S. stipitis CBS 6054 was developed on the basis of its genomic, transcriptomic and literature information. The model iTL885 consists of 885 genes, 870 metabolites, and 1240 reactions. During the reconstruction process, 36 putative sugar transporters were reannotated and the metabolisms of 7 sugars were illuminated. Essentiality study was conducted to predict essential genes on different growth media. Key factors affecting cell growth and ethanol formation were investigated by the use of constraint-based analysis. Furthermore, the uptake systems and metabolic routes of xylose were elucidated, and the optimization strategies for the overproduction of ethanol were proposed from both genetic and environmental perspectives. Conclusions Systems biology modelling has proven to be a powerful tool for targeting metabolic changes. Thus, this systematic investigation of the metabolism of S. stipitis could be used as a starting point for future experiment designs aimed at identifying the metabolic bottlenecks of this important yeast.

  2. Alexa Fluor-labeled Fluorescent Cellulose Nanocrystals for Bioimaging Solid Cellulose in Spatially Structured Microenvironments

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Mo, Kai-For; Shin, Yongsoon; Vasdekis, Andreas; Warner, Marvin G.; Kelly, Ryan T.; Orr, Galya; Hu, Dehong; Dehoff, Karl J.; Brockman, Fred J.; Wilkins, Michael J.

    2015-03-18

    Cellulose nanocrystal materials have been labeled with modern Alexa Fluor dyes in a process that first links the dye to a cyanuric chloride molecule. Subsequent reaction with cellulose nanocrystals provides dyed solid microcrystalline cellulose material that can be used for bioimaging and suitable for deposition in films and spatially structured microenvironments. It is demonstrated with single molecular fluorescence microscopy that these films are subject to hydrolysis by cellulose enzymes.

  3. Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

    Science.gov (United States)

    Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

    2011-05-25

    Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.

  4. Improvement of tolerance of Saccharomyces cerevisiae to hot-compressed water-treated cellulose by expression of ADH1

    Energy Technology Data Exchange (ETDEWEB)

    Jayakody, Lahiru N.; Horie, Kenta; Kitagaki, Hiroshi [Saga Univ. (Japan). Dept. of Environmental Sciences; Hayashi, Nobuyuki [Saga Univ. (Japan). Dept. of Applied Biochemistry and Food Science

    2012-04-15

    Hot-compressed water treatment of cellulose and hemicellulose for subsequent bioethanol production is a novel, economically feasible, and nonhazardous method for recovering sugars. However, the hot-compressed water-treated cellulose and hemicellulose inhibit subsequent ethanol fermentation by the yeast Saccharomyces cerevisiae. To overcome this problem, we engineered a yeast strain with improved tolerance to hot-compressed water-treated cellulose. We first determined that glycolaldehyde has a greater inhibitory effect than 5-HMF and furfural and a combinational effect with them. On the basis of the hypothesis that the reduction of glycolaldehyde to ethylene glycol should detoxify glycolaldehyde, we developed a strain overexpressing the alcohol dehydrogenase gene ADH1. The ADH1-overexpressing strain exhibits an improved fermentation profile in a glycolaldehyde-containing medium. The conversion ratio of glycolaldehyde to ethylene glycol is 30 {+-} 1.9% when the control strain is used; this ratio increases to 77 {+-} 3.6% in the case of the ADH1-overexpressing strain. A glycolaldehyde treatment and the overexpression of ADH1 cause changes in the fermentation products so as to balance the metabolic carbon flux and the redox status. Finally, the ADH1-overexpressing strain shows a statistically significantly improved fermentation profile in a hot-compressed water-treated cellulose-containing medium. The conversion ratio of glycolaldehyde to ethylene glycol is 33 {+-} 0.85% when the control strain is used but increases to 72 {+-} 1.7% in the case of the ADH1-overexpressing strain. These results show that the reduction of glycolaldehyde to ethylene glycol is a promising strategy to decrease the toxicity of hot-compressed water-treated cellulose. This is the first report on the improvement of yeast tolerance to hot-compressed water-treated cellulose and glycolaldehyde.

  5. Metabolic engineering of Escherichia coli for ethanol production without foreign genes

    Science.gov (United States)

    Kim, Youngnyun

    Worldwide dependence on finite petroleum-based energy necessitates alternative energy sources that can be produced from renewable resources. A successful example of an alternative transportation fuel is bioethanol, produced by microorganisms, from corn starch that is blended with gasoline. However, corn, currently the main feedstock for bioethanol production, also occupies a significant role in human food and animal feed chains. As more corn is diverted to bioethanol, the cost of corn is expected to increase with an increase in the price of food, feed and ethanol. Using lignocellulosic biomass for ethanol production is considered to resolve this problem. However, this requires a microbial biocatalyst that can ferment hexoses and pentoses to ethanol. Escherichia coli is an efficient biocatalyst that can use all the monomeric sugars in lignocellulose, and recombinant derivatives of E. coli have been engineered to produce ethanol as the major fermentation product. In my study, ethanologenic E. coli strains were isolated from a ldhA-, pflB- derivative without introduction of foreign genes. These isolates grew anaerobically and produced ethanol as the main fermentation product. The mutation responsible for anaerobic growth and ethanol production was mapped in the lpdA gene and the mutation was identified as E354K in three of the isolates tested. Another three isolates carried an lpdA mutation, H352Y. Enzyme kinetic studies revealed that the mutated form of the dihydrolipoamide dehydrogenase (LPD) encoded by the lpdA was significantly less sensitive to NADH inhibition than the native LPD. This reduced NADH sensitivity of the mutated LPD was translated into lower sensitivity to NADH of the pyruvate dehydrogenase complex in strain SE2378. The net yield of 4 moles of NADH and 2 moles of acetyl-CoA per mole of glucose produced by a combination of glycolysis and PDH provided a logical basis to explain the production of 2 moles of ethanol per glucose. The development of E

  6. Water Resources Implications of Cellulosic Biofuel Production at a Regional Scale

    Science.gov (United States)

    Christopher, S. F.; Schoenholtz, S. H.; Nettles, J. E.

    2011-12-01

    Recent increases in oil prices, a strong national interest in greater energy independence, and a concern for the role of fossil fuels in global climate change, have led to a dramatic expansion in use of alternative renewable energy sources in the U.S. The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, of which 16 billion gallons are required to be cellulosic biofuels. Production of cellulosic biomass offers a promising alternative to corn-based systems because large-scale production of corn-based ethanol often requires irrigation and is associated with increased erosion, excess sediment export, and enhanced leaching of nitrogen and phosphorus. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water quality impacts associated with annual crops. Catchlight Energy LLC is examining the feasibility and sustainability of intercropping switchgrass in loblolly pine plantations in the southeastern U.S. Ongoing research is determining efficient operational techniques and information needed to evaluate effects of these practices on water resources in small watershed-scale (~25 ha) studies. Three sets of four to five sub-watersheds are fully instrumented and currently collecting calibration data in North Carolina, Alabama, and Mississippi. These watershed studies will provide detailed information to understand processes and guide management decisions. However, environmental implications of cellulosic systems need to be examined at a regional scale. We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine water quantity effects of various land use change scenarios ranging from switchgrass intercropping a small percentage of managed pine forest land to conversion of all managed

  7. A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

    Science.gov (United States)

    Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

    2017-08-01

    This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Process development studies on the bioconversion of cellulose and production of ethanol. Progress report, September 1, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1978-09-01

    Progress is reported in studies on the pretreatment of cellulosic materials to facilitate enzymatic hydrolysis, sulfuric acid hydrolysis, investigation of the Purdue processing scheme including an economic analysis, and the fermentability of the enzymatic hydrolyzate. Progress is also reported on enzyme fermentation studies, hydrolysis reactor development, and utilization of hemicellulose sugars. (JSR)

  9. Physicochemical analysis of cellulose from microalgae ...

    African Journals Online (AJOL)

    USER

    2016-06-15

    Jun 15, 2016 ... The extraction method of algae cellulose was a modification of ... triplicate. Characterization of cellulose. Analysis of ... The current analysis of the cellulose extracted .... Cellulose nanomaterials review: structure, properties and.

  10. Isolation and Characterization of Two Cellulose Morphology Mutants of Gluconacetobacter hansenii ATCC23769 Producing Cellulose with Lower Crystallinity

    Science.gov (United States)

    Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M.; Tien, Ming; Kao, Teh-hui

    2015-01-01

    Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

  11. Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

    Directory of Open Access Journals (Sweden)

    Ying Deng

    Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

  12. Energy and Environmental Performance of Bioethanol from Different Lignocelluloses

    Directory of Open Access Journals (Sweden)

    Lin Luo

    2010-01-01

    Full Text Available Climate change and the wish to reduce the dependence on oil are the incentives for the development of alternative energy sources. The use of lignocellulosic biomass together with cellulosic processing technology provides opportunities to produce fuel ethanol with less competition with food and nature. Many studies on energy analysis and life cycle assessment of second-generation bioethanol have been conducted. However, due to the different methodology used and different system boundary definition, it is difficult to compare their results. To permit a direct comparison of fuel ethanol from different lignocelluloses in terms of energy use and environmental impact, seven studies conducted in our group were summarized in this paper, where the same technologies were used to convert biomass to ethanol, the same system boundaries were defined, and the same allocation procedures were followed. A complete set of environmental impacts ranging from global warming potential to toxicity aspects is used. The results provide an overview on the energy efficiency and environmental performance of using fuel ethanol derived from different feedstocks in comparison with gasoline.

  13. Individual Differences in the Attribution of Incentive Salience to a Pavlovian Alcohol Cue

    Science.gov (United States)

    Villaruel, Franz R.; Chaudhri, Nadia

    2016-01-01

    Individual differences exist in the attribution of incentive salience to conditioned stimuli associated with food. Here, we investigated whether individual differences also manifested with a Pavlovian alcohol conditioned stimulus (CS). We compiled data from five experiments that used a Pavlovian autoshaping paradigm and tests of conditioned reinforcement. In all experiments, male, Long-Evans rats with unrestricted access to food and water were acclimated to 15% ethanol. Next, rats received Pavlovian autoshaping training, in which a 10 s presentation of a retractable lever served as the CS and 0.2 mL of 15% ethanol served as the unconditioned stimulus (US). Finally, rats underwent conditioned reinforcement tests in which nose-pokes to an active aperture led to brief presentations of the lever-CS, but nose-pokes to an inactive aperture had no consequence. Rats were categorized as sign-trackers, goal-trackers and intermediates based on a response bias score that reflected their tendencies to sign-track or goal-track at different times during training. We found that distinct groups of rats either consistently interacted with the lever-CS (“sign-trackers”) or routinely approached the port during the lever-CS (“goal-trackers”) across a majority of the training sessions. However, some individuals (“shifted sign-trackers”) with an early tendency to goal-track later shifted to comparable asymptotic levels of sign-tracking as the group identified as sign-trackers. The lever-CS functioned as a conditioned reinforcer for sign-trackers and shifted sign-trackers, but not for goal-trackers. These results provide evidence of robust individual differences in the extent to which a Pavlovian alcohol cue gains incentive salience and functions as a conditioned reinforcer. PMID:28082877

  14. Individual Differences in the Attribution of Incentive Salience to a Pavlovian Alcohol Cue.

    Science.gov (United States)

    Villaruel, Franz R; Chaudhri, Nadia

    2016-01-01

    Individual differences exist in the attribution of incentive salience to conditioned stimuli associated with food. Here, we investigated whether individual differences also manifested with a Pavlovian alcohol conditioned stimulus (CS). We compiled data from five experiments that used a Pavlovian autoshaping paradigm and tests of conditioned reinforcement. In all experiments, male, Long-Evans rats with unrestricted access to food and water were acclimated to 15% ethanol. Next, rats received Pavlovian autoshaping training, in which a 10 s presentation of a retractable lever served as the CS and 0.2 mL of 15% ethanol served as the unconditioned stimulus (US). Finally, rats underwent conditioned reinforcement tests in which nose-pokes to an active aperture led to brief presentations of the lever-CS, but nose-pokes to an inactive aperture had no consequence. Rats were categorized as sign-trackers, goal-trackers and intermediates based on a response bias score that reflected their tendencies to sign-track or goal-track at different times during training. We found that distinct groups of rats either consistently interacted with the lever-CS ("sign-trackers") or routinely approached the port during the lever-CS ("goal-trackers") across a majority of the training sessions. However, some individuals ("shifted sign-trackers") with an early tendency to goal-track later shifted to comparable asymptotic levels of sign-tracking as the group identified as sign-trackers. The lever-CS functioned as a conditioned reinforcer for sign-trackers and shifted sign-trackers, but not for goal-trackers. These results provide evidence of robust individual differences in the extent to which a Pavlovian alcohol cue gains incentive salience and functions as a conditioned reinforcer.

  15. Cellulolytic enzyme expression and simultaneous conversion of lignocellulosic sugars into ethanol and xylitol by a new Candida tropicalis strain.

    Science.gov (United States)

    Mattam, Anu Jose; Kuila, Arindam; Suralikerimath, Niranjan; Choudary, Nettem; Rao, Peddy V C; Velankar, Harshad Ravindra

    2016-01-01

    Lignocellulosic ethanol production involves major steps such as thermochemical pretreatment of biomass, enzymatic hydrolysis of pre-treated biomass and the fermentation of released sugars into ethanol. At least two different organisms are conventionally utilized for producing cellulolytic enzymes and for ethanol production through fermentation, whereas in the present study a single yeast isolate with the capacity to simultaneously produce cellulases and xylanases and ferment the released sugars into ethanol and xylitol has been described. A yeast strain isolated from soil samples and identified as Candida tropicalis MTCC 25057 expressed cellulases and xylanases over a wide range of temperatures (32 and 42 °C) and in the presence of different cellulosic substrates [carboxymethylcellulose and wheat straw (WS)]. The studies indicated that the cultivation of yeast at 42 °C in pre-treated hydrolysate containing 0.5 % WS resulted in proportional expression of cellulases (exoglucanases and endoglucanases) at concentrations of 114.1 and 97.8 U g(-1) ds, respectively. A high xylanase activity (689.3 U g(-1) ds) was also exhibited by the yeast under similar growth conditions. Maximum expression of cellulolytic enzymes by the yeast occurred within 24 h of incubation. Of the sugars released from biomass after pretreatment, 49 g L(-1) xylose was aerobically converted into 15.8 g L(-1) of xylitol. In addition, 25.4 g L(-1) glucose released after the enzymatic hydrolysis of biomass was fermented by the same yeast to obtain an ethanol titer of 7.3 g L(-1). During the present study, a new strain of C. tropicalis was isolated and found to have potential for consolidated bioprocessing (CBP) applications. The strain could grow in a wide range of process conditions (temperature, pH) and in the presence of lignocellulosic inhibitors such as furfural, HMF and acetic acid. The new yeast produced cellulolytic enzymes over a wide temperature range and in the presence of

  16. Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

    Directory of Open Access Journals (Sweden)

    Anand Kumar Veeramachineni

    2016-06-01

    Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

  17. A comparison of cellulosic fuel yields and separated soil-surface CO2 fluxes in maize and prairie biofuel cropping systems

    Science.gov (United States)

    Nichols, Virginia A.

    It has been suggested that strategic incorporation of perennial vegetation into agricultural landscapes could provide ecosystem services while maintaining agricultural productivity. To evaluate potential use of prairie as a Midwestern cellulosic feedstock, we investigated theoretical cellulosic fuel yields, as well as soil-surface carbon dioxide emissions of prairie-based biofuel systems as compared to maize-based systems on fertile soils in Boone County, IA, USA. Investigated systems were: a maize-soybean rotation grown for grain only, continuous maize grown for grain and stover both with and without a winter rye cover crop, and a 31-species reconstructed prairie grown with and without spring nitrogen fertilization for fall-harvested biomass. From 2009-2013, the highest producing system was N-fertilized prairie, averaging 10.4 Mg ha -1 yr-1 above-ground biomass with average harvest removals of 7.8 Mg ha-1 yr-1. The unfertilized prairie produced 7.4 Mg ha-1 yr-1, averaging harvests of 5.3 Mg ha-1 yr-1. Lowest cellulosic biomass harvests were realized from continuous maize systems, averaging 3.5 Mg ha -1 yr-1 when grown with, and 3.7 Mg ha-1 yr-1 when grown without a winter rye cover crop, respectively. Un-fertilized prairie biomass and maize stover had equivalent dietary conversion ratios at 330 g ethanol kg-1 dry biomass, but N-fertilized prairie was lower at 315. Over four years prairie systems averaged 1287 L cellulosic ethanol ha-1 yr-1 more than maize systems, with fertilization increasing prairie ethanol production by 865 L ha-1 yr-1. Harvested biomass accounted for >90% of ethanol yield variation. A major hurdle in carbon cycling studies is the separation of the soil-surface CO2 flux into its respective components. From 2012-2013 we used a shading method to separate soil-surface CO2 resulting from oxidation of soil organic matter and CO2 derived from live-root activity in three systems: unfertilized prairie, N-fertilized prairie, and continuous maize

  18. Improvement of enzymatic hydrolysis and ethanol production from corn stalk by alkali and N-methylmorpholine-N-oxide pretreatments.

    Science.gov (United States)

    Cai, Ling-Yan; Ma, Yu-Long; Ma, Xiao-Xia; Lv, Jun-Min

    2016-07-01

    A combinative technology of alkali and N-methylmorpholine-N-oxide (NMMO) was used to pretreat corn stalk (CS) for improving the efficiencies of subsequent enzymatic hydrolysis and ethanol fermentation. The results showed that this strategy could not only remove hemicellulose and lignin but also decrease the crystallinity of cellulose. About 98.0% of enzymatic hydrolysis yield was obtained from the pretreated CS as compared with 46.9% from the untreated sample. The yield for corresponding ethanol yield was 64.6% while untreated CS was only 18.8%. Besides, xylose yield obtained from the untreated CS was only 11.1%, while this value was 93.8% for alkali with NMMO pretreated sample. These results suggest that a combination of alkali with 50% (wt/wt) NMMO solution may be a promising alternative for pretreatment of lignocellulose, which can increase the productions of subsequent enzymatic hydrolysis and ethanol fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Effect of Reaction Conditions on the Surface Modification of Cellulose Nanofibrils with Aminopropyl Triethoxysilane

    Directory of Open Access Journals (Sweden)

    Eduardo Robles

    2018-04-01

    Full Text Available Nine different surface modifications of cellulose nanofibrils (CNF with 3-aminopropyl triethoxysilane (ATS by using three different solvent systems (water, ethanol, and a mixture of both were investigated. The effect of reaction conditions, such as silane to cellulose ratio and solvent type were evaluated to determine their contribution to the extent of the silane modification. Nanofibril properties were evaluated by infrared spectroscopy, powder X-ray diffraction, surface free energy, thermogravimetry, 13C and 29Si nuclear magnetic resonance, and electronic microscopy. The influence of the solvent in the solvolysis of the silane was reflected in the presence or absence of ethoxy groups in the silane. On the other hand, whereas the surface modification was increased directly proportionally to silane ratio on the reaction, the aggregation of nanofibrils was also increased, which can play a negative role in certain applications. The increment of silane modification also had substantial repercussions on the crystallinity of the nanofibrils by the addition of amorphous components to the crystalline unit; moreover, silane surface modifications enhanced the hydrophobic character of the nanofibrils.

  20. 40 CFR 80.1100 - How is the statutory default requirement for 2006 implemented?

    Science.gov (United States)

    2010-07-01

    ..., greases, and oils, sugarcane, sugar beets, sugar components, tobacco, potatoes, or other biomass; or (B... cellulosic biomass ethanol, waste derived ethanol, biodiesel, and any blending components derived from renewable fuel. (2) Cellulosic biomass ethanol means ethanol derived from any lignocellulosic or...

  1. A Molecular Description of Cellulose Biosynthesis

    Science.gov (United States)

    McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

    2016-01-01

    Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

  2. Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose by a new route

    Directory of Open Access Journals (Sweden)

    K. L. Wang

    2017-12-01

    Full Text Available A new and convenient route to the regiocontrolled synthesis of a cellulose-based derivate copolymer (2,3-di-O-polycaprolactone-cellulose grafting ε-caprolactone (ε-CL from α-cellulose, cellulose-graft-polycaprolactone (cellulose-g-PCL, by a classical ring-opening polymerization (ROP reaction, using stannous octoate (Sn(Oct2 as catalyst, in 68% concentration of zinc chloride aqueous solution at 120 °C was presented. By controlling the hydroxyl of cellulose/ε-CL, catalyst/monomer ratio and the reaction time, the molecular architecture of the copolymers can be altered. The solubility of cellulose in zinc chloride aqueous was indicated by UV/VIS spectrometer and rheological measurements. The structures and thermal properties of cellulose-g-polycaprolactone copolymers were characterized using Fourier Transform Infrared (FT-IR, Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR, X-ray Diffraction (XRD, Thermogravimetric Analysis (TGA, Differential Scanning Calorimetry (DSC and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The interesting results confirm that zinc chloride solution can break the intra-molecular hydrogen bonds of cellulose selectively (not only O3H···O5, but also O2H···O6, and has no effect on the inter-molecular hydrogen bonds (O6H···O3. And the grafting reactivity of hydroxyl on cellulose is C2–OH > C3–OH >> C6–OH in zinc chloride solution, and this is clearly different from other researches. Most importantly, this work confirms that the method to regiocontrolled synthesis cellulose-based derivative polymers by regiobreaking hydrogen bonds is feasible. It is strongly believed that the new discovery may give a novel, environmental, simple and inexpensive method to modify cellulose chemically with various side chains grafted on a given hydroxyl, through liberating hydroxyl as reactive group from hydrogen bonds broken selectively by different solvents.

  3. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara; Akhtar, Faheem Hassan; Ogieglo, Wojciech; Alharbi, Ohoud; Peinemann, Klaus-Viktor

    2018-01-01

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration

  4. Techno-Economic Analysis of Bioethanol Production from Lignocellulosic Biomass in China: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

    Directory of Open Access Journals (Sweden)

    Lili Zhao

    2015-05-01

    Full Text Available Lignocellulosic biomass-based ethanol is categorized as 2nd generation bioethanol in the advanced biofuel portfolio. To make sound incentive policy proposals for the Chinese government and to develop guidance for research and development and industrialization of the technology, the paper reports careful techno-economic and sensitivity analyses performed to estimate the current competitiveness of the bioethanol and identify key components which have the greatest impact on its plant-gate price (PGP. Two models were developed for the research, including the Bioethanol PGP Assessment Model (BPAM and the Feedstock Cost Estimation Model (FCEM. Results show that the PGP of the bioethanol ranges $4.68–$6.05/gal (9,550–12,356 yuan/t. The key components that contribute most to bioethanol PGP include the conversion rate of cellulose to glucose, the ratio of five-carbon sugars converted to ethanol, feedstock cost, and enzyme loading, etc. Lignocellulosic ethanol is currently unable to compete with fossil gasoline, therefore incentive policies are necessary to promote its development. It is suggested that the consumption tax be exempted, the value added tax (VAT be refunded upon collection, and feed-in tariff for excess electricity (byproduct be implemented to facilitate the industrialization of the technology. A minimum direct subsidy of $1.20/gal EtOH (2,500 yuan/t EtOH is also proposed for consideration.

  5. Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

    International Nuclear Information System (INIS)

    Faria-Tischer, Paula C.S.; Tischer, Cesar A.; Heux, Laurent; Le Denmat, Simon; Picart, Catherine; Sierakowski, Maria-R.

    2015-01-01

    The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III I (Cel III I ) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel III I was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel III I resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs

  6. Deletion of the hfsB gene increases ethanol production in Thermoanaerobacterium saccharolyticum and several other thermophilic anaerobic bacteria.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Murphy, Sean Jean-Loup; Maloney, Marybeth; Lanahan, Anthony; Giannone, Richard J; Hettich, Robert L; Tripathi, Shital A; Beldüz, Ali Osman; Lynd, Lee R; Olson, Daniel G

    2017-01-01

    With the discovery of interspecies hydrogen transfer in the late 1960s (Bryant et al. in Arch Microbiol 59:20-31, 1967), it was shown that reducing the partial pressure of hydrogen could cause mixed acid fermenting organisms to produce acetate at the expense of ethanol. Hydrogen and ethanol are both more reduced than glucose. Thus there is a tradeoff between production of these compounds imposed by electron balancing requirements; however, the mechanism is not fully known. Deletion of the hfsA or B subunits resulted in a roughly 1.8-fold increase in ethanol yield. The increase in ethanol production appears to be associated with an increase in alcohol dehydrogenase activity, which appears to be due, at least in part, to increased expression of the adhE gene, and may suggest a regulatory linkage between hfsB and adhE . We studied this system most intensively in the organism Thermoanaerobacterium saccharolyticum ; however, deletion of hfsB also increases ethanol production in other thermophilic bacteria suggesting that this could be used as a general technique for engineering thermophilic bacteria for improved ethanol production in organisms with hfs -type hydrogenases. Since its discovery by Shaw et al. (JAMA 191:6457-64, 2009), the hfs hydrogenase has been suspected to act as a regulator due to the presence of a PAS domain. We provide additional support for the presence of a regulatory phenomenon. In addition, we find a practical application for this scientific insight, namely increasing ethanol yield in strains that are of interest for ethanol production from cellulose or hemicellulose. In two of these organisms ( T. xylanolyticum and T. thermosaccharolyticum ), the ethanol yields are the highest reported to date.

  7. Cellulose nanocrystal properties and their applications

    Directory of Open Access Journals (Sweden)

    mahdi jonoobi

    2015-05-01

    Full Text Available The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance, their renewability, high strength and stiffness, being eco-friendly, and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals from various sources. The rod-like cellulose nanocrystals (CNC can be isolated from sources like wood, plant fibers, agriculture and industrial bio residues, tunicates, and bacterial cellulose using acid hydrolysis process. Following this, the paper focused on characterization methods, materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.

  8. A new magnesium bisulfite pretreatment (MBSP) development for bio-ethanol production from corn stover.

    Science.gov (United States)

    Yu, Heng; Ren, Jiwei; Liu, Lei; Zheng, Zhaojuan; Zhu, Junjun; Yong, Qiang; Ouyang, Jia

    2016-01-01

    This study established a new more neutral magnesium bisulfate pretreatment (MBSP) using magnesium bisulfate as sulfonating agent for improving the enzymatic hydrolysis efficiency of corn stover. Using the MBSP with 5.21% magnesium bisulfate, 170°C and pH 5.2 for 60 min, about 90% of lignin and 80% of hemicellulose were removed from biomass and more than 90% cellulose conversion of substrate was achieved after 48 h hydrolysis. About 6.19 kg raw corn stover could produce 1 kg ethanol by Saccharomyces cerevisiae. Meanwhile, MBSP also could protect sugars from excessive degradation, prevent fermentation inhibition formation and directly convert the hemicelluloses into xylooligosaccharides as higher-value products. These results suggested that the MBSP method offers an alternative approach to the efficient conversion of nonwoody lignocellulosic biomass to ethanol and had broad space for development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Economic analysis of U.S. ethanol expansion issues

    Science.gov (United States)

    Chaudhuri, Malika

    The dependency of the U.S. economy on crude oil imported from politically unstable countries, escalating energy demand world wide, growing nationwide environmental consciousness, and the Renewable Fuels Standards (RFS) government mandates are some of the primary factors that have provided a favorable environment for the growth and development of the U.S. ethanol industry. The first essay derives decision rules for a discrete-time dynamic hedging model in a multiple commodity framework under expected utility maximization and basis risk. It compares hedging performance of three types of hedging models, namely constant hedging, time-varying static hedging model and the new dynamic hedging rule derived in this study. Findings show that natural gas futures contracts were effective instruments for hedging ethanol spot price risk before March, 2005, when ethanol futures trading was initiated on the CBOT. However, post-March, 2005, corn and ethanol futures contracts proved to be efficient hedging instruments. Results also indicate that ethanol producers may effectively decrease variance of cumulative cash flows by hedging using ethanol, natural gas and corn futures prices using the traditional techniques. The study concludes that using the new dynamic hedge model in a three period and two commodity set up, producers can effectively reduce variance of cumulative cash flow by 13.2% as compared to the 'no hedge' scenario. In my second essay, I use choice based, conjoint analysis methods to estimate consumers' willingness to pay (WTP) for alternative transportation fuels in the U.S. In this study, I consider unleaded gasoline and ethanol, which may be derived from corn or three different sources of cellulosic biomass as alternative transportation fuels. Results suggest that age and household income are some of the socioeconomic variables that significantly influence consumer's choice behavior. Results indicate considerable consumer preference heterogeneity. Welfare effects are

  10. Polymorphy in native cellulose: recent developments

    International Nuclear Information System (INIS)

    Atalla, R.H.

    1984-01-01

    In a number of earlier studies, the authors developed a model of cellulose structure based on the existence of two stable, linearly ordered conformations of the cellulose chain that are dominant in celluloses I and II, respectively. The model rests on extensive Raman spectral observations together with conformational considerations and solid-state 13 C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13 C-NMR observations, that native celluloses are composites of two distinct crystalline forms that coexist in different proportions in all native celluloses. In the present work, they examine the Raman spectra of the native celluloses, and reconcile their view of conformational differences with the new level of crystalline polymorphy of native celluloses revealed in the solid-state 13 C-NMR investigations

  11. Biochemistry of cellulose degradation and cellulose utilization for feeds and for protein

    Energy Technology Data Exchange (ETDEWEB)

    Sadara, J C; Lachke, A H; Shewale, J G

    1979-01-01

    A review discussing production of single-cell protein, fuel, and glucose from cellulose decomposition; surface or solid fermentations of single-cell protein; production of cellulases; and the biochemistry of cellulose degradation was presented.

  12. Co-downregulation of the hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase and coumarate 3-hydroxylase significantly increases cellulose content in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Tong, Zongyong; Li, Heng; Zhang, Rongxue; Ma, Lei; Dong, Jiangli; Wang, Tao

    2015-10-01

    Lignin is a component of the cell wall that is essential for growth, development, structure and pathogen resistance in plants, but high lignin is an obstacle to the conversion of cellulose to ethanol for biofuel. Genetically modifying lignin and cellulose contents can be a good approach to overcoming that obstacle. Alfalfa (Medicago sativa L.) is rich in lignocellulose biomass and used as a model plant for the genetic modification of lignin in this study. Two key enzymes in the lignin biosynthesis pathway-hydroxycinnamoyl -CoA:shikimate hydroxycinnamoyl transferase (HCT) and coumarate 3-hydroxylase (C3H)-were co-downregulated. Compared to wild-type plants, the lignin content in the modified strain was reduced by 38%, cellulose was increased by 86.1%, enzyme saccharification efficiency was increased by 10.9%, and cell wall digestibility was increased by 13.0%. The modified alfalfa exhibited a dwarf phenotype, but normal above ground biomass. This approach provides a new strategy for reducing lignin and increasing cellulose contents and creates a new genetically modified crop with enhanced value for biofuel. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. All-cellulose composites of regenerated cellulose fibres by surface selective dissolution

    NARCIS (Netherlands)

    Soykeabkaew, N.; Nishino, T.; Peijs, Ton

    2009-01-01

    All-cellulose composites of Lyocell and high modulus/strength cellulose fibres were successfully prepared using a surface selective dissolution method. The effect of immersion time of the fibres in the solvent during composite's preparation and the effect of the starting fibre's structure on their

  14. Team incentives in relational contracts

    International Nuclear Information System (INIS)

    Kvaloey, Ola

    2003-01-01

    Incentive schemes for teams are compared. I ask: under which conditions are relational incentive contracts based on joint performance evaluation, relative performance evaluation and independent performance evaluation self-enforceable. The framework of Che and Yoo (2001) on team incentives is combined with the framework of Baker, Gibbons and Murphy (2002) on relational contracts. In a repeated game between one principal and two agents, I find that incentives based on relative or independent performance are expected to dominate when the productivity of effort is high, while joint performance evaluation dominates when productivity is low. Incentives based on independent performance are more probable if the agents own critical assets. (author)

  15. Methodology for the optimal design of an integrated first and second generation ethanol production plant combined with power cogeneration.

    Science.gov (United States)

    Bechara, Rami; Gomez, Adrien; Saint-Antonin, Valérie; Schweitzer, Jean-Marc; Maréchal, François

    2016-08-01

    The application of methodologies for the optimal design of integrated processes has seen increased interest in literature. This article builds on previous works and applies a systematic methodology to an integrated first and second generation ethanol production plant with power cogeneration. The methodology breaks into process simulation, heat integration, thermo-economic evaluation, exergy efficiency vs. capital costs, multi-variable, evolutionary optimization, and process selection via profitability maximization. Optimization generated Pareto solutions with exergy efficiency ranging between 39.2% and 44.4% and capital costs from 210M$ to 390M$. The Net Present Value was positive for only two scenarios and for low efficiency, low hydrolysis points. The minimum cellulosic ethanol selling price was sought to obtain a maximum NPV of zero for high efficiency, high hydrolysis alternatives. The obtained optimal configuration presented maximum exergy efficiency, hydrolyzed bagasse fraction, capital costs and ethanol production rate, and minimum cooling water consumption and power production rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Ethanol production from SPORL-pretreated lodgepole pine. Preliminary evaluation of mass balance and process energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.Y. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Wisconsin Univ., Madison, WI (United States). Dept. of Biological Systems Engineering; Zhu, Wenyuan [South China Univ. of Technology, Guangzhou (China). State Key Lab Pulp and Paper Engineering; OBryan, Patricia; Dien, Bruce S. [USDA Agricultural Research Service, Peoria, IL (United States). National Center for Agricultural Utilization Research; Tian, Shen [Capital Normal Univ., Beijing (China). College of Life Science; Gleisner, Rolland [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Pan, X.J. [Wisconsin Univ., Madison, WI (United States). Dept. of Biological Systems Engineering

    2010-05-15

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quasi-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance. (orig.)

  17. Ethanol production from SPORL-pretreated lodgepole pine: preliminary evaluation of mass balance and process energy efficiency.

    Science.gov (United States)

    Zhu, J Y; Zhu, Wenyuan; Obryan, Patricia; Dien, Bruce S; Tian, Shen; Gleisner, Rolland; Pan, X J

    2010-05-01

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quais-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 degrees C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance.

  18. Bioconversion of cellulose to liquid fuel (ethanol). Final report, Stage 2, 1983-06-30

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B

    1983-01-01

    The process routes of the conversion have been investigated. The material which contains lignocellulose should be pretreated, and the separate processes are to be integrated. The price of raw materials and enzymes influences the process economy. The efficiency of biocatalysts on fermentation and saccharification are being studied and the reuse of enzymes is discussed. The process for the production of ethanol out of lignocellulose is shown to be very complicated. The optimization of the process will necessitate computerized simulation.

  19. Ethanol production by Kluyveromyces marxianus IMB3 during growth on straw-supplemented whiskey distillery spent wash at 45 C

    Energy Technology Data Exchange (ETDEWEB)

    Barron, N.; Mulholland, H.; Boyle, M.; McHale, A.P. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine, Co. Londonderry, BT52 1SA (United Kingdom)

    1997-11-01

    The thermotolerant, ethanol-producing yeast strain, Kluyveromyces marxianus IMB3 was grown on media consisting of straw-supplemented distillery spent wash from The Old Bushmill`s Distillery Co. Ltd., Bushmills, Co Antrim, Northern Ireland. Media were supplemented with cellulase activity and fermentations were carried out at 45 C. When pulverized straw was used as substrate in this system at concentrations of 2, 4 and 6% (w/v), ethanol concentrations increased to maxima of 1.45, 2.2 and 3 g/l, respectively. Based on straw containing a maximum of 40% cellulose, these ethanol concentrations accounted for 36, 27 and 24% of the maximum theoretical yield, respectively. When the straw was pre-treated with NaOH and used in the spent wash containing system at concentrations of 2, 4 and 6% (w/v) ethanol, concentrations increased to maxima of 3, 6.2 and 10.5 g/l, respectively and these accounted for 75, 76 and 86% of the maximum theoretical yield. When these results are compared with previously published data relating to the use of straw in laboratory-based media, they suggest that whiskey distillery spent wash may provide an adequate medium for supplementation with complex carbohydrate and subsequent ethanol production in simultaneous saccharification and fermentation processes. (orig.) With 2 figs., 17 refs.

  20. Strong and Optically Transparent Films Prepared Using Cellulosic Solid Residue Recovered from Cellulose Nanocrystals Production Waste Stream

    Science.gov (United States)

    Qianqian Wang; J.Y. Zhu; John M. Considine

    2013-01-01

    We used a new cellulosic material, cellulosic solid residue (CSR), to produce cellulose nanofibrils (CNF) for potential high value applications. Cellulose nanofibrils (CNF) were produced from CSR recovered from the hydrolysates (waste stream) of acid hydrolysis of a bleached Eucalyptus kraft pulp (BEP) to produce nanocrystals (CNC). Acid hydrolysis greatly facilitated...

  1. 21 CFR 573.420 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl cellulose. 573.420 Section 573.420 Food and... Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether containing...

  2. 21 CFR 172.868 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  3. Nitrogen-fixing and cellulose-producing Gluconacetobacter kombuchae sp. nov., isolated from Kombucha tea.

    Science.gov (United States)

    Dutta, Debasree; Gachhui, Ratan

    2007-02-01

    A few members of the family Acetobacteraceae are cellulose-producers, while only six members fix nitrogen. Bacterial strain RG3T, isolated from Kombucha tea, displays both of these characteristics. A high bootstrap value in the 16S rRNA gene sequence-based phylogenetic analysis supported the position of this strain within the genus Gluconacetobacter, with Gluconacetobacter hansenii LMG 1527T as its nearest neighbour (99.1 % sequence similarity). It could utilize ethanol, fructose, arabinose, glycerol, sorbitol and mannitol, but not galactose or xylose, as sole sources of carbon. Single amino acids such as L-alanine, L-cysteine and L-threonine served as carbon and nitrogen sources for growth of strain RG3T. Strain RG3T produced cellulose in both nitrogen-free broth and enriched medium. The ubiquinone present was Q-10 and the DNA base composition was 55.8 mol% G+C. It exhibited low values of 5.2-27.77 % DNA-DNA relatedness to the type strains of related gluconacetobacters, which placed it within a separate taxon, for which the name Gluconacetobacter kombuchae sp. nov. is proposed, with the type strain RG3T (=LMG 23726T=MTCC 6913T).

  4. Mergers, managerial incentives, and efficiencies

    OpenAIRE

    Jovanovic, Dragan

    2014-01-01

    We analyze the effects of synergies from horizontal mergers in a Cournot oligopoly where principals provide their agents with incentives to cut marginal costs prior to choosing output. We stress that synergies come at a cost which possibly leads to a countervailing incentive effect: The merged firm's principal may be induced to stifle managerial incentives in order to reduce her agency costs. Whenever this incentive effect dominates the well-known direct synergy effect, synergies actually red...

  5. Cellulose-binding domains: tools for innovation in cellulosic fibre production and modification

    NARCIS (Netherlands)

    Quentin, M.G.E.; Valk, van der H.C.P.M.; Dam, van J.E.G.; Jong, de E.

    2003-01-01

    Plant cell walls are composed of cellulose, nature's most abundant macromolecule, and therefore represent a renewable resource of special technical importance. Cellulose degrading enzymes involved in plant cell wall loosening (expansins), or produced by plant pathogenic microorganisms (cellulases),

  6. Internally plasticised cellulose polymers

    International Nuclear Information System (INIS)

    Burnup, M.; Hayes, G.F.; Fydelor, P.J.

    1981-01-01

    Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

  7. Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase.

    Science.gov (United States)

    Cho, Sung Hyun; Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Díaz-Moreno, Sara M; Bulone, Vincent; Zimmer, Jochen; Kumar, Manish; Nixon, B Tracy

    2017-09-01

    Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. © 2017 American Society of Plant Biologists. All Rights Reserved.

  8. Cellulose Nanomaterials in Water Treatment Technologies

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

    2015-01-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  9. Cellulose nanomaterials in water treatment technologies.

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-05

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

  10. PRENATAL ETHANOL EXPOSURE LEADS TO GREATER ETHANOL-INDUCED APPETITIVE REINFORCEMENT

    Science.gov (United States)

    Pautassi, Ricardo M.; Nizhnikov, Michael E.; Spear, Norman E.; Molina, Juan C.

    2012-01-01

    Prenatal ethanol significantly heightens later alcohol consumption, but the mechanisms that underlie this phenomenon are poorly understood. Little is known about the basis of this effect of prenatal ethanol on the sensitivity to ethanol’s reinforcing effects. One possibility is that prenatal ethanol exposure makes subjects more sensitive to the appetitive effects of ethanol or less sensitive to ethanol’s aversive consequences. The present study assessed ethanol-induced second-order conditioned place preference (CPP) and aversion and ethanol-induced conditioned taste aversion (CTA) in infant rats prenatally exposed to ethanol (2.0 g/kg) or vehicle (water) or left untreated. The involvement of the κ opioid receptor system in ethanol-induced CTA was also explored. When place conditioning occurred during the ascending limb of the blood-ethanol curve (Experiment 1), the pups exposed to ethanol in utero exhibited greater CPP than untreated controls, with a shift to the right of the dose-response curve. Conditioning during a later phase of intoxication (30–45 min post-administration; Experiment 2) resulted in place aversion in control pups exposed to vehicle during late gestation but not in pups that were exposed to ethanol in utero. Ethanol induced a reliable and similar CTA (Experiment 3) in the pups treated with vehicle or ethanol during gestation, and CTA was insensitive to κ antagonism. These results suggest that brief exposure to a moderate ethanol dose during late gestation promotes ethanol-mediated reinforcement and alters the expression of conditioned aversion by ethanol. This shift in the motivational reactivity to ethanol may be an underlying basis of the effect of prenatal ethanol on later ethanol acceptance. PMID:22698870

  11. Co-production of ethanol, biogas, protein fodder and natural fertilizer in organic farming--evaluation of a concept for a farm-scale biorefinery.

    Science.gov (United States)

    Oleskowicz-Popiel, Piotr; Kádár, Zsófia; Heiske, Stefan; Klein-Marcuschamer, Daniel; Simmons, Blake A; Blanch, Harvey W; Schmidt, Jens Ejbye

    2012-01-01

    The addition of a biorefinery to an organic farm was investigated, where ethanol was produced from germinated rye grains and whey, and the effluent was separated into two streams: the protein-rich solid fraction, to be used as animal feed, and the liquid fraction, which can be co-digested with clover grass silage to produce biogas. A method for ethanol production from rye was applied by utilizing inherent amylase activity from germination of the seed. Biogas potential of ethanol fermentation effluent was measured through anaerobic digestion trials. The effluent from the trials was assumed to serve as natural fertilizer. A technoeconomic analysis was also performed; total capital investment was estimated to be approximately 4 M USD. Setting a methane selling price according to available incentives for "green electricity" (0.72 USD/m(3)) led to a minimum ethanol selling price of 1.89 USD/L (project lifetime 25 yr, at a discount rate 10%). Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2013-05-01

    Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  13. The NILE Project - Advances in the Conversion of Lignocellulosic Materials into Ethanol

    International Nuclear Information System (INIS)

    Monot, F.; Margeot, A.; Hahn-Haegerdal, B.; Lindstedt, J.; Slade, R.

    2013-01-01

    NILE ('New Improvements for Lignocellulosic Ethanol') was an integrated European project (2005-2010) devoted to the conversion of lignocellulosic raw materials to ethanol. The main objectives were to design novel enzymes suitable for the hydrolysis of cellulose to glucose and new yeast strains able to efficiently converting all the sugars present in lignocellulose into ethanol. The project also included testing these new developments in an integrated pilot plant and evaluating the environmental and socio-economic impacts of implementing lignocellulosic ethanol on a large scale. Two model raw materials - spruce and wheat straw - both preconditioned with similar pretreatments, were used. Several approaches were explored to improve the saccharification of these pretreated raw materials such as searching for new efficient enzymes and enzyme engineering. Various genetic engineering methods were applied to obtain stable xylose- and arabinose-fermenting Saccharomyces cerevisiae strains that tolerate the toxic compounds present in lignocellulosic hydrolysates. The pilot plant was able to treat 2 tons of dry matter per day, and hydrolysis and fermentation could be run successively or simultaneously. A global model integrating the supply chain was used to assess the performance of lignocellulosic ethanol from an economical and environmental perspective. It was found that directed evolution of a specific enzyme of the cellulolytic cocktail produced by the industrial fungus, Trichoderma reesei, and modification of the composition of this cocktail led to improvements of the enzymatic hydrolysis of pretreated raw material. These results, however, were difficult to reproduce at a large scale. A substantial increase in the ethanol conversion yield and in specific ethanol productivity was obtained through a combination of metabolic engineering of yeast strains and fermentation process development. Pilot trials confirmed the good behaviour of the yeast strains in industrial

  14. Variation in Incentive Effects across Neighbourhoods

    Directory of Open Access Journals (Sweden)

    Mark J Hanly

    2014-03-01

    Full Text Available Small monetary incentives increase survey cooperation rates, however evidence suggests that the appeal of incentives may vary across sample subgroups. Fieldwork budgets can be most effectively distributed by targeting those subgroups where incentives will have the strongest appeal. We examine data from a randomised experiment implemented in the pilot phase of the Irish Longitudinal Study of Ageing, which randomly assigned households to receive a higher (€25 or lower (€10 incentive amount. Using a random effects logistic regression model, we observe a variable effect of the higher incentive across geographic neighbourhoods. The higher incentive has the largest impact in neighbourhoods where baseline cooperation is low, as predicted by Leverage-Saliency theory. Auxiliary neighbourhood-level variables are linked to the sample frame to explore this variation further, however none of these moderate the incentive effect, suggesting that richer information is needed to identify sample subgroups where incentive budgets should be directed.

  15. Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

    Science.gov (United States)

    Griffiths, Jonathan S; North, Helen M

    2017-05-01

    The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

  16. Incentives Between Firms (and Within)

    OpenAIRE

    Robert Gibbons

    2005-01-01

    This paper reviews the significant progress in Üagency theoryÝ (i.e., the economic theory of incentives) during the 1990s, with an eye toward applications to supply transactions. I emphasize six recent models, in three pairs: (1) new foundations for the theory of incentive contracts, (2) new directions in incentive theory, and (3) new applications to supply transactions. By reviewing these six models, I hope to establish three things. First, the theory of incentive contracts needed and receiv...

  17. Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films.

    Science.gov (United States)

    Aaronson, Barak D B; Wigmore, David; Johns, Marcus A; Scott, Janet L; Polikarpov, Igor; Marken, Frank

    2017-09-25

    Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl. Reconstituted α-cellulose films provide "cationic diodes" (due to predominant cation conductivity) whereas chitosan-doped cellulose shows "anionic diode" effects (due to predominant anion conductivity). The current rectification, or "ionic diode" behaviour, is investigated as a function of NaCl concentration, pH, microhole diameter, and molecular weight of the chitosan dopant. Future applications are envisaged exploiting the surface charge induced switching of diode currents for signal amplification in sensing.

  18. Characterization of Cellulose Synthesis in Plant Cells

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  19. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  20. Valorization of lignin and cellulose in acid-steam-exploded corn stover by a moderate alkaline ethanol post-treatment based on an integrated biorefinery concept

    OpenAIRE

    Yang, Sheng; Zhang, Yue; Yue, Wen; Wang, Wei; Wang, Yun-Yan; Yuan, Tong-Qi; Sun, Run-Cang

    2016-01-01

    Background Due to the unsustainable consumption of fossil resources, great efforts have been made to convert lignocellulose into bioethanol and commodity organic compounds through biological methods. The conversion of cellulose is impeded by the compactness of plant cell wall matrix and crystalline structure of the native cellulose. Therefore, appropriate pretreatment and even post-treatment are indispensable to overcome this problem. Additionally, an adequate utilization of coproduct lignin ...