WorldWideScience

Sample records for yield ethanol production

  1. Energy yield for the production of ethanol from corn

    International Nuclear Information System (INIS)

    Chavanne, X.; Frangi, J.P.

    2008-01-01

    This article establishes the primary energy balance for making ethanol out of corn in the USA, calculated from the farm to the fuel station, following a methodology described in Chavanne and Frangi (C. R. Geoscience 339 (2007) 519-535). Raw data (direct energy and material consumption as well as their heat value and external costs) come from published papers related to this topic, technical textbooks, as well as reports from the US Departments of Agriculture and Energy. For the 2001 harvest, over the area producing more than 90% of ethanol and for the 2005 network of working refineries, 100 J of ethanol and recovery of by-products (the energy saved by the replacement of animal feed by these by-products is around 12% of the ethanol heat value) needed 86 ± 3 J of energy spending, of which more than 50 J is natural gas and 62 J is used in refineries. A third of the area of Nebraska corn must be irrigated with water pumped from underground, at an added cost of 26 ± 3 J. In 1996, the extra drying required, because of heavy rains, added 6 J. By comparison, 100 J of gasoline cost less than 25 J to be produced out of crude oil. Complementary studies of resource availability are not performed here. The largest possible reduction in energy costs can be achieved at the refinery stage, by fermenting by-products, gas residues, (from 62 J to around 12 J). The article gives also an expression for the expenditure to enable comparison between different energy systems, including everything from biomass to transport. For the ethanol case, the average cost is 130 J for 100 J of corn grain heat. (authors)

  2. 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.

    Science.gov (United States)

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

    2014-01-01

    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 feeding through a multi-disciplinary approach. Seven scenarios are evaluated: four considering the impact of technological advances on corn grain production, two focused on improved efficiencies in ethanol processing, and one reflecting greater use of ethanol co-products (that is, distillers dried grains with solubles) in diets for dairy cattle, pigs, and poultry. For each scenario, land area attributed to corn ethanol production is estimated for three time horizons: 2011 (current), the time period at which the 15 billion gallon cap for corn ethanol as per the Renewable Fuel Standard is achieved, and 2026 (15 years out). Although 40.5% of corn grain was channeled to ethanol processing in 2011, only 25% of US corn acreage was attributable to ethanol when accounting for feed co-product utilization. By 2026, land area attributed to corn ethanol production is reduced to 11% to 19% depending on the corn grain yield level associated with the four corn production scenarios, considering oil replacement associated with the soybean meal substituted in livestock diets with distillers dried grains with solubles. Efficiencies in ethanol processing, although producing more ethanol per bushel of processed corn, result in less co-products and therefore less offset of corn acreage. Shifting the use of distillers dried grains with solubles in feed to dairy cattle, pigs, and poultry substantially reduces land area attributed to corn ethanol production. However, because distillers dried grains with solubles

  3. Optimization of ethanol production from garcinia cambogia residues and the effects of its medicinal component on production yield

    International Nuclear Information System (INIS)

    Ma, H.; Zhang, F.

    2017-01-01

    Garcinia cambogia, a Chinese herbal medicine, was popular due to its effect for weight loss. The main medical component inside was determined to be hydroxycitric acid (HCA). To realize the resource technology of garcinia cambogia residue, Optimum ethanol production from residues was investigated, and the effects of remaining HCA on the ethanol yield were investigated. A Plackett-Burman experimental design was used to screen the significance of several influencing factors, and cellulase, yeast extract, and KH2PO4 were observed to exert important effects. The optimum ethanol fermentation conditions were determined through an orthogonal design to include a cellulase concentration of 100 U/g, a yeast extract concentration of 15 g/L, and a KH2PO4 concentration of 1.0 g/L. The ethanol concentration obtained under optimal conditions was 4.0 g/L. The remained HCA in the residues showed minimal influences on ethanol fermentation and could even increase ethanol yield at low concentrations. (author)

  4. Improving conversion yield of fermentable sugars into fuel ethanol in 1st generation yeast-based production processes.

    Science.gov (United States)

    Gombert, Andreas K; van Maris, Antonius J A

    2015-06-01

    Current fuel ethanol production using yeasts and starch or sucrose-based feedstocks is referred to as 1st generation (1G) ethanol production. These processes are characterized by the high contribution of sugar prices to the final production costs, by high production volumes, and by low profit margins. In this context, small improvements in the ethanol yield on sugars have a large impact on process economy. Three types of strategies used to achieve this goal are discussed: engineering free-energy conservation, engineering redox-metabolism, and decreasing sugar losses in the process. Whereas the two former strategies lead to decreased biomass and/or glycerol formation, the latter requires increased process and/or yeast robustness. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Kolleurp, F; Daugulis, A J

    1985-05-01

    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 which 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. The model predicts an 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 dilution rate of 5.0 h . This is more than 10 times higher than for a conventional chemostat fermentation of a 250 g/L glucose feed. In light of this, a systematic approach to extractive fermentation has been undertaken involving the screening of more than 1,000 solvents for their extractive properties. UNIFAC and UNIQUAC estimates of distribution coefficients and selectivities were compiled and ranked in a database, together with other important physical properties, such as density, surface tension and viscosity. Preliminary shake-flask and chemostat biocompatibility studies on the most promising solvents have been undertaken. The previous predictive, data base and experimental results are discussed.

  6. Anaerobic digestion in combination with 2nd generation ethanol production for maximizing biofuels yield from lignocellulosic biomass – testing in an integrated pilot-scale biorefinery plant

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Ahring, Birgitte Kiær

    An integrated biorefinery concept for 2nd generation bioethanol production together with biogas production from the fermentation effluent was tested in pilot-scale. The pilot plant comprised pretreatment, enzymatic hydrolysis, hexose and pentose fermentation into ethanol and anaerobic digestion......-VS/(m3•d) a methane yield of 340 L/kg-VS was achieved for thermophilic operation while 270 L/kg-VS was obtained under mesophilic conditions. Thermophilic operation was, however, less robust towards further increase of the loading rate and for loading rates higher than 5 kg-VS/(m3•d) the yield was higher...... for mesophilic than for thermophilic operation. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher biofuels yield in the biorefinery compared to a system...

  7. Ethanol yield and volatile compound content in fermentation of agave must by Kluyveromyces marxianus UMPe-1 comparing with Saccharomyces cerevisiae baker's yeast used in tequila production.

    Science.gov (United States)

    López-Alvarez, Arnoldo; Díaz-Pérez, Alma Laura; Sosa-Aguirre, Carlos; Macías-Rodríguez, Lourdes; Campos-García, Jesús

    2012-05-01

    In tequila production, fermentation is an important step. Fermentation determines the ethanol productivity and organoleptic properties of the beverage. In this study, a yeast isolated from native residual agave must was identified as Kluyveromyces marxianus UMPe-1 by 26S rRNA sequencing. This yeast was compared with the baker's yeast Saccharomyces cerevisiae Pan1. Our findings demonstrate that the UMPe-1 yeast was able to support the sugar content of agave must and glucose up to 22% (w/v) and tolerated 10% (v/v) ethanol concentration in the medium with 50% cells survival. Pilot and industrial fermentation of agave must tests showed that the K. marxianus UMPe-1 yeast produced ethanol with yields of 94% and 96% with respect to fermentable sugar content (glucose and fructose, constituting 98%). The S. cerevisiae Pan1 baker's yeast, however, which is commonly used in some tequila factories, showed 76% and 70% yield. At the industrial level, UMPe-1 yeast shows a maximum velocity of fermentable sugar consumption of 2.27g·L(-1)·h(-1) and ethanol production of 1.38g·L(-1)·h(-1), providing 58.78g ethanol·L(-1) at 72h fermentation, which corresponds to 96% yield. In addition, the major and minor volatile compounds in the tequila beverage obtained from UMPe-1 yeast were increased. Importantly, 29 volatile compounds were identified, while the beverage obtained from Pan1-yeast contained fewer compounds and in lower concentrations. The results suggest that the K. marxianus UMPe-1 is a suitable yeast for agave must fermentation, showing high ethanol productivity and increased volatile compound content comparing with a S. cerevisiae baker's yeast used in tequila production. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  8. Hydrogen yield from low temperature steam reforming of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Das, N.K.; Dalai, A.K. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering, Catalysis and Chemical Reaction Engineering Laboratories; Ranganathan, R. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2007-02-15

    Interest in the use of ethanol for fuel cell hydrogen production was discussed with particular reference to a study in which the production of hydrogen was maximized through low temperature steam reforming of ethanol in the temperature range of 200 to 360 degrees C. The primary objective of this study was to determine the effect of Mn concentration on a Cu/Al{sub 2}O{sub 3} catalyst for steam reforming of ethanol to produce hydrogen. The purpose was to maximize ethanol conversion and hydrogen selectivity in the lowest possible reaction temperature for the ideal catalyst activity. The optimum reaction conditions in the presence of a suitable catalyst can produce the desired products of hydrogen and carbon dioxide. Cu/Al{sub 2}O{sub 3} catalysts with six different concentrations ranging from 0 to 10 weight per cent Mn, were prepared, characterized and studied for the ethanol-steam reforming reaction. The effects of different process variables were studied, including water-to-ethanol feed ratio, space time and catalyst reduction temperatures on ethanol conversion and hydrogen yield. Maximum ethanol conversion of 60.7 per cent and hydrogen yield of 3.74 (mol of hydrogen per mol of ethanol converted) were observed at 360 degrees C for a catalyst with 2.5 weight per cent Mn loading. 29 refs., 3 tabs., 12 figs.

  9. 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.

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

    Science.gov (United States)

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

    2017-07-01

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

  11. Implications of increased ethanol production

    International Nuclear Information System (INIS)

    1992-06-01

    The implications of increased ethanol production in Canada, assuming a 10% market penetration of a 10% ethanol/gasoline blend, are evaluated. Issues considered in the analysis include the provision of new markets for agricultural products, environmental sustainability, energy security, contribution to global warming, potential government cost (subsidies), alternative options to ethanol, energy efficiency, impacts on soil and water of ethanol crop production, and acceptance by fuel marketers. An economic analysis confirms that ethanol production from a stand-alone plant is not economic at current energy values. However, integration of ethanol production with a feedlot lowers the break-even price of ethanol by about 35 cents/l, and even further reductions could be achieved as technology to utilize lignocellulosic feedstock is commercialized. Ethanol production could have a positive impact on farm income, increasing cash receipts to grain farmers up to $53 million. The environmental impact of ethanol production from grain would be similar to that from crop production in general. Some concerns about ethanol/gasoline blends from the fuel industry have been reduced as those blends are now becoming recommended in some automotive warranties. However, the concerns of the larger fuel distributors are a serious constraint on an expansion of ethanol use. The economics of ethanol use could be improved by extending the federal excise tax exemption now available for pure alcohol fuels to the alcohol portion of alcohol/gasoline blends. 9 refs., 10 tabs

  12. High ethanol yields using Aspergillus oryzae koji and corn media

    Energy Technology Data Exchange (ETDEWEB)

    Ziffer, J.; Iosif, M.C.

    1982-01-01

    High ethanol and stillage solids were achieved using whole corn mashes. Ethanol yields of 14% (98.5% of theory) and stillage levels of approximately 23% were obtained in 74-90 hours using mild acid pretreatment with A. oryzae wheat bran koji saccharification. High ethanol yields were also obtained with bacterial amylase, instead of the acid treatment, when the sterilization step was omitted. The implications of ethanol fermentation process modifications are explored.

  13. Rewiring Lactococcus lactis for Ethanol Production

    DEFF Research Database (Denmark)

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

    2013-01-01

    to redirect the metabolism of LAB model organism Lactococcus lactis toward ethanol production. Codon-optimized Zymomonas mobilis pyruvate decarboxylase (PDC) was introduced and expressed from synthetic promoters in different strain backgrounds. In the wild-type L. lactis strain MG1363 growing on glucose, only...... 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...

  14. Impact of cultivar selection and process optimization on ethanol yield from different varieties of sugarcane

    Science.gov (United States)

    2014-01-01

    Background The development of ‘energycane’ varieties of sugarcane is underway, targeting the use of both sugar juice and bagasse for ethanol production. The current study evaluated a selection of such ‘energycane’ cultivars for the combined ethanol yields from juice and bagasse, by optimization of dilute acid pretreatment optimization of bagasse for sugar yields. Method A central composite design under response surface methodology was used to investigate the effects of dilute acid pretreatment parameters followed by enzymatic hydrolysis on the combined sugar yield of bagasse samples. The pressed slurry generated from optimum pretreatment conditions (maximum combined sugar yield) was used as the substrate during batch and fed-batch simultaneous saccharification and fermentation (SSF) processes at different solid loadings and enzyme dosages, aiming to reach an ethanol concentration of at least 40 g/L. Results Significant variations were observed in sugar yields (xylose, glucose and combined sugar yield) from pretreatment-hydrolysis of bagasse from different cultivars of sugarcane. Up to 33% difference in combined sugar yield between best performing varieties and industrial bagasse was observed at optimal pretreatment-hydrolysis conditions. Significant improvement in overall ethanol yield after SSF of the pretreated bagasse was also observed from the best performing varieties (84.5 to 85.6%) compared to industrial bagasse (74.5%). The ethanol concentration showed inverse correlation with lignin content and the ratio of xylose to arabinose, but it showed positive correlation with glucose yield from pretreatment-hydrolysis. The overall assessment of the cultivars showed greater improvement in the final ethanol concentration (26.9 to 33.9%) and combined ethanol yields per hectare (83 to 94%) for the best performing varieties with respect to industrial sugarcane. Conclusions These results suggest that the selection of sugarcane variety to optimize ethanol

  15. Optimization of dilute sulfuric acid pretreatment to maximize combined sugar yield from sugarcane bagasse for ethanol production.

    Science.gov (United States)

    Benjamin, Y; Cheng, H; Görgens, J F

    2014-01-01

    Increasing fermentable sugar yields per gram of biomass depends strongly on optimal selection of varieties and optimization of pretreatment conditions. In this study, dilute acid pretreatment of bagasse from six varieties of sugarcane was investigated in connection with enzymatic hydrolysis for maximum combined sugar yield (CSY). The CSY from the varieties were also compared with the results from industrial bagasse. The results revealed considerable differences in CSY between the varieties. Up to 22.7 % differences in CSY at the optimal conditions was observed. The combined sugar yield difference between the best performing variety and the industrial bagasse was 34.1 %. High ratio of carbohydrates to lignin and low ash content favored the release of sugar from the substrates. At mild pretreatment conditions, the differences in bioconversion efficiency between varieties were greater than at severe condition. This observation suggests that under less severe conditions the glucose recovery was largely determined by chemical composition of biomass. The results from this study support the possibility of increasing sugar yields or improving the conversion efficiency when pretreatment optimization is performed on varieties with improved properties.

  16. 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.

  17. Improvement of ethanol yield from glycerol via conversion of pyruvate to ethanol in metabolically engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Yu, Kyung Ok; Jung, Ju; Ramzi, Ahmad Bazli; Kim, Seung Wook; Park, Chulhwan; Han, Sung Ok

    2012-02-01

    The conversion of low-priced glycerol to higher value products has been proposed as a way to improve the economic viability of the biofuels industry. In a previous study, the conversion of glycerol to ethanol in a metabolically engineered strain of Saccharomyces cerevisiae was accomplished by minimizing the synthesis of glycerol, the main by-product in ethanol fermentation processing. To further improve ethanol production, overexpression of the native genes involved in conversion of pyruvate to ethanol in S. cerevisiae was successfully accomplished. The overexpression of an alcohol dehydrogenase (adh1) and a pyruvate decarboxylase (pdc1) caused an increase in growth rate and glycerol consumption under fermentative conditions, which led to a slight increase of the final ethanol yield. The overall expression of the adh1 and pdc1 genes in the modified strains, combined with the lack of the fps1 and gpd2 genes, resulted in a 1.4-fold increase (about 5.4 g/L ethanol produced) in fps1Δgpd2Δ (pGcyaDak, pGupCas) (about 4.0 g/L ethanol produced). In summary, it is possible to improve the ethanol yield by overexpression of the genes involved in the conversion of pyruvate to ethanol in engineered S. cerevisiae using glycerol as substrate.

  18. Establishing an ethanol production business

    International Nuclear Information System (INIS)

    1993-01-01

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

  19. Optimization of fermentation conditions for ethanol production from whey

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, F J; Izaguirre, M F; Michelena, V; Moreno, B

    1982-01-01

    Optimal conditions for ethanol production in 7% whey solutions by the yeast Candida pseudotropicalis ATCC 8619 included an initial pH of 4.57 and 30 degrees. Complete fermentation of the available lactose took place without supplementary nutrients; additions of N and P salts, yeast extract, or corn steep liquor resulted in increased yeast production and lower ethanol yields. A possible correlation was observed between increases in yeast inocula and lactose utilization and ethanol production rates; 8.35 g ethanol/L was obtained within 22 hours by using a yeast inoculum of 13.9 g/L. No differences in fermentation rates or ethanol yields were observed when whole or deproteinized whey solutions were used. Concentrated whey permeates, obtained after removal of the valuable proteins from whey, can be effectively fermented for ethanol production.

  20. Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Dong Xiaoyu; Yuan Yulian; Tang Qian; Dou Shaohua; Di Lanbo; Zhang Xiuling

    2014-01-01

    In this study, Saccharomyces cerevisiae (S. cerevisiae) was exposed to dielectric barrier discharge plasma (DBD) to improve its ethanol production capacity during fermentation. Response surface methodology (RSM) was used to optimize the discharge-associated parameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply voltage, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge-induced enhancement in ethanol yield were plasma exposure time of 1 min, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control. (plasma technology)

  1. Fission product yields

    International Nuclear Information System (INIS)

    Valenta, V.; Hep, J.

    1978-01-01

    Data are summed up necessary for determining the yields of individual fission products from different fissionable nuclides. Fractional independent yields, cumulative and isobaric yields are presented here for the thermal fission of 235 U, 239 Pu, 241 Pu and for fast fission (approximately 1 MeV) of 235 U, 238 U, 239 Pu, 241 Pu; these values are included into the 5th version of the YIELDS library, supplementing the BIBFP library. A comparison is made of experimental data and possible improvements of calculational methods are suggested. (author)

  2. Production of Hydrogen from Bio-ethanol

    International Nuclear Information System (INIS)

    Fabrice Giroudiere; Christophe Boyer; Stephane His; Robert Sanger; Kishore Doshi; Jijun Xu

    2006-01-01

    IFP and HyRadix are collaborating in the development of a new hydrogen production system from liquid feedstock such as bio-ethanol. Reducing greenhouse gas (GHG) emissions along with high hydrogen yield are the key objectives. Market application of the system will be hydrogen refueling stations as well as medium scale hydrogen consumers including the electronics, metals processing, and oils hydrogenation industries. The conversion of bio-ethanol to hydrogen will be performed within a co-developed process including an auto-thermal reformer working under pressure. The technology will produce high-purity hydrogen with ultralow CO content. The catalytic auto-thermal reforming technology combines the exothermic and endothermic reaction and leads to a highly efficient heat integration. The development strategy to reach a high hydrogen yield target with the bio-ethanol hydrogen generator is presented. (authors)

  3. Production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-10

    Ethanol is produced by fermentation with a photohardening resin-immobilized yeast preparation. The ethanol producing yeast may be selected from Saccharomyces, Zygosaccharomyces, or Schizosaccharomyces. The photohardening resin for yeast immobilization is a hydrophilic unsaturated compound, especially polyurethane acrylate, with an average molecular weight of 300-80,000 and containing at least 2 photopolymerizable ethylene groups. The immobilized yeast preparation is prepared by irradiating an aqueous suspension of yeast and a photohardening resin with UV light; the average size of the immobilized yeast is 0.1-3.0 mm and with various shapes. Thus, an aqueous suspension containing Saccharomyces formosensis cells (5 parts), a poly(ethylene glycol)isopharone diisocyanate-2-hydroxyethyl methacrylate copolymer (50 parts), and benzoin ethyl ether (0.5 parts) was homogenized, spread on a polypropylene tray (1.0 mm depth), and irradiated with a 3600 A Hg lamp for 5-10 minutes to form a yeast-containing polyurethane acrylate sheet (1.0 mm thickness), which was then sliced into bits of approximately 1.0 mm. When a molasses substrate solution (pH 4.5-5.0) was passed through a column (200 x 20 mm) packed with the polyurethane acrylate-immobilized yeast preparation, eluates containing 7% (weight/volume) ethanol were produced for >3000 hours.

  4. Effect of the presence of initial ethanol on ethanol production in sugar cane juice fermented by Zymomonas mobilis

    OpenAIRE

    Tano,Marcia Sadae; Buzato,João Batista

    2003-01-01

    Ethanol production in sugar cane juice in high initial sugar concentration, fermented by Z. mobilis in the presence and absence of ethanol, was evaluated. Ethanol production was low in both media. The presence of initial ethanol in the sugar cane juice reduced ethanol production by 48.8%, biomass production by 25.0% and the total sugar consumption by 28.3%. The presence of initial ethanol in the medium did not affect significantly levan production and biomass yield coefficient (g biomass/g su...

  5. Comprehensive evaluation of nitrogen removal rate and biomass, ethanol, and methane production yields by combination of four major duckweeds and three types of wastewater effluent.

    Science.gov (United States)

    Toyama, Tadashi; Hanaoka, Tsubasa; Tanaka, Yasuhiro; Morikawa, Masaaki; Mori, Kazuhiro

    2018-02-01

    To assess the potential of duckweeds as agents for nitrogen removal and biofuel feedstocks, Spirodela polyrhiza, Lemna minor, Lemna gibba, and Landoltia punctata were cultured in effluents of municipal wastewater, swine wastewater, or anaerobic digestion for 4 days. Total dissolved inorganic nitrogen (T-DIN) of 20-50 mg/L in effluents was effectively removed by inoculating with 0.3-1.0 g/L duckweeds. S. polyrhiza showed the highest nitrogen removal (2.0-10.8 mg T-DIN/L/day) and biomass production (52.6-70.3 mg d.w./L/day) rates in all the three effluents. Ethanol and methane were produced from duckweed biomass grown in each effluent. S. polyrhiza and L. punctata biomass showed higher ethanol (0.168-0.191, 0.166-0.172 and 0.174-0.191 g-ethanol/g-biomass, respectively) and methane (340-413 and 343-408 NL CH 4 /kg VS, respectively) production potentials than the others, which is related to their higher carbon and starch contents and calorific values. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Ethanol Production from Different Intermediates of Sugar Beet Processing

    Directory of Open Access Journals (Sweden)

    Mladen Pavlečić

    2010-01-01

    Full Text Available In this investigation, the production of ethanol from the raw sugar beet juice and raw sugar beet cossettes has been studied. For ethanol production from the raw sugar beet juice, batch and fed-batch cultivation techniques in the stirred tank bioreactor were used, while batch ethanol production from the raw sugar beet cossettes was carried out in horizontal rotating tubular bioreactor (HRTB. In both cases, Saccharomyces cerevisiae was used as a production microorganism. During batch ethanol production from the raw sugar beet juice, ethanol yield was 59.89 g/L and production efficiency 78.8 %, and in fed-batch process the yield was 92.78 g/L and efficiency 93.4 %. At the same time, ethanol production in HRTB from the raw sugar beet cossettes with inoculum of 16.7 % V/m (raw sugar beet cossettes resulted in the highest ethanol yield of 54.53 g/L and production efficiency of 79.5 %. The obtained results clearly show that both intermediates of sugar beet processing can be successfully used for ethanol production.

  7. Production of ethanol from cellulose (sawdust)

    OpenAIRE

    Otulugbu, Kingsley

    2012-01-01

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

  8. Cell recycle batch fermentation of high-solid lignocellulose using a recombinant cellulase-displaying yeast strain for high yield ethanol production in consolidated bioprocessing.

    Science.gov (United States)

    Matano, Yuki; Hasunuma, Tomohisa; Kondo, Akihiko

    2013-05-01

    The aim of this study is to develop a scheme of cell recycle batch fermentation (CRBF) of high-solid lignocellulosic materials. Two-phase separation consisting of rough removal of lignocellulosic residues by low-speed centrifugation and solid-liquid separation enabled effective collection of Saccharomyces cerevisiae cells with decreased lignin and ash. Five consecutive batch fermentation of 200 g/L rice straw hydrothermally pretreated led to an average ethanol titer of 34.5 g/L. Moreover, the display of cellulases on the recombinant yeast cell surface increased ethanol titer to 42.2 g/L. After, five-cycle fermentation, only 3.3 g/L sugar was retained in the fermentation medium, because cellulase displayed on the cell surface hydrolyzed cellulose that was not hydrolyzed by commercial cellulases or free secreted cellulases. Fermentation ability of the recombinant strain was successfully kept during a five-cycle repeated batch fermentation with 86.3% of theoretical yield based on starting biomass. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. 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

  10. The metabolic costs of improving ethanol yield by reducing glycerol formation capacity under anaerobic conditions in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pagliardini, Julien; Hubmann, Georg; Alfenore, Sandrine; Nevoigt, Elke; Bideaux, Carine; Guillouet, Stephane E

    2013-03-28

    Finely regulating the carbon flux through the glycerol pathway by regulating the expression of the rate controlling enzyme, glycerol-3-phosphate dehydrogenase (GPDH), has been a promising approach to redirect carbon from glycerol to ethanol and thereby increasing the ethanol yield in ethanol production. Here, strains engineered in the promoter of GPD1 and deleted in GPD2 were used to investigate the possibility of reducing glycerol production of Saccharomyces cerevisiae without jeopardising its ability to cope with process stress during ethanol production. For this purpose, the mutant strains TEFmut7 and TEFmut2 with different GPD1 residual expression were studied in Very High Ethanol Performance (VHEP) fed-batch process under anaerobic conditions. Both strains showed a drastic reduction of the glycerol yield by 44 and 61% while the ethanol yield improved by 2 and 7% respectively. TEFmut2 strain showing the highest ethanol yield was accompanied by a 28% reduction of the biomass yield. The modulation of the glycerol formation led to profound redox and energetic changes resulting in a reduction of the ATP yield (YATP) and a modulation of the production of organic acids (acetate, pyruvate and succinate). Those metabolic rearrangements resulted in a loss of ethanol and stress tolerance of the mutants, contrarily to what was previously observed under aerobiosis. This work demonstrates the potential of fine-tuned pathway engineering, particularly when a compromise has to be found between high product yield on one hand and acceptable growth, productivity and stress resistance on the other hand. Previous study showed that, contrarily to anaerobiosis, the resulting gain in ethanol yield was accompanied with no loss of ethanol tolerance under aerobiosis. Moreover those mutants were still able to produce up to 90 gl-1 ethanol in an anaerobic SSF process. Fine tuning metabolic strategy may then open encouraging possibilities for further developing robust strains with improved

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  12. Ethanol yield and energy potential of stems from a spectrum of sorghum biomass types

    Energy Technology Data Exchange (ETDEWEB)

    McBee, G.G.; Creelman, R.A.; Miller, F.R.

    1988-01-01

    Sorghum biomass is a renewable resource that offers significant potential for energy utilization. Six sorghum cultivars, representing an array of stem types, were evaluated for ethanol yield. Ethanol production was individually obtained for both the total stem and the pith of each type by anaerobic yeast fermentation. Value of the energy contained in the rind was determined by calorimetry. The highest yield of ethanol from total stem fermentation was 3418.3 liters ha/sup -1/ produced from Rio. Fermentation of Rio pith to ethanol and combustion of the rind resulted in the highest total energy value of the cultivars. The least and greatest energy values were 6.3 and 44.3 x 10/sup 6/ kcal ha/sup -1/ for SC0056-14 and Rio, respectively. Conversion ratios of potentially fermentable carbohydrates (within the vegetative biomass) to ethanol produced, averaged 0.438 for the pith and 0.406 for total stems.

  13. Ethanol production from paper sludge using Kluyveromyces marxianus

    International Nuclear Information System (INIS)

    Madrid, Lina Maria; Quintero Diaz, Juan Carlos

    2011-01-01

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

  14. Ethanol production in China: Potential and technologies

    International Nuclear Information System (INIS)

    Li, Shi-Zhong; Chan-Halbrendt, Catherine

    2009-01-01

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

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

    DEFF Research Database (Denmark)

    Chang, Tinghong; Yao, Shuo

    2011-01-01

    of cellulolytic and saccharolytic thermophilic bacteria for lignocellulosic ethanol production because of their unique properties. First of all, thermophilic bacteria possess unique cellulolytic and hemicellulolytic systems and are considered as potential sources of highly active and thermostable enzymes...... for efficient biomass hydrolysis. Secondly, thermophilic bacteria ferment a broad range of carbohydrates into ethanol, and some of them display potential for ethanologenic fermentation at high yield. Thirdly, the establishment of the genetic tools for thermophilic bacteria has allowed metabolic engineering......, 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...

  16. 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...

  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. Influence of Sowing Times, Densities, and Soils to Biomass and Ethanol Yield of Sweet Sorghum

    Directory of Open Access Journals (Sweden)

    Tran Dang Xuan

    2015-08-01

    Full Text Available The use of biofuels helps to reduce the dependency on fossil fuels and therefore decreases CO2 emission. Ethanol mixed with gasoline in mandatory percentages has been used in many countries. However, production of ethanol mainly depends on food crops, commonly associated with problems such as governmental policies and social controversies. Sweet sorghum (Sorghum bicolor (L. Moench is one of the most potential and appropriate alternative crops for biofuel production because of its high biomass and sugar content, strong tolerance to environmental stress conditions and diseases, and wide adaptability to various soils and climates. The aim of this study was to select prospective varieties of sweet sorghum, optimum sowing times and densities to achieve high yields of ethanol production and to establish stable operational conditions in cultivating this crop. The summer-autumn cropping season combined with the sowing densities of 8.3–10.9 plant m−2 obtained the highest ethanol yield. Among cultivated locations, the soil with pH of 5.5 and contents of Al and Zn of 39.4 and 0.6 g kg−1, respectively, was the best condition to have an ethanol yield >5000 L ha−1. The pH ≥ 6.0 may be responsible for the significant reduction of zinc content in soils, which decreases both biomass of sweet sorghum and ethanol yield, while contents of N, P, K, organic carbon (OC and cation exchange capacity (CEC, and Fe likely play no role. The cultivar 4A was the preferred candidate for ethanol production and resistant to pests and diseases, especially cut worm (Agrotis spp..

  19. Biofilm reactors for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Vega, J L; Clausen, E C; Gaddy, J L

    1988-07-01

    Whole cell immobilization has been studied in the laboratory during the last few years as a method to improve the performance and economics of most fermentation processes. Among the various techniques available for cell immobilization, methods that provide generation of a biofilm offer reduced diffusional resistance, high productivities, and simple operation. This paper reviews some of the important aspects of biofilm reactors for ethanol production, including reactor start-up, steady state behavior, process stability, and mathematical modeling. Special emphasis is placed on covalently bonded Saccharomyces cerevisiae in packed bed reactors.

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

    Directory of Open Access Journals (Sweden)

    Carolina B. Codato

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

  1. Improving carbon dioxide yields and cell efficiencies for ethanol oxidation by potential scanning

    Science.gov (United States)

    Majidi, Pasha; Pickup, Peter G.

    2014-12-01

    An ethanol electrolysis cell with aqueous ethanol supplied to the anode and nitrogen at the cathode has been operated under potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At ambient temperature, faradaic yields of CO2 as high as 26% have been achieved, while only transient CO2 production was observed at constant potential. Yields increased substantially at higher temperatures, with maximum values at Pt anodes reaching 45% at constant potential and 65% under potential cycling conditions. Use of a PtRu anode increased the cell efficiency by decreasing the anode potential, but this was offset by decreased CO2 yields. Nonetheless, cycling increased the efficiency relative to constant potential. The maximum yields at PtRu and 80 °C were 13% at constant potential and 32% under potential cycling. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO, which occurs at lower potentials on PtRu than on Pt. These results will be important in the optimization of operating conditions for direct ethanol fuel cells and for the electrolysis of ethanol to produce clean hydrogen.

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

    Directory of Open Access Journals (Sweden)

    Edem Cudjoe Bensah

    2015-08-01

    Full Text Available 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 °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 (15.26 g/100 g TS. All other local biomass types studied exhibited sugar and ethanol yields below 33% and 35% of the theoretical maximum, respectively. Thus, elephant grass is a highly promising biomass source for ethanol production in Africa.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  4. Ethanol production from soybean molasses by Zymomonas mobilis

    International Nuclear Information System (INIS)

    Letti, Luiz Alberto Junior; Karp, Susan Grace; Woiciechowski, Adenise Lorenci; Soccol, Carlos Ricardo

    2012-01-01

    This work deals with the utilization of soybean molasses (a low cost byproduct) to produce ethanol, an important biofuel, using the microorganism Zymomonas mobilis NRRL 806, a gram negative bacterium. At the first part of the work, laboratorial scale tests, using 125 mL flasks were performed to evaluate the effect of three variables on ethanol production: soybean molasses concentration (the sole carbon and nitrogen source), pH and period of previous aerobial phase. The optimal soybean concentration was around 200 g L -1 of soluble solids, pH between 6.0 and 7.0, and the period of previous aerobial phase did not provide significant effect. At the second part, kinetic tests were performed to compare the fermentation yields of Zymomonas mobilis NRRL 806 in flasks and in a bench scale batch reactor (it was obtained respectively 78.3% and 96.0% of the maximum theoretical yields, with productions of 24.2 and 29.3 g L -1 of ethanol). The process with a reactor fermentation using Saccharomyces cerevisiae LPB1 was also tested (it was reached 89.3% of the theoretical maximum value). A detailed kinetic behavior of the molasses sugars metabolism for Z. mobilis was also shown, either in reactor or in flasks. This work is a valuable tool for further works in the subject of ethanol production from agro-industrial by-products. -- Highlights: ► Zymomonas mobilis was able to grow and produce ethanol on diluted soybean molasses. ► Best conditions for ethanol production:200g L -1 of soluble solids; pH around 6,5. ► Z. mobilis had better ethanol production and yield when compared to S. cerevisiae. ► In reactor, Z. mobilis produced 29.3 g L -1 of ethanol, 96.0% of the maximum yield.

  5. Ethanol production by immobilized cells with forced substrate supply

    Energy Technology Data Exchange (ETDEWEB)

    Mitani, Y.; Nishizawa, Y.; Nagai, S.

    1984-01-01

    Ethanol fermentation by a forced substrate supply into an immobilized cell layer was carried out to increase the ethanol production rate and to eliminate the diffusion dependency of substrate supply in an ordinary immobilized cell reaction. Saccharomyces cerevisiae IFO 2347 was immobilized in a mixture of k-carrageenan, locust bean gum, and celite (2: 0.5: 40 wt/vol %). A glucose minimal medium was fed into the immobilized cell layer (5 to 22 mm in thickness) at retention times between 0.6 and 2.8 h under pressure. The stable ethanol fermentation could be maintained for more than 3 weeks with an ethanol yield of 0.48 g ethanol/g glucose and ethanol productivity of 63 g.(l gel)/sup -1/.h/sup -1/ at a retention time of 1.5 h. The yeast cells were well distributed through the gel layer with a vertical gradient, and an average cell density was ca. 8.0 X 10/sup 9/ cells/ml gel, 4-fold higher than that of ordinary immobilized cells. A small filter press reactor was constructed to examine the applicability of ethanol fermentation with this forced substrate supply. The operation could be continued for a month at a retention time of 2 h yielding 96 g/l of ethanol from 200 g/l of glucose. 6 references, 5 figures, 3 tables.

  6. Selective ethanol production from reducing sugars in a saccharide mixture.

    Science.gov (United States)

    Ohara, Satoshi; Kato, Taku; Fukushima, Yasuhiro; Sakoda, Akiyoshi

    2013-05-01

    Fermentation profiles of four different yeasts reportedly defective in sucrose utilization indicate that all strains tested removed particular sugar via selective conversion to ethanol in a saccharide mixture. At the temperature of pressed sugarcane juice, Saccharomyces dairenensis and Saccharomyces transvaalensis performed better in ethanol production rate and yield, respectively. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Engineering microorganisms to increase ethanol production by metabolic redirection

    Science.gov (United States)

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

    2017-10-31

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

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

    Science.gov (United States)

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

    2016-02-01

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

  9. Characterization of wine yeasts for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, J.; Benitez, T.

    1986-11-01

    Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth (..mu..) and fermentation rates (..nu..) were increasingly inhibited by increasing ethanol and glucose concentrations, ''flor'' yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in laboratory medium were also the best at fermenting molasses. Invertase activity was not a limiting step in ethanol production, ..nu.. being accelerated by supplementing molasses with ammonia and biotine, and by cell recycle.

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

    Science.gov (United States)

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

    2013-10-10

    We report on engineering Escherichia coli to produce ethanol at high yield from gluconic acid (gluconate). Knocking out genes encoding for the competing pathways (l-lactate dehydrogenase and pyruvate formate lyase A) in E. coli KO11 eliminated lactate production, lowered the carbon flow toward acetate production, and improved the ethanol yield from 87.5% to 97.5% of the theoretical maximum, while the growth rate of the mutant strain was about 70% of the wild type. The corresponding genetic modifications led to a small improvement of ethanol yield from 101.5% to 106.0% on glucose. Deletion of the pyruvate dehydrogenase gene (pdh) alone improved the ethanol yield from 87.5% to 90.4% when gluconate was a substrate. The growth rate of the mutant strain was identical to that of the wild type. The corresponding genetic modification led to no improvements on ethanol yield on glucose. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Grain sorghum stillage recycling: Effect on ethanol yield and stillage quality.

    Science.gov (United States)

    Egg, R P; Sweeten, J M; Coble, C G

    1985-12-01

    Stillage obtained from ethanol production of grain sorghum was separated into two fractions: thin stillage and wet solids. A portion of the thin stillage was recycled as cooking water in subsequent fermentation runs using both bench- and full-scale ethanol production plants. When thin stillage replaced 50-75% of the cooking water, large increases occurred in solids content, COD, and EC of the resulting thin stillage. It was found that while the volume of thin stillage requiring treatment or disposal was reduced, there was little reduction in the total pollutant load. Stillage rcycling had little effect on the quality of the stillage wet solids fraction. At the high levels of stillage recycle used, ethanol yield was reduced after three to five runs of consecutive recycling.

  12. 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.)

  13. Improved ethanol yield and reduced Minimum Ethanol Selling Price (MESP by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 1 Experimental

    Directory of Open Access Journals (Sweden)

    Chen Xiaowen

    2012-08-01

    Full Text Available Abstract Background Historically, acid pretreatment technology for the production of bio-ethanol from corn stover has required severe conditions to overcome biomass recalcitrance. However, the high usage of acid and steam at severe pretreatment conditions hinders the economic feasibility of the ethanol production from biomass. In addition, the amount of acetate and furfural produced during harsh pretreatment is in the range that strongly inhibits cell growth and impedes ethanol fermentation. The current work addresses these issues through pretreatment with lower acid concentrations and temperatures incorporated with deacetylation and mechanical refining. Results The results showed that deacetylation with 0.1 M NaOH before acid pretreatment improved the monomeric xylose yield in pretreatment by up to 20% while keeping the furfural yield under 2%. Deacetylation also improved the glucose yield by 10% and the xylose yield by 20% during low solids enzymatic hydrolysis. Mechanical refining using a PFI mill further improved sugar yields during both low- and high-solids enzymatic hydrolysis. Mechanical refining also allowed enzyme loadings to be reduced while maintaining high yields. Deacetylation and mechanical refining are shown to assist in achieving 90% cellulose yield in high-solids (20% enzymatic hydrolysis. When fermentations were performed under pH control to evaluate the effect of deacetylation and mechanical refining on the ethanol yields, glucose and xylose utilizations over 90% and ethanol yields over 90% were achieved. Overall ethanol yields were calculated based on experimental results for the base case and modified cases. One modified case that integrated deacetylation, mechanical refining, and washing was estimated to produce 88 gallons of ethanol per ton of biomass. Conclusion The current work developed a novel bio-ethanol process that features pretreatment with lower acid concentrations and temperatures incorporated with deacetylation

  14. Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields

    Science.gov (United States)

    Majidi, Pasha; Pickup, Peter G.

    2014-12-01

    A direct ethanol fuel cell has been operated under sinusoidal (AC) potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At 80 °C, faradaic yields of CO2 as high as 25% have been achieved with a PtRu anode catalyst, while the maximum CO2 production at constant potential was 13%. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO. These results will be important in the optimization of operating conditions for direct ethanol fuel cells, where the benefits of potential cycling are projected to increase as catalysts that produce CO2 more efficiently are implemented.

  15. Ethanol production using engineered mutant E. coli

    Science.gov (United States)

    Ingram, Lonnie O.; Clark, David P.

    1991-01-01

    The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

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

    African Journals Online (AJOL)

    Juliana

    2015-02-11

    Feb 11, 2015 ... The use of vegetable biomass as substrate for ethanol production could reduce the ... Fermentation was performed in a laboratory scale using the J10 and FT858 ... Key words: Hydrolysis of sugarcane straw and pointers, sugarcane juice, ..... Ethanol: An Overview about Composition, Pretreatment Methods,.

  17. Availability of crop cellulosics for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, R.D.

    1982-10-01

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

  18. 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

  19. Wet oxidation pretreatment of rape straw for ethanol production

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  20. Cassava as feedstock for ethanol production in South Africa | Marx ...

    African Journals Online (AJOL)

    It can be grown on marginal lands where frost is not prevalent. In this study, the production of ethanol from unpeeled Cassava roots and cassava peels were investigated. It was found that temperature; pH and biomass loading had a significant effect on glucose yield during hydrolysis. Simultaneous saccharification and ...

  1. 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....

  2. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  3. 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.

  4. 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)

  5. Yield and properties of ethanol biofuel produced from different whole cassava flours.

    Science.gov (United States)

    Ademiluyi, F T; Mepba, H D

    2013-01-01

    The yield and properties of ethanol biofuel produced from five different whole cassava flours were investigated. Ethanol was produced from five different whole cassava flours. The effect of quantity of yeast on ethanol yield, effect of whole cassava flour to acid and mineralized media ratio on the yield of ethanol produced, and the physical properties of ethanol produced from different cassava were investigated. Physical properties such as distillation range, density, viscosity, and flash point of ethanol produced differ slightly for different cultivars, while the yield of ethanol and electrical conductivity of ethanol from the different cassava cultivars varies significantly. The variation in mineral composition of the different whole cassava flours could also lead to variation in the electrical conductivity of ethanol produced from the different cassava cultivars. The differences in ethanol yield are attributed to differences in starch content, protein content, and dry matter of cassava cultivars. High yield of ethanol from whole cassava flour is best produced from cultivars with high starch content, low protein content, and low fiber.

  6. Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

    Science.gov (United States)

    Slavens, Shelyn Gehle

    Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

  7. Thermodynamic analysis of ethanol reforming for hydrogen production

    International Nuclear Information System (INIS)

    Sun, Shaohui; Yan, Wei; Sun, Peiqin; Chen, Junwu

    2012-01-01

    This work presents the simulated equilibrium compositions of ethanol steam reforming (SR), partial oxidation (POX) and auto-thermal reforming (ATR) at a large temperature range, steam-to-ethanol and oxygen-to-ethanol molar ratios. The simulation work shows that the moles of hydrogen yield per mole ethanol are of this order: SR > ATR > POX. The results are compared with other simulation works and fitted models, which show that all the simulation results obtained with different methods agree well with each other. And the fitted models are in highly consistency with very small deviations. Moreover, the thermal-neutral point in corresponding to temperature, steam-to-ethanol and oxygen-to-ethanol mole ratios of ethanol ATR is estimated. The result shows that with the increasing of oxygen-to-ethanol mole ratio, the T-N point moves to higher temperatures; with the increasing of steam-to-ethanol mole ratio, the T-N point moves to lower temperatures. Furthermore, the energy exchanges of the reforming process and the whole process and the thermal efficiencies are also analyzed in the present work and that the energy demands and generated in the whole process are greater than the reforming process can be obtained. Finally, the optimum reaction conditions are selected. -- Highlights: ► The equilibrium compositions simulated by different researchers with different methods are compared. ► The simulation results are fitted with polynomials for convenient reference. ► The energy balance and thermal efficiencies are analyzed. ► The optimum reaction conditions of ethanol POX, SR and ATR for hydrogen production are selected.

  8. Bio ethanol production from oil palm empty fruit bunches

    International Nuclear Information System (INIS)

    Loh Soh Kheang; Muhammad Asyraf Kasim; Nasrin Abu Bakar

    2010-01-01

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

  9. Production of fuel ethanol from molasses by thermotolerant yeast

    International Nuclear Information System (INIS)

    Hamad, S. H.

    2009-01-01

    A thermotolerant strain of the yeast Kluyveromyces marxians, isolated from Kenana sugar factory in the Sudan, was used for the production of ethanol from molasses. Fermentations were carried out in a bioreactor with 10-litre working volume at three temperatures and three sugar concentrations in batch and at one temperature and three feeding rates in fed-batch processes. In the batch fermentations, the best results were obtained at 40 o C and 20% sugar, where a maximum of 9.2% (w/v) ethanol concentration was produced in 30 hours with a yield of 90% of the theoretical and a maximum ethanol specific productivity of 0.65 g per gramme yeast and hour. In the fed-batch process at 40 o C , the best results were obtained at 0.5 1/h feeding rate of a substrate with 400 g/1 sugar. Under such conditions, the yeast produced up to 9.34% (w/v) ethanol with 91.6% of the theoretical yield in 14 hours of fermentation and a maximum specific ethanol productivity of 0.9 g per gramme yeast and hour. (Author)

  10. Ethanol Production from Lignocellulose by the Dimorphic Fungus Mucor Indicus

    Energy Technology Data Exchange (ETDEWEB)

    Lennartsson, P.R.; Taherzadeh, M.J. (School of Engineering, Univ. of Boraas, SE-50190, Boraas (Sweden)). e-mail: Patrik.Lennartsson@hb.se; Karimi, K. (Dept. of Chemical Engineering, Isfahan Univ. of Technology, 84156-83111, Isfahan (IR)); Edebo, L. (Dept. of Clinical Bacteriology, Univ. of Goeteborg, SE-41346, Goeteborg (Sweden))

    2008-10-15

    Ethanol production from dilute-acid lignocellulosic hydrolyzate by the dimorphic fungus Mucor indicus was investigated. A mixture of different forest wood chips dominated by spruce was hydrolyzed with 0.5 g/L sulfuric acid at 15 bar for 10 min, yielding different sugars including galactose, glucose, mannose, and xylose, but also different fermentation inhibitors such as acetic acid, furfural, hydroxymethyl furfural (HMF), and phenolic compounds. We induced different morphological growth of M. indicus from purely filamentous, mostly filamentous, mostly yeast-like to purely yeast-like. The different forms were then used to ferment the hydrolyzate. They tolerated the presence of the inhibitors under anaerobic batch cultivation well and the ethanol yield was 430-440 g/kg consumed sugars. The ethanol productivity depended on the morphology. Judging from these results, we conclude that M. indicus, is useful for ethanol production from toxic substrates independent of its morphology. Keywords: bio-ethanol, lignocellulosic materials, dilute acid hydrolysis, Mucor indicus, dimorphic fungi

  11. 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.)

  12. Greenprint on ethanol production in Saskatchewan

    International Nuclear Information System (INIS)

    2002-04-01

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

  13. Cashew apple bagasse as a source of sugars for ethanol production by Kluyveromyces marxianus CE025.

    Science.gov (United States)

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

    2011-08-01

    The potential of cashew apple bagasse as a source of sugars for ethanol production by Kluyveromyces marxianus CE025 was evaluated in this work. This strain was preliminarily cultivated in a synthetic medium containing glucose and xylose and was able to produce ethanol and xylitol at pH 4.5. Next, cashew apple bagasse hydrolysate (CABH) was prepared by a diluted sulfuric acid pretreatment and used as fermentation media. This hydrolysate is rich in glucose, xylose, and arabinose and contains traces of formic acid and acetic acid. In batch fermentations of CABH at pH 4.5, the strain produced only ethanol. The effects of temperature on the kinetic parameters of ethanol fermentation by K. marxianus CE025 using CABH were also evaluated. Maximum specific growth rate (μ(max)), overall yields of ethanol based on glucose consumption [Formula: see text] and based on glucose + xylose consumption (Y ( P/S )), overall yield of ethanol based on biomass (Y ( P/X )), and ethanol productivity (P (E)) were determined as a function of temperature. Best results of ethanol production were achieved at 30°C, which is also quite close to the optimum temperature for the formation of biomass. The process yielded 12.36 ± 0.06 g l(-1) of ethanol with a volumetric production rate of 0.257 ± 0.002 g l(-1) h(-1) and an ethanol yield of 0.417 ± 0.003 g g(-1) glucose.

  14. Enhancing Ethanol Production by Fermentation Using Saccharomyces cereviseae under Vacuum Condition in Batch Operation

    Directory of Open Access Journals (Sweden)

    A Abdullah

    2012-04-01

    Full Text Available Ethanol is one of renewable energy, which considered being an excellent alternativeclean-burning fuel to replaced gasoline. In fact, the application of ethanol as fuel still blended withgasoline. The advantages of using ethanol as fuel are that the raw material mostly from renewableresources and the product has low emission which means environmental friendly. Ethanol can beproduced by fermentation of sugars (glucose/fructose. The constraint in the ethanol fermentationbatch or continuous process is the ethanol product inhibition. Inhibition in ethanol productivityand cell growth can be overcome by taking the product continuously from the fermentor. Theprocess can be done by using a vacuum fermentation. The objective of this research is toinvestigate the effect of pressure and glucose concentration in ethanol fermentation. The researchwas conducted in laboratory scale and batch process. Equipment consists of fermentor withvacuum system. The observed responses were dried cells of yeast, concentration of glucose, andconcentration of ethanol. Observations were made every 4 hours during a day of experiment. Theresults show that the formation of ethanol has a growth-associated product characteristic undervacuum operation. Vacuum condition can increase the cell formation productivity and the ethanolformation, as it is compared with fermentation under atmospheric condition. The maximum cellsproductivity and ethanol formation in batch operation under vacuum condition was reached at166.6 mmHg of pressure. The maximum numbers of cells and ethanol formation was reached at141.2 mm Hg of pressure. High initial glucose concentration significantly can affect the productivityand the yield of ethanol.

  15. The productive potentials of sweet sorghum ethanol in China

    International Nuclear Information System (INIS)

    Zhang, Caixia; Xie, Gaodi; Li, Shimei; Ge, Liqiang; He, Tingting

    2010-01-01

    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 2 ) are only as much as 78.6 x 10 4 hm 2 ; and the productive potentials of ethanol from these lands are 157.1 x 10 4 -294.6 x 10 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 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.

  16. 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

  17. Production of 16% ethanol from 35% sucrose

    International Nuclear Information System (INIS)

    Breisha, Gaber Z.

    2010-01-01

    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 -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 -1 together with thiamine at a level of 0.2 g l -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 3 min -1 m 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.

  18. 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)

  19. The sustainability of ethanol production from sugarcane

    International Nuclear Information System (INIS)

    Goldemberg, Jose; Coelho, Suani Teixeira; Guardabassi, Patricia

    2008-01-01

    The rapid expansion of ethanol production from sugarcane in Brazil has raised a number of questions regarding its negative consequences and sustainability. Positive impacts are the elimination of lead compounds from gasoline and the reduction of noxious emissions. There is also the reduction of CO 2 emissions, since sugarcane ethanol requires only a small amount of fossil fuels for its production, being thus a renewable fuel. These positive impacts are particularly noticeable in the air quality improvement of metropolitan areas but also in rural areas where mechanized harvesting of green cane is being introduced, eliminating the burning of sugarcane. Negative impacts such as future large-scale ethanol production from sugarcane might lead to the destruction or damage of high-biodiversity areas, deforestation, degradation or damaging of soils through the use of chemicals and soil decarbonization, water resources contamination or depletion, competition between food and fuel production decreasing food security and a worsening of labor conditions on the fields. These questions are discussed here, with the purpose of clarifying the sustainability aspects of ethanol production from sugarcane mainly in Sao Paulo State, where more than 60% of Brazil's sugarcane plantations are located and are responsible for 62% of ethanol production. (author)

  20. 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 gro...... 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....

  1. Increasing anaerobic acetate consumption and ethanol yields in Saccharomyces cerevisiae with NADPH-specific alcohol dehydrogenase.

    Science.gov (United States)

    Henningsen, Brooks M; Hon, Shuen; Covalla, Sean F; Sonu, Carolina; Argyros, D Aaron; Barrett, Trisha F; Wiswall, Erin; Froehlich, Allan C; Zelle, Rintze M

    2015-12-01

    Saccharomyces cerevisiae has recently been engineered to use acetate, a primary inhibitor in lignocellulosic hydrolysates, as a cosubstrate during anaerobic ethanolic fermentation. However, the original metabolic pathway devised to convert acetate to ethanol uses NADH-specific acetylating acetaldehyde dehydrogenase and alcohol dehydrogenase and quickly becomes constrained by limited NADH availability, even when glycerol formation is abolished. We present alcohol dehydrogenase as a novel target for anaerobic redox engineering of S. cerevisiae. Introduction of an NADPH-specific alcohol dehydrogenase (NADPH-ADH) not only reduces the NADH demand of the acetate-to-ethanol pathway but also allows the cell to effectively exchange NADPH for NADH during sugar fermentation. Unlike NADH, NADPH can be freely generated under anoxic conditions, via the oxidative pentose phosphate pathway. We show that an industrial bioethanol strain engineered with the original pathway (expressing acetylating acetaldehyde dehydrogenase from Bifidobacterium adolescentis and with deletions of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2) consumed 1.9 g liter(-1) acetate during fermentation of 114 g liter(-1) glucose. Combined with a decrease in glycerol production from 4.0 to 0.1 g liter(-1), this increased the ethanol yield by 4% over that for the wild type. We provide evidence that acetate consumption in this strain is indeed limited by NADH availability. By introducing an NADPH-ADH from Entamoeba histolytica and with overexpression of ACS2 and ZWF1, we increased acetate consumption to 5.3 g liter(-1) and raised the ethanol yield to 7% above the wild-type level. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Prospects for ethanol production from whey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, K R

    1978-05-01

    Whey is a by-product of the manufacture of cheese and casein. Casein whey is not as fully utilized as cheese whey although in the last five years commercial processes have been developed to recover the whey proteins, either in denatured form as lactalbumin or in their soluble form as Solac. The removal of the whey proteins makes little difference to the polluting strength or volume of the whey and a crude lactose solution - serum or permeate - remains to be processed. Many processes have been evaluated for the use of this crude lactose solution; one is microbial transformation to produce products such as methane, ethanol, acetone and butanol and etc. The technologies for these processes are well known and it is the economic evaluation which ultimately determines the feasibility of the process being considered. For the purposes of this paper, the prospects for ethanol production have been evaluated. Unless there is a significant reduction in capital costs, it is concluded that ethanol production from whey is not a viable proposition as an energy source for New Zealand. Industrial ethanol (annual imports; 3.5 x 10/sup 6/ 1 CIF value 32 c/1) and potable ethanol production may be worth contemplating.

  3. How does petroleum price and corn yield volatility affect ethanol markets with and without an ethanol use mandate?

    International Nuclear Information System (INIS)

    Thompson, Wyatt; Meyer, Seth; Westhoff, Pat

    2009-01-01

    The recent increase in ethanol use in the US strengthens and changes the nature of links between agricultural and energy markets. Here, we explore the interaction of market volatility and the scope for policy to affect this interaction, with a focus on how corn yields and petroleum prices affect ethanol prices. Mandates associated with new US energy legislation may intervene in these links in the medium-term future. We simulate stochastically a structural model that represents these markets, and that includes mandates, in order to assess how shocks to corn or oil markets can affect ethanol price and use. We estimate that the mandate makes ethanol producer prices more sensitive to corn yields and less sensitive to changes in petroleum prices overall. We note a discontinuity in these links that is caused by the mandate. Ethanol use can exceed the mandate if petroleum prices and corn yields are high enough, but the mandate limits downside adjustments in ethanol use to low petroleum prices or corn yields

  4. Ethanol production from sugarcane bagasse hydrolysate using Pichia stipitis.

    Science.gov (United States)

    Canilha, Larissa; Carvalho, Walter; Felipe, Maria das Graças de Almeida; Silva, João Batista de Almeida e; Giulietti, Marco

    2010-05-01

    The objective of this study was to evaluate the ethanol production from the sugars contained in the sugarcane bagasse hemicellulosic hydrolysate with the yeast Pichia stipitis DSM 3651. The fermentations were carried out in 250-mL Erlenmeyers with 100 mL of medium incubated at 200 rpm and 30 degrees C for 120 h. The medium was composed by raw (non-detoxified) hydrolysate or by hydrolysates detoxified by pH alteration followed by active charcoal adsorption or by adsorption into ion-exchange resins, all of them supplemented with yeast extract (3 g/L), malt extract (3 g/L), and peptone (5 g/L). The initial concentration of cells was 3 g/L. According to the results, the detoxification procedures removed inhibitory compounds from the hemicellulosic hydrolysate and, thus, improved the bioconversion of the sugars into ethanol. The fermentation using the non-detoxified hydrolysate led to 4.9 g/L ethanol in 120 h, with a yield of 0.20 g/g and a productivity of 0.04 g L(-1) h(-1). The detoxification by pH alteration and active charcoal adsorption led to 6.1 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.13 g L(-1) h(-1). The detoxification by adsorption into ion-exchange resins, in turn, provided 7.5 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.16 g L(-1) h(-1).

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

    International Nuclear Information System (INIS)

    Mangmeechai, Aweewan; Pavasant, Prasert

    2013-01-01

    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

  6. 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.

  7. 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....

  8. An Indirect Route for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-29

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

  9. 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

  10. 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)

  11. Grain sorghum is a viable feedstock for ethanol production.

    Science.gov (United States)

    Wang, D; Bean, S; McLaren, J; Seib, P; Madl, R; Tuinstra, M; Shi, Y; Lenz, M; Wu, X; Zhao, R

    2008-05-01

    Sorghum is a major cereal crop in the USA. However, sorghum has been underutilized as a renewable feedstock for bioenergy. The goal of this research was to improve the bioconversion efficiency for biofuels and biobased products from processed sorghum. The main focus was to understand the relationship among "genetics-structure-function-conversion" and the key factors impacting ethanol production, as well as to develop an energy life cycle analysis model (ELCAM) to quantify and prioritize the saving potential from factors identified in this research. Genetic lines with extremely high and low ethanol fermentation efficiency and some specific attributes that may be manipulated to improve the bioconversion rate of sorghum were identified. In general, ethanol yield increased as starch content increased. However, no linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include protein digestibility, level of extractable proteins, protein and starch interaction, mash viscosity, amount of phenolic compounds, ratio of amylose to amylopectin, and formation of amylose-lipid complexes in the mash. A platform ELCAM with a base case showed a positive net energy value (NEV) = 25,500 Btu/gal EtOH. ELCAM cases were used to identify factors that most impact sorghum use. For example, a yield increase of 40 bu/ac resulted in NEV increasing from 7 million to 12 million Btu/ac. An 8% increase in starch provided an incremental 1.2 million Btu/ac.

  12. 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.

  13. 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

  14. 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.

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

    African Journals Online (AJOL)

    The use of vegetable biomass as substrate for ethanol production could reduce the existing usage of fossil fuels, thereby minimizing negative environmental impacts. Due to mechanical harvesting of sugarcane, the amount of pointer and straw has increased in sugarcane fields, becoming inputs of great energy potential.

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

    African Journals Online (AJOL)

    Juliana

    2015-02-11

    Feb 11, 2015 ... Author(s) agree that this article remains permanently open access under the terms of the Creative Commons Attribution License · 4.0 International .... Statistical analysis. The results of cell viability and ethanol production were subjected to analysis of variance by the F test, and the comparison of the means.

  17. Enhancing Ethanol Production by Fermentation Using Saccharomyces cereviseae under Vacuum Condition in Batch Operation

    Directory of Open Access Journals (Sweden)

    A Abdullah

    2012-02-01

    Full Text Available Ethanol is one of renewable energy, which considered being an excellent alternative clean-burning fuel to replaced gasoline. In fact, the application of ethanol as fuel still blended with gasoline. The advantages of using ethanol as fuel are that the raw material mostly from renewable resources and the product has low emission which means environmental friendly. Ethanol can be produced by fermentation of sugars (glucose/fructose. The constraint in the ethanol fermentation batch or continuous process is the ethanol product inhibition. Inhibition in ethanol productivity and cell growth can be overcome by taking the product continuously from the fermentor. The process can be done by using a vacuum fermentation. The objective of this research is to investigate the effect of pressure and glucose concentration in ethanol fermentation. The research was conducted in laboratory scale and batch process. Equipment consists of fermentor with vacuum system. The observed responses were dried cells of yeast, concentration of glucose, and concentration of ethanol. Observations were made every 4 hours during a day of experiment. The results show that the formation of ethanol has a growth-associated product characteristic under vacuum operation. Vacuum condition can increase the cell formation productivity and the ethanol formation, as it is compared with fermentation under atmospheric condition. The maximum cells productivity and ethanol formation in batch operation under vacuum condition was reached at 166.6 mmHg of pressure. The maximum numbers of cells and ethanol formation was reached at 141.2 mm Hg of pressure. High initial glucose concentration significantly can affect the productivity and the yield of ethanol.

  18. Fuel ethanol production from sweet sorghum using repeated-batch fermentation.

    Science.gov (United States)

    Chohnan, Shigeru; Nakane, Megumi; Rahman, M Habibur; Nitta, Youji; Yoshiura, Takanori; Ohta, Hiroyuki; Kurusu, Yasurou

    2011-04-01

    Ethanol was efficiently produced from three varieties of sweet sorghum using repeated-batch fermentation without pasteurization or acidification. Saccharomyces cerevisiae cells could be recycled in 16 cycles of the fermentation process with good ethanol yields. This technique would make it possible to use a broader range of sweet sorghum varieties for ethanol production. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. 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.

  20. Wet oxidation pretreatment of rape straw for ethanol production

    DEFF Research Database (Denmark)

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

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via...... Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole...... gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid...

  1. Vinasse from Sugarcane Ethanol Production: Better Treatment or Better Utilization?

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Reis, Cristiano E.; Hu, Bo, E-mail: bhu@umn.edu [Department of Bioproducts and Biosystems Engineering, University of Minnesota, Saint Paul, MN (United States)

    2017-04-10

    Ethanol production from sugarcane in Brazil is a well-established industry, with relatively simple operations and high yield. The ethanol primarily serves as a renewable fuel blending with gasoline and diesel to increase the energy security in Brazil. Several environmental concerns are emerged around the by-products from this industry. Vinasse, the liquid fraction generated from the rectification and distillation operations of ethanol, is a sulfur-rich, low pH, dark-colored, and odorous effluent, produced at volumes as high as 20-fold of ethanol. Traditional wastewater treatments, such as bioprocessing, advanced oxidative processes, anaerobic digestion (AD), and chemical-based processes, have been applied to vinasse management. Despite most of its utilization being in fertirrigation practices, vinasse may represent a key factor in enhancing profitability and environmental outcomes of a sugarcane-to-ethanol plant. The application of some upgrade solutions to sugarcane-derived vinasse may represent additional sources of energy, production of animal feed components, and reduction in water consumption within a plant. The use of mature technologies, yet not widespread in the sugarcane-to-ethanol industry, could help attenuate environmental concerns. Oxidation and chemical processes, AD, and microbial fermentation have been presented as alternative impactful alternatives to (i) reduce its organic and mineral load, converting it to a feedstock with fewer environmental applications when applied as fertilizer and (ii) to convert organic matter and nutrients to a nutritious biomass, simultaneously increasing water reclamation potential by plants. This mini-review article provides a critical and comprehensive summary of the alternatives developed or under development to vinasse management.

  2. Immobilization of Saccharomyces Cerevisiae in Rice Hulls for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Edita Martini

    2011-05-01

    Full Text Available The whole cell immobilization in ethanol fermentation can be done by using natural carriers or through synthetic carriers. All of these methods have the same purpose of retaining high cell concentrations within a certain defined region of space which leads to higher ethanol productivity. Lignocellulosic plant substance represents one of highly potential sources in ethanol production. Some studies have found that cellulosic substances substances can also be used as a natural carrier in cell immobilization by re-circulating pre-culture medium into a reactor. In this experiment, rice hulls without any treatment were used to immobilize Saccharomyces cerevisiae through semi solid state incubation combined with re-circulating pre-culture medium. The scanning electron microscopy (SEM pictures of the carrier show that the yeast cells are absorbed and embedded to the rice hull pore. In liquid batch fermentation system with an initial sugar concentration of 50 g/L, nearly 100% total sugar was consumed after 48 hours. This resulted in an ethanol yield of 0.32 g ethanol/g glucose, which is 62.7% of the theoretical value. Ethanol productivity of 0.59 g/(L.h is 2.3 fold higher than that of free cells which is 0.26 g/(L.h. An effort to reuse the immobilized cells in liquid fermentation system showed poor results due to cell desorption in the first batch which led to high sugar concentration inhibitory effect in the second batch fermentation. This might be solved by using semi solid fermentation process in the future work.

  3. 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...

  4. Utilization of household food waste for the production of ethanol at high dry material content.

    Science.gov (United States)

    Matsakas, Leonidas; Kekos, Dimitris; Loizidou, Maria; Christakopoulos, Paul

    2014-01-08

    Environmental issues and shortage of fossil fuels have turned the public interest to the utilization of renewable, environmentally friendly fuels, such as ethanol. In order to minimize the competition between fuels and food production, researchers are focusing their efforts to the utilization of wastes and by-products as raw materials for the production of ethanol. household food wastes are being produced in great quantities in European Union and their handling can be a challenge. Moreover, their disposal can cause severe environmental issues (for example emission of greenhouse gasses). On the other hand, they contain significant amounts of sugars (both soluble and insoluble) and they can be used as raw material for the production of ethanol. Household food wastes were utilized as raw material for the production of ethanol at high dry material consistencies. A distinct liquefaction/saccharification step has been included to the process, which rapidly reduced the viscosity of the high solid content substrate, resulting in better mixing of the fermenting microorganism. This step had a positive effect in both ethanol production and productivity, leading to a significant increase in both values, which was up to 40.81% and 4.46 fold, respectively. Remaining solids (residue) after fermentation at 45% w/v dry material (which contained also the unhydrolyzed fraction of cellulose), were subjected to a hydrothermal pretreatment in order to be utilized as raw material for a subsequent ethanol fermentation. This led to an increase of 13.16% in the ethanol production levels achieving a final ethanol yield of 107.58 g/kg dry material. In conclusion, the ability of utilizing household food waste for the production of ethanol at elevated dry material content has been demonstrated. A separate liquefaction/saccharification process can increase both ethanol production and productivity. Finally, subsequent fermentation of the remaining solids could lead to an increase of the overall

  5. Continuous ethanol production from sugar beet molasses using an osmotolerant mutant strain of zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.C.; Baratti, J.C. (Univ. de Provence, Marseille (France). Centre National de la Recherche Scientifique)

    1992-01-25

    In conventional alcohol fermentation processes using yeast species, the substrate cost represents a major fraction of the total production cost. Therefore, it may be very attractive to use the bacterium Zymomonas mobilis, since it has shown higher ethanol yields than yeasts when grown on a glucose-based medium. A report is made on the use of mutant strain of Zymomonas mobilis for ethanol production from hydrolyzed sugar beet molasses in a two-stage continuous culture which showed high ethanol yield and an ethanol concentration sufficiently high for economical recovery. A single stage continuous culture was first operated in an attempt to reduce the formation of sorbitol. Further on, a second fermentor was added with additional substrate feeding to increase the effluent ethanol concentration. An ethanol concentration of 59.9g/l was obtained at 97% sugar conversion and at high ethanol yield. The volumetric ethanol productivity was superior to that of batch fermentation but inferior to that of a single-stage continuous system with the same medium. However, the ethanol concentration was increased to a level acceptable for economical recovery. 18 refs., 3 figs., 5 tabs.

  6. A novel spiral reactor for biodiesel production in supercritical ethanol

    International Nuclear Information System (INIS)

    Farobie, Obie; Sasanami, Kazuma; Matsumura, Yukihiko

    2015-01-01

    Highlights: • A novel spiral reactor for biodiesel production in supercritical ethanol was proposed. • The spiral reactor employed in this study successfully recovered heat. • The effects of temperature and time on FAEE yield were investigated. • FAEE yield as high as 0.937 mol/mol was obtained at 350 °C after 30 min. • The second-order kinetic model expressed the experimental yield well. - Abstract: A spiral reactor is proposed as a novel reactor design for biodiesel production under supercritical conditions. Since the spiral reactor serves as a heat exchanger, it offers the advantage of reduced apparatus space compared to conventional supercritical equipment. Experimental investigations were carried out at reaction temperatures of 270–400 °C, pressure of 20 MPa, oil-to-ethanol molar ratio of 1:40, and reaction times of 3–30 min. An FAEE yield of 0.937 mol/mol was obtained in a short reaction time of 30 min at 350 °C and oil-to-ethanol molar ratio of 1:40 under a reactor pressure of 20 MPa. The spiral reactor was not only as effective as conventional reactor in terms of transesterification reactor but also was superior in terms of heat recovery. A second-order kinetic model describing the transesterification of canola oil in supercritical ethanol was proposed, and the reaction was observed to follow Arrhenius behavior. The corresponding reaction rate constants and the activation energies as well as pre-exponential factors were determined

  7. Ethanol Production from Different Intermediates of Sugar Beet Processing

    OpenAIRE

    Mladen Pavlečić; Ivna Vrana; Kristijan Vibovec; Mirela Ivančić Šantek; Predrag Horvat; Božidar Šantek

    2010-01-01

    In this investigation, the production of ethanol from the raw sugar beet juice and raw sugar beet cossettes has been studied. For ethanol production from the raw sugar beet juice, batch and fed-batch cultivation techniques in the stirred tank bioreactor were used, while batch ethanol production from the raw sugar beet cossettes was carried out in horizontal rotating tubular bioreactor (HRTB). In both cases, Saccharomyces cerevisiae was used as a production microorganism. During batch ethanol ...

  8. 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.

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

    International Nuclear Information System (INIS)

    Kunchada Sangasintu; Petchporn Chawakitchareon

    2010-01-01

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

  10. 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.

  11. Potential feedstock sources for ethanol production in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Mohammad [Univ. of Florida, Gainesville, FL (United States); Hodges, Alan [Univ. of Florida, Gainesville, FL (United States)

    2015-10-01

    This study presents information on the potential feedstock sources that may be used for ethanol production in Florida. Several potential feedstocks for fuel ethanol production in Florida are discussed, such as, sugarcane, corn, citrus byproducts and sweet sorghum. Other probable impacts need to be analyzed for sugarcane to ethanol production as alternative uses of sugarcane may affect the quantity of sugar production in Florida. While citrus molasses is converted to ethanol as an established process, the cost of ethanol is higher, and the total amount of citrus molasses per year is insignificant. Sorghum cultivars have the potential for ethanol production. However, the agricultural practices for growing sweet sorghum for ethanol have not been established, and the conversion process must be tested and developed at a more expanded level. So far, only corn shipped from other states to Florida has been considered for ethanol production on a commercial scale. The economic feasibility of each of these crops requires further data and technical analysis.

  12. 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

  13. Ethanol production from lignocellulosic byproducts of olive oil extraction.

    Science.gov (United States)

    Ballesteros, I; Oliva, J M; Saez, F; Ballesteros, M

    2001-01-01

    The recent implementation of a new two-step centrifugation process for extracting olive oil in Spain has substantially reduced water consumption, thereby eliminating oil mill wastewater. However, a new high sugar content residue is still generated. In this work the two fractions present in the residue (olive pulp and fragmented stones) were assayed as substrate for ethanol production by the simultaneous saccharification and fermentation (SSF) process. Pretreatment of fragmented olive stones by sulfuric acid-catalyzed steam explosion was the most effective treatment for increasing enzymatic digestibility; however, a pretreatment step was not necessary to bioconvert the olive pulp into ethanol. The olive pulp and fragmented olive stones were tested by the SSF process using a fed-batch procedure. By adding the pulp three times at 24-h intervals, 76% of the theoretical SSF yield was obtained. Experiments with fed-batch pretreated olive stones provided SSF yields significantly lower than those obtained at standard SSF procedure. The preferred SSF conditions to obtain ethanol from olives stones (61% of theoretical yield) were 10% substrate and addition of cellulases at 15 filter paper units/g of substrate.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

  15. 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.

  16. 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.

  17. 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.

  18. Yield optimization in a cycled trickle-bed reactor: ethanol catalytic oxidation as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Ayude, A.; Haure, P. [INTEMA, CONICET, Mar del Plata (Argentina); Cassanello, M. [Universidad de Buenos Aires, PINMATE, Departamento de Industrias, FCEyN, Buenos Aires (Argentina); Martinez, O. [Departamento de Ingenieria Quimica, FI-UNLP-CINDECA, La Plata (Argentina)

    2012-05-15

    The effect of slow ON-OFF liquid flow modulation on the yield of consecutive reactions is investigated for oxidation of aqueous ethanol solutions using a 0.5 % Pd/Al{sub 2}O{sub 3} commercial catalyst in a laboratory trickle-bed reactor. Experiments with modulated liquid flow rate (MLFR) were performed under the same hydrodynamic conditions (degree of wetting, liquid holdup) as experiments with constant liquid flow rate (CLFR). Thus, the impact of the duration of wet and dry cycles as well as the period can be independently investigated. Depending on cycling conditions, acetaldehyde or acetic acid production is favored with MLFR compared to CLFR. Results suggest both the opportunity and challenge of finding a way to tune the cycling parameters for producing the most appropriate product. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Fuel ethanol production from sweet sorghum bagasse using microwave irradiation

    International Nuclear Information System (INIS)

    Marx, Sanette; Ndaba, Busiswa; Chiyanzu, Idan; Schabort, Corneels

    2014-01-01

    Sweet sorghum is a hardy crop that can be grown on marginal land and can provide both food and energy in an integrated food and energy system. Lignocellulose rich sweet sorghum bagasse (solid left over after starch and juice extraction) can be converted to bioethanol using a variety of technologies. The largest barrier to commercial production of fuel ethanol from lignocellulosic material remains the high processing costs associated with enzymatic hydrolysis and the use of acids and bases in the pretreatment step. In this paper, sweet sorghum bagasse was pretreated and hydrolysed in a single step using microwave irradiation. A total sugar yield of 820 g kg −1 was obtained in a 50 g kg −1 sulphuric acid solution in water, with a power input of 43.2 kJ g −1 of dry biomass (i.e. 20 min at 180 W power setting). An ethanol yield based on total sugar of 480 g kg −1 was obtained after 24 h of fermentation using a mixed culture of organisms. These results show the potential for producing as much as 0.252 m 3  tonne −1 or 33 m 3  ha −1 ethanol using only the lignocellulose part of the stalks, which is high enough to make the process economically attractive. - Highlights: • Different sweet sorghum cultivars were harvested at 3 and 6 months. • Sweet sorghum bagasse was converted to ethanol. • Microwave pretreatment and hydrolysis was done in a single step. • Sugar rich hydrolysates were converted to ethanol using co-fermentation

  20. Techno-economic analysis of fuel ethanol production from cassava ...

    African Journals Online (AJOL)

    Moncada Botero, J. (Jonathan)

    Key words: Fuel-ethanol, cassava, Tanzania, process modelling. INTRODUCTION ..... mathematical calculations such as Matlab, Octave and Polymath were also ... models. To start the different simulation procedures in ethanol production, a.

  1. Ethanol addition enhances acid treatment to eliminate Lactobacillus fermentum from the fermentation process for fuel ethanol production.

    Science.gov (United States)

    Costa, M A S; Cerri, B C; Ceccato-Antonini, S R

    2018-01-01

    Fermentation is one of the most critical steps of the fuel ethanol production and it is directly influenced by the fermentation system, selected yeast, and bacterial contamination, especially from the genus Lactobacillus. To control the contamination, the industry applies antibiotics and biocides; however, these substances can result in an increased cost and environmental problems. The use of the acid treatment of cells (water-diluted sulphuric acid, adjusted to pH 2·0-2·5) between the fermentation cycles is not always effective to combat the bacterial contamination. In this context, this study aimed to evaluate the effect of ethanol addition to the acid treatment to control the bacterial growth in a fed-batch system with cell recycling, using the industrial yeast strain Saccharomyces cerevisiae PE-2. When only the acid treatment was used, the population of Lactobacillus fermentum had a 3-log reduction at the end of the sixth fermentation cycle; however, when 5% of ethanol was added to the acid solution, the viability of the bacterium was completely lost even after the first round of cell treatment. The acid treatment +5% ethanol was able to kill L. fermentum cells without affecting the ethanol yield and with a low residual sugar concentration in the fermented must. In Brazilian ethanol-producing industry, water-diluted sulphuric acid is used to treat the cell mass at low pH (2·0) between the fermentative cycles. This procedure reduces the number of Lactobacillus fermentum from 10 7 to 10 4  CFU per ml. However, the addition of 5% ethanol to the acid treatment causes the complete loss of bacterial cell viability in fed-batch fermentation with six cell recycles. The ethanol yield and yeast cell viability are not affected. These data indicate the feasibility of adding ethanol to the acid solution replacing the antibiotic use, offering a low cost and a low amount of residue in the biomass. © 2017 The Society for Applied Microbiology.

  2. Bio-Ethanol Production from Poultry Manure

    African Journals Online (AJOL)

    john

    ethanol. Fuel ethanol is known as bio-ethanol, since it is produced from plant materials by biological processes. Bioethanol is mainly produced by fermentation of sugar containing crops like corn, maize, wheat, sugar cane, sugar beet, potatoes, ...

  3. [Optimization of fuel ethanol production from kitchen waste by Plackett-Burman design].

    Science.gov (United States)

    Ma, Hong-Zhi; Gong, Li-Juan; Wang, Qun-Hui; Zhang, Wen-Yu; Xu, Wen-Long

    2008-05-01

    Kitchen garbage was chosen to produce ethanol through simultaneous saccharification and fermentation (SSF) by Zymomonas mobilis. Plackett-Burman design was employed to screen affecting parameters during SSF process. The parameters were divided into two parts, enzymes and nutritions. None of the nutritions added showed significant effect during the experiment, which demonstrated that the kitchen garbage could meet the requirement of the microorganism without extra supplementation. Protease and glucoamylase were determined to be affecting factors for ethanol production. Single factor experiment showed that the optimum usage of these two enzymes were both 100 U/g and the corresponding maximum ethanol was determined to be 53 g/L. The ethanol yield could be as high as 44%. The utilization of kitchen garbage to produce ethanol could reduce threaten of waste as well as improve the protein content of the spent. This method could save the ethanol production cost and benefit for the recycle of kitchen garbage.

  4. Overexpression of pyruvate decarboxylase in the yeast Hansenula polymorpha results in increased ethanol yield in high-temperature fermentation of xylose.

    Science.gov (United States)

    Ishchuk, Olena P; Voronovsky, Andriy Y; Stasyk, Oleh V; Gayda, Galina Z; Gonchar, Mykhailo V; Abbas, Charles A; Sibirny, Andriy A

    2008-11-01

    Improvement of xylose fermentation is of great importance to the fuel ethanol industry. The nonconventional thermotolerant yeast Hansenula polymorpha naturally ferments xylose to ethanol at high temperatures (48-50 degrees C). Introduction of a mutation that impairs ethanol reutilization in H. polymorpha led to an increase in ethanol yield from xylose. The native and heterologous (Kluyveromyces lactis) PDC1 genes coding for pyruvate decarboxylase were expressed at high levels in H. polymorpha under the control of the strong constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH). This resulted in increased pyruvate decarboxylase activity and improved ethanol production from xylose. The introduction of multiple copies of the H. polymorpha PDC1 gene driven by the strong constitutive promoter led to a 20-fold increase in pyruvate decarboxylase activity and up to a threefold elevation of ethanol production.

  5. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Atiya Techaparin

    Full Text Available Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v, respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ at 40 °C were achieved using the Box-Behnken experimental design (BBD. The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

  6. Effect of Sugar Concentration in Jerusalem Artichoke Extract on Kluyveromyces marxianus Growth and Ethanol Production

    OpenAIRE

    Margaritis, Argyrios; Bajpai, Pratima

    1983-01-01

    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−1 at 50 g of sugar per liter to 0.13 h−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.

  7. Utilization of concentrate after membrane filtration of sugar beet thin juice for ethanol production.

    Science.gov (United States)

    Kawa-Rygielska, Joanna; Pietrzak, Witold; Regiec, Piotr; Stencel, Piotr

    2013-04-01

    The subject of this study was to investigate the feasibility of the concentrate obtained after membrane ultrafiltration of sugar beet thin juice for ethanol production and selection of fermentation conditions (yeast strain and media supplementation). Resulting concentrate was subjected to batch ethanol fermentation using two strains of Saccharomyces cerevisiae (Ethanol Red and Safdistill C-70). The effect of different forms of media supplementation (mineral salts: (NH4)2SO4, K2HPO4, MgCl2; urea+Mg3(PO4)2 and yeast extract) on the fermentation course was also studied. It was stated that sugar beet juice concentrate is suitable for ethanol production yielding, depending on the yeast strain, ca. 85-87 g L(-1) ethanol with ca. 82% practical yield and more than 95% of sugars consumption after 72 h of fermentation. Nutrients enrichment further increased ethanol yield. The best results were obtained for media supplemented with urea+Mg3(PO4)2 yielding 91.16-92.06 g L(-1) ethanol with practical yield ranging 84.78-85.62% and full sugars consumption. Copyright © 2013. Published by Elsevier Ltd.

  8. Enhanced Ethanol Production with Mixed Lignocellulosic Substrates from Commercial Furfural and Cassava Residues

    Directory of Open Access Journals (Sweden)

    Li Ji

    2015-01-01

    Full Text Available Simultaneous saccharification and fermentation (SSF is an attractive process configuration for bio-ethanol production. Further reductions in process cost of SSF are expected with the use of waste agricultural or industrial materials as feedstock. In the current study, two industrial lignocellulosic wastes, cassava residues (CR and furfural residues (FR, were combined during SSF for ethanol production due to their value-added applications and positive environmental impacts. After CR were liquefied and saccharified, saccharification liquid was added to SSF of FR. The effect of substrate fractions was investigated in terms of ethanol yield, byproduct concentration and the number of yeast cells. Besides, a natural surfactant, Gleditsia saponin, was added to investigate the effect of FR lignin on SSF with 20% substrate concentration. The results showed that increasing the ratio of CR/FR improved the ethanol yield and that the ethanol yield was also increased gradually by increasing the substrate concentration from 6% to 12%. A high ethanol concentration of 36.0 g/L was obtained under the condition of CR:FR = 2:1 with 12% substrate concentration, reaching 71.1% of the theoretical yield. However, Gleditsia saponin did not affect the ethanol yield, indicating the insignificant effect of lignin in SSF with low lignin content in the reaction system.

  9. Understanding the reductions in US corn ethanol production costs: An experience curve approach

    International Nuclear Information System (INIS)

    Hettinga, W.G.; Junginger, H.M.; Dekker, S.C.; Hoogwijk, M.; McAloon, A.J.; Hicks, K.B.

    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 using the experience curve approach, scrutinizing costs of dry grind ethanol production over the timeframe 1980-2005. Cost reductions are differentiated between feedstock (corn) production and industrial (ethanol) processing. Corn production costs in the US have declined by 62% over 30 years, down to 100$ 2005 /tonne in 2005, while corn production volumes almost doubled since 1975. A progress ratio (PR) of 0.55 is calculated indicating a 45% cost decline over each doubling in cumulative production. Higher corn yields and increasing farm sizes are the most important drivers behind this cost decline. Industrial processing costs of ethanol have declined by 45% since 1983, to below 130$ 2005 /m 3 in 2005 (excluding costs for corn and capital), equivalent to a PR of 0.87. Total ethanol production costs (including capital and net corn costs) have declined approximately 60% from 800$ 2005 /m 3 in the early 1980s, to 300$ 2005 /m 3 in 2005. Higher ethanol yields, lower energy use and the replacement of beverage alcohol-based production technologies have mostly contributed to this substantial cost decline. In addition, the average size of dry grind ethanol plants increased by 235% since 1990. For the future it is estimated that solely due to technological learning, production costs of ethanol may decline 28-44%, though this excludes effects of the current rising corn and fossil fuel costs. It is also concluded that experience curves are a valuable tool to describe both past and potential future cost reductions in US corn-based ethanol production

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

    Science.gov (United States)

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

    2013-02-28

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

  11. Ethanol production from SPORL-pretreated lodgepole pine : preliminary evaluation of mass balance and process energy efficiency

    Science.gov (United States)

    Junyong Zhu; Wenyuan Zhu; Patricia OBryan; Bruce S. Dien; Shen Tian; Roland Gleisner; X.J. Pan

    2010-01-01

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-...

  12. Zymomonas mobilis for fuel ethanol and higher value products.

    Science.gov (United States)

    Rogers, P L; Jeon, Y J; Lee, K J; Lawford, H G

    2007-01-01

    High oil prices, increasing focus on renewable carbohydrate-based feedstocks for fuels and chemicals, and the recent publication of its genome sequence, have provided continuing stimulus for studies on Zymomonas mobilis. However, despite its apparent advantages of higher yields and faster specific rates when compared to yeasts, no commercial scale fermentations currently exist which use Z. mobilis for the manufacture of fuel ethanol. This may change with the recent announcement of a Dupont/Broin partnership to develop a process for conversion of lignocellulosic residues, such as corn stover, to fuel ethanol using recombinant strains of Z. mobilis. The research leading to the construction of these strains, and their fermentation characteristics, are described in the present review. The review also addresses opportunities offered by Z. mobilis for higher value products through its metabolic engineering and use of specific high activity enzymes.

  13. 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.

  14. Autohydrolysis pretreatment assessment in ethanol production from agave bagasse.

    Science.gov (United States)

    Rios-González, Leopoldo J; Morales-Martínez, Thelma K; Rodríguez-Flores, María F; Rodríguez-De la Garza, José A; Castillo-Quiroz, David; Castro-Montoya, Agustín J; Martinez, Alfredo

    2017-10-01

    The aim of the present work was to assess the autohydrolysis pretreatment of Agave tequilana bagasse for ethanol production. The pretreatment was conducted using a one-liter high pressure Parr reactor under different severity factors (SF) at a 1:6w/v ratio (solid:liquid) and 200rpm. The solids obtained under the selected autohydrolysis conditions were subjected to enzymatic hydrolysis with a commercial cellulase cocktail, and the enzymatic hydrolysate was fermented using Saccharomyces cerevisiae. The results obtained from the pretreatment process showed that the glucan content in the pretreated solid was mostly preserved, and an increase in the digestibility was observed for the case with a SF of 4.13 (190°C, 30min). Enzymatic hydrolysis of the pretreated solids showed a yield of 74.3%, with a glucose concentration of 126g/L, resulting in 65.26g/L of ethanol after 10h of fermentation, which represent a 98.4% conversion according to the theoretical ethanol yield value. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Co-production of hydrogen and ethanol by Escherichia coli SS1 and its recombinant

    Directory of Open Access Journals (Sweden)

    Chiu-Shyan Soo

    2017-11-01

    Conclusions: HybC could improve glycerol consumption rate and ethanol productivity of E. coli despite lower hydrogen and ethanol yields. Higher glycerol consumption rate of recombinant hybC could be an advantage for bioconversion of glycerol into biofuels. This study could serve as a useful guidance for dissecting the role of hydrogenase in glycerol metabolism and future development of effective strain for biofuels production.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    Li Yongchao

    2012-01-01

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

  19. Simultaneous production of bio-ethanol and bleached pulp from red algae.

    Science.gov (United States)

    Yoon, Min Ho; Lee, Yoon Woo; Lee, Chun Han; Seo, Yung Bum

    2012-12-01

    The red algae, Gelidium corneum, was used to produce bleached pulp for papermaking and ethanol. Aqueous extracts obtained at 100-140 °C were subjected to saccharification, purification, fermentation, and distillation to produce ethanol. The solid remnants were bleached with chlorine dioxide and peroxide to make pulp. In the extraction process, sulfuric acid and sodium thiosulfate were added to increase the extract yield and to improve de-polymerization of the extracts, as well as to generate high-quality pulp. An extraction process incorporating 5% sodium thiosulfate by dry weight of the algae provided optimal production conditions for the production of both strong pulp and a high ethanol yield. These results suggest that it might be possible to utilize algae instead of trees and starch for pulp and ethanol production, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Jessen, Jan Eric; Orlygsson, Johann

    2012-01-01

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

  1. 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.

  2. 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

  3. Continuous production of ethanol from hexoses and pentoses using immobilized mixed cultures of Escherichia coli strains

    Science.gov (United States)

    Unrean, Pornkamol; Srienc, Friedrich

    2010-01-01

    We have developed highly efficient ethanologenic E. coli strains that selectively consume pentoses and/or hexoses. Mixed cultures of these strains can be used to selectively adjust the sugar utilization kinetics in ethanol fermentations. Based on the kinetics of sugar utilization, we have designed and implemented an immobilized cell system for the optimized continuous conversion of sugars into ethanol. The results confirm that immobilized mixed cultures support a simultaneous conversion of hexoses and pentoses into ethanol at high yield and at a faster rate than immobilized homogenous cells. Continuous ethanol production has been maintained for several weeks at high productivity with near complete sugar utilization. The control of sugar utilization using immobilized mixed cultures can be adapted to any composition of hexoses and pentoses by adjusting the strain distribution of immobilized cells. The approach, therefore, holds promise for ethanol fermentation from lignocellulosic hydrolysates where the feedstock varies in sugar composition. PMID:20699108

  4. Changes in carbon footprint when integrating production of filamentous fungi in 1st generation ethanol plants.

    Science.gov (United States)

    Brancoli, Pedro; Ferreira, Jorge A; Bolton, Kim; Taherzadeh, Mohammad J

    2018-02-01

    Integrating the cultivation of edible filamentous fungi in the thin stillage from ethanol production is presently being considered. This integration can increase the ethanol yield while simultaneously producing a new value-added protein-rich biomass that can be used for animal feed. This study uses life cycle assessment to determine the change in greenhouse gas (GHG) emissions when integrating the cultivation of filamentous fungi in ethanol production. The result shows that the integration performs better than the current scenario when the fungal biomass is used as cattle feed for system expansion and when energy allocation is used. It performs worse if the biomass is used as fish feed. Hence, integrating the cultivation of filamentous fungi in 1st generation ethanol plants combined with proper use of the fungi can lead to a reduction of GHG emissions which, considering the number of existing ethanol plants, can have a significant global impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 I: production of xylitol and ethanol.

    Science.gov (United States)

    Bura, Renata; Vajzovic, Azra; Doty, Sharon L

    2012-07-01

    An endophytic yeast, Rhodotorula mucilaginosa strain PTD3, that was isolated from stems of hybrid poplar was found to be capable of production of xylitol from xylose, of ethanol from glucose, galactose, and mannose, and of arabitol from arabinose. The utilization of 30 g/L of each of the five sugars during fermentation by PTD3 was studied in liquid batch cultures. Glucose-acclimated PTD3 produced enhanced yields of xylitol (67% of theoretical yield) from xylose and of ethanol (84, 86, and 94% of theoretical yield, respectively) from glucose, galactose, and mannose. Additionally, this yeast was capable of metabolizing high concentrations of mixed sugars (150 g/L), with high yields of xylitol (61% of theoretical yield) and ethanol (83% of theoretical yield). A 1:1 glucose:xylose ratio with 30 g/L of each during double sugar fermentation did not affect PTD3's ability to produce high yields of xylitol (65% of theoretical yield) and ethanol (92% of theoretical yield). Surprisingly, the highest yields of xylitol (76% of theoretical yield) and ethanol (100% of theoretical yield) were observed during fermentation of sugars present in the lignocellulosic hydrolysate obtained after steam pretreatment of a mixture of hybrid poplar and Douglas fir. PTD3 demonstrated an exceptional ability to ferment the hydrolysate, overcome hexose repression of xylose utilization with a short lag period of 10 h, and tolerate sugar degradation products. In direct comparison, PTD3 had higher xylitol yields from the mixed sugar hydrolysate compared with the widely studied and used xylitol producer Candida guilliermondii.

  7. An economic assessment of potential ethanol production pathways in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Deverell, Rory; McDonnell, Kevin; Ward, Shane; Devlin, Ger [Department of Biosystems Engineering, Agriculture and Food Science Building, University College Dublin 4, Belfield (Ireland)

    2009-10-15

    An economic assessment was conducted on five biomass-to-ethanol production pathways utilising the feedstock: wheat, triticale, sugarbeet, miscanthus and straw. The analysis includes the costs and margins for all the stakeholders along the economic chain. This analysis reveals that under current market situations in Ireland, the production of ethanol under the same tax regime as petrol makes it difficult to compete against that fuel, with tax breaks, however, it can compete against petrol. On the other hand, even under favourable tax breaks it will be difficult for indigenously produced ethanol to compete against cheaper sources of imported ethanol. Therefore, the current transport fuel market has no economic reason to consume indigenously produced ethanol made from the indigenously grown feedstock analysed at a price that reflects all the stakeholders' costs. To deliver a significant penetration of indigenous ethanol into the market would require some form of compulsory inclusion or else considerable financial supports to feedstock and ethanol producers. (author)

  8. An economic assessment of potential ethanol production pathways in Ireland

    International Nuclear Information System (INIS)

    Deverell, Rory; McDonnell, Kevin; Ward, Shane; Devlin, Ger

    2009-01-01

    An economic assessment was conducted on five biomass-to-ethanol production pathways utilising the feedstock: wheat, triticale, sugarbeet, miscanthus and straw. The analysis includes the costs and margins for all the stakeholders along the economic chain. This analysis reveals that under current market situations in Ireland, the production of ethanol under the same tax regime as petrol makes it difficult to compete against that fuel, with tax breaks, however, it can compete against petrol. On the other hand, even under favourable tax breaks it will be difficult for indigenously produced ethanol to compete against cheaper sources of imported ethanol. Therefore, the current transport fuel market has no economic reason to consume indigenously produced ethanol made from the indigenously grown feedstock analysed at a price that reflects all the stakeholders' costs. To deliver a significant penetration of indigenous ethanol into the market would require some form of compulsory inclusion or else considerable financial supports to feedstock and ethanol producers.

  9. 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.)

  10. Ethanol production of banana shell and cassava starch

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  11. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Cassava as feedstock for ethanol production in South Africa

    African Journals Online (AJOL)

    Sanette

    2013-07-31

    Jul 31, 2013 ... substitute a minimum of 2% of the country's transportation fuel with biomass based fuels. ... and fermentation (SSF) showed the highest ethanol yield and direct ... of co-immobilized yeast cells to ferment cassava starch.

  13. 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.

  14. Environmental sustainability assessment of bio-ethanol production in Thailand

    International Nuclear Information System (INIS)

    Silalertruksa, Thapat; Gheewala, Shabbir H.

    2009-01-01

    Bio-ethanol is playing an important role in renewable energy for transport according to Thai government policy. This study aims to evaluate the energy efficiency and renewability of bio-ethanol system and identify the current significant environmental risks and availability of feedstocks in Thailand. Four of the seven existing ethanol plants contributing 53% of the total ethanol fuel production in Thailand have been assessed by the net energy balance method and Life Cycle Assessment (LCA). A renewability and net energy ratio portfolio has been used to indicate whether existing bio-ethanol production systems have net energy gain and could help reduce dependency on fossil energy. In addition, LCA has been conducted to identify and evaluate the environmental hotspots of 'cradle to gate' bio-ethanol production. The results show that there are significant differences of energy and environmental performance among the four existing production systems even for the same feedstock. The differences are dependent on many factors such as farming practices, feedstock transportion, fuel used in ethanol plants, operation practices and technology of ethanol conversion and waste management practices. Recommendations for improving the overall energy and environmental performance of the bio-ethanol system are suggested in order to direct the bio-ethanol industry in Thailand towards environmental sustainability.

  15. Evaluation of hardboard manufacturing process wastewater as a feedstream for ethanol production.

    Science.gov (United States)

    Groves, Stephanie; Liu, Jifei; Shonnard, David; Bagley, Susan

    2013-07-01

    Waste streams from the wood processing industry can serve as feedstream for ethanol production from biomass residues. Hardboard manufacturing process wastewater (HPW) was evaluated on the basis of monomeric sugar recovery and fermentability as a novel feedstream for ethanol production. Dilute acid hydrolysis, coupled with concentration of the wastewater resulted in a hydrolysate with 66 g/l total fermentable sugars. As xylose accounted for 53 % of the total sugars, native xylose-fermenting yeasts were evaluated for their ability to produce ethanol from the hydrolysate. The strains selected were, in decreasing order by ethanol yields from xylose (Y p/s, based on consumed sugars), Scheffersomyces stipitis ATCC 58785 (CBS 6054), Pachysolen tannophilus ATCC 60393, and Kluyveromyces marxianus ATCC 46537. The yeasts were compared on the basis of substrate utilization and ethanol yield during fermentations of the hydrolysate, measured using an HPLC. S. stipitis, P. tannophilus, and K. marxianus produced 0.34, 0.31, and 0.36 g/g, respectively. The yeasts were able to utilize between 58 and 75 % of the available substrate. S. stipitis outperformed the other yeast during the fermentation of the hydrolysate; consuming the highest concentration of available substrate and producing the highest ethanol concentration in 72 h. Due to its high sugar content and low inhibitor levels after hydrolysis, it was concluded that HPW is a suitable feedstream for ethanol production by S. stipitis.

  16. 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.

  17. 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

  18. 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)

  19. 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.

  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. 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. 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.

  3. Flocculating Zymomonas mobilis is a promising host to be engineered for fuel ethanol production from lignocellulosic biomass.

    Science.gov (United States)

    Zhao, Ning; Bai, Yun; Liu, Chen-Guang; Zhao, Xin-Qing; Xu, Jian-Feng; Bai, Feng-Wu

    2014-03-01

    Whereas Saccharomyces cerevisiae uses the Embden-Meyerhof-Parnas pathway to metabolize glucose, Zymomonas mobilis uses the Entner-Doudoroff (ED) pathway. Employing the ED pathway, 50% less ATP is produced, which could lead to less biomass being accumulated during fermentation and an improved yield of ethanol. Moreover, Z. mobilis cells, which have a high specific surface area, consume glucose faster than S. cerevisiae, which could improve ethanol productivity. We performed ethanol fermentations using these two species under comparable conditions to validate these speculations. Increases of 3.5 and 3.3% in ethanol yield, and 58.1 and 77.8% in ethanol productivity, were observed in ethanol fermentations using Z. mobilis ZM4 in media containing ∼100 and 200 g/L glucose, respectively. Furthermore, ethanol fermentation bythe flocculating Z. mobilis ZM401 was explored. Although no significant difference was observed in ethanol yield and productivity, the flocculation of the bacterial species enabled biomass recovery by cost-effective sedimentation, instead of centrifugation with intensive capital investment and energy consumption. In addition, tolerance to inhibitory byproducts released during biomass pretreatment, particularly acetic acid and vanillin, was improved. These experimental results indicate that Z. mobilis, particularly its flocculating strain, is superior to S. cerevisiae as a host to be engineered for fuel ethanol production from lignocellulosic biomass. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 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.

  5. Continuous ethanol production using immobilized yeast cells entrapped in loofa-reinforced alginate carriers

    Directory of Open Access Journals (Sweden)

    Phoowit Bangrak

    2011-06-01

    Full Text Available A culture of Saccharomyces cerevisiae M30 entrapped in loofa-reinforced alginate was used for continuous ethanol fermentation in a packed-bed reactor with initial sugar concentrations of 200-248 g/L. Maximum ethanol productivity of 11.5 g/(L·h was obtained at an ethanol concentration of 57.4 g/L, an initial sugar concentration of 220 g/L and a dilution rate (D of 0.2 h-1. However, a maximum ethanol concentration of 82.1 g/L (productivity of 9.0 g/(L·h was obtained at a D of 0.11 h-1. Ethanol productivity in the continuous culture was 6-8-fold higher than that in the batch culture. Due to the developed carrier's high biocompatibility, high porosity, and good mechanical strength, advantages such as cell regeneration, reusability, altered mechanical strength, and high capacity to trap active cells in the reactor were achieved in this study. The immobilized cell reactor was successfully operated for 30 days without any loss in ethanol productivity. The average conversion yield was 0.43-0.45 throughout the entire operation, with an immobilization yield of 47.5%. The final total cell concentration in the reactor was 37.3 g/L (17.7 g/L immobilized cells and 19.6 g/L suspended cells. The concentration of suspended cells in the effluent was 0.8 g/L.

  6. 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.

  7. 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

  8. The Canadian Petroleum Products Institute : position on ethanol

    International Nuclear Information System (INIS)

    2002-01-01

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

  9. 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.

  10. 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.

  11. 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....... cerevisiae tolerance to inhibitory conditions of lignocellulosic ethanol production processes is the lack of knowledge about basic aspects of its cellular signaling network in response to stress. Here, we highlight the inhibitory conditions found in ethanol production processes, the targeted cellular...... functions, the key contributions of integrated -omics analysis to reveal cellular stress responses according to these inhibitors, and current status on design-based engineering of tolerant and efficient S. cerevisiae strains for ethanol production from lignocellulose....

  12. 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.

  13. 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

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

    International Nuclear Information System (INIS)

    Silalertruksa, Thapat; Gheewala, Shabbir H.

    2010-01-01

    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. - Research highlights: →Bioethanol in Thailand derived from molasses, cassava, sugarcane juice could yield reductions of 64%, 49% and 87% in GHGs when compared to conventional gasoline. →High yields improvement are required for a reliable and sufficient supply of molasses, cassava and sugarcane to satisfy the long-term demands for bio-ethanol and other related industries. →Other factors to enhance long-term security of feedstocks supply for sustainable bioethanol production in Thailand include increasing use of sugarcane juice as feedstock and promoting production of bioethanol derived from agricultural residues.

  15. 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.

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

    Science.gov (United States)

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

    2013-03-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  18. Study of advanced control of ethanol production through continuous fermentation

    Directory of Open Access Journals (Sweden)

    AbdelHamid Ajbar

    2017-01-01

    Full Text Available This paper investigates the control of an experimentally validated model of production of bioethanol. The analysis of the open loop system revealed that the maximum productivity occurred at a periodic point. A robust control was needed to avoid instabilities that may occur when disturbances are injected into the process that may drive it toward or through the unstable points. A nonlinear model predictive controller (NLMPC was used to control the process. Simulation tests were carried out using three controlled variables: the ethanol concentration, the productivity and the inverse of the productivity. In the third configuration, the controller was required to seek the maximum operating point through the optimization capability built in the NLMPC algorithm. Simulation tests presented overall satisfactory closed-loop performance for both nominal servo and regulatory control problems as well as in the presence of modeling errors. The third control configuration managed to steer the process toward the existing maximum productivity even when the process operation or its parameters changed. For comparison purposes, a standard PI controller was also designed for the same control objectives. The PI controller yielded satisfactory performance when the ethanol concentration was chosen as the controlled variable. When, on the other hand, the productivity was chosen as the controlled output, the PI controller did not work properly and needed to be adjusted using gain scheduling. In all cases, it was observed that the closed-loop response suffered from slow dynamics, and any attempt to speed up the feedback response via tuning may result in an unstable behavior.

  19. Direct Ethanol Production from Breadfruit Starch (Artocarpus communis Forst. by Engineered Simultaneous Saccharification and Fermentation (ESSF using Microbes Consortium

    Directory of Open Access Journals (Sweden)

    Iftachul Farida

    2015-02-01

    Full Text Available Breadfruit (Artocarpus communis Forst. is one of sources for ethanol production, which has high starch content (89%. Ethanol production from breadfruit starch was conducted by Simultaneous Saccharification and Fermentation (SSF technology using microbes consortium. The aim of the research was to examine a method to produce ethanol by SSF technology using microbes consortium at high yield and efficiency. The main research consisted of two treatments, namely normal SSF and enginereed SSF. The results showed that normal SSF using aeration and agitation during cultivation could produce ethanol at 11.15 ± 0.18 g/L, with the yield of product (Yp/s 0.34 g ethanol/g substrate; and yield of biomass (Yx/s 0.29 g cell/g substrate, respectively. A better result was obtained using engineered SSF in which aeration was stopped after biomass condition has reached the end of the exponential phase. The ethanol produced was 12.75 ± 0.04 g/L, with the yields of product (Yp/s 0.41 g ethanol/g substrate, and the yield of cell (Yx/s 0.09 g cell/g substrate.

  20. 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.

  1. Production of ethanol from thin stillage by metabolically engineered Escherichia coli.

    Science.gov (United States)

    Gonzalez, Ramon; Campbell, Paul; Wong, Matthew

    2010-03-01

    Thin stillage is a by-product generated in large amounts during the production of ethanol that is rich in carbon sources like glycerol, glucose and maltose. Unfortunately, the fermentation of thin stillage results in a mixture of organic acids and ethanol and minimum utilization of glycerol, the latter a compound that can represent up to 80% of the available substrates in this stream. We report here the efficient production of ethanol from thin stillage by a metabolically engineered strain of Escherichia coli. Simultaneous utilization of glycerol and sugars was achieved by overexpressing either the fermentative or the respiratory glycerol-utilization pathway. However, amplification of the fermentative pathway (encoded by gldA and dhaKLM) led to more efficient consumption of glycerol and promoted the synthesis of reduced products, including ethanol. A previously constructed strain, EH05, containing mutations that prevented the accumulation of competing by-products (i.e. lactate, acetate, and succinate) and overexpressing the fermentative pathway for glycerol utilization [i.e. strain EH05 (pZSKLMgldA)], efficiently converted thin stillage supplemented with only mineral salts to ethanol at yields close to 85% of the theoretical maximum. Ethanol accounted for about 90% (w/w) of the product mixture. These results, along with the comparable performance of strain EH05 (pZSKLMgldA) in 0.5 and 5 l fermenters, indicate a great potential for the adoption of this process by the biofuels industry.

  2. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  4. Investigation of ethanol productivity of cassava crop as a sustainable ...

    African Journals Online (AJOL)

    The ethanol productivity of cassava crop was investigated in a laboratory experiment by correlating volumes and masses of ethanol produced to the masses of samples used. Cassava tubers (variety TMS 30555) were peeled, cut and washed. 5, 15, 25 and 35 kg samples of the tubers were weighed in three replicates, ...

  5. Preliminary studies on ethanol production from Garcinia kola (bitter ...

    African Journals Online (AJOL)

    Dr. J. T. Ekanem

    A study on yeast fermentation of bitter kola pod( agricultural waste) was ... optimization of the ethanol production were investigated. ... components of biomass to produce a liquid .... Mani, S., Tabil, L. G. and Opoku, A. (2002). Ethanol from Agricultural crop residues-An. Overview. ... Effect of acid hydrolysis of Garcinia kola.

  6. Bioelectrochemical ethanol production through mediated acetate reduction by mixed cultures.

    Science.gov (United States)

    Steinbusch, Kirsten J J; Hamelers, Hubertus V M; Schaap, Joris D; Kampman, Christel; Buisman, Cees J N

    2010-01-01

    Biological acetate reduction with hydrogen is a potential method to convert wet biomass waste into ethanol. Since the ethanol concentration and reaction rates are low, this research studies the feasibility of using an electrode, in stead of hydrogen, as an electron donor for biological acetate reduction in conjunction of an electron mediator. Initially, the effect of three selected mediators on metabolic flows during acetate reduction with hydrogen was explored; subsequently, the best performing mediator was used in a bioelectrochemical system to stimulate acetate reduction at the cathode with mixed cultures at an applied cathode potential of -550 mV. In the batch test, methyl viologen (MV) was found to accelerate ethanol production 6-fold and increased ethanol concentration 2-fold to 13.5 +/- 0.7 mM compared to the control. Additionally, MV inhibited n-butyrate and methane formation, resulting in high ethanol production efficiency (74.6 +/- 6%). In the bioelectrochemical system, MV addition to an inoculated cathode led directly to ethanol production (1.82 mM). Hydrogen was coproduced at the cathode (0.0035 Nm(3) hydrogen m(-2) d(-1)), so it remained unclear whether acetate was reduced to ethanol by electrons supplied by the mediator or by hydrogen. As MV reacted irreversibly at the cathode, ethanol production stopped after 5 days.

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

    International Nuclear Information System (INIS)

    Nguyen, Q.

    1990-03-01

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

  8. 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.

  9. 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).

  10. 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).

  11. 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.

  12. 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

  13. Evidence for the existence of water:ethanol clusters from o-Ps yields

    International Nuclear Information System (INIS)

    Smith, F.A.; Beling, C.D.

    1982-01-01

    Lifetime measurements have been made in mixtures of water and ethanol at 293 K. Fluctuations are observed in both o-Ps yield and decay rate as a function of water concentration with local maxima occurring at molecular ratios (EtOH:H 2 O) of 4:1 and 1:1. The results are interpreted in terms of cluster formation at these concentrations. (Auth.)

  14. Integration of Microbial Electrolysis Cells (MECs) in the Biorefinery for Production of Ethanol, H2 and Phenolics

    DEFF Research Database (Denmark)

    Thygesen, Anders; Thomsen, Anne Belinda; Possemiers, Sam

    2010-01-01

    production. The mass and energy balances as well as the economical evaluations, show that this strategy may be useful for additional generation of hydrogen and lignin, thereby increasing the final yield of this biorefinery. From one ton of straw, the yield of ethanol upon yeast fermentation is estimated......In a biorefinery, biomass is converted into a variety of chemicals, materials and energy. A typical example is the lignocellulosic ethanol biorefinery process, in which substrates such as wheat straw are used as a feedstock for production of ethanol. In this work, an integrated biorefinery...

  15. 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.

  16. Improving the yield from fermentative hydrogen production.

    Science.gov (United States)

    Kraemer, Jeremy T; Bagley, David M

    2007-05-01

    Efforts to increase H(2) yields from fermentative H(2) production include heat treatment of the inoculum, dissolved gas removal, and varying the organic loading rate. Although heat treatment kills methanogens and selects for spore-forming bacteria, the available evidence indicates H(2) yields are not maximized compared to bromoethanesulfonate, iodopropane, or perchloric acid pre-treatments and spore-forming acetogens are not killed. Operational controls (low pH, short solids retention time) can replace heat treatment. Gas sparging increases H(2) yields compared to un-sparged reactors, but no relationship exists between the sparging rate and H(2) yield. Lower sparging rates may improve the H(2) yield with less energy input and product dilution. The reasons why sparging improves H(2) yields are unknown, but recent measurements of dissolved H(2) concentrations during sparging suggest the assumption of decreased inhibition of the H(2)-producing enzymes is unlikely. Significant disagreement exists over the effect of organic loading rate (OLR); some studies show relatively higher OLRs improve H(2) yield while others show the opposite. Discovering the reasons for higher H(2) yields during dissolved gas removal and changes in OLR will help improve H(2) yields.

  17. 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.

  18. Ethanol production from Jerusalem artichoke by strains of Saccharomyces cheresiensis and Saccharomyces beticus

    Energy Technology Data Exchange (ETDEWEB)

    Pourrat, H.; Barthomeuf, C.; Regerat, F.; Carnat, A.P.; Carnat, A.

    1983-03-01

    Ethanol production from Jerusalem artichoke which is the most interesting autochtonous material has been studied. Two selected and acclimatised strains of Saccharomyces: Saccharomyces cheresiensis and Saccharomyces beticus were retained. The fermentation conditions, exactly definited, makes it possible to obtain in 4 days a theoric yield.

  19. Thermodynamic analysis of fermentation and anaerobic growth of baker's yeast for ethanol production.

    Science.gov (United States)

    Teh, Kwee-Yan; Lutz, Andrew E

    2010-05-17

    Thermodynamic concepts have been used in the past to predict microbial growth yield. This may be the key consideration in many industrial biotechnology applications. It is not the case, however, in the context of ethanol fuel production. In this paper, we examine the thermodynamics of fermentation and concomitant growth of baker's yeast in continuous culture experiments under anaerobic, glucose-limited conditions, with emphasis on the yield and efficiency of bio-ethanol production. We find that anaerobic metabolism of yeast is very efficient; the process retains more than 90% of the maximum work that could be extracted from the growth medium supplied to the chemostat reactor. Yeast cells and other metabolic by-products are also formed, which reduces the glucose-to-ethanol conversion efficiency to less than 75%. Varying the specific ATP consumption rate, which is the fundamental parameter in this paper for modeling the energy demands of cell growth, shows the usual trade-off between ethanol production and biomass yield. The minimum ATP consumption rate required for synthesizing cell materials leads to biomass yield and Gibbs energy dissipation limits that are much more severe than those imposed by mass balance and thermodynamic equilibrium constraints. 2010 Elsevier B.V. All rights reserved.

  20. Systematics of Fission-Product Yields

    International Nuclear Information System (INIS)

    Wahl, A.C.

    2002-01-01

    Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z F = 90 thru 98, mass number A F = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru ∼200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from ∼ 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron (∼ fission spectrum) induced fission reactions

  1. Systematics of Fission-Product Yields

    Energy Technology Data Exchange (ETDEWEB)

    A.C. Wahl

    2002-05-01

    Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z{sub F} = 90 thru 98, mass number A{sub F} = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru {approx}200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from {approx} 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron ({approx} fission spectrum) induced fission reactions.

  2. 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.

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

    Science.gov (United States)

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

  4. Sequential ethanol fermentation and anaerobic digestion increases bioenergy yields from duckweed.

    Science.gov (United States)

    Calicioglu, O; Brennan, R A

    2018-06-01

    The potential for improving bioenergy yields from duckweed, a fast-growing, simple, floating aquatic plant, was evaluated by subjecting the dried biomass directly to anaerobic digestion, or sequentially to ethanol fermentation and then anaerobic digestion, after evaporating ethanol from the fermentation broth. Bioethanol yields of 0.41 ± 0.03 g/g and 0.50 ± 0.01 g/g (glucose) were achieved for duckweed harvested from the Penn State Living-Filter (Lemna obscura) and Eco-Machine™ (Lemna minor/japonica and Wolffia columbiana), respectively. The highest biomethane yield, 390 ± 0.1 ml CH 4 /g volatile solids added, was achieved in a reactor containing fermented duckweed from the Living-Filter at a substrate-to-inoculum (S/I) ratio (i.e., duckweed to microorganism ratio) of 1.0. This value was 51.2% higher than the biomethane yield of a replicate reactor with raw (non-fermented) duckweed. The combined bioethanol-biomethane process yielded 70.4% more bioenergy from duckweed, than if anaerobic digestion had been run alone. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. The transcription factor Ace2 and its paralog Swi5 regulate ethanol production during static fermentation through their targets Cts1 and Rps4a in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wu, Yao; Du, Jie; Xu, Guoqiang; Jiang, Linghuo

    2016-05-01

    Saccharomyces cerevisiae is the most widely used fermentation organism for ethanol production. However, the gene expression regulatory networks behind the ethanol fermentation are still not fully understood. Using a static fermentation model, we examined the ethanol yields on biomass of deletion mutants for 77 yeast genes encoding nonessential transcription factors, and found that deletion mutants for ACE2 and SWI5 showed dramatically increased ethanol yields. Overexpression of ACE2 or SWI5 in wild type cells reduced their ethanol yields. Furthermore, among the 34 target genes regulated by Ace2 and Swi5, deletion of CTS1,RPS4a,SIC1,EGT2,DSE2, or SCP160 led to increased ethanol yields, with the former two showing higher effects. Overexpression of CTS1 or RPS4a in both ace2/ace2 and swi5/swi5 mutants reduced their ethanol yields. In contrast, deletion of MCR1 or HO significantly decreased ethanol yields, with the former one showing the highest effect. Therefore, Ace2 and Swi5 are two negative regulators of ethanol yield during static fermentation of yeast cells, and both CTS1 and RPS4a are major effectors mediating these two transcription factors in regulating ethanol production. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Modelling of Ethanol Production from Red Beet Juice by Saccharomyces cerevisiae under Thermal and Acid Stress Conditions

    Directory of Open Access Journals (Sweden)

    Donaji Jiménez-Islas

    2014-01-01

    Full Text Available In this work the effects of pH and temperature on ethanol production from red beet juice by the strains Saccharomyces cerevisiae ITD00196 and S. cerevisiae ATCC 9763 are studied. Logistic, Pirt, and Luedeking-Piret equations were used to describe quantitatively the microbial growth, substrate consumption, and ethanol production, respectively. The two S. cerevisiae strains used in this study were able to produce ethanol with high yield and volumetric productivity under acid and thermal stress conditions. The equations used to model the fermentation kinetics fit very well with the experimental data, thus establishing that ethanol production was growth associated under the evaluated conditions. The yeast S. cerevisiae ITD00196 had the best fermentative capacity and could be considered as an interesting option to develop bioprocesses for ethanol production.

  7. Ethanol production from lignocellulosic hydrolysates using engineered Saccharomyces cerevisiae harboring xylose isomerase-based pathway.

    Science.gov (United States)

    Ko, Ja Kyong; Um, Youngsoon; Woo, Han Min; Kim, Kyoung Heon; Lee, Sun-Mi

    2016-06-01

    The efficient co-fermentation of glucose and xylose is necessary for the economically feasible bioethanol production from lignocellulosic biomass. Even with xylose utilizing Saccharomyces cerevisiae, the efficiency of the lignocellulosic ethanol production remains suboptimal mainly due to the low conversion yield of xylose to ethanol. In this study, we evaluated the co-fermentation performances of SXA-R2P-E, a recently engineered isomerase-based xylose utilizing strain, in mixed sugars and in lignocellulosic hydrolysates. In a high-sugar fermentation with 70g/L of glucose and 40g/L of xylose, SXA-R2P-E produced 50g/L of ethanol with an yield of 0.43gethanol/gsugars at 72h. From dilute acid-pretreated hydrolysates of rice straw and hardwood (oak), the strain produced 18-21g/L of ethanol with among the highest yield of 0.43-0.46gethanol/gsugars ever reported. This study shows a highly promising potential of a xylose isomerase-expressing strain as an industrially relevant ethanol producer from lignocellulosic hydrolysates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Ethanol production potential of local yeast strains isolated from ripe ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... ... of these studies, the preferred candidate for industrial production of ethanol ... The yeast strains were isolated using the method of Ameh et al. (1989), on ... gas in the Durham tube during the incubation period. Fermentation ...

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... pre-treatment, enzymatic saccharification, detoxification of inhibitors and fermentation of Sorghum bicolor straw for ethanol production ..... The authors wish to acknowledge financial support from ... Official energy statistics from.

  10. Development of ethanol production from cooking oil glycerol waste ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-12

    Oct 12, 2016 ... glycerol waste by mutant Enterobacter aerogenes ... wild type strain was altered for enhancing ethanol production using UV irradiation and chemical method. .... microbial medium analytical methods were of laboratory and.

  11. Ethanol production from biomass: technology and commercialisation status

    Energy Technology Data Exchange (ETDEWEB)

    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. (Author)

  12. 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.

  13. Increase of ethanol productivity by cell-recycle fermentation of flocculating yeast.

    Science.gov (United States)

    Wang, F Z; Xie, T; Hui, M

    2011-01-01

    Using the recombinant flocculating Angel yeast F6, long-term repeated batch fermentation for ethanol production was performed and a high volumetric productivity resulted from half cells not washed and the optimum opportunity of residual glucose 20 g l(-1) of last medium. The obtained highest productivity was 2.07 g l-(1) h(-1), which was improved by 75.4% compared with that of 1.18 g l(-1) h(-1) in the first batch fermentation. The ethanol concentration reached 8.4% corresponding to the yield of 0.46 g g(-1). These results will contribute greatly to the industrial production of fuel ethanol using the commercial method with the flocculating yeast.

  14. Evaluation of ethanol productivity from cellulose by Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-01-01

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

  15. Process and technoeconomic analysis of leading pretreatment technologies for lignocellulosic ethanol production using switchgrass.

    Science.gov (United States)

    Tao, Ling; Aden, Andy; Elander, Richard T; Pallapolu, Venkata Ramesh; Lee, Y Y; Garlock, Rebecca J; Balan, Venkatesh; Dale, Bruce E; Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R; Falls, Matthew; Holtzapple, Mark T; Sierra, Rocio; Shi, Jian; Ebrik, Mirvat A; Redmond, Tim; Yang, Bin; Wyman, Charles E; Hames, Bonnie; Thomas, Steve; Warner, Ryan E

    2011-12-01

    Six biomass pretreatment processes to convert switchgrass to fermentable sugars and ultimately to cellulosic ethanol are compared on a consistent basis in this technoeconomic analysis. The six pretreatment processes are ammonia fiber expansion (AFEX), dilute acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide-impregnated steam explosion (SO(2)). Each pretreatment process is modeled in the framework of an existing biochemical design model so that systematic variations of process-related changes are consistently captured. The pretreatment area process design and simulation are based on the research data generated within the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) 3 project. Overall ethanol production, total capital investment, and minimum ethanol selling price (MESP) are reported along with selected sensitivity analysis. The results show limited differentiation between the projected economic performances of the pretreatment options, except for processes that exhibit significantly lower monomer sugar and resulting ethanol yields. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Enhancement of ethanol production from green liquor-ethanol-pretreated sugarcane bagasse by glucose-xylose cofermentation at high solid loadings with mixed Saccharomyces cerevisiae strains.

    Science.gov (United States)

    You, Yanzhi; Li, Pengfei; Lei, Fuhou; Xing, Yang; Jiang, Jianxin

    2017-01-01

    Efficient cofermentation of glucose and xylose is necessary for economically feasible bioethanol production from lignocellulosic biomass. Here, we demonstrate pretreatment of sugarcane bagasse (SCB) with green liquor (GL) combined with ethanol (GL-Ethanol) by adding different GL amounts. The common Saccharomyces cerevisiae (CSC) and thermophilic S. cerevisiae (TSC) strains were used and different yeast cell mass ratios (CSC to TSC) were compared. The simultaneous saccharification and cofermentation (SSF/SSCF) process was performed by 5-20% (w/v) dry substrate (DS) solid loadings to determine optimal conditions for the co-consumption of glucose and xylose. Compared to previous studies that tested fermentation of glucose using only the CSC, we obtained higher ethanol yield and concentration (92.80% and 23.22 g/L) with 1.5 mL GL/g-DS GL-Ethanol-pretreated SCB at 5% (w/v) solid loading and a CSC-to-TSC yeast cell mass ratio of 1:2 (w/w). Using 10% (w/v) solid loading under the same conditions, the ethanol concentration increased to 42.53 g/L but the ethanol yield decreased to 84.99%. In addition, an increase in the solid loading up to a certain point led to an increase in the ethanol concentration from 1.5 mL GL/g-DS-pretreated SCB. The highest ethanol concentration (68.24 g/L) was obtained with 15% (w/v) solid loading, using a CSC-to-TSC yeast cell mass ratio of 1:3 (w/w). GL-Ethanol pretreatment is a promising pretreatment method for improving both glucan and xylan conversion efficiencies of SCB. There was a competitive relationship between the two yeast strains, and the glucose and xylose utilization ability of the TSC was better than that of the CSC. Ethanol concentration was obviously increased at high solid loading, but the yield decreased as a result of an increase in the viscosity and inhibitor levels in the fermentation system. Finally, the SSCF of GL-Ethanol-pretreated SCB with mixed S. cerevisiae strains increased ethanol concentration and was an

  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 fuel ethanol from steam-explosion pretreated olive tree pruning

    Energy Technology Data Exchange (ETDEWEB)

    Cristobal Cara; Encarnacion Ruiz; Mercedes Ballesteros; Paloma Manzanares; Ma Jose Negro; Eulogio Castro [University of Jaen, Jaen (Spain). Department of Chemical, Environmental and Materials Engineering

    2008-05-15

    This work deals with the production of fuel ethanol from olive tree pruning. This raw material is a renewable, low cost, largely available, and lacking of economic alternatives agricultural residue. Olive tree pruning was submitted to steam explosion pre-treatment in the temperature range 190-240{sup o}C, with or without previous impregnation by water or sulphuric acid solutions. The influence of both pre-treatment temperature and impregnation conditions on sugar and ethanol yields was investigated by enzymatic hydrolysis and simultaneous saccharification and fermentation on the pretreated solids. Results show that the maximum ethanol yield (7.2 g ethanol/100 g raw material) is obtained from water impregnated, steam pretreated residue at 240{sup o}C. Nevertheless if all sugars solubilized during pre-treatment are taken into account, up to 15.9 g ethanol/100 g raw material may be obtained (pre-treatment conditions: 230{sup o}C and impregnation with 1% w/w sulphuric acid concentration), assuming theoretical conversion of these sugars to ethanol. 29 refs., 2 figs., 5 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-04-01

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

  20. Ethanol production from biodiesel-derived crude glycerol by newly isolated Kluyvera cryocrescens

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Won Jae; Hartono, Maria Regina; Chan, Weng Heng; Yeo, Suan Siong [Agency for Science, Technology and Research (A*STAR), Jurong Island (Singapore). Inst. of Chemical and Engineering Sciences

    2011-02-15

    The rapidly expanding market for biodiesel has increased the supply and reduced the cost of glycerol, making it an attractive sustainable feed stock for the fuel and chemical industry. Glycerol-based biorefinery is the microbial fermentation of crude glycerol to produce fuels and chemicals. A major challenge is to obtain microbes tolerant to inhibitors such as salts and organic solvents present in crude glycerol. Microbial screening was attempted to isolate novel strain capable of growing on crude glycerol as a sole carbon source. The newly isolated bacteria, identified as nonpathogenic Kluyvera cryocrescens S26 could convert biodiesel-derived crude glycerol to ethanol with high yield and productivity. The supplementation of nutrients such as yeast extract resulted in distinguished enhancement in cell growth as well as ethanol productivity under anaerobic condition. When glycerol fermentation is performed under microaerobic condition, there is also a remarkable improvement in cell growth, ethanol productivity and yield, compared with those under strict anaerobic condition. In batch fermentation under microaerobic condition, K. cryocrescens S26 produced 27 g/l of ethanol from crude glycerol with high molar yield of 80% and productivity of 0.61 g/l/h. (orig.)

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

    Science.gov (United States)

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

    2016-07-01

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

  2. 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.

  3. 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...

  4. Direct ethanol production from starch, wheat bran and rice straw by the white rot fungus Trametes hirsuta.

    Science.gov (United States)

    Okamoto, Kenji; Nitta, Yasuyuki; Maekawa, Nitaro; Yanase, Hideshi

    2011-03-07

    The white rot fungus Trametes hirsuta produced ethanol from a variety of hexoses: glucose, mannose, cellobiose and maltose, with yields of 0.49, 0.48, 0.47 and 0.47 g/g of ethanol per sugar utilized, respectively. In addition, this fungus showed relatively favorable xylose consumption and ethanol production with a yield of 0.44 g/g. T. hirsuta was capable of directly fermenting starch, wheat bran and rice straw to ethanol without acid or enzymatic hydrolysis. Maximum ethanol concentrations of 9.1, 4.3 and 3.0 g/l, corresponding to 89.2%, 78.8% and 57.4% of the theoretical yield, were obtained when the fungus was grown in a medium containing 20 g/l starch, wheat bran or rice straw, respectively. The fermentation of rice straw pretreated with ball milling led to a small improvement in the ethanol yield: 3.4 g ethanol/20 g ball-milled rice straw. As T. hirsuta is an efficient microorganism capable of hydrolyzing biomass to fermentable sugars and directly converting them to ethanol, it may represent a suitable microorganism in consolidated bioprocessing applications. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Yeast metabolic engineering for hemicellulosic ethanol production

    Science.gov (United States)

    Jennifer Van Vleet; Thomas W. Jeffries

    2009-01-01

    Efficient fermentation of hemicellulosic sugars is critical for the bioconversion of lignocellulosics to ethanol. Efficient sugar uptake through the heterologous expression of yeast and fungal xylose/glucose transporters can improve fermentation if other metabolic steps are not rate limiting. Rectification of cofactor imbalances through heterologous expression of...

  6. High Titer Ethanol and Lignosulfonate Production from SPORL Pretreated Poplar at Pilot Scale

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Haifeng [Key Laboratory of Low Carbon Energy and Chemical Engineering, Shandong University of Science and Technology, Qingdao (China); Forest Products Laboratory, USDA Forest Service, Madison, WI (United States); Zhu, J. Y., E-mail: jzhu@fs.fed.us; Gleisner, Roland [Forest Products Laboratory, USDA Forest Service, Madison, WI (United States); Qiu, Xueqing [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Horn, Eric [BioPulping International, Inc., Madison, WI (United States)

    2015-04-27

    Poplar NE222 (Populus deltoides Bartr. ex Marsh × P. nigra L.) wood chips were pretreated in a 390 L pilot-scale rotating wood-pulping digester using a dilute sulfite solution of approximately pH 1.8 at 160°C for 40 min for bioconversion to ethanol and lignosulfonate (LS). An estimated combined hydrolysis factor (CHF) of 3.3 was used to scale the sulfite pretreatment temperature and time from laboratory bench scale experiments, which balanced sugar yield and inhibitor formation to facilitate high titer ethanol production through fermentation using S. cerevisiae YRH400 without detoxification. A terminal ethanol titer of 43.6 g L{sup -1} with a yield of 247 L tonne wood{sup -1} was achieved at total solids loading of 20%. The relatively low ethanol yield compared with yield from Sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL)-pretreated softwoods was due to inefficient utilization of xylose. The LS from SPORL has a substantially higher phenolic group (Ph-OH) content, though it was less sulfonated and had a lower molecular weight than a purified commercial softwood LS, and therefore has potential for certain commercial markets and future novel applications through further processing. The conversion efficiency achieved through process integration and simplification, demonstrated here, has significant importance to the entire supply chain of biofuel production from woody biomass.

  7. Process analysis and optimization of simultaneous saccharification and co-fermentation of ethylenediamine-pretreated corn stover for ethanol production.

    Science.gov (United States)

    Qin, Lei; Zhao, Xiong; Li, Wen-Chao; Zhu, Jia-Qing; Liu, Li; Li, Bing-Zhi; Yuan, Ying-Jin

    2018-01-01

    Improving ethanol concentration and reducing enzyme dosage are main challenges in bioethanol refinery from lignocellulosic biomass. Ethylenediamine (EDA) pretreatment is a novel method to improve enzymatic digestibility of lignocellulose. In this study, simultaneous saccharification and co-fermentation (SSCF) process using EDA-pretreated corn stover was analyzed and optimized to verify the constraint factors on ethanol production. Highest ethanol concentration was achieved with the following optimized SSCF conditions at 6% glucan loading: 12-h pre-hydrolysis, 34 °C, pH 5.4, and inoculum size of 5 g dry cell/L. As glucan loading increased from 6 to 9%, ethanol concentration increased from 33.8 to 48.0 g/L, while ethanol yield reduced by 7%. Mass balance of SSCF showed that the reduction of ethanol yield with the increasing solid loading was mainly due to the decrease of glucan enzymatic conversion and xylose metabolism of the strain. Tween 20 and BSA increased ethanol concentration through enhancing enzymatic efficiency. The solid-recycled SSCF process reduced enzyme dosage by 40% (from 20 to 12 mg protein/g glucan) to achieve the similar ethanol concentration (~ 40 g/L) comparing to conventional SSCF. Here, we established an efficient SSCF procedure using EDA-pretreated biomass. Glucose enzymatic yield and yeast viability were regarded as the key factors affecting ethanol production at high solid loading. The extensive analysis of SSCF would be constructive to overcome the bottlenecks and improve ethanol production in cellulosic ethanol refinery.

  8. 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.

  9. 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.

  10. 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.

  11. Ethanol production from glucose and xylose by immobilized Thermoanaerobacter pentosaceus at 70 °C in an up-flow anaerobic sludge blanket (UASB) reactor

    DEFF Research Database (Denmark)

    Sittijunda, Sureewan; Tomás, Ana Faria; Reungsang, Alissara

    2013-01-01

    The newly isolated extreme thermophilic ethanologen Thermoanaerobacter pentosaceus was immobilized in different support materials in order to improve its ethanol production ability. In batch fermentation, a maximum ethanol yield of 1.36 mol mol-1 consumed sugars was obtained by T. pentosaceus...... occurred at an HRT of 6 h. The maximum ethanol yield and concentration, 1.50 mol mol-1 consumed sugars and 12.4 g l-1, were obtained with an HRT of 12 h. The latter represented an improvement of 60 % in relation to previously obtained results. This indicates that immobilization of T. pentosaceus...... immobilized on rapeseed straw. Additionally, immobilized T. pentosaceus’ ethanol production was improved by 11 % in comparison to free cells. In continuous mode, it was shown that hydraulic retention time (HRT) affected ethanol yield, and a dramatic shift from ethanol to acetate and lactate production...

  12. 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.

  13. Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae and Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Shuvashish; Mohanty, Rama Chandra [Department of Botany, Utkal University, Vanivihar, Bhubaneswar 751004, Orissa (India); Ray, Ramesh Chandra [Microbiology Laboratory, Central Tuber Crops Research Institute (Regional Centre), Bhubaneswar 751019, Orissa (India)

    2010-07-15

    Mahula (Madhuca latifolia L.) flower is a suitable alternative cheaper carbohydrate source for production of bio-ethanol. Recent production of bio-ethanol by microbial fermentation as an alternative energy source has renewed research interest because of the increase in the fuel price. Saccharomyces cerevisiae (yeast) and Zymomonas mobilis (bacteria) are two most widely used microorganisms for ethanol production. In this study, experiments were carried out to compare the potential of the yeast S. cerevisiae (CTCRI strain) with the bacterium Z. mobilis (MTCC 92) for ethanol fermentation from mahula flowers. The ethanol production after 96 h fermentation was 149 and 122.9 g kg{sup -1} flowers using free cells of S. cerevisiae and Z. mobilis, respectively. The S. cerevisiae strain showed 21.2% more final ethanol production in comparison to Z. mobilis. Ethanol yield (Yx/s), volumetric product productivity (Qp), sugar to ethanol conversion rate (%) and microbial biomass concentration (X) obtained by S. cerevisiae were found to be 5.2%, 21.1%, 5.27% and 134% higher than Z. mobilis, respectively after 96 h of fermentation. (author)

  14. Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae and Zymomonas mobilis

    International Nuclear Information System (INIS)

    Behera, Shuvashish; Mohanty, Rama Chandra; Ray, Ramesh Chandra

    2010-01-01

    Mahula (Madhuca latifolia L.) flower is a suitable alternative cheaper carbohydrate source for production of bio-ethanol. Recent production of bio-ethanol by microbial fermentation as an alternative energy source has renewed research interest because of the increase in the fuel price. Saccharomyces cerevisiae (yeast) and Zymomonas mobilis (bacteria) are two most widely used microorganisms for ethanol production. In this study, experiments were carried out to compare the potential of the yeast S. cerevisiae (CTCRI strain) with the bacterium Z. mobilis (MTCC 92) for ethanol fermentation from mahula flowers. The ethanol production after 96 h fermentation was 149 and 122.9 g kg -1 flowers using free cells of S. cerevisiae and Z. mobilis, respectively. The S. cerevisiae strain showed 21.2% more final ethanol production in comparison to Z. mobilis. Ethanol yield (Yx/s), volumetric product productivity (Qp), sugar to ethanol conversion rate (%) and microbial biomass concentration (X) obtained by S. cerevisiae were found to be 5.2%, 21.1%, 5.27% and 134% higher than Z. mobilis, respectively after 96 h of fermentation. (author)

  15. Metabolic engineering to improve ethanol production in Thermoanaerobacter mathranii

    DEFF Research Database (Denmark)

    Yao, Shuo; Mikkelsen, Marie Just

    2010-01-01

    acquired the capability to utilize glycerol as an extra carbon source in the presence of xylose, and utilization of the more reduced substrate glycerol resulted in a higher ethanol yield. Electronic supplementary material The online version of this article (doi:10.1007/s00253-010-2703-3) contains...

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

    African Journals Online (AJOL)

    Sweet sorghum (sugar sorghum, Sorghum bicolor) is one kind of non-grain energy crops. As a novel green regenerated high-energy crop with high utility value, high yield of biomass, the sweet sorghum is widely used and developed in China. Stalk juice of sweet sorghum was used as the main substrate for ethanol ...

  17. 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.

  18. Ethanol production by extractive fermentation - Process development and technology transfer

    International Nuclear Information System (INIS)

    Daugulis, A.J.; Axford, D.B.; Mau, T.K.

    1991-01-01

    Extractive Fermentation is an ethanol processing strategy in which the operations of fermentation and product recovery are integrated and undertaken simultaneously in a single step. In this process an inert and biocompatible organic solvent is introduced directly into the fermentation vessel to selectively extract the ethanol product. The ethanol is readily recovered from the solvent at high concentration by means of flash vaporization, and the solvent is recycled in a closed loop back to the fermentor. This process is characterized by a high productivity (since ethanol does not build up to inhibitory levels), continuous operation, significantly reduced water consumption, and lower product recovery costs. The technical advantages of this processing strategy have been extensively demonstrated by means of a continuous, fully integrated and computer-controlled Process Demonstration Unit in the authors' laboratory. Numerous features of this technology have been protected by US patent. A thorough economic comparison of Extractive Fermentation relative to modern ethanol technology (continuous with cell recycle) has been completed for both new plants and retrofitting of existing facilities for a capacity of 100 million liters of ethanol per year. Substantial cost savings are possible with Extractive Fermentation ranging, depending on the process configuration, from 5 cents to 16 cents per liter. Activities are under way to transfer this proprietary technology to the private sector

  19. Ethanol and methanol can improve huperzine A production from endophytic Colletotrichum gloeosporioides ES026.

    Science.gov (United States)

    Zhao, Xin-Mei; Wang, Zhang-Qian; Shu, Shao-Hua; Wang, Wen-Juan; Xu, Hai-Jie; Ahn, Young-Joon; Wang, Mo; Hu, Xuebo

    2013-01-01

    Huperzine A (HupA) is a plant alkaloid that is of great interest as a therapeutic candidate for the treatment of Alzheimer's disease. However, the current production of HupA from plants in large quantity is unsustainable because the plant resource is scarce and the content of HupA in plants is extremely low. Surprisingly, this compound was recently found to be produced by various endophytic fungi, which are much more controllable than the plants due to simpler genetics and ease of manipulation. However, it might be due to the innate properties of endophytic symbiosis, that production of this chemical in large quantity from endophytes has not yet been put into practice. Endophytic Colletotrichum gloeosporioides ES026 was previously isolated from a HupA producing plant and the fungi also proved to produce HupA. In this study, various fermentation conditions were tried to optimize the production of HupA from C. gloeosporioides ES026. Optimization of these parameters resulted in a 25.58% increase in HupA yield. Potato extracts supplemented with glucose or sucrose but not maltose facilitated HupA producing from the fungi. A final concentration of 0.5-2% ethanol stimulated the growth of fungi while methanol with the same treatment slightly inhibited the growth. However, both methanol and ethanol greatly increased the HupA production with the highest yield of HupA (51.89% increment) coming from ethanol treatment. Further analysis showed that both ethanol and methanol were strong inducers of HupA production, while ethanol was partially used as a carbon source during fermentation. It was noticed that the color of that ethanol treated mycelia gradually became dark while methanol treated ones stayed grey during fermentation. The present study sheds light on the importance of optimizing the fermentation process, which, combined with effective inducers, maximizes production of chemicals of important economic interest from endophytic fungi.

  20. Ethanol and methanol can improve huperzine A production from endophytic Colletotrichum gloeosporioides ES026.

    Directory of Open Access Journals (Sweden)

    Xin-Mei Zhao

    Full Text Available Huperzine A (HupA is a plant alkaloid that is of great interest as a therapeutic candidate for the treatment of Alzheimer's disease. However, the current production of HupA from plants in large quantity is unsustainable because the plant resource is scarce and the content of HupA in plants is extremely low. Surprisingly, this compound was recently found to be produced by various endophytic fungi, which are much more controllable than the plants due to simpler genetics and ease of manipulation. However, it might be due to the innate properties of endophytic symbiosis, that production of this chemical in large quantity from endophytes has not yet been put into practice. Endophytic Colletotrichum gloeosporioides ES026 was previously isolated from a HupA producing plant and the fungi also proved to produce HupA. In this study, various fermentation conditions were tried to optimize the production of HupA from C. gloeosporioides ES026. Optimization of these parameters resulted in a 25.58% increase in HupA yield. Potato extracts supplemented with glucose or sucrose but not maltose facilitated HupA producing from the fungi. A final concentration of 0.5-2% ethanol stimulated the growth of fungi while methanol with the same treatment slightly inhibited the growth. However, both methanol and ethanol greatly increased the HupA production with the highest yield of HupA (51.89% increment coming from ethanol treatment. Further analysis showed that both ethanol and methanol were strong inducers of HupA production, while ethanol was partially used as a carbon source during fermentation. It was noticed that the color of that ethanol treated mycelia gradually became dark while methanol treated ones stayed grey during fermentation. The present study sheds light on the importance of optimizing the fermentation process, which, combined with effective inducers, maximizes production of chemicals of important economic interest from endophytic fungi.

  1. Yeast flocculation: New story in fuel ethanol production.

    Science.gov (United States)

    Zhao, X Q; Bai, F W

    2009-01-01

    Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

  2. Enhanced enzymatic hydrolysis and ethanol production from cashew apple bagasse pretreated with alkaline hydrogen peroxide.

    Science.gov (United States)

    da Costa, Jessyca Aline; Marques, José Edvan; Gonçalves, Luciana Rocha Barros; Rocha, Maria Valderez Ponte

    2015-03-01

    The effect of combinations and ratios between different enzymes has been investigated in order to assess the optimal conditions for hydrolysis of cashew apple bagasse pretreated with alkaline hydrogen peroxide (the solids named CAB-AHP). The separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes were evaluated in the ethanol production. The enzymatic hydrolysis conducted with cellulase complex and β-glucosidase in a ratio of 0.61:0.39, enzyme loading of 30FPU/g(CAB-AHP) and 66CBU/g(CAB-AHP), respectively, using 4% cellulose from CAB-AHP, turned out to be the most effective conditions, with glucose and xylose yields of 511.68 mg/g(CAB-AHP) and 237.8 mg/g(CAB-AHP), respectively. Fermentation of the pure hydrolysate by Kluyveromyces marxianus ATCC 36907 led to an ethanol yield of 61.8kg/ton(CAB), corresponding to 15 g/L ethanol and productivity of 3.75 g/( Lh). The ethanol production obtained for SSF process using K. marxianus ATCC 36907 was 18 g/L corresponding to 80% yield and 74.2kg/ton(CAB). Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Life cycle assessment of sugarcane ethanol and palm oil biodiesel joint production

    International Nuclear Information System (INIS)

    Souza, Simone Pereira; Turra de Ávila, Márcio; Pacca, Sérgio

    2012-01-01

    Sugarcane (Saccharum spp.) and palm tree (Elaeis guianeensis) are crops with high biofuel yields, 7.6 m 3 ha −1 y −1 of ethanol and 4 Mg ha −1 y −1 of oil, respectively. The joint production of these crops enhances the sustainability of ethanol. The objective of this work was comparing a traditional sugarcane ethanol production system (TSES) with a joint production system (JSEB), in which ethanol and biodiesel are produced at the same biorefinery but only ethanol is traded. The comparison is based on ISO 14.040:2006 and ISO 14044:2006, and appropriate indicators. Production systems in Cerrado (typical savannah), Cerradão (woody savannah) and pastureland ecosystems were considered. Energy and carbon balances, and land use change impacts were evaluated. The joint system includes 100% substitution of biodiesel for diesel, which is all consumed in different cropping stages. Data were collected by direct field observation methods, and questionnaires applied to Brazilian facilities. Three sugarcane mills situated in São Paulo State and one palm oil refinery located in Para State were surveyed. The information was supplemented by secondary sources. Results demonstrated that fossil fuel use and greenhouse gas emissions decreased, whereas energy efficiency increased when JSEB was compared to TSES. In comparison with TSES, the energy balance of JSEB was 1.7 greater. In addition, JSEB released 23% fewer GHG emissions than TSES. The ecosystem carbon payback time for Cerrado, Cerradão, and Degraded Grassland of JSEB was respectively 4, 7.7 and −7.6 years. These are typical land use types of the Brazilian Cerrado region for which JSEB was conceived. -- Highlights: ► LCA of ethanol and biodiesel joint production system. ► Sugarcane based biorefinery assessment in Brazil. ► Original Brazilian LCI data on ethanol and palm oil biodiesel production. ► Biofuel LCA with LUC sensitivity analisis for the Brazilian Cerrado Region.

  4. Direct ethanol production from lignocellulosic sugars and sugarcane bagasse by a recombinant Trichoderma reesei strain HJ48.

    Science.gov (United States)

    Huang, Jun; Chen, Dong; Wei, Yutuo; Wang, Qingyan; Li, Zhenchong; Chen, Ying; Huang, Ribo

    2014-01-01

    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.

  5. Methods for high yield production of terpenes

    Energy Technology Data Exchange (ETDEWEB)

    Kutchan, Toni; Higashi, Yasuhiro; Feng, Xiaohong

    2017-01-03

    Provided are enhanced high yield production systems for producing terpenes in plants via the expression of fusion proteins comprising various combinations of geranyl diphosphate synthase large and small subunits and limonene synthases. Also provided are engineered oilseed plants that accumulate monoterpene and sesquiterpene hydrocarbons in their seeds, as well as methods for producing such plants, providing a system for rapidly engineering oilseed crop production platforms for terpene-based biofuels.

  6. 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.

  7. 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)

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

    International Nuclear Information System (INIS)

    Sorapipatana, Chumnong; Yoosin, Suthamma

    2011-01-01

    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)

  9. Sugar palm (Argena pinnata). Potential of sugar palm for bio-ethanol production

    OpenAIRE

    Elbersen, H.W.; Oyen, L.P.A.

    2010-01-01

    The energetic and economic feasibility of bioethanol production from sugar palm is virtually unknown. A positive factor are the potentially very high yields while the long non-productive juvenile phase and the high labor needs can be seen as problematic. Expansion to large scale sugar palm cultivation comes with risks. Small-scale cultivation of sugar palm perfectly fits into local farming systems. In order to make a proper assessment of the value palm sugar as bio-ethanol crop more informati...

  10. Cultivation and utilization of Jerusalem artichoke for ethanol, single cell protein, and high-fructose syrup production

    Energy Technology Data Exchange (ETDEWEB)

    Bajpai, P.K.; Bajpai, Pratima (Thapar Corporate Research and Development Center, Patiala (IN). Div. of Chemical and Biochemical Engineering)

    1991-04-01

    Jerusalem artichoke has one of the highest carbohydrate yields of the known agricultural crops and has many distinct advantages over traditional crops. This brief review presents data on the yield and composition of Jerusalem artichoke, techniques of carbohydrate extraction and its utilization for the production of ethanol, single cell protein (SCP), and high-fructose syrup, along with economic considerations. (author).

  11. 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

  12. Environmental aspects of eucalyptus based ethanol production and use

    International Nuclear Information System (INIS)

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

    2012-01-01

    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: ► The identification of the environmental implications of the production and use of eucalyptus based ethanol was carried out. ► Eucalyptus is a Spanish common and abundant fast-growing short

  13. Quality and Yield of Cannabis Products

    DEFF Research Database (Denmark)

    Kastorp, Grith; Lindholst, Christian

    2011-01-01

    Abstract. 180 seizures containing 667 different samples of cannabis products from 5 police districts in Jutland were examined from 2008 to the present. The samples were divided into the groups: hashish, marihuana (leaves and buds) and whole plants (indoors and outdoors). Cannabis seized from indoor...... cultivation was examined in order to determine THC content and yield. The results are used by the Danish Police Attorney to estimate expected yields in cases with unripe cannabis plants. The results indicate that the THC content found in locally grown marihuana is slightly higher than in hashish. However...

  14. High titer ethanol and lignosulfonate production from SPORL pretreated poplar at pilot-scale

    Directory of Open Access Journals (Sweden)

    Junyong (J.Y. eZhu

    2015-04-01

    Full Text Available Poplar NE222 (Populus deltoides Bartr. ex Marsh × P. nigra L. wood chips were pretreated in a 390 L pilot-scale rotating wood-pulping digester using a dilute sulfite solution of approximately pH  1.8 at 160°C for 40 min for bioconversion to ethanol and lignosulfonate (LS. An estimated combined hydrolysis factor (CHF of 3.3 was used to scale the pretreatment temperature and time from laboratory bench scale experiments, which balanced sugar yield and inhibitor formation to facilitate high titer ethanol production through fermentation using S. cerevisiae YRH400 without detoxification. A terminal ethanol titer of 43.6 g L-1 with a yield of 247 L tonne wood-1 was achieved at total solids loading of 20%. The relatively low ethanol yield compared with yield from SPORL-pretreated softwoods was due to inefficient utilization of xylose. The LS from SPORL has a substantially higher phenolic group (Ph-OH content although it is less sulfonated and has a lower molecular weight than a purified commercial softwood LS, and therefore has potential for certain commercial markets and future novel applications through further processing.

  15. A lignocellulosic ethanol strategy via nonenzymatic sugar production: process synthesis and analysis.

    Science.gov (United States)

    Han, Jeehoon; Luterbacher, Jeremy S; Alonso, David Martin; Dumesic, James A; Maravelias, Christos T

    2015-04-01

    The work develops a strategy for the production of ethanol from lignocellulosic biomass. In this strategy, the cellulose and hemicellulose fractions are simultaneously converted to sugars using a γ-valerolactone (GVL) solvent containing a dilute acid catalyst. To effectively recover GVL for reuse as solvent and biomass-derived lignin for heat and power generation, separation subsystems, including a novel CO2-based extraction for the separation of sugars from GVL, lignin and humins have been designed. The sugars are co-fermented by yeast to produce ethanol. Furthermore, heat integration to reduce utility requirements is performed. It is shown that this strategy leads to high ethanol yields and the total energy requirements could be satisfied by burning the lignin. The integrated strategy using corn stover feedstock leads to a minimum selling price of $5 per gallon of gasoline equivalent, which suggests that it is a promising alternative to current biofuels production approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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). Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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.

  18. 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)

  19. 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.

  20. 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.

  1. Solving ethanol production problems with genetically modified yeast strains.

    Science.gov (United States)

    Abreu-Cavalheiro, A; Monteiro, G

    2013-01-01

    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.

  2. Enhanced ethanol and glucosamine production from rice husk by NAOH pretreatment and fermentation by fungus Mucor hiemalis

    Directory of Open Access Journals (Sweden)

    Maryam Omidvar

    2016-09-01

    Full Text Available Ethanol production from rice husk by simultaneous saccharification and fermentation using Mucor hiemalis was investigated. To reach the maximum ethanol production yield, the most important influencing factors in the pretreatment process, including temperature (0-100°C, NaOH concentration (1-3 M, and the pretreatment time (30-180 min, were optimized using an experimental design by a response surface methodology (RSM. The maximum ethanol production yield of 86.7 % was obtained after fungal cultivation on the husk pretreated with 2.6 M NaOH at 67°C for 150 min. This was higher than the yield of 57.7% obtained using Saccharomyces cerevisiae as control. Furthermore, fermentation using M. hiemalis under the optimum conditions led to the production of a highly valuable fungal biomass, containing 60 g glucosamine (GlcN, 410 g protein, and 160 g fungal oil per each kg of the fungal biomass.

  3. Deletion of the hfsB gene increases ethanol production in Thermoanaerobacterium saccharolyticum and several other thermophilic anaerobic bacteria.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Murphy, Sean Jean-Loup; Maloney, Marybeth; Lanahan, Anthony; Giannone, Richard J; Hettich, Robert L; Tripathi, Shital A; Beldüz, Ali Osman; Lynd, Lee R; Olson, Daniel G

    2017-01-01

    With the discovery of interspecies hydrogen transfer in the late 1960s (Bryant et al. in Arch Microbiol 59:20-31, 1967), it was shown that reducing the partial pressure of hydrogen could cause mixed acid fermenting organisms to produce acetate at the expense of ethanol. Hydrogen and ethanol are both more reduced than glucose. Thus there is a tradeoff between production of these compounds imposed by electron balancing requirements; however, the mechanism is not fully known. Deletion of the hfsA or B subunits resulted in a roughly 1.8-fold increase in ethanol yield. The increase in ethanol production appears to be associated with an increase in alcohol dehydrogenase activity, which appears to be due, at least in part, to increased expression of the adhE gene, and may suggest a regulatory linkage between hfsB and adhE . We studied this system most intensively in the organism Thermoanaerobacterium saccharolyticum ; however, deletion of hfsB also increases ethanol production in other thermophilic bacteria suggesting that this could be used as a general technique for engineering thermophilic bacteria for improved ethanol production in organisms with hfs -type hydrogenases. Since its discovery by Shaw et al. (JAMA 191:6457-64, 2009), the hfs hydrogenase has been suspected to act as a regulator due to the presence of a PAS domain. We provide additional support for the presence of a regulatory phenomenon. In addition, we find a practical application for this scientific insight, namely increasing ethanol yield in strains that are of interest for ethanol production from cellulose or hemicellulose. In two of these organisms ( T. xylanolyticum and T. thermosaccharolyticum ), the ethanol yields are the highest reported to date.

  4. The role of stress mediators in modulation of cytokine production by ethanol

    International Nuclear Information System (INIS)

    Glover, Mitzi; Cheng Bing; Fan Ruping; Pruett, Stephen

    2009-01-01

    Acute ethanol exposure in humans and in animal models activates the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS); the resultant increases in concentration of neuroendocrine mediators contribute to some of the immunosuppressive effects of ethanol. However, the role of these mediators in the ethanol-induced inhibition of inflammatory responses is not clear. This is complicated by the fact that most inflammatory stimuli also activate the HPA axis and SNS, and it has not been determined if ethanol plus an inflammatory stimulus increases these stress responses. Addressing this issue is the major focus of the study described herein. Complementary approaches were used, including quantitative assessment of the stress response in mice treated with polyinosinic-polycytidylic acid (poly I:C, as an inflammatory stimulus) and inhibition of the production or action of key HPA axis and SNS mediators. Treatment of mice with ethanol shortly before treatment with poly I:C yielded a significant increase in the corticosterone response as compared to the response to poly I:C alone, but the increase was small and not likely sufficient to account for the anti-inflammatory effects of ethanol. Inhibition of catecholamine and glucocorticoid production by adrenalectomy, and inhibition of catecholamine action with a sustained release antagonist (nadalol) supported this conclusion and revealed that 'excess' stress responses associated with ethanol treatment is not the mechanism of suppression of pro-inflammatory cytokine production, but stress-induced corticosterone does regulate production of several of these cytokines, which has not previously been reported.

  5. The role of stress mediators in modulation of cytokine production by ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Mitzi; Bing, Cheng; Ruping, Fan [LSU Health Sciences Center, Department of Cellular Biology and Anatomy, Shreveport, LA 71130 (United States); Pruett, Stephen [LSU Health Sciences Center, Department of Cellular Biology and Anatomy, Shreveport, LA 71130 (United States); Mississippi State University College of Veterinary Medicine, Department of Basic Sciences, P.O. Box 6100, Mississippi State, MS 39762-6100 (United States)], E-mail: pruett@cvm.msstate.edu

    2009-08-15

    Acute ethanol exposure in humans and in animal models activates the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS); the resultant increases in concentration of neuroendocrine mediators contribute to some of the immunosuppressive effects of ethanol. However, the role of these mediators in the ethanol-induced inhibition of inflammatory responses is not clear. This is complicated by the fact that most inflammatory stimuli also activate the HPA axis and SNS, and it has not been determined if ethanol plus an inflammatory stimulus increases these stress responses. Addressing this issue is the major focus of the study described herein. Complementary approaches were used, including quantitative assessment of the stress response in mice treated with polyinosinic-polycytidylic acid (poly I:C, as an inflammatory stimulus) and inhibition of the production or action of key HPA axis and SNS mediators. Treatment of mice with ethanol shortly before treatment with poly I:C yielded a significant increase in the corticosterone response as compared to the response to poly I:C alone, but the increase was small and not likely sufficient to account for the anti-inflammatory effects of ethanol. Inhibition of catecholamine and glucocorticoid production by adrenalectomy, and inhibition of catecholamine action with a sustained release antagonist (nadalol) supported this conclusion and revealed that 'excess' stress responses associated with ethanol treatment is not the mechanism of suppression of pro-inflammatory cytokine production, but stress-induced corticosterone does regulate production of several of these cytokines, which has not previously been reported.

  6. 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.

  7. Analysis of ethanol production potential from cellulosic feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Stone, J E

    1982-03-01

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

  8. Effect of Furfural on Saccharomyces carlsbergensis Growth, Physiology and Ethanol Production.

    Science.gov (United States)

    Lopes da Silva, Teresa; Santo, Rui; Reis, Alberto; Passarinho, Paula C

    2017-06-01

    This work described the effect of furfural, a product resulting from the lignocellulosic material pretreatment, on Saccharomyces carlsbergensis growth and ethanol production. Flow cytometry was used to evaluate the yeast membrane potential, membrane integrity, reactive oxygen species production and lipid content. Above 0.3 g/L of furfural, a progressive decrease in the maximal specific growth rate was observed, reaching 53% of the value obtained in the absence of toxic when the cells were grown in the presence of 4 g/L of furfural. In general, the yeast biomass concentration and yield were less affected by the furfural presence than the specific growth rate, and a maximum reduction of 25% was observed for the assay at 4 g/L. The ethanol production was even less affected by the furfural presence than the yeast growth. At 4 g/L of furfural, the maximum ethanol concentration was reduced by only 10% relatively to the maximum ethanol concentration observed in the absence of toxic. At 5 g/L of furfural, the yeast cells were barely able to keep metabolic functions and produced a final ethanol concentration of 0.87 g/L although growth was undetectable. S. carlsbergensis membrane potential was affected by the furfural presence, concomitantly with the ethanol production. However, at 4 g/L, most of the yeast cells (90%) displayed the cytoplasmic membrane depolarized. The proportion of cells with increasing reactive oxygen species (ROS) production levels increased for the experiments at 0-4 g/L. For the experiment at 4.5 g/L of furfural, ROS production was observed for only 11% of the yeast cells. The yeast lipid content was also severely affected by the furfural presence. Both polar and neutral lipids decreased in the presence of furfural, and this reduction was more notorious during the stationary phase.

  9. Water consumption in the production of ethanol and petroleum gasoline.

    Science.gov (United States)

    Wu, May; Mintz, Marianne; Wang, Michael; Arora, Salil

    2009-11-01

    We assessed current water consumption during liquid fuel production, evaluating major steps of fuel lifecycle for five fuel pathways: bioethanol from corn, bioethanol from cellulosic feedstocks, gasoline from U.S. conventional crude obtained from onshore wells, gasoline from Saudi Arabian crude, and gasoline from Canadian oil sands. Our analysis revealed that the amount of irrigation water used to grow biofuel feedstocks varies significantly from one region to another and that water consumption for biofuel production varies with processing technology. In oil exploration and production, water consumption depends on the source and location of crude, the recovery technology, and the amount of produced water re-injected for oil recovery. Our results also indicate that crop irrigation is the most important factor determining water consumption in the production of corn ethanol. Nearly 70% of U.S. corn used for ethanol is produced in regions where 10-17 liters of water are consumed to produce one liter of ethanol. Ethanol production plants are less water intensive and there is a downward trend in water consumption. Water requirements for switchgrass ethanol production vary from 1.9 to 9.8 liters for each liter of ethanol produced. We found that water is consumed at a rate of 2.8-6.6 liters for each liter of gasoline produced for more than 90% of crude oil obtained from conventional onshore sources in the U.S. and more than half of crude oil imported from Saudi Arabia. For more than 55% of crude oil from Canadian oil sands, about 5.2 liters of water are consumed for each liter of gasoline produced. Our analysis highlighted the vital importance of water management during the feedstock production and conversion stage of the fuel lifecycle.

  10. 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.

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

    Science.gov (United States)

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

    2016-04-01

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

  12. Improved Ethanol Production from Xylose by Candida shehatae Induced by Dielectric Barrier Discharge Air Plasma

    International Nuclear Information System (INIS)

    Chen Huixia; Xiu Zhilong; Bai Fengwu

    2014-01-01

    Xylose fermentation is essential for ethanol production from lignocellulosic biomass. Exposure of the xylose-fermenting yeast Candida shehatae (C. shehatae) CICC1766 to atmospheric pressure dielectric barrier discharge (DBD) air plasma yields a clone (designated as C81015) with stability, which exhibits a higher ethanol fermentation rate from xylose, giving a maximal enhancement in ethanol production of 36.2% compared to the control (untreated). However, the biomass production of C81015 is lower than that of the control. Analysis of the NADH (nicotinamide adenine dinucleotide)- and NADPH (nicotinamide adenine dinucleotide phosphate)-linked xylose reductases and NAD + -linked xylitol dehydrogenase indicates that their activities are enhanced by 34.1%, 61.5% and 66.3%, respectively, suggesting that the activities of these three enzymes are responsible for improving ethanol fermentation in C81015 with xylose as a substrate. The results of this study show that DBD air plasma could serve as a novel and effective means of generating microbial strains that can better use xylose for ethanol fermentation

  13. 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.

  14. Improved Ethanol Production from Xylose by Candida shehatae Induced by Dielectric Barrier Discharge Air Plasma

    Science.gov (United States)

    Chen, Huixia; Xiu, Zhilong; Bai, Fengwu

    2014-06-01

    Xylose fermentation is essential for ethanol production from lignocellulosic biomass. Exposure of the xylose-fermenting yeast Candida shehatae (C. shehatae) CICC1766 to atmospheric pressure dielectric barrier discharge (DBD) air plasma yields a clone (designated as C81015) with stability, which exhibits a higher ethanol fermentation rate from xylose, giving a maximal enhancement in ethanol production of 36.2% compared to the control (untreated). However, the biomass production of C81015 is lower than that of the control. Analysis of the NADH (nicotinamide adenine dinucleotide)- and NADPH (nicotinamide adenine dinucleotide phosphate)-linked xylose reductases and NAD+-linked xylitol dehydrogenase indicates that their activities are enhanced by 34.1%, 61.5% and 66.3%, respectively, suggesting that the activities of these three enzymes are responsible for improving ethanol fermentation in C81015 with xylose as a substrate. The results of this study show that DBD air plasma could serve as a novel and effective means of generating microbial strains that can better use xylose for ethanol fermentation.

  15. Energy and GHG balances of ethanol production from cane molasses in Indonesia

    International Nuclear Information System (INIS)

    Khatiwada, Dilip; Venkata, Bharadwaj K.; Silveira, Semida; Johnson, Francis X.

    2016-01-01

    Highlights: • This study performs LCA analysis of sugarcane-based bioethanol production. • Energy and GHG balances are evaluated in the entire production chain. • Sensitivity analysis is performed to identify key influencing parameters. • Efficient cogeneration and biogas recovery enhances energy and climate gains. • Results of LCA studies and issues related to land use change impact are discussed. - Abstract: This study analyses the sustainability of fuel ethanol production from cane molasses in Indonesia. Life cycle assessment (LCA) is performed to evaluate the net emissions (climate change impact) and energy inputs (resource consumption) in the production chain. The lifecycle greenhouse gas (GHG) emissions in the production and use of ethanol are estimated at 29 gCO 2eq per MJ of ethanol produced which is a 67% reduction in comparison to gasoline emissions. Net Energy Value (NEV) and Net Renewable Energy Value (NREV) are −7 MJ/l and 17.7 MJ/l, while the energy yield ratio (ER) is 6.1. Economic allocation is chosen for dividing environmental burdens and resource consumption between sugar (i.e. main product) and molasses (i.e. co-product used for fuel production). Sensitivity analysis of various parameters is performed. The emissions and energy values are highly sensitive to sugarcane yield, ethanol yield, and the price of molasses. The use of sugarcane biomass residues (bagasse/trash) for efficient cogeneration, and different waste management options for the treatment of spent wash (effluent of distilleries) are also explored. Surplus bioelectricity generation in the efficient cogeneration plant, biogas recovery from wastewater treatment plant, and their use for fossil fuel substitution can help improve energy and environmental gains. The study also compares important results with other relevant international studies and discusses issues related to land use change (LUC) impact.

  16. Optimization and Scale-Up of Coffee Mucilage Fermentation for Ethanol Production

    Directory of Open Access Journals (Sweden)

    David Orrego

    2018-03-01

    Full Text Available Coffee, one of the most popular food commodities and beverage ingredients worldwide, is considered as a potential source for food industry and second-generation biofuel due to its various by-products, including mucilage, husk, skin (pericarp, parchment, silver-skin, and pulp, which can be produced during the manufacturing process. A number of research studies have mainly investigated the valuable properties of brewed coffee (namely, beverage, functionalities, and its beneficial effects on cognitive and physical performances; however, other residual by-products of coffee, such as its mucilage, have rarely been studied. In this manuscript, the production of bioethanol from mucilage was performed both in shake flasks and 5 L bio-reactors. The use of coffee mucilage provided adequate fermentable sugars, primarily glucose with additional nutrient components, and it was directly fermented into ethanol using a Saccharomyces cerevisiae strain. The initial tests at the lab scale were evaluated using a two-level factorial experimental design, and the resulting optimal conditions were applied to further tests at the 5 L bio-reactor for scale up. The highest yields of flasks and 5 L bio-reactors were 0.46 g ethanol/g sugars, and 0.47 g ethanol/g sugars after 12 h, respectively, which were equal to 90% and 94% of the theoretically achievable conversion yield of ethanol.

  17. Production of sorbitol and ethanol from Jerusalem artichokes by Saccharomyces cerevisiae ATCC 36859

    Energy Technology Data Exchange (ETDEWEB)

    Duvnjak, Z.; Duan, Z.D. (Ottawa Univ., ON (Canada). Dept. of Chemical Engineering); Turcotte, G. (Acadia Univ., Wolfville, NS (Canada). Dept. of Food Science)

    1991-09-01

    This study shows the possible use of Jerusalem artichokes for the production of sorbitol and ethanol by Saccharomyces cerevisiae ATCC 36859. Ethanol was produced from the beginning of the process, while sorbitol production started after glucose had been entirely consumed from Jerusalem artichoke (J.a.) juice. The importance of yeast extract and inoculum concentrations on the production of sorbitol from the above raw material was demonstrated. With a low initial biomass concentration sorbitol was not produced in pure J.a. juice. When the juice was supplemented with 3% yeast extract, the concentration of sorbitol was 4.6%. The sorbitol, ethanol and biomass yields (gram of product produced per gram of sugars consumed) were 0.259, 0.160 and 0.071 at the end of the process respectively. Adding glucose to increase its concentration to about 9% in the J.a. juice with 3% yeast extract had a positive effect on the production of ethanol, while commencement of the production of sorbitol was delayed and its final concentration was less than 50% of its concentration in the medium without added glucose. The effect of glucose was much stronger when it was added during the process than when added at the beginning of the process. (orig.).

  18. 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.

  19. Insights from the Fungus Fusarium oxysporum Point to High Affinity Glucose Transporters as Targets for Enhancing Ethanol Production from Lignocellulose

    Science.gov (United States)

    Ali, Shahin S.; Nugent, Brian; Mullins, Ewen; Doohan, Fiona M.

    2013-01-01

    Ethanol is the most-widely used biofuel in the world today. Lignocellulosic plant biomass derived from agricultural residue can be converted to ethanol via microbial bioprocessing. Fungi such as Fusarium oxysporum can simultaneously saccharify straw to sugars and ferment sugars to ethanol. But there are many bottlenecks that need to be overcome to increase the efficacy of microbial production of ethanol from straw, not least enhancement of the rate of fermentation of both hexose and pentose sugars. This research tested the hypothesis that the rate of sugar uptake by F. oxysporum would enhance the ethanol yields from lignocellulosic straw and that high affinity glucose transporters can enhance ethanol yields from this substrate. We characterized a novel hexose transporter (Hxt) from this fungus. The F. oxysporum Hxt represents a novel transporter with homology to yeast glucose signaling/transporter proteins Rgt2 and Snf3, but it lacks their C-terminal domain which is necessary for glucose signalling. Its expression level decreased with increasing glucose concentration in the medium and in a glucose uptake study the Km(glucose) was 0.9 mM, which indicated that the protein is a high affinity glucose transporter. Post-translational gene silencing or over expression of the Hxt in F. oxysporum directly affected the glucose and xylose transport capacity and ethanol yielded by F. oxysporum from straw, glucose and xylose. Thus we conclude that this Hxt has the capacity to transport both C5 and C6 sugars and to enhance ethanol yields from lignocellulosic material. This study has confirmed that high affinity glucose transporters are ideal candidates for improving ethanol yields from lignocellulose because their activity and level of expression is high in low glucose concentrations, which is very common during the process of consolidated processing. PMID:23382943

  20. Insights from the fungus Fusarium oxysporum point to high affinity glucose transporters as targets for enhancing ethanol production from lignocellulose.

    Directory of Open Access Journals (Sweden)

    Shahin S Ali

    Full Text Available Ethanol is the most-widely used biofuel in the world today. Lignocellulosic plant biomass derived from agricultural residue can be converted to ethanol via microbial bioprocessing. Fungi such as Fusarium oxysporum can simultaneously saccharify straw to sugars and ferment sugars to ethanol. But there are many bottlenecks that need to be overcome to increase the efficacy of microbial production of ethanol from straw, not least enhancement of the rate of fermentation of both hexose and pentose sugars. This research tested the hypothesis that the rate of sugar uptake by F. oxysporum would enhance the ethanol yields from lignocellulosic straw and that high affinity glucose transporters can enhance ethanol yields from this substrate. We characterized a novel hexose transporter (Hxt from this fungus. The F. oxysporum Hxt represents a novel transporter with homology to yeast glucose signaling/transporter proteins Rgt2 and Snf3, but it lacks their C-terminal domain which is necessary for glucose signalling. Its expression level decreased with increasing glucose concentration in the medium and in a glucose uptake study the Km((glucose was 0.9 mM, which indicated that the protein is a high affinity glucose transporter. Post-translational gene silencing or over expression of the Hxt in F. oxysporum directly affected the glucose and xylose transport capacity and ethanol yielded by F. oxysporum from straw, glucose and xylose. Thus we conclude that this Hxt has the capacity to transport both C5 and C6 sugars and to enhance ethanol yields from lignocellulosic material. This study has confirmed that high affinity glucose transporters are ideal candidates for improving ethanol yields from lignocellulose because their activity and level of expression is high in low glucose concentrations, which is very common during the process of consolidated processing.

  1. Value Chain Structures that Define European Cellulosic Ethanol Production

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  2. Identification and Overexpression of a Bifunctional Aldehyde/Alcohol Dehydrogenase Responsible for Ethanol Production in Thermoanaerobacter mathranii

    DEFF Research Database (Denmark)

    Yao, Shuo; Just Mikkelsen, Marie

    2010-01-01

    Thermoanaerobacter mathranii contains four genes, adhA, adhB, bdhA and adhE, predicted to code for alcohol dehydrogenases involved in ethanol metabolism. These alcohol dehydrogenases were characterized as NADP(H)-dependent primary alcohol dehydrogenase (AdhA), secondary alcohol dehydrogenase (Adh....... Overexpressions of AdhE in strain BG1E1 with xylose as a substrate facilitate the production of ethanol at an increased yield. Copyright © 2010 S. Karger AG, Basel...

  3. Effects of Nitrogen Application on Growth and Ethanol Yield of Sweet Sorghum [Sorghum bicolor (L. Moench] Varieties

    Directory of Open Access Journals (Sweden)

    Oluwatoyin Olugbemi

    2016-01-01

    Full Text Available A study was carried out in two locations, Ilorin (8° 29′ N; 4° 35′ E; about 310 m asl and Ejiba (8° 17′ N; 5° 39′ E; about 246 m asl, at the Southern Guinea Savannah agroecological zone of Nigeria to assess the effect of nitrogen fertilizer on the growth and ethanol yield of four sweet sorghum varieties (NTJ-2, 64 DTN, SW Makarfi 2006, and SW Dansadau 2007. Five N fertilizer levels (0, 40, 80, 120, and 160 kg ha−1 were used in a 4 × 5 factorial experiment, laid out in split-plots arrangement. The application of nitrogen fertilizer was shown to enhance the growth of sweet sorghum as observed in the plant height, LAI, CGR, and other growth indices. Nitrogen fertilizer application also enhanced the ethanol yield of the crop, as variations in growth parameters and ethanol yield were observed among the four varieties studied. The variety SW Dansadau 2007 was observed as the most promising in terms of growth and ethanol yield, and the application of 120 kg N ha−1 resulted in the best ethanol yield at the study area.

  4. Carbon dioxide fixation by Calvin-Cycle enzymes improves ethanol yield in yeast

    NARCIS (Netherlands)

    Guadalupe-Medina, V.; Wisselink, H.W.; Luttik, M.A.H.; De Hulster, E.; Daran, J.M.; Pronk, J.T.; Van Maris, A.J.A.

    2013-01-01

    Background Redox-cofactor balancing constrains product yields in anaerobic fermentation processes. This challenge is exemplified by the formation of glycerol as major by-product in yeast-based bioethanol production, which is a direct consequence of the need to reoxidize excess NADH and causes a loss

  5. Production of ethanol in batch and fed-batch fermentation of soluble sugar

    International Nuclear Information System (INIS)

    Chaudhary, M.Y.; Shah, M.A.; Shah, F.H.

    1991-01-01

    Keeping in view of the demand and need for alternate energy source, especially liquid fuels and the availability of raw materials in Pakistan, we have carried out biochemical and technological studies for ethanol through fermentation of renewable substrates. Molasses and sugar cane have been used as substrate for yeast fermentation. Selected yeast were used in both batch and semi continuous fermentation of molasses. Clarified dilute molasses were fermented with different strains of Saccharomyces cerevisiae. Ethanol concentration after 64 hours batch fermentation reached 9.4% with 90% yield based on sugar content. During feed batch system similar results were obtained after a fermentation cycle of 48 hours resulting in higher productivity. Similarly carbohydrates in fruit juices and hydro lysates of biomass can be economically fermented to ethanol to be used as feed stock for other chemicals. (author)

  6. The economics of ethanol production by extractive fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Daugulis, A J; Axford, D B; McLellan, P J [Queen' s Univ., Kingston, ON (Canada)

    1991-04-01

    Extractive fermentation is a processing strategy in which reaction and recovery occur simultaneously in a fermentation vessel through the use of a water-immiscible solvent which selectively removes an inhibitory product. An ethanol-extractive fermentation process has been developed, incorporating continuous operation and the ability to ferment concentrated feedstocks. A detailed economic assessment of this process is provided relative to current technology for an annual capacity of 100 million litres of ethanol. Extractive fermentation provides significant economic advantages for both grass roots and retrofitted plants. Total production costs are estimated at 45{cents}/l for a conventional plant and 29.4{cents}/l for a retrofitted plant. The main cost saving achievable by extractive fermentation is in energy, used for evaporation and drying, since the process uses significantly less water in its conversion of concentrated feedstocks. Producing anhydrous ethanol without distillation is also a prospect. 15 refs., 5 fig., 10 tabs.

  7. Monosaccharides and Ethanol Production from Superfine Ground Sugarcane Bagasse Using Enzyme Cocktail

    Directory of Open Access Journals (Sweden)

    Jingbo Li

    2014-03-01

    Full Text Available In this work, the effect of particle size on the enzymatic hydrolysis of milled and sieved sugarcane bagasse (SCB was studied. The enzymatic hydrolysis and fermentability of superfine ground SCB (SGP400 using an enzyme cocktail strategy were also explored. Particle size reduction improved the enzymatic hydrolysis. The highest glucose yield was 44.75%, which was obtained from SGP400. The enzyme cocktail strategy greatly enhanced the glucose and xylose yield. The maximum glucose and xylose yield was from the enzyme cocktail of cellulase, xylanase, and pectinase. Synergistic action between xylanase and pectinase as well as cellulase and pectinase was quite noticeable. Hydrolysis times affected the degree of synergism. Ethanol production was carried out by employing simultaneous saccharification and fermentation (SSF and semi-SSF using enzymes and their cocktails. Semi-SSF was found to be the better one compared with SSF. Xylanase and pectinase aided the ethanol production in both fermentation modes. Ethanol yield was 7.81 and 7.30 g/L for semi-SSF and SSF, respectively by using an enzyme cocktail of cellulase, β-glucosidase, pectinase, and xylanase.

  8. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 II: production of xylitol and ethanol in the presence of inhibitors.

    Science.gov (United States)

    Vajzovic, Azra; Bura, Renata; Kohlmeier, Kevin; Doty, Sharon L

    2012-10-01

    A systematic study was conducted characterizing the effect of furfural, 5-hydroxymethylfurfural (5-HMF), and acetic acid concentration on the production of xylitol and ethanol by a novel endophytic yeast, Rhodotorula mucilaginosa strain PTD3. The influence of different inhibitor concentrations on the growth and fermentation abilities of PTD3 cultivated in synthetic nutrient media containing 30 g/l xylose or glucose were measured during liquid batch cultures. Concentrations of up to 5 g/l of furfural stimulated production of xylitol to 77 % of theoretical yield (10 % higher compared to the control) by PTD3. Xylitol yields produced by this yeast were not affected in the presence of 5-HMF at concentrations of up to 3 g/l. At higher concentrations of furfural and 5-HMF, xylitol and ethanol yields were negatively affected. The higher the concentration of acetic acid present in a media, the higher the ethanol yield approaching 99 % of theoretical yield (15 % higher compared to the control) was produced by the yeast. At all concentrations of acetic acid tested, xylitol yield was lowered. PTD3 was capable of metabolizing concentrations of 5, 15, and 5 g/l of furfural, 5-HMF, and acetic acid, respectively. This yeast would be a potent candidate for the bioconversion of lignocellulosic sugars to biochemicals given that in the presence of low concentrations of inhibitors, its xylitol and ethanol yields are stimulated, and it is capable of metabolizing pretreatment degradation products.

  9. 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)

  10. Production of bio-fuel ethanol from distilled grain waste eluted from Chinese spirit making process.

    Science.gov (United States)

    Tan, Li; Sun, Zhaoyong; Zhang, Wenxue; Tang, Yueqin; Morimura, Shigeru; Kida, Kenji

    2014-10-01

    Distilled grain waste eluted from Chinese spirit making is rich in carbohydrates, and could potentially serve as feedstock for the production of bio-fuel ethanol. Our study evaluated two types of saccharification methods that convert distilled grain waste to monosaccharides: enzymatic saccharification and concentrated H2SO4 saccharification. Results showed that enzymatic saccharification performed unsatisfactorily because of inefficient removal of lignin during pretreatment. Concentrated H2SO4 saccharification led to a total sugar recovery efficiency of 79.0 %, and to considerably higher sugar concentrations than enzymatic saccharification. The process of ethanol production from distilled grain waste based on concentrated H2SO4 saccharification was then studied. The process mainly consisted of concentrated H2SO4 saccharification, solid-liquid separation, decoloration, sugar-acid separation, oligosaccharide hydrolysis, and continuous ethanol fermentation. An improved simulated moving bed system was employed to separate sugars from acid after concentrated H2SO4 saccharification, by which 95.8 % of glucose and 85.8 % of xylose went into the sugar-rich fraction, while 83.3 % of H2SO4 went into the acid-rich fraction. A flocculating yeast strain, Saccharomyces cerevisiae KF-7, was used for continuous ethanol fermentation, which produced an ethanol yield of 91.9-98.9 %, based on glucose concentration.

  11. The effects of furfural on ethanol production by Saccharomyces cerevisiae in batch culture

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, L.J.; Vega, J.L.; Klasson, K.T.; Clausen, E.C.; Gaddy, J.L. (Arkansas Univ., Fayetteville, AR (US). Dept. of Chemical Engineering)

    1992-01-01

    Browning reaction products such as furfural and 5-hydroxy-methyl-furfural (HMF) have been shown to inhibit microbial growth and metabolism in ethanol fermentations using Saccharomyces cerevisiae. This paper quantifies the extent of furfural inhibition and yeast growth, glucose utilization, and ethanol production as a function of inoculum size (0.1-9 gl{sup -1}). Batch culture experiments were conducted using furfural concentrations in the range of 0 to 2.0 gl{sup -1} and mathematical correlations were proposed and tested. The results indicate that the specific growth rate decreased with increasing furfural concentration and inoculum size, while the maintenance coefficients were unaffected. The apparent and true cell yield coefficients on glucose were depressed with the addition of furfural. Specific production rates were unaffected at the furfural levels used but ethanol inhibition was apparent. The specific production rate was less inhibited by ethanol at higher inoculum sizes. Global specific productivities were not affected by the presence of furfural. At a 0.1 gl{sup -1} inoculum size, furfural depletion was complete within 15-20 h, depending upon the furfural concentration employed. At higher incoculum levels (2-9 gl{sup -1}), all furfural was depleted in less than 5 h. (author).

  12. Evaluation of Ethanol Production and Cogeneration of Energy by Sweet Sorghum Culture

    Directory of Open Access Journals (Sweden)

    Fábio Olivieri De Nóbile

    2014-06-01

    Full Text Available The scarcity of fossil fuels and environmental pollution have led to the discussions of new biofuels. For this reason new sources of renewable fuels are sought and an alternative to ethanol production, besides sugar cane, is sweet sorghum, using it as a complement, not as a competitor of sugar cane, considering that the demand for biofuels is growing on a large scale worldwide. The aim was to analyze the production of ethanol and the cogeneration of sweet sorghum in the offseason of sugar cane, and to compare the yield of sweet sorghum with sugar cane, the processes to obtain and to produce etnhanol from sweet sorgo and the production cost, supplying the lack of raw materials in the offseason and increasing the period of grinding mill. The methodology used was a bibliographical review in scientific journals, books and internet. In a near future, with research of new more productive varieties, sweet sorghum is an alternative to produce ethanol during the offseason of sugar cane for its short cycle of sowing and harvesting, besides climatic factors which favor its development and utilization of the same systems used for the production of ethanol from sugar cane.

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

    Energy Technology Data Exchange (ETDEWEB)

    Arvaniti, E

    2010-12-15

    solution was fermented via Simultaneous Saccharification and Fermentation (SSF) assisted by liquefaction step, with Cellubrix L and baker's yeast achieved ethanol yield was 67% based on sugars in raw material (12.5% DM). Optimization of ethanol production from rape straw then focused to enzymatic hydrolysis and benchmarking available commercial enzyme mixtures. It was found that hydrolysis rate increased considerably, if adequate amount of beta-glycosidase is present in enzyme mixture. Best mixture of enzymes was Celluclast 1.5L supplemented by Novozym 188 (5:1 v/v ratio), which in 24 hours it hydrolyzed 77% of pretreated rape straw C6 sugars. In an attempt to produce enzymes from pretreated rape straw, the most promising carbon source was a mixture of cellulose and hemicellulose (81:19 w/w sugars ratio). The produced cellulolytic enzymes in turn hydrolyzed pretreated rape straw by 70% in 24 hours enzyme hydrolysis test. These enzymes were produced after 11 days of fermentation with enzyme yielded 109 FPU/g sugars (pretreated rape straw). Finally, ethanol fermentation was optimized using the selected pretreatment method, and best enzyme mixture. Assessment of optimal fermentation conditions included determination of optimal highest fermenting temperature among three strains; the best pH pattern for maximum ethanol production; and finally assessing potentials of fermentations at increased dry matter. Results have shown that S. cerevisiae has thermotollerance up to 37 deg. C, and that pH was the catalytic factor for the progress of ethanol fermentation as well as contamination by lactic acid bacteria, in both shake flasks and scale up experiments. Highest ethanol yield was 77% achieved with 16% DM at 37 deg. C by an isolate strain from baker' yeast within 120 hours of SSF. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Arvaniti, E.

    2010-12-15

    solution was fermented via Simultaneous Saccharification and Fermentation (SSF) assisted by liquefaction step, with Cellubrix L and baker's yeast achieved ethanol yield was 67% based on sugars in raw material (12.5% DM). Optimization of ethanol production from rape straw then focused to enzymatic hydrolysis and benchmarking available commercial enzyme mixtures. It was found that hydrolysis rate increased considerably, if adequate amount of beta-glycosidase is present in enzyme mixture. Best mixture of enzymes was Celluclast 1.5L supplemented by Novozym 188 (5:1 v/v ratio), which in 24 hours it hydrolyzed 77% of pretreated rape straw C6 sugars. In an attempt to produce enzymes from pretreated rape straw, the most promising carbon source was a mixture of cellulose and hemicellulose (81:19 w/w sugars ratio). The produced cellulolytic enzymes in turn hydrolyzed pretreated rape straw by 70% in 24 hours enzyme hydrolysis test. These enzymes were produced after 11 days of fermentation with enzyme yielded 109 FPU/g sugars (pretreated rape straw). Finally, ethanol fermentation was optimized using the selected pretreatment method, and best enzyme mixture. Assessment of optimal fermentation conditions included determination of optimal highest fermenting temperature among three strains; the best pH pattern for maximum ethanol production; and finally assessing potentials of fermentations at increased dry matter. Results have shown that S. cerevisiae has thermotollerance up to 37 deg. C, and that pH was the catalytic factor for the progress of ethanol fermentation as well as contamination by lactic acid bacteria, in both shake flasks and scale up experiments. Highest ethanol yield was 77% achieved with 16% DM at 37 deg. C by an isolate strain from baker' yeast within 120 hours of SSF. (Author)

  15. Optimization of the production of ethyl esters by ultrasound assisted reaction of soybean oil and ethanol

    OpenAIRE

    Rodrigues,S.; Mazzone,L. C. A.; Santos,F. F. P.; Cruz,M. G. A.; Fernandes,F. A. N.

    2009-01-01

    Biodiesel is a renewable liquid fuel that can be produced by a transesterification reaction between a vegetable oil and an alcohol. This paper evaluates and optimizes the production of ethyl esters (biodiesel) from soybean oil and ethanol. The reaction was carried out by applying ultrasound under atmospheric pressure and ambient temperature. Response surface methodology was used to evaluate the influence of alcohol to oil molar ratio and catalyst concentration on the yield of conversion of so...

  16. Design and analysis of fuel ethanol production from raw glycerol

    International Nuclear Information System (INIS)

    Posada, J.A.; Cardona, C.A.

    2010-01-01

    Three configurations for fuel ethanol production from raw glycerol using Escherichia coli were simulated and economically assessed using Aspen Plus and Aspen Icarus, respectively. These assessments considered raw glycerol (60 wt%) purification to both crude glycerol (88 wt%) and pure glycerol (98 wt%). The highest purification cost (PC) was obtained using pure glycerol due to its higher energy consumption in the distillation stage. In addition, the remaining methanol in the raw glycerol stream was recovered and recycled, decreasing the purification costs. The E. coli strain is able to convert crude glycerol (at 10 g/L or 20 g/L), or pure glycerol (at 10 g/L) to ethanol. Among these three glycerol concentrations, the lowest bioconversion cost was obtained when crude glycerol was diluted at 20 g/L. Purification and global production costs were compared with the commercial prices of glycerol and fuel ethanol from corn and sugarcane. Purification costs of raw glycerol were lower than previously reported values due to the methanol recovery. Global production costs for fuel ethanol from glycerol were lower than the reported values for corn-based production and higher than those for cane-based production. (author)

  17. Ethanol Production by Soy Fiber Treatment and Simultaneous Saccharification and Co-Fermentation in an Integrated Corn-Soy Biorefinery

    Directory of Open Access Journals (Sweden)

    Jasreen K. Sekhon

    2018-05-01

    Full Text Available Insoluble fiber (IF recovered from the enzyme-assisted aqueous extraction process (EAEP of soybeans is a fraction rich in carbohydrates and proteins. It can be used to enhance ethanol production in an integrated corn-soy biorefinery, which combines EAEP with traditional corn-based ethanol processing. The present study evaluated IF as a substrate for ethanol production. The effects of treatment of IF (soaking in aqueous ammonia (SAA, liquid hot water (LHW, and enzymatic hydrolysis, primarily simultaneous saccharification and co-fermentation (SSCF, as well as scaling up (250 mL to 60 L on ethanol production from IF alone or a corn and IF slurry were investigated. Enzymatic hydrolysis (pectinase, cellulase, and xylanase, each added at 5% soy solids during simultaneous saccharification and fermentation/SSCF was the best treatment to maximize ethanol production from IF. Ethanol yield almost doubled when SSCF of IF was performed with Saccharomyces cerevisiae and Escherichia coli KO11. Addition of IF in dry-grind corn fermentation increased the ethanol production rate (~31%, but low ethanol tolerance of E. coli KO11 was a limiting factor for employing SSCF in combination corn and IF fermentation. Nonlinear Monod modeling accurately predicted the effect of ethanol concentration on E. coli KO11 growth kinetics by Hanes-Woolf linearization. Collectively, the results from this study suggest a potential of IF as a substrate, alone or in dry-grind corn fermentation, where it enhances the ethanol production rate. IF can be incorporated in the current bioethanol industry with no added capital investment, except enzymes.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

  19. Co-Utilization of Glucose and Xylose for Enhanced Lignocellulosic Ethanol Production with Reverse Membrane Bioreactors

    Science.gov (United States)

    Ishola, Mofoluwake M.; Ylitervo, Päivi; Taherzadeh, Mohammad J.

    2015-01-01

    Integrated permeate channel (IPC) flat sheet membranes were examined for use as a reverse membrane bioreactor (rMBR) for lignocellulosic ethanol production. The fermenting organism, Saccharomyces cerevisiae (T0936), a genetically-modified strain with the ability to ferment xylose, was used inside the rMBR. The rMBR was evaluated for simultaneous glucose and xylose utilization as well as in situ detoxification of furfural and hydroxylmethyl furfural (HMF). The synthetic medium was investigated, after which the pretreated wheat straw was used as a xylose-rich lignocellulosic substrate. The IPC membrane panels were successfully used as the rMBR during the batch fermentations, which lasted for up to eight days without fouling. With the rMBR, complete glucose and xylose utilization, resulting in 86% of the theoretical ethanol yield, was observed with the synthetic medium. Its application with the pretreated wheat straw resulted in complete glucose consumption and 87% xylose utilization; a final ethanol concentration of 30.3 g/L was obtained, which corresponds to 83% of the theoretical yield. Moreover, complete in situ detoxification of furfural and HMF was obtained within 36 h and 60 h, respectively, with the rMBR. The use of the rMBR is a promising technology for large-scale lignocellulosic ethanol production, since it facilitates the co-utilization of glucose and xylose; moreover, the technology would also allow the reuse of the yeast for several batches. PMID:26633530

  20. Co-Utilization of Glucose and Xylose for Enhanced Lignocellulosic Ethanol Production with Reverse Membrane Bioreactors

    Directory of Open Access Journals (Sweden)

    Mofoluwake M. Ishola

    2015-12-01

    Full Text Available Integrated permeate channel (IPC flat sheet membranes were examined for use as a reverse membrane bioreactor (rMBR for lignocellulosic ethanol production. The fermenting organism, Saccharomyces cerevisiae (T0936, a genetically-modified strain with the ability to ferment xylose, was used inside the rMBR. The rMBR was evaluated for simultaneous glucose and xylose utilization as well as in situ detoxification of furfural and hydroxylmethyl furfural (HMF. The synthetic medium was investigated, after which the pretreated wheat straw was used as a xylose-rich lignocellulosic substrate. The IPC membrane panels were successfully used as the rMBR during the batch fermentations, which lasted for up to eight days without fouling. With the rMBR, complete glucose and xylose utilization, resulting in 86% of the theoretical ethanol yield, was observed with the synthetic medium. Its application with the pretreated wheat straw resulted in complete glucose consumption and 87% xylose utilization; a final ethanol concentration of 30.3 g/L was obtained, which corresponds to 83% of the theoretical yield. Moreover, complete in situ detoxification of furfural and HMF was obtained within 36 h and 60 h, respectively, with the rMBR. The use of the rMBR is a promising technology for large-scale lignocellulosic ethanol production, since it facilitates the co-utilization of glucose and xylose; moreover, the technology would also allow the reuse of the yeast for several batches.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kuwornoo, David. K. [Faculty of Chemical and Materials Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Private Mail Bag, Kumasi (Ghana); Ahiekpor, Julius C. [Chemical Engineering Department, Kumasi Polytechnic, P.O. Box 854, Kumasi (Ghana)

    2010-07-01

    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 deg C.

  2. A CORN STEM AS BIOMATERIAL FOR SACCHAROMYCES CEREVISIAE CELLS IMMOBILIZATION FOR THE ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Vesna Vučurović

    2008-11-01

    Full Text Available This study provides a preliminary contribution to the development of a bioprocess for the production of ethanol using Saccharomyces cerevisiae cells immobilized onto a corn stem. For this purpose, the yeast cells were submitted to the batch tests in situ adsorption onto 0.5 cm long corn stem. Cells immobilization was analyzed by optical microscopy. The number of the yeast cells, fermentation kinetics, the ethanol yield in the presence or the absence of the support in the fermentation medium was investigated. It was determined that the addition of the corn stem led to the abrupt increase of the yeast cells number in substrate, ethanol yield, pH value, a total dissolved salts content and substrate conductivity. The addition of 5 and 10g of the corn stem pith per liter of the medium decreased the amount of residual sugar. The results indicate that a corn stem might be a good carrier for the yeast cell immobilization, and also a cheap alternative recourse of mineral components with the possibility of application for improving ethanol productivities.

  3. Environmental benefits of the integrated production of ethanol and biodiesel

    International Nuclear Information System (INIS)

    Souza, Simone Pereira; Seabra, Joaquim E.A.

    2013-01-01

    Highlights: ► Integrated bioenergy systems can favor the sustainability of biofuels. ► We analyzed the integrated production of ethanol and biodiesel in Brazil. ► GHG emissions and fossil energy use in the ethanol life cycle would be reduced. ► Socio-economic and other environmental aspects must be analyzed in future works. -- Abstract: The biorefinery of the future will be an integrated complex that makes a variety of products (e.g., biofuels, chemicals, power and protein) from a variety of feedstocks. The objective of this work was to evaluate the environmental benefits, compared to the traditional sugarcane ethanol system, of the integrated production of ethanol and biodiesel through a sugarcane–soybean biorefinery concept in Brazil. The environmental aspects considered here were the fossil energy use and the greenhouse gases (GHGs) emissions associated with ethanol production. In the Integrated System, soybean would be cultivated in part of the sugarcane reforming areas, which represents ∼17% of the total sugarcane area. Sugarcane and soybean oil would be processed in a combined ethanol–biodiesel plant, which would use only bagasse as fuel. All the demand for utilities of the biodiesel plant would be provided by the distillery. The output products of the combined plant would comprise sugarcane ethanol, soybean biodiesel (which would be used as diesel (B5) substitute in the sugarcane cultivation), bioelectricity and glycerin. The results indicate that the Integrated System can reduce the fossil energy consumption from 75 to 37 kJ/MJ of ethanol, when compared to the traditional system. For GHG emissions, the value would drop from 22.5 to 19.7 g CO 2 eq/MJ of ethanol. This analysis shows that the Integrated System is an important option to contribute to ethanol’s life cycle independence from fossil resources. This is an attractive environmental aspect, but socio-economic (as well as other environmental) aspects should also be analyzed in order to

  4. Improvement of enzymatic hydrolysis and ethanol production from corn stalk by alkali and N-methylmorpholine-N-oxide pretreatments.

    Science.gov (United States)

    Cai, Ling-Yan; Ma, Yu-Long; Ma, Xiao-Xia; Lv, Jun-Min

    2016-07-01

    A combinative technology of alkali and N-methylmorpholine-N-oxide (NMMO) was used to pretreat corn stalk (CS) for improving the efficiencies of subsequent enzymatic hydrolysis and ethanol fermentation. The results showed that this strategy could not only remove hemicellulose and lignin but also decrease the crystallinity of cellulose. About 98.0% of enzymatic hydrolysis yield was obtained from the pretreated CS as compared with 46.9% from the untreated sample. The yield for corresponding ethanol yield was 64.6% while untreated CS was only 18.8%. Besides, xylose yield obtained from the untreated CS was only 11.1%, while this value was 93.8% for alkali with NMMO pretreated sample. These results suggest that a combination of alkali with 50% (wt/wt) NMMO solution may be a promising alternative for pretreatment of lignocellulose, which can increase the productions of subsequent enzymatic hydrolysis and ethanol fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. [Optimization of ethylene production from ethanol dehydration using Zn-Mn-Co/HZSM-5 by response surface methodology].

    Science.gov (United States)

    Wang, Wei; Cheng, Keke; Xue, Jianwei; Zhang, Jian'an

    2011-03-01

    The effects of reaction temperature, ethanol concentration and weight hourly space velocity (WHSV) on the ethylene production from ethanol dehydration using zinc, manganese and cobalt modified HZSM-5 catalyst were investigated by response surface methodology (RSM). The results showed that the most significant effect among factors was reaction temperature and the factors had interaction. The optimum conditions were found as 34.4% ethanol concentration, 261.3 0 degrees C of reaction temperature and 1.18 h(-1) of WHSV, under these conditions the yield of ethylene achieved 98.69%.

  6. Continuous co-production of ethanol and xylitol from rice straw hydrolysate in a membrane bioreactor.

    Science.gov (United States)

    Zahed, Omid; Jouzani, Gholamreza Salehi; Abbasalizadeh, Saeed; Khodaiyan, Faramarz; Tabatabaei, Meisam

    2016-05-01

    The present study was set to develop a robust and economic biorefinery process for continuous co-production of ethanol and xylitol from rice straw in a membrane bioreactor. Acid pretreatment, enzymatic hydrolysis, detoxification, yeast strains selection, single and co-culture batch fermentation, and finally continuous co-fermentation were optimized. The combination of diluted acid pretreatment (3.5 %) and enzymatic conversion (1:10 enzyme (63 floating-point unit (FPU)/mL)/biomass ratio) resulted in the maximum sugar yield (81 % conversion). By concentrating the hydrolysates, sugars level increased by threefold while that of furfural reduced by 50 % (0.56 to 0.28 g/L). Combined application of active carbon and resin led to complete removal of furfural, hydroxyl methyl furfural, and acetic acid. The strains Saccharomyces cerevisiae NCIM 3090 with 66.4 g/L ethanol production and Candida tropicalis NCIM 3119 with 9.9 g/L xylitol production were selected. The maximum concentrations of ethanol and xylitol in the single cultures were recorded at 31.5 g/L (0.42 g/g yield) and 26.5 g/L (0.58 g/g yield), respectively. In the batch co-culture system, the ethanol and xylitol productions were 33.4 g/L (0.44 g/g yield) and 25.1 g/L (0.55 g/g yield), respectively. The maximum ethanol and xylitol volumetric productivity values in the batch co-culture system were 65 and 58 % after 25 and 60 h, but were improved in the continuous co-culture mode and reached 80 % (55 g/L) and 68 % (31 g/L) at the dilution rate of 0.03 L per hour, respectively. Hence, the continuous co-production strategy developed in this study could be recommended for producing value-added products from this hugely generated lignocellulosic waste.

  7. Ethanol production in fermentation of mixed sugars containing xylose

    Science.gov (United States)

    Viitanen, Paul V [West Chester, PA; Mc Cutchen, Carol M [Wilmington, DE; Li,; Xu, [Newark, DE; Emptage, Mark [Wilmington, DE; Caimi, Perry G [Kennett Square, PA; Zhang, Min [Lakewood, CO; Chou, Yat-Chen [Lakewood, CO; Franden, Mary Ann [Centennial, CO

    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.

  8. Cassava as feedstock for ethanol production in South Africa

    African Journals Online (AJOL)

    Sanette

    2013-07-31

    Jul 31, 2013 ... Rising crude oil prices, lower crop prices on world ... industrial strategy of South Africa suggests the use of sugar based crops, ... Development of the biofuels industry in South Africa is ... production of ethanol from cassava is both economical ... In the SSF process, the saccharification step and fermentation.

  9. Production, transport, and metabolism of ethanol in eastern cottonwood

    International Nuclear Information System (INIS)

    MacDonald, R.C.

    1991-01-01

    In plant tissues, the production of acetaldehyde and ethanol are usually thought to occur as a mechanism to allow tolerance of hypoxic conditions. Acetaldehyde and ethanol were found to be common in vascular cambium and the transpiration stream of trees. Ethanol concentrations in the vascular cambium of Populus deltoides were not changed by placing logs from nonflooded trees in a pure oxygen environment for as long as 96 h, but increased by almost 3 orders of magnitude when exposed to low external pO 2 s. Ethanol is present in the xylem sap of flooded and nonflooded trees. Because of the constitutive presence of alcohol dehydrogenase in the mature leaves of woody plants, it was hypothesized that the leaves and shoots of trees had the ability to metabolize ethanol supplied by the transpiration stream. 1-[ 14 C]ethanol was supplied to excised leaves and shoots of Populus deltoides Bartr. in short- and long-term experiments. Greater than 99% of the radiolabel was incorporated into plant tissue in short-term experiments, with more than 95% of the label remaining in plant tissue after 24 h. Very little label reached the leaf mesophyll cells of excised shoots, as revealed by autoradiography. Radiolabel appeared primarily in the water- and chloroform-soluble fractions in short-term experiments, while in long-term experiments, label was also incorporated into protein. When labelled ethanol was supplied to excised petioles in a 5 min pulse, 41% of the label was incorporated into organic acids. Some label was also incorporated into amino acids, protein, and the chloroform-soluble fraction, with very little appearing in neutral sugars, starch, or the insoluble pellet. Labelled organic acids were separated by HPLC, and were comprised of acetate, isocitrate, α-ketoglutarate, and succinate. There was no apparent incorporation of label into phosphorylated compounds

  10. Production of ethanol from winter barley by the EDGE (enhanced dry grind enzymatic process

    Directory of Open Access Journals (Sweden)

    Kurantz M

    2010-04-01

    Full Text Available Abstract Background US legislation requires the use of advanced biofuels to be made from non-food feedstocks. However, commercialization of lignocellulosic ethanol technology is more complex than expected and is therefore running behind schedule. This is creating a demand for non-food, but more easily converted, starch-based feedstocks other than corn that can fill the gap until the second generation technologies are commercially viable. Winter barley is such a feedstock but its mash has very high viscosity due to its high content of β-glucans. This fact, along with a lower starch content than corn, makes ethanol production at the commercial scale a real challenge. Results A new fermentation process for ethanol production from Thoroughbred, a winter barley variety with a high starch content, was developed. The new process was designated the EDGE (enhanced dry grind enzymatic process. In this process, in addition to the normal starch-converting enzymes, two accessory enzymes were used to solve the β-glucan problem. First, β-glucanases were used to hydrolyze the β-glucans to oligomeric fractions, thus significantly reducing the viscosity to allow good mixing for the distribution of the yeast and nutrients. Next, β-glucosidase was used to complete the β-glucan hydrolysis and to generate glucose, which was subsequently fermented in order to produce additional ethanol. While β-glucanases have been previously used to improve barley ethanol production by lowering viscosity, this is the first full report on the benefits of adding β-glucosidases to increase the ethanol yield. Conclusions In the EDGE process, 30% of total dry solids could be used to produce 15% v/v ethanol. Under optimum conditions an ethanol yield of 402 L/MT (dry basis or 2.17 gallons/53 lb bushel of barley with 15% moisture was achieved. The distillers dried grains with solubles (DDGS co-product had extremely low β-glucan (below 0.2% making it suitable for use in both ruminant

  11. Impact of zinc supplementation on the improvement of ethanol tolerance and yield of self-flocculating yeast in continuous ethanol fermentation.

    Science.gov (United States)

    Zhao, X Q; Xue, C; Ge, X M; Yuan, W J; Wang, J Y; Bai, F W

    2009-01-01

    The effects of zinc supplementation were investigated in the continuous ethanol fermentation using self-flocculating yeast. Zinc sulfate was added at the concentrations of 0.01, 0.05 and 0.1 g l(-1), respectively. Reduced average floc sizes were observed in all the zinc-supplemented cultures. Both the ethanol tolerance and thermal tolerance were significantly improved by zinc supplements, which correlated well with the increased ergosterol and trehalose contents in the yeast flocs. The highest ethanol concentration by 0.05 g l(-1) zinc sulfate supplementation attained 114.5 g l(-1), in contrast to 104.1 g l(-1) in the control culture. Glycerol production was decreased by zinc supplementations, with the lowest level 3.21 g l(-1), about 58% of the control. Zinc content in yeast cells was about 1.4 microMol g(-1) dry cell weight, about sixfold higher than that of control in all the zinc-supplemented cultures, and close correlation of zinc content in yeast cells with the cell viability against ethanol and heat shock treatment was observed. These studies suggest that exogenous zinc addition led to a reprogramming of cellular metabolic network, resulting in enhanced ethanol tolerance and ethanol production.

  12. Ethanol production from the seaweed Gelidium amansii, using specific sugar acclimated yeasts.

    Science.gov (United States)

    Cho, Hyeyoung; Ra, Chae-Hun; Kim, Sung-Koo

    2014-02-28

    For the production of ethanol from seaweed as the source material, thermal acid hydrolysis and enzymatic saccharification were carried out for monosugars production of 25.5 g/l galactose and 7.6 g/l glucose using Gelidium amansii. The fermentation was performed with Pichia stipitis KCTC 7228 or Saccharomyces cerevisiae KCCM 1129. When wild P. stipitis and S. cerevisiae were used, the ethanol productions of 11.2 g/l and 6.9 g/l were produced, respectively. The ethanol productions of 16.6 g/l and 14.6 g/l were produced using P. stipitis and S. cerevisiae acclimated to high concentration of galactose, respectively. The yields of ethanol fermentation increased to 0.5 and 0.44 from 0.34 and 0.21 using acclimated P. stipitis and S. cerevisiae, respectively. Therefore, acclimation of yeasts to a specific sugar such as galactose reduced the glucose-induced repression on the transport of galactose.

  13. Production of ethanol from blackstrap molasses by saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Elahi, S.; Hashmi, Abu-S.; Akhtar, C.M.; Ilahi, A.; Rajoka, M.I.

    1991-01-01

    Blackstrap molasses was analyzed for its composition and its fermentation was brought about by the yeast S. cerevisiae at predetermined optimal environmental conditions such as pH, temperature, Sugar concentration, and incubation period. The results revealed that sugar concentration 17%, pH 4.5, temperature 30 C and incubation period of 72 hours were the optimal conditions for producing maximum (73 g/l) ethanol. Clearance of molasses by 20% single superphosphate enhanced ethanol production by only 0.2%. (author)

  14. Value Chain Structures that Define European Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Jay Sterling Gregg

    2017-01-01

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

  15. Ethanol production kinetics by a thermo-tolerant mutant of saccharomyces cerevisiae from starch industry waste (hydrol)

    International Nuclear Information System (INIS)

    Shah, F.A.; Aziz, S.

    2010-01-01

    A thermo-tolerant and deoxyglucose-resistant mutant of Saccharomyces cerevisiae was developed and employed to convert them to fuel ethanol in a 150 litre fermenter. Maximum ethanol production was achieved when fermentation of dextrozyme- treated hydrol was carried out for about 36 hours under optimized fermenting conditions. The maximum specific ethanol production rate (qP), and overall ethanol yield (YP/S) were found to be 2.82 g L/sup -1/ h/sup -1/ and 0.49 g/g respectively. Determination of activation energy for cell growth (Ea= 20.8 kJ/mol) and death (Ed = 19.1 kJ/mol) and product formation and inactivation (EP=35.8 kJ/mol and Edp = 33.5 kJ/mol) revealed the thermo-stability of the organism for up to 47 deg. C. (author)

  16. Ethanol Production Kinetics by a Thermo-Tolerant Mutant of Saccharomyces Cerevisiae from Starch Industry Waste (Hydrol

    Directory of Open Access Journals (Sweden)

    Farman Ali Shah

    2010-06-01

    Full Text Available A thermo-tolerant and deoxyglucose-resistant mutant of Saccharomyces cerevisiae was developed and employed to convert them to fuel ethanol in a 150 litre fermenter. Maximum ethanol production was achieved when fermentation of dextrozyme- treated hydrol was carried out for about 36 hours under optimized fermenting conditions. The maximum specific ethanol production rate (qP, and overall ethanol yield (YP/S were found to be 2.82 g L-1 h-1 and 0.49 g/g respectively. Determination of activation energy for cell growth (Ea= 20.8 kJ/mol and death (Ed = 19.1 kJ/mol and product formation and inactivation (EP=35.8 kJ/mol and Edp = 33.5 kJ/mol revealed the thermo-stability of the organism for up to 47°C.

  17. Catalytic steam reforming of ethanol for hydrogen production: Brief status

    Directory of Open Access Journals (Sweden)

    Bineli Aulus R.R.

    2016-01-01

    Full Text Available Hydrogen represents a promising fuel since it is considered as a cleanest energy carrier and also because during its combustion only water is emitted. It can be produced from different kinds of renewable feedstocks, such as ethanol, in this sense hydrogen could be treated as biofuel. Three chemical reactions can be used to achieve this purpose: the steam reforming (SR, the partial oxidation (POX and the autothermal reforming (ATR. In this study, the catalysts implemented in steam reforming of ethanol were reviewed. A wide variety of elements can be used as catalysts for this reaction, such as base metals (Ni, Cu and Co or noble metals (Rh, Pt and Ru usually deposited on a support material that increases surface area and improves catalytic function. The use of Rh, Ni and Pt supported or promoted with CeO2, and/or La2O3 shows excellent performance in ethanol SR catalytic process. The ratio of water to ethanol, reaction temperatures, catalysts loadings, selectivity and activity are also discussed as they are extremely important for high hydrogen yields.

  18. The modeling of ethanol production by Kluyveromyces marxianus using whey as substrate in continuous A-Stat bioreactors.

    Science.gov (United States)

    Gabardo, Sabrina; Pereira, Gabriela Feix; Rech, Rosane; Ayub, Marco Antônio Záchia

    2015-09-01

    We investigated the kinetics of whey bioconversion into ethanol by Kluyveromyces marxianus in continuous bioreactors using the "accelerostat technique" (A-stat). Cultivations using free and Ca-alginate immobilized cells were evaluated using two different acceleration rates (a). The kinetic profiles of these systems were modeled using four different unstructured models, differing in the expressions for the specific growth (μ) and substrate consumption rates (r s), taking into account substrate limitation and product inhibition. Experimental data showed that the dilution rate (D) directly affected cell physiology and metabolism. The specific growth rate followed the dilution rate (μ≈D) for the lowest acceleration rate (a = 0.0015 h(-2)), condition in which the highest ethanol yield (0.52 g g(-1)) was obtained. The highest acceleration rate (a = 0.00667 h(-2)) led to a lower ethanol yield (0.40 g g(-1)) in the system where free cells were used, whereas with immobilized cells ethanol yields increased by 23 % (0.49 g g(-1)). Among the evaluated models, Monod and Levenspiel combined with Ghose and Tyagi models were found to be more appropriate for describing the kinetics of whey bioconversion into ethanol. These results may be useful in scaling up the process for ethanol production from whey.

  19. 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

  20. Uncertainty in techno-economic estimates of cellulosic ethanol production due to experimental measurement uncertainty

    Directory of Open Access Journals (Sweden)

    Vicari Kristin J

    2012-04-01

    Full Text Available Abstract Background Cost-effective production of lignocellulosic biofuels remains a major financial and technical challenge at the industrial scale. A critical tool in biofuels process development is the techno-economic (TE model, which calculates biofuel production costs using a process model and an economic model. The process model solves mass and energy balances for each unit, and the economic model estimates capital and operating costs from the process model based on economic assumptions. The process model inputs include experimental data on the feedstock composition and intermediate product yields for each unit. These experimental yield data are calculated from primary measurements. Uncertainty in these primary measurements is propagated to the calculated yields, to the process model, and ultimately to the economic model. Thus, outputs of the TE model have a minimum uncertainty associated with the uncertainty in the primary measurements. Results We calculate the uncertainty in the Minimum Ethanol Selling Price (MESP estimate for lignocellulosic ethanol production via a biochemical conversion process: dilute sulfuric acid pretreatment of corn stover followed by enzymatic hydrolysis and co-fermentation of the resulting sugars to ethanol. We perform a sensitivity analysis on the TE model and identify the feedstock composition and conversion yields from three unit operations (xylose from pretreatment, glucose from enzymatic hydrolysis, and ethanol from fermentation as the most important variables. The uncertainty in the pretreatment xylose yield arises from multiple measurements, whereas the glucose and ethanol yields from enzymatic hydrolysis and fermentation, respectively, are dominated by a single measurement: the fraction of insoluble solids (fIS in the biomass slurries. Conclusions We calculate a $0.15/gal uncertainty in MESP from the TE model due to uncertainties in primary measurements. This result sets a lower bound on the error bars of

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

    DEFF Research Database (Denmark)

    Cannella, David; Jørgensen, Henning

    2014-01-01

    proven essential for economic feasibility at industrial scale. Historically, simultaneous saccharification and fermentation (SSF) was found to give better ethanol yields compared to separate hydrolysis and fermentation (SHF), but data in literature are typically based on operating the process at low dry...... matter conditions. In this work the impact of selected enzyme preparation and processing strategy (SHF, presaccharification and simultaneous saccharification and fermentation—PSSF, and SSF) on final ethanol yield and overall performance was investigated with pretreated wheat straw up to 30% DM...... cellulose to around 94%, revealing that the most relevant products could be accounted for. One observation was the presence of oxidized sugar (gluconic acid) upon enzymatic hydrolysis with the latest enzyme preparation. Experiments showed gluconic acid formation by recently discovered enzymatic class...

  2. Analysis of transesterification comparing processes with methanol and ethanol for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Anna Leticia Montenegro Turtelli; Zorzeto, Thais Queiroz; Park, Kil Jin [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: annalets@feagri.unicamp.br; Bevilaqua, Gabriela [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2008-07-01

    The increasing demand for energy on the industrialized world stimulates researches in a renewable fuel. Biodiesel appears like an alternative and utilizes a vegetable oil or animal fat as raw material. The most common method for conversion of the raw material in fuel that can be utilized in Diesel engines is called transesterification. Brazil has a big agricultural potential to produce grains and oils. One of them is the peanut oil that is predominantly cultivated in the southeast of Brazil. There is a prevision that the peanut production reaches 232 thousand tons this year. In this work was evaluated the methanol transesterification and ethanol transesterification of peanut oil using a basic catalyst. The comparison between reactions with the two alcohols showed that methyl esters yield was greater than ethyl esters, with maximum yield of 88.04% for methanol and 84.64% for ethanol. Besides the higher yield, reactions with methanol are easily conducted than with ethanol, the biodiesel purification treatment of final product is quickly and the separation between esters and glycerol is instantaneous. (author)

  3. 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.

  4. CO2 emissions from the production and combustion of fuel ethanol from corn

    International Nuclear Information System (INIS)

    Marland, G.; Turhollow, A.F.

    1991-01-01

    This paper deals with the carbon dioxide fluxes associated with the use of one biomass fuel, ethanol derived from corn. In a sustainable agricultural system, there is no net CO 2 flux to the atmosphere from the corn itself but there is a net CO 2 flux due to the fossil-fuel supplements currently used to produce and process corn. A comparison between ethanol from corn and gasoline from crude oil becomes very complex because of the variability of corn yield, the lack of available data on corn processing, and the complexity of treating the multiple products from corn processing. When the comparison is made on an energy content basis only, with no consideration of how the products are to be used, and at the margin of the current U.S. energy system, it appears that there is a net CO 2 saving associated with ethanol from corn. This net saving in CO 2 emissions may be as large as 40% or as small as 20%, depending on how one chooses to evaluate the by-product credits. This analysis also demonstrates that the frequently posed question, whether the energy inputs to ethanol exceed the energy outputs, would not be an over-riding consideration even if it were true, because most of the inputs are as coal and natural gas, whereas the output is as a high-quality liquid fuel. (author)

  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. A systems approach for the evaluation of ethanol production based on forages

    Energy Technology Data Exchange (ETDEWEB)

    Alvo, P. [McGill Univ., Ste. Anne de Bellevue, PQ (Canada). Macdonald Coll.; Savoie, P. [Agriculture and Agri-Food Canada, Quebec, PQ (Canada). Saine-Foy Research Centre; Tremblay, D. [Laval Univ., Quebec, PQ (Canada). Dept. de Genie Rural; Emond, J.-P.; Turcotte, G. [Laval Univ., Quebec City, PQ (Canada). Dept. de Sciences et Technologie des Aliments

    1996-04-01

    A systems approach is proposed to simultaneously consider the agronomic aspects of forage production and the processing aspects related to the extraction of a glucose or xylose substrate, its fermentation into ethanol and the optimal utilization of co-products (protein meal, fibrous residue). The energy to produce and transport forage on the farm was estimated to be only 375 MJ/t dry matter (DM) when liquid manure was used and 1165 MJ/t DM when mineral fertilizer was used. An additional 126 MJ/t DM would be required to transport it to a processing plant. In contrast, whole-plant corn production using mineral fertilizer required about 3211 MJ/t DM, but it had a potential ethanol yield 3.2 times greater per unit area than perennial forage. A forage system with mechanical juice extraction resulted in 8-20% of the original forage dry matter available in a liquid substrate with subsequent protein meal separation and the fermentation of soluble sugars into ethanol. Another forage system with relatively complete conversion of cellulose and hemicellulose into simple sugars by thermal, acidic and enzymatic treatments was estimated to produce 12-28 times more ethanol per unit area than the mechanically extracted juice. Complete conversion of perennial forages would meet the petroleum industry`s needs more consistently than simple extraction of soluble components. (Author)

  7. Bacterial laminarinase for application in ethanol production from brown algae Sargassum sp. using halotolerant yeast

    Directory of Open Access Journals (Sweden)

    C.M.T. Perez

    2018-03-01

    Full Text Available Macroalgae are known to have many industrial applications, with current research targeting the potential of macroalgal biomass as feedstock in production of biofuels. Marine algal biomass is rich in storage carbohydrates, laminarin, and cellulose, which can be converted to fermentable sugars using appropriate enzymes, for fermentation to ethanol. This study focused on ethanol production from macroalgae using only enzymatic treatment for saccharification of algal biomass. This involved the isolation and identification of cellulase and laminarinase-producing microorganisms from mangrove area in the Philippines and production of partially purified enzymes for algal biomass saccharification. Results showed that the partially purified laminarinase produced from Bacillus sp. was capable of hydrolyzing the laminarin present in the macroalage. Fermentation of the algal hydrolysate yielded only small amount of ethanol due to lack of other pre-treatment methods, however, it was observed that higher ethanol was produced in saccharification treatments using a combination of cellulase and laminarinase which implies a possible synergistic effect between the two enzymes.

  8. Ethanol production by Mucor indicus and Rhizopus oryzae from rice straw by separate hydrolysis and fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Abedinifar, Sorahi [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran); Karimi, Keikhosro [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran); School of Engineering, University of Boraas, SE-501 90 Boraas (Sweden); Khanahmadi, Morteza [Isfahan Agriculture and Natural Resources Research Centre, Isfahan (Iran); Taherzadeh, Mohammad J. [School of Engineering, University of Boraas, SE-501 90 Boraas (Sweden)

    2009-05-15

    Rice straw was successfully converted to ethanol by separate enzymatic hydrolysis and fermentation by Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae. The hydrolysis temperature and pH of commercial cellulase and {beta}-glucosidase enzymes were first investigated and their best performance obtained at 45 C and pH 5.0. The pretreatment of the straw with dilute-acid hydrolysis resulted in 0.72 g g{sup -1} sugar yield during 48 h enzymatic hydrolysis, which was higher than steam-pretreated (0.60 g g{sup -1}) and untreated straw (0.46 g g{sup -1}). Furthermore, increasing the concentration of the dilute-acid pretreated straw from 20 to 50 and 100 g L{sup -1} resulted in 13% and 16% lower sugar yield, respectively. Anaerobic cultivation of the hydrolyzates with M. indicus resulted in 0.36-0.43 g g{sup -1} ethanol, 0.11-0.17 g g{sup -1} biomass, and 0.04-0.06 g g{sup -1} glycerol, which is comparable with the corresponding yields by S. cerevisiae (0.37-0.45 g g{sup -1} ethanol, 0.04-0.10 g g{sup -1} biomass and 0.05-0.07 glycerol). These two fungi produced no other major metabolite from the straw and completed the cultivation in less than 25 h. However, R. oryzae produced lactic acid as the major by-product with yield of 0.05-0.09 g g{sup -1}. This fungus had ethanol, biomass and glycerol yields of 0.33-0.41, 0.06-0.12, and 0.03-0.04 g g{sup -1}, respectively. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-01

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

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

    Science.gov (United States)

    Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

    2017-05-01

    Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

  11. 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.

  12. 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

  13. 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.

  14. Wood blocks as a carrier for Saccharomyces cerevisiae cells used in the production of fructose and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, Maryse

    1993-10-01

    The selective conversion of glucose to a product more easily separated from fructose would reduce the fructose separation problem and reduce costs of fructose purification. The production of a valuable byproduct would make the process even more profitable. Accordingly, Saccharomyces cerevisiae ATCC 39859 was immobilized onto small cubes of wood in order to produce highly enriched fructose syrup from synthetic glucose/fructose mixtures, through the selective fermentation of glucose. The kinetics of growth and byproduct ethanol production rates were measured. Tests were conducted to assess the influence of substrate and product concentration on production rates, and appropriate rate equations were proposed as a design basis for continuous immobilized reactors. The growth and ethanol production rates were found to be inhibited linearly by both substrate and product concentrations. A maximum ethanol productivity of 21.9 g/l/h was attained from a feed containing 10 wt % glucose and 10 wt % fructose. The ethanol concentration was 29.6 g/l, glucose conversion was 78%, and fructose yield was 99%, resulting in a fructose to glucose ratio of 2.7. At lower ethanol productivity levels, the fructose/glucose ratio increases, as does the ethanol concentration in the effluent. Addition of oleic acid, a known anaerobic growth factor, increased the productivity by 13%. Ethanol productivity peaked at 32.6[degree]C and approached 0 near 44[degree]C. Batch fermentation productivity was not high due to low biomass concentration leaving the reactor. Addition of yeast extract or active biomass increased productivity substantially. The immobilized cell bioreactor was also used to produce sorbitol continuously from fructose. 124 refs., 28 figs., 27 tabs.

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

    DEFF Research Database (Denmark)

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

    2018-01-01

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

  16. 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...... alcohol (azeotropic mixture) is produced from excess ethylene containing propylene and methane as impurities. The design work is based on a systematic approach consisting of 12 tasks performed in a specified hierarchy. According to this 12-tasks design procedure, information about the product and process...... of the designed process. The resulting design utilizes 75 million kg/year ethylene feed in order to obtain an ethyl alcohol production of 90.5 million kg/year. The total capital investment has been estimated to 43 million USD and the total product cost without depreciation estimated to 58.5 million USD...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  18. Ethanol production from tropical sugar beet juice

    African Journals Online (AJOL)

    Sanette

    2012-07-05

    Jul 5, 2012 ... South Africa and transport costs constitute approximately. 20% of South Africa's gross domestic product (Singh,. 2006). Globally transportation accounts for 30% of the energy demand and is responsible ..... fermentation by wine yeasts in media containing structurally complex nitrogen sources. J. Inst. Brew.

  19. Effects of Plant Growth Hormones on Mucor indicus Growth and Chitosan and Ethanol Production.

    Science.gov (United States)

    Safaei, Zahra; Karimi, Keikhosro; Golkar, Poorandokht; Zamani, Akram

    2015-07-22

    The objective of this study was to investigate the effects of indole-3-acetic acid (IAA) and kinetin (KIN) on Mucor indicus growth, cell wall composition, and ethanol production. A semi-synthetic medium, supplemented with 0-5 mg/L hormones, was used for the cultivations (at 32 °C for 48 h). By addition of 1 mg/L of each hormone, the biomass and ethanol yields were increased and decreased, respectively. At higher levels, however, an inverse trend was observed. The glucosamine fraction of the cell wall, as a representative for chitosan, followed similar but sharper changes, compared to the biomass. The highest level was 221% higher than that obtained without hormones. The sum of glucosamine and N-acetyl glucosamine (chitin and chitosan) was noticeably enhanced in the presence of the hormones. Increase of chitosan was accompanied by a decrease in the phosphate content, with the lowest phosphate (0.01 g/g cell wall) being obtained when the chitosan was at the maximum (0.45 g/g cell wall). In conclusion, IAA and KIN significantly enhanced the M. indicus growth and chitosan production, while at the same time decreasing the ethanol yield to some extent. This study shows that plant growth hormones have a high potential for the improvement of fungal chitosan production by M. indicus.

  20. Cellulase production using biomass feed stock and its application in lignocellulose saccharification for bio-ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Sukumaran, Rajeev K.; Singhania, Reeta Rani; Mathew, Gincy Marina; Pandey, Ashok [Biotechnology Division, National Institute for Interdisciplinary Science and Technology, CSIR, Trivandrum-695 019 (India)

    2009-02-15

    A major constraint in the enzymatic saccharification of biomass for ethanol production is the cost of cellulase enzymes. Production cost of cellulases may be brought down by multifaceted approaches which include the use of cheap lignocellulosic substrates for fermentation production of the enzyme, and the use of cost efficient fermentation strategies like solid state fermentation (SSF). In the present study, cellulolytic enzymes for biomass hydrolysis were produced using solid state fermentation on wheat bran as substrate. Crude cellulase and a relatively glucose tolerant BGL were produced using fungi Trichoderma reesei RUT C30 and Aspergillus niger MTCC 7956, respectively. Saccharification of three different feed stock, i.e. sugar cane bagasse, rice straw and water hyacinth biomass was studied using the enzymes. Saccharification was performed with 50 FPU of cellulase and 10 U of {beta}-glucosidase per gram of pretreated biomass. Highest yield of reducing sugars (26.3 g/L) was obtained from rice straw followed by sugar cane bagasse (17.79 g/L). The enzymatic hydrolysate of rice straw was used as substrate for ethanol production by Saccharomyces cerevisiae. The yield of ethanol was 0.093 g per gram of pretreated rice straw. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

  2. Effect of oleic acid on the production of ethanol and fructose from glucose/fructose mixtures in an immobilized cell reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guenette, M E [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; [IOGEN Corp., Ottawa, ON (Canada); Duvnjak, Z [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; [IOGEN Corp., Ottawa, ON (Canada)

    1996-12-31

    Saccharomyces cerevisiae ATCC 39859 was immobilized onto small cubes of wood to produce ethanol and very enriched fructose syrup from glucose/fructose mixtures through the selective fermentation of glucose. A maximum ethanol productivity of 21.9 g/l.h was attained from a feed containing 9.7% (w/v) glucose and 9.9% (w/v) fructose. An ethanol concentration, glucose conversion and fructose yield of 29.6 g/l, 62% and 99% were obtained, respectively. This resulted in a final fructose/glucose ratio of 2.7. At lower ethanol productivity levels the fructose/glucose ratio increases, as does the ethanol concentration in the effluent. The addition of 30 mg/l oleic acid to the medium increased the ethanol productivity and its concentration by 13% at a dilution rate of 0.74 h{sup -1}. (orig.)

  3. 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

  4. Co-solvent pretreatment reduces costly enzyme requirements for high sugar and ethanol yields from lignocellulosic biomass.

    Science.gov (United States)

    Nguyen, Thanh Yen; Cai, Charles M; Kumar, Rajeev; Wyman, Charles E

    2015-05-22

    We introduce a new pretreatment called co-solvent-enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low-cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme  gglucan (-1) . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF-pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute-acid-pretreated solids if both were optimized for corn stover. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Directory of Open Access Journals (Sweden)

    Christakopoulos Paul

    2009-02-01

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

  6. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Extreme thermophilic ethanol production from rapeseed straw: using the newly isolated Thermoanaerobacter pentosaceus and combining it with Saccharomyces cerevisiae in a two-step process

    DEFF Research Database (Denmark)

    Tomás, Ana Faria; Karagöz, Pınar; Karakashev, Dimitar Borisov

    2013-01-01

    from the liquid fraction of pretreated rapeseed straw, without any dilution or need for additives. However, when the hydrolysate was used undiluted the ethanol yield was only 37% compared to yield of the control, in which pure sugars in synthetic medium were used. The decrease of ethanol yield...... showed that the two strains together could achieve up to 85% of the theoretical ethanol yield based on the sugar composition of the rapeseed straw, which was 14% and 50% higher compared to the yield with the yeast or the bacteria alone, respectively. Biotechnol. Bioeng. © 2012 Wiley Periodicals, Inc.......The newly isolated extreme thermophile Thermoanaerobacter pentosaceus was used for ethanol production from alkaline-peroxide pretreated rapeseed straw (PRS). Both the liquid and solid fractions of PRS were used. T. pentosaceus was able to metabolize the typical process inhibitors present...

  9. Effects of NADH-preferring xylose reductase expression on ethanol production from xylose in xylose-metabolizing recombinant Saccharomyces cerevisiae.

    Science.gov (United States)

    Lee, Sung-Haeng; Kodaki, Tsutomu; Park, Yong-Cheol; Seo, Jin-Ho

    2012-04-30

    Efficient conversion of xylose to ethanol is an essential factor for commercialization of lignocellulosic ethanol. To minimize production of xylitol, a major by-product in xylose metabolism and concomitantly improve ethanol production, Saccharomyces cerevisiae D452-2 was engineered to overexpress NADH-preferable xylose reductase mutant (XR(MUT)) and NAD⁺-dependent xylitol dehydrogenase (XDH) from Pichia stipitis and endogenous xylulokinase (XK). In vitro enzyme assay confirmed the functional expression of XR(MUT), XDH and XK in recombinant S. cerevisiae strains. The change of wild type XR to XR(MUT) along with XK overexpression led to reduction of xylitol accumulation in microaerobic culture. More modulation of the xylose metabolism including overexpression of XR(MUT) and transaldolase, and disruption of the chromosomal ALD6 gene encoding aldehyde dehydrogenase (SX6(MUT)) improved the performance of ethanol production from xylose remarkably. Finally, oxygen-limited fermentation of S. cerevisiae SX6(MUT) resulted in 0.64 g l⁻¹ h⁻¹ xylose consumption rate, 0.25 g l⁻¹ h⁻¹ ethanol productivity and 39% ethanol yield based on the xylose consumed, which were 1.8, 4.2 and 2.2 times higher than the corresponding values of recombinant S. cerevisiae expressing XR(MUT), XDH and XK only. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Viability and application of ethanol production coupled with solar cooling

    International Nuclear Information System (INIS)

    Americano da Costa, Marcus V.; Pasamontes, Manuel; Normey-Rico, Julio E.; Guzmán, José L.; Berenguel, Manuel

    2013-01-01

    Highlights: ► Two types of clean energy were analized together: bioethanol and solar. ► The ethanol fermentation process was modeled. ► An advanced control was implemented in the unit model. ► A real plant of solar energy was operated. ► The experiments were performed using the Hardware in the Loop technique. -- Abstract: This work presents a combined optimization system to use solar energy as support for the ethanol industry. Solar radiation is used to produce energy in order to assist the cooling systems in the fermentation process. The experiments have been performed following a hardware in the loop technique by mixing the solar cooling plant in the Centro de Investigación de Energía Solar (CIESOL) located at the University of Almería (Spain), and a simulator of ethanol fermentation processes in Brazilian factories. The results are analyzed in detail to show the main advantages (important increment in ethanol production and use of clean energies) compared to the mode of operation of the current factories in Brazil.

  11. Steam pretreatment of dry and ensiled industrial hemp for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Sipos, Balint; Reczey, Kati [Budapest University of Technology and Economics, Department of Applied Biotechnology and Food Science, Szt. Gellert ter 4., H-1111 Budapest (Hungary); Kreuger, Emma; Bjoernsson, Lovisa [Lund University, Department of Biotechnology, P.O. Box 124, SE-221 00 Lund (Sweden); Svensson, Sven-Erik [Swedish University of Agricultural Sciences, Department of Agriculture - Farming Systems, Technology and Product Quality, P.O. Box 104, SE-230 53 Alnarp (Sweden); Zacchi, Guido [Lund University, Department of Chemical Engineering, P.O. Box 124, SE-221 00 Lund (Sweden)

    2010-12-15

    Biomass can be converted into liquid and gaseous biofuels with good efficiency. In this study, the conversion of industrial hemp (Cannabis sativa L.), a biomass source that can be cultivated with a high biomass yield per hectare, was used. Steam pretreatment of dry and ensiled hemp was investigated prior to ethanol production. The pretreatment efficiency was evaluated in terms of sugar recovery and polysaccharide conversion in the enzymatic hydrolysis step. For both materials, impregnation with 2% SO{sub 2} followed by steam pretreatment at 210 C for 5 min were found to be the optimal conditions leading to the highest overall yield of glucose. Simultaneous saccharification and fermentation experiments carried out with optimised pretreatment conditions resulted in ethanol yields of 163 g kg{sup -1} ensiled hemp (dry matter) (71% of the theoretical maximum) and 171 g kg{sup -1} dry hemp (74%), which corresponds to 206-216 l Mg{sup -1} ethanol based on initial dry material. (author)

  12. Ethanol production from olive prunings by autohydrolysis and fermentation with Candida tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Martin, Juan Francisco; Bravo, Vicente [Department of Chemical Engineering, University of Granada, Campus Universitario de Fuentenueva, 18071 Granada (Spain); Cuevas, Manuel; Sanchez, Sebastian [Department of Chemical, Environmental and Materials Engineering, University of Jaen, Campus Las Lagunillas, 23071 Jaen (Spain)

    2010-07-15

    Hydrolysates from olive prunings (a renewable, low-cost, easily available, agricultural residue) were fermented with the unconventional yeast Candida tropicalis NBRC 0618 to produce not only ethanol fuel but also xylitol as a by-product, which adds value to the economic viability of the bioprocess. Autohydrolysis took place at 200 C in a stirred stainless-steel tank reactor. The influence of the solid/liquid ratio in the reactor was studied. Fermentation experiments were conducted in a batch-culture reactor at a temperature of 30 C, a stirring rate of 500 rpm and pH values of between 5.0 and 6.5. Under the operating conditions tested the highest yields of ethanol and xylitol were obtained with the hydrolysate fermented at pH 5.0 and solely the airflow that entered via the stirring vortex. Under these conditions, the instantaneous ethanol yield was 0.44 g g{sup -1} and the overall xylitol yield 0.13 g g{sup -1}. (author)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  14. Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw.

    Science.gov (United States)

    Todhanakasem, Tatsaporn; Tiwari, Rashmi; Thanonkeo, Pornthap

    2016-01-01

    Z. mobilis cell immobilization has been proposed as an effective means of improving ethanol production. In this work, polystyrene and corn silk were used as biofilm developmental matrices for Z. mobilis ethanol production with rice straw hydrolysate as a substrate. Rice straw was hydrolyzed by dilute sulfuric acid (H2SO4) and enzymatic hydrolysis. The final hydrolysate contained furfural (271.95 ± 76.30 ppm), 5-hydroxymethyl furfural (0.07 ± 0.00 ppm), vanillin (1.81 ± 0.00 ppm), syringaldehyde (5.07 ± 0.83 ppm), 4-hydroxybenzaldehyde (4-HB) (2.39 ± 1.20 ppm) and acetic acid (0.26 ± 0.08%). Bacterial attachment or biofilm formation of Z. mobilis strain TISTR 551 on polystyrene and delignified corn silk carrier provided significant ethanol yields. Results showed up to 0.40 ± 0.15 g ethanol produced/g glucose consumed when Z. mobilis was immobilized on a polystyrene carrier and 0.51 ± 0.13 g ethanol produced/g glucose consumed when immobilized on delignified corn silk carrier under batch fermentation by Z. mobilis TISTR 551 biofilm. The higher ethanol yield from immobilized, rather than free living, Z. mobilis could possibly be explained by a higher cell density, better control of anaerobic conditions and higher toxic tolerance of Z. mobilis biofilms over free cells.

  15. 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

  16. Enhancing ethanol yields through d-xylose and l-arabinose co-fermentation after construction of a novel high efficient l-arabinose-fermenting Saccharomyces cerevisiae strain.

    Science.gov (United States)

    Caballero, Antonio; Ramos, Juan Luis

    2017-04-01

    Lignocellulose contains two pentose sugars, l-arabinose and d-xylose, neither of which is naturally fermented by first generation (1G) ethanol-producing Saccharomyces cerevisiae yeast. Since these sugars are inaccessible to 1G yeast, a significant percentage of the total carbon in bioethanol production from plant residues, which are used in second generation (2G) ethanol production, remains unused. Recombinant Saccharomyces cerevisiae strains capable of fermenting d-xylose are available on the market; however, there are few examples of l-arabinose-fermenting yeasts, and commercially, there are no strains capable of fermenting both d-xylose and l-arabinose because of metabolic incompatibilities when both metabolic pathways are expressed in the same cell. To attempt to solve this problem we have tested d-xylose and l-arabinose co-fermentation. To find efficient alternative l-arabinose utilization pathways to the few existing ones, we have used stringent methodology to screen for new genes (metabolic and transporter functions) to facilitate l-arabinose fermentation in recombinant yeast. We demonstrate the feasibility of this approach in a successfully constructed yeast strain capable of using l-arabinose as the sole carbon source and capable of fully transforming it to ethanol, reaching the maximum theoretical fermentation yield (0.43 g g-1). We demonstrate that efficient co-fermentation of d-xylose and l-arabinose is feasible using two different co-cultured strains, and observed no fermentation delays, yield drops or accumulation of undesired byproducts. In this study we have identified a technically efficient strategy to enhance ethanol yields by 10 % in 2G plants in a process based on C5 sugar co-fermentation.

  17. Energy analysis of ethanol production from sweet sorghum

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

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

  18. Investigating the potential of thermophilic species for ethanol production from industrial spent sulfite liquor

    Directory of Open Access Journals (Sweden)

    Michaela Weissgram

    2015-10-01

    Full Text Available Thermophilic microorganisms hold a great potential for bioethanol production on waste biomass, due to their ability to utilize pentoses and hexoses alike. However, to date hardly any data on thermophiles growing directly on industrial substrates like spent sulfite liquor (SSL are available. This contribution investigates the ability of Thermoanaerobacter species to utilize the main sugars in the used SSL (mannose, glucose and xylose and the effect of process parameters (pH, temperature and sugar concentration on their growth. Based on these results the strain T. mathranii was chosen for further studies. The ability of T. mathranii to grow directly on SSL was investigated and the effect of several inhibiting substances on growth was elucidated. Furthermore it was tested whether pretreatment with activated charcoal can increase the fermentability of SSL. The fermentations were evaluated based on yields and specific rates. It could be shown that T. mathranii was able to ferment all sugars in the investigated softwood SSL and fermented diluted, untreated SSL (up to 2.7% (w/w dry matter. Pretreatment with activated charcoal could slightly reduce the amount of phenols in the substrate and thus facilitate growth and ethanol production on higher SSL concentrations (up to 4.7% (w/v dry matter. Ethanol yields of 0.29-0.44 Cmmol of ethanol per Cmmol sugar were obtained on untreated and pretreated spent sulfite liquor, respectively. These results on an industrial substrate strengthen the claim that thermophilic microorganisms might be the optimal candidates for forest biorefinery.

  19. Ethanol from sugar beet in The Netherlands: energy production and efficiency

    NARCIS (Netherlands)

    Langeveld, J.W.A.; Ven, van de G.W.J.; Vries, de S.C.; Brink, van den L.; Visser, de C.L.M.

    2014-01-01

    Prospects for ethanol production from sugar beet in The Netherlands have been analysed using measured production data from two experimental farms and literature on beet to ethanol conversion. The analyses include beet cultivation and harvesting, transport to the factory, conversion into ethanol and

  20. 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...

  1. Performances comparison between three technologies for continuous ethanol production from molasses

    International Nuclear Information System (INIS)

    Bouallagui, Hassib; Touhami, Youssef; Hanafi, Nedia; Ghariani, Amine; Hamdi, Moktar

    2013-01-01

    Molasses are a potential feedstock for ethanol production. The successful application of anaerobic fermentation for ethanol production from molasses is critically dependent to the development and the use of high rate bioreactors. In this study the fermentation of sugar cane molasses by Saccharomyces cerevisiae for the ethanol production in a continuously stirred tank reactor (CSTR), an immobilised cell reactor (ICR) and a membrane reactor (MBR) was investigated. Ethanol production and reactor productivities were compared under different dilution rates (D). When using the CSTR, a decent ethanol productivity (Qp) of 6.8 g L −1 h −1 was obtained at a dilution rate of 0.5 h −1 . The Qp was improved by 48% and the residual sugar concentration was reduced by using the ICR. Intensifying the production of ethanol was investigated in the MBR to achieve a maximum ethanol concentration and a Qp of 46.5 g L −1 and 19.2 g L −1 h −1 , respectively. The achieved results in the MBR worked with high substrate concentration are promising for the scale up operation. -- Highlights: ► We compare three reactors for ethanol production from sugar cane molasses. ► The ethanol productivity of 6.8 g L -1 h -1 was obtained using the CSTR. ► The ethanol productivity was improved by 48% by using the ICR. ► Intensifying ethanol productivity (19.2 g L -1 h -1 ) was investigated in the MBR

  2. Ethanol production from lignocellulosic materials. Fermentation and on-line analysis

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, L.

    1994-04-01

    The fermentation performance of bacteria, yeast and fungi was investigated in lignocellulosic hydrolysates with the aim of finding microorganisms which both withstand the inhibitors and that have the ability to ferment pentoses. Firstly, the performance of Saccharomyces cidri, Saccharomyces cerevisiae, Lactobacillus brevis, Lactococcus lactis ssp lactis, Escherichia coli and Zymomonas mobilis was investigated in spent sulphite liquor and enzymatic hydrolysate of steam-pretreated willow. Secondly, the performance of natural and recombinant E. coli, Pichia stipitis, recombinant S. cerevisiae, S. cerevisiae in combination with xylose isomerase and Fusarium oxysporum was investigated in a xylose-rich acid hydrolysate of corn cob. Recombinant E. coli was the best alternative for fermentation of lignocellulosic hydrolysates, giving both high yields and productivities. The main drawback was that detoxification was necessary. The kinetics of the fermentation with recombinant E. coli KO11 was investigated in the condensate of steam-pretreated willow. A cost analysis of the ethanol production from willow was made, which predicted an ethanol production cost of 3.9 SEK/l for the pentose fermentation. The detoxification cost constituted 22% of this cost. The monitoring of three monosaccharides and ethanol in lignocellulosic hydro lysates is described. The monosaccharides were determined using immobilized pyranose oxidase in an on-line amperometric analyser. Immobilization and characterization of pyranose oxidase from Phanerochaete chrysosporium is also described. The ethanol was monitored on-line using a micro dialysis probe as an in situ sampling device. The dialysate components were then separated in a column liquid chromatographic system and the ethanol was selectively detected by an amperometric alcohol bio sensor. The determinations with on-line analysis methods agreed well with off-line methods. 248 refs, 4 figs, 12 tabs

  3. 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...... production was examined. When substrate concentration was controlled at 100 mM total carbon, hydrogen was used as an additional electron donor. The highest caproate concentration of 3.11 g/L was obtained at an ethanol/acetate ratio of 7:3. No additional electron donor was needed upon an ethanol/acetate ratio...... ≥7:3. Caproate production increased with the increase of carbon source until ethanol concentration over 700 mM, which inhibited the fermentation process. The highest caproate concentration of 8.42 g/L was achieved from high ethanol strength wastewater with an ethanol/acetate ratio of 10:1 (550 m...

  4. Membrane bioreactors' potential for ethanol and biogas production: a review.

    Science.gov (United States)

    Ylitervo, Päivi; Akinbomia, Julius; Taherzadeha, Mohammad J

    2013-01-01

    Companies developing and producing membranes for different separation purposes, as well as the market for these, have markedly increased in numbers over the last decade. Membrane and separation technology might well contribute to making fuel ethanol and biogas production from lignocellulosic materials more economically viable and productive. Combining biological processes with membrane separation techniques in a membrane bioreactor (MBR) increases cell concentrations extensively in the bioreactor. Such a combination furthermore reduces product inhibition during the biological process, increases product concentration and productivity, and simplifies the separation of product and/or cells. Various MBRs have been studied over the years, where the membrane is either submerged inside the liquid to be filtered, or placed in an external loop outside the bioreactor. All configurations have advantages and drawbacks, as reviewed in this paper. The current review presents an account of the membrane separation technologies, and the research performed on MBRs, focusing on ethanol and biogas production. The advantages and potentials of the technology are elucidated.

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

    Science.gov (United States)

    Bátori, Veronika; Ferreira, Jorge A; Taherzadeh, Mohammad J; Lennartsson, Patrik R

    2015-01-01

    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 m(3) 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 m(3) ethanol/year.

  6. 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.

  7. Status of fission product yield data

    International Nuclear Information System (INIS)

    Cuninghame, J.G.

    1978-01-01

    The topics covered in this paper are: (a) cumulative yields in thermal neutron fission and in fast fission up to 14 MeV incident neutron energy, (b) dependence of the yields on incident neutron energy and spectrum, (c) independent yields, (d) charge dispersion and distribution, and (e) yields of light particles from ternary fission. The paper reviews information on these subjects for fission of actinides from 232 Th upwards with special emphasis on data published since the 1973 Bologna FPND Panel, compares data sets, and discusses the gaps still to be found in them. (author)

  8. 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. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. Physico-chemical parameter for production of lactic acid or ethanol of (corynebacterium glutamicum) bacteria

    International Nuclear Information System (INIS)

    Castellanos, Angelica; Garcia, Lina Marcela; Astudillo, Myriam; Lopez Galan, Jorge Enrique; Florez Pardo, Luz Marina.

    2011-01-01

    The interest to obtain products for the bio-fuel industry from renewable resources has directed research to find resistant and costs-effective biotechnological systems. Corynebacterium glutamicum, is a microorganism used to produce amino acids, that grows in wide variety of substrates and its resistance during fermentation to pH, temperature, osmotic pressure variations and alcohol aggregate, renders this organism a suitable candidate to improve by genetic modifications lactic acid and ethanol synthesis. However, some aspects of its physiology remain unknown, such us increase lactic acid and ethanol production from C5 and C6 sugars. For this reason, the main aim in our work was to identify the most important variables with impact on culture and the best culture conditions to produce lactic acid or ethanol in batch culture. To achieve this objective, eight variables were tested in culture using a statistical model. The best culture conditions were obtained and tested in a bacth bioreactor system. Temperature, biotin and glucose concentration were the variables with most impact (p - 1 , 16 g/l of lactic acid was obtained after 15 h of culture with an efficiency of 32%. High glucose consumption was observed during bacterial growth, which leads to low concentration of substrate for the production process; this suggests a culture feeding at the end of exponential growth phase, which can increase the production yield.

  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. Separate hydrolysis and co-fermentation for improved xylose utilization in integrated ethanol production from wheat meal and wheat straw

    Directory of Open Access Journals (Sweden)

    Erdei Borbála

    2012-03-01

    Full Text Available Abstract Background The commercialization of second-generation bioethanol has not been realized due to several factors, including poor biomass utilization and high production cost. It is generally accepted that the most important parameters in reducing the production cost are the ethanol yield and the ethanol concentration in the fermentation broth. Agricultural residues contain large amounts of hemicellulose, and the utilization of xylose is thus a plausible way to improve the concentration and yield of ethanol during fermentation. Most naturally occurring ethanol-fermenting microorganisms do not utilize xylose, but a genetically modified yeast strain, TMB3400, has the ability to co-ferment glucose and xylose. However, the xylose uptake rate is only enhanced when the glucose concentration is low. Results Separate hydrolysis and co-fermentation of steam-pretreated wheat straw (SPWS combined with wheat-starch hydrolysate feed was performed in two separate processes. The average yield of ethanol and the xylose consumption reached 86% and 69%, respectively, when the hydrolysate of the enzymatically hydrolyzed (18.5% WIS unwashed SPWS solid fraction and wheat-starch hydrolysate were fed to the fermentor after 1 h of fermentation of the SPWS liquid fraction. In the other configuration, fermentation of the SPWS hydrolysate (7.0% WIS, resulted in an average ethanol yield of 93% from fermentation based on glucose and xylose and complete xylose consumption when wheat-starch hydrolysate was included in the feed. Increased initial cell density in the fermentation (from 5 to 20 g/L did not increase the ethanol yield, but improved and accelerated xylose consumption in both cases. Conclusions Higher ethanol yield has been achieved in co-fermentation of xylose and glucose in SPWS hydrolysate when wheat-starch hydrolysate was used as feed, then in co-fermentation of the liquid fraction of SPWS fed with the mixed hydrolysates. Integration of first-generation and

  12. A Mutated Yeast Strain with Enhanced Ethanol Production Efficiency and Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Naghmeh Hemmati1*, David A. Lightfoot1,2, and Ahmed Fakhoury3

    2012-05-01

    Full Text Available One of the strategies to improve and optimize bio-ethanolproduction from new feed stocks is to develop new strainsof Saccharomyces cerevisiae with tolerance to stresses. Themain objectives here were to; generate S. cerevisiae mutantstolerant to high ethanol concentrations; test for their abilityto ferment maize starch; and partially characterize the mutationsresponsible for the new phenotypes. A combinationof mutagenesis, selection and cross-stress protection methodswere used. EMS (ethyl methanesulfonate was used tomutagenize one S. cerevisiae strain. The mutagenized yeaststrain was exposed to high concentrations of ethanol andtolerant mutants were isolated. Mutants showed improvedethanol yield (0.02-0.03 g/g of maize and fermentation efficiency(3-5%. Finally, AFLP (Amplified Fragment LengthPolymorphism was performed to identify polymorphisms inthe mutants that might underlie the strains ethanol tolerance.The best performing mutant isolate had four altered genetranscripts encoding; an arginine uptake and canavanine resistanceprotein (CAN1; mitochondrial membrane proteins(SLS1; a putative membrane glycoprotein (VTH1; and cytochromeC oxidase (COX6; EC 1.9.3.1 among about 1,000tested. It was concluded these mutations might underlie theimproved ethanol production efficiency and stress tolerance.

  13. 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.

  14. New approaches for improving the production of the 1st and 2nd generation ethanol by yeast.

    Science.gov (United States)

    Kurylenko, Olena; Semkiv, Marta; Ruchala, Justyna; Hryniv, Orest; Kshanovska, Barbara; Abbas, Charles; Dmytruk, Kostyantyn; Sibirny, Andriy

    2016-01-01

    Increase in the production of 1st generation ethanol from glucose is possible by the reduction in the production of ethanol co-products, especially biomass. We have developed a method to reduce biomass accumulation of Saccharomyces cerevisiae by the manipulation of the intracellular ATP level due to overexpression of genes of alkaline phosphatase, apyrase or enzymes involved in futile cycles. The strains constructed accumulated up to 10% more ethanol on a cornmeal hydrolysate medium. Similar increase in ethanol accumulation was observed in the mutants resistant to the toxic inhibitors of glycolysis like 3-bromopyruvate and others. Substantial increase in fuel ethanol production will be obtained by the development of new strains of yeasts that ferment sugars of the abundant lignocellulosic feedstocks, especially xylose, a pentose sugar. We have found that xylose can be fermented under elevated temperatures by the thermotolerant yeast, Hansenula polymorpha. We combined protein engineering of the gene coding for xylose reductase (XYL1) along with overexpression of the other two genes responsible for xylose metabolism in yeast (XYL2, XYL3) and the deletion of the global transcriptional activator CAT8, with the selection of mutants defective in utilizing ethanol as a carbon source using the anticancer drug, 3-bromopyruvate. Resulted strains accumulated 20-25 times more ethanol from xylose at the elevated temperature of 45°C with up to 12.5 g L(-1) produced. Increase in ethanol yield and productivity from xylose was also achieved by overexpression of genes coding for the peroxisomal enzymes: transketolase (DAS1) and transaldolase (TAL2), and deletion of the ATG13 gene.

  15. Optimization of prehydrolysis time and substrate feeding to improve ethanol production by simultaneous saccharification and fermentation of furfural process residue.

    Science.gov (United States)

    He, Jianlong; Zhang, Wenbo; Liu, Xiaoyan; Xu, Ning; Xiong, Peng

    2016-11-01

    Ethanol is a very important industrial chemical. In order to improve ethanol productivity using Saccharomyces cerevisiae in fermentation from furfural process residue, we developed a process of simultaneous saccharification and fermentation (SSF) of furfural process residue, optimizing prehydrolysis cellulase loading concentration, prehydrolysis time, and substrate feeding strategy. The ethanol concentration obtained from the optimized process was 19.3 g/L, corresponding 76.5% ethanol yield, achieved by running SSF for 48 h from 10% furfural process residue with prehydrolysis at 50°C for 4 h and cellulase loading of 15 FPU/g furfural process residue. For higher ethanol concentrations, fed-batch fermentation was performed. The optimized fed-batch process increased the ethanol concentration to 37.6 g/L, 74.5% yield, obtained from 10% furfural process residue with two additions of 5% substrate at 12 and 24 h. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Development of rapid bioconversion with integrated recycle technology for ethanol production from extractive ammonia pretreated corn stover.

    Science.gov (United States)

    Jin, Mingjie; Liu, Yanping; da Costa Sousa, Leonardo; Dale, Bruce E; Balan, Venkatesh

    2017-08-01

    High enzyme loading and low productivity are two major issues impeding low cost ethanol production from lignocellulosic biomass. This work applied rapid bioconversion with integrated recycle technology (RaBIT) and extractive ammonia (EA) pretreatment for conversion of corn stover (CS) to ethanol at high solids loading. Enzymes were recycled via recycling unhydrolyzed solids. Enzymatic hydrolysis with recycled enzymes and fermentation with recycled yeast cells were studied. Both enzymatic hydrolysis time and fermentation time were shortened to 24 h. Ethanol productivity was enhanced by two times and enzyme loading was reduced by 30%. Glucan and xylan conversions reached as high as 98% with an enzyme loading of as low as 8.4 mg protein per g glucan. The overall ethanol yield was 227 g ethanol/kg EA-CS (191 g ethanol/kg untreated CS). Biotechnol. Bioeng. 2017;114: 1713-1720. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

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

    2010-11-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  19. Effect of structural characteristics of corncob hemicelluloses fractionated by graded ethanol precipitation on furfural production.

    Science.gov (United States)

    Li, Huiling; Dai, Qingqing; Ren, Junli; Jian, Longfei; Peng, Feng; Sun, Runcang; Liu, Guoliang

    2016-01-20

    In the present study, a graded ethanol precipitation technique was employed to obtain hemicelluloses from the alkali-extracted corncob liquid. The relationship between the structural characteristics of alkali-soluble corncob hemicelluloses and the production of furfural was investigated by a heterogeneous process in a biphasic system. Results showed that alkali-soluble corncob hemicelluloses mainly consisted of glucuronoarabinoxylans and L-arabino-(4-O-methylglucurono)-D-xylans, and the drying way had less influence on the sugar composition, molecular weights and the functional groups of hemicelluloses obtained by the different ethanol concentration precipitation except for the thermal property, the amorphous structure and the ability for the furfural production. Furthermore, alkali-soluble corncob hemicelluloses with higher xylose content, lower branch degree, higher polydispersity and crystallinity contributed to the furfural production. A highest furfural yield of 45.41% with the xylose conversion efficiency of 99.06% and the furfural selectivity of 45.84% was obtained from the oven-dried hemicelluloses precipitated at the 30% (v/v) ethanol concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Modelling the growth and ethanol production of Brettanomyces bruxellensis at different glucose concentrations.

    Science.gov (United States)

    Aguilar-Uscanga, M G; Garcia-Alvarado, Y; Gomez-Rodriguez, J; Phister, T; Delia, M L; Strehaiano, P

    2011-08-01

    To study the effect of glucose concentrations on the growth by Brettanomyces bruxellensis yeast strain in batch experiments and develop a mathematical model for kinetic behaviour analysis of yeast growing in batch culture. A Matlab algorithm was developed for the estimation of model parameters. Glucose fermentation by B. bruxellensis was studied by varying its concentration (5, 9.3, 13.8, 16.5, 17.6 and 21.4%). The increase in substrate concentration up to a certain limit was accompanied by an increase in ethanol and biomass production; at a substrate concentration of 50-138 g l(-1), the ethanol and biomass production were 24, 59 and 6.3, 11.4 g l(-1), respectively. However, an increase in glucose concentration to 165 g l(-1) led to a drastic decrease in product formation and substrate utilization. The model successfully simulated the batch kinetic observed in all cases. The confidence intervals were also estimated at each phase at a 0.95 probability level in a t-Student distribution for f degrees of freedom. The maximum ethanol and biomass yields were obtained with an initial glucose concentration of 138 g l(-1). These experiments illustrate the importance of using a mathematical model applied to kinetic behaviour on glucose concentration by B. bruxellensis. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  1. Fed-batch production of concentrated fructose syrup and ethanol using Saccharomyces cerevisiae ATCC 36859

    Energy Technology Data Exchange (ETDEWEB)

    Koren, D W [CANMET, Ottawa, ON (Canada); Duvnjak, Z [Univ. of Ottawa, ON (Canada). Dept. of Chemical Engineering

    1992-01-01

    A fed-batch process is used for the production of concentrated pure fructose syrup and ethanol from various glucose/fructose mixtures by S.cerevisiae ATCC 36859. Applying this technique, glucose-free fructose syrups with over 250 g/l of this sugar were obtained using High Fructose Corn Syrup and hydrolyzed Jerusalem artichoke juice. Bey encouraging ethanol evaporation from the reactor and condensing it, a separate ethanol product with a concentration of up to 350 g/l was also produced. The rates of glucose consumption and ethanol production were higher than in classical batch ethanol fermentation processes. (orig.).

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

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, U

    1986-07-03

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

  3. Ethanol production from a biomass mixture of furfural residues with green liquor-peroxide saccarified cassava liquid.

    Science.gov (United States)

    Ji, Li; Zheng, Tianran; Zhao, Pengxiang; Zhang, Weiming; Jiang, Jianxin

    2016-06-01

    As the most abundant renewable resources, lignocellulosic materials are ideal candidates as alternative feedstock for bioethanol production. Cassava residues (CR) are byproducts of the cassava starch industry which can be mixed with lignocellulosic materials for ethanol production. The presence of lignin in lignocellulosic substrates can inhibit saccharification by reducing the cellulase activity. Simultaneous saccharification and fermentation (SSF) of furfural residues (FR) pretreated with green liquor and hydrogen peroxide (GL-H2O2) with CR saccharification liquid was investigated. The final ethanol concentration, yield, initial rate, number of live yeast cells, and the dead yeast ratio were compared to evaluate the effectiveness of combining delignificated lignocellulosic substrates and starchy substrates for ethanol production. Our results indicate that 42.0 % of FR lignin removal was achieved on FR using of 0.06 g H2O2/g-substrate and 9 mL GL/g-substrate at 80 °C. The highest overall ethanol yield was 93.6 % of the theoretical. When the ratio of 0.06 g/g-H2O2-GL-pretreated FR to CR was 5:1, the ethanol concentration was the same with that ratio of untreated FR to CR of 1:1. Using 0.06 g/g-H2O2-GL-pretreated FR with CR at a ratio of 2:1 resulted in 51.9 g/L ethanol concentration. Moreover, FR pretreated with GL-H2O2 decreased the concentration of byproducts in SSF compared with that obtained in the previous study. The lignin in FR would inhibit enzyme activity and GL-H2O2 is an advantageous pretreatment method to treat FR and high intensity of FR pretreatment increased the final ethanol concentration. The efficiency of ethanol fermentation of was improved when delignification increased. GL-H2O2 is an advantageous pretreatment method to treat FR. As the pretreatment dosage of GL-H2O2 on FR increased, the proportion of lignocellulosic substrates was enhanced in the SSF of the substrate mixture of CR and FR as compared with untreated FR. Moreover, the

  4. Optimization of the production of ethyl esters by ultrasound assisted reaction of soybean oil and ethanol

    Directory of Open Access Journals (Sweden)

    S. Rodrigues

    2009-06-01

    Full Text Available Biodiesel is a renewable liquid fuel that can be produced by a transesterification reaction between a vegetable oil and an alcohol. This paper evaluates and optimizes the production of ethyl esters (biodiesel from soybean oil and ethanol. The reaction was carried out by applying ultrasound under atmospheric pressure and ambient temperature. Response surface methodology was used to evaluate the influence of alcohol to oil molar ratio and catalyst concentration on the yield of conversion of soybean oil into ethyl esters. The process resulted in a maximum yield of 91.8% after 30 minutes of reaction. The process variables alcohol to oil ratio and catalyst to oil ratio were statistically significant regarding the yield of ethyl esters. The optimal operating condition was obtained applying an alcohol to oil molar ratio of 10.2 and a catalyst to oil weight ratio of 0.0035.

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

    International Nuclear Information System (INIS)

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

    2011-10-01

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

  6. optimization of the ethanol fermentation of cassava wastewater

    African Journals Online (AJOL)

    Umo

    production would improve the ethanol yield, and thereby reduce the cost of production. KEYWORDS: Ethanol, cassava ... biomass sources are receiving attention globally. .... HYDROLYZED CASSAVA WASTEWATER. A blank solution ..... A Global Overview of Biomass Potentials ... Pretreatment of Lignocellulosic Wastes.

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

    Directory of Open Access Journals (Sweden)

    Fengqin Gao

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

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

    Science.gov (United States)

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

    2014-01-01

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

  9. 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

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

    DEFF Research Database (Denmark)

    Cannella, David

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

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

    International Nuclear Information System (INIS)

    Lythcke-Jørgensen, Christoffer; Haglind, Fredrik; Clausen, Lasse R.

    2014-01-01

    Highlights: • We model a system where lignocellulosic ethanol production is integrated with a combined heat and power (CHP) plant. • We conduct an exergy analysis for the ethanol production in six different system operation points. • Integrated operation, district heating (DH) production and low CHP loads all increase the exergy efficiency. • Separate operation has the largest negative impact on the exergy efficiency. • Operation is found to have a significant impact on the exergy efficiency of the ethanol production. - Abstract: Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol 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, and a gas boiler is used as back-up when integration is not possible. The system was evaluated according to six operation points that alternate on the following three different operation parameters: Load in the CHP unit, integrated versus separate operation, and inclusion of district heating production in the ethanol facility. The calculated standard exergy efficiency of the ethanol facility varied from 0.564 to 0.855, of which the highest was obtained for integrated operation at reduced CHP load and full district heating production in the ethanol facility, and the lowest for separate operation with zero 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

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

    Directory of Open Access Journals (Sweden)

    Bondesson Pia-Maria

    2013-01-01

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

  13. 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.

  14. Evaluation of factors that may influence the simultaneous saccharification-fermentation process for the production of ethanol from amylaceous materials

    International Nuclear Information System (INIS)

    Miranda Morales, Barbara; Molina Cordoba, Manuel

    2015-01-01

    The possibility of performing the steps of saccharification and fermentation simultaneously, was evaluated in order to reduce the time of production of ethanol from starch. Factors such as type and concentration of starch, concentration of ethanol, time and temperature of saccharification, presence of ethanol and nutrients (K_2HPO_4, MgSO_4• 7H_2O, NH_4NO_3 y peptone) were evaluated during the hydrolysis step of the starch, fermentation temperature. The yield of reducing sugars was measured using a type of starch and its concentration without being significantly affected. Furthermore, the activity of the enzyme AMG neither was affected with the presence of ethanol in concentrations of 0% and up to 12% v/v during the saccharification at temperatures of 60 degrees and 32 degrees. The time of saccharification affect significantly the production of reducing sugars. Nutrients at concentrations usual for a fermentation were added to the enzyme AMG during the hydrolysis of the starch without affecting its activity. To increase the yield of reducing sugars we conclude that the best combination of temperature and time of saccharification was: 60 degrees and 2 h. Also, it was concluded that the saccharification and fermentation steps may take place simultaneously even when operating at 32 degrees. The results of concentration of ethanol obtained (6.0 to 7.5) % v/v are comparable to those values in industry. (author) [es

  15. Process development and modeling of fluidized-bed reactor with coimmobilized biocatalyst for fuel ethanol production

    Science.gov (United States)

    Sun, May Yongmei

    This research focuses on two steps of commercial fuel ethanol production processes: the hydrolysis starch process and the fermentation process. The goal of this research is to evaluate the performance of co-immobilized biocatalysts in a fluidized bed reactor with emphasis on economic and engineering aspects and to develop a predictive mathematical model for this system. The productivity of an FBR is higher than productivity of a traditional batch reactor or CSTR. Fluidized beds offer great advantages over packed beds for immobilized cells when small particles are used or when the reactant feed contains suspended solids. Plugging problems, excessive pressure drops (and thus attrition), or crushing risks may be avoided. No mechanical stirring is required as mixing occurs due to the natural turbulence in the fluidized process. Both enzyme and microorganism are immobilized in one catalyst bead which is called co-immobilization. Inside this biocatalyst matrix, starch is hydrolyzed by the enzyme glucoamylase to form glucose and then converted to ethanol and carbon dioxide by microorganisms. Two biocatalysts were evaluated: (1) co-immobilized yeast strain Saccharomyces cerevisiae and glucoamylase. (2) co-immobilized Zymomonas mobilis and glucoamylase. A co-immobilized biocatalyst accomplishes the simultaneous saccharification and fermentation (SSF process). When compared to a two-step process involving separate saccharification and fermentation stages, the SSF process has productivity values twice that given by the pre-saccharified process when the time required for pre-saccharification (15--25 h) was taken into account. The SSF process should also save capital cost. The information about productivity, fermentation yield, concentration profiles along the bed, ethanol inhibition, et al., was obtained from the experimental data. For the yeast system, experimental results showed that: no apparent decrease of productivity occurred after two and half months, the productivity

  16. Power-law approach to modeling biological systems. II. Application to ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Voit, E O; Savageau, M A

    1982-01-01

    The use of the power-law formalism is illustrated by modeling yeast ethanol production in batch culture at high cell densities. Parameter values are estimated from experimental data. The results suggest that ethanol killing of viable cells and lysis of nonviable cells are major determinants of system behavior, whereas catabolism of ethanol and inhibition of cell growth by ethanol appear to be insignificant under these experimental conditions.

  17. Mutants of Pachysolen tannophilus with Improved Production of Ethanol from d-Xylose †

    OpenAIRE

    Lee, Hung; James, Allen P.; Zahab, Diana M.; Mahmourides, George; Maleszka, Ryszard; Schneider, Henry

    1986-01-01

    The conversion of d-xylose to ethanol by the yeast Pachysolen tannophilus is relatively inefficient in batch culture. The inefficiency has been attributed in part to concurrent utilization of ethanol in the presence of appreciable concentrations of d-xylose and to the formation of xylitol and other by-products. To increase the concentration of ethanol accumulated in batch cultures, UV-induced mutants of P. tannophilus were selected on the basis of diminished growth on ethanol. Eleven independ...

  18. Production of xylose, furfural, fermentable sugars and ethanol from agricultural residues

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; Das, K.; Sharma, D.K.

    1984-02-01

    With the developing shortage of petroleum, reliance on biomass as a source of chemicals and fuels will increase. In the present work, bagasse and rice husk were subjected to dilute acid (H2SO4) hydrolysis using pressurised water to obtain furfural and fermentable sugars. Various process conditions such as particle size, solid-liquid ratio, acid concentration, reaction time and temperature have been studied to optimise yields of furfural, xylose and other fermentable sugars. The use of particle sizes smaller than 495 mu m did not further increase the yield of reducing sugars. A solid-liquid ratio of 1:15 was found to be the most suitable for production of reducing sugars. Hydrolysis using 0.4% H2SO4 at 453 K resulted in selective yields (g per 100 g of dried agricultural residues) of xylose from bagasse (22.5%) and rice husk (21.5%). A maximum yield of furfural was obtained using 0.4% H2SO4 at 473 K from bagasse (11.5%) and rice husk (10.9%). It was also found that hydrolysis using 1% H2SO4 at 493 K resulted in maximum yields of total reducing sugar from bagasse (53.5%) and rice husk (50%). The reducing sugars obtained were fermented to ethanol after removal of furfural. The effect of furfural on the fermentation of sugars to ethanol was also studied. Based on these studies, an integrated two-step process for the production of furfural and fermentable sugars could be envisaged. In the first step, using 0.4% H2SO4 at 473 K, furfural could be obtained, while in the second step, the use of 1% H2SO4 at 493 K should result in the production of fermentable sugars. (Refs. 22).

  19. Plasma-Assisted Pretreatment of Wheat Straw for Ethanol Production

    DEFF Research Database (Denmark)

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

    2011-01-01

    (0–7 h), e.g., oxalic acid and acetovanillon. Interestingly, washing had no effect on the ethanol production with pretreatment times up to 1 h. Washing improved the glucose availability with pretreatment times of more than 2 h. One hour of ozonisation was found to be optimal for the use of washed...... carboxylic acids and phenolic compounds were found, e.g., vanillic acid, acetic acid, and formic acid. Some components had the highest concentration at the beginning of the ozonisation process (0.5, 1 h), e.g., 4-hydroxybenzladehyde, while the concentration of others increased during the entire pretreatment...

  20. Assessing the Environmental Performance of Integrated Ethanol and Biogas Production

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Michael; Svensson, Niclas; Fonseca, Jorge (Linkoeping Univ., Environmental Technology and Management, Linkoeping (Sweden)), e-mail: michael.martin@liu.se

    2011-06-15

    As the production of biofuels continues to expand worldwide, criticism about, e.g. the energy output versus input and the competition with food has been questioned. However, biofuels may be optimized to increase the environmental performance through the concepts of industrial symbiosis. This paper offers a quantification of the environmental performance of industrial symbiosis in the biofuel industry through integration of biogas and ethanol processes using a life cycle approach. Results show that although increasing integration is assumed to produce environmental benefits in industrial symbiosis, not all impact categories have achieved this and the results depend upon the allocation methods chosen

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

    Directory of Open Access Journals (Sweden)

    M Samsuri

    2010-10-01

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

  2. Saccharomyces cerevisiae strains for second-generation ethanol production: from academic exploration to industrial implementation

    Science.gov (United States)

    Jansen, Mickel L. A.; Bracher, Jasmine M.; Papapetridis, Ioannis; Verhoeven, Maarten D.; de Bruijn, Hans; de Waal, Paul P.; van Maris, Antonius J. A.; Klaassen, Paul

    2017-01-01

    Abstract The recent start-up of several full-scale ‘second generation’ ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. After a discussion of the challenges that these novel industrial contexts impose on yeast strains, this minireview describes key metabolic engineering strategies that have been developed to address these challenges. Additionally, it outlines how proof-of-concept studies, often developed in academic settings, can be used for the development of robust strain platforms that meet the requirements for industrial application. Fermentation performance of current engineered industrial S. cerevisiae strains is no longer a bottleneck in efforts to achieve the projected outputs of the first large-scale second-generation ethanol plants. Academic and industrial yeast research will continue to strengthen the economic value position of second-generation ethanol production by further improving fermentation kinetics, product yield and cellular robustness under process conditions. PMID:28899031

  3. Ethanol production with a flocculating mutant of Zymomonas mobilis and immobilized glycoside hydrolases. Ethanolgewinnung mit einer flockenden Mutante von Zymomonas mobilis und immobilisierten Glycosidhydrolasen

    Energy Technology Data Exchange (ETDEWEB)

    Tramm-Werner, S.

    1987-05-25

    A method to extend the substrate spectrum of Z. mobilis was developed. Higher ethanol yields were achieved by simultaneous use of hydrolases cross-linked with glutar aldehyde together with the flocculating Zymomonas cells (TW 602). Apart from the high product yields, the method is characterized by low susceptibility to infections.

  4. Ethanol production from hydrothermal pretreated corn stover with a loop reactor

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda [National Lab for Sustainable Energy, Biosystems Department, Risoe-DTU, P.O. Box 49, DK-4000 Roskilde (Denmark)

    2010-03-15

    Hydrothermal pretreatment on raw corn stover (RCS) with a loop reactor was investigated at 195 C for different times varying between 10 min and 30 min. After pretreatment, the slurry was separated into water-insoluble solid (WIS) and liquid phase. Glucan and xylan were found in the both phases. The pretreatment condition showed a significant impact on xylan recovery. As the pretreatment time prolonged from 10 min to 30 min, the xylan recovery from liquid phase changed between 39.5% and 45.6% and the total xylan recoveries decreased from 84.7% to 61.6%. While the glucan recovery seemed not sensitive to the different pretreatment times. The glucan recovered from liquid was from 4.9% to 5.6% and the total glucan recoveries from all the pretreatments were higher than 98%. Besides HMF and furfural, acetic, lactic, formic and glycolic acids were also found in the liquid phase. All the concentrations of these potential inhibitors were lower enough not to affect the activity of the Saccharomyces cerevisiae (S. cerevisiae). Compared with the ethanol production of 32.4% from the RCS with S. cerevisiae, all the WISs gave higher ethanol productions ranging between 61.2% and 71.2%. When the xylan was taken into consideration, the best pretreatment condition would be 195 C, 15 min and the estimated total ethanol production was 201 g kg{sup -1} RCS by assuming the fermentation of both C-6 and C-5 with the ethanol yield of 0.51 g g{sup -1} and 0.47 g g{sup -1}, respectively. (author)

  5. Ethanol production from hydrothermal pretreated corn stover with a loop reactor

    International Nuclear Information System (INIS)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-01-01

    Hydrothermal pretreatment on raw corn stover (RCS) with a loop reactor was investigated at 195 o C for different times varying between 10 min and 30 min. After pretreatment, the slurry was separated into water-insoluble solid (WIS) and liquid phase. Glucan and xylan were found in the both phases. The pretreatment condition showed a significant impact on xylan recovery. As the pretreatment time prolonged from 10 min to 30 min, the xylan recovery from liquid phase changed between 39.5% and 45.6% and the total xylan recoveries decreased from 84.7% to 61.6%. While the glucan recovery seemed not sensitive to the different pretreatment times. The glucan recovered from liquid was from 4.9% to 5.6% and the total glucan recoveries from all the pretreatments were higher than 98%. Besides HMF and furfural, acetic, lactic, formic and glycolic acids were also found in the liquid phase. All the concentrations of these potential inhibitors were lower enough not to affect the activity of the Saccharomyces cerevisiae (S. cerevisiae). Compared with the ethanol production of 32.4% from the RCS with S. cerevisiae, all the WISs gave higher ethanol productions ranging between 61.2% and 71.2%. When the xylan was taken into consideration, the best pretreatment condition would be 195 o C, 15 min and the estimated total ethanol production was 201 g kg -1 RCS by assuming the fermentation of both C-6 and C-5 with the ethanol yield of 0.51 g g -1 and 0.47 g g -1 , respectively.

  6. Sustainability assessment of sugarcane biorefinery and molasses ethanol production in Thailand using eco-efficiency indicator

    International Nuclear Information System (INIS)

    Silalertruksa, Thapat; Gheewala, Shabbir H.; Pongpat, Patcharaporn

    2015-01-01

    Highlights: • Sugarcane biorefinery in Thailand is evaluated using the eco-efficiency concept. • Green cane along with cane trash use for electricity yields highest eco-efficiency. • Proposed biorefinery system increases eco-efficiency by 20–70%. - Abstract: The study aims to evaluate the sugarcane biorefinery and molasses ethanol production in Thailand using the combined environmental and economic sustainability indicator, so called “Eco-efficiency”. Four sugarcane biorefinery scenarios in Thailand are evaluated. The total output values (US$) and the life cycle greenhouse gas (GHG) emissions (kg CO_2eq) are selected as the indicators for characterizing economic and environmental performance, respectively. The results show that the biorefinery system of mechanized farming along with cane trash utilization for power generation yields the highest eco-efficiency. The benefits come from the increased value added of the biorefinery together with the decreased GHG emissions of the biorefinery system. As compared to the base case scenario, the new systems proposed result in the eco-efficiency improvement by around 20–70%. The biorefinery concept induces reduction of GHG emissions attributed to molasses ethanol. Green cane production and harvesting results in further lowering of the GHG emissions. Integration of sugarcane biomass utilization across the entire sugarcane complex would enhance the sustainability of the sugarcane production system.

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

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

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

  8. Energy, carbon dioxide and water use implications of hydrous ethanol production

    International Nuclear Information System (INIS)

    Saffy, Howard A.; Northrop, William F.; Kittelson, David B.; Boies, Adam M.

    2015-01-01

    Highlights: • We use a chemical refinery model and exergy analysis to determine the impact of hydrous ethanol. • The process is 70% efficient with 86% of the losses from fermentation, steam generation and drying. • We found that producing 86 wt% ethanol is optimal for thermal energy consumption. • Hydrous ethanol production can reduce energy costs and emissions by ∼8%. • Hydrous ethanol reduces water use by decreasing evaporation in cooling towers. - Abstract: Sub-azeotropic hydrous ethanol has been demonstrated as an effective diesel fuel replacement when used in dual-fuel compression ignition engines. Previous studies have also suggested that hydrous ethanol may be more efficient to produce from corn than anhydrous ethanol. In this study, we investigate corn ethanol production from a dry-mill, natural gas-fired corn ethanol refinery, producing ethanol with a range of ethanol concentrations from 58 wt% to 100 wt% to determine the effect on energy use, water consumption and greenhouse gas (GHG) emissions in the refining stage of the corn ethanol lifecycle. A second law (exergy) analysis of anhydrous ethanol refining revealed the overall process to be 70% efficient, whereby 86% of the exergy losses could be accounted for by three processes: fermentation (34%), steam generation (29%) and distiller’s grains and solubles drying (23%). We found that producing 86 wt% ethanol is optimal as thermal energy consumption decreases by a maximum of 10% (from 7.7 MJ/L to 6.9 MJ/L). These savings have the potential to reduce energy costs by approximately 8% ($0.34/L) and reduce refinery emissions by 8% (2 g CO 2 e/MJ). Production of hydrous ethanol reduced refinery water use due to decreased evaporative losses in the cooling towers, leading to water savings of between 3% and 6% at 86 wt% ethanol.

  9. 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.

  10. Intermediate products of radiolytic conversions of 6-aminophenalenone in ethanol

    International Nuclear Information System (INIS)

    Semenova, G.V.; Ponomarev, A.V.; Kartasheva, L.I.; Pikaev, A.K.

    1992-01-01

    Intermediate products of the conversions of 6-aminophenalenone in ethanol were investigated by pulse radiolysis. In alkaline medium the main product is the 6-aminophenalenone radical cation, the optical absorption spectrum of which contains two bands with maxima at 355 and 400 nm. The precursors of this particle are e s , CH 3 CHOH and CH 3 CHO - radicals. In neutral and acid medium, radical cations are protonated in reactions with alcohol and hydrogen ions. The H-adduct of 6-aminophenalenone that arises has optical absorption maxima at 350 and 390 nm. The presence of two maxima is due to two different structures of the product. The molar extinction coefficients of the radical anions and H-adducts of 6-aminophenalenone and the rate constants of the reactions involving them were estimated. 6 refs., 4 figs., 2 tabs

  11. DESIGN AND CONSTRUCTION OF A REFLUX COLUMN DISTILLATION UNIT FOR BIO-ETHANOL PRODUCTION FROM SUGARCANE SUBSTRATE

    Directory of Open Access Journals (Sweden)

    J. O. Olaoye

    2011-06-01

    Full Text Available A bio-ethanol distilling tank was designed and constructed to distil ethanol from sugarcane substrate. The machine has a capacity to process 200 litres of substrate at full load of the boiler. The distiller has mlntemalReflux Still Condenser (IRSC that controls the internal re-distillation process and the separation of the final output. The column diameter was 40 mm. An anaerobic fermentation of substrate was adopted before distillation could be carried out. The fermented substrate was adjusted to an optimum pH level value of 4-5 by addition of 0.1 M HjSQ, and the optimum temperature was within the temperature range of 29-38°C. A charcoal pot was used as heat source. The results of the machine evaluation showed that optimum yield occurred at 0.0325 ratio of substrate to ethanol yield. An average distilled product of 2.1 litres was obtained at highest ratio of substrate to ethanol yield of 0.033 when the distillation time was 45 minutes. The total distilled products after 1XA hours of distillation was estimated at 4.25 litres. It was observed that the fermentation and distillation processes were done in situ, and could definitely affect clear separation of the fermentable portion of the fermented sugar solution.

  12. Effect of agitation rate on ethanol production from sugar maple hemicellulosic hydrolysate by Pichia stipitis.

    Science.gov (United States)

    Shupe, Alan M; Liu, Shijie

    2012-09-01

    Concentrated dilute acid hydrolysate was obtained from hot water extracts of Acer saccharum (sugar maple) and was fermented to ethanol by Pichia stipitis in a 1.3-L-benchtop bioreactor. The conditions under which the highest ethanol yield was achieved were when the air flow rate was set to 100 cm(3) and the agitation rate was set to 150 rpm resulting in an overall mass transfer coefficient (K(L)a) of 0.108 min(-1). A maximum ethanol concentration of 29.7 g/L was achieved after 120 h of fermentation; however, after 90 h of fermentation, the ethanol concentration was only slightly lower at 29.1 g/L with a yield of 0.39 g ethanol per gram of sugar consumed. Using the same air flow rate and adjusting the agitation rate resulted in lower ethanol yields of 0.25 g/g at 50 rpm and 0.30 g/g at 300 rpm. The time it takes to reach the maximum ethanol concentration was also affected by the agitation rate. The ethanol concentration continued to increase even after 130 h of fermentation when the agitation rate was set at 50 rpm, whereas the maximum ethanol concentration was reached after only 68.5 h at 300 rpm.

  13. 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."

  14. Ethanol Production from Kitchen Garbage Using Zymomonas mobilis: Optimization of Parameters through Statistical Experimental Designs

    OpenAIRE

    Ma, H.; Wang, Q.; Gong, L.; Wang, X.; Yin, W.

    2008-01-01

    Plackett-Burman design was employed to screen 8 parameters for ethanol production from kitchen garbage by Zymomonas mobilis in simultaneous saccharification and fermentation. The parameters were divided into two parts, four kinds of enzymes and supplementation nutrients. The result indicated that the nutrient inside kitchen garbage could meet the requirement of ethanol production without supplementation, only protease and glucoamylase were needed to accelerate the ethanol production. The opti...

  15. Improved rapeseed oil extraction yield and quality via cold separation of ethanol miscella

    Directory of Open Access Journals (Sweden)

    Citeau Morgane

    2018-03-01

    Full Text Available In the extraction of vegetable oils, the idea of using ethanol as a solvent, allowing solvent recycling without distillation, can be attested as early as 1948 (Beckel, yet it is now seldom envisaged. The development of organic farming and a growing demand for a more natural diet prompted us to revisit this approach, which takes advantage of the relatively low affinity of ethanol for lipids to produce pure crude oils and meal with higher protein content. This method is based on the change of oil solubility in ethanol with temperature. Rapeseed oil extraction was carried out by hot pressurized ethanol (subcritical extraction condition. Oil was then recovered by cooling the miscella and demixing of two phases, an oil-rich phase and a solvent-rich phase. This study, after verifying the kinetics of extraction, focused on the optimization of the demixing temperature based on the amount and quality of recovered oil. The results show that ethanol extraction followed by cold demixing of the miscella makes it possible to obtain a high quality oil, free of free fatty acids and phospholipids.

  16. 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......Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol...

  17. [Fission product yields of 60 fissioning reactions]. Final report

    International Nuclear Information System (INIS)

    Rider, B.F.

    1995-01-01

    In keeping with the statement of work, I have examined the fission product yields of 60 fissioning reactions. In co-authorship with the UTR (University Technical Representative) Talmadge R. England ''Evaluation and Compilation of Fission Product Yields 1993,'' LA-UR-94-3106(ENDF-349) October, (1994) was published. This is an evaluated set of fission product Yields for use in calculation of decay heat curves with improved accuracy has been prepared. These evaluated yields are based on all known experimental data through 1992. Unmeasured fission product yields are calculated from charge distribution, pairing effects, and isomeric state models developed at Los Alamos National Laboratory. The current evaluation has been distributed as the ENDF/B-VI fission product yield data set

  18. Evaluation of three cultivars of sweet sorghum as feedstocks for ethanol production in the Southeast United States

    Directory of Open Access Journals (Sweden)

    Daniel E. Ekefre

    2017-12-01

    Full Text Available Sweet sorghum has become a promising alternative feedstock for biofuel production because it can be grown under reduced inputs, responds to stress more efficiently than traditional crops, and has large biomass production potential. A three-year field study was conducted to evaluate three cultivars of sweet sorghum as bioenergy crops in the Southeast United States (Fort Valley, Georgia: Dale, M81 E and Theis. Parameters evaluated were: plant density, stalk height, and diameter, number of nodes, biomass yield, juice yield, °Bx, sugar production, and theoretical ethanol yields. Yields were measured at 85, 99, and 113 days after planting. Plant fresh weight was the highest for Theis (1096 g and the lowest for Dale (896 g. M81 E reported the highest stalk dry weight (27 Mg ha−1 and Theis reported the lowest (21 Mg ha−1. Theis ranked the highest °Bx (14.9, whereas M81 E was the lowest (13.2. Juice yield was the greatest for M81 E (10915 L ha−1 and the lowest for Dale (6724 L ha−1. Theoretical conservative sugar yield was the greatest for Theis (13 Mg ha−1 and the lowest for Dale (9 Mg ha−1. Theoretical ethanol yield was the greatest for Theis (7619 L ha−1 and the lowest for Dale (5077 L ha−1.

  19. Improving ethanol yield in acetate-reducing Saccharomyces cerevisiae by cofactor engineering of 6-phosphogluconate dehydrogenase and deletion of ALD6.

    Science.gov (United States)

    Papapetridis, Ioannis; van Dijk, Marlous; Dobbe, Arthur P A; Metz, Benjamin; Pronk, Jack T; van Maris, Antonius J A

    2016-04-26

    Acetic acid, an inhibitor of sugar fermentation by yeast, is invariably present in lignocellulosic hydrolysates which are used or considered as feedstocks for yeast-based bioethanol production. Saccharomyces cerevisiae strains have been constructed, in which anaerobic reduction of acetic acid to ethanol replaces glycerol formation as a mechanism for reoxidizing NADH formed in biosynthesis. An increase in the amount of acetate that can be reduced to ethanol should further decrease acetic acid concentrations and enable higher ethanol yields in industrial processes based on lignocellulosic feedstocks. The stoichiometric requirement of acetate reduction for NADH implies that increased generation of NADH in cytosolic biosynthetic reactions should enhance acetate consumption. Replacement of the native NADP(+)-dependent 6-phosphogluconate dehydrogenase in S. cerevisiae by a prokaryotic NAD(+)-dependent enzyme resulted in increased cytosolic NADH formation, as demonstrated by a ca. 15% increase in the glycerol yield on glucose in anaerobic cultures. Additional deletion of ALD6, which encodes an NADP(+)-dependent acetaldehyde dehydrogenase, led to a 39% increase in the glycerol yield compared to a non-engineered strain. Subsequent replacement of glycerol formation by an acetate reduction pathway resulted in a 44% increase of acetate consumption per amount of biomass formed, as compared to an engineered, acetate-reducing strain that expressed the native 6-phosphogluconate dehydrogenase and ALD6. Compared to a non-acetate reducing reference strain under the same conditions, this resulted in a ca. 13% increase in the ethanol yield on glucose. The combination of NAD(+)-dependent 6-phosphogluconate dehydrogenase expression and deletion of ALD6 resulted in a marked increase in the amount of acetate that was consumed in these proof-of-principle experiments, and this concept is ready for further testing in industrial strains as well as in hydrolysates. Altering the cofactor

  20. Study of growth kinetic and modeling of ethanol production by ...

    African Journals Online (AJOL)

    ... coefficient (0.96299). Based on Leudking-Piret model, it could be concluded that ethanol batch fermentation is a non-growth associated process. Key words: Kinetic parameters, simulation, cell growth, ethanol, Saccharomyces cerevisiae.

  1. Techno-Economic Analysis of Integrating First and Second-Generation Ethanol Production Using Filamentous Fungi: An Industrial Case Study

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2016-05-01

    Full Text Available The 2nd generation plants producing ethanol from lignocelluloses demand risky and high investment costs. This paper presents the energy- and economical evaluations for integrating lignocellulose in current 1st generation dry mill ethanol processes, using filamentous fungi. Dry mills use grains and have mills, liquefactions, saccharifications, fermentation, and distillation to produce ethanol, while their stillage passes centrifugation, and evaporation to recycle the water and dry the cake and evaporated syrup into animal feed. In this work, a bioreactor was considered to cultivate fungi on the stillage either before or after the centrifugation step together with pretreated lignocellulosic wheat bran. The results showed that the integrated 1st and 2nd generation ethanol process requires a capital investment of 77 million USD, which could yield NPV of 162 million USD after 20 years. Compared to the fungal cultivation on thin stillage modified 1st generation process, the integrated process resulted in 53 million USD higher NPV. The energy analysis showed that the thin stillage modified 1st generation process could reduce the overall energy consumption by 2.5% and increase the ethanol production by 4%. Such modifications in the 1st generation processes and integration concepts could be interesting for the ethanol industries, as integrating lignocelluloses to their existing setup requires less capital investment.

  2. Kinetics of ethanol production by immobilized Kluyveromyces marxianus cells at varying sugar concentrations of Jerusalem artichoke juice

    Energy Technology Data Exchange (ETDEWEB)

    Bajpai, P.; Margaritis, A.

    1987-08-01

    Kinetics of ethanol fermentation at varying sugar concentrations of Jerusalem artichoke tuber extract has been studied using Kluyveromyces marxianus cells immobilized in calcium alginate gel beads. A maximum ethanol concentration of 111 g/l was achieved at an initial sugar concentration of 260 g/l in 20 hours, when the immobilized cell concentration in the calcium alginate beads was 53.3 g dry wt./l bead volume. Ethanol yield remained almost unaffected by initial sugar concentration up to 250 g/l and was found to be about 88% of the theoretical. Maximum rate of ethanol production decreased from 22.5 g ethanol/l/h to 10.5 g ethanol/l/h while the maximum rate of total sugars utilization decreased from 74.9 g sugars/l/h to 28.5 g sugars/l/h as the initial substrate concentration was increased from 100 to 300 g/l. The concentration of free cells in the fermentation broth was low.

  3. Ethanol production by Kluyveromyces marxianus IMB3 during growth on straw-supplemented whiskey distillery spent wash at 45 C

    Energy Technology Data Exchange (ETDEWEB)

    Barron, N.; Mulholland, H.; Boyle, M.; McHale, A.P. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine, Co. Londonderry, BT52 1SA (United Kingdom)

    1997-11-01

    The thermotolerant, ethanol-producing yeast strain, Kluyveromyces marxianus IMB3 was grown on media consisting of straw-supplemented distillery spent wash from The Old Bushmill`s Distillery Co. Ltd., Bushmills, Co Antrim, Northern Ireland. Media were supplemented with cellulase activity and fermentations were carried out at 45 C. When pulverized straw was used as substrate in this system at concentrations of 2, 4 and 6% (w/v), ethanol concentrations increased to maxima of 1.45, 2.2 and 3 g/l, respectively. Based on straw containing a maximum of 40% cellulose, these ethanol concentrations accounted for 36, 27 and 24% of the maximum theoretical yield, respectively. When the straw was pre-treated with NaOH and used in the spent wash containing system at concentrations of 2, 4 and 6% (w/v) ethanol, concentrations increased to maxima of 3, 6.2 and 10.5 g/l, respectively and these accounted for 75, 76 and 86% of the maximum theoretical yield. When these results are compared with previously published data relating to the use of straw in laboratory-based media, they suggest that whiskey distillery spent wash may provide an adequate medium for supplementation with complex carbohydrate and subsequent ethanol production in simultaneous saccharification and fermentation processes. (orig.) With 2 figs., 17 refs.

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

    OpenAIRE

    M. Rakin; J. Pejin; O. Grujić; Lj. Mojović; D. Pejin

    2009-01-01

    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. With the addition of the thin still...

  5. 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. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle. Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage.

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

    Directory of Open Access Journals (Sweden)

    Weerawate Utto

    2014-04-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  8. Efficient ethanol production from brown macroalgae sugars by a synthetic yeast platform.

    Science.gov (United States)

    Enquist-Newman, Maria; Faust, Ann Marie E; Bravo, Daniel D; Santos, Christine Nicole S; Raisner, Ryan M; Hanel, Arthur; Sarvabhowman, Preethi; Le, Chi; Regitsky, Drew D; Cooper, Susan R; Peereboom, Lars; Clark, Alana; Martinez, Yessica; Goldsmith, Joshua; Cho, Min Y; Donohoue, Paul D; Luo, Lily; Lamberson, Brigit; Tamrakar, Pramila; Kim, Edward J; Villari, Jeffrey L; Gill, Avinash; Tripathi, Shital A; Karamchedu, Padma; Paredes, Carlos J; Rajgarhia, Vineet; Kotlar, Hans Kristian; Bailey, Richard B; Miller, Dennis J; Ohler, Nicholas L; Swimmer, Candace; Yoshikuni, Yasuo

    2014-01-09

    The increasing demands placed on natural resources for fuel and food production require that we explore the use of efficient, sustainable feedstocks such as brown macroalgae. The full potential of brown macroalgae as feedstocks for commercial-scale fuel ethanol production, however, requires extensive re-engineering of the alginate and mannitol catabolic pathways in the standard industrial microbe Saccharomyces cerevisiae. Here we present the discovery of an alginate monomer (4-deoxy-L-erythro-5-hexoseulose uronate, or DEHU) transporter from the alginolytic eukaryote Asteromyces cruciatus. The genomic integration and overexpression of the gene encoding this transporter, together with the necessary bacterial alginate and deregulated native mannitol catabolism genes, conferred the ability of an S. cerevisiae strain to efficiently metabolize DEHU and mannitol. When this platform was further adapted to grow on mannitol and DEHU under anaerobic conditions, it was capable of ethanol fermentation from mannitol and DEHU, achieving titres of 4.6% (v/v) (36.2 g l(-1)) and yields up to 83% of the maximum theoretical yield from consumed sugars. These results show that all major sugars in brown macroalgae can be used as feedstocks for biofuels and value-added renewable chemicals in a manner that is comparable to traditional arable-land-based feedstocks.

  9. Ethanol production potential of local yeast strains isolated from ripe ...

    African Journals Online (AJOL)

    The ability of different yeast strains isolated from ripe banana peels to produce ethanol was investigated. Of the 8 isolates screened for their fermentation ability, 5 showed enhanced performance and were subsequently identified and assessed for important ethanol fermentation attributes such as ethanol producing ability, ...

  10. Simultaneous production of 2,3-butanediol, ethanol and hydrogen with a Klebsiella sp. strain isolated from sewage sludge.

    Science.gov (United States)

    Wu, Ken-Jer; Saratale, Ganesh D; Lo, Yung-Chung; Chen, Wen-Ming; Tseng, Ze-Jing; Chang, Ming-Ching; Tsai, Ben-Ching; Su, Ay; Chang, Jo-Shu

    2008-11-01

    A Klebsiella sp. HE1 strain isolated from hydrogen-producing sewage sludge was examined for its ability to produce H2 and other valuable soluble metabolites (e.g., ethanol and 2,3-butanediol) from sucrose-based medium. The effect of pH and carbon substrate concentration on the production of soluble and gaseous products was investigated. The major soluble metabolite produced from Klebsiella sp. HE1 was 2,3-butanediol, accounting for over 42-58% of soluble microbial products (SMP) and its production efficiency enhanced after increasing the initial culture pH to 7.3 (without pH control). The HE1 strain also produced ethanol (contributing to 29-42% of total SMP) and a small amount of lactic acid and acetic acid. The gaseous products consisted of H2 (25-36%) and CO2 (64-75%). The optimal cumulative hydrogen production (2.7 l) and hydrogen yield (0.92mol H2 mol sucrose(-1)) were obtained at an initial sucrose concentration of 30g CODl(-1) (i.e., 26.7gl(-1)), which also led to the highest production rate for H2 (3.26mmol h(-1)l(-1)), ethanol (6.75mmol h(-1)l(-1)) and 2,3-butanediol (7.14mmol h(-1)l(-1)). The highest yield for H2, ethanol and 2,3-butanediol was 0.92, 0.81 and 0.59molmol-sucrose(-1), respectively. As for the overall energy production performance, the highest energy generation rate was 27.7kJ h(-1)l(-1) and the best energy yield was 2.45kJmolsucrose(-1), which was obtained at a sucrose concentration of 30 and 20g CODl(-1), respectively.

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

    Science.gov (United States)

    Edwards, Meredith C; Doran-Peterson, Joy

    2012-08-01

    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.

  12. 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.)

  13. Cellulosic ethanol production from agricultural residues in Nigeria

    International Nuclear Information System (INIS)

    Iye, Edward; Bilsborrow, Paul

    2013-01-01

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

  14. 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

  15. The sustainability of Brazilian ethanol-An assessment of the possibilities of certified production

    International Nuclear Information System (INIS)

    Smeets, Edward; Junginger, Martin; Faaij, Andre; Walter, Arnaldo; Dolzan, Paulo; Turkenburg, Wim

    2008-01-01

    In this article the environmental and socio-economical impacts of the production of ethanol from sugarcane in the state of Sao 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. Seventeen environmental and socio-economic areas of concern are analysed. Four parameters are used to evaluate if an area of concern is a bottleneck: (1) the importance of the area of concern, based on the severity of the impact and the frequency of which an aspect is mentioned in the literature as an area of concern, (2) the availability of indicators and criteria, (3) the necessity of improvement strategies to reach compliance with Brazilian and/or (inter) national legislation, standards, guidelines and sustainability criteria, and (4) the impact of these improvement strategies on the costs and potential of ethanol production. Fourteen areas of concern are classified as a minor or medium bottleneck. For 7 areas of concern the additional costs to avoid or reduce undesirable effects have been calculated at ≤+10% for each area of concern. Due to higher yields and overlapping costs the total additional production costs of compliance with various environmental and socio-economic criteria are about +36%. This study also shows that the energy input to output ratio can be increased and the greenhouse gas emissions reduced by increasing the ethanol production per tonne cane and by increasing the use of sugarcane waste for electricity production. A major bottleneck for a sustainable and certified production is the increase in cane production and the possible impacts on biodiversity and the competition with food production. Genetically modified cane is presently being developed, but is at this moment not (yet) applied. Both a ban on and the allowance of the use of genetically modified cane could become a major bottleneck considering the potentially large benefits and

  16. 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.

  17. ENDF/B-5. Fission Product Yields File

    International Nuclear Information System (INIS)

    Schwerer, O.

    1985-10-01

    The ENDF/B-5 Fission Product Yields File contains a complete set of independent and cumulative fission product yields, representing the final data from ENDF/B-5 as received at the IAEA Nuclear Data Section in June 1985. Yields for 11 fissioning nuclides at one or more neutron incident energies are included. The data are available costfree on magnetic tape from the IAEA Nuclear Data Section. (author). 4 refs

  18. Production yield analysis in the poultry processing industry

    NARCIS (Netherlands)

    Somsen, D.J.; Capelle, A.; Tramper, J.

    2004-01-01

    The paper outlines a case study where the PYA-method (production yield analysis) was implemented at a poultry-slaughtering line, processing 9000 broiler chicks per hour. It was shown that the average live weight of a flock of broilers could be used to predict the maximum production yield of the

  19. Effect of operating conditions on direct liquefaction of low-lipid microalgae in ethanol-water co-solvent for bio-oil production

    International Nuclear Information System (INIS)

    Ji, Changhao; He, Zhixia; Wang, Qian; Xu, Guisheng; Wang, Shuang; Xu, Zhixiang; Ji, Hengsong

    2017-01-01

    Highlights: • Low-lipid microalgae was selected as feedstock for DL in ethanol-water co-solvent. • Operating conditions had great influence on product yields and conversion rate. • Bio-oil could be obtained from all three main components. • Ethanol and water showed obviously synergistic effect during the DL of microalgae. • Bio-oil composition from DL of microalgae was different from lignocellulose biomass. - Abstract: In this work, the direct liquefaction (DL) of low-lipid microalgae Spirulina was investigated in a 50 ml autoclave reactor with ethanol and water as co-solvent. The objective of this research was carried out to examine the effect of operating conditions such as reaction temperature, reaction time, solvent/microalgae (S/M) ratio and ethanol-water co-solvent (EWCS) composition on product distribution and bio-oil characterization. The results revealed that the optimal operating conditions for bio-oil yield and conversion rate were reaction temperature of 300 °C, reaction time of 45 min, ethanol content of 50 vol.% and S/M ratio of 40/4 ml/g, which gave the bio-oil yield of 59.5% and conversion rate of 94.73%. Conversion rate in EWCS was significantly higher than that in pure water or ethanol, suggesting the synergistic effect between ethanol and water during microalgae DL. Distinct difference in composition and relative content of compound among bio-oils in different solvents were observed by GC–MS and FT-IR. Compared with hydrothermal liquefaction, the most abundant compounds in bio-oil from both EWCS and pure ethanol were esters. The presence of ethanol could enhance the bio-oil yield and improve bio-oil quality by promoting the formation of esters.

  20. A modified indirect mathematical model for evaluation of ethanol production efficiency in industrial-scale continuous fermentation processes.

    Science.gov (United States)

    Canseco Grellet, M A; Castagnaro, A; Dantur, K I; De Boeck, G; Ahmed, P M; Cárdenas, G J; Welin, B; Ruiz, R M

    2016-10-01

    To calculate fermentation efficiency in a continuous ethanol production process, we aimed to develop a robust mathematical method based on the analysis of metabolic by-product formation. This method is in contrast to the traditional way of calculating ethanol fermentation efficiency, where the ratio between the ethanol produced and the sugar consumed is expressed as a percentage of the theoretical conversion yield. Comparison between the two methods, at industrial scale and in sensitivity studies, showed that the indirect method was more robust and gave slightly higher fermentation efficiency values, although fermentation efficiency of the industrial process was found to be low (~75%). The traditional calculation method is simpler than the indirect method as it only requires a few chemical determinations in samples collected. However, a minor error in any measured parameter will have an important impact on the calculated efficiency. In contrast, the indirect method of calculation requires a greater number of determinations but is much more robust since an error in any parameter will only have a minor effect on the fermentation efficiency value. The application of the indirect calculation methodology in order to evaluate the real situation of the process and to reach an optimum fermentation yield for an industrial-scale ethanol production is recommended. Once a high fermentation yield has been reached the traditional method should be used to maintain the control of the process. Upon detection of lower yields in an optimized process the indirect method should be employed as it permits a more accurate diagnosis of causes of yield losses in order to correct the problem rapidly. The low fermentation efficiency obtained in this study shows an urgent need for industrial process optimization where the indirect calculation methodology will be an important tool to determine process losses. © 2016 The Society for Applied Microbiology.

  1. Rice bran extract: an inexpensive nitrogen source for the production of 2G ethanol from sugarcane bagasse hydrolysate.

    Science.gov (United States)

    Milessi, Thais S S; Antunes, Felipe A F; Chandel, Anuj K; Silva, Silvio S

    2013-10-01

    Selection of the raw material and its efficient utilization are the critical factors in economization of second generation (2G) ethanol production. Fermentation of the released sugars into ethanol by a suitable ethanol producing microorganism using cheap media ingredients is the cornerstone of the overall process. This study evaluated the potential of rice bran extract (RBE) as a cheap nitrogen source for the production of 2G ethanol by Scheffersomyces (Pichia) stipitis NRRL Y-7124 using sugarcane bagasse (SB) hemicellulosic hydrolysate. Dilute acid hydrolysis of SB showed 12.45 g/l of xylose and 0.67 g/l of glucose along with inhibitors. It was concentrated by vacuum evaporation and submitted to sequential detoxification (neutralization by calcium hydroxide and charcoal adsorption). The detoxified hydrolysate revealed the removal of furfural (81 %) and 5-hydroxymethylfurfural (61 %) leading to the final concentration of glucose (1.69 g/l) and xylose (33.03 g/l). S. stipitis was grown in three different fermentation media composed of detoxified hydrolysate as carbon source supplemented with varying nitrogen sources i.e. medium #1 (RBE + ammonium sulfate + calcium chloride), medium #2 (yeast extract + peptone) and medium #3 (yeast extract + peptone + malt extract). Medium #1 showed maximum ethanol production (8.6 g/l, yield 0.22 g/g) followed by medium #2 (8.1 g/l, yield 0.19 g/g) and medium #3 (7.4 g/l, yield 0.18 g/g).

  2. Ethanol production from Sorghum bicolor using both separate and simultaneous saccharification and fermentation in batch and fed batch systems

    DEFF Research Database (Denmark)

    Mehmood, Sajid; Gulfraz, M.; Rana, N. F.

    2009-01-01

    The objective of this work was to find the best combination of different experimental conditions during pre-treatment, enzymatic saccharification, detoxification of inhibitors and fermentation of Sorghum bicolor straw for ethanol production. The optimization of pre-treatment using different...... were used in order to increase the monomeric sugar during enzymatic hydrolysis and it has been observed that the addition of these surfactants contributed significantly in cellulosic conversion but no effect was shown on hemicellulosic hydrolysis. Fermentability of hydrolyzate was tested using...... Saccharomyces cerevisiae Ethanol Red (TM) and it was observed that simultaneous saccharification and fermentation ( SSF) with both batch and fed batch resulted in better ethanol yield as compared to separate hydrolysis and fermentation ( SHF). Detoxification of furan during SHF facilitated reduction...

  3. 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.

  4. Evaluation and optimization of ethanol production from carob pod extract by Zymomonas mobilis using response surface methodology.

    Science.gov (United States)

    Vaheed, Hossein; Shojaosadati, Seyed Abbas; Galip, Hasan

    2011-01-01

    In this research, ethanol production from carob pod extract (extract) using Zymomonas mobilis with medium optimized by Plackett-Burman (P-B) and response surface methodologies (RSM) was studied. Z. mobilis was recognized as useful for ethanol production from carob pod extract. The effects of initial concentrations of sugar, peptone, and yeast extract as well as agitation rate (rpm), pH, and culture time in nonhydrolyzed carob pod extract were investigated. Significantly affecting variables (P = 0.05) in the model obtained from RSM studies were: weights of bacterial inoculum, initial sugar, peptone, and yeast extract. Acid hydrolysis was useful to complete conversion of sugars to glucose and fructose. Nonhydrolyzed extract showed higher ethanol yield and residual sugar compared with hydrolyzed extract. Ethanol produced (g g(-1) initial sugar, as the response) was not significantly different (P = 0.05) when Z. mobilis performance was compared in hydrolyzed and nonhydrolyzed extract. The maximum ethanol of 0.34 ± 0.02 g g(-1) initial sugar was obtained at 30°C, initial pH 5.2, and 80 rpm, using concentrations (g per 50 mL culture media) of: inoculum bacterial dry weight, 0.017; initial sugar, 5.78; peptone, 0.43; yeast extract, 0.43; and culture time of 36 h.

  5. Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

    Science.gov (United States)

    2012-01-01

    Background A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses. Results The study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum organic loading rate (OLR) of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate. Conclusions The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production. Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production. PMID:23167984

  6. Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor.

    Science.gov (United States)

    España-Gamboa, Elda I; Mijangos-Cortés, Javier O; Hernández-Zárate, Galdy; Maldonado, Jorge A Domínguez; Alzate-Gaviria, Liliana M

    2012-11-21

    A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses. The study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum organic loading rate (OLR) of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate. The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production.Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production.

  7. Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

    Directory of Open Access Journals (Sweden)

    España-Gamboa Elda I

    2012-11-01

    Full Text Available Abstract Background A modified laboratory-scale upflow anaerobic sludge blanket (UASB reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses. Results The study showed that chemical oxygen demand (COD removal efficiency was 69% at an optimum organic loading rate (OLR of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate. Conclusions The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production. Methanogen groups (Methanobacteriales and Methanosarcinales detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production.

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

    Science.gov (United States)

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

    2017-03-01

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

  9. Direct Fungal Production of Ethanol from High-Solids Pulps by the Ethanol-fermenting White-rot Fungus Phlebia sp. MG-60

    Directory of Open Access Journals (Sweden)

    Ichiro Kamei

    2014-07-01

    Full Text Available A white-rot fungus, Phlebia sp. MG-60, was applied to the fermentation of high-solid loadings of unbleached hardwood kraft pulp (UHKP without the addition of commercial cellulase. From 4.7% UHKP, 19.6 g L-1 ethanol was produced, equivalent to 61.7% of the theoretical maximum. The highest ethanol concentration (25.9 g L-1, or 46.7% of the theoretical maximum was observed in the culture containing 9.1% UHKP. The highest filter paper activity (FPase was observed in the culture containing 4.7% UHKP, while the production of FPase in the 16.5% UHKP culture was very low. Temporarily removing the silicone plug from Erlenmeyer flasks, which relieved the pressure and allowed a small amount of aeration, improved the yield of ethanol produced from the 9.1% UHKP, which reached as high as 37.3 g L-1. These results indicated that production of cellulase and ensuing saccharification and fermentation by Phlebia sp. MG-60 is affected by water content and benefits from a small amount of aeration.

  10. Methane hydrate synthesis from ice: Influence of pressurization and ethanol on optimizing formation rates and hydrate yield

    Science.gov (United States)

    Chen, Po-Chun.; Huang, Wuu-Liang; Stern, Laura A.

    2010-01-01

    Polycrystalline methane gas hydrate (MGH) was synthesized using an ice-seeding method to investigate the influence of pressurization and ethanol on the hydrate formation rate and gas yield of the resulting samples. When the reactor is pressurized with CH4 gas without external heating, methane hydrate can be formed from ice grains with yields up to 25% under otherwise static conditions. The rapid temperature rise caused by pressurization partially melts the granular ice, which reacts with methane to form hydrate rinds around the ice grains. The heat generated by the exothermic reaction of methane hydrate formation buffers the sample temperature near the melting point of ice for enough time to allow for continuous hydrate growth at high rates. Surprisingly, faster rates and higher yields of methane hydrate were found in runs with lower initial temperatures, slower rates of pressurization, higher porosity of the granular ice samples, or mixtures with sediments. The addition of ethanol also dramatically enhanced the formation of polycrystalline MGH. This study demonstrates that polycrystalline MGH with varied physical properties suitable for different laboratory tests can be manufactured by controlling synthesis procedures or parameters. Subsequent dissociation experiments using a gas collection apparatus and flowmeter confirmed high methane saturation (CH 4·2O, with n = 5.82 ± 0.03) in the MGH. Dissociation rates of the various samples synthesized at diverse conditions may be fitted to different rate laws, including zero and first order.

  11. Influence of pressure and humidity on ethanol distillery power production

    International Nuclear Information System (INIS)

    Zumalacarregui de Cardenas, Lourdes; Perez Ones, Osney; Rodriguez Ramos, Pedro; Lombardi, Geraldo

    2011-01-01

    A distillery for the Generation of Renewable Energy Integrated to Food Production (GERIPA), that produces 125 000 L/day of ethanol, presents advantages in comparison with the traditional distilleries. In this paper the available thermal energy in sugar cane and sorghum, bagasse and straw, and also in biogas are calculated. This energy produces vapor for the process and electricity, using a boiler with 88 % of efficiency and a two stages with intermediate extraction turbine. The dependence of electric power surplus with vapor pressure is evaluated, finding that between 60 and 100 MPa, the electric power surplus reaches 7.15 to 7.82 MW. This electricity can be send to the electro-energetic system. The effective efficiency is calculated for 6 to 10 MPa finding values lower than 25 %. It is shown that a bagasse dryer can be used to increase the efficiency. (author)

  12. Ethanol production from SPORL-pretreated lodgepole pine. Preliminary evaluation of mass balance and process energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.Y. [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Wisconsin Univ., Madison, WI (United States). Dept. of Biological Systems Engineering; Zhu, Wenyuan [South China Univ. of Technology, Guangzhou (China). State Key Lab Pulp and Paper Engineering; OBryan, Patricia; Dien, Bruce S. [USDA Agricultural Research Service, Peoria, IL (United States). National Center for Agricultural Utilization Research; Tian, Shen [Capital Normal Univ., Beijing (China). College of Life Science; Gleisner, Rolland [USDA Forest Service, Madison, WI (United States). Forest Products Lab.; Pan, X.J. [Wisconsin Univ., Madison, WI (United States). Dept. of Biological Systems Engineering

    2010-05-15

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quasi-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance. (orig.)

  13. Ethanol production from SPORL-pretreated lodgepole pine: preliminary evaluation of mass balance and process energy efficiency.

    Science.gov (United States)

    Zhu, J Y; Zhu, Wenyuan; Obryan, Patricia; Dien, Bruce S; Tian, Shen; Gleisner, Rolland; Pan, X J

    2010-05-01

    Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quais-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 degrees C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance.

  14. Techno-economic analysis of fuel ethanol production from cassava ...

    African Journals Online (AJOL)

    Moncada Botero, J. (Jonathan)

    Remarks. Complexity. Investment in equipment and strain development. 1 .... 1. Standalone medium feedstock. Production Plant capacity 160,000 L/day increased fresh cassava yield (single plant). 2. Standalone .... Some data on physical properties of the components required during the simulation were obtained from the ...

  15. Biohydrogen production from ethanol-type fermentation of molasses in an expanded granular sludge bed (EGSB) reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wan-Qian; Ren, Nan-Qi; Ding, Jie; Qu, Yuan-Yuan; Zhang, Lu-Si [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Haihe Road 204, Nangang District, Harbin, Heilongjiang 150090 (China); Wang, Xiang-Jing; Xiang, Wen-Sheng [Research Center of Life Science and Biotechnology, Northeast Agricultural University, Harbin 150030 (China); Meng, Zhao-Hui [The Architectural Design and Research Institute of Harbin Institute of Technology, Harbin 150090 (China)

    2008-10-15

    An expanded granular sludge bed (EGSB) process with granular activated carbon (GAC) was developed for fermentative hydrogen production from molasses-containing wastewater by mixed microbial cultures. No pH regulation was performed during the whole operation period. Running at the temperature of 35 C, the EGSB reactor presented a high hydrogen production ability as the hydrogen production rate (HPR) maximized at 0.71 L/L h. At the same time, the hydrogen yield (HY) peaked at 3.47 mol/mol sucrose and the maximum specific hydrogen production rate (SHPR) was found to be 3.16 mmol H{sub 2}/g VSS h. Hydrogen volume content was estimated to be 30-53% of the total biogas and the biogas was free of methane throughout the study. Dissolved fermentation products were predominated by acetate and ethanol, with smaller quantities of propionate, butyrate and valerate. It was found that high hydrogen yield was always associated with a high level of ethanol production. When the pH value and alkalinity ranged from 4.2-4.4 mg CaCO{sub 3}/L to 280-340 mg CaCO{sub 3}/L, respectively, stable ethanol-type fermentation was formed with the sum of ethanol and acetate concentration ratio of 89.1% to the total liquid products. The average attached biofilm concentration was estimated to be 17.1 g/L, which favored hydrogen production efficiently. With high biomass retention at high organic loading rate (OLR), this EGSB system showed to be a promising high-efficient bioprocess for hydrogen production from high-strength wastewater. (author)

  16. Optimization of pretreatment, enzymatic hydrolysis and fermentation for more efficient ethanol production by Jerusalem artichoke stalk.

    Science.gov (United States)

    Li, Kai; Qin, Jin-Cheng; Liu, Chen-Guang; Bai, Feng-Wu

    2016-12-01

    Jerusalem artichoke (JA) is a potential energy crop for biorefinery due to its unique agronomic traits such as resistance to environmental stresses and high biomass yield in marginal lands. Although JA tubers have been explored for inulin extraction and biofuels production, there is little concern on its stalk (JAS). In this article, the pretreatment of JAS by alkaline hydrogen peroxide was optimized using the response surface methodology to improve sugars yield and reduce chemicals usage. Scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis were applied to characterize the structures of the pretreated JAS to evaluate the effectiveness of the pretreatment. Furthermore, the feeding of the pretreated JAS and cellulase was performed for high solid uploading (up to 30%) to increase ethanol titer, and simultaneous saccharification and fermentation with 55.6g/L ethanol produced, 36.5% more than that produced through separate hydrolysis and fermentation, was validated to be more efficient. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 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

    2013-01-01

    produces ethanol, solid biofuel, molasses, and is able to produce district heating hot water. Considering all products equally valuable, the exergy efficiency of the ethanol facility was found to be 0.790 during integrated operation with zero district heating production, and 0.852 during integrated...

  18. Exergy analysis of thermochemical ethanol production via biomass gasification and catalytic synthesis

    NARCIS (Netherlands)

    van der Heijden, H.H.J.L.; Ptasinski, K.J.

    2012-01-01

    In this paper an exergy analysis of thermochemical ethanol production from biomass is presented. This process combines a steam-blown indirect biomass gasification of woody feedstock, with a subsequent conversion of produced syngas into ethanol. The production process involves several process

  19. Evaluation of the multi-seeded (msd) mutant of sorghum for ethanol production

    Science.gov (United States)

    Grain sorghum [Sorghum bicolor (L.) Moench], a cost effective crop in semiarid regions, is an underestimated supplement to corn in starch based ethanol production. Twenty three multi-seeded (msd) mutant sorghums and one wild type sorghum BTx623 were evaluated for ethanol production and effect of che...

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

    Directory of Open Access Journals (Sweden)

    Edem Cudjoe Bensah

    2013-01-01

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

  1. Pervaporation membrane bioreactor with permeate fractional condensation and mechanical vapor compression for energy efficient ethanol production

    International Nuclear Information System (INIS)

    Fan, Senqing; Xiao, Zeyi; Li, Minghai; Li, Sizhong

    2016-01-01

    Graphical abstract: Pervaporation membrane bioreactor with permeate partial condensation and mechanical vapor compression is developed for an energy efficient ethanol production. - Highlights: • PVMBR-MVC for energy efficient ethanol production. • Process separation factor of 20–44 for ethanol achieved by fractional condensation. • Energy production of 20.25 MJ and hourly energy production of 56.25 kJ/h achieved. • Over 50% of energy saved in PVMBR-MVC compared with PVMBR-LTC. • Integrated heat pump with COP of 7–9 for the energy recovery of the permeate. - Abstract: Improved process separation factor and heat integration are two key issues to increase the energy efficiency of ethanol production in a pervaporation membrane bioreactor (PVMBR). A PVMBR with permeate fractional condensation and mechanical vapor compression was developed for energy efficient ethanol production. A condensation model based on the mass balance and thermodynamic equilibrium in the partial vacuum condenser was developed for predicting the purification performance of t