WorldWideScience

Sample records for corn-based ethanol production

  1. 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...

  2. Assessing the Effects of Corn-Based Ethanol Production on Stream Water Quality

    Science.gov (United States)

    Alexander, R. B.; Smith, R. A.; Schwarz, G. E.

    2007-12-01

    Corn grain-based ethanol production nearly doubled over the past five years in response to energy security concerns and the use of ethanol as a gasoline additive. Corn prices show similar increases with much of the rise occurring in more recent years. Farmers responded by planting 93 million acres of corn in 2007, a 19 percent increase over 2006, with most of the new acreage converted from lands in soybeans and cotton. The projected doubling of corn-based ethanol production by 2016 is expected to exert a continued demand for increased corn acreage and production. Both the recent and projected increases in corn production have raised concerns about the degradation of stream water quality; these include the water-quality effects of possible conversions of Conservation Reserve Program lands of which 16 million enrolled acres are slated to expire in 2007. However, no studies of the potential water-quality impacts have been conducted to date. Corn-based agriculture is currently recognized as a major source of nitrogen to Midwestern streams and the northern Gulf of Mexico where increased nitrogen has contributed to coastal eutrophication over the last several decades. Phosphorus from agricultural sources, including corn-based crops, is also known to impair the quality of inland streams and rivers. We use the spatially explicit water-quality model SPARROW (Spatially Referenced Regression on Watershed Attributes) to simulate the potential effects of recent and projected ethanol-related corn production on stream nutrient loads and coastal nutrient delivery. We simulate mean-annual total nitrogen and phosphorus loads in major streams of the conterminous United States, based on the use of a previously estimated national model. The model accounts for major sources and inputs of nutrients to watersheds (e.g., agricultural, atmospheric deposition, human wastes); these are mediated in the model by the effects of climate, topography, soils, and aquatic attenuation processes on

  3. Life cycle assessment of corn-based ethanol production in Argentina.

    Science.gov (United States)

    Pieragostini, Carla; Aguirre, Pío; Mussati, Miguel C

    2014-02-15

    The promotion of biofuels as energy for transportation in the world is mainly driven by the perspective of oil depletion, the concerns about energy security and global warming. In Argentina, the legislation has imposed the use of biofuels in blend with fossil fuels (5 to 10%) in the transport sector. The aim of this paper is to assess the environmental impact of corn-based ethanol production in the province of Santa Fe in Argentina based on the life cycle assessment methodology. The studied system includes from raw materials production to anhydrous ethanol production using dry milling technology. The system is divided into two subsystems: agricultural system and refinery system. The treatment of stillage is considered as well as the use of co-products (distiller's dried grains with solubles), but the use and/or application of the produced biofuel is not analyzed: a cradle-to-gate analysis is presented. As functional unit, 1MJ of anhydrous ethanol at biorefinery is chosen. Two life cycle impact assessment methods are selected to perform the study: Eco-indicator 99 and ReCiPe. SimaPro is the life cycle assessment software used. The influence of the perspectives on the model is analyzed by sensitivity analysis for both methods. The two selected methods identify the same relevant processes. The use of fertilizers and resources, seeds production, harvesting process, corn drying, and phosphorus fertilizers and acetamide-anillide-compounds production are the most relevant processes in agricultural system. For refinery system, corn production, supplied heat and burned natural gas result in the higher contributions. The use of distiller's dried grains with solubles has an important positive environmental impact.

  4. Erosion analysis related to corn-based ethanol production in the US

    Science.gov (United States)

    Since the Renewable Fuel Standard has encouraged the development of biofuels, the US has seen an increase in corn production for conversion to ethanol. In many of these agricultural regions, increased corn production is accompanied with increased erosion. An erosion analysis w...

  5. Corn-Based Ethanol Production and Environmental Quality: A Case of Iowa and the Conservation Reserve Program

    Science.gov (United States)

    Secchi, Silvia; Gassman, Philip W.; Williams, Jimmy R.; Babcock, Bruce A.

    2009-10-01

    Growing demand for corn due to the expansion of ethanol has increased concerns that environmentally sensitive lands retired from agricultural production and enrolled into the Conservation Reserve Program (CRP) will be cropped again. Iowa produces more ethanol than any other state in the United States, and it also produces the most corn. Thus, an examination of the impacts of higher crop prices on CRP land in Iowa can give insight into what we might expect nationally in the years ahead if crop prices remain high. We construct CRP land supply curves for various corn prices and then estimate the environmental impacts of cropping CRP land through the Environmental Policy Integrated Climate (EPIC) model. EPIC provides edge-of-field estimates of soil erosion, nutrient loss, and carbon sequestration. We find that incremental impacts increase dramatically as higher corn prices bring into production more and more environmentally fragile land. Maintaining current levels of environmental quality will require substantially higher spending levels. Even allowing for the cost savings that would accrue as CRP land leaves the program, a change in targeting strategies will likely be required to ensure that the most sensitive land does not leave the program.

  6. Nitrification characteristics of nitrobacteria immobilized in waterborne polyurethane in wastewater of corn-based ethanol fuel production

    Institute of Scientific and Technical Information of China (English)

    Yamei Dong; Zhenjia Zhang; Yongwei Jin; Jian Lu; Xuehang Cheng; Jun Li; Yan-yan Deng; Ya-nan Feng; Dongning Chen

    2012-01-01

    A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater (ethanol fuel production) treatment has been designed.The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane (WPU) gel carrier were evaluated after acclimation.In the acclimation period,nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction (PCR) was also carried out to investigate the change in ammonium-oxidizing bacteria.The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/(L-pellet-hr) and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation.A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% (V/V).Under the conditions of 75 mg/L influent ammonia,hydraulic retention time (HRT) of 3.7-5,6 hr,and dissolved oxygen (DO) of 4 mg/L,the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%.While the highest ammonia removal rate,162 mg-N/(L-pellet-hr),was observed when the HRT was 1.3 hr.

  7. Nitrification characteristics of nitrobacteria immobilized in waterborne polyurethane in wastewater of corn-based ethanol fuel production.

    Science.gov (United States)

    Dong, Yamei; Zhang, Zhenjia; Jin, Yongwei; Lu, Jian; Cheng, Xuehang; Li, Jun; Deng, Yan-Yan; Feng, Ya-Nan; Chen, Dongning

    2012-01-01

    A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater (ethanol fuel production) treatment has been designed. The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane (WPU) gel carrier were evaluated after acclimation. In the acclimation period, nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction (PCR) was also carried out to investigate the change in ammonium-oxidizing bacteria. The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/(L-pellet x hr) and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation. A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% (V/V). Under the conditions of 75 mg/L influent ammonia, hydraulic retention time (HRT) of 3.7-5.6 hr, and dissolved oxygen (DO) of 4 mg/L, the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%. While the highest ammonia removal rate, 162 mg-N/(L-pellet x hr), was observed when the HRT was 1.3 hr.

  8. Greenhouse-gas Consequences of US Corn-based Ethanol in a Flat World

    Science.gov (United States)

    Davidson, E. A.; Coe, M. T.; Nepstad, D. C.; Donner, S. D.; Bustamante, M. M.; Neill, C.

    2008-12-01

    Competition for arable land is now occurring among food, fiber, and fuel production sectors. In the USA, increased corn production for ethanol has come primarily at the expense of reduced soybean production. Only a few countries, mainly Brazil, have appropriate soils, climate, and infrastructure needed for large absolute increases in cropped area in the next decade that could make up the lost US soybean production. Our objective is to improve estimates of the potential net greenhouse gas (GHG) consequences, both domestically and in Brazil, of meeting the new goals established by the US Congress for expansion of corn- based ethanol in the USA. To meet this goal of 57 billion liters per year of corn-based ethanol production, an additional 1-7 million hectares will need to be planted in corn, depending upon assumptions regarding future increases in corn yield. Net GHG emissions saved in the USA by substituting ethanol for gasoline are estimated at 14 Tg CO2-equivalents once the production goal of 57 million L/yr is reached. If reduced US soybean production caused by this increase in US corn planting results in a compensatory increase in Brazilian production of soybeans in the Cerrado and Amazon regions, we estimate a potential net release of 1800 to 9100 Tg CO2-equivalents of GHG emissions due to land-use change. Many opportunities exist for agricultural intensification that would minimize new land clearing and its environmental impacts, but if Brazilian deforestation is held to only 15% of the area estimated here to compensate lost US soybean production, the GHG mitigation of US corn-based ethanol production during the next 15 years would be more than offset by emissions from Brazilian land-use change. Other motivations for advancing corn-based ethanol production in the USA, such as reduced reliance on foreign oil and increased prosperity for farming communities, must be considered separately, but the greenhouse-gas-mitigation rationale is clearly unsupportable.

  9. Long-Run Impact of Corn-Based Ethanol on the Grain, Oilseed, and Livestock Sectors: A Preliminary Assessment, The

    OpenAIRE

    Amani Elobeid; Simla Tokgoz; Dermot J. Hayes; Bruce A. Babcock; Hart, Chad E.

    2006-01-01

    The ongoing growth of corn-based ethanol production raises some fundamental questions about what impact continued growth will have on U.S. and world agriculture. Estimates of the long-run potential for ethanol production can be made by calculating the corn price at which the incentive to expand ethanol production disappears. Under current ethanol tax policy, if the prices of crude oil, natural gas, and distillers grains stay at current levels, then the break-even corn price is $4.05 per bushe...

  10. Succinic Acid as a Byproduct in a Corn-based Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    MBI International

    2007-12-31

    MBI endeavored to develop a process for succinic acid production suitable for integration into a corn-based ethanol biorefinery. The project investigated the fermentative production of succinic acid using byproducts of corn mill operations. The fermentation process was attuned to include raw starch, endosperm, as the sugar source. A clean-not-sterile process was established to treat the endosperm and release the monomeric sugars. We developed the fermentation process to utilize a byproduct of corn ethanol fermentations, thin stillage, as the source of complex nitrogen and vitamin components needed to support succinic acid production in A. succinogenes. Further supplementations were eliminated without lowering titers and yields and a productivity above 0.6 g l-1 hr-1was achieved. Strain development was accomplished through generation of a recombinant strain that increased yields of succinic acid production. Isolation of additional strains with improved features was also pursued and frozen stocks were prepared from enriched, characterized cultures. Two recovery processes were evaluated at pilot scale and data obtained was incorporated into our economic analyses.

  11. A practical method for extending the biuret assay to protein determination of corn-based products.

    Science.gov (United States)

    Liu, Zelong; Pan, Junhui

    2017-06-01

    A modified biuret method suitable for protein determination of corn-based products was developed by introducing a combination of an alkaline reagent with sodium dodecyl sulfate (reagent A) and heat treatments. The method was tested on seven corn-based samples. The results showed mostly good agreement (P>0.05) as compared to the Kjeldahl values. The proposed method was found to enhance the accuracy of prediction on zein content using bovine serum albumin as standard. Reagent A and sample treatment were proved to effectively improve protein solubilization for the thermally-dried corn-based products, e.g. corn gluten meal. The absorbance was stable for at least 1-h. Moreover, the whole measurement of protein content only needs 15-20min more than the traditional biuret assay, and can be performed in batches. The findings suggest that the proposed method could be a timesaving alternative for routine protein analyses in corn processing factories.

  12. 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.

  13. 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.

  14. Reuse of Enzymatic Hydrolyzed Waste Liquid of Corn Based Ethanol Fermentation%玉米酒精糟液经酶水解后的回配利用

    Institute of Scientific and Technical Information of China (English)

    王丹姝

    2012-01-01

    The waste liquid from ethanol fermentation was centrifuged.And then the complex enzyme,Fhm-5 was added for hydrolysis.The hydrolysate was reused for proportioning as nutrient broth.The utilization of the raw material was improved.Per unit of water consumption and volume of sewage to be treated were reduced.The fermentation time was shortened.The economic benefit of corn based ethanol fermentation was improved.To produce one ton of ethanol three tons of corn were required,and approximately 12 cubic meters of waste liquor were discharged.%酒精糟液经离心分离,并通过添加复合酶Fhm-5水解后作为营养液回用于配料的重新利用,提高了原料利用率,降低了水的单耗和污水处理量,缩短了发酵周期,提高了玉米酒精的经济效益。每生产1吨酒精需3吨玉米,排出糟液约为12m3。

  15. Alfalfa baleage with increased concentration of nonstructural carbohydrates supplemented with a corn-based concentrate did not improve production and nitrogen utilization in early lactation dairy cows.

    Science.gov (United States)

    Brito, A F; Tremblay, G F; Bertrand, A; Castonguay, Y; Bélanger, G; Michaud, R; Lafrenière, C; Martineau, R; Berthiaume, R

    2014-11-01

    The objective of this study was to investigate the effects of feeding alfalfa baleage with different concentrations of nonstructural carbohydrates (NSC) supplemented with a common corn-based concentrate on performance, ruminal fermentation profile, N utilization, and omasal flow of nutrients in dairy cows during early lactation. Ten multiparous (8 ruminally cannulated) and 8 primiparous Holstein cows were randomly assigned to treatments (high- or low-NSC diet) in a crossover design. The difference in NSC concentration between the 2 alfalfa baleages fed from d14 to 21 averaged 14 g of NSC/kg of dry matter (DM). Forages and concentrate were offered in separate meals with forages fed once and concentrate offered 3 times daily. Except for the molar proportion of valerate, which was lowest in cows fed the high-NSC diet, no other changes in ruminal fermentation were observed. Omasal flows of most nitrogenous fractions, including bacterial nonammonia N and AA, were not affected by treatments. Apparent ruminal digestibilities of neutral and acid detergent fiber and N were lowest, whereas that of total ethanol-soluble carbohydrates was highest when feeding the high-NSC diet. Postruminal digestibilities of DM, organic matter, fiber, and N were highest in cows fed the high-NSC diet, resulting in no difference in total-tract digestibilities. Total-tract digestibility of total ethanol-soluble carbohydrates was highest in cows fed the high-NSC diet, but that of starch did not differ across treatments. Although milk yield and total DM intake did not differ between treatments, yields of milk fat and 4% fat-corrected milk decreased significantly in cows fed the high-NSC diet. Milk concentration of urea N was lowest, and that of ruminal NH3-N highest, in cows fed the high-NSC diet. Plasma urea N concentration tended to be decreased in cows fed the high-NSC diet, but concentrations of AA were not affected by treatments, with the exception of Asp and Cys, both of which were lowest in

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. Biological production of ethanol fom coal

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    Research is continuing in an attempt to increase both the ethanol concentration and product ratio using C. ljungdahlii. The purpose of this report is to present data (acetate to ethanol) utilizing a medium prepared especially for C. ljungdahlii. Medium development studies are presented, as well as reactor studies with the new medium in batch reactors. Continuous stirred tank reactor (CSTR) with cell recycle. The use of this new medium has resulted in significant improvements in cell concentration, ethanol concentration and product ratio.

  2. 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....

  3. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  4. Ethanol production using hemicellulosic hydrolyzate and sugarcane ...

    African Journals Online (AJOL)

    Juliana

    2015-02-11

    Feb 11, 2015 ... Fermentation was performed in a laboratory scale using the J10 and FT858 yeast strains using 500 ml ... provides recovery of up to 90% of fermentable sugars ..... ethanol production in the clarified broth of sugarcane juice.

  5. Ethanol production using hemicellulosic hydrolyzate and sugarcane ...

    African Journals Online (AJOL)

    Ethanol production using hemicellulosic hydrolyzate and sugarcane juice with yeasts that ... yeast strains using 500 ml Erlenmeyer flasks with 180 ml of must prepared ... Key words: Hydrolysis of sugarcane straw and pointers, sugarcane juice, ...

  6. 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.

  7. Occurrence of zearalenone in wheat- and corn-based products commercialized in the State of Paraná, Brazil

    Science.gov (United States)

    Almeida-Ferreira, Giovanna Caputo; Barbosa-Tessmann, Ione Parra; Sega, Rose; Machinski, Miguel

    2013-01-01

    The productivity of wheat and corn crops depends on climatic conditions and resistance against phytopathogenic fungi such as those of the genus Fusarium. Some species of this genus produce zearalenone (ZEA), a mycotoxin with hyperestrogenic effects. The objective of this study was to investigate the presence of ZEA in samples of cracked wheat (n = 109), popcorn (n = 51) and corn grits (n = 50) commercialized in the State of Paraná, Brazil. Commercial samples of each crop were collected between September 2007 and June 2008 and analyzed by thin-layer chromatography. The method used for detection of the mycotoxin in wheat and corn derivatives presented a recovery rate of 94.5% and 99.5%, respectively, detection limit of 40 μg.kg−1 and quantification limit of 55 μg.kg−1. No contamination with ZEA was detected in cracked wheat samples. Among the corn derivatives, only one cracked corn sample was contaminated with ZEA (64 μg.kg−1). Despite the low contamination observed, monitoring the occurrence of mycotoxins in foods is important to ensure safety. PMID:24294224

  8. 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.

  9. Rewiring Lactococcus lactis for Ethanol Production

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...... 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...... fermentation product was obtained by further inactivating the phosphotransacetylase (PTA) and the native alcohol dehydrogenase (ADHE)....

  10. 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.)

  11. 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.

  12. Production of 16% ethanol from 35% sucrose

    Energy Technology Data Exchange (ETDEWEB)

    Breisha, Gaber Z. [Department of Agricultural Microbiology, Faculty of Agriculture, Minia University, Minia (Egypt)

    2010-08-15

    A strain of Saccharomyces cerevisiae, which showed marked fermentation activity, ethanol and temperature tolerance and good flocculation ability, was selected for ethanol production. A stuck fermentation occurred at sucrose concentration of 25%. Increasing the yeast inoculum volume from 3% to 6% showed positive effects on fermentation from 25% sucrose. The ratio of added nitrogen to sucrose, which gave the best results (for the selected yeast strain), was determined. It was concluded that this ratio (nitrogen as ammonium sulphate at a rate of 5 mg g{sup -1} of consumed sucrose) is constant at various sugar concentrations. Addition of nitrogen at this ratio produced 11.55% ethanol with complete consumption of 25% sucrose after 48 h of fermentation. However fermentation of 30% sucrose at the above optimum conditions was not complete. Addition of yeast extract at a level of 6 g l{sup -1} together with thiamine at a level of 0.2 g l{sup -1} led to complete utilization of 30% sucrose with resultant 14% ethanol production. However the selected yeast strain was not able to ferment 35% sucrose at the same optimum conditions. Addition of air at a rate of 150 dm{sup 3} min{sup -1} m{sup 3} of reactor volume during the first 12 h of fermentation led to complete consumption of 35% sucrose and 16% ethanol was produced. This was approximately the theoretical maximum for ethanol production. (author)

  13. An applied investigation of corn-based distillers dried grains with solubles in the production of natural fiber-plastic composites

    Science.gov (United States)

    Castillo, Hugo Eudosio

    The main objective of this research was to examine uses for distillers dried grains with solubles (DDGS), a coproduct of ethanol production plant, in the fiber-reinforced plastic composites industry. Initially the effort intended to take advantage of the DDGS components, using chemical reactions, to produce coupling agents to improve the physical properties of the composite. Four different chemicals plus water were used to convert proteins into soluble amino acids. The results were not as expected, and appeared to show an early pyrolysis of DDGS components. This may be due to regeneration of proteins when pH of solutions is neutralized. Procedures were then investigated to utilize DDGS for different markets. Considering that oils and proteins of DDGS can thermally decompose, it seemed important to separate the major components and work with DDGS fiber alone. A procedure to extract oil from DDGS using ethanol and then to hydrolyze proteins with ethanol diluted with water, acid and sodium sulfite, was developed. The resulting DDGS fiber or residual material, with a low content of oil and proteins, was used as filler in a propylene matrix with a lubricant and coupling agent to make natural fiber plastic composites (NFPC). Composites containing wood flour (WPC) were prepared simultaneously with those of DDGS fiber to compare tensile properties and fracture surfaces of the specimens by scanning electron microscope (SEM). This study demonstrates that DDGS fiber can replace wood fiber as a filler in NFPC.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fuel ethanol production: process design trends and integration opportunities.

    Science.gov (United States)

    Cardona, Carlos A; Sánchez, Oscar J

    2007-09-01

    Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. In this work, the key role that process design plays during the development of cost-effective technologies is recognized through the analysis of major trends in process synthesis, modeling, simulation and optimization related to ethanol production. Main directions in techno-economical evaluation of fuel ethanol processes are described as well as some prospecting configurations. The most promising alternatives for compensating ethanol production costs by the generation of valuable co-products are analyzed. Opportunities for integration of fuel ethanol production processes and their implications are underlined. Main ways of process intensification through reaction-reaction, reaction-separation and separation-separation processes are analyzed in the case of bioethanol production. Some examples of energy integration during ethanol production are also highlighted. Finally, some concluding considerations on current and future research tendencies in fuel ethanol production regarding process design and integration are presented.

  19. Enhanced ethanol production from stalk juice of sweet sorghum by ...

    African Journals Online (AJOL)

    user

    2012-03-15

    Mar 15, 2012 ... ethanol production by a Saccharomyces cerevisiae strain because of the high content of sugar. ... Key words: Ethanol, sweet sorghum, stalk juice, medium ..... production from Kinnow mandarin (Citrus reticulata) waste via a.

  20. Fact sheet: Ethanol co-products

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-31

    During the conversion of starch to sugars by enzymes, and by fermentation of these sugars to ethanol and carbon dioxide, the non-fermentable portion of the grain contains most of the non-starch nutritive elements of the kernel, which is the source of a variety of co-products. The wet milling process is used exclusively for corn, whereas the dry milling process is the one usually employed for wheat , corn and other grains. The carbon dioxide produced in both these processes is used as a refrigerant, in carbonated beverages and for flushing oil wells. Co-products produced from wet milling include (1) corn oil, used in producing food products for human consumption, and (2) amino acids, corn gluten meal and corn gluten feed used as animal feed additives. Dry milling gives rise to dry distiller`s grains which are also used as high protein and high energy animal feed. Fibrotein{sup T}M , is also a co-product of ethanol from wheat and is used as a high fibre and protein food additive. Ethanol, carbon dioxide and co-products each represent about one third of the products of the fermentation process.

  1. 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.

  2. 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).

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Production of bio ethanol from waste potatoes

    Science.gov (United States)

    Jaber Noufal, Mohamad; Li, Baizhan; Maalla, Zena Ali

    2017-03-01

    In this research, production of ethanol from waste potatoes fermentation was studied using Saccharomyces cerevisiae. Potato Flour prepared from potato tubers after cooking and drying at 85°C. A homogenous slurry of potato flour prepared in water at solid-liquid ratio 1:10. Liquefaction of potato starch slurry was done with α-amylase at 80°C for 40 min followed by saccharification process which was done with glucoamylase at 65°C for two hr. Fermentation of hydrolysate with Saccharomyces cerevisiae at 35°C for two days resulted in the production of 33 g/l ethanol. The following parameters have been analysed: temperature, time of fermentation and pH. It found that Saccharification process is affected by enzyme Amylase 300 concentration and concentration of 1000μl/100ml gives the efficient effect of the process. The best temperature for fermentation process was found to be about 35°C. Also, it noticed that ethanol production increased as a time of fermentation increased but after 48 hr further growth in fermentation time did not have an appreciable effect. Finally, the optimal value of pH for fermentation process was about 5 to 6.

  8. 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.

  9. 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.)

  10. 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...

  11. 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....

  12. 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.

  13. Bacterial Community Structure and Dynamics During Corn-Based Bioethanol Fermentation.

    Science.gov (United States)

    Li, Qing; Heist, E Patrick; Moe, Luke A

    2016-02-01

    Corn-based fuel ethanol facilities mix enzymatically treated, gelatinized corn starch with water to generate a "mash" that is used as the substrate in large-scale (∼500,000 gallon) yeast-based fermentations. In contrast to other food and beverage fermentations (e.g., cheese, wine), bioethanol production is presumed to be optimal when bacteria are absent from the fermentation-thus maximizing conversion of glucose to ethanol-yet the facilities are not sterilized. Culture-based analysis has suggested that lactic acid bacteria occupy this niche and, under certain circumstances, can outcompete the dedicated fermentation yeast for nutrients. Here, we use 16S rRNA gene amplicon sequencing to probe bacterial community structure during bioethanol fermentation. Nineteen total batches from five corn-based fuel ethanol fermentation facilities were analyzed. From each batch, five samples were taken. This includes the contents of the yeast propagation tank at inoculation, three samples taken at intervals during the fermentation, and a sample taken at the end of fermentation. Bacterial community structure was compared with time, between facility, between fermentor, between batches from the same fermentor, and against environmental variables within each fermentation. Communities were dominated by members of the Firmicutes and Proteobacteria phyla, with lactic acid bacteria dominating the communities in two of the five facilities. In the other facilities, Proteobacteria (largely members of the Pseudomonas and Escherichia-Shigella genera) outcompete the lactic acid bacteria. In most cases, the yeast propagation tank inoculum imparted a rich bacterial community, but the batches vary regarding whether this inoculum was the primary driver of the fermentation community structure.

  14. Effects of ionophores and antibiotics on in vitro hydrogen sulfide production, dry matter disappearance, and total gas production in cultures with a steam-flaked corn-based substrate with or without added sulfur.

    Science.gov (United States)

    Quinn, M J; May, M L; Hales, K E; DiLorenzo, N; Leibovich, J; Smith, D R; Galyean, M L

    2009-05-01

    Effects of 3 ionophores and 2 antibiotics on in vitro H(2)S production, IVDMD, total gas production, and VFA profile with or without added S were examined. In Exp. 1, ruminal fluid from 2 ruminally cannulated steers fed a steam-flaked corn-based diet (75% concentrate) without ionophore and antibiotics for 28 d before collection was used to inoculate in vitro cultures. Treatments were control (no ionophore or antibiotic), 3 ionophores (lasalocid sodium and monensin sodium at 5 mg/L or laidlomycin propionate at 1.65 mg/L), and 2 antibiotics (chlortetracycline hydrochloride at 5 mg/L and tylosin tartarate at 1.25 mg/L). Cultures also had 0 or 1.75 mg of S/L (from sodium sulfate). No S x ionophore-antibiotic treatment interactions were noted (P > 0.53) for IVDMD, total gas production, and H(2)S production. Hydrogen sulfide (mumol/g of fermentable DM) was increased (P production tended (P = 0.09) to be increased with additional S; however, IVDMD was not affected by added S (P = 0.90). Production of H(2)S was not affected by ionophores or antibiotics (P > 0.18). On average, IVDMD (P = 0.05) was greater for ionophores than for antibiotics, whereas total gas production was less for ionophores than for control (P antibiotics (P 0.20) in acetate, propionate, or acetate:propionate between ionophores and control (S x treatment interaction, P = 0.03). In Exp. 2, the effects of ionophore-antibiotic combinations with added S were examined using the same procedures as in Exp. 1. Treatments were control, monensin plus tylosin (MT), and lasalocid plus chlortetracycline (LCTC), with concentrations of the ionophores and antibiotics as in Exp. 1. No differences were observed among treatments for H(2)S production (P > 0.55). Treatments MT and LCTC tended (P = 0.06) to increase IVDMD and decreased (P = 0.02) gas production vs. control. Proportion of acetate (P = 0.01) and acetate:propionate (P antibiotics we evaluated did not affect production of H(2)S gas in an in vitro rumen culture

  15. 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.

  16. 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...

  17. 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.

  18. 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

    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.......In ethanol production from sugarcane juice, sugarcane bagasse is used as fuel for the boiler, to meet the steam and electric energy demand of the process. However, a surplus of bagasse is common, which can be used either to increase electric energy or ethanol production. While the first option uses...... already established processes, there are still many uncertainties about the techno-economic feasibility of the second option. In this study, some key parameters of the second generation ethanol production process were analyzed and their influence in the process feasibility assessed. The simulated process...

  19. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Donal F. Day

    2009-03-31

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

  1. Bioenergy from stillage anaerobic digestion to enhance the energy balance ratio of ethanol production.

    Science.gov (United States)

    Fuess, Lucas Tadeu; Garcia, Marcelo Loureiro

    2015-10-01

    The challenges associated with the availability of fossil fuels in the past decades intensified the search for alternative energy sources, based on an ever-increasing demand for energy. In this context, the application of anaerobic digestion (AD) as a core treatment technology in industrial plants should be highlighted, since this process combines the pollution control of wastewaters and the generation of bioenergy, based on the conversion of the organic fraction to biogas, a methane-rich gaseous mixture that may supply the energetic demands in industrial plants. In this context, this work aimed at assessing the energetic potential of AD applied to the treatment of stillage, the main wastewater from ethanol production, in an attempt to highlight the improvements in the energy balance ratio of ethanol by inserting the heating value of methane as a bioenergy source. At least 5-15% of the global energy consumption in the ethanol industry could be supplied by the energetic potential of stillage, regardless the feedstock (i.e. sugarcane, corn or cassava). The association between bagasse combustion and stillage anaerobic digestion in sugarcane-based distilleries could provide a bioenergy surplus of at least 130% of the total fossil fuel input into the ethanol plant, considering only the energy from methane. In terms of financial aspects, the economic gains could reach US$ 0.1901 and US$ 0.0512 per liter of produced ethanol, respectively for molasses- (Brazil) and corn-based (EUA) production chains. For large-scale (∼1000 m(3)EtOH per day) Brazilian molasses-based plants, an annual economic gain of up to US$ 70 million could be observed. Considering the association between anaerobic and aerobic digestion, for the scenarios analyzed, at least 25% of the energetic potential of stillage would be required to supply the energy consumption with aeration, however, more suitable effluents for agricultural application could be produced. The main conclusion from this work

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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.

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

    DEFF Research Database (Denmark)

    Caspeta, Luis; Castillo, Tania; Nielsen, Jens

    2015-01-01

    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. ...

  8. 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)...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Genome shuffling to improve thermotolerance, ethanol tolerance and ethanol productivity of Saccharomyces cerevisiae.

    Science.gov (United States)

    Shi, Dong-jian; Wang, Chang-lu; Wang, Kui-ming

    2009-01-01

    Genome shuffling is a powerful strategy for rapid engineering of microbial strains for desirable industrial phenotypes. Here we improved the thermotolerance and ethanol tolerance of an industrial yeast strain SM-3 by genome shuffling while simultaneously enhancing the ethanol productivity. The starting population was generated by protoplast ultraviolet irradiation and then subjected for the recursive protoplast fusion. The positive colonies from the library, created by fusing the inactivated protoplasts were screened for growth at 35, 40, 45, 50 and 55 degrees C on YPD-agar plates containing different concentrations of ethanol. Characterization of all mutants and wild-type strain in the shake-flask indicated the compatibility of three phenotypes of thermotolerance, ethanol tolerance and ethanol yields enhancement. After three rounds of genome shuffling, the best performing strain, F34, which could grow on plate cultures up to 55 degrees C, was obtained. It was found capable of completely utilizing 20% (w/v) glucose at 45-48 degrees C, producing 9.95% (w/v) ethanol, and tolerating 25% (v/v) ethanol stress.

  16. 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.

  17. 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)

  18. Production of Ethanol Fuel from Organic and Food Wastes

    Directory of Open Access Journals (Sweden)

    Uduak George AKPAN, Adamu Ali ALHAKIM, and Udeme Joshua Josiah IJAH

    2008-12-01

    Full Text Available Production of ethanol fuel from organic and food waste has been carried out with the singular aim of converting the waste to useful material. To achieve this, the conversion of organic waste (Old newspapers and food waste (maize were respectively carried out via acid and microbial hydrolysis, which yielded 42% and 63% fermentable sugar wort. This was then converted into ethanol by fermentation process using Sacchromyces ceverisiae. 95% ethanol was obtained by fractional distillation of the fermentable wort and the total volume of ethanol produced from 2,500 grams of the organic and food wastes was 0.86 liters.Fermentation Kinetic parameters were evaluated. Considering the percentage fermentable sugar yield from the biomasses in study, it is more economical to produce ethanol from food waste (maize than old organic waste (old newspaper.

  19. 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

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

    Data.gov (United States)

    NSGIC State | GIS Inventory — 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...

  1. 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...

  2. 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.

  3. 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.

  4. Allocation of Energy Use in the Biomass-based Fuel Ethanol System and Its Use in Decision Making

    Institute of Scientific and Technical Information of China (English)

    LENG Ru-bo; YU Sui-ran; FANG Fang; DAI Du; WANG Cheng-tao

    2005-01-01

    The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue. To investigate the energy use in the three biomass-base ethanol fuel systems, energy content approach, Market value approach and Product displacement approach methods were used to allocate the energy use based on life cycle energy assessment. The results shows that the net energy of corn based, wheat based, and cassava-based ethanol fuel are 12543MJ, 10299MJ and 13112MJ when get one ton biomassbased ethanol, respectively, and they do produce positive net energy.

  5. 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.

  6. 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.

  7. Ethanol production from modern biorefinery: Robotic platform for production of Saccharomyces cerevisiae engineered to convert pretreated lignocellulosic sugars to ethanol anaerobically

    Science.gov (United States)

    Biorefineries to produce ethanol are becoming abundant but the future of ethanol requires that cellulosic ethanol paradigms are researched. A discussion of the existing ethanol production and biorefinery capacity will be made. The USDA, ARS, NCAUR, BBC group has developed a robotic platform to scr...

  8. 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.

  9. 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

  10. 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)

  11. The productive potentials of sweet sorghum ethanol in China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Caixia; Li, Shimei; Ge, Liqiang [Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Xie, Gaodi [Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101 (China); He, Tingting [Macquarie University, NSW2109 (Australia)

    2010-07-15

    As one of the important non-grain energy crops, sweet sorghum has attracted the attention of scientific community and decision makers of the world since decades. But insufficient study has been done about the spatial suitability distribution and ethanol potential of sweet sorghum in China. This paper attempts to probe into the spatial distribution and ethanol potential of sweet sorghum in China by ArcGIS methods. Data used for the analysis include the spatial data of climate, soil, topography and land use, and literatures relevant for sweet sorghum studies. The results show that although sweet sorghum can be planted in the majority of lands in China, the suitable unused lands for large-scale planting (unit area not less than 100 hm{sup 2}) are only as much as 78.6 x 10{sup 4} hm{sup 2}; and the productive potentials of ethanol from these lands are 157.1 x 10{sup 4}-294.6 x 10{sup 4} t/year, which can only meet 24.8-46.4% of current demand for E10 (gasoline mixed with 10% ethanol) in China (assumption of the energy efficiency of E10 is equivalent to that of pure petroleum). If all the common grain sorghum at present were replaced by sweet sorghum, the average ethanol yield of 244.0 x 10{sup 4} t/year can be added, and thus the productive potentials of sweet sorghum ethanol can satisfy 63.2-84.9% of current demand for E10 of China. In general, Heilongjiang, Jilin, Inner Mongolia and Liaoning rank the highest in productive potentials of sweet sorghum ethanol, followed by Hebei, Shanxi, Sichuan, and some other provinces. It is suggested that these regions should be regarded as the priority development zones for sweet sorghum ethanol in China. (author)

  12. 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

  13. 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

  14. 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

  15. Ethanol production and a case study of ethanol produced from sweet sorghum stalks via solid state fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Geng, X. [China Agricultural Univ., Beijing (China). Resource and Environmental Engineering College; Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology; Li, S.Z. [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology

    2008-07-01

    Ethanol has excellent fuel properties, such as high octane, high heat of vaporization and low photochemical reactivity in the atmosphere. It is less volatile than gasoline and there is lower smog formation from evaporative emissions of pure ethanol compared to gasoline. As such, ethanol has emerged as an important alternative energy source that is sustainable, efficient, cost effective, convenient and safe. In 2006, global production of ethanol reached 13.5 billion gallons, up from 12.1 billion gallons in 2005. However, in light of the current debate of food versus fuel, the industry must shift to non-food feedstocks. This paper described an emerging technology to cost-effectively produce ethanol from sweet sorghum stalks, the most promising alternative feedstock to corn, via solid state fermentation (SSF). Experiments of advanced solid state fermentation (ASSF) for ethanol production from sweet sorghum by Saccharomyces cerevisiae were conducted in laboratory and pilot scales studies. The process parameters were monitored during the fermentation in three scales. The highest ethanol concentration was achieved in pilot fermentation after 44 hours of incubation when a high yield of ethanol of 94.48 per cent was obtained. In comparison, corn ethanol fermentation yielded 91.5 per cent ethanol after 55 hours of incubation. Ethanol concentration decreased slowly after 44 hours of incubation due to the consumption of sugars and the inhibitory effects of ethanol. Ethanol is a typical primary metabolite whose production closely couples with the growth of yeast cell, indicating yeast is produced as a co-product. Under the same fermentation conditions the fermentation in non-sterilized medium gave the similar ethanol concentration to that of a sterilized medium, which has the advantages of saving in equipment and energy costs for industrialization of ethanol production from sweet sorghum via SSF. 39 refs., 6 figs.

  16. 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. © 2015 The Society for Applied Microbiology.

  17. 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.

  18. 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.

  19. 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.

  20. Whey and dry milk products as feedstocks for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, T C

    1979-10-01

    Surplus whey and dry milk could have supplied about 1,383,723,000 lbs of lactose in 1978 for conversion to approximately 84,632,171 gallons of ethanol. This would be about .00085% of the total gasoline used in the US, or .0085% of the ethanol needed to produce a 10% ethanol/gasoline blend nationwide. To the extent that these are surpluses not desired for food purposes, whey and dry milk can contribute to ethanol supply in a small way. However, no energy or economic assessment has been made so the cost/benefit relationship is unknown.

  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. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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

  10. 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.

  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. 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.

  13. 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.

  14. 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).

  15. An enzyme to improve the ethanol production; Une enzyme pour ameliorer la production d'ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-07-01

    The American firm Genecor launches a technology which allows to improve the production of ethanol from agricultural resources. This technology involves in particular a decrease of the energy consumption and of the production costs and a best yield. In the process, is used a mixture of enzymes composed of alpha-amylase and gluco-amylase. (O.M.)

  16. 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…

  17. 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

  18. 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.

  19. 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.

  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. Plasma-Assisted Pretreatment of Wheat Straw for Ethanol Production

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Kádár, Zsófia; Thomsen, Anne Belinda

    2011-01-01

    The potential of wheat straw for ethanol production after pretreatment with O3 generated in a plasma at atmospheric pressure and room temperature followed by fermentation was investigated. We found that cellulose and hemicellulose remained unaltered after ozonisation and a subsequent washing step...

  2. 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...

  3. 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 ...

  4. 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.

  5. Life-cycle assessment of corn-based butanol as a potential transportation fuel.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, M.; Wang, M.; Liu, J.; Huo, H.; Energy Systems

    2007-12-31

    Butanol produced from bio-sources (such as corn) could have attractive properties as a transportation fuel. Production of butanol through a fermentation process called acetone-butanol-ethanol (ABE) has been the focus of increasing research and development efforts. Advances in ABE process development in recent years have led to drastic increases in ABE productivity and yields, making butanol production worthy of evaluation for use in motor vehicles. Consequently, chemical/fuel industries have announced their intention to produce butanol from bio-based materials. The purpose of this study is to estimate the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. The study employs a well-to-wheels analysis tool--the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET) model developed at Argonne National Laboratory--and the Aspen Plus{reg_sign} model developed by AspenTech. The study describes the butanol production from corn, including grain processing, fermentation, gas stripping, distillation, and adsorption for products separation. The Aspen{reg_sign} results that we obtained for the corn-to-butanol production process provide the basis for GREET modeling to estimate life-cycle energy use and greenhouse gas emissions. The GREET model was expanded to simulate the bio-butanol life cycle, from agricultural chemical production to butanol use in motor vehicles. We then compared the results for bio-butanol with those of conventional gasoline. We also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. Our study shows that, while the use of corn-based butanol achieves energy benefits and reduces greenhouse gas emissions, the results are affected by the methods used to treat the acetone that is co-produced in butanol plants.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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...

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

    DEFF Research Database (Denmark)

    Xu, Jian; Chen, Hongzhang; Kádár, Zsófia

    2011-01-01

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

  12. 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

  13. Value Chain Structures that Define European Cellulosic Ethanol Production

    DEFF Research Database (Denmark)

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

    2017-01-01

    production plants across Europe from a global value chain (GVC) perspective. We find that most CE production plants in the EU focus largely on intellectual property and are therefore only at the pilot or demonstration scale. Crescentino, the largest CE production facility in Europe, is also more interested...... petroleum markets and higher financial risks. We argue that, to increase CE production, policies should consider value chains, promote the wider bio-economy of products and focus on economies of scope. Whereas the EU and its member states have ethanol quotas and blending targets, a more effective policy...

  14. 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

  15. 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

  16. An Update on Ethanol Production and Utilization in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Bloyd, Cary N.

    2009-10-01

    Thailand has continued to promote domestic biofuel utilization. Production and consumption of biofuel in Thailand have continued to increase at a fast rate due to aggressive policies of the Thai government in reducing foreign oil import and increasing domestic renewable energy utilization. This paper focuses on ethanol production and consumption, and the use of gasohol in Thailand. The paper is an update on the previous paper--Biofuel Infrastructure Development and Utilization in Thailand--in August 2008.

  17. Bio-Ethanol Production from Poultry Manure

    African Journals Online (AJOL)

    john

    methanol, methane, natural gas, propane, hydrogen, etc. Nevertheless, the .... promise and is capturing the interest of the bio-products industry. However, further ... solid fraction was refrigerated at 4°C in plastic bottles prior to acid hydrolysis.

  18. 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.

  19. 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.

  20. 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...... before ethanol fermentation. Treatment with three white rot fungi, Phaneroachaete chrysosporium, Ceriporiopsis subvermispora and Ceriolopsis polyzona has been applied on olive cake in order to investigate the potential for performing delignification and thus enhancing the efficiency of the subsequent...

  1. 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.

  2. Ethanol: the promise and the peril : Should Manitoba expand ethanol subsidies?[A critical analysis of the case for subsidizing ethanol production in Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Sopuck, R.D. [Frontier Centre for Public Policy, Winnipeg, MB (Canada). Rural Renaissance Project

    2002-10-01

    Ethanol is produced through the fermentation of wheat. Blending ethanol with gasoline results in an ethanol-blended gasoline (EBG). Manitoba has already established an ethanol industry in the province and the government of the province is studying the feasibility of expansion. Every year in Manitoba, approximately 90 million litres of EBG are consumed, and the province's ethanol facility also produces a high protein cattle feed called distillers dry grain. Controversies surround the ethanol industry over both the economics and the environmental benefits and impacts. At issue is the economic efficiency of the production of ethanol, where opponents claim that the final product contains less energy than that required to produce it. A small gain is obtained, as revealed by a recent study. It is difficult to quantify the environmental effects of the ethanol industry, whether they be negative or positive. The author indicates that no matter what happens, the gasoline market in Manitoba is so small when compared to the rest of the world that the effect will not be significant. The three methods for the production of ethanol are: (1) the most risky and expensive method is the stand alone ethanol production facility, (2) integrated facilities where other products are produced, such as wet mash or nutraceuticals, and (3) integrated facilities where dry mash can be exported as a high protein feed. The production of a wide range of products is clearly the best option to be considered during the design of an ethanol facility. Price collapse and the capitalizing of subsidies into prices are the main risks facing the expansion of ethanol production in Manitoba. The author states that direct subsidies and price supports should be avoided, since subsidies would encourage the conversion of more feed grain into ethanol. The feed shortage would worsen especially as Manitoba does not currently produce enough feed to support its growing livestock industry. The author concludes that

  3. 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...

  4. 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

  5. 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. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. 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.

  7. Production of syngas by ethanol reforming on Ni catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Catapan, Rafael C.; Oliveira, Amir A.M.; Donadel, Karina; Oliveira, Antonio Pedro N.; Rambo, Carlos R. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Mechanical Engineering. Lab. of Combustion and Thermal Systems Engineering], Emails: catapan@labcet.ufsc.br, donadel@emc.ufsc.br, pedronovaes@emc.ufsc.br, rambo@enq.ufsc.br; Oliveira, Therezinha Maria N.; Wagner, Theodoro M. [Universidade da Regiao de Joinville, SC (Brazil). Campus Universitario Bom Retiro], E-mails: tnovais@univille.br, theowag@terra.com.br

    2010-07-01

    In the recent literature, attention has been directed to the development of noble metals based catalysts for the ethanol reforming. However, the high costs and low availability of noble metals, e.g. platinum, as a resource justify the development of alternatives technologically, economically and environmentally viable such as Ni-based catalysts. Here, the thermal decomposition, partial oxidation and steam reforming of ethanol over SiO{sub 2} supported Ni was studied in a packed bed reactor in the 673 - 973 K temperature range at 1 atm. The catalyst was produced from 10% NiO, 5% of bentonite and 85% (wt.) of natural amorphous silica fibers (NASF). Scanning Electron Microscopy (SEM) evaluation revealed that particles of Ni were homogeneously distributed over the NASF. The X-ray diffraction (XRD) patterns did not show peaks related to silicates in all spectra, which indicates that there is no, apparently, interaction between the nickel catalysts and SiO{sub 2} or devitrification The reactions of ethanol on this catalyst occurs mainly by the dehydrogenation reaction generating acetaldehyde. Further, CH{sub 3}CHO is decomposed to CH{sub 4} and CO. In parallel to this route, ethanol is dehydrated producing ethylene, which is successively dehydrogenated in Ni sites generating carbon on the surface. Also, carbon can be produced by consecutive dehydrogenation of CH{sub 4}. Both reactions contribute to increase the production of H{sub 2} to values higher than those predicted by the thermodynamic equilibrium. (author)

  8. 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.

  9. Production of ethanol from excess ethylene

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... with respect to heat integration and process optimization (tasks 10-11). In the final task-12, the environmental impact of the process design is evaluated together with some of the key sustainability measures. In addition to PRO/II, the following software is used: ICAS (for property prediction, analysis...

  10. Production of ethanol from excess ethylene

    DEFF Research Database (Denmark)

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

    2012-01-01

    ) and ECON (cost and economic analysis). This design therefore covers all stages of conceptual design, starting from the consideration of qualitative aspects of the process flowsheet and preliminary calculations to detailed process simulations, equipment sizing, costing and an economic evaluation......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...

  11. 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.

  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. 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...

  14. The effect of sulfide and ammonia on cassava fermentation for ethanol production in an ethanol-methane coupled system.

    Science.gov (United States)

    Wang, Ke; Jiang, Li; Mao, Zhonggui; Zhang, Chengming; Zhang, Jianhua; Zhang, Hongjian

    2011-01-01

    An ethanol-methane coupled system was proposed to resolve wastewater pollution in cassava ethanol production. The wastewater originated from ethanol distillation is treated with two-stage anaerobic digestion and then recycled for medium preparation for the next batch ethanol fermentation, thus eliminating wastewater discharge and saving fresh water. The constituents of the two-stage anaerobic digestion effluent were complex which influenced the ethanol fermentation performance. This paper aimed to study the effect of two constituents in the effluent, i.e. sulfide and ammonia, on cassava-based ethanol fermentation performance. It was found that sulfide reduced the consumption rate of total sugar by significantly inhibiting the growth of Saccharomyces cerevisiae, but the total consumption amount of total sugar at the end of fermentation was not influenced. S. cerevisiae produced more glycerol and less ethanol at the end of fermentation containing higher concentration of sodium sulfide. Ethanol fermentation performance could be hardly influenced by the sulfide in the two-stage effluent because of the very low concentration. More glycerol was produced while final ethanol concentration was reduced when the level of ammonia in the two-stage effluent was higher.

  15. Biological caproate production by Clostridium kluyveri from ethanol and acetate as carbon sources

    DEFF Research Database (Denmark)

    Yin, Yanan; Zhang, Yifeng; Karakashev, Dimitar Borisov

    2017-01-01

    Caproate is a valuable industrial product and chemical precursor. In this study, batch tests were conducted to investigate the fermentative caproate production through chain elongation from acetate and ethanol. The effect of acetate/ethanol ratio and initial ethanol concentration on caproate prod...

  16. 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...

  17. 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)

  18. 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...

  19. Ethanol and Protein from Ethanol Plant By-Products Using Edible Fungi Neurospora intermedia and Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Veronika Bátori

    2015-01-01

    Full Text Available Feasible biorefineries for production of second-generation ethanol are difficult to establish due to the process complexity. An alternative is to partially include the process in the first-generation plants. Whole stillage, a by-product from dry-mill ethanol processes from grains, is mostly composed of undegraded bran and lignocelluloses can be used as a potential substrate for production of ethanol and feed proteins. Ethanol production and the proteins from the stillage were investigated using the edible fungi Neurospora intermedia and Aspergillus oryzae, respectively. N. intermedia produced 4.7 g/L ethanol from the stillage and increased to 8.7 g/L by adding 1 FPU of cellulase/g suspended solids. Saccharomyces cerevisiae produced 0.4 and 5.1 g/L ethanol, respectively. Under a two-stage cultivation with both fungi, up to 7.6 g/L of ethanol and 5.8 g/L of biomass containing 42% (w/w crude protein were obtained. Both fungi degraded complex substrates including arabinan, glucan, mannan, and xylan where reductions of 91, 73, 38, and 89% (w/v were achieved, respectively. The inclusion of the current process can lead to the production of 44,000 m3 of ethanol (22% improvement, around 12,000 tons of protein-rich biomass for animal feed, and energy savings considering a typical facility producing 200,000 m3 ethanol/year.

  20. 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.

  1. 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.

  2. 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). PMID:23097596

  3. 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).

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

    DEFF Research Database (Denmark)

    Cannella, David

    are the leftover of agricultural productions (straws), not edible crops (giant reed) or wood, thus the ethanol so produced is also called second generation (or 2G ethanol), which differs from the first generation produced from starch (sugar beets mostly). In the industrial production of cellulosic ethanol high...... 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...

  5. 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.

  6. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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....

  13. Structural Analysis of Alkaline Pretreated Rice Straw for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Paripok Phitsuwan

    2017-01-01

    Full Text Available Rice straw (RS is an abundant, readily available agricultural waste, which shows promise as a potential feedstock for Asian ethanol production. To enhance release of glucose by enzymatic hydrolysis, RS was pretreated with aqueous ammonia (27% w/w at two pretreatment temperatures: room temperature and 60°C. Statistical analysis indicated similarity of enzymatic glucose production at both pretreatment temperatures after 3-day incubation. Chemical composition, FTIR, and EDX analyses confirmed the retention of glucan and xylan in the pretreated solid, but significant reduction of lignin (60.7% removal and silica. SEM analysis showed the disorganized surfaces and porosity of the pretreated RS fibers, thus improving cellulose accessibility for cellulase. The crystallinity index increased from 40.5 to 52.3%, indicating the higher exposure of cellulose. With 10% (w/v solid loadings of pretreated RS, simultaneous saccharification and fermentation yielded a final ethanol concentration of 24.6 g/L, corresponding to 98% of maximum theoretical yield. Taken together, aqueous ammonia pretreatment is an effective method to generate highly digestible pretreated RS for bioethanol production and demonstrates potential application in biorefinery industry.

  14. 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.

  15. 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.

  16. 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.

  17. 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."

  18. Effect of malic enzyme on ethanol production by Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Yoshikawa, Katsunori; Hirasawa, Takashi; Shimizu, Hiroshi

    2015-01-01

    We investigated effects of malic enzyme on ethanol production by Synechocystis sp. PCC 6803 under autotrophic conditions. Deletion of me, which encodes malic enzyme, decreased ethanol production, whereas its overexpression had no effect. Our results suggest that maintaining optimal malic enzyme activity controls ethanol production by Synechocystis sp. PCC 6803. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. Optimizing Blendstock Composition and Ethanol Feedstock to Reduce Gasoline Well-to-Pump CO 2 Emission

    KAUST Repository

    Zhang, Bo

    2017-06-02

    Lifecycle CO2 emission of ethanol blended gasoline was simulated to investigate how fuel properties and composition affect overall emission. Fuel research octane number (RON), octane sensitivity and ethanol content (derived from sugarcane and corn) were varied in the simulations to formulate blended fuels that economically achieve target specifications. The well-to-pump (WTP) simulation results were then analyzed to understand the effects of fuel composition on emission. Elevated ethanol content displaces aromatics and olefins required in gasoline blendstock to reach a target fuel specification. The addition of greater sugarcane-based ethanol percentage in constant aromatics and olefins fuel reduces its WTP CO2 emission. Corn-based ethanol blending does not offer CO2 emission offset due to its high production emissions. The mixing of sugarcane-based with corn-based ethanol is shown to be a potentially effective method for achieving a blended fuel with a lower lifecycle CO2 emission. Besides CO2 emission, the total greenhouse gas (GHG) emission from land-use conversions (LUC), CH4, and N2O are also significant in determining the optimal fuel blend. Herein, we present preliminary results showing that total GHG emissions significantly increase when either corn or sugarcane ethanol is blended at even small percentages; detailed results will be addressed in future communications.

  20. 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...... district heating production in the ethanol facility. The results suggest that the efficiency of integrating lignocellulosic ethanol production in CHP plants is highly dependent on operation, and it is therefore suggested that the expected operation pattern of such polygeneration system is taken...

  1. 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.

  2. Improving Saccharomyces cerevisiae ethanol production and tolerance via RNA polymerase II subunit Rpb7

    National Research Council Canada - National Science Library

    Zilong Qiu; Rongrong Jiang

    2017-01-01

    .... Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II...

  3. 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.

  4. 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.)

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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....

  12. Consolidated briefing of biochemical ethanol production from lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Spyridon Achinas

    2016-09-01

    Full Text Available Bioethanol production is one pathway for crude oil reduction and environmental compliance. Bioethanol can be used as fuel with significant characteristics like high octane number, low cetane number and high heat of vaporization. Its main drawbacks are the corrosiveness, low flame luminosity, lower vapor pressure, miscibility with water, and toxicity to ecosystems. One crucial problem with bioethanol fuel is the availability of raw materials. The supply of feedstocks for bioethanol production can vary season to season and depends on geographic locations. Lignocellulosic biomass, such as forest-based woody materials, agricultural residues and municipal waste, is prominent feedstock for bioethanol cause of its high availability and low cost, even though the commercial production has still not been established. In addition, the supply and the attentive use of microbes render the bioethanol production process highly peculiar. Many conversion technologies and techniques for biomass-based ethanol production are under development and expected to be demonstrated. In this work a technological analysis of the biochemical method that can be used to produce bioethanol is carried out and a review of current trends and issues is conducted.

  13. Biological production of ethanol fom coal. [Quarterly report], December 22, 1991--March 21, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    Research is continuing in an attempt to increase both the ethanol concentration and product ratio using C. ljungdahlii. The purpose of this report is to present data (acetate to ethanol) utilizing a medium prepared especially for C. ljungdahlii. Medium development studies are presented, as well as reactor studies with the new medium in batch reactors. Continuous stirred tank reactor (CSTR) with cell recycle. The use of this new medium has resulted in significant improvements in cell concentration, ethanol concentration and product ratio.

  14. 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...

  15. Study on genotypic variation for ethanol production from sweet sorghum juice

    Energy Technology Data Exchange (ETDEWEB)

    Ratnavathi, C.V.; Suresh, K.; Kumar, B.S. Vijay; Pallavi, M.; Komala, V.V.; Seetharama, N. [Directorate of Sorghum Research, Rajendranagar, Hyderabad 500030, Andhra Pradesh (India)

    2010-07-15

    Sugarcane molasses is the main source for ethanol production in India. Sweet sorghum with its juicy stem containing sugars equivalent to that of sugarcane is a very good alternative for bio-ethanol production to meet the energy needs of the country. Sweet sorghum is drought resistant, water logging resistant and saline-alkaline tolerant. Growing sweet sorghum for ethanol production is relatively easy and economical and ethanol produced from sweet sorghum is eco-friendly. In view of this, it is important to identify superior genotypes for ethanol production in terms of percent juice brix, juice extractability, total fermentable sugars, ethanol yield and fermentation efficiency. This paper presents the study on the variability observed for the production of ethanol by various sweet sorghum genotypes in a laboratory fermentor. Five Sweet Sorghum (Sorghum bicolor L. Moench) genotypes were evaluated for ethanol production from stalk juice (Keller, SSV 84, Wray, NSSH 104 and BJ 248). Sweet sorghum juice differs from cane juice mainly in its higher content of starch and aconitic acid. Data were collected for biomass yield; stalk sugar yield and ethanol production in five genotypes. Maximum ethanol production of 9.0%w/v ethanol was obtained with Keller variety (20% sugar concentration was used), and decreased for other genotypes. A distiller's strain of Saccharomyces cerevisiae (gifted by Seagram Distilleries Ltd.) was employed for fermentation. The fermentation efficiency (FE) was 94.7% for this strain. High biomass of yeast was obtained with BJ 248 variety. When the similar experiments were conducted with unsterile sweet sorghum juice (15% sugar concentration) 6.47%w/v ethanol was produced. (author)

  16. 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.

  17. 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

  18. 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...

  19. Bio-ethanol Production from Green Onion by Yeast in Repeated Batch.

    Science.gov (United States)

    Robati, Reza

    2013-09-01

    Considered to be the cleanest liquid fuel, bio-ethanol can be a reliable alternative to fossil fuels. It is produced by fermentation of sugar components of plant materials. The common onions are considered to be a favorable source of fermentation products as they have high sugar contents as well as contain various nutrients. This study focused on the effective production of ethanol from Green onion (Allium fistulosum L.) by the yeast "Saccharomyces cerevisiae" in repeated batch. The results showed that the total sugar concentration of onion juice was 68.4 g/l. The maximum rate of productivity, ethanol yield and final bio-ethanol percentage was 7 g/l/h (g ethanol per liter of onion juice per hour), 35 g/l (g ethanol per liter of onion juice) and 90 %, respectively.

  20. Sweet sorghum biorefinery for production of fuel ethanol and value-added co-products

    Science.gov (United States)

    An integrated process has been developed for a sweet-sorghum biorefinery in which all carbohydrate components of the feedstock were used for production of fuel ethanol and industrial chemicals. In the first step, the juice was extracted from the stalks. The resulted straw (bagasse) then was pretreat...

  1. 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 ...

  2. 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…

  3. 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.

  4. 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.

  5. 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.

  6. A Shortcut to the Production of High Ethanol Concentration from Jerusalem Artichoke Tubers

    Directory of Open Access Journals (Sweden)

    Wei-Guo Zhang

    2005-01-01

    Full Text Available Aspergillus niger SL-09, a newly isolated exoinulinase-hyperproducing strain, and Saccharomyces cerevisiae Z-06, with high ethanol tolerance, were used in a fed-batch process for simultaneous saccharification and fermentation of Jerusalem artichoke tuber mash and flour. S. cerevisiae Z-06 utilized 98 % of the total sugar and produced 19.6 % of ethanol in 48 h. In this process the conversion efficiency of the fermentation of Jerusalem artichoke and the production of ethanol were 90 % of the theoretical ethanol yield and the cost of the production of flour was cut nearly into half.

  7. 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....

  8. Metabolic engineering of Synechocystis sp. PCC 6803 for enhanced ethanol production based on flux balance analysis.

    Science.gov (United States)

    Yoshikawa, Katsunori; Toya, Yoshihiro; Shimizu, Hiroshi

    2017-05-01

    Synechocystis sp. PCC 6803 is an attractive host for bio-ethanol production due to its ability to directly convert atmospheric carbon dioxide into ethanol using photosystems. To enhance ethanol production in Synechocystis sp. PCC 6803, metabolic engineering was performed based on in silico simulations, using the genome-scale metabolic model. Comprehensive reaction knockout simulations by flux balance analysis predicted that the knockout of NAD(P)H dehydrogenase enhanced ethanol production under photoautotrophic conditions, where ammonium is the nitrogen source. This deletion inhibits the re-oxidation of NAD(P)H, which is generated by ferredoxin-NADP(+) reductase and imposes re-oxidation in the ethanol synthesis pathway. The effect of deleting the ndhF1 gene, which encodes NADH dehydrogenase subunit 5, on ethanol production was experimentally evaluated using ethanol-producing strains of Synechocystis sp. PCC 6803. The ethanol titer of the ethanol-producing ∆ndhF1 strain increased by 145%, compared with that of the control strain.

  9. Economic evaluation of United States ethanol production from ligno-cellulosic feedstocks

    Science.gov (United States)

    Choi, Youn-Sang

    This paper evaluates the economic feasibility and economy-wide impacts of the U. S. ethanol production from lignocellulosic feedstocks (LCF) using Tennessee Valley Authority's (TVA's) dilute acid hydrolysis process. A nonlinear mathematical programming model of a single ethanol producer, whose objective is profit maximization, is developed. Because of differences in their chemical composition and production process, lignocellulosic feedstocks are divided into two groups: Biomass feedstocks, which refer to crop residues, energy crops and woody biomass, and municipal solid waste (MSW). Biomass feedstocks are more productive and less costly in producing ethanol and co-products, while MSW generates an additional income to the producer from a tipping fee and recycling. The analysis suggests that, regardless of types of feedstocks used, TVA's conversion process can enhance the economic viability of ethanol production as long as furfural is produced from the hemicellulose fraction of feedstocks as a co-product. The high price of furfural makes it a major factor in determining the economic feasibility of ethanol production. Along with evaluating economic feasibility of LCF-to-ethanol production, the optimal size of a plant producing ethanol using TVA's conversion process is estimated. The larger plant would have the advantage of economies of scale, but also have a disadvantage of increased collection and transportation costs for bulky biomass from more distant locations. We assume that the plant is located in the state of Missouri and utilizes only feedstocks produced in the state. The results indicate that the size of a plant using Biomass feedstocks is much bigger than one using MSW. The difference of plant sizes results from plant location and feedstock availability. One interesting finding is that energy crops are not feasible feedstocks for LCF-to-ethanol production due to their high price. Next, a static CGE model is developed to estimate the U.S. economy

  10. 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 ...

  11. 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 ...

  12. 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.

  13. 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.

  14. Selective approach to efficient ethanol production using adaptation of producer Saccharomyces cerevisiae to hyperosmotic medium

    Directory of Open Access Journals (Sweden)

    Yelena A. Oleinikova

    2017-06-01

    Full Text Available The resistance to ethanol of 18 strains of alcoholic yeast Saccharomyces cerevisiae, including production strains, was studied. It is shown that yeast growth was inhibited by increasing the concentration of ethanol in the medium above 7% (v/v. Successive adaptation of alcohol yeast to gradually increased concentrations of sodium chloride in the medium was carried out. Yeast variants that exceeded production strains in fermentation activity on the medium with 10% (v/v ethanol were received. The use of selected strains will increase the productivity of the process of ethyl alcohol production at the same costs.

  15. 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.

  16. 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)

  17. 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.

  18. Improving ethanol production from alfalfa stems via ambient-temperature acid pretreatment and washing.

    Science.gov (United States)

    Zhou, Shengfei; Weimer, Paul J; Hatfield, Ronald D; Runge, Troy M; Digman, Matthew

    2014-10-01

    The concept of co-production of liquid fuel (ethanol) along with animal feed on farm was proposed, and the strategy of using ambient-temperature acid pretreatment, ensiling and washing to improve ethanol production from alfalfa stems was investigated. Alfalfa stems were separated and pretreated with sulfuric acid at ambient-temperature after harvest, and following ensiling, after which the ensiled stems were subjected to simultaneous saccharification and fermentation (SSF) for ethanol production. Ethanol yield was improved by ambient-temperature sulfuric acid pretreatment before ensiling, and by washing before SSF. It was theorized that the acid pretreatment at ambient temperature partially degraded hemicellulose, and altered cell wall structure, resulted in improved cellulose accessibility, whereas washing removed soluble ash in substrates which could inhibit the SSF. The pH of stored alfalfa stems can be used to predict the ethanol yield, with a correlation coefficient of +0.83 for washed alfalfa stems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Ethanol Production from Enzymatically Treated Dried Food Waste Using Enzymes Produced On-Site

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2015-01-01

    Full Text Available The environmental crisis and the need to find renewable fuel alternatives have made production of biofuels an important priority. At the same time, the increasing production of food waste is an important environmental issue. For this reason, production of ethanol from food waste is an interesting approach. Volumes of food waste are reduced and ethanol production does not compete with food production. In this work, we evaluated the possibility of using source-separated household food waste for the production of ethanol. To minimize the cost of ethanol production, the hydrolytic enzymes that are necessary for cellulose hydrolysis were produced in-house using the thermophillic fungus Myceliophthora thermophila. At the initial stage of the study, production of these thermophilic enzymes was studied and optimized, resulting in an activity of 0.28 FPU/mL in the extracellular broth. These enzymes were used to saccharify household food waste at a high dry material consistency of 30% w/w, followed by fermentation. Ethanol production reached 19.27 g/L with a volumetric productivity of 0.92 g/L·h, whereas only 5.98 g/L of ethanol was produced with a volumetric productivity of 0.28 g/L·h when no enzymatic saccharification was used.

  1. 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.

  2. Ethanol production from food waste at high solid contents with vacuum recovery technology

    Science.gov (United States)

    Ethanol production from food wastes does not only solve the environmental issues but also provide renewable biofuel to partially substitute fossil fuels. This study investigated the feasibility of utilization of food wastes for producing ethanol at high solid contents (35%, w/w). Vacuum recovery sys...

  3. 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

  4. 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.

  5. 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...

  6. 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...

  7. Understanding the reductions in US corn ethanol production costs: an experience curve approach

    NARCIS (Netherlands)

    Hettinga, W.; Junginger, H.M.|info:eu-repo/dai/nl/202130703; Dekker, S.C.|info:eu-repo/dai/nl/203449827; 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

  8. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shoubao [Huainan Normal Univ., Anhui (China). School of Life Science; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao [Chinese Academy of Sciences, Hefei (China). Key Lab. of Ion Beam Bio-engineering of Inst. of Plasma Physics

    2012-05-15

    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. (orig.)

  9. 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

    .), hydrolysis (inhibition constant for xylose on conversion of cellulose and cellobiose, etc) and co-fermentation (ethanol yield on xylose, inhibition constant on microbial growth, etc.), are the most significant sources of uncertainties affecting the unit production cost of ethanol with a standard deviation...

  10. 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...

  11. 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

  12. 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.

  13. Atmospheric emission of reactive nitrogen during biofuel ethanol production.

    Science.gov (United States)

    Machado, Cristine M D; Cardoso, Arnaldo A; Allen, Andrew G

    2008-01-15

    This paper evaluates emissions to the atmosphere of biologically available nitrogen compounds in a region characterized by intensive sugar cane biofuel ethanol production. Large emissions of NH3 and NOx, as well as particulate nitrate and ammonium, occur at the harvest when the crop is burned, with the amount of nitrogen released equivalent to approximately 35% of annual fertilizer-N application. Nitrogen oxides concentrations show a positive association with fire frequency, indicating that biomass burning is a major emission source, with mean concentrations of NOx doubling in the dry season relative to the wetseason. During the dry season biomass burning is a source of NH3, with other sources (wastes, soil, biogenic) predominant during the wet season. Estimated NO2-N, NH3-N, NO3- -N and NH4+ -N emission fluxes from sugar cane burning in a planted area of ca. 2.2 x 10(6) ha are 11.0, 1.1, 0.2, and 1.2 Gg N yr(-1), respectively.

  14. Accounting for the water impacts of ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Fingerman, Kevin R; Torn, Margaret S; Kammen, Daniel M [Energy and Resources Group, University of California, Berkeley, 310 Barrows Hall, Berkeley, CA 94720-3050 (United States); O' Hare, Michael H, E-mail: kfingerman@berkeley.ed [Goldman School of Public Policy, University of California, Berkeley, 2607 Hearst Avenue, Berkeley, CA 94720-7320 (United States)

    2010-01-15

    Biofuels account for 1-2% of global transportation fuel and their share is projected to continue rising, with potentially serious consequences for water resources. However, current literature does not present sufficient spatial resolution to characterize this localized effect. We used a coupled agro-climatic and life cycle assessment model to estimate the water resource impacts of bioenergy expansion scenarios at a county-level resolution. The study focused on the case of California, with its range of agroecological conditions, water scarcity, and aggressive alternative fuel incentive policies. Life cycle water consumption for ethanol production in California is up to 1000 times that of gasoline due to a cultivation phase that consumes over 99% of life cycle water use for agricultural biofuels. This consumption varies by up to 60% among different feedstocks and by over 350% across regions in California. Rigorous policy analysis requires spatially resolved modeling of water resource impacts and careful consideration of the various metrics that might act to constrain technology and policy options.

  15. 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% from FPM. Coupled with the PSA recovery rate, 72.7%, the unit could achieve overall energy performance of 52.7%, or 74.4% working in co-generation of hydrogen and heat. (author)

  16. High yield simultaneous hydrogen and ethanol production under extreme-thermophilic (70 C) mixed culture environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chenxi [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); O-Thong, Sompong [Department of Biology, Faculty of Science, Thaksin University, Patthalung 93110 (Thailand); Karakashev, Dimitar; Angelidaki, Irini [Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); Lu, Wenjing; Wang, Hongtao [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2009-07-15

    The effect of pH and medium composition on extreme-thermophilic (70 C) dark fermentative simultaneous hydrogen and ethanol production (process performance and microbial ecology) was investigated. Hydrogen and ethanol yields were optimized with respect to glucose, peptone, FeSO{sub 4}, NaHCO{sub 3}, yeast extract, trace mineral salts, vitamins, and phosphate buffer concentrations as well as initial pH as independent variables. A combination of low levels of both glucose ({<=}2 g/L) and vitamin solutions ({<=}1 mL/L) and high levels of initial pH ({>=}7), mineral salts solution ({>=}5 mL/L) and FeSO{sub 4} ({>=}100 mg/L) stimulated the hydrogen production, while high level of glucose ({>=}5 g/L) and low levels of both initial pH ({<=}5.5) and mineral salts solution ({<=}1 mL/L) enhanced the ethanol production. High yield of simultaneous hydrogen and ethanol production (1.58 mol H{sub 2}/mol glucose combined with an ethanol yield of 0.90 mol ethanol/mol glucose) was achieved under extreme-thermophilic mixed culture environment. Results obtained showed that the shift of the metabolic pathways favouring either hydrogen or ethanol production was affected by the change in cultivation conditions (pH and medium composition). The mixed culture in this study demonstrated flexible ability for simultaneous hydrogen and ethanol production, depending on pH and nutrients formulation. The microorganisms involved could be regarded as simultaneous hydrogen/ethanol producers, as hydrogen and ethanol fermentation under all conditions was carried out by a group of extreme-thermophilic bacterial species related to Thermoanaerobacter, Thermoanaerobacterium and Caldanaerobacter. (author)

  17. The Development of Materials for the Production of Hydrogen from Bio-ethanol

    Institute of Scientific and Technical Information of China (English)

    Pilar; Ramírez; de; la; Piscina; Narcís; Homs

    2007-01-01

    1 Results There is an increased interest in the hydrogen production from renewable sources. In this context, recently, numerous studies which use ethanol for hydrogen production have appeared. Ethanol is easily handled, non-toxic, and it can be obtained from biomass. The steam-reforming of bioethanol has been shown to beeffective for hydrogen production:C2H5OH + 3 H2O  6 H2 + 2 CO2. Six moles of hydrogen can be yielded for each mole of ethanol reacted. However, depending on the catalyst used, other und...

  18. Effects of production and market factors on ethanol profitability for an integrated first and second generation ethanol plant using the whole sugarcane as feedstock.

    Science.gov (United States)

    Macrelli, Stefano; Galbe, Mats; Wallberg, Ola

    2014-02-21

    Sugarcane is an attractive feedstock for ethanol production, especially if the lignocellulosic fraction can also be treated in second generation (2G) ethanol plants. However, the profitability of 2G ethanol is affected by the processing conditions, operating costs and market prices. This study focuses on the minimum ethanol selling price (MESP) and maximum profitability of ethanol production in an integrated first and second generation (1G + 2G) sugarcane-to-ethanol plant. The feedstock used was sugarcane juice, bagasse and leaves. The lignocellulosic fraction was hydrolysed with enzymes. Yields were assumed to be 95% of the theoretical for each of the critical steps in the process (steam pretreatment, enzymatic hydrolysis (EH), fermentation, solid/liquid separation, anaerobic digestion) in order to obtain the best conditions possible for ethanol production, to assess the lowest production costs. Techno-economic analysis was performed for various combinations of process options (for example use of pentoses, addition of leaves), EH conditions (water-insoluble solids (WIS) and residence time), operating cost (enzymes) and market factors (wholesale prices of electricity and ethanol, cost of the feedstock). The greatest reduction in 2G MESP was achieved when using the pentoses for the production of ethanol rather than biogas. This was followed, in decreasing order, by higher enzymatic hydrolysis efficiency (EHE), by increasing the WIS to 30% and by a short residence time (48 hours) in the EH. The addition of leaves was found to have a slightly negative impact on 1G + 2G MESP, but the effect on 2G MESP was negligible. Sugarcane price significantly affected 1G + 2G MESP, while the price of leaves had a much lower impact. Net present value (NPV) analysis of the most interesting case showed that integrated 1G + 2G ethanol production including leaves could be more profitable than 1G ethanol, despite the fact that the MESP was higher than in 1G ethanol

  19. Bacteria engineered for fuel ethanol production: current status

    Energy Technology Data Exchange (ETDEWEB)

    Dien, B.S.; Cotta, M.A. [National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, IL (United States); Jeffries, T.W. [Inst. for Microbial and Biochemical Technology, Forest Service, Forest Products Lab., USDA, Madison, WI (United States)

    2004-07-01

    The lack of industrially suitable microorganisms for converting biomass into fuel ethanol has traditionally been cited as a major technical roadblock to developing a bioethanol industry. In the last two decades, numerous microorganisms have been engineered to selectively produce ethanol. Lignocellulosic biomass contains complex carbohydrates that necessitate utilizing microorganisms capable of fermenting sugars not fermentable by brewers' yeast. The most significant of these is xylose. The greatest successes have been in the engineering of gram-negative bacteria: Escherichia coli, Klebsiella oxytoca, and Zymomonas mobilis. E. coli and K. oxytoca are naturally able to use a wide spectrum of sugars, and work has concentrated on engineering these strains to selectively produce ethanol. Z. mobilis produces ethanol at high yields, but ferments only glucose and fructose. Work on this organism has concentrated on introducing pathways for the fermentation of arabinose and xylose. The history of constructing these strains and current progress in refining them are detailed in this review. (orig.)

  20. Ethanol Production from Hydrothermally-Treated Biomass from West Africa

    DEFF Research Database (Denmark)

    Bensah, Edem C.; Kádár, Zsófia; Mensah, Moses Y.

    2015-01-01

    Despite the abundance of diverse biomass resources in Africa, they have received little research and development focus. This study presents compositional analysis, sugar, and ethanol yields of hydrothermal pretreated (195 degrees C, 10 min) biomass from West Africa, including bamboo wood, rubber...... wood, elephant grass, Siam weed, and coconut husk, benchmarked against those of wheat straw. The elephant grass exhibited the highest glucose and ethanol yields at 57.8% and 65.1% of the theoretical maximums, respectively. The results show that the glucose yield of pretreated elephant grass was 3.......5 times that of the untreated material, while the ethanol yield was nearly 2 times higher. Moreover, the sugar released by the elephant grass (30.8 g/100 g TS) was only slightly lower than by the wheat straw (33.1 g/100 g TS), while the ethanol yield (16.1 g/100 g TS) was higher than that of the straw (15...

  1. 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

  2. Effect of acetic acid in recycling water on ethanol production for cassava in an integrated ethanol-methane fermentation process.

    Science.gov (United States)

    Yang, Xinchao; Wang, Ke; Zhang, Jianhua; Tang, Lei; Mao, Zhonggui

    2016-11-01

    Recently, the integrated ethanol-methane fermentation process has been studied to prevent wastewater pollution. However, when the anaerobic digestion reaction runs poorly, acetic acid will accumulate in the recycling water. In this paper, we studied the effect of low concentration of acetic acid (≤25 mM) on ethanol fermentation at different initial pH values (4.2, 5.2 or 6.2). At an initial pH of 4.2, ethanol yields increased by 3.0% and glycerol yields decreased by 33.6% as the acetic acid concentration was increased from 0 to 25 mM. Raising the concentration of acetic acid to 25 mM increased the buffering capacity of the medium without obvious effects on biomass production in the cassava medium. Acetic acid was metabolized by Saccharomyces cerevisiae for the reason that the final concentration of acetic acid was 38.17% lower than initial concentration at pH 5.2 when 25 mM acetic acid was added. These results confirmed that a low concentration of acetic acid in the process stimulated ethanol fermentation. Thus, reducing the acetic acid concentration to a controlled low level is more advantageous than completely removing it.

  3. 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.

  4. 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.

  5. Stillage reflux in food waste ethanol fermentation and its by-product accumulation.

    Science.gov (United States)

    Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Tashiro, Yukihiro; Sonomoto, Kenji

    2016-06-01

    Raw materials and pollution control are key issues for the ethanol fermentation industry. To address these concerns, food waste was selected as fermentation substrate, and stillage reflux was carried out in this study. Reflux was used seven times during fermentation. Corresponding ethanol and reducing sugar were detected. Accumulation of by-products, such as organic acid, sodium chloride, and glycerol, was investigated. Lactic acid was observed to accumulate up to 120g/L, and sodium chloride reached 0.14mol/L. Other by-products did not accumulate. The first five cycles of reflux increased ethanol concentration, which prolonged fermentation time. Further increases in reflux time negatively influenced ethanol fermentation. Single-factor analysis with lactic acid and sodium chloride demonstrated that both factors affected ethanol fermentation, but lactic acid induced more effects.

  6. 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.

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

    Science.gov (United States)

    Dogaris, Ioannis; Mamma, Diomi; Kekos, Dimitris

    2013-02-01

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

  8. Effect of crude glycerol-derived inhibitors on ethanol production by Enterobacter aerogenes.

    Science.gov (United States)

    Lee, Sang Jun; Kim, Sung Bong; Kang, Seong Woo; Han, Sung Ok; Park, Chulhwan; Kim, Seung Wook

    2012-01-01

    In this study, ethanol production from pure and crude glycerol using Enterobacter aerogenes ATCC 29007 was evaluated under anaerobic culture conditions. Inhibitory effects of substrate concentrations, pH, and salt concentrations were investigated based on crude glycerol components. Ethanol production was performed with pure glycerol concentrations ranging from 5 to 30 g/L to evaluate the effects of substrate concentration and osmotic pressure. The consumed glycerol was 5-14.33 g/L, and the yield of ethanol was higher than 0.75 mol ethanol/mol glycerol after 24 h of cultivation. To evaluate the inhibitory effects of salts (NaCl and KCl), experiments were performed with 0-20 g/L of each salt. Inhibitory effects of salts were strongest at high salt concentrations. The inhibitory effect of pH was performed in the pH range 4-10, and cell growth and ethanol production were highest at pH 5-6. Also, ethanol production was slightly inhibited at low concentration of crude glycerol comparison with pure glycerol. However, significant inhibitory effects were not observed at 1.5 and 2% crude glycerol which showed higher ethanol production compared to pure glycerol.

  9. Ethanol Production from High Solids Loading of Alkali-Pretreated Sugarcane Bagasse with an SSF Process

    Directory of Open Access Journals (Sweden)

    Yueshu Gao

    2014-04-01

    Full Text Available A fed-batch process and high-temperature simultaneous saccharification and fermentation (SSF process were investigated to obtain high sugar yield and ethanol concentration. Different amounts of alkali-pretreated sugarcane bagasse were added during the first 24 h. For the highest final dry matter (DM content of 25% (w/v, a maximal glucose and total sugar concentration of 79.53 g/L and 135.39 g/L, respectively, were achieved with 8.3 FPU/g substrate after 120 h of hydrolysis. Based on the hydrolysis experiment, two processes for ethanol production from sugarcane bagasse, simultaneous saccharification and fermentation (SSF and separate hydrolysis and fermentation (SHF, were also compared using S. cerevisiae. The results indicated that ethanol concentration and yield in the SHF were higher, while ethanol productivity (gram per unit volume and over time was lower. For 25% substrate loading, the ethanol productivity and ethanol concentration could reach 0.38 g.L-1.h-1 and 36.25 g/L SSF in 96 h, respectively, while that of SHF could reach 0.32 g.L-1.h-1, with an ethanol concentration of 47.95 g/L in 152 h for SHF. When high-temperature simultaneous saccharification and fermentation (SSF process was performed by using Kluyveromyces marxianus NCYC 587 at 42 °C, 42.21 g/L ethanol (with an ethanol productivity of 0.44 g.L-1.h-1 was produced with 25% dry matter content and 8.3 FPU cellulase/g substrate, which meant 16.4% more ethanol when compared with SSF of S. cerevisiae.

  10. Effect of controlled oxygen limitation on Candida shehatae physiology for ethanol production from xylose and glucose.

    Science.gov (United States)

    Fromanger, Romain; Guillouet, S E; Uribelarrea, J L; Molina-Jouve, C; Cameleyre, X

    2010-05-01

    Carbon distribution and kinetics of Candida shehatae were studied in fed-batch fermentation with xylose or glucose (separately) as the carbon source in mineral medium. The fermentations were carried out in two phases, an aerobic phase dedicated to growth followed by an oxygen limitation phase dedicated to ethanol production. Oxygen limitation was quantified with an average specific oxygen uptake rate (OUR) varying between 0.30 and 2.48 mmolO(2) g dry cell weight (DCW)(-1) h(-1), the maximum value before the aerobic shift. The relations among respiration, growth, ethanol production and polyol production were investigated. It appeared that ethanol was produced to provide energy, and polyols (arabitol, ribitol, glycerol and xylitol) were produced to reoxidize NADH from assimilatory reactions and from the co-factor imbalance of the two-first enzymatic steps of xylose uptake. Hence, to manage carbon flux to ethanol production, oxygen limitation was a major controlled parameter; an oxygen limitation corresponding to an average specific OUR of 1.19 mmolO(2) g DCW(-1) h(-1) allowed maximization of the ethanol yield over xylose (0.327 g g(-1)), the average productivity (2.2 g l(-1) h(-1)) and the ethanol final titer (48.81 g l(-1)). For glucose fermentation, the ethanol yield over glucose was the highest (0.411 g g(-1)) when the specific OUR was low, corresponding to an average specific OUR of 0.30 mmolO(2) g DCW(-1) h(-1), whereas the average ethanol productivity and ethanol final titer reached the maximum values of 1.81 g l(-1) h(-1) and 54.19 g l(-1) when the specific OUR was the highest.

  11. 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

  12. Development of High-Productivity Continuous Ethanol Production using PVA-Immobilized Zymomonas mobilis in an Immobilized-Cells Fermenter

    Directory of Open Access Journals (Sweden)

    Nurhayati Nurhayati

    2015-07-01

    Full Text Available Ethanol as one of renewable energy was being considered an excellent alternative clean-burning fuel to replace gasoline. Continuous ethanol fermentation systems had offered important economic advantages compared to traditional systems. Fermentation rates were significantly improved, especially when continuous fermentation was integrated with cell immobilization techniques to enrich the cells concentration in fermentor. Growing cells of Zymomonas mobilis immobilized in polyvinyl alcohol (PVA gel beads were employed in an immobilized-cells fermentor for continuous ethanol fermentation from glucose. The glucose loading, dilution rate, and cells loading were varied in order to determine which best condition employed in obtaining both high ethanol production and low residual glucose with high dilution rate. In this study, 20 g/L, 100 g/L, 125 g/L and 150 g/L of glucose concentration and 20% (w/v, 40% (w/v and 50% (w/v of cells loading were employed with range of dilution rate at 0.25 to 1 h-1. The most stable production was obtained for 25 days by employing 100 g/L of glucose loading. Meanwhile, the results also exhibited that 125 g/L of glucose loading as well as 40% (w/v of cells loading yielded high ethanol concentration, high ethanol productivity, and acceptable residual glucose at 62.97 g/L, 15.74 g/L/h and 0.16 g/L, respectively. Furthermore, the dilution rate of 4 hour with 100 g/L and 40% (w/v of glucose and cells loading was considered as the optimum condition with ethanol production, ethanol productivity and residual glucose obtained were 49.89 g/L, 12.47 g/L/h, and 2.04 g/L, respectively. This recent study investigated ethanol inhibition as well. The present research had proved that high sugar concentration was successfully converted to ethanol. These achieved results were promising for further study.

  13. Evaluation of potential salivary acetaldehyde production from ethanol in oral cancer patients and healthy subjects

    National Research Council Canada - National Science Library

    Kocaelli, H; Apaydin, A; Aydil, B; Ayhan, M; Karadeniz, A; Ozel, S; Yılmaz, E; Akgün, B; Eren, B

    2014-01-01

    .... In this study, saliva samples from oral cancer patients and healthy individuals were incubated in vitro with ethanol in order to investigate factors which can influence salivary acetaldehyde production...

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  15. Ethanol production from steam exploded rapeseed straw and the process simulation using artificial neural networks

    DEFF Research Database (Denmark)

    Talebnia, Farid; Mighani, Moein; Rahimnejad, Mostafa

    2015-01-01

    Rapeseed straw was utilized as a cheap raw material for ethanol production. Effects of steam explosion on chemical composition, enzymatic hydrolysis (EH) and simultaneous saccharification and fermentation (SSF) were studied. Changes in the pretreatment conditions showed strong effects...

  16. CONTINUOUS PRODUCTION OF ETHANOL IN BED PACKED BIOREACTORS WITH IMMOBILIZED YEAST CELLS ON LIGNOCELLULOSIC WASTE

    National Research Council Canada - National Science Library

    LINA MARÍA AGUDELO ESCOBAR; URIEL SALAZAR ÁLVAREZ; MARIANA PEÑUELA

    2012-01-01

    .... In this work, we evaluated the continuous production of ethanol in bed packed reactors with yeast cells immobilized on lignocellulosic waste of wood shaving, cane bagasse, corn leave and corn cob...

  17. Improving Saccharomyces cerevisiae ethanol production and tolerance via RNA polymerase II subunit Rpb7.

    Science.gov (United States)

    Qiu, Zilong; Jiang, Rongrong

    2017-01-01

    Classical strain engineering methods often have limitations in altering multigenetic cellular phenotypes. Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II), which plays a central role in synthesizing mRNAs. This is the first report on using directed evolution method to engineer RNAP II to alter S. cerevisiae strain phenotypes. Error-prone PCR was employed to engineer the subunit Rpb7 of RNAP II to improve yeast ethanol tolerance and production. Based on previous studies and the presumption that improved ethanol resistance would lead to enhanced ethanol production, we first isolated variant M1 with much improved resistance towards 8 and 10% ethanol. The ethanol titers of M1 was ~122 g/L (96.58% of the theoretical yield) under laboratory very high gravity (VHG) fermentation, 40% increase as compared to the control. DNA microarray assay showed that 369 genes had differential expression in M1 after 12 h VHG fermentation, which are involved in glycolysis, alcoholic fermentation, oxidative stress response, etc. This is the first study to demonstrate the possibility of engineering eukaryotic RNAP to alter global transcription profile and improve strain phenotypes. Targeting subunit Rpb7 of RNAP II was able to bring differential expression in hundreds of genes in S. cerevisiae, which finally led to improvement in yeast ethanol tolerance and production.

  18. Increased ethanol production by deletion of HAP4 in recombinant xylose-assimilating Saccharomyces cerevisiae.

    Science.gov (United States)

    Matsushika, Akinori; Hoshino, Tamotsu

    2015-12-01

    The Saccharomyces cerevisiae HAP4 gene encodes a transcription activator that plays a key role in controlling the expression of genes involved in mitochondrial respiration and reductive pathways. This work examines the effect of knockout of the HAP4 gene on aerobic ethanol production in a xylose-utilizing S. cerevisiae strain. A hap4-deleted recombinant yeast strain (B42-DHAP4) showed increased maximum concentration, production rate, and yield of ethanol compared with the reference strain MA-B42, irrespective of cultivation medium (glucose, xylose, or glucose/xylose mixtures). Notably, B42-DHAP4 was capable of producing ethanol from xylose as the sole carbon source under aerobic conditions, whereas no ethanol was produced by MA-B42. Moreover, the rate of ethanol production and ethanol yield (0.44 g/g) from the detoxified hydrolysate of wood chips was markedly improved in B42-DHAP4 compared to MA-B42. Thus, the results of this study support the view that deleting HAP4 in xylose-utilizing S. cerevisiae strains represents a useful strategy in ethanol production processes.

  19. 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.

  20. 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

  1. Fuel ethanol production from lignocellulose: a challenge for metabolic engineering and process integration

    DEFF Research Database (Denmark)

    Zaldivar, Jesus; Nielsen, Jens; Olsson, Lisbeth

    2001-01-01

    With industrial development growing rapidly, there is a need for environmentally sustainable energy sources. Bioethanol (ethanol from biomass) is an attractive, sustainable energy source to fuel transportation. Based on the premise that fuel bioethanol can contribute to a cleaner environment...... and with the implementation of environmental protection laws in many countries, demand for this fuel is increasing. Efficient ethanol production processes and cheap substrates are needed. Current ethanol production processes using crops such as sugar cane and corn are well-established; however, utilization of a cheaper...

  2. Steam Explosion Pretreatment of Cotton Gin Waste for Fuel Ethanol Production

    OpenAIRE

    Jeoh, Tina

    1998-01-01

    Steam Explosion Pretreatment of Cotton Gin Waste for Ethanol Production By Tina Jeoh Foster A. Agblevor, Chair Biological Systems Engineering ABSTRACT The current research investigates the utilization of cotton gin waste as a feedstock to produce a value-added product - fuel ethanol. Cotton gin waste consists of pieces of burs, stems, motes (immature seeds) and cotton fiber, and is considered to be a lignocellulosic material. The three main chemical constituents are ce...

  3. Pretreatment of empty fruit bunch from oil palm for fuel ethanol production and proposed biorefinery process.

    Science.gov (United States)

    Tan, Liping; Yu, Yongcheng; Li, Xuezhi; Zhao, Jian; Qu, Yinbo; Choo, Yuen May; Loh, Soh Kheang

    2013-05-01

    This study evaluates the effects of some pretreatment processes to improve the enzymatic hydrolysis of oil palm empty fruit bunch (EFB) for ethanol production. The experimental results show that the bisulfite pretreatment was practical for EFB pretreatment. Moreover, the optimum pretreatment conditions of the bisulfite pretreatment (180 °C, 30 min, 8% NaHSO3, 1% H2SO4) were identified. In the experiments, a biorefinery process of EFB was proposed to produce ethanol, xylose products, and lignosulfonates.

  4. Comparison of several ethanol productions using xylanase, inorganic salts, surfactant

    Science.gov (United States)

    Wu, Yan; Lu, Jie; Yang, Rui-feng; Song, Wen-jing; Li, Hai-ming; Wang, Hai-song; Zhou, Jing-hui

    2017-03-01

    Liquid hot water (LHW) pretreatment is an effective and environmentally friendly method to produce bioethanol with lignocellulosic materials. Corn stover was pretreated with liquid hot water (LHW) and then subjected to semi-simultaneous saccharification and fermentation (S-SSF) to obtain high ethanol concentration and yield. The present study aimed to confirm the effect of several additives on the fermentation digestibility of unwashed WIS of corn stover pretreated with LHW. So we also investigated the process, such as enzyme addition, inorganic salts, surfactant and different loading Triton. Results show that high ethanol concentration is necessary to add xylanase in the stage of saccharification. The ethanol concentration increased mainly with magnesium ion on fermentation. Comparing with Tween 80, Span 80 and Polyethylene glycol, Triton is the best surfactant. In contrast to using xylanase and Triton respectively, optimization can make up the lack of stamina and improve effect of single inorganic salts.

  5. Ultrasound-assisted production of biodiesel and ethanol from spent coffee grounds.

    Science.gov (United States)

    Rocha, Maria Valderez Ponte; de Matos, Leonardo José Brandão Lima; Lima, Larissa Pinto de; Figueiredo, Pablo Marciano da Silva; Lucena, Izabelly Larissa; Fernandes, Fabiano André Narciso; Gonçalves, Luciana Rocha Barros

    2014-09-01

    This study evaluates the production of biodiesel and ethanol from spent coffee grounds (SCG). The extraction of oil from SCG, biodiesel production and ethanol production processes were studied. The liquid-to-solid ratio and temperature were evaluated in the ultrasound-assisted extraction of the oil from SCG. The highest yield (12%) was obtained using 4 mL g(-1) liquid-to-solid ratio at 60°C for 45 min. The process to produce biodiesel showed a yield of 97% into fatty acid methyl esters (FAME). The highest glucose yield (192 mg g SCG(-1)) was obtained by hydrolysis with 0.4 mol L(-1) sulfuric acid at 121°C for 15 min. The hydrolysate was used as fermentation medium for ethanol production by Saccharomyces cerevisiae obtaining 19.0 g L(-1) at 10h of process of ethanol with a yield of ethanol and productivity of 0.50 g g(-1) and 1.90 g L(-1)h(-1), respectively. Spent coffee grounds were considered a potential feedstock for biodiesel and ethanol production.

  6. Ethanol production from industrial hemp: effect of combined dilute acid/steam pretreatment and economic aspects.

    Science.gov (United States)

    Kuglarz, Mariusz; Gunnarsson, Ingólfur B; Svensson, Sven-Erik; Prade, Thomas; Johansson, Eva; Angelidaki, Irini

    2014-07-01

    In the present study, combined steam (140-180°C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis and ethanol yields was also evaluated. Pretreatment with 1% sulfuric acid at 180°C resulted in the highest glucose yield (73-74%) and ethanol yield of 75-79% (0.38-0.40 g-ethanol/g-glucose). Taking into account the costs of biomass processing, from field to ethanol facility storage, the field-dried hemp pretreated at the optimal conditions showed positive economic results. The type of hemp cultivation (organic or conventional) did not influence significantly the effectiveness of the pretreatment as well as subsequent enzymatic hydrolysis and ethanol fermentation.

  7. Disruption of ubiquitin-related genes in laboratory yeast strains enhances ethanol production during sake brewing.

    Science.gov (United States)

    Wu, Hong; Watanabe, Tomoko; Araki, Yoshio; Kitagaki, Hiroshi; Akao, Takeshi; Takagi, Hiroshi; Shimoi, Hitoshi

    2009-06-01

    Sake yeast can produce high levels of ethanol in concentrated rice mash. While both sake and laboratory yeast strains belong to the species Saccharomyces cerevisiae, the laboratory strains produce much less ethanol. This disparity in fermentation activity may be due to the strains' different responses to environmental stresses, including ethanol accumulation. To obtain more insight into the stress response of yeast cells under sake brewing conditions, we carried out small-scale sake brewing tests using laboratory yeast strains disrupted in specific stress-related genes. Surprisingly, yeast strains with disrupted ubiquitin-related genes produced more ethanol than the parental strain during sake brewing. The elevated fermentation ability conferred by disruption of the ubiquitin-coding gene UBI4 was confined to laboratory strains, and the ubi4 disruptant of a sake yeast strain did not demonstrate a comparable increase in ethanol production. These findings suggest different roles for ubiquitin in sake and laboratory yeast strains.

  8. Ethanol from sugar cane with simultaneous production of electrical energy and biofertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Filgueiras, G.

    1981-08-04

    A flexible nonpolluting industrial scheme is described for converting sugar cane into fuel-grade ethanol, fertilizer, and electric power. The cleaned cane is treated in a diffuser to separate the juice, which is enzymically hydrolyze d to ethanol, and bagasse containing 65-85% moisture, which is mechanically ground with the rest of the cane plant (leaves and buds) and biochemically digested to provide liquid and solid fertilizers as well as a methane-containing gas, which is burned in a gas turbine to generate electricity. The vinasse from the ethanol fermentation is also cycled to the digestion step. The process conditions can be varied depending upon the desired product ratio; if fuel is preferred, each ton of cane (dry weight) can produce 135 L ethanol, 50 kW electric power, and 150 kg fertilizer; if electric energy is preferred, each ton can give 75 L ethanol, 115 kW power, and 220 kg fertilizer.

  9. 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.

  10. Ethanol production from the enzymatic hydrolysis of non-detoxified steam-exploded corn stalk.

    Science.gov (United States)

    Yang, Xiushan; Zhang, Sijin; Zuo, Zhuang; Men, Xun; Tian, Shen

    2011-09-01

    To reduce water consumption and equipment investment, and simplify the technological process, a Pichia stipitis-adapted strain with improved tolerance against inhibitors and ethanol was used in ethanol production. The steam-exploded corn stalk was directly enzymatically hydrolyzed without detoxification, and then the enzymatic hydrolysate was used as the fermentation substrate. Results from laboratory experiments in shake flasks and fermentation tanks indicated that, after fermentation for 48 h, ethanol concentration reached to 43.42 g/L; the ethanol yield was 0.47 g(p)/g(s), which was 92.16% of the theoretical ethanol yield. The results of the present research demonstrated that the application of this strain avoided detoxification of the steam-pretreated material through washing, thus simplifying the technological process. In addition, the application of the adapted strain reduced water consumption and lowered the equipment investment of ethanol production from corn stalk, which are important factors in further promotion of the development of ethanol production from straw.

  11. 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.

  12. Continuous ethanol production from Jerusalem artichokes stalks using immobilized cells of Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Bajpai, P.; Margaritis, A.

    1986-01-01

    Continuous production of ethanol from the extract of Jerusalem artichoke stalks was investigated in a packed bed bioreactor using Kluyveromyces marxianus cells immobilized in calcium alginate gel beds. Maximum conversion of the sugars to ethanol was achieved with a yield of about 98% of the theoretical. Volumetric ethanol productivities of 102 grams of ethanol per litre per hour and 92 grams ethanol per liter per hour were obtained at 87% and 90% conversion respectively for an inlet substrate concentration of 100 gram sugars per liter. The maximum specific ethanol production rate and maximum specific total sugar uptake rate of the immobilized cells were found to be 0.96 gram ethanol per gram immobilized cells per hour and 2.06 gram sugars per gram immobilized cells per hour respectively. The immobilized cell bioreactor was run continuously at a dilution rate of 2.12 per hour for 30 days which resulted in a loss of 30% of the original activity. The half life of the bioreactor was estimated to be about 56 days.

  13. Assessment of potential life-cycle energy and greenhouse gas emission effects from using corn-based butanol as a transportation fuel.

    Science.gov (United States)

    Wu, May; Wang, Michael; Liu, Jiahong; Huo, Hong

    2008-01-01

    Since advances in the ABE (acetone-butanol-ethanol) fermentation process in recent years have led to significant increases in its productivity and yields, the production of butanol and its use in motor vehicles have become an option worth evaluating. This study estimates the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. It employs a well-to-wheels (WTW) analysis tool: the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The estimates of life-cycle energy use and greenhouse gas (GHG) emissions are based on an Aspen Plus(R) simulation for a corn-to-butanol production process, which describes grain processing, fermentation, and product separation. Bio-butanol-related WTW activities include corn farming, corn transportation, butanol production, butanol transportation, and vehicle operation. In this study, we also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. We then compared the results for bio-butanol with those of conventional gasoline. Our study shows that driving vehicles fueled with corn-based butanol produced by the current ABE fermentation process could result in substantial fossil energy savings (39%-56%) and avoid large percentage of the GHG emission burden, yielding a 32%-48% reduction relative to using conventional gasoline. On energy basis, a bushel of corn produces less liquid fuel from the ABE process than that from the corn ethanol dry mill process. The coproduction of a significant portion of acetone from the current ABE fermentation presents a challenge. A market analysis of acetone, as well as research and development on robust alternative technologies and processes that minimize acetone while increase the butanol yield, should be conducted.

  14. Continuous Ethanol Production Using Immobilized-Cell/Enzyme Biocatalysts in Fluidized-Bed Bioreactor (FBR)

    Energy Technology Data Exchange (ETDEWEB)

    Nghiem, NP

    2003-11-16

    The immobilized-cell fluidized-bed bioreactor (FBR) was developed at Oak Ridge National Laboratory (ORNL). Previous studies at ORNL using immobilized Zymomonas mobilis in FBR at both laboratory and demonstration scale (4-in-ID by 20-ft-tall) have shown that the system was more than 50 times as productive as industrial benchmarks (batch and fed-batch free cell fermentations for ethanol production from glucose). Economic analysis showed that a continuous process employing the FBR technology to produce ethanol from corn-derived glucose would offer savings of three to six cents per gallon of ethanol compared to a typical batch process. The application of the FBR technology for ethanol production was extended to investigate more complex feedstocks, which included starch and lignocellulosic-derived mixed sugars. Economic analysis and mathematical modeling of the reactor were included in the investigation. This report summarizes the results of these extensive studies.

  15. Effect of acid pretreatment on different parts of corn stalk for second generation ethanol production.

    Science.gov (United States)

    Li, Ping; Cai, Di; Luo, Zhangfeng; Qin, Peiyong; Chen, Changjing; Wang, Yong; Zhang, Changwei; Wang, Zheng; Tan, Tianwei

    2016-04-01

    In this study, the effects of different parts of corn stalk, including stem, leaf, flower, cob and husk on second generation ethanol production were evaluated. FTIR, XRD and SEM were performed to investigate the effect of dilute acid pretreatment. The bagasse obtained after pretreatment were further hydrolyzed by cellulase and used as the substrate for ethanol fermentation. As results, hemicelluloses fractions in different parts of corn stalk were dramatically removed and the solid fractions showed vivid compositions and crystallinities. Compared with other parts of corn stalk, the cob had higher sugar content and better enzymatic digestibility. The highest glucose yield of 94.2% and ethanol production of 24.0 g L(-1) were achieved when the cob was used as feedstock, while the glucose yield and the ethanol production were only 86.0% and 17.1 g L(-1) in the case of flower.

  16. 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.

  17. Life cycle assessment of the production of ethanol from eastern redcedar.

    Science.gov (United States)

    Olukoya, Ife A; Ramachandriya, Karthikeyan D; Wilkins, Mark R; Aichele, Clint P

    2014-12-01

    This life cycle assessment (LCA) evaluates the environmental impacts of an ethanol production system using eastern redcedar (Juniperus virginiana L.) as the feedstock. Aspen Plus® was used to model the acid bisulfite pretreatment, enzymatic hydrolysis, fermentation, and distillation steps. A cradle-to-gate LCA was conducted to evaluate the environmental impacts from cutting the trees to the production of anhydrous ethanol. The environmental impacts of the redcedar ethanol process were compared to those from the production of corn ethanol. Inventory data for the system were collected and used to calculate a life cycle impact assessment (LCIA) using the IMPACT 2002+ and BEES+ framework in SimaPro 8.0.0. Four impact categories were evaluated: land occupation, water use, greenhouse gas (GHG) emissions, and non-renewable energy use. Results indicate that acid bisulfite pretreatment contributed to 65% of GHG emissions, 81% of non-renewable energy use, and 77% of water use of the overall process.

  18. Kinetics of ethanol production from Jerusalem artichoke juice with some Kluyveromyces species

    Energy Technology Data Exchange (ETDEWEB)

    Kuvnjak, Z.; Kosaric, N.; Hayes, R.D.

    1981-01-01

    The kinetics of ethanol production by Kluyveromyces marxianus ATCC 12708 and ATCC 10606, K. cicerisporus ATCC 22295 and K. fragilis 105 were studied using raw juice of the Jerusalem artichoke in which the carbohydrates were not hydrolyzed prior to fermentation. This juice contains enough nutrients and can serve as a complete medium without additional nutrients both for growth of the yeasts and for ethanol production. Both specific ethanol productivity and specific glucose uptake rates were the highest with K. marxianus ATCC 12708 (1.68 gg-1 h-1 and 3.78 gg-1h-1, respectively). This microorganism produced an ethanol yield of 87.5% of the theoretical value in 25 hours.

  19. Ethanol production from food waste at high solids content with vacuum recovery technology.

    Science.gov (United States)

    Huang, Haibo; Qureshi, Nasib; Chen, Ming-Hsu; Liu, Wei; Singh, Vijay

    2015-03-18

    Ethanol production from food wastes does not only solve environmental issues but also provides renewable biofuels. This study investigated the feasibility of producing ethanol from food wastes at high solids content (35%, w/w). A vacuum recovery system was developed and applied to remove ethanol from fermentation broth to reduce yeast ethanol inhibition. A high concentration of ethanol (144 g/L) was produced by the conventional fermentation of food waste without a vacuum recovery system. When the vacuum recovery is applied to the fermentation process, the ethanol concentration in the fermentation broth was controlled below 100 g/L, thus reducing yeast ethanol inhibition. At the end of the conventional fermentation, the residual glucose in the fermentation broth was 5.7 g/L, indicating incomplete utilization of glucose, while the vacuum fermentation allowed for complete utilization of glucose. The ethanol yield for the vacuum fermentation was found to be 358 g/kg of food waste (dry basis), higher than that for the conventional fermentation at 327 g/kg of food waste (dry basis).

  20. Ethanol production from Jerusalem artichoke tubers (Helianthus tuberosus) using Kluyveromyces marxianus and Saccharomyces rosei

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.

    1982-04-01

    This article examines the potential of Jerusalem artichoke as a source for ethanol and single-cell protein SCP. In addition, experimental results are presented on batch fermentation kinetics employing two strains of Kluyveromyces marxianus and one strain of Saccharomyces rosei grown in the extract derived from the tubers of Jeusalem artichoke. Of the three cultures examined, Kluyveromyces marxianus UCD (EST) 55-82 was found to be the best producer of ethanol grown in a simple medium at 35/sup 0/C. The ethanol production was found to be growth-associated haveing a ..mu../sub max/ = 0.41 h/sup -1/ and the ethanol and biomass yields were determined to be Y/sub p///sub = 0.45 (88% of the theoretical) and Y/sub x///sub s/ = 0.04 with 92% of the original sugars utilized. On the basis of carbohydrate yields of Jerusalem artichoke reported in the literature and these batch kinetic studies with K. marxianus, the calculated ethanol yields were found to range from 1400 kg ethanol acre/sup -1/ yr /sup -1/ to a maximum of 2700 kg ethanol acre/sup -1/ yr/sup -1/. The SCP yields for K. marxianus were calculated to range between 130 to 250 kg dry wt cell acre/sup -1/ yr/sup -1/. The potential for developing an integrated process to produce ethanol and SCP is also discussed.

  1. Ethanol production from Jerusalem artichoke tubers (Helianthus tuberosus). Using Kluyveromyces marxcianus and Saccharomyces rosei

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.

    1982-04-01

    This article examines the potential of Jerusalem artichoke as a source for ethanol and single-cell protein SCP. In addition, experimental results are presented on batch fermentation kinetics employing two strains of Kluyveromyces marxianus and one strain of Saccharomyces rosei grown on the extract derived from the tubers of Jerusalem artichoke. Of the three cultures examined, Kluyveromyces marxianus UCD (FST) 55-82 was found to be the best producer of ethanol grown in a simple medium at 35 degrees C. The ethanol production was found to be growth-associated having a mu max = 0.41/h and the ethanol and biomass yields were determined to be Y p/s = 0.45 (88% of the theoretical) and Y x/s = 0.04 with 92% of the original sugars utilized. On the basis of carbohydrate yields of Jerusalem artichoke reported in the literature and these batch kinetic studies with Kluyveromyces marxianus, the calculated ethanol yields were found to range from 1400 kg ethanol/acre/yr to a maximum of 2700 kg ethanol/acre/yr. The SCP yields for Kluyveromyces marxianus were calculated to range between 130 to 250 kg dry wt cell/acre/yr. The potential for developing an integrated process to produce ethanol and SCP is also discussed. (Refs. 27).

  2. Presence and biological activity of antibiotics used in fuel ethanol and corn co-product production.

    Science.gov (United States)

    Compart, D M Paulus; Carlson, A M; Crawford, G I; Fink, R C; Diez-Gonzalez, F; Dicostanzo, A; Shurson, G C

    2013-05-01

    Antibiotics are used in ethanol production to control bacteria from competing with yeast for nutrients during starch fermentation. However, there is no published scientific information on whether antibiotic residues are present in distillers grains (DG), co-products from ethanol production, or whether they retain their biological activity. Therefore, the objectives of this study were to quantify concentrations of various antibiotic residues in DG and determine whether residues were biologically active. Twenty distillers wet grains and 20 distillers dried grains samples were collected quarterly from 9 states and 43 ethanol plants in the United States. Samples were analyzed for DM, CP, NDF, crude fat, S, P, and pH to describe the nutritional characteristics of the samples evaluated. Samples were also analyzed for the presence of erythromycin, penicillin G, tetracycline, tylosin, and virginiamycin M1, using liquid chromatography and mass spectrometry. Additionally, virginiamycin residues were determined, using a U.S. Food and Drug Administration-approved bioassay method. Samples were extracted and further analyzed for biological activity by exposing the sample extracts to 10(4) to 10(7) CFU/mL concentrations of sentinel bacterial strains Escherichia coli ATCC 8739 and Listeria monocytogenes ATCC 19115. Extracts that inhibited bacterial growth were considered to have biological activity. Physiochemical characteristics varied among samples but were consistent with previous findings. Thirteen percent of all samples contained low (≤1.12 mg/kg) antibiotic concentrations. Only 1 sample extract inhibited growth of Escherichia coli at 10(4) CFU/mL, but this sample contained no detectable concentrations of antibiotic residues. No extracts inhibited Listeria monocytogenes growth. These data indicate that the likelihood of detectable concentrations of antibiotic residues in DG is low; and if detected, they are found in very low concentrations. The inhibition in only 1 DG

  3. Ethanol-induced yeast flocculation directed by the promoter of TPS1 encoding trehalose-6-phosphate synthase 1 for efficient ethanol production.

    Science.gov (United States)

    Li, Qian; Zhao, Xin-Qing; Chang, Alan K; Zhang, Qiu-Mei; Bai, Feng-Wu

    2012-01-01

    Yeast flocculation is an important trait in the brewing industry as well as in ethanol production, through which biomass can be recovered by cost-effective sedimentation. However, mass transfer limitation may affect yeast growth and ethanol fermentation if the flocculation occurs earlier before fermentation is completed. In this article, a novel type of cell-cell flocculation induced by trehalose-6-phosphate synthase 1 (TPS1) promoter was presented. The linear cassette HO-P(TPS1)-FLO1(SPSC01)-KanMX4-HO was constructed to transform the non-flocculating industrial yeast S. cerevisiae 4126 by chromosome integration to obtain a new flocculating yeast strain, ZLH01, whose flocculation was induced by ethanol produced during fermentation. The experimental results illustrated that flocculation of ZLH01 was triggered by 3% (v/v) ethanol and enhanced as ethanol concentration increased till complete flocculation was achieved at ethanol concentration of 8% (v/v). Real time PCR analysis confirmed that the expression of FLO1(SPSC01) was dependent on ethanol concentration. The growth and ethanol fermentation of ZLH01 were improved significantly, compared with the constitutive flocculating yeast BHL01 engineered with the same FLO gene but directed by the constitutive 3-phosphoglycerate kinase promoter PGK1, particularly under high temperature conditions. These characteristics make the engineered yeast more suitable for ethanol production from industrial substrates under high gravity and temperature conditions. In addition, this strategy offers advantage in inducing differential expression of other genes for metabolic engineering applications of S. cerevisiae.

  4. Dekkera bruxellensis and Lactobacillus vini Form a Stable Ethanol-Producing Consortium in a Commercial Alcohol Production Process▿

    Science.gov (United States)

    Passoth, Volkmar; Blomqvist, Johanna; Schnürer, Johan

    2007-01-01

    The ethanol production process of a Swedish alcohol production plant was dominated by Dekkera bruxellensis and Lactobacillus vini, with a high number of lactic acid bacteria. The product quality, process productivity, and stability were high; thus, D. bruxellensis and L. vini can be regarded as commercial ethanol production organisms. PMID:17483277

  5. Dekkera bruxellensis and Lactobacillus vini form a stable ethanol-producing consortium in a commercial alcohol production process.

    Science.gov (United States)

    Passoth, Volkmar; Blomqvist, Johanna; Schnürer, Johan

    2007-07-01

    The ethanol production process of a Swedish alcohol production plant was dominated by Dekkera bruxellensis and Lactobacillus vini, with a high number of lactic acid bacteria. The product quality, process productivity, and stability were high; thus, D. bruxellensis and L. vini can be regarded as commercial ethanol production organisms.

  6. Dekkera bruxellensis and Lactobacillus vini Form a Stable Ethanol-Producing Consortium in a Commercial Alcohol Production Process▿

    OpenAIRE

    Passoth, Volkmar; Blomqvist, Johanna; Schnürer, Johan

    2007-01-01

    The ethanol production process of a Swedish alcohol production plant was dominated by Dekkera bruxellensis and Lactobacillus vini, with a high number of lactic acid bacteria. The product quality, process productivity, and stability were high; thus, D. bruxellensis and L. vini can be regarded as commercial ethanol production organisms.

  7. Ethanol production from biomass by repetitive solid-state fed-batch fermentation with continuous recovery of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Moukamnerd, Churairat; Kino-oka, Masahiro; Sugiyama, Minetaka; Kaneko, Yoshinobu; Harashima, Satoshi; Katakura, Yoshio [Osaka Univ. (Japan). Dept. of Biotechnology; Boonchird, Chuenchit [Mahidol Univ., Bangkok (Thailand). Dept. of Biotechnology; Noda, Hideo [Kansai Chemical Engineering Co., Ltd., Amagasaki (Japan); Ninomiya, Kazuaki [Kanazawa Univ. (Japan). Inst. of International Environment Technology; Shioya, Suteaki [Sojo Univ., Kumamoto (Japan). Dept. of Applied Life Science

    2010-09-15

    To save cost and input energy for bioethanol production, a consolidated continuous solid-state fermentation system composed of a rotating drum reactor, a humidifier, and a condenser was developed. Biomass, saccharifying enzymes, yeast, and a minimum amount of water are introduced into the system. Ethanol produced by simultaneous saccharification and fermentation is continuously recovered as vapor from the headspace of the reactor, while the humidifier compensates for the water loss. From raw corn starch as a biomass model, 95 {+-} 3, 226 {+-} 9, 458 {+-} 26, and 509 {+-} 64 g l{sup -1} of ethanol solutions were recovered continuously when the ethanol content in reactor was controlled at 10-20, 30-50, 50-70 and 75-85 g kg-mixture{sup -1}, respectively. The residue showed a lesser volume and higher solid content than that obtained by conventional liquid fermentation. The cost and energy for intensive waste water treatment are decreased, and the continuous fermentation enabled the sustainability of enzyme activity and yeast in the system. (orig.)

  8. Production of ethanol from refinery waste gases. Phase 2, technology development, annual report

    Energy Technology Data Exchange (ETDEWEB)

    Arora, D.; Basu, R.; Phillips, J.R.; Wikstrom, C.V.; Clausen, E.C.; Gaddy, J.L.

    1995-07-01

    Oil refineries discharge large volumes of H{sub 2}, CO, and CO{sub 2} from cracking, coking, and hydrotreating operations. This program seeks to develop a biological process for converting these waste gases into ethanol, which can be blended with gasoline to reduce emissions. Production of ethanol from all 194 US refineries would save 450 billion BTU annually, would reduce crude oil imports by 110 million barrels/year and emissions by 19 million tons/year. Phase II efforts has yielded at least 3 cultures (Clostridium ljungdahlii, Isolate O-52, Isolate C-01) which are able to produce commercially viable concentrations of ethanol from CO, CO{sub 2}, and H{sub 2} in petroleum waste gas. Single continuous stirred tank reactor studies have shown that 15-20 g/L of ethanol can be produced, with less than 5 g/L acetic acid byproduct. Culture and reactor optimization in Phase III should yield even higher ethanol concentrations and minimal acetic acid. Product recovery studies showed that ethanol is best recovered in a multi-step process involving solvent extraction/distillation to azeotrope/azeotropic distillation or pervaporation, or direct distillation to the azeotrope/azeotropic distillation or pervaporation. Projections show that the ethanol facility for a typical refinery would require an investment of about $30 million, which would be returned in less than 2 years.

  9. Ethanol production from corn, corn stover and corncob from the Jilin Province of China

    Energy Technology Data Exchange (ETDEWEB)

    Varga, E.; Thomsen, A.B. [Risoe National Lab., Biosystem Dept., Roskilde (Denmark); Feng, L. [Jilin Light Industry Design and Reserch Inst., Changchun City (China)

    2005-06-01

    Among the available agricultural by-products, corn stover is far the most abundant lignocellulosic raw material for fuel ethanol production in China. More than 120 million tons of corn stover is produced annually, representing approximately 40 million tons of ethanol. In this study ethanol was produced from corn and alkaline wet oxidized (WO) corn stover and corncob followed by non-isothermal simultaneous saccharification and fermentation (SSF) using Saccharomyces cerevisiae. Eight different combinations of reaction temperature and time were applied for wet oxidation of corn stover and corncob using Na{sub 2}CO{sub 3} and NH{sub 3} as catalysts to find the best reaction conditions, resulting in both high glucose and ethanol yield. The best condition (200 deg. C, 8 min, 2g/L Na{sub 2}CO{sub 3}) increased the enzymatic conversion from cellulose to glucose of corn stover more then four times and resulted in 87% ethanol yield of theoretical, based on the cellulose available in the WO corn stover. This was achieved with a substrate concentration of 6% (w/w) dry material at 20 FPU/g DM enzyme loading after 120 h of SSF. The pretreatment with NH{sub 3} at the same conditions resulted slightly lower cellulose conversion to glucose, but also gave promising ethanol yield (75%), demonstrated, that the baker's yeast still could adapt to the WO material and ferment the glucose content to ethanol efficiently. (au)

  10. Improvements of tolerance to stress conditions by genetic engineering in Saccharomyces cerevisiae during ethanol production.

    Science.gov (United States)

    Doğan, Ayşegül; Demirci, Selami; Aytekin, Ali Özhan; Şahin, Fikrettin

    2014-09-01

    Saccharomyces cerevisiae, industrial yeast isolate, has been of great interest in recent years for fuel ethanol production. The ethanol yield and productivity depend on many inhibitory factors during the fermentation process such as temperature, ethanol, compounds released as the result of pretreatment procedures, and osmotic stress. An ideal strain should be able to grow under different stress conditions occurred at different fermentation steps. Development of tolerant yeast strains can be achieved by reprogramming pathways supporting the ethanol metabolism by regulating the energy balance and detoxicification processes. Complex gene interactions should be solved for an in-depth comprehension of the yeast stress tolerance mechanism. Genetic engineering as a powerful biotechnological tool is required to design new strategies for increasing the ethanol fermentation performance. Upregulation of stress tolerance genes by recombinant DNA technology can be a useful approach to overcome inhibitory situations. This review presents the application of several genetic engineering strategies to increase ethanol yield under different stress conditions including inhibitor tolerance, ethanol tolerance, thermotolerance, and osmotolerance.

  11. Ethanol production by selected intestinal microorganisms and lactic acid bacteria growing under different nutritional conditions

    Directory of Open Access Journals (Sweden)

    Fouad M.F. Elshaghabee

    2016-01-01

    Full Text Available To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD, some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose, pentoses (arabinose and ribose, disaccharides (lactose and lactulose, and inulin. Highest amounts of ethanol were produced by S. cerevisiae, L. fermentum and W. confusa on glucose and by S. cerevisiae and W. confusa on fructose. Due to mannitol-dehydrogenase expressed in L. fermentum, ethanol production on fructose was significantly (P < 0.05 reduced. Pyruvate and citrate, two potential electron acceptors for regeneration of NAD+/NADP+, drastically reduced ethanol production with acetate produced instead in L. fermentum grown on glucose and W. confusa grown on glucose and fructose, respectively. In fecal slurries prepared from feces of four overweight volunteers, ethanol was found to be produced upon addition of fructose. Addition of A. caccae, L. acidophilus, L. fermentum, as well as citrate and pyruvate, respectively, abolished ethanol production. However, addition of W. confusa resulted in significantly (P < 0.05 increased production of ethanol. These results indicate that microorganisms like W. confusa, a hetero-fermentative, mannitol-dehydrogenase negative lactic acid bacterium, may promote NAFLD through ethanol produced from sugar fermentation, while other intestinal bacteria and homo- and hetero-fermentative but mannitol-dehydrogenase positive lactic acid bacteria may not promote NAFLD. Also, our studies indicate that dietary factors interfering with gastrointestinal microbiota and

  12. Fusion of pyruvate decarboxylase and alcohol dehydrogenase increases ethanol production in Escherichia coli.

    Science.gov (United States)

    Lewicka, Aleksandra J; Lyczakowski, Jan J; Blackhurst, Gavin; Pashkuleva, Christiana; Rothschild-Mancinelli, Kyle; Tautvaišas, Dainius; Thornton, Harry; Villanueva, Hugo; Xiao, Weike; Slikas, Justinas; Horsfall, Louise; Elfick, Alistair; French, Christopher

    2014-12-19

    Ethanol is an important biofuel. Heterologous expression of Zymomonas mobilis pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) increases ethanol production in Escherichia coli. A fusion of PDC and ADH was generated and expressed in E. coli. The fusion enzyme was demonstrated to possess both activities. AdhB activity was significantly lower when fused to PDC than when the two enzymes were expressed separately. However, cells expressing the fusion protein generated ethanol more rapidly and to higher levels than cells coexpressing Pdc and AdhB, suggesting a specific rate enhancement due to the fusion of the two enzymes.

  13. 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...

  14. Prostaglandin production by rat vaginal tissue, in vitro, in response to ethanol, a mild mucosal irritant.

    Science.gov (United States)

    Dubin, N H; Wolff, M C; Thomas, C L; DiBlasi, M C

    1985-05-01

    Toxicological testing of vaginal irritants currently involves in vivo testing in rabbits. While chemical-induced irritation or inflammation involves numerous biologic responses, these responses appear to be to a large extent mediated by prostaglandin release. Since vaginal tissue of the rat produces prostaglandins, this tissue was studied in vitro to determine if it would respond to ethanol, a mild irritant. Small vaginal segments were rinsed in Krebs-Ringer bicarbonate buffer (pH 7.0) and exposed to various concentrations of ethanol. The segments were then transferred to fresh buffer and incubated for 30 min in a shaking 37 degrees C water bath. Ethanol (70%) exposure for 30 sec increased prostaglandin E2 and F2 alpha production by vaginal tissue. While ethanol exposure resulted in increases in prostaglandin production regardless of the stage of the cycle from which the tissue was derived, the relative increase was greatest in tissues from the diestrous stage of the cycle. The prostaglandin production response of vaginal tissue, and of cervical and uterine tissue, was related to the concentration of ethanol to which these tissues were exposed. Indomethacin blocked this response in a dose-dependent manner. These experiments demonstrate that vaginal tissue responds to ethanol by increasing production of PGF2 alpha and PGE2. This in vitro system may prove useful as an alternative to live-animal testing in the screening of irritants of the vaginal mucosa or other tissues as well.

  15. Production of ethanol from molasses at 45 C using alginate-immobilized Kluyveromyces marxianus imb3

    Energy Technology Data Exchange (ETDEWEB)

    Gough, S. [Biotechnology Research Group, Univ. of Ulster (United Kingdom); Brady, D. [Biotechnology Research Group, Univ. of Ulster (United Kingdom); Nigam, P. [Biotechnology Research Group, Univ. of Ulster (United Kingdom); Marchant, R. [Biotechnology Research Group, Univ. of Ulster (United Kingdom); McHale, A.P. [Biotechnology Research Group, Univ. of Ulster (United Kingdom)

    1997-05-01

    The thermotolerant, ethanol-producing yeast strain, Kluyveromyces marxianus IMB3, has been immobilized in calcium alginate matrices. The ability of the biocatalyst to produce ethanol from cane molasses originating in Guatemala, Honduras, Senegal, Guyana and the Philippines was examined. In each case the molasses was diluted to yield a sugar concentration of 140 g/l and fermentations were carried out in batch-fed mode at 45 C. During the first 24 hours, the maximum ethanol concentrations obtained ranged from 43-57 g/l with optimum production on the molasses from Honduras. Ethanol production during subsequent re-feeding of the fermentations at 24-hour intervals over a 120-hour period, decreased steadily to concentrations ranging from 20-36 g/l and it was found that ethanol productivity remained highest in fermentations containing the molasses from Guyana. When each set of fermentations was re-fed at 120 h and allowed to continue for 48 h, ethanol production again increased to a maximum with concentrations ranging from 25-52 g/l. It was also found however, that increasing the time between re-feeding at this stage in fermentation had a detrimental effect on the functionality of the biocatalyst. (orig.). With 2 figs.

  16. Continuous ethanol production from Jerusalem artichoke tubers. I. Use of free cells of Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.

    1982-07-01

    The continuous fermentation of Jerusalem artichoke juice to ethanol by free cells of Kluyveromyces marxianus UCD (FST) 55-82 has been studied in a continuous-stirred tank bioreactor at 35 degrees C and pH 4.6. A maximum ethanol yield of 90% of the theoretical was obtained at a dilution rate of 0.05/h. About 95% of the sugars were utilized at dilution rates lower than 0.15/h. Volumetric ethanol productivity and volumetric biomass productivity reached maximum values of 7 g EtOH/L/h and 0.6 g dry wt/L/h, respectively, at a dilution rate of 0.2h. The maintenance energy coefficient for Kluyveromyces marxianus culture was found to be 0.46 g sugar/g biomass/h. Oscillatory behavior was observed following a change in dilution rate from a previous steady state and from batch to continuous culture. Values of specific ethanol production rate and specific sugar uptake were found to increase almost linearly with the increase of the dilution rate. The maximum specific ethanol production rate and maximum specific sugar uptake rate were found to be 2.6 g ethanol/g cell/h and 7.9 sugars/g cell/h, respectively. Washout occurred at a dilution rate of 0.41/h. (Refs. 21).

  17. Continuous ethanol production from Jerusalem artichoke tubers. II. Use of immobilized cells of Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.

    1982-07-01

    Kluyveromyces marxianus UCD (FST) 55-82 cells were immobilized in Na alginate beads and used in a packed-bed bioreactor system for the continuous production of ethanol from the extract of Jerusalem artichoke tubers. Volumetric ethanol productivities of 104 and 80 g ethanol/L/h were obtained at 80 and 92% sugar utilization, respectively. The maximum volumetric ethanol productivity of the immobilized cell bioreactor system was found to be 15 times higher than that of an ordinary continuous-stirred-tank (CST) bioreactor using free cells of Kluyveromyces marxianus. The immobilized cell bioreactor system was operated continuously at a constant dilution rate of 0.66/h for 12 days resulting in only an 8% loss of the original immobilized cell activity, which corresponds to an estimated half-life of ca. 72 days. The maximum specific ethanol productivity and maximum specific sugar uptake rate of the immobilized cells were found to be 0.55 g ethanol/g biomass/h and 1.21 g sugars/g biomass/h, respectively. (Refs. 27).

  18. Opuntia ficus-indica cladodes as feedstock for ethanol production by Kluyveromyces marxianus and Saccharomyces cerevisiae.

    Science.gov (United States)

    Kuloyo, Olukayode O; du Preez, James C; García-Aparicio, Maria del Prado; Kilian, Stephanus G; Steyn, Laurinda; Görgens, Johann

    2014-12-01

    The feasibility of ethanol production using an enzymatic hydrolysate of pretreated cladodes of Opuntia ficus-indica (prickly pear cactus) as carbohydrate feedstock was investigated, including a comprehensive chemical analysis of the cladode biomass and the effects of limited aeration on the fermentation profiles and sugar utilization. The low xylose and negligible mannose content of the cladode biomass used in this study suggested that the hemicellulose structure of the O. ficus-indica cladode was atypical of hardwood or softwood hemicelluloses. Separate hydrolysis and fermentation and simultaneous saccharification and fermentation procedures using Kluyveromyces marxianus and Saccharomyces cerevisiae at 40 and 35 °C, respectively, gave similar ethanol yields under non-aerated conditions. In oxygen-limited cultures K. marxianus exhibited almost double the ethanol productivity compared to non-aerated cultures, although after sugar depletion utilization of the produced ethanol was evident. Ethanol concentrations of up to 19.5 and 20.6 g l(-1) were obtained with K. marxianus and S. cerevisiae, respectively, representing 66 and 70 % of the theoretical yield on total sugars in the hydrolysate. Because of the low xylan content of the cladode biomass, a yeast capable of xylose fermentation might not be a prerequisite for ethanol production. K. marxianus, therefore, has potential as an alternative to S. cerevisiae for bioethanol production. However, the relatively low concentration of fermentable sugars in the O. ficus-indica cladode hydrolysate presents a technical constraint for commercial exploitation.

  19. Possibilities of utilization of co-products from corn grain ethanol and starch production

    Directory of Open Access Journals (Sweden)

    Semenčenko Valentina V.

    2013-01-01

    Full Text Available In recent decades, the expansion of alternative fuels production from crops traditionally used for food and animal feed has led to significant changes in the field of energy production, agriculture and food industry. Starch and sugar feedstocks for ethanol production (corn, wheat, sugar beet, sugar cane, etc. require increasing arable land to meet market demands for the biofuel production. Although intensive studies are being carried out in order to identify improved and more cost-effective methods for the utilization of lignocellulosic and communal waste in the production of alcohol fuel, the possibility of using dry distillers’ grains with solubles (DDGS, by-product of bioethanol production from corn and wheat as well as alcoholic beverages industry, is now in focus. Application of DDGS in livestock and poultry diets in concentrations greater than traditional could positively affect the economic viability of this biofuel production, but also stabilize the current imbalance in the food and animal feed market. However, DDGS feedstuff should not be treated as a perfect substitute for corn because the complexity of ration formulation determined at the farm or feedlot level is driven by energy and protein and other nutrient requirements, as well as their relative costs in the ration. Nevertheless, processing of corn by wet milling provides a multitude of co-products suitable for feedstuffs, food industry, pharmaceuticals, chemistry etc. Some of the most important wet milling co-products that have their use in feedstuffs are corn gluten feed and corn gluten meal. The use of DDGS as a substitute for traditional feed could prevent indirect land-use changes associated with biofuel production, and therefore preserve the environmental destruction by saving the forests and permanent pastures. The use of distiller’s grains can be beneficial to biofuel growth as this is an additional, the second largest, source of income accounting of 10-20% total

  20. Ethanol production using xylitol synthesis mutant of xylose-utilizing zymomonas

    Science.gov (United States)

    Viitanen, Paul V.; McCutchen, Carol M.; Emptage, Mark; Caimi, Perry G.; Zhang, Min; Chou, Yat-Chen

    2010-06-22

    Production of ethanol using a strain of xylose-utilizing Zymomonas with a genetic modification of the glucose-fructose oxidoreductase gene was found to be improved due to greatly reduced production of xylitol, a detrimental by-product of xylose metabolism synthesized during fermentation.

  1. 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.

  2. Establishment and assessment of a novel cleaner production process of corn grain fuel ethanol.

    Science.gov (United States)

    Wang, Ke; Zhang, Jianhua; Tang, Lei; Zhang, Hongjian; Zhang, Guiying; Yang, Xizhao; Liu, Pei; Mao, Zhonggui

    2013-11-01

    An integrated corn ethanol-methane fermentation system was proposed to solve the problem of stillage handling, where thin stillage was treated by anaerobic digestion and then reused to make mash for the following ethanol fermentation. This system was evaluated at laboratory and pilot scale. Anaerobic digestion of thin stillage ran steadily with total chemical oxygen demand removal efficiency of 98% at laboratory scale and 97% at pilot scale. Ethanol production was not influenced by recycling anaerobic digestion effluent at laboratory and pilot scale. Compared with dried distillers' grains with solubles produced in conventional process, dried distillers' grains in the proposed system exhibited higher quality because of increased protein concentration and decreased salts concentration. Energetic assessment indicated that application of this novel process enhanced the net energy balance ratio from 1.26 (conventional process) to 1.76. In conclusion, the proposed system possessed technical advantage over the conventional process for corn fuel ethanol production.

  3. Influence of fermentation by-products on the purification of ethanol from water using pervaporation.

    Science.gov (United States)

    Chovau, S; Gaykawad, S; Straathof, A J J; Van der Bruggen, B

    2011-01-01

    Pervaporation is claimed to be a promising separation technique for the purification of ethanol from fermentation broths during bio-ethanol production. In this study, influence of fermentation by-products on the purification of ethanol from water during hydrophobic pervaporation was investigated. Sugars and salts were found to increase the membrane performance. Reason for this was a change in vapor/liquid equilibrium. 2,3-butanediol decreased the ethanol flux and selectivity factor, while glycerol exhibited no effect. This was explained by a strong sorption of butanediol into PDMS and no sorption of glycerol. Due to the presence of carboxylic acids, hydrophobicity degree of the Pervap 4060 membrane decreased, which resulted in an irreversible increase in water flux and decrease in separation performance. These observations suggested the presence of silicalite-based fillers in the membrane. When the pH was raised to a value above the dissociation constant, no changes in hydrophobicity degree and membrane performance were found.

  4. Production of rare sugars from common sugars in subcritical aqueous ethanol.

    Science.gov (United States)

    Gao, Da-Ming; Kobayashi, Takashi; Adachi, Shuji

    2015-05-15

    A new isomerization reaction was developed to synthesize rare ketoses. D-tagatose, D-xylulose, and D-ribulose were obtained in the maximum yields of 24%, 38%, and 40%, respectively, from the corresponding aldoses, D-galactose, D-xylose, and D-ribose, by treating the aldoses with 80% (v/v) subcritical aqueous ethanol at 180°C. The maximum productivity of D-tagatose was ca. 80 g/(Lh). Increasing the concentration of ethanol significantly increased the isomerization of D-galactose. Variation in the reaction temperature did not significantly affect the production of D-tagatose from D-galactose. Subcritical aqueous ethanol converted both 2,3-threo and 2,3-erythro aldoses to the corresponding C-2 ketoses in high yields. Thus, the treatment of common aldoses in subcritical aqueous ethanol can be regarded as a new method to synthesize the corresponding rare sugars.

  5. Performance Assessment of SOFC Systems Integrated with Bio-Ethanol Production and Purification Processes

    Directory of Open Access Journals (Sweden)

    Sumittra Charojrochkul

    2010-03-01

    Full Text Available The overall electrical efficiencies of the integrated systems of solid oxide fuel cell (SOFC and bio-ethanol production with purification processes at different heat integration levels were investigated. The simulation studies were based on the condition with zero net energy. It was found that the most suitable operating voltage is between 0.7 and 0.85 V and the operating temperature is in the range from 973 to 1173 K. For the effect of percent ethanol recovery, the optimum percent ethanol recovery is at 95%. The most efficient case is the system with full heat integration between SOFC and bio-ethanol production and purification processes with biogas reformed for producing extra hydrogen feed for SOFC which has the overall electrical efficiency = 36.17%. However more equipment such as reformer and heat exchangers are required and this leads to increased investment cost.

  6. Valorization of sunflower meal through the production of ethanol from the hemicellulosic fraction

    Directory of Open Access Journals (Sweden)

    Bruna Tavares

    Full Text Available ABSTRACT Sunflower is among the major oil seeds crop grown in the world and the by-products generated during the seeds processing represent an attractive source of lignocellulosic biomass for bioprocesses. The conversion of lignocellulosic fibers into fermentable sugars has been considered as a promising alternative to increase the demand for ethanol. The present study aimed to establish the fermentation conditions for ethanol production by Scheffersomyces stipitis ATCC 58376 in sunflower meal hemicellulosic hydrolysate, through a 23 CCRD (Central Composite Rotational Design factorial design. Under the selected conditions (pH 5.25, 29 ºC and 198 rpm the final ethanol concentration was 13.92 g L-1 and the ethanol yield was 0.49 g g-1.

  7. Kinetics of ethanol production from Jerusalem artichoke juice with some Klugveromyces species

    Energy Technology Data Exchange (ETDEWEB)

    Duvnjak, Z.; Kosaric, N.; Hayes, R.D.

    1981-01-01

    The kinetics of ethanol produce by Kluyveromyces marxianus ATCC 12708 and ATCC 10606, K. cicerisporus ATCC 22295, and K. fragilis 105 have been studied using raw juice of the Jerusalem artichoke in which the carbohydrates were not hydrolyzed prior to fermentation. The experiments revealed that this juice contains enough nutrients and can serve as a complete medium without additional nutrients both for growth of the yeasts and for ethanol production. It was found that both specific ethanol productivity and specific uptake rates were the highest with K. marxianus ATCC 12708 (1.68 g/g/hour and 3.78 g/g/hour respectively). This microorganism produced an ethanol yield of 87.5% of the theoretical value in 25 hours. (Refs. 15).

  8. Economic analysis of fuel ethanol production from corn starch using fluidized-bed bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M.S.; Davison, B.H.; Nghiem, N.P. [Oak Ridge National Laboratory (United States). Chemical Technology Division; Taylor, F. [USDA, Wyndmoor, PA (United States). Eastern Regional Research

    2000-11-01

    The economics of fuel ethanol production from dry-milled corn starch were studied in fluidized-bed bioreactors (FBRs) using immobilized biocatalysts. Glucoamylase immobilized on porous diatomaceous earth was used for hydrolysis of the starch to glucose in a packed-bed reactor. The fermentation of glucose to ethanol was carried out in FBRs using Zymomonas mobilis immobilized in {kappa}-carrageenan beads. Volumetric ethanol productivities of up to 24 g/l h were achieved in non-optimized laboratory-scale systems. For a 15 million gal/yr ethanol plant, an economic analysis of this process was performed with Aspen Plus (Aspen Technology, Cambridge, MA) process simulation software. The analysis shows that an operating cost savings in the range of 1.1-3.1 cents/gal can be realized by using the FBR technology. (author)

  9. Production of ethanol from barley by a conventional process and the EDGE (Enhanced Dry Grind Enzymatic) process

    Science.gov (United States)

    Corn ethanol production is not sufficient to meet the future demand for transportation liquid fuels and lignocellulosic ethanol technology is still not ready for commercialization. Therefore, another starch feedstock for fuel ethanol is needed. Barley is suitable for this role since it can be grow...

  10. Utilization of damaged sorghum and rice grains for ethanol production by simultaneous saccharification and fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, K.; Kiran Sree, N.; Venkateswer Rao, L. [Osmania Univ., Hyderabad (India). Dept. of Microbiology

    1999-06-01

    The simultaneous saccharification and fermentation (SSF) of damaged grains of sorghum and rice was carried out using Aspergillus niger (NCIM 1248) and Saccharomyces cerevisiae VSJ1. More ethanol was produced from the damaged sorghum (2.90% v/v) than damaged rice (2.09% v/v) under optimal fermentation conditions. This study reveals that damaged grains can be utilized efficiently by an SSF process for the production of ethanol. (Author)

  11. Technoeconomic assessment of lignocellulosic ethanol production via DME hydrocarbonylation

    OpenAIRE

    García Haro, Pedro; Ollero de Castro, Pedro Antonio; Villanueva Perales, Ángel Luis; Reyes Valle, Carmen Maria

    2012-01-01

    In this study, a new thermochemical route to produce lignocellulosic ethanol based on DME (dimethyl ether) hydrocarbonylation is proposed and economically assessed. The process is designed and evaluated using current kinetic laboratory data for hydrocarbonylation reactions. Only available technologies or those expected to be available in the short term are considered for the process design, which involves biomass pretreatment and gasification (indirect circulating fluidized bed), gas clean-up...

  12. Siting Evaluation for Biomass-Ethanol Production in Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, C.M.; Zhou, J.

    2000-10-15

    This report examines four Hawaiian islands, Oahu, Hawaii, Maui, and Kauai, to identify three best combinations of potential sites and crops for producing dedicated supplies of biomass for conversion to ethanol. Key technical and economic factors considered in the siting evaluation include land availability (zoning and use), land suitability (agronomic conditions), potential quantities and costs of producing biomass feedstocks, infrastructure (including water and power supplies), transportation, and potential bioresidues to supplement dedicated energy crops.

  13. Engineering of the glycerol decomposition pathway and cofactor regulation in an industrial yeast improves ethanol production.

    Science.gov (United States)

    Zhang, Liang; Tang, Yan; Guo, Zhongpeng; Shi, Guiyang

    2013-10-01

    Glycerol is a major by-product of industrial ethanol production and its formation consumes up to 4 % of the sugar substrate. This study modified the glycerol decomposition pathway of an industrial strain of Saccharomyces cerevisiae to optimize the consumption of substrate and yield of ethanol. This study is the first to couple glycerol degradation with ethanol formation, to the best of our knowledge. The recombinant strain overexpressing GCY1 and DAK1, encoding glycerol dehydrogenase and dihydroxyacetone kinase, respectively, in glycerol degradation pathway, exhibited a moderate increase in ethanol yield (2.9 %) and decrease in glycerol yield (24.9 %) compared to the wild type with the initial glucose concentration of 15 % under anaerobic conditions. However, when the mhpF gene, encoding acetylating NAD⁺-dependent acetaldehyde dehydrogenase from Escherichia coli, was co-expressed in the aforementioned recombinant strain, a further increase in ethanol yield by 5.5 % and decrease in glycerol yield by 48 % were observed for the resultant recombinant strain GDMS1 when acetic acid was added into the medium prior to inoculation compared to the wild type. The process outlined in this study which enhances glycerol consumption and cofactor regulation in an industrial yeast is a promising metabolic engineering strategy to increase ethanol production by reducing the formation of glycerol.

  14. Impacts of retrofitting analysis on first generation ethanol production: process design and techno-economics.

    Science.gov (United States)

    Rajendran, Karthik; Rajoli, Sreevathsava; Teichert, Oliver; Taherzadeh, Mohammad J

    2015-02-01

    More than half of the bioethanol plants in operation today use corn or grains as raw materials. The downstream processing of mash after fermentation to produce ethanol and distiller grains is an energy-demanding process, which needs retrofitting for optimization. In addition, the fluctuation in the ethanol and grain prices affects the overall profitability of the plant. For this purpose, a process simulation was performed in Aspen Plus(®) based on an existing industrial plant located in Sweden. The simulations were compared using different scenarios including different concentrations of ethanol, using the stillage for biogas production to produce steam instead of distiller grains as a by-product, and altering the purity of the ethanol produced. Using stillage for biogas production, as well as utilizing the steam, reduced the overall energy consumption by 40% compared to the plant in operation. The fluctuations in grain prices had a high impact on the net present value (NPV), where grain prices greater than 349 USD/ton reached a zero NPV. After 20 years, the plant in operation producing 41,600 tons ethanol/year can generate a profit of 78 million USD. Compared to the base case, the less purified ethanol resulted in a lower NPV of 30 million USD.

  15. Fermentative production of ethanol from syngas using novel moderately alkaliphilic strains of Alkalibaculum bacchi.

    Science.gov (United States)

    Liu, Kan; Atiyeh, Hasan K; Tanner, Ralph S; Wilkins, Mark R; Huhnke, Raymond L

    2012-01-01

    Ethanol production from syngas using three moderately alkaliphilic strains of a novel genus and species Alkalibaculum bacchi CP11(T), CP13 and CP15 was investigated in 250 ml bottle fermentations containing 100ml of yeast extract medium at 37 °C and pH 8.0. Two commercial syngas mixtures (Syngas I: 20% CO, 15% CO(2), 5% H(2), 60% N(2)) and (Syngas II: 40% CO, 30% CO(2), 30% H(2)) were used. Syngas I and Syngas II represent gasified biomass and coal, respectively. The maximum ethanol concentration (1.7 g l(-1)) and yield from CO (76%) were obtained with strain CP15 and Syngas II after 360 h. CP15 produced over twofold more ethanol with Syngas I compared to strains CP11(T) and CP13. In addition, CP15 produced 18% and 71% more ethanol using Syngas II compared to strains CP11(T) and CP13, respectively. These results show that CP15 is the most promising for ethanol production because of its higher growth and ethanol production rates and yield compared to CP11(T) and CP13.

  16. Selection of Thai starter components for ethanol production utilizing malted rice from waste paddy

    Directory of Open Access Journals (Sweden)

    Sirilux Chaijamrus

    2011-04-01

    Full Text Available The use of mixed herbs in Thai rice wine starter (Loog-pang were investigated in order to directly maintain theefficiency of the microbial community (Saccharomycopsis fibuligera, Amylomyces sp., Gluconobacter sp. and Pediocccuspentosaceus. The optimum formula was galanga, garlic, long pepper, licorice, and black pepper at the ratio of 0.5:8:1:4:1,respectively. Previously, waste paddy has been used directly as a renewable resource for fuel ethanol production using solidstate fermentation (SSF with Loog-pang. In this study, hydrolyzed malted rice starch was used as the sole nutrient source insubmerged fermentation (SmF to enhance the process yield. The maximum ethanol productivity (4.08 g/kg waste paddy h-1and the highest ethanol concentration (149±7.0 g/kg waste paddy were obtained after 48 hrs of incubation. The resultsindicated that starch saccharification provided a higher ethanol yield (48.38 g/100g sugar consumed than SSF. In addition,the efficiency of ethanol fermentation was 67% which is similar to that of the malted rice made from normal paddy (68%.This result suggests that waste paddy could be used as an alternative raw material for ethanol production.

  17. Immobilization of Saccharomyces cerevisiae on to modified carboxymethylcellulose for production of ethanol.

    Science.gov (United States)

    Gökgöz, Murat; Yiğitoğlu, Mustafa

    2011-09-01

    In this work, modified carboxymethylcellulose (CMC) was used as a new support material for production of ethanol. Crosslinked graft copolymers of CMC with N-vinyl-2-pyrrolidone (N-VP) were prepared in different grafting yields. The beads material was characterized by means of fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and swelling experiment. Saccharomyces cerevisiae was immobilized using entrapment method in the graft copolymers of carboxymethylcellulose-g-poly(N-vinyl-2-pyrrolidone) (CMC-g-PVP) for ethanol fermentation. The effects of grafting yield, initial glucose concentration and crosslinker concentration on the yield of ethanol process were investigated. Reusability of the immobilized yeasts was investigated and found that the materials can be used four times without losing their activity. Ethanol production increased to 59.3 g/L from 46.4 g/L when percentage of N-VP in the graft copolymer was increased. The highest ethanol productivity was found to be 1.75-2.25 g/L h. Fermentation time decreased with the decreasing of crosslinker concentration. The results suggest that the proposed method for immobilization of Saccharomyces cerevisiae has potential in industrial applications for ethanol process.

  18. Effects of solution volume on hydrogen production by pulsed spark discharge in ethanol solution

    Science.gov (United States)

    Xin, Y. B.; Sun, B.; Zhu, X. M.; Yan, Z. Y.; Liu, H.; Liu, Y. J.

    2016-07-01

    Hydrogen production from ethanol solution (ethanol/water) by pulsed spark discharge was optimized by varying the volume of ethanol solution (liquid volume). Hydrogen yield was initially increased and then decreased with the increase in solution volume, which achieved 1.5 l/min with a solution volume of 500 ml. The characteristics of pulsed spark discharge were studied in this work; the results showed that the intensity of peak current, the rate of current rise, and energy efficiency of hydrogen production can be changed by varying the volume of ethanol solution. Meanwhile, the mechanism analysis of hydrogen production was accomplished by monitoring the process of hydrogen production and the state of free radicals. The analysis showed that decreasing the retention time of gas production and properly increasing the volume of ethanol solution can enhance the hydrogen yield. Through this research, a high-yield and large-scale method of hydrogen production can be achieved, which is more suitable for industrial application.

  19. Enhanced ethanol production at commercial scale from molasses using high gravity technology by mutant S. cerevisiae.

    Science.gov (United States)

    Arshad, Muhammad; Hussain, Tariq; Iqbal, Munawar; Abbas, Mazhar

    2017-02-16

    Very high gravity (VHG) technology was employed on industrial scale to produce ethanol from molasses (fermented) as well as by-products formation estimation. The effect of different Brix° (32, 36 and 40) air-flow rates (0.00, 0.20, 0.40, and 0.60vvm) was studied on ethanol production. The maximum ethanol production was recorded to be 12.2% (v/v) at 40 Brix° with 0.2vvm air-flow rate. At optimum level aeration and 40 Brix° VHG, the residual sugar level was recorded in the range of 12.5-18.5g/L, whereas the viable cell count remained constant up to 50h of fermentation and dry matter production increased with fermentation time. Both water and steam consumption reduced significantly under optimum conditions of Brix° and aeration rate with compromising the ethanol production. Results revealed VHG with continuous air flow is viable technique to reduce the ethanol production cost form molasses at commercial scale.

  20. Effects of solution volume on hydrogen production by pulsed spark discharge in ethanol solution

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Y. B.; Sun, B., E-mail: sunb88@dlmu.edu.cn; Zhu, X. M.; Yan, Z. Y.; Liu, H.; Liu, Y. J. [College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026 (China)

    2016-07-15

    Hydrogen production from ethanol solution (ethanol/water) by pulsed spark discharge was optimized by varying the volume of ethanol solution (liquid volume). Hydrogen yield was initially increased and then decreased with the increase in solution volume, which achieved 1.5 l/min with a solution volume of 500 ml. The characteristics of pulsed spark discharge were studied in this work; the results showed that the intensity of peak current, the rate of current rise, and energy efficiency of hydrogen production can be changed by varying the volume of ethanol solution. Meanwhile, the mechanism analysis of hydrogen production was accomplished by monitoring the process of hydrogen production and the state of free radicals. The analysis showed that decreasing the retention time of gas production and properly increasing the volume of ethanol solution can enhance the hydrogen yield. Through this research, a high-yield and large-scale method of hydrogen production can be achieved, which is more suitable for industrial application.

  1. Consolidated bioprocessing strategy for ethanol production from Jerusalem artichoke tubers by Kluyveromyces marxianus under high gravity conditions.

    Science.gov (United States)

    Yuan, W J; Chang, B L; Ren, J G; Liu, J P; Bai, F W; Li, Y Y

    2012-01-01

    Developing an innovative process for ethanol fermentation from Jerusalem artichoke tubers under very high gravity (VHG) conditions. A consolidated bioprocessing (CBP) strategy that integrated inulinase production, saccharification of inulin contained in Jerusalem artichoke tubers and ethanol production from sugars released from inulin by the enzyme was developed with the inulinase-producing yeast Kluyveromyces marxianus Y179 and fed-batch operation. The impact of inoculum age, aeration, the supplementation of pectinase and nutrients on the ethanol fermentation performance of the CBP system was studied. Although inulinase activities increased with the extension of the seed incubation time, its contribution to ethanol production was negligible because vigorously growing yeast cells harvested earlier carried out ethanol fermentation more efficiently. Thus, the overnight incubation that has been practised in ethanol production from starch-based feedstocks is recommended. Aeration facilitated the fermentation process, but compromised ethanol yield because of the negative Crabtree effect of the species, and increases the risk of contamination under industrial conditions. Therefore, nonaeration conditions are preferred for the CBP system. Pectinase supplementation reduced viscosity of the fermentation broth and improved ethanol production performance, particularly under high gravity conditions, but the enzyme cost should be carefully balanced. Medium optimization was performed, and ethanol concentration as high as 94·2 g l(-1) was achieved when 0·15 g l(-1) K(2) HPO(4) was supplemented, which presents a significant progress in ethanol production from Jerusalem artichoke tubers. A CBP system using K. marxianus is suitable for efficient ethanol production from Jerusalem artichoke tubers under VHG conditions. Jerusalem artichoke tubers are an alternative to grain-based feedstocks for ethanol production. The high ethanol concentration achieved using K. marxianus with the

  2. Ethanol production from kitchen waste using the flocculating yeast Saccharomyces cerevisiae strain KF-7

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yue-Qin; Liu, Kai; An, Ming-Zhe; Morimura, Shigeru; Kida, Kenji [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Koike, Yoji [Tokyo Gas Co., Ltd., 1-7-7 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa 230-0045 (Japan); Wu, Xiao-Lei [Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2008-11-15

    A process for producing ethanol from kitchen waste was developed in this study. The process consists of freshness preservation of the waste, saccharification of the sugars in the waste, continuous ethanol fermentation of the saccharified liquid, and anaerobic treatment of the saccharification residue and the stillage. Spraying lactic acid bacteria (LCB) on the kitchen waste kept the waste fresh for over 1 week. High glucose recovery (85.5%) from LCB-sprayed waste was achieved after saccharification using Nagase N-40 glucoamylase. The resulting saccharified liquid was used directly for ethanol fermentation, without the addition of any nutrients. High ethanol productivity (24.0 g l{sup -1} h{sup -1}) was obtained when the flocculating yeast strain KF-7 was used in a continuous ethanol fermentation process at a dilution rate of 0.8 h{sup -1}. The saccharification residue was mixed with stillage and treated in a thermophilic anaerobic continuous stirred tank reactor (CSTR); a VTS loading rate of 6 g l{sup -1} d{sup -1} with 72% VTS digestion efficiency was achieved. Using this process, 30.9 g ethanol, and 65.2 l biogas with 50% methane, was produced from 1 kg of kitchen waste containing 118.0 g total sugar. Thus, energy in kitchen waste can be converted to ethanol and methane, which can then be used as fuels, while simultaneously treating kitchen waste. (author)

  3. Elucidating central metabolic redox obstacles hindering ethanol production in Clostridium thermocellum.

    Science.gov (United States)

    Thompson, R Adam; Layton, Donovan S; Guss, Adam M; Olson, Daniel G; Lynd, Lee R; Trinh, Cong T

    2015-11-01

    Clostridium thermocellum is an anaerobic, Gram-positive, thermophilic bacterium that has generated great interest due to its ability to ferment lignocellulosic biomass to ethanol. However, ethanol production is low due to the complex and poorly understood branched metabolism of C. thermocellum, and in some cases overflow metabolism as well. In this work, we developed a predictive stoichiometric metabolic model for C. thermocellum which incorporates the current state of understanding, with particular attention to cofactor specificity in the atypical glycolytic enzymes and the complex energy, redox, and fermentative pathways with the goal of aiding metabolic engineering efforts. We validated the model's capability to encompass experimentally observed phenotypes for the parent strain and derived mutants designed for significant perturbation of redox and energy pathways. Metabolic flux distributions revealed significant alterations in key metabolic branch points (e.g., phosphoenol pyruvate, pyruvate, acetyl-CoA, and cofactor nodes) in engineered strains for channeling electron and carbon fluxes for enhanced ethanol synthesis, with the best performing strain doubling ethanol yield and titer compared to the parent strain. In silico predictions of a redox-imbalanced genotype incapable of growth were confirmed in vivo, and a mutant strain was used as a platform to probe redox bottlenecks in the central metabolism that hinder efficient ethanol production. The results highlight the robustness of the redox metabolism of C. thermocellum and the necessity of streamlined electron flux from reduced ferredoxin to NAD(P)H for high ethanol production. The model was further used to design a metabolic engineering strategy to phenotypically constrain C. thermocellum to achieve high ethanol yields while requiring minimal genetic manipulations. The model can be applied to design C. thermocellum as a platform microbe for consolidated bioprocessing to produce ethanol and other reduced

  4. Bio-ethanol production by a novel autochthonous thermo-tolerant yeast isolated from wastewater.

    Science.gov (United States)

    Tofighi, Azadeh; Mazaheri Assadi, Mahnaz; Asadirad, Mohammad Hosein Arash; Zare Karizi, Shohreh

    2014-01-01

    It has been known for years that ethanol is a bio-fuel to replace fossil fuels. The ethanol industry requires the utilization of micro-organisms capable production with stresses. The purpose of present study was to isolate and characterize ethanologenic yeast with high potential application at high temperature to produce bio-ethanol. To isolate ethanologenic yeasts, wastewater samples from a starch producer plant in Varamin, Iran were used. The isolates were identified by molecular characterization. Characteristics of the isolated strains were determined at 30, 35, 40 and 45°C for 48 hours. 50 yeast strains capable of growing well in agar plates in a temperature range of 30-45°C were isolated. Out of the isolated strains, only three strains were screened for their ability to grow at 45°C. Selected yeast, designated as AT-3 strain which showed efficient flocculation capabilities with higher ethanol production and grew faster as compared to the rest of strains in media with 180 g/L glucose at 35°C. The selected yeast was identified as a new strain of Saccharomyces cerevisiae and submitted to the Gene-Bank database. Its' optimum growth temperature was between 35 and 40°C. The results showed that during the bio-ethanol production 2.5 × 10(10) and 8.5 × 10(9) (CFU/mL) were a good indication of strain capability in heat tolerance. Also, ethanol produced at a raise of 6.9% and 6.85% (w/v) at 35 and 40°C, respectively, whereas glucose-to-ethanol conversion yield was about 75% of the theoretical value. Results emphasized that the isolated strain identified as Saccharomyces cerevisiae. This specific strain has thermo-tolerant, osmo-tolerant, flocculating capabilities with potential for application in developing a low cost ethanol industry.

  5. 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

  6. 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.

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

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia

    The aim of this study was 1) present an oilseed rape whole crop biorefinery; 2) to investigate the best available experimental conditions for production of cellulosic ethanol from rape straw, and included the processes of thermo-chemical pretreatment, enzymatic hydrolysis, and C6 fermentation......, and 3) to couple cellulosic ethanol production to production of cellulolytic enzymes that are needed for cellulosic ethanol production, inside a rape straw biorefinery. For the first is based less on available experiments, and more on literature review. The second and third study conclusions were drawn...... based more on experimental findings, and less to literature review. In Chapter 1, the problem context and background theory for biorefineries is presented. Finally, latest developments of upscaled biorefineries in Europe are summarized. In Chapter 2, a scenario about upgrading and expanding a typical...

  8. Process simulation of ethanol production from biomass gasification and syngas fermentation.

    Science.gov (United States)

    Pardo-Planas, Oscar; Atiyeh, Hasan K; Phillips, John R; Aichele, Clint P; Mohammad, Sayeed

    2017-09-01

    The hybrid gasification-syngas fermentation platform can produce more bioethanol utilizing all biomass components compared to the biochemical conversion technology. Syngas fermentation operates at mild temperatures and pressures and avoids using expensive pretreatment processes and enzymes. This study presents a new process simulation model developed with Aspen Plus® of a biorefinery based on a hybrid conversion technology for the production of anhydrous ethanol using 1200tons per day (wb) of switchgrass. The simulation model consists of three modules: gasification, fermentation, and product recovery. The results revealed a potential production of about 36.5million gallons of anhydrous ethanol per year. Sensitivity analyses were also performed to investigate the effects of gasification and fermentation parameters that are keys for the development of an efficient process in terms of energy conservation and ethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Aflatoxinas em produtos à base de milho comercializados no Brasil e riscos para a saúde humana Aflatoxins in corn-based food products traded in Brazil and risks to human health

    Directory of Open Access Journals (Sweden)

    Kassia Ayumi Segawa do Amaral

    2006-06-01

    data demonstrate low occurence of aflatoxins in the maize products analysed. Despite this, Average Probable Daily Intake (APDI of AFB1 was above Tolerable Daily Intake (TDI, indicating a risk of liver carcinogenicity for Brazilian population due to the consumption of maize products. The ELISA method revealed to be simple, fast, and uses less organic solvent, however, it presented positive and negative presumptive results, what makes necessary the confirmation of the mycotoxins identity by TLC.

  10. Evaluating the impact of ammonia fiber expansion (AFEX) pretreatment conditions on the cost of ethanol production.

    Science.gov (United States)

    Bals, Bryan; Wedding, Chris; Balan, Venkatesh; Sendich, Elizabeth; Dale, Bruce

    2011-01-01

    Ammonia fiber expansion (AFEX) pretreatment is an ammonia-based process for improving the susceptibility of lignocellulosic biomass to enzymatic attack. Four parameters--ammonia loading, water loading, reaction temperature, and residence time--can be varied in order to optimize AFEX pretreatment. The effect of these parameters on process economics of ethanol production was studied using a leading biorefinery model. Ammonia loading and residence time had the greatest impact on the economics of ethanol production, primarily due to processing costs for the chilled water condenser and the capital cost of the AFEX reactor. Water loading and reaction temperature had only modest impact on process economics. In addition, the impact of pretreatment conditions on makeup ammonia requirements was explored experimentally, which ranged from 15 to 25 g ammonia/kg biomass. Overall, pretreatment conditions can change the costs of ethanol production by up to 35 cents per gallon ethanol in an 850 ton/day refinery. By linking the results obtained from this Aspen model to experimental results for ethanol production and makeup ammonia recovery, this study can be used to create an economic optimum for AFEX pretreatment in contrast with simply maximizing fermentable sugar production. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

  12. Fuel from farms: a guide to small-scale ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-02-01

    A guide on fermentation processes with emphasis on small-scale production of ethanol using farm crops as a source of raw material is published. The current status of on-farm ethanol production as well as an overview of some of the technical and economic factors is presented. Decision and planning worksheets and a sample business plan for use in decision making are included. Specifics in production including information on the raw materials, system components, and operational requirements are also provided. Diagrams of fermentors and distilling apparatus are included. (DC)

  13. Fuel from farms: A guide to small-scale ethanol production: Second edition

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    This guide presents the current status of on-farm fermentation ethanol production as well as an overview of some of the technical and economic factors. Tools such as decision and planning worksheets and a sample business plan for use in exploring whether or not to go into ethanol production are given. Specifics in production including information on the raw materials, system components, and operational requirements are also provided. Recommendation of any particular process is deliberately avoided because the choice must be tailored to the needs and resources of each individual producer. The emphasis is on providing the facts necessary to make informed judgments. 98 refs., 14 figs., 9 tabs.

  14. Increasing efficiency in ethanol production: Water footprint and economic productivity of sugarcane ethanol under nine different water regimes in north-eastern Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Chico

    2015-06-01

    Full Text Available Ethanol production in Brazil has grown by 219% between 2001 and 2012, increasing the use of land and water resources. In the semi-arid north-eastern Brazil, irrigation is the main way for improving sugarcane production. This study aimed at quantifying water consumed in ethanol production from sugarcane in this region using the water footprint (WF indicator and complementing it with an evaluation of the water apparent productivity (WAP. This way we were able to provide a measure of the crop´s physical and economic water productivity using, respectively, the WF and WAP concepts. We studied sugarcane cultivation under nine different water regimes, including rainfed and full irrigation. Data from a mill of the state of Alagoas for three production seasons were used. Irrigation influenced sugarcane yield increasing total profit per hectare and economic water productivity. Full irrigation showed the lowest WF, 1229 litres of water per litre of ethanol (L/L, whereas rainfed production showed the highest WF, 1646 L/L. However, the lower WF in full irrigation as compared to the rest of the water regimes implied the use of higher volumes of blue water per cultivated hectare. Lower water regimes yielded the lowest economic productivity, 0.72 US$/m3 for rainfed production as compared to 1.11 US$/m3 for full irrigation. Since economic revenues are increased with higher water regimes, there are incentives for the development of these higher water regimes. This will lead to higher general crop water and economic productivity at field level, as green water is replaced by blue water consumption.

  15. Increasing efficiency in ethanol production: Water footprint and economic productivity of sugarcane ethanol under nine different water regimes in north-eastern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Chico, D.; Santiago, A. D.; Garrido, A.

    2015-07-01

    Ethanol production in Brazil has grown by 219% between 2001 and 2012, increasing the use of land and water resources. In the semi-arid north-eastern Brazil, irrigation is the main way for improving sugarcane production. This study aimed at quantifying water consumed in ethanol production from sugarcane in this region using the water footprint (WF) indicator and complementing it with an evaluation of the water apparent productivity (WAP). This way we were able to provide a measure of the crop´s physical and economic water productivity using, respectively, the WF and WAP concepts. We studied sugarcane cultivation under nine different water regimes, including rainfed and full irrigation. Data from a mill of the state of Alagoas for three production seasons were used. Irrigation influenced sugarcane yield increasing total profit per hectare and economic water productivity. Full irrigation showed the lowest WF, 1229 litres of water per litre of ethanol (L/L), whereas rainfed production showed the highest WF, 1646 L/L. However, the lower WF in full irrigation as compared to the rest of the water regimes implied the use of higher volumes of blue water per cultivated hectare. Lower water regimes yielded the lowest economic productivity, 0.72 US$/m3 for rainfed production as compared to 1.11 US$/m3 for full irrigation. Since economic revenues are increased with higher water regimes, there are incentives for the development of these higher water regimes. This will lead to higher general crop water and economic productivity at field level, as green water is replaced by blue water consumption. (Author)

  16. Acetone-butanol-ethanol production with high productivity using Clostridium acetobutylicum BKM19.

    Science.gov (United States)

    Jang, Yu-Sin; Malaviya, Alok; Lee, Sang Yup

    2013-06-01

    Conventional acetone-butanol-ethanol (ABE) fermentation is severely limited by low solvent titer and productivities. Thus, this study aims at developing an improved Clostridium acetobutylicum strain possessing enhanced ABE production capability followed by process optimization for high ABE productivity. Random mutagenesis of C. acetobutylicum PJC4BK was performed by screening cells on fluoroacetate plates to isolate a mutant strain, BKM19, which exhibited the total solvent production capability 30.5% higher than the parent strain. The BKM19 produced 32.5 g L(-1) of ABE (17.6 g L(-1) butanol, 10.5 g L(-1) ethanol, and 4.4 g L(-1) acetone) from 85.2 g L(-1) glucose in batch fermentation. A high cell density continuous ABE fermentation of the BKM19 in membrane cell-recycle bioreactor was studied and optimized for improved solvent volumetric productivity. Different dilution rates were examined to find the optimal condition giving highest butanol and ABE productivities. The maximum butanol and ABE productivities of 9.6 and 20.0 g L(-1)  h(-1) , respectively, could be achieved at the dilution rate of 0.85 h(-1) . Further cell recycling experiments were carried out with controlled cell-bleeding at two different bleeding rates. The maximum solvent productivities were obtained when the fermenter was operated at a dilution rate of 0.86 h(-1) with the bleeding rate of 0.04 h(-1) . Under the optimal operational condition, butanol and ABE could be produced with the volumetric productivities of 10.7 and 21.1 g L(-1)  h(-1) , and the yields of 0.17 and 0.34 g g(-1) , respectively. The obtained butanol and ABE volumetric productivities are the highest reported productivities obtained from all known-processes. Copyright © 2013 Wiley Periodicals, Inc.

  17. 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.

  18. Contamination issues in a continuous ethanol production corn wet milling facility.

    Science.gov (United States)

    Khullar, Esha; Kent, Angela D; Leathers, Timothy D; Bischoff, Kenneth M; Rausch, Kent D; Tumbleson, M E; Singh, Vijay

    2013-05-01

    Low ethanol yields and poor yeast viability were investigated at a continuous ethanol production corn wet milling facility. Using starch slurries and recycle streams from a commercial ethanol facility, laboratory hydrolysates were prepared by reproducing starch liquefaction and saccharification steps in the laboratory. Fermentations with hydrolysates prepared in the laboratory were compared with plant hydrolysates for final ethanol concentrations and total yeast counts. Fermentation controls were prepared using hydrolysates (plant and laboratory) that were not inoculated with yeast. Hydrolysates prepared in the laboratory resulted in higher final ethanol concentrations (15.8 % v/v) than plant hydrolysate (13.4 % v/v). Uninoculated controls resulted in ethanol production from both laboratory (12.2 % v/v) and plant hydrolysates (13.7 % v/v), indicating the presence of a contaminating microorganism. Yeast colony counts on cycloheximide and virginiamycin plates confirmed the presence of a contaminant. DNA sequencing and fingerprinting studies also indicated a number of dissimilar communities in samples obtained from fermentors, coolers, saccharification tanks, and thin stillage.

  19. Comparative Study on Two Commercial Strains of Saccharomyces cerevisiae for Optimum Ethanol Production on Industrial Scale

    Directory of Open Access Journals (Sweden)

    K. Mukhtar

    2010-01-01

    Full Text Available Two commercial strains of Saccharomyces cerevisiae, Saf-Instant (Baker's yeast and Ethanol red (Mutant were compared for ethanol production during hot summer season, using molasses diluted up to 6-7∘ Brix containing 4%-5% sugars. The yeasts were then propagated in fermentation vessels to study the effects of yeast cell count and varying concentrations of Urea, DAP, inoculum size and Lactrol (Antibiotic. Continuous circulation of mash was maintained for 24 hours and after this fermenter was allowed to stay for a period of 16 hours to give time for maximum conversion of sugars into ethanol. Saccharomyces cerevisiae strain (Saf-instant with cell concentration of 400 millions/mL at molasses sugar level of 13%–15% (pH 4.6±0.2, Temp. 32∘C±1, inoculum size of 25% (v/v, urea concentration, 150 ppm, DAP, 53.4 ppm and Lactrol,150 ppm supported maximum ethanol production (8.8% with YP/S=250 L ethanol per tone molasses (96.5% yield, and had significantly lower concentrations of byproducts. By selecting higher ethanol yielding yeast strain and optimizing the fermentation parameters both yield and economics of the fermentation process can be improved.

  20. Ethanol Production by Fermentation of Various Sweet-Stalk Sorghum Juices Using Various Yeast Strains

    Directory of Open Access Journals (Sweden)

    Donny Widianto

    2015-11-01

    Full Text Available The ethanol production by fermentation of sweet-stalk sorghum juice is affected by the juice composition and the capability of the yeast strain to ferment it. Eight yeast strains were tested on their growth and ethanol fermentation abilities in sweet-stalk sorghum juices extracted from three cultivars of sweet sorghum. The best specific growth rate of the yeast strains grown aerobically in the yeast extract peptone dextrose (YEPD broth and the sweet-stalk sorghum juices of KCS105, FS501, and FS902 cultivars, were achieved by OUT7903, OUT7913, OUT7903, and OUT7027 yeast strains, respectively. However, the best specific CO2 evolution rate of the yeast strain during fermentation of the juices was achieved by OUT7027 yeast strains. The highest ethanol concentration, ethanol yield, and sugar conversion efficiency (SCE were obtained by strain OUT7921 when it was employed to ferment sweet-stem sorghum juice of FS902 cultivar. It was also observed that the juice extracted from sweet-stalk sorghum of FS902 cultivar is the most suitable medium for all yeast strains to achieve their best fermentation abilities. Thus, it is likely that the growth and ethanol production ability of a yeast strain in sweet-stalk sorghum juice depend on the physiological responses of the yeasts to nutrientcomposition of the sorghum juice and the sorghum cultivar from which the juice was extracted.Key words : Sweet-stalk sorghum juice, ethanol, fermentation, yeast

  1. 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.

  2. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    Science.gov (United States)

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  3. Ethanol production via fungal decomposition and fermentation of biomass. Phase II (FY 1981) annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Antonopoulos, A. A.; Wene, E. G.

    1981-10-01

    This program has as its main goal the isolation and development of Fusarium strains that can efficiently and economically decompose plant polysaccharides to pentoses and hexoses and ferment them to ethanol for fuel purposes. During Phase II (FY 1981) of this program, more than 800 new Fusarium isolates were isolated and screened. All showed cellulolytic activity. The Fusarium mutant ANL 3-72181 (derived after uv exposure of ANL 22 isolate) produced 2.45 iu cellulase after 14 days. This cellulase activity was achieved in the presence of 0.7 mg/mL extracellular protein. In separate tests, the use of both proteose peptone and yeast extract with 1% cellulose increased the production of extracellular protein three times over that on cellulose alone. Initial fermentation by Fusarium strains on 1% glucose produced up to 4.2 mg/mL ethanol in 48 hours. All Fusarium isolates and mutants found during this period were screened for xylose fermentation. Ethanol production during early experimentation required from 120 to 144 hours to yield 4.0 to 4.5 mg/mL ethanol from 1% xylose solutions. Through continuous selection of isolates, this time was reduced to 66 hours. By recycling Fusarium cell mass, fermentations of 1% xylose yielded 4.0 to 4.3 mg/mL ethanol in 48 hours. Consecutive fermentations of 2% xylose produced an average of 8.1 mg/mL ethanol in 48 hours. Fermentation of a 4.5% xylose + 2% glucose solution produced 21 mg/mL ethanol and 0.8 mg/mL acetic acid, while fermentation of a 7% xylose + 2% glucose solution yielded 25.5 mg/mL ethanol and 0.85 mg/mL acetic acid; these fermentations were aerated at a rate of 0.03 v/v-min.

  4. Ethanol Production from Banana Fruit and its Lignocellulosic Residues: Exergy and Renewability Analysis

    Directory of Open Access Journals (Sweden)

    Silvio de Oliveira Júnior

    2009-09-01

    Full Text Available

    Tropical countries such as Brazil and Colombia have the possibility of using their lands for growing vegetable products to produce biofuels such as biodiesel and ethanol. The objective of this work is to apply exergy analysis to evaluate the renewability of anhydrous ethanol production from surplus banana fruit production and its residual biomass. The study takes into account all production stages: growing, feedstock transport, hydrolysis, fermentation, distillation, and dehydration. It also considers the cogeneration plant and residues treatment. Four production routes were analyzed according to the biomass used as feedstock: banana pulp, banana fruit, hanging cluster or banana skin. Based on the exergy concept, performance indicators are proposed and calculated. In order to quantify the renewability of the ethanol production processes, a new indicator called “Renewability Performance Indicator” is defined and applied to the four ethanol production routes studied. The results show that when amilaceous material is used, better results than lignocellulosic material are obtained and four production processes studied must be classified as non-renewable.

    • This paper is an updated version of a paper published in the ECOS'08 proceedings. 

  5. Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

    NARCIS (Netherlands)

    Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel; Rossum, van Guus; Berruti, Franco; Kersten, Sascha; Rehmann, Lars

    2016-01-01

    Background One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when comp

  6. Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach

    NARCIS (Netherlands)

    Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel Johannes Maria; van Rossum, G.; Berruti, Franco; Kersten, Sascha R.A.; Rehmann, Lars

    2016-01-01

    Background One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when

  7. 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.

  8. High temperature dilute phosphoric acid pretreatment of corn stover for furfural and ethanol production

    Science.gov (United States)

    Furfural was produced from corn stover by one stage pretreatment process using dilute H3PO4 and solid residues following furfural production were used for ethanol production by Saccharomyces cerevisiae NRRL- Y2034. A series of experiments were conducted at varied temperatures (140-200 oC) and acid ...

  9. Xylitol synthesis mutant of xylose-utilizing zymomonas for ethanol production

    Science.gov (United States)

    Viitanen, Paul V.; Chou, Yat-Chen; McCutchen, Carol M.; Zhang, Min

    2010-06-22

    A strain of xylose-utilizing Zymomonas was engineered with a genetic modification to the glucose-fructose oxidoreductase gene resulting in reduced expression of GFOR enzyme activity. The engineered strain exhibits reduced production of xylitol, a detrimental by-product of xylose metabolism. It also consumes more xylose and produces more ethanol during mixed sugar fermentation under process-relevant conditions.

  10. Ethanol production from hot-water sugar maple wood extract hydrolyzate: fermentation media optimization for Escherichia coli FBWHR

    National Research Council Canada - National Science Library

    Yang Wang; Chenhui Liang; Shijie Liu

    2015-01-01

    .... Response surface methodology was employed to investigate the effect of fermentation media on the ethanol production from concentrated hot-water sugar maple hemicellulosic wood extract hydrolyzate...

  11. Expansion of sugarcane ethanol production in Brazil: environmental and social challenges.

    Science.gov (United States)

    Martinelli, Luiz A; Filoso, Solange

    2008-06-01

    Several geopolitical factors, aggravated by worries of global warming, have been fueling the search for and production of renewable energy worldwide for the past few years. Such demand for renewable energy is likely to benefit the sugarcane ethanol industry in Brazil, not only because sugarcane ethanol has a positive energetic balance and relatively low production costs, but also because Brazilian ethanol has been successfully produced and used as biofuel in the country since the 1970s. However, environmental and social impacts associated with ethanol production in Brazil can become important obstacles to sustainable biofuel production worldwide. Atmospheric pollution from burning of sugarcane for harvesting, degradation of soils and aquatic systems, and the exploitation of cane cutters are among the issues that deserve immediate attention from the Brazilian government and international societies. The expansion of sugarcane crops to the areas presently cultivated for soybeans also represent an environmental threat, because it may increase deforestation pressure from soybean crops in the Amazon region. In this paper, we discuss environmental and social issues linked to the expansion of sugarcane in Brazil for ethanol production, and we provide recommendations to help policy makers and the Brazilian government establish new initiatives to produce a code for ethanol production that is environmentally sustainable and economically fair. Recommendations include proper planning and environmental risk assessments for the expansion of sugarcane to new regions such as Central Brazil, improvement of land use practices to reduce soil erosion and nitrogen pollution, proper protection of streams and riparian ecosystems, banning of sugarcane burning practices, and fair working conditions for sugarcane cutters. We also support the creation of a more constructive approach for international stakeholders and trade organizations to promote sustainable development for biofuel

  12. Continuous ethanol production from pineapple cannery waste using immobilized yeast cells.

    Science.gov (United States)

    Nigam, J N

    2000-06-23

    The cells of Saccharomyces cerevisiae ATCC 24553, were immobilized in k-carrageenan and packed in a tapered glass column reactor for ethanol production from pineapple cannery waste at temperature 30 degrees C and pH 4.5. The maximum productivity was 42.8 g ethanol 1(-1) h(-1) at a dilution rate of 1.5 h(-1). The volumetric ethanol productivity of the immobilized cells was ca. 11.5 times higher than the free cells. The immobilized cell reactor was operated over a period of 87 days at a dilution rate of 1.0 h(-1), without any loss in the immobilized cell activity. The maximum specific ethanol productivity and specific sugar uptake rate of the immobilized cells were 1.2 g ethanol g(-1) dry wt. cell h(-1) and 2.6 g sugar g(-1) dry wt. cell h(-1), respectively, at a dilution rate of 1.5 h(-1).

  13. Ethanol increase PGE and thromboxane production in mouse pregnant uterine tissue

    Energy Technology Data Exchange (ETDEWEB)

    Anton, R.F.; Becker, H.C.; Randall, C.L. (Veterans Administration Medical Center, Charleston, SC (USA))

    1990-01-01

    The teratogenic effect of ethanol in the C57BL/6J mouse can be attenuated by pretreatment with aspirin (ASA). One prominent effect of ASA is to inhibit prostaglandin (PGE) and thromboxane (TXB{sub 2}) production. We examined the effect in vivo ethanol exposure on PGE and TXB{sub 2} production in a uterine-embryo tissue sample of C57BL/6J mice either before or after in vivo ASA pretreatment on day 10 of gestation. Ethanol increase both PGE and TXB{sub 2} production by approximately 20%. ASA caused a marked reduction of PGE and TXB{sub 2} in both control and ethanol groups by approximately 80-90%. The mouse strain, gestation time, and study parameters used in this study were the same as in the previously reported ASA attenuation of the teratogenic effect of ethanol. Therefore, the present data add additional support to the hypothesis that prostaglandin and/or thromboxane production may be involved in at least some aspects of fetal alcohol syndrome.

  14. 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

  15. Enhancement of xylose utilization from corn stover by a recombinant Escherichia coli strain for ethanol production.

    Science.gov (United States)

    Saha, Badal C; Qureshi, Nasib; Kennedy, Gregory J; Cotta, Michael A

    2015-08-01

    Effects of substrate-selective inoculum prepared by growing on glucose, xylose, arabinose, GXA (glucose, xylose, arabinose, 1:1:1) and corn stover hydrolyzate (dilute acid pretreated and enzymatically hydrolyzed, CSH) on ethanol production from CSH by a mixed sugar utilizing recombinant Escherichia coli (strain FBR5) were investigated. The initial ethanol productivity was faster for the seed grown on xylose followed by GXA, CSH, glucose and arabinose. Arabinose grown seed took the longest time to complete the fermentation. Delayed saccharifying enzyme addition in simultaneous saccharification and fermentation of dilute acid pretreated CS by the recombinant E. coli strain FBR5 allowed the fermentation to finish in a shorter time than adding the enzyme simultaneously with xylose grown inoculum. Use of substrate selective inoculum and fermenting pentose sugars first under glucose limited condition helped to alleviate the catabolite repression of the recombinant bacterium on ethanol production from lignocellulosic hydrolyzate.

  16. Bio-ethanol production from non-food parts of cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Nuwamanya, Ephraim; Chiwona-Karltun, Linley; Kawuki, Robert S; Baguma, Yona

    2012-05-01

    Global climate issues and a looming energy crisis put agriculture under pressure in Sub-Saharan Africa. Climate adaptation measures must entail sustainable development benefits, and growing crops for food as well as energy may be a solution, removing people from hunger and poverty without compromising the environment. The present study investigated the feasibility of using non-food parts of cassava for energy production and the promising results revealed that at least 28% of peels and stems comprise dry matter, and 10 g feedstock yields >8.5 g sugar, which in turn produced >60% ethanol, with pH ≈ 2.85, 74-84% light transmittance and a conductivity of 368 mV, indicating a potential use of cassava feedstock for ethanol production. Thus, harnessing cassava for food as well as ethanol production is deemed feasible. Such a system would, however, require supportive policies to acquire a balance between food security and fuel.

  17. Biological production of ethanol from coal. Task 4 report, Continuous reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    1992-10-01

    The production of ethanol from synthesis gas by the anaerobic bacterium C. ljungdahlii has been demonstrated in continuous stirred tank reactors (CSTRs), CSTRs with cell recycle and trickle bed reactors. Various liquid media were utilized in these studies including basal medium, basal media with 1/2 B-vitamins and no yeast extract and a medium specifically designed for the growth of C. ljungdahlii in the CSTR. Ethanol production was successful in each of the three reactor types, although trickle bed operation with C. ljungdahlii was not as good as with the stirred tank reactors. Operation in the CSTR with cell recycle was particularly promising, producing 47 g/L ethanol with only minor concentrations of the by-product acetate.

  18. Bio-ethanol production from non-food parts of Cassava (Manihot esculenta Crantz)

    Energy Technology Data Exchange (ETDEWEB)

    Nuwamanya, Ephraim; Kawuki, Robert S.; Baguma, Yona [National Agricultural Research organization, National Crops Resources Research Inst. (NaCRRI), Kampala (Uganda); Chiwona-Karltun, Linley [Dept. of Urban and Rural Development, Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)], email: Linley.karltun@slu.se

    2012-03-15

    Global climate issues and a looming energy crisis put agriculture under pressure in Sub-Saharan Africa. Climate adaptation measures must entail sustainable development benefits, and growing crops for food as well as energy may be a solution, removing people from hunger and poverty without compromising the environment. The present study investigated the feasibility of using non-food parts of cassava for energy production and the promising results revealed that at least 28% of peels and stems comprise dry matter, and 10 g feedstock yields >8.5 g sugar, which in turn produced >60% ethanol, with pH {approx} 2.85, 74-84% light transmittance and a conductivity of 368 mV, indicating a potential use of cassava feedstock for ethanol production. Thus, harnessing cassava for food as well as ethanol production is deemed feasible. Such a system would, however, require supportive policies to acquire a balance between food security and fuel.

  19. Correct quantitative determination of ethanol and volatile compounds in alcohol products

    CERN Document Server

    Charapitsa, Siarhei; Sytova, Svetlana; Yakuba, Yurii

    2014-01-01

    Determination of the volume content of ethanol in the alcohol products in practice is usually determined by pycnometry, electronic densimetry, or densimetry using a hydrostatic balance in accordance with Commission Regulation No 2870/2000. However, these methods determine directly only density of the tested liquid sample and does not take into account the effects of other volatile components such as aldehydes, esters and higher alcohols. So they are appropriate only for binary water-ethanol solutions in accordance with international table adopted by the International Legal Metrology Organization in its Recommendation No 22. Availability notable concentrations of the higher alcohols and ethers in different alcohol-based products, e. g. in whisky, cognac, brandy, wine as well as in waste alcohol and alcohol beverage production, leads to the significant contribution of these compounds in the value of the density of tested alcohol-containing sample. As a result, determination of the volume of ethanol content for ...

  20. Optimization of a corn steep medium for production of ethanol from synthesis gas fermentation by Clostridium ragsdalei.

    Science.gov (United States)

    Saxena, Jyotisna; Tanner, Ralph S

    2012-04-01

    Fermentation of biomass derived synthesis gas to ethanol is a sustainable approach that can provide more usable energy and environmental benefits than food-based biofuels. The effects of various medium components on ethanol production by Clostridium ragsdalei utilizing syngas components (CO:CO(2)) were investigated, and corn steep liquor (CSL) was used as an inexpensive nutrient source for ethanol production by C. ragsdalei. Elimination of Mg(2+), NH(4) (+) and PO(4) (3-) decreased ethanol production from 38 to 3.7, 23 and 5.93 mM, respectively. Eliminating Na(+), Ca(2+), and K(+) or increasing Ca(2+), Mg(2+), K(+), NH(4) (+) and PO(4) (3-) concentrations had no effect on ethanol production. However, increased Na(+) concentration (171 mM) inhibited growth and ethanol production. Yeast extract (0.5 g l(-1)) and trace metals were necessary for growth of C. ragsdalei. CSL alone did not support growth and ethanol production. Nutrients limiting in CSL were trace metals, NH(4) (+) and reducing agent (Cys: cysteine sulfide). Supplementation of trace metals, NH(4) (+) and CyS to CSL (20 g l(-1), wet weight basis) yielded better growth and similar ethanol production as compared to control medium. Using 10 g l(-1), the nutritional limitation led to reduced ethanol production. Higher concentrations of CSL (50 and 100 g l(-1)) were inhibitory for cell growth and ethanol production. The CSL could replace yeast extract, vitamins and minerals (excluding NH(4) (+)). The optimized CSL medium produced 120 and 50 mM of ethanol and acetate, respectively. The CSL could provide as an inexpensive source of most of the nutrients required for the syngas fermentation, and thus could improve the economics of ethanol production from biomass derived synthesis gas by C. ragsdalei.

  1. Ethanol and hydrogen production by two thermophilic, anaerobic bacteria isolated from Icelandic geothermal areas.

    Science.gov (United States)

    Koskinen, Perttu E P; Beck, Steinar R; Orlygsson, Jóhann; Puhakka, Jaakko A

    2008-11-01

    Microbial fermentations are potential producers of sustainable energy carriers. In this study, ethanol and hydrogen production was studied by two thermophilic bacteria (strain AK15 and AK17) isolated from geothermal springs in Iceland. Strain AK15 was affiliated with Clostridium uzonii (98.8%), while AK17 was affiliated with Thermoanaerobacterium aciditolerans (99.2%) based on the 16S rRNA gene sequence analysis. Both strains fermented a wide variety of sugar residues typically found in lignocellulosic materials, and some polysaccharides. In the batch cultivations, strain AK17 produced ethanol from glucose and xylose fermentations of up to 1.6 mol-EtOH/mol-glucose (80% of the theoretical maximum) and 1.1 mol-EtOH/mol-xylose (66%), respectively. The hydrogen yields by AK17 were up to 1.2 mol-H2/ mol-glucose (30% of the theoretical maximum) and 1.0 mol-H2/mol-xylose (30%). The strain AK15 produced hydrogen as the main fermentation product from glucose (up to 1.9 mol-H2/mol-glucose [48%]) and xylose (1.1 mol-H2/mol-xylose [33%]). The strain AK17 tolerated exogenously added ethanol up to 4% (v/v). The ethanol and hydrogen production performance from glucose by a co-culture of the strains AK15 and AK17 was studied in a continuous-flow bioreactor at 60 degrees C. Stable and continuous ethanol and hydrogen co-production was achieved with ethanol yield of 1.35 mol-EtOH/mol-glucose, and with the hydrogen production rate of 6.1 mmol/h/L (H2 yield of 0.80 mol-H2/mol-glucose). PCR-DGGE analysis revealed that the AK17 became the dominant bacterium in the bioreactor. In conclusion, strain AK17 is a promising strain for the co-production of ethanol and hydrogen with a wide substrate utilization spectrum, relatively high ethanol tolerance, and ethanol yields among the highest reported for thermoanaerobes.

  2. Ethanol-induced leakage in Saccharomyces cerevisiae: kinetics and relationship to yeast ethanol tolerance and alcohol fermentation productivity

    Energy Technology Data Exchange (ETDEWEB)

    Salgueiro, S.P.; Sa-Correia, I.; Novais, J.M.

    1988-04-01

    Ethanol stimulated the leakage of amino acids and 260-nm-light-absorbing compounds from cells of Saccharomyces cerevisiae. The efflux followed first-order kinetics over an initial period. In the presence of lethal concentrations of ethanol, the efflux rates at 30 and 36/sup 0/C were an exponential function of ethanol concentration. At 36/sup 0/C, as compared with the corresponding values at 30/sup 0/C, the efflux rates were higher and the minimal concentration of ethanol was lower. The exponential constants for the enhancement of the rate of leakage had similar values at 30 or 36/sup 0/C and were of the same order of magnitude as the corresponding exponential constants for ethanol-induced death. Under isothermic conditions (30/sup 0/C) and up to 22% (vol/vol) ethanol, the resistance to ethanol-induced leakage of 260-nm-light-absorbing compounds was found to be closely related with the ethanol tolerance of three strains of yeasts, Kluyveromyces marxianus, Saccharomyces cerevisiae, and Saccharomyces bayanus. The resistance to ethanol-induced leakage indicates the possible adoption of the present method for the rapid screening of ethanol-tolerant strains. The addition to a fermentation medium of the intracellular material obtained by ethanol permeabilization of yeast cells led to improvements in alcohol fermentation by S. cerevisiae and S. bayanus. The action of the intracellular material, by improving yeast ethanol tolerance, and the advantages of partially recycling the fermented medium after distillation were discussed.

  3. Direct ethanol production from glucose, xylose and sugarcane bagasse by the corn endophytic fungi Fusarium verticillioides and Acremonium zeae.

    Science.gov (United States)

    de Almeida, Maíra N; Guimarães, Valéria M; Falkoski, Daniel L; Visser, Evan M; Siqueira, Germano A; Milagres, Adriane M F; de Rezende, Sebastião T

    2013-10-10

    Production of ethanol with two corn endophytic fungi, Fusarium verticillioides and Acremonium zeae, was studied. The yield of ethanol from glucose, xylose and a mixture of both sugars were 0.47, 0.46 and 0.50g/g ethanol/sugar for F. verticillioides and 0.37, 0.39 and 0.48g/g ethanol/sugar for A. zeae. Both fungi were able to co-ferment glucose and xylose. Ethanol production from 40g/L of pre-treated sugarcane bagasse was 4.6 and 3.9g/L for F. verticillioides and A. zeae, respectively, yielding 0.31g/g of ethanol per consumed sugar. Both fungi studied were capable of co-fermenting glucose and xylose at high yields. Moreover, they were able to produce ethanol directly from lignocellulosic biomass, demonstrating to be suitable microorganisms for consolidated bioprocessing.

  4. Automated production GMAX-L strains of Saccharomyces cereviciae for profitable sustainable cellulosic ethanol production combined with valuable coproduct isolation in mixed biorefinery settings

    Science.gov (United States)

    Second generation cellulosic ethanol production is beginning in a variety of formats and using various ethanologenic microbes. The best possibility would be to produce cellulosic ethanol using a Saccharomyces cereviciae that has been engineered to produce ethanol from pentose as well as hexose suga...

  5. Improvement of the ethanol productivity in a high gravity brewing at pilot plant scale.

    Science.gov (United States)

    Dragone, Giuliano; Silva, Daniel P; de Almeida e Silva, João Batista; de Almeida Lima, Urgel

    2003-07-01

    A 23 full factorial design was used to study the influence of different experimental variables, namely wort gravity, fermentation temperature and nutrient supplementation, on ethanol productivity from high gravity wort fermentation by Saccharomyces cerevisiae (lager strain), under pilot plant conditions. The highest ethanol productivity (0.69 g l(-1) h(-1)) was obtained at 20 degrees P [degrees P is the weight of extract (sugar) equivalent to the weight of sucrose in a 100 g solution at 20 degrees C], 15 degrees C, with the addition of 0.8% (w/v) yeast extract, 24 mg l(-1) ergosterol and 0.24% (v/v) Tween 80.

  6. Reaction product analysis of aconitine in dilute ethanol using ESI-Q-ToF-MS.

    Science.gov (United States)

    Tan, Peng; Liu, Yong-Gang; Li, Fei; Qiao, Yan-Jiang

    2012-04-01

    The study was done to identify the reaction products of aconitine in dilute ethanol using electrospray ionization-triple quad time-of-flight mass spectrometry (ESI-Q-TOF-MS). Five hydrolysates were detected, their pseudo-molecules are 632, 604, 586, 570, 500, they are 8-ethyoxyl-14-benzoylaconitine, benzoylaconine, pyraconitine, 8-acetyl-14-ethyoxylaconitine, aconine, respectively. Among them, 8-ethyoxyl-14-benzoylaconitine and 8-acetyl-14-ethyoxylaconitine were identified firstly as reaction products of aconitine in dilute ethanol, and can thus be used as indicators in quality control of medicinal Aconitum preparations used in Traditional Chinese Medicine.

  7. Effects of potassium chloride on ethanol production by an osmotolerant mutant of Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.C.; Baratti, K. (Centre National de la Recherche Scientifique, Lab. de Chimie Bacterienne Universite de Provence, 13 - Marseille (France))

    1993-01-01

    The effect of increasing the KCl concentration in the culture medium of an alcoholic fermentation of glucose using the bacterium Zymomanas mobilis was investigated. Data obtained with the wild-type strain (ZM4, ATCC 31821) and with a newly isolated osmotolerant mutant (SBE15) were compared. It was observed that, at high salt concentration, inhibition of growth occurred (specific growth rate and biomass yield) while ethanol production (specific ethanol productivity and ethanol yield) was unaffected. In contrast, the specific rate of in-vitro ethanol production, using either cell-free extract or washed cells, was strongly inhibited by increasing the KCl concentration in the incubation mixture. Therefore, it was concluded that the intracellular concentration of KCl was maintained below the inhibitory concentration by an active transport system. In addition, the fermentation performances of the osmotolerant mutant strain were higher than those of the parent strain at all the KCl concentrations tested, suggesting the utility of the former to run ethanolic fermentations in crude industrial media with a high salt content. Furthermore, the fermentation data on media containing added KCl agreed well with those obtained on molasses media, suggesting that the inhibition observed on these media was due to their high osmolality. (orig.).

  8. Kinetic modeling of simultaneous saccharification and fermentation of corn starch for ethanol production.

    Science.gov (United States)

    Białas, Wojciech; Czerniak, Adrian; Szymanowska-Powałowska, Daria

    2014-01-01

    Fuel ethanol production, using a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed using Saccharomyces cerevisiae and a granular starch hydrolyzing enzyme. The quantitative effects of mash concentration, enzyme dose and pH were investigated with the use of a Box-Wilson central composite design protocol. Proceeding from results obtained in optimal fermentation conditions, a kinetics model relating the utilization rates of starch and glucose as well as the production rates of ethanol and biomass was tested. Moreover, scanning electron microscopy (SEM) was applied to investigate corn starch granule surface after the SFF process. A maximum ethanol concentration of 110.36 g/l was obtained for native corn starch using a mash concentration of 25%, which resulted in ethanol yield of 85.71%. The optimal conditions for the above yield were found with an enzyme dose of 2.05 ml/kg and pH of 5.0. These results indicate that by using a central composite design, it is possible to determine optimal values of the fermentation parameters for maximum ethanol production. The investigated kinetics model can be used to describe SSF process conducted with granular starch hydrolyzing enzymes. The SEM micrographs reveal randomly distributed holes on the surface of granules.

  9. Enhancing ethanol production from thermophilic and mesophilic solid digestate using ozone combined with aqueous ammonia pretreatment.

    Science.gov (United States)

    Wang, Dianlong; Xi, Jiang; Ai, Ping; Yu, Liang; Zhai, Hong; Yan, Shuiping; Zhang, Yanlin

    2016-05-01

    Pretreatment with ozone combined with aqueous ammonia was used to recover residual organic carbon from recalcitrant solid digestate for ethanol production after anaerobic digestion (AD) of rice straw. Methane yield of AD at mesophilic and thermophilic conditions, and ethanol production of solid digestate were investigated. The results showed that the methane yield at thermophilic temperature was 72.2% higher than that at mesophilic temperature under the same conditions of 24days and 17% solid concentration. And also the ethanol production efficiency of solid digestate after thermophilic process was 24.3% higher than that of solid digestate after mesophilic process. In this study, the optimal conditions for integrated methane and ethanol processes were determined as 55°C, 17% solid concentration and 24days. 58.6% of glucose conversion, 142.8g/kg of methane yield and 65.2g/kg of ethanol yield were achieved, and the highest net energy balance was calculated as 6416kJ/kg.

  10. Impact of Furfural on Rapid Ethanol Production Using a Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Mohammad J. Taherzadeh

    2013-03-01

    Full Text Available A membrane bioreactor was developed to counteract the inhibition effect of furfural in ethanol production. Furfural, a major inhibitor in lignocellulosic hydrolyzates, is a highly toxic substance which is formed from pentose sugars released during the acidic degradation of lignocellulosic materials. Continuous cultivations with complete cell retention were performed at a high dilution rate of 0.5 h−1. Furfural was added directly into the bioreactor by pulse injection or by addition into the feed medium to obtain furfural concentrations ranging from 0.1 to 21.8 g L−1. At all pulse injections of furfural, the yeast was able to convert the furfural very rapidly by in situ detoxification. When injecting 21.8 g L−1 furfural to the cultivation, the yeast converted it by a specific conversion rate of 0.35 g g−1 h−1. At high cell density, Saccharomyces cerevisiae could tolerate very high furfural levels without major changes in the ethanol production. During the continuous cultures when up to 17.0 g L−1 furfural was added to the inlet medium, the yeast successfully produced ethanol, whereas an increase of furfural to 18.6 and 20.6 g L−1 resulted in a rapidly decreasing ethanol production and accumulation of sugars in the permeate. This study show that continuous ethanol fermentations by total cell retention in a membrane bioreactor has a high furfural tolerance and can conduct rapid in situ detoxification of medium containing high furfural concentrations.

  11. Ethanol production using whole plant biomass of Jerusalem artichoke by Kluyveromyces marxianus CBS1555.

    Science.gov (United States)

    Kim, Seonghun; Park, Jang Min; Kim, Chul Ho

    2013-03-01

    Jerusalem artichoke is a low-requirement sugar crop containing cellulose and hemicellulose in the stalk and a high content of inulin in the tuber. However, the lignocellulosic component in Jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. In this study, Jerusalem artichoke stalk was pretreated sequentially with dilute acid and alkali, and then hydrolyzed enzymatically. During enzymatic hydrolysis, approximately 88 % of the glucan and xylan were converted to glucose and xylose, respectively. Batch and fed-batch simultaneous saccharification and fermentation of both pretreated stalk and tuber by Kluyveromyces marxianus CBS1555 were effectively performed, yielding 29.1 and 70.2 g/L ethanol, respectively. In fed-batch fermentation, ethanol productivity was 0.255 g ethanol per gram of dry Jerusalem artichoke biomass, or 0.361 g ethanol per gram of glucose, with a 0.924 g/L/h ethanol productivity. These results show that combining the tuber and the stalk hydrolysate is a useful strategy for whole biomass utilization in effective bioethanol fermentation from Jerusalem artichoke.

  12. Enhanced camptothecin production by ethanol addition in the suspension culture of the endophyte, Fusarium solani.

    Science.gov (United States)

    Venugopalan, Aarthi; Srivastava, Smita

    2015-01-01

    Ethanolic extract of a non-camptothecin producing plant, Catharanthus roseus when added in the suspension culture of the endophyte Fusarium solani known to produce camptothecin, resulted in enhanced production of camptothecin by 10.6-fold in comparison to that in control (2.8 μg/L). Interestingly, addition of pure ethanol (up to 5% v/v) in the suspension culture of F. solani resulted in maximum enhancement in camptothecin production (up to 15.5-fold) from that obtained in control. In the presence of ethanol, a reduced glucose uptake (by ∼ 40%) and simultaneous ethanol consumption (up to 9.43 g/L) was observed during the cultivation period (14 days). Also, the total NAD level and the protein content in the biomass increased by 3.7- and 1.9-fold, respectively, in comparison to that in control. The study indicates a dual role of ethanol, presumably as an elicitor and also as a carbon/energy source, leading to enhanced biomass and camptothecin production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Bio-ethanol steam reforming: Insights on the mechanism for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Benito, M.; Sanz, J.L.; Isabel, R.; Padilla, R.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), Campus Cantoblanco, 28049 Madrid (Spain); Arjona, R. [Greencell (ABENGOA BIOENERGIA), Av. de la Buhaira 2, 41018 Sevilla (Spain)

    2005-10-10

    New catalysts for hydrogen production by steam reforming of bio-ethanol have been developed. Catalytic tests have been performed at laboratory scale, with the reaction conditions demanded in a real processor: i.e. ethanol and water feed, without a diluent gas. Catalyst ICP0503 has shown high activity and good resistance to carbon deposition. Reaction results show total conversion, high selectivity to hydrogen (70%), CO{sub 2}, CO and CH{sub 4} being the only by-products obtained. The reaction yields 4.25mol of hydrogen by mol of ethanol fed, close to the thermodynamic equilibrium prediction. The temperature influence on the catalytic activity for this catalyst has been studied. Conversion reaches 100% at temperature higher than 600{sup o}C. In the light of reaction results obtained, a reaction mechanism for ethanol steam reforming is proposed. Long-term reaction experiments have been performed in order to study the stability of the catalytic activity. The excellent stability of the catalyst ICP0503 indicates that the reformed stream could be fed directly to a high temperature fuel cell (MCFC, SOFC) without a further purification treatment. These facts suggest that ICP0503 is a good candidate to be implemented in a bio-ethanol processor for hydrogen production to feed a fuel cell. (author)

  14. Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations

    Directory of Open Access Journals (Sweden)

    Päivi Ylitervo

    2014-07-01

    Full Text Available The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L−1 acetic acid at pH 5.0, at a dilution rate of 0.5 h−1. The cultivations were performed at both high (~25 g·L−1 and very high (100–200 g·L−1 yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L−1 sucrose, at volumetric rates of 5–6 g·L−1·h−1 at acetic acid concentrations up to 15.0 g·L−1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L−1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials.

  15. Security of feedstocks supply for future bio-ethanol production in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Silalertruksa, Thapat; Gheewala, Shabbir H. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 126 Prachauthit Road, Bangkok 10140 (Thailand)

    2010-11-15

    This study assesses the security of feedstock supply to satisfy the increased demand for bio-ethanol production based on the recent 15 years biofuels development plan and target (year 2008-2022) of the Thai government. Future bio-ethanol systems are modeled and the feedstock supply potentials analyzed based on three scenarios including low-, moderate- and high-yields improvement. The three scenarios are modeled and key dimensions including availability; diversity; and environmental acceptability of feedstocks supply in terms of GHG reduction are evaluated through indicators such as net feedstock balances, Shannon index and net life cycle GHG emissions. The results show that only the case of high yields improvement scenario can result in a reliable and sufficient supply of feedstocks to satisfy the long-term demands for bio-ethanol and other related industries. Cassava is identified as the critical feedstock and a reduction in cassava export is necessary. The study concludes that to enhance long-term security of feedstocks supply for sustainable bio-ethanol production in Thailand, increasing use of sugarcane juice as feedstock, improved yields of existing feedstocks and promoting production of bio-ethanol derived from agricultural residues are three key recommendations that need to be urgently implemented by the policy makers. (author)

  16. Determination of Ethanol in Kombucha Products: Single-Laboratory Validation, First Action 2016.12.

    Science.gov (United States)

    Ebersole, Blake; Liu, Ying; Schmidt, Rich; Eckert, Matt; Brown, Paula N

    2017-05-01

    Kombucha is a fermented nonalcoholic beverage that has drawn government attention due to the possible presence of excess ethanol (≥0.5% alcohol by volume; ABV). A validated method that provides better precision and accuracy for measuring ethanol levels in kombucha is urgently needed by the kombucha industry. The current study validated a method for determining ethanol content in commercial kombucha products. The ethanol content in kombucha was measured using headspace GC with flame ionization detection. An ethanol standard curve ranging from 0.05 to 5.09% ABV was used, with correlation coefficients greater than 99.9%. The method detection limit was 0.003% ABV and the LOQ was 0.01% ABV. The RSDr ranged from 1.62 to 2.21% and the Horwitz ratio ranged from 0.4 to 0.6. The average accuracy of the method was 98.2%. This method was validated following the guidelines for single-laboratory validation by AOAC INTERNATIONAL and meets the requirements set by AOAC SMPR 2016.001, "Standard Method Performance Requirements for Determination of Ethanol in Kombucha."

  17. Ethanolic fermentation in whey and whey-molasses mixtures. Pt. 2. Two-stage fermentation process of ethanol production from whey and beet molasses

    Energy Technology Data Exchange (ETDEWEB)

    Zakrzewski, E.; Zmarlicki, S.

    1988-01-01

    A two-stage fermentation process has been developed for ethanol production from regular or partly concentrated whey and molasses. In the first stage ethanolic fermentation in whey is performed with Kluyveromyces marxianus subsp. marxianus. Such prefermented whey is then used for dilution of molasses instead of water and the resulting medium subjected to the second stage fermentation performed with Saccharomyces cerevisiae. The process enables complete fermentation of lactose and all fermentble sugars from molasses, leading to an ethanol content of about 10% in the final medium, which makes the distillation much more economical than the separate processing of whey and molasses into spirit.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    2000-08-16

    Ethanol competes with methyl tertiary butyl ether (MTBE) to satisfy oxygen, octane, and volume requirements of certain gasolines. However, MTBE has water quality problems that may create significant market opportunities for ethanol. Oak Ridge National Laboratory (ORNL) has used its Refinery Yield Model to estimate ethanol demand in gasolines with restricted use of MTBE. Reduction of the use of MTBE would increase the costs of gasoline production and possibly reduce the gasoline output of U.S. refineries. The potential gasoline supply problems of an MTBE ban could be mitigated by allowing a modest 3 vol percent MTBE in all gasoline. In the U.S. East and Gulf Coast gasoline producing regions, the 3 vol percent MTBE option results in costs that are 40 percent less than an MTBE ban. In the U.S. Midwest gasoline producing region, with already high use of ethanol, an MTBE ban has minimal effect on ethanol demand unless gasoline producers in other regions bid away the local supply of ethanol. The ethanol/MTBE issue gained momentum in March 2000 when the Clinton Administration announced that it would ask Congress to amend the Clean Air Act to provide the authority to significantly reduce or eliminate the use of MTBE; to ensure that air quality gains are not diminished as MTBE use is reduced; and to replace the existing oxygenate requirement in the Clean Air Act with a renewable fuel standard for all gasoline. Premises for the ORNL study are consistent with the Administration announcement, and the ethanol demand curve estimates of this study can be used to evaluate the impact of the Administration principles and related policy initiatives.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......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...

  20. Enhanced Bio-Ethanol Production from Industrial Potato Waste by Statistical Medium Optimization.

    Science.gov (United States)

    Izmirlioglu, Gulten; Demirci, Ali

    2015-10-15

    Industrial wastes are of great interest as a substrate in production of value-added products to reduce cost, while managing the waste economically and environmentally. Bio-ethanol production from industrial wastes has gained attention because of its abundance, availability, and rich carbon and nitrogen content. In this study, industrial potato waste was used as a carbon source and a medium was optimized for ethanol production by using statistical designs. The effect of various medium components on ethanol production was evaluated. Yeast extract, malt extract, and MgSO₄·7H₂O showed significantly positive effects, whereas KH₂PO₄ and CaCl₂·2H₂O had a significantly negative effect (p-valueindustrial waste potato, 50 g/L malt extract, and 4.84 g/L MgSO₄·7H₂O was found optimal and yielded 24.6 g/L ethanol at 30 °C, 150 rpm, and 48 h of fermentation. In conclusion, this study demonstrated that industrial potato waste can be used effectively to enhance bioethanol production.

  1. Enhanced Bio-Ethanol Production from Industrial Potato Waste by Statistical Medium Optimization

    Directory of Open Access Journals (Sweden)

    Gulten Izmirlioglu

    2015-10-01

    Full Text Available Industrial wastes are of great interest as a substrate in production of value-added products to reduce cost, while managing the waste economically and environmentally. Bio-ethanol production from industrial wastes has gained attention because of its abundance, availability, and rich carbon and nitrogen content. In this study, industrial potato waste was used as a carbon source and a medium was optimized for ethanol production by using statistical designs. The effect of various medium components on ethanol production was evaluated. Yeast extract, malt extract, and MgSO4·7H2O showed significantly positive effects, whereas KH2PO4 and CaCl2·2H2O had a significantly negative effect (p-value < 0.05. Using response surface methodology, a medium consisting of 40.4 g/L (dry basis industrial waste potato, 50 g/L malt extract, and 4.84 g/L MgSO4·7H2O was found optimal and yielded 24.6 g/L ethanol at 30 °C, 150 rpm, and 48 h of fermentation. In conclusion, this study demonstrated that industrial potato waste can be used effectively to enhance bioethanol production.

  2. Enzymatical hydrolysis of food waste and ethanol production from the hydrolysate

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shoubao; Yao, Jianming [Key Laboratory of Ion Beam Bio-engineering of Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Jun; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao; Ye, Jianfeng [Hefei Research Center of Ion Beam Engineering and Technology, Hefei 230088 (China)

    2011-04-15

    The aim of present paper was to investigate the prospect for the use of food waste, an important municipal waste, as a potential substrate to generate hydrolysates for fuel ethanol production. The critical variables that affected reducing sugar production from food waste were identified by Plackett-Burman design (glucoamylase loud, time, temperature and pH) and further optimized by using a four factor central composite design of response surface methodology. According to the results of response surface analysis, the optimum conditions for reducing sugar production were determined to be glucoamylase loud of 142.2 u/g, saccharification pH of 4.82, enzyme reaction temperature of 55 C, enzyme reaction time of 2.48 h. Reducing sugar production (164.8 g/L) in the optimized condition was in good agreement with the value predicted by the quadratic model (164.3 g/L), thereby confirming its validity. Furthermore, the obtained liquid phase of food waste hydrolysate was utilized for production of ethanol by using Saccharomyces cerevisiae H058 fermentation. In order to develop an economical process for transforming food waste hydrolysates to ethanol, non-sterilized and sterilized processes were compared in the experiments. The result shows non-sterilized fermentation without undergoing heat treatment was better due to the unspoiled nutrients inside. These results helped to find the effective strategies to utilize food waste for ethanol production. (author)

  3. Obtaining petrochemical products from ethanol; Obtencao de produtos petroquimicos a partir do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Silverio, Carlos Augusto N.; Oliveira, Claudia Vasconcellos R. de; Joao, Rafael Richard; Hashizume, Tulio Kenji C. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Currently, high oil prices, low availability of traditional raw material (natural gas and petrochemical naphtha), increasing recognition of the importance of the preservation of nature and reducing emissions of pollutants have been creating a great opportunity for the petrochemical industry to seek alternative materials from renewable resources. The ethanol, which obtained a virtuous journey as fuel, is a very promising alternative to be used for the production of petrochemical products. However, the use of ethanol as a raw material will require a considerable increase in its production, what can be achieved through the development of new production technologies based on biomass and the construction of integrated biorefineries. So, this study aims to identify and compare conventional petrochemical routes with routes from this renewable raw material in order to evaluate their technical and economic feasibility. A preliminary analysis was performed between four petrochemical products: acetic acid, acetaldehyde, the ethyl acetate and ethylene. From this initial analysis, acetic acid and ethylene were selected for a more comprehensive feasibility study considering their production using ethanol as raw material, what is called ethanol chemistry. (author)

  4. Guide to commercial-scale ethanol production and financing

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    This document is designed to lead the potential investor through all the steps necessary to develop a business plan and prepare a feasibility analysis for a site-specific project. Emphasis is placed on marketing, financing, management, and incentives rather than primarily technical matters. The introduction provides an overview of the perspectives and issues in the alcohol fuels industry. Chapter II seeks to surface factors which affect the decisionmaking process. The chapter attempts to lead the investor step-by-step through the series of decisions and choices to be made before reaching the final decision to enter the business. Chapter III describes the types of feedstocks available and relates them to areas within the United States. Trends and fluctuations in the price of the major grain feedstocks are also discussed in terms of their potential use and value compared to other feeds. Chapter IV discusses the market potential of ethanol and its coproducts, and examines how the location of the ethanol markets in relation to those of the feedstock supplies may influence selection of a plant site. Various aspects of plant design are discussed. A 50 million gallon per year plant is analyzed to provide the general technical background and costing data required in analyzing plants of various sizes and designs. Safety aspects and environmental concerns are treated in Chapters VI and VII. The regulations are reviewed and their impact on plant design and operation is discussed. The basic elements of a business plan are described which lead to an approach for development of the feasibility study. Other information on financial assistance, regulations, current legislation, and reference material is given in the Appendices.

  5. Inhibition of ethanol-producing yeast and bacteria by degradation products produced during pre-treatment of biomass

    DEFF Research Database (Denmark)

    Klinke, H.B.; Thomsen, A.B.; Ahring, Birgitte Kiær

    2004-01-01

    An overview of the different inhibitors formed by pre-treatment of lignocellulosic materials and their inhibition of ethanol production in yeast and bacteria is given. Different high temperature physical pre-treatment methods are available to render the carbohydrates in lignocellulose accessible...... degradation, phenol monomers from lignin degradation are important co-factors in hydrolysate inhibition, and inhibitory effects of these aromatic compounds on different ethanol producing microorganisms is reviewed. The furans and phenols generally inhibited growth and ethanol production rate (Q...

  6. 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.

  7. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca.

    Science.gov (United States)

    van der Wal, Hetty; Sperber, Bram L H M; Houweling-Tan, Bwee; Bakker, Robert R C; Brandenburg, Willem; López-Contreras, Ana M

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).

  8. Effect of media supplementation on ethanol production by simultaneous saccharification and fermentation process

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, I.; Oliva, J.M.; Carrasco, J.C.; Ballesteros, M. (IER-CIEMAT, Madrid (Spain))

    In this study, fermentation tests of different initial glucose concentrations, ranging from 100 to 200 g/L, were conducted to identify the ethanol tolerance of Kluyveromyces marxianus (EMS-26 strain) at 42[degrees]C. Lipid and nutrient additions to the fermentation medium were made in order to improve the ethanol production at 42[degrees]C. The results obtained showed that the addition of unsaturated fatty acids and sterols to the SSF media reduced hydrolysis yields and ethanol production as compared to tests carried out on controls without lipid supplementation. These results seem to indicate that cellulases performed better when no lipid supplementation was used. The decrease in the saccharification in the presence of 0.5% Tween 80 (10% decrease in the filter paper activity) seems to be closely related to the denaturation of the cellulase complex rather than lipids interference with cellulase binding. 22 refs., 4 figs., 2 tabs.

  9. Ethanol production from oil palm trunks treated with aqueous ammonia and cellulase.

    Science.gov (United States)

    Jung, Young Hoon; Kim, In Jung; Kim, Jae Jin; Oh, Kyeong Keun; Han, Jong-In; Choi, In-Geol; Kim, Kyoung Heon

    2011-08-01

    Oil palm trunks are a possible lignocellulosic source for ethanol production. Low enzymatic digestibility of this type of material (11.9% of the theoretical glucose yield) makes pretreatment necessary. An enzymatic digestibility of 95.4% with insoluble solids recovery of 49.8% was achieved after soaking shredded oil palm trunks in ammonia under optimum conditions (80°C, 1:12 solid-to-liquid ratio, 8h and 7% (w/w) ammonia solution). Treatment with 60 FPU of commercial cellulase (Accellerase 1000) per gram of glucan and fermentation with Saccharomyces cerevisiae D(5)A resulted in an ethanol concentration of 13.3g/L and an ethanol yield of 78.3% (based on the theoretical maximum) after 96 h. These results indicate that oil palm trunks are a biomass feedstock that can be used for bioethanol production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Continuous Production of Ethanol from Starch Using Glucoamylase and Yeast Co-Immobilized in Pectin Gel

    Science.gov (United States)

    Giordano, Raquel L. C.; Trovati, Joubert; Schmidell, Willibaldo

    This work presents a continuous simultaneous saccharification and fermentation (SSF) process to produce ethanol from starch using glucoamylase and Saccharomyces cerevisiae co-immobilized in pectin gel. The enzyme was immobilized on macroporous silica, after silanization and activation of the support with glutaraldehyde. The silicaenzyme derivative was co-immobilized with yeast in pectin gel. This biocatalyst was used to produce ethanol from liquefied manioc root flour syrup, in three fixed bed reactors. The initial reactor yeast load was 0.05 g wet yeast/ml of reactor (0.1 g wet yeast/g gel), used in all SSF experiments. The enzyme concentration in the reactor was defined by running SSF batch assays, using different amount of silica-enzyme derivative, co-immobilized with yeast in pectin gel. The chosen reactor enzyme concentration, 3.77 U/ml, allowed fermentation to be the rate-limiting step in the batch experiment. In this condition, using initial substrate concentration of 166.0 g/1 of total reducing sugars (TRS), 1 ml gel/1 ml of medium, ethanol productivity of 8.3 g/l/h was achieved, for total conversion of starch to ethanol and 91% of the theoretical yield. In the continuous runs, feeding 163.0 g/1 of TRS and using the same enzyme and yeast concentrations used in the batch run, ethanol productivity was 5.9 g ethanol/1/h, with 97% of substrate conversion and 81% of the ethanol theoretical yield. Diffusion effects in the extra-biocatalyst film seemed to be reduced when operating at superficial velocities above 3.7 × 10-4 cm/s.

  11. Butanol production in acetone-butanol-ethanol fermentation with in situ product recovery by adsorption.

    Science.gov (United States)

    Xue, Chuang; Liu, Fangfang; Xu, Mengmeng; Tang, I-Ching; Zhao, Jingbo; Bai, Fengwu; Yang, Shang-Tian

    2016-11-01

    Activated carbon Norit ROW 0.8, zeolite CBV901, and polymeric resins Dowex Optipore L-493 and SD-2 with high specific loadings and partition coefficients were studied for n-butanol adsorption. Adsorption isotherms were found to follow Langmuir model, which can be used to estimate the amount of butanol adsorbed in acetone-butanol-ethanol (ABE) fermentation. In serum-bottle fermentation with in situ adsorption, activated carbon showed the best performance with 21.9g/L of butanol production. When operated in a fermentor, free- and immobilized-cell fermentations with adsorption produced 31.6g/L and 54.6g/L butanol with productivities of 0.30g/L·h and 0.45g/L·h, respectively. Thermal desorption produced a condensate containing ∼167g/L butanol, which resulted in a highly concentrated butanol solution of ∼640g/L after spontaneous phase separation. This in situ product recovery process with activated carbon is energy efficient and can be easily integrated with ABE fermentation for n-butanol production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Production of multiple extracellular enzyme activities by novel submerged culture of Aspergillus kawachii for ethanol production from raw cassava flour.

    Science.gov (United States)

    Sugimoto, Toshikazu; Makita, Tomohiro; Watanabe, Koutaro; Shoji, Hiroshi

    2012-04-01

    Cassava is a starch-containing root crop that is widely used as a raw material in a variety of industrial applications, most recently in the production of fuel ethanol. In the present study, ethanol production from raw (uncooked) cassava flour by simultaneous saccharification and fermentation (SSF) using a preparation consisting of multiple enzyme activities from Aspergillus kawachii FS005 was investigated. The multi-activity preparation was obtained from a novel submerged fermentation broth of A. kawachii FS005 grown on unmilled crude barley as a carbon source. The preparation was found to consist of glucoamylase, acid-stable α-amylase, acid carboxypeptidase, acid protease, cellulase and xylanase activities, and exhibited glucose and free amino nitrogen (FAN) production rates of 37.7 and 118.7 mg/l/h, respectively, during A. kawachii FS005-mediated saccharification of uncooked raw cassava flour. Ethanol production from 18.2% (w/v) dry uncooked solids of raw cassava flour by SSF with the multi-activity enzyme preparation yielded 9.0% (v/v) of ethanol and 92.3% fermentation efficiency. A feasibility study for ethanol production by SSF with a two-step mash using raw cassava flour and the multi-activity enzyme preparation manufactured on-site was verified on a pilot plant scale. The enzyme preparation obtained from the A. kawachii FS005 culture broth exhibited glucose and FAN production rates of 41.1 and 135.5 mg/l/h, respectively. SSF performed in a mash volume of about 1,612 l containing 20.6% (w/v) dry raw cassava solids and 106 l of on-site manufactured A. kawachii FS005 culture broth yielded 10.3% (v/v) ethanol and a fermentation efficiency of 92.7%.

  13. Ethanol production from dry-mill corn starch in a fluidized-bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M.S.; Nghiem, N.P.; Davison, B.H.

    1998-08-01

    The development of a high-rate process for the production of fuel ethanol from dry-mill corn starch using fluidized-bed bioreactor (FBR) technology is discussed. Experiments were conducted in a laboratory scale FBR using immobilized biocatalysts. Two ethanol production process designs were considered in this study. In the first design, simultaneous saccharification and fermentation was performed at 35 C using {kappa}-carageenan beads (1.5 mm to 1.5 mm in diameter) of co-immobilized glucoamylase and Zymomonas mobilis. For dextrin feed concentration of 100 g/L, the single-pass conversion ranged from 54% to 89%. Ethanol concentrations of 23 to 36 g/L were obtained at volumetric productivities of 9 to 15 g/L-h. No accumulation of glucose was observed, indicating that saccharification was the rate-limiting step. In the second design, saccharification and fermentation were carried out sequentially. In the first stage, solutions of 150 to 160 g/L dextrins were pumped through an immobilized glucoamylase packed column maintained at 55 C. Greater than 95% conversion was obtained at a residence time of 1 h, giving a product of 165 to 170 g glucose/L. In the second stage, these glucose solutions were fed to the FBR containing Z. mobilis immobilized in {kappa}-carageenan beads. At a residence time of 2 h, 94% conversion and ethanol concentration of 70 g/L was achieved, giving an overall productivity of 23 g/L-h.

  14. Feasibility of converting a sugar beet plant to fuel ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hammaker, G S; Pfost, H B; David, M L; Marino, M L

    1981-04-01

    This study was performed to assess the feasibility of producing fuel ethanol from sugar beets. Sugar beets are a major agricultural crop in the area and the beet sugar industry is a major employer. There have been some indications that increasing competition from imported sugar and fructose sugar produced from corn may lead to lower average sugar prices than have prevailed in the past. Fuel ethanol might provide an attractive alternative market for beets and ethanol production would continue to provide an industrial base for labor. Ethanol production from beets would utilize much of the same field and plant equipment as is now used for sugar. It is logical to examine the modification of an existing sugar plant from producing sugar to ethanol. The decision was made to use Great Western Sugar Company's plant at Mitchell as the example plant. This plant was selected primarily on the basis of its independence from other plants and the availability of relatively nearby beet acreage. The potential feedstocks assessed included sugar beets, corn, hybrid beets, and potatoes. Markets were assessed for ethanol and fermentation by-products saleability. Investment and operating costs were determined for each prospective plant. Plants were evaluated using a discounted cash flow technique to obtain data on full production costs. Environmental, health, safety, and socio-economic aspects of potential facilities were examined. Three consulting engineering firms and 3 engineering-construction firms are considered capable of providing the desired turn-key engineering design and construction services. It was concluded that the project is technically feasible. (DMC)

  15. Jerusalem artichoke as a platform for inulin, ethanol and feed production in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Anyia, A.O.; Mostafa, H.; Melnichuk, R.; Slaski, J.J. [Alberta Research Council, Vegreville, AB (Canada). Bioresource Technologies Unit

    2009-07-01

    The Alberta Research Council (ARC) is developing an extraction and fermentation process for making ethanol from Jerusalem artichoke (JA). In particular, ARC has collaborated with Olds College in developing an extraction process and an engineering process for the commercial production of inulin, ethanol, polymers and animal feed from JA tubers. Fresh JA tubers contain about 20 per cent of water soluble carbohydrates, which occur primarily in the form of inulin. Several health promoting benefits are associated with intake of inulin. High volumes of dry residual aerial biomass following tuber harvest contain 40 to 50 per cent water soluble carbohydrates that are fermentable to ethanol. Some studies have shown that under optimal climatic conditions, JA can yield more ethanol per ha than sugarcane. ARC has the exclusive North American rights to several high yielding JA cultivars. Jerusalem artichoke is not a designated food crop and has a high biomass yield for soluble sugars. This perennial crop forms tubers, has a deep root system that can be adapted to marginal lands. ARC's research involves a seed to final product technology development approach that includes new variety development, agronomy and processing. ARC applied a hot water extraction technique along with a low liquid to JA stalk ratio to achieve more than 40 per cent total water soluble carbohydrates per gram of biomass that are fermentable to ethanol without the need for weak acid or enzymatic hydrolysis. A 400 hectare plantation of JA in Alberta could produce about 1,500 tonnes of inulin and 1.5 million liters of ethanol per year in a pilot scale bio-refining plant. An economic and market analysis showed that capital investments in an inulin production plant in Alberta will be a profitable venture. ARC has estimated a 5 year Internal Rate of Return (IRR) to range from 10 to 30 per cent and payback period of 4 to 5 years depending on plant location and value of by-products. tabs., figs.

  16. Response surface optimization for ethanol production from Pennisetum Alopecoider by Klebsiella oxytoca THLC0409

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chi-Wen; I, Yet-Pole [Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin 64002 (China); Tran, Dang-Thuan [Department of Chemical Engineering, National Cheng-Kung University, Tainan City 701 (China); Lai, Chi-Yung [Department of Biology, National Changhua University of Education, Changhua (China); Wu, Chih-Hung [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Yunlin 64002 (China)

    2010-12-15

    The strain Klebsiella oxytoca THLC0409 was isolated from a lignocellulose-degrading microflora and used in the direct conversion of Napiergrass powder to ethanol. Central Composite Design (CCD), part of the Response Surface Methodology (RSM) was adopted to study the effects of the fermentation time, the initial pH of the liquid medium, the cultivation temperature, and the yeast extract (YE) concentration on ethanol production. A second-order model that relates the ethanol concentration to four basic factors was developed. Regression analysis revealed that the maximum ethanol concentration of 472 ppm could be reached at a fermentation time of about 11 days, an initial pH of 7.04, a cultivating temperature of 31 C, and a YE concentration of 7.0 g l{sup -1}. The adjusted R-square of the regression model was 0.996, indicating a good fit at 99.6% confidence level. The highest ethanol yield and productivity were estimated to be 82 g kg{sup -1} and 360 mg kg{sup -1} h{sup -1}, respectively. (author)

  17. 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.

  18. Internal combustion engine with thermochemical recuperation fed by ethanol steam reforming products - feasibility study

    Science.gov (United States)

    Cesana, O.; Gutman, M.; Shapiro, M.; Tartakovsky, L.

    2016-08-01

    This research analyses the performance of a spark ignition engine fueled by ethanol steam reforming products. The basic concept involves the use of the internal combustion engine's (ICE) waste heat to promote onboard reforming of ethanol. The reformer and the engine performance were simulated and analyzed using GT-Suite, Chem CAD and Matlab software. The engine performance with different compositions of ethanol reforming products was analyzed, in order to find the optimal working conditions of the ICE - reformer system. The analysis performed demonstrated the capability to sustain the endothermic reactions in the reformer and to reform the liquid ethanol to hydrogen-rich gaseous fuel using the heat of the exhaust gases. However, the required reformer's size is quite large: 39 x 89 x 73 cm, which makes a feasibility of its mounting on board a vehicle questionable. A comparison with ICE fed by gasoline or liquid ethanol doesn't show a potential of efficiency improvement, but can be considered as a tool of additional emissions reduction.

  19. The use of a thermotolerant fermentative Kluyveromyces marxianus IMB3 yeast strain for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Banat, I.M. [Univ. of the United Arab Emirates, Al-Ain (United Arab Emirates). Dept. of Biolology; Singh, D. [Haryana Agriculture Univ., Hisar (India). Dept. of Microbiology; Marchant, R. [Ulster Univ. (United Kingdom). School of Applied Biological and Chemical Sciences

    1996-12-31

    An investigation was carried out on the growth and ethanol production of a novel thermotolerant ethanol-producing Kluyveromyces marxianus IMB3 yeast strain. It grew aerobically on glucose, lactose, cellobiose, xylose and whey permeate and fermented all the above carbon sources to ethanol at 45 C. This strain was capable of growing under anaerobic chemostat fermentation conditions at 45 C and a dilution rate of 0.15 h{sup -1} and produced {<=}0.9 g/l biomass and 1.8% (v/v) ethanol. An increase in biomass (up to 10.0 g/l) and ethanol (up to 4.3% v/v at 45 C and 7.7% v/v at 40 C) were achieved by applying a continuous two-stage fermentation in sequence (one aerobic and one anerobic stage) or a two-stage anaerobic fermentation with cell recycling. Potential applications, involving alcohol production systems, for use in dairy and wood related industries, were discussed. (orig.)

  20. Hydrogen production via autothermal reforming of ethanol over noble metal catalysts supported on oxides

    Institute of Scientific and Technical Information of China (English)

    Hongqing Chen; Hao Yu; Yong Tang; Minqiang Pan; Guangxing Yang; Feng Peng; Hongjuan Wang; Jian Yang

    2009-01-01

    Hydrogen was produced over noble metal (Ir, Ru, Rh, Pd) catalysts supported on various oxides, including γ-Al2O3, CeO2, ZrO2 and La2O3, via the autothermai reforming reaction of ethanol (ATRE) and oxidative reforming reaction of ethanol (OSRE). The conversion of ethanol and selectivites for hydrogen and byproducts such as methane, ethylene and acetaldehyde were studied. It was found that lanthana alone possessed considerable activity for the ATRE reaction, which could be used as a functional support for ATRE catalysts. It was demonstrated that Ir/La2O3 prevented the formation of methane, and Rh/La2O3 encumbered the production of ethylene and acetaldehyde. ATRE reaction was carried out over La2O3-supported catalysts (Ir/La2O3) with good stability on stream, high conversion, and excellent hydrogen selectivity approaching thermodynamic limit under autothermal condition. Typically, 3.4 H2 molecules can be extracted from a pair of ethanol and water molecules over Ir(5wt%)/La2O3. The results presented in this paper indicate that Ir/La2O3 can be used as a promising catalyst for hydrogen production via ATRE reaction from renewable ethanol.

  1. Solvent extraction of organic acids from stillage for its re-use in ethanol production process.

    Science.gov (United States)

    Castro, G A; Caicedo, L A; Alméciga-Díaz, C J; Sanchez, O F

    2010-06-01

    Stillage re-use in the fermentation stage in ethanol production is a technique used for the reduction of water and fermentation nutrients consumption. However, the inhibitory effect on yeast growth of the by-products and feed components that remains in stillage increases with re-use and reduces the number of possible recycles. Several methods such as ultrafiltration, electrodialysis and advanced oxidation processes have been used in stillage treatment prior its re-use in the fermentation stage. Nevertheless, few studies evaluating the effect of solvent extraction as a stillage treatment option have been performed. In this work, the inhibitory effect of serial stillage recycling over ethanol and biomass production was determined, using acetic acid as a monitoring compound during the fermentation and solvent extraction process. Raw palm oil methyl ester showed the highest acetic acid extraction from the aqueous phase, presenting a distribution coefficient of 3.10 for a 1:1 aqueous phase mixture:solvent ratio. Re-using stillage without treatment allowed up to three recycles with an ethanol production of 53.7 +/- 2.0 g L(-1), which was reduced 25% in the fifth recycle. Alternatively, treated stillage allowed up to five recycles with an ethanol final concentration of 54.7 +/- 1.3 g L(- 1). These results show that reduction of acetic acid concentration by an extraction process with raw palm oil methyl ester before re-using stillage improves the number of recycles without a major effect on ethanol production. The proposed process generates a palm oil methyl ester that contains organic acids, among other by-products, that could be used for product recovery and as an alternative fuel.

  2. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    KAUST Repository

    Zhang, Bo

    2016-08-16

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

  3. 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.

  4. 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

  5. Production of ethanol from mesquite [Prosopis juliflora (SW) D.C.] pods mash by Zymomonas mobilis in submerged fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Celiane Gomes Maia da [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Ciencias Domesticas; Andrade, Samara Alvachian Cardoso; Schuler, Alexandre Ricardo Pereira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Quimica; Souza, Evandro Leite de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Nutricao; Stamford, Tania Lucia Montenegro [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Nutricao], E-mail: tlmstamford@yahoo.com.br

    2011-01-15

    Mesquite [Prosopis juliflora (SW) D.C.], a perennial tropical plant commonly found in Brazilian semi-arid region, is a viable raw material for fermentative processes because of its low cost and production of pods with high content of hydrolyzable sugars which generate many compounds, including ethanol. This study aimed to evaluate the use of mesquite pods as substrate for ethanol production by Z. mobilis UFPEDA- 205 in a submerged fermentation. The fermentation was assessed for rate of substrate yield to ethanol, rate of ethanol production and efficiency of fermentation. The very close theoretical (170 g L{sup -1}) and experimental (165 g L{sup -1}) maximum ethanol yields were achieved at 36 h of fermentation. The highest counts of Z. mobilis UFEPEDA-205 (both close to 6 Log cfu mL{sup -1}) were also noted at 36 h. Highest rates of substrate yield to ethanol (0.44 g ethanol g glucose{sup -1}), of ethanol production (4.69 g L{sup -1} h{sup -1}) and of efficiency of fermentation (86.81%) were found after 30 h. These findings suggest mesquite pods as an interesting substrate for ethanol production using submerged fermentation by Z. mobilis. (author)

  6. Starch hydrolysis modeling: application to fuel ethanol production.

    Science.gov (United States)

    Murthy, Ganti S; Johnston, David B; Rausch, Kent D; Tumbleson, M E; Singh, Vijay

    2011-09-01

    Efficiency of the starch hydrolysis in the dry grind corn process is a determining factor for overall conversion of starch to ethanol. A model, based on a molecular approach, was developed to simulate structure and hydrolysis of starch. Starch structure was modeled based on a cluster model of amylopectin. Enzymatic hydrolysis of amylose and amylopectin was modeled using a Monte Carlo simulation method. The model included the effects of process variables such as temperature, pH, enzyme activity and enzyme dose. Pure starches from wet milled waxy and high-amylose corn hybrids and ground yellow dent corn were hydrolyzed to validate the model. Standard deviations in the model predictions for glucose concentration and DE values after saccharification were less than ± 0.15% (w/v) and ± 0.35%, respectively. Correlation coefficients for model predictions and experimental values were 0.60 and 0.91 for liquefaction and 0.84 and 0.71 for saccharification of amylose and amylopectin, respectively. Model predictions for glucose (R2 = 0.69-0.79) and DP4+ (R2 = 0.8-0.68) were more accurate than the maltotriose and maltose for hydrolysis of high-amylose and waxy corn starch. For yellow dent corn, simulation predictions for glucose were accurate (R2 > 0.73) indicating that the model can be used to predict the glucose concentrations during starch hydrolysis.

  7. Enhancement of xylose utilization from corn stover by a recombinant bacterium for ethanol production

    Science.gov (United States)

    Effects of substrate-selective inoculum prepared by growing on glucose, xylose, arabinose, GXA (glucose, xylose, arabinose, 1:1:1) and corn stover hydrolyzate (dilute acid pretreated and enzymatically hydrolyzed, CSH) on ethanol production from CSH by a mixed sugar utilizing recombinant Escherichia ...

  8. The composition and impact of stakeholders' agendas on U.S. ethanol production

    NARCIS (Netherlands)

    Talamini, E.; Dewes, H.; Padula, A.D.; Wubben, E.F.M.

    2012-01-01

    This paper aims to identify the macro-environmental dimensions under which journalists, scientists and policy-makers have framed the liquid biofuels in the US over time. The number of publications concerning liquid biofuels from mass media, scientific community and government with ethanol production

  9. Modelling Methane Production and Sulfate Reduction in Anaerobic Granular Sludge Reactor with Ethanol as Electron Donor

    Science.gov (United States)

    Sun, Jing; Dai, Xiaohu; Wang, Qilin; Pan, Yuting; Ni, Bing-Jie

    2016-10-01

    In this work, a mathematical model based on growth kinetics of microorganisms and substrates transportation through biofilms was developed to describe methane production and sulfate reduction with ethanol being a key electron donor. The model was calibrated and validated using experimental data from two case studies conducted in granule-based Upflow Anaerobic Sludge Blanket reactors. The results suggest that the developed model could satisfactorily describe methane and sulfide productions as well as ethanol and sulfate removals in both systems. The modeling results reveal a stratified distribution of methanogenic archaea, sulfate-reducing bacteria and fermentative bacteria in the anaerobic granular sludge and the relative abundances of these microorganisms vary with substrate concentrations. It also indicates sulfate-reducing bacteria can successfully outcompete fermentative bacteria for ethanol utilization when COD/SO42‑ ratio reaches 0.5. Model simulation suggests that an optimal granule diameter for the maximum methane production efficiency can be achieved while the sulfate reduction efficiency is not significantly affected by variation in granule size. It also indicates that the methane production and sulfate reduction can be affected by ethanol and sulfate loading rates, and the microbial community development stage in the reactor, which provided comprehensive insights into the system for its practical operation.

  10. Energy ratio analysis of genetically-optimized potato for ethanol production in the Chilean market

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, A.; Diaz, G.; Gallardo, L.; Loaiza, R.

    2010-07-01

    The continuous increase in energy demand, the high cost of imported oil, and the growing concerns about climate change have sparked a number of initiatives from governments around the world to increase production of energy from renewable sources. Along these lines, the Chilean government is analyzing the introduction of a law to set a reference value of 5% of bio fuel production to be placed on the market by 2013. The analysis of different options to meet this new regulatory measure needs to consider different alternatives such as bio diesel and bio ethanol from crops or lignocellulose biomass. This paper analyzes the energy ratio of some of the most common crops grown in Chile that can be utilized for ethanol production. Using a methodology adapted to local conditions of agriculture and transportation, the results indicate that a potato cultivar specially bred for high yield, high starch and dry matter content can obtain a positive net energy balance with an energy ratio of 1.8. The results also show yields near 60 tons ha{sup -}1 which translate to approximately 9,000 L ha{sup -}1 of ethanol making the genetically optimized cultivar of potato a suitable local source for ethanol production. (Author) 48 refs.

  11. Integration of succinic acid and ethanol production within a corn or barley biorefinery

    Science.gov (United States)

    Production of succinic acid from glucose by Escherichia coli strain AFP184 was studied in a batch fermentor. The bases used for pH control included NaOH, KOH, NH4OH, and Na2CO3. The yield of succinic acid without and with carbon dioxide supplied by an adjacent ethanol fermentor using either corn or ...

  12. Simultaneous saccharification and fermentation of industrial sweetpotatoes for ethanol production and anthocyanins extraction

    Science.gov (United States)

    A simultaneous saccharification fermentation (SSF) system was studied for ethanol production in flour industrial sweetpotato (ISP) feedstocks (lines: white DM02-180 and purple NC-413) as an integrated cost saving process, and to examine the feasibility of extracting anthocyanins from flour purple IS...

  13. Simultaneous production of hydrogen and ethanol from waste glycerol by Enterobacter aerogenes KKU-S1

    DEFF Research Database (Denmark)

    Reungsang, Alissara; Sittijunda, Sureewan; Angelidaki, Irini

    2013-01-01

    Factors affecting simultaneous hydrogen and ethanol production from waste glycerol by a newly isolated bacterium Enterobacter aerogenes KKU-S1 were investigated employing response surface methodology (RSM) with central composite design (CCD). The Plackett-Burman design was first used to screen th...

  14. Production of ethanol and biomass starting to present lactose in the milk whey

    Energy Technology Data Exchange (ETDEWEB)

    Angeles-Ramirez, K.; Arana-cuenca, A.; Tellez-Jurado, A.

    2009-07-01

    Milk whey is a by-product of the milk industry, a highly polluting waste due to the quantity of COD and BOD that it contains. The contamination caused by milk whey is mostly due to its lactose content. The fermentation of milk whey to ethanol is a possible road to reduce the polluting effect. (Author)

  15. Economic feasibility of on-farm fuel ethanol production from cassava ...

    African Journals Online (AJOL)

    ufuoma

    2013-09-11

    Sep 11, 2013 ... On a small scale, a fed-batch mode where 4 kg of koji, 2 kg of gelatinized ... At this price, the ethanol production cost would be ₦58.53/l (US$0.366/l). The process is ..... meals in animal feed. Starch content of ..... Continuous.

  16. Ethanol production by Escherichia coli KO11; Producao de etanol por Escherichia coli KO11

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Katia Gianni de Carvalho [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Lab. de Microbiologia de Alimentos]. E-mail: gianni@usp.br; Takahashi, Caroline Maki; Alterthum, Flavio [Sao Paulo Univ., SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia

    2002-08-01

    This paper discusses the potential use of Escherichia coli KO11 in production of ethanol, based on observation that this organism can efficiently metabolize sugar complex moistures obtained from the acid hydrolysis of lignocellulose materials such as sugar-cane bagasse, corncob, corn husk, Pinus sp and oak wood.

  17. Zymomonas with improved ethanol production in medium containing concentrated sugars and acetate

    Science.gov (United States)

    Caimi, Perry G.; Chou, Yat-Chen; Franden, Mary Ann; Knoke, Kyle; Tao, Luan; Viitanen, Paul V.; Zhang, Min; Zhang, Yuying

    2010-09-28

    Through screening of a Zymomonas mutant library the himA gene was found to be involved in the inhibitory effect of acetate on Zymomonas performance. Xylose-utilizing Zymomonas further engineered to reduce activity of the himA gene were found to have increased ethanol production in comparison to a parental strain, when cultured in medium comprising xylose and acetate.

  18. Crop Management Effects on the Energy and Carbon Balances of Maize Stover-Based Ethanol Production

    Directory of Open Access Journals (Sweden)

    Prem Woli

    2014-12-01

    Full Text Available This study was conducted to identify the crop management options—the combinations of various cultivars, irrigation amounts, planting dates, and soils—that would maximize the energy sustainability and eco-friendliness of maize (Zea mays L. stover-based ethanol production systems in the Mississippi Delta. Stover yields simulated with CERES-Maize were used to compute net energy value (NEV and carbon credit balance (CCB, the indicators of sustainability and eco-friendliness of ethanol production, respectively, for various scenarios. As the results showed, deeper soils with higher water holding capacities had larger NEV and CCB values. Both NEV and CCB had sigmoid relationships with irrigation amount and planting date and could be maximized by planting the crop during the optimum planting window. Stover yield had positive effects on NEV and CCB, whereas travel distance had negative. The influence of stover yield was larger than that of travel distance, indicating that increasing feedstock yields should be emphasized over reducing travel distance. The NEV and CCB values indicated that stover-based ethanol production in the Mississippi Delta is sustainable and environmentally friendly. The study demonstrated that the energy sustainability and eco-friendliness of maize stover-based ethanol production could be increased with alternative crop management options.

  19. Ethanol and xylitol production from glucose and xylose at high temperature by Kluyveromyces sp. IIPE453.

    Science.gov (United States)

    Kumar, Sachin; Singh, Surendra P; Mishra, Indra M; Adhikari, Dilip K

    2009-12-01

    A yeast strain Kluyveromyces sp. IIPE453 (MTCC 5314), isolated from soil samples collected from dumping sites of crushed sugarcane bagasse in Sugar Mill, showed growth and fermentation efficiency at high temperatures ranging from 45 degrees C to 50 degrees C. The yeast strain was able to use a wide range of substrates, such as glucose, xylose, mannose, galactose, arabinose, sucrose, and cellobiose, either for growth or fermentation to ethanol. The strain also showed xylitol production from xylose. In batch fermentation, the strain showed maximum ethanol concentration of 82 +/- 0.5 g l(-1) (10.4% v/v) on initial glucose concentration of 200 g l(-1), and ethanol concentration of 1.75 +/- 0.05 g l(-1) as well as xylitol concentration of 11.5 +/- 0.4 g l(-1) on initial xylose concentration of 20 g l(-1) at 50 degrees C. The strain was capable of simultaneously using glucose and xylose in a mixture of glucose concentration of 75 g l(-1) and xylose concentration of 25 g l(-1), achieving maximum ethanol concentration of 38 +/- 0.5 g l(-1) and xylitol concentration of 14.5 +/- 0.2 g l(-1) in batch fermentation. High stability of the strain was observed in a continuous fermentation by feeding the mixture of glucose concentration of 75 g l(-1) and xylose concentration of 25 g l(-1) by recycling the cells, achieving maximum ethanol concentration of 30.8 +/- 6.2 g l(-1) and xylitol concentration of 7.35 +/- 3.3 g l(-1) with ethanol productivity of 3.1 +/- 0.6 g l(-1) h(-1) and xylitol productivity of 0.75 +/- 0.35 g l(-1) h(-1), respectively.

  20. Production of ethanol from kitchen waste by using flocculating Saccharomyces cerevisiae KF-7.

    Science.gov (United States)

    Wang, Yan-Fang; Tan, Li; Wang, Ting; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

    2017-02-01

    Kitchen waste is rich in carbohydrates and can potentially serve as feedstock for ethanol production. Starch was the primary carbohydrate in kitchen waste obtained from the canteen in the Sichuan University, which was used to evaluate long-term ethanol fermentation performance in this study. The optimal conditions for liquefaction and saccharification of the kitchen waste were as follows: adding α-amylase at 0.3 μL/g glucan for liquefaction at 90°C for 30 min, and adding glucoamylase at 4 μL/g glucan for saccharification at 50°C. Glucose yield obtained under the optimal conditions was over 80%. Addition of cellulase did not enhance glucose yield, but decreased the viscosity of the saccharified slurry. Repeated-batch presaccharification followed by simultaneous saccharification and fermentation of 20 batches was successfully carried out at an aeration of 0.1 vvm. Ethanol concentration of 43.9-45.0 g/L was achieved, corresponding to ethanol yield and productivity of 88.9-91.2% and 3.3-3.5 g/L/h, respectively, and the CO2/ethanol molar ratio was approximately 1. Continuous PSSF was stably carried out at a dilution rate of ≤0.3 h(-1). Productivity was 11.5 g/L/h at a dilution rate of 0.3 h(-1). Ethanol concentration and yield were 42.0 g/L and 82.8% at a dilution rate of 0.2 h(-1), respectively.

  1. 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

  2. The role of aldehyde/alcohol dehydrogenase (AdhE) in ethanol production from glycerol by Klebsiella pneumoniae.

    Science.gov (United States)

    Oh, Baek-Rock; Hong, Won-Kyung; Heo, Sun-Yeon; Joe, Min-ho; Seo, Jeong-Woo; Kim, Chul Ho

    2013-02-01

    Transcriptome analysis of a K. pneumoniae GEM167 mutant strain derived by irradiation with gamma rays, which exhibited high-level production of ethanol from glycerol, showed that the mutant expressed AdhE at a high level. Ethanol production decreased significantly, from 8.8 to 0.5 g l(-1), when an adhE-deficient derivative of that strain was grown on glycerol. Bacterial growth was also reduced under such conditions, showing that AdhE plays a critical role in maintenance of redox balance by catalyzing ethanol production. Overexpression of AdhE enhanced ethanol production, from pure or crude glycerol, to a maximal level of 31.9 g l(-1) under fed-batch fermentation conditions; this is the highest level of ethanol production from glycerol reported to date.

  3. Ethanol dry reforming for syngas production over Ir/CeO2 catalyst

    Institute of Scientific and Technical Information of China (English)

    侯腾飞; 雷雨声; 张绍印; 张江华; 蔡伟杰

    2015-01-01

    Syngas production from CO2 reforming of ethanol over an Ir/CeO2 catalyst was investigated. Catalysts characterization was conducted by X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and temperature programmed oxidation (TPO). The Ir/CeO2 catalyst was more active and stable toward syngas formation (molar ratio~1). The superior catalytic performance was interpreted in terms of the strong interaction between Ir particles and ceria support which was crucial for efficient ethanol/CO2 activation and coke removal on the catalyst surface.

  4. Ethanol Production by Fermentation of Various Sweet-Stalk Sorghum Juices Using Various Yeast Strains

    OpenAIRE

    Donny Widianto; Akbar Arofatullah; Triwibowo Yuwono; Irfan Dwidya Prijambada

    2015-01-01

    The ethanol production by fermentation of sweet-stalk sorghum juice is affected by the juice composition and the capability of the yeast strain to ferment it. Eight yeast strains were tested on their growth and ethanol fermentation abilities in sweet-stalk sorghum juices extracted from three cultivars of sweet sorghum. The best specific growth rate of the yeast strains grown aerobically in the yeast extract peptone dextrose (YEPD) broth and the sweet-stalk sorghum juices of KCS105, FS501, and...

  5. DIFFERENCES BETWEEN WHEAT CULTIVARS IN GRAIN PARAMETERS RELATED TO ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Daniela Mikulíková

    2011-12-01

    Full Text Available Wheat grain samples from sixteen winter cultivars originated from four localities were evaluated and compared in traits related to ethanol production as grain yield, grain hardness, content of protein, starch and amylose, and α-amylase activity. Results obtained indicate significant differences between cultivars in amylose content, α-amylase activity, and grain hardness compared to grain yield, protein content, and starch content where differences were not significant. The amylose content, α-amylase activity, and grain hardness were affected by cultivar. Both testing methods for starch fermentation - separated hydrolysis and fermentation (SHF and simultaneous saccharification and fermentation (SSF revealed difference between cultivars in ethanol yield.

  6. 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)

  7. Ethanol production by a flocculant yeast strain in a CSTR type fermentor with cell recycling.

    Science.gov (United States)

    Hojo, O; Hokka, C O; Major, A M

    1999-01-01

    Tests were performed in a continuous stirred tank reactor (CSTR), with and without cell recycling, to produce ethanol. The reactor without cell recycling produced the kinetic model of ethanol production, whereas the reactor with cell recycling allowed for a study of process stability. The Levenspiel kinetic model was adopted; however, in the case of fermentation with cell recycling, the coefficient of cell death was added. It was observed that cellular viability varied greatly throughout the fermenting process and that microaeration is of fundamental importance in maintaining the stability of the process.

  8. 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...

  9. Efficient ethanol production from dried oil palm trunk treated by hydrothermolysis and subsequent enzymatic hydrolysis.

    Science.gov (United States)

    Eom, In-Yong; Yu, Ju-Hyun; Jung, Chan-Duck; Hong, Kyung-Sik

    2015-01-01

    Oil palm trunk (OPT) is a valuable bioresource for the biorefinery industry producing biofuels and biochemicals. It has the distinct feature of containing a large amount of starch, which, unlike cellulose, can be easily solubilized by water when heated and hydrolyzed to glucose by amylolytic enzymes without pretreatment for breaking down the biomass recalcitrance. Therefore, it is suggested as beneficial to extract most of the starch from OPT through autoclaving and subsequent amylolytic hydrolysis prior to pretreatment. However, this treatment requires high capital and operational costs, and there could be a high probability of microbial contamination during starch processing. In terms of biochemical conversion of OPT, this study aimed to develop a simple and efficient ethanol conversion process without any chemical use such as acids and bases or detoxification. For comparison with the proposed efficient ethanol conversion process, OPT was subjected to hydrothermal treatment at 180 °C for 30 min. After enzymatic hydrolysis of PWS, 43.5 g of glucose per 100 g dry biomass was obtained, which corresponds to 81.3 % of the theoretical glucose yield. Through subsequent alcohol fermentation, 81.4 % ethanol yield of the theoretical ethanol yield was achieved. To conduct the proposed new process, starch in OPT was converted to ethanol through enzymatic hydrolysis and subsequent fermentation prior to hydrothermal treatment, and the resulting slurry was subjected to identical processes that were applied to control. Consequently, a high-glucose yield of 96.3 % was achieved, and the resulting ethanol yield was 93.5 %. The proposed new process was a simple method for minimizing the loss of starch during biochemical conversion and maximizing ethanol production as well as fermentable sugars from OPT. In addition, this methodology offers the advantage of reducing operational and capital costs due to minimizing the process for ethanol production by excluding expensive

  10. Dekkera/Brettanomyces yeasts for ethanol production from renewable sources under oxygen-limited and low-pH conditions.

    Science.gov (United States)

    Galafassi, Silvia; Merico, Annamaria; Pizza, Francesca; Hellborg, Linda; Molinari, Francesco; Piškur, Jure; Compagno, Concetta

    2011-08-01

    Industrial fermentation of lignocellulosic hydrolysates to ethanol requires microorganisms able to utilise a broad range of carbon sources and generate ethanol at high yield and productivity. D. bruxellensis has recently been reported to contaminate commercial ethanol processes, where it competes with Saccharomyces cerevisiae [4, 26]. In this work Brettanomyces/Dekkera yeasts were studied to explore their potential to produce ethanol from renewable sources under conditions suitable for industrial processes, such as oxygen-limited and low-pH conditions. Over 50 strains were analysed for their ability to utilise a variety of carbon sources, and some strains grew on cellobiose and pentoses. Two strains of D. bruxellensis were able to produce ethanol at high yield (0.44 g g(-1) glucose), comparable to those reported for S. cerevisiae. B. naardenensis was shown to be able to produce ethanol from xylose. To obtain ethanol from synthetic lignocellulosic hydrolysates we developed a two-step fermentation strategy: the first step under aerobic conditions for fast production of biomass from mixtures of hexoses and pentoses, followed by a second step under oxygen limitation to promote ethanol production. Under these conditions we obtained biomass and ethanol production on synthetic lignocellulosic hydrolysates, with ethanol yields ranging from 0.2 to 0.3 g g(-1) sugar. Hexoses, xylose and arabinose were consumed at the end of the process, resulting in 13 g l(-1) of ethanol, even in the presence of furfural. Our studies showed that Brettanomyces/Dekkera yeasts have clear potential for further development for industrial processes aimed at production of ethanol from renewable sources.

  11. 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.

  12. Ethanol production from the organic fraction obtained after thermal pretreatment of municipal solid waste.

    Science.gov (United States)

    Ballesteros, Mercedes; Sáez, Felicia; Ballesteros, Ignacio; Manzanares, Paloma; Negro, Maria Jose; Martínez, Jose Maria; Castañeda, Rafael; Oliva Dominguez, Jose Miguel

    2010-05-01

    In this work, the use of organic fraction from municipal solid waste (MSW) as substrate for ethanol production based on enzymatic hydrolysis was evaluated. MSW was subjected to a thermal pretreatment (active hygienization) at 160 degrees C from 5 to 50 min. The organic fiber obtained after 30 min was used as substrate in a simultaneous saccharification and fermentation (SSF) and fed-batch SSF process using cellulases and amylases. In a fed-batch mode with 25% (w/w) substrate loading, final ethanol concentration of 30 g/L was achieved (60% of theoretical). In these conditions, more than 160 L of ethanol per ton of dry matter could be produced from the organic fraction of MSW.

  13. 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.

  14. Physiological response of Clostridium ljungdahlii DSM 13528 of ethanol production under different fermentation conditions.

    Science.gov (United States)

    Xie, Bin-Tao; Liu, Zi-Yong; Tian, Lei; Li, Fu-Li; Chen, Xiao-Hua

    2015-02-01

    In this study, cell growth, gene expression and ethanol production were monitored under different fermentation conditions. Like its heterotrophical ABE-producing relatives, a switch from acidogenesis to solventogenesis of Clostridium ljungdahlii during the autotrophic fermentation with CO/CO2 could be observed, which occurred surprisingly in the late-log phase rather than in the transition phase. The gene expression profiles indicated that aor1, one of the putative aldehyde oxidoreductases in its genome played a critical role in the formation of ethanol, and its transcription could be induced by external acids. Moreover, a low amount of CaCO3 was proved to have positive influences on the cell density and substrate utilization, followed by an increase of over 40% ethanol and 30% acetate formation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Optimization of ethanol production from hot-water extracts of sugar maple chips

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jian; Liu, Shijie [Department of Paper and Bioprocess Engineering, College of Environmental Science and Forestry, State University of New York, 1 Forestry Drive, Syracuse, NY 13210 (United States)

    2009-11-15

    Hot-water extracts from sugar maple chips prior to papermaking was employed in this study to produce ethanol by Pichia stipitis 58784. The effects of several factors, seed culture age, fermentation time, inoculum quantity, agitation rate, percent extract, concentration of inorganic nitrogen source (NH{sub 4}){sub 2}SO{sub 4} and pH value, on ethanol production were investigated by orthogonal experiments. Orthogonal analysis shows that the optimal fermentation was obtained in the condition of 48-h seed culture, 120-h fermentation, 16% inoculum, 180 rpm, containing 30% extracts, 8% ammonium sulphate supplement and pH 5. This optimal condition was verified at 800-mL level in a 1.3 L fermentor. The ethanol yield reached 82.27% of the theoretical (20.57 g/L) after 120 h. (author)

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

    Directory of Open Access Journals (Sweden)

    Madan Bhawna

    2011-11-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  18. 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.

  19. Inhibitory Effects of Biomass Degradation Products on Ethanol Fermentation and a Strategy to Overcome Them

    Directory of Open Access Journals (Sweden)

    Shiyu Fu

    2014-06-01

    Full Text Available The influence of buffers, as well as inhibitors such as formic acid, furfural, HMF, guaiacol, and vanillin, on ethanol formation was investigated. Compared to phosphoric buffer, the acetic and citric buffers were less inhibitory on ethanol fermentation. The addition of formic acid (2.5 g/L to the buffer reduced the ethanol yield by 8%. Guaiacol (3 g/L and vanillin (2.5 g/L decreased ethanol production by 50% and 20%, respectively. Furfural and HMF delayed the yeast fermentation without reducing the total yield. The fermentation was seriously inhibited by the mixture of furfural (1 g/L, HMF (1 g/L, formic acid (1 g/L, vanillin (1 g/L, and guaiacol (1 g/L. The ethanol yield of the fermentation based on enzymatic hydrolyzate from treated biomass was 82%. The addition of 1 g/L MgSO4 as a shielding protector rehabilitated nearly 100% of the total yield.

  20. A Mathematical model for ethanol production by extractive fermentation in a continuous stirred tank fermentor.

    Science.gov (United States)

    Kollerup, F; Daugulis, A J

    1985-09-01

    Extractive fermentation is a technique that can be used to reduce the effect of end product inhibition through the use of a water-immiscible phase that removes fermentation products in situ. This has the beneficial effect of not only removing inhibitory products as they are formed (thus keeping reaction rates high) but also has the potential for reducing product recovery costs. We have chosen to examine the ethanol fermentation as a model system for end product inhibition and extractive fermentation and have developed a computer model predicting the productivity enhancement possible with this technique together with other key parameters such as extraction efficiency and residual glucose concentration. The model accommodates variable liquid flowrates entering and leaving the system, since it was found that the aqueous outlet flowrate could be up to 35% lower than the inlet flowrate during extractive fermentation of concentrated glucose feeds due to the continuous removal of ethanol from the fermentation broth by solvent extraction. The model predicts a total ethanol productivity of 82.6 g/L h if a glucose feed of 750 g/L is fermented with a solvent having a distribution coefficient of 0.5 at a solvent dilution rate of 5.0 h(-1). This is more than 10 times higher than for a conventional chemostat fermentation of a 250 g/L glucose feed. The model has furthermore illustrated the possible trade-offs that exist between obtaining a high extraction efficiency and a low residual glucose concentration.

  1. Hydrogen production by plasma electrolysis reactor of KOH-ethanol solution

    Science.gov (United States)

    Saksono, N.; Batubara, T.; Bismo, S.

    2016-11-01

    Plasma electrolysis has great potential in industrial hydrogen production, chlor-alkali production, and waste water treatment. Plasma electrolysis produces more hydrogen with less energy consumption than hydrocarbon or Faraday electrolysis. This paper investigated the hydrogen production by plasma electrolysis of KOH-ethanol solution at 80 °C and 1 atm. The effects of voltage, KOH solution, ethanol addition, and cathode deep on plasma electrolysis performance were studied. The hydrogen production was analyzed using bubble flow meter and hydrogen analyzer. The electrical energy consumption was measured by a digital multimeter. The effectiveness of plasma electrolysis in terms of hydrogen production was evaluated by comparing it with Faraday Electrolysis. The results showed that hydrogen produced by plasma electrolysis is 149 times higher than the hydrogen produced by Faraday electrolysis. The optimum hydrogen production was 50.71 mmol/min, obtained at 700 V with 0.03 M KOH, 10% vol ethanol and 6.6 cm cathode deep, with energy consumption 1.49 kJ/mmol. The result demonstrates a promising path for hydrogen production by utilizing plasma electrolysis reactor.

  2. 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.

  3. Organosolv pretreatment of rice straw for efficient acetone, butanol, and ethanol production.

    Science.gov (United States)

    Amiri, Hamid; Karimi, Keikhosro; Zilouei, Hamid

    2014-01-01

    Acetone-butanol-ethanol (ABE) was produced from rice straw using a process containing ethanol organosolv pretreatment, enzymatic hydrolysis, and fermentation by Clostridium acetobutylicum bacterium. Pretreatment of the straw with 75% (v/v) aqueous ethanol containing 1% w/w sulfuric acid at 150 °C for 60 min resulted in the highest total sugar concentration of 31 g/L in the enzymatic hydrolysis. However, the highest ABE concentration and productivity (10.5 g/L and 0.20 g/Lh, respectively) were obtained from the straw pretreated at 180 °C for 30 min. Enzymatic hydrolysis of the straw pretreated at 180 °C for 30 min with 5% solid loading resulted in glucose yield of 46.2%, which was then fermented to 80.3 g butanol, 21.1 g acetone, and 22.5 g ethanol, the highest overall yield of ABE production. Thus, the organosolv pretreatment can be applied for efficient production of the solvents from rice straw. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Cane molasses fermentation for continuous ethanol production in an immobilized cells reactor by Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Farshid; Younesi, Habibollah; Esmaeili Sari, Abbas [Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, P.O. Box: 64414-356 (Iran); Najafpour, Ghasem [Department of Chemical Engineering, Faculty of Engineering, Noshirvani University of Technology, Babol (Iran)

    2011-02-15

    Sodium-alginate immobilized yeast was employed to produce ethanol continuously using cane molasses as a carbon source in an immobilized cell reactor (ICR). The immobilization of Saccharomyces cerevisiae was performed by entrapment of the cell cultured media harvested at exponential growth phase (16 h) with 3% sodium alginate. During the initial stage of operation, the ICR was loaded with fresh beads of mean diameter of 5.01 mm. The ethanol production was affected by the concentration of the cane molasses (50, 100 and 150 g/l), dilution rates (0.064, 0.096, 0.144 and 0.192 h{sup -1}) and hydraulic retention time (5.21, 6.94, 10.42 and 15.63 h) of the media. The pH of the feed medium was set at 4.5 and the fermentation was carried out at an ambient temperature. The maximum ethanol production, theoretical yield (Y{sub E/S}), volumetric ethanol productivity (Q{sub P}) and total sugar consumption was 19.15 g/l, 46.23%, 2.39 g l{sup -1} h{sup -1} and 96%, respectively. (author)

  6. Improvements in ethanol production from xylose by mating recombinant xylose-fermenting Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Kato, Hiroko; Suyama, Hiroaki; Yamada, Ryosuke; Hasunuma, Tomohisa; Kondo, Akihiko

    2012-06-01

    To improve the ability of recombinant Saccharomyces cerevisiae strains to utilize the hemicellulose components of lignocellulosic feedstocks, the efficiency of xylose conversion to ethanol needs to be increased. In the present study, xylose-fermenting, haploid, yeast cells of the opposite mating type were hybridized to produce a diploid strain harboring two sets of xylose-assimilating genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase. The hybrid strain MN8140XX showed a 1.3- and 1.9-fold improvement in ethanol production compared to its parent strains MT8-1X405 and NBRC1440X, respectively. The rate of xylose consumption and ethanol production was also improved by the hybridization. This study revealed that the resulting improvements in fermentation ability arose due to chromosome doubling as well as the increase in the copy number of xylose assimilation genes. Moreover, compared to the parent strain, the MN8140XX strain exhibited higher ethanol production under elevated temperatures (38 °C) and acidic conditions (pH 3.8). Thus, the simple hybridization technique facilitated an increase in the xylose fermentation activity.

  7. Ethanol production from xylose in engineered Saccharomyces cerevisiae strains. Current state and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Matsushika, Akinori; Inoue, Hiroyuki; Sawayama, Shigeki [National Inst. of Advanced Industrial Science and Technology (AIST), Hiroshima (JP). Biomass Technology Research Center (BTRC); Kodaki, Tsutomu [Kyoto Univ. (Japan). Inst. of Advanced Energy

    2009-08-15

    Bioethanol production from xylose is important for utilization of lignocellulosic biomass as raw materials. The research on yeast conversion of xylose to ethanol has been intensively studied especially for genetically engineered Saccharomyces cerevisiae during the last 20 years. S. cerevisiae, which is a very safe microorganism that plays a traditional and major role in industrial bioethanol production, has several advantages due to its high ethanol productivity, as well as its high ethanol and inhibitor tolerance. However, this yeast cannot ferment xylose, which is the dominant pentose sugar in hydrolysates of lignocellulosic biomass. A number of different strategies have been applied to engineer yeasts capable of efficiently producing ethanol from xylose, including the introduction of initial xylose metabolism and xylose transport, changing the intracellular redox balance, and overexpression of xylulokinase and pentose phosphate pathways. In this review, recent progress with regard to these studies is discussed, focusing particularly on xylose-fermenting strains of S. cerevisiae. Recent studies using several promising approaches such as host strain selection and adaptation to obtain further improved xylose-utilizing S. cerevisiae are also addressed. (orig.)

  8. The cost of ethanol production from lignocellulosic biomass -- A comparison of selected alternative processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grethlein, H.E.; Dill, T.

    1993-04-30

    The purpose of this report is to compare the cost of selected alternative processes for the conversion of lignocellulosic biomass to ethanol. In turn, this information will be used by the ARS/USDA to guide the management of research and development programs in biomass conversion. The report will identify where the cost leverages are for the selected alternatives and what performance parameters need to be achieved to improve the economics. The process alternatives considered here are not exhaustive, but are selected on the basis of having a reasonable potential in improving the economics of producing ethanol from biomass. When other alternatives come under consideration, they should be evaluated by the same methodology used in this report to give fair comparisons of opportunities. A generic plant design is developed for an annual production of 25 million gallons of anhydrous ethanol using corn stover as the model substrate at $30/dry ton. Standard chemical engineering techniques are used to give first order estimates of the capital and operating costs. Following the format of the corn to ethanol plant, there are nine sections to the plant; feed preparation, pretreatment, hydrolysis, fermentation, distillation and dehydration, stillage evaporation, storage and denaturation, utilities, and enzyme production. There are three pretreatment alternatives considered: the AFEX process, the modified AFEX process (which is abbreviated as MAFEX), and the STAKETECH process. These all use enzymatic hydrolysis and so an enzyme production section is included in the plant. The STAKETECH is the only commercially available process among the alternative processes.

  9. 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.

  10. Comparative Ethanol Productivities of Two Different Recombinant Fermenting Strains on Source-Separated Organic Waste

    Directory of Open Access Journals (Sweden)

    Valeriy Bekmuradov

    2014-10-01

    Full Text Available Production of biofuel such as ethanol from lignocellulosic biomass is a beneficial way to meet sustainability and energy security in the future. The main challenge in bioethanol conversion is the high cost of processing, in which enzymatic hydrolysis and fermentation are the major steps. Among the strategies to lower processing costs are utilizing both glucose and xylose sugars present in biomass for conversion. An approach featuring enzymatic hydrolysis and fermentation steps, identified as separate hydrolysis and fermentation (SHF was used in this work. Proposed solution is to use "pre-processing" technologies, including the thermal screw press (TSP and cellulose-organic-solvent based lignocellulose fractionation (COSLIF pretreatments. Such treatments were conducted on a widely available feedstock such as source separated organic waste (SSO to liberate all sugars to be used in the fermentation process. Enzymatic hydrolysis was featured with addition of commercial available enzyme, Accellerase 1500, to mediate enzymatic hydrolysis process. On average, the sugar yield from the TSP and COSLIF pretreatments followed by enzymatic hydrolysis was remarkable at 90%. In this work, evaluation of the SSO hydrolysate obtained from COSLIF and enzymatic hydrolysis pretreaments on ethanol yields was compared by fermentation results with two different recombinant strains: Zymomonas mobilis 8b and Saccharomyces cerevisiae DA2416. At 48 hours of fermentation, ethanol yield was equivalent to 0.48g of ethanol produced per gram of SSO biomass by Z.mobilis 8b and 0.50g of ethanol produced per gram of SSO biomass by S. cerevisiae DA2416. This study provides important insights for investigation of the source-separated organic (SSO waste on ethanol production by different strains and becomes a useful tool to facilitate future process optimization for pilot scale facilities.

  11. Influence of high gravity process conditions on the environmental impact of ethanol production from wheat straw.

    Science.gov (United States)

    Janssen, Matty; Tillman, Anne-Marie; Cannella, David; Jørgensen, Henning

    2014-12-01

    Biofuel production processes at high gravity are currently under development. Most of these processes however use sugars or first generation feedstocks as substrate. This paper presents the results of a life cycle assessment (LCA) of the production of bio-ethanol at high gravity conditions from a second generation feedstock, namely, wheat straw. The LCA used lab results of a set of 36 process configurations in which dry matter content, enzyme preparation and loading, and process strategy were varied. The LCA results show that higher dry matter content leads to a higher environmental impact of the ethanol production, but this can be compensated by reducing the impact of enzyme production and use, and by polyethylene glycol addition at high dry matter content. The results also show that the renewable and non-renewable energy use resulting from the different process configurations ultimately determine their environmental impact.

  12. Performance of tapered column packed-bed bioreactor for ethanol production.

    Science.gov (United States)

    Hamamci, H; Ryu, D D

    1987-06-01

    A tapered column type of bioreactor system packed with immobilized Saccharomyces cerevisiae was used to study the bioreactor performance as a function of design and operating variables. The performance of tapered column bioreactor system was found to be better than that of the conventional cylindrical column reactor system for the ethanol fermentation. The new bioreactor design alleviated problems associated with carbon dioxide evolution and provided a significantly better flow pattern for both liquid and gas phases in the bioreactor without local channelling. A mathematical simulation model, which takes into account of the axial convection and dispersion, interphase mass transfer, and apparent kinetic design parameters, was developed. The effect of radial concentration gradients on the bioreactor performance was found to be insignificant. For the reactor system studied, the maximum ethanol productivity obtained was 60 g ethanol/L gel/h, and the maximum glucose assimilation rate was 140 g glucose/L gel/h. One of the most important findings from this study was that the apparent kinetic parameters change at the glucose concentration of 2 g/L This change was found to be due to the changes in yeast physiology and metabolism. The values of V(m) (') and V(m) (') decreased from 0.8 to 0.39 g ethanol/g cell/h and from 97mM to 11mM, respectively. The substrate inhibition constant was estimated as 0.76M and the product inhibition constant was determined as 113 g ethanol/L The degree of product inhibition showed practically a linear relationship with an increasing ethanol concentration. Based on the hydro-dynamic analysis of the bioreactor system, it was found that the Peclet number, N(Pe) was not a strong function of the flow velocity at low flow rates through the bioreactor system, but its value decreased somewhat at an interstitial velocity greater than 0.03 cm/s. The tapered column bioreactor system showed a much better flow pattern of gas and liquid phases within the

  13. Effect of poultry litter biochar on Saccharomyces cerevisiae growth and ethanol production from steam-exploded poplar and corn stover

    Science.gov (United States)

    Diallo, Oumou

    The use of ethanol produced from lignocellulosic biomass for transportation fuel offers solutions in reducing environmental emission and the use of non-renewable fuels. However, lignocellulosic ethanol production is still hampered by economic and technical obstacles. For instance, the inhibitory effect of toxic compounds produced during biomass pretreatment was reported to inhibit the fermenting microorganisms, hence there was a decrease in ethanol yield and productivity. Thus, there is a need to improve the bioconversion of lignocellulosic biomass to ethanol in order to promote its commercialization. The research reported here investigated the use of poultry litter biochar to improve the ethanol production from steam-exploded poplar and corn stover. The effect of poultry litter biochar was first studied on Saccharomyces cerevisiae ATCC 204508/S288C growth, and second on the enzyme hydrolysis and fermentation of two steam-exploded biomasses: (poplar and corn stover). The third part of the study investigated optimal process parameters (biochar loading, biomass loading, and enzyme loading) on the reducing sugars production, and ethanol yield from steam-exploded corn stover. In this study, it has been shown that poultry litter biochar improved the S. cerevisiae growth and ethanol productivity; therefore poultry litter biochar could potentially be used to improve the ethanol production from steam-exploded lignocellulosic biomass.

  14. 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.

  15. Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion

    Science.gov (United States)

    Mu, Dongyan; Seager, Thomas; Rao, P. Suresh; Zhao, Fu

    2010-10-01

    Lignocellulosic biomass can be converted into ethanol through either biochemical or thermochemical conversion processes. Biochemical conversion involves hydrolysis and fermentation while thermochemical conversion involves gasification and catalytic synthesis. Even though these routes produce comparable amounts of ethanol and have similar energy efficiency at the plant level, little is known about their relative environmental performance from a life cycle perspective. Especially, the indirect impacts, i.e. emissions and resource consumption associated with the production of various process inputs, are largely neglected in previous studies. This article compiles material and energy flow data from process simulation models to develop life cycle inventory and compares the fossil fuel consumption, greenhouse gas emissions, and water consumption of both biomass-to-ethanol production processes. The results are presented in terms of contributions from feedstock, direct, indirect, and co-product credits for four representative biomass feedstocks i.e., wood chips, corn stover, waste paper, and wheat straw. To explore the potentials of the two conversion pathways, different technological scenarios are modeled, including current, 2012 and 2020 technology targets, as well as different production/co-production configurations. The modeling results suggest that biochemical conversion has slightly better performance on greenhouse gas emission and fossil fuel consumption, but that thermochemical conversion has significantly less direct, indirect, and life cycle water consumption. Also, if the thermochemical plant operates as a biorefinery with mixed alcohol co-products separated for chemicals, it has the potential to achieve better performance than biochemical pathway across all environmental impact categories considered due to higher co-product credits associated with chemicals being displaced. The results from this work serve as a starting point for developing full life cycle

  16. 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)

  17. Transcriptomic response to prolonged ethanol production in the cyanobacterium Synechocystis sp. PCC6803.

    Science.gov (United States)

    Dienst, Dennis; Georg, Jens; Abts, Thomas; Jakorew, Lew; Kuchmina, Ekaterina; Börner, Thomas; Wilde, Annegret; Dühring, Ulf; Enke, Heike; Hess, Wolfgang R

    2014-02-06

    The production of biofuels in photosynthetic microalgae and cyanobacteria is a promising alternative to the generation of fuels from fossil resources. To be economically competitive, producer strains need to be established that synthesize the targeted product at high yield and over a long time. Engineering cyanobacteria into forced fuel producers should considerably interfere with overall cell homeostasis, which in turn might counteract productivity and sustainability of the process. Therefore, in-depth characterization of the cellular response upon long-term production is of high interest for the targeted improvement of a desired strain. The transcriptome-wide response to continuous ethanol production was examined in Synechocystis sp. PCC6803 using high resolution microarrays. In two independent experiments, ethanol production rates of 0.0338% (v/v) ethanol d-1 and 0.0303% (v/v) ethanol d-1 were obtained over 18 consecutive days, measuring two sets of biological triplicates in fully automated photobioreactors. Ethanol production caused a significant (~40%) delay in biomass accumulation, the development of a bleaching phenotype and a down-regulation of light harvesting capacity. However, microarray analyses performed at day 4, 7, 11 and 18 of the experiment revealed only three mRNAs with a strongly modified accumulation level throughout the course of the experiment. In addition to the overexpressed adhA (slr1192) gene, this was an approximately 4 fold reduction in cpcB (sll1577) and 3 to 6 fold increase in rps8 (sll1809) mRNA levels. Much weaker modifications of expression level or modifications restricted to day 18 of the experiment were observed for genes involved in carbon assimilation (Ribulose bisphosphate carboxylase and Glutamate decarboxylase). Molecular analysis of the reduced cpcB levels revealed a post-transcriptional processing of the cpcBA operon mRNA leaving a truncated mRNA cpcA* likely not competent for translation. Moreover, western blots and zinc

  18. Effect of Ethanol and Ethanol Biodegradation Products on Prospects for Natural Anaerobic Biodegradation of Benzene at Gasoline Spill Sites

    Science.gov (United States)

    There has been an increasing use of biofuels (ethanol in particular) in the fuel supply nationwide, and an increase in the number of stations that sell gasoline that contains more than 10% ethanol. The U.S. EPA needs to understand the fate of these materials if they are released ...

  19. Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum

    Science.gov (United States)

    Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

    2016-01-01

    Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from these enzymes were: AdhE1 > BdhB > BdhA ≈ YqhD > SMB_P058 > AdhE2. For ethanol production, the contributions were: AdhE1 > BdhB > YqhD > SMB_P058 > AdhE2 > BdhA. AdhE1 and BdhB are two essential enzymes for butanol and ethanol production. AdhE1 was relatively specific for butanol production over ethanol, while BdhB, YqhD, and SMB_P058 favor ethanol production over butanol. Butanol synthesis was increased in the adhE2 mutant, which had a higher butanol/ethanol ratio (8.15:1) compared with wild type strain (6.65:1). Both the SMB_P058 mutant and yqhD mutant produced less ethanol without loss of butanol formation, which led to higher butanol/ethanol ratio, 10.12:1 and 10.17:1, respectively. To engineer a more efficient butanol-producing strain, adhE1 could be overexpressed, furthermore, adhE2, SMB_P058, yqhD are promising gene inactivation targets. This work provides useful information guiding future strain improvement for butanol production. PMID:27321949

  20. Hydrogen Photo-production from Ethanol and Water over Au/TiO2 Rutile Single Crystal

    Science.gov (United States)

    2014-03-26

    Approved for Public Release; Distribution Unlimited Hydrogen Photo-production from Ethanol and Water over Au/ TiO2 Rutile Single Crystal The views...production from Ethanol and Water over Au/ TiO2 Rutile Single Crystal Report Title This project in its final form has focused on hydrogen production from...Hydrogen Production from Ethanol over Au/ TiO2 Nanoparticles”, Nature Chemistry, 3 (6) 489-492 ( 2011.) [2] I.R.Macdonald, R.F.Howe, X.Yang, W.Zhou, “In

  1. 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.

  2. Production of laccase by Pynoporus sanguineus using 2,5 - Xylidine and ethanol

    Science.gov (United States)

    Valeriano, Viviane S.; Silva, Anna Maria F.; Santiago, Mariângela F.; Bara, Maria T. F.; Garcia, Telma A.

    2009-01-01

    Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5-xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5-xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus. PMID:24031426

  3. Enhanced enzymatic hydrolysis of waste paper for ethanol production using separate saccharification and fermentation.

    Science.gov (United States)

    Guerfali, Mohamed; Saidi, Adel; Gargouri, Ali; Belghith, Hafedh

    2015-01-01

    Ethanol produced from lignocellulosic biomass is a renewable alternative to diminishing petroleum-based liquid fuels. In this study, the feasibility of ethanol production from waste paper using the separate hydrolysis and fermentation (SHF) was investigated. Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as a renewable feedstock for the production of fermentable sugars via enzymatic hydrolysis of their cellulose fractions. Hydrolysis step was conducted with a mixture of cellulolytic enzymes produced locally by Trichoderma reesei Rut-C30 (cellulase-overproducing mutant) and Aspergillus niger F38 cultures. Surfactant pretreatment effect on waste paper enzymatic digestibility was studied and Triton X-100 at 0.5 % (w w(-1)) has improved the digestibility of newspaper about 45 %. The effects of three factors (dry matter quantity, phosphoric acid pretreatment and hydrolysis time) on the extent of saccharification were also assessed and quantified by using a methodical approach based on response surface methodology. Under optimal hydrolysis conditions, maximum degrees of saccharification of newspaper and office paper were 67 and 92 %, respectively. Sugars released from waste paper were subsequently converted into ethanol (0.38 g ethanol g(-1) sugar) with Saccharomyces cerevisiae CTM-30101.

  4. Effect of phosphate on glucosamine production by ethanolic fungus Mucor indicus.

    Science.gov (United States)

    Mohammadi, Marzieh; Zamani, Akram; Karimi, Keikhosro

    2013-11-01

    In this study, the effect of phosphorous compound concentration on the production of glucosamine by Mucor indicus was investigated. Changes in the yield of ethanol, the major metabolite of the fungus, were also followed besides. The alkali insoluble material of the biomass of the fungus mainly contained phosphates and polymers of glucosamine and N-acetyl glucosamine, i.e., chitin and chitosan. Yields of glucosamine (78-113 g/kg dry fungal biomass) and ethanol (200-370 g/kg glucose) were significantly affected by the phosphorous concentration. The results showed that lower concentrations of phosphorous favored the production of glucosamine while higher ethanol as well as biomass yields was obtained at higher concentrations. The best concentration was 0.5 g/l where glucosamine yield was 0.37 g/l (11 % of the biomass). At this phosphate concentration, ethanol and biomass yields were 360 and 76 g/kg glucose, respectively. On average, proteins comprised 51.5 % of the biomass. Glycerol was the second important metabolite during the fermentation by the fungus which appeared at lower yields (20-34 g/kg glucose).

  5. Two-stage transcriptional reprogramming in Saccharomyces cerevisiae for optimizing ethanol production from xylose.

    Science.gov (United States)

    Cao, Limin; Tang, Xingliang; Zhang, Xinyuan; Zhang, Jingtao; Tian, Xuelei; Wang, Jingyu; Xiong, Mingyong; Xiao, Wei

    2014-07-01

    Conversion of lignocellulosic material to ethanol is a major challenge in second generation bio-fuel production by yeast Saccharomyces cerevisiae. This report describes a novel strategy named "two-stage transcriptional reprogramming (TSTR)" in which key gene expression at both glucose and xylose fermentation phases is optimized in engineered S. cerevisiae. Through a combined genome-wide screening of stage-specific promoters and the balancing of the metabolic flux, ethanol yields and productivity from mixed sugars were significantly improved. In a medium containing 50g/L glucose and 50g/L xylose, the top-performing strain WXY12 rapidly consumed glucose within 12h and within 84h it consistently achieved an ethanol yield of 0.48g/g total sugar, which was 94% of the theoretical yield. WXY12 utilizes a KGD1 inducible promoter to drive xylose metabolism, resulting in much higher ethanol yield than a reference strain using a strong constitutive PGK1 promoter. These promising results validate the TSTR strategy by synthetically regulating the xylose assimilation pathway towards efficient xylose fermentation.

  6. Production of bio-ethanol from pretreated agricultural byproduct using enzymatic hydrolysis and simultaneous saccharification.

    Science.gov (United States)

    Gomathi, D; Muthulakshmi, C; Kumar, D Guru; Ravikumar, G; Kalaiselvi, M; Uma, C

    2012-01-01

    Global warming alerts and threats are on the rise due to the utilization of fossil fuels. Alternative fuel sources like bio-ethanol and biodiesel are being produced to combat against these threats. Bio-ethanol can be produced from a range of substrate. The present study is aimed at the Production of bioethanol from pretreated agricultural substrate using enzymatic hydrolysis and simultaneous saccharification with the addition of purified fungal enzyme. Most cellulosic biomass is not fermentable without appropriate pretreatment methods and so dilute sulfuric acid pretreatment was applied to make the cellulose contained in the waste susceptible to endoglucanase enzyme. A range of acid pretreatment of wheat bran was made in which the sample that was pretreated with 1% dilute sulfuric acid gave maximum yield of ethanol in both methods such as 5.83 g L(-1) and 5.27 g L(-1), respectively. Ethanol produced from renewable and cheap agricultural products (wheat bran) provides reduction in green house gas emission, carbon monoxide, sulfur, and helps to eliminate smog from the environment.

  7. 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).

  8. Optimization of factors affecting the production of biodiesel from crude palm kernel oil and ethanol

    Directory of Open Access Journals (Sweden)

    David K. Kuwornoo, Julius C. Ahiekpor

    2010-07-01

    Full Text Available Biodiesel, an alternative diesel fuel made from renewable sources such as vegetable oils and animal fats, has been identified by government to play a key role in the socio-economic development of Ghana. The utilization of biodiesel is expected to be about 10% of the total liquid fuel mix of the country by the year 2020. Despite this great potential and the numerous sources from which biodiesel could be developed in Ghana, studies on the sources of biodiesel and their properties as a substitute for fossil diesel have tended to be limited to Jatropha oil. This paper, however, reports the parameters that influences the production of biodiesel from palm kernel oil, one of the vegetable oils obtained from oil palm which is the highest vegetable oil source in Ghana. The parameters studied are; mass ratio of ethanol to oil, reaction temperature, catalyst concentration, and reaction time using completely randomized 24 factorial design. Results indicated that ethanol to oil mass ratio, catalyst concentration and reaction time were the most important factors affecting the ethyl ester yield. There was also an interaction effect between catalyst and time and ethanol- oil ratio and time on the yield. Accordingly, the optimal conditions for the production of ethyl esters from crude palm kernel oil were determined as; 1:5 mass ratio of ethanol to oil, 1% catalyst concentration by weight of oil, 90 minutes reaction time at a temperature of 30 oC.

  9. Consolidated briefing of biochemical ethanol production from lignocellulosic biomass

    NARCIS (Netherlands)

    Achinas, Spyridon; Euverink, Gerrit Jan Willem

    2016-01-01

    Bioethanol production is one pathway for crude oil reduction and environmental compliance. Bioethanol can be used as fuel with significant characteristics like high octane number, low cetane number and high heat of vaporization. Its main drawbacks are the corrosiveness, low flame luminosity, lower v

  10. Consolidated briefing of biochemical ethanol production from lignocellulosic biomass

    NARCIS (Netherlands)

    Achinas, Spyridon; Euverink, Gerrit Jan Willem

    2016-01-01

    Bioethanol production is one pathway for crude oil reduction and environmental compliance. Bioethanol can be used as fuel with significant characteristics like high octane number, low cetane number and high heat of vaporization. Its main drawbacks are the corrosiveness, low flame luminosity, lower

  11. Production of ethanol and furfural from corn stover

    Science.gov (United States)

    Corn stover has potential for economical production of biofuels and value-added chemicals. The conversion of corn stover to sugars involves pretreatment and enzymatic hydrolysis. We have optimized hydrothermal, dilute H2SO4 and dilute H3PO4 pretreatments of corn stover for enzymatic saccharificati...

  12. 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 .

  13. The development and microbiology of bioprocesses for the production of hydrogen and ethanol by dark fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, P.

    2008-07-01

    This work investigated the production of hydrogen and ethanol from carbohydrates by bacterial dark fermentation. Meso and thermophilic fermenters were enriched from the environment, and their H{sub 2} and/or ethanol production in batch determined. Continuous biofilm, suspended-cell and granular-cell processes for H{sub 2} or ethanol+H{sub 2} production from glucose were developed and studied. Dynamics of microbial communities in processes were determined based on the 16S rRNA gene sequence analyses. Mesophilic enrichment, obtained from anaerobic digester sludge, produced 1.24 mol-H{sub 2} mol-glucose-1 in batch assays. Hydrogen production by the enrichment in a mesophilic fluidized-bed bioreactor (FBR) was found to be unstable - prompt onset of H{sub 2} production along with butyrate-acetate was followed by rapid decrease and cease associated with propionate-acetate production. Intermittent batch (semi-continuous) operation allowed a momentary recovery of H{sub 2} production in the FBR. The highest H{sub 2} production rate (HPR) observed in FBR was 28.8 mmol h-1 L-1, which corresponded to a relatively high hydrogen yield (HY) of 1.90 mol-H{sub 2} mol-glucose-1. Mesophilic, completely-mixed column reactor (CMCR), with a similar inoculum and feed as used in the FBR, provided a prolonged H{sub 2} production for 5 months. Highest HPR observed in the CMCR was 18.8 mmol h-1 L-1 (HY of 1.70 mol-H{sub 2} mol-glucose-1), while it in general remained between 1 and 6 mmol h-1 L-1. Hydrogen production in the CMCR was decreased by shifts in microbial community metabolism from initial butyrate-acetate metabolism, first to ethanol-acetate, followed by acetate-dominated metabolism, and finally to propionate-acetate metabolism, which ceased H{sub 2} production. The transitions of dominant metabolisms were successfully detected and visualized by self-organizing maps (SOMs). Developed Clustering hybrid regression (CHR) model, performed well in modeling the HPR based on the data on

  14. Efficient ethanol production from potato and corn processing industry waste using E. coli engineered to express Vitreoscilla haemoglobin.

    Science.gov (United States)

    Sumer, Fatma; Stark, Benjamin C; Yesilcimen Akbas, Meltem

    2015-01-01

    Engineering of ethanologenic E. coli to express the haemoglobin (VHb) from the bacterium Vitreoscilla has been shown to enhance ethanol production by fermentation of pure sugars, sugars from hydrolysis of lignocellulose, components of whey, and sugars from wastewater produced during potato processing. Here, these studies were extended to see whether the same effect could be seen when a mixture of waste materials from processing of potatoes and corn into potato and corn chips were used as sugar sources. Consistent increases in ethanol production coincident with VHb expression were seen in shake flasks at both low aeration and high aeration conditions. The ethanol increases were due almost entirely to increases in the amount of ethanol produced per unit of cell mass. The VHb strategy for increasing fermentation to ethanol (and perhaps other valuable fermentation products) may be of general use, particularly regarding conversion of otherwise discarded materials into valuable commodities.

  15. Direct Ethanol Production from Lignocellulosic Sugars and Sugarcane Bagasse by a Recombinant Trichoderma reesei Strain HJ48

    Directory of Open Access Journals (Sweden)

    Jun Huang

    2014-01-01

    Full Text Available Trichoderma reesei can be considered as a candidate for consolidated bioprocessing (CBP microorganism. However, its ethanol yield needs to be improved significantly. Here the ethanol production of T. reesei CICC 40360 was improved by genome shuffling while simultaneously enhancing the ethanol resistance. The initial mutant population was generated by nitrosoguanidine treatment of the spores, and an improved population producing more than fivefold ethanol than wild type was obtained by genome shuffling. The results show that the shuffled strain HJ48 can efficiently convert lignocellulosic sugars to ethanol under aerobic conditions. Furthermore, it was able to produce ethanol directly from sugarcane bagasse, demonstrating that the shuffled strain HJ48 is a suitable microorganism for consolidated bioprocessing.

  16. Lack of effects of a "sobering" product, "Eezup!", on the blood ethanol and congener alcohol concentration.

    Science.gov (United States)

    Wunder, Cora; Hain, Sarah; Koelzer, Sarah C; Paulke, Alexander; Verhoff, Marcel A; Toennes, Stefan W

    2017-09-01

    The lifestyle product 'Eezup!' appeared on the German market and promised to normalize energy metabolism. Among vitamins (B1, B2, B6, C, E and zinc), rice protein and fructose the addition of alcohol dehydrogenase and catalase enzymes is a novel approach. The product was advertised as capable of boosting the rate of alcohol elimination. Seventeen subjects (11 men, 6 women, 19-58 years old), participated in a two-way crossover drinking study. Unfiltered wheat beer (4.4g% alcohol content) was drank within one hour to reach blood alcohol concentrations of 1‰ (1g/kg whole blood). On one day "Eezup!" was taken according to the manufacturer's instructions before and after drinking which was substituted for a placebo on the second test day. Blood samples were taken during 9h and ethanol and congener alcohols were determined. A comparison of Cmax, tmax, area under the curve (AUC) for ethanol and congener alcohols, and the hourly elimination rate of ethanol (β60) was performed to investigate an effect of Eezup!. Ethanol concentrations (Cmax) were in the range of 0,63-1,00‰ (median 0,85‰) and 0.62-1.22‰ (median 0.84‰) in the placebo and "Eezup!" condition, respectively, and not statistically different. Also tmax (1-2.5h) and AUCs did not differ. The ethanol elimination rates were 0.16‰/h (0.14-0.19‰/h) and 0.17‰/h (0.14-0.22 ‰/h) in the placebo and "Eezup!" condition without significant difference. The pharmacokinetic parameters of the congener alcohols (1-propanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol) as well as of methanol did also not differ. The results of the present study failed to show any effect of the sobering product "Eezup!" on the amount of ethanol and congener alcohols absorbed (Cmax, tmax, AUC) and on the ethanol elimination rate (β60). Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Use of tower reactors for continuous ethanol production

    Directory of Open Access Journals (Sweden)

    M.C. Viegas

    2002-04-01

    Full Text Available The purpose of this work was to develop a continuous fermentation system operating with a tower reactor using some flocculent yeast strains isolated from an industrial process. The strain was an used in the trial of the proposed system, composed of two serial glass tower reactor. The effects of the following variables were studied on the yield and productivity of the system: total reducing sugar (TRS, concentration in feeding, recycle flow in the second reactor, residence time and diameter/height ratio of the reactors. It was observed that the TRS concentration in feeding and residence time is the variables that interfere most with the productivity of the system. Yield was not affected by any of the variables within the range of values studied. All trials were performed according to a factorial experimental design (making up a total of 19 trials and the results were evaluated by response surface.

  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. High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.

    Science.gov (United States)

    Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

    2014-07-01

    Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.

  20. 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 ...

  1. Influence of temperature, pH and yeast on in-field production of ethanol from unsterilized sweet sorghum juice

    Energy Technology Data Exchange (ETDEWEB)

    Kundiyana, Dimple K.; Bellmer, Danielle D.; Huhnke, Raymond L.; Wilkins, Mark R. [Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078 (United States); Claypool, P.L. [Department of Statistics, Oklahoma State University, Stillwater, OK 74078 (United States)

    2010-10-15

    It is inevitable that ethanol production in the United States will continue to increase. Sweet sorghum has the potential to be used as a renewable energy crop, and is a viable candidate for ethanol production. Previous barriers to commercialization of sweet sorghum to ethanol have primarily been the high capital cost involved in building a central processing plant that may be operated only seasonally. In order to reduce the investment necessary in a central processing facility, the proposed process involves in-field production of ethanol from sweet sorghum. The overall objective of the research was to determine whether fermentation can take place in the environment with no process control. The goals were to evaluate the effects of yeast type, pH, and nutrients on fermentation process efficiency. Results indicated that both strains of Saccharomyces cerevisiae tested were able to perform fermentation within a wide ambient temperature range (10-25 C). Maximum ethanol produced was 7.9% w v{sup -1} in 120 h under ambient temperature conditions. Other process variables such as adding urea or lowering pH did not significantly improve the sugar to ethanol conversion efficiency of yeasts. Results indicate that in-field fermentation of sweet sorghum juice to ethanol is possible with minimal or no process controls and is a feasible process for ethanol production. (author)

  2. Selective inhibition of methanogenesis to enhance ethanol and n-butyrate production through acetate reduction in mixed culture fermentation

    NARCIS (Netherlands)

    Steinbusch, K.J.J.; Arvaniti, E.; Hamelers, H.V.M.; Buisman, C.J.N.

    2009-01-01

    Acetate reduction is an alternative digestion process to convert organic waste into ethanol. Using acetate for fuel ethanol production offers the opportunity to use organic waste materials instead of sugar-containing feedstock. Methanogenesis, however, competes with acetate reduction for acetate and

  3. Ethanol Production from SPORL-pretreated Lodgepole Pine: Preliminary Evaluation of Mass Balance and Process Energy Efficiency

    Science.gov (United States)

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 liters (73 gallons) per ton of wood or 72% of theoretical. The lodgepole pine chips were directly subject to the sulfite pretreatment to ...

  4. Potassium sorbate reduces production of ethanol and 2 esters in corn silage.

    Science.gov (United States)

    Hafner, Sasha D; Franco, Roberta B; Kung, Limin; Rotz, C Alan; Mitloehner, Frank

    2014-12-01

    The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor air quality and reduce feed intake. Silage additives may reduce VOC production in silage by inhibiting the activity of bacteria or yeasts that produce them. We produced corn silage in 18.9-L bucket silos using the following treatments: (1) control (distilled water); (2) Lactobacillus buchneri 40788, with 400,000 cfu/g of wet forage; (3) Lactobacillus plantarum MTD1, with 100,000 cfu/g; (4) a commercial buffered propionic acid-based preservative (68% propionic acid, containing ammonium and sodium propionate and acetic, benzoic, and sorbic acids) at a concentration of 1 g/kg of wet forage (0.1%); (5) a low dose of potassium sorbate at a concentration of 91 mg/kg of wet forage (0.0091%); (6) a high dose of potassium sorbate at a concentration of 1g/kg of wet forage (0.1%); and (7) a mixture of L. plantarum MTD1 (100,000 cfu/g) and a low dose of potassium sorbate (91 mg/kg). Volatile organic compound concentrations within silage were measured after ensiling and sample storage using a headspace gas chromatography method. The high dose of potassium sorbate was the only treatment that inhibited the production of multiple VOC. Compared with the control response, it reduced ethanol by 58%, ethyl acetate by 46%, and methyl acetate by 24%, but did not clearly affect production of methanol or 1-propanol. The effect of this additive on ethanol production was consistent with results from a small number of earlier studies. A low dose of this additive does not appear to be effective. Although it did reduce methanol production by 24%, it increased ethanol production by more than 2-fold and did not reduce the ethyl acetate concentration. All other treatments increased ethanol production

  5. Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach.

    Science.gov (United States)

    Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel; van Rossum, Guus; Berruti, Franco; Kersten, Sascha; Rehmann, Lars

    2016-01-01

    One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when compared to dried distillers grains (DDG), the main by-product of corn ethanol. Fast pyrolysis is an alternative thermal conversion technology for processing biomass. It has recently been optimized to produce a stream rich in levoglucosan, a fermentable glucose precursor for biofuel production. Additional product streams might be of value to the petrochemical industry. However, biomass heterogeneity is known to impact the composition of pyrolytic product streams, as a complex mixture of aromatic compounds is recovered with the sugars, interfering with subsequent fermentation. The present study investigates the feasibility of fast pyrolysis to produce fermentable pyrolytic glucose from two abundant lignocellulosic biomass sources in Ontario, switchgrass (potential energy crop) and corn cobs (by-product of corn industry). Demineralization of biomass removes catalytic centers and increases the levoglucosan yield during pyrolysis. The ash content of biomass was significantly decreased by 82-90% in corn cobs when demineralized with acetic or nitric acid, respectively. In switchgrass, a reduction of only 50% for both acids could be achieved. Conversely, levoglucosan production increased 9- and 14-fold in corn cobs when rinsed with acetic and nitric acid, respectively, and increased 11-fold in switchgrass regardless of the acid used. After pyrolysis, different configurations for upgrading the pyrolytic sugars were assessed and the presence of potentially inhibitory compounds was approximated at each step as double integral of the UV spectrum signal of an HPLC assay. The results showed that water extraction followed by acid hydrolysis and solvent extraction was the best upgrading strategy

  6. 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

  7. Technique of ethanol food grade production with batch distillation and dehydration using starch-based adsorbent

    Science.gov (United States)

    Widjaja, Tri; Altway, Ali; Ni'mah, Hikmatun; Tedji, Namira; Rofiqah, Umi

    2015-12-01

    Development and innovation of ethanol food grade production are becoming the reasearch priority to increase economy growth. Moreover, the government of Indonesia has established regulation for increasing the renewable energy as primary energy. Sorghum is cerealia plant that contains 11-16% sugar that is optimum for fermentation process, it is potential to be cultivated, especially at barren area in Indonesia. The purpose of this experiment is to learn about the effect of microorganisms in fermentation process. Fermentation process was carried out batchwise in bioreactor and used 150g/L initial sugar concentration. Microorganisms used in this experiment are Zymomonas mobilis mutation (A3), Saccharomyces cerevisiae and mixed of Pichia stipitis. The yield of ethanol can be obtained from this experiment. For ethanol purification result, distillation process from fermentation process has been done to search the best operation condition for efficiency energy consumption. The experiment for purification was divided into two parts, which are distillation with structured packing steel wool and adsorption (dehydration) sequencely. In distillation part, parameters evaluation (HETP and pressure drop) of distillation column that can be used for scale up are needed. The experiment was operated at pressure of 1 atm. The distillation stage was carried out at 85 °C and reflux ratio of 0.92 with variety porosities of 20%, 40%, and 60%. Then the adsorption process was done at 120°C and two types of adsorbent, which are starch - based adsorbent with ingredient of cassava and molecular sieve 3A, were used. The adsorption process was then continued to purify the ethanol from impurities by using activated carbon. This research shows that the batch fermentation process with Zymomonas mobilis A3 obtain higher % yield of ethanol of 40,92%. In addition to that, for purification process, the best operation condition is by using 40% of porosity of stuctured packing steel wool in distillation

  8. Low temperature hydrogen production from ethanol over cerium and nickel based oxyhydrides

    Energy Technology Data Exchange (ETDEWEB)

    Pirez, Cyril; Jalowiecki-Duhamel, L.; Capron, M.; Dumeignil, F. [Univ. des Sciences et Technologies de Lille (France). UCCS Unite de Catalyse et de Chimie du Solide

    2010-07-01

    In theory, hydrogen production from biomass or biomass derived liquids can be a carbon emission free process since all carbon dioxide produced can be recycled back to plants using solar energy. Besides, ethanol is also safe, simple to handle, transport and store, so ethanol lends itself very well to a distributed-production strategy. A very interesting use of hydrogen is based on its conversion into power in fuel cell systems. The wide-spread application of fuel cells becomes closer to reality, so increased attention is focused on hydrogen production technology. Solid oxide fuel cells (SOFCs) are under development as energy production devices, they allow the use of carbon-monoxide resistant nickel anodes and the use of fuels different from hydrogen at the anode, in the so-called direct internal reforming SOFC. However the high operating temperatures undergo catalytic deactivation due to sintering of nickel crystallites and carbon deposition. Hence, worldwide efforts are in progress to discover novel, more active and more stable catalysts. Performing the reaction at lower temperature than 600 C is a challenging goal. C{sub 2}H{sub 5}OH + 3 H{sub 2}O {yields} 2 CO{sub 2} + 6 H{sub 2} (1). Hydrogen production from ethanol steam reforming (H{sub 2}O/C{sub 2}H{sub 5}OH = 3) was investigated over cerium nickel CeNi{sub X}O{sub Y} and (0 < x {<=} 5) mixed oxide catalysts. The influence of different parameters was analysed, such as reaction temperature, Ni content and in-situ pre-treatment in H{sub 2}. While an ethanol conversion of 100 % is reached at 400 C, a stable activity i.e. ethanol conversion, and H{sub 2} selectivity can be obtained at very low temperature (200 C) when the solid is previously in-situ treated in H{sub 2} in a temperature range between 200 C and 300 C. In the present study, we report on H{sub 2} formation activity over CeNi{sub X}O{sub Y} catalysts for reforming of ethanol. The aim of this work was to develop a highly active, selective, stable and

  9. The occurrence and identification of microbiological contamination in fuel ethanol production

    Directory of Open Access Journals (Sweden)

    Katarzyna Leja

    2009-12-01

    Full Text Available Background. Bacterial contamination is a major problem for commercial fuel ethanol production in distilleries all over the world. The contaminating microorganisms produce acetic and lactic acid that has a detrimental effect on fermentation efficiency. The aim of this work was to calculate the number of bacterial contaminants in some distilleries. Moreover, in this study it was signified what kind of bacteria contaminate ethanol production process. Material and methods. Grains were obtained from five distilleries from some regions in Poland, in this work hereafter referred to as α, β, γ, δ, and ε distilleries. Corn was the raw material in the α, β, and γ distilleries, triticale in δ distillery, and rye in the ε one. From these five distilleries, sweet mashes during fermentation and after it, were also analysed. The total number of microorganisms, the number of lactic acid bacteria, the number of anaerobic bacteria and the quantity of yeasts and moulds in raw materials were calculated. Results. The number of total viable bacteria (CFU/g, lactic acid bacteria (CFU/g, anaerobic bacteria (CFU/g, moulds, and yeasts (CFU/g occur in the samples were determined. In all distilleries tested, all groups of microorganism were present. Conclusions. The results of our study show that all tested distilleries have a lot of difficulties with microbiology pollution which leads to a decrease of ethanol production and economical problems. From the economical point of view, reduction of microbial contamination makes it possible to increase the production volume.

  10. Screening of Jerusalem artichoke varieties for bio-ethanol production in Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Passarinho, P.C.; Oliveira, A.C.; Rosa, M.F. [INETI, Departamento de Energias Renovaveis, Estrada do Paco do Lumiar, Ed. G, 1649-038, Lisboa (Portugal)

    2008-07-01

    The aim of this work was the evaluation of the potential of 9 Jerusalem artichoke varieties for the sustainable production of bio-ethanol in Portugal. The tubers, which are the part of the plant with higher sugar content, were harvested at different stages of development (29 to 55 weeks), and crashed for juice extraction. The two phases obtained were characterized in terms of total sugars, protein, ash and dry matter. The ethanol productivity of the different J. artichoke varieties was then evaluated fermenting juice or mixtures of juice and pulp aqueous extract with a strain of Kluyveromyces marxianus, a yeast able to hydrolyze and ferment inulin polymers. The chamical characteristic more dependable on the harvest period was the amount of total sugars in the tubers. Juices, obtained until 48 weeks development, contained 173 - 235 g/L of total sugars while juices from the last harvest presented markedly lower sugar contents, indicating crop degradation or sugar migration to the soil. Regarding the fermentative process, ethanol yields ranged from 0.3 to 0.5 g/g. The main conclusion of this work indicates C13 variety as the best. Although bearing a lower sugar concentration in tubers, the substantially higher agricultural productivities (kg/m2) after 8 months growing allowed to estimate productions higher than 10 000 L/ha.

  11. Separation and characterization of lignin from bio-ethanol production residue.

    Science.gov (United States)

    Guo, Guowan; Li, Shujun; Wang, Lu; Ren, Shixue; Fang, Guizhen

    2013-05-01

    In order to develop an adequate method to separate lignin from bio-ethanol production residue, solvent extraction was conducted by using benzyl alcohol, dioxane and ethanol. Compared to the conventional alkali-solution and acid-isolation method, benzyl alcohol and dioxane extraction could reach higher lignin yield of 71.55% and 74.14% respectively. FTIR and XRD analysis results indicate that sodium hydroxide solution dissolved most of the lignin in the raw material. However, the low lignin yield by this method may be attributed to the products loss during the complex separation process. GPC and (1)H NMR results revealed that the dioxane-lignin had closer molecular weight with alkali-lignin, lower S/G ratio (0.22) and higher OHPh/OHAl ratio (0.45) with respect to benzyl alcohol-lignin. The results divulge that the lignin products separated from bio-ethanol production residue by dioxane extraction had fairly potential application with better chemical activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Optimization of ethanol production in Saccharomyces cerevisiae by metabolic engineering of the ammonium assimilation.

    Science.gov (United States)

    Nissen, T L; Kielland-Brandt, M C; Nielsen, J; Villadsen, J

    2000-01-01

    Ethanol is still one of the most important products originating from the biotechnological industry with respect to both value and amount. In addition to ethanol, a number of byproducts are formed during an anaerobic fermentation of Saccharomyces cerevisiae. One of the most important of these compounds, glycerol, is produced by yeast to reoxidize NADH, formed in synthesis of biomass and secondary fermentation products, to NAD+. The purpose of this study was to evaluate whether a reduced formation of surplus NADH and an increased consumption of ATP in biosynthesis would result in a decreased glycerol yield and an increased ethanol yield in anaerobic cultivations of S. cerevisiae. A yeast strain was constructed in which GLN1, encoding glutamine synthetase, and GLT1, encoding glutamate synthase, were overexpressed, and GDH1, encoding the NADPH-dependent glutamate dehydrogenase, was deleted. Hereby the normal NADPH-consuming synthesis of glutamate from ammonium and 2-oxoglutarate was substituted by a new pathway in which ATP and NADH were consumed. The resulting strain TN19 (gdh1-A1 PGK1p-GLT1 PGK1p-GLN1) had a 10% higher ethanol yield and a 38% lower glycerol yield compared to the wild type in anaerobic batch fermentations. The maximum specific growth rate of strain TN19 was slightly lower than the wild-type value, but earlier results suggest that this can be circumvented by increasing the specific activities of Gln1p and Glt1p even more. Thus, the results verify the proposed concept of increasing the ethanol yield in S. cerevisiae by metabolic engineering of pathways involved in biomass synthesis.

  13. Improving the performance of a continuous process for the production of ethanol from starch.

    Science.gov (United States)

    Trovati, Joubert; Giordano, Roberto C; Giordano, Raquel L C

    2009-05-01

    In a previous work, a continuous simultaneous saccharification and fermentation process to produce ethanol from cassava starch was studied, using a set of fixed-bed reactors. The biocatalyst consisted of glucoamylase immobilized in silica particles and co-immobilized with S. cerevisiae in pectin gel. Using 3.8 U mL(-1) (reactor) and 0.05 g(wet yeast) mL(-1) (reactor) at start-up, starch hydrolysis was the rate-limiting step. Maximum ethanol productivity was 5.8 g(ethanol) L(-1) h(-1), with 94.0% conversion of total reducing sugars (TRS) and 83.0% of the ethanol theoretical yield. In this work, the molar mass of the substrate and the biocatalyst particle size were reduced in an attempt to improve the bioreactor performance. The diameters of silica and pectin gel particles were reduced from 100 mum and 3-4 mm, respectively, to 60 mum and 1-1.5 mm, and the degree of substrate prehydrolysis by alpha-amylase was increased. The bioreactor performance was assessed for different loads of immobilized glucoamylase (2.1, 2.8, and 3.8 U mL(-1) (reactor)), for the same initial cell concentration (0.05 g(wet yeast.)mL(-1) (reactor)). Feeding with 154.0 g L(-1) of TRS and using 3.8 U mL(-1) (reactor), fermentation became the rate-limiting step. Productivity reached 11.7 g L(-1) h(-1), with 97.0% of TRS conversion and 92.0% of the ethanol theoretical yield. The reactor was operated during 275 h without any indication of destabilization.

  14. Dynamics of ethanol production from deproteinized whey by Kluyveromyces marxianus: An analysis about buffering capacity,thermal and nitrogen tolerance

    OpenAIRE

    Nathalia Lima Moreira; Leandro Freire dos Santos; Carlos Ricardo Soccol; Hélio Hiroshi Suguimoto

    2015-01-01

    The production of value-added products could be a valuable option for cheese wastewater management. However, this kind of study cannot just focus alone on getting the final product. This also necessitates studies on the dynamics of bioprocesses. With these as background, the present investigation aimed at evaluating the buffering capacity of deproteinized whey and effect of temperature and nitrogen source on ethanol yields from it. The batch fermentation conditions used to evaluate ethanol pr...

  15. The bio-ethanol production with the thin stillage recirculation

    Directory of Open Access Journals (Sweden)

    M. Rakin

    2009-01-01

    Full Text Available In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield was 97.96 %, which implicates that the experiment conditions were chosen and performed well.