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Sample records for cellulosic ethanol production

  1. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......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...... 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...

  2. Prospects for Irradiation in Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Anita Saini

    2015-01-01

    Full Text Available Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol.

  3. Production of ethanol from cellulose using Clostridum thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Zertuche, L.; Zall, R.R.

    1982-01-01

    Clostridium thermocellum was used to produce ethanol from cellulose in a continuous system. Batch fermentations were first performed to observe the effects of buffers and agitation on generation time and ethanol production. Continuous fermentations were carried out at 60/sup 0/C and pH 7 using pure cellulose as the limiting substrate. The maximum ethanol concentrations produced with 1.5 and 3% cellulose fermenting liquid were 0.3 and 0.9% respectively. The yield of ethanol was about 0.3 grams per gram of cellulose consumed. While the continuous fermentaion of cellulose with Clostridium thermocellum appears to be feasible, it may not be economically promising due to the slow growth of the organism.

  4. Value Chain Structures that Define European Cellulosic Ethanol Production

    DEFF Research Database (Denmark)

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

    2017-01-01

    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...

  5. 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.

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

    OpenAIRE

    Jinaporn Wongwatanapaiboon; Kunn Kangvansaichol; Vorakan Burapatana; Ratanavalee Inochanon; Pakorn Winayanuwattikun; Tikamporn Yongvanich; Warawut Chulalaksananukul

    2012-01-01

    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....

  7. Review: Continuous hydrolysis and fermentation for cellulosic ethanol production.

    Science.gov (United States)

    Brethauer, Simone; Wyman, Charles E

    2010-07-01

    Ethanol made biologically from a variety of cellulosic biomass sources such as agricultural and forestry residues, grasses, and fast growing wood is widely recognized as a unique sustainable liquid transportation fuel with powerful economic, environmental, and strategic attributes, but production costs must be competitive for these benefits to be realized. Continuous hydrolysis and fermentation processes offer important potential advantages in reducing costs, but little has been done on continuous processing of cellulosic biomass to ethanol. As shown in this review, some continuous fermentations are now employed for commercial ethanol production from cane sugar and corn to take advantage of higher volumetric productivity, reduced labor costs, and reduced vessel down time for cleaning and filling. On the other hand, these systems are more susceptible to microbial contamination and require more sophisticated operations. Despite the latter challenges, continuous processes could be even more important to reducing the costs of overcoming the recalcitrance of cellulosic biomass, the primary obstacle to low cost fuels, through improving the effectiveness of utilizing expensive enzymes. In addition, continuous processing could be very beneficial in adapting fermentative organisms to the wide range of inhibitors generated during biomass pretreatment or its acid catalyzed hydrolysis. If sugar generation rates can be increased, the high cell densities in a continuous system could enable higher productivities and yields than in batch fermentations.

  8. 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."

  9. 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.

  10. The potential of cellulosic ethanol production from grasses in Thailand.

    Science.gov (United States)

    Wongwatanapaiboon, Jinaporn; Kangvansaichol, Kunn; Burapatana, Vorakan; Inochanon, Ratanavalee; Winayanuwattikun, Pakorn; Yongvanich, Tikamporn; Chulalaksananukul, Warawut

    2012-01-01

    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).

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

    OpenAIRE

    Murthy Ganti S; Kumar Deepak

    2011-01-01

    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 th...

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

    Science.gov (United States)

    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....

  14. 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 ...

  15. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Campiche, Jody L [Department of Agricultural Economics, 528 Ag Hall, Oklahoma State University, Stillwater, OK 74078 (United States); Bryant, Henry L; Richardson, James W [Department of Agricultural Economics, Agricultural and Food Policy Center, Texas A and M University, 2124 TAMU, College Station, TX 77843-2124 (United States)

    2010-01-15

    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.

  17. Preliminary Economics for the Production of Pyrolysis Oil from Lignin in a Cellulosic Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Susanne B.; Zhu, Yunhua

    2009-04-01

    Cellulosic ethanol biorefinery economics can be potentially improved by converting by-product lignin into high valued products. Cellulosic biomass is composed mainly of cellulose, hemicellulose and lignin. In a cellulosic ethanol biorefinery, cellulose and hemicellullose are converted to ethanol via fermentation. The raw lignin portion is the partially dewatered stream that is separated from the product ethanol and contains lignin, unconverted feed and other by-products. It can be burned as fuel for the plant or can be diverted into higher-value products. One such higher-valued product is pyrolysis oil, a fuel that can be further upgraded into motor gasoline fuels. While pyrolysis of pure lignin is not a good source of pyrolysis liquids, raw lignin containing unconverted feed and by-products may have potential as a feedstock. This report considers only the production of the pyrolysis oil and does not estimate the cost of upgrading that oil into synthetic crude oil or finished gasoline and diesel. A techno-economic analysis for the production of pyrolysis oil from raw lignin was conducted. comparing two cellulosic ethanol fermentation based biorefineries. The base case is the NREL 2002 cellulosic ethanol design report case where 2000 MTPD of corn stover is fermented to ethanol (NREL 2002). In the base case, lignin is separated from the ethanol product, dewatered, and burned to produce steam and power. The alternate case considered in this report dries the lignin, and then uses fast pyrolysis to generate a bio-oil product. Steam and power are generated in this alternate case by burning some of the corn stover feed, rather than fermenting it. This reduces the annual ethanol production rate from 69 to 54 million gallons/year. Assuming a pyrolysis oil value similar to Btu-adjusted residual oil, the estimated ethanol selling price ranges from $1.40 to $1.48 (2007 $) depending upon the yield of pyrolysis oil. This is considerably above the target minimum ethanol selling

  18. Lower-cost cellulosic ethanol production using cellobiose fermenting yeast Clavispora NRRL Y-50464

    Science.gov (United States)

    For ethanol production from cellulosic materials, there are generally two major steps needed including enzymatic hydrolysis to break down biomass sugars and microbial fermentation to convert available simple sugars into ethanol. It often requires two different kinds of microorganisms since ethanolog...

  19. Enhancement of fermentative hydrogen/ethanol production from cellulose using mixed anaerobic cultures

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chiu-Yue; Hung, Wen-Chin [BioHydrogen Laboratory, Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724 (China)

    2008-07-15

    Batch tests were conducted to evaluate the enhancement of hydrogen/ethanol (EtOH) productivity using cow dung microflora to ferment {alpha}-cellulose and saccharification products (glucose and xylose). Hydrogen/ethanol production was evaluated based on hydrogen/ethanol yields (HY/EY) under 55 C at various initial pH conditions (5.5-9.0). Our test results indicate that cow dung sludge is a good mixed natural-microflora seed source for producing biohydrogen/ethanol from cellulose and xylose. The heat-pretreatment, commonly used to produce hydrogen more efficiently from hexose, applied to mixed anaerobic cultures did not help cow dung culture convert cellulose and xylose into hydrogen/ethanol. Instead of heat-pretreatment, the mixed culture received enrichments cultivated at 55 C for 4 days. Positive results were observed: hydrogen/ethanol production from fermenting cellulose and xylose was effectively enhanced at increases of 4.8 (ethanol) to 8 (hydrogen) and 2.4 (ethanol) to 15.6 (hydrogen) folds, respectively. In which, the ethanol concentration produced from xylose reached 4-4.4 g/L, an output comparable to that of using heat-treated sewage sludge and better than that (1.25-3 g/L) using pure cultures. Our test results show that for the enriched cultures the initial cultivation pH can affect hydrogen/ethanol production including HY, EY and liquid fermentation product concentration and distribution. These results were also concurred using a denaturing gradient gel electrophoresis analysis saying that both cultivation pH and substrate can affect the enriched cow dung culture microbial communities. The enriched cow dung culture had an optimal initial cultivation pH range of 7.6-8.0 with peak HY/EY values of 2.8 mmol-H{sub 2}/g-cellulose, 5.8 mmol-EtOH/g-cellulose, 0.3 mol-H{sub 2}/mol-xylose and 1 mol-EtOH/mol-xylose. However, a pH change of 0.5 units from the optimal values reduced hydrogen/ethanol production efficiency by 20%. Strategies based on the experimental

  20. 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.

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

    DEFF Research Database (Denmark)

    Cannella, David

    fermentation at high solids loading, in terms of maximized final conversion yield, is the overall aim of the work conducted. This thesis also revisits the knowledge already acquired in light of new enzymatic activities recently discovered i.e. lytic polysaccharides mono oxygenases (LPMOs), and how these ffects...... cellulosic ethanol processing at high solids conditions. Moreover for the first time in literature the activity of LPMOs on real lignocellulosic substrate and during cellulosic ethanol production is characterized. Hence describing the enzymatic scale dynamics when resembling in planta conditions, i...

  2. 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.

  3. Life Cycle Assessment of Switchgrass Cellulosic Ethanol Production in the Wisconsin and Michigan Agricultural Contexts

    Energy Technology Data Exchange (ETDEWEB)

    Sinistore, Julie C.; Reinemann, D. J.; Izaurralde, Roberto C.; Cronin, Keith R.; Meier, Paul J.; Runge, Troy M.; Zhang, Xuesong

    2015-04-25

    Spatial variability in yields and greenhouse gas emissions from soils has been identified as a key source of variability in life cycle assessments (LCAs) of agricultural products such as cellulosic ethanol. This study aims to conduct an LCA of cellulosic ethanol production from switchgrass in a way that captures this spatial variability and tests results for sensitivity to using spatially averaged results. The Environment Policy Integrated Climate (EPIC) model was used to calculate switchgrass yields, greenhouse gas (GHG) emissions, and nitrogen and phosphorus emissions from crop production in southern Wisconsin and Michigan at the watershed scale. These data were combined with cellulosic ethanol production data via ammonia fiber expansion and dilute acid pretreatment methods and region-specific electricity production data into an LCA model of eight ethanol production scenarios. Standard deviations from the spatial mean yields and soil emissions were used to test the sensitivity of net energy ratio, global warming potential intensity, and eutrophication and acidification potential metrics to spatial variability. Substantial variation in the eutrophication potential was also observed when nitrogen and phosphorus emissions from soils were varied. This work illustrates the need for spatially explicit agricultural production data in the LCA of biofuels and other agricultural products.

  4. 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.

  5. Pretreatment of cellulosic biomass in improved production of ethanol and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ningjun; Gong, C.S.; Tsao, G.T. [Purdue Univ., West Lafayette, IN (United States); Yutang Huang [Jilin Corn Research and Development Center (China)

    1996-12-31

    A highly efficient process of simultaneous saccharification and fermentation (SSF) of cellulose using fungal cellulose and yeast to produce ethanol from lignocellulose pretreated with ammonia was developed. The process entails steeping the biomass with ammonia at ambient temperature to remove and extract lignin. This is followed by dilute acid hydrolysis at 100-108{degrees}C under atmospheric pressure to remove and recover a xylose-rich hemicellulose fraction as hemicellulose hydrolysate. This xylose-rich (92% xylose) hydrolysate was used as substrate for xylitol production by yeast and cellulose fraction was used for ethanol production in the SSF process with yeast. The same substrate was also used for 2,3-butanediol production in the SSF process with Klebsiella pneumonia. Experiments show that 98% of ammonia is recoverable for reuse and that the treated ground corn cob gives close to 86% theoretical yield of ethanol based on cellulose content. An ethanol concentration of over 60 g/L was obtained within 72 hours of SSF. 8 refs., 7 figs.

  6. 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

  7. A novel process for ethanol or biogas production from cellulose in blended-fibers waste textiles.

    Science.gov (United States)

    Jeihanipour, Azam; Karimi, Keikhosro; Niklasson, Claes; Taherzadeh, Mohammad J

    2010-12-01

    A novel process has been developed for separation of the cellulose, i.e. cotton and viscose, from blended-fibers waste textiles. An environmentally friendly cellulose solvent, N-methylmorpholine-N-oxide (NMMO) was used in this process for separation and pretreatment of the cellulose. This solvent was mixed with blended-fibers textiles at 120 °C and atmospheric pressure to dissolve the cellulose and separate it from the undissolved non-cellulosic fibers. Water was then added to the solution in order to precipitate the cellulose, while both water and NMMO were reused after separation by evaporation. The cellulose was then either hydrolyzed by cellulase enzymes followed by fermentation to ethanol, or digested directly to produce biogas. The process was verified by testing 50/50 polyester/cotton and 40/60 polyester/viscose-blended textiles. The polyesters were purified as fibers after the NMMO treatments, and up to 95% of the cellulose fibers were regenerated and collected on a filter. A 2-day enzymatic hydrolysis and 1-day fermentation of the regenerated cotton and viscose resulted in 48 and 50 g ethanol/g regenerated cellulose, which were 85% and 89% of the theoretical yields, respectively. This process also resulted in a significant increase of the biogas production rate. While untreated cotton and viscose fibers were converted to methane by respectively, 0.02% and 1.91% of their theoretical yields in 3 days of digestion, the identical NMMO-treated fibers resulted into about 30% of yield at the same period of time.

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

    Science.gov (United States)

    Ryu, Seunghyun; Karim, Muhammad Nazmul

    2011-08-01

    In this research, a recombinant whole cell biocatalyst was developed by expressing three cellulases from Clostridium cellulolyticum--endoglucanase (Cel5A), exoglucanase (Cel9E), and β-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.

  9. Ethanol production from high cellulose concentration by the basidiomycete fungus Flammulina velutipes.

    Science.gov (United States)

    Maehara, Tomoko; Ichinose, Hitomi; Furukawa, Takanori; Ogasawara, Wataru; Takabatake, Koji; Kaneko, Satoshi

    2013-03-01

    Ethanol production by Flammulina velutipes from high substrate concentrations was evaluated. F. velutipes produces approximately 40-60 g l(-1) ethanol from 15% (w/v) D-glucose, D-fructose, D-mannose, sucrose, maltose, and cellobiose, with the highest conversion rate of 83% observed using cellobiose as a carbon source. We also attempted to assess direct ethanol fermentation from sugarcane bagasse cellulose (SCBC) by F. velutipes. The hydrolysis rate of 15% (w/v) SCBC with commercial cellulase was approximately 20%. In contrast, F. velutipes was able to produce a significant amount of ethanol from 15% SCBC with the production of β-glucosidase, cellobohydrolase, and cellulase, although the addition of a small amount of commercial cellulase to the culture was required for the conversion. When 9 mg g(-1) biomass of commercial cellulase was added to cultures, 0.36 g of ethanol was produced from 1 g of cellulose, corresponding to an ethanol conversion rate of 69.6%. These results indicate that F. velutipes would be useful for consolidated bioprocessing of lignocellulosic biomass to bioethanol.

  10. Cellulosic Ethanol Production by Recombinant Cellulolytic Bacteria Harbouring pdc and adh II Genes of Zymomonas mobilis.

    Science.gov (United States)

    Piriya, P Sobana; Vasan, P Thirumalai; Padma, V S; Vidhyadevi, U; Archana, K; Vennison, S John

    2012-01-01

    The ethanol fermenting genes such as pyruvate decarboxylase (pdc) and alcohol dehydrogenase II (adh II) were cloned from Zymomonas mobilis and transformed into three different cellulolytic bacteria, namely Enterobacter cloacae JV, Proteus mirabilis JV and Erwinia chrysanthemi and their cellulosic ethanol production capability was studied. Recombinant E. cloacae JV was found to produce 4.5% and 3.5% (v/v) ethanol, respectively, when CMC and 4% NaOH pretreated bagasse were used as substrates, whereas recombinant P. mirabilis and E. chrysanthemi with the same substrates could only produce 4%, 3.5%, 1%, and 1.5 % of ethanol, respectively. The recombinant E. cloacae strain produced twofold higher percentage of ethanol than the wild type. The recombinant E. cloacae strain could be improved further by increasing its ethanol tolerance capability through media optimization and also by combining multigene cellulase expression for enhancing ethanol production from various types of lignocellulosic biomass so that it can be used for industrial level ethanol production.

  11. Cellulosic Ethanol Production by Recombinant Cellulolytic Bacteria Harbouring pdc and adh II Genes of Zymomonas mobilis

    Directory of Open Access Journals (Sweden)

    P. Sobana Piriya

    2012-01-01

    Full Text Available The ethanol fermenting genes such as pyruvate decarboxylase (pdc and alcohol dehydrogenase II (adh II were cloned from Zymomonas mobilis and transformed into three different cellulolytic bacteria, namely Enterobacter cloacae JV, Proteus mirabilis JV and Erwinia chrysanthemi and their cellulosic ethanol production capability was studied. Recombinant E. cloacae JV was found to produce 4.5% and 3.5% (v/v ethanol, respectively, when CMC and 4% NaOH pretreated bagasse were used as substrates, whereas recombinant P. mirabilis and E. chrysanthemi with the same substrates could only produce 4%, 3.5%, 1%, and 1.5 % of ethanol, respectively. The recombinant E. cloacae strain produced twofold higher percentage of ethanol than the wild type. The recombinant E. cloacae strain could be improved further by increasing its ethanol tolerance capability through media optimization and also by combining multigene cellulase expression for enhancing ethanol production from various types of lignocellulosic biomass so that it can be used for industrial level ethanol production.

  12. Recycling cellulases for cellulosic ethanol production at industrial relevant conditions

    DEFF Research Database (Denmark)

    Lindedam, Jane; Haven, Mai Østergaard; Chylenski, Piotr;

    2013-01-01

    wheat straw. Industrial conditions were used to study the impact of hydrolysis temperature (40 or 50. °C) and residence time on recyclability. Enzyme recycling at 12% DM indicated that hydrolysis at 50. °C, though ideal for ethanol yield, should be kept short or carried out at lower temperature...

  13. 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.

  14. 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.

  15. Improved process for the production of cellulose sulfate using sulfuric acid/ethanol solution.

    Science.gov (United States)

    Chen, Guo; Zhang, Bin; Zhao, Jun; Chen, Hongwen

    2013-06-05

    An improved process for production of cellulose sulfate (CS) was developed by using sulfuric acid/ethanol solution as sulfonating agent and Na2SO4 as water absorbent. The FTIR, SEM and TG analysis were used to characterize the CS prepared. The total degree of substitution and viscosity of the product solution (2%, w/v) were ranging from 0.28 to 0.77 and from 115 to 907 mPa s, respectively, by changing the process parameters such as the amount of Na2SO4, the reaction time, the temperature, the sulfuric acid/alcohol ratio and liquid/solid ratio. The results indicated that the product with DS (0.28-0.77) and η2% (115-907) mPa s could be produced by using this improved process and more cellulose sulfate could be produced when cellulose was sulfonated for 3-4 h at -2 °C in sulfuric acid/ethanol (1.4-1.6) solution with addition of 0.8 g Na2SO4. The (13)C NMR indicated that the sulfate group of CS produced using sulfuric acid/ethanol solution was at C6 position.

  16. 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.

  17. The effects of ethanol on hydrolysis of cellulose and pretreated barley straw by some commercial cellulolytic enzyme products

    Science.gov (United States)

    The effect of ethanol at levels ranging from 2.5% v/v to 15% v/v on the activities of two recently developed commercial cellulosic biomass hydrolytic enzyme products, Accellerase® 1500 and Accellerase® XY, was investigated. The substrates used for study of the effect of ethanol on Accellerase® 1500 ...

  18. Energy consumption and greenhouse gas emissions from enzyme and yeast manufacture for corn and cellulosic ethanol production.

    Science.gov (United States)

    Dunn, Jennifer B; Mueller, Steffen; Wang, Michael; Han, Jeongwoo

    2012-12-01

    Enzymes and yeast are important ingredients in the production of ethanol, yet the energy consumption and emissions associated with their production are often excluded from life-cycle analyses of ethanol. We provide new estimates for the energy consumed and greenhouse gases (GHGs) emitted during enzyme and yeast manufacture, including contributions from key ingredients such as starch, glucose, and molasses. We incorporated these data into Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model and observed that enzymes and yeast together contribute 1.4 and 27 % of farm-to-pump GHG emissions for corn and cellulosic ethanol, respectively. Over the course of the entire corn ethanol life cycle, yeast and enzymes contribute a negligible amount of GHG emissions, but increase GHG emissions from the cellulosic ethanol life cycle by 5.6 g CO(2)e/MJ.

  19. 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.

  20. 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.

  1. Cellulosic ethanol production using a yeast consortium displaying a minicellulosome and β-glucosidase

    Directory of Open Access Journals (Sweden)

    Kim Sujin

    2013-02-01

    Full Text Available Abstract Background Cellulosic biomass is considered as a promising alternative to fossil fuels, but its recalcitrant nature and high cost of cellulase are the major obstacles to utilize this material. Consolidated bioprocessing (CBP, combining cellulase production, saccharification, and fermentation into one step, has been proposed as the most efficient way to reduce the production cost of cellulosic bioethanol. In this study, we developed a cellulolytic yeast consortium for CBP, based on the surface display of cellulosome structure, mimicking the cellulolytic bacterium, Clostridium thermocellum. Results We designed a cellulolytic yeast consortium composed of four different yeast strains capable of either displaying a scaffoldin (mini CipA containing three cohesin domains derived from C. thermocellum, or secreting one of the three types of cellulases, C. thermocellum CelA (endoglucanase containing its own dockerin, Trichoderma reesei CBHII (exoglucanase fused with an exogenous dockerin from C. thermocellum, or Aspergillus aculeatus BGLI (β-glucosidase. The secreted dockerin-containing enzymes, CelA and CBHI, were randomly assembled to the surface-displayed mini CipA via cohesin-dockerin interactions. On the other hand, BGLI was independently assembled to the cell surface since we newly found that it already has a cell adhesion characteristic. We optimized the cellulosome activity and ethanol production by controlling the combination ratio among the four yeast strains. A mixture of cells with the optimized mini CipA:CelA:CBHII:BGLI ratio of 2:3:3:0.53 produced 1.80 g/l ethanol after 94 h, indicating about 20% increase compared with a consortium composed of an equal amount of each cell type (1.48 g/l. Conclusions We produced cellulosic ethanol using a cellulolytic yeast consortium, which is composed of cells displaying mini cellulosomes generated via random assembly of CelA and CBHII to a mini CipA, and cells displaying BGLI independently. One

  2. 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.)

  3. 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.

  4. Improvement of bacterial cellulose production by manipulating the metabolic pathways in which ethanol and sodium citrate involved.

    Science.gov (United States)

    Li, Yuanjing; Tian, Chunjie; Tian, Hua; Zhang, Jiliang; He, Xin; Ping, Wenxiang; Lei, Hong

    2012-12-01

    Nowadays, bacterial cellulose has played more and more important role as new biological material for food industry and medical and industrial products based on its unique properties. However, it is still a difficult task to improve the production of bacterial cellulose, especially a large number of byproducts are produced in the metabolic biosynthesis processes. To improve bacterial cellulose production, ethanol and sodium citrate are added into the medium during the fermentation, and the activities of key enzymes and concentration of extracellular metabolites are measured to assess the changes of the metabolic flux of the hexose monophosphate pathway (HMP), the Embden-Meyerhof-Parnas pathway (EMP), and the tricarboxylic acid cycle (TCA). Our results indicate that ethanol functions as energy source for ATP generation at the early stage of the fermentation in the HMP pathway and the supplementation of ethanol significantly reduces glycerol generation (a major byproduct). While in the EMP pathway, sodium citrate plays a key role, and its supplementation results in the byproducts (mainly acetic acid and pyruvic acid) entering the gluconeogenesis pathway for cellulose synthesis. Furthermore, by adding ethanol and sodium citrate, the main byproduct citric acid in the TCA cycle is also reduced significantly. It is concluded that bacterial cellulose production can be improved by increasing energy metabolism and reducing the formation of metabolic byproducts through the metabolic regulations of the bypasses.

  5. 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.

  6. Production of cellulosic ethanol from sugarcane bagasse by steam explosion: Effect of extractives content, acid catalysis and different fermentation technologies.

    Science.gov (United States)

    Neves, P V; Pitarelo, A P; Ramos, L P

    2016-05-01

    The production of cellulosic ethanol was carried out using samples of native (NCB) and ethanol-extracted (EECB) sugarcane bagasse. Autohydrolysis (AH) exhibited the best glucose recovery from both samples, compared to the use of both H3PO4 and H2SO4 catalysis at the same pretreatment time and temperature. All water-insoluble steam-exploded materials (SEB-WI) resulted in high glucose yields by enzymatic hydrolysis. SHF (separate hydrolysis and fermentation) gave ethanol yields higher than those obtained by SSF (simultaneous hydrolysis and fermentation) and pSSF (pre-hydrolysis followed by SSF). For instance, AH gave 25, 18 and 16 g L(-1) of ethanol by SHF, SSF and pSSF, respectively. However, when the total processing time was taken into account, pSSF provided the best overall ethanol volumetric productivity of 0.58 g L(-1) h(-1). Also, the removal of ethanol-extractable materials from cane bagasse had no influence on the cellulosic ethanol production of SEB-WI, regardless of the fermentation strategy used for conversion.

  7. 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.

  8. Cellulose ethanol is ready to go

    Energy Technology Data Exchange (ETDEWEB)

    Hladik, M. [Iogen Corp., Ottawa, ON (Canada)

    2006-07-01

    Ottawa-based Iogen Corporation is a leader in industrial biotechnology with a focus on cellulose-based enzyme technology. The company designed and operates the world's first and largest cellulose ethanol demonstration facility making ethanol from biomass. This presentation described Iogen's cellulose ethanol demonstration facility and outlined the innovative process in which enzymes prepare the plant fibres for fermentation, distillation and finally conversion to cellulose ethanol fuel. Hydrolysis and fermentation are achieved using a multi-stage hydrolysis process. It is anticipated that biorefineries will use the residues from locally grown agriculture to produce the ethanol, but stakeholder alliances will have to be built in order to form the elements of commercialization. Feedstocks, government policy, infrastructure issues, investment climate and ethanol sales all contribute to the success of a commercial plant. An assessment of preliminary global feedstock availability was presented with reference to total wheat, coarse grains, barley, oats, rye, sorghum, rice straw and sugar cane production. To date, the use of cellulose ethanol fuel has been demonstrated in vehicle trials in Bonn, Germany, as well as fleet vehicles operated by Natural Resources Canada and Agriculture Canada. Sample feedstock basins in Germany, Canada and the United States were highlighted. The supply of cellulose feedstock is large enough to contribute significantly to reductions in fossil fuel consumption. The United States Department of Energy claims that cellulose ethanol could displace over 30 per cent of the current petroleum consumption in the United States, and that land resources in the United States are capable of producing a sustainable supply of biomass. However, technology, financing and government policies are the factors which currently affect the commercialization of emerging technologies. tabs., figs.

  9. 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.

  10. 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

  11. Immobilized Kluyveromyces marxianus cells in carboxymethyl cellulose for production of ethanol from cheese whey: experimental and kinetic studies.

    Science.gov (United States)

    Roohina, Fatemeh; Mohammadi, Maedeh; Najafpour, Ghasem D

    2016-09-01

    Cheese whey fermentation to ethanol using immobilized Kluyveromyces marxianus cells was investigated in batch and continuous operation. In batch fermentation, the yeast cells were immobilized in carboxymethyl cellulose (CMC) polymer and also synthesized graft copolymer of CMC with N-vinyl-2-pyrrolidone, denoted as CMC-g-PVP, and the efficiency of the two developed cell entrapped beads for lactose fermentation to ethanol was examined. The yeast cells immobilized in CMC-g-PVP performed slightly better than CMC with ethanol production yields of 0.52 and 0.49 g ethanol/g lactose, respectively. The effect of supplementation of cheese whey with lactose (42, 70, 100 and 150 g/l) on fermentative performance of K. marxianus immobilized in CMC beads was considered and the results were used for kinetic studies. The first order reaction model was suitable to describe the kinetics of substrate utilization and modified Gompertz model was quite successful to predict the ethanol production. For continuous ethanol fermentation, a packed-bed immobilized cell reactor (ICR) was operated at several hydraulic retention times; HRTs of 11, 15 and 30 h. At the HRT of 30 h, the ethanol production yield using CMC beads was 0.49 g/g which implies that 91.07 % of the theoretical yield was achieved.

  12. Microbial community analysis in a combined anaerobic and aerobic digestion system for treatment of cellulosic ethanol production wastewater.

    Science.gov (United States)

    Shan, Lili; Yu, Yanling; Zhu, Zebing; Zhao, Wei; Wang, Haiman; Ambuchi, John J; Feng, Yujie

    2015-11-01

    This study investigated the microbial diversity established in a combined system composed of a continuous stirred tank reactor (CSTR), expanded granular sludge bed (EGSB) reactor, and sequencing batch reactor (SBR) for treatment of cellulosic ethanol production wastewater. Excellent wastewater treatment performance was obtained in the combined system, which showed a high chemical oxygen demand removal efficiency of 95.8% and completely eliminated most complex organics revealed by gas chromatography-mass spectrometry (GC-MS). Denaturing gradient gel electrophoresis (DGGE) analysis revealed differences in the microbial community structures of the three reactors. Further identification of the microbial populations suggested that the presence of Lactobacillus and Prevotella in CSTR played an active role in the production of volatile fatty acids (VFAs). The most diverse microorganisms with analogous distribution patterns of different layers were observed in the EGSB reactor, and bacteria affiliated with Firmicutes, Synergistetes, and Thermotogae were associated with production of acetate and carbon dioxide/hydrogen, while all acetoclastic methanogens identified belonged to Methanosaetaceae. Overall, microorganisms associated with the ability to degrade cellulose, hemicellulose, and other biomass-derived organic carbons were observed in the combined system. The results presented herein will facilitate the development of an improved cellulosic ethanol production wastewater treatment system.

  13. Direct fermentation of cellulose to ethanol by a cellulolytic filamentous fungus, monilia sp

    Energy Technology Data Exchange (ETDEWEB)

    Gong, C.S.; Maun, C.M.; Tsao, G.T.

    1981-01-01

    Monilia, isolated from bagasse compost, utilized many polysaccharides (including cellulose) and displayed cellulase and hemicellulase activities. Monilia also fermented glucose, xylose, and cellulosic materials to ethanol. Over 60% of the solid cellulose substrate added to Monilia cultures was converted to ethanol as the major fermentation product. Thus, Monilia is a potential organism for the direct conversion of cellulosic biomass to ethanol.

  14. 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.

  15. Selection of a thermotolerant Kluyveromyces marxianus strain with potential application for cellulosic ethanol production by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Castro, Rafael Cunha A; Roberto, Inês C

    2014-02-01

    The development of technologies for cellulosic ethanol production by simultaneous saccharification and fermentation (SSF) depends on the use of microorganisms with high fermentative rates and thermotolerance. In this study, the ability of five Kluyveromyces marxianus strains to produce ethanol from glucose at 45 °C was investigated. The highest fermentative parameters were observed with K. marxianus NRRL Y-6860, which was then further studied. An initial evaluation of the oxygen supply on ethanol production by the selected yeast and a comparison of SSF process from acid pretreated rice straw between K. marxianus NRRL Y-6860 and Saccharomyces cerevisiae at 30 and 45 °C were carried out. Under the lowest evaluated conditions of aeration and agitation, K. marxianus NRRL Y-6860 produced 21.5 g/L ethanol from 51.3 g/L glucose corresponding to YP/S of 0.44 g/g and QP of 3.63 g/L h. In the SSF experiments, K. marxianus NRRL Y-6860 was more efficient than S. cerevisiae at both evaluated temperatures (30 and 45 °C), attained at the highest temperature an ethanol yield of 0.24 g/g and productivity of 1.44 g/L h.

  16. 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

    -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......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...... suggest that selection of cultivars for improved biofuel feedstock of wheat straw is possible, because heritability of sugar release is 57% and there are few adverse correlations to other agronomic traits....

  17. Pilot plant studies of the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1977-06-30

    Progress is reported in the following studies on analysis and evaluation of potential raw materials: preliminary pretreatment studies using wheat straw; extraction of wheat straw with alcohol and water at elevated temperatures; extraction of ground wood with alcohol and water at elevated temperatures; and, delignification of newsprint with ethylene glycol. Other research in progress includes studies on: utilization of hemicellulose sugars; process design and economics of hydrolysis processes and ethanol fermentation; and, pilot plant process development and design, including cell-recycle systems for cellulase production, continuous hydrolysis, countercurrent hydrolysis, and ethanol fermentation studies. (JGB)

  18. Automotive fuels from cellulose materials. [Production of ethanol and methane simultaneously

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, B.; Thornton, R.H.

    1980-01-01

    The results of this investigation showed that it was feasible to link the alcohol fermentation and anaerobic digestion processes into a system for the production of both alcohol and methane from organic substrates. The rate of ethanol production has been determined with respect to cell concentration and the prerequisite of both a high cell concentration and yeast recycling has been shown. Ethanol fermentation under reduced pressure has been shown to be feasible and to give higher ethanol productivities. Although optimization of fermentation has been attempted in this report, with due regard to energy conservation, for industrial application the cost of sugar will be the overriding factor. Cysewski and Wilke (7) pointed out that the cost of sugar overwhelms all other costs in the production of ethanol by fermetation: up to 70 to 80% of the total cost of the ethanol. Results showed that the resultant fermentation spent wash and extracted crop residues could be anaerobically digested to produce methane (and carbon dioxide). A hydraulic retention time of 10 days or longer was needed for effective digestion in which a reduction of chemical oxygen demand (COD) of up to 85% was achieved. Results indicated that further reduction in retention time may be possible if the microbial biomass could be either retained on support media, or recycled more effectively. A gas production rate of 4270 liters gas/m/sup 3/ culture/day at 11.6 day retention time was obtained with the anaerobic contact digester using fodder beet spent wash. Using the same substrate, results over short periods with the anaerobic filter system could produce up to 4.8 liters gas/litre culture/day. The high methane composition of this gas (75 to 80%) make this an attractive proposition.

  19. Process development studies of the bioconversion of cellulose and production of ethanol. Semi annual report

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-04-01

    Progress in the following process development studio is reported: economic evaluation of hydrolysis and ethanol fermentation schemes, economic evaluation of alternative fermentation processes, raw materials evaluation, and evaluation of pretreatment process. Microbiological and enzymatic studies reported are: production of cellulase enzyme from high yielding mutants, hydrolysis reactor development, xylose fermentation, and xylanese production. Fermentation and separation processes include: process development studies on vacuum fermentation and distillation, evaluation of low energy separations processes, large scale hollow fiber reactor development. (MHR)

  20. 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.

  1. 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

  2. Agronomic impacts of production scale harvesting of corn stover for cellulosic ethanol production in Central Iowa

    Science.gov (United States)

    Schau, Dustin

    This thesis investigates the impacts of corn stover harvest in Central Iowa with regards to nutrient removal, grain yield impacts and soil tilth. Focusing on phosphorus and potassium removal due to production of large, square bales of corn stover, 3.7 lb P2O5 and 18.7 lb K 2O per ton of corn stover were removed in 2011. P2O 5 removal remained statistically the same in 2012, but K2O decreased to 15.1 lb per ton of corn stover. Grain cart data showed no statistical difference in grain yield between harvest treatments, but yield monitor data showed a 3 - 17 bu/ac increase in 2012 and hand samples showed a 4 - 21 bu/ac increase in 2013. Corn stover residue levels decreased below 30% coverage when corn stover was harvested the previous fall and conventional tillage methods were used, but incorporating reduced tillage practices following corn stover harvest increased residue levels back up to 30% coverage. Corn emergence rates increased by at least 2,470 more plants per acre within the first three days of spiking, but final populations between harvest and nonharvest corn stover treatments were the same. Inorganic soil nitrogen in the form of ammonium and nitrate were not directly impacted by corn stover harvest, but it is hypothesized that weather patterns had a greater impact on nitrogen availability. Lastly, soil organic matter did not statistically change from 2011 to 2013 due to corn stover removal, even when analyzed within single soil types.

  3. Nitrogen fertilization affects corn cellulosic biomass and ethanol yields

    Science.gov (United States)

    Research results on the effects of N management on corn (Zea mays L.) grain production in high-yielding cropping systems are widely available, but information on its effects on cellulosic ethanol potential from corn stover and cobs is limited. Stover and cob biomass and respective ethanol yields all...

  4. Woody biomass pretreatment for cellulosic ethanol production: Technology and energy consumption evaluation.

    Science.gov (United States)

    Zhu, J Y; Pan, X J

    2010-07-01

    This review presents a comprehensive discussion of the key technical issues in woody biomass pretreatment: barriers to efficient cellulose saccharification, pretreatment energy consumption, in particular energy consumed for wood-size reduction, and criteria to evaluate the performance of a pretreatment. A post-chemical pretreatment size-reduction approach is proposed to significantly reduce mechanical energy consumption. Because the ultimate goal of biofuel production is net energy output, a concept of pretreatment energy efficiency (kg/MJ) based on the total sugar recovery (kg/kg wood) divided by the energy consumption in pretreatment (MJ/kg wood) is defined. It is then used to evaluate the performances of three of the most promising pretreatment technologies: steam explosion, organosolv, and sulfite pretreatment to overcome lignocelluloses recalcitrance (SPORL) for softwood pretreatment. The present study found that SPORL is the most efficient process and produced highest sugar yield. Other important issues, such as the effects of lignin on substrate saccharification and the effects of pretreatment on high-value lignin utilization in woody biomass pretreatment, are also discussed.

  5. Economic and environmental assessment of cellulosic ethanol production scenarios annexed to a typical sugar mill.

    Science.gov (United States)

    Ali Mandegari, Mohsen; Farzad, Somayeh; Görgens, Johann F

    2017-01-01

    In this work different biorefinery scenarios were investigated, concerning the co-production of bioethanol and electricity from available lignocellulose at a typical sugar mill, as possible extensions to the current combustion of bagasse for steam and electricity production and burning trash on-filed. In scenario 1, the whole bagasse and brown leaves is utilized in a biorefinery and coal is burnt in the existing inefficient sugar mill boiler. Scenario 2 & 3 are assumed with a new centralized CHP unit without/with coal co-combustion, respectively. Also, through scenarios 4 & 5, the effect of water insoluble loading were studied. All scenarios provided energy for the sugarmill and the ethanol plant, with the export of surplus electricity. Economic analysis determined that scenario 1 was the most viable scenario due to less capital cost and economies-of scale. Based on Life Cycle Assessment (LCA) results, scenario 2 outperformed the other scenarios, while three scenarios showed lower contribution to environmental burdens than the current situation.

  6. Net energy of cellulosic ethanol from switchgrass.

    Science.gov (United States)

    Schmer, M R; Vogel, K P; Mitchell, R B; Perrin, R K

    2008-01-15

    Perennial herbaceous plants such as switchgrass (Panicum virgatum L.) are being evaluated as cellulosic bioenergy crops. Two major concerns have been the net energy efficiency and economic feasibility of switchgrass and similar crops. All previous energy analyses have been based on data from research plots (biomass energy crop in field trials of 3-9 ha (1 ha = 10,000 m2) on marginal cropland on 10 farms across a wide precipitation and temperature gradient in the midcontinental U.S. to determine net energy and economic costs based on known farm inputs and harvested yields. In this report, we summarize the agricultural energy input costs, biomass yield, estimated ethanol output, greenhouse gas emissions, and net energy results. Annual biomass yields of established fields averaged 5.2-11.1 Mg x ha(-1) with a resulting average estimated net energy yield (NEY) of 60 GJ x ha(-1) x y(-1). Switchgrass produced 540% more renewable than nonrenewable energy consumed. Switchgrass monocultures managed for high yield produced 93% more biomass yield and an equivalent estimated NEY than previous estimates from human-made prairies that received low agricultural inputs. Estimated average greenhouse gas (GHG) emissions from cellulosic ethanol derived from switchgrass were 94% lower than estimated GHG from gasoline. This is a baseline study that represents the genetic material and agronomic technology available for switchgrass production in 2000 and 2001, when the fields were planted. Improved genetics and agronomics may further enhance energy sustainability and biofuel yield of switchgrass.

  7. 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.

  8. Ethanol production from waste materials

    Directory of Open Access Journals (Sweden)

    Muhammad Shahid Iqbal

    2012-08-01

    Full Text Available Experiment was designed for ethanol production using corn andother organic waste material containing starch contents andcellulosic material while barely used for diastase and acidicdigestion methods. The effect of temperature, yeast, barely diastaseand various dilutions of acid (sulfuric acids were investigated onethanol production. The result showed that corn yielded highamount of ethanol (445ml as compared to cellulosic material whichproduced 132ml of ethanol from one kg of weight. It was also notedthat with the increase of barely and yeast amount in a proper mannercan increase ethanol production from different starch sources. It wasalso noted that acid dilutions affected cellulose digestion where highyield of reducing sugar was noted at 0.75% of sulfuric acid dilution.It was concluded from the present experiment that economicalsources of starch and various dilutions of acids should be tried oncellulose digestion for bio-fuel production to withstand in thisenergy crisis time.

  9. Effects of Ethanol Pulping on the Length of Bamboo Cellulose

    Institute of Scientific and Technical Information of China (English)

    Tao Yang; Liao Junhe; Luo Xuegang

    2006-01-01

    On the conditions of different ethanol concentration, acids and catalyzers, the effects of ethanol pulping on the cellulose length of bamboo were studied. The results indicates that ethanol pulping has remarkable effects on the length of cellulose, which is clearly reduced with adding ethanol and acid. The margin of length of cellulose become smaller with the increase of the catalyzer. When the ethanol concentration was 70%, the concentration of acid was 0.3% and some NaOH was used as catalyzer, the length of cellulose was the longest.

  10. 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.

  11. 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

  12. 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.

  13. Produção conjunta de fibras celulósicas e etanol a partir do bambu Combined production of cellulosic fibers and ethanol from bamboo culm

    Directory of Open Access Journals (Sweden)

    Anisio Azzini

    1987-01-01

    Full Text Available No presente estudo com Bambusa vulgaris Schrad., procurou-se desenvolver um novo processo de utilização do bambu, visando à produção conjunta de etanol e fibras celulósicas para papel. Os rendimentos em fibras celulósicas e etanol foram obtidos em função da idade do colmo (1, 3 e 5 anos e região de amostragem em cada colmo (base, meio e ponta. Esses rendimentos, bem como outros relacionados com a fração fibrosa, glicose e amido, foram determinados com solução diluída de ácido sulfúrico. A densidade básica dos colmos foi determinada em cavacos antes do seu tratamento. Pelos resultados obtidos, é tecnicamente possível a produção conjunta de etanol e fibras celulósicas a partir do bambu. Os rendimentos em fibras celulósicas (46,85 a 56,04% e etanol (12,77 a 14,79 litros/100 kg de cavacos foram mais elevados nas regiões mediana e ponta dos colmos mais velhos. Essa mesma tendência foi observada para a glicose (teores de 22,80 a 26,41% e amido hidrolisado (18,99 a 24,27%. O rendimento em fibras brutas ou fração fibrosa (69,35 a 76,35% foi mais elevado nos cavacos provenientes dos colmos mais novos. A densidade básica dos cavacos não variou em função da idade do colmo (0,573 a 0,628 g/cm³, mas em função da região de amostragem (0,518 a 0,683 g/cm³, sendo mais densos os cavacos das regiões mediana e ponta dos colmos.In this study with Bambusa vulgaris Schrad, a new process of bamboo utilization was established to produce cellulosic fibers for papermaking and ethanol. The yields of ethanol and cellulosic fibers were determined in function of culm age (1, 3 and 5 years and portion of sampling in each culm (base, middle and top. The yields of cellulosic fibers, ethanol and compounds like glucose and starch were determined in shreddered chips after treatment with diluted sulphuric acid solution. The combined production of ethanol and cellulosic fibers was feasible technically. The yields of cellulosic fibers varied from

  14. Assessing resource intensity and renewability of cellulosic ethanol technologies using eco-LCA.

    Science.gov (United States)

    Baral, Anil; Bakshi, Bhavik R; Smith, Raymond L

    2012-02-21

    Recognizing the contributions of ecosystem services and the lack of their comprehensive accounting in life cycle assessment (LCA), an in-depth analysis of their contribution in the life cycle of cellulosic ethanol derived from five different feedstocks was conducted, with gasoline and corn ethanol as reference fuels. The relative use intensity of natural resources encompassing land and ecosystem goods and services by cellulosic ethanol was estimated using the Eco-LCA framework. Despite being resource intensive compared to gasoline, cellulosic ethanol offers the possibility of a reduction in crude oil consumption by as much as 96%. Soil erosion and land area requirements can be sources of concern for cellulosic ethanol derived directly from managed agriculture. The analysis of two broad types of thermodynamic metrics, namely: various types of physical return on investment and a renewability index, which indicate competitiveness and sustainability of cellulosic ethanol, respectively, show that only ethanol from waste resources combines a favorable thermodynamic return on investment with a higher renewability index. However, the production potential of ethanol from waste resources is limited. This finding conveys a possible dilemma of biofuels: combining high renewability, high thermodynamic return on investment, and large production capacity may remain elusive. A plot of renewability versus energy return on investment is suggested as one of the options for providing guidance on future biofuel selection.

  15. 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.

  16. Recycling cellulases for cellulosic ethanol production at industrial relevant conditions: potential and temperature dependency at high solid processes.

    Science.gov (United States)

    Lindedam, Jane; Haven, Mai Østergaard; Chylenski, Piotr; Jørgensen, Henning; Felby, Claus

    2013-11-01

    Different versions of two commercial cellulases were tested for their recyclability of enzymatic activity at high dry matter processes (12% or 25% DM). Recyclability was assessed by measuring remaining enzyme activity in fermentation broth and the ability of enzymes to hydrolyse fresh, pretreated wheat straw. Industrial conditions were used to study the impact of hydrolysis temperature (40 or 50°C) and residence time on recyclability. Enzyme recycling at 12% DM indicated that hydrolysis at 50°C, though ideal for ethanol yield, should be kept short or carried out at lower temperature to preserve enzymatic activity. Best results for enzyme recycling at 25% DM was 59% and 41% of original enzyme load for a Celluclast:Novozyme188 mixture and a modern cellulase preparation, respectively. However, issues with stability of enzymes and their strong adsorption to residual solids still pose a challenge for applicable methods in enzyme recycling.

  17. 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.

  18. 我国纤维素乙醇生产技术的专利研究近况%Study and Patent Analysis of the Cellulosic Ethanol Production Technology

    Institute of Scientific and Technical Information of China (English)

    李志瑞; 张忠营; 张全; 李微

    2016-01-01

    木质纤维素是地球上现存量最大的生物质资源,利用该类原料生产燃料乙醇是木质纤维素类生物质工业化的一个重要方向。选取纤维素乙醇生产工艺中的原料预处理、水解糖化、乙醇发酵,以及废水处理等关键技术点,利用专利文献的检索与分析方法,介绍了不同关键技术点的专利研究近况,旨在全面了解纤维素乙醇生产技术国内发展现状,从而为该项技术的研究方向和产业发展提供一定的专利参考信息。%Lignocellulose is the largest biomass resource on the earth, and using lignocellulose to produce fuel ethanol is an important direction of the industrialization of this biomass. In this paper, taking material pre-treatment, saccharification, alcohol fermentation, wastewater treatment and other key technical points in the process of cellulosic ethanol production as research objectives, in order to comprehensively understand the current development status and development trend of the cellulosic ethanol production technology, the global patent technology distribution and domestic patent technology status of the cellulosic ethanol production technology were studied by using retrieval analysis method of patent documents, important reference information was provided for the technology research and industrial development.

  19. SYNTHESIS AND CHARACTERIZATION OF CELLULOSE-SILICA COMPOSITE FIBER IN ETHANOL/WATER MIXED SOLVENTS

    Directory of Open Access Journals (Sweden)

    Ning Jia

    2011-04-01

    Full Text Available Cellulose-silica composite fiber samples have been successfully synthesized using cellulose solution, tetraethoxysilane, and NH3•H2O in ethanol/water mixed solvents at room temperature for 24 h. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in a solvent mixture of N,N-dimethylacetamide (DMAc/lithium chloride (LiCl. The effect of the tetraethoxysilane concentration on the product was investigated. The products were characterized by X-ray powder diffraction (XRD, thermogravimetric analysis (TG, differential scanning calorimetric analysis (DSC, scanning electron microscopy (SEM, Fourier transform infrared spectrometry (FT-IR, energy-dispersive X-ray spectrum (EDS, and cross polarization magic angle spinning (CP/MAS solid state 13C-NMR. The morphology of the cellulose-silica composite fiber was investigated by SEM, while their composition was established from EDS measurements combined with the results of FT-IR spectral analysis and XRD patterns. The XRD, FT-IR and EDS results indicated that the obtained product was cellulose-silica composite fiber. The SEM micrographs showed that the silica particles were homogeneously dispersed in the cellulose fiber. The CP/MAS solid state 13C-NMR results indicated that the silica concentration had an influence on the crystallinity of the cellulose. This method is simple for preparation of cellulose-based composites.

  20. 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).

  1. 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

    The choice of a suitable pretreatment method and the adjustment of the pretreatment parameters for efficient conversion of biomass are crucial for a successful biorefinery concept. In this study, cocksfoot grass, a suitable lignocellulosic biomass with a potential for large-scale production was inv...

  2. Effect of cellulosic sugar degradation products (furfural and hydroxymethylfurfural) on acetone-butanol-ethanol (ABE) fermentation using Clostridium beijerinckii P260

    Science.gov (United States)

    Studies were performed to identify chemicals present in wheat straw hydrolysate (WSH) that enhance acetone butanol ethanol (ABE) productivity. These chemicals were identified as furfural and hydroxymethyl furfural (HMF). Control experiment resulted in the production of 21.09-21.66 gL**-1 ABE with a ...

  3. 纤维素乙醇的原料预处理方法及工艺流程研究进展%Feedstock pretreatment and technological process of cellulose ethanol production

    Institute of Scientific and Technical Information of China (English)

    杨娟; 滕虎; 刘海军; 徐友海; 吕继萍; 王继艳

    2013-01-01

    木质纤维生物质是储量丰富且最有前景的生产燃料乙醇的可再生生物质资源,利用木质纤维生物质生产乙醇主要包括以下步骤:原料预处理、发酵以及产物分离纯化,其中,原料的预处理工艺是限制纤维素乙醇产业化的一个技术瓶颈.本文对酸法、碱法、蒸汽爆破法、合成气法等7种典型预处理方法进行了介绍并对其工艺流程进行简要的说明,同时对不同的预处理方法的优劣、适用范围和工艺流程转化效率等进行了对比,以期为纤维素乙醇预处理方法的工艺选择和评价提供一些参考.提出了纤维素乙醇的产业化前景:不同预处理技术的合理结合使用会有效提高转化率;较好的过程设计能够降低成本,有利于整个过程的经济性.%Lignocellulose is a promising resource for bioethanol production due to its abundance, renewablility, and low cost. Ethanol production from lignocellulose biomass comprises the following critical steps: feedstock pretreatment, sugar fermentation, separation and purification of the ethanol, among which pretreatment step is identified as technological bottleneck for commercialization of cellulosic ethanol technology. The characteristics and technological processes of typical pretreatment methods are reviewed, such as acid pretreatment, alkali pretreatment, steam explosion, syngas etc., and the advantages and disadvantages, available materials and process efficiency of those methods are compared and discussed to provide guidance for the selection and evaluation of pretreatment process in cellulose ethanol production. Finally, the prospect of commercialization of fuel ethanol production from cellulosic biomass is presented. Reasonable integration of different pretreatment technologies will effectively improve the conversion rate. A preferable process design can help in reducing cost, contributing to the economy of the whole process.

  4. Comparative study on processes of simultaneous saccharification and fermentation with high solid concentration for cellulosic ethanol production%高底物浓度纤维乙醇同步糖化发酵工艺的比较

    Institute of Scientific and Technical Information of China (English)

    常春; 王铎; 王林风; 马晓建

    2012-01-01

    The effects of various simultaneous saccharification fermentation (SSF) technologies on ethanol yield from cellulose were investigated. Using steam-exploded corn stalks as raw materials, five SSF technologies, including traditional SSF, SSF combined with preliminary enzymatic hydrolysis, fed-batch SSF coupled with preliminary enzymatic hydrolysis, SSF united with preliminary enzymatic hydrolysis coupling with vacuum separation and fed-batch SSF associated with preliminary enzymatic hydrolysis coupling with vacuum separation, were used for decomposition of the stalks. By comparing the fermentation process with higher solid concentration including 15% (mass) and 30% (mass), it was found that the fed-batch SSF combined with preliminary enzymatic hydrolysis is an effective way for raising substrate concentration. However, higher substrate concentration may lead to decrease of final ethanol yield. Moreover, SSF coupled with vacuum separation can weaken the product inhibition, and increase the ethanol yield. The ethanol productivity by the fed-batch SSF associated with preliminary enzymatic hydrolysis coupling with vacuum separation is 0. 40 g · L-1 · h-1, the highest value obtained, indicating that this technology can be a potential new technology.

  5. Systems biology and pathway engineering enable Saccharomyces cerevisiae to utilize C-5 and C-6 sugars simultaneously for cellulosic ethanol production

    Science.gov (United States)

    Saccharomyces cerevisiae is a traditional industrial workhorse for ethanol production. However, conventional ethanologenic yeast is superior in fermentation of hexose sugars (C-6) such as glucose but unable to utilize pentose sugars (C-5) such as xylose richly embedded in lignocellulosic biomass. In...

  6. Biofuel Food Disasters and Cellulosic Ethanol Problems

    Science.gov (United States)

    Pimentel, David

    2009-01-01

    As shortages of fossil energy, especially oil and natural gas, become evident, the United States has moved to convert corn grain into ethanol with the goal to make the nation oil independent. Using more than 20% of all U.S. corn on 15 million acres in 2007 was providing the nation with less than 1% of U.S. oil consumption. Because the corn ethanol…

  7. Extraction of cellulose with subcritical and supercritical ethanol

    Institute of Scientific and Technical Information of China (English)

    Qian Xueren; Li Jian

    1999-01-01

    Cotton cellulose was extracted with ethanol in sub-and supercritical states dynamically. The degree of conversion was 95.4% and the extract yield was 55.2% when cotton cellulose was non-isothermally extracted with ethanol from 20℃ to 400℃. From an engineering standpoint, in the temperature range from 200℃ to 320℃,the rate of extract formation could adequately be described by a second-order reaction kinetics equation with the activation energy of 105.3 k J/mol and the pre-exponential factor of 3.53 × 107 s-1. With the non-isothermal experimental technique, it was possible to determine the kinetic parameters; conversion degree and extract yield by one experiment.

  8. Converting Chemical Oxygen Demand (COD) of Cellulosic Ethanol Fermentation Wastewater into Microbial Lipid by Oleaginous Yeast Trichosporon cutaneum.

    Science.gov (United States)

    Wang, Juan; Hu, Mingshan; Zhang, Huizhan; Bao, Jie

    2017-01-27

    Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.

  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. CELLULOSIC ETHANOL VIA BIOCHEMICAL PROCESSING POSES A CHALLENGE FOR DEVELOPERS AND IMPLEMENTORS

    Directory of Open Access Journals (Sweden)

    Ilkka Virkajärvi

    2009-11-01

    Full Text Available In the future liquid biofuels will need to be renewable, sustainable, as well as technically and economically viable. This paper provides an overview of the challenges that the biochemical production of cellulosic ethanol process still faces. The main emphasis of the paper is on challenges that emerge from the scale of liquid biofuel production. These challenges include raw material availability, other consumables, and side stream handling. The pretreatment, C5 fermentation, and concentration of sugars in processing need improvements, too. Sustainability issues and greenhouse gas reduction also pose a challenge for implementation and require development of internationally recognized sustainability principles and standards, and certification of sustainable operation. Economics of cellulosic ethanol processes are still also an area under development and debate. Yet, the Energy Independence and Security Act mandate together with the European Union Renewable Energy Directive and other local targets are driving the development and implementation forward towards more significant contribution of biofuels in the transportation sector.

  11. 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.

  12. 纤维素乙醇产业进展%Industry Progress of Cellulosic Ethanol

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    燃料乙醇已发展成为世界可再生能源产业之一,在经济、环境、能源等领域发挥着重要作用。利用能量及环境效益更佳的木质纤维素作为原料生产燃料乙醇,已是这一产业可持续发展的基石。自2014年下半年开始剧烈下跌的原油价格虽然带来了一些不确定因素,但在政策性因素引导下,世界燃料乙醇产业有序发展,在年产量创出新高的同时,纤维素乙醇示范装置也在加速建设。2017年纤维素乙醇生产能力有望突破100万吨。本文在综述世界燃料乙醇产业发展现状基础上,详细介绍了纤维素乙醇的产业进展,并对纤维素乙醇的发展趋势作了展望。%Fuel ethanol has become one of the world's renewable energy industries, and plays an important role in areas such as economy, environment and energy. To use lignocellulose with good energy efficient and environment benefit as raw material to produce fuel ethanol has become a footstone for the sustainable development of the fuel ethanol industry. Although sharp decrease of crude oil price has brought some uncertainties in the second half of 2014, the world ethanol industry continued development with positive policies. Not only the annual production set a new record, but also the construction of cellulosic ethanol commercial facilities accelerated. It is expected that the cellulosic ethanol production capacity will exceed 1 million tons in 2017. In this paper, current status of the fuel ethanol industry was introduced, progress of the cellulosic ethanol industry was reviewed, and development trend of the cellulosic ethanol industry is also discussed.

  13. 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.

  14. Ligno cellulosic-ethanol : a second opinion

    NARCIS (Netherlands)

    Zessen, van E.; Weismann, M.; Bakker, R.R.C.; Elbersen, H.W.; Reith, J.H.; Uil, den H.

    2003-01-01

    Up to now renewable energy sources are primarily used in the Netherlands for electricity production. At the end of the past decade the GAVE programme was launched to facilitate the introduction of climate neutral gaseous and liquid fuels. A comprehensive study by ADL evaluated a large number of opti

  15. Integration of Feedstock Assembly System and Cellulosic Ethanol Conversion Models to Analyze Bioenergy System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Jared M. Abodeely; Douglas S. McCorkle; Kenneth M. Bryden; David J. Muth; Daniel Wendt; Kevin Kenney

    2010-09-01

    Research barriers continue to exist in all phases of the emerging cellulosic ethanol biorefining industry. These barriers include the identification and development of a sustainable and abundant biomass feedstock, the assembly of viable assembly systems formatting the feedstock and moving it from the field (e.g., the forest) to the biorefinery, and improving conversion technologies. Each of these phases of cellulosic ethanol production are fundamentally connected, but computational tools used to support and inform analysis within each phase remain largely disparate. This paper discusses the integration of a feedstock assembly system modeling toolkit and an Aspen Plus® conversion process model. Many important biomass feedstock characteristics, such as composition, moisture, particle size and distribution, ash content, etc. are impacted and most effectively managed within the assembly system, but generally come at an economic cost. This integration of the assembly system and the conversion process modeling tools will facilitate a seamless investigation of the assembly system conversion process interface. Through the integrated framework, the user can design the assembly system for a particular biorefinery by specifying location, feedstock, equipment, and unit operation specifications. The assembly system modeling toolkit then provides economic valuation, and detailed biomass feedstock composition and formatting information. This data is seamlessly and dynamically used to run the Aspen Plus® conversion process model. The model can then be used to investigate the design of systems for cellulosic ethanol production from field to final product.

  16. Metabolic engineering of bacteria for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, L.O.; Gomez, P.F.; Lai, X.; Moniruzzaman, M.; Wood, B.E.; Yomano, L.P.; York, S.W. [Univ. of Florida, Gainesville, FL (United States). Dept. of Microbiology and Cell Science

    1998-04-20

    Technologies are available which will allow the conversion of lignocellulose into fuel ethanol using genetically engineered bacteria. Assembling these into a cost-effective process remains a challenge. The authors` work has focused primarily on the genetic engineering of enteric bacteria using a portable ethanol production pathway. Genes encoding Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase have been integrated into the chromosome of Escherichia coli B to produce strain KO11 for the fermentation of hemicellulose-derived syrups. This organism can efficiently ferment all hexose and pentose sugars present in the polymers of hemicellulose. Klebsiella oxytoca M5A1 has been genetically engineered in a similar manner to produce strain P2 for ethanol production from cellulose. This organism has the native ability to ferment cellobiose and cellotriose, eliminating the need for one class of cellulase enzymes. The optimal pH for cellulose fermentation with this organism is near that of fungal cellulases. The general approach for the genetic engineering of new biocatalysts has been most successful with enteric bacteria thus far. However, this approach may also prove useful with gram-positive bacteria which have other important traits for lignocellulose conversion. Many opportunities remain for further improvements in the biomass to ethanol processes.

  17. Bio Diesel Cellulosic Ethanol Research Project

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, Edward A. [County of Hendry, FL (United States); Capece, John C. [County of Hendry, FL (United States); McAvoy, Eugene [County of Hendry, FL (United States); Hodges, Alan Wayne [County of Hendry, FL (United States); Shukla, Sanjay [County of Hendry, FL (United States); Ozores-Hamilton, Monica [County of Hendry, FL (United States); Gilbert, Rob [County of Hendry, FL (United States); Wright, Alan [County of Hendry, FL (United States); Baucum, L. [County of Hendry, FL (United States)

    2017-02-07

    The objective of the project is to create the Hendry County Sustainable Biofuels Center and initiate its research, development, and education programs. The mission is to develop engineering and economic assessment methods to evaluate the natural resources impacts of biomass farming and fuel conversion systems; provide sustainability assessments of specific biofuels productions proposals; develop biomass farming and fuel conversion systems that are compatible with south Florida ecosystem restoration priorities; create ecosystem services opportunities and structures to diversify farm income; monitor the range of research and development activities necessary to the creation of sutstainable biofuels production systems in south Florida, identify gaps in the regional research, and assist in the development and coordination of additional projects to fill out the required knowledge base; prepare the workforce of southwest Florida for employment in biofuels related professions; and assist businesses & governmental design and realize sustainable biofuels projects.

  18. 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.

  19. 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.

    2011-01-01

    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. PMID:22482027

  20. 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.

  1. Production of cellulosic ethanol and enzyme from waste fiber sludge using SSF, recycling of hydrolytic enzymes and yeast, and recombinant cellulase-producing Aspergillus niger.

    Science.gov (United States)

    Cavka, Adnan; Alriksson, Björn; Rose, Shaunita H; van Zyl, Willem H; Jönsson, Leif J

    2014-08-01

    Bioethanol and enzymes were produced from fiber sludges through sequential microbial cultivations. After a first simultaneous saccharification and fermentation (SSF) with yeast, the bioethanol concentrations of sulfate and sulfite fiber sludges were 45.6 and 64.7 g/L, respectively. The second SSF, which included fresh fiber sludges and recycled yeast and enzymes from the first SSF, resulted in ethanol concentrations of 38.3 g/L for sulfate fiber sludge and 24.4 g/L for sulfite fiber sludge. Aspergillus niger carrying the endoglucanase-encoding Cel7B gene of Trichoderma reesei was grown in the spent fiber sludge hydrolysates. The cellulase activities obtained with spent hydrolysates of sulfate and sulfite fiber sludges were 2,700 and 2,900 nkat/mL, respectively. The high cellulase activities produced by using stillage and the significant ethanol concentrations produced in the second SSF suggest that onsite enzyme production and recycling of enzyme are realistic concepts that warrant further attention.

  2. A pilot plant scale reactor/separator for ethanol from cellulosics. ERIP/DOE quarterly report no. 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.; Moelhman, M.; Butters, R.

    1998-12-01

    The objective of this project is to develop and demonstrate a continuous, low energy process for the conversion of cellulosics to ethanol. This process involves a pretreatment step followed by enzymatic release of sugars and the consecutive simultaneous saccharification/fermentation (SSF) of cellulose (glucans) followed by hemi-cellulose (pentosans) in a multi-stage continuous stirred reactor separator (CSRS). During quarters 3 and 4, we have completed a literature survey on cellulase production, activated one strain of Trichoderma reesei. We continued developing our proprietary Steep Delignification (SD) process for biomass pretreatment. Some problems with fermentations were traces to bad cellulase enzyme. Using commercial cellulase enzymes from Solvay & Genecor, SSF experiments with wheat straw showed 41 g/L ethanol and free xylose of 20 g/L after completion of the fermentation. From corn stover, we noted 36 g/L ethanol production from the cellulose fraction of the biomass, and 4 g/L free xylose at the completion of the SSF. We also began some work with paper mill sludge as a cellulose source, and in some preliminary experiments obtained 23 g/L ethanol during SSF of the sludge. During year 2, a 130 L process scale unit will be operated to demonstrate the process using straw or cornstalks. Co-sponsors of this project include the Indiana Biomass Grants Program, Bio-Process Innovation.

  3. Marine Microorganisms: perspectives for getting involved in cellulosic ethanol.

    Science.gov (United States)

    Intriago, Pablo

    2012-08-29

    The production of ethanol has been considered as an alternative to replace part of the petroleum derivate. Brazil and the US are the leading producers, but more environmentally friendly alternatives are needed. Lignocellulose has an enormous potential but technology has to be still improve in order to economically produce ethanol. The present paper reviews the potential and problems of this technology and proposes the study of a group of microorganisms with the largest genetic pool, marine microorganism.

  4. Marine Microorganisms: perspectives for getting involved in cellulosic ethanol

    OpenAIRE

    Intriago, Pablo

    2012-01-01

    The production of ethanol has been considered as an alternative to replace part of the petroleum derivate. Brazil and the US are the leading producers, but more environmentally friendly alternatives are needed. Lignocellulose has an enormous potential but technology has to be still improve in order to economically produce ethanol. The present paper reviews the potential and problems of this technology and proposes the study of a group of microorganisms with the largest genetic pool, marine mi...

  5. Metabolic and process engineering of Clostridium cellulovorans for biofuel production from cellulose.

    Science.gov (United States)

    Yang, Xiaorui; Xu, Mengmeng; Yang, Shang-Tian

    2015-11-01

    Production of cellulosic biofuels has drawn increasing attention. However, currently no microorganism can produce biofuels, particularly butanol, directly from cellulosic biomass efficiently. Here we engineered a cellulolytic bacterium, Clostridium cellulovorans, for n-butanol and ethanol production directly from cellulose by introducing an aldehyde/alcohol dehydrogenase (adhE2), which converts butyryl-CoA to n-butanol and acetyl-CoA to ethanol. The engineered strain was able to produce 1.42 g/L n-butanol and 1.60 g/L ethanol directly from cellulose. Moreover, the addition of methyl viologen as an artificial electron carrier shifted the metabolic flux from acid production to alcohol production, resulting in a high biofuel yield of 0.39 g/g from cellulose, comparable to ethanol yield from corn dextrose by yeast fermentation. This study is the first metabolic engineering of C. cellulovorans for n-butanol and ethanol production directly from cellulose with significant titers and yields, providing a promising consolidated bioprocessing (CBP) platform for biofuel production from cellulosic biomass.

  6. Catalytic conversion of sugarcane bagasse to cellulosic ethanol: TiO2 coupled nanocellulose as an effective hydrolysis enhancer.

    Science.gov (United States)

    Jabasingh, S Anuradha; Lalith, D; Prabhu, M Arun; Yimam, Abubekker; Zewdu, Taye

    2016-01-20

    The present study deals with the production of cellulosic ethanol from bagasse using the synthesized TiO2 coupled nanocellulose (NC-TiO2) as catalyst. Aspergillus nidulans AJSU04 cellulase was used for the hydrolysis of bagasse. NC-TiO2 at various concentrations was added to bagasse in order to enhance the yield of reducing sugars. Complex interaction between cellulase, bagasse, NC-TiO2 and the reaction environment is thoroughly studied. A mathematical model was developed to describe the hydrolysis reaction. Ethanol production from enzymatically hydrolyzed sugarcane bagasse catalyzed with NC-TiO2 was carried out using Saccharomyces cerevisiae ATCC 20602. The glucose release rates and ethanol concentrations were determined. Ethanol produced was found to be strongly dependent on pretreatment given, hydrolysis and fermentation conditions. The study confirmed the promising accessibility of NC-TiO2, for enhanced glucose production rates and improved ethanol yield.

  7. 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.

  8. Fuel ethanol production from alkaline peroxide pretreated corn stover

    Science.gov (United States)

    Corn stover (CS) has the potential to serve as an abundant low-cost feedstock for production of fuel ethanol. Due to heterogeneous complexity and recalcitrance of lignocellulosic feedstocks, pretreatment is required to break the lignin seal and/or disrupt the structure of crystalline cellulose to in...

  9. Comparing the fermentation performance of Escherichia coli KO11, Saccharomyces cerevisiae 424A(LNH-ST and Zymomonas mobilis AX101 for cellulosic ethanol production

    Directory of Open Access Journals (Sweden)

    Dale Bruce E

    2010-05-01

    Full Text Available Abstract Background Fermentations using Escherichia coli KO11, Saccharomyces cerevisiae 424A(LNH-ST, and Zymomonas mobilis AX101 are compared side-by-side on corn steep liquor (CSL media and the water extract and enzymatic hydrolysate from ammonia fiber expansion (AFEX-pretreated corn stover. Results The three ethanologens are able produce ethanol from a CSL-supplemented co-fermentation at a metabolic yield, final concentration and rate greater than 0.42 g/g consumed sugars, 40 g/L and 0.7 g/L/h (0-48 h, respectively. Xylose-only fermentation of the tested ethanologenic bacteria are five to eight times faster than 424A(LNH-ST in the CSL fermentation. All tested strains grow and co-ferment sugars at 15% w/v solids loading equivalent of ammonia fiber explosion (AFEX-pretreated corn stover water extract. However, both KO11 and 424A(LNH-ST exhibit higher growth robustness than AX101. In 18% w/w solids loading lignocellulosic hydrolysate from AFEX pretreatment, complete glucose fermentations can be achieved at a rate greater than 0.77 g/L/h. In contrast to results from fermentation in CSL, S. cerevisiae 424A(LNH-ST consumed xylose at the greatest extent and rate in the hydrolysate compared to the bacteria tested. Conclusions Our results confirm that glucose fermentations among the tested strains are effective even at high solids loading (18% by weight. However, xylose consumption in the lignocellulosic hydrolysate is the major bottleneck affecting overall yield, titer or rate of the process. In comparison, Saccharomyces cerevisiae 424A(LNH-ST is the most relevant strains for industrial production for its ability to ferment both glucose and xylose from undetoxified and unsupplemented hydrolysate from AFEX-pretreated corn stover at high yield.

  10. Product inhibition of enzymatic hydrolysis of cellulose: are we running the reactions all wrong?

    DEFF Research Database (Denmark)

    Meyer, Anne S.

    2012-01-01

    Enzyme catalyzed deconstruction of cellulose to glucose is an important technology step in lignocellulose-to-ethanol processing as well as in the future biorefinery based production of novel products to replace fossil oil based chemistry. The main goals of the enzymatic biomass saccharification i....... Based on cellulose inhibition kinetics the talk will illustrate the suitability of membrane reactor technology for improving cellulose substrate conversion efficiency....... include high substrate conversion (maximal yields), maximal enzyme efficiency, maximal volumetric reactor productivity, minimal equipment investment, minimal size, and short reaction time. The classic batch type STR reactions used for enzymatic cellulose hydrolysis prevent these goals to be fulfilled...

  11. Enteric bacterial catalysts for fuel ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, L.O.; Aldrich, H.C.; Borges, A.C.C. [and others

    1999-10-01

    The technology is available to produce fuel ethanol from renewable lignocellulosic biomass. The current challenge is to assemble the various process options into a commercial venture and begin the task of incremental improvement. Current process designs for lignocellulose are far more complex than grain to ethanol processes. This complexity results in part from the complexity of the substrate and the biological limitations of the catalyst. Their work at the University of Florida has focused primarily on the genetic engineering of Enteric bacteria using genes encoding Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase. These two genes have been assembled into a portable ethanol production cassette, the PET operon, and integrated into the chromosome of Escherichia coli B for use with hemicellulose-derived syrups. The resulting strain, KO11, produces ethanol efficiently from all hexose and pentose sugars present in the polymers of hemicellulose. By using the same approach, the authors integrated the PET operon into the chromosome of Klebsiella oxytoca to produce strain P2 for use in the simultaneous saccharification and fermentation (SSF) process for cellulose. Strain P2 has the native ability to ferment cellobiose and cellotriose, eliminating the need for one class of cellulase enzymes.

  12. 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

  13. 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)

  14. Effect of ethanol on the water permeability of controlled release films composed of ethyl cellulose and hydroxypropyl cellulose.

    Science.gov (United States)

    Larsson, Mikael; Hjärtstam, Johan; Berndtsson, Jolina; Stading, Mats; Larsson, Anette

    2010-11-01

    The robustness of controlled release formulations when co-ingested with alcohol is a current concern expressed by regulatory authorities, especially with regard to dose dumping. One such controlled release formulation commonly used is film coating composed of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC). The aim of this study was to investigate how the presence of ethanol in the dissolution medium affects the water permeability of such films. Film samples were prepared in various EC-HPC compositions, and the effect of different ethanol concentrations in the dissolution medium on the permeability was studied using a modified Ussing chamber and tritiated water. It was found that the effect of ethanol on the film permeability varied depending on the composition of the films. The results were interpreted in terms of swelling of the EC in the films, where the swelling increased with increasing ethanol concentration. Thus, for films with low HPC content (non-interconnected pores), the water permeability of the films increased with increasing ethanol concentration as the diffusion through the ethyl cellulose increased due to swelling. However, for films with higher HPC content (having interconnected pores through the films), the permeability decreased, likely due to the swelling of the ethyl cellulose blocking the pores. The interpretation of the results was supported by dynamic mechanic analysis and SEM analysis.

  15. Cellulose Fuel Ethanol Research Development%纤维素燃料乙醇研究进展

    Institute of Scientific and Technical Information of China (English)

    李煜; 李慧

    2013-01-01

    Fuel ethanol from lignocellulosic biomass attracted increasing attention in the field of renewable bioenergy research. Cellulose fuel ethanol production technology and the industry development are reviewed. The key technical issues in cellulose fuel ethanol industry process are analyzed, and suggestions are proposed.%  纤维素燃料乙醇是当今世界可再生生物质能源研究的热点。文章综述了纤维素燃料乙醇生产技术以及纤维素燃料乙醇产业的发展概况。分析了纤维素燃料乙醇产业化过程中出现的关键技术问题,并提出了相应建议。

  16. Cellulosic ethanol fermentation using Saccharomyces cerevisiae seeds cultured by pretreated corn stover material.

    Science.gov (United States)

    Qureshi, Abdul Sattar; Zhang, Jian; Bao, Jie

    2015-03-01

    Utilization of lignocellulose materials to replace the pure glucose for preparation of the fermenting yeast seeds could reduce the cost of ethanol fermentation, because a large quantity of glucose is saved in the large-scale seed fermentor series. In this study, Saccharomyces cerevisiae DQ1 was cultured using the freshly pretreated corn stover material as the carbon source, and then the culture broth was used as the inoculation seeds after a series of seed transfer and inoculated into the ethanol production fermentor. The results show that the yeast cell growth and ethanol fermentation performance have essentially no difference when the yeast seeds were cultured by glucose, the corn stover hydrolysate liquid, and the pretreated corn stover solids as carbon sources, respectively. Approximately 22% of the yeast cell culture cost was saved, and the process flow sheet in industrial scale plants was simplified by using the pretreated corn stover for seed culture. The results provided a practical method for materials and operational cost reduction for cellulosic ethanol production.

  17. Anaerobic digestion as final step of a cellulosic ethanol biorefinery:

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Ahring, Birgitte Kiær

    2010-01-01

    In order to lower the costs for second generation bioethanol from lignocellulosic biomass anaerobic digestion of the effluent from ethanol fermentation was implemented using an upflow anaerobic sludge blanket (UASB) reactor system in a pilot-scale biorefinery plant. Both thermophilic (538C...... were, however, higher under mesophilic conditions compared to thermophilic conditions. The conversion of dissolved organic matter (VSdiss) was between 68% and 91%. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. However, a high content...... of suspended matter reduced the degradation efficiency. The retention time of the anaerobic system could be reduced from 70 to 7 h by additional removal of suspended matter by clarification. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher carbon utilization...

  18. Cellulosic fuel ethanol: alternative fermentation process designs with wild-type and recombinant Zymomonas mobilis.

    Science.gov (United States)

    Lawford, Hugh G; Rousseau, Joyce D

    2003-01-01

    Iogen (Canada) is a major manufacturer of industrial cellulase and hemicellulase enzymes for the textile, pulp and paper, and poultry feed industries. Iogen has recently constructed a 40 t/d biomass-to-ethanol demonstration plant adjacent to its enzyme production facility. The integration of enzyme and ethanol plants results in significant reduction in production costs and offers an alternative use for the sugars generated during biomass conversion. Iogen has partnered with the University of Toronto to test the fermentation performance characteristics of metabolically engineered Zymomonas mobilis created at the National Renewable Energy Laboratory. This study focused on strain AX101, a xylose- and arabinose-fermenting stable genomic integrant that lacks the selection marker gene for antibiotic resistance. The "Iogen Process" for biomass depolymerization consists of a dilute-sulpfuric acid-catalyzed steam explosion, followed by enzymatic hydrolysis. This work examined two process design options for fermentation, first, continuous cofermentation of C5 and C6 sugars by Zm AX101, and second, separate continuous fermentations of prehydrolysate by Zm AX101 and cellulose hydrolysate by either wildtype Z. mobilis ZM4 or an industrial yeast commonly used in the production of fuel ethanol from corn. Iogen uses a proprietary process for conditioning the prehydrolysate to reduce the level of inhibitory acetic acid to at least 2.5 g/L. The pH was controlled at 5.5 and 5.0 for Zymomonas and yeast fermentations, respectively. Neither 2.5 g/L of acetic acid nor the presence of pentose sugars (C6:C5 = 2:1) appreciably affected the high-performance glucose fermentation of wild-type Z. mobilis ZM4. By contrast, 2.5 g/L of acetic acid significantly reduced the rate of pentose fermentation by strain AX101. For single-stage continuous fermentation of pure sugar synthetic cellulose hydrolysate (60 g/L of glucose), wild-type Zymomonas exhibited a four-fold higher volumetric productivity

  19. Metabolic engineering for improved production of ethanol by Corynebacterium glutamicum.

    Science.gov (United States)

    Jojima, Toru; Noburyu, Ryoji; Sasaki, Miho; Tajima, Takahisa; Suda, Masako; Yukawa, Hideaki; Inui, Masayuki

    2015-02-01

    Recombinant Corynebacterium glutamicum harboring genes for pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adhB) can produce ethanol under oxygen deprivation. We investigated the effects of elevating the expression levels of glycolytic genes, as well as pdc and adhB, on ethanol production. Overexpression of four glycolytic genes (pgi, pfkA, gapA, and pyk) in C. glutamicum significantly increased the rate of ethanol production. Overexpression of tpi, encoding triosephosphate isomerase, further enhanced productivity. Elevated expression of pdc and adhB increased ethanol yield, but not the rate of production. Fed-batch fermentation using an optimized strain resulted in ethanol production of 119 g/L from 245 g/L glucose with a yield of 95% of the theoretical maximum. Further metabolic engineering, including integration of the genes for xylose and arabinose metabolism, enabled consumption of glucose, xylose, and arabinose, and ethanol production (83 g/L) at a yield of 90 %. This study demonstrated that C. glutamicum has significant potential for the production of cellulosic ethanol.

  20. Cellulosic Ethanol: Securing the Planet Future Energy Needs

    Directory of Open Access Journals (Sweden)

    Hannah Uckelmann

    2008-05-01

    Full Text Available Bioenergy is fairly recognized as not only a necessity, but an inevitable path to secure the planet future energy needs. There is however a global consensus that the overall feasibility of bioenergy will require an integrated approach based on diversified feedstocks and conversion processes. As illustrated in the Brazilian experience, the thrust of any bioenergy program should be centered on the principles and criteria of sustainable production. In general the trends are towards exploiting low value cellulosic materials to obtain high-end value energy products. To this end, it is expected that scientific or technical innovation will come to play a critical role on the future prospects and potential of any bioenergy initiative.

  1. Analysis of a Modern Hybrid and an Ancient Sugarcane Implicates a Complex Interplay of Factors in Affecting Recalcitrance to Cellulosic Ethanol Production.

    Directory of Open Access Journals (Sweden)

    Viviane Guzzo de Carli Poelking

    Full Text Available Abundant evidence exists to support a role for lignin as an important element in biomass recalcitrance. However, several independent studies have also shown that factors apart from lignin are also relevant and overall, the relative importance of different recalcitrance traits remains in dispute. In this study we used two genetically distant sugarcane genotypes, and performed a correlational study with the variation in anatomical parameters, cell wall composition, and recalcitrance factors between these genotypes. In addition we also tracked alterations in these characteristics in internodes at different stages of development. Significant differences in the development of the culm between the genotypes were associated with clear differential distributions of lignin content and composition that were not correlated with saccharification and fermentation yield. Given the strong influence of the environment on lignin content and composition, we hypothesized that sampling within a single plant could allow us to more easily interpret recalcitrance and changes in lignin biosynthesis than analysing variations between different genotypes with extensive changes in plant morphology and culm anatomy. The syringyl/guaiacyl (S/G ratio was higher in the oldest internode of the modern genotype, but S/G ratio was not correlated with enzymatic hydrolysis yield nor fermentation efficiency. Curiously we observed a strong positive correlation between ferulate ester level and cellulose conversion efficiency. Together, these data support the hypothesis that biomass enzymatic hydrolysis recalcitrance is governed by a quantitative heritage rather than a single trait.

  2. 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

  3. Microbial Investigation on Assimilation and Ethanol Fermentation of Levoglucosan from Cellulosic Pyrolysis Products%纤维素热解产物内醚糖的微生物同化与乙醇发酵测试

    Institute of Scientific and Technical Information of China (English)

    余志晟; 宁洎英; 张玲; 张洪勋

    2011-01-01

    以纤维素的热解产物1,6-缩水-β-D-吡喃葡萄糖(Levoglucosan,简称内醚糖)为唯一碳源对89株微生物(大部分为产酒菌株)进行了同化和乙醇发酵测试,并对319份土样进行了分离纯化培养.筛选结果表明,在89株微生物中,一株Sporobolomyces酵母、一株Rhodotonda酵母、4株Rhizopus霉菌、2株Monascus霉菌有同化内醚糖的能力,但它们利用内醚糖的能力都较弱,在培养3天后,2%内醚糖的利用率低于30%;在319份土样中,发现77份土样有微生物生长,并从中分离到70株酵母和10株细菌.通过内醚糖同化比较测试,发现Y215号菌的同化能力最强,在培养3天后,2%内醚糖的利用率达到了64.12%,经鉴定为斯达油脂酵母(Lipomyces starkeyi).然而,在所有测试和分离的微生物中,没有发现既能同化又能发酵内醚糖为乙醇的菌株.本研究为通过遗传工程方法构建发酵内醚糖为乙醇的工程菌株提供了较好的菌种资源.%The levoglucosan-assimilating and ethanol-producing microorganisms were screened using 1,6-anhydro-β-D-glucopyranose (levoglucosan) of cellulosic pyrolysis products as a sole carbon source from 89 strains of microorganisms (mostly producing ethanol) and 319 soil samples, respectively. 2 strains of yeasts (Sporobolomyces 1 and Rhodotorula 1) and 6 strains of moulds (Rhizopus 4 and Monascus 2) had weak levoglucosan-assimilating ability in 89 strains of microorganisms. 70 strains of yeasts and 10 strains of bacteria were isolated from the 319 soil samples. In all isolated microorganisms, the strain of No. Y215 showed the strongest levoglucosan-asaimilating ability. After it was cultured for three days, the utilization rate of 2% levoglucosan was up to 64.12%. This strain was classified as Lipomyces starkeyi according to a taxonomic identification. Among all tested microorganisms, no microorganisms could ferment levoglucosan to ethanol. The results gave microbial strains for constructing

  4. 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

  5. Rapid saccharification for production of cellulosic biofuels.

    Science.gov (United States)

    Lee, Dae-Seok; Wi, Seung Gon; Lee, Soo Jung; Lee, Yoon-Gyo; Kim, Yeong-Suk; Bae, Hyeun-Jong

    2014-04-01

    The economical production of biofuels is hindered by the recalcitrance of lignocellulose to processing, causing high consumption of processing enzymes and impeding hydrolysis of pretreated lignocellulosic biomass. We determined the major rate-limiting factor in the hydrolysis of popping pre-treated rice straw (PPRS) by examining cellulase adsorption to lignin and cellulose, amorphogenesis of PPRS, and re-hydrolysis. Based on the results, equivalence between enzyme loading and the open structural area of cellulose was required to significantly increase productive adsorption of cellulase and to accelerate enzymatic saccharification of PPRS. Amorphogenesis of PPRS by phosphoric acid treatment to expand open structural area of the cellulose fibers resulted in twofold higher cellulase adsorption and increased the yield of the first re-hydrolysis step from 13% to 46%. The total yield from PPRS was increased to 84% after 3h. These results provide evidence that cellulose structure is one of major effects on the enzymatic hydrolysis.

  6. A framework for model-based optimization of bioprocesses under uncertainty: Lignocellulosic ethanol production case

    DEFF Research Database (Denmark)

    Morales Rodriguez, Ricardo; Meyer, Anne S.; Gernaey, Krist;

    2012-01-01

    metrics via uncertainty analysis. Finally, stochastic programming is applied to drive the process development efforts forward subject to these uncertainties. The framework is evaluated on four different process configurations for cellulosic ethanol production including Simultaneous Saccharification and Co......, the framework evaluated here for uncertainties in the technical domain, can also be used to evaluate the impact of market uncertainties (feedstock prices, selling price of ethanol, etc) and political uncertainties (such as subsidies) on the economic feasibility of lignocellulosic ethanol production....

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

    DEFF Research Database (Denmark)

    Qiang, zhang; Thomsen, Anne Belinda

    2012-01-01

    In order to find out appropriate process for ethanol production from corn stover, wet oxidation (195°C, 15 minutes) and simultaneous saccharification and fermentation (SSF) was carried out to produce ethanol. The results showed that the cellulose recovery of 92.9% and the hemicellulose recovery...

  8. FRACTIONATION OF LIGNOCELLULOSIC BIOMASS FOR FUEL-GRADE ETHANOL PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    F.D. Guffey; R.C. Wingerson

    2002-10-01

    PureVision Technology, Inc. (PureVision) of Fort Lupton, Colorado is developing a process for the conversion of lignocellulosic biomass into fuel-grade ethanol and specialty chemicals in order to enhance national energy security, rural economies, and environmental quality. Lignocellulosic-containing plants are those types of biomass that include wood, agricultural residues, and paper wastes. Lignocellulose is composed of the biopolymers cellulose, hemicellulose, and lignin. Cellulose, a polymer of glucose, is the component in lignocellulose that has potential for the production of fuel-grade ethanol by direct fermentation of the glucose. However, enzymatic hydrolysis of lignocellulose and raw cellulose into glucose is hindered by the presence of lignin. The cellulase enzyme, which hydrolyzes cellulose to glucose, becomes irreversibly bound to lignin. This requires using the enzyme in reagent quantities rather than in catalytic concentration. The extensive use of this enzyme is expensive and adversely affects the economics of ethanol production. PureVision has approached this problem by developing a biomass fractionator to pretreat the lignocellulose to yield a highly pure cellulose fraction. The biomass fractionator is based on sequentially treating the biomass with hot water, hot alkaline solutions, and polishing the cellulose fraction with a wet alkaline oxidation step. In September 2001 PureVision and Western Research Institute (WRI) initiated a jointly sponsored research project with the U.S. Department of Energy (DOE) to evaluate their pretreatment technology, develop an understanding of the chemistry, and provide the data required to design and fabricate a one- to two-ton/day pilot-scale unit. The efforts during the first year of this program completed the design, fabrication, and shakedown of a bench-scale reactor system and evaluated the fractionation of corn stover. The results from the evaluation of corn stover have shown that water hydrolysis prior to

  9. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  10. Cellulosic ethanol from municipal solid waste: a case study of the economic, energy, and greenhouse gas impacts in California.

    Science.gov (United States)

    Chester, Mikhail; Martin, Elliot

    2009-07-15

    As cellulosic ethanol technologies advance, states could use the organic content of municipal solid waste as a transportation fuel feedstock and simultaneously reduce externalities associated with waste disposal. We examine the major processes required to support a lignocellulosic (employing enzymatic hydrolysis) municipal solid waste-to-ethanol infrastructure computing cost, energy, and greenhouse gas effects for California. The infrastructure is compared against the Business As Usual case where the state continues to import most of its ethanol needs from the Midwest. Assuming between 60% and 90% practical yields for ethanol production, California could produce between 1.0 and 1.5 billion gallons per year of ethanol from 55% of the 40 million metric tonnes of waste currently sent to landfills annually. The classification of organic wastes and ethanol plant operation represent almost the entire system cost (between $3.5 and $4.5 billion annually) while distribution has negligible cost effects and savings from avoided landfilling is small. Fossil energy consumption from Business As Usual decreases between 82 and 130 PJ largely due to foregone gasoline consumption. The net greenhouse gas impacts are ultimately dependent on how well landfills control their emissions of decomposing organics. Based on the current landfill mix in the state, the cellulosic infrastructure would experience a slight gain in greenhouse gas emissions. However, net emissions can rise if organics diversion releases carbon that would otherwise be flared and sequestered. Emissions would be avoided if landfills are not capable of effectively controlling emissions during periods of active waste decay. There is currently considerable uncertainty surrounding the recovery efficiency of landfill emissions controls. In either case, burying lignin appears to be better than burning lignin because of its decay properties, energy and carbon content We estimate the breakeven price for lignocellulosic ethanol

  11. Simultaneous cellulose conversion and hydrogen production assisted by cellulose decomposition under UV-light photocatalysis.

    Science.gov (United States)

    Zhang, Guan; Ni, Chengsheng; Huang, Xiubing; Welgamage, Aakash; Lawton, Linda A; Robertson, Peter K J; Irvine, John T S

    2016-01-28

    Photocatalytic conversion of cellulose to sugars and carbon dioxide with simultaneous production of hydrogen assisted by cellulose decomposition under UV or solar light irradiation was achieved upon immobilization of cellulose onto a TiO2 photocatalyst. This approach enables production of hydrogen from water without using valuable sacrificial agents, and provides the possibility for recovering sugars as liquid fuels.

  12. Ethanol Demand in United States Gasoline Production

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    1998-11-24

    The Oak Ridge National Laboratory (OWL) Refinery Yield Model (RYM) has been used to estimate the demand for ethanol in U.S. gasoline production in year 2010. Study cases examine ethanol demand with variations in world oil price, cost of competing oxygenate, ethanol value, and gasoline specifications. For combined-regions outside California summer ethanol demand is dominated by conventional gasoline (CG) because the premised share of reformulated gasoline (RFG) production is relatively low and because CG offers greater flexibility for blending high vapor pressure components like ethanol. Vapor pressure advantages disappear for winter CG, but total ethanol used in winter RFG remains low because of the low RFG production share. In California, relatively less ethanol is used in CG because the RFG production share is very high. During the winter in California, there is a significant increase in use of ethanol in RFG, as ethanol displaces lower-vapor-pressure ethers. Estimated U.S. ethanol demand is a function of the refiner value of ethanol. For example, ethanol demand for reference conditions in year 2010 is 2 billion gallons per year (BGY) at a refiner value of $1.00 per gallon (1996 dollars), and 9 BGY at a refiner value of $0.60 per gallon. Ethanol demand could be increased with higher oil prices, or by changes in gasoline specifications for oxygen content, sulfur content, emissions of volatile organic compounds (VOCS), and octane numbers.

  13. Hydrothermal pretreatment conditions to enhance ethanol production from poplar biomass.

    Science.gov (United States)

    Negro, Maria José; Manzanares, Paloma; Ballesteros, Ignacio; Oliva, Jose Miguel; Cabañas, Araceli; Ballesteros, Mercedes

    2003-01-01

    Pretreatment has been recognized as a key step in enzyme-based conversion processes of lignocellulose biomass to ethanol. The aim of this study is to evaluate two hydrothermal pretreatments (steam explosion and liquid hot water) to enhance ethanol production from poplar (Populus nigra) biomass by a simultaneous saccharification and fermentation (SSF) process. The composition of liquid and solid fractions obtained after pretreatment, enzymatic digestibility, and ethanol production of poplar biomass pretreated at different experimental conditions was analyzed. The best results were obtained in steam explosion pretreatment at 210 C and 4 min, taking into account cellulose recovery above 95%, enzymatic hydrolysis yield of about 60%, SSF yield of 60% of theoretical, and 41% xylose recovery in the liquid fraction. Large particles can be used for poplar biomass in both pretreatments, since no significant effect of particle size on enzymatic hydrolysis and SSF was obtained.

  14. 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

    In order to find out the appropriate process for ethanol production from corn straw, alkaline wet-oxidation pretreatment (195°C, 15 min, Na2CO3 2 g/L, O2 1200 kPa) and simultaneous saccharification and fermentation (SSF) were adopted to produce ethanol. The results showed that 90% of cellulose...... was obtained. The estimated total ethanol production was 262.7 kg/t raw material by assuming the consumption of both C-6 and C-5. No obvious inhibition effect occurred during SSF. These offered experiment evidences for ethanol production from corn straw....

  15. Maleic acid treatment of bioabated corn stover liquors improves cellulose conversion to ethanol

    Science.gov (United States)

    Elimination of inhibitory compounds released during pretreatment of lignocellulose is critical for efficient cellulose conversion and ethanol fermentation. This study examined the effect of bioabated liquor from pretreated corn stover on enzyme hydrolysis of Solka Floc or pretreated corn stover soli...

  16. Microcrystalline Cellulose from Plant Wastes through Sodium Hydroxide-Anthraquinone-Ethanol Pulping

    Directory of Open Access Journals (Sweden)

    Olugbenga Oludayo Oluwasina

    2014-08-01

    Full Text Available Microcrystalline cellulose was prepared from wastes of Tithonia diversifolia, inflorescence stems of Musa sapientum, and Musa paradisiaca by soda-anthraquinone–ethanol pulping method. They were bleached by sodium chlorite and then alpha-cellulose was isolated, followed by preparation of microcrystalline cellulose. The study revealed the effect of various processing stages on the properties of the cellulose obtained. Yields of more than 80% of microcrystalline cellulose were obtained. Fourier transform infrared (FTIR and solid state 13C Nuclear magnetic resonance (13C NMR confirmed the presence of the major expected peaks in microcrystalline cellulose. Scanning electron microscopy (SEM revealed that Musa species had short fiber length and mixtures of non-aggregated spherical, rod-shaped and thread like microcrystalline cellulose, but Tithonia diversifolia had aggregate crystal packed formation. The results compared well with those of other authors and were able to meet most of the requirements specified in British Pharmacopoeia. The study revealed that a drug excipient like microcrystalline cellulose that could protect thermo-labile active ingredients could be successfully obtained from abundant non-woody agricultural wastes.

  17. Application in the Ethanol Fermentation of Immobilized Yeast Cells in Matrix of Alginate/Magnetic Nanoparticles, on Chitosan-Magnetite Microparticles and Cellulose-coated Magnetic Nanoparticles

    CERN Document Server

    Ivanova, Viara; Hristov, Jordan

    2011-01-01

    Saccharomyces cerevisiae cells were entrapped in matrix of alginate and magnetic nanoparticles and covalently immobilized on magnetite-containing chitosan and cellulose-coated magnetic nanoparticles. Cellulose-coated magnetic nanoparticles with covalently immobilized thermostable {\\alpha}-amylase and chitosan particles with immobilized glucoamylase were also prepared. The immobilized cells and enzymes were applied in column reactors - 1/for simultaneous corn starch saccharification with the immobilized glucoamylase and production of ethanol with the entrapped or covalently immobilized yeast cells, 2/ for separate ethanol fermentation of the starch hydrolysates with the fixed yeasts. Hydrolysis of corn starch with the immobilized {\\alpha}-amylase and glucoamylase, and separate hydrolysis with the immobilized {\\alpha}-amylase were also examined. In the first reactor the ethanol yield reached approx. 91% of the theoretical; the yield was approx. 86% in the second. The ethanol fermentation was affected by the typ...

  18. PRODUCTION AND CHARACTERIZATION OF ECONOMICAL BACTERIAL CELLULOSE

    Directory of Open Access Journals (Sweden)

    Houssni El-Saied

    2008-11-01

    Full Text Available The present study investigates the economical production of bacterial cellulose (BC by Gluconacetobacter subsp. Xylinus (ATCC 10245 in 250 ml Erlenmeyer flasks cultivated under static conditions. The fermentation media used contained food industrial by-product liquors, such as black strap molasses solution and corn steep liquor (CSL, which represents some of the most economical carbon and nitrogen sources. However, because of the presence of undesirable components in molasses (such as coloring substances, heavy metals, and other compounds that may act as inhibitors, and in order to eliminate them, crude molasses has been treated with an acid, as an attempt to increase BC productivity. The amount of BC produced using these carbon and nitrogen sources was determined and compared to that produced using previously reported fermentation media. The characterizations of the bacterial cellulose (BC pellicles obtained using either conventional or by-product media were studied by thermal and spectral techniques and compared to those of plant-derived cellulose such as cotton linter, viscose pulp, and microcrystalline cellulose.

  19. Understanding the Growth of the Cellulosic Ethanol Industry

    Energy Technology Data Exchange (ETDEWEB)

    Sandor, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wallace, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Peterson, S. [Peterson Group, Anchorage, AK (United States)

    2008-04-01

    Report identifies and documents plausible scenarios for producing significant quantities of lignocellulosic ethanol in 2017 as a guide for setting government policy and targeting government investment to areas with greatest potential impact.

  20. Understanding the Growth of the Cellulosic Ethanol Industry

    Energy Technology Data Exchange (ETDEWEB)

    Sandor, D.; Wallace, R.; Peterson, S.

    2008-04-01

    This report identifies, outlines, and documents a set of plausible scenarios for producing significant quantities of lignocellulosic ethanol in 2017. These scenarios can provide guidance for setting government policy and targeting government investment to the areas with greatest potential impact.

  1. Feasibility of ethanol production from coffee husks.

    Science.gov (United States)

    Gouvea, B M; Torres, C; Franca, A S; Oliveira, L S; Oliveira, E S

    2009-09-01

    The objective of this work was to evaluate the feasibility of ethanol production by fermentation of coffee husks by Saccharomyces cerevisiae. Batch fermentation studies were performed employing whole and ground coffee husks, and aqueous extract from ground coffee husks. It was observed that fermentation yield decreased with an increase in yeast concentration. The best results were obtained for the following conditions: whole coffee husks, 3 g yeast/l substrate, temperature of 30 degrees C. Under these conditions ethanol production was 8.49 +/- 0.29 g/100 g dry basis (13.6 +/- 0.5 g ethanol/l), a satisfactory value in comparison to literature data for other residues such as corn stalks, barley straw and hydrolyzed wheat stillage (5-11 g ethanol/l). Such results indicate that coffee husks present excellent potential for residue-based ethanol production.

  2. Lignocellulosic ethanol production at high-gravity: challenges and perspectives.

    Science.gov (United States)

    Koppram, Rakesh; Tomás-Pejó, Elia; Xiros, Charilaos; Olsson, Lisbeth

    2014-01-01

    In brewing and ethanol-based biofuel industries, high-gravity fermentation produces 10-15% (v/v) ethanol, resulting in improved overall productivity, reduced capital cost, and reduced energy input compared to processing at normal gravity. High-gravity technology ensures a successful implementation of cellulose to ethanol conversion as a cost-competitive process. Implementation of such technologies is possible if all process steps can be performed at high biomass concentrations. This review focuses on challenges and technological efforts in processing at high-gravity conditions and how these conditions influence the physiology and metabolism of fermenting microorganisms, the action of enzymes, and other process-related factors. Lignocellulosic materials add challenges compared to implemented processes due to high inhibitors content and the physical properties of these materials at high gravity.

  3. 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...... 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...

  4. Ethanol production from bread residues

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, Fatemeh; Roodpeyma, Shapoor [Chemical Engineering Department, Isfahan University of Technology, Isfahan (Iran); Khanahmadi, Morteza [Agricultural Engineering Research Department, Isfahan Center for the Research of Agricultural Science and Natural Resources, Isfahan (Iran); Taherzadeh, Mohammad J. [School of Engineering, University of Boraas, SE-50190 Boraas (Sweden)

    2008-04-15

    Bread residues were converted into a suitable fermentation feed via a two-step starch hydrolysis using amylolytic enzymes. Wheat flour hydrolysis was also carried out at the same conditions for comparison. For the first stage, namely liquefaction, effects of temperature (50-85{sup o}C) and substrate concentration (20% and 35%) were investigated. The 3-h liquefaction of the 20% bread suspension made 70% of initial dry matter soluble regardless of the temperature. The liquefaction of the 35% bread suspension had to be carried out by a fed-batch method due to the pasty behavior of the suspension. It resulted in a 65% dissolution of the suspended bread at 85{sup o}C. Saccharification of the latter product led to a fermentation feedstock having a dextrose equivalent (DE) of more than 95 and almost 80% dissolution of the initial dry matter. The prepared feedstock was then cultivated using Saccharomyces cerevisiae, which resulted in an overall yield of 350 g ethanol per kg of initial bread dry matter. Staling of the bread for a week had no effect on liquefaction, saccharification and ethanol yield. (author)

  5. 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

  6. 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.

  7. Ethanol production from steam-explosion pretreated wheat straw.

    Science.gov (United States)

    Ballesteros, Ignacio; Negro, Ma José; Oliva, José Miguel; Cabañas, Araceli; Manzanares, Paloma; Ballesteros, Mercedes

    2006-01-01

    Bioconversion of cereal straw to bioethanol is becoming an attractive alternative to conventional fuel ethanol production from grains. In this work, the best operational conditions for steam-explosion pretreatment of wheat straw for ethanol production by a simultaneous saccharification and fermentation process were studied, using diluted acid [H2SO4 0.9% (w/w)] and water as preimpregnation agents. Acid- or water-impregnated biomass was steam-exploded at different temperatures (160-200 degrees C) and residence times (5, 10, and 20 min). Composition of solid and filtrate obtained after pretreatment, enzymatic digestibility and ethanol production of pretreated wheat straw at different experimental conditions was analyzed. The best pretreatment conditions to obtain high conversion yield to ethanol (approx 80% of theoretical) of cellulose-rich residue after steam-explosion were 190 degrees C and 10 min or 200 degrees C and 5 min, in acid-impregnated straw. However, 180 degrees C for 10 min in acid-impregnated biomass provided the highest ethanol yield referred to raw material (140 L/t wheat straw), and sugars recovery yield in the filtrate (300 g/kg wheat straw).

  8. 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.

  9. 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.

  10. 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).

  11. The new gold rush: fueling ethanol production while protecting water quality.

    Science.gov (United States)

    Simpson, Thomas W; Sharpley, Andrew N; Howarth, Robert W; Paerl, Hans W; Mankin, Kyle R

    2008-01-01

    Renewable fuel production, particularly grain-based ethanol, is expanding rapidly in the USA. Although subsidized grain-based ethanol may provide a competitively priced transportation fuel, concerns exist about potential environmental impacts. This contribution focuses on potential water quality implications of expanded grain-based ethanol production and potential impacts of perennial-grass-based cellulosic ethanol. Expanded grain-based ethanol will increase and intensify corn production. Even with recommended fertilizer and land conservation measures, corn acreage can be a major source of N loss to water (20-40 kg ha(-1) yr(-1)). A greater acreage of corn is estimated to increase N and P loss to water by 37% (117 million kg) and 25% (9 million kg), respectively, and measures to encourage adoption of conservation practices are essential to mitigate water quality impairments. Dried distiller's grains remaining after ethanol production from corn grain are used as animal feed and can increase manure P content and may increase N content. Cellulosic fuel-stocks from perennials such as switchgrass and woody materials have the potential to produce ethanol. Although production, storage, and handling of cellulosic materials and conversion technology are limitations, accelerating development of cellulosic ethanol has the potential to reduce dependence on grain fuel-stocks and provide water quality and other environmental benefits. All alternative fuel production technologies could have environmental impacts. There is a need to understand these impacts to help guide policy and help make programmatic and scientific decisions that avoid or mitigate unintended environmental consequences of biofuel production.

  12. Increase in ethanol yield via elimination of lactate production in an ethanol-tolerant mutant of Clostridium thermocellum.

    Directory of Open Access Journals (Sweden)

    Ranjita Biswas

    Full Text Available Large-scale production of lignocellulosic biofuel is a potential solution to sustainably meet global energy needs. One-step consolidated bioprocessing (CBP is a potentially advantageous approach for the production of biofuels, but requires an organism capable of hydrolyzing biomass to sugars and fermenting the sugars to ethanol at commercially viable titers and yields. Clostridium thermocellum, a thermophilic anaerobe, can ferment cellulosic biomass to ethanol and organic acids, but low yield, low titer, and ethanol sensitivity remain barriers to industrial production. Here, we deleted the hypoxanthine phosphoribosyltransferase gene in ethanol tolerant strain of C. thermocellum adhE*(EA in order to allow use of previously developed gene deletion tools, then deleted lactate dehydrogenase (ldh to redirect carbon flux towards ethanol. Upon deletion of ldh, the adhE*(EA Δldh strain produced 30% more ethanol than wild type on minimal medium. The adhE*(EA Δldh strain retained tolerance to 5% v/v ethanol, resulting in an ethanol tolerant platform strain of C. thermocellum for future metabolic engineering efforts.

  13. Increase in ethanol yield via elimination of lactate production in an ethanol-tolerant mutant of Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Ranjita [ORNL; Prabhu, Sandeep [ORNL; Lynd, Lee R [Thayer School of Engineering at Dartmouth; Guss, Adam M [ORNL

    2014-01-01

    Large-scale production of lignocellulosic biofuel is a potential solution to sustainably meet global energy needs. One-step consolidated bioprocessing (CBP) is a potentially advantageous approach for the production of biofuels, but requires an organism capable of hydrolyzing biomass to sugars and fermenting the sugars to ethanol at commercially viable titers and yields. Clostridium thermocellum, a thermophilic anaerobe, can ferment cellulosic biomass to ethanol and organic acids, but low yield, low titer, and ethanol sensitivity remain barriers to industrial production. Here, we deleted the hypoxanthine phosphoribosyltransferase gene in ethanol tolerant strain of C. thermocellum adhE*(EA) in order to allow use of previously developed gene deletion tools, then deleted lactate dehydrogenase (ldh) to redirect carbon flux towards ethanol. Upon deletion of ldh, the adhE*(EA) ldh strain produced 30% more ethanol than wild type on minimal medium. The adhE*(EA) ldh strain retained tolerance to 5% v/v ethanol, resulting in an ethanol tolerant platform strain of C. thermocellum for future metabolic engineering efforts.

  14. Biochemical suitability of crop residues for cellulosic ethanol: disincentives to nitrogen fertilization in corn agriculture.

    Science.gov (United States)

    Gallagher, Morgan E; Hockaday, William C; Masiello, Caroline A; Snapp, Sieglinde; McSwiney, Claire P; Baldock, Jeffrey A

    2011-03-01

    Concerns about energy security and climate change have increased biofuel demand, particularly ethanol produced from cellulosic feedstocks (e.g., food crop residues). A central challenge to cropping for cellulosic ethanol is the potential environmental damage from increased fertilizer use. Previous analyses have assumed that cropping for carbohydrate in residue will require the same amount of fertilizer as cropping for grain. Using (13)C nuclear magnetic resonance, we show that increases in biomass in response to fertilization are not uniform across biochemical classes (carbohydrate, protein, lipid, lignin) or tissues (leaf and stem, grain, reproductive support). Although corn grain responds vigorously and nonlinearly, corn residue shows only modest increases in carbohydrate yields in response to high levels of fertilization (25% increase with 202 kg N ha(-1)). Lignin yields in the residue increased almost twice as much as carbohydrate yields in response to nitrogen, implying that residue feedstock quality declines as more fertilizer is applied. Fertilization also increases the decomposability of corn residue, implying that soil carbon sequestration becomes less efficient with increased fertilizer. Our results suggest that even when corn is grown for grain, benefits of fertilization decline rapidly after the ecosystem's N demands are met. Heavy application of fertilizer yields minimal grain benefits and almost no benefits in residue carbohydrates, while degrading the cellulosic ethanol feedstock quality and soil carbon sequestration capacity.

  15. Assessing solid digestate from anaerobic digestion as feedstock for ethanol production.

    Science.gov (United States)

    Teater, Charles; Yue, Zhengbo; MacLellan, James; Liu, Yan; Liao, Wei

    2011-01-01

    Ethanol production using solid digestate (AD fiber) from a completely stirred tank reactor (CSTR) anaerobic digester was assessed comparing to an energy crop of switchgrass, and an agricultural residue of corn stover. A complete random design was fulfilled to optimize the reaction conditions of dilute alkali pretreatment. The most effective dilute alkali pretreatment conditions for raw CSTR AD fiber were 2% sodium hydroxide, 130 °C, and 3 h. Under these pretreatment conditions, the cellulose concentration of the AD fiber was increased from 34% to 48%. Enzymatic hydrolysis of 10% (dry basis) pretreated AD fiber produced 49.8 g/L glucose, while utilizing 62.6% of the raw cellulose in the AD fiber. The ethanol fermentation on the hydrolysate had an 80.3% ethanol yield. The cellulose utilization efficiencies determined that the CSTR AD fiber was a suitable biorefining feedstock compared to switchgrass and corn stover.

  16. The potential of C4 grasses for cellulosic biofuel production

    Directory of Open Access Journals (Sweden)

    Tim eWeijde

    2013-05-01

    Full Text Available With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulose feedstock for biofuel production is discussed. These include three important field crops - maize, sugarcane and sorghum - and two undomesticated perennial energy grasses - miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of

  17. 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.

  18. 40 CFR 80.1155 - What are the additional requirements for a producer of cellulosic biomass ethanol or waste...

    Science.gov (United States)

    2010-07-01

    ..., 40 CFR part 32, or the Debarment, Suspension and Ineligibility provisions of the Federal Acquisition Regulations, 48 CFR, part 9, subpart 9.4, shall be deemed noncompliance with the requirements of this section... for a producer of cellulosic biomass ethanol or waste derived ethanol? 80.1155 Section...

  19. Secondary liquefaction in ethanol production

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method of producing ethanol by fermentation, said method comprising a secondary liquefaction step in the presence of a themostable acid alpha-amylase or, a themostable maltogenic acid alpha-amylase.......The invention relates to a method of producing ethanol by fermentation, said method comprising a secondary liquefaction step in the presence of a themostable acid alpha-amylase or, a themostable maltogenic acid alpha-amylase....

  20. 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.

  1. Study on the treatment of wastewater from cellulose ethanol production and its engineering application%纤维素乙醇废水处理研究与工程应用

    Institute of Scientific and Technical Information of China (English)

    王宗华; 郑伟花

    2012-01-01

    采用铁炭微电解-Fenton+UASB+MBR组合工艺处理纤维素乙醇废水,并对工程设计运行参数和污染物去除机理进行了探索.结果表明:在微电解反应5h,UASB停留时间36 h,MBR停留时间25h条件下处理纤维素乙醇废水,经絮凝脱色后出水COD、氨氮等指标均达到《发酵酒精和白酒工业水污染物排放标准》(GB 27631—2011)中的规定,且运行效果稳定,费用较低.%A combined process of iron-carbon micro-electrolysis-Fenton+UASB+membrane bioreactor(MBR) has been used for treating cellulose ethanol wastewater. Its engineering design operation parameters and pollutant re-moving mechanisms have been explored. The results show that after the flocculation decolonization process, all of th< indexes,such as effluent COD,ammonia-nitrogen,etc. can reach the requirements of the Discharge Standard of Water Pollutants from Fermentation Alcohol and Distilled Spirits Industry (GB 27631—2011) ,the effect of the operation is stable,and cost is low,under the following conditions: reaction time of micro-electrolysis is 5 h,UASB retention time 36 h, and MBR retention time 25 h.

  2. 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.

  3. 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.

  4. Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept

    DEFF Research Database (Denmark)

    Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar Borisov

    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...

  5. Potential Uses of Bagasse for Ethanol Production Versus Electricity Production

    Directory of Open Access Journals (Sweden)

    Zumalacárregui-De Cárdenas Lourdes Margarita

    2015-07-01

    Full Text Available The procedure to carry out the energy balance for ethanol production by bagasse’s hydrolysis is presented. The loss of potentialities for electric power generation when bagasse is used to produce ethanol instead of electricity directly is calculated. Potential losses are 45-64% according to the efficiency of the lignocellulosic ethanol production. The relationship that exists between the volume of ethanol and the efficiency of Otto and Rankine cycles is analyzed. Those cycles are used to produce electricity from ethanol and bagasse, respectively.

  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. Methods of detection using a cellulose binding domain fusion product

    Energy Technology Data Exchange (ETDEWEB)

    Shoseyov, Oded (Shimshon, IL); Shpiegl, Itai (North Gallilea, IL); Goldstein, Marc A. (Davis, CA); Doi, Roy H. (Davis, CA)

    1999-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  8. Ethanol and lignin production from Brazilian empty fruit bunch biomass.

    Science.gov (United States)

    Raman, Jegannathan Kenthorai; Gnansounou, Edgard

    2014-11-01

    Brazil Government is promoting palm plantations to use degraded land for biofuels. Palm production is expected to increase 35 per cent in future and there would be profuse biomass available that needs to be handled efficiently. Therefore, in this study the potential of EFB from Brazil as raw material for biorefinery was explored by compositional analysis and pretreatment conditions optimization to produce ethanol and co-products. EFB from Brazil contains significant cellulose, hemicellulose, lignin and low ash content. The optimized dilute sulfuric acid pretreatment conditions for efficient cellulose and hemicellulose separation were 160°C temperature, 1.025% v/v acid concentration, 10.5min and 20% solid loading. Under optimum pretreatment process conditions, low enzyme loading (10FPU, 20IU cellulase and glucosidase enzyme/g glucan) and 15% solid loading, 51.1g ethanol, 344.1g solid residue (65% lignin and 24.87MJ/kg LHV) and 3.7l xylose rich liquid could be produced per kg dry EFB.

  9. Conversion of corn milling low-value co-products to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Dien, B.S.; Hespell, R.B.; Bothast, R.J. [Dept. of Agriculture, Peoria, IL (United States); Ingram, L.O. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-31

    Most of the fuel ethanol produced in the United States is derived from corn starch. The ethanol yield can be significantly increased if the hemicellulose fraction of the corn kernel is also fermented. The hemicellulose and cellulose fractions are presently marketed as cattle feed. Conversion of the hemicellulose fraction to ethanol is problematic because, in addition to glucose from the residual starch, hydrolysis of the hemicellulose gives a mixture of pentoses (arabinose and xylose) and traditional industrial yeast do not ferment pentoses. We have evaluated non-traditional recombinant microorganisms for conversion of the hemicellulose fractions into ethanol. The hemicellulose were hydrolyzed with weak acid solutions and resulting sugar mixtures fermented using recombinant Escherichia coli strains K011 and SL40. Results of the fermentation are discussed in terms of volumetric ethanol production rates, ethanol yields, and effect of inhibitors produced during hydrolysis. 4 refs., 7 figs.

  10. Production of ethanol from wheat straw

    Directory of Open Access Journals (Sweden)

    Smuga-Kogut Małgorzata

    2015-09-01

    Full Text Available This study proposes a method for the production of ethanol from wheat straw lignocellulose where the raw material is chemically processed before hydrolysis and fermentation. The usefulness of wheat straw delignification was evaluated with the use of a 4:1 mixture of 95% ethanol and 65% HNO3 (V. Chemically processed lignocellulose was subjected to enzymatic hydrolysis to produce reducing sugars, which were converted to ethanol in the process of alcoholic fermentation. Chemical processing damages the molecular structure of wheat straw, thus improving ethanol yield. The removal of lignin from straw improves fermentation by eliminating lignin’s negative influence on the growth and viability of yeast cells. Straw pretreatment facilitates enzymatic hydrolysis by increasing the content of reducing sugars and ethanol per g in comparison with untreated wheat straw.

  11. 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.

  12. Rewiring Lactococcus lactis for Ethanol Production

    DEFF Research Database (Denmark)

    Solem, Christian; Dehli, Tore Ibsen; Jensen, Peter Ruhdal

    2013-01-01

    genes ldhX, ldhB, and ldh and introducing codon-optimized Z. mobilis alcohol dehydrogenase (ADHB) in addition to PDC resulted in high-yield ethanol formation when strains were grown on glucose, with only minor amounts of by-products formed. Finally, a strain with ethanol as the sole observed......Lactic acid bacteria (LAB) are known for their high tolerance toward organic acids and alcohols (R. S. Gold, M. M. Meagher, R. Hutkins, and T. Conway, J. Ind. Microbiol. 10:45–54, 1992) and could potentially serve as platform organisms for production of these compounds. In this study, we attempted...... small amounts of ethanol were obtained after introducing PDC, probably due to a low native alcohol dehydrogenase activity. When the same strains were grown on maltose, ethanol was the major product and lesser amounts of lactate, formate, and acetate were formed. Inactivating the lactate dehydrogenase...

  13. Ethanol production using nuclear petite yeast mutants

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, A.; Oliver, S.G. [Department of Biomolecular Sciences, UMIST, Manchester (United Kingdom)

    1998-12-31

    Two respiratory-deficient nuclear petites, FY23{Delta}pet191 and FY23{Delta}cox5a, of the yeast Saccharomyces cerevisiae were generated using polymerase-chain-reaction-mediated gene disruption, and their respective ethanol tolerance and productivity assessed and compared to those of the parental grande, FY23WT, and a mitochondrial petite, FY23{rho}{sup 0}. Batch culture studies demonstrated that the parental strain was the most tolerant to exogenously added ethanol with an inhibition constant. K{sub i}, of 2.3% (w/v) and a specific rate of ethanol production, q{sub p}, of 0.90 g ethanol g dry cells{sup -1} h{sup -1}. FY23{rho}{sup 0} was the most sensitive to ethanol, exhibiting a K{sub i} of 1.71% (w/v) and q{sub p} of 0.87 g ethanol g dry cells{sup -1} h{sup -1}. Analyses of the ethanol tolerance of the nuclear petites demonstrate that functional mitochondria are essential for maintaining tolerance to the toxin with the 100% respiratory-deficient nuclear petite, FY23{Delta}pet191, having a K{sub i} of 2.14% (w/v) and the 85% respiratory-deficient FY23{Delta}cox5a, having a K{sub i} of 1.94% (w/v). The retention of ethanol tolerance in the nuclear petites as compared to that of FY23{rho}{sup 0} is mirrored by the ethanol productivities of these nuclear mutants, being respectively 43% and 30% higher than that of the respiratory-sufficient parent strain. This demonstrates that, because of their respiratory deficiency, the nuclear petites are not subject of the Pasteur effect and so exhibit higher rates of fermentation. (orig.)

  14. Wastepaper as a feedstock for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, P.W.; Riley, C.J.

    1991-11-01

    The possibility of using wastepaper as a cheap feedstock for production of ethanol is discussed. As the single largest material category in the municipal solid waste (MSW) stream, wastepaper is the main target of efforts to reduce the volume of MSW. And in the process for producing ethanol from lignocellulosics, the feedstock represents the highest cost. If wastepaper could be obtained cheaply in large enough quantities and if conversion process cost and efficiency prove to be similar to those for wood, the cost of ethanol could be significantly reduced. At the same time, the volume of wastepaper that must be disposed of in landfills could be lessened. 13 refs., 3 figs., 7 tabs.

  15. 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...... of glucan (>30 g glucan per 100 g total solids (TS)). HTT did show better results in both enzymatic convertibility and fermentation, but evaluated on the overall ethanol yield the low-tech pretreatment methods are viable alternatives with similar levels to the HTT (13.4–15.2 g ethanol per 100 g TS raw...

  16. 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.

  17. Further development of chemical and biological processes for production of bio-ethanol; Videreudvikling af kemiske og biologiske processer til produktion af bio-ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Ahring, B.K.; Clausen, A.; Loeth, A.H.

    1999-08-01

    The production of ethanol from both the hemicellulose and cellulose fraction of wet oxidated wheat straw was investigated. Saccharomyces cerevisiae was used to produce of ethanol from the cellulose fraction. Thermoanaerobacter mathranii A3M4 was used for ethanol production from the hemicellulose fraction. The utilisation of the hemicellulose fraction was investigated both after separation of cellulose and hemicellulose fraction and by using one combined process including both cellulose and hemicellulose. The conditions for wet oxidation proved to be the best for fermentation, when the oxygen pressure was 3 atm, and sodium carbonate was added. The ethanol yield was 9.9 mM with Thermoanaerobacter mathranii A3M4. To increase the accessibility of xylose, the wet oxidated wheat straw was treated with different enzymes. Celluclast improved the ethanol yield. Addition of Pentopan{sup TH}, Mono BG or Pulpzyme HC had no effect on the ethanol yield from Thermoanaerobacter mathranii A3M4. Glucose in the medium increased the ethanol yield from xylose significantly with Thermoanaerobacter mathranii A3M4. Acid hydrolysis of the hydrolysates had no positive effect on ethanol yield with Thermoanaerobacter mathranii A3M4. By using the combined process the ethanol yield from Saccharomyces cerevisiae was 142 mM, 27 mM with Thermoanaerobacter mathranii A3M4, and 63,6 m3 methane/ton wheat straw from purification of the process water for acetate and rest sugar with a consort of methanogenic bacteria from digested household waste. This corresponds to 51% of the theoretical ethanol yield. Omission /addition of yeast extract to the fermentation substrate had no effect on ethanol yield from Saccharomyces cerevisiae, whereas ethanol yield decreased 5-6 fold if the yeast extract was omitted by fermentation with Thermoanaerobacter mathranii A3M4. No inhibition effect was observed for either organism. 50% of the process water can be recycled to ferment with Saccharomyces cerevisiae. To increase

  18. Develop and Demonstrate the Cellulose to Ethanol Process: Executive Summary of the Final Technical Report, 17 September 1980 - 17 March 1982

    Energy Technology Data Exchange (ETDEWEB)

    Emert, George H.; Becker, Dana K.; Bevernitz, Kurt J.; Gracheck, Stephen J.; Kienholz, Eldon W.; Rivers, Dougals B.; Zoldak, Bernadette R.; Woodford, Lindley C.

    1982-01-01

    The Biomass Research Center at the University of Arkansas was contracted by the Solar Energy Research Institute to 'Develop and Demonstrate the Cellulose to Ethanol Process.' The purpose of the contract was to accelerate site selection, site specific engineering, and research and development leading to the determination of the feasibility of economically operating a cellulose to ethanol commercial scale plant.

  19. 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%.

  20. Increasing cellulose production and transgenic plant growth in forest tree species

    Institute of Scientific and Technical Information of China (English)

    TANG Wei; Aaron Nelson; Emmanuel Johnson

    2005-01-01

    Cellulose is one of many important polymers in plants. Cellulose is made of repeat units of the monomer glucose. Cellulose is a major industrial biopolymer in the forest products, textile, and chemical industries. It also forms a large portion of the biomass useful in the generation of energy. Moreover, cellulose-based biomass is a renewable energy source that can be used for the generation of ethanol as a fuel. Cellulose is synthesized by a variety of living organisms such as plants and algae. It is the major component of plant cell walls with secondary cell walls having a much higher content of cellulose. The relationship between cellulose and lignin biosynthesis is complicated, but it is confirmed that inhibition of lignin biosynthesis in transgenic trees will increase cellulose biosynthesis and plant growth. Cellulose accumulation may be increased by down-regulating 4-coumarate:coenzyme A ligase (4CL, EC 6.2.1.12) as shown in transgenic aspen. There is no similar reports on down-regulating 4CL in transgenic conifers. Based on our established Agrobacterium tumefaciens-mediated transformation system in loblolly pine, we are able to produce antisense 4-CL transgenic loblolly pine which is predicted to have increasing cellulose accumulation. The overall objective of this project is to genetically engineer forest tree species such as loblolly pine with reduced amount of lignin and increased cellulose content. The research strategy includes: (1) isolate the 4-coumarate:coenzyme A ligase gene from loblolly pine seedlings by reverse transcription-polymerase chain reaction (RT-PCR) and Rapid Amplification of cDNA Ends-Polymerase Chain Reaction (RACE-PCR) techniques from the cDNA library; (2) construct binary expression vectors with antisense 4CL coding sequences and introduce antisense constructs of the 4-coumarate:coenzyme A ligase gene cloned from loblolly pine into the loblolly pine to down regulate the 4-coumarate:coenzyme A ligase gene expression; (3) study the

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

    Energy Technology Data Exchange (ETDEWEB)

    Derr, Dan

    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.

  2. Biological production of ethanol from coal

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    Due to the abundant supply of coal in the United States, significant research efforts have occurred over the past 15 years concerning the conversion of coal to liquid fuels. Researchers at the University of Arkansas have concentrated on a biological approach to coal liquefaction, starting with coal-derived synthesis gas as the raw material. Synthesis gas, a mixture of CO, H[sub 2], CO[sub 2], CH[sub 4] and sulfur gases, is first produced using traditional gasification techniques. The CO, CO[sub 2] and H[sub 2] are then converted to ethanol using a bacterial culture of Clostridium 1jungdahlii. Ethanol is the desired product if the resultant product stream is to be used as a liquid fuel. However, under normal operating conditions, the wild strain'' produces acetate in favor of ethanol in conjunction with growth in a 20:1 molar ratio. Research was performed to determine the conditions necessary to maximize not only the ratio of ethanol to acetate, but also to maximize the concentration of ethanol resulting in the product stream.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. Study on Scale-up Experiment and Comparison of the Processes of the Cellulosic Ethanol Production%纤维乙醇发酵工艺的比较及放大试验研究

    Institute of Scientific and Technical Information of China (English)

    常春; 赖智乐; 马晓建

    2011-01-01

    为了得到高效的纤维乙醇发酵方式,在酶解和发酵适宜的条件下,以汽爆玉米秸秆为原料对分步糖化发酵、同步糖化发酵、预酶解补料批式糖化发酵和变温同步糖化发酵生产乙醇的4种工艺进行了对比研究.试验表明:变温同步糖化发酵效率较高,其乙醇体积分数为4.98%,比同步糖化发酵提高了7.56%,比预酶解分批补料糖化发酵提高了12.60%,比分步糖化发酵提高了23.07%.在50 L发酵罐内进行了变温同步糖化发酵的放大实验,乙醇体积分数为4.26%;同时对放大实验中酵母浓度随时间的变化关系、残糖浓度随时间的变化关系和乙醇的体积分数随时间的变化关系进行了考察.%Several processes of the SSF based on steam-exploded corn stalk were compared in this paper. The best process of the simultaneous saccharification and fermentation is in the condition of variable-temperature. In this condition the efficiency of the ethanol production improved by 7.56% compared with the simultaneous saccharification and fermentation, improved by 12.60% compared with the pre-hydrolysis of the fed-batch saccharification and fermentation, and improved by 23.07% compared with the score-step saccharification and fermentation. Besides the amplification of the variable-temperature simultaneous saccharification and fermentation test was studied in 50 L fermenter and the volume of ethanol is 4.26%. At the same time ,the variations of the concentration of yeast, the concentration of residual sugar and the alcohol content with time in scale-up experiment were also studied.

  8. An Indirect Route for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Eggeman, T.; Verser, D.; Weber, E.

    2005-04-29

    The ZeaChem indirect method is a radically new approach to producing fuel ethanol from renewable resources. Sugar and syngas processing platforms are combined in a novel way that allows all fractions of biomass feedstocks (e.g. carbohydrates, lignins, etc.) to contribute their energy directly into the ethanol product via fermentation and hydrogen based chemical process technologies. The goals of this project were: (1) Collect engineering data necessary for scale-up of the indirect route for ethanol production, and (2) Produce process and economic models to guide the development effort. Both goals were successfully accomplished. The projected economics of the Base Case developed in this work are comparable to today's corn based ethanol technology. Sensitivity analysis shows that significant improvements in economics for the indirect route would result if a biomass feedstock rather that starch hydrolyzate were used as the carbohydrate source. The energy ratio, defined as the ratio of green energy produced divided by the amount of fossil energy consumed, is projected to be 3.11 to 12.32 for the indirect route depending upon the details of implementation. Conventional technology has an energy ratio of 1.34, thus the indirect route will have a significant environmental advantage over today's technology. Energy savings of 7.48 trillion Btu/yr will result when 100 MMgal/yr (neat) of ethanol capacity via the indirect route is placed on-line by the year 2010.

  9. Innovative production technology ethanol from sweet sorghum

    Science.gov (United States)

    Kashapov, N. F.; Nafikov, M. M.; Gazetdinov, M. X.; Nafikova, M. M.; Nigmatzyanov, A. R.

    2016-06-01

    The paper considers the technological aspects of production of ethanol from nontraditional for Russian Federation crops - sweet sorghum. Presents the technological scheme of alcohol production and fuel pellets from sweet sorghum. Special attention is paid to assessing the efficiency of alcohol production from sweet sorghum. The described advantage of sugar content in stem juice of sweet sorghum compared with other raw materials. Allegedly, the use of the technology for producing alcohol from sweet sorghum allows to save resources.

  10. Progress of cellulose ethanol research & development%纤维素乙醇研究开发进展

    Institute of Scientific and Technical Information of China (English)

    胡徐腾

    2011-01-01

    Cellulose ethanol has become a priority of research with a bright future. It may become one of the most important renewable energy sources in the future. Cellulose ethanol research &development is reviewed, and the development history and the latest worldwide progress of cellulose ethanol research & development are summarized. The difficulties and problems in current cellulose ethanol commercialization are analyzed. The directions of research & development are presented.%纤维素乙醇是当今的研究热点,具有广阔的发展前景,将成为未来最重要的可再生能源之一.本文介绍了纤维素乙醇的研发概况,综述了国内外研究开发历程与最新进展,分析了目前纤维素乙醇燃料产业化存在的困难和问题,指出了当前和今后的研发方向.

  11. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products.

    Science.gov (United States)

    Kavitha Sankar, P C; Ramakrishnan, Reshmi; Rosemary, M J

    2016-04-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product.

  12. RECTIFIED ETHANOL PRODUCTION COST ANALYSIS

    Directory of Open Access Journals (Sweden)

    Nikola J Budimir

    2011-01-01

    Full Text Available This paper deals with the impact of the most important factors of the total production costs in bioethanol production. The most influential factors are: total investment costs, price of raw materials (price of biomass, enzymes, yeast, and energy costs. Taking into account these factors, a procedure for estimation total production costs was establish. In order to gain insight into the relationship of production and selling price of bioethanol, price of bioethanol for some countries of the European Union and the United States are given.

  13. Production of fuels by cellulose liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Datta, B.K.; McAuliffe, C.A. [Univ. of Manchester Institute of Science and Technology (United Kingdom)

    1993-12-31

    The effect of temperature on the liquefaction of cellulose was investigated in a range 200{degrees} to 350{degrees}C in aqueous medium with 5% pt/Al{sub 2}O{sub 3} catalyst, at 35 bars of hydrogen as reducing gas and a reaction time of 2 hours. Experiments were conducted in a 1 liter batch rocker autoclave reactor. The conversion increased from 46.5% at 200{degrees}C to 92.46% at 350{degrees}C, the oil yield increased from 18% at 200{degrees} to 33% at 350{degrees}C. At the high temperature, 350{degrees}C, the water soluble fraction and char formation decreased due to the conversion of the above to various gases. Moreover, ether solubles in water soluble fractions also decreased while the production of water increased from 8% at 200{degrees}C to 29% at 350{degrees}C. It suggests the possibility of removal of oxidants from the feedstocks as water. Initial dehydration reactions were obviously responsible for the high yield of water. Water yield increased gradually with the increase in temperature which was probably due to the dehydration of the intermediary products and the concurrent removal of oxygen atom as water instead of as CO or CO{sub 2}. At high temperatures, more CO{sub 2} gas was formed due to the water gas shift reaction. The formation of CO{sub 2} is favored over the formation of CO. At high temperatures more hydrocarbon gases were formed. Solvent extraction of the oils showed that the maximum percentage of carboxylic acids and phenolic compounds formed in comparison with carbonyl and neutral compounds when temperature increased.

  14. 中国纤维素乙醇技术的研究进展%Advancing Cellulosic Ethanol Technology in China

    Institute of Scientific and Technical Information of China (English)

    杨斌; Charles; E.; Wyman

    2007-01-01

    中国面临着严重的能源短缺和环境污染问题,中国政府正在局部几个省份内政策性鼓励燃料乙醇生产和使用.尽管当前主要是用玉米和谷物作为生产乙醇的原料,然而中国具有大量潜在的低成本的纤维素生物质原料,可以极大地扩大乙醇的产量,降低原料成本.近20年来,由于技术的革命性进步,已使得纤维素乙醇的生产成本从4美元/加仑以上,降低至约1.2-1.5美元/加仑.其中,每吨生物质约44美元.因此,目前乙醇掺汽油具有十分强的市场竞争力.已有几个公司正在建造首批商业纤维素乙醇工厂,虽然这些刚起步的小型设施在合理利用和管理上风险较小,但规模经济需要较大型工厂.尽管配送生物质原料的成本会随需求的增加而增加,但在乙醇生产基础上的生物精炼技术的发展,尤其是化工产品和动力的协同生产,将会使全过程的经济可行性大大提高.进一步深入的基础研究,将解决低成本下实现纤维素的完全利用,以确保在无政策性补贴的前提下,真正使纤维素乙醇成为具有市场竞争力的低成本纯液体燃料.%China now faces very serious energy shortages and environmental pollution problems. Thus, the Chinese government is encouraging ethanol use as an alternative transportation fuel by introducing fuel ethanol production and distribution within several provinces. Although the current emphasis is on ethanol production from corn and other grains,China has huge quantities of low cost cellulosic biomass that could significantly expand ethanol production volume and reduce feedstock costs. Over the last 20 years, a number of technical advances have dropped the cost of making cellulosic ethanol from more than $4.00/gallon to only about $1.20-1.50/gallon for biomass costing about $44 per ton. At this cost, ethanol is competitive for blending with gasoline, and several companies are working to build the first commercial

  15. Production of Cellulosic Polymers from Agricultural Wastes

    Directory of Open Access Journals (Sweden)

    A. U. Israel

    2008-01-01

    Full Text Available Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm (Elais guineensis, raffia, piassava, bamboo pulp, bamboo bark from raphia palm (Raphia hookeri, stem and cob of maize plant (Zea mays, fruit fiber from coconut fruit (Cocos nucifera, sawdusts from cotton tree (Cossypium hirsutum, pear wood (Manilkara obovata, stem of Southern gamba green (Andropogon tectorus, sugarcane baggase (Saccharium officinarum and plantain stem (Musa paradisiaca. They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate. The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform.

  16. Sorghum as Dry Land Feedstock for Fuel Ethanol Production

    Institute of Scientific and Technical Information of China (English)

    WANG Donghai; WU Xiaorong

    2010-01-01

    Dry land crops such as sorghums(grain sorghum,sweet sorghum and forage sorghum)have been identified aspromising feedstocks for fuel ethanol production.The major issue for using the sweet sorghum as feedstock is its stability at room temperature.At room temperature,the sweet sorghum juice could lose from 40%to50%of its fermentable sugars from 7to14 days.No significant sugar content and profile changes were observed in juice stored at refrigerator temperature in two weeks.Ethanolfermentation efficiencies of fresh and frozen juice were high(-93%).Concentrated juice(≥25%sugar)had significantly lower efficiencies and large amounts of fructose left in finished beer; however,winery yeast strains and novel fermentation techniques maysolve these problems.The ethanol yield from sorghum grain increased as starch content increased.No linear relationship betweenstarch content and fermentation efficiency was found.Key factors affecting the ethanol fermentation efficiency of sorghum includestarches and protein digestibility,amylose-lipid complexes,tannin content,and mash viscosity.Life cycle analysis showed a positivenet energy value(NEV)=25 500 Btu/gal ethanol.Fourier transform infrared(FTIR)spectroscopy and X-ray diffraction(XRD)were used to determine changes in the structure and chemical composition of sorghum biomasses.Dilute sulfuric acid pretreatment waseffective in removing the hemicellulose from biomasses and exposing the cellulose for enzymatic hydrolysis.Forage sorghum ligninhad a lower syringyl/guaiacyl ratio and its pretreated biomass was easier to hydrolyze.Up to 72% hexose yield and 94% pentoseyield were obtained by using a modified steam explosion with 2% sulfuric acid at 140"C for 30 min and enzymatic hydrolysis withcellulase.

  17. 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.

  18. Effect of microbial pretreatment on enzymatic hydrolysis and fermentation of cotton stalks for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian; Sharma-Shivappa, Ratna R.; Chinn, Mari [Department of Biological and Agricultural Engineering, Campus Box 7625, North Carolina State University, Raleigh, NC 27695-7625 (United States); Howell, Noura [North Carolina School of Science and Mathematics, Durham, NC 27715 (United States)

    2009-01-15

    The potential of microbial pretreatment of cotton stalks by Phanerochaete chrysosporium to degrade lignin and facilitate fuel ethanol production was investigated under two culture conditions: submerged cultivation (SmC) and solid state (SSC) cultivation. Although microbial pretreatments showed significant lignin degradation (LD) (19.38% and 35.53% for SmC and SSC, respectively), a study on hydrolysis and fermentation of the microbial-pretreated cotton stalks showed no increase in cellulose conversion (10.98% and 3.04% for SmC and SSC pretreated samples, respectively) compared to untreated cotton stalks (17.93%). Solid state cultivation demonstrated better selectivity of 0.82 than 0.70 with submerged pretreatment. Washing of pretreated cotton stalks did not significantly increase cellulose conversion. However, heating and washing remarkably improved (P<0.05) cellulose conversion to 14.94% and 17.81% for SmC and SSC 14 day pretreatment, respectively. Ethanol yields, up to 0.027 g ethanol g{sup -1} initial cotton stalks, were low for all untreated and pretreated samples mainly due to the low cellulose conversion. Although potential and some critical aspects of fungal pretreatment using P. chrysosporium have been explored in this study, additional investigation is still required especially to improve the selectivity for preferential LD and to optimize hydrolysis efficiency. The mechanism of catalytic binding of cellulolytic enzymes to cotton stalks as affected by the presence of fungal mycelia also warrants further study. (author)

  19. Ethanol production from fodder beet

    Energy Technology Data Exchange (ETDEWEB)

    Kosaric, M.; Wieczorek, A.; Kliza, S.

    1983-07-01

    Various yeasts such as two strains of Saccharomyces cerevisiae, Saccharomyces diastaticus, and Kluyveromyces marxianus were investigated for their ability to ferment fodder beet juice to alcohol. Juice extracted from fodder beet roots without any additives was used as a fermentation substrate. The fermentation kinetic parameters were determined and compared for each species of yeast tested. The best species for fodder beet juice fermentation was chosen and products obtained by fermentation of one hectare of fodder beet plants are given. (Refs. 8).

  20. Improved ethanol production by engineered Saccharomyces cerevisiae expressing a mutated cellobiose transporter during simultaneous saccharification and fermentation.

    Science.gov (United States)

    Lee, Won-Heong; Jin, Yong-Su

    2017-03-10

    Although simultaneous saccharification and fermentation (SSF) of cellulosic biomass can offer efficient hydrolysis of cellulose through alleviating feed-back inhibition of cellulases by glucose, supplementation of β-glucosidase is necessary because most fermenting microorganisms cannot utilize cellobiose. Previously, we observed that SSF of cellulose by an engineered Saccharomyces cerevisiae expressing a cellobiose transporter (CDT-1) and an intracellular β-glucosidase (GH1-1) without β-glucosidase could not be performed as efficiently as the traditional SSF with extracellular β-glucosidase. However, we improved the ethanol production from SSF of cellulose by employing a further engineered S. cerevisiae expressing a mutant cellobiose transporter [CDT-1 (F213L) exhibiting higher VMAX than CDT-1] and GH1-1 in this study. Furthermore, limitation of cellobiose formation by reducing the amounts of cellulases mixture in SSF could lead the further engineered strain to produce ethanol considerably better than the parental strain with β-glucosidase. Probably, better production of ethanol by the further engineered strain seemed to be due to a higher affinity to cellobiose, which might be attributed to not only 2-times lower Monod constant (KS) for cellobiose than KS of the parental strain for glucose but also 5-times lower KS than Michaelis-Menten constant (KM) of the extracellular β-glucosidase for glucose. Our results suggest that modification of the cellobiose transporter in the engineered yeast to transport lower level of cellobiose enables a more efficient SSF for producing ethanol from cellulose.

  1. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  2. 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.

  3. 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.

  4. Prospect of Bio-ethylene from Cellulose Fuel Ethanol%纤维乙醇制生物乙烯前景展望

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      介绍了近年来国内外纤维素乙醇及生物乙烯技术的发展状况,阐述了纤维乙醇制生物乙烯的产业化焦点,展望了纤维乙醇制生物乙烯的发展。%The development of cellulose fuel ethanol and bio-ethylene technology in recent years was introduced. The industry focus of bio-ethylene from cellulose fuel ethanol was summarized. The development strategies of bio-ethylene from cellulose fuel ethanol was discussed.

  5. Xylo-oligosaccharides and Ethanol Production from Liquid Hot Water Hydrolysate of Sugarcane Bagasse

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    2014-11-01

    Full Text Available With the objective of maximizing the use of liquid hot water hydrolysate of sugarcane bagasse, xylo-oligosaccharides and ethanol were respectively produced by the methods of purification and microbial fermentation. The processes of purification with activated charcoal, overliming, solvent extraction, vacuum evaporation, and use of an ion exchange resin were evaluated, and the results indicated that anion exchange chromatography performed well in terms of by-product removal. The recovery and purity of xylo-oligosaccharides reached 92.0% and 90.4%, respectively, using column chromatography with the resin LS30 at a flow rate of 2 mL/min at 25 C. The hydrolysate was used in ethanol fermentation with Pichia stipitis CBS6054 followed by the production of fermentable saccharides and detoxification. The highest ethanol concentration was 4.12 g/L with a theoretical yield of 47.9% for the hydrolysate after xylanase digestion and resin detoxification, similar to the data of the control experiment, which had an ethanol concentration of 4.64 g/L and a yield of 49.6%. However, the former had a higher ethanol productivity of 0.0860 g/(L∙h, and the highest ethanol concentration appeared 12 to 24 h earlier compared to the control. This study suggests that combined generation of xylo-oligosaccharides and cellulosic ethanol could help maximize profits for a cane sugar factory.

  6. Production of Biocellulosic Ethanol from Wheat Straw

    Directory of Open Access Journals (Sweden)

    Ismail

    2012-01-01

    Full Text Available Wheat straw is an abundant lignocellulosic feedstock in many parts of the world, and has been selected for producing ethanol in an economically feasible manner. It contains a mixture of sugars (hexoses and pentoses.Two-stage acid hydrolysis was carried out with concentrates of perchloric acid, using wheat straw. The hydrolysate was concentrated by vacuum evaporation to increase the concentration of fermentable sugars, and was detoxified by over-liming to decrease the concentration of fermentation inhibitors. After two-stage acid hydrolysis, the sugars and the inhibitors were measured. The ethanol yields obtained from by converting hexoses and pentoses in the hydrolysate with the co-culture of Saccharomyces cerevisiae and Pichia stipites were higher than the ethanol yields produced with a monoculture of S. cerevisiae. Various conditions for hysdrolysis and fermentation were investigated. The ethanol concentration was 11.42 g/l in 42 h of incubation, with a yield of 0.475 g/g, productivity of 0.272 gl ·h, and fermentation efficiency of 92.955 %, using a co-culture of Saccharomyces cerevisiae and Pichia stipites

  7. Microwaves and the industrial production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Senise, J.T.; Concone, B.R.V.; Moraes, V.L.V.; Doin, P.A.; Medugno, C.C.; Andrade, A.O.M.; Perri, E.B.; Perin, A.H.

    1981-01-01

    Production of ethanol from starchy materials is now being investigated in Brazil as an alternative source for alcohol production apart from sugar cane. In the present work, with the objective of optimizing the energy balance of the process, substitution of conventional sources of energy by electricity at one stage of the process is sought. Cooking and dextrinization of cassava roots, previously treated by conventional pretreatments, by microwaves heating (at 2450 MHz) has been studied. Results of saccharification and fermentation of the mash thus obtained were used to evaluate the technical feasibility of the process. Specific energy consumption figures (for the cooking and dextrinization stage) of 600 kcal/l of ethanol produced and efficiencies of 90% (in terms of the theoretical maximum yield from the available starch) were easily and consistently obtained.

  8. Energy consumption in the production of cellulose and paper

    Energy Technology Data Exchange (ETDEWEB)

    Kubelka, V.

    1979-01-01

    The specific consumption of energy in the cellulose and paper industry of Czechoslovakia is 20% higher than in Austria and the Federal Republic of Germany. For the last 20 years, the specific consumption of fuel decreased by 29% in the Austrian cellulose and paper industry, while the consumption of electricity increased by 16%. The possibility for decreasing the specific consumption of energy in Czechoslovakia by burning by-products, heat recovery, equipment modernization, etc. are examined.

  9. Ethanol Production for Automotive Fuel Usage

    Energy Technology Data Exchange (ETDEWEB)

    May, S.C.; Stenzel, R.A.; Weekes, M.C.; Yu, J.

    1979-10-01

    The production of ethanol from potatoes, sugar beet, and wheat using geothermal resources at the Raft River area of idaho is being evaluated. The south central section of Idaho produces approximately 18 million bushels of wheat, 1.3 million tons of sugar beet and 24 million cwt potatoes annually. Based on these production figures, a 20 million gallon/yr ethanol facility has been selected as the largest scale plant that can be supported with the current agricultural resources. The plant will operate on all three feedstocks nominally processing potatoes for five months, sugar beet for four months and wheat for three months of the year. The process facility will use conventional alcohol technology utilizing geothermal fluid at a maximum of 280 F as an energy source. The process flow diagrams for all three feedstocks are currently being prepared. There will be basically three feedstock preparation sections, although the liquefaction and saccharification steps for potatoes and wheat will involve common equipment. The fermentation, distillation and by-product handling sections will be common to all three feedstocks. Three geothermal energy extraction systems were considered to accommodate the energy requirements of the ethanol facility (flashed steam, pressurized fluid and secondary heat transfer). Pressured geothermal fluid with direct heat transfer has been selected as the usage mode to minimize scale deposition. Tentatively, the geothermal supply wells will be laid out in square grids with 1/4 mile spacing. The number of wells required will be determined after the process heat load is calculated.

  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. Production of pure hydrogen by ethanol dehydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Santacesaria, E.; Carotenuto, G.; Tesser, R.; Di Serio, M. [Naples ' ' Federico II' ' Univ. (Italy). Dept. of Chemistry

    2010-12-30

    Hydrogen production from bio-ethanol is one of the most promising renewable processes to generate electricity using fuel cells. In this work, we have studied the production of pure hydrogen as by product of ethanol dehydrogenation reaction. This reaction is promoted by copper based catalysts and according to the catalyst used and the operative conditions gives place to acetaldehyde or ethyl acetate as main products. We studied in particular the performance of a commercial copper/copper chromite catalyst, supported on alumina and containing barium chromate as promoter that has given the best results. By operating at low pressure and temperature with short residence times, acetaldehyde is more selectively produced, while, by increasing the pressure (10-30 bars), the temperature (200-260 C) and the residence time (about 100 (grams hour/mol) of ethanol contact time) the selectivity is shifted to the production of ethyl acetate. However, in both cases pure hydrogen is obtained, as by product, that can easily be separated. Hydrogen obtained in this way is exempt of CO and can be directly fed to fuel cells without any inconvenience. In this work, runs performed in different operative conditions have been reported with the scope to individuate the best conditions. A carrier of H{sub 2} 6% in N{sub 2} has been used. The studied catalyst has also shown a good thermal stability with respect to sintering phenomena, that generally occurs during the dehydrogenation on other copper catalysts. Hydrogen productivities of 8-39 mol{sub H2} (gcat){sup -1}(h){sup -1} have been obtained for the explored temperature range 200-260 C. At last, the most accredited reaction mechanism is reported and discussed on the basis of the obtained results. (orig.)

  12. Efficient utilization of hemicellulose and cellulose in alkali liquor-pretreated corncob for bioethanol production at high solid loading by Spathaspora passalidarum U1-58.

    Science.gov (United States)

    Yu, Hai; Guo, Jian; Chen, Yefu; Fu, Gengxin; Li, Baozhong; Guo, Xuewu; Xiao, Dongguang

    2017-02-11

    The bioethanol fermentation of pretreated corncob was investigated using Spathaspora passalidarum U1-58, which simultaneously utilizes glucose and xylose for high-efficiency ethanol production. Two approaches, namely, separate hydrolysis and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF), were optimized to test the ethanol fermentation potential of U1-58. The highest ethanol titer of 42.46g/L and yield of 72.12% were acquired in SHCF, whereas 53.24g/L ethanol and yield of 75.35% were obtained in SSCF at solid-to-liquid ratio of 1:5 (w/v). Approximately 86.20% of cellulose and 82.99% of hemicellulose were consumed in SSCF after 96h, and at least 10.49g/L ethanol was produced from hemicellulose, which corresponded to 37.59% of the theoretical yield. Compared with the published cellulosic ethanol fermentation cases, the present work presented high ethanol titer and yield, and cellulose and hemicellulose could be efficiently utilized for ethanol production.

  13. Thermophilic, lignocellulolytic bacteria for ethanol production: current state and perspectives

    DEFF Research Database (Denmark)

    Chang, Tinghong; Yao, Shuo

    2011-01-01

    , in particular with emphasis on improving ethanol yield, and this facilitates their employment for ethanol production. Finally, different processes for second-generation ethanol production based on thermophilic bacteria have been proposed with the aim to achieve cost-competitive processes. However, thermophilic...

  14. Well-to-wheels energy use and greenhouse gas emissions of ethanol from corn, sugarcane and cellulosic biomass for US use

    Science.gov (United States)

    Wang, Michael; Han, Jeongwoo; Dunn, Jennifer B.; Cai, Hao; Elgowainy, Amgad

    2012-12-01

    Globally, bioethanol is the largest volume biofuel used in the transportation sector, with corn-based ethanol production occurring mostly in the US and sugarcane-based ethanol production occurring mostly in Brazil. Advances in technology and the resulting improved productivity in corn and sugarcane farming and ethanol conversion, together with biofuel policies, have contributed to the significant expansion of ethanol production in the past 20 years. These improvements have increased the energy and greenhouse gas (GHG) benefits of using bioethanol as opposed to using petroleum gasoline. This article presents results from our most recently updated simulations of energy use and GHG emissions that result from using bioethanol made from several feedstocks. The results were generated with the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model. In particular, based on a consistent and systematic model platform, we estimate life-cycle energy consumption and GHG emissions from using ethanol produced from five feedstocks: corn, sugarcane, corn stover, switchgrass and miscanthus. We quantitatively address the impacts of a few critical factors that affect life-cycle GHG emissions from bioethanol. Even when the highly debated land use change GHG emissions are included, changing from corn to sugarcane and then to cellulosic biomass helps to significantly increase the reductions in energy use and GHG emissions from using bioethanol. Relative to petroleum gasoline, ethanol from corn, sugarcane, corn stover, switchgrass and miscanthus can reduce life-cycle GHG emissions by 19-48%, 40-62%, 90-103%, 77-97% and 101-115%, respectively. Similar trends have been found with regard to fossil energy benefits for the five bioethanol pathways.

  15. [Life cycle assessment of energy consumption and greenhouse gas emissions of cellulosic ethanol from corn stover].

    Science.gov (United States)

    Tian, Wang; Liao, Cuiping; Li, Li; Zhao, Daiqing

    2011-03-01

    Life Cycle Assessment (LCA) is the only standardized tool currently used to assess environmental loads of products and processes. The life cycle analysis, as a part of LCA, is a useful and powerful methodology for studying life cycle energy efficiency and life cycle GHG emission. To quantitatively explain the potential of energy saving and greenhouse gas (GHG) emissions reduction of corn stover-based ethanol, we analyzed life cycle energy consumption and GHG emissions of corn stover-based ethanol by the method of life cycle analysis. The processes are dilute acid prehydrolysis and enzymatic hydrolysis. The functional unit was defined as 1 km distance driven by the vehicle. Results indicated: compared with gasoline, the corn stover-based E100 (100% ethanol) and E10 (a blend of 10% ethanol and 90% gasoline by volume) could reduce life cycle fossil energy consumption by 79.63% and 6.25% respectively, as well as GHG emissions by 53.98% and 6.69%; the fossil energy consumed by biomass stage was 68.3% of total fossil energy input, N-fertilizer and diesel were the main factors which contributed 45.78% and 33.26% to biomass stage; electricity production process contributed 42.06% to the net GHG emissions, the improvement of technology might reduce emissions markedly.

  16. Continuous hydrogen production during fermentation of alpha-cellulose by the thermophillic bacterium Clostridium thermocellum.

    Science.gov (United States)

    Magnusson, Lauren; Cicek, Nazim; Sparling, Richard; Levin, David

    2009-02-15

    Continuous hydrogen (H2) production during fermentation of alpha-cellulose was established using the thermophillic, anaerobic bacterium Clostridium thermocellum ATCC 27405. The objectives of this work were to characterize growth of C. thermocellum, quantify H2 production and determine soluble end-product synthesis patterns during fermentation of a cellulosic substrate under continuous culture conditions. A 5 L working volume fermentor was established and growth experiments were maintained for over 3,000 h. Substrate concentrations were varied from 1 to 4 g/L and the feed was introduced with continuous nitrogen gas sparging to prevent clogging of the feed-line. The pH and temperature of the reactor were maintained at 7.0 and 600 degrees C, respectively, throughout the study. At concentrations above 4 g/L, the delivery of alpha-cellulose was impaired due to feed-line clogging and it became difficult to maintain a homogenous suspension. The highest total gas (H2 plus CO2) production rate, 56.6 mL L(-1) h(-1), was observed at a dilution rate of 0.042 h(-1) and substrate concentration of 4 g/L. Under these conditions, the H2 production rate was 5.06 mmol h(-1). Acetate and ethanol were the major soluble end-products, while lactate and formate were greatly reduced compared to production in batch cultures. Concentrations of all metabolites increased with increasing substrate concentration, with the exception of lactate. Despite a number of short-term electrical and mechanical failures during the testing period, the system recovered quickly, exhibiting substantial robustness. A carbon balance was completed to ensure that all end-products were accounted for, with final results indicating near 100% carbon recovery. This study shows that long-term, stable H2 production can be achieved during direct fermentation of an insoluble cellulosic substrate under continuous culture conditions.

  17. Pectin-rich biomass as feedstock for fuel ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Meredith C.; Doran-Peterson, Joy [Georgia Univ., Athens, GA (United States). Dept. of Microbiology

    2012-08-15

    The USA has proposed that 30 % of liquid transportation fuel be produced from renewable resources by 2030 (Perlack and Stokes 2011). It will be impossible to reach this goal using corn kernel-based ethanol alone. Pectin-rich biomass, an under-utilized waste product of the sugar and juice industry, can augment US ethanol supplies by capitalizing on this already established feedstock. Currently, pectin-rich biomass is sold (at low value) as animal feed. This review focuses on the three most studied types of pectin-rich biomass: sugar beet pulp, citrus waste and apple pomace. Fermentations of these materials have been conducted with a variety of ethanologens, including yeasts and bacteria. Escherichia coli can ferment a wide range of sugars including galacturonic acid, the primary component of pectin. However, the mixed acid metabolism of E. coli can produce unwanted side products. Saccharomyces cerevisiae cannot naturally ferment galacturonic acid nor pentose sugars but has a homoethanol pathway. Erwinia chrysanthemi is capable of degrading many of the cell wall components of pectin-rich materials, including pectin. Klebsiella oxytoca can metabolize a diverse array of sugars including cellobiose, one degradation product of cellulose. However, both E. chrysanthemi and K. oxytoca produce side products during fermentation, similar to E. coli. Using pectin-rich residues from industrial processes is beneficial because the material is already collected and partially pretreated to facilitate enzymatic deconstruction of the plant cell walls. Using biomass already produced for other purposes is an attractive practice because fewer greenhouse gases (GHG) will be anticipated from land-use changes. (orig.)

  18. 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

  19. Market for ethanol feed joint products

    Energy Technology Data Exchange (ETDEWEB)

    Hertzmark, D.; Gould, B.

    1979-10-01

    This report presents results of econometric estimations and mathematical simulations of markets for joint feed products of motor ethanol. The major issues considered are the nature of current market price relationships, effects on prices, including feed substitutes prices, and effects of demands for increased use of distillers' grains and gluten meal. The econometric section shows that soybean meal was by far the dominant force in the pricing of the two products. However, neither one could be adequately explained without the inclusion of corn in the estimating equations. Later research shows that this was due to the importance of both feeds for metabolizable energy as well as for protein in livestock diets. Current ration formulations would require some discounting of the value of the protein content of the two feeds. Careful siting of the ethanol facilities, and flexible design of the plants so that a maximum number of products may be extracted from the feedstock, seem necessary. Finally, the analysis indicates that substitution in animal diets of these joint products for the corn or milo used originally requires that additional energy be supplied to the animal by some type of forage crop. This implies that additional land may be required for energy production, for such marginal crops as hay and alfalfa, rather than for row crops.

  20. MN Center for Renewable Energy: Cellulosic Ethanol, Optimization of Bio-fuels in Internal Combustion Engines, & Course Development for Technicians in These Areas

    Energy Technology Data Exchange (ETDEWEB)

    John Frey

    2009-02-22

    This final report for Grant #DE-FG02-06ER64241, MN Center for Renewable Energy, will address the shared institutional work done by Minnesota State University, Mankato and Minnesota West Community and Technical College during the time period of July 1, 2006 to December 30, 2008. There was a no-cost extension request approved for the purpose of finalizing some of the work. The grant objectives broadly stated were to 1) develop educational curriculum to train technicians in wind and ethanol renewable energy, 2) determine the value of cattails as a biomass crop for production of cellulosic ethanol, and 3) research in Optimization of Bio-Fuels in Internal Combustion Engines. The funding for the MN Center for Renewable Energy was spent on specific projects related to the work of the Center.

  1. 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)

  2. 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.

  3. Maize stover and cob cell wall composition and ethanol potential as affected by nitrogen fertilization

    Science.gov (United States)

    Maize (Zea mays L.) stover and cobs are potential feedstock sources for cellulosic ethanol production. Nitrogen (N) fertilization is an important management decision that influences cellulosic biomass and grain production, but its effect on cell wall composition and subsequent cellulosic ethanol pro...

  4. ECOLOGY SAFE METHOD OF OBTAINING FROM FIR-WOOD THE CELLULOSIC PRODUCT WITH HIGH CONTENT OF ALFA-CELLULOSE

    OpenAIRE

    Владимир Александрович Левданский; Александр Владимирович Левданский; Борис Николаевич Кузнецов

    2014-01-01

    The «green» method of obtaining from fir-wood the cellulosic product with high content of alpha-cellulose was developed. It consists of the stage of wood delignification by hydrogen peroxide in the medium «acetic acid – water – sulfuric acid catalyst» and of the stage of alkaline treatment by NaOH. Preparation conditions were selected which allow to obtain with an acceptable yield (30–31% mas.) the cellulosic product containing 97,3–98,0% mas. of alpha-cellulose.

  5. 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.

  6. Comparison of different pretreatment strategies for ethanol production of West African biomass.

    Science.gov (United States)

    Thomsen, Sune Tjalfe; Londoño, Jorge Enrique González; Schmidt, Jens Ejbye; Kádár, Zsófia

    2015-03-01

    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 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 of glucan (>30 g glucan per 100 g total solids (TS)). HTT did show better results in both enzymatic convertibility and fermentation, but evaluated on the overall ethanol yield the low-tech pretreatment methods are viable alternatives with similar levels to the HTT (13.4-15.2 g ethanol per 100 g TS raw material).

  7. Sustainable Ethanol Production from Common Reed (Phragmites australis through Simultaneuos Saccharification and Fermentation

    Directory of Open Access Journals (Sweden)

    Franco Cotana

    2015-09-01

    Full Text Available Phragmites australis (common reed is a perennial grass that grows in wetlands or near inland waterways. Due to its fast-growing properties and low requirement in nutrients and water, this arboreal variety is recognized as a promising source of renewable energy although it is one of the least characterized energy crops. In this experiment, the optimization of the bioethanol production process from Phragmites australis was carried out. Raw material was first characterized according to the standard procedure (NREL to evaluate its composition in terms of cellulose, hemicellulose, and lignin content. Common reed was pretreated by steam explosion process at three different severity factor (R0 values. The pretreatment was performed in order to reduce biomass recalcitrance and to make cellulose more accessible to enzymatic attack. After the pretreatment, a water insoluble substrate (WIS rich in cellulose and lignin and a liquid fraction rich in pentose sugars (xylose and arabinose and inhibitors were collected and analyzed. The simultaneous saccharification and fermentation (SSF of the WIS was performed at three different solid loadings (SL 10%, 15%, 20% (w/w. The same enzyme dosage, equal to 20% (g enzyme/g cellulose, was used for all the WIS loadings. The efficiency of the whole process was evaluated in terms of ethanol overall yield (g ethanol/100 g raw material. The maximum ethanol overall yields achieved were 16.56 and 15.80 g ethanol/100 g RM dry basis for sample AP10 and sample AP4.4, respectively. The yields were reached working at lower solid loading (10% and at the intermediate LogR0 value for the former and at intermediate solid loading (15% and high LogR0 value for the latter, respectively.

  8. SACCHARIFICATION BY FUNGI AND ETHANOL PRODUCTION BY BACTERIA USING LIGNOCELLULOSIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Srivastava Ajeet Kumar

    2012-05-01

    Full Text Available Lignocellulosic material is one of the most abundant, renewable and inexpensive energy resources for bioethanol production. These materials are mainly composed of three groups of polymers namely cellulose, hemicellulose and lignin. Cellulose and hemicellulose are sugar rich fractions of interest for use in fermentation processes such as ethanol production. Cellulase production by the different fungi like Trichoderma reesei (MTCC-4876, Phanerochaete chrysosporium (MTCC-787 and Aspergillus awamori (MTCC-6652 were studied using different substrates (rice straw, wheat straw and rice husk by keeping the concentration constant at 5g/ 150 ml. The subculture medium was a salt solution consisting of KH2PO4, CaCl2, etc. Fungal cells were sub-cultured in an orbital shaker (180 rpm at 30°C for 1-2 generations (two days for each generation and were then used as inoculums. The maximum cellulase production and saccharification observed in the presence of combination of fungi with treated rice straw. Further Zymomonas mobilis bacteria was used for carrying out fermentation of sugars to ethanol production. Among the three raw materials studied the ethanol yield was observed to be the highest in rice straw ( 9.5 g/l .

  9. 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.

  10. 75 FR 42745 - Production Incentives for Cellulosic Biofuels: Notice of Program Intent

    Science.gov (United States)

    2010-07-22

    ... of Energy Efficiency and Renewable Energy Production Incentives for Cellulosic Biofuels: Notice of..., biofuels producers and other interested parties are invited to submit pre-auction eligibility information..., ``Production Incentives for Cellulosic Biofuels; Reverse Auction Procedures and Standards,'' (74 FR...

  11. 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)

  12. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain.

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Abbott, James; Micklem, Chris N; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-06-14

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology.

  13. Enzymatic degradation of plutonium-contaminated cellulose products

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, C.E.; Rainwater, K.A.; Swift, L.M. [Texas Tech Univ., Lubbock, TX (United States); Barnes, D.L. [Amarillo National Resource Center for Plutonium, TX (United States); Worl, L.; Avens, L. [Los Alamos National Lab., NM (United States)

    1999-03-01

    Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with radionuclides. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste that must be disposed of in secured storage areas.

  14. Enzymatic degradation of plutonium-contaminated cellulose products

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, C.E.; Rainwater, K.A.; Swift, L.M. [Texas Tech Univ., Lubbock, TX (United States); Barnes, D.L. [Amarillo National Resource Center for Plutonium, TX (United States); Worl, L.A. [Los Alamos National Lab., NM (United States)

    1999-06-01

    Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown previously that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with uranium. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}, manufactured by Genencor, Rochester, NY) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste destined for costly disposal options.

  15. Cationization of Alpha-Cellulose to Develop New Sustainable Products

    Directory of Open Access Journals (Sweden)

    Ana Moral

    2015-01-01

    Full Text Available Papermaking has been using high quantities of retention agents, mainly cationic substances and organic compounds such as polyamines. The addition of these agents is related to economic and environmental issues, increasing contamination of the effluents. The aim of this work is to develop a cationic polymer for papermaking purposes based on the utilization of alpha-cellulose. The cationization of mercerized alpha-cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC is governed by a pseudo-second-order reaction. The initial amorphous fraction of cellulose is reacted with CHPTAC until the equilibrium value of nitrogen substitution is reached. Nitrogen is incorporated as a quaternary ammonium group in the polymer. Also, the kinetic constant increased with decreasing crystallinity index, showing the importance of the previous alkalization stage. The use of modified natural polysaccharides is a sustainable alternative to synthetic, nonbiodegradable polyelectrolytes and thus is desirable with a view to developing new products and new processes.

  16. Isolation and characterization of a ß-glucosidase from a Clavispora strain with potential applications in bioethanol production from cellulosic materials

    Science.gov (United States)

    We previously reported on a new yeast strain of Clavispora sp. NRRL Y-50464 that is capable of utilizing cellobiose as sole source of carbon and energy by producing sufficient native ß-glucosidase enzyme activity without further enzyme supplementation for cellulosic ethanol production using simultan...

  17. Pilot plant study for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.S. [Korea Inst. of Science and Technology, Seoul (Korea, Republic of)

    1996-02-01

    Most of domestic alcohol fermentation factory adopt batch process of which productivity is lower than continuous fermentation process. They have made great effort to increase productivity by means of partial unit process automatization and process improvement with their accumulated experience but there is technical limitation in productivity of batch fermentation process. To produce and supply fuel alcohol, economic aspects must be considered first of all. Therefore, development of continuous fermentation process, of which productivity is high, is prerequisite to produce and use fuel alcohol but only a few foreign company possess continuous fermentation technic and use it in practical industrial scale fermentation. We constructed pilot plant (5 Stage CSTR 1 kl 99.5 v/v% ethanol/Day scale) to study some aspects stated below and our ultimate aims are production of industrial scale fuel alcohol and construction of the plant by ourselves. Some study concerned with energy saving separation and contamination control technic were entrusted to KAIST, A-ju university and KIST respectively. (author) 67 refs., 100 figs., 58 tabs.

  18. An Economic Analysis of Corn-based Ethanol Production

    OpenAIRE

    Koo, Won W.; Taylor, Richard D.

    2008-01-01

    A global multi-commodity simulation model was developed to estimate the impact of changes in ethanol production on the U.S. corn industry. Increased ethanol production under the Energy Acts of 2005 and 2007 resulted in a significant increase in the price of corn. However, for corn-based ethanol production, the break-even price of corn is approximately $4.52 per bushel with a federal subsidy of $0.51 per gallon of pure ethanol and $2.50 gasoline. With a corn price of $4.52, the economically de...

  19. Second Generation Ethanol Production from Brewers’ Spent Grain

    OpenAIRE

    Rossana Liguori; Carlos Ricardo Soccol; Luciana Porto de Souza Vandenberghe; Adenise Lorenci Woiciechowski; Vincenza Faraco

    2015-01-01

    Ethanol production from lignocellulosic biomasses raises a global interest because it represents a good alternative to petroleum-derived energies and reduces the food versus fuel conflict generated by first generation ethanol. In this study, alkaline-acid pretreated brewers’ spent grain (BSG) was evaluated for ethanol production after enzymatic hydrolysis with commercial enzymes. The obtained hydrolysate containing a glucose concentration of 75 g/L was adopted, after dilution up to 50 g/L, fo...

  20. Production of ethanol from pineapple wastes

    Energy Technology Data Exchange (ETDEWEB)

    Ban, K.L.; Kouadio, K.G.; Kouadio, N' d.; Kamenan, A.

    1988-12-01

    Ethanol of pharmaceutical quality, is obtained by fermentation of juice extract produced from pineapple wastes and fruits left after sorting since they contain an important amount of glucides. The optimization of fermentation parameters proved the feasibility of such a process. The pH of fresh pineapple juice varies from 3.4 to 3.6. The fermentation can be achieved without sterilization by using saccharomyces cerevisiae from 8 g/l of juice over a period of 8 hours. The fermented juice has a density of 1.053 and an acidity level of 6 g of H/sub 2/SO/sub 4//l. The analysis of the produced alcohol using a gas chromatograph reveals a high content of this product.

  1. Hydrogen and volatile fatty acid production during fermentation of cellulosic substrates by a thermophilic consortium at 50 and 60 °C.

    Science.gov (United States)

    Carver, Sarah M; Nelson, Michael C; Lepistö, Raghida; Yu, Zhongtang; Tuovinen, Olli H

    2012-01-01

    The purpose of this study was to characterize the effect of temperature and cellulosic substrates on fermentative metabolites, H(2) production, and community successions in an anaerobic, cellulolytic consortium, TC60. Pyrosequencing analysis indicated that the consortium was predominated by Thermoanaerobacter and Clostridium spp. Metabolite production was analyzed with four cellulosic substrates at 4 kg/m(3). Triplicate cultures of each substrate were incubated at 50 or 60 °C. The main fermentation products (H(2), CO(2), ethanol, and acetate) were monitored over time. The ANOVA model for production rates showed a significant temperature effect (Phydrogen-producing microorganisms.

  2. Metabolic engineering to improve ethanol production in Thermoanaerobacter mathranii

    DEFF Research Database (Denmark)

    Yao, Shuo; Mikkelsen, Marie Just

    2010-01-01

    Thermoanaerobacter mathranii can produce ethanol from lignocellulosic biomass at high temperatures, but its biotechnological exploitation will require metabolic engineering to increase its ethanol yield. With a cofactor-dependent ethanol production pathway in T. mathranii, it may become crucial...... to regenerate cofactor to increase the ethanol yield. Feeding the cells with a more reduced carbon source, such as mannitol, was shown to increase ethanol yield beyond that obtained with glucose and xylose. The ldh gene coding for lactate dehydrogenase was previously deleted from T. mathranii to eliminate...... an NADH oxidation pathway. To further facilitate NADH regeneration used for ethanol formation, a heterologous gene gldA encoding an NAD+-dependent glycerol dehydrogenase was expressed in T. mathranii. One of the resulting recombinant strains, T. mathranii BG1G1 (Δldh, P xyl GldA), showed increased ethanol...

  3. 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.

  4. [Biogas production from cellulose-containing substrates: a review].

    Science.gov (United States)

    Tsavkelova, E A; Netrusov, A I

    2012-01-01

    Anaerobic microbial conversion of organic substrates to various biofuels is one of the alternative energy sources attracting the greatest attention of scientists. The advantages of biogas production over other technologies are the ability of methanogenic communities to degrade a broad range of substrates and concomitant benefits: neutralization of organic waste, reduction of greenhouse gas emission, and fertilizer production. Cellulose-containing materials are a good substrate, but their full-scale utilization encounters a number of problems, including improvement of the quality and amount ofbiogas produced and maintenance of the stability and high efficiency of microbial communities. We review data on microorganisms that form methanogenic cellulolytic communities, enzyme complexes of anaerobes essential for cellulose fiber degradation, and feedstock pretreatment, as biodegradation is hindered in the presence of lignin. Methods for improving biogas production by optimization of microbial growth conditions are considered on the examples of biogas formation from various types of plant and paper materials: writing paper and cardboard.

  5. Ethanol Manufacture through One-step Cellulose Liquefaction Developed by Zhongren Bioenergy Company

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The pilot scale tests of one-step direct liquefaction of cel-lulose biomass developed by a Sino-US joint venture, the Huaibei Zhongren Bioenergy Technical Development Company, Ltd. in Anhui province, have made great success. This method aiming to produce fuel and chemical feedstocks from cellulose biomass requires mild reaction conditions and all organic substances contained in the cellulose biom-ass can be completely converted without losses (without carbonization and gasification).

  6. Lactic Acid and Biosurfactants Production from Residual Cellulose Films.

    Science.gov (United States)

    Portilla Rivera, Oscar Manuel; Arzate Martínez, Guillermo; Jarquín Enríquez, Lorenzo; Vázquez Landaverde, Pedro Alberto; Domínguez González, José Manuel

    2015-11-01

    The increasing amounts of residual cellulose films generated as wastes all over the world represent a big scale problem for the meat industry regarding to environmental and economic issues. The use of residual cellulose films as a feedstock of glucose-containing solutions by acid hydrolysis and further fermentation into lactic acid and biosurfactants was evaluated as a method to diminish and revalorize these wastes. Under a treatment consisting in sulfuric acid 6% (v/v); reaction time 2 h; solid liquid ratio 9 g of film/100 mL of acid solution, and temperature 130 °C, 35 g/L of glucose and 49% of solubilized film was obtained. From five lactic acid strains, Lactobacillus plantarum was the most suitable for metabolizing the glucose generated. The process was scaled up under optimized conditions in a 2-L bioreactor, producing 3.4 g/L of biomass, 18 g/L of lactic acid, and 15 units of surface tension reduction of a buffer phosphate solution. Around 50% of the cellulose was degraded by the treatment applied, and the liqueurs generated were useful for an efficient production of lactic acid and biosurfactants using L. plantarum. Lactobacillus bacteria can efficiently utilize glucose from cellulose films hydrolysis without the need of clarification of the liqueurs.

  7. 2013 DOE Bioenergy Technologies Office (BETO) Project Peer Review—Biodiesel Cellulosic Ethanol Research Project (Hendry County Sustainable Biofuels Center)

    Energy Technology Data Exchange (ETDEWEB)

    Capece, John [Intelligentsia International Inc., LaBelle, FL (United States)

    2013-05-22

    The presentation provides an overview of the Biodiesel Cellulosic Ethanol Research Project (Hendry County Sustainable Biofuels Center). It summarizes the project history, timeline, budget, partners, objectives, goals, future plans and in closer detail reviews the used approaches and technical accomplishments. The main project goals were (1) developing strategies and tools that assist in the creation of economically and environmentally sustainable bioenergy industries within ecologically-sensitive regions such as South Florida and, in particular, the greater Everglades, (2) using these bioenergy strategies and tools in evolving the existing agricultural, urban, and ecological sectors towards more sustainable structures and practices and (3) using bioenergy as a focal point in the larger effort to mitigate climate change and sea level rise, realities with particularly catastrophic consequences for South Florida. The project started on Oct 1, 2010 and ended on Feb 28, 2013. It yearly average budget was $369,770, with the Dept. of Energy annual cost share of $317,167. The main project partners were Hendry County, University of Florida - Institute of Food and Agricultural Sciences, Intelligentsia International, Inc., Edison State College and University of South Florida. Used approaches, main accomplishments and results in the categories of (1) technical research, (2) education and (3) business development are presented in detail. The project uniqueness is mainly related to the use of system approaches and integrating several systems analyses. Relevance of the project applicable to sustainability of bioenergy, food production, & restoration is explained, critical success factors are challenges are outlined and future work drafted. Finally, the main publications and presentations catalogue list is presented.

  8. Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan; Meyer, Anne S.; Mikkelsen, Jørn Dalgaard

    2013-01-01

    Product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. The optimal reaction conditions for two Emericella (Aspergillus) nidulans-derived cellobiohydrolases I and II produced in Pichia pastoris were identified as CBHI: 52 °C, pH 4.5–6.5, and CBHII: 46 °C, pH 4.......8. The optimum in a mixture of the two was 50 °C, pH 4.9. An almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kDa cut-off): The conversion of cotton cellulose after 72 h was ~19 % by weight, whereas the conversion...

  9. 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.

  10. Ethanol production from whey in a membrane recycle bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Tin, C.S.F.; Mawson, A.J. (Massey Univ., Palmerston North (New Zealand). Dept. of Biotechnology)

    1993-01-01

    Ethanol production from sulphuric acid whey permeate by Kluyveromyces marxianus Y-113 was examined in a membrane recycle bioreactor. The system was operated with 100% cell recycle and at a steady-state with 10 g litre [sup -1] biomass. At rate constant D=0.44h[sup -1] almost complete utilization of 53g litre [sup -1] lactose was achieved with an ethanol productivity of 8.6g litre [sup -1]h[sup -1]. Increasing the inlet lactose concentration or dilution rate increased the ethanol productivity but at the expense of lactose utilization. Elevated biomass or ethanol concentrations markedly decreased the specific growth rate and specific ethanol production rate. (author)

  11. Modifying yeast tolerance to inhibitory conditions of ethanol production processes

    Directory of Open Access Journals (Sweden)

    Luis eCaspeta

    2015-11-01

    Full Text Available Saccharomyces cerevisiae strains having a broad range of substrate utilization, rapid substrate consumption and conversion to ethanol, as well as good tolerance to inhibitory conditions are ideal for cost-competitive ethanol production from lignocellulose. A major drawback to directly design S. cerevisiae tolerance to inhibitory conditions of lignocellulosic ethanol production processes is the lack of knowledge about basic aspects of its cellular signaling network in response to stress. Here we highlight the inhibitory conditions found in ethanol production processes, the targeted cellular functions, the key contributions of integrated –omics analysis to reveal cellular stress responses according to these inhibitors, and current status on design-based engineering of tolerant and efficient S. cerevisiae strains for ethanol production from lignocellulose.

  12. Modifying Yeast Tolerance to Inhibitory Conditions of Ethanol Production Processes

    DEFF Research Database (Denmark)

    Caspeta, Luis; Castillo, Tania; Nielsen, Jens

    2015-01-01

    . cerevisiae tolerance to inhibitory conditions of lignocellulosic ethanol production processes is the lack of knowledge about basic aspects of its cellular signaling network in response to stress. Here, we highlight the inhibitory conditions found in ethanol production processes, the targeted cellular......Saccharomyces cerevisiae strains having a broad range of substrate utilization, rapid substrate consumption, and conversion to ethanol, as well as good tolerance to inhibitory conditions are ideal for cost-competitive ethanol production from lignocellulose. A major drawback to directly design S...... functions, the key contributions of integrated -omics analysis to reveal cellular stress responses according to these inhibitors, and current status on design-based engineering of tolerant and efficient S. cerevisiae strains for ethanol production from lignocellulose....

  13. 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)

  14. Use of sorghum straw (Sorghum bicolor for second generation ethanol production: pretreatment and enzymatic hydrolysis

    Directory of Open Access Journals (Sweden)

    Wilton Soares Cardoso

    2013-01-01

    Full Text Available Agronomic biomass yields of forage sorghum BRS 655 presented similar results to other energy crops, producing 9 to 12.6 tons/ha (dry mass of sorghum straw. The objective of this study was to evaluate the lignocellulosic part of this cultivar in terms of its potential in the different unit processes in the production of cellulosic ethanol, measuring the effects of pretreatment and enzymatic hydrolysis. Three types of pre-treatments for two reaction times were conducted to evaluate the characteristics of the pulp for subsequent saccharification. The pulp pretreated by alkali, and by acid followed by delignification, attained hydrolysis rates of over 90%.

  15. Hydrolysis of the fiber fraction from wheat based production of ethanol. Final report; Hydrolys av fiberfraktionen fraan vetebaserad etanolproduktion. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Zacchi, Guido [Lund Inst. of Technology (Sweden). Dept of Chemical Engineering

    2004-05-01

    This was a preliminary study to investigate the potential of using a larger fraction of the raw material in the production of bio-ethanol from wheat. The study comprised both the fibre fraction in the wheat kernel, i. e. the hemi cellulose and cellulose fraction that remain after the starch hydrolysis, and wheat straw which could contribute to an increase of the ethanol yield per hectare raised wheat. The project has been performed in co-operation with Agroetanol AB that provided samples from their ethanol production plant. Samples were taken at various locations in the process, i. e. the raw material, after starch hydrolysis, before and after fermentation and from the stillage after distillation. The materials were analysed for starch, hemicellulose, cellulose and lignin in the liquid and solids fractions to investigate how the hemicellulose and cellulose were affected in the process. The materials were also subjected to heat treatmen, enzymatic hydrolysis and a combination of the two to investigate how much sugars that could be released from the hemicellulose and the cellulose. In the existing process more than 80 % of the cellulose (glucan) was in the solid residue after the distillation step. The corresponding figures for the hemicellulose sugars were 60% for xylan, 70 % for arabinan and 40 % for galactan. The conclusions from the study are that the sugars in the hemicellulose fraction could be released by enzymatic hydrolysis resulting in an increase of the total sugar yield with up to 14% of the present yield. However, to utilise these sugars for ethanol production a pentose fermenting micro organism is required. To release the cellulose sugar in the solid material requires a combination of heat treatment with addition of about 0. 1 % H{sub 2}SO{sub 4} followed by enzymatic hydrolysis. On the other side this would yield sugars that directly fermentable by the baker's yeast used in the process today. Steam treatment of wheat straw has been performed after

  16. 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.

  17. Sequential saccharification of corn fiber and ethanol production by the brown rot fungus Gloeophyllum trabeum.

    Science.gov (United States)

    Rasmussen, M L; Shrestha, P; Khanal, S K; Pometto, A L; Hans van Leeuwen, J

    2010-05-01

    Degradation of lignocellulosic biomass to sugars through a purely biological process is a key to sustainable biofuel production. Hydrolysis of the corn wet-milling co-product-corn fiber-to simple sugars by the brown rot fungus Gloeophyllum trabeum was studied in suspended-culture and solid-state fermentations. Suspended-culture experiments were not effective in producing harvestable sugars from the corn fiber. The fungus consumed sugars released by fungal extracellular enzymes. Solid-state fermentation demonstrated up to 40% fiber degradation within 9days. Enzyme activity assays on solid-state fermentation filtrates confirmed the involvement of starch- and cellulose-degrading enzymes. To reduce fungal consumption of sugars and to accelerate enzyme activity, 2- and 3-d solid-state fermentation biomasses (fiber and fungus) were submerged in buffer and incubated at 37 degrees C without shaking. This anaerobic incubation converted up to almost 11% of the corn fiber into harvestable reducing sugars. Sugars released by G. trabeum were fermented to a maximum yield of 3.3g ethanol/100g fiber. This is the first report, to our knowledge, of G. trabeum fermenting sugar to ethanol. The addition of Saccharomyces cerevisiae as a co-culture led to more rapid fermentation to a maximum yield of 4.0g ethanol/100g fiber. The findings demonstrate the potential for this simple fungal process, requiring no pretreatment of the corn fiber, to produce more ethanol by hydrolyzing and fermenting carbohydrates in this lignocellulosic co-product.

  18. Recombinant host cells and media for ethanol production

    Science.gov (United States)

    Wood, Brent E; Ingram, Lonnie O; Yomano, Lorraine P; York, Sean W

    2014-02-18

    Disclosed are recombinant host cells suitable for degrading an oligosaccharide that have been optimized for growth and production of high yields of ethanol, and methods of making and using these cells. The invention further provides minimal media comprising urea-like compounds for economical production of ethanol by recombinant microorganisms. Recombinant host cells in accordance with the invention are modified by gene mutation to eliminate genes responsible for the production of unwanted products other than ethanol, thereby increasing the yield of ethanol produced from the oligosaccharides, relative to unmutated parent strains. The new and improved strains of recombinant bacteria are capable of superior ethanol productivity and yield when grown under conditions suitable for fermentation in minimal growth media containing inexpensive reagents. Systems optimized for ethanol production combine a selected optimized minimal medium with a recombinant host cell optimized for use in the selected medium. Preferred systems are suitable for efficient ethanol production by simultaneous saccharification and fermentation (SSF) using lignocellulose as an oligosaccharide source. The invention also provides novel isolated polynucleotide sequences, polypeptide sequences, vectors and antibodies.

  19. Antimicrobial peptides against contaminating bacteria in fuel ethanol production

    Science.gov (United States)

    Lactic acid bacteria (LAB) are commonly found as contaminants of fuel ethanol production, resulting in reduced ethanol yields (1). Recent reports suggest that LAB can develop resistance to antibiotics such as virginiamycin and penicillin that are commonly used to control bacterial contamination (2)...

  20. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  1. Screening of the effective cellulose-degradable strain and its application in the production of cellulose bioethanol

    Institute of Scientific and Technical Information of China (English)

    Peng-fei Gao; Dai-di Fan; Pei Ma; Yan-e Luo; Xiao-xuan Ma; Chen-hui Zhu; Jun-feng Hui

    2009-01-01

    Strains from the cellulose-containing environment were collected. Primary screening(by filter-paper Hutchison solid culture medium and sodium carboxymethylcellulose solid culture medium) and reelection(by filter-paper inorganic salt culture medium and sodium carboxymethylcellulosc Congo red coltnre medium) indicated that five strains obtained were best suited for high performance cellulose degradation. Determination of sodium carboxymethylcellulose activity(CMCA) and filter paper activity(FPA) was accomplished for each of the five. The strongest of the five in CMCA and FPA was applied to the production of cellulose bioethanol by separate hydrolysis and fermentation(SHF) and simultaneous saccharification and fermentation(SSF) respectively.

  2. Production and properties of micro-cellulose reinforced thermoplastic starch

    Science.gov (United States)

    Kmetty, Á.; Karger-Kocsis, J.; Czigány, T.

    2015-02-01

    Thermoplastic starch (TPS)/micro-fibrillated cellulose (MFC) composites were prepared from maize starch with different amount of distilled water, glycerol and cellulose reinforcement. The components were homogenized by kneader and twin roll technique. The produced TPS and TPS-based polymer composites were qualified by static and dynamic mechanical tests and their morphology was analysed by microscopic techniques. The results showed that the amount of water and the order of the production steps control the properties of both the TPS and its MFC reinforced version. With increasing content of MFC the stiffness and strength of the TPS matrix increased, as expected. Microscopic inspection revealed that the TPS has a homogenous structure and the MFC is well dispersed therein when suitable preparation conditions were selected.

  3. Crystalline structure and morphological properties of porous cellulose/clay composites: The effect of water and ethanol as coagulants.

    Science.gov (United States)

    Ahmadzadeh, Safoura; Desobry, Stephane; Keramat, Javad; Nasirpour, Ali

    2016-05-05

    In this study, cellulose foams incorporated with surface-modified montmorillonite (SM-MMT) were prepared following NaOH dissolution and regeneration into water and ethanol. According to the SEM images, the type of coagulating agent significantly affected the morphological properties of composite foams. The crystalline parameters were evaluated using wide-angle X-ray diffraction (WAXD), which showed an increase in crystal size as the effect of SM-MMT; however, the crystal size decreased for the samples treated with ethanol. The distribution of hydrogen bond types was also investigated using Fourier transform infrared (FTIR). Resolving the hydrogen-bonded OH stretching band at around 3340 into five bands indicated that presence of SM-MMT caused the shift of OH-stretching vibration band to lower wave number due to new hydrogen bonds between cellulose and SM-MMT. In general, the results indicated a change in the contents of the intra- and inter-molecular hydrogen bonds when the coagulant was changed or SM-MMT was incorporated.

  4. Continuous SSCF of AFEX™ pretreated corn stover for enhanced ethanol productivity using commercial enzymes and Saccharomyces cerevisiae 424A (LNH-ST).

    Science.gov (United States)

    Jin, Mingjie; Gunawan, Christa; Balan, Venkatesh; Yu, Xiurong; Dale, Bruce E

    2013-05-01

    High productivity processes are critical for commercial production of cellulosic ethanol. One high productivity process-continuous hydrolysis and fermentation-has been applied in corn ethanol industry. However, little research related to this process has been conducted on cellulosic ethanol production. Here, we report and compare the kinetics of both batch SHF (separate hydrolysis and co-fermentation) and SSCF (simultaneous saccharification and co-fermentation) of AFEX™ (Ammonia Fiber Expansion) pretreated corn stover (AFEX™-CS). Subsequently, we designed a SSCF process to evaluate continuous hydrolysis and fermentation performance on AFEX™-CS in a series of continuous stirred tank reactors (CSTRs). Based on similar sugar to ethanol conversions (around 80% glucose-to-ethanol conversion and 47% xylose-to-ethanol conversion), the overall process ethanol productivity for continuous SSCF was 2.3- and 1.8-fold higher than batch SHF and SSCF, respectively. Slow xylose fermentation and high concentrations of xylose oligomers were the major factors limiting further enhancement of productivity.

  5. GENETICALLY MODIFIED LIGNOCELLULOSIC BIOMASS FOR IMPROVEMENT OF ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Qijun Wang

    2010-02-01

    Full Text Available Production of ethanol from lignocellulosic feed-stocks is of growing interest worldwide in recent years. However, we are currently still facing significant technical challenges to make it economically feasible on an industrial scale. Genetically modified lignocellulosic biomass has provided a potential alternative to address such challenges. Some studies have shown that genetically modified lignocellulosic biomass can increase its yield, decreasing its enzymatic hydrolysis cost and altering its composition and structure for ethanol production. Moreover, the modified lignocellulosic biomass also makes it possible to simplify the ethanol production procedures from lignocellulosic feed-stocks.

  6. Low temperature hydrolysis for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.; Fischer, J.R.; Iannotti, E.L.

    1982-12-01

    Hydrolysis of corn was compared at two temperatures of 100/sup 0/C and 75/sup 0/C. Starch conversion to dextrose and then ethanol were determined. Yields were 10.69% ethanol in the fermented beer for 100/sup 0/C and 9.89% for 75/sup 0/C. The 75/sup 0/C hydrolysis required about 100 MJ less thermal energy than the 100/sup 0/C hydrolysis. The effects of contamination and respiration were also assessed.

  7. 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.

  8. Second Generation Ethanol Production from Brewers’ Spent Grain

    Directory of Open Access Journals (Sweden)

    Rossana Liguori

    2015-03-01

    Full Text Available Ethanol production from lignocellulosic biomasses raises a global interest because it represents a good alternative to petroleum-derived energies and reduces the food versus fuel conflict generated by first generation ethanol. In this study, alkaline-acid pretreated brewers’ spent grain (BSG was evaluated for ethanol production after enzymatic hydrolysis with commercial enzymes. The obtained hydrolysate containing a glucose concentration of 75 g/L was adopted, after dilution up to 50 g/L, for fermentation by the strain Saccharomyces cerevisiae NRRL YB 2293 selected as the best producer among five ethanologenic microorganims. When the hydrolysate was supplemented with yeast extract, 12.79 g/L of ethanol, corresponding to 0.28 g of ethanol per grams of glucose consumed (55% efficiency, was obtained within 24 h, while in the non-supplemented hydrolysate, a similar concentration was reached within 48 h. The volumetric productivity increased from 0.25 g/L·h in the un-supplemented hydrolysate to 0.53 g/L h in the yeast extract supplemented hydrolysate. In conclusion, the strain S. cerevisiae NRRL YB 2293 was shown able to produce ethanol from BSG. Although an equal amount of ethanol was reached in both BSG hydrolysate media, the nitrogen source supplementation reduced the ethanol fermentation time and promoted glucose uptake and cell growth.

  9. Nitrogen Sources Screening for Ethanol Production Using Carob Industrial Wastes.

    Science.gov (United States)

    Raposo, S; Constantino, A; Rodrigues, F; Rodrigues, B; Lima-Costa, M E

    2017-02-01

    Nowadays, bioethanol production is one of the most important technologies by the necessity to identify alternative energy resources, principally when based on inexpensive renewable resources. However, the costs of 2nd-generation bioethanol production using current biotechnologies are still high compared to fossil fuels. The feasibility of bioethanol production, by obtaining high yields and concentrations of ethanol, using low-cost medium, is the primary goal, leading the research done today. Batch Saccharomyces cerevisiae fermentation of high-density sugar from carob residues with different organic (yeast extract, peptone, urea) and inorganic nitrogen sources (ammonium sulfate, ammonium nitrate) was performed for evaluating a cost-effective ethanol production, with high ethanol yield and productivity. In STR batch fermentation, urea has proved to be a very promising nitrogen source in large-scale production of bioethanol, reaching an ethanol yield of 44 % (w/w), close to theoretical maximum yield value and an ethanol production of 115 g/l. Urea at 3 g/l as nitrogen source could be an economical alternative with a great advantage in the sustainability of ethanol production from carbohydrates extracted from carob. Simulation studies, with experimental data using SuperPro Design software, have shown that the bioethanol production biorefinery from carob wastes could be a very promising way to the valorization of an endogenous resource, with a competitive cost.

  10. Engineering Escherichia coli for improved ethanol production from gluconate.

    Science.gov (United States)

    Hildebrand, Amanda; Schlacta, Theresa; Warmack, Rebeccah; Kasuga, Takao; Fan, Zhiliang

    2013-10-10

    We report on engineering Escherichia coli to produce ethanol at high yield from gluconic acid (gluconate). Knocking out genes encoding for the competing pathways (l-lactate dehydrogenase and pyruvate formate lyase A) in E. coli KO11 eliminated lactate production, lowered the carbon flow toward acetate production, and improved the ethanol yield from 87.5% to 97.5% of the theoretical maximum, while the growth rate of the mutant strain was about 70% of the wild type. The corresponding genetic modifications led to a small improvement of ethanol yield from 101.5% to 106.0% on glucose. Deletion of the pyruvate dehydrogenase gene (pdh) alone improved the ethanol yield from 87.5% to 90.4% when gluconate was a substrate. The growth rate of the mutant strain was identical to that of the wild type. The corresponding genetic modification led to no improvements on ethanol yield on glucose.

  11. BAMBOO CELLULOSIC PULP PRODUCED BY THE ETHANOL/WATER PROCESS FOR REINFORCEMENT APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Viviane da Costa Correia

    2015-01-01

    Full Text Available Organosolv pulping is the clean chemical process of using organic solvents to aid in the removal of lignin and hemicellulose from lignocellulosic raw materials. This method provides facility for solvent recovery at the end of the process. In this work, it was to produce bamboo cellulosic pulp by the organosolv process evaluating different temperatures and reaction times, and the pulps were analyzed aiming their future application in the reinforcement of composites. The production of bamboo pulp by the organosolv process was studied varying the cooking conditions at 1, 2 and 3 h and 150, 170 and 190oC of temperature, in order to achieve the ideal conditions of yield, chemical and morphological characteristics of the pulp for its potential application in the reinforcement of composites. The best results for delignification (kappa number of 38, with relatively lower fiber degradation (viscosity of 625 cm3 g-1, aspect ratio of 40.4 and the index zero-span of 204 Nm g-1, were achieved for the pulping process at 190oC for 2 h. These pulping conditions can be considered as the more appropriate in the range of time intervals evaluated in this work. The higher mechanical strength and the lower incidence of morphological defects in the fiber (6.0% of curls and 10.6% of kinks can demonstrate the potential of organosolv bamboo pulp as a reinforcing element.

  12. 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

  13. Insights into engineering of cellulosic ethanol%纤维素乙醇工程化探讨

    Institute of Scientific and Technical Information of China (English)

    岳国君; 武国庆; 林鑫

    2014-01-01

    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.%出于对能源安全、大气污染的担忧以及促进农村经济发展的考虑,世界许多国家使用乙醇作为含氧添加剂或交通运输燃料来替代汽油.纤维素乙醇生产原料丰富,且具有明显的低碳排放特性而备受关注.随着全球范围内几套大型纤维素乙醇示范装置的相继试车,工程化问题将得到解决,并有望在2015-2016年完成装置的经济性考核,逐步进入商业化阶段.为避免原料“与人争粮,与粮争地”,1代燃料乙醇将逐步向2代纤维素乙醇过渡.本文在综述近期国内外纤维素乙醇产业化概况的基础上,从化学工程和生物工程的角度对预处理、酶制剂及酶解工艺、戊糖/己糖共发酵

  14. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Science.gov (United States)

    Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

    2015-01-01

    The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients. PMID:26140376

  15. Bacterial Cellulose Production from Industrial Waste and by-Product Streams.

    Science.gov (United States)

    Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

    2015-07-01

    The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g · water/g · dry bacterial cellulose, viscosities of 4.7-9.3 dL/g, degree of polymerization of 1889.1-2672.8, stress at break of 72.3-139.5 MPa and Young's modulus of 0.97-1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

  16. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Directory of Open Access Journals (Sweden)

    Erminda Tsouko

    2015-07-01

    Full Text Available The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L and commercial sucrose (4.9 g/L were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

  17. Influence of Crystal Allomorph and Crystallinity on the Products and Behavior of Cellulose during Fast Pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mukarakate, Calvin; Mittal, Ashutosh; Ciesielski, Peter N.; Budhi, Sridhar; Thompson, Logan; Iisa, Kristiina; Nimlos, Mark R.; Donohoe, Bryon S.

    2016-09-06

    Cellulose is the primary biopolymer responsible for maintaining the structural and mechanical integrity of cell walls and, during the fast pyrolysis of biomass, may be restricting cell wall expansion and inhibiting phase transitions that would otherwise facilitate efficient escape of pyrolysis products. Here, we test whether modifications in two physical properties of cellulose, its crystalline allomorph and degree of crystallinity, alter its performance during fast pyrolysis. We show that both crystal allomorph and relative crystallinity of cellulose impact the slate of primary products produced by fast pyrolysis. For both cellulose-I and cellulose-II, changes in crystallinity dramatically impact the fast pyrolysis product portfolio. In both cases, only the most highly crystalline samples produced vapors dominated by levoglucosan. Cellulose-III, on the other hand, produces largely the same slate of products regardless of its relative crystallinity and produced as much or more levoglucosan at all crystallinity levels compared to cellulose-I or II. In addition to changes in products, the different cellulose allomorphs affected the viscoelastic properties of cellulose during rapid heating. Real-time hot-stage pyrolysis was used to visualize the transition of the solid material through a molten phase and particle shrinkage. SEM analysis of the chars revealed additional differences in viscoelastic properties and molten phase behavior impacted by cellulose crystallinity and allomorph. Regardless of relative crystallinity, the cellulose-III samples displayed the most obvious evidence of having transitioned through a molten phase.

  18. Vitamin C enhances bacterial cellulose production in Gluconacetobacter xylinus.

    Science.gov (United States)

    Keshk, Sherif M A S

    2014-01-01

    Influence of vitamin C (ascorbic acid) on bacterial cellulose (BC) production and crystal structure was studied using four strains of Gluconacetobacter xylinus (ATCC 10245, IFO 13693, 13772 and 13773). BC productivity of all strains was increased in presence of vitamin C (0.5% w/w), the average BC production reached 0.47 g/30 ml compared with 0.25 g/30 ml without vitamin C. Enhanced productivity is associated with a decrease in gluconic acid concentration that is produced from Gluconacetobacter xylinus during BC production. X-ray results showed that the crystallinity index of BC produced in presence of ascorbic acid was the lowest with remarkable change in d-spacing. These results were confirmed by using solid state (13)CNMR. The increase in BC yield in presence of vitamin C is due to its antioxidant behavior and confirms our past work on lignosulfonate influence on BC.

  19. Ethanol production from biomass: technology and commercialization status.

    Science.gov (United States)

    Mielenz, J R

    2001-06-01

    Owing to technical improvements in the processes used to produce ethanol from biomass, construction of at least two waste-to-ethanol production plants in the United States is expected to start this year. Although there are a number of robust fermentation microorganisms available, initial pretreatment of the biomass and costly cellulase enzymes remain critical targets for process and cost improvements. A highly efficient, very low-acid pretreatment process is approaching pilot testing, while research on cellulases for ethanol production is expanding at both enzyme and organism level.

  20. Effects of ionic catalysis on hydrogen production by the steam gasification of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Su, Shen [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Li, Wen; Bai, Zongqing; Bai, Jin [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Xiang, Hongwei [Graduate University of Chinese Academy of Sciences, Beijing 100039 (China)

    2010-05-15

    In this study, significant effects of ionic catalysis on the formation of H{sub 2} and CO during the steam gasification process of cellulose are revealed. The energy of the C-H bonds of cellulose can be remarkably reduced by Na{sup +} and OH{sup -} ions produced by the dissociation of NaOH, enabling dehydrogenation of cellulose at low temperature. Dehydrogenation of cellulose is evidently affected by the concentration of Na{sup +} and OH{sup -} ions that cellulose can come into contact with. Higher concentrations of Na{sup +} and OH{sup -} ions can reduce the initial dehydrogenation temperature of cellulose to lower than 403 K. The production of CO increases after this remarkable dehydrogenation of cellulose, which indicates that the C-O bonds of cellulose are prone to forming CO by pyrolysis. (author)

  1. 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)

  2. Techno-economic Analysis of Cellulosic Ethanol%纤维素燃料乙醇技术经济分析

    Institute of Scientific and Technical Information of China (English)

    姜芹; 孙亚琴; 滕虎; 修志龙; 刘春朝

    2012-01-01

    考察了以玉米秸秆为原料生产燃料乙醇的工艺流程,对年产5万t燃料乙醇的生产工艺进行了技术经济和敏感性分析.蒸馏能耗分析表明,当发酵醪中乙醇浓度高于4%(ω)时蒸馏的能耗比较低.年产5万t燃料乙醇的直接固定成本约1.37亿元,乙醇的最低成本为8425 (¥)/t.该工艺能副产3.75万t CO2和215 t杂醇油,可带来额外收益2386万元.经济敏感性分析表明,纤维素酶价格对生产成本的影响较显著,副产物CO2的回收利用可明显增加收益.%The process technology for fuel ethanol production from corn straw was investigated, and then the techno-economic and sensitivity analysis were conducted on an annual capacity of 50 000 t ethanol. The simulation shows that the energy consumption of crude distillation tower is obviously low when the ethanol concentration in fermentation broth is higher than 4%(ω). Direct fixed capital of the process is about 137 million yuan and the lowest cost for cellulosic ethanol is 8425 ¥/t. The annual by-product output of 37500 t CO2 and 215 t fusel oil would bring additional revenue 23.86 million yuan. The economic sensitivity analysis shows that the price of cellulase is relatively sensitive to the production cost of ethanol, and the recovery and utilization of CO2 are obviously favorable for profit of process.

  3. Flowsheet Simulation of Cellulosic Ethanol Mini-plant on Aspen plus Platform%纤维素乙醇微型工厂的Aspenplus流程模拟

    Institute of Scientific and Technical Information of China (English)

    张怀庆; 乔庆安; 张建; 张茂芬; 鲍杰

    2011-01-01

    The flowsheet simulation raodel of the cellulosic ethanol mini-plant with the capacity of 1 kg/d ethanol production from corn stover and the physical property database were developed on the Aspen plus platform. The mass balance and energy balance of the mini-plant process were calculated and the results show that, producing 1 kg cellulosic ethanol required 2. 595 7 kg fresh water and 3. 605 4 kg stream, 8. 061 6 kg waste water under the maximum productivity of the cellulosic ethanol mini-plant, which was lower than the consumption of the corn based ethanol process; required energy input 36. 515 2 MJ and generated 53. 574 9 MJ, which means that the energy generation was greater than the energy consumption; the integrated energy consumption was 1. 826 9 kg standard coal, while the energy generation during this process was 1. 828 0 kg standard coal, which suggested that there was an energy balance between the output and the input.%在Aspenplus平台上对日产1kg乙醇的纤维素乙醇微型工厂流程建立流程模拟模型,并构建了完整的生物质组分物性数据库;对微型工厂流程进行了基于微型工厂实验数据和严格热力学模型基础上的物料衡算和能耗计算,并进行了水分回收分析和综合能耗折算。结果表明:在纤维素乙醇微型工厂最大生产能力下,用玉米秸秆生产1kg纤维乙醇的水用量2.5957kg,蒸汽用量3.6054kg,废水量8.0616kg,均低于目前工艺水平下的玉米淀粉生产乙醇的水用量和废水量;1kg乙醇消耗各种形式能量36.5152MJ,产出能量为53.5749MJ,能量产出大于能量投入;1kg乙醇的综合能耗折合1.8269kg标准煤,加工过程中的产出能量折合1.8280kg标准煤,能量投入和能量产出基本平衡。

  4. Granular starch hydrolysis for fuel ethanol production

    Science.gov (United States)

    Wang, Ping

    Granular starch hydrolyzing enzymes (GSHE) convert starch into fermentable sugars at low temperatures (≤48°C). Use of GSHE in dry grind process can eliminate high temperature requirements during cooking and liquefaction (≥90°C). In this study, GSHE was compared with two combinations of commercial alpha-amylase and glucoamylase (DG1 and DG2, respectively). All three enzyme treatments resulted in comparable ethanol concentrations (between 14.1 to 14.2% v/v at 72 hr), ethanol conversion efficiencies and ethanol and DDGS yields. Sugar profiles for the GSHE treatment were different from DG1 and DG2 treatments, especially for glucose. During simultaneous saccharification and fermentation (SSF), the highest glucose concentration for the GSHE treatment was 7% (w/v); for DG1 and DG2 treatments, maximum glucose concentration was 19% (w/v). GSHE was used in one of the fractionation technologies (enzymatic dry grind) to improve recovery of germ and pericarp fiber prior to fermentation. The enzymatic dry grind process with GSHE was compared with the conventional dry grind process using GSHE with the same process parameters of dry solids content, pH, temperature, time, enzyme and yeast usages. Ethanol concentration (at 72 hr) of the enzymatic process was 15.5% (v/v), which was 9.2% higher than the conventional process (14.2% v/v). Distillers dried grains with solubles (DDGS) generated from the enzymatic process (9.8% db) was 66% less than conventional process (28.3% db). Three additional coproducts, germ 8.0% (db), pericarp fiber 7.7% (db) and endosperm fiber 5.2% (db) were produced. Costs and amounts of GSHE used is an important factor affecting dry grind process economics. Proteases can weaken protein matrix to aid starch release and may reduce GSHE doses. Proteases also can hydrolyze protein into free amino nitrogen (FAN), which can be used as a yeast nutrient during fermentation. Two types of proteases, exoprotease and endoprotease, were studied; protease and urea

  5. Fuel Processing Plants - ETHANOL_PRODUCTION_FACILITIES_IN: Ethanol Production Facilities in Indiana (Indiana Geological Survey, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This GIS layer shows the locations of ethanol production facilities in the state of Indiana. Attributes include the name and address of the facility, and information...

  6. 加快我国纤维乙醇产业发展的建议%Suggestions to Speed Up the Development of Cellulosic Ethanol Industry in China

    Institute of Scientific and Technical Information of China (English)

    刘钺; 杜风光

    2014-01-01

    With the continuous growth of China�s car ownership,vehicle emissions has become one of the important factors that affect air quality. Cellulosic ethanol, with the superiority of being a kind of green, environmentally friendly and renewable resource,can contribute to promote combustion and to reduce emissions. This paper summarized the importance and necessity of developing cellulosic ethanol industry considering from the national energy security,food security,farmers�income, environmental pollution and other aspects. Meanwhile, combined with the current development status of cellulosic ethanol industry, this paper also proposed policy recommendations for cellulosic ethanol industry.%随着我国汽车保有量的不断增长,机动车尾气排放成为影响空气质量的重要因素之一。燃料乙醇具有绿色、环保、可再生的资源优势,能够促进燃烧、减少排放污染。本文从国家能源安全、粮食安全、农民增收和环境污染等多方面综述了发展纤维乙醇产业的重要性和必要性,同时结合当前纤维乙醇产业的发展现状对纤维乙醇产业政策提出了建议。

  7. Cellulosic Ethanol Commercialization Status and Development Suggestions%纤维素乙醇商业化现状及发展建议

    Institute of Scientific and Technical Information of China (English)

    郭卫军

    2015-01-01

    In this paper, the technical progress in pretreatment of raw materials, enzymatic hydrolysis and fermentation is reviewed. Cellulosic ethanol commercialization status is emphatically discussed and the problems existing in the industrialization of cellulosic ethanol are analyzed. Suggestions on the development of fuel ethanol industry in China are proposed, cellulosic ethanol industry development should come from strengthening supply chain, breaking through the key technology, accelerating demonstration in comprehensive utilization of cellulose resources.%综述了纤维素乙醇的原料预处理、酶解和发酵工艺技术进展;重点介绍了纤维素乙醇商业化现状,并对纤维素乙醇产业化存在的问题进行了分析;针对我国燃料乙醇产业发展提出了建议:我国应构建原料供应体系,突破关键技术,加快综合利用纤维素资源示范,促进纤维素乙醇产业快速发展。

  8. Effects of Fractionation Methods on the Isolation of Fiber-rich Cake from Alfalfa and Ethanol Production from the Cake

    Directory of Open Access Journals (Sweden)

    Shuangning Xiu

    2014-04-01

    Full Text Available Freshly harvested alfalfa was fractionated using centrifugation and filtration, whereby alfalfa was separated into a fiber-rich cake and a nutrient-rich juice. The solid cakes from the above separation processes were used as the feedstock for ethanol production using separate hydrolysis and fermentation. The filtration process proved to be more efficient at reducing the solids mass transfer to the juice than the centrifuge process. Glucose from filtered alfalfa solid cake can be efficiently fermented to ethanol with 75% of the theoretical yield. In conclusion, centrifugation was not as effective as filtration in removing particulates and colloidal matter from alfalfa. The filtration process resulted in a solid cake with a higher cellulose digestibility, which leads to a higher ethanol production.

  9. 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

  10. Ethanol production in Brazil: a bridge between science and industry

    Directory of Open Access Journals (Sweden)

    Mario Lucio Lopes

    Full Text Available ABSTRACT In the last 40 years, several scientific and technological advances in microbiology of the fermentation have greatly contributed to evolution of the ethanol industry in Brazil. These contributions have increased our view and comprehension about fermentations in the first and, more recently, second-generation ethanol. Nowadays, new technologies are available to produce ethanol from sugarcane, corn and other feedstocks, reducing the off-season period. Better control of fermentation conditions can reduce the stress conditions for yeast cells and contamination by bacteria and wild yeasts. There are great research opportunities in production processes of the first-generation ethanol regarding high-value added products, cost reduction and selection of new industrial yeast strains that are more robust and customized for each distillery. New technologies have also focused on the reduction of vinasse volumes by increasing the ethanol concentrations in wine during fermentation. Moreover, conversion of sugarcane biomass into fermentable sugars for second-generation ethanol production is a promising alternative to meet future demands of biofuel production in the country. However, building a bridge between science and industry requires investments in research, development and transfer of new technologies to the industry as well as specialized personnel to deal with new technological challenges.

  11. Ethanol production in Brazil: a bridge between science and industry.

    Science.gov (United States)

    Lopes, Mario Lucio; Paulillo, Silene Cristina de Lima; Godoy, Alexandre; Cherubin, Rudimar Antonio; Lorenzi, Marcel Salmeron; Giometti, Fernando Henrique Carvalho; Bernardino, Claudemir Domingues; Amorim Neto, Henrique Berbert de; Amorim, Henrique Vianna de

    2016-12-01

    In the last 40 years, several scientific and technological advances in microbiology of the fermentation have greatly contributed to evolution of the ethanol industry in Brazil. These contributions have increased our view and comprehension about fermentations in the first and, more recently, second-generation ethanol. Nowadays, new technologies are available to produce ethanol from sugarcane, corn and other feedstocks, reducing the off-season period. Better control of fermentation conditions can reduce the stress conditions for yeast cells and contamination by bacteria and wild yeasts. There are great research opportunities in production processes of the first-generation ethanol regarding high-value added products, cost reduction and selection of new industrial yeast strains that are more robust and customized for each distillery. New technologies have also focused on the reduction of vinasse volumes by increasing the ethanol concentrations in wine during fermentation. Moreover, conversion of sugarcane biomass into fermentable sugars for second-generation ethanol production is a promising alternative to meet future demands of biofuel production in the country. However, building a bridge between science and industry requires investments in research, development and transfer of new technologies to the industry as well as specialized personnel to deal with new technological challenges.

  12. Recent Advances in Second Generation Ethanol Production by Thermophilic Bacteria

    Directory of Open Access Journals (Sweden)

    Sean Michael Scully

    2014-12-01

    Full Text Available There is an increased interest in using thermophilic bacteria for the production of bioethanol from complex lignocellulosic biomass due to their higher operating temperatures and broad substrate range. This review focuses upon the main genera of thermophilic anaerobes known to produce ethanol, their physiology, and the relevance of various environmental factors on ethanol yields including the partial pressure of hydrogen, ethanol tolerance, pH and substrate inhibition. Additionally, recent development in evolutionary adaptation and genetic engineering of thermophilic bacteria is highlighted. Recent developments in advanced process techniques used for ethanol production are reviewed with an emphasis on the advantages of using thermophilic bacteria in process strategies including separate saccharification and fermentation, simultaneous saccharification and fermentation (SSF, and consolidated bioprocessing (CBP.

  13. Ethanol Production from Traditional and Emerging Raw Materials

    Science.gov (United States)

    Rudolf, Andreas; Karhumaa, Kaisa; Hahn-Hägerdal, Bärbel

    The ethanol industry of today utilizes raw materials rich in saccharides, such as sugar cane or sugar beets, and raw materials rich in starch, such as corn and wheat. The concern about supply of liquid transportation fuels, which has brought the crude oil price above 100 /barrel during 2006, together with the concern about global warming, have turned the interest towards large-scale ethanol production from lignocellulosic materials, such as agriculture and forestry residues. Baker's yeast Saccharomyces cerevisiae is the preferred fermenting microorganism for ethanol production because of its superior and well-documented industrial performance. Extensive work has been made to genetically improve S. cerevisiae to enable fermentation of lignocellulosic raw materials. Ethanolic fermentation processes are conducted in batch, fed-batch, or continuous mode, with or without cell recycling, the relative merit of which will be discussed.

  14. 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

  15. 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.

  16. Bacterial cellulose production from the litchi extract by Gluconacetobacter xylinus.

    Science.gov (United States)

    Yang, Xiao-Yan; Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Luo, Jun; Wang, Bo; Lin, Xiao-Qing; Chen, Xue-Fang; Chen, Xin-De

    2016-01-01

    Although litchi has both nutrient and edible value, the extremely short preservation time limited its further market promotion. To explore processed litchi products with longer preservation time, litchi extract was selected as an alternative feedstock for production of bacterial cellulose (BC). After 2 weeks of static fermentation, 2.53 g/L of the BC membrane was obtained. The trace elements including magnesium (Mg) and sodium (Na) in the litchi extract were partly absorbed in the BC membrane, but no potassium (K) element was detected in it, curiously. Scanning electron microscope (SEM) photographs exhibited an ultrafine network nanostructure for the BC produced in the litchi extract. Analysis of the fourier-transform infrared spectroscopy (FTIR) confirmed the pellicles to be a cellulosic material. Interestingly, X-ray diffraction (XRD) results showed the BC membrane obtained from litchi extract had higher crystallinity of 94.0% than that from HS medium. Overall, the work showed the potential of producing high value-added polymer from litchi resources.

  17. Acid hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  18. Advances in ethanol reforming for the production of hydrogen

    Directory of Open Access Journals (Sweden)

    Laura Guerrero

    2014-06-01

    Full Text Available Catalytic steam reforming of ethanol (SRE is a promising route for the production of renewable hydrogen (H2. This article reviews the influence of doping supported-catalysts used in SRE on the conversion of ethanol, selectivity for H2, and stability during long reaction periods. In addition, promising new technologies such as membrane reactors and electrochemical reforming for performing SRE are presented.

  19. Production d'éthanol a partir de biomasse lignocellulosique Ethanol Production from Lignocellulosic Biomass

    Directory of Open Access Journals (Sweden)

    Ogier J. C.

    2006-12-01

    the short or middle term. Lignocellulosic biomass is a complex substrate, and essentially made of cellulose, hemicellulose and lignin. The processes which have been considered, attempt to recover a maximum amount of sugars from the hydrolysis of cellulose and hemicellulose, and to ferment them into ethanol. The hydrolysis processes used in the past are essentially chemical processes, but the acid recovery costs and the formation of toxic products make them uncompetitive. They are now substituted by enzymatic processes, which are more specific and allow higher hydrolysis yields under less severe conditions. However, the cellulose that is the target of the enzymatic hydrolysis, is not directly accessible to the enzymes. It is the reason why a pretreatment step has to precede the enzymatic hydrolysis, in order to improve the enzymatic susceptibility of the cellulose, and to hydrolyse the hemicellulosic fraction. Different types of pretreatment have been studied, but three methods appear more efficient: dilute acid hydrolysis, steam explosion with catalyst addition and thermohydrolysis. These pretreatments could result in high hydrolysis yields of the cellulose fraction (close to 100%, and in a maximum recovery of the sugars from the hemicellulosic fraction. Enzymatic hydrolysis has yet to be improved in order to reduce the cost of consumption of the enzymes. Research works will have to focus upon the enzyme specific activity, in order to achieve higher efficiencies such as those obtained with amylases. The SSF (Saccharfication and Simultaneous Fermentation process improves the enzyme efficiency by reducing the feed-back inhibition from the hydrolysis products. The screening of efficient fermentative microorganisms under high temperature conditions (45°C has thus to be further implemented. The last technological barrier of the process concerns the ethanolic fermentation of the pentoses. Indeed, the pentoses, originating from the hemicellulosic fraction, can represent up

  20. Ethanol Production from Waste Potato Mash by Using Saccharomyces Cerevisiae

    Directory of Open Access Journals (Sweden)

    Gulten Izmirlioglu

    2012-10-01

    Full Text Available Bio-ethanol is one of the energy sources that can be produced by renewable sources. Waste potato mash was chosen as a renewable carbon source for ethanol fermentation because it is relatively inexpensive compared with other feedstock considered as food sources. However, a pretreatment process is needed: specifically, liquefaction and saccharification processes are needed to convert starch of potato into fermentable sugars before ethanol fermentation. In this study, hydrolysis of waste potato mash and growth parameters of the ethanol fermentation were optimized to obtain maximum ethanol production. In order to obtain maximum glucose conversions, the relationship among parameters of the liquefaction and saccharification process was investigated by a response surface method. The optimum combination of temperature, dose of enzyme (α-amylase and amount of waste potato mash was 95 °C, 1 mL of enzyme (18.8 mg protein/mL and 4.04 g dry-weight/100 mL DI water, with a 68.86% loss in dry weight for liquefaction. For saccharification, temperature, dose of enzyme and saccharification time were optimized and optimum condition was determined as 60 °C-72 h-0.8 mL (300 Unit/mL of amyloglucosidase combination, yielded 34.9 g/L glucose. After optimization of hydrolysis of the waste potato mash, ethanol fermentation was studied. Effects of pH and inoculum size were evaluated to obtain maximum ethanol. Results showed that pH of 5.5 and 3% inolculum size were optimum pH and inoculum size, respectively for maximum ethanol concentration and production rate. The maximum bio-ethanol production rate was obtained at the optimum conditions of 30.99 g/L ethanol. Since yeast extract is not the most economical nitrogen source, four animal-based substitutes (poultry meal, hull and fines mix, feather meal, and meat and bone meal were evaluated to determine an economical alternative nitrogen source to yeast extract. Poultry meal and feather meal were able to produce 35 g/L and

  1. Life cycle cost of ethanol production from cassava in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Sorapipatana, Chumnong; Yoosin, Suthamma [Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Pracha-Uthit Rd., Tungkru, Bangmod, Bangkok 10140 (Thailand); Center for Energy Technology and Environment, Commission on Higher Education, Ministry of Education, Bangkok (Thailand)

    2011-02-15

    To increase the security of energy supply, lessen dependence on crude oil import and buffer against the impacts of large change in crude oil prices, the Thai government initiated and officially announced the national ethanol fuel program in year 2000. Since then, domestic ethanol demand has grown rapidly. Presently, all commercial ethanol in Thailand is produced from molasses as Thai law prohibits producing it from sugar cane directly. This is likely to limit ethanol supply in the near future. One possible solution is to supply more ethanol from cassava which is widely cultivated in this country. However, its production cost has not yet been known for certain. The objective of this study is to estimate the life cycle cost of ethanol production from cassava and to assess its economic competitiveness with gasoline in the Thai fuel market. Based on the record of cassava prices during the years 2002-2005, it was found that using it as feedstock would share more than 50% of the ethanol from cassava total production cost. It was also found that a bio-ethanol plant, with a capacity of 150,000 l/day, can produce ethanol from cassava in a range of ex-factory costs from 16.42 to 20.83 baht/l of gasoline equivalent (excluding all taxes), with an average cost of 18.15 baht/l of gasoline equivalent (41, 52 and 45 US cents/l gasoline equivalent respectively, based on 2005 exchange rate). In the same years, the range of 95-octane gasoline prices in Thailand varied from 6.18 baht to 20.86 baht/l, with an average price of 11.50 baht/l (15, 52 and 29 US cents/l respectively, based on 2005 exchange rate) which were much cheaper than the costs of ethanol made from cassava. Thus, we conclude that under the scenario of low to normal crude oil price, ethanol from cassava is not competitive with gasoline. The gasoline price has to rise consistently above 18.15 baht (45 US cents)/l before ethanol made from cassava can be commercially competitive with gasoline. (author)

  2. Feasibility of Bioethanol Production From Lignocellulosic Biomass

    Science.gov (United States)

    Aunina, Zane; Bazbauers, Gatis; Valters, Karlis

    2010-01-01

    The objective of the paper is to discuss the potential of cellulosic ethanol production processes and compare them, to find the most appropriate production method for Latvia's situation, to perform theoretical calculations and to determine the potential ethanol price. In addition, price forecasts for future cellulosic and grain ethanol are compared. A feasibility estimate to determine the price of cellulosic ethanol in Latvia, if production were started in 2010, was made. The grain and cellulosic ethanol price comparison (future forecast) was made through to the year 2018.

  3. Endogenous ethanol production in trauma victims associated with medical treatment.

    Science.gov (United States)

    Moriya, F; Hashimoto, Y

    1996-08-01

    Four cases of trauma, where endogenous ethanol production was suspected to have been occurred in association with medical treatment, are reported. To discriminate endogenous ethanol produced de novo by bacteria from exogenous ethanol by drinking, various tissues and body fluids, such as brain and cerebrospinal fluid, together with blood obtained from various locations, were subjected to analysis for both ethanol and n-propanol. The first individual was a 40-year-old man who had been stabbed in the abdomen with a knife and had died of bleeding about 12 h after peritoneotomy, and autopsied 12 h later. In the heart blood, 0.44 mg/g ethanol and 0.005 mg/g n-propanol were detected. Ethanol levels in the cerebrospinal fluid, vitreous humor and brain, reflecting exogenous ethanol levels, were 0.08-0.16 mg/g, and no n-propanol was detected in any of the specimens. The second individual was a 45-year-old man who had been punched hard in the head and face and had died of traumatic shock about 12 h after hospitalization, and autopsied 12 h later. The heart blood concentrations of ethanol and n-propanol were 0.15 and 0.008 mg/g respectively, and a subdural hematoma contained only 0.05 mg/g ethanol and non n-propanol. The third individual was a 34-year-old man who suffered incised wounds of the left arm and head with a sickle and had died of hemorrhagic shock. In the heart blood, 0.30 mg/g ethanol and 0.026 mg/g n-propanol were detected; there was 0.04 mg/g ethanol and no n-propanol in the brain. The fourth individual was a 76-year-old woman who had been hit by a motorcycle and had died of liver rupture about 1 h after admission to a hospital. The heart blood contained 0.22 mg/g ethanol and 0.002 mg/g n-propanol. Only a trace of ethanol and no n-propanol were detected in the pericardial sac fluid and cerebrospinal fluid.

  4. Production of fungal protein from cellulosic plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Sitaram, N.; Kunhi, A.A.M.; Geethadevi, B.R.; Rao, T.N.R.

    1979-01-01

    The ability of 5 Aspergillus niger strains, a Penicillium chrysogenum strain, a Pestalotia strain, and a basidiomycete to produce microbial protein on 3 alkali-treated cellulosic substrates (rice straw, bagasse, and peanut shells) was evaluated. Most strains grew better on rice straw than on the other 2 substrates. Penicillium chrysogenum St-F3B produced more protein on all 3 substrates than did any of the other strains with a maximum production on rice straw of 85 mg/g substrate after 72 h incubation on a rotary shaker at pH 3.5 to 6.0. An inverse relation between substrate concentration and protein production per g substrate was observed with this organism.

  5. Bridging the logistics gap for sustainable ethanol production: the CentroSul ethanol pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Megiolaro, Moacir; Daud, Rodrigo; Pittelli, Fernanda [CentroSul Transportadora Dutoviaria, SP (Brazil); Singer, Eugenio [EMS Consultant, Sao Paulo, SP (Brazil)

    2009-07-01

    The continuous increase of ethanol production and growth in consumption in Brazil is a reality that poses significant logistics challenges both for producers and consumers. The Brazilian local market absorbs a great portion of the country's production of ethanol, but the export market is also experiencing significant expansion so that both local and external market consumption will require more adequate transportation solutions. The alternative routes for Brazilian ethanol exports within the South and Southeast regions of Brazil range from the port of Paranagua, in the state of Parana, to the port of Vitoria, in the state of Espirito Santo. Each of these routes is about 1,000 km distance from the main production areas in the Central South states of Brazil. Brazilian highways and railways systems are overly congested and do not present efficient logistics alternatives for the transportation of large ethanol flows over long distances (cross-country) from the central Midwest regions of the country to the consumer and export markets in the Southeast. In response to the challenge to overcome such logistic gaps, CentroSul Transportadora Dutoviaria 'CentroSul', a company recently founded by a Brazilian ethanol producer group, the Brenco Group, is developing a project for the first fully-dedicated ethanol pipeline to be constructed in Brazil. The ethanol pipeline will transport 3,3 million m{sup 3} of Brenco - Brazilian Renewable Energy Company's ethanol production and an additional 4,7 million cubic meters from other Brazilian producers. The pipeline, as currently projected, will, at its full capacity, displace a daily vehicle fleet equivalent to 500 trucks which would be required to transport the 8,0 million cubic meters from their production origins to the delivery regions. In addition, the project will reduce GHG (trucking) emissions minimizing the project's overall ecological footprint. Key steps including conceptual engineering, environmental

  6. Progress on Pyrolysis of Cellulose and Its Conversion to Ethanol%纤维素热解及其产物转化乙醇的研究进展

    Institute of Scientific and Technical Information of China (English)

    常冬冬; 余志晟; 张洪勋

    2012-01-01

    为了研究纤维素物质热解产物的乙醇转化,综述了国内外近几年纤维素热解影响因素及其产物(主要为内醚糖)转化乙醇的研究现状,研究发现以往的研究并没有重视热解过程中各影响因素的综合作用、获得的产物,如内醚糖产率不够理想,同时对热解液主要采取水解后发酵的方式生产乙醇,也不经济可行.通过基因工程技术构建乙醇工程菌,从而实现纤维素热解液向乙醇的直接转化将成为未来发展趋势.%In order to explore the conversion of cellulose biomass to ethanol, the author reviewe the current research progress on the pyrolysis conditions of cellulose and converting its pyrolysate (mainly levoglucosan) to ethanol at home and abroad in recent years. It' s found that previous studies are short of caring combinations with different pyrolysis conditions, which may be responsible for the yield of the product such as levoglucosan in the process of the pyrolysis, and also the conventional way via fermenting the hydrolysate of pyrolysate to ethanol is not economical. It would be a trend that the direct conversion of cellulose via pyrolysis to ethanol could be realized by constructing ethanologenic microbial strains with genetic engineering technologies in the future.

  7. Environmental aspects of eucalyptus based ethanol production and use

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, Sara, E-mail: sara.gez.garcia@gmail.com [Division of Biology, Department of Life Sciences, Sir Alexander Fleming Building, Imperial College of London, South Kensington Campus, London SW7 2AZ (United Kingdom); Moreira, Ma. Teresa; Feijoo, Gumersindo [Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782-Santiago de Compostela (Spain)

    2012-11-01

    A renewable biofuel economy is projected as a pathway to decrease dependence on fossil fuels as well as to reduce greenhouse gases (GHG) emissions. Ethanol produced on large-scale from lignocellulosic materials is considered the automotive fuel with the highest potential. In this paper, a life cycle assessment (LCA) study was developed to evaluate the environmental implications of the production of ethanol from a fast-growing short rotation crop (SRC): eucalyptus as well as its use in a flexi-fuel vehicle (FFV). The aim of the analysis was to assess the environmental performance of three ethanol based formulations: E10, E85 and E100, in comparison with conventional gasoline. The standard framework of LCA from International Standards Organization was followed and the system boundaries included the cultivation of the eucalyptus biomass, the processing to ethanol conversion, the blending with gasoline (when required) and the final use of fuels. The environmental results show reductions in all impact categories under assessment when shifting to ethanol based fuels, excluding photochemical oxidant formation, eutrophication as well as terrestrial and marine ecotoxicity which were considerably influenced by upstream activities related to ethanol manufacture. The LCA study remarked those stages where the researchers and technicians need to work to improve the environmental performance. Special attention must be paid on ethanol production related activities, such as on-site energy generation and distillation, as well as forest activities oriented to the biomass production. The use of forest machinery with higher efficiency levels, reduction of fertilizers dose and the control of diffuse emissions from the conversion plant would improve the environmental profile. -- Highlights: Black-Right-Pointing-Pointer The identification of the environmental implications of the production and use of eucalyptus based ethanol was carried out. Black-Right-Pointing-Pointer Eucalyptus is a

  8. Sweet sorghum as feedstock for ethanol production: enzymatic hydrolysis of steam-pretreated bagasse.

    Science.gov (United States)

    Sipos, Bálint; Réczey, Jutka; Somorai, Zsolt; Kádár, Zsófia; Dienes, Dóra; Réczey, Kati

    2009-05-01

    Sweet sorghum is an attractive feedstock for ethanol production. The juice extracted from the fresh stem is composed of sucrose, glucose, and fructose and can therefore be readily fermented to alcohol. The solid fraction left behind, the so-called bagasse, is a lignocellulosic residue which can also be processed to ethanol. The objective of our work was to test sweet sorghum, the whole crop, as a potential raw material of ethanol production, i.e., both the extracted sugar juice and the residual bagasse were tested. The juice was investigated at different harvesting dates for sugar content. Fermentability of juices extracted from the stem with and without leaves was compared. Sweet sorghum bagasse was steam-pretreated using various pretreatment conditions (temperatures and residence times). Efficiency of pretreatments was characterized by the degree of cellulose hydrolysis of the whole pretreated slurry and the separated fiber fraction. Two settings of the studied conditions (190 degrees C, 10 min and 200 degrees C, 5 min) were found to be efficient to reach conversion of 85-90%.

  9. Metabolic engineering of ethanol production in Thermoanaerobacter mathranii

    Energy Technology Data Exchange (ETDEWEB)

    Shou Yao

    2010-11-15

    Strain BG1 is a xylanolytic, thermophilic, anaerobic, Gram-positive bacterium originally isolated from an Icelandic hot spring. The strain belongs to the species Thermoanaerobacter mathranii. The strain ferments glucose, xylose, arabinose, galactose and mannose simultaneously and produces ethanol, acetate, lactate, CO{sub 2}, and H2 as fermentation end-products. As a potential ethanol producer from lignocellulosic biomass, tailor-made BG1 strain with the metabolism redirected to produce ethanol is needed. Metabolic engineering of T. mathranii BG1 is therefore necessary to improve ethanol production. Strain BG1 contains four alcohol dehydrogenase (ADH) encoding genes. They are adhA, adhB, bdhA and adhE encoding primary alcohol dehydrogenase, secondary alcohol dehydrogenase, butanol dehydrogenase and bifunctional alcohol/acetaldehyde dehydrogenase, respectively. The presence in an organism of multiple alcohol dehydrogenases with overlapping specificities makes the determination of the specific role of each ADH difficult. Deletion of each individual adh gene in the strain revealed that the adhE deficient mutant strain fails to produce ethanol as the fermentation product. The bifunctional alcohol/acetaldehyde dehydrogenase, AdhE, is therefore proposed responsible for ethanol production in T. mathranii BG1, by catalyzing sequential NADH-dependent reductions of acetyl-CoA to acetaldehyde and then to ethanol under fermentative conditions. Moreover, AdhE was conditionally expressed from a xylose-induced promoter in a recombinant strain (BG1E1) with a concomitant deletion of a lactate dehydrogenase. Over-expression of AdhE in strain BG1E1 with xylose as a substrate facilitates the production of ethanol at an increased yield. With a cofactor-dependent ethanol production pathway in T. mathranii BG1, it may become crucial to regenerate cofactor to increase the ethanol yield. Feeding the cells with a more reduced carbon source, such as mannitol, was shown to increase ethanol

  10. The state of autotrophic ethanol production in Cyanobacteria.

    Science.gov (United States)

    Dexter, J; Armshaw, P; Sheahan, C; Pembroke, J T

    2015-07-01

    Ethanol production directly from CO2 , utilizing genetically engineered photosynthetic cyanobacteria as a biocatalyst, offers significant potential as a renewable and sustainable source of biofuel. Despite the current absence of a commercially successful production system, significant resources have been deployed to realize this goal. Utilizing the pyruvate decarboxylase from Zymomonas species, metabolically derived pyruvate can be converted to ethanol. This review of both peer-reviewed and patent literature focuses on the genetic modifications utilized for metabolic engineering and the resultant effect on ethanol yield. Gene dosage, induced expression and cassette optimizat-ion have been analyzed to optimize production, with production rates of 0·1-0·5 g L(-1) day(-1) being achieved. The current 'toolbox' of molecular manipulations and future directions focusing on applicability, addressing the primary challenges facing commercialization of cyanobacterial technologies are discussed.

  11. Solving ethanol production problems with genetically modified yeast strains

    Directory of Open Access Journals (Sweden)

    A. Abreu-Cavalheiro

    2013-09-01

    Full Text Available The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast.

  12. Improvement of acetone, butanol, and ethanol production from woody biomass using organosolv pretreatment.

    Science.gov (United States)

    Amiri, Hamid; Karimi, Keikhosro

    2015-10-01

    A suitable pretreatment is a prerequisite of efficient acetone-butanol-ethanol (ABE) production from wood by Clostridia. In this study, organosolv fractionation, an effective pretreatment with ability to separate lignin as a co-product, was evaluated for ABE production from softwood pine and hardwood elm. ABE production from untreated woods was limited to the yield of 81 g ABE/kg wood and concentration of 5.5 g ABE/L. Thus, the woods were pretreated with aqueous ethanol at elevated temperatures before hydrolysis and fermentation to ABE by Clostridium acetobutylicum. Hydrolysis of pine and elm pretreated at 180 °C for 60 min resulted in the highest sugar concentrations of 16.8 and 23.2 g/L, respectively. The hydrolysate obtained from elm was fermented to ABE with the highest yield of 121.1 g/kg and concentration of 11.6 g/L. The maximum yield of 87.9 g/kg was obtained from pine pretreated for 30 min at 150 °C. Moreover, structural modifications in the woods were investigated and related to the improvements. The woody biomasses are suitable feedstocks for ABE production after the organosolv pretreatment. Effects of the pretreatment conditions on ABE production might be related to the reduced cellulose crystallinity, reduced lignin and hemicellulose content, and lower total phenolic compounds in the hydrolysates.

  13. Process Alternatives for Second Generation Ethanol Production from Sugarcane Bagasse

    DEFF Research Database (Denmark)

    F. Furlan, Felipe; Giordano, Roberto C.; Costa, Caliane B. B.

    2015-01-01

    includes the enzymatic hydrolysis of sugarcane bagasse pretreated with liquid hot water, and the analyzed parameters were the solid consistency in the hydrolysis and pretreatment reactors and the hydrolysis reaction time. The solid consistency in the hydrolysis reactor had the highest influence...... on the economic feasibility of the process. For the economic scenario considered in this study, using bagasse to increase ethanol production yielded higher ethanol production costs compared to using bagasse for electric energy production, showing that further improvements in the process are still necessary....

  14. 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.

  15. Methods for increasing the production of ethanol from microbial fermentation

    Science.gov (United States)

    Gaddy, James L.; Arora, Dinesh K.; Ko, Ching-Whan; Phillips, John Randall; Basu, Rahul; Wikstrom, Carl V.; Clausen, Edgar C.

    2007-10-23

    A stable continuous method for producing ethanol from the anaerobic bacterial fermentation of a gaseous substrate containing at least one reducing gas involves culturing a fermentation bioreactor anaerobic, acetogenic bacteria in a liquid nutrient medium; supplying the gaseous substrate to the bioreactor; and manipulating the bacteria in the bioreactor by reducing the redox potential, or increasing the NAD(P)H TO NAD(P) ratio, in the fermentation broth after the bacteria achieves a steady state and stable cell concentration in the bioreactor. The free acetic acid concentration in the bioreactor is maintained at less than 5 g/L free acid. This method allows ethanol to be produced in the fermentation broth in the bioreactor at a productivity greater than 10 g/L per day. Both ethanol and acetate are produced in a ratio of ethanol to acetate ranging from 1:1 to 20:1.

  16. 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%).

  17. Hydrogen peroxide production from fibrous pectic cellulose analogs and effect on dermal fibroblasts

    Science.gov (United States)

    Naturally derived products with folklore remedies have in recent years been reconsidered for their benefit to wound healing i.e., honey’s application to chronic wound dressing products. Similarly, we have undertaken an evaluation of Fibrous pectin-cellulose (FPC) (cellulose blended with primary cel...

  18. Protease increases fermentation rate and ethanol yield in dry-grind ethanol production.

    Science.gov (United States)

    Johnston, David B; McAloon, Andrew J

    2014-02-01

    The effects of acid protease and urea addition during the fermentation step were evaluated. The fermentations were also tested with and without the addition of urea to determine if protease altered the nitrogen requirements of the yeast. Results show that the addition of the protease had a statistically significant effect on the fermentation rate and yield. Fermentation rates and yields were improved with the addition of the protease over the corresponding controls without protease. Protease addition either with or with added urea resulted in a higher final ethanol yield than without the protease addition. Urea addition levels >1200 ppm of supplemental nitrogen inhibited ethanol production. The economic effects of the protease addition were evaluated by using process engineering and economic models developed at the Eastern Regional Research Center. The decrease in overall processing costs from protease addition was as high as $0.01/L (4 ¢/gal) of denatured ethanol produced.

  19. Ethanol production from carob extract by using Saccharomyces cerevisiae.

    Science.gov (United States)

    Turhan, Irfan; Bialka, Katherine L; Demirci, Ali; Karhan, Mustafa

    2010-07-01

    Carob has been widely grown in the Mediterranean region for a long time. It has been regarded as only a forest tree and has been neglected for other economical benefits. However, in recent years, this fruit has gained attention for several applications. As petroleum has become depleted, renewable energy production has started to gain attention all over the world; including the production of ethanol from underutilized agricultural products such as carob. In this project, the optimum extraction conditions were determined for the carob fruit by using the response surface design method. The obtained extract was utilized for production of ethanol by using suspended Saccharomyces cerevisiae fermentation. The effect of various fermentation parameters such as pH, media content and inoculum size were evaluated for ethanol fermentation in carob extract. Also, in order to determine economically appropriate nitrogen sources, four different nitrogen sources were evaluated. The optimum extraction condition for carob extract was determined to be 80 degrees C, 2h in 1:4 dilution rate (fruit: water ratio) according to the result of response surface analysis (115.3g/L). When the fermentation with pH at 5.5 was applied, the final ethanol concentration and production rates were 42.6g/L and 3.37 g/L/h, respectively, which were higher than using an uncontrolled pH. Among inoculum sizes of 1%, 3%, and 5%, 3% was determined as the best inoculum size. The maximum production rate and final ethanol concentration were 3.48 g/L/h and 44.51%, respectively, with an alternative nitrogen source of meat-bone meal. Overall, this study suggested that carob extract can be utilized for production of ethanol in order to meet the demands of renewable energy.

  20. Corn ethanol production, food exports, and indirect land use change.

    Science.gov (United States)

    Wallington, T J; Anderson, J E; Mueller, S A; Kolinski Morris, E; Winkler, S L; Ginder, J M; Nielsen, O J

    2012-06-05

    The approximately 100 million tonne per year increase in the use of corn to produce ethanol in the U.S. over the past 10 years, and projections of greater future use, have raised concerns that reduced exports of corn (and other agricultural products) and higher commodity prices would lead to land-use changes and, consequently, negative environmental impacts in other countries. The concerns have been driven by agricultural and trade models, which project that large-scale corn ethanol production leads to substantial decreases in food exports, increases in food prices, and greater deforestation globally. Over the past decade, the increased use of corn for ethanol has been largely matched by the increased corn harvest attributable mainly to increased yields. U.S. exports of corn, wheat, soybeans, pork, chicken, and beef either increased or remained unchanged. Exports of distillers' dry grains (DDG, a coproduct of ethanol production and a valuable animal feed) increased by more than an order of magnitude to 9 million tonnes in 2010. Increased biofuel production may lead to intensification (higher yields) and extensification (more land) of agricultural activities. Intensification and extensification have opposite impacts on land use change. We highlight the lack of information concerning the magnitude of intensification effects and the associated large uncertainties in assessments of the indirect land use change associated with corn ethanol.

  1. New co-products from grain-based fuel ethanol production and their drying performance

    Science.gov (United States)

    Fuel ethanol production in the U.S. and elsewhere is an important and growing industry. In the U.S, about 40% of annual corn production is now converted into fuel ethanol. During co-product recovery, condensed distillers solubles (CDS) has to be mixed with distillers wet grains before drying due to ...

  2. 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

  3. Bacterial Cellulose Production by Gluconacetobacter sp. RKY5 in a Rotary Biofilm Contactor

    Science.gov (United States)

    Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

    A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

  4. Bacterial Cellulose Production by Acetobacter xylinum Strains from Agricultural Waste Products

    Science.gov (United States)

    Kongruang, Sasithorn

    Bacterial cellulose is a biopolysaccharide produced from the bacteria, Acetobacter xylinum. Static batch fermentations for bacterial cellulose production were studied in coconut and pineapple juices under 30 °C in 5-1 fermenters by using three Acetobacter strains: A. xylinum TISTR 998, A. xylinum TISTR 975, and A. xylinum TISTR 893. Experiments were carried out to compare bacterial cellulose yields along with growth kinetic analysis. Results showed that A. xylinum TISTR 998 produced a bacterial cellulose yield of 553.33 g/l, while A. xylinum TISTR 893 produced 453.33 g/l and A. xylinum TISTR 975 produced 243.33 g/l. In pineapple juice, the yields for A. xylinum TISTR 893, 975, and 998 were 576.66, 546.66, and 520 g/l, respectively. The strain TISTR 998 showed the highest productivity when using coconut juice. Morphological properties of cellulose pellicles, in terms of texture and color, were also measured, and the textures were not significantly different among treatments.

  5. Fermentative bio-hydrogen production from cellulose by cow dung compost enriched cultures

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Nan-Qi; Xu, Ji-Fei; Gao, Ling-Fang; Xin, Liang; Qiu, Jie; Su, Dong-Xia [State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2010-04-15

    The performance of hydrogen production from cellulose by the cow dung compost enriched continuously in defined medium containing cellulose was investigated. In the initial experiments, batch-fermentation was carried out to observe the effects of different substrate concentration conditions on the rate of cellulose-degrading, growth of bacteria and the capability of hydrogen-producing from cellulose. The result showed that the cellulose degradation decreased from 55% at 5 g/l to 22% at 30 g/l. The maximum cumulative hydrogen production and the rate of hydrogen production first increased from 828 ml/l at 5 g/l to 1251 ml/l at 10 g/l then remained constant beyond 10 g/l. The maximum hydrogen production potential, the rate of hydrogen production and the yield of hydrogen was 1525 ml/l, 33 ml/l.h, and 272 ml/g-cellulose (2.09 mol/mol-hexose) was obtained at substrate concentration 10 g/l, the hydrogen concentration in biogas was 47-50%(v/v) and there was no methane observed. During the conversion of cellulose into hydrogen, acetate and butyrate were main liquid end-products in the metabolism of hydrogen fermentation. These results proposed that cow dung compost enriched cultures were ideal microflora for hydrogen production from cellulose. (author)

  6. KINETIC EVALUATION OF ETHANOL-TOLERANT THERMOPHILE Geobacillus thermoglucosidasius M10EXG FOR ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Eny Ida Riyanti

    2016-10-01

    Full Text Available Thermophiles are challenging to be studied for ethanol production using agricultural waste containing lignocellulosic materials rich in hexose and pentose. These bacteria have many advantages such as utilizing a wide range of substrates, including pentose (C5 and hexose (C6. In ethanol production, it is important to use ethanol tolerant strain capable in converting lignocellulosic hydrolysate. This study was aimed to investigate the growth profile of ethanol-tolerant thermophile Geobacillus thermoglucosidasius M10EXG using a defined growth medium consisted of single carbon glucose (TGTV, xylose (TXTV, and a mixture of glucose and xylose (TGXTV, together with the effect of yeast extract additionto the media. The experiments were conducted at the School of Biotechnology and Biomolecular Sciences of The University of New South Wales, Australia on a shake flask fermentation at 60°C in duplicate experiment. Cultures were sampled every two hours and analised for their kinetic parameters including the maximum specific growth rate (µmax, biomass yield (Yx/s, ethanol and by-product yields (acetate and L-lactate (Yp/s, and the doubling time (Td. Results showed that this strain was capable of growing on minimal medium containing glucose or xylose as a single carbon source. This strain utilized glucose and xylose simultaneously (co-fermentation, although there was glucose repression of xylose at relatively low glucose concentration (0.5% w/v, particularly when yeast extract (0.2% w/v was added to the medium. The highest biomass yield was obtained at 0.5 g l-1 on glucose medium; the yield increased when yeast extract was added (at 0.59 g l-1. The highest specific growth rate of 0.25 was obtained in the phase I growth when the strain was grown on a mixture of glucose and xylose (0.5% : 0.5% w/v medium. Diauxic growth was shown on the mixture of glucose, xylose, and yeast extract. The strain produced low level of ethanol (0.1

  7. Comparing Scales of Environmental Effects from Gasoline and Ethanol Production

    Science.gov (United States)

    Parish, Esther S.; Kline, Keith L.; Dale, Virginia H.; Efroymson, Rebecca A.; McBride, Allen C.; Johnson, Timothy L.; Hilliard, Michael R.; Bielicki, Jeffrey M.

    2013-02-01

    Understanding the environmental effects of alternative fuel production is critical to characterizing the sustainability of energy resources to inform policy and regulatory decisions. The magnitudes of these environmental effects vary according to the intensity and scale of fuel production along each step of the supply chain. We compare the spatial extent and temporal duration of ethanol and gasoline production processes and environmental effects based on a literature review and then synthesize the scale differences on space-time diagrams. Comprehensive assessment of any fuel-production system is a moving target, and our analysis shows that decisions regarding the selection of spatial and temporal boundaries of analysis have tremendous influences on the comparisons. Effects that strongly differentiate gasoline and ethanol-supply chains in terms of scale are associated with when and where energy resources are formed and how they are extracted. Although both gasoline and ethanol production may result in negative environmental effects, this study indicates that ethanol production traced through a supply chain may impact less area and result in more easily reversed effects of a shorter duration than gasoline production.

  8. Comparing Scales of Environmental Effects from Gasoline and Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Parish, Esther S [ORNL; Kline, Keith L [ORNL; Dale, Virginia H [ORNL; Efroymson, Rebecca Ann [ORNL; McBride, Allen [ORNL; Johnson, Timothy L [U.S. Environmental Protection Agency, Raleigh, North Carolina; Hilliard, Michael R [ORNL; Bielicki, Dr Jeffrey M [University of Minnesota

    2013-01-01

    Understanding the environmental effects of alternative fuel production is critical to characterizing the sustainability of energy resources to inform policy and regulatory decisions. The magnitudes of these environmental effects vary according to the intensity and scale of fuel production along each step of the supply chain. We compare the scales (i.e., spatial extent and temporal duration) of ethanol and gasoline production processes and environmental effects based on a literature review, and then synthesize the scale differences on space-time diagrams. Comprehensive assessment of any fuel-production system is a moving target, and our analysis shows that decisions regarding the selection of spatial and temporal boundaries of analysis have tremendous influences on the comparisons. Effects that strongly differentiate gasoline and ethanol supply chains in terms of scale are associated with when and where energy resources are formed and how they are extracted. Although both gasoline and ethanol production may result in negative environmental effects, this study indicates that ethanol production traced through a supply chain may impact less area and result in more easily reversed effects of a shorter duration than gasoline production.

  9. Environmental aspects of eucalyptus based ethanol production and use.

    Science.gov (United States)

    González-García, Sara; Moreira, Ma Teresa; Feijoo, Gumersindo

    2012-11-01

    A renewable biofuel economy is projected as a pathway to decrease dependence on fossil fuels as well as to reduce greenhouse gases (GHG) emissions. Ethanol produced on large-scale from lignocellulosic materials is considered the automotive fuel with the highest potential. In this paper, a life cycle assessment (LCA) study was developed to evaluate the environmental implications of the production of ethanol from a fast-growing short rotation crop (SRC): eucalyptus as well as its use in a flexi-fuel vehicle (FFV). The aim of the analysis was to assess the environmental performance of three ethanol based formulations: E10, E85 and E100, in comparison with conventional gasoline. The standard framework of LCA from International Standards Organization was followed and the system boundaries included the cultivation of the eucalyptus biomass, the processing to ethanol conversion, the blending with gasoline (when required) and the final use of fuels. The environmental results show reductions in all impact categories under assessment when shifting to ethanol based fuels, excluding photochemical oxidant formation, eutrophication as well as terrestrial and marine ecotoxicity which were considerably influenced by upstream activities related to ethanol manufacture. The LCA study remarked those stages where the researchers and technicians need to work to improve the environmental performance. Special attention must be paid on ethanol production related activities, such as on-site energy generation and distillation, as well as forest activities oriented to the biomass production. The use of forest machinery with higher efficiency levels, reduction of fertilizers dose and the control of diffuse emissions from the conversion plant would improve the environmental profile.

  10. Do new cellulolytic enzyme preparations affect the industrial strategies for high solids lignocellulosic ethanol production?

    Science.gov (United States)

    Cannella, David; Jørgensen, Henning

    2014-01-01

    Production of ethanol from lignocellulosic materials has a promising market potential, but the process is still only at pilot/demonstration scale due to the technical and economical difficulties of the process. Operating the process at very high solids concentrations (above 20% dry matter-DM) has 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. The experiments revealed that an SSF strategy was indeed better than SHF when applying an older generation enzyme cocktail (Celluclast-Novozym 188). In case of the newer product Cellic CTec 2, SHF resulted in 20% higher final ethanol yield compared to SSF. It was possible to close the mass balance around 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 of lytic polysaccharides monoxygenases (LPMO's) to be depending on the processing strategy. The lowest concentration was achieved in SSF, which could be correlated with less available oxygen due to simultaneous oxygen consumption by the yeast. Quantity of glycerol and cell mass was also depending on the selected processing strategy.

  11. Ethanol, biomass and enzyme production for whey waste abatement

    Energy Technology Data Exchange (ETDEWEB)

    Maiorella, B.L.; Castillo, F.J.

    1984-08-01

    Methods of ethanol, biomass, and lactase production are evaluated for the treatment of whey waste. These processes can all reduce the whey BOD load of 35,000 ppm by at least 90%. Plant designs are evaluated at the scale of 25,000 l whey per day, corresponding to the output of a typical independent cheese factory. Ethanol production is the most practical of the alternatives evaluated and the waste treatment would add 7.3 US cents per kilogramme to the cost of cheese manufacture. 57 references.

  12. Use of post-harvest sugarcane residue for ethanol production.

    Science.gov (United States)

    Dawson, Letha; Boopathy, Raj

    2007-07-01

    Agricultural residues are produced in large quantities throughout the world. Approximately, 1kg of residue is produced for each kilogram of grains harvested. This ratio of grain/residue translates into an excess of 40 billion ton of crop residue produced each year in the USA. These residues are renewable resources that could be used to produce ethanol and many other value added products. In this study, we demonstrate that the post-harvest sugar cane residue could be used to produce fuel grade ethanol. A chemical pre-treatment process using alkaline peroxide or acid hydrolysis was applied to remove lignin, which acts as physical barrier to cellulolytic enzymes. Yeast Saccharomyces cerevisiae ATCC strain 765 was used in the experiment. The pre-treatment process effectively removed lignin. Ethanol production in the culture sample was monitored using high performance liquid chromatography. The results indicate that ethanol can be made from the sugarcane residue. The fermentation system needs to be optimized further to scale up the process for large-scale production of ethanol from sugar cane residue.

  13. Biological production of ethanol from coal. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    Due to the abundant supply of coal in the United States, significant research efforts have occurred over the past 15 years concerning the conversion of coal to liquid fuels. Researchers at the University of Arkansas have concentrated on a biological approach to coal liquefaction, starting with coal-derived synthesis gas as the raw material. Synthesis gas, a mixture of CO, H{sub 2}, CO{sub 2}, CH{sub 4} and sulfur gases, is first produced using traditional gasification techniques. The CO, CO{sub 2} and H{sub 2} are then converted to ethanol using a bacterial culture of Clostridium 1jungdahlii. Ethanol is the desired product if the resultant product stream is to be used as a liquid fuel. However, under normal operating conditions, the ``wild strain`` produces acetate in favor of ethanol in conjunction with growth in a 20:1 molar ratio. Research was performed to determine the conditions necessary to maximize not only the ratio of ethanol to acetate, but also to maximize the concentration of ethanol resulting in the product stream.

  14. Fuel From Farms: A Guide to Small-Scale Ethanol Production.

    Science.gov (United States)

    Solar Energy Research Inst., Golden, CO.

    Ethanol and blends of ethanol and gasoline (such as gasohol) offer a near-term fuel alternative to oil. The focus of this handbook is upon the small-scale production of ethanol using farm crops as the source of raw materials. Provided are chapters on ethanol production procedures, feedstocks, plant design, and financial planning. Also presented…

  15. Supply chain optimization of sugarcane first generation and eucalyptus second generation ethanol production in Brazil

    NARCIS (Netherlands)

    Jonker, J. G G; Junginger, H. M.; Verstegen, J. A.; Lin, T.; Rodríguez, L. F.; Ting, K. C.; Faaij, A. P C; van der Hilst, F.

    2016-01-01

    The expansion of the ethanol industry in Brazil faces two important challenges: to reduce total ethanol production costs and to limit the greenhouse gas (GHG) emission intensity of the ethanol produced. The objective of this study is to economically optimize the scale and location of ethanol product

  16. Applicability of unconventional energy raw materials in ethanol production

    Directory of Open Access Journals (Sweden)

    Małgorzata Gumienna

    2009-12-01

    Full Text Available Background. The difficult position of Polish agriculture, including one of its branches, i.e. sugar industry, is conducive of search for solutions aiming at an improvement of the condition of industry. One of the potential solutions in this respect may be to focus on alternative raw materials and search for ways to overcome recession in renewable energy sources. The aim of this work was to evaluate the possibilities of using non-starchy materials – sugar materials, without enzymatic treatment for ethanol production using selected yeast strains. Material and methods. Sugar beet pulp and thick juice, as a semi product from sugar beet, were fermented. The efficiency of the process was assessed using two Saccharomyces cerevisiae preparations – Ethanol Red, Fermiol. Fermentation was run for 72 h at 30°C. Quality of produced raw distillates was evaluated using the GC method. Results. The research on fermentation processes showed that sugar beet pulp let obtain higher ethanol yield – 87% of theoretical than sugar beet thick juice – 84% of theoretical, both for Ethanol Red and Fermiol yeast preparations. Moreover, it was exhibited that the increase of sugar concentration in the fermentation medium obtained from thick juice, statistically importantly influenced ethanol yield decrease, for both yeast preparations. The distillates’ quality analysis showed the influence of raw materials and microorganism used for fermentation on pollution degree. Distillate obtained from thick juice was characterised with the lowest by-products content after fermentation with Ethanol Red. Conclusions. The results make additional possibilities for sugar beet utilization in distillery industry and new markets using production surpluses both for sugar beet and its semi-product – thick juice.

  17. Metabolic flux analysis of Gluconacetobacter xylinus for bacterial cellulose production.

    Science.gov (United States)

    Zhong, Cheng; Zhang, Gui-Cai; Liu, Miao; Zheng, Xin-Tong; Han, Pei-Pei; Jia, Shi-Ru

    2013-07-01

    Metabolic flux analysis was used to reveal the metabolic distributions in Gluconacetobacter xylinus (CGMCC no. 2955) cultured on different carbon sources. Compared with other sources, glucose, fructose, and glycerol could achieve much higher bacterial cellulose (BC) yields from G. xylinus (CGMCC no. 2955). The glycerol led to the highest BC production with a metabolic yield of 14.7 g/mol C, which was approximately 1.69-fold and 2.38-fold greater than that produced using fructose and glucose medium, respectively. The highest BC productivity from G. xylinus CGMCC 2955 was 5.97 g BC/L (dry weight) when using glycerol as the sole carbon source. Metabolic flux analysis for the central carbon metabolism revealed that about 47.96 % of glycerol was transformed into BC, while only 19.05 % of glucose and 24.78 % of fructose were transformed into BC. Instead, when glucose was used as the sole carbon source, 40.03 % of glucose was turned into the by-product gluconic acid. Compared with BC from glucose and fructose, BC from the glycerol medium showed the highest tensile strength at 83.5 MPa, with thinner fibers and lower porosity. As a main byproduct of biodiesel production, glycerol holds great potential to produce BC with superior mechanical and microstructural characteristics.

  18. Efficient production of glucose by microwave-assisted acid hydrolysis of cellulose hydrogel.

    Science.gov (United States)

    Sun, Binzhe; Duan, Lian; Peng, Gege; Li, Xiaoxia; Xu, Aihua

    2015-09-01

    To improve the production of glucose from cellulose, a simple and effective route was developed. This process uses a combination of a step of cellulose dissolution in aqueous NaOH/urea solution and then regeneration with water, followed by an acid hydrolysis step under microwave irradiation. The method is effective to obtain glucose from α-cellulose, microcrystalline cellulose, filter paper, ramie fiber and absorbent cotton. Increased with the acid concentration the glucose yield from hydrogel hydrolysis increased from 0.42% to 44.6% at 160 °C for 10 min. Moreover, the ozone treatment of cellulose in NaOH/urea solution before regeneration significantly enhanced the hydrolysis efficiency with a glucose yield of 59.1%. It is believed that the chains in cellulose hydrogel are relatively free approached, making that the acids easily access the β-glycosidic bonds.

  19. Recovery of phenolic compounds from biomass during ethanol production

    Science.gov (United States)

    Biomass to ethanol conversion represents an alternative liquid fuel technology that does not need to compete with food crops. Maintaining agricultural production of commodity crops such as corn and soybeans for the food supply and using agricultural waste or low input energy crops grown on marginal ...

  20. Ethanol production in fermentation of mixed sugars containing xylose

    Science.gov (United States)

    Viitanen, Paul V.; Mc Cutchen, Carol M.; Li; Xu; Emptage, Mark; Caimi, Perry G.; Zhang, Min; Chou, Yat-Chen; Franden, Mary Ann

    2009-12-08

    Xylose-utilizing Z. mobilis strains were found to have improved ethanol production when grown in medium containing mixed sugars including xylose if sorbitol or mannitol was included in the medium. The effect was seen in concentrations of mixed sugars where no growth lag period occurs, as well as in higher sugars concentrations.

  1. COMPLEX PROCESSING OF CELLULOSE WASTE FROM POULTRY AND SUGAR PRODUCTION

    Directory of Open Access Journals (Sweden)

    E. V. Sklyadnev

    2015-01-01

    Full Text Available Summary.To solve the problem of disposing of huge volumes of cellulose waste from sugar production in the form of beet pulp and waste of poultry farms in the form of poultry manure is proposed to use the joint use of two methods of thermal processing of waste - pyrolysis and gasification. The possibility of using pyrolysis applied to the waste are confirmed by experimental results. Based on the results of laboratory studies of the properties of by-products resulting from the thermal processing of the feedstock, it is proposed complex processing to produce useful products, to be implemented in the form of marketable products, and the organization's own process energy utilization. Developed flow diagram of an integrated processing said waste comprises 3 sections, which successively carried out: pyrolytic decomposition of the feedstock to obtain a secondary product in the form of solid, liquid and gas fractions, the gasification of solids to obtain combustible gas and separating the liquid fraction by distillation to obtain valuable products. The main equipment in the first region is the pyrolysis reactor cascade condensers; the second section - gasifiers layers and stream type; the third - one or more distillation columns with the necessary strapping. Proper power supply installation is organized by the use of the heat produced during combustion of the synthesis gas for heating and gasification reactor. For the developed scheme presents calculations of the heat balance of the installation, supporting the energy efficiency of the proposed disposal process. Developments carried out in the framework of the project the winner of the Youth Prize Competition Government of Voronezh region to support youth programs in the 2014-2015.

  2. Research on the Ethanol Produced from the Simultaneous Glycation and Fermentation of Cellulose%纤维素同步糖化发酵生产乙醇

    Institute of Scientific and Technical Information of China (English)

    孙武举; 翁海波; 李萍萍; 晋果果

    2011-01-01

    [目的]利用微生物方法生产乙醇,从而替代化石能源.[方法]土曲霉M11利用纤维素为原料产酶并糖化纤维素成还原糖,利用酿酒酵母发酵生成乙醇.[结果]通过对土曲霉M11生长条件的研究,确定了土曲霉M11的最佳培养时间是3d,最佳接种量为200μl,最适培养湿度为80%,最适培养温度为45℃,最适培养pH为3.0,此条件下可获得最大的产酶量.通过对糖化过程的研究,确定了纤维素酶的最适糖化温度为55℃,最适pH为5.0,此条件下可获得较高的还原糖量,且在酸性条件下酶活力较高,具有很好的热稳定性.通过发酵.还原糖量占原材料干重的62.42%,产生的乙醇占原材料干重的21.36%.[结论]此方法可以应用于工业发酵生产乙醇,有利于保护环境、降低成本、提高社会效益,有很好的应用价值.%[Objective] The ethanol was produced by means of microbiological processes for the replacing approach of energy source. [ Method] The reducing sugar was produced from the cellulose, which was saccharified by the enzyme that was from the cellulose as raw material was acted by Aspergillus teneus-Mll,,and the ethanol was produced based on the fermentation of yeast. [ Result] The experimental result indicated that the optimal culture condition of Aspergillus terreus-Mll growth was that the best time was 3 days,the best inoculation was 200 μl,the optimal culture humidity was 80% ,the optimum temperature was 45℃ and the optimal culture pH was 3.0,under which condition,the largest amount of enzyme-producing was available. And the experiment in the glycation process of cellulase showed the optimal temperature was 55 ℃ and the optimum pH was 5.0,under which condition the production of reducing sugar,which enzyme activity under acidic condition was higher and had good thermal stability,was relevantly high. By fermentation,the reduced sugar accounted for 62.42% of the dry weight of raw material and the produced ethanol

  3. A pilot plant scale reactor/separator for ethanol from cellulosics. Quarterly report No. 1 & 2, October 1, 1997--March 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.

    1998-06-01

    The basic objective of this project is to develop and demonstrate a continuous, low energy process for the conversion of cellulosics to ethanol. This process involves a pretreatment step followed by enzymatic release of sugars and the consecutive saccharification/fermentation of cellulose (glucans) followed by hemi-cellulose (glucans) in a multi-stage continuous stirred reactor separator (CSRS). During year 1, pretreatment and bench scale fermentation trials will be performed to demonstrate and develop the process, and during year 2, a 130 L or larger process scale unit will be operated to demonstrate the process using straw or cornstalks. Co-sponsors of this project include the Indiana Biomass Grants Program, Bio-Process Innovation, Xylan Inc as a possible provider of pretreated biomass.

  4. 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......, 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....

  5. Estimating the Future Economic Impact of Corn Ethanol Production in the U.S.

    OpenAIRE

    Swenson, David A.

    2007-01-01

    This brief exercise assesses the potential economic impact value of ethanol production comparing current, 2007, estimates with a future level of production for 2016 and a long run equilibrium level (LRE) for 2025. The values for this estimate are driven by current Food and Agricultural Policy Research Institute (FAPRI) forecasts of corn and ethanol production. All of the estimates assume corn ethanol production only. No other kind of ethanol production is measured nor should be implied. By 20...

  6. Simultaneous saccharification and fermentation of cassava waste for ethanol production

    Directory of Open Access Journals (Sweden)

    C. Pothiraj

    2015-03-01

    Full Text Available The efficiency of enzymatic and microbial saccharification of cassava waste for ethanol production was investigated and the effective parameters were optimized. The mixture of amylase and amyloglucosidase (AMG resulted in a significantly higher rate of saccharification (79.6% than the amylase alone (68.7%. Simultaneous saccharification and fermentation (SSF yielded 6.2 g L-1 ethanol representing 64.5% of the theoretical yield. Saccharification and fermentation using pure and co-cultures of fungal isolates including Rhizopus stolonifer, Aspergillus terreus, Saccharomyces diastaticus and Zymomonas mobilis revealed that the co-culture system involving S. diastaticus and Z. mobilis was highly suitable for the bio-conversion of cassava waste into ethanol, resulting in 20.4 g L-1 in 36 h (91.3% of the theoretical yield.

  7. Analysis on chemical components changes in preparation process of cellulosic ethanol from poplar wood%杨木制备纤维乙醇过程中化学成分变化的分析

    Institute of Scientific and Technical Information of China (English)

    闫兴伟; 崔琳; 张林; 王芳; 陈茜文

    2015-01-01

    杨树是我国重要的速生树种。以杨木为原料制备生物乙醇是解决当今能源问题的一项新的尝试。对杨木原料蒸汽爆破预处理后以及菌处理后的化学成分及化学性质进行了测定分析。通过对比其化学成分(纤维素、木素、半纤维素、抽出物、灰分及蛋白质)的变化,研究了以杨木为原料制备生物乙醇生产过程中化学成分变化机理,旨在为指导杨木制备木质纤维乙醇的生产,并为发酵后副产物的回收再利用提供理论依据。%Poplar is an important fast-growing species in China. The preparation of bio-ethanol with poplar wood as the raw material is a new attempt to solve today’s energy problems. After steam-exploded pretreatment and then bacteria treatment to the poplar wood raw materials, the materials’ chemical composition and properties were measured and analyzed. Through contrasting the changes of the materials’ chemical composition(cellulose, lignin, hemicelluloses, extracts, ash and protein), the mechanism of chemical change of the tested materials in the bioethanol production process prepared from poplar wood was studied, the surplus product contained 64.07%lignin, 6.78% cellulose and 6.88% hemicellulose. The results provide a theoretical basis for guiding the preparation of poplar wood cellulosic ethanol production, and the subsequent recycling of fermentation by-products.

  8. Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.

    Science.gov (United States)

    Lay, C H; Chang, F Y; Chu, C Y; Chen, C C; Chi, Y C; Hsieh, T T; Huang, H H; Lin, C Y

    2011-01-01

    Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

  9. Enhanced ethanol production from brewer's spent grain by a Fusarium oxysporum consolidated system

    Directory of Open Access Journals (Sweden)

    Christakopoulos Paul

    2009-02-01

    Full Text Available Abstract Background Brewer's spent grain (BG, a by-product of the brewing process, is attracting increasing scientific interest as a low-cost feedstock for many biotechnological applications. BG in the present study is evaluated as a substrate for lignocellulolytic enzyme production and for the production of ethanol by the mesophilic fungus Fusarium oxysporum under submerged conditions, implementing a consolidated bioconversion process. Fermentation experiments were performed with sugar mixtures simulating the carbohydrate content of BG in order to determine the utilization pattern that could be expected during the fermentation of the cellulose and hemicellulose hydrolysate of BG. The sugar mixture fermentation study focused on the effect of the initial total sugar concentration and on the effect of the aeration rate on fermenting performance of F. oxysporum. The alkali pretreatment of BG and different aeration levels during the ethanol production stage were studied for the optimization of the ethanol production by F. oxysporum. Results Enzyme yields as high as 550, 22.5, 6.5, 3225, 0.3, 1.25 and 3 U per g of carbon source of endoglucanase, cellobiohydrolase, β-D-glucosidase, xylanase, feruloyl esterase, β-D-xylosidase and α-L-arabinofuranosidase respectively, were obtained during the growth stage under optimized submerged conditions. An ethanol yield of 109 g ethanol per kg of dry BG was obtained with alkali-pretreated BG under microaerobic conditions (0.01 vvm, corresponding to 60% of the theoretical yield based on total glucose and xylose content of BG. Conclusion The enzymatic profile of the extracellular extract from F. oxysporum submerged cultures using BG and corn cob as the carbon source was proved efficient for a successful hydrolysis of BG. The fermentation study carried out using sugar mixtures simulating BG's carbohydrates content and consecutively alkali-pretreated and untreated BG, indicates that BG hydrolysis is the bottleneck

  10. Ethanol production by recombinant and natural xylose-utilising yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, Anna

    2000-07-01

    The xylose-fermenting capacity of recombinant Saccharomyces cerevisiae carrying XYL1 and XYL2 from Pichia stipitis, which encode xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, is poor due to high xylitol formation. Whereas, P. stipitis exhibits high ethanol yield on xylose, the tolerance towards inhibitors in the lignocellulosic hydrolysate is low. A recombinant strain possessing the advantageous characteristics of both S. cerevisiae and P. stipitis would constitute a biocatalyst capable of efficient ethanol production from lignocellulosic hydrolysate. In the work presented in this thesis, factors influencing xylose fermentation in recombinant S. cerevisiae and in the natural xylose-fermenting yeast P. stipitis have been identified and investigated. Anaerobic xylulose fermentation was compared in strains of Zygosaccharomyces and S. cerevisiae, mutants and wild-type strains to identify host strain background and genetic modifications beneficial for xylose fermentation. The greatest positive effect was found for over-expression of the gene XKS1 for the pentose phosphate pathway (PPP) enzyme xylulokinase (XK), which increased the ethanol yield by almost 85%. The Zygosaccharomyces strains tested formed large amounts of polyols, making them unsuitable as host strains. The XR/XDH/XK ratio was found to determine whether carbon accumulated in a xylitol pool or was further utilised for ethanol production in recombinant xylose-utilising S. cerevisiae. Simulations, based on a kinetic model, and anaerobic xylose cultivation experiments implied that a 1:{>=}10:{>=}4 relation was optimal in minimising xylitol formation. Ethanol formation increased with decreasing XR/XDH ratio, whereas xylitol formation decreased and XK overexpression was necessary for adequate ethanol formation. Based on the knowledge of optimal enzyme ratios, a stable, xylose-utilising strain, S. cerevisiae TMB 3001, was constructed by chromosomal integration of the XYL1 and XYL2 genes

  11. Ethanol production by recombinant and natural xylose-utilising yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, Anna

    2000-07-01

    The xylose-fermenting capacity of recombinant Saccharomyces cerevisiae carrying XYL1 and XYL2 from Pichia stipitis, which encode xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, is poor due to high xylitol formation. Whereas, P. stipitis exhibits high ethanol yield on xylose, the tolerance towards inhibitors in the lignocellulosic hydrolysate is low. A recombinant strain possessing the advantageous characteristics of both S. cerevisiae and P. stipitis would constitute a biocatalyst capable of efficient ethanol production from lignocellulosic hydrolysate. In the work presented in this thesis, factors influencing xylose fermentation in recombinant S. cerevisiae and in the natural xylose-fermenting yeast P. stipitis have been identified and investigated. Anaerobic xylulose fermentation was compared in strains of Zygosaccharomyces and S. cerevisiae, mutants and wild-type strains to identify host strain background and genetic modifications beneficial for xylose fermentation. The greatest positive effect was found for over-expression of the gene XKS1 for the pentose phosphate pathway (PPP) enzyme xylulokinase (XK), which increased the ethanol yield by almost 85%. The Zygosaccharomyces strains tested formed large amounts of polyols, making them unsuitable as host strains. The XR/XDH/XK ratio was found to determine whether carbon accumulated in a xylitol pool or was further utilised for ethanol production in recombinant xylose-utilising S. cerevisiae. Simulations, based on a kinetic model, and anaerobic xylose cultivation experiments implied that a 1:{>=}10:{>=}4 relation was optimal in minimising xylitol formation. Ethanol formation increased with decreasing XR/XDH ratio, whereas xylitol formation decreased and XK overexpression was necessary for adequate ethanol formation. Based on the knowledge of optimal enzyme ratios, a stable, xylose-utilising strain, S. cerevisiae TMB 3001, was constructed by chromosomal integration of the XYL1 and XYL2 genes

  12. 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.

  13. The production of fuels and chemicals from food processing wastes & cellulosics. Final research report

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.; Okos, M.; Burgos, N. [and others

    1997-06-15

    High strength food wastes of about 15-20 billion pounds solids are produced annually by US food producers. Low strength food wastes of 5-10 billion pounds/yr. are produced. Estimates of the various components of these waste streams are shown in Table 1. Waste paper/lignocellulosic crops could produce 2 to 5 billion gallons of ethanol per year or other valuable chemicals. Current oil imports cost the US about $60 billion dollars/yr. in out-going balance of trade costs. Many organic chemicals that are currently derived from petroleum can be produced through fermentation processes. Petroleum based processes have been preferred over biotechnology processes because they were typically cheaper, easier, and more efficient. The technologies developed during the course of this project are designed to allow fermentation based chemicals and fuels to compete favorably with petroleum based chemicals. Our goals in this project have been to: (1) develop continuous fermentation processes as compared to batch operations; (2) combine separation of the product with the fermentation, thus accomplishing the twin goals of achieving a purified product from a fermentation broth and speeding the conversion of substrate to product in the fermentation broth; (3) utilize food or cellulosic waste streams which pose a current cost or disposal problem as compared to high cost grains or sugar substrates; (4) develop low energy recovery methods for fermentation products; and finally (5) demonstrate successful lab scale technologies on a pilot/production scale and try to commercialize the processes. The scale of the wastes force consideration of {open_quotes}bulk commodity{close_quotes} type products if a high fraction of the wastes are to be utilized.

  14. Ethanol production process from banana fruit and its lignocellulosic residues: Energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Arredondo, H.I. [Grupo de Investigacion Bioprocesos y Flujos Reactivos, Universidad Nacional de Colombia, Sede Medellin, Calle 59 A N 63-20 (Colombia); Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, Avenida Professor Mello Moraes 2231 (Brazil); Ruiz-Colorado, A.A. [Grupo de Investigacion Bioprocesos y Flujos Reactivos, Universidad Nacional de Colombia, Sede Medellin, Calle 59 A N 63-20 (Colombia); De Oliveira, S. Jr. [Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, Avenida Professor Mello Moraes 2231 (Brazil)

    2010-07-15

    Tropical countries, such as Brazil and Colombia, have the possibility of using agricultural lands for growing biomass to produce bio-fuels such as biodiesel and ethanol. This study applies an energy analysis to the production process of anhydrous ethanol obtained from the hydrolysis of starch and cellulosic and hemicellulosic material present in the banana fruit and its residual biomass. Four different production routes were analyzed: acid hydrolysis of amylaceous material (banana pulp and banana fruit) and enzymatic hydrolysis of lignocellulosic material (flower stalk and banana skin). The analysis considered banana plant cultivation, feedstock transport, hydrolysis, fermentation, distillation, dehydration, residue treatment and utility plant. The best indexes were obtained for amylaceous material for which mass performance varied from 346.5 L/t to 388.7 L/t, Net Energy Value (NEV) ranged from 9.86 MJ/L to 9.94 MJ/L and the energy ratio was 1.9 MJ/MJ. For lignocellulosic materials, the figures were less favorable; mass performance varied from 86.1 to 123.5 L/t, NEV from 5.24 to 8.79 MJ/L and energy ratio from 1.3 to 1.6 MJ/MJ. The analysis showed, however, that both processes can be considered energetically feasible. (author)

  15. 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.

  16. 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.

  17. Yeast selection for fuel ethanol production in Brazil.

    Science.gov (United States)

    Basso, Luiz C; de Amorim, Henrique V; de Oliveira, Antonio J; Lopes, Mario L

    2008-11-01

    Brazil is one of the largest ethanol biofuel producers and exporters in the world and its production has increased steadily during the last three decades. The increasing efficiency of Brazilian ethanol plants has been evident due to the many technological contributions. As far as yeast is concerned, few publications are available regarding the industrial fermentation processes in Brazil. The present paper reports on a yeast selection program performed during the last 12 years aimed at selecting Saccharomyces cerevisiae strains suitable for fermentation of sugar cane substrates (cane juice and molasses) with cell recycle, as it is conducted in Brazilian bioethanol plants. As a result, some evidence is presented showing the positive impact of selected yeast strains in increasing ethanol yield and reducing production costs, due to their higher fermentation performance (high ethanol yield, reduced glycerol and foam formation, maintenance of high viability during recycling and very high implantation capability into industrial fermenters). Results also suggest that the great yeast biodiversity found in distillery environments could be an important source of strains. This is because during yeast cell recycling, selective pressure (an adaptive evolution) is imposed on cells, leading to strains with higher tolerance to the stressful conditions of the industrial fermentation.

  18. Postmortem degradation of administered ethanol-d6 and production of endogenous ethanol: experimental studies using rats and rabbits.

    Science.gov (United States)

    Takayasu, T; Ohshima, T; Tanaka, N; Maeda, H; Kondo, T; Nishigami, J; Nagano, T

    1995-12-18

    Deuterium-labeled ethanol-d6 was employed to study the metabolism and postmortem change of ethanol in putrefied organ tissues. First, 4 ml/kg body weight of 25% (w/v) solution of ethanol-d6 was administered orally to each of 15 rats. The heart blood and organs were collected 15-90 min after the administration and the ethanol-d6 was analyzed by head space gas chromatography/mass spectrometry. The ethanol-d6 concentration in the organ tissues reached its maximum at 15 min after the administration and then gradually declined, showing the same pattern as human ethanol metabolism. Ethanol-d6 (3 ml of the same solution/kg body weight) was injected into the vein of a rabbit's ear (total of 12 rabbits). The rabbit was killed with carbon monoxide 30 min after the administration and the carcass was allowed to stand for 1-4 days at 30 degrees C in a moist chamber. The concentration of ethanol-d6 decreased moderately. Postmortem ethanol and 1-propanol concentrations, in contrast, showed marked increases 2.5 days and more after sacrifice in line with the degree of putrefaction of each organ tissue including skeletal muscle. This suggests the postmortem activation of micro-organism activity. These results indicate that ethanol concentrations in cadaver tissues must be carefully assessed with due consideration of postmortem degradation and production.

  19. Characterization of cellulosic wastes and gasification products from chicken farms.

    Science.gov (United States)

    Joseph, Paul; Tretsiakova-McNally, Svetlana; McKenna, Siobhan

    2012-04-01

    The current article focuses on gasification as a primary disposal solution for cellulosic wastes derived from chicken farms, and the possibility to recover energy from this process. Wood shavings and chicken litter were characterized with a view to establishing their thermal parameters, compositional natures and calorific values. The main products obtained from the gasification of chicken litter, namely, producer gas, bio-oil and char, were also analysed in order to establish their potential as energy sources. The experimental protocol included bomb calorimetry, pyrolysis combustion flow calorimetry (PCFC), thermo-gravimetric analyses (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, elemental analyses, X-ray diffraction (XRD), mineral content analyses and gas chromatography. The mass and energy balances of the gasification unit were also estimated. The results obtained confirmed that gasification is a viable method of chicken litter disposal. In addition to this, it is also possible to recover some energy from the process. However, energy content in the gas-phase was relatively low. This might be due to the low energy efficiency (19.6%) of the gasification unit, which could be improved by changing the operation parameters.

  20. “A Step Towards Environmental Waste Management And Sustainable Biofuel (Ethanol Production From Waste Banana Peelings”

    Directory of Open Access Journals (Sweden)

    Nazim Ali

    2016-08-01

    Full Text Available Most nations, whether economically advanced or at different stages of development are facing two major challenges, energy crisis and proper waste disposal. In this paper a study has been done on environmental waste management and sustainable biofuel (ethanol production from waste banana peelings. The peels of BASRAI variety of bananas are taken as they are rich in cellulose and are kept in hot oven at 338K and dried sample is taken and is dissolved in hot water for starch extraction through soxhlet extractor. This solution is treated with amylase enzyme for hydrolysis of starch to occur. Solution obtained is then subjected to fermentation process by inoculation of S.cerevisiae for 4-5 days at 300K which results in the production of ethanol. The ethanol formed is characterized by potassium dichromate method .The effect of pH; sugar content and rate of ethanol production were studied for 8 days. After extraction of starch the banana powder is than burnt with butane flame. We get potassium carbonate solution after gravity filtration. The residue left can be used as fertilizers.

  1. Novel technologies for enhanced production of ethanol: impact of high productivity on process economics

    Science.gov (United States)

    In these studies Saccharomyces cerevisiae NRRL Y-566 was used to produce ethanol from a concentrated glucose (250-300 gL-1) solution. When fermentation media were supplemented with CaCO3 and CaCl2, ethanol concentrations, yield, and productivities were improved significantly. In control batch fermen...

  2. Life cycle assessment of sugarcane ethanol production in India in comparison to Brazil

    NARCIS (Netherlands)

    Tsiropoulos, Ioannis; Faaij, André P C; Seabra, Joaquim E A; Lundquist, Lars; Schenker, Urs; Briois, Jean François; Patel, Martin K.

    2014-01-01

    Purpose: India's biofuel programme relies on ethanol production from sugarcane molasses. However, there is limited insight on environmental impacts across the Indian ethanol production chain. This study closes this gap by assessing the environmental impacts of ethanol production from sugarcane molas

  3. Optimisation of the biological pretreatment of wheat straw with white-rot fungi for ethanol production.

    Science.gov (United States)

    López-Abelairas, M; Álvarez Pallín, M; Salvachúa, D; Lú-Chau, T; Martínez, M J; Lema, J M

    2013-09-01

    The biological pretreatment of lignocellulosic biomass for the production of bioethanol is an environmentally friendly alternative to the most frequently used process, steam explosion (SE). However, this pretreatment can still not be industrially implemented due to long incubation times. The main objective of this work was to test the viability of and optimise the biological pretreatment of lignocellulosic biomass, which uses ligninolytic fungi (Pleurotus eryngii and Irpex lacteus) in a solid-state fermentation of sterilised wheat straw complemented with a mild alkali treatment. In this study, the most important parameters of the mechanical and thermal substrate conditioning processes and the most important parameters of the fungal fermentation process were optimised to improve sugar recovery. The largest digestibilities were achieved with fermentation with I. lacteus under optimised conditions, under which cellulose and hemicellulose digestibility increased after 21 days of pretreatment from 16 to 100 % and 12 to 87 %, respectively. The maximum glucose yield (84 %) of cellulose available in raw material was obtained after only 14 days of pretreatment with an overall ethanol yield of 74 % of the theoretical value, which is similar to that reached with SE.

  4. Microbial Cellulose Production from Bacteria Isolated from Rotten Fruit

    Directory of Open Access Journals (Sweden)

    B. E. Rangaswamy

    2015-01-01

    Full Text Available Microbial cellulose, an exopolysaccharide produced by bacteria, has unique structural and mechanical properties and is highly pure compared to plant cellulose. Present study represents isolation, identification, and screening of cellulose producing bacteria and further process optimization. Isolation of thirty cellulose producers was carried out from natural sources like rotten fruits and rotten vegetables. The bacterial isolates obtained from rotten pomegranate, rotten sweet potato, and rotten potato were identified as Gluconacetobacter sp. RV28, Enterobacter sp. RV11, and Pseudomonas sp. RV14 through morphological and biochemical analysis. Optimization studies were conducted for process parameters like inoculum density, temperature, pH, agitation, and carbon and nitrogen sources using Gluconacetobacter sp. RV28. The strain produced 4.7 g/L of cellulose at optimum growth conditions of temperature (30°C, pH (6.0, sucrose (2%, peptone (0.5%, and inoculum density (5%. Characterization of microbial cellulose was done by scanning electron microscopy (SEM.

  5. Production of ethanol from excess ethylene

    DEFF Research Database (Denmark)

    Kadhim, Adam S.; Carlsen, Kim B.; Bisgaard, Thomas

    2012-01-01

    Ethyl alcohol is one of the most important and used chemicals. Two common routes exist for the production: synthetic route typically based on petroleum feedstock and a fermentation route. The fermentation route comprises the majority of the produced ethyl alcohol. In this work, however, we...... will focus on the synthetic method, which employs direct hydration of ethylene. A conceptual process design of an ethyl alcohol producing plant is performed in a MSc-level course on Process Design at the Department of Chemical and Biochemical Engineering at DTU. In the designed process, 190 proof ethyl...... is obtained in tasks 1-2. A preliminary process flowsheet is obtained in task 3 using a modified Douglas hierarchical process synthesis method. The next tasks involves making design decisions and then further refining them in tasks 4-7 related to separation factors, reactor operating conditions, product...

  6. Exploring Potential U.S. Switchgrass Production for Lignocellulosic Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Carla A [ORNL; Davis, Ethan [ORNL; Jager, Yetta [ORNL; West, Tristram O. [ORNL; Perlack, Robert D [ORNL; Brandt, Craig C [ORNL; Wullschleger, Stan D [ORNL; Baskaran, Latha Malar [ORNL; Webb, Erin [ORNL; Downing, Mark [ORNL

    2008-08-01

    In response to concerns about oil dependency and the contributions of fossil fuel use to climatic change, the U.S. Department of Energy has begun a research initiative to make 20% of motor fuels biofuel based in 10 years, and make 30% of fuels bio-based by 2030. Fundamental to this objective is developing an understanding of feedstock dynamics of crops suitable for cellulosic ethanol production. This report focuses on switchgrass, reviewing the existing literature from field trials across the United States, and compiling it for the first time into a single database. Data available from the literature included cultivar and crop management information, and location of the field trial. For each location we determined latitude and longitude, and used this information to add temperature and precipitation records from the nearest weather station. Within this broad database we were able to identify the major sources of variation in biomass yield, and to characterize yield as a function of some of the more influential factors, e.g., stand age, ecotype, precipitation and temperature in the year of harvest, site latitude, and fertilization regime. We then used a modeling approach, based chiefly on climatic factors and ecotype, to predict potential yields for a given temperature and weather pattern (based on 95th percentile response curves), assuming the choice of optimal cultivars and harvest schedules. For upland ecotype varieties, potential yields were as high as 18 to 20 Mg/ha, given ideal growing conditions, whereas yields in lowland ecotype varieties could reach 23 to 27 Mg/ha. The predictive equations were used to produce maps of potential yield across the continental United States, based on precipitation and temperature in the long term climate record, using the Parameter-elevation Regressions on Independent Slopes Model (PRISM) in a Geographic Information System (GIS). Potential yields calculated via this characterization were subsequently compared to the Oak Ridge

  7. Ethanol production from cotton-based waste textiles.

    Science.gov (United States)

    Jeihanipour, Azam; Taherzadeh, Mohammad J

    2009-01-01

    Ethanol production from cotton linter and waste of blue jeans textiles was investigated. In the best case, alkali pretreatment followed by enzymatic hydrolysis resulted in almost complete conversion of the cotton and jeans to glucose, which was then fermented by Saccharomyces cerevisiae to ethanol. If no pretreatment applied, hydrolyses of the textiles by cellulase and beta-glucosidase for 24 h followed by simultaneous saccharification and fermentation (SSF) in 4 days, resulted in 0.140-0.145 g ethanol/g textiles, which was 25-26% of the corresponding theoretical yield. A pretreatment with concentrated phosphoric acid prior to the hydrolysis improved ethanol production from the textiles up to 66% of the theoretical yield. However, the best results obtained from alkali pretreatment of the materials by NaOH. The alkaline pretreatment of cotton fibers were carried out with 0-20% NaOH at 0 degrees C, 23 degrees C and 100 degrees C, followed by enzymatic hydrolysis up to 4 days. In general, higher concentration of NaOH resulted in a better yield of the hydrolysis, whereas temperature had a reverse effect and better results were obtained at lower temperature. The best conditions for the alkali pretreatment of the cotton were obtained in this study at 12% NaOH and 0 degrees C and 3 h. In this condition, the materials with 3% solid content were enzymatically hydrolyzed at 85.1% of the theoretical yield in 24 h and 99.1% in 4 days. The alkali pretreatment of the waste textiles at these conditions and subsequent SSF resulted in 0.48 g ethanol/g pretreated textiles used.

  8. Cellulosic ethanol: interactions between cultivar and enzyme loading in wheat straw processing

    Directory of Open Access Journals (Sweden)

    Felby Claus

    2010-11-01

    Full Text Available Abstract 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 yields than coarse particles. The amount of coarse particles from the cultivar with lowest sugar yield was negatively correlated with sugar conversion. Conclusions We conclude that genetic differences in sugar yield and response to enzyme loading exist for wheat straw at pilot scale, depending on differences in removal of hemicellulose, accumulation of ash and particle-size distribution introduced by the pretreatment.

  9. Comparison of Bacterial Cellulose Production among Different Strains and Fermented Media

    Directory of Open Access Journals (Sweden)

    Maryam Jalili Tabaii

    2015-12-01

    Full Text Available The effect of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus (PTCC 1734 and two newly isolated strains (from vinegar under static culture conditions was studied. The production of bacterial cellulose was examined in modified Hestrin-Shramm medium by replacing D-glucose with other carbon sources. The results showed that the yield and characteristics of bacterial cellulose were influenced by the type of carbon source. Glycerol gave the highest yield in all of the studied strains (6%, 9.7% and 3.8% for S, A2 strain and Gluconacetobacter xylinus (PTCC 1734, respectively. The maximum dry bacterial cellulose weight in the glycerol containing medium is due to A2 strain (1.9 g l-1 in comparison to Gluconacetobacter xylinus as reference strain (0.76 g l-1. Although all of the studied strains were in Gluconacetobacter family, each used different sugars for maximum production after glycerol (mannitol and fructose for two newly isolated strains and glucose for Gluconacetobacter xylinus. The maximum moisture content was observed when sucrose and food-grade sucrose were used as carbon source. Contrary to expectations, while the maximum thickness of bacterial cellulose membrane was attained when glycerol was used, bacterial cellulose from glycerol had less moisture content than the others. The oxidized cellulose showed antibacterial activities, which makes it as a good candidate for food-preservatives.

  10. Use of microwave ovens in the production of industrial ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Senise, J.T.; Concone, B.R.V.; Moraes, V.L.V.; Doin, P.A.; Medugno, C.C.; Andrade, A.O.M.; Perri, E.B.; Perin, A.H.

    1980-01-01

    Production of ethanol from starchy materials is now being investigated in Brazil as an alternative source for alcohol production apart from sugar cane. In the present work, with the objective of optimizing the energy balance of the process, substitution of conventional sources of energy by electricity at one stage of the process is sought. Cooking and dextrinization of cassava roots, previously treated by conventional pretreatments, by microwaves heating (at 2450/sup -/ MHz) has been studied. Results of saccharification and fermentation of the mash thus obtained were used to evaluate the technical feasibility of the process. Specific energy consumption figures (for the cooking and dextrinization stage) of 600 kcal/l of ethanol produced and efficiencies of 90% (in terms of the theoretical maximum yield from the available starch) were easily and consistently obtained.

  11. Development of mutated Kluyveromyces marxianus strains for ethanol production at elevated temperature from biomass hydrolysate

    Science.gov (United States)

    The yeast K. marxianus has advantages over the most commonly used industrial ethanologen, Saccharomyces cerevisiae, such as the ability to grow at 47°C, to produce ethanol at temperatures above 40°C, and to grow on a wide variety of substrates, including starch, sucrose, pectins, and cellulosic biom...

  12. 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...... liquid hydrolysate from the pretreatment at higher severity (180°C, 15 min, 87 psi oxygen and 190°C, 15 min, 0.2% sulfuric acid) was fully inhibited probable by the presence of higher concentrations of inhibitory compounds such as furfural, HMF and acetic acid. The ethanol yield among other WEx...

  13. Biorefining of wood: combined production of ethanol and xylanase from waste fiber sludge.

    Science.gov (United States)

    Cavka, Adnan; Alriksson, Björn; Rose, Shaunita H; van Zyl, Willem H; Jönsson, Leif J

    2011-08-01

    The possibility to utilize fiber sludge, waste fibers from pulp mills and lignocellulose-based biorefineries, for combined production of liquid biofuel and biocatalysts was investigated. Without pretreatment, fiber sludge was hydrolyzed enzymatically to monosaccharides, mainly glucose and xylose. In the first of two sequential fermentation steps, the fiber sludge hydrolysate was fermented to cellulosic ethanol with the yeast Saccharomyces cerevisiae. Although the final ethanol yields were similar, the ethanol productivity after 9.5 h was 3.3 g/l/h for the fiber sludge hydrolysate compared with only 2.2 g/l/h for a reference fermentation with similar sugar content. In the second fermentation step, the spent fiber sludge hydrolysate (the stillage obtained after distillation) was used as growth medium for recombinant Aspergillus niger expressing the xylanase-encoding Trichoderma reesei (Hypocrea jecorina) xyn2 gene. The xylanase activity obtained with the spent fiber sludge hydrolysate (8,500 nkat/ml) was higher than that obtained in a standard medium with similar monosaccharide content (1,400 nkat/ml). Analyses based on deglycosylation with N-glycosidase F suggest that the main part of the recombinant xylanase was unglycosylated and had molecular mass of 20.7 kDa, while a minor part had N-linked glycosylation and molecular mass of 23.6 kDa. Chemical analyses of the growth medium showed that important carbon sources in the spent fiber sludge hydrolysate included xylose, small aliphatic acids, and oligosaccharides. The results show the potential of converting waste fiber sludge to liquid biofuel and enzymes as coproducts in lignocellulose-based biorefineries.

  14. Fermentative hydrogen production from hydrolyzed cellulosic feedstock prepared with a thermophilic anaerobic bacterial isolate

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yung Chung [Department of Chemical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 701 (China); Huang, Chi-Yu.; Fu, Tzu-Ning [Department of Environmental Engineering and Science, Tunghai University, Taichung 407 (China); Chen, Chun-Yen; Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, No. 1 University Road, Tainan 701 (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan (China)

    2009-08-15

    Hydrogen gas was produced via dark fermentation from natural cellulosic materials and {alpha}-cellulose via a two-step process, in which the cellulosic substrates were first hydrolyzed by an isolated cellulolytic bacterium Clostridium strain TCW1, and the resulting hydrolysates were then used as substrate for fermentative H{sub 2} production. The TCW1 strain was able to hydrolyze all the cellulosic materials examined to produce reducing sugars (RS), attaining the best reducing sugar production yield of 0.65 g reducing sugar/g substrate from hydrolysis of {alpha}-cellulose. The hydrolysates of those cellulosic materials were successfully converted to H{sub 2} via dark fermentation using seven H{sub 2}-producing bacterial isolates. The bioH{sub 2} production performance was highly dependent on the type of cellulosic feedstock used, the initial reducing sugar concentration (C{sub RS,o}) (ranging from 0.7 to 4.5 mg/l), as well as the composition of sugar and soluble metabolites present in the cellulosic hydrolysates. It was found that Clostridium butyricum CGS5 displayed the highest H{sub 2}-producing efficiency with a cumulative H{sub 2} production of 270 ml/l from {alpha}-cellulose hydrolysate (C{sub RS,o} = 4.52 mg/l) and a H{sub 2} yield of 7.40 mmol/g RS (or 6.66 mmol/g substrate) from napier grass hydrolysate (C{sub RS,o} = 1.22 g/l). (author)

  15. Biological pretreatment and ethanol production from olive cake

    DEFF Research Database (Denmark)

    Jurado, Esperanza; Gavala, Hariklia N.; Baroi, George Nabin

    2010-01-01

    Olive oil is one of the major Mediterranean products, whose nutritional and economic importance is well-known. However the extraction of olive oil yields a highly contaminating residue that causes serious environmental concerns in the olive oil producing countries. The olive cake (OC) coming out...... of the three-phase olive oil production process could be used as low price feedstock for lignocellulosic ethanol production due to its high concentration in carbohydrates. However, the binding of the carbohydrates with lignin may significantly hinder the necessary enzymatic hydrolysis of the polymeric sugars...

  16. Consolidated bioprocessing (CBP) performance of Clostridium phytofermentans on AFEX-treated corn stover for ethanol production.

    Science.gov (United States)

    Jin, Mingjie; Balan, Venkatesh; Gunawan, Christa; Dale, Bruce E

    2011-06-01

    Consolidated bioprocessing (CBP) is believed to be a potentially cost-efficient and commercially viable way to produce cellulosic biofuels. In this study, we have evaluated the performance of the CBP organism Clostridium phytofermentans (ATCC 700394) on AFEX-treated corn stover (AFEX-CS). Fermentation conditions including temperature, inoculation size, nutrients, and initial pH were investigated. At optimal conditions with 0.5% (w/w) glucan loading of AFEX-CS, C. phytofermentans hydrolyzed 76% of glucan and 88.6% of xylan in 10 days. These values reached 87% and 102% of those obtained by simultaneous saccharification and co-fermentation (SSCF) using commercial enzymes and S. cerevisiae 424A. Ethanol titer for CBP was found to be 2.8 g/L which was 71.8% of that yielded by SSCF (3.9 g/L). Decomposition products from AFEX-CS helped to increase ethanol yield somewhat during CBP. Particle size played a crucial role in the enhancement of sugar conversion by CBP.

  17. Microbial pretreatment of corn stover with Ceriporiopsis subvermispora for enzymatic hydrolysis and ethanol production.

    Science.gov (United States)

    Wan, Caixia; Li, Yebo

    2010-08-01

    The feasibility of concurrent wet storage and microbial pretreatment of corn stover with Ceriporiopsis subvermispora for ethanol production was investigated in this study. The effects of particle size (5-15 mm), moisture content (45-85%), pretreatment time (18-35 d), and temperature (4-37 degrees C) on lignin degradation and enzymatic hydrolysis yield were studied. The results showed that C. subvermispora selectively degraded lignin up to 31.59% with a limited cellulose loss of less than 6% during an 18-d pretreatment. When 5mm corn stover was pretreated at 28 degrees C with 75% moisture content, overall glucose yields of 57.67%, 62.21%, and 66.61% were obtained with 18-, 28-, and 35-d microbial pretreated corn stover, respectively. For the above conditions, the highest overall ethanol yield of 57.80% was obtained with 35-d-pretreated corn stover. Enzymatic hydrolysis yield was highly related to the lignin removal during microbial pretreatment.

  18. 美国纤维素乙醇商业化项目的进展情况%Progress of U.S. Cellulosic ethanol Commercial Project

    Institute of Scientific and Technical Information of China (English)

    宋锦玉

    2011-01-01

    纤维素乙醇以农作物秸秆、森林采伐和木材加工剩余物等非粮作物为原料,对缓解能源危机、保护环境具有重要的意义,将逐步取代以玉米等粮食作物为原料的第一代生物乙醇.主要介绍了美国纤维素乙醇商业化项目的进展情况.%Straw and other non-grain crops like forest harvesting and wood processing residues can be used as raw materials to produce cellulose ethyl alcohol, which has great significance to alleviate the energy crisis and to protect environment. Cellulose ethyl alcohol will replace first generation bio-ethanol prepared firom grains such as com and so on. In this paper, progress of U.S. cellulosic ethanol commercial project was introduced.

  19. Hydrogen production by catalytic gasification of cellulose in supercritical water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cellulose,one of the important components of biomass,was gasified in supercritical water to produce hydrogen-rich gas in an autoclave which was operated batch-wise under high-pressure.K2CO3 and Ca(OH)2 were selected as the catalysts (or promoters).The temperature was kept between 450℃ and 500℃ while pressure was maintained at 24-26 MPa.The reaction time was 20 min.Experimental results showed that the two catalysts had good catalytic effect and optimum amounts were observed for each catalyst.When 0.2 g K2CO3 was added,the hydrogen yield could reach 9.456 mol.kg-1 which was two times of the H2 amount produced without catalyst.When 1.6 g Ca(OH)2 was added,the H2 yield was K2CO3 as catalyst but is still 1.7 times that achieved without catalyst.Comparing with the results obtained using KaCO3 or Ca(OH)2 alone,the use of a combination of K2CO3 and Ca(OH)2 could increase the H2 yield by up to 2.5 times that without catalyst and 25% and 45% more than that obtained using K2CO3 and Ca(OH)2 alone,respectively.It was found that methane was the dominant product at relatively low temperature.When the temperature was increased,the methane reacts with water and is converted to hydrogen and carbon dioxide.

  20. Improvement production of bacterial cellulose by semi-continuous process in molasses medium.

    Science.gov (United States)

    Cakar, Fatih; Ozer, Işılay; Aytekin, A Özhan; Sahin, Fikrettin

    2014-06-15

    Bacterial cellulose (BC) has unique properties such as structural, functional, physical and chemical. The mass production of BC for industrial application has recently become attractive to produce more economical and high productive cellulose. In this study, to improve the productivity of bacterial cellulose (BC), BC production by Gluconacetobacter xylinus FC01 was investigated in molasses medium with static semi-continuous operation mode. Cell dry weight, polysaccharide, sugar and cellulose concentrations were monitored and cellulose was characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The highest cellulose yield (1.637 g/L) was obtained in SCP50-7d, which molasses of 1/2 ratio for 7 days by static semi-continuous operation mode. The results show that BC can be highly produced by G. xylinus in molasses with static semi-continuous process than batch process. We claimed that low-cost medium with semi-continuous operation mode in static culture is a good candidate for industrial scale BC productions.

  1. Production of nanocrystalline cellulose from lignocellulosic biomass: technology and applications.

    Science.gov (United States)

    Brinchi, L; Cotana, F; Fortunati, E; Kenny, J M

    2013-04-15

    The use of renewables materials for industrial applications is becoming impellent due to the increasing demand of alternatives to scarce and unrenewable petroleum supplies. In this regard, nanocrystalline cellulose, NCC, derived from cellulose, the most abundant biopolymer, is one of the most promising materials. NCC has unique features, interesting for the development of new materials: the abundance of the source cellulose, its renewability and environmentally benign nature, its mechanical properties and its nano-scaled dimensions open a wide range of possible properties to be discovered. One of the most promising uses of NCC is in polymer matrix nanocomposites, because it can provide a significant reinforcement. This review provides an overview on this emerging nanomaterial, focusing on extraction procedures, especially from lignocellulosic biomass, and on technological developments and applications of NCC-based materials. Challenges and future opportunities of NCC-based materials will be are discussed as well as obstacles remaining for their large use.

  2. Furfural and ethanol production from corn stover by dilute phosphoric acid pretreatment

    Science.gov (United States)

    Lignocellulosic biomass is the most abundant carbohydrate source in the world and has potential for economical production of biofuels, especially ethanol. However, its composition is an obstacle for the production of ethanol by the conventional ethanol producing yeast Saccharomyces cerevisiae as it...

  3. Acetone-butanol-ethanol fermentation of corn stover: current production methods, economic viability and commercial use.

    Science.gov (United States)

    Baral, Nawa R; Slutzky, Lauren; Shah, Ajay; Ezeji, Thaddeus C; Cornish, Katrina; Christy, Ann

    2016-03-01

    Biobutanol is a next-generation liquid biofuel with properties akin to those of gasoline. There is a widespread effort to commercialize biobutanol production from agricultural residues, such as corn stover, which do not compete with human and animal foods. This pursuit is backed by extensive government mandates to expand alternative energy sources. This review provides an overview of research on biobutanol production using corn stover feedstock. Structural composition, pretreatment, sugar yield (following pretreatment and hydrolysis) and generation of lignocellulose-derived microbial inhibitory compounds (LDMICs) from corn stover are discussed. The review also discusses different Clostridium species and strains employed for biobutanol production from corn stover-derived sugars with respect to solvent yields, tolerance to LDMICs and in situ solvent recovery (integrated fermentation). Further, the economics of cellulosic biobutanol production are highlighted and compared to corn starch-derived ethanol and gasoline. As discussed herein, the economic competitiveness of biobutanol production from corn stover largely depends on feedstock processing and fermentation process design.

  4. Ethanol Demand in United States Regional Production of Oxygenate-limited Gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    2000-08-01

    The Energy Policy Act of 1992 (the Act) outlined a national energy strategy that called for reducing the nation's dependency on petroleum imports. The Act directed the Secretary of Energy to establish a program to promote and expand the use of renewable fuels. The Office of Transportation Technologies (OTT) within the U.S. Department of Energy (DOE) has evaluated a wide range of potential fuels and has concluded that cellulosic ethanol is one of the most promising near-term prospects. Ethanol is widely recognized as a clean fuel that helps reduce emissions of toxic air pollutants. Furthermore, cellulosic ethanol produces less greenhouse gas emissions than gasoline or any of the other alternative transportation fuels being considered by DOE.

  5. High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Zhao, Chi; Li, Zhongkui; Li, Tao; Zhang, Yingjiao; Bryant, Donald A; Zhao, Jindong

    2015-01-01

    Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc-ccp-cesAB-cesC-cesD-bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications.

  6. Evaluation of yeast strains for production of fuel ethanol from biomass hydrolysates

    Science.gov (United States)

    Robust industrial yeast strains are needed for profitable production of fuel ethanol from mixed biomass waste. USDA, ARS, NCAUR, RPT has been evaluating ethanol-producing yeasts, including Saccharomyces cerevisiae, engineered GMAX Saccharomyces cerevisiae, irradiated Kluyveromyces marxianus, and Pi...

  7. Arrowroot as a novel substrate for ethanol production by solid state simultaneous saccharification and fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tian-xiang; Tang, Qing-li; Zhu, Zuo-hua [School of Chemical Engineering, Guizhou University, Guizhou, Guiyang 550003 (China); Wang, Feng [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-08-15

    Ethanol production from Canna edulis Ker was successfully carried out by solid state simultaneous saccharification and fermentation. The enzymatic hydrolysis conditions of C. edulis were optimized by Plackett-Burman design. The effect of inert carrier (corncob and rice bran) on ethanol fermentation and the kinetics of solid state simultaneous saccharification and fermentation was investigated. It was found that C. edulis was an alternative substrate for ethanol production, 10.1% (v/v) of ethanol concentration can attained when 40 g corncob and 10 g rice bran per 100 g C. edulis powder were added for ethanol fermentation. No shortage of fermentable sugars was observed during solid state simultaneous saccharification and fermentation. There was no wastewater produced in the process of ethanol production from C. edulis with solid state simultaneous saccharification and fermentation and the ethanol yield of more than 0.28 tonne per one tonne feedstock was achieved. This is first report for ethanol production from C. edulis powder. (author)

  8. Production of succinic acid from oil palm empty fruit bunch cellulose using Actinobacillus succinogenes

    Science.gov (United States)

    Pasma, Satriani Aga; Daik, Rusli; Maskat, Mohamad Yusof

    2013-11-01

    Succinic acid is a common metabolite in plants, animals and microorganisms. It has been used widely in agricultural, food and pharmaceutical industries. Enzymatic hydrolysate glucose from oil palm empty fruit bunch (OPEFB) cellulose was used as a substrate for succinic acid production using Actinobacillus succinogenes. Using cellulose extraction from OPEFB can enhance the production of glucose as a main substrate for succinic acid production. The highest concentration of glucose produced from enzymatic hydrolysis is 167 mg/mL and the sugar recovery is 0.73 g/g of OPEFB. By optimizing the culture medium for succinic acid fermentation with enzymatic hydrolysate of OPEFB cellulose, the nitrogen sources could be reduced to just only 2.5 g yeast extract and 2.5 g corn step liquor. Batch fermentation was carried out using enzymatic hydrolysate of OPEFB cellulose with yeast extract, corn steep liquor and the salts mixture, 23.5 g/L succinic acid was obtained with consumption of 72 g/L glucose in enzymatic hydrolysate of OPEFB cellulose at 38 hours and 37°C. This study suggests that enzymatic hydrolysate of OPEFB cellulose maybe an alternative substrate for the efficient production of succinic acid by Actinobacillus succinogenes.

  9. Spittlebug impacts on sugarcane quality and ethanol production

    Directory of Open Access Journals (Sweden)

    Gisele Cristina Ravaneli

    2011-02-01

    Full Text Available The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS; high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.

  10. 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...... by cellulases more than three times compared to the untreated control. During this wet oxidation, 51.7% of the hemicellulose and 58.3% of the lignin were solubilized, whereas 87.1% of the cellulose remained in the solids. After enzymatic hydrolysis of pretreated fibers from the same treatment, the conversion......Common reed (Phragmites australis) is often recognized as a promising source of renewable energy. However, it is among the least characterized crops from the bioethanol perspective. Although one third of reed dry matter is cellulose, without pretreatment, it resists enzymatic hydrolysis like...

  11. 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.

  12. Industrial scale-up of pH-controlled liquid hot water pretreatment of corn fiber for fuel ethanol production.

    Science.gov (United States)

    Mosier, Nathan S; Hendrickson, Richard; Brewer, Mark; Ho, Nancy; Sedlak, Miroslav; Dreshel, Richard; Welch, Gary; Dien, Bruce S; Aden, Andy; Ladisch, Michael R

    2005-05-01

    The pretreatment of cellulose in corn fiber by liquid hot water at 160 degrees C and a pH above 4.0 dissolved 50% of the fiber in 20 min. The pretreatment also enabled the subsequent complete enzymatic hydrolysis of the remaining polysaccharides to monosaccharides. The carbohydrates dissolved by the pretreatment were 80% soluble oligosaccharides and 20% monosaccharides with products. Only a minimal amount of protein was dissolved, thus enriching the protein content of the undissolved material. Replication of laboratory results in an industrial trial at 43 gallons per minute (163 L/min) of fiber slurry with a residence time of 20 min illustrates the utility and practicality of this approach for pretreating corn fiber. The added costs owing to pretreatment, fiber, and hydrolysis are equivalent to less than 0.84 dollars/gal of ethanol produced from the fiber. Minimizing monosaccharide formation during pretreatment minimized the formation of degradation products; hence, the resulting sugars were readily fermentable to ethanol by the recombinant hexose and by pentose-fermenting Saccharomyces cerevisiae 424A(LNH-ST) and ethanologenic Escherichia coli at yields >90% of theoretical based on the starting fiber. This cooperative effort and first successful trial opens the door for examining the robustness of the pretreatment system under extended run conditions as well as pretreatment of other cellulose-containing materials using water at controlled pH.

  13. Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' Manual and Technical Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States); Qin, Zhangcai [Argonne National Lab. (ANL), Argonne, IL (United States); Mueller, Steffen [Univ. of Illinois at Chicago, Chicago, IL (United States); Kwon, Ho-young [International Food Policy Research Institute (IFPRI), Washington, DC (United States); Wander, Michelle M. [Univ. of Illinois, Urbana-Champaign, IL (United States); Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-09-01

    The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, Miscanthus, and switchgrass. This document discusses the version of CCLUB released September 30, 2014 which includes corn and three cellulosic feedstocks: corn stover, Miscanthus, and switchgrass.

  14. 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.)

  15. Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

    Directory of Open Access Journals (Sweden)

    Carla Eliana Todero Ritter

    2013-01-01

    Full Text Available The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v soy bran; 0.1% (w/v wheat bran; and a solution of salts. The highest filter paper activity (FPA ( IU·mL−1 was obtained on the seventh day in the medium containing 0.5% (w/v sorbitol and 0.5% (w/v cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day ( IU·mL−1 in the medium containing 0.75% (w/v sorbitol and 0.75% (w/v cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v sorbitol and 0.25% (w/v cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

  16. 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)

  17. Utilization of makgeolli sludge filtrate (MSF) as low-cost substrate for bacterial cellulose production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Hyun, Jo Yi; Mahanty, Biswanath; Kim, Chang Gyun

    2014-04-01

    Search for efficient low-cost substrate/additives are gaining significant impetus in bacterial cellulose (BC) production. Makgeolli sludge (a traditional Korean wine distillery waste) is enriched with organic acid, alcohol, and sugar. Using makgeolli sludge filtrate (MSF) and Hestrin-Schramm (HS) medium (g/l of distilled water: glucose, 10.0; peptone, 5.0; yeast extract, 5.0; disodium phosphate, 2.7; citric acid, 1.15; pH 5.0), two different media-namely the modified HS media (ingredients of HS media except glucose dissolved in MSF) and mixed modified HS media (equal volume mixture of original and modified HS media)-were formulated. BC production with Gluconacetobacter xylinus was studied using the two above referred medium. Keeping HS medium as reference, effect of initial pH, glucose, ethanol, and organic acid concentration on BC production was also studied. It suggests that increasing initial glucose (up to 25 g/l) though improves BC production but results in poor BC yield above 15 g/l of glucose. However, addition of alcohol (up to 1%v/v) or citric acid (up to 20 mM) escalate productivity up to four and two times, respectively. In both modified HS media and mixed modified HS medium, BC production was four to five times higher than that of original HS medium. Even MSF alone surpassed HS medium in BC production. Scanning electron microscopy showed that BC microfibrils from MSF based media were several micrometers long and about 25-60 nm widths. X-ray diffraction patterns suggested the produced BC were of cellulose I polymorph.

  18. Genetic improvement of plants for enhanced bio-ethanol production.

    Science.gov (United States)

    Saha, Sanghamitra; Ramachandran, Srinivasan

    2013-04-01

    The present world energy situation urgently requires exploring and developing alternate, sustainable sources for fuel. Biofuels have proven to be an effective energy source but more needs to be produced to meet energy goals. Whereas first generation biofuels derived from mainly corn and sugarcane continue to be used and produced, the contentious debate between "feedstock versus foodstock" continues. The need for sources that can be grown under different environmental conditions has led to exploring newer sources. Lignocellulosic biomass is an attractive source for production of biofuel, but pretreatment costs to remove lignin are high and the process is time consuming. Genetically modified plants that have increased sugar or starch content, modified lignin content, or produce cellulose degrading enzymes are some options that are being explored and tested. This review focuses on current research on increasing production of biofuels by genetic engineering of plants to have desirable characteristics. Recent patents that have been filed in this area are also discussed.

  19. Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

    2014-01-01

    production. An exergy analysis is carried out for a modelled polygeneration system in which lignocellulosic ethanol production based on hydrothermal pretreatment is integrated in an existing combined heat and power (CHP) plant. The ethanol facility is driven by steam extracted from the CHP unit when feasible...... in the ethanol facility. The calculated standard exergy efficiency of the ethanol facility varied from 0.564 to 0.855, of which the highest was obtained for integrated operation at reduced CHP load and full district heating production in the ethanol facility, and the lowest for separate operation with zero...

  20. Production of Biodiesel Using Ethanol Way and Alkaline Catalyst

    Directory of Open Access Journals (Sweden)

    Cesar Aparecido da Silva

    2010-06-01

    Full Text Available The potential inputs to promote the supply of the demand for power generation has become the aim of several scientific researches to mitigate environmental impacts. The biodiesel is the highlight solution that can be obtained through the transesterification process. The aim this present work was the biodiesel production using ethanol and crude oil sunflower as inputs and potassium ethoxide such as catalyst for the rection. Were produced seven samples using different parameters. The product with high rate of ethyl ester was the one with catalyst and reaction time optimized. However, it has showed the presence of glycerol, suggesting the use of other unit operations such as cooling and centrifugation to improve the purity of the biodiesel formed is necessary. The parameters used in this experiment (oil, catalyst and water washing contents, reaction time, temperature and agitation speed showed critical endpoints to be monitored during the production of biodiesel due interfering the quality and yield to the final product. In addition, the inappropriate speed of agitation in the reactor for ethanol way in the presence of an alkaline catalyst can gelatinize the mixture of reactants due the emulsion formed.

  1. Enzymatic production of hydrogen gas from glucose and cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Mattingly, S.M.; Woodward, J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    An enzymatic process has been used to convert glucose to molecular hydrogen with the ultimate goal of converting cellulose to hydrogen. Two enzymes from the Archae, Thermoplasma acidophilium glucose dehydrogenase (GDH) and Pyrococcus furiosus hydrogenase, were used to oxidize glucose and NADPH respectively, resulting in the formation of molecular hydrogen. The stoichiometric yield of hydrogen from glucose was close to the theoretical maximum expected. Further, the molar amount of hydrogen produced was greater than the molar equivalent of NADP{sup +} present in the reaction mixture indicating that this GDH cofactor was regenerated throughout the course of the reaction. Hydrogen was also shown to be produced from cellulose if cellulase was included in the reaction mixture.

  2. Fate of virginiamycin through the fuel ethanol production process.

    Science.gov (United States)

    Bischoff, Kenneth M; Zhang, Yanhong; Rich, Joseph O

    2016-05-01

    Antibiotics are frequently used to prevent and treat bacterial contamination of commercial fuel ethanol fermentations, but there is concern that antibiotic residues may persist in the distillers grains coproducts. A study to evaluate the fate of virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research Center, Edwardsville, IL. Three 15,000-liter fermentor runs were performed: one with no antibiotic (F1), one dosed with 2 parts per million (ppm) of a commercial virginiamycin product (F2), and one dosed at 20 ppm of virginiamycin product (F3). Fermentor samples, distillers dried grains with solubles (DDGS), and process intermediates (whole stillage, thin stillage, syrup, and wet cake) were collected from each run and analyzed for virginiamycin M and virginiamycin S using a liquid chromatography-mass spectrometry method. Virginiamycin M was detected in all process intermediates of the F3 run. On a dry-weight basis, virginiamycin M concentrations decreased approximately 97 %, from 41 μg/g in the fermentor to 1.4 μg/g in the DDGS. Using a disc plate bioassay, antibiotic activity was detected in DDGS from both the F2 and F3 runs, with values of 0.69 μg virginiamycin equivalent/g sample and 8.9 μg/g, respectively. No antibiotic activity (<0.6 μg/g) was detected in any of the F1 samples or in the fermentor and process intermediate samples from the F2 run. These results demonstrate that low concentrations of biologically active antibiotic may persist in distillers grains coproducts produced from fermentations treated with virginiamycin.

  3. Altered Lignin Biosynthesis Improves Cellulosic Bioethanol Production in Transgenic Maize Plants Down-Regulated for Cinnamyl Alcohol Dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    Silvia Fornalé; Pere Puigdomènech; Joan Rigau; David Caparrós-Ruiz; Montserrat Capellades; Antonio Encina; Kan Wang; Sami Irar; Catherine Lapierre; Katia Ruel; Jean-Paul Joseleau; Jordi Berenguer

    2012-01-01

    Cinnamyl alcohol dehydrogenase(CAD)is a key enzyme involved in the last step of monolignol biosynthesis.The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize.Transgenic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alterations in cell wall composition.Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content.In addition,these cell walls accumulate higher levels of cellulose and arabinoxylans.In contrast,cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides.In vitro degradability assays showed that,although to a different extent,the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants.CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass.Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type,making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.

  4. Biofilm formation, phenotypic production of cellulose and gene expression in Salmonella enterica decrease under anaerobic conditions.

    Science.gov (United States)

    Lamas, A; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

    2016-12-05

    Salmonella enterica subsp. enterica is one of the main food-borne pathogens. This microorganism combines an aerobic life outside the host with an anaerobic life within the host. One of the main concerns related to S. enterica is biofilm formation and cellulose production. In this study, biofilm formation, morphotype, cellulose production and transcription of biofilm and quorum sensing-related genes of 11 S. enterica strains were tested under three different conditions: aerobiosis, microaerobiosis, and anaerobiosis. The results showed an influence of oxygen levels on biofilm production. Biofilm formation was significantly higher (Pbiofilm and quorum sensing-related genes. Thus, the results from this study indicate that biofilm formation and cellulose production are highly influenced by atmospheric conditions. This must be taken into account as contamination with these bacteria can occur during food processing under vacuum or modified atmospheres.

  5. Very high gravity ethanol and fatty acid production of Zymomonas mobilis without amino acid and vitamin.

    Science.gov (United States)

    Wang, Haoyong; Cao, Shangzhi; Wang, William Tianshuo; Wang, Kaven Tianyv; Jia, Xianhui

    2016-06-01

    Very high gravity (VHG) fermentation is the mainstream technology in ethanol industry, which requires the strains be resistant to multiple stresses such as high glucose concentration, high ethanol concentration, high temperature and harsh acidic conditions. To our knowledge, it was not reported previously that any ethanol-producing microbe showed a high performance in VHG fermentations without amino acid and vitamin. Here we demonstrate the engineering of a xylose utilizing recombinant Zymomonas mobilis for VHG ethanol fermentations. The recombinant strain can produce ethanol up to 136 g/L without amino acid and vitamin with a theoretical yield of 90 %, which is significantly superior to that produced by all the reported ethanol-producing strains. The intracellular fatty acids of the bacterial were about 16 % of the bacterial dry biomass, with the ratio of ethanol:fatty acids was about 273:1 (g/g). The recombinant strain was achieved by a multivariate-modular strategy tackles with the multiple stresses which are closely linked to the ethanol productivity of Z. mobilis. The over-expression of metB/yfdZ operon enabled the growth of the recombinant Z. mobilis in a chemically defined medium without amino acid and vitamin; and the fatty acids overproduction significantly increased ethanol tolerance and ethanol production. The coupled production of ethanol with fatty acids of the Z. mobilis without amino acid and vitamin under VHG fermentation conditions may permit a significant reduction of the production cost of ethanol and microbial fatty acids.

  6. Determining the fate of virginiamycin in the fuel ethanol production process

    Science.gov (United States)

    Antibiotics are frequently used to prevent and treat bacterial contamination at commercial fuel ethanol facilities. A study to evaluate the fate of the antibiotic virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research...

  7. Water Footprints of Cassava- and Molasses-Based Ethanol Production in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Mangmeechai, Aweewan, E-mail: aweewan.m@nida.ac.th [National Institute of Development Administration, International College (Major in Public Policy and Management) (Thailand); Pavasant, Prasert [Chulalongkorn University, Department of Chemical Engineering, Faculty of Engineering (Thailand)

    2013-12-15

    The Thai government has been promoting renewable energy as well as stimulating the consumption of its products. Replacing transport fuels with bioethanol will require substantial amounts of water and enhance water competition locally. This study shows that the water footprint (WF) of molasses-based ethanol is less than that of cassava-based ethanol. The WF of molasses-based ethanol is estimated to be in the range of 1,510-1,990 L water/L ethanol, while that of cassava-based ethanol is estimated at 2,300-2,820 L water/L ethanol. Approximately 99% of the water in each of these WFs is used to cultivate crops. Ethanol production requires not only substantial amounts of water but also government interventions because it is not cost competitive. In Thailand, the government has exploited several strategies to lower ethanol prices such as oil tax exemptions for consumers, cost compensation for ethanol producers, and crop price assurances for farmers. For the renewable energy policy to succeed in the long run, the government may want to consider promoting molasses-based ethanol production as well as irrigation system improvements and sugarcane yield-enhancing practices, since molasses-based ethanol is more favorable than cassava-based ethanol in terms of its water consumption, chemical fertilizer use, and production costs.

  8. 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.

  9. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Final report, February 1, 1978-January 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    This is a coordinated program to effect the microbiological degradation of cellulosic biomasses and will focus on the use of anaerobic microorganisms which possess cellulolytic enzyme. The studies will attempt to increase the enzyme levels through genetics, mutation and strain selection. In addition, the direct conversion from cellulosic biomasses to liquid fuel (ethanol) and/or soluble sugars by the cellulolytic, anaerobic organism is also within the scope of this program. Process and engineering scale-up, along with economic analyses, will be performed throughout the course of the program. The second area of our major effort is devoted to the production of chemical feedstocks. In particular, three fermentations have been identified for exploration. These are: acrylic acid, acetone/butanol and acetic acid. The main efforts in these fermentations will address means for the reduction of the cost of manufacturing for these large volume chemicals.

  10. Feasibility study for co-locating and integrating ethanol production plants from corn starch and lignocellulosic feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibsen, Kelly [National Renewable Energy Lab. (NREL), Golden, CO (United States); McAloon, Andrew [U.S. Department of Agriculture, Washington, D.C. (United States); Yee, Winnie [U.S. Department of Agriculture, Washington, D.C. (United States)

    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.

  11. Recent trends in acetone, butanol, and ethanol (ABE production

    Directory of Open Access Journals (Sweden)

    Keikhosro Karim

    2015-12-01

    Full Text Available Among the renewable fuels considered as a suitable substitute to petroleum-based gasoline, butanol has attracted a great deal of attention due to its unique properties. Acetone, butanol, and ethanol (ABE can be produced biologically from different substrates, including sugars, starch, lignocelluloses, and algae. This process was among the very first biofuel production processes which was commercialized during the First World War. The present review paper discusses the different aspects of the ABE process and the recent progresses made. Moreover, the microorganisms and the biochemistry of the ABE fermentation as well as the feedstocks used are reviewed. Finally, the challenges faced such as low products concentration and products` inhibitory effects on the fermentation are explained and different possible solutions are presented and reviewed.

  12. Combined heat treatment and acid hydrolysis of cassava grate waste (CGW) biomass for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Agu, R.C.; Amadife, A.E.; Ude, C.M.; Onyia, A.; Ogu, E.O. [Enugu State Univ. of Science and Technology (Nigeria). Faculty of Applied Natural Sciences; Okafor, M.; Ezejiofor, E. [Nnamdi Azikiwe Univ., Awka (Nigeria). Dept. of Applied Microbiology

    1997-12-31

    The effect of combined heat treatment and acid hydrolysis (various concentrations) on cassava grate waste (CGW) biomass for ethanol production was investigated. At high concentrations of H{sub 2}SO{sub 4} (1--5 M), hydrolysis of the CGW biomass was achieved but with excessive charring or dehydration reaction. At lower acid concentrations, hydrolysis of CGW biomass was also achieved with 0.3--0.5 M H{sub 2}SO{sub 4}, while partial hydrolysis was obtained below 0.3 M H{sub 2}SO{sub 4} (the lowest acid concentration that hydrolyzed CGW biomass) at 120 C and 1 atm pressure for 30 min. A 60% process efficiency was achieved with 0.3 M H{sub 2}SO{sub 4} in hydrolyzing the cellulose and lignin materials present in the CGW biomass. High acid concentration is therefore not required for CGW biomass hydrolysis. The low acid concentration required for CGW biomass hydrolysis, as well as the minimal cost required for detoxification of CGW biomass because of low hydrogen cyanide content of CGW biomass would seem to make this process very economical. From three liters of the CGW biomass hydrolysate obtained from hydrolysis with 0.3M H{sub 2}SO{sub 4}, ethanol yield was 3.5 (v/v%) after yeast fermentation. However, although the process resulted in gainful utilization of CGW biomass, additional costs would be required to effectively dispose new by-products generated from CGW biomass processing.

  13. Ethanol production from sugars obtained during enzymatic hydrolysis of elephant grass (Pennisetum purpureum, Schum.) pretreated by steam explosion.

    Science.gov (United States)

    Scholl, Angélica Luisi; Menegol, Daiane; Pitarelo, Ana Paula; Fontana, Roselei Claudete; Zandoná Filho, Arion; Ramos, Luiz Pereira; Dillon, Aldo José Pinheiro; Camassola, Marli

    2015-09-01

    In this work, steam explosion was used a pretreatment method to improve the conversion of elephant grass (Pennisetum purpureum) to cellulosic ethanol. This way, enzymatic hydrolysis of vaccum-drained and water-washed steam-treated substrates was carried out with Penicillium echinulatum enzymes while Saccharomyces cerevisiae CAT-1 was used for fermentation. After 48 h of hydrolysis, the highest yield of reducing sugars was obtained from vaccum-drained steam-treated substrates that were produced after 10 min at 200 °C (863.42 ± 62.52 mg/g). However, the highest glucose yield was derived from water-washed steam-treated substrates that were produced after 10 min at 190 °C (248.34 ± 6.27 mg/g) and 200 °C (246.00 ± 9.60 mg/g). Nevertheless, the highest ethanol production was obtained from water-washed steam-treated substrates that were produced after 6 min at 200 °C. These data revealed that water washing is a critical step for ethanol production from steam-treated elephant grass and that pretreatment generates a great deal of water soluble inhibitory compounds for hydrolysis and fermentation, which were partly characterized as part of this study.

  14. Mechanism of product inhibition for cellobiohydrolase Cel7A during hydrolysis of insoluble cellulose

    DEFF Research Database (Denmark)

    Olsen, Johan P.; Alasepp, Kadri; Kari, Jeppe;

    2016-01-01

    implemented an electrochemical biosensor assay for product inhibition studies of cellulases acting on their natural substrate, cellulose. Using this method we measured the hydrolytic rate of Cel7A as a function of both product (inhibitor) concentration and substrate load. This data enabled analyses along...

  15. Ethanol and biogas production after steam pretreatment of corn stover with or without the addition of sulphuric acid

    Directory of Open Access Journals (Sweden)

    Bondesson Pia-Maria

    2013-01-01

    Full Text Available Abstract Background Lignocellulosic biomass, such as corn stover, is a potential raw material for ethanol production. One step in the process of producing ethanol from lignocellulose is enzymatic hydrolysis, which produces fermentable sugars from carbohydrates present in the corn stover in the form of cellulose and hemicellulose. A pretreatment step is crucial to achieve efficient conversion of lignocellulosic biomass to soluble sugars, and later ethanol. This study has investigated steam pretreatment of corn stover, with and without sulphuric acid as catalyst, and examined the effect of residence time (5–10 min and temperature (190–210°C on glucose and xylose recovery. The pretreatment conditions with and without dilute acid that gave the highest glucose yield were then used in subsequent experiments. Materials pretreated at the optimal conditions were subjected to simultaneous saccharification and fermentation (SSF to produce ethanol, and remaining organic compounds were used to produce biogas by anaerobic digestion (AD. Results The highest glucose yield achieved was 86%, obtained after pretreatment at 210°C for 10 minutes in the absence of catalyst, followed by enzymatic hydrolysis. The highest yield using sulphuric acid, 78%, was achieved using pretreatment at 200°C for 10 minutes. These two pretreatment conditions were investigated using two different process configurations. The highest ethanol and methane yields were obtained from the material pretreated in the presence of sulphuric acid. The slurry in this case was split into a solid fraction and a liquid fraction, where the solid fraction was used to produce ethanol and the liquid fraction to produce biogas. The total energy recovery in this case was 86% of the enthalpy of combustion energy in corn stover. Conclusions The highest yield, comprising ethanol, methane and solids, was achieved using pretreatment in the presence of sulphuric acid followed by a process configuration in

  16. 稀酸浸渍气爆预处理对纤维素乙醇同步糖化发酵的影响%Influence of dilute acid impregnation/steam-explosion pretreatment on simultaneous saccharification and fermentation of cellulosic ethanol

    Institute of Scientific and Technical Information of China (English)

    赵鹏翔; 吴毅; 李强

    2013-01-01

    Ethanol produced by lignocellulose takes the most attention of the fuel ethanol. The low efficiency of the pretreatment process limits the development of cellulosic ethanol. In this study, the traditional steam explosion pretreatment process is improved by introducing dilute acid impregnation, which enhances the simultaneous saccharification and fermentation (SSF) of cellulosic ethanol effectively. The final ethanol concentration after the SSF using sulfuric acid and acetic acid impregnation reaches 27. 5 g/L and 25. 5 g/L,respectively,which corresponds to 81% and 77% of the theoretical ethanol yield as well. However,by using the traditional steam explosion pretreatment,the final ethanol concentration is only 17.5 g/L, which is 63% of the theoretical ethanol yield. Compared with the traditional steam explosion pretreatment, dilute acid impregnation can effectively improve the result of steam explosion pretreatment and reduce the formation of the inhibitors, thereby increasing the production efficiency and reducing costs. This new method has potential to be applied to the industrialized production of cellulosic ethanol.%纤维素乙醇预处理过程效率偏低是影响纤维素乙醇发展的一个重要因素.通过改进传统蒸汽爆破预处理方法,在蒸汽爆破前加入稀酸浸渍,有效地提高了后续同步糖化发酵的水平.采用硫酸浸渍气爆预处理后的草浆同步糖化发酵乙醇质量浓度达到27.5 g/L,达到葡萄糖乙醇理论产率的81%;采用乙酸浸渍气爆预处理后的草浆同步糖化发酵乙醇质量浓度达到25.5 g/L,达到葡萄糖乙醇理论产率的77%;相比传统气爆草浆用于同步糖化发酵,稀酸预处理能有效地减少抑制物的生成,提高后续直接利用草浆进行同步糖化发酵的水平,从而提高生产效率,降低生产成本,是可应用于工业化纤维素乙醇生产的重要方法.

  17. Occurrence of Cellulose-Producing Gluconacetobacter spp. in Fruit Samples and Kombucha Tea, and Production of the Biopolymer.

    Science.gov (United States)

    Neera; Ramana, Karna Venkata; Batra, Harsh Vardhan

    2015-06-01

    Cellulose producing bacteria were isolated from fruit samples and kombucha tea (a fermented beverage) using CuSO4 solution in modified Watanabe and Yamanaka medium to inhibit yeasts and molds. Six bacterial strains showing cellulose production were isolated and identified by 16S rRNA gene sequencing as Gluconacetobacter xylinus strain DFBT, Ga. xylinus strain dfr-1, Gluconobacter oxydans strain dfr-2, G. oxydans strain dfr-3, Acetobacter orientalis strain dfr-4, and Gluconacetobacter intermedius strain dfr-5. All the cellulose-producing bacteria were checked for the cellulose yield. A potent cellulose-producing bacterium, i.e., Ga. xylinus strain DFBT based on yield (cellulose yield 5.6 g/L) was selected for further studies. Cellulose was also produced in non- conventional media such as pineapple juice medium and hydrolysed corn starch medium. A very high yield of 9.1 g/L cellulose was obtained in pineapple juice medium. Fourier transform infrared spectrometer (FT-IR) analysis of the bacterial cellulose showed the characteristic peaks. Soft cellulose with a very high water holding capacity was produced using limited aeration. Scanning electron microscopy (SEM) was used to analyze the surface characteristics of normal bacterial cellulose and soft cellulose. The structural analysis of the polymer was performed using (13)C solid-state nuclear magnetic resonance (NMR). More interfibrillar space was observed in the case of soft cellulose as compared to normal cellulose. This soft cellulose can find potential applications in the food industry as it can be swallowed easily without chewing.

  18. Effect of aqueous and ethanolic extracts of Pimpinella anisum L. seeds on milk production in rats.

    Science.gov (United States)

    Hosseinzadeh, Hossein; Tafaghodi, Mohsen; Abedzadeh, Shirin; Taghiabadi, Elahe

    2014-08-01

    Pimpinella anisum L. (P. anisum) is used as a galactagogue in traditional medicine; hence, the effect of aqueous and ethanolic extracts of P. anisum seeds on milk production in rats was evaluated. The milk production was assessed by measuring the pups' weights during the suckling period. The intraperitoneal LD(50) values of P. anisum aqueous and ethanolic extracts were 4.93 and 3.77 g/kg, respectively. The aqueous (1 g/kg) and ethanolic extracts (1 g/kg) increased the milk production significantly (p anisum aqueous and ethanolic extracts can increase milk production in rats.

  19. Simultaneous saccharification and fermentation of steam-pretreated lespedeza stalks for the production of ethanol

    Institute of Scientific and Technical Information of China (English)

    Jiang Jian-xin; Zhu Li-wei; Wang Kun; Wang Wei-gan

    2006-01-01

    Lespedeza stalks were subjected to steam pretreatment at 210℃ for some steaming time before simultaneous saccharification and fermentation (SSF). Cellulose-derived glucose was extensively utilized by yeast during SSF. The ethanol yields after steam pretreatment of the lespedeza stalks at 210℃ were 59.3%, 72.8% and 62.2% of the theoretically expected values when the steaming times were 2, 4 and 6 min, respectively. The highest yield from α-cellulose was 92.7% of the theoretical value. Steam explosion pretreatment of lespedeza stalks increased ethanol yields by a factor of 4.4, from 16.4% (untreated) to 72.8% (steam explosion pretreated).

  20. Simulation of Fuel Ethanol Production from Lignocellulosic Biomass

    Institute of Scientific and Technical Information of China (English)

    张素平; Francois Maréchal; Martin Gassner; 任铮伟; 颜涌捷; Daniel Favrat

    2009-01-01

    Models for hydrolysis, fermentation and concentration process, production and utilization of biogas as well as lignin gasification are developed to calculate the heat demand of ethanol production process and the amounts of heat and power generated from residues and wastewater of the process. For the energy analysis, all relevant information about the process streams, physical properties, and mass and energy balances are considered. Energy integration is investigated for establishing a network of facilities for heat and power generation from wastewater and residues treatment aiming at the increase of energy efficiency. Feeding the lignin to an IGCC process, the electric efficiency is increased by 4.4% compared with combustion, which leads to an overall energy efficiency of 53.8%. A detailed sensitivity analysis on energy efficiency is also carried out.

  1. Catalytic Production of Ethanol from Biomass-Derived Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G. [Colorado School of Mines, Golden, CO (United States); Smith, Ryan G. [Iowa State Univ., Ames, IA (United States)

    2016-06-01

    Heterogeneous catalysts have been developed for the conversion of biomass-derived synthetic gas (syngas) to ethanol. The objectives of this project were to develop a clean synthesis gas from biomass and develop robust catalysts with high selectivity and lifetime for C2 oxygenate production from biomass-derived syngas and surrogate syngas. During the timeframe for this project, we have made research progress on the four tasks: (1) Produce clean bio-oil generated from biomass, such as corn stover or switchgrass, by using fast pyrolysis system, (2) Produce clean, high pressure synthetic gas (syngas: carbon monoxide, CO, and hydrogen, H2) from bio-oil generated from biomass by gasification, (3) Develop and characterize mesoporous mixed oxide-supported metal catalysts for the selective production of ethanol and other alcohols, such as butanol, from synthesis gas, and (4) Design and build a laboratory scale synthesis gas to ethanol reactor system evaluation of the process. In this final report, detailed explanations of the research challenges associated with this project are given. Progress of the syngas production from various biomass feedstocks and catalyst synthesis for upgrading the syngas to C2-oxygenates is included. Reaction properties of the catalyst systems under different reaction conditions and different reactor set-ups are also presented and discussed. Specifically, the development and application of mesoporous silica and mesoporous carbon supports with rhodium nanoparticle catalysts and rhodium nanoparticle with manganese catalysts are described along with the significant material characterizations we completed. In addition to the synthesis and characterization, we described the activity and selectivity of catalysts in our micro-tubular reactor (small scale) and fixed bed reactor (larger scale). After years of hard work, we are proud of the work done on this project, and do believe that this work will provide a solid

  2. Ethanol Production from Biomass: Large Scale Facility Design Project

    Energy Technology Data Exchange (ETDEWEB)

    Berson, R. Eric [Univ. of Louisville, KY (United States)

    2009-10-29

    High solids processing of biomass slurries provides the following benefits: maximized product concentration in the fermentable sugar stream, reduced water usage, and reduced reactor size. However, high solids processing poses mixing and heat transfer problems above about 15% for pretreated corn stover solids due to their high viscosities. Also, highly viscous slurries require high power consumption in conventional stirred tanks since they must be run at high rotational speeds to maintain proper mixing. An 8 liter scraped surface bio-reactor (SSBR) is employed here that is designed to efficiently handle high solids loadings for enzymatic saccharification of pretreated corn stover (PCS) while maintaining power requirements on the order of low viscous liquids in conventional stirred tanks. Saccharification of biomass exhibit slow reaction rates and incomplete conversion, which may be attributed to enzyme deactivation and loss of activity due to a variety of mechanisms. Enzyme deactivation is classified into two categories here: one, deactivation due to enzyme-substrate interactions and two, deactivation due to all other factors that are grouped together and termed “non-specific” deactivation. A study was conducted to investigate the relative extents of “non-specific” deactivation and deactivation due to “enzyme-substrate interactions” and a model was developed that describes the kinetics of cellulose hydrolysis by considering the observed deactivation effects. Enzyme substrate interactions had a much more significant effect on overall deactivation with a deactivation rate constant about 20X higher than the non-specific deactivation rate constant (0.35 h-1 vs 0.018 h-1). The model is well validated by the experimental data and predicts complete conversion of cellulose within 30 hours in the absence of enzyme substrate interactions.

  3. 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

  4. 硝酸乙醇法测定纤维素含量%Determination the content of cellulose by nitric acid-ethanol method

    Institute of Scientific and Technical Information of China (English)

    王林风; 程远超

    2011-01-01

    根据秸秆乙醇的工艺特点,对硝酸乙醇法测定玉米秸秆、小麦秸秆、稻草及其预处理后物料的纤维素含量进行了研究.优化了粉碎时长、硝酸-乙醇混合液处理遍数、试样粒度及抽滤漏斗孔径四个参数.确定了优化后的测定方法:秸秆试样粉碎时长15 s,硝酸-乙醇混合液处理4遍,粒度40~60目,使用G2玻璃砂芯漏斗.秸秆预处理后物料试样粉碎时长3 s,硝酸-乙醇混合液处理3遍,粒度40~60目,使用G3玻璃砂芯漏斗.%The contents of cellulose of corn stalk, wheat straw, rice straw and the pretreated sample of straws have been researched by nitric acid-ethanol methodology according to the characteristics of straws biofuel ethanol. Four parameters as the duration of comminuting sample, the times of treating sample by nitric acid-ethanol liquid mixture, the particle size of sample and the aperture of tundish for sucking filtration have been optimized. The optimized pev-rameters: for straw sample, comminut 15 s, treat by nitric acid-ethanol liquid mixture 4 times, sample aperture 40 - 60 mesh, use G2 glass sand core tundish. For pretreated sample, comminut 3 s, treat by nitric acid-ethanol liquid mixture 3 times, sample aperture 40 - 60 mesh, use G3 glass sand core tundish.

  5. Acetone, butanol, and ethanol production from wastewater algae.

    Science.gov (United States)

    Ellis, Joshua T; Hengge, Neal N; Sims, Ronald C; Miller, Charles D

    2012-05-01

    Acetone, butanol, and ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4 using wastewater algae biomass as a carbon source was demonstrated. Algae from the Logan City Wastewater Lagoon system grow naturally at high rates providing an abundant source of renewable algal biomass. Batch fermentations were performed with 10% algae as feedstock. Fermentation of acid/base pretreated algae produced 2.74 g/L of total ABE, as compared with 7.27 g/L from pretreated algae supplemented with 1% glucose. Additionally, 9.74 g/L of total ABE was produced when xylanase and cellulase enzymes were supplemented to the pretreated algae media. The 1% glucose supplement increased total ABE production approximately 160%, while supplementing with enzymes resulted in a 250% increase in total ABE production when compared to production from pretreated algae with no supplementation of extraneous sugar and enzymes. Additionally, supplementation of enzymes produced the highest total ABE production yield of 0.311 g/g and volumetric productivity of 0.102 g/Lh. The use of non-pretreated algae produced 0.73 g/L of total ABE. The ability to engineer novel methods to produce these high value products from an abundant and renewable feedstock such as algae could have significant implications in stimulating domestic energy economies.

  6. Factors affecting release of ethanol vapour in active modified atmosphere packaging systems for horticultural products

    Directory of Open Access Journals (Sweden)

    Weerawate Utto

    2014-04-01

    Full Text Available The active modified atmosphere packaging (active MAP system , which provides interactive postharvest control , using ethanol vapour controlled release, is one of the current interests in the development of active packaging for horticultural products. A number of published research work have discussed the relationship between the effectiveness of ethanol vapour and its concentration in the package headspace, including its effect on postharvest decay and physiological controls. This is of importance because a controlled release system should release and maintain ethanol vapour at effective concentrations during the desired storage period. A balance among the mass transfer processes of ethanol vapour in the package results in ethanol vapour accumulation in the package headspace. Key factors affecting these processes include ethanol loading, packaging material, packaged product and storage environment (temperature and relative h umidity. This article reviews their influences and discusses future work required to better understand their influences on ethanol vapour release and accumulations in active MAP.

  7. Performance Evaluation of Sweet Sorghum Juice and Sugarcane Molasses for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Hatamipour Mohammad Sadegh

    2015-09-01

    Full Text Available Sweet sorghum juice and traditional ethanol substrate i.e. sugarcane molasses were used for ethanol production in this work. At the end of the fermentation process, the sweet sorghum juice yielded more ethanol with higher ethanol concentration compared to sugarcane molasses in all experiments. The sweet sorghum juice had higher cell viability at high ethanol concentrations and minimum sugar concentration at the end of the fermentation process. The ethanol concentration and yield were 8.9% w/v and 0.45 g/g for sweet sorghum in 80 h and 6.5% w/v and 0.37 g/g for sugarcane molasses in 60 h, respectively. The findings on the physical properties of sweet sorghum juice revealed that it has better physical properties compared to sugarcane molasses, resulting to enhanced performance of sweet sorghum juice for ethanol production

  8. Optimized Monitoring of Production of Cellulose Nanowhiskers from Opuntia ficus-indica (Nopal Cactus

    Directory of Open Access Journals (Sweden)

    Horacio Vieyra

    2015-01-01

    Full Text Available Preparation of cellulose nanowhiskers (CNWs has grown significantly because they are useful for a wide range of applications. Additional advantage in their design requires that they meet the following characteristics: nontoxicity, abundance, sustainability, renewability, and low cost. To address these requirements, nanowhiskers were prepared from Opuntia ficus-indica (nopal cellulose by acid hydrolysis. Monitoring the process of CNWs preparation is necessary to ensure maximum yield and purity of the end product. In this study, the cellulose preparation was monitored by analyzing microscopic morphology by SEM; the purity degree was determined by fluorescence microscopy as a novel and rapid technique, and FTIR spectroscopy was used for confirmation. The additional parameters that monitored the process were the crystallinity index by X-ray diffraction and the size of the particle by dynamic light scattering (DLS. Nopal cellulose was found to be comparable to commercial microcrystalline cellulose. The use of Opuntia ficus-indica is a viable alternative for the production of highly pure CNWs and the strategy to supervise the preparation process was rapid.

  9. Ethanol production from agricultural wastes using Saccharomyces cerevisiae.

    Science.gov (United States)

    Irfan, Muhammad; Nadeem, Muhammad; Syed, Quratualain

    2014-01-01

    The main objective of this study was production of ethanol from three lignocellulosic biomasses like sugarcane bagasse, rice straw and wheat straw by Sacchromyces cervisae. All the three substrates were ground to powder form (2 mm) and pretreated with 3%H2O2 + 2% NaOH followed by steaming at 130 °C for 60 min. These substrates were hydrolyzed by commercial cellulase enzyme. The whole fermentation process was carried out in 500 mL Erlenmeyer flask under anaerobic conditions in submerged fermentation at 30 °C for three days of incubation period. FTIR analysis of the substrates indicated significant changes in the alteration of the structure occurred after pretreatment which leads to efficient saccharification. After pretreatment the substrates were hydrolyzed by commercial cellulase enzyme and maximum hydrolysis was observed in sugarcane bagasse (64%) followed by rice straw (40%) and wheat straw (34%). Among all these tested substrates, sugarcane bagasse (77 g/L) produced more ethanol as compared to rice straw (62 g/L) and wheat straw (44 g/L) using medium composition of (%) 0.25 (NH4)2SO4, 0.1 KH2PO4, 0.05 MgSO4, 0.25 Yeast extract by S. cervisae.

  10. Ethanol production from agricultural wastes using Sacchromyces cervisae

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan

    2014-06-01

    Full Text Available The main objective of this study was production of ethanol from three lignocellulosic biomasses like sugarcane bagasse, rice straw and wheat straw by Sacchromyces cervisae. All the three substrates were ground to powder form (2 mm and pretreated with 3%H2O2 + 2% NaOH followed by steaming at 130 °C for 60 min. These substrates were hydrolyzed by commercial cellulase enzyme. The whole fermentation process was carried out in 500 mL Erlenmeyer flask under anaerobic conditions in submerged fermentation at 30 °C for three days of incubation period. FTIR analysis of the substrates indicated significant changes in the alteration of the structure occurred after pretreatment which leads to efficient saccharification. After pretreatment the substrates were hydrolyzed by commercial cellulase enzyme and maximum hydrolysis was observed in sugarcane bagasse (64% followed by rice straw (40% and wheat straw (34%. Among all these tested substrates, sugarcane bagasse (77 g/L produced more ethanol as compared to rice straw (62 g/L and wheat straw (44 g/L using medium composition of (% 0.25 (NH42SO4, 0.1 KH2PO4, 0.05 MgSO4, 0.25 Yeast extract by S. cervisae.

  11. Tolerant yeast in situ detoxifies major class of toxic chemicals while producing ethanol

    Science.gov (United States)

    Renewable lignocellulosic materials contain abundant sugar source and biofuels conversion including cellulosic ethanol production from lignocellulosic biomass provides a sustainable alternative energy resource for a cleaner environment. In order to release the biomass sugars from the complex cellulo...

  12. 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

  13. Use of lignocellulosic biomass to produce ethanol. Aprovechamiento de la biomasa lignocelulosica para la produccion de etanol

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, J.M.

    1993-01-01

    Gasohol is an automobile fuel with 10% ethanol and 90% gasoline used in USA. A 20/80% mixture is also used in Brasil. Lignocellulosic biomass can be a source to produce ethanol. It is a mixture of cellulose (30%), Memicellulose (32%), lignine (17%) and other (13%). The fundamentals of the ethanol production process are presented. (Author)

  14. Estimation of Economic Impacts of Cellulosic Biofuel Production: A Comparative Analysis of Three Biofuel Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yimin; Goldberg, Marshall; Tan, Eric; Meyer, Pimphan Aye

    2016-05-01

    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: (i) cellulosic ethanol via biochemical conversion in Iowa, (ii) renewable diesel blendstock via biological conversion in Georgia, and (iii) renewable diesel and gasoline blendstock via fast pyrolysis in Mississippi. Combining direct, indirect (revenue- and supply-chain-related), and induced effects, capital investment associated with the construction of a biorefinery processing 2000 dry metric tons of biomass per day (DMT/day) could yield between 5960 and 8470 full-time equivalent (FTE) jobs during the construction period, depending on the biofuel pathways. Fast pyrolysis biorefineries produce the most jobs on a project level thanks to the highest capital requirement among the three pathways. Normalized on the scale of $1 million of capital investment, the fast pyrolysis biorefineries are estimated to yield slighter higher numbers of 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 2000 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. Unlike construction jobs, these operation-related jobs are necessary over the entire life of the biorefineries. Our results show that indirect effects stimulated by the operation of biorefineries are the primary contributor to job growth. The agriculture/forest, services, and

  15. Estimation of Economic Impacts of Cellulosic Biofuel Production: A Comparative Analysis of Three Biofuel Pathways

    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.

  16. Komagataeibacter rhaeticus as an alternative bacteria for cellulose production.

    Science.gov (United States)

    Machado, Rachel T A; Gutierrez, Junkal; Tercjak, Agnieszka; Trovatti, Eliane; Uahib, Fernanda G M; Moreno, Gabriela de Padua; Nascimento, Andresa P; Berreta, Andresa A; Ribeiro, Sidney J L; Barud, Hernane S

    2016-11-01

    A strain isolated from Kombucha tea was isolated and used as an alternative bacterium for the biosynthesis of bacterial cellulose (BC). In this study, BC generated by this novel bacterium was compared to Gluconacetobacter xylinus biosynthesized BC. Kinetic studies reveal that Komagataeibacter rhaeticus was a viable bacterium to produce BC according to yield, thickness and water holding capacity data. Physicochemical properties of BC membranes were investigated by UV-vis and Fourier transform infrared spectroscopies (FTIR), thermogravimetrical analysis (TGA) and X-ray diffraction (XRD). Additionally, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were also used for morphological characterization. Mechanical properties at nano and macroscale were studied employing PeakForce quantitative nanomechanical property mapping (QNM) and dynamic mechanical analyzer (DMA), respectively. Results confirmed that BC membrane biosynthesized by Komagataeibacter rhaeticus had similar physicochemical, morphological and mechanical properties than BC membrane produced by Gluconacetobacter xylinus and can be widely used for the same applications.

  17. Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol.

    Science.gov (United States)

    Todero Ritter, Carla Eliana; Camassola, Marli; Zampieri, Denise; Silveira, Mauricio Moura; Dillon, Aldo José Pinheiro

    2013-01-01

    The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v) sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v) soy bran; 0.1% (w/v) wheat bran; and a solution of salts. The highest filter paper activity (FPA) (1.95  ±  0.04 IU·mL(-1)) was obtained on the seventh day in the medium containing 0.5% (w/v) sorbitol and 0.5% (w/v) cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day (9.99 ± 0.75 IU·mL(-1)) in the medium containing 0.75% (w/v) sorbitol and 0.75% (w/v) cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v) sorbitol and 0.25% (w/v) cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

  18. Batch and Fed-Batch Fermentation System on Ethanol Production from Whey using Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2013-10-01

    Full Text Available Nowadays reserve of fossil fuel has gradually depleted. This condition forces many researchers to  find energy alternatives which is renewable and sustainable in the future. Ethanol derived from cheese industrial waste (whey using fermentation process can be a new perspective in order to secure both energy and environment. The aim of this study was  to compare the operation modes (batch and fed-batch of fermentation system on ethanol production from whey using Kluyveromyces marxianus. The result showed that the fermentation process for ethanol production by fed-batch system was higher at some point of parameters compared with batch system. Growth rate and ethanol yield (YP/S of fed-batch fermentation were 0.122/h and 0.21 gP/gS respectively; growth rate and ethanol yield (YP/S of batch fermentation were 0.107/h, and 0.12 g ethanol/g substrate, respectively. Based on the data of biomass and ethanol concentrations, the fermentation process for ethanol production by fed-batch system were higher at some point of parameters compared to batch system. Periodic substrate addition performed on fed-batch system leads the yeast growth in low substrate concentrations and consequently  increasing their activity and ethanol productivity. Keywords: batch; ethanol; fed-batch; fermentation;Kluyveromyces marxianus, whey

  19. 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.

  20. Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization

    OpenAIRE

    Mumm, Rita H.; Goldsmith, Peter D.; Rausch, Kent D; Stein, Hans H

    2014-01-01

    Background Although the system for producing yellow corn grain is well established in the US, its role among other biofeedstock alternatives to petroleum-based energy sources has to be balanced with its predominant purpose for food and feed as well as economics, land use, and environmental stewardship. We model land usage attributed to corn ethanol production in the US to evaluate the effects of anticipated technological change in corn grain production, ethanol processing, and livestock feedi...

  1. Optimisation of the composition and production of mannitol/microcrystalline cellulose tablets

    NARCIS (Netherlands)

    Westerhuis, J.A; de Haan, P; Zwinkels, J; Jansen, W.T; Coenegracht, P.M J; Lerk, C.F

    1996-01-01

    Mixtures of mannitol and microcrystalline cellulose (MCC) were investigated on a small-production scale by granulation in a high-shear mixer and compression into tablets. For both excipients only a few cases of incompatibilities with active ingredients are known. Tablets with only MCC as the filler

  2. Cellulose Nanocrystals Obtained from Rice By-Products and Their Binding Potential to Metallic Ions

    Directory of Open Access Journals (Sweden)

    Vanessa L. Albernaz

    2015-01-01

    Full Text Available The present study aimed to develop and optimize a method to obtain cellulose nanocrystals from the agricultural by-products rice husk and straw and to evaluate their electrostructural modifications in the presence of metallic ions. First, different particle formation conditions and routes were tested and analyzed by spectrophotometry, dynamic light scattering (DLS, and Zeta potential measurements. Then, electrostructural effects of ions Na(I, Cd(II, and Al(III on the optimized nanoparticles were analyzed by atomic force microscopy (AFM, scanning electron microscopy (SEM, and electrical conductivity (EC assessments. The produced cellulose nanocrystals adopted a rod-like shape. AFM height distribution and EC data indicated that the nanocrystals have more affinity in binding with Na(I > Al(III > Cd(II. These data suggest that the use of these cellulose nanocrystals in the bioremediation field is promising, both in metal sorption from wastewater and as an alternative for water desalination.

  3. Utilizing Protein-lean Co-products from Corn Containing Recombinant Pharmaceutical Proteins for Ethanol Production

    Science.gov (United States)

    Protein-lean fractions of corn (maize) containing recombinant (r) pharmaceutical proteins were used to produce fuel ethanol and residual r-proteins in the co-product, distillers dry grains with solubles (DDGS), were determined. Transgenic corn lines containing recombinant green fluorescence protein ...

  4. Techno-economic analysis of ethanol production from sugarcane bagasse using a Liquefaction plus Simultaneous Saccharification and co-Fermentation process.

    Science.gov (United States)

    Gubicza, Krisztina; Nieves, Ismael U; Sagues, William J; Barta, Zsolt; Shanmugam, K T; Ingram, Lonnie O

    2016-05-01

    A techno-economic analysis was conducted for a simplified lignocellulosic ethanol production process developed and proven by the University of Florida at laboratory, pilot, and demonstration scales. Data obtained from all three scales of development were used with Aspen Plus to create models for an experimentally-proven base-case and 5 hypothetical scenarios. The model input parameters that differed among the hypothetical scenarios were fermentation time, enzyme loading, enzymatic conversion, solids loading, and overall process yield. The minimum ethanol selling price (MESP) varied between 50.38 and 62.72 US cents/L. The feedstock and the capital cost were the main contributors to the production cost, comprising between 23-28% and 40-49% of the MESP, respectively. A sensitivity analysis showed that overall ethanol yield had the greatest effect on the MESP. These findings suggest that future efforts to increase the economic feasibility of a cellulosic ethanol process should focus on optimization for highest ethanol yield.

  5. Evaluation of Saccharomyces cerevisiae Y5 for ethanol production from enzymatic hydrolysate of non-detoxified steam-exploded corn stover.

    Science.gov (United States)

    Li, Yun; Gao, Kai; Tian, Shen; Zhang, Sijin; Yang, Xiushan

    2011-11-01

    Saccharomyces cerevisiae Y5 was used to produce ethanol from enzymatic hydrolysate of non-detoxified steam-exploded corn stover, with and without a nitrogen source, and decreasing inoculum size. The results indicated that the ethanol concentration of 44.55 g/L, corresponding to 94.5% of the theoretical yield was obtained after 24 h, with an inoculum size of 10% (v/v) and nitrogen source (corn steep liquor, CSL) of 40 mL/L. With the same inoculum size, and without CSL, the ethanol concentration was 43.21 g/L, corresponding to 91.7% of the theoretical value after 60 h. With a decreased inoculum size of 5% (v/v), and without CSL, the ethanol concentration was 40.00 g/L, corresponding to 85.8% of the theoretical value after 72 h. The strain offers the potential to improve the economy of cellulosic ethanol production by simplifying the production process and reducing the costs associated with the process such as water, capital equipment and nutrient supplementation.

  6. A Simple Laboratory Exercise for Ethanol Production by Immobilized Bakery Yeasts ("Saccharomyces Cerevisiae")

    Science.gov (United States)

    Vullo, Diana L.; Wachsman, Monica B.

    2005-01-01

    This laboratory experiment was designed for Chemistry, Food Technology, Biology, and Chemical Engineering undergraduate students. This laboratory experience shows the advantages of immobilized bakery yeasts in ethanol production by alcoholic fermentation. The students were able to compare the ethanol production yields by free or calcium alginate…

  7. The sustainability of Brazilian ethanol - an assessment of the possibilities of certified production

    NARCIS (Netherlands)

    Smeets, E.M.W.; Junginger, H.M.; Faaij, A.P.C.; Walter, A.; Dolzan, P.; Turkenburg, W.C.

    2008-01-01

    In this article the environmental and socio-economical impacts of the production of ethanol from sugarcane in the state of São Paulo (Brazil) are evaluated. Subsequently, an attempt is made to determine to what extent these impacts are a bottleneck for a sustainable and certified ethanol production.

  8. Effect of addition of sodium alginate on bacterial cellulose production by Acetobacter xylinum.

    Science.gov (United States)

    Zhou, L L; Sun, D P; Hu, L Y; Li, Y W; Yang, J Z

    2007-07-01

    Bacterial cellulose (BC) production by Acetobacter xylinum NUST4.1 was carried out in the shake flask and in a stirred-tank reactor by means of adding sodium alginate (NaAlg) into the medium. When 0.04% (w/v) NaAlg was added in the shake flask, BC production reached 6.0 g/l and the terminal yield of the cellulose was 27% of the total sugar initially added, compared with 3.7 g/l and 24% in the control, respectively. The variation between replicates in all determinations was less than 5%. During the cultivation in the stirred-tank reactor, the addition of NaAlg changed the morphology of cellulose from the irregular clumps and fibrous masses entangled in the internals to discrete masses dispersing into the broth, which indicates that NaAlg hinders formation of large clumps of BC, and enhances cellulose yield. Because the structure of cellulose is changed depending on the culture condition such as additives, structural characteristics of BC produced in the NaAlg-free and NaAlg medium are compared using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD). SEM photographs show some differences in reticulated structures and ribbon width and FT-IR spectra indicate that there is the hydrogen bonding interaction between BC and NaAlg, then X-ray diffraction (XRD) analysis reveals that BC produced with NaAlg-added has a lower crystallinity and a smaller crystalline size. The results show that enhanced yields and modification of cellulose structure occur in the presence of NaAlg.

  9. Pathway engineering to improve ethanol production by thermophilic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lynd, L.R.

    1998-12-31

    Continuation of a research project jointly funded by the NSF and DOE is proposed. The primary project goal is to develop and characterize strains of C. thermocellum and C. thermosaccharolyticum having ethanol selectivity similar to more convenient ethanol-producing organisms. An additional goal is to document the maximum concentration of ethanol that can be produced by thermophiles. These goals build on results from the previous project, including development of most of the genetic tools required for pathway engineering in the target organisms. As well, we demonstrated that the tolerance of C. thermosaccharolyticum to added ethanol is sufficiently high to allow practical utilization should similar tolerance to produced ethanol be demonstrated, and that inhibition by neutralizing agents may explain the limited concentrations of ethanol produced in studies to date. Task 1 involves optimization of electrotransformation, using either modified conditions or alternative plasmids to improve upon the low but reproducible transformation, frequencies we have obtained thus far.

  10. Direct hydrogen production from cellulosic waste materials with a single-step dark fermentation process

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, Lauren; Islam, Rumana; Levin, David; Cicek, Nazim [Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB (Canada); Sparling, Richard [Department of Microbiology, University of Manitoba, Winnipeg, MB (Canada)

    2008-10-15

    Biohydrogen production from cellulosic waste materials using dark fermentation is a promising technology for producing renewable energy. The purpose of this study was to evaluate residual cellulosic materials generated from local sources for their H{sub 2} production potential without any pretreatment. Clostridium thermocellum ATCC 27405, a cellulolytic, thermophilic bacterium that has been shown to be capable of H{sub 2} production on both cellobiose and {alpha}-cellulose substrates, was used in simultaneous batch fermentation experiments with dried distillers grain (DDGs), barley hulls (BH) and fusarium head blight contaminated barley hulls (CBH) as the carbon source. Overall, the dried distillers grain produced the highest concentration of hydrogen gas at 1.27 mmol H{sub 2}/glucose equivalent utilized. CBH and BH produced 1.18 and 1.24 mmol H{sub 2}/glucose equivalent utilized, respectively. Overall, this study indicates that hydrogen derived from a variety of cellulosic waste biomass sources is a possible candidate for the development of sustainable energy. (author)

  11. Effect of xylose and nutrients concentration on ethanol production by a newly isolated extreme thermophilic bacterium

    DEFF Research Database (Denmark)

    Tomás, Ana Faria; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2011-01-01

    An extreme thermophilic ethanol-producing strain was isolated from an ethanol high-yielding mixed culture, originally isolated from a hydrogen producing reactor operated at 70 °C. Ethanol yields were assessed with increasing concentrations of xylose, up to 20 g/l. The ability of the strain to grow...... product under most of the conditions tested, including in media lacking vitamins, peptone and yeast extract. The results indicate that this new organism is a promising candidate for the development of a second generation bio-ethanol production process. © IWA Publishing 2011....

  12. Potential inhibitors from wet oxidation of wheat straw and their effect on ethanol production of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klinke, H.B.; Olsson, L.; Thomsen, A.B.;

    2003-01-01

    Alkaline wet oxidation (WO) (using water, 6.5 g/L sodium carbonate and 12 bar oxygen at 195degreesC) was used as pretreatment method for wheat straw (60 g/L), resulting in a hydrolysate and a cellulosic solid fraction. The hydrolysate consisted of soluble hemicellulose (8 g/L), low......-molecular-weight carboxylic acids (3.9 g/L), phenols (0.27 g/L = 1.7 mM) and 2-furoic acid (0.007 g/L). The wet oxidized wheat straw hydrolysate caused no inhibition of ethanol production by Saccharomyces cerevisiae ATCC 96581. Nine phenols and 2-furoic acid, identified to be present in the hydrolysate, were each tested...

  13. Degradation of cellulosic biomass and its subsequent utilization for the production of chemical feedstocks. Progress report, March 1, 1977--May 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-06-01

    The degradation of cellulosic biomass continues to focus on the anaerobic thermophile Clostridium thermocellum. When grown on crystalline cellulose (MN300) in batch culture, there is an initial rapid accumulation of reducing sugars but the sugars are rapidly metabolized in later times during the fermentation. When grown on Solka floc with periodic addition of the substrate, there is a continual accumulation of reducing sugars (xylose, glucose, and cellobiose) as well as ethanol and acetic acid during the entire course of the fermentation. In the presence of surfactant in the growth medium, there is an increased appearance of extracellular cellulases. A chemically defined medium is being developed for growth Cl. thermocellum in order to study the enzyme regulations. Lastly, a trinitrophenyl-carboxylmethyl cellulose substrate for determining cellulose activity appears to be a promising and rapid assay. Progress in the genetic manipulations has been cautious but promising. Preliminary evidence leads to optimistic projection on the presence of plasmids and bacteriophage in Cl. thermocellum. The production of chemical feedstocks continues to focus on acrylic acid, acetone/butanol and acetic acid. Studies with cell free extracts of Clostridium propionicum have shown the production and accumulation of acrylic acid from lactic acid. The use of electron acceptor in cell-free systems has shown effective prevention on the reduction of acrylic acid to propionic acid. Medium development and strain selection using available acetone/butanol producing Cl. acetobutylicum have been initiated. There is every indication that these strains are capable to produce mixed solvents close to the theoretical maximum yield. An accurate and rapid method for quantifying acetic acid was developed. This technique is being used to examine the pertinent parameters on the production of acetic acid by Clostridium thermoaceticum.

  14. Ethanol production from cashew apple bagasse: improvement of enzymatic hydrolysis by microwave-assisted alkali pretreatment.

    Science.gov (United States)

    Rodrigues, Tigressa Helena Soares; Rocha, Maria Valderez Ponte; de Macedo, Gorete Ribeiro; Gonçalves, Luciana R B

    2011-07-01

    In this work, the potential of microwave-assisted alkali pretreatment in order to improve the rupture of the recalcitrant structures of the cashew able bagasse (CAB), lignocellulosic by-product in Brazil with no commercial value, is obtained from cashew apple process to juice production, was studied. First, biomass composition of CAB was determined, and the percentage of glucan and lignin was 20.54 ± 0.70% and 33.80 ± 1.30%, respectively. CAB content in terms of cellulose, hemicelluloses, and lignin, 19.21 ± 0.35%, 12.05 ± 0.37%, and 38.11 ± 0.08%, respectively, was also determined. Results showed that, after enzymatic hydrolysis, alkali concentration exerted influence on glucose formation, after pretreatment with 0.2 and 1.0 mo L(-1) of NaOH (372 ± 12 and 355 ± 37 mg g(glucan)(-1) ) when 2% (w/v) of cashew apple bagasse pretreated by microwave-assisted alkali pretreatment (CAB-M) was used. On the other hand, pretreatment time (15-30 min) and microwave power (600-900 W) exerted no significant effect on hydrolysis. On enzymatic hydrolysis step, improvement on solid percentage (16% w/v) and enzyme load (30 FPU g (CAB-M) (-1) ) increased glucose concentration to 15 g L(-1). The fermentation of the hydrolyzate by Saccharomyces cerevesiae resulted in ethanol concentration and productivity of 5.6 g L(-1) and 1.41 g L(-1) h(-1), respectively.

  15. Bacterial cellulose production by Gluconacetobacter xylinus by employing alternative culture media

    OpenAIRE

    Jozala,Angela Faustino; Pértile, Renata Aparecida Nedel; Santos, Carolina Alves dos; Ebinuma, Valéria de Carvalho Santos; Seckler, Marcelo Martins; Gama, F. M.; Pessoa Júnior, Adalberto

    2015-01-01

    Bacterial cellulose (BC) is used in different fields as a biological material due to its unique properties. Despite there being many BC applications, there still remain many problems associated with bioprocess technology, such as increasing productivity and decreasing production cost. New technologies that use waste from the food industry as raw materials for culture media promote economic advantages because they reduce environmental pollution and stimulate new research for science sustainabi...

  16. An alternative feedstock of corn meal for industrial fuel ethanol production: delignified corncob residue.

    Science.gov (United States)

    Lei, Cheng; Zhang, Jian; Xiao, Lin; Bao, Jie

    2014-09-01

    Delignified corncob residue is an industrial solid waste from xylose production using corncob as feedstock. In this study, delignified corncob residue was used as the feedstock of ethanol production by simultaneous saccharification and fermentation (SSF) and the optimal fermentation performance was investigated under various operation conditions. The ethanol titer and yield reached 75.07 g/L and 89.38%, respectively, using a regular industrial yeast strain at moderate cellulase dosage and high solids loading. A uniform SSF temperature of 37°C at both prehydrolysis and SSF stages was tested. The fermentation performance and cost of delignified corncob residue and corn meal was compared as feedstock of ethanol fermentation. The result shows that the delignified corncob residue is competitive to corn meal as ethanol production feedstock. The study gives a typical case to demonstrate the potential of intensively processed lignocellulose as the alternative feedstock of corn meal for industrial fuel ethanol production.

  17. Biorefinery of corn cob for microbial lipid and bio-ethanol production: An environmental friendly process.

    Science.gov (United States)

    Cai, Di; Dong, Zhongshi; Wang, Yong; Chen, Changjing; Li, Ping; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-07-01

    Microbial lipid and bio-ethanol were co-generated by an integrated process using corn cob bagasse as raw material. After pretreatment, the acid hydrolysate was used as substrate for microbial lipid fermentation, while the solid residue was further enzymatic hydrolysis for bio-ethanol production. The effect of acid loading and pretreatment time on microbial lipid and ethanol production were evaluated. Under the optimized condition for ethanol production, ∼131.3g of ethanol and ∼11.5g of microbial lipid were co-generated from 1kg raw material. On this condition, ∼71.6% of the overall fermentable sugars in corn cob bagasse could be converted into valuable products. At the same time, at least 33% of the initial COD in the acid hydrolysate was depredated.

  18. Enhanced production of bacterial cellulose by using Gluconacetobacter hansenii NCIM 2529 strain under shaking conditions.

    Science.gov (United States)

    Mohite, Bhavna V; Salunke, Bipinchandra K; Patil, Satish V

    2013-03-01

    Bacterial cellulose (BC), a biopolymer, due to its unique properties is valuable for production of vital products in food, textile, medicine, and agriculture. In the present study, the optimal fermentation conditions for enhanced BC production by Gluconacetobacter hansenii NCIM 2529 were investigated under shaking conditions. The investigation on media components and culture parameters revealed that 2 % (w/v) sucrose as carbon source, 0.5 % (w/v) potassium nitrate as nitrogen source, 0.4 % (w/v) disodium phosphate as phosphate source, 0.04 % (w/v) magnesium sulfate, and 0.8 % (w/v) calcium chloride as trace elements, pH5.0, temperature 25 °C, and agitation speed 170 rpm with 6 days of fermentation period are optimal for maximum BC production. Production of BC using optimized media components and culture parameters was 1.66 times higher (5.0 g/l) than initial non optimized media (3.0 g/l). Fourier transform infrared spectroscopy spectrum and comparison with the available literature suggests that the produced component by G. hansenii in the present study is pure bacterial cellulose. The specific action of cellulase out of the investigated hydrolytic enzymes (cellulase, amylase, and protease) further confirmed purity of the produced BC. These findings give insight into conditions necessary for enhanced production of bacterial cellulose, which can be used for a variety of applications.

  19. Endogenous ethanol production and hepatic disease following jejunoileal bypass for morbid obesity.

    Science.gov (United States)

    Mezey, E; Imbembo, A L; Potter, J J; Rent, K C; Lombardo, R; Holt, P R

    1975-11-01

    In this study, we sought to determine whether or not elevated levels of ethanol were present in the systemic circulation, resulting from endogenous ethanol production, which might contribute to the hepatic damage following jejunoileal bypass for morbid obesity. Venous serum samples for assay of ethanol by gas-liquid chromatography were obtained in 8 normal subjects, 9 obese patients prior to surgery, 20 obese patients 2 weeks to 40 months after jejunoileal bypass, and in 2 dogs before and after jejunoileal bypass. Ethanol was detected after jejunoileal bypass in only 7 of the 20 patients and in the 2 dogs. Serum ethanol concentrations ranged from 0.15 to 4.12 mg/100 ml with a mean of 1.18 +/- 1.59 (SD)( mg/100 ml in the 7 patients and ranged from 0.20 to 2.23 mg/100 ml in the dogs. Incubation of the contents of the bypassed intestine of a dog with dextrose resulted in the production of significant amounts of ethanol. However, there was no correlation between the presence of ethanol in the serum and liver histology, when liver biopsy was obtained, postoperatively. Since ethanol was detected in the serum in only small concentrations and in only one-third of the patients, it is unlikely that ethanol production by bacteria in the intestine is of significance in the pathogenesis of liver disease following jejunoileal bypass.

  20. Technology and economics of conversion of cellulose (wood) and corn starch to sugars, alcohol and yeast. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wolnak, B.

    1978-08-01

    The present status of the technology and economics for the production of glucose, alcohol, and yeast from cellulose (wood), corn starch, and molasses is analyzed. The basic processes for producing glucose and the factors affecting the economics of its production are reviewed. The costs of producing ethanol and yeast from the glucose are derived. Market availability of glucose, ethanol, and yeast is surveyed. (JSR)

  1. Optimization of SO2-catalyzed steam pretreatment of corn fiber for ethanol production.

    Science.gov (United States)

    Bura, Renata; Bothast, Rodney J; Mansfield, Shawn D; Saddler, John N

    2003-01-01

    A batch reactor was employed to steam explode corn fiber at various degrees of severity to evaluate the potential of using this feedstock as part of an enzymatically mediated cellulose-to-ethanol process. Severity was controlled by altering temperature (150-230 degrees C), residence time (1-9 min), and SO2 concentration (0-6% [w/w] dry matter). The effects of varying the different parameters were assessed by response surface modeling. The results indicated that maximum sugar yields (hemicellulose-derived water soluble, and cellulose-derived following enzymatic hydrolysis) were recovered from corn fiber pretreated at 190 degrees C for 5 minutes after exposure to 3% SO2. Sequential SO2-catalyzed steam explosion and enzymatic hydrolysis resulted in a conversion efficiency of 81% of the combined original hemicellulose and cellulose in the corn fiber to monomeric sugars. An additional posthydrolysis step performed on water soluble hemicellulose stream increased the concentration of sugars available for fermentation by 10%, resulting in the high conversion efficiency of 91%. Saccharomyces cerevisiae was able to ferment the resultant corn fiber hydrolysates, perhydrolysate, and liquid fraction from the posthydrolysis steps to 89, 94, and 85% of theoretical ethanol conversion, respectively. It was apparent that all of the parameters investigated during the steam explosion pretreatment had a significant effect on sugar recovery, inhibitory formation, enzymatic conversion efficiency, and fermentation capacity of the yeast.

  2. A laboratory and pilot plant scaled continuous stirred reactor separator for the production of ethanol from sugars, corn grits/starch or biomass streams

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.; Lei, Shuiwang; Zhou, Chongde

    1995-10-01

    An improved bio-reactor has been developed to allow the high speed, continues, low energy conversion of various substrates to ethanol. The Continuous Stirred Reactor Separator (CSRS) incorporates gas stripping of the ethanol using a recalculating gas stream between cascading stirred reactors in series. We have operated a 4 liter lab scale unit, and built and operated a 24,000 liter pilot scale version of the bioreactor. High rates of fermentation are maintained in the reactor stages using a highly flocculent yeast strain. Ethanol is recovered from the stripping gas using a hydrophobic solvent absorber (isothermal), after which the gas is returned to the bioreactor. Ethanol can then be removed from the solvent to recover a highly concentrated ethanol product. We have applied the lab scale CSRS to sugars (glucose/sucrose), molasses, and raw starch with simultaneous saccharification and fermentation of the starch granules (SSF). The pilot scale CSRS has been operated as a cascade reactor using dextrins as a feed. Operating data from both the lab and pilot scale CSRS are presented. Details of how the system might be applied to cellulosics, with some preliminary data are also given.

  3. Production of bacterial cellulose membranes in a modified airlift bioreactor by Gluconacetobacter xylinus.

    Science.gov (United States)

    Wu, Sheng-Chi; Li, Meng-Hsun

    2015-10-01

    In this study, a novel bioreactor for producing bacterial cellulose (BC) is proposed. Traditional BC production uses static culture conditions and produces a gelatinous membrane. The potential for using various types of bioreactor, including a stirred tank, conventional airlift, and modified airlift with a rectangular wire-mesh draft tube, in large-scale production has been investigated. The BC obtained from these bioreactors is fibrous or in pellet form. Our proposed airlift bioreactor produces a membrane-type BC from Gluconacetobacter xylinus, the water-holding capacity of which is greater than that of cellulose types produced using static cultivation methods. The Young's modulus of the product can be manipulated by varying the number of net plates in the modified airlift bioreactor. The BC membrane produced using the proposed bioreactor exhibits potential for practical application.

  4. Utilization of residues from agro-forest industries in the production of high value bacterial cellulose.

    Science.gov (United States)

    Carreira, Pedro; Mendes, Joana A S; Trovatti, Eliane; Serafim, Luísa S; Freire, Carmen S R; Silvestre, Armando J D; Neto, Carlos Pascoal

    2011-08-01

    Bacterial cellulose (BC), a very peculiar form of cellulose, is gaining considerable importance due to its unique properties. In this study, several residues, from agro-forestry industries, namely grape skins aqueous extract, cheese whey, crude glycerol and sulfite pulping liquor were evaluated as economic carbon and nutrient sources for the production of BC. The most relevant BC amounts attained with the residues from the wine and pulp industries were 0.6 and 0.3 g/L, respectively, followed by biodiesel crude residue and cheese whey with productions of about, 0.1 g/L after 96 h of incubation. Preliminary results on the addition of other nutrient sources (yeast extract, nitrogen and phosphate) to the residues-based culture media indicated that, in general, these BC productions could be increased by ~200% and ~100% for the crude glycerol and grape skins, respectively, after the addition organic or inorganic nitrogen.

  5. Automated UV-C mutagenesis of Kluyveromyces marxianus NRRL Y-1109 and selection for microaerophilic growth and ethanol production at elevated temperature on biomass sugars.

    Science.gov (United States)

    Hughes, Stephen R; Bang, Sookie S; Cox, Elby J; Schoepke, Andrew; Ochwat, Kate; Pinkelman, Rebecca; Nelson, Danielle; Qureshi, Nasib; Gibbons, William R; Kurtzman, Cletus P; Bischoff, Kenneth M; Liu, Siqing; Cote, Gregory L; Rich, Joseph O; Jones, Marjorie A; Cedeño, David; Doran-Peterson, Joy; Riaño-Herrera, Nestor M; Rodríguez-Valencia, Nelson; López-Núñez, Juan C

    2013-08-01

    The yeast Kluyveromyces marxianus is a potential microbial catalyst for fuel ethanol production from a wide range of biomass substrates. To improve its growth and ethanol yield at elevated temperature under microaerophilic conditions, K. marxianus NRRL Y-1109 was irradiated with UV-C using automated protocols on a robotic platform for picking and spreading irradiated cultures and for processing the resulting plates. The plates were incubated under anaerobic conditions on xylose or glucose for 5 mo at 46 °C. Two K. marxianus mutant strains (designated 7-1 and 8-1) survived and were isolated from the glucose plates. Both mutant strains, but not wild type, grew aerobically on glucose at 47 °C. All strains grew anaerobically at 46 °C on glucose, galactose, galacturonic acid, and pectin; however, only 7-1 grew anaerobically on xylose at 46 °C. Saccharomyces cerevisiae NRRL Y-2403 did not grow at 46 °C on any of these substrates. With glucose as a carbon source, ethanol yield after 3 d at 46 °C was higher for 8-1 than for wild type (0.51 and 0.43 g ethanol/g glucose, respectively). With galacturonic acid as a carbon source, the ethanol yield after 7 d at 46 °C was higher for 7-1 than for wild type (0.48 and 0.34 g ethanol/g galacturonic acid, respectively). These mutant strains have potential application in fuel ethanol production at elevated temperature from sugar constituents of starch, sucrose, pectin, and cellulosic biomass.

  6. Perspectives on the production of polyhydroxyalkanoates in biorefineries associated with the production of sugar and ethanol.

    Science.gov (United States)

    Silva, Luiziana Ferreira; Taciro, Marilda Keico; Raicher, Gil; Piccoli, Rosane Aparecida Moniz; Mendonça, Thatiane Teixeira; Lopes, Mateus Schreiner Garcez; Gomez, José Gregório Cabrera

    2014-11-01

    Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible bacterial thermoplastic polymers that can be obtained from renewable resources. The high impact of the carbon source in the final cost of this polymer has been one of the major limiting factors for PHA production and agricultural residues, mainly lignocellulosic materials, have gained attention to overcome this problem. In Brazil, production of 2nd generation ethanol from the glucose fraction, derived from sugarcane bagasse hydrolysate has been studied. The huge amounts of remaining xylose will create an opportunity for the development of other bioprocesses, generating new products to be introduced into a biorefinery model. Although PHA production from sucrose integrated to a 1G ethanol and sugar mill has been proposed in the past, the integration of the process of 2G ethanol in the context of a biorefinery will provide enormous amounts of xylose, which could be applied to produce PHA, establishing a second-generation of PHA production process. Those aspects and perspectives are presented in this article.

  7. Inhibitory effect of ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Wan, Wei; Wang, Jianlong [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China)

    2008-12-15

    The inhibitory effect of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 C and initial pH 7.0, during the fermentative hydrogen production, the substrate degradation efficiency, hydrogen production potential, hydrogen yield and hydrogen production rate all trended to decrease with increasing added ethanol, acetic acid, propionic acid and butyric acid concentration from 0 to 300 mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those of added acetic acid, propionic acid and butyric acid. The modified Han-Levenspiel model could describe the inhibitory effects of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production rate in this study successfully. The modified Logistic model could describe the progress of cumulative hydrogen production. (author)

  8. Enzyme characterization for hydrolysis of AFEX and liquid hot-water pretreated distillers' grains and their conversion to ethanol

    Science.gov (United States)

    Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production, was investigated as a feedstock for additional ethanol production. DDGS was pretreated with liquid hot water (LHW) and ammonia fiber explosion (AFEX) processes. Cellulose was readily converted to glucose from bo...

  9. A critical analyses of the Grey Water Footprint in the production of cellulose

    Directory of Open Access Journals (Sweden)

    Vanessa Lucena Empinotti

    2014-09-01

    Full Text Available While the Water Footprint (WF is used as a management tool by the private sector, few published studies simultaneously consider all three of its constituent components in its estimation. The components are the Blue Water Footprint (WFblue, the Green Water Footprint (WFgreen, and the Grey Water Footprint (WFgrey. In the case of cellulose production, the only paper published to date did not consider the WFgrey because of the difficulty in finding data relative to natural water quality or to the effluents’ composition. In this context, this article seeks to analyze the WFgrey contribution to the WF of cellulose as well as its consequences for actions to mitigate the negative impact of production processes on water bodies. The study took place in a hypothetical industry located at the Paraíba do Sul River watershed, Brazil. The analyses considered pollutants, such as total chloride, total phosphorous, and phenol—all present in pulp production effluent and regulated by legislation in the three main producer countries in the world. The results showed that the industrial WFgrey can account for up to 55% of the total WF for cellulose production. Additionally, the results indicated considerable variations in environmental standards as well as in the chosen pollutants. Finally, the reduction of the WFgrey values should not be considered an end in itself, without considering the environmental and political context in which the production process takes place.

  10. The mechanism for thermal decomposition of cellulose and its main products.

    Science.gov (United States)

    Shen, D K; Gu, S

    2009-12-01

    Experiment is performed to investigate the mechanism of the cellulose pyrolysis and the formation of the main products. The evolution of the gaseous products is examined by the 3-D FTIR spectrogram at the heating rate of 5-60 K/min. A pyrolysis unit, composed of fluidized bed reactor, carbon filter, vapour condensing system and gas storage, is employed to investigate the products of the cellulose pyrolysis under different temperatures (430-730 degrees C) and residence time (0.44-1.32 s). The composition in the bio-oil is characterized by GC-MS while the gases sample is analyzed by GC. The effects of temperature and residence time on the main products in bio-oil (LG, 5-HMF, FF, HAA, HA and PA) are examined thoroughly. Furthermore the possible routes for the formation of the products are developed from the direct conversion of cellulose molecules and the secondary reactions of the fragments. It is found that the formation of CO is enhanced with elevated temperature and residence time, while slight change is observed for the yield of CO(2).

  11. 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.

  12. Effect of sugar concentration in Jerusalem artichoke extract on Kluyveromyces marxianus growth and ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.

    1983-02-01

    The effect of inulin sugars concentration on the growth and ethanol production by Kluyveromyces marxianus UCD (FST) 55-82 was studied. A maximum ethanol concentration of 102 g/liter was obtained from 250 g of sugars per liter initial concentration. The maximum specific growth rate varied from 0.44 h/sup -1/ at 50 g of sugar per liter to 0.13 h/sup -1/ at 300 g of sugar per liter, whereas the ethanol yield remained almost constant at 0.45 g of ethanol per g of sugars utilized.

  13. Screening of the effective cellulose-degradable strain and its application in the production of cellulose bioethanol

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Strains from the cellulose-containing environment were collected. Primary screening(by filter-paper Hutchison solid culture medium and sodium carboxymethylcellulose solid culture medium) and reelection(by filter-paper inorganic salt culture medium and sodium carboxymethylcellulose Congo red culture medium) indicated that five strains obtained were best suited for high performance cellulose degradation. Determination of sodium carboxymethylcellulose activity(CMCA) and filter paper activity(FPA) was accomplis...

  14. Bioeconomic Sustainability of Cellulosic Biofuel Production on Marginal Lands

    Science.gov (United States)

    Gutierrez, Andrew Paul; Ponti, Luigi

    2009-01-01

    The use of marginal land (ML) for lignocellulosic biofuel production is examined for system stability, resilience, and eco-social sustainability. A North American prairie grass system and its industrialization for maximum biomass production using biotechnology and agro-technical inputs is the focus of the analysis. Demographic models of ML biomass…

  15. Evaluation of Cashew Apple Juice for the Production of Fuel Ethanol

    Science.gov (United States)

    Pinheiro, Álvaro Daniel Teles; Rocha, Maria Valderez Ponte; Macedo, Gorete R.; Gonçalves, Luciana R. B.

    A commercial strain of Saccharomyces cerevisiae was used for the production of ethanol by fermentation of cashew apple juice. Growth kinetics and ethanol productivity were calculated for batch fermentation with different initial sugar (glucose + fructose) concentrations. Maximal ethanol, cell, and glycerol concentrations were obtained when 103.1 g L-1 of initial sugar concentration was used. Cell yield (Yx/s) was calculated as 0.24 (g microorganism)/(g glucose + fructose) using cashew apple juice medium with 41.3 g L-1 of initial sugar concentration. Glucose was exhausted first, followed by fructose. Furthermore, the initial concentration of sugars did not influence ethanol selectivity. These results indicate that cashew apple juice is a suitable substrate for yeast growth and ethanol production.

  16. Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation

    Directory of Open Access Journals (Sweden)

    Teixeira Miguel C

    2012-07-01

    Full Text Available Abstract Background The understanding of the molecular basis of yeast tolerance to ethanol may guide the design of rational strategies to increase process performance in industrial alcoholic fermentations. A set of 21 genes encoding multidrug transporters from the ATP-Binding Cassette (ABC Superfamily and Major Facilitator Superfamily (MFS in S. cerevisiae were scrutinized for a role in ethanol stress resistance. Results A yeast multidrug resistance ABC transporter encoded by the PDR18 gene, proposed to play a role in the incorporation of ergosterol in the yeast plasma membrane, was found to confer resistance to growth inhibitory concentrations of ethanol. PDR18 expression was seen to contribute to decreased 3 H-ethanol intracellular concentrations and decreased plasma membrane permeabilization of yeast cells challenged with inhibitory ethanol concentrations. Given the increased tolerance to ethanol of cells expressing PDR18, the final concentration of ethanol produced during high gravity alcoholic fermentation by yeast cells devoid of PDR18 was lower than the final ethanol concentration produced by the corresponding parental strain. Moreover, an engineered yeast strain in which the PDR18 promoter was replaced in the genome by the stronger PDR5 promoter, leading to increased PDR18 mRNA levels during alcoholic fermentation, was able to attain a 6 % higher ethanol concentration and a 17 % higher ethanol production yield than the parental strain. The improved fermentative performance of yeast cells over-expressing PDR18 was found to correlate with their increased ethanol tolerance and ability to restrain plasma membrane permeabilization induced throughout high gravity fermentation. Conclusions PDR18 gene over-expression increases yeast ethanol tolerance and fermentation performance leading to the production of highly inhibitory concentrations of ethanol. PDR18 overexpression in industrial yeast strains appears to be a promising approach to

  17. Understanding the reductions in US corn ethanol production costs: an experience curve approach

    NARCIS (Netherlands)

    Hettinga, W.; Junginger, H.M.; Dekker, S.C.; Hoogwijk, M.; McAloon, A.; Hicks, K.

    2009-01-01

    The US is currently the world's largest ethanol producer. An increasing percentage is used as transportation fuel, but debates continue on its costs competitiveness and energy balance. In this study, technological development of ethanol production and resulting cost reductions are investigated by us

  18. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk.

    Science.gov (United States)

    Yan, Shoubao; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao

    2012-05-01

    The aim of the present study was to examine ethanol production from concentrated food waste hydrolysates using whole cells of S. cerevisiae immobilized on corn stalks. In order to improve cell immobilization efficiency, biological modification of the carrier was carried out by cellulase hydrolysis. The results show that proper modification of the carrier with cellulase hydrolysis was suitable for cell immobilization. The mechanism proposed, cellulase hydrolysis, not only increased the immobilized cell concentration, but also disrupted the sleek surface to become rough and porous, which enhanced ethanol production. In batch fermentation with an initial reducing sugar concentration of 202.64 ± 1.86 g/l, an optimal ethanol concentration of 87.91 ± 1.98 g/l was obtained using a modified corn stalk-immobilized cell system. The ethanol concentration produced by the immobilized cells was 6.9% higher than that produced by the free cells. Ethanol production in the 14th cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in an immobilized cell reactor, the maximum ethanol concentration of 84.85 g/l, and the highest ethanol yield of 0.43 g/g (of reducing sugar) were achieved at hydraulic retention time (HRT) of 3.10 h, whereas the maximum volumetric ethanol productivity of 43.54 g/l/h was observed at a HRT of 1.55 h.

  19. Understanding the reductions in US corn ethanol production costs: an experience curve approach

    Science.gov (United States)

    The US is currently the world's largest ethanol producer. An increasing percentage is used as transportation fuel, but debates continue on its cost competitiveness and energy balance. In this study, technological development of ethanol production and resulting cost reductions are investigated by usi...

  20. Production of cellulose phosphate from oil palm empty fruit bunch: Effect of chemical ratio

    Science.gov (United States)

    Rohaizu, R.; Wanrosli, W. D.

    2015-06-01

    Cellulose phosphate was synthesized from oil palm biomass residue that has the potential to represent a considerable added value product for the oil palm biomass utilization. Cellulose phosphate (CP) is prepared viaa phosphorylation process using the H3PO4/P2O5/Et3PO4/hexanol sequence using oil palm empty fruit bunch microcrystalline cellulose (OPEFB-MCC) as the starting material. Various factors affect its synthesis; one of them which is the subject of this investigation is the orthophosphoric acid (H3PO4) to triethylphosphate(Et3PO4) ratio which have the capability to increase the phosphorus content of CP. It is believed that during this reaction, the esterification of the free hydroxyl groups of the cellulose occurred. The H3PO4/Et3PO4 ratios applied were 0.16, 1.00, and 1.84. The effect of the H3PO4/Et3PO4 ratio on phosphorus content, yield, water swelling and molecular structure of CP are discussed.

  1. 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

  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

    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...... of cellulose. The applied pre-treatment methods are organosolv, hydrothermal, and alkaline. Hydrothermally pretreated wheat straw gave the highest cellulose conversion with 80% glucose yield and 0.8% oxidized cellulose products. Recent studies have shown that lignin is able to boost the activity...

  3. CHARACTERIZATION OF FAST GROWING TREES SPECIES FOR ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    P. V. ANBU*, K. T. PARTHIBAN1, I. SEKAR U. SIVAKUMAR3,S.UMESHKANNA1 ,V. SARAVANA P. DURAIRASU1

    2014-09-01

    Full Text Available The fast growing trees were had the acceptable growth, chemical composition and morphological properties that make it suitable for ethanol recovery. The growth attained average level from 1.57m to 3.73m at the end of ninth month. The chemical composition such as higher proportion of holocellulose and lower content of lignin of the fast growing trees expected the more ethanol recovery with minimum recalcitrant. Due to long fiber length, wider fiber width, and wide lumen diameter with thin cell wall thickness of the fast growing trees were preferable for ethanol conversion.

  4. Hydrogen production by autothermal reforming of ethanol: pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Marin Neto, Antonio Jose; Camargo, Joao Carlos; Lopes, Daniel Gabriel; Ferreira, Paulo F.P. [Hydrogen Technology (HyTron), Campinas, SP (Brazil)], Email: antonio@hytron.com.br; Neves Junior, Newton Pimenta; Pinto, Edgar A. de Godoi Rodrigues; Silva, Ennio Peres da [Universidade Estadual de Campinas (DFA/ IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Fisica Aplicada; Furlan, Andre Luis [Universidade Estadual de Campinas (FEC/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica

    2010-07-01

    This work provides information about the development of an integrated unit for hydrogen production by auto thermal reforming of ethanol with nominal capacity of 1 kg/h H{sub 2} 4.5 (99.995%). The unit is composed by a Fuel Processing Module (FPM), resulting from auto thermal and shift reactor integration, responsible for the thermochemical step, plus an over heater of the liquid input (EtOH and H{sub 2}O), operated recovering thermal energy from PSA blown-down (H{sub 2} Purification Module - MPH2), besides other thermal equipment which completes the integration. Using a computational routine for scaling the process and preliminary performance analysis, it was possible to optimize operating conditions, essential along unit operations design. Likewise, performance estimation of the integrated unit proceeds, which shows efficiency about 72.5% f