WorldWideScience

Sample records for maximum ethanol yield

  1. 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.

  2. Achieving maximum sustainable yield in mixed fisheries

    NARCIS (Netherlands)

    Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan Jaap; Rindorf, Anna

    2017-01-01

    Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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)

  11. Maximum and minimum entropy states yielding local continuity bounds

    Science.gov (United States)

    Hanson, Eric P.; Datta, Nilanjana

    2018-04-01

    Given an arbitrary quantum state (σ), we obtain an explicit construction of a state ρɛ * ( σ ) [respectively, ρ * , ɛ ( σ ) ] which has the maximum (respectively, minimum) entropy among all states which lie in a specified neighborhood (ɛ-ball) of σ. Computing the entropy of these states leads to a local strengthening of the continuity bound of the von Neumann entropy, i.e., the Audenaert-Fannes inequality. Our bound is local in the sense that it depends on the spectrum of σ. The states ρɛ * ( σ ) and ρ * , ɛ (σ) depend only on the geometry of the ɛ-ball and are in fact optimizers for a larger class of entropies. These include the Rényi entropy and the minimum- and maximum-entropies, providing explicit formulas for certain smoothed quantities. This allows us to obtain local continuity bounds for these quantities as well. In obtaining this bound, we first derive a more general result which may be of independent interest, namely, a necessary and sufficient condition under which a state maximizes a concave and Gâteaux-differentiable function in an ɛ-ball around a given state σ. Examples of such a function include the von Neumann entropy and the conditional entropy of bipartite states. Our proofs employ tools from the theory of convex optimization under non-differentiable constraints, in particular Fermat's rule, and majorization theory.

  12. Configuration of LWR fuel enrichment or burnup yielding maximum power

    International Nuclear Information System (INIS)

    Bartosek, V.; Zalesky, K.

    1976-01-01

    An analysis is given of the spatial distribution of fuel burnup and enrichment in a light-water lattice of given dimensions with slightly enriched uranium, at which the maximum output is achieved. It is based on the spatial solution of neutron flux using a one-group diffusion model in which linear dependence may be expected of the fission cross section and the material buckling parameter on the fuel burnup and enrichment. Two problem constraints are considered, i.e., the neutron flux value and the specific output value. For the former the optimum core configuration remains qualitatively unchanged for any reflector thickness, for the latter the cases of a reactor with and without reflector must be distinguished. (Z.M.)

  13. 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)

  14. 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.

  15. Ethanol production and maximum cell growth are highly correlated with membrane lipid composition during fermentation as determined by lipidomic analysis of 22 Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Henderson, Clark M; Lozada-Contreras, Michelle; Jiranek, Vladimir; Longo, Marjorie L; Block, David E

    2013-01-01

    Optimizing ethanol yield during fermentation is important for efficient production of fuel alcohol, as well as wine and other alcoholic beverages. However, increasing ethanol concentrations during fermentation can create problems that result in arrested or sluggish sugar-to-ethanol conversion. The fundamental cellular basis for these problem fermentations, however, is not well understood. Small-scale fermentations were performed in a synthetic grape must using 22 industrial Saccharomyces cerevisiae strains (primarily wine strains) with various degrees of ethanol tolerance to assess the correlation between lipid composition and fermentation kinetic parameters. Lipids were extracted at several fermentation time points representing different growth phases of the yeast to quantitatively analyze phospholipids and ergosterol utilizing atmospheric pressure ionization-mass spectrometry methods. Lipid profiling of individual fermentations indicated that yeast lipid class profiles do not shift dramatically in composition over the course of fermentation. Multivariate statistical analysis of the data was performed using partial least-squares linear regression modeling to correlate lipid composition data with fermentation kinetic data. The results indicate a strong correlation (R(2) = 0.91) between the overall lipid composition and the final ethanol concentration (wt/wt), an indicator of strain ethanol tolerance. One potential component of ethanol tolerance, the maximum yeast cell concentration, was also found to be a strong function of lipid composition (R(2) = 0.97). Specifically, strains unable to complete fermentation were associated with high phosphatidylinositol levels early in fermentation. Yeast strains that achieved the highest cell densities and ethanol concentrations were positively correlated with phosphatidylcholine species similar to those known to decrease the perturbing effects of ethanol in model membrane systems.

  16. Setting maximum sustainable yield targets when yield of one species affects that of other species

    DEFF Research Database (Denmark)

    Rindorf, Anna; Reid, David; Mackinson, Steve

    2012-01-01

    species. But how should we prioritize and identify most appropriate targets? Do we prefer to maximize by focusing on total yield in biomass across species, or are other measures targeting maximization of profits or preserving high living qualities more relevant? And how do we ensure that targets remain...

  17. 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..

  18. Maximum credibly yield for deuteriuim-filled double shell imaging targets meeting requirements for yield bin Category A

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Douglas Carl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Loomis, Eric Nicholas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-17

    We are anticipating our first NIF double shell shot using an aluminum ablator and a glass inner shell filled with deuterium shown in figure 1. The expected yield is between a few 1010 to a few 1011 dd neutrons. The maximum credible yield is 5e+13. This memo describes why, and what would be expected with variations on the target. This memo evaluates the maximum credible yield for deuterium filled double shell capsule targets with an aluminum ablator shell and a glass inner shell in yield Category A (< 1014 neutrons). It also pertains to fills of gas diluted with hydrogen, helium (3He or 4He), or any other fuel except tritium. This memo does not apply to lower z ablator dopants, such as beryllium, as this would increase the ablation efficiency. This evaluation is for 5.75 scale hohlraum targets of either gold or uranium with helium gas fills with density between 0 and 1.6 mg/cc. It could be extended to other hohlraum sizes and shapes with slight modifications. At present only laser pulse energies up to 1.5 MJ were considered with a single step laser pulse of arbitrary shape. Since yield decreases with laser energy for this target, the memo could be extended to higher laser energies if desired. These maximum laser parameters of pulses addressed here are near the edge of NIF’s capability, and constitute the operating envelope for experiments covered by this memo. We have not considered multiple step pulses, would probably create no advantages in performance, and are not planned for double shell capsules. The main target variables are summarized in Table 1 and explained in detail in the memo. Predicted neutron yields are based on 1D and 2D clean simulations.

  19. 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

  20. 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.

  1. 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.

  2. Potential of commodity chemicals to become bio-based according to maximum yields and petrochemical prices

    NARCIS (Netherlands)

    Straathof, Adrie J.J.; Bampouli, A.

    2017-01-01

    Carbohydrates are the prevailing biomass components available for bio-based production. The most direct way to convert carbohydrates into commodity chemicals is by one-step conversion at maximum theoretical yield, such as by anaerobic fermentation without side product formation. Considering these

  3. 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

  4. 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.)

  5. 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.

  6. 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.

  7. Maximum sustainable yield and species extinction in a prey-predator system: some new results.

    Science.gov (United States)

    Ghosh, Bapan; Kar, T K

    2013-06-01

    Though the maximum sustainable yield (MSY) approach has been legally adopted for the management of world fisheries, it does not provide any guarantee against from species extinction in multispecies communities. In the present article, we describe the appropriateness of the MSY policy in a Holling-Tanner prey-predator system with different types of functional responses. It is observed that for both type I and type II functional responses, harvesting of either prey or predator species at the MSY level is a sustainable fishing policy. In the case of combined harvesting, both the species coexist at the maximum sustainable total yield (MSTY) level if the biotic potential of the prey species is greater than a threshold value. Further, increase of the biotic potential beyond the threshold value affects the persistence of the system.

  8. Possible ecosystem impacts of applying maximum sustainable yield policy in food chain models.

    Science.gov (United States)

    Ghosh, Bapan; Kar, T K

    2013-07-21

    This paper describes the possible impacts of maximum sustainable yield (MSY) and maximum sustainable total yield (MSTY) policy in ecosystems. In general it is observed that exploitation at MSY (of single species) or MSTY (of multispecies) level may cause the extinction of several species. In particular, for traditional prey-predator system, fishing under combined harvesting effort at MSTY (if it exists) level may be a sustainable policy, but if MSTY does not exist then it is due to the extinction of the predator species only. In generalist prey-predator system, harvesting of any one of the species at MSY level is always a sustainable policy, but harvesting of both the species at MSTY level may or may not be a sustainable policy. In addition, we have also investigated the MSY and MSTY policy in a traditional tri-trophic and four trophic food chain models. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Impact of marine reserve on maximum sustainable yield in a traditional prey-predator system

    Science.gov (United States)

    Paul, Prosenjit; Kar, T. K.; Ghorai, Abhijit

    2018-01-01

    Multispecies fisheries management requires managers to consider the impact of fishing activities on several species as fishing impacts both targeted and non-targeted species directly or indirectly in several ways. The intended goal of traditional fisheries management is to achieve maximum sustainable yield (MSY) from the targeted species, which on many occasions affect the targeted species as well as the entire ecosystem. Marine reserves are often acclaimed as the marine ecosystem management tool. Few attempts have been made to generalize the ecological effects of marine reserve on MSY policy. We examine here how MSY and population level in a prey-predator system are affected by the low, medium and high reserve size under different possible scenarios. Our simulation works shows that low reserve area, the value of MSY for prey exploitation is maximum when both prey and predator species have fast movement rate. For medium reserve size, our analysis revealed that the maximum value of MSY for prey exploitation is obtained when prey population has fast movement rate and predator population has slow movement rate. For high reserve area, the maximum value of MSY for prey's exploitation is very low compared to the maximum value of MSY for prey's exploitation in case of low and medium reserve. On the other hand, for low and medium reserve area, MSY for predator exploitation is maximum when both the species have fast movement rate.

  10. Forage yield and nutritive value of Panicum maximum genotypes in the Brazilian savannah

    Directory of Open Access Journals (Sweden)

    Francisco Duarte Fernandes

    2014-02-01

    Full Text Available The narrow genetic variability of grasslands and the incidence of new biotic and abiotic stresses have motivated the selection of new Panicum maximum genotypes for use as forage for beef cattle in the Brazilian savannah. This study aimed to evaluate forage yield and nutritive value of P. maximum genotypes including 14 accessions (PM30 to PM43, four intraspecific hybrids (PM44 to PM47 and six cultivars (Aruana, Massai, Milênio, Mombaça, Tanzania and Vencedor, examining 24 genotypes over two years (2003 and 2004. Milênio cultivar was the genotype with the highest dry matter yield (DMY in both years (18.4 t ha-1 and 20.9 t ha-1, respectively although it presented a high proportion of stems (~ 30%. Genotypes that showed higher Leaf DMY in both years were the accession PM34 (14.7 t ha-1 and the hybrid PM46 (14.0 t ha-1, while Mombaça and Tanzania yielded 12.5 and 11.0 t ha-1, respectively. Leaf organic matter digestibility and leaf DMY for PM40 and PM46 genotypes exceeded the mean (> 656 g kg-1 and > 11.7 t ha-1, respectively. For this reason, PM40 and PM46 can be considered promising P. maximum genotypes for use as forage for grazing systems in the Brazilian savannah.

  11. 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.

  12. Comparison, artificial neural network modeling and genetic algorithm optimization of the resinoid and potassium yields from white lady’s bedstraw (Galium mollugo L. by conventional, reflux and ultrasound-assisted aqueous-ethanolic extraction

    Directory of Open Access Journals (Sweden)

    Milić Petar S.

    2013-01-01

    Full Text Available In this work, the yields of resinoid and potassium obtained from aerial parts of white lady’s bedstraw (Galium mollugo L. by maceration, reflux extraction and ultrasound-assisted extraction using aqueous ethanol solutions as solvents. The main goal was to define the influence of the extraction technique and the ethanol concentration on the resinoid and potassium yields. The resinoid and potassium yields were determined by the solvent evaporation from the liquid extracts to constant weight and the AAS emission method, respectively. The dependence of resinoid and potassium yields on the ethanol concentration was described by linear and quadratic polynomial models, respectively. The best potassium extraction selectivity of 0.077 g K/g of dry extract was achieved by maceration at the ethanol concentrations of 10 g/100 g. The artificial neural network (ANN was successfully applied to estimate the resinoid and potassium yields based on the ethanol concentration in the extracting solvent and the time duration for all three extraction techniques employed. The response surface methodology was also used to present the dependence of ANN results on the operating factors. The extraction process was optimized using the ANN model coupled with genetic algorithm. The maximum predicted resinoid and potassium yields of 30.4 and 1.67 g/100 g of dry plant were obtained by the ultrasonic extraction (80 min using the 10 g/100 g aqueous ethanol solution.

  13. 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

  14. Manufactering of par-fried french-fries. Part 3: a blueprint to predict the maximum production yield

    NARCIS (Netherlands)

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

    2004-01-01

    Very little research on the production yield of par-fried French-fries has been reported in the literature. This paper bridges the knowledge gap and outlines the development of a model to predict the maximum production yield of par-fried French-fries. This yield model can be used to calculate the

  15. 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.

  16. 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)

  17. 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)

  18. Ecological dynamics of age selective harvesting of fish population: Maximum sustainable yield and its control strategy

    International Nuclear Information System (INIS)

    Jana, Debaldev; Agrawal, Rashmi; Upadhyay, Ranjit Kumar; Samanta, G.P.

    2016-01-01

    Highlights: • Age-selective harvesting of prey and predator are considered by multi-delayed prey-predator system. • System experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation depending upon the parametric restrictions. • MSY, bionomic equilibrium and optimal harvesting policy are also depending upon the age-selection of prey and predator. • All the analytic results are delay dependent. • Numerical examples support the analytical findings. - Abstract: Life history of ecological resource management and empirical studies are increasingly documenting the impact of selective harvesting process on the evolutionary stable strategy of both aquatic and terrestrial ecosystems. In the present study, the interaction between population and their independent and combined selective harvesting are framed by a multi-delayed prey-predator system. Depending upon the age selection strategy, system experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation. Economic evolution of the system which is mainly featured by maximum sustainable yield (MSY), bionomic equilibrium and optimal harvesting vary largely with the commensurate age selections of both population because equilibrium population abundance becomes age-selection dependent. Our study indicates that balance between harvesting delays and harvesting intensities should be maintained for better ecosystem management. Numerical examples support the analytical findings.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. Dry Matter Yield And Competitiveness Of Alang-alang (Imperata Cylindrica) And Guinea Grass (Panicum Maximum) In Intercropping

    OpenAIRE

    Rusdy, M

    2012-01-01

    The objectives of this experiment were to determine dry matter yield and competitiveness of alang-alang (Imperata cylindrica) and Guinea grass (Panicum maximum) in intercropping. The experiment was arranged in factorial combinations of four planting proportions, two levels of nitrogen fertilization and three harvesting intervals with three replications. Planting proportions were 0, 33.3, 66.7, and 100% of alang-alang (planting densities of 0, 1, 2 and 3 plants/pot) combined with 100, 66.7, 33...

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. Ethanol yields and cell wall properties in divergently bred switchgrass genotypes

    Science.gov (United States)

    Genetic modification of herbaceous plant cell walls to increase biofuels yields from harvested biomass is a primary bioenergy research goal. The focus of much of this research has been on cell wall lignin concentration. Using switchgrass genotypes developed by divergent breeding for ruminant diges...

  10. 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.

  11. 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.

  12. 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.

  13. Direct ethanol conversion of pretreated straw by Fusarium oxysporum

    Energy Technology Data Exchange (ETDEWEB)

    Christakopoulos, P.; Koullas, D.P.; Kekos, D.; Koukios, E.G.; Macris, B.J. (National Technical Univ., Athens (GR). Dept. of Chemical Engineering)

    1991-01-01

    Factors affecting the direct conversion of alkali pretreated straw to ethanol by Fusarium oxysporum F3 were investigated and the alkali level used for pretreatment and the degree of delignification of straw were found to be the most important. A linear correlation between ethanol yield and both the degree of straw delignification and the alkali level was observed. At optimum delignified straw concentration (4% w/v), a maximum ethanol yield of 0.275 g ethanol g{sup -1} of straw was obtained corresponding to 67.8% of the theoretical yield. (author).

  14. 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.

  15. Ecosystem approach to fisheries: Exploring environmental and trophic effects on Maximum Sustainable Yield (MSY reference point estimates.

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    Full Text Available We present a comprehensive analysis of estimation of fisheries Maximum Sustainable Yield (MSY reference points using an ecosystem model built for Mille Lacs Lake, the second largest lake within Minnesota, USA. Data from single-species modelling output, extensive annual sampling for species abundances, annual catch-survey, stomach-content analysis for predatory-prey interactions, and expert opinions were brought together within the framework of an Ecopath with Ecosim (EwE ecosystem model. An increase in the lake water temperature was observed in the last few decades; therefore, we also incorporated a temperature forcing function in the EwE model to capture the influences of changing temperature on the species composition and food web. The EwE model was fitted to abundance and catch time-series for the period 1985 to 2006. Using the ecosystem model, we estimated reference points for most of the fished species in the lake at single-species as well as ecosystem levels with and without considering the influence of temperature change; therefore, our analysis investigated the trophic and temperature effects on the reference points. The paper concludes that reference points such as MSY are not stationary, but change when (1 environmental conditions alter species productivity and (2 fishing on predators alters the compensatory response of their prey. Thus, it is necessary for the management to re-estimate or re-evaluate the reference points when changes in environmental conditions and/or major shifts in species abundance or community structure are observed.

  16. 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...

  17. Production of ethanol from lepthochloa fusca L. (kallar grass) and panicum maximum using cellulases from trichoderma SSP and cultures of saccharomyces carlsbergensis

    International Nuclear Information System (INIS)

    Rajoka, M.I.; Malik, K.A.

    1991-01-01

    Saline sodic soils have been used for production of biomass using salt tolerant grass, kallar grass followed by lesser tolerant plants, namely, sasbania aculeata or Panicum maximum or to provide biomass throughout the year for it utilization for microbial conversion. These substrates have been utilized to produce single cell protein and cellases or hemicellulases. The enzyme titer obtained after growth of cellulomonas biazotea on kallar grass could saccharify wheat straw ad bagasse for subsequent conversion to ethanol but kallar grass itself was saccharified to lesser extent, however, enzyme titres from different fungi could saccherify the biomass produced on saline lands to monomeric sugars. In these studies, the enzyme titre from Trichoderma spp. were used for saccharification purpose. (author)

  18. Corrigendum to "Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields" [J. Power Sources 268 (5 December 2014) 439-442

    Science.gov (United States)

    Majidi, Pasha; Pickup, Peter G.

    2016-09-01

    The authors regret that Equation (5) is incorrect and has resulted in errors in Fig. 4 and the efficiencies stated on p. 442. The corrected equation, figure and text are presented below. In addition, the title should be 'Sinusoidal potential cycling operation of a direct ethanol fuel cell to improve carbon dioxide yields', and the reversible cell potential quoted on p. 441 should be 1.14 V. The authors would like to apologise for any inconvenience caused.

  19. Improved Sugar Conversion and Ethanol Yield for Forage Sorghum (Sorghum bicolor L. Moench) Lines with Reduced Lignin Contents

    Science.gov (United States)

    Lignin is known to impede conversion of lignocellulose into ethanol. In this study, forage sorghum plants carrying brown midrib (bmr) mutations, which reduce lignin contents, were evaluated as bioenergy feedstocks. The near isogenic lines evaluated were: wild-type, bmr-6, bmr-12, and bmr-6 bmr-12...

  20. Repeatability, number of harvests, and phenotypic stability of dry matter yield and quality traits of Panicum maximum jacq.

    Directory of Open Access Journals (Sweden)

    Francisco Duarte Fernandes

    2017-04-01

    Full Text Available Selection of superior forage genotypes is based on agronomic traits assayed in repeated measures. The questions are how repeatable the performance of individual genotypes is and how many harvests are needed to select the best genotypes. The objectives were to estimate repeatability coefficients of dry matter yield (DMY and forage quality, their phenotypic stability and the number of harvests needed for an accurate selection. Two randomized complete block design experiments data with 24 genotypes each, undergoing 12 and 16 harvests, over a period of 2 and 3 years, respectively, were used. The DMY repeatability estimates ranged from 0.42 to 0.55, suggesting a low heritability. The mean numbers of repeated measures were 5 and 7 harvests for 0.80 and 0.85 accuracy, respectively. The inclusion of the first two harvests negatively affects the estimates. Repeatability for quality traits ranged from 0.30 to 0.69, indicating low to moderate heritability.

  1. Optimizing selective cutting strategies for maximum carbon stocks and yield of Moso bamboo forest using BIOME-BGC model.

    Science.gov (United States)

    Mao, Fangjie; Zhou, Guomo; Li, Pingheng; Du, Huaqiang; Xu, Xiaojun; Shi, Yongjun; Mo, Lufeng; Zhou, Yufeng; Tu, Guoqing

    2017-04-15

    The selective cutting method currently used in Moso bamboo forests has resulted in a reduction of stand productivity and carbon sequestration capacity. Given the time and labor expense involved in addressing this problem manually, simulation using an ecosystem model is the most suitable approach. The BIOME-BGC model was improved to suit managed Moso bamboo forests, which was adapted to include age structure, specific ecological processes and management measures of Moso bamboo forest. A field selective cutting experiment was done in nine plots with three cutting intensities (high-intensity, moderate-intensity and low-intensity) during 2010-2013, and biomass of these plots was measured for model validation. Then four selective cutting scenarios were simulated by the improved BIOME-BGC model to optimize the selective cutting timings, intervals, retained ages and intensities. The improved model matched the observed aboveground carbon density and yield of different plots, with a range of relative error from 9.83% to 15.74%. The results of different selective cutting scenarios suggested that the optimal selective cutting measure should be cutting 30% culms of age 6, 80% culms of age 7, and all culms thereafter (above age 8) in winter every other year. The vegetation carbon density and harvested carbon density of this selective cutting method can increase by 74.63% and 21.5%, respectively, compared with the current selective cutting measure. The optimized selective cutting measure developed in this study can significantly promote carbon density, yield, and carbon sink capacity in Moso bamboo forests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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

  3. Enzymatic hydrolysis and fermentation of agricultural residues to ethanol

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  4. 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...

  5. 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.

  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. Effect of phytase application during high gravity (HG) maize mashes preparation on the availability of starch and yield of the ethanol fermentation process.

    Science.gov (United States)

    Mikulski, D; Kłosowski, G; Rolbiecka, A

    2014-10-01

    Phytic acid present in raw materials used in distilling industry can form complexes with starch and divalent cations and thus limit their biological availability. The influence of the enzymatic hydrolysis of phytate complexes on starch availability during the alcoholic fermentation process using high gravity (HG) maize mashes was analyzed. Indicators of the alcoholic fermentation as well as the fermentation activity of Saccharomyces cerevisiae D-2 strain were statistically evaluated. Phytate hydrolysis improved the course of the alcoholic fermentation of HG maize mashes. The final ethanol concentration in the media supplemented with phytase applied either before or after the starch hydrolysis increased by 1.0 and 0.6 % v/v, respectively, as compared to the control experiments. This increase was correlated with an elevated fermentation yield that was higher by 5.5 and 2.0 L EtOH/100 kg of starch, respectively. Phytate hydrolysis resulted also in a statistically significant increase in the initial concentration of fermenting sugars by 14.9 mg/mL of mash, on average, which was a consequence of a better availability of starch for enzymatic hydrolysis. The application of phytase increased the attenuation of HG media fermentation thus improving the economical aspect of the ethanol fermentation process.

  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. 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.

  10. FeCl3-catalyzed ethanol pretreatment of sugarcane bagasse boosts sugar yields with low enzyme loadings and short hydrolysis time.

    Science.gov (United States)

    Zhang, Hongdan; Zhang, Shuaishuai; Yuan, Hongyou; Lyu, Gaojin; Xie, Jun

    2018-02-01

    An organosolv pretreatment system consisting of 60% ethanol and 0.025 mol·L -1 FeCl 3 under various temperatures was developed in this study. During the pretreatment, the highest xylose yield was 11.4 g/100 g raw material, representing 49.8% of xylose in sugarcane bagasse. Structural features of raw material and pretreated substrates were characterized to better understand how hemicellulose removal and delignification affected subsequent enzymatic hydrolysis. The 160 °C pretreated solid presented a remarkable glucose yield of 93.8% for 72 h. Furthermore, the influence of different additives on the enzymatic hydrolysis of pretreated solid was investigated. The results indicated that the addition of Tween 80 shortened hydrolysis time to 6 h and allowed a 50% reduction of enzyme loading to achieve the same level of glucose yield. This work suggested that FeCl 3 -catalyzed organosolv pretreatment could improve the enzymatic hydrolysis significantly and reduce the hydrolysis time and enzyme dosage with the addition of Tween 80. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Bioconversion of crude glycerol feedstocks into ethanol by Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying; Jensen, Peter Ruhdal; Workman, Mhairi

    2012-01-01

    Glycerol, the by-product of biodiesel production, is considered as a waste by biodiesel producers. This study demonstrated the potential of utilising the glycerol surplus through conversion to ethanol by the yeast Pachysolen tannophilus (CBS4044). This study demonstrates a robust bioprocess which...... was not sensitive to the batch variability in crude glycerol dependent on raw materials used for biodiesel production. The oxygen transfer rate (OTR) was a key factor for ethanol production, with lower OTR having a positive effect on ethanol production. The highest ethanol production was 17.5 g/L on 5% (v/v) crude...... glycerol, corresponding to 56% of the theoretical yield. A staged batch process achieved 28.1 g/L ethanol, the maximum achieved so far for conversion of glycerol to ethanol in a microbial bioprocess. The fermentation physiology has been investigated as a means to designing a competitive bioethanol...

  12. Cellulosic ethanol

    DEFF Research Database (Denmark)

    Lindedam, Jane; Bruun, Sander; Jørgensen, Henning

    2010-01-01

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

  13. Thermoanaerobacter pentosaceus sp. nov., an anaerobic, extreme thermophilic, high ethanol-yielding bacterium isolated from household waste

    DEFF Research Database (Denmark)

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

    2013-01-01

    of approximately 0.5 µm. Optimal growth occurred at 70 °C and pH(25°C) 7, with a maximum growth rate of 0.1 h-1. DNA G+C content was 34.2 mol %. Strain DTU01(T) could ferment arabinose, cellobiose, fructose, galactose, glucose, inulin, lactose, mannose, melibiose, pectin, starch, sucrose, xylan, yeast extract...

  14. 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.

  15. Simulation of the maximum yield of sugar cane at different altitudes: effect of temperature on the conversion of radiation into biomass

    International Nuclear Information System (INIS)

    Martine, J.F.; Siband, P.; Bonhomme, R.

    1999-01-01

    To minimize the production costs of sugar cane, for the diverse sites of production found in La Réunion, an improved understanding of the influence of temperature on the dry matter radiation quotient is required. Existing models simulate poorly the temperature-radiation interaction. A model of sugar cane growth has been fitted to the results from two contrasting sites (mean temperatures: 14-30 °C; total radiation: 10-25 MJ·m -2 ·d -1 ), on a ratoon crop of cv R570, under conditions of non-limiting resources. Radiation interception, aerial biomass, the fraction of millable stems, and their moisture content, were measured. The time-courses of the efficiency of radiation interception differed between sites. As a function of the sum of day-degrees, they were similar. The dry matter radiation quotient was related to temperature. The moisture content of millable stems depended on the day-degree sum. On the other hand, the leaf/stem ratio was independent of temperature. The relationships established enabled the construction of a simple model of yield potential. Applied to a set of sites representing the sugar cane growing area of La Réunion, it gave a good prediction of maximum yields. (author) [fr

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. Bioconversion of starch to ethanol in a single-step process by coculture of amylolytic yeasts and Saccharomyces cerevisiae 21

    Energy Technology Data Exchange (ETDEWEB)

    Verma, G.; Singh, D.; Chaudhary, K. [CCS Haryana Agricultural Univ., Hisar (India). Dept. of Biotechnology and Molecular Biology; Nigam, P. [Ulster Univ., Coleraine, Northern Ireland (United Kingdom). School of Applied Biological and Chemical Sciences

    2000-05-01

    Ethanol production by a coculture of Saccharomyces diastaticus and Saccharomyces cerevisiae 21 was 24.8 g/l using raw unhydrolysed starch in a single-step fermentation. This was 48% higher than the yield obtained with the monoculture of S. diastaticus (16.8 g/l). The maximum ethanol fermentation efficiency was achieved (93% of the theoretical value) using 60 g/l starch concentration. In another coculture fermentation with E. capsularis and S. cerevisiae 21, maximum ethanol yield was 16.0 g/l, higher than the yield with the monoculture of Endomycopsis capsularis. In batch fermentations using cocultures maximum ethanol production occurred in 48 h of fermentation at 30{sup o}C using 60 g/l starch. Fermentation efficiency was found lower in a two-step process using {alpha}-amylase and glucoamylase-treated starch. (Author)

  1. 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)

  2. Selection of yeast able to produce ethanol from glucose at 40/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Hacking, A J; Taylor, I W.F.; Hanas, C M

    1984-05-01

    A total of 55 yeast strains selected from 7 genera known to ferment carbohydrates to ethanol were screened for their ability to ferment glucose to ethanol in shaken flask culture at 37/sup 0/, 40/sup 0/ and 45/sup 0/C. Yields of more than 50% of the theoretical maximum were obtained with 28 strains at 37/sup 0/C, but only 12 at 40/sup 0/C. Only 6 could grow at 45/sup 0/C, but they produced poor yields. In general Kluyveromyces strains were more thermotolerant than Saccharomyces and Candida strains, but Saccharomyces strains produced higher ethanol yields. The 8 strains with the highest yields at 40/sup 0/C were evaluated in batch fermentations. Three of these, two Saccharomyces and one Candida, were able to meet minimum commercial targets set at 8% (v/v) ethanol from 14% (w/v) glucose at 40/sup 0/C.

  3. 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.

  4. 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.

  5. [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.

  6. 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.

  7. 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)

  8. 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

  9. 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.

  10. Plasma-catalytic reforming of ethanol: influence of air activation rate and reforming temperature

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya.; Fedirchuk, I.I.; Demchina, V.P.; Bortyshevsky, V.A.; Korzh, R.V.

    2016-01-01

    This paper presents the study of the influence that air activation rate and reforming temperature have on the gaseous products composition and conversion efficiency during the plasma-catalytic reforming of ethanol. The analysis of product composition showed that the conversion efficiency of ethanol has a maximum in the studied range of reforming temperatures. Researched system provided high reforming efficiency and high hydrogen energy yield at the lower temperatures than traditional conversion technologies

  11. 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)

  12. 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%.

  13. 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)

  14. 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.

  15. 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.

  16. Thermogravimetric analysis and kinetic modeling of low-transition-temperature mixtures pretreated oil palm empty fruit bunch for possible maximum yield of pyrolysis oil.

    Science.gov (United States)

    Yiin, Chung Loong; Yusup, Suzana; Quitain, Armando T; Uemura, Yoshimitsu; Sasaki, Mitsuru; Kida, Tetsuya

    2018-05-01

    The impacts of low-transition-temperature mixtures (LTTMs) pretreatment on thermal decomposition and kinetics of empty fruit bunch (EFB) were investigated by thermogravimetric analysis. EFB was pretreated with the LTTMs under different duration of pretreatment which enabled various degrees of alteration to their structure. The TG-DTG curves showed that LTTMs pretreatment on EFB shifted the temperature and rate of decomposition to higher values. The EFB pretreated with sucrose and choline chloride-based LTTMs had attained the highest mass loss of volatile matter (78.69% and 75.71%) after 18 h of pretreatment. For monosodium glutamate-based LTTMs, the 24 h pretreated EFB had achieved the maximum mass loss (76.1%). Based on the Coats-Redfern integral method, the LTTMs pretreatment led to an increase in activation energy of the thermal decomposition of EFB from 80.00 to 82.82-94.80 kJ/mol. The activation energy was mainly affected by the demineralization and alteration in cellulose crystallinity after LTTMs pretreatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. 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.)

  18. Optimization of Pretreatment and Enzymatic Saccharification of Cogon Grass Prior Ethanol Production

    OpenAIRE

    Jhalique Jane R. Fojas; Ernesto J. Del Rosario

    2013-01-01

    The dilute acid pretreatment and enzymatic saccharification of lignocellulosic substrate, cogon grass (Imperata cylindrical, L.) was optimized prior ethanol fermentation using simultaneous saccharification and fermentation (SSF) method. The optimum pretreatment conditions, temperature, sulfuric acid concentration, and reaction time were evaluated by determining the maximum sugar yield at constant enzyme loading. Cogon grass, at 10% w/v substrate loading, has optimum pretr...

  19. 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.

  20. Ethanol Basics

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-01-30

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  1. Converting developing and mature sugarcane carbohydrates into ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Rolz, Carlos; De Leon, Roberto [Biochemical Engineering Center, Research Institute, Universidad del Valle de Guatemala (Guatemala)

    2010-10-15

    Experiments were performed employing cane particles obtained from sugarcane at different growth stages until maturation measuring the amount of ethanol produced and the carbohydrate consumption in order to estimate the sugarcane growth stage where both parameters were optimized. Two non-flowering commercial cane varieties NA56 and PR752002 were cultivated and samples taken at different time intervals. Two Saccharomyces cerevisae strains were also compared in the trials. Sucrose was poorly consumed in young cane, which was an unexpected result. Fructose on the other hand was the hexose that remained in the medium at the end of the fermentations specially when using mature sugarcane. There was an increasing trend in ethanol production as a function of days after planting (DAP) as expected; however, a plateau was reached after 225 DAP and the maximum value obtained was between 300 and 325 DAP. When these figures were compared with the corresponding DAP used for sugar production, only 25 days less were needed in the field for maximum ethanol production. On the other hand, it was clear from the data that cane harvesting for ethanol production should not be done after the recommended DAP for commercial sugar production. If this is done, the excess fructose present will not be completely utilized by yeast. Finally, it was observed that the yeast with more affinity for sugarcane fibers showed better ethanol yields in all samples tested. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  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. Verification of Radicals Formation in Ethanol-Water Mixture Based Solution Plasma and Their Relation to the Rate of Reaction.

    Science.gov (United States)

    Sudare, Tomohito; Ueno, Tomonaga; Watthanaphanit, Anyarat; Saito, Nagahiro

    2015-12-03

    Our previous research demonstrated that using ethanol-water mixture as a liquid medium for the synthesis of gold nanoparticles by the solution plasma process (SPP) could lead to an increment of the reaction rate of ∼35.2 times faster than that in pure water. This drastic change was observed when a small amount of ethanol, that is, at an ethanol mole fraction (χethanol) of 0.089, was added in the system. After this composition, the reaction rate decreased continuously. To better understand what happens in the ethanol-water mixture-based SPP, in this study, effect of the ethanol content on the radical formation in the system was verified. We focused on detecting the magnetic resonance of electronic spins using electron spin resonance spectroscopy to determine the type and quantity of the generated radicals at each χethanol. Results indicated that ethanol radicals were generated in the ethanol-water mixtures and exhibited maximum quantity at the xethanol of 0.089. Relationship between the ethanol radical yield and the rate of reaction, along with possible mechanism responsible for the observed phenomenon, is discussed in this paper.

  4. 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.

  5. Cash Management Yields Many Maximum Returns.

    Science.gov (United States)

    Traynham, William W., Jr

    1987-01-01

    Outlines the cash management program developed by the Orangeburg School District (SC) for the district's funds. They take bids from banks before deciding which bank to use for all their services, including an investment program. This new system has saved $30,000 in the first year. Sidebars tell how to shop for bank services and list technical…

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.)

  11. Sequential high gravity ethanol fermentation and anaerobic digestion of steam explosion and organosolv pretreated corn stover.

    Science.gov (United States)

    Katsimpouras, Constantinos; Zacharopoulou, Maria; Matsakas, Leonidas; Rova, Ulrika; Christakopoulos, Paul; Topakas, Evangelos

    2017-11-01

    The present work investigates the suitability of pretreated corn stover (CS) to serve as feedstock for high gravity (HG) ethanol production at solids-content of 24wt%. Steam explosion, with and without the addition of H 2 SO 4 , and organosolv pretreated CS samples underwent a liquefaction/saccharification step followed by simultaneous saccharification and fermentation (SSF). Maximum ethanol concentration of ca. 76g/L (78.3% ethanol yield) was obtained from steam exploded CS (SECS) with 0.2% H 2 SO 4 . Organosolv pretreated CS (OCS) also resulted in high ethanol concentration of ca. 65g/L (62.3% ethanol yield). Moreover, methane production through anaerobic digestion (AD) was conducted from fermentation residues and resulted in maximum methane yields of ca. 120 and 69mL/g volatile solids (VS) for SECS and OCS samples, respectively. The results indicated that the implementation of a liquefaction/saccharification step before SSF employing a liquefaction reactor seemed to handle HG conditions adequately. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Ethanol fermentation from molasses at high temperature by thermotolerant yeast Kluyveromyces sp. IIPE453 and energy assessment for recovery.

    Science.gov (United States)

    Dasgupta, Diptarka; Ghosh, Prasenjit; Ghosh, Debashish; Suman, Sunil Kumar; Khan, Rashmi; Agrawal, Deepti; Adhikari, Dilip K

    2014-10-01

    High temperature ethanol fermentation from sugarcane molasses B using thermophilic Crabtree-positive yeast Kluyveromyces sp. IIPE453 was carried out in batch bioreactor system. Strain was found to have a maximum specific ethanol productivity of 0.688 g/g/h with 92 % theoretical ethanol yield. Aeration and initial sugar concentration were tuning parameters to regulate metabolic pathways of the strain for either cell mass or higher ethanol production during growth with an optimum sugar to cell ratio 33:1 requisite for fermentation. An assessment of ethanol recovery from fermentation broth via simulation study illustrated that distillation-based conventional recovery was significantly better in terms of energy efficiency and overall mass recovery in comparison to coupled solvent extraction-azeotropic distillation technique for the same.

  13. Conversion of bakery wastes to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.E.

    1984-10-04

    The project had the following goals: (1) determine the actual yields of ethanol from the waste products of major bakeries in the Denver area by distillation in a laboratory bench scale distillation column; (2) determine the expected yields of ethanol from the major types of wastes produced by the large bakeries in the Denver area; (3) increase alcohol yields to the maximum possible by identifying any inhibitors and taking steps to remove them; (4) purify the distilled alcohol if necessary to remove any by-products distilled off with the alcohol. The production of alcohol from bakery wastes is feasible. The average yield of the bread type products is 19.8% by weight with yields ranging up to 25%. In other words, on the average, for every 1000 pounds of waste, 198 pounds or 30 gallons of alcohol would be produced. This estimate is conservative since a larger facility would tend to get a better yield (due to the difficulties of getting all the alcohol out of the small batches run). The major variable appeared to be the yeast. Fresh yeast should always be used. No yeast nutrients were tried in these experiments, since the yeast seemed to grow well. However, this could be an area of further investigation. It is possible that the yields could be kept consistently high by providing the yeast with nutrients. Finally, contamination of the alcohol with oils can be a problem, although not necessarily a very significant one. Methods do exist to remove the oil during the actual distillation, as well as, before distillation. Careful distillation also tends to lessen the problem. 7 references, 4 figures, 2 tables.

  14. 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)

  15. 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.

  16. 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...

  17. Social opportunity and ethanol drinking in rats.

    Science.gov (United States)

    Tomie, Arthur; Burger, Kelly M; Di Poce, Jason; Pohorecky, Larissa A

    2004-11-01

    Two experiments were designed to evaluate the effects of pairings of ethanol sipper conditioned stimulus (CS) with social opportunity unconditioned stimulus (US) on ethanol sipper CS-directed drinking in rats. In both experiments, rats were deprived of neither food nor water, and initiation of drinking of unsweetened 3% ethanol was evaluated, as were the effects of increasing the concentration of unsweetened ethanol (3-10%) across sessions. In Experiment 1, Group Paired (n=8) received 35 trials per session wherein the ethanol sipper CS was presented for 10 s immediately prior to 15 s of social opportunity US. All rats initiated sipper CS-directed drinking of 3% ethanol. Increasing the concentration of ethanol in the sipper CS [(3%, 4%, 6%, 8%, 10% (vol./vol.)] across sessions induced escalation of daily g/kg ethanol intake. To evaluate the hypothesis that the drinking in Group Paired was due to autoshaping, Experiment 2 included a pseudoconditioning control that received sipper CS and social opportunity US randomly with respect to one another. All rats in Group Paired (n=6) and in Group Random (n=6) initiated sipper CS-directed drinking of 3% ethanol and daily mean g/kg ethanol intake in the two groups was comparable. Also comparable was daily g/kg ethanol intake, which increased for both groups with the availability of higher concentrations of ethanol in the sipper CS, up to a maximum of approximately 0.8 g/kg ethanol intake of 10% ethanol. Results indicate that random presentations of ethanol sipper CS and social opportunity US induced reliable initiation and escalation of ethanol intake, and close temporally contiguous presentations of CS and US did not induce still additional ethanol intake. This may indicate that autoshaping CR performance is not induced by these procedures, or that high levels of ethanol intake induced by factors related to pseudoconditioning produces a ceiling effect. Implications for ethanol drinking in humans are discussed.

  18. Modeling and optimization of ethanol fermentation using Saccharomyces cerevisiae: Response surface methodology and artificial neural network

    Directory of Open Access Journals (Sweden)

    Esfahanian Mehri

    2013-01-01

    Full Text Available In this study, the capabilities of response surface methodology (RSM and artificial neural networks (ANN for modeling and optimization of ethanol production from glucoseusing Saccharomyces cerevisiae in batch fermentation process were investigated. Effect of three independent variables in a defined range of pH (4.2-5.8, temperature (20-40ºC and glucose concentration (20-60 g/l on the cell growth and ethanol production was evaluated. Results showed that prediction accuracy of ANN was apparently similar to RSM. At optimum condition of temperature (32°C, pH (5.2 and glucose concentration (50 g/l suggested by the statistical methods, the maximum cell dry weight and ethanol concentration obtained from RSM were 12.06 and 16.2 g/l whereas experimental values were 12.09 and 16.53 g/l, respectively. The present study showed that using ANN as fitness function, the maximum cell dry weight and ethanol concentration were 12.05 and 16.16 g/l, respectively. Also, the coefficients of determination for biomass and ethanol concentration obtained from RSM were 0.9965 and 0.9853 and from ANN were 0.9975 and 0.9936, respectively. The process parameters optimization was successfully conducted using RSM and ANN; however prediction by ANN was slightly more precise than RSM. Based on experimental data maximum yield of ethanol production of 0.5 g ethanol/g substrate (97 % of theoretical yield was obtained.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Xylose fermentation to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  6. 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.

  7. 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.

  8. Application of acetate buffer in pH adjustment of sorghum mash and its influence on fuel ethanol fermentation.

    Science.gov (United States)

    Zhao, Renyong; Bean, Scott R; Crozier-Dodson, Beth Ann; Fung, Daniel Y C; Wang, Donghai

    2009-01-01

    A 2 M sodium acetate buffer at pH 4.2 was tried to simplify the step of pH adjustment in a laboratory dry-grind procedure. Ethanol yields or conversion efficiencies of 18 sorghum hybrids improved significantly with 2.0-5.9% (3.9% on average) of relative increases when the method of pH adjustment changed from traditional HCl to the acetate buffer. Ethanol yields obtained using the two methods were highly correlated (R (2) = 0.96, P ethanol production were inhibited during exponential phase but promoted during stationary phase. The maximum growth rate constants (mu(max)) were 0.42 and 0.32 h(-1) for cells grown in mashes with pH adjusted by HCl and the acetate buffer, respectively. Viable cell counts of yeast in mashes with pH adjusted by the acetate buffer were 36% lower than those in mashes adjusted by HCl during stationary phase. Coupled to a 5.3% relative increase in ethanol, a 43.6% relative decrease in glycerol was observed, when the acetate buffer was substituted for HCl. Acetate helped to transfer glucose to ethanol more efficiently. The strain tested did not use acetic acid as carbon source. It was suggested that decreased levels of ATP under acetate stress stimulate glycolysis to ethanol formation, increasing its yield at the expense of biomass and glycerol production.

  9. Ethanol demand in Brazil: Regional approach

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Luciano Charlita de, E-mail: lucianofreitas@hiroshima-u.ac.j [Graduate School for International Development and Cooperation, Development Policy, Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529 (Japan); Kaneko, Shinji [Graduate School for International Development and Cooperation, Development Policy, Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529 (Japan)

    2011-05-15

    Successive studies attempting to clarify national aspects of ethanol demand have assisted policy makers and producers in defining strategies, but little information is available on the dynamic of regional ethanol markets. This study aims to analyze the characteristics of ethanol demand at the regional level taking into account the peculiarities of the developed center-south and the developing north-northeast regions. Regional ethanol demand is evaluated based on a set of market variables that include ethanol price, consumer's income, vehicle stock and prices of substitute fuels; i.e., gasoline and natural gas. A panel cointegration analysis with monthly observations from January 2003 to April 2010 is employed to estimate the long-run demand elasticity. The results reveal that the demand for ethanol in Brazil differs between regions. While in the center-south region the price elasticity for both ethanol and alternative fuels is high, consumption in the north-northeast is more sensitive to changes in the stock of the ethanol-powered fleet and income. These, among other evidences, suggest that the pattern of ethanol demand in the center-south region most closely resembles that in developed nations, while the pattern of demand in the north-northeast most closely resembles that in developing nations. - Research highlights: {yields} Article consists of a first insight on regional demand for ethanol in Brazil. {yields} It proposes a model with multiple fuels, i.e., hydrous ethanol, gasohol and natural gas. {yields} Results evidence that figures for regional demand for ethanol differ amongst regions and with values reported for national demand. {yields} Elasticities for the center-south keep similarities to patterns for fuel demand in developed nations while coefficients for the north-northeast are aligned to patterns on developing countries.

  10. 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.

  11. Supercritical CO2 extraction of raw propolis and its dry ethanolic extract

    Directory of Open Access Journals (Sweden)

    L. C. Paviani

    2012-06-01

    Full Text Available Three types of propolis extract were prepared and analyzed with respect to their global extraction yields and with respect to the concentration of the following markers: 3,5-diprenyl-4-hydroxycinnamic acid; 3-prenyl-4-hydroxycinnamic acid; 4-hydroxycinnamic acid and 4-methoxy-3,5,7-trihydroxyflavone. The extract EEP (ethanolic extract of propolis was obtained by the conventional method from raw propolis using ethanol as solvent. The extracts (SFE were obtained by supercritical solvent extraction from the raw propolis using supercritical carbon dioxide (sc-CO2, with and without the addition of ethanol as a co-solvent. The fractionated supercritical extracts (FSCE were obtained by fractionation (extract and raffinate of the dry EEP with sc-CO2. EEP yields of 39.5% were obtained and maximum global extraction yields were 7.3% for SFE with no co-solvent, 51% for SFE with 15% ethanol and 18% for the FSCE extract fraction. The concentrations of the markers in the different extracts differed as a function of the operational parameters, indicating that the addition of co-solvent and the selectivity of sc-CO2 could be manipulated so as to obtain extracts with the yields and concentrations of interest.

  12. Requirements of Saccharomyces Cerevisiae,Y 10 for Bioconversion of Lignocellulose Substrates to Ethanol under Simultaneous Saccharification and Fermentation Processes

    International Nuclear Information System (INIS)

    Rady, A.H.; Younis, N.A.; Sidkey, N.M.; Ouda, S.M.

    2006-01-01

    Ethanol production increased gradually with increasing the incubation period to a maximum value at 72 hrs for rice straw, bagasse and CHW (Cellulosic hospital wastes) under simultaneous saccharification and fermentation technique (SSF). bagasse was the best substrate for maximum production . maximum Values of ethanol were recorded when crude cellulses were 1.79, 0.597 and 1.19 (FPU /ml fermentation medium) for substrates respectively. the optimum inoculum number of yeast was (9x10 8 free cells / ml for rice straw, (1.2x10 9 cells/ml) of immobilized and free yeast for bagasse and CHW respectively. Maximum yield was recorded with ph 5 at 30 degree C for the three substrates. Fe SO 4 .7H 2 O(0.05%) increased ethanol production from pretreated bagasse and CHW .L-Iysine increased the productivity for both bagasse and CHW. molasses (9 g/l) achieved the highest productivity from treated rice straw, while thiamine B1 (100 and 200 ppm) for treated bagsse and CHW respectively. Gamma rays at doses 0.05 and 0.8 K.Gy increased ethanol yield 7.5 and 2 % for treated bagasse and CHW respectively. Highest values recorded at 300,200 and 100 rpm. for treated rice straw, bagasse and CHW, respectively

  13. 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...

  14. 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.

  15. Sorghum to Ethanol Research

    Energy Technology Data Exchange (ETDEWEB)

    Dahlberg, Jeffrey A. [Univ. of California, Parlier, CA (United States). Kearney Research and Extension Center; Wolfrum, Edward J. [National Renewable Energy Lab. (NREL), Golden, CO (United States). Process and Analytical Engineering Group

    2010-09-28

    The development of a robust source of renewable transportation fuel will require a large amount of biomass feedstocks. It is generally accepted that in addition to agricultural and forestry residues, we will need crops grown specifically for subsequent conversion into fuels. There has been a lot of research on several of these so-called "dedicated bioenergy crops" including switchgrass, miscanthus, sugarcane, and poplar. It is likely that all of these crops will end up playing a role as feedstocks, depending on local environmental and market conditions. Many different types of sorghum have been grown to produce syrup, grain, and animal feed for many years. It has several features that may make it as compelling as other crops mentioned above as a renewable, sustainable biomass feedstock; however, very little work has been done to investigate sorghum as a dedicated bioenergy crop. The goal of this project was to investigate the feasibility of using sorghum biomass to produce ethanol. The work performed included a detailed examination of the agronomics and composition of a large number of sorghum varieties, laboratory experiments to convert sorghum to ethanol, and economic and life-cycle analyses of the sorghum-to-ethanol process. This work showed that sorghum has a very wide range of composition, which depended on the specific sorghum cultivar as well as the growing conditions. The results of laboratory- and pilot-scale experiments indicated that a typical high-biomass sorghum variety performed very similarly to corn stover during the multi-step process required to convert biomass feedstocks to ethanol; yields of ethanol for sorghum were very similar to the corn stover used as a control in these experiments. Based on multi-year agronomic data and theoretical ethanol production, sorghum can achieve more than 1,300 gallons of ethanol per acre given the correct genetics and environment. In summary, sorghum may be a compelling dedicated bioenergy crop that could help

  16. Optimization of suitable ethanol blend ratio for motorcycle engine using response surface method.

    Science.gov (United States)

    Chen, Yu-Liang; Chen, Suming; Tsai, Jin-Ming; Tsai, Chao-Yin; Fang, Hsin-Hsiung; Yang, I-Chang; Liu, Sen-Yuan

    2012-01-01

    In view of energy shortage and air pollution, ethanol-gasoline blended fuel used for motorcycle engine was studied in this work. The emissions of carbon monoxide (CO), nitrogen oxides (NO(X)) and engine performance of a 125 cc four-stroke motorcycle engine with original carburetor using ethanol-gasoline fuels were investigated. The model of three-variable Box Behnken design (BBD) was used for experimental design, the ethanol blend ratios were prepared at 0, 10, 20 vol%; the speeds of motorcycle were selected as 30, 45, 60 km/h; and the throttle positions were set at 30, 60, 90 %. Both engine performance and air pollutant emissions were then analyzed by response surface method (RSM) to yield optimum operation parameters for tolerable pollutant emissions and maximum engine performance. The RSM optimization analysis indicated that the most suitable ethanol-gasoline blended ratio was found at the range of 3.92-4.12 vol% to yield a comparable fuel conversion efficiency, while considerable reductions of exhaust pollutant emissions of CO (-29 %) and NO(X) (-12 %) when compared to pure gasoline fuel. This study demonstrated low ethanol-gasoline blended fuels could be used in motorcycle carburetor engines without any modification to keep engine power while reducing exhaust pollutants.

  17. Mixed waste paper to ethanol fuel

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The objectives of this study were to evaluate the use of mixed waste paper for the production of ethanol fuels and to review the available conversion technologies, and assess developmental status, current and future cost of production and economics, and the market potential. This report is based on the results of literature reviews, telephone conversations, and interviews. Mixed waste paper samples from residential and commercial recycling programs and pulp mill sludge provided by Weyerhauser were analyzed to determine the potential ethanol yields. The markets for ethanol fuel and the economics of converting paper into ethanol were investigated.

  18. High ethanol producing derivatives of Thermoanaerobacter ethanolicus

    Science.gov (United States)

    Ljungdahl, L.G.; Carriera, L.H.

    1983-05-24

    Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).

  19. Ethanol dehydration

    OpenAIRE

    Ana María Uyazán; Iván Dario Gil; J L Aguilar; Gerardo Rodríguez Niño; Luis Alfonso Caicedo

    2004-01-01

    This review outlines ethanol dehydration processes and their most important characteristics. It also deals with the main operating variables and some criteria used in designing the separation scheme. A differentiation is made between processes involving liquid steam balance in separation operations and those doing it by screening the difference in molecule size. The last part presents a comparison between the three main industrial processes, stressing their stengths and weaknesses from the op...

  20. Ethanol dehydration

    Directory of Open Access Journals (Sweden)

    Ana María Uyazán

    2004-09-01

    Full Text Available This review outlines ethanol dehydration processes and their most important characteristics. It also deals with the main operating variables and some criteria used in designing the separation scheme. A differentiation is made between processes involving liquid steam balance in separation operations and those doing it by screening the difference in molecule size. The last part presents a comparison between the three main industrial processes, stressing their stengths and weaknesses from the operational, energy consumption and industrial services points of view.

  1. Optimization of process parameters for ethanol production from sugar cane molasses by Zymomonas mobilis using response surface methodology and genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, Bodhisatta; Shekhawat, Mitali; Srivastava, Pradeep [Banaras Hindu Univ., Varanasi (India). School of Biochemical Engineering; Rathore, Ankita [Nizam College, Hyderabad (India). Dept. of Biotechnology; Srivastava, Saurav [National Institute of Technology, Durgapur (India). Dept. of Biotechnology

    2011-04-15

    Ethanol is a potential energy source and its production from renewable biomass has gained lot of popularity. There has been worldwide research to produce ethanol from regional inexpensive substrates. The present study deals with the optimization of process parameters (viz. temperature, pH, initial total reducing sugar (TRS) concentration in sugar cane molasses and fermentation time) for ethanol production from sugar cane molasses by Zymomonas mobilis using Box-Behnken experimental design and genetic algorithm (GA). An empirical model was developed through response surface methodology to analyze the effects of the process parameters on ethanol production. The data obtained after performing the experiments based on statistical design was utilized for regression analysis and analysis of variance studies. The regression equation obtained after regression analysis was used as a fitness function for the genetic algorithm. The GA optimization technique predicted a maximum ethanol yield of 59.59 g/L at temperature 31 C, pH 5.13, initial TRS concentration 216 g/L and fermentation time 44 h. The maximum experimental ethanol yield obtained after applying GA was 58.4 g/L, which was in close agreement with the predicted value. (orig.)

  2. 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...

  3. Improving the performance of industrial ethanol-producing yeast by expressing the aspartyl protease on the cell surface.

    Science.gov (United States)

    Guo, Zhong-peng; Zhang, Liang; Ding, Zhong-yang; Wang, Zheng-Xiang; Shi, Gui-Yang

    2010-12-01

    The yeasts used in fuel ethanol manufacture are unable to metabolize soluble proteins. The PEP4 gene, encoding a vacuolar aspartyl protease in Saccharomyces cerevisiae, was either secretively or cell-surface anchored expressed in industrial ethanol-producing S. cerevisiae. The obtained recombinant strains APA (expressing the protease secretively) and APB (expressing the protease on the cell wall) were studied under ethanol fermentation conditions in feed barley cultures. The effects of expression of the protease on product formation, growth and cell protein content were measured. The biomass yield of the wild-type was clearly lower than that of the recombinant strains (0.578 ± 0.12 g biomass/g glucose for APA and 0.582 ± 0.08 g biomass/g glucose for APB). In addition, nearly 98-99% of the theoretical maximum level of ethanol yield was achieved (relative to the amount of substrate consumed) for the recombinant strains, while limiting the nitrogen source resulted in dissatisfactory fermentation for the wild-type and more than 30 g/l residual sugar was detected at the end of fermentation. In addition, higher growth rate, viability and lower yields of byproducts such as glycerol and pyruvic acid for recombinant strains were observed. Expressing acid protease can be expected to lead to a significant increase in ethanol productivity. Copyright © 2010 John Wiley & Sons, Ltd.

  4. 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.

  5. Fermentation of hexoses to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Lena [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology]|[Chalmers Univ. of Technology, Goeteborg (Sweden). Dept of Chemical Reaction Engineering

    2000-06-01

    The Goals of the project has been: to increase the ethanol yield by reducing the by-product formation, primarily biomass and glycerol, and to prevent stuck fermentations, i.e. to maintain a high ethanol production rate simultaneously with a high ethanol yield. The studies have been performed both in defined laboratory media and in a mixture of wood- and wheat hydrolysates. The yeast strains used have been both industrial strains of bakers yeast, Saccharomyces cerevisiae, and haploid laboratory strains. The Relevance of these studies with respect to production of ethanol to be used as fuel is explained by: With the traditional process design used today, it is very difficult to reach a yield of more than 90 % of the theoretical maximal value of ethanol based on fermented hexose. During 'normal' growth and fermentation conditions in either anaerobic batch or chemostat cultures, substrate is lost as biomass and glycerol in the range of 8 to 11 % and 6 to 11 % of the substrate consumed (kg/kg). It is essential to reduce these by-products. Traditional processes are mostly batch processes, in which there is a risk that the biocatalyst, i.e. the yeast, may become inactivated. If for example yeast biomass production is avoided by use of non-growing systems, the ethanol production rate is instantaneously reduced by at least 50%. Unfortunately, even if yeast biomass production is not avoided on purpose, it is well known that stuck fermentations caused by cell death is a problem in large scale yeast processes. The main reason for stuck fermentations is nutrient imbalances. For a good process economy, it is necessary to ensure process accessibility, i.e. to maintain a high and reproducible production rate. This will both considerably reduce the necessary total volume of the fermentors (and thereby the investment costs), and moreover minimize undesirable product fall-out.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • High solids (30% dry matter) pretreatment, enzymatic hydrolysis and fermentation. • Horizontal rotary reactor for hydrolysis and fermentation. • In situ hydrolysates detoxification using inhibitors adsorbing PEI polymer. • 50% of inhibitors recovered as by-product, recyclability of PEI polymer up to 5 times. • 76% of maximum theoretical ethanol was fermented at final concentration of 51 g/kg. - Abstract: Performing the bioethanol production process at high solids loading is a requirement for economic feasibility at industrial scale. So far this has successfully been achieved using wheat straw and other agricultural residues at 30% of water insoluble solids (WIS), but for softwood species (i.e. spruce) this has been difficult to reach. The main reason behind this difference is the higher recalcitrance of woody substrates which require harsher pretreatment conditions, thus generating higher amounts of inhibitory compounds, ultimately lowering fermentation performances. In this work we studied ethanol production from spruce performing the whole process, from pretreatment to hydrolysis and fermentation, at 30% dry matter (equivalent to ∼20% WIS). Hydrolysis and fermentation was performed in a horizontal free fall mixing reactor enabling efficient mixing at high solids loadings. In batch simultaneous saccharification and fermentation (SSF), up to 76% cellulose to ethanol conversion was achieved resulting in a concentration of 51 g/kg of ethanol. Key to obtaining this high ethanol yield at these conditions was the use of a detoxification technology based on applying a soluble polyelectrolyte polymer (polyethylenimine, PEI) to absorb inhibitory compounds in the material. On average 50% removal and recovery of the main inhibitors (HMF, furfural, acetic acid and formic acid) was achieved dosing 1.5% w/w of soluble PEI. The use of PEI was compatible with operating the process at high solids loadings and enabled fermentation of hydrolysates, which

  7. 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.

  8. Sugar palm ethanol. Analysis of economic feasibility and sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Van de Staaij, J.; Van den Bos, A.; Hamelinck, C. [Ecofys Netherlands, Utrecht (Netherlands); Martini, E.; Roshetko, J.; Walden, D. [Winrock, Little Rock, AR (United States)

    2011-08-15

    This study evaluates whether sugar palm is a suitable crop for biofuels and how production of ethanol from sugar palm in a large-scale setting is sustainable and economically feasible. Key questions are: Are the assumed high yields realistic in practice for sustained periods in largescale plantations?; Can sugar palm indeed compete economically with other crops for biofuels?; What are the effects of large-scale cultivation and processing of sugar palm for the natural environment and the local community? To answer these questions, Ecofys and Winrock have assessed the feasibility of largescale sugar palm cultivation for the production of ethanol using empirical data from existing sugar palm plantings. We analysed two production models to investigate the range of outcomes when varying important parameters: (1) a conservative system, whereby sugar palms are mixed with other crops and (2) an intensive system to explore the theoretical maximum yield when solely focusing on sugar palm. As background, Chapter 2 first describes the process of sugar palm cultivation, the 'tapping' and conversion into ethanol. Chapter 3 describes the data collection by Winrock. It presents an overview of the collected field data and explains the main empirical findings. Chapter 4 elaborates the two production systems and presents the results of the economic analyses (summarized in cash flow diagrams showing the timing of costs and benefits). Chapter 5 analyses the possible sustainability risks and benefits of sugar palm ethanol and investigates the integration possibilities of sugar palm in agro-forestry systems with other crops. Finally, Chapter 6 concludes by evaluating the potential of sugar palm as a source of biofuel and providing recommendations.

  9. An alternative approach to the bioconversion of sweet sorghum carbohydrates to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Mamma, D.; Christakopoulos, P.; Koullas, D.; Kekos, D.; Macris, B.J.; Koukios, E. [National Technical Univ. of Athens (Greece). Dept. of Chemical Engineering

    1995-10-01

    The ethanol fermentation of juice and press case, resulting from the squeezing of sweet sorghum stalks at high pressure was investigated. The juice was fermented by Saccharomyces cerevisiae and yielded 4.8 g ethanol per 100 g of fresh stalks. The press cake was fermented directly to ethanol by a mixed culture of Fusarium oxysporum and Saccharomyces cerevisiae and yielded 5.1 g ethanol per 100 g of fresh stalks. An overall ethanol concentration and yield of 5.6% (w/v) and 9.9 g of ethanol per 100 g of fresh stalks respectively was obtained. Based on soluble carbohydrates, the ethanol yield from press cake was doubled while the overall theoretical yield was enhanced by 20.7% due to the bioconversion of a significant portion of cell wall polysaccharides to ethanol. The process was found promising for further investigation. (Author)

  10. 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.

  11. 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.

  12. 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)

  13. Efficient sugar release by acetic acid ethanol-based organosolv pretreatment and enzymatic saccharification.

    Science.gov (United States)

    Zhang, Hongdan; Wu, Shubin

    2014-12-03

    Acetic acid ethanol-based organosolv pretreatment of sugar cane bagasse was performed to enhance enzymatic hydrolysis. The effect of different parameters (including temperature, reaction time, solvent concentration, and acid catalyst dose) on pretreatment prehydrolyzate and subsequent enzymatic digestibility was determined. During the pretreatment process, 11.83 g of xylose based on 100 g of raw material could be obtained. After the ethanol-based pretreatment, the enzymatic hydrolysis was enhanced and the highest glucose yield of 40.99 g based on 100 g of raw material could be obtained, representing 93.8% of glucose in sugar cane bagasse. The maximum total sugar yields occurred at 190 °C, 45 min, 60:40 ethanol/water, and 5% dosage of acetic acid, reaching 58.36 g (including 17.69 g of xylose and 40.67 g of glucose) based on 100 g of raw material, representing 85.4% of total sugars in raw material. Furthermore, characterization of the pretreated sugar cane bagasse using X-ray diffraction and scanning electron microscopy analyses were also developed. The results suggested that ethanol-based organosolv pretreatment could enhance enzymatic digestibilities because of the delignification and removal of xylan.

  14. Thermo tolerant and ethanol producing saccharomyces cerevisiae mutants using gamma radiation

    International Nuclear Information System (INIS)

    Karima, H.M.; Ismail, A.A.; El-Batal, A.I.

    1997-01-01

    Gene manipulation now plays the main role in fermentation industries. However, throughout ethanol production processes, it appeared the requirements for the selection of higher-producing isolate(s) associated, at the same time, with heat-resistant to overcome higher degrees above 30-35 degree, a step which, actually, will reduce final - producing costs. A total of 43 yeast isolates were selected, after exposure of the strain saccharomyces cervisiae to different doses of gamma radiation. Isolated varied in colony size from the original strain as well as among themselves. These isolates were screened for their ability to grow on glucose and supplemented cane molasses media at 30 degree and 40 degree. Out fo them, only 13 isolates proved to grow well on 40 degree. Furthermore, determination of ethanol production by each of these mutants revealed that yielded in general, 16 to 52.0% increase in alcohol production at 40 degree on cane molasses medium (17.5% w/v initial sugars), compared to the original strain. At 40 degree, maximum ethanol yield was 0.63 coupled with 9.5% ethanol concentration and 85.1% sugar conversion which represents 40, 46.2 and 3.4% increase, respectively from the parental strain

  15. 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

  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. 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...

  18. 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.

  19. Kinetics of sugars consumption and ethanol inhibition in carob pulp fermentation by Saccharomyces cerevisiae in batch and fed-batch cultures.

    Science.gov (United States)

    Lima-Costa, Maria Emília; Tavares, Catarina; Raposo, Sara; Rodrigues, Brígida; Peinado, José M

    2012-05-01

    The waste materials from the carob processing industry are a potential resource for second-generation bioethanol production. These by-products are small carob kibbles with a high content of soluble sugars (45-50%). Batch and fed-batch Saccharomyces cerevisiae fermentations of high density sugar from carob pods were analyzed in terms of the kinetics of sugars consumption and ethanol inhibition. In all the batch runs, 90-95% of the total sugar was consumed and transformed into ethanol with a yield close to the theoretical maximum (0.47-0.50 g/g), and a final ethanol concentration of 100-110 g/l. In fed-batch runs, fresh carob extract was added when glucose had been consumed. This addition and the subsequent decrease of ethanol concentrations by dilution increased the final ethanol production up to 130 g/l. It seems that invertase activity and yeast tolerance to ethanol are the main factors to be controlled in carob fermentations. The efficiency of highly concentrated carob fermentation makes it a very promising process for use in a second-generation ethanol biorefinery.

  20. Sucrose-supplemented distillery spent wash as a medium for production of ethanol at 45 C by free and alginate-immobilized preparations of Kluyveromyces marxianus IMB3

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, P.; Mulholland, H.; Barron, N.; Brady, D.; McHale, A.P. [Biotechnology Research Group, School of Applied Biological and Chemical Sciences, University of Ulster (United Kingdom)

    1998-04-01

    Ethanol production by the thermotolerant, ethanol-producing yeast strain Kluyveromyces marxianus IMB3, was compared during growth on sucrose-supplemented laboratory-based media and distillery spent wash from the Old Bushmill`s Distillery Co., Ltd., Co. Antrim, Northern Ireland. Fermentations were carried out using preparations of the free and alginate-immobilized microorganism as inocula in media supplemented with 2 and 10% (w/v) sucrose. Maximum ethanol concentrations accounted for 75-99% of the maximum theoretical yield and in all cases maximum concentrations obtained using the spent wash were similar if not slightly higher than those obtained on the sucrose-supplemented yeast growth media. In addition, the highest concentrations of ethanol were produced by the alginate-immobilized biocatalyst on both types of media. Analysis of exhausted media in the spent wash-based systems demonstrated significant decreases in the total organic carbon content following fermentation. These results confirm our earlier suggestion that ethanol production based on this microorganism in a recycle system may provide a more cost-effective means of disposing of whiskey distillery spent wash. (orig.) With 1 tab., 8 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-03-01

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

  2. Low-Temperature Miscibility of Ethanol-Gasoline-Water Blends in Flex Fuel Applications

    DEFF Research Database (Denmark)

    Johansen, T.; Schramm, Jesper

    2009-01-01

    The miscibility of blends of gasoline and hydrous ethanol was investigated experimentally at - 25 degrees C and - 2 degrees C. Furthermore, the maximum water content was found for ethanol in flex fuel blends. The results strongly indicate that blends containing ethanol with a water content above...... that of the ethanol/water azeotrope (4.4% water by mass) can be used as Flex Fuel blends together with gasoline at ambient temperatures of 25 degrees C and 2 degrees C, without phase separation occurring. Additionally, it was shown that the ethanol purity requirement of ethanol-rich flex fuel blends falls...... with increasing ethanol content in the gasoline-rich flex fuel blend....

  3. 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)

  4. 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.

  5. 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)

  6. 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)

  7. A comparative study of GERIPA ethanol with other fuels

    Directory of Open Access Journals (Sweden)

    Geraldo Lombardi

    2009-05-01

    Full Text Available The GERIPA project aimed at generating renewable energy integrated with food production has led to a beneficial option for pro- ducing ethanol and electricity. Ethanol has economic, social and environmental potential. Considering just the first one, Brazil consumes 39 billion litres per year-LD/yr of diesel oil, 18% of it being imported. The Federal Government has a recovery pro- gramme for the soybean agribusiness aimed at soybean biodiesel (SBD production in which a 10% addition to diesel has been proposed. This 10% involves producing 10.7 million LSBD/d. Soybean bio-diesel production is not self-sustainable and such pro- posal could require an annual subsidy of up to US$1.33 billion. Soybean plantations would need about 10 to 12 times more land than is necessary for sugarcane plantations to produce the same equivalent thermal energy (ETE. Sixty-seven GERIPA pro- jects (GP producing 80,000 litres of ethanol per day (GP80 could be set up with the sum of US$1.33 billion; this would substitute current Brazilian biodiesel demand by 4.28%, adding the same value for each new subsidiary. Considering ETE, e- thanol-GP cost would be 37% to 50% below that for a litre of SBD on account of its raw material (RM and region. The diesel cycle’s thermal efficiency (ηt yield is around 50% and that of the Otto cycle engine ηt is around 37%. The cost per km driven (CKD by substituting SBD for ethanol-GP80 would thus indicate an 18% minimum and 59% maximum cost reduction for vehicle engines.

  8. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

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

    2010-12-01

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

  9. Comparison of yield, composition, and antioxidant activity of turmeric (Curcuma longa L.) extracts obtained using various techniques.

    Science.gov (United States)

    Braga, Mara E M; Leal, Patrícia F; Carvalho, João E; Meireles, M Angela A

    2003-10-22

    Turmeric extracts were obtained from two lots of raw material (M and S) using various techniques: hydrodistillation, low pressure solvent extraction, Soxhlet, and supercritical extraction using carbon dioxide and cosolvents. The solvents and cosolvents tested were ethanol, isopropyl alcohol, and their mixture in equal proportions. The composition of the extracts was determined by gas chromatography-flame ionization detection (GC-FID) and UV. The largest yield (27%, weight) was obtained in the Soxhlet extraction (turmeric (S), ethanol = 1:100); the lowest yield was detected in the hydrodistillation process (2.1%). For the supercritical extraction, the best cosolvent was a mixture of ethanol and isopropyl alcohol. Sixty percent of the light fraction of the extracts consisted of ar-turmerone, (Z)-gamma-atlantone, and (E)-gamma-atlantone, except for the Soxhlet extracts (1:100, ethanol), for which only ar-turmeronol and (Z)-alpha-atlantone were detected. The maximum amount of curcuminoids (8.43%) was obtained using Soxhlet extraction (ethanol/isopropyl alcohol). The Soxhlet and low pressure extract exhibited the strongest antioxidant activities.

  10. Fuel ethanol discussion paper

    International Nuclear Information System (INIS)

    1992-01-01

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

  11. 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.

  12. Equity yields

    NARCIS (Netherlands)

    Vrugt, E.; van Binsbergen, J.H.; Koijen, R.S.J.; Hueskes, W.

    2013-01-01

    We study a new data set of dividend futures with maturities up to ten years across three world regions: the US, Europe, and Japan. We use these asset prices to construct equity yields, analogous to bond yields. We decompose the equity yields to obtain a term structure of expected dividend growth

  13. Ethanol Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  14. 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

  15. Enzymatic hydrolysis at high-solids loadings for the conversion of agave bagasse to fuel ethanol

    International Nuclear Information System (INIS)

    Caspeta, Luis; Caro-Bermúdez, Mario A.; Ponce-Noyola, Teresa; Martinez, Alfredo

    2014-01-01

    Highlights: • Conversion of agave bagasse to fuel ethanol. • Ethanosolv-pretreatment variables were statistically adjusted. • 91% of total sugars found in agave bagasse were recovered. • 225 g/L glucose from 30%-consistency hydrolysis using mini-reactors with peg-mixers. • 0.25 g of ethanol per g of dry agave bagasse was obtained. - Abstract: Agave bagasse is the lignocellulosic residue accumulated during the production of alcoholic beverages in Mexico and is a potential feedstock for the production of biofuels. A factorial design was used to investigate the effect of temperature, residence time and concentrations of acid and ethanol on ethanosolv pretreatment and enzymatic hydrolysis of agave bagasse. This method and the use of a stirred in-house-made mini-reactor increased the digestibility of agave bagasse from 30% observed with the dilute-acid method to 98%; also allowed reducing the quantity of enzymes used to hydrolyze samples with solid loadings of 30% w/w and glucose concentrations up to 225 g/L were obtained in the enzymatic hydrolysates. Overall this process allows the recovery of 91% of the total fermentable sugars contained in the agave bagasse (0.51 g/g) and 69% of total lignin as co-product (0.11 g/g). The maximum ethanol yield under optimal conditions using an industrial yeast strain for the fermentation was 0.25 g/g of dry agave bagasse, which is 86% of the maximum theoretical (0.29 g/g). The effect of the glucose concentration and solid loading on the conversion of cellulose to glucose is discussed, in addition to prospective production of about 50 million liters of fuel ethanol using agave bagasse residues from the tequila industry as a potential solution to the disposal problems

  16. Ethanol from lignocellulosic biomasses

    International Nuclear Information System (INIS)

    Ricci, E.; Viola, E.; Zimbardi, F.; Braccio, G.; Cuna, D.

    2001-01-01

    In this report are presented results achieved on the process optimisation of bioethanol production from wheat straw, carried out within the ENEA's project of biomass exploitation for renewable energy. The process consists of three main steps: 1) biomass pretreatment by means of steam explosion; 2) enzymatic hydrolysis of the cellulose fraction; 3) fermentation of glucose. To perform the hydrolysis step, two commercial enzymatic mixtures have been employed, mainly composed by β-glucosidase (cellobiase), endo-glucanase and exo-glucanase. The ethanologenic yeast Saccharomyces cerevisiae has been used to ferment the glucose in he hydrolyzates. Hydrolysis yield of 97% has been obtained with steam exploded wheat straw treated at 220 0 C for 3 minutes and an enzyme to substrate ratio of 4%. It has been pointed out the necessity of washing with water the pretreated what straw, in order to remove the biomass degradation products, which have shown an inhibition effect on the yeast. At the best process conditions, a fermentation yield of 95% has been achieved. In the Simultaneous Saccharification and Fermentation process, a global conversion of 92% has been obtained, which corresponds to the production of about 170 grams of ethanol per kilogram of exploded straw [it

  17. Optimization of the Ethanol Fermentation of Cassava Wastewater ...

    African Journals Online (AJOL)

    This research work focused on the optimisation of the cassava wastewater medium for ethanol fermentation. The main thrust was the investigation of the influence of the glucose concentration, nutrient (NH4Cl) level, and cell concentration on the yield of ethanol from cassava wastewater. Twenty experiments based on ...

  18. 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)

  19. 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.

  20. 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.

  1. Ethanol vapour sensing properties of screen printed WO 3 thick films

    Indian Academy of Sciences (India)

    The ethanol vapour sensing properties of these thick films were investigated at different operating temperatures and ethanol vapour concentrations. The WO3 thick films exhibit excellent ethanol vapour sensing properties with a maximum sensitivity of ∼1424.6% at 400°C in air atmosphere with fast response and recovery ...

  2. 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.

  3. Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw.

    Science.gov (United States)

    Nair, Ramkumar B; Kabir, Maryam M; Lennartsson, Patrik R; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

    2018-01-01

    Integration of wheat straw for a biorefinery-based energy generation process by producing ethanol and biogas together with the production of high-protein fungal biomass (suitable for feed application) was the main focus of the present study. An edible ascomycete fungal strain Neurospora intermedia was used for the ethanol fermentation and subsequent biomass production from dilute phosphoric acid (0.7 to 1.2% w/v) pretreated wheat straw. At optimum pretreatment conditions, an ethanol yield of 84 to 90% of the theoretical maximum, based on glucan content of substrate straw, was observed from fungal fermentation post the enzymatic hydrolysis process. The biogas production from the pretreated straw slurry showed an improved methane yield potential up to 162% increase, as compared to that of the untreated straw. Additional biogas production, using the syrup, a waste stream obtained post the ethanol fermentation, resulted in a combined total energy output of 15.8 MJ/kg wheat straw. Moreover, using thin stillage (a waste stream from the first-generation wheat-based ethanol process) as a co-substrate to the biogas process resulted in an additional increase by about 14 to 27% in the total energy output as compared to using only wheat straw-based substrates. ᅟ.

  4. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  5. 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.

  6. 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)

  7. 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.

  8. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

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

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2016-03-01

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

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  12. Enhancement of ethanol fermentation in Saccharomyces cerevisiae sake yeast by disrupting mitophagy function.

    Science.gov (United States)

    Shiroma, Shodai; Jayakody, Lahiru Niroshan; Horie, Kenta; Okamoto, Koji; Kitagaki, Hiroshi

    2014-02-01

    Saccharomyces cerevisiae sake yeast strain Kyokai no. 7 has one of the highest fermentation rates among brewery yeasts used worldwide; therefore, it is assumed that it is not possible to enhance its fermentation rate. However, in this study, we found that fermentation by sake yeast can be enhanced by inhibiting mitophagy. We observed mitophagy in wild-type sake yeast during the brewing of Ginjo sake, but not when the mitophagy gene (ATG32) was disrupted. During sake brewing, the maximum rate of CO2 production and final ethanol concentration generated by the atg32Δ laboratory yeast mutant were 7.50% and 2.12% higher than those of the parent strain, respectively. This mutant exhibited an improved fermentation profile when cultured under limiting nutrient concentrations such as those used during Ginjo sake brewing as well as in minimal synthetic medium. The mutant produced ethanol at a concentration that was 2.76% higher than the parent strain, which has significant implications for industrial bioethanol production. The ethanol yield of the atg32Δ mutant was increased, and its biomass yield was decreased relative to the parent sake yeast strain, indicating that the atg32Δ mutant has acquired a high fermentation capability at the cost of decreasing biomass. Because natural biomass resources often lack sufficient nutrient levels for optimal fermentation, mitophagy may serve as an important target for improving the fermentative capacity of brewery yeasts.

  13. 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.

  14. Efficient bioconversion of rice straw to ethanol with TiO2/UV pretreatment.

    Science.gov (United States)

    Kang, Hee-Kyoung; Kim, Doman

    2012-01-01

    Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretical for glucose (339 ± 13 mg/g rice straw) and 50.3 ± 2.8% for xylose (64 ± 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47%. TiO(2)/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.

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

    Science.gov (United States)

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

    2012-07-01

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

  16. Catalytic depolymerization of lignin in supercritical ethanol

    NARCIS (Netherlands)

    Huang, X.; Koranyi, T.I.; Boot, M.D.; Hensen, E.J.M.

    2014-01-01

    One-step valorization of soda lignin in supercritical ethanol using a CuMgAlOx catalyst results in high monomer yield (23 wt¿%) without char formation. Aromatics are the main products. The catalyst combines excellent deoxygenation with low ring-hydrogenation activity. Almost half of the monomer

  17. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  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. Pathway engineering to improve ethanol production by thermophilic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lynd, L.R.

    1998-12-31

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

  20. Influence of high temperature and ethanol on thermostable lignocellulolytic enzymes

    DEFF Research Database (Denmark)

    Skovgaard, Pernille Anastasia; Jørgensen, Henning

    2013-01-01

    the influence of temperature and ethanol on enzyme activity and stability in the distillation step, where most enzymes are inactivated due to high temperatures. Two enzyme mixtures, a mesophilic and a thermostable mixture, were exposed to typical process conditions [temperatures from 55 to 65 °C and up to 5...... % ethanol (w/v)] followed by specific enzyme activity analyses and SDS-PAGE. The thermostable and mesophilic mixture remained active at up to 65 and 55 °C, respectively. When the enzyme mixtures reached their maximum temperature limit, ethanol had a remarkable influence on enzyme activity, e.g., the more...... ethanol, the faster the inactivation. The reason could be the hydrophobic interaction of ethanol on the tertiary structure of the enzyme protein. The thermostable mixture was more tolerant to temperature and ethanol and could therefore be a potential candidate for recycling after distillation....

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

    DEFF Research Database (Denmark)

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

    2018-01-01

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

  2. 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).

  3. 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.

  4. Effect of the Ethanol Injection Moment During Compression Stroke on the Combustion of Ethanol - Diesel Dual Direct Injection Engine

    Science.gov (United States)

    Liang, Yu; Zhou, Liying; Huang, Haomin; Xu, Mingfei; Guo, Mei; Chen, Xin

    2018-01-01

    A set of GDI system is installed on a F188 single-cylinder, air-cooled and direct injection diesel engine, which is used for ethanol injection, with the injection time controlled by the crank angle signal collected by AVL angle encoder. The injection of ethanol amounts to half of the thermal equivalent of an original diesel fuel. A 3D combustion model is established for the ethanol - diesel dual direct injection engine. Diesel was injected from the original fuel injection system, with a fuel supply advance angle of 20°CA. The ethanol was injected into the cylinder during compression process. Diesel injection began after the completion of ethanol injection. Ethanol injection starting point of 240°CA, 260°CA, 280°CA, 300°CA and 319.4°CA were simulated and analyzed. Due to the different timing of ethanol injection, the ignition of the ethanol mixture when diesel fires, results in non-uniform ignition distribution and flame propagation rate, since the distribution and concentration gradients of the ethanol mixture in the cylinder are different, thus affecting the combustion process. The results show that, when ethanol is injected at 319.4°CA, the combustion heat release rate and the pressure rise rate during the initial stage are the highest. Also, the maximum combustion pressure, with a relatively advance phase, is the highest. In case of later initial ethanol injection, the average temperature in the cylinder during the initial combustion period will have a faster rise. In case of initial injection at 319.4°CA, the average temperature in the cylinder is the highest, followed by 240°CA ethanol injection. In the post-combustion stage, the earlier ethanol injection will result in higher average temperature in the cylinder and more complete fuel combustion. The injection of ethanol at 319.4°CA produces earlier and highest NOX emissions.

  5. Ethanol production from paper sludge using Kluyveromyces marxianus

    International Nuclear Information System (INIS)

    Madrid, Lina Maria; Quintero Diaz, Juan Carlos

    2011-01-01

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

  6. 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...

  7. 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.

  8. 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)

  9. Mathematical modeling of the fermentation of acid-hydrolyzed pyrolytic sugars to ethanol by the engineered strain Escherichia coli ACCC 11177.

    Science.gov (United States)

    Chang, Dongdong; Yu, Zhisheng; Islam, Zia Ul; Zhang, Hongxun

    2015-05-01

    Pyrolysate from waste cotton was acid hydrolyzed and detoxified to yield pyrolytic sugars, which were fermented to ethanol by the strain Escherichia coli ACCC 11177. Mathematical models based on the fermentation data were also constructed. Pyrolysate containing an initial levoglucosan concentration of 146.34 g/L gave a glucose yield of 150 % after hydrolysis, suggesting that other compounds were hydrolyzed to glucose as well. Ethyl acetate-based extraction of bacterial growth inhibitors with an ethyl acetate/hydrolysate ratio of 1:0.5 enabled hydrolysate fermentation by E. coli ACCC 11177, without a standard absorption treatment. Batch processing in a fermenter exhibited a maximum ethanol yield and productivity of 0.41 g/g and 0.93 g/L·h(-1), respectively. The cell growth rate (r x ) was consistent with a logistic equation [Formula: see text], which was determined as a function of cell growth (X). Glucose consumption rate (r s ) and ethanol formation rate (r p ) were accurately validated by the equations [Formula: see text] and [Formula: see text], respectively. Together, our results suggest that combining mathematical models with fermenter fermentation processes can enable optimized ethanol production from cellulosic pyrolysate with E. coli. Similar approaches may facilitate the production of other commercially important organic substances.

  10. Modeling bacterial contamination of fuel ethanol fermentation.

    Science.gov (United States)

    Bischoff, Kenneth M; Liu, Siqing; Leathers, Timothy D; Worthington, Ronald E; Rich, Joseph O

    2009-05-01

    The emergence of antibiotic-resistant bacteria may limit the effectiveness of antibiotics to treat bacterial contamination in fuel ethanol plants, and therefore, new antibacterial intervention methods and tools to test their application are needed. Using shake-flask cultures of Saccharomyces cerevisiae grown on saccharified corn mash and strains of lactic acid bacteria isolated from a dry-grind ethanol facility, a simple model to simulate bacterial contamination and infection was developed. Challenging the model with 10(8) CFU/mL Lactobacillus fermentum decreased ethanol yield by 27% and increased residual glucose from 6.2 to 45.5 g/L. The magnitude of the effect was proportional to the initial bacterial load, with 10(5) CFU/mL L. fermentum still producing an 8% decrease in ethanol and a 3.2-fold increase in residual glucose. Infection was also dependent on the bacterial species used to challenge the fermentation, as neither L. delbrueckii ATCC 4797 nor L. amylovorus 0315-7B produced a significant decrease in ethanol when inoculated at a density of 10(8) CFU/mL. In the shake-flask model, treatment with 2 microg/mL virginiamycin mitigated the infection when challenged with a susceptible strain of L. fermentum (MIC for virginiamycin model may find application in developing new antibacterial agents and management practices for use in controlling contamination in the fuel ethanol industry. Copyright 2008 Wiley Periodicals, Inc.

  11. Market penetration of biodiesel and ethanol

    Science.gov (United States)

    Szulczyk, Kenneth Ray

    This dissertation examines the influence that economic and technological factors have on the penetration of biodiesel and ethanol into the transportation fuels market. This dissertation focuses on four aspects. The first involves the influence of fossil fuel prices, because biofuels are substitutes and have to compete in price. The second involves biofuel manufacturing technology, principally the feedstock-to-biofuel conversion rates, and the biofuel manufacturing costs. The third involves prices for greenhouse gas offsets. The fourth involves the agricultural commodity markets for feedstocks, and biofuel byproducts. This dissertation uses the Forest and Agricultural Sector Optimization Model-Greenhouse Gas (FASOM-GHG) to quantitatively examine these issues and calculates equilibrium prices and quantities, given market interactions, fossil fuel prices, carbon dioxide equivalent prices, government biofuel subsidies, technological improvement, and crop yield gains. The results indicate that for the ranges studied, gasoline prices have a major impact on aggregate ethanol production but only at low prices. At higher prices, one runs into a capacity constraint that limits expansion on the capacity of ethanol production. Aggregate biodiesel production is highly responsive to gasoline prices and increases over time. (Diesel fuel price is proportional to the gasoline price). Carbon dioxide equivalent prices expand the biodiesel industry, but have no impact on ethanol aggregate production when gasoline prices are high again because of refinery capacity expansion. Improvement of crop yields shows a similar pattern, expanding ethanol production when the gasoline price is low and expanding biodiesel. Technological improvement, where biorefinery production costs decrease over time, had minimal impact on aggregate ethanol and biodiesel production. Finally, U.S. government subsidies have a large expansionary impact on aggregate biodiesel production. Finally, U.S. government

  12. Ethanol vapour sensing properties of screen printed WO3 thick films

    Indian Academy of Sciences (India)

    TECS

    trations. The WO3 thick films exhibit excellent ethanol vapour sensing properties with a maximum sensitivity ... methanol, acetone, isopropanol and acetic acid, have been reported .... maximum sensitivity was obtained at an operating tem-.

  13. Ethanol Transportation Backgrounder

    OpenAIRE

    Denicoff, Marina R.

    2007-01-01

    For the first 6 months of 2007, U.S. ethanol production totaled nearly 3 billion gallons—32 percent higher than the same period last year. As of August 29, there were 128 ethanol plants with annual production capacity totaling 6.78 billion gallons, and an additional 85 plants were under construction. U.S. ethanol production capacity is expanding rapidly and is currently expected to exceed 13 billion gallons per year by early 2009, if not sooner. Ethanol demand has increased corn prices and le...

  14. 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).

  15. Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

    Science.gov (United States)

    Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

    2014-01-01

    This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter. Copyright © 2013. Published by Elsevier Ltd.

  16. 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

  17. Market penetration of ethanol

    International Nuclear Information System (INIS)

    Szulczyk, Kenneth R.; McCarl, Bruce A.; Cornforth, Gerald

    2010-01-01

    This research examines in detail the technology and economics of substituting ethanol for gasoline. This endeavor examines three issues. First, the benefits of ethanol/gasoline blends are examined, and then the technical problems of large-scale implementation of ethanol. Second, ethanol production possibilities are examined in detail from a variety of feedstocks and technologies. The feedstocks are the starch/sugar crops and crop residues, while the technologies are corn wet mill, dry grind, and lignocellulosic fermentation. Examining in detail the production possibilities allows the researchers to identity the extent of technological change, production costs, byproducts, and GHG emissions. Finally, a U.S. agricultural model, FASOMGHG, is updated which predicts the market penetration of ethanol given technological progress, variety of technologies and feedstocks, market interactions, energy prices, and GHG prices. FASOMGHG has several interesting results. First, gasoline prices have a small expansionary impact on the U.S. ethanol industry. Both agricultural producers' income and cost both increase with higher energy prices. If wholesale gasoline is $4 per gallon, the predicted ethanol market penetration attains 53% of U.S. gasoline consumption in 2030. Second, the corn wet mill remains an important industry for ethanol production, because this industry also produces corn oil, which could be converted to biodiesel. Third, GHG prices expand the ethanol industry. However, the GHG price expands the corn wet mill, but has an ambiguous impact on lignocellulosic ethanol. Feedstocks for lignocellulosic fermentation can also be burned with coal to generate electricity. Both industries are quite GHG efficient. Finally, U.S. government subsidies on biofuels have an expansionary impact on ethanol production, but may only increase market penetration by an additional 1% in 2030, which is approximately 6 billion gallons. (author)

  18. 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)

  19. 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)

  20. Canadian ethanol retailers' directory

    International Nuclear Information System (INIS)

    1998-06-01

    This listing is a directory of all ethanol-blended gasoline retailers in Quebec, Ontario, Manitoba, Saskatchewan, Alberta, British Columbia, and the Yukon. The listing includes the name and address of the retailer. Bulk purchase facilities of ethanol-blended fuels are also included, but in a separate listing

  1. Canada's ethanol retail directory

    International Nuclear Information System (INIS)

    1996-11-01

    A directory was published listing all ethanol-blended gasoline retailers in Quebec, Ontario, Manitoba, Saskatchewan, Alberta, British Columbia, and the Yukon. The listings include the name and address of the retailer. A list of bulk purchase facilities of ethanol-blended fuels is also included

  2. 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.

  3. Transesterification of Vegetable Oils with Ethanol and Characterization of the Key Fuel Properties of Ethyl Esters

    Directory of Open Access Journals (Sweden)

    Stamoulis Stournas

    2009-06-01

    Full Text Available The transesterification reactions of four different vegetable oils (sunflower, rapeseed, olive oil and used frying oil with ethanol, using sodium hydroxide as catalyst, were studied. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil (0.25 – 1.5%, the molar ratio of ethanol to oil (6:1 – 12:1, and the reaction temperature (35 – 90 °C were studied for the conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transesterification were an ethanol/oil molar ratio of 12:1, NaOH amount (1% wt/wt, and 80 °C temperature, whereas the maximum yield of ethyl esters reached 81.4% wt/wt. In the second stage, the yield of ethyl esters was improved by 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. The fuel properties of the esters were measured according to EN test methods. Based on the experimental results one can see that the ethyl esters do not differ significantly from methyl esters. Moreover, the results showed that the values of density, viscosity, and higher heating value of ethyl esters were similar to those of automotive and heavy duty engine diesel fuel. However, the CFPP values were higher, which may contribute to potential difficulties in cold starts. On the other hand, the flash points, which were higher than those of diesel fuel constituted a safety guarantee from the point of view of handling and storage.

  4. 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.

  5. 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.

  6. Bioconversion of Agricultural Waste to Ethanol by SSF Using Recombinant Cellulase from Clostridium thermocellum

    Directory of Open Access Journals (Sweden)

    Ruchi Mutreja

    2011-01-01

    Full Text Available The effect of different pretreatment methods, temperature, and enzyme concentration on ethanol production from 8 lignocellulosic agrowaste by simultaneous saccharification and fermentation (SSF using recombinant cellulase and Saccharomyces cerevisiae were studied. Recombinant cellulase was isolated from E. coli BL21 cells transformed with CtLic26A-Cel5-CBM11 full-length gene from Clostridium thermocellum and produced in both batch and fed-batch processes. The maximum cell OD and specific activity in batch mode were 1.6 and 1.91 U/mg, respectively, whereas in the fed-batch mode, maximum cell OD and specific activity were 3.8 and 3.5 U/mg, respectively, displaying a 2-fold increase. Eight substrates, Syzygium cumini (jamun, Azadirachta indica (neem, Saracens indica (asoka, bambusa dendrocalmus (bamboo, Populas nigra (poplar, Achnatherum hymenoides (wild grass, Eucalyptus marginata (eucalyptus, and Mangifera indica (mango, were subjected to SSF. Of three pretreatments, acid, alkali, and steam explosion, acid pretreatment Syzygium cumini (Jamun at 30°C gave maximum ethanol yield of 1.42 g/L.

  7. Bioconversion of Agricultural Waste to Ethanol by SSF Using Recombinant Cellulase from Clostridium thermocellum.

    Science.gov (United States)

    Mutreja, Ruchi; Das, Debasish; Goyal, Dinesh; Goyal, Arun

    2011-01-01

    The effect of different pretreatment methods, temperature, and enzyme concentration on ethanol production from 8 lignocellulosic agrowaste by simultaneous saccharification and fermentation (SSF) using recombinant cellulase and Saccharomyces cerevisiae were studied. Recombinant cellulase was isolated from E. coli BL21 cells transformed with CtLic26A-Cel5-CBM11 full-length gene from Clostridium thermocellum and produced in both batch and fed-batch processes. The maximum cell OD and specific activity in batch mode were 1.6 and 1.91 U/mg, respectively, whereas in the fed-batch mode, maximum cell OD and specific activity were 3.8 and 3.5 U/mg, respectively, displaying a 2-fold increase. Eight substrates, Syzygium cumini (jamun), Azadirachta indica (neem), Saracens indica (asoka), bambusa dendrocalmus (bamboo), Populas nigra (poplar), Achnatherum hymenoides (wild grass), Eucalyptus marginata (eucalyptus), and Mangifera indica (mango), were subjected to SSF. Of three pretreatments, acid, alkali, and steam explosion, acid pretreatment Syzygium cumini (Jamun) at 30°C gave maximum ethanol yield of 1.42 g/L.

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

    International Nuclear Information System (INIS)

    C. Saricks; D. Santini; M. Wang

    1999-01-01

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

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

    International Nuclear Information System (INIS)

    C. Saricks; D. Santini; M. Wang

    1999-01-01

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

  10. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-01-01

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

  12. Recovery of ethanol from municipal solid waste

    International Nuclear Information System (INIS)

    Ackerson, M.D.; Clausen, E.C.; Gaddy, J.L.

    1992-01-01

    Methods for disposal of MSW that reduce the potential for groundwater or air pollution will be essential in the near future. Seventy percent of MSW consists of paper, food waste, yard waste, wood and textiles. These lignocellulosic components may be hydrolyzed to sugars with mineral acids, and the sugars may be subsequently fermented to ethanol or other industrial chemicals. This chapter presents data on the hydrolysis of the lignocellulosic fraction of MSW with concentrated HC1 and the fermentation of the sugars to ethanol. Yields, kinetics, and rates are presented and discussed. Design and economic projections for a commercial facility to produce 20 MM gallons of ethanol per year are developed. Novel concepts to enhance the economics are discussed

  13. Analysis of Metabolic Pathways and Fluxes in a Newly Discovered Thermophilic and Ethanol-Tolerant Geobacillus Strain

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yinjie J.; Sapra, Rajat; Joyner, Dominique; Hazen, Terry C.; Myers, Samuel; Reichmuth, David; Blanch, Harvey; Keasling, Jay D.

    2009-01-20

    A recently discovered thermophilic bacterium, Geobacillus thermoglucosidasius M10EXG, ferments a range of C5 (e.g., xylose) and C6 sugars (e.g., glucose) and istolerant to high ethanol concentrations (10percent, v/v). We have investigated the central metabolism of this bacterium using both in vitro enzyme assays and 13C-based flux analysis to provide insights into the physiological properties of this extremophile and explore its metabolism for bio-ethanol or other bioprocess applications. Our findings show that glucose metabolism in G. thermoglucosidasius M10EXG proceeds via glycolysis, the pentose phosphate pathway, and the TCA cycle; the Entner?Doudoroff pathway and transhydrogenase activity were not detected. Anaplerotic reactions (including the glyoxylate shunt, pyruvate carboxylase, and phosphoenolpyruvate carboxykinase) were active, but fluxes through those pathways could not be accuratelydetermined using amino acid labeling. When growth conditions were switched from aerobic to micro-aerobic conditions, fluxes (based on a normalized glucose uptake rate of 100 units (g DCW)-1 h-1) through the TCA cycle and oxidative pentose phosphate pathway were reduced from 64+-3 to 25+-2 and from 30+-2 to 19+-2, respectively. The carbon flux under micro-aerobic growth was directed formate. Under fully anerobic conditions, G. thermoglucosidasius M10EXG used a mixed acid fermentation process and exhibited a maximum ethanol yield of 0.38+-0.07 mol mol-1 glucose. In silico flux balance modeling demonstrates that lactate and acetate production from G. thermoglucosidasius M10EXG reduces the maximum ethanol yieldby approximately threefold, thus indicating that both pathways should be modified to maximize ethanol production.

  14. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  15. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  16. Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis.

    Science.gov (United States)

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Young; Kang, Chang Han; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-01

    The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m(2)/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-15

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

  18. Retooling the ethanol industry: thermophilic anaerobic digestion of thin stillage for methane production and pollution prevention.

    Science.gov (United States)

    Schaefer, Scott H; Sung, Shihwu

    2008-02-01

    Anaerobic digestion of corn ethanol thin stillage was tested at thermophilic temperature (55 degrees C) with two completely stirred tank reactors. The thin stillage wastestream was organically concentrated with 100 g/L total chemical oxygen demand and 60 g/L volatiles solids and a low pH of approximately 4.0. Steady-state was achieved at 30-, 20-, and 15-day hydraulic retention times (HRTs) and digester failure at a 12-day HRT. Significant reduction of volatile solids was achieved, with a maximum reduction (89.8%) at the 20-day HRT. Methane yield ranged from 0.6 to 0.7 L methane/g volatile solids removed during steady-state operation. Effluent volatile fatty acids below 200 mg/L as acetic acid were achieved at 20- and 30-day HRTs. Ultrasonic pretreatment was used for one digester, although no significant improvement was observed. Ethanol plant natural gas consumption could be reduced 43 to 59% with the methane produced, while saving an estimated $7 to $17 million ($10 million likely) for a facility producing 360 million L ethanol/y.

  19. Continuous high-solids corn liquefaction and fermentation with stripping of ethanol.

    Science.gov (United States)

    Taylor, Frank; Marquez, Marco A; Johnston, David B; Goldberg, Neil M; Hicks, Kevin B

    2010-06-01

    Removal of ethanol from the fermentor during fermentation can increase productivity and reduce the costs for dewatering the product and coproduct. One approach is to recycle the fermentor contents through a stripping column, where a non-condensable gas removes ethanol to a condenser. Previous research showed that this approach is feasible. Savings of $0.03 per gallon were predicted at 34% corn dry solids. Greater savings were predicted at higher concentration. Now the feasibility has been demonstrated at over 40% corn dry solids, using a continuous corn liquefaction system. A pilot plant, that continuously fed corn meal at more than one bushel (25 kg) per day, was operated for 60 consecutive days, continuously converting 95% of starch and producing 88% of the maximum theoretical yield of ethanol. A computer simulation was used to analyze the results. The fermentation and stripping systems were not significantly affected when the CO(2) stripping gas was partially replaced by nitrogen or air, potentially lowering costs associated with the gas recycle loop. It was concluded that previous estimates of potential cost savings are still valid. (c) 2010. Published by 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. 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...

  2. PRODUKSI ETANOL DARI TETES TEBU OLEH Saccharomyces cerevisiae PEMBENTUK FLOK (NRRL – Y 265 (Ethanol Production from Cane Molasses by Flocculant Saccharomyces cerevisiae (NRRL – Y 265

    Directory of Open Access Journals (Sweden)

    Agustin Krisna Wardani

    2013-08-01

    Full Text Available The potential use of sugar cane molasses by flocculant Saccharomyces cerevisiae in ethanol production was investigated. In order to minimize the negative effect of calcium on yeast growth, pretreated sugar cane molasses with dilute acid was performed. The influence of process parameters such as sugar concentration and inoculum concentration were evaluated for enhancing bioethanol production. Result showed that maximum ethanol concentration of 8,792% (b/v was obtained at the best condition of inoculum concentration 10% (v/v and sugar concentration 15% (b/v. Based on the experimental data, maximum yield of ethanol production of 65% was obtained. This result demonstrated the potential of molasses as promising biomass resources for ethanol production. Keywords: Ethanol, preteated cane molasses, flocculant Saccharomyces cerevisiae, fermentation   ABSTRAK Efisiensi produksi bioetanol diperoleh melalui ketepatan pemilihan jenis mikroorganisme, bahan baku, dan kontrol proses fermentasi. Alternatif proses untuk meminimalisasi biaya produksi etanol adalah dengan mengeliminasi tahap pemisahan sentrifugasi sel dari produk karena memerlukan biaya instalasi dan biaya perawatan yang tinggi. Proses sentrifugasi merupakan tahapan penting untuk memisahkan sel mikroba dari medium fermentasi pada produksi bioetanol. Untuk meminimalisir biaya produksi akibat proses tersebut digunakan inokulum Saccharomyces cerevisiae pembentuk flok dan tetes tebu sebagai sumber gula. Penelitian ini bertujuan untuk mendapatkan konsentrasi penambahan inokulum Saccharomyces cerevisiae pembentuk flok dan konsentrasi sumber gula dalam tetes tebu yang tepat dalam produksi etanol yang maksimum. Saccharomyces cerevisiae sebanyak 5%, 10%, dan 15% (v/v diinokulasikan pada medium tetes tebu hasil pretreatment dengan kandungan gula 15%, 20%, dan 25% (b/v pada pH 5. Fermentasi dilakukan pada suhu 30°C dan agitasi 100 rpm selama 72 jam. Etanol tertinggi didapat pada kondisi konsentrasi inokulum

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

    NARCIS (Netherlands)

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

    2011-01-01

    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

  4. Speichim cuts ethanol energy

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-08

    France's Speichim has reported low-pressure steam consumption of only 0.7kg/l in the production of industrial-grade ethanol. Mechanical compression of distillation vapours can reduce this energy demand even more.

  5. Environmental benefits of ethanol

    International Nuclear Information System (INIS)

    1998-11-01

    The environmental benefits of ethanol blended fuels in helping to reduce harmful emissions into the atmosphere are discussed. The use of oxygenated fuels such as ethanol is one way of addressing air pollution concerns such as ozone formation. The state of California has legislated stringent automobile emissions standards in an effort to reduce emissions that contribute to the formation of ground-level ozone. Several Canadian cities also record similar hazardous exposures to carbon monoxide, particularly in fall and winter. Using oxygenated fuels such as ethanol, is one way of addressing the issue of air pollution. The net effect of ethanol use is an overall decrease in ozone formation. For example, use of a 10 per cent ethanol blend results in a 25-30 per cent reduction in carbon monoxide emissions by promoting a more complete combustion of the fuel. It also results in a 6-10 per cent reduction of carbon dioxide, and a seven per cent overall decrease in exhaust VOCs (volatile organic compounds). The environmental implications of feedstock production associated with the production of ethanol for fuel was also discussed. One of the Canadian government's initiatives to address the climate change challenge is its FleetWise initiative, in which it has agreed to a phased-in acquisition of alternative fuel vehicles by the year 2005. 9 refs

  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. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  8. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  9. 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....

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  11. The consequence of fetal ethanol exposure and adolescent odor re-exposure on the response to ethanol odor in adolescent and adult rats

    Directory of Open Access Journals (Sweden)

    Molina Juan C

    2009-01-01

    Full Text Available Abstract Background An epidemiologic predictive relationship exists between fetal ethanol exposure and the likelihood for adolescent use. Further, an inverse relationship exists between the age of first experience and the probability of adult abuse. Whether and how the combined effects of prenatal and adolescent ethanol experiences contribute to this progressive pattern remains unknown. Fetal ethanol exposure directly changes the odor attributes of ethanol important for both ethanol odor preference behavior and ethanol flavor perception. These effects persist only to adolescence. Here we tested whether adolescent ethanol odor re-exposure: (Experiment 1 augments the fetal effect on the adolescent behavioral response to ethanol odor; and/or (Experiment 2 perpetuates previously observed adolescent behavioral and neurophysiological responses into adulthood. Methods Pregnant rats received either an ethanol or control liquid diet. Progeny (observers experienced ethanol odor in adolescence via social interaction with a peer (demonstrators that received an intragastric infusion of either 1.5 g/kg ethanol or water. Social interactions were scored for the frequency that observers followed their demonstrator. Whole-body plethysmography evaluated the unconditioned behavioral response of observers to ethanol odor in adolescence (P37 or adulthood (P90. The olfactory epithelium of adults was also examined for its neural response to five odorants, including ethanol. Results Experiment 1: Relative to fetal or adolescent exposure alone, adolescent re-exposure enhanced the behavioral response to ethanol odor in P37 animals. Compared to animals with no ethanol experience, rats receiving a single experience (fetal or adolescent show an enhanced, yet equivalent, ethanol odor response. Fetal ethanol experience also increased olfactory-guided following of an intoxicated peer. Experiment 2: Combined exposure yielded persistence of the behavioral effects only in adult

  12. Interaction of biogenic amines with ethanol.

    Science.gov (United States)

    Smith, A A

    1975-01-01

    Ethanol through its primary catabolite, acetaldehyde, competitively inhibits oxidation of aldehyde dehydrogenase substrates. As a consequence biogenic amines form increased quantities of alcohols rather than the corresponding acids. During this biotransformation, condensation reactions between deaminated and intact amines may occur which can yield tetrahydropapaverolines. These compounds are closely related to precursors of opioids which is cause to link ethanol abuse to morphine addiction. There is, however, no pharmacological or clinical evidence suggesting similarities between ethanol dependence or opiod addiction. Acetaldehyde plays an additional role in alkaloidal formation in vitro. Biogenic amines may react with acetaldehyde to form isoquinoline or carboline compounds. Some of these substances have significant pharmacological activity. Furthermore, they may enter neural stores and displace the natural neurotransmitter. Thus, they can act as false neurotransmitters. Some investigators believe that chronic ethanol ingestion leads to significant formation of such aberrant compounds which may then upset autonomic nervous system balance. This disturbance may explain the abnormal sympathetic activity seen in withdrawal. While these ideas about the etiology of alcohol abuse have a definite appeal, they are naturally based on in vitro preliminary work. Much study of the quantitative pharmacology of these compounds in animals is required before judgement can be made as to the merits of the proposed hypotheses. In the meantime, pharmacological studies on the ability of ethanol to depress respiration in the mouse has revealed that unlike opioids or barbituates, respiratory depression induced by ethanol requires the presence in brain of serotonin. This neurotransmitter also mediates the respiratory effects of several other alcohols but curiously, not chloral hydrate, yet this compound is purported to alter biogenic amine metabolism much like ethanol. Thus, the response

  13. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  14. Xylose fermentation to ethanol. A review

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J D

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  15. 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)

  16. Bioconversion of cellulose to ethanol

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-06-20

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

  17. Yield of ethanol from enzyme-hydrolyzed yam (Dioscorea rotundata ...

    African Journals Online (AJOL)

    Fresh whole yam tubers and cocoyam corms were separately processed into flours by washing, peeling, blanching, slicing,drying and milling. The flours were enzyme-hydrolyzed by mixing 500g of flour with 2Lof water followed by treatment with a combination of bacterial alpha amylase, limit dextrinase and fungal alpha ...

  18. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  19. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  20. 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.

  1. Simultaneous hydrogen and ethanol production from cascade utilization of mono-substrate in integrated dark and photo-fermentative reactor.

    Science.gov (United States)

    Liu, Bing-Feng; Xie, Guo-Jun; Wang, Rui-Qing; Xing, De-Feng; Ding, Jie; Zhou, Xu; Ren, Hong-Yu; Ma, Chao; Ren, Nan-Qi

    2015-01-01

    Integrating hydrogen-producing bacteria with complementary capabilities, dark-fermentative bacteria (DFB) and photo-fermentative bacteria (PFB), is a promising way to completely recover bioenergy from waste biomass. However, the current coupled models always suffer from complicated pretreatment of the effluent from dark-fermentation or imbalance between dark and photo-fermentation, respectively. In this work, an integrated dark and photo-fermentative reactor (IDPFR) was developed to completely convert an organic substrate into bioenergy. In the IDPFR, Ethanoligenens harbinese B49 and Rhodopseudomonas faecalis RLD-53 were separated by a membrane into dark and photo chambers, while the acetate produced by E. harbinese B49 in the dark chamber could freely pass through the membrane into the photo chamber and serve as a carbon source for R. faecalis RLD-53. The hydrogen yield increased with increasing working volume of the photo chamber, and reached 3.38 mol H2/mol glucose at the dark-to-photo chamber ratio of 1:4. Hydrogen production by the IDPFR was also significantly affected by phosphate buffer concentration, glucose concentration, and ratio of dark-photo bacteria. The maximum hydrogen yield (4.96 mol H2/mol glucose) was obtained at a phosphate buffer concentration of 20 mmol/L, a glucose concentration of 8 g/L, and a ratio of dark to photo bacteria of 1:20. As the glucose and acetate were used up by E. harbinese B49 and R. faecalis RLD-53, ethanol produced by E. harbinese B49 was the sole end-product in the effluent from the IDPFR, and the ethanol concentration was 36.53 mmol/L with an ethanol yield of 0.82 mol ethanol/mol glucose. The results indicated that the IDPFR not only circumvented complex pretreatments on the effluent in the two-stage process, but also overcame the imbalance of growth and metabolic rate between DFB and PFB in the co-culture process, and effectively enhanced cooperation between E. harbinense B49 and R. faecalis RLD-53. Moreover

  2. Ethanol fuels in Brazil

    International Nuclear Information System (INIS)

    Trindade, S.C.

    1993-01-01

    The largest alternative transportation fuels program in the world today is Brazil's Proalcool Program. About 6.0 million metric tons of oil equivalent (MTOE) of ethanol, derived mainly from sugar cane, were consumed as transportation fuels in 1991 (equivalent to 127,000 barrels of crude oil per day). Total primary energy consumed by the Brazilian economy in 1991 was 184.1 million MTOE, and approximately 4.3 million vehicles -- about one third of the total vehicle fleet or about 40 percent of the total car population -- run on hydrous or open-quotes neatclose quotes ethanol at the azeotropic composition (96 percent ethanol, 4 percent water, by volume). Additional transportation fuels available in the country are diesel and gasoline, the latter of which is defined by three grades. Gasoline A (regular, leaded gas)d has virtually been replaced by gasoline C, a blend of gasoline and up to 22 percent anhydrous ethanol by volume, and gasoline B (premium gasoline) has been discontinued as a result of neat ethanol market penetration

  3. 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.

  4. 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

  5. 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.

  6. Bioconversion of corn stover hydrolysate to ethanol by a recombinant yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jing; Xia, Liming

    2010-12-15

    Three corn stover hydrolysates, enzymatic hydrolysates prepared from acid and alkaline pretreatments separately and hemicellulosic hydrolysate prepared from acid pretreatment, were evaluated in composition and fermentability. For enzymatic hydrolysate from alkaline pretreatment, ethanol yield on fermentable sugars and fermentation efficiency reached highest among the three hydrolysates; meanwhile, ethanol yield on dry corn stover reached 0.175 g/g, higher than the sum of those of two hydrolysates from acid pretreatment. Fermentation process of the enzymatic hydrolysate from alkaline pretreatment was further investigated using free and immobilized cells of recombinant Saccharomyces cerevisiae ZU-10. Concentrated hydrolysate containing 66.9 g/L glucose and 32.1 g/L xylose was utilized. In the fermentation with free cells, 41.2 g/L ethanol was obtained within 72 h with an ethanol yield on fermentable sugars of 0.416 g/g. Immobilized cells greatly enhanced the ethanol productivity, while the ethanol yield on fermentable sugars of 0.411 g/g could still be reached. Repeated batch fermentation with immobilized cells was further attempted up to six batches. The ethanol yield on fermentable sugars maintained above 0.403 g/g with all glucose and more than 92.83% xylose utilized in each batch. These results demonstrate the feasibility and efficiency of ethanol production from corn stover hydrolysates. (author)

  7. Improved ethanol fermentation of a yeast mutant by C-12 ion beam irradiation

    International Nuclear Information System (INIS)

    Lu Dong; Liu Qingfang; Wu Xin; Wang Ying; Wang Jufang; Ma Shuang; Li Wenjian

    2010-01-01

    The yeast Saccharomyces cerevisiae YY was irradiated with 100 MeV/u 12 C 6+ ion beams. After screening,we obtained the mutant strain C03A of high ethanol yield. The influence of fermentation temperature, pH and concentration of sugar on ethanol fermentation were studied. The range analysis and analysis of variance were applied for the result of orthogonal experiments. The optimal ethanol fermentation conditions are: fermentation temperature 35 degree C, pH value 5.0, and sugar concentration 24%. The results of fermentation in the 10 L bioreactor showed that the ethanol fermentation of the mutant strain could be completed in 36 hours, the production of ethanol was to 13.2%(V/V), which means 12 hours faster and 1.6%(V /V) ethanol yield higher than original strain. (authors)

  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. Taste-aversion-prone (TAP) rats and taste-aversion-resistant (TAR) rats differ in ethanol self-administration, but not in ethanol clearance or general consumption.

    Science.gov (United States)

    Orr, T Edward; Whitford-Stoddard, Jennifer L; Elkins, Ralph L

    2004-05-01

    Taste-aversion (TA)-prone (TAP) rats and TA-resistant (TAR) rats have been developed by means of bidirectional selective breeding on the basis of their behavioral responses to a TA conditioning paradigm. The TA conditioning involved the pairing of an emetic-class agent (cyclophosphamide) with a novel saccharin solution as the conditioned stimulus. Despite the absence of ethanol in the selective breeding process, these rat lines differ widely in ethanol self-administration. In the current study, blood alcohol concentrations (BACs) were determined after 9 days of limited (2 h per day) access to a simultaneous, two-bottle choice of a 10% ethanol in water solution [volume/volume (vol./vol.)] or plain water. The BACs correlated highly with ethanol intake among TAR rats, but an insufficient number of TAP rats yielded measurable BACs to make the same comparison within this rat line. The same rats were subsequently exposed to 24-h access of a two-bottle choice (10% ethanol or plain water) for 8 days. Ethanol consumption during the 24-h access period correlated highly with that seen during limited access. Subsequent TA conditioning with these rats yielded line-typical differences in saccharin preferences. In a separate group of rats, ethanol clearance was determined by measuring BACs at 1, 4, and 7 h after injection of a 2.5-g/kg dose of ethanol. Ethanol clearance was not different between the two lines. Furthermore, the lines did not differ with respect to food and water consumption. Therefore, the TAP rat-TAR rat differences in ethanol consumption cannot be attributed to line differences in ethanol metabolism or in general consummatory behavior. The findings support our contention that the line differences in ethanol consumption are mediated by differences in TA-related mechanisms. The findings are discussed with respect to genetically based differences in the subjective experience of ethanol.

  10. Ethanol and ethyl glucuronide urine concentrations after ethanol-based hand antisepsis with and without permitted alcohol consumption.

    Science.gov (United States)

    Gessner, Stephan; Below, Elke; Diedrich, Stephan; Wegner, Christian; Gessner, Wiebke; Kohlmann, Thomas; Heidecke, Claus-Dieter; Bockholdt, Britta; Kramer, Axel; Assadian, Ojan; Below, Harald

    2016-09-01

    During hand antisepsis, health care workers (HCWs) are exposed to alcohol by dermal contact and by inhalation. Concerns have been raised that high alcohol absorptions may adversely affect HCWs, particularly certain vulnerable individuals such as pregnant women or individuals with genetic deficiencies of aldehyde dehydrogenase. We investigated the kinetics of HCWs' urinary concentrations of ethanol and its metabolite ethyl glucuronide (EtG) during clinical work with and without previous consumption of alcoholic beverages by HCWs. The median ethanol concentration was 0.7 mg/L (interquartile range [IQR], 0.5-1.9 mg/L; maximum, 9.2 mg/L) during abstinence and 12.2 mg/L (IQR, 1.5-139.6 mg/L; maximum, 1,020.1 mg/L) during alcohol consumption. During abstinence, EtG reached concentrations of up to 958 ng/mL. When alcohol consumption was permitted, the median EtG concentration of all samples was 2,593 ng/mL (IQR, 890.8-3,576 ng/mL; maximum, 5,043 ng/mL). Although alcohol consumption was strongly correlated with both EtG and ethanol in urine, no significant correlation for the frequency of alcoholic hand antisepsis was observed in the linear mixed models. The use of ethanol-based handrub induces measurable ethanol and EtG concentrations in urine. Compared with consumption of alcoholic beverages or use of consumer products containing ethanol, the amount of ethanol absorption resulting from handrub applications is negligible. In practice, there is no evidence of any harmful effect of using ethanol-based handrubs as much as it is clinically necessary. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  11. Characterisation of thermotolerant, ethanol tolerant fermentative Saccharomyces cerevisiae for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Kiransree, N.; Sridhar, M.; Venkateswar Rao, L. [Department of Microbiology, Osmania University, Hyderabad (India)

    2000-03-01

    Of the four thermotolerant, osmotolerant, flocculating yeasts (VS{sub 1}, VS{sub 2}, VS{sub 3} and VS{sub 4}) isolated from the soil samples collected within the hot regions of Kothagudem Thermal Power Plant, located in Khammam Dt., Andhra Pradesh, India, VS{sub 1} and VS{sub 3} were observed as better performers. They were identified as Saccharomyces cerevisiae. VS{sub 1} and VS{sub 3} were tested for their growth characteristics and fermentation abilities on various carbon sources including molasses at 30 C and 40 C respectively. More biomass and fermentation was observed in sucrose, fructose and glucose. Maximum amount of ethanol produced by VS{sub 3} containing 150 (g/l) of these substrates were 74, 73, and 72 (g/l) at 30 C and 64, 61 and 63 (g/l) at 40 C respectively. With molasses containing 14% sugar, the amount of ethanol produced by VS{sub 3} was 53.2 and 45 (g/l) at 30 C and 40 C respectively. VS{sub 3} strain showed 12% W/V ethanol tolerance. VS{sub 3} strain was also characterised for its ethanol producing ability using various starchy substrates in solid state and submerged fermentation. More ethanol was produced in submerged than solid state fermentation. (orig.)

  12. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  13. Internal energy selection in vacuum ultraviolet photoionization of ethanol and ethanol dimers

    Science.gov (United States)

    Bodi, Andras

    2013-10-01

    Internal energy selected ethanol monomer and ethanol dimer ions were prepared by threshold photoionization of a supersonic molecular beam seeded with ethanol. The dissociative photoionization processes of the monomer, the lowest-energy CH3-loss channel of the dimer, and the fragmentation of larger clusters were found to be disjunct from the ionization onset to about 12 eV, which made it possible to determine the 0 K appearance energy of C-C bond breaking in the H-donor unit of the ethanol dimer cation as 9.719 ± 0.004 eV. This reaction energy is used together with ab initio calculations in a thermochemical cycle to determine the binding energy change from the neutral ethanol dimer to a protonated ethanol-formaldehyde adduct. The cycle also shows general agreement between experiment, theory, and previously published enthalpies of formation. The role of the initial ionization site, or rather the initial photoion state, is also discussed based on the dimer breakdown diagram and excited state calculations. There is no evidence for isolated state behavior, and the ethanol dimer dissociative photoionization processes appear to be governed by statistical theory and the ground electronic state of the ion. In the monomer breakdown diagram, the smoothly changing branching ratio between H and CH3 loss is at odds with rate theory predictions, and shows that none of the currently employed few-parameter rate models, appropriate for experimental rate curve fitting, yields a correct description for this process in the experimental energy range.

  14. Effect of ethanol and methanol on growth of ruminal bacteria Selenomonas ruminantium and Butyrivibrio fibrisolvens.

    Science.gov (United States)

    Patterson, J A; Ricke, S C

    2015-01-01

    The effect of ethanol and methanol on growth of several ruminal bacterial strains was examined. Ethanol concentrations as low as 0.2% had a significant, but moderate, inhibitory effect on lag time or growth over time and 3.3% ethanol significantly inhibited maximum optical density obtained by both Selenomonas ruminantium and Butyrivibrio fibrisolvens. Little growth of either strain occurred at 10% ethanol concentrations. Methanol concentrations below 0.5% had little effect on either growth or maximum optical density of Selenomonas ruminantium whereas methanol concentrations below 3.3% had little effect on growth or maximum optical density of Butyrivibrio fibrisolvens. Higher methanol concentrations increasingly inhibited growth of both strains and no growth occurred at a 10% methanol concentration. Concentrations of ethanol or methanol used to add hydrophobic compounds to culture media should be kept below 1%.

  15. 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.

  16. 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.

  17. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  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. 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-...

  20. Synthesis of ethanol {sup 14}C-1; Synthese d'ethanol {sup 14}C-1

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, R E; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The direct reduction by LiAlH{sub 4}, of a suspension of anhydrous sodium acetate in tetra-hydro-furfuryl-oxy-tetra-hydro-pyran is described. This study has shown that the ethanol thus obtained is impure and that the yields are erratic. On the contrary the reduction of acetyl chloride 1-{sup 14}C by LiAlH{sub 4}, in 'diethyl carbitol' leads to ethanol 1-{sup 14}C of satisfactory purity with a yield of about 71 percent. (author) [French] Une etude de la reduction directe par LiAlH{sub 4}, de l'acetate de soude anhydre en suspension dans le tetrahydrofurfuryloxytetrahydropyrane est decrite. Cette etude a montre que l'on obtient de l'ethanol souille d'impuretes, avec un rendement variable. Par contre, la reduction du chlorure d'acetyle {sup 14}C-1 par LiAlH{sub 4}, dans le 'diethyl carbitol' conduit a l'ethanol {sup 14}C-1 de purete convenable avec un rendement de l'ordre de 71 pour cent. (auteur)

  1. 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)

  2. Supercritical fluid extraction of peach (Prunus persica) almond oil: process yield and extract composition.

    Science.gov (United States)

    Mezzomo, Natália; Mileo, Bruna R; Friedrich, Maria T; Martínez, Julian; Ferreira, Sandra R S

    2010-07-01

    Peach kernels are industrial residues from the peach processing, contain oil with important therapeutic properties and attractive nutritional aspects because of the high concentration of oleic and linoleic acids. The extraction method used to obtain natural compounds from raw matter is critical for product quality definition. Thus, the aim of this work was to compare peach almond extraction yields obtained by different procedures: soxhlet extractions (Sox) with different solvents; hydrodistillation (HD); ethanolic maceration (Mac) followed by fractionation with various solvents, and supercritical fluid extraction (SFE) at 30, 40 and 50 degrees C and at 100, 200 and 300bar, performed with pure CO(2) and with a co-solvent. The extracts were evaluated with respect to fatty acid composition (FAC), fractionated chemical profile (FCP) and total phenolic content (TPC). The Sox total yields were generally higher than those obtained by SFE. The crossover pressure for SFE was between 260 and 280bar. The FAC results show oleic and linoleic acids as main components, especially for Sox and SFE extracts. The FCP for samples obtained by Sox and Mac indicated the presence of benzaldehyde and benzyl alcohol, components responsible for almond flavor and with important industrial uses, whereas the SFE extracts present a high content of a possible flavonoid. The higher TPC values were obtained by Sox and Mac with ethanol. In general, the maximum pressure in SFE produced the highest yield, TPC and oleic acid content. The use of ethanol at 5% as co-solvent in SFE did not result in a significant effect on any evaluated parameter. The production of peach almond oil through all techniques is substantially adequate and SFE presented advantages, with respect to the quality of the extracts due to the high oleic acid content, as presented by some Sox samples. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  3. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  4. 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

  5. Performance of a passive direct ethanol fuel cell

    Science.gov (United States)

    Pereira, J. P.; Falcão, D. S.; Oliveira, V. B.; Pinto, A. M. F. R.

    2014-06-01

    Ethanol emerges as an attractive fuel since it is less toxic and has higher energy density than methanol and can be produced from biomass. Direct ethanol fuel cells (DEFCs) appear as a good choice for producing sustainable energy for portable applications. However, they are still far from attaining acceptable levels of power output, since their performance is affected by the slow electrochemical ethanol oxidation and water and ethanol crossover. In the present work, an experimental study on the performance of a passive DEFC is described. Tailored MEAs (membrane electrode assembly) with different catalyst loadings, anode diffusion layers and membranes were tested in order to select optimal working conditions at high ethanol concentrations and low ethanol crossover. The performance increased with an increase of membrane and anode diffusion layer thicknesses and anode catalyst loading. A maximum power density of 1.33 mW cm-2, was obtained using a Nafion 117 membrane, 4 mg cm-2 of Pt-Ru and 2 mg cm-2 of Pt on the anode and cathode catalyst layers, ELAT as anode diffusion layer, carbon cloth as cathode diffusion layer and an ethanol concentration of 2 M. As far as the authors are aware this is the first work reporting an experimental optimization of passive DEFCs.

  6. Chronic ethanol feeding modulates the synthesis of digestive enzymes

    International Nuclear Information System (INIS)

    Ponnappa, B.C.; Hoek, J.B.; Rubin, E.

    1987-01-01

    The effects of chronic ethanol feeding on pancreatic protein synthesis were investigated. Protein synthesis was assessed by studying the rate of incorporation of 3 H-leucine into TCA-precipitable proteins in isolated pancreatic acini from rats. Chronic ethanol ingestion increased the rate of pancreatic protein synthesis by 2-4 fold. The onset of the increase in protein synthesis was detectable two days after ethanol feeding, reached a maximum after 7 days and remained unchanged after 4 months on the ethanol-containing diet. The rate of synthesis of individual digestive enzymes was studied by SDS-PAGE on extracts obtained from purified zymogen granules. Ethanol feeding induced an increase in the rate of synthesis of most of the digestive enzymes; chymotrypsinogen, trypsinogen and an unidentified protein were increased to a greater extent than other digestive enzymes. By contrast, the synthesis of amylase was selectively decreased after ethanol feeding. These results suggest that chronic ethanol ingestion has specific effects on the rate of synthesis of individual digestive enzymes in the exocrine pancreas

  7. Carbonaceous Aerosols Emitted from Light-Duty Vehicles Operating on Ethanol Fuel Blends

    Science.gov (United States)

    Air pollution is among the many environmental and public health concerns associated with increased ethanol use in vehicles. Jacobson [2007] showed for the U.S. market that full conversion to e85 ([85% ethanol, 15% gasoline]—the maximum standard blend used in modern dual fuel veh...

  8. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  9. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  10. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  11. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  12. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  13. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  14. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  15. Promoting chain elongation in mixed culture acidification reactors by addition of ethanol

    International Nuclear Information System (INIS)

    Grootscholten, T.I.M.; Kinsky dal Borgo, F.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    In this research we investigate a microbial production process to produce medium chain fatty acids (MCFAs) based on the organic fraction of municipal solid waste (OFMSW). In this microbial production process, called chain elongation, bacteria produce medium chain fatty acids (MCFAs) from ethanol and volatile fatty acids (VFAs). MCFAs could be used as new biomass based building blocks for the chemical and fuel industry. The objective of this article is to investigate whether chain elongation can be promoted during acidification of OFMSW by addition of ethanol. The results show that chain elongation can be promoted during acidification of OFMSW by addition of ethanol. However, the hydrolysis rate and the carboxylic acid yield of the OFMSW in reactors with ethanol additions were lower than the hydrolysis rate and the carboxylic acid yield than in reactors without ethanol additions. Further research is required to determine whether a combined chain elongation and acidification reactor or a separated reactor system is more advantageous for MCFA production from OFMSW. -- Highlights: ► Production of medium chain fatty acids from municipal solid waste and ethanol. ► Insight in production of caproate and consumption of in-situ produced ethanol. ► Ethanol additions reduced propionate, butyrate and valerate concentrations. ► Ethanol additions hardly reduced acetate concentrations. ► Hydrolysis rate was lower in experiments with ethanol additions

  16. 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.

  17. Effect of ozonolysis pretreatment parameters on the sugar release, ozone consumption and ethanol production from sugarcane bagasse.

    Science.gov (United States)

    Travaini, Rodolfo; Barrado, Enrique; Bolado-Rodríguez, Silvia

    2016-08-01

    A L9(3)(4) orthogonal array (OA) experimental design was applied to study the four parameters considered most important in the ozonolysis pretreatment (moisture content, ozone concentration, ozone/oxygen flow and particle size) on ethanol production from sugarcane bagasse (SCB). Statistical analysis highlighted ozone concentration as the highest influence parameter on reaction time and sugars release after enzymatic hydrolysis. The increase on reaction time when decreasing the ozone/oxygen flow resulted in small differences of ozone consumptions. Design optimization for sugars release provided a parameters combination close to the best experimental run, where 77.55% and 56.95% of glucose and xylose yields were obtained, respectively. When optimizing the grams of sugar released by gram of ozone, the highest influence parameter was moisture content, with a maximum yield of 2.98gSUGARS/gO3. In experiments on hydrolysates fermentation, Saccharomyces cerevisiae provided ethanol yields around 80%, while Pichia stipitis was completely inhibited. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 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

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

    Science.gov (United States)

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

    2012-11-01

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

  20. A theoretical evaluation of growth yields of yeasts

    NARCIS (Netherlands)

    Verduyn, C.; Stouthamer, A.H.; Scheffers, W.A.; Van Dijken, J.P.

    1991-01-01

    Growth yields of Saccharomyces cerevisiae and Candida utilis in carbon-limited chemostat cultures were evaluated. The yields on ethanol and acetate were much lower in S. cerevisiae, in line with earlier reports that site I phosphorylation is absent in this yeast. However, during aerobic growth on

  1. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...

  2. Ethanol Forensic Toxicology.

    Science.gov (United States)

    Perry, Paul J; Doroudgar, Shadi; Van Dyke, Priscilla

    2017-12-01

    Ethanol abuse can lead to negative consequences that oftentimes result in criminal charges and civil lawsuits. When an individual is suspected of driving under the influence, law enforcement agents can determine the extent of intoxication by measuring the blood alcohol concentration (BAC) and performing a standardized field sobriety test. The BAC is dependent on rates of absorption, distribution, and elimination, which are influenced mostly by the dose of ethanol ingested and rate of consumption. Other factors contributing to BAC are gender, body mass and composition, food effects, type of alcohol, and chronic alcohol exposure. Because of individual variability in ethanol pharmacology and toxicology, careful extrapolation and interpretation of the BAC is needed, to justify an arrest and assignment of criminal liability. This review provides a summary of the pharmacokinetic properties of ethanol and the clinical effects of acute intoxication as they relate to common forensic questions. Concerns regarding the extrapolation of BAC and the implications of impaired memory caused by alcohol-induced blackouts are discussed. © 2017 American Academy of Psychiatry and the Law.

  3. Bio-ethanol

    DEFF Research Database (Denmark)

    Wenzel, Henrik

    2007-01-01

    , there is not enough biomass for 'everyone', not physically and not in terms of money to promote its use. This leads to the conclusion that any use of biomass for energy purposes will have to compare to the lost opportunity of using it for something else. In this perspective, the choice to use biomass for bio......-ethanol production will not lead to reduction but to increase in CO2 emission and fossil fuel dependency. Both first and second generation bio-ethanol suffer from a biomass-to-ethanol energy conversion efficiency as low as 30-40 %, and moreover external fossil fuels are used to run the conversion. There is only......, but they do not improve the energy balance enough for bio-ethanol to compete with alternative uses of the biomass. When using biomass to substitute fossil fuels in heat & power production, a close to 100% substitution efficiency is achieved. The best alternative for CO2 reduction and oil saving is, therefore...

  4. 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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  6. 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

  7. 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

  8. Continuous Ethanol Fermentation of Pretreated Lignocellulosic Biomasses, Waste Biomasses, Molasses and Syrup Using the Anaerobic, Thermophilic Bacterium Thermoanaerobacter italicus Pentocrobe 411

    Science.gov (United States)

    Andersen, Rasmus Lund; Jensen, Karen Møller; Mikkelsen, Marie Just

    2015-01-01

    Lignocellosic ethanol production is now at a stage where commercial or semi-commercial plants are coming online and, provided cost effective production can be achieved, lignocellulosic ethanol will become an important part of the world bio economy. However, challenges are still to be overcome throughout the process and particularly for the fermentation of the complex sugar mixtures resulting from the hydrolysis of hemicellulose. Here we describe the continuous fermentation of glucose, xylose and arabinose from non-detoxified pretreated wheat straw, birch, corn cob, sugar cane bagasse, cardboard, mixed bio waste, oil palm empty fruit bunch and frond, sugar cane syrup and sugar cane molasses using the anaerobic, thermophilic bacterium Thermoanaerobacter Pentocrobe 411. All fermentations resulted in close to maximum theoretical ethanol yields of 0.47–0.49 g/g (based on glucose, xylose, and arabinose), volumetric ethanol productivities of 1.2–2.7 g/L/h and a total sugar conversion of 90–99% including glucose, xylose and arabinose. The results solidify the potential of Thermoanaerobacter strains as candidates for lignocellulose bioconversion. PMID:26295944

  9. Growth and ethanol fermentation ability on hexose and pentose sugars and glucose effect under various conditions in thermotolerant yeast Kluyveromyces marxianus.

    Science.gov (United States)

    Rodrussamee, Nadchanok; Lertwattanasakul, Noppon; Hirata, Katsushi; Suprayogi; Limtong, Savitree; Kosaka, Tomoyuki; Yamada, Mamoru

    2011-05-01

    Ethanol fermentation ability of the thermotolerant yeast Kluyveromyces marxianus, which is able to utilize various sugars including glucose, mannose, galactose, xylose, and arabinose, was examined under shaking and static conditions at high temperatures. The yeast was found to produce ethanol from all of these sugars except for arabinose under a shaking condition but only from hexose sugars under a static condition. Growth and sugar utilization rate under a static condition were slower than those under a shaking condition, but maximum ethanol yield was slightly higher. Even at 40°C, a level of ethanol production similar to that at 30°C was observed except for galactose under a static condition. Glucose repression on utilization of other sugars was observed, and it was more evident at elevated temperatures. Consistent results were obtained by the addition of 2-deoxyglucose. The glucose effect was further examined at a transcription level, and it was found that KmGAL1 for galactokinase and KmXYL1 for xylose reductase for galactose and xylose/arabinose utilization, respectively, were repressed by glucose at low and high temperatures, but KmHXK2 for hexokinase was not repressed. We discuss the possible mechanism of glucose repression and the potential for utilization of K. marxianus in high-temperature fermentation with mixed sugars containing glucose.

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

    Science.gov (United States)

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

    2009-12-01

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

  11. Growth and ethanol fermentation ability on hexose and pentose sugars and glucose effect under various conditions in thermotolerant yeast Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Rodrussamee, Nadchanok; Hirata, Katsushi; Suprayogi [Yamaguchi Univ., Ube (Japan). Graduate School of Medicine; Lertwattanasakul, Noppon; Kosaka, Tomoyuki [Yamaguchi Univ. (Japan). Faculty of Agriculture; Limtong, Savitree [Kasetsart Univ., Bangkok (Thailand). Faculty of Science; Yamada, Mamoru [Yamaguchi Univ., Ube (Japan). Graduate School of Medicine; Yamaguchi Univ. (Japan). Faculty of Agriculture

    2011-05-15

    Ethanol fermentation ability of the thermotolerant yeast Kluyveromyces marxianus, which is able to utilize various sugars including glucose, mannose, galactose, xylose, and arabinose, was examined under shaking and static conditions at high temperatures. The yeast was found to produce ethanol from all of these sugars except for arabinose under a shaking condition but only from hexose sugars under a static condition. Growth and sugar utilization rate under a static condition were slower than those under a shaking condition, but maximum ethanol yield was slightly higher. Even at 40 C, a level of ethanol production similar to that at 30 C was observed except for galactose under a static condition. Glucose repression on utilization of other sugars was observed, and it was more evident at elevated temperatures. Consistent results were obtained by the addition of 2-deoxyglucose. The glucose effect was further examined at a transcription level, and it was found that KmGAL1 for galactokinase and KmXYL1 for xylose reductase for galactose and xylose/arabinose utilization, respectively, were repressed by glucose at low and high temperatures, but KmHXK2 for hexokinase was not repressed. We discuss the possible mechanism of glucose repression and the potential for utilization of K. marxianus in high-temperature fermentation with mixed sugars containing glucose. (orig.)

  12. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports.

    Science.gov (United States)

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H

    2013-05-30

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/Al S.G. ) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/Al S.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/Al S.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.

  13. ETHANOL ORGANOSOLV PRETREATMENT OF BAMBOO FOR EFFICIENT ENZYMATIC SACCHARIFICATION

    Directory of Open Access Journals (Sweden)

    Zhiqiang Li,

    2012-06-01

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

  14. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  15. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

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

    Science.gov (United States)

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

    2018-01-01

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

  17. Deacetylation Followed by Fractionation of Yellow Poplar Sawdust for the Production of Toxicity-Reduced Hemicellulosic Sugar for Ethanol Fermentation

    Directory of Open Access Journals (Sweden)

    Seong Ju Kim

    2018-02-01

    Full Text Available In order to produce bioethanol from yellow poplar sawdust without detoxification, deacetylation (mild alkali treatment was performed with aqueous ammonia solution. To select the optimal conditions, deacetylation was carried out under different conditions: NH4OH loading (2–10% (w/v and a solid-to-liquid ratio of 1:4–1:10 at 121 °C for 60 min. In order to assess the effectiveness of deacetylation, fractionation of deacetylated yellow poplar sawdust was performed using dilute acid (H2SO4, 0.5–2.0% (w/v at a reaction temperature of 130–150 °C for 10–80 min. The toxicity-reduced hemicellulosic hydrolyzates that were obtained through a two-step treatment at optimized conditions were fermented using Pichia stipitis for ethanol production, without any further detoxification. The maximum ethanol production was 4.84 g/L, corresponding to a theoretical ethanol yield of 82.52%, which is comparable to those of intentionally made hydrolyzates as controls.

  18. 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.

  19. Palladium-based electrocatalysts for ethanol oxidation reaction in alkaline direct ethanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Leticia Poras Reis de; Amico, Sandro Campos; Malfatti, Celia de Fraga, E-mail: leticiamoraes@usp.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil); Matos, Bruno R.; Santiago, Elisabete Inacio; Fonseca, Fabio Coral [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: Direct ethanol fuel cells require adequate electrocatalysts to promote the carbon carbon cleavage of ethanol molecule. Typical electrocatalysts are based on platinum, which have shown improved activity in acidic media. However, Pt-based catalysts have high cost and are easily deactivated by CO poisoning. Therefore, novel catalysts have been developed, and among then, palladium-based materials have shown promising results for the oxidation of ethanol in alkaline media. The present study reports on the performance of alkaline direct ethanol fuel cell (ADEFC) by using carbon-supported Pd, PdSn, PdNi, and PdNiSn produced by impregnation-reduction of the metallic precursors. The effect of chemical functionalization by acid treatment of the carbon support (Vulcan) was investigated. The electrocatalysts were studied by thermogravimetric analysis (TGA), X-rays diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and ADEFC tests. TGA measurements of functionalized Vulcan evidenced the characteristic weight losses attributed to the presence of surface functional groups due to the acid treatment. A high degree of alloying between Pd and Sn was inferred from XRD data, whereas in both PdNi and PdNiSn, Ni occurs mostly segregated in the oxide form. TEM analyses indicated agglomeration of Pd and PdSn particles, whereas a more uniform particle distribution was observed for PdNi and PdNiSn samples. CV curves showed that the peak potential for the oxidation of ethanol shifts towards negative values for all samples supported on functionalized Vulcan indicating that ethanol oxidation is facilitated. Microstructural and electrochemical features were confirmed by ADEFC tests, which revealed that the highest open circuit voltage and maximum power density were achieved for PdNiSn electrocatalysts supported on functionalized Vulcan with uniform particle distribution and improved triple phase boundaries. (author)

  20. Palladium-based electrocatalysts for ethanol oxidation reaction in alkaline direct ethanol fuel cell

    International Nuclear Information System (INIS)

    Moraes, Leticia Poras Reis de; Amico, Sandro Campos; Malfatti, Celia de Fraga; Matos, Bruno R.; Santiago, Elisabete Inacio; Fonseca, Fabio Coral

    2016-01-01

    Full text: Direct ethanol fuel cells require adequate electrocatalysts to promote the carbon carbon cleavage of ethanol molecule. Typical electrocatalysts are based on platinum, which have shown improved activity in acidic media. However, Pt-based catalysts have high cost and are easily deactivated by CO poisoning. Therefore, novel catalysts have been developed, and among then, palladium-based materials have shown promising results for the oxidation of ethanol in alkaline media. The present study reports on the performance of alkaline direct ethanol fuel cell (ADEFC) by using carbon-supported Pd, PdSn, PdNi, and PdNiSn produced by impregnation-reduction of the metallic precursors. The effect of chemical functionalization by acid treatment of the carbon support (Vulcan) was investigated. The electrocatalysts were studied by thermogravimetric analysis (TGA), X-rays diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and ADEFC tests. TGA measurements of functionalized Vulcan evidenced the characteristic weight losses attributed to the presence of surface functional groups due to the acid treatment. A high degree of alloying between Pd and Sn was inferred from XRD data, whereas in both PdNi and PdNiSn, Ni occurs mostly segregated in the oxide form. TEM analyses indicated agglomeration of Pd and PdSn particles, whereas a more uniform particle distribution was observed for PdNi and PdNiSn samples. CV curves showed that the peak potential for the oxidation of ethanol shifts towards negative values for all samples supported on functionalized Vulcan indicating that ethanol oxidation is facilitated. Microstructural and electrochemical features were confirmed by ADEFC tests, which revealed that the highest open circuit voltage and maximum power density were achieved for PdNiSn electrocatalysts supported on functionalized Vulcan with uniform particle distribution and improved triple phase boundaries. (author)

  1. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    KAUST Repository

    Zhang, Bo

    2016-08-16

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

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

    Science.gov (United States)

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

    2017-01-01

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

  3. 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.

  4. 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.

  5. Agricultural sector impacts of making ethanol from grain

    Energy Technology Data Exchange (ETDEWEB)

    Hertzmark, D.; Ray, D.; Parvin, G.

    1980-03-01

    This report presents the results of a model of the effects on the agricultural sector of producing ethanol from corn in the United States between 1979 and 1983. The model is aggregated at the national level, and results are given for all of the major food and feed crops, ethanol joint products, farm income, government payment, and agricultural exports. A stochastic simulation was performed to ascertain the impacts of yield and demand variations on aggregate performance figures. Results indicate minimal impacts on the agricultural sector for production levels of less than 1 billion gallons of ethanol per year. For higher production levels, corn prices will rise sharply, the agricultural sector will be more vulnerable to variations in yields and demands, and joint-product values will fall. Possibilities for ameliorating such effects are discussed, and such concepts as net energy and the biomass refinery are explored.

  6. Phytochemical Screening and antimicrobial activity of ethanol and ...

    African Journals Online (AJOL)

    Furthermore, minimum inhibitory concentration (MIC) of the extracts was evaluated. Bioactive compounds from all the parts were found to contain tannin, flavonoids, steroids, glycosides and alkaloids in addition to certain other minor compounds. Maximum zone of inhibition was found with the ethanolic root extract against S.

  7. Mixed waste paper to ethanol fuel. A technology, market, and economic assessment for Washington

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The objectives of this study were to evaluate the use of mixed waste paper for the production of ethanol fuels and to review the available conversion technologies, and assess developmental status, current and future cost of production and economics, and the market potential. This report is based on the results of literature reviews, telephone conversations, and interviews. Mixed waste paper samples from residential and commercial recycling programs and pulp mill sludge provided by Weyerhauser were analyzed to determine the potential ethanol yields. The markets for ethanol fuel and the economics of converting paper into ethanol were investigated.

  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. Continuous production of bio-oil by catalytic liquefaction from wet distiller’s grain with solubles (WDGS) from bio-ethanol production

    International Nuclear Information System (INIS)

    Toor, Saqib Sohail; Rosendahl, Lasse; Nielsen, Mads Pagh; Glasius, Marianne; Rudolf, Andreas; Iversen, Steen Brummerstedt

    2012-01-01

    Bio-refinery concepts are currently receiving much attention due to the drive toward flexible, highly efficient systems for utilization of biomass for food, feed, fuel and bio-chemicals. One way of achieving this is through appropriate process integration, in this particular case combining enzymatic bio-ethanol production with catalytic liquefaction of the wet distillers grains with soluble, a byproduct from the bio-ethanol process. The catalytic liquefaction process is carried out at sub-critical conditions (280–370 °C and 25 MPa) in the presence of a homogeneous alkaline and a heterogeneous Zirconia catalyst, a process known as the Catliq ® process. In the current work, catalytic conversion of WDGS was performed in a continuous pilot plant with a maximum capacity of 30 dm 3 h −1 of wet biomass. In the process, WDGS was converted to bio-oil, gases and water-soluble organic compounds. The oil obtained was characterized using several analysis methods, among them elementary analysis and GC–MS. The study shows that WDGS can be converted to bio oil with high yields. The results also indicate that through the combination of bio-ethanol production and catalytic liquefaction, it is possible to significantly increase the liquid product yield and scope, opening up for a wider end use applicability. -- Highlights: ► Hydrothermal liquefaction of wet biomass. ► Product phase analysis: oil, acqeous, gas and mineral phase. ► Energy and mass balance evaluation.

  10. 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 ...

  11. 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...

  12. 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 ...

  13. 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.

  14. Effects of ethanol extract of Bersama engleriana leaves on oxidative ...

    African Journals Online (AJOL)

    Pesticides are used to improve agricultural yields; meanwhile they have detrimental effects on human and animal reproduction. This study aimed at evaluating the protective effects of ethanol extract of Bersama engleriana leaves against cypermethrin-induced oxidative stress and reproductive toxicity. Fifty male guinea.

  15. Overcoming bacterial contamination of fuel ethanol fermentations -- alterntives to antibiotics

    Science.gov (United States)

    Fuel ethanol fermentations are not performed under aseptic conditions and microbial contamination reduces yields and can lead to costly "stuck fermentations". Antibiotics are commonly used to combat contaminants, but these may persist in the distillers grains co-product. Among contaminants, it is kn...

  16. Operant ethanol self-administration in ethanol dependent mice.

    Science.gov (United States)

    Lopez, Marcelo F; Becker, Howard C

    2014-05-01

    While rats have been predominantly used to study operant ethanol self-administration behavior in the context of dependence, several studies have employed operant conditioning procedures to examine changes in ethanol self-administration behavior as a function of chronic ethanol exposure and withdrawal experience in mice. This review highlights some of the advantages of using operant conditioning procedures for examining the motivational effects of ethanol in animals with a history of dependence. As reported in rats, studies using various operant conditioning procedures in mice have demonstrated significant escalation of ethanol self-administration behavior in mice rendered dependent via forced chronic ethanol exposure in comparison to nondependent mice. This paper also presents a summary of these findings, as well as suggestions for future studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. 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.

  18. Innovative inexpensive ethanol

    International Nuclear Information System (INIS)

    Mackek, S.

    1991-01-01

    New Energy Company of Indiana which produces 70 million gallons of ethanol per year, avoids the headaches often associated with organic by-products by creating an efficient and profitable sideline business. This paper reports that stretching across 55 acres in South Bend, Ind., New Energy's plant is the largest in the U.S. built specifically for fuel alcohol. The $186-million complex is a dramatic advance in the art of producing ethanol and its co-products. As the demand grows in the coming years for fuel alcohol-proven as an octane booster and a clean-burning alternative fuel. New Energy looks forward to increase production and profits. At the company's six-year-old plant, fuel alcohol is made from 26 million bushels a year of No. 2 yellow dent corn. Left at the bottom of the first column, after the alcohol has been boiled off, is stillage that contains more than 90% of the corn's protein and fat content, and virtually all of its vitamins and minerals, along with the yeast used to make the ethanol. While technically a waste product of the fuel alcohol process, this material's quantity and organic content not only make it difficult and costly to dispose, but its nutritional quality makes it an excellent candidate to be further processed into animal feed

  19. Fact sheet: Ethanol from corn

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-31

    This fact sheet is intended to provide an overview of the advantages of ethanol from corn, emphasizing ethanol`s contribution to environmental protection and sustainable agriculture. Ethanol, an alternative fuel used as an octane enhancer is produced through the conversion of starch to sugars by enzymes, and fermentation of these sugars to ethanol by yeast. The production process may involve wet milling or dry milling. Both these processes produce valuable by-products, in addition to ethanol and carbon dioxide. Ethanol contains about 32,000 BTU per litre. It is commonly believed that using state-of-the-art corn farming and corn processing processes, the amount of energy contained in ethanol and its by-products would be more than twice the energy required to grow and process corn into ethanol. Ethanol represents the third largest market for Ontario corn, after direct use as animal feed and wet milling for starch, corn sweetener and corn oil. The environmental consequences of using ethanol are very significant. It is estimated that a 10 per cent ethanol blend in gasoline would result in a 25 to 30 per cent decrease in carbon monoxide emissions, a 6 to 10 per cent decrease in net carbon dioxide, a slight increase in nitrous oxide emissions which, however, would still result in an overall decrease in ozone formation, since the significant reduction in carbon monoxide emissions would compensate for any slight increase in nitrous oxide. Volatile organic compounds emission would also decrease by about 7 per cent with a 10 per cent ethanol blend. High level blends could reduce VOCs production by as much as 30 per cent. 7 refs.

  20. Use of continuous lactose fermentation for ethanol production by Kluveromyces marxianus for verification and extension of a biochemically structured model

    DEFF Research Database (Denmark)

    Sansonetti, S.; Hobley, Timothy John; Curcio, S.

    2013-01-01

    A biochemically structured model has been developed to describe the continuous fermentation of lactose to ethanol by Kluveromyces marxianus and allowed metabolic coefficients to be determined. Anaerobic lactose-limited chemostat fermentations at different dilution rates (0.02 – 0.35 h-1) were...... performed. Species specific rates of consumption/formation, as well as yield coefficients were determined. Ethanol yield (0.655 C-mol ethanol*C-mol lactose-1) was as high as 98 % of theoretical. The modeling procedure allowed calculation of maintenance coefficients for lactose consumption and ethanol...

  1. Electron beam irradiation enhances the digestibility and fermentation yield of water-soaked lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Jin Seop Bak

    2014-12-01

    Full Text Available In order to overcome the limitation of commercial electron beam irradiation (EBI, lignocellulosic rice straw (RS was pretreated using water soaking-based electron beam irradiation (WEBI. This environment-friendly pretreatment, without the formation (or release of inhibitory compounds (especially hydroxymethylfurfural and furfural, significantly increased the enzymatic hydrolysis and fermentation yields of RS. Specifically, when water-soaked RS (solid:liquid ratio of 100% was treated with WEBI doses of 1 MeV at 80 kGy, 0.12 mA, the glucose yield after 120 h of hydrolysis was 70.4% of the theoretical maximum. This value was predominantly higher than the 29.5% and 52.1% measured from untreated and EBI-treated RS, respectively. Furthermore, after simultaneous saccharification and fermentation for 48 h, the ethanol concentration, production yield, and productivity were 9.3 g/L, 57.0% of the theoretical maximum, and 0.19 g/L h, respectively. Finally, scanning electron microscopy images revealed that WEBI induced significant ultrastructural changes to the surface of lignocellulosic fibers.

  2. 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.)

  3. Effect of pretreatment of molasses and recycling of yeast on ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Samaniego, R; Srivastas, R L

    1971-01-01

    The effect of pretreatment of molasses and recycling yeast for the removal of calcium, potassium, coloring matter, and colloidal substances on the production of ethanol from the fermentation of molasses was studied. Highest yield of ethanol (9.1%) was obtained from molasses pretreated with egg albumin followed by the treatment with ethanol(8.5%) and H/sub 2/SO/sub 4/ (8.1%) as compared to control (7.9%). Pretreatment with Al/sub 2/(SO/sub 4/)/sub 3/ and activated C did not improve yield. Lowest yield was recorded with tartaric acid. The washing of yeast with HCl (pH 3.5) resulted in higher yields of ethanol as compared to control in all stages of recyclings. Pretreatment of yeast with 5% NaCl retarded the fermentation rate and caused low yield of ethanol. A combined effect of H/sub 2/SO/sub 4/ and HCl showed no essential difference in yields of ethanol except in the third recycling.

  4. Fuel consumption of gasoline ethanol blends at different engine rotational

    Directory of Open Access Journals (Sweden)

    Y. Barakat

    2016-09-01

    Full Text Available Fuel consumption (mf kg/h was estimated for two hydrocarbon gasolines (BG1-OE and BG2-OE and their ethanol blends which contain from 4 to 20 vol.% of ethanol. Fuel consumption experiments for sixteen fuel samples (5 L each, were conducted on a four cylinder, four stroke spark ignition test vehicle Sahin car, Type 1.45, model 2001. The engine has a swept volume of 1400 c.c., a compression ratio of 8.3:1 and a maximum power of 78 HP at 5500 rpm. The obtained data reveal that the relation between fuel consumption and ethanol concentration is linear. Six linear equations for BG1-ethanol blends and BG2-ethanol ones at the investigated rotational speeds, were developed. Fuel consumption values of the first set of gasoline-ethanol blends are lower than that of the second set. This may be attributed to the difference in the chemical composition of base gasolines BG1 in the first set which is enriched in the less volatile reformate if compared with the second set which is more enriched in isomerate, the more volatile refinery stream.

  5. 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)

  6. A biochemically structured model for ethanol fermentation by Kluyveromyces marxianus: A batch fermentation and kinetic study

    DEFF Research Database (Denmark)

    Sansonetti, Sascha; Hobley, Timothy John; Calabrò, V.

    2011-01-01

    Anaerobic batch fermentations of ricotta cheese whey (i.e. containing lactose) were performed under different operating conditions. Ethanol concentrations of ca. 22gL−1 were found from whey containing ca. 44gL−1 lactose, which corresponded to up to 95% of the theoretical ethanol yield within 15h......, lactose, biomass and glycerol during batch fermentation could be described within a ca. 6% deviation, as could the yield coefficients for biomass and ethanol produced on lactose. The model structure confirmed that the thermodynamics considerations on the stoichiometry of the system constrain the metabolic...... coefficients within a physically meaningful range thereby providing valuable and reliable insight into fermentation processes....

  7. Direct conversion of sorghum carbohydrates to ethanol by a mixed microbial culture

    Energy Technology Data Exchange (ETDEWEB)

    Christakopoulos, Paul; Lianwu Li; Kekos, Dimitris; Macris, B.J. (National Technical Univ. of Athens (Greece). Dept. of Chemical Engineering)

    1993-01-01

    The carbohydrates of sweet sorghum were directly converted to ethanol by a mixed culture of Fusarium oxysporum F3 and Saccharomyces cerevisiae 2541. A number of factors affecting this bioconversion was studied. Optimum ethanol yields of 33.2 g/100 g of total sorghum carbohydrates, corresponding to 10.3 g/100 g of fresh stalks, were obtained. These values represented 68.6% of the theoretical yield based on total polysaccharides and exceeded that based on oligosaccharides of sorghum by 53.7%. The results demonstrated that more than half of the sorghum polysaccharides were directly fermented to ethanol, thus making the process worthy of further investigation. (author)

  8. Simultaneous Coproduction of Hydrogen and Ethanol in Anaerobic Packed-Bed Reactors

    Directory of Open Access Journals (Sweden)

    Cristiane Marques dos Reis

    2014-01-01

    Full Text Available This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT (1–8 h. Two reactors filled with expanded clay and fed with glucose (3136–3875 mg L−1 were operated at different total upflow velocities: 0.30 cm s−1 (R030 and 0.60 cm s−1 (R060. The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3 and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h−1 L−1 in R030 at HRT of 1 h. Furthermore, the highest hydrogen yield of 2.39 mol H2 mol−1 glucose was obtained in R060. No clear trend was observed by doubling the upflow velocities at this experiment. High ethanol production was also observed, indicating that the ethanol-pathway prevailed throughout the experiment.

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

    Science.gov (United States)

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

    2017-06-01

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

  10. Effects of PEMFC operating parameters on the performance of an integrated ethanol processor

    Energy Technology Data Exchange (ETDEWEB)

    Francesconi, Javier A.; Mussati, Miguel C.; Aguirre, Pio A. [INGAR Instituto de Desarrollo y Diseno (CONICET-UTN), Avellaneda 3657, CP:S3002GJC, Santa Fe (Argentina)

    2010-06-15

    In this paper the performance of a complete fuel cell system processing ethanol fuel has been analyzed as a function of the main fuel cell operating parameters. The fuel processor is based on the steam reforming process, followed by high- and low-temperature shift reactors, and carbon monoxide preferential oxidation reactor, which are coupled to a polymeric fuel cell (PEMFC). The goal was to analyze and improve the fuel cell system performance by simulation techniques. PEMFC operation has been analyzed using an available parametric model, which was implemented within HYSYS environment software. Pinch Analysis concepts were used to investigate the process energy integration and determine the maximum efficiency minimizing ethanol consumption. The system performance was analyzed for the SR-12 Modular PEM Generator, the Ballard Mark V fuel cell and the BCS 500 W stack. The net system efficiency is dependent on the required power demand. Efficiency values higher than 50% at low loads and less than 30% at high power demands are computed. In addition, the effect of fuel cell temperature, pressure and hydrogen utilization was analyzed. The trade-off between the reformer yield and the fuel cell performance defines the optimal operation pressure. The cell temperature determines operating zones where the water, involved in the reforming reactions, can be produced or demanded. (author)

  11. Modelling Extraction of White Tea Polyphenols: The Influence of Temperature and Ethanol Concentration

    Directory of Open Access Journals (Sweden)

    Sara Peiró

    2014-10-01

    Full Text Available The optimization of the extraction of natural antioxidants from white tea has fostered intensive research. This study has investigated the effects of ethanol-water mixtures, temperature and time on the extraction of polyphenols and antioxidant components from white tea. The response surface methodology was applied to identify the best extraction conditions. The best conditions to maximize the extraction of total polyphenols were: ethanol, 50%, for 47.5 min. Although the yield of polyphenols was optimal at 65 °C, the maximum antioxidant capacity was achieved with an extraction temperature of 90 °C. This study has identified the optimal conditions for the extraction of tea liquor with the best antioxidant properties. Epigallocatechin gallate, epicatechin gallate, epigallocatechin and epicatechin were extracted from white tea at concentrations up to 29.6 ± 10.6, 5.40 ± 2.09, 5.04 ± 0.20 and 2.48 ± 1.10 mg/100 g.

  12. A Probabilistic Analysis of the Switchgrass Ethanol Cycle

    Directory of Open Access Journals (Sweden)

    Tadeusz W. Patzek

    2010-09-01

    Full Text Available The switchgrass-driven process for producing ethanol has received much popular attention. However, a realistic analysis of this process indicates three serious limitations: (a If switchgrass planted on 140 million hectares (the entire area of active U.S. cropland were used as feedstock and energy source for ethanol production, the net ethanol yield would replace on average about 20% of today’s gasoline consumption in the U.S. (b Because nonrenewable resources are required to produce ethanol from switchgrass, the incremental gas emissions would be on average 55 million tons of equivalent carbon dioxide per year to replace just 10% of U.S. automotive gasoline. (c In terms of delivering electrical or mechanical power, ethanol from 1 hectare (10,000 m2 of switchgrass is equivalent, on average, to 30 m2 of low-efficiency photovoltaic cells. This analysis suggests that investing toward more efficient and durable solar cells, and batteries, may be more promising than investing in a process to convert switchgrass to ethanol.

  13. Ethanol dehydration to ethylene in a stratified autothermal millisecond reactor.

    Science.gov (United States)

    Skinner, Michael J; Michor, Edward L; Fan, Wei; Tsapatsis, Michael; Bhan, Aditya; Schmidt, Lanny D

    2011-08-22

    The concurrent decomposition and deoxygenation of ethanol was accomplished in a stratified reactor with 50-80 ms contact times. The stratified reactor comprised an upstream oxidation zone that contained Pt-coated Al(2)O(3) beads and a downstream dehydration zone consisting of H-ZSM-5 zeolite films deposited on Al(2)O(3) monoliths. Ethanol conversion, product selectivity, and reactor temperature profiles were measured for a range of fuel:oxygen ratios for two autothermal reactor configurations using two different sacrificial fuel mixtures: a parallel hydrogen-ethanol feed system and a series methane-ethanol feed system. Increasing the amount of oxygen relative to the fuel resulted in a monotonic increase in ethanol conversion in both reaction zones. The majority of the converted carbon was in the form of ethylene, where the ethanol carbon-carbon bonds stayed intact while the oxygen was removed. Over 90% yield of ethylene was achieved by using methane as a sacrificial fuel. These results demonstrate that noble metals can be successfully paired with zeolites to create a stratified autothermal reactor capable of removing oxygen from biomass model compounds in a compact, continuous flow system that can be configured to have multiple feed inputs, depending on process restrictions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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)

  15. A study on immobilized ethanol yeast cells by radiation technique

    International Nuclear Information System (INIS)

    Li Zhengkui; Zhang Bosen

    1994-01-01

    Hydrophilic monomer 2-hydroxyethyl acrylate (HEA) and a series of polyethylene glycol dimethacrylate monomers were copolymerized by radiation technique at low temperature (-78 degree C) and hydrophilic hydrogels were obtained. The immobilization of yeast cells with these copolymer carriers led to a higher ethanol productivity than free cells. Of all copolymer carriers, the ethanol yield with poly (HEA-14 G) was the highest, about 2.45 times as high as that of free yeast cells. In addition, the ethanol productivity of 12 batch repeated reactions with poly (HEA-14G) carrier was all higher than that of free yeast cells. The ethanol productivity of immobilized yeast cells was dependent on the proportion of hydrophilic monomer to other monomers in copolymer systems, the chain length of the bifunctional monomer, the degree of hydration of copolymer carriers, the structure of copolymer carriers and porosity in the internal structure of carriers. The ethanol yield of immobilized cells depended on swelling ability and porosity of copolymer carriers

  16. 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

  17. Determination of the efficiency of ethanol oxidation in a proton exchange membrane electrolysis cell

    Science.gov (United States)

    Altarawneh, Rakan M.; Majidi, Pasha; Pickup, Peter G.

    2017-05-01

    Products and residual ethanol in the anode and cathode exhausts of an ethanol electrolysis cell (EEC) have been analyzed by proton NMR and infrared spectrometry under a variety of operating conditions. This provides a full accounting of the fate of ethanol entering the cell, including the stoichiometry of the ethanol oxidation reaction (i.e. the average number of electrons transferred per ethanol molecule), product distribution and the crossover of ethanol and products through the membrane. The reaction stoichiometry (nav) is the key parameter that determines the faradaic efficiency of both EECs and direct ethanol fuel cells. Values determined independently from the product distribution, amount of ethanol consumed, and a simple electrochemical method based on the dependence of the current on the flow rate of the ethanol solution are compared. It is shown that the electrochemical method yields results that are consistent with those based on the product distribution, and based on the consumption of ethanol when crossover is accounted for. Since quantitative analysis of the cathode exhaust is challenging, the electrochemical method provides a valuable alternative for routine determination of nav, and hence the faradaic efficiency of the cell.

  18. Canada's directory of ethanol retailers

    International Nuclear Information System (INIS)

    1997-07-01

    This document is a directory listing all ethanol-blended gasoline retailers in Quebec, Ontario, Manitoba, Saskatchewan, Alberta, British Columbia, and the Yukon. The listings include the name and address of the retailer by province from west to east. Appendices providing a list of bulk purchase facilities of ethanol-blended fuels was also included, as well as a list of ethanol-blended gasoline retailers

  19. 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

  20. Cellulosic ethanol. Potential, technology and development status

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  1. Ethyl glucuronide, ethyl sulfate, and ethanol in urine after sustained exposure to an ethanol-based hand sanitizer.

    Science.gov (United States)

    Reisfield, Gary M; Goldberger, Bruce A; Crews, Bridgit O; Pesce, Amadeo J; Wilson, George R; Teitelbaum, Scott A; Bertholf, Roger L

    2011-03-01

    To assess the degree of ethanol absorption and subsequent formation of urinary ethyl glucuronide (EtG) and ethyl sulfate (EtS) following sustained application of hand sanitizer, 11 volunteers cleansed their hands with Purell(™) hand sanitizer (62% ethanol) every 5 min for 10 h on three consecutive days. Urine specimens were obtained at the beginning and end of each day of the study, and on the morning of the fourth day. Urinary creatinine, ethanol, EtG, and EtS concentrations were measured. EtG was undetectable in all pre-study urine specimens, but two pre-study specimens had detectable EtS (73 and 37 ng/mL). None of the pre-study specimens had detectable ethanol. The maximum EtG and EtS concentrations over the course of the study were 2001 and 84 ng/mL, respectively, and nearly all EtG- and EtS-positive urine specimens were collected at the conclusion of the individual study days. Only two specimens had detectable EtG at the beginning of any study day (96 and 139 ng/mL), and only one specimen had detectable EtS at the beginning of a study day (64 ng/mL), in addition to the two with detectable EtS prior to the study. Creatinine-adjusted maximum EtG and EtS concentrations were 1998 and 94 μg/g creatinine, respectively. In patients being monitored for ethanol use by urinary EtG concentrations, currently accepted EtG cutoffs do not distinguish between ethanol consumption and incidental exposures, particularly when urine specimens are obtained shortly after sustained use of ethanolcontaining hand sanitizer. Our data suggest that EtS may be an important complementary biomarker in distinguishing ethanol consumption from dermal exposure.

  2. Environmental efficiency among corn ethanol plants

    International Nuclear Information System (INIS)

    Sesmero, Juan P.; Perrin, Richard K.; Fulginiti, Lilyan E.

    2012-01-01

    Economic viability of the US corn ethanol industry depends on prices, technical and economic efficiency of plants and the extent of policy support. Public policy support is tied to the environmental efficiency of plants measured as their impact on emissions of greenhouse gases. This study evaluates the environmental efficiency of seven recently constructed ethanol plants in the North Central region of the US, using nonparametric data envelopment analysis (DEA). The minimum feasible level of GHG emissions per unit of ethanol is calculated for each plant and this level is decomposed into its technical and allocative sources. Results show that, on average, plants in our sample may be able to reduce GHG emissions by a maximum of 6% or by 2.94 Gg per quarter. Input and output allocations that maximize returns over operating costs (ROOC) are also found based on observed prices. The environmentally efficient allocation, the ROOC-maximizing allocation, and the observed allocation for each plant are combined to calculate economic (shadow) cost of reducing greenhouse gas emissions. These shadow costs gauge the extent to which there is a trade off or a complementarity between environmental and economic targets. Results reveal that, at current activity levels, plants may have room for simultaneous improvement of environmental efficiency and economic profitability. -- Highlights: ► Environmental efficiency of ethanol plants in the North Central US is evaluated. ► Economic (shadow) cost of reducing greenhouse gas emissions is calculated. ► Feasible changes in the mix of inputs and byproducts can reduce GHG emissions. ► On average plants may be able to reduce GHG emissions by 2.94 Gg per quarter. ► GHG reductions may be achieved at a moderate or zero operating cost.

  3. Nucleoside adducts are formed by cooperative reaction of acetaldehyde and alcohols: Possible mechanism for the role of ethanol in carcinogenesis

    International Nuclear Information System (INIS)

    Fraenkel-Conrat, H.; Singer, B.

    1988-01-01

    The exocyclic amino groups of ribonucleosides and deoxyribonucleosides react rapidly at ambient temperature with acetaldehyde and alcohols to yield mixed acetals [-NH-CH(CH 3 )OR]. Nucleotides and nucleoside di- and triphosphates also react. Depending on the nucleoside used and on the relative amounts of aldehyde, alcohol, and water, preparative reactions reach equilibrium with yields up to 75% in a few house. The structures have been confirmed by fast atom bombardment MS and proton NMR. Half-lives at 37 degree C have been determined, and maximum stability is in the pH range of 7.5-9.5. In the absence of alcohol, acetaldehyde-nucleoside adducts could be isolated at 4 degree C, but these were too unstable to characterize except for their UV spectra, also at 4 degree C. Ethanol is often present in human blood and tissues, and acetaldehyde is its initial metabolic product, as well as being formed by many other metabolic processes. Both chemicals have separately been implicated in carcinogenic and other cytophathologic processes, but no cooperative mechanism has been proposed. The reactions reported here are of biological concern because they also occur in dilute aqueous solution. These finding supply a mechanism by which ethanol can be covalently bound to nucleic acids under physiological conditions

  4. Comparative environmental performance of lignocellulosic ethanol from different feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, Sara; Moreira, M. Teresa; Feijoo, Gumersindo [Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2010-09-15

    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 raw materials is considered the most potential next generation automotive fuel. In this paper, a Life Cycle Assessment model was developed to evaluate the environmental implications of the production of ethanol from five lignocellulosic materials: alfalfa stems, poplar, Ethiopian mustard, flax shives and hemp hurds and its use in passenger cars. Two ethanol-based fuel applications, E10 (a mixture of 10% ethanol and 90% gasoline by volume) and E85 (85% ethanol and 15% gasoline by volume) were assessed and the results were compared to those of conventional gasoline (CG) in an equivalent car. The environmental performance was assessed in terms of fossil fuels requirements, global warming, photochemical oxidant formation, acidification and eutrophication by means of the Life Cycle Assessment (LCA) methodology in order to identify the best environmental friendly lignocellulosic source. The results show that, compared to CG, life cycle greenhouse gases emissions are lower for etanol blends, specifically up to 145% lower for E85-fueled car derived from Ethiopian mustard. This crop is also the best option in terms of eutrophying emissions regardless the ratio of ethanol in the blend. In the remaining impact categories, other feedstocks are considered beneficial, that is, poplar in the case of photochemical oxidants formation and flax shives for acidification. Concerning fossil fuels requirements, decreases up to 10% and 63% for E10 and E85 derived from hemp hurds and Ethiopian mustard, respectively, were obtained. According to the results, the study clearly demonstrates the importance of using low intensive energy and high biomass yield crops. LCA procedure helps to identify the key areas in the ethanol production life cycle where the researchers and technicians need to work

  5. 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.

  6. Scale-up and integration of alkaline hydrogen peroxide pretreatment, enzymatic hydrolysis, and ethanolic fermentation.

    Science.gov (United States)

    Banerjee, Goutami; Car, Suzana; Liu, Tongjun; Williams, Daniel L; Meza, Sarynna López; Walton, Jonathan D; Hodge, David B

    2012-04-01

    Alkaline hydrogen peroxide (AHP) has several attractive features as a pretreatment in the lignocellulosic biomass-to-ethanol pipeline. Here, the feasibility of scaling-up the AHP process and integrating it with enzymatic hydrolysis and fermentation was studied. Corn stover (1 kg) was subjected to AHP pretreatment, hydrolyzed enzymatically, and the resulting sugars fermented to ethanol. The AHP pretreatment was performed at 0.125 g H(2) O(2) /g biomass, 22°C, and atmospheric pressure for 48 h with periodic pH readjustment. The enzymatic hydrolysis was performed in the same reactor following pH neutralization of the biomass slurry and without washing. After 48 h, glucose and xylose yields were 75% and 71% of the theoretical maximum. Sterility was maintained during pretreatment and enzymatic hydrolysis without the use of antibiotics. During fermentation using a glucose- and xylose-utilizing strain of Saccharomyces cerevisiae, all of the Glc and 67% of the Xyl were consumed in 120 h. The final ethanol titer was 13.7 g/L. Treatment of the enzymatic hydrolysate with activated carbon prior to fermentation had little effect on Glc fermentation but markedly improved utilization of Xyl, presumably due to the removal of soluble aromatic inhibitors. The results indicate that AHP is readily scalable and can be integrated with enzyme hydrolysis and fermentation. Compared to other leading pretreatments for lignocellulosic biomass, AHP has potential advantages with regard to capital costs, process simplicity, feedstock handling, and compatibility with enzymatic deconstruction and fermentation. Biotechnol. Bioeng. 2012; 109:922-931. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

  7. 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)

  8. A combined experimental and theoretical study on ethanol conversion to propylene over Y/ZrO2 catalyst

    Science.gov (United States)

    Wang, Fangfang; Xia, Wei; Mu, Xichuan; Chen, Kun; Si, Huimin; Li, Zhihao

    2018-05-01

    ZrO2-based catalysts doped with Y were prepared by co-precipitation method. The effect of yttrium modification on the selective conversion of bio-ethanol to propylene over ZrO2 catalysts was investigated. The physical and chemical properties of the catalysts were characterized by N2 adsorption-desorption method, temperature programmed desorption and X-ray diffraction. The maximum yield of propylene reached 44.0% over 0.03Y/ZrO2 catalyst. A coordination of acid-base properties accounts for the remarkable improvement of reaction activities over Y-doped ZrO2 catalysts in this investigation. On the basis of calculation results, it can be concluded that significant charge transfer occurs as a result of introduction of Y or O-vacancy. The adsorption of ethanol and propylene on perfect t-ZrO2 (1 0 1), defect t-ZrO2 (1 0 1) and Y/ZrO2 (1 0 1) surfaces were investigated with density functional theory (DFT). The adsorption for ethanol on Y/ZrO2 (1 0 1) and defect t-ZrO2 (1 0 1) surfaces are more stable than that on perfect t-ZrO2 (1 0 1). On the defect t-ZrO2 (1 0 1) surface, ethanol dominantly absorbs at the O-vacancy site, indicating that O-vacancy becomes the favorable adsorption site. On the Y/ZrO2 (1 0 1) and defect t-ZrO2 (1 0 1) surfaces, the adsorption energy of propylene decreases, which makes propylene desorb quickly after formation.

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

    Science.gov (United States)

    Sun, May Yongmei

    was 25--44g/L-hr (based on reactor volume), the average yield was 0.45 g ethanol/g starch, the biocatalyst retained physical integrity and contamination did not affect fermentation. For the Z. mobilis system the maximum volumetric productivity was 38 g ethanol/L-h, the average yield was 0.51 g ethanol/g starch and the FBR was successfully operated for almost one month. In order to develop, scale-up and economically evaluate this system more efficiently, a predictive mathematical model that is based on fundamental principles was developed and verified. This model includes kinetics of reactions, transport phenomena of the reactant and product by diffusion within the biocatalyst bead, and the hydrodynamics of the three phase fluidized bed. The co-immobilized biocatalyst involves a consecutive reaction mechanism The mathematical descriptions of the effectiveness factors of reactant and the intermediate product were developed. Hydrodynamic literature correlations were used to develop the dispersion coefficient and gas, liquid, and solid holdup. The solutions of coupled non-linear second order equations for biocatalyst bead and reactor together with the boundary conditions were solved numerically. This model gives considerable information about the system, such as concentration profiles inside both the beads and column, flow rate and feed concentration influences on productivity and phase hold up, and the influence of enzyme and cell mass loading in the catalyst. This model is generic in nature such that it can be easily applied to a diverse set of applications and operating conditions.

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

    Science.gov (United States)

    Jessen, Jan Eric; Orlygsson, Johann

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jan Eric Jessen

    2012-01-01

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

  12. Subcritical ethanol extraction of flavonoids from Moringa oleifera leaf and evaluation of antioxidant activity.

    Science.gov (United States)

    Wang, Yongqiang; Gao, Yujie; Ding, Hui; Liu, Shejiang; Han, Xu; Gui, Jianzhou; Liu, Dan

    2017-03-01

    A large-scale process to extract flavonoids from Moringa oleifera leaf by subcritical ethanol was developed and HPLC-MS analysis was conducted to qualitatively identify the compounds in the extracts. To optimize the effects of process parameters on the yield of flavonoids, a Box-Behnken design combined with response surface methodology was conducted in the present work. The results indicated that the highest extraction yield of flavonoids by subcritical ethanol extraction could reach 2.60% using 70% ethanol at 126.6°C for 2.05h extraction. Under the optimized conditions, flavonoids yield was substantially improved by 26.7% compared with the traditional ethanol reflux method while the extraction time was only 2h, and obvious energy saving was observed. FRAP and DPPH assays showed that the extracts had strong antioxidant and free radical scavenging activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Biological Conversion of Glycerol to Ethanol by Enterobacter aerogenes

    Science.gov (United States)

    Nwachukwu, Raymond E. S.

    In a search to turn the economically and environmentally non-valuable "waste" streams of biodiesel production into a profitable byproduct, a mutant strain of Enterobacter aerogenes ATCC 13048 was developed by six-tube subculturing technique. This technique is based on the principle of adaptive evolution, and involved subculturing the bacterium in a tryptic soy broth without dextrose (TSB) containing specific glycerol and ethanol concentration for six consecutive times. Then, the six consecutive subculturing was repeated in a fresh TSB of higher glycerol and ethanol concentrations. A new mutant strain, E. aerogenes S012, which could withstand a combination of 200 g/l glycerol and 30 g/l ethanol concentrations, was developed. The wild and mutant strains were used for the fermentation of pure (P-) and recovered (R-) glycerol. Taguchi and full factorial methods of design of experiments were used to screen and optimize the important process factors that influence the microbial production of ethanol. A statistically sound regression model was used to establish the mathematical relationship between the process variables and ethanol production. Temperature of 38°C, agitation speed of 200 rpm, pH of 6.3-6.6, and microaerobic condition were the optimum process conditions. Different pretreatment methods to recover glycerol from the crude glycerol and the subsequent fermentation method showed that direct acidification using 85% H3PO4 was the best. The R-glycerol contained 51% pure glycerol and 21% methanol. The wild strain, E. aerogenes ATCC 13048, produced only 12 g/l and 12.8 g/l ethanol from 20 g/l P- and R-glycerol respectively, and could not utilize higher glycerol concentrations. The mutant, E. aerogenes S012, produced ethanol amount and yield of 43 g/l and 1.12 mol/mol-glycerol from P-glycerol, respectively within 96 h. It also produced ethanol amount and yield of 26.8 g/l and 1.07 mol/mol-glycerol, respectively, from R-glycerol within the same duration. In a

  14. Antifungal activities of ethanolic extract from Jatropha curcas seed cake.

    Science.gov (United States)

    Saetae, Dolaporn; Suntornsuk, Worapot

    2010-02-01

    Phorbol ester extraction was carried out from Jatropha curcas seed cake, a by-product from the bio-diesel fuel industry. Four repeated extractions from 5 g J. curcas seed cake using 15 ml of 90% (v/v) ethanol and a shaking speed of 150 rev/min gave the highest yield of phosbol esters. The ethanolic extract of J. curcas seed cake showed antifungal activities against important phytofungal pathogens: Fusarium oxysporum, Pythium aphanidermatum, Lasiodiplodia theobromae, Curvularia lunata, Fusarium semitectum, Colletotrichum capsici and Colletotrichum gloeosporiodes. The extract contained phorbol esters mainly responsible for antifungal activities. The extract could therefore be used as an antifungal agent for agricultural applications.

  15. 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

  16. 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, ...

  17. Alternative Fuels Data Center: Ethanol Fueling Stations

    Science.gov (United States)

    ... More in this section... Ethanol Basics Benefits & Considerations Stations Locations Infrastructure fueling stations by location or along a route. Infrastructure Development Learn about ethanol fueling infrastructure; codes, standards, and safety; and ethanol equipment options. Maps & Data E85 Fueling Station

  18. 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.

  19. Metabolomics-based prediction models of yeast strains for screening of metabolites contributing to ethanol stress tolerance

    Science.gov (United States)

    Hashim, Z.; Fukusaki, E.

    2016-06-01

    The increased demand for clean, sustainable and renewable energy resources has driven the development of various microbial systems to produce biofuels. One of such systems is the ethanol-producing yeast. Although yeast produces ethanol naturally using its native pathways, production yield is low and requires improvement for commercial biofuel production. Moreover, ethanol is toxic to yeast and thus ethanol tolerance should be improved to further enhance ethanol production. In this study, we employed metabolomics-based strategy using 30 single-gene deleted yeast strains to construct multivariate models for ethanol tolerance and screen metabolites that relate to ethanol sensitivity/tolerance. The information obtained from this study can be used as an input for strain improvement via metabolic engineering.

  20. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  1. 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.

  2. Brazilian third world ethanol pilot

    Energy Technology Data Exchange (ETDEWEB)

    Butler, P

    1981-01-01

    A financial cost model has been developed in Brazil, under contract from th United Nations Industrial Development Organization, for fermentation ethanol production based on sugar cane molasses, sugar cane juice and cassava. The model is designed to help in analysing the feasibility and implementation of ethanol programs in developing countries.

  3. Ethanol from mixed waste paper

    International Nuclear Information System (INIS)

    Kerstetter, J.D.; Lyons, J.K.

    1991-01-01

    The technology, markets, and economics for converting mixed waste paper to ethanol in Washington were assessed. The status of enzymatic and acid hydrolysis projects were reviewed. The market for ethanol blended fuels in Washington shows room for expansion. The economics for a hypothetical plant using enzymatic hydrolysis were shown to be profitable

  4. Reactions of ethanol on Ru

    NARCIS (Netherlands)

    Sturm, Jacobus Marinus; Liu, Feng; Lee, Christopher James; Bijkerk, Frederik

    2012-01-01

    The adsorption and reactions of ethanol on Ru(0001) were studied with temperatureprogrammed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. Heating to 250 K resulted in formation of ethoxy groups, which undergo

  5. Alumina Yield in the Bayer Process

    Science.gov (United States)

    Den Hond, R.

    The alumina industry has historically been able to reduce alumina production costs, by increasing the liquor alumina yield. To know the potential for further yield increases, the phase diagram of the ternary system Na2O-Al2O -H2O at various temperature levels was analysed. It was found that the maximum theorical precipitation alumina yield is 160 g/l, while that for digestion was calculated to be 675 g/l.

  6. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  7. A Development of Ethanol/Percarbonate Membraneless Fuel Cell

    Directory of Open Access Journals (Sweden)

    M. Priya

    2014-01-01

    Full Text Available The electrocatalytic oxidation of ethanol on membraneless sodium percarbonate fuel cell using platinum electrodes in alkaline-acidic media is investigated. In this cell, ethanol is used as the fuel and sodium percarbonate is used as an oxidant for the first time in an alkaline-acidic media. Sodium percarbonate generates hydrogen peroxide in aqueous medium. At room temperature, the laminar-flow-based microfluidic membraneless fuel cell can reach a maximum power density of 18.96 mW cm−2 with a fuel mixture flow rate of 0.3 mL min−2. The developed fuel cell features no proton exchange membrane. The simple planar structured membraneless ethanol fuel cell presents with high design flexibility and enables easy integration of the microscale fuel cell into actual microfluidic systems and portable power applications.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  13. The Role of Molecule Clustering by Hydrogen Bond in Hydrous Ethanol on Laminar Burning Velocity

    Directory of Open Access Journals (Sweden)

    I Made Suarta

    2016-01-01

    Full Text Available The role of hydrogen bond molecule clustering in laminar burning velocities was observed. The water in hydrous ethanol can change the interaction between water-ethanol molecules. A certain amount of water can become oxygenated which increases the burning velocity. The hydrogen bond interaction pattern of ethanol and water molecules was modeled. Based on the molecular model, azeotropic behavior emerges from ethanol-water hydrogen bond, which is at a 95.1%v composition. The interaction with water molecule causes the ethanol molecule to be clustered with centered oxygenated compound. So, it supplies extra oxygen and provides intermolecular empty spaces that are easily infiltrated by the air. In the azeotropic composition, the molecular bond chain is the shortest, so hypothetically the burning velocity is anticipated to increase. The laminar burning velocity of ethanol fuel was tested in a cylindrical explosion bomb in lean, stoichiometric, and rich mixtures. The experimental result showed that the maximum burning velocity occurred at hydrous ethanol of 95.5%v composition. This discrepancy is the result of the addition of energy from 7.7% free ethanol molecules that are not clustered. At the rich mixture, the burning velocity of this composition is higher than that of anhydrous ethanol.

  14. Ethanol fermentation with Kluyveromyces marxianus from Jerusalem artichoke grown in salina and irrigated with a mixture of seawater and freshwater.

    Science.gov (United States)

    Yuan, W J; Zhao, X Q; Ge, X M; Bai, F W

    2008-12-01

    To study fuel ethanol fermentation with Kluyveromyces marxianus ATCC8554 from Jerusalem artichoke (Helianthus tuberosus) grown in salina and irrigated with a mixture of seawater and freshwater. The growth and ethanol fermentation of K. marxianus ATCC8554 were studied using inulin as substrate. The activity of inulinase, which attributes to the hydrolysis of inulin, the main carbohydrate in Jerusalem artichoke, was monitored. The optimum temperatures were 38 degrees C for growth and inulinase production, and 35 degrees C for ethanol fermentation. Aeration was not necessary for ethanol fermentation with the K. marxianus from inulin. Then, the fresh Jerusalem artichoke tubers grown in salina and irrigated with 25% and 50% seawater were further examined for ethanol fermentation with the K. marxianus, and a higher ethanol yield was achieved for the Jerusalem artichoke tuber irrigated with 25% seawater. Furthermore, the dry meal of the Jerusalem artichoke tubers irrigated with 25% seawater was examined for ethanol fermentation at three solid concentrations of 200, 225 and 250 g l(-1), and the highest ethanol yield of 0.467, or 91.5% of the theoretical value of 0.511, was achieved for the slurry with a solid concentration of 200 g l(-1). Halophilic Jerusalem artichoke can be used for fuel ethanol production. Halophilic Jerusalem artichoke, not competing with grain crops for arable land, is a sustainable feedstock for fuel ethanol production.

  15. 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.

  16. The state of autotrophic ethanol production in Cyanobacteria.

    Science.gov (United States)

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

    2015-07-01

    Ethanol production directly from CO2 , utilizing genetically engineered photosynthetic cyanobacteria as a biocatalyst, offers significant potential as a renewable and sustainable source of biofuel. Despite the current absence of a commercially successful production system, significant resources have been deployed to realize this goal. Utilizing the pyruvate decarboxylase from Zymomonas species, metabolically derived pyruvate can be converted to ethanol. This review of both peer-reviewed and patent literature focuses on the genetic modifications utilized for metabolic engineering and the resultant effect on ethanol yield. Gene dosage, induced expression and cassette optimizat-ion have been analyzed to optimize production, with production rates of 0·1-0·5 g L(-1) day(-1) being achieved. The current 'toolbox' of molecular manipulations and future directions focusing on applicability, addressing the primary challenges facing commercialization of cyanobacterial technologies are discussed. © 2015 The Society for Applied Microbiology.

  17. 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.

  18. 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....

  19. Performance of direct alcohol fuel cells fed with mixed methanol/ethanol solutions

    Energy Technology Data Exchange (ETDEWEB)

    Wongyao, N. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand); Therdthianwong, A., E-mail: apichai.the@kmutt.ac.t [Fuel Cell and Hydrogen Research and Engineering Center, Clean Energy System Group, PDTI, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand); Therdthianwong, S. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand)

    2011-07-15

    Research highlights: {yields} We examined the performance of direct alcohol fuel cells fed with mixed alcohol. {yields} PtRu-PtSn/C and PtRu/C as catalysts for mixed alcohol electrooxidation reaction. {yields} Misplace adsorption of ethanol on PtRu/C caused the cell performance drop. {yields} PtRu/C showed higher performance than PtRu-PtSn/C for mixed alcohol fuel. -- Abstract: In combining the advantages of both methanol and ethanol, direct alcohol fuel cells fed with mixed alcohol solutions (1 M methanol and 1 M ethanol in varying volume ratios) were tested for performance. Employing a PtRu-PtSn/C catalyst as anode, cell performance was found to diminish rapidly even at 2.5% by volume ethanol mixture. Further increase of ethanol exceeded 10%, the cell performance gradually decreased and finally approached that of direct ethanol fuel cells. The causes of the decrease in the cell performance were the slow electro-oxidation of ethanol and the misplaced adsorption of ethanol on PtRu/C. By comparing the PtRu-PtSn/C cell with the PtRu/C cell operated with mixed alcohol solutions, the cell using PtRu/C as an anode catalyst provided higher power density since more PtRu/C surface was available for methanol oxidation reaction and less ohmic resistance of PtRu/C than that of PtRu-PtSn/C. In order to reach optimization of DAFC performance fed with mixed alcohol, the electrocatalyst used for the anode must selectively adsorb an alcohol, especially ethanol.

  20. Ethylphenidate as a selective dopaminergic agonist and methylphenidate-ethanol transesterification biomarker.

    Science.gov (United States)

    Patrick, Kennerly S; Corbin, Timothy R; Murphy, Cristina E

    2014-12-01

    We review the pharmaceutical science of ethylphenidate (EPH) in the contexts of drug discovery, drug interactions, biomarker for dl-methylphenidate (MPH)-ethanol exposure, potentiation of dl-MPH abuse liability, contemporary "designer drug," pertinence to the newer transdermal and chiral switch MPH formulations, as well as problematic internal standard. d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters. This selectivity carries implications for the advancement of tailored attention-deficit/hyperactivity disorder (ADHD) pharmacotherapy in the era of genome-based diagnostics. Abuse of dl-MPH often involves ethanol coabuse. Carboxylesterase 1 enantioselectively transesterifies l-MPH with ethanol to yield l-EPH accompanied by significantly increased early exposure to d-MPH and rapid potentiation of euphoria. The pharmacokinetic component of this drug interaction can largely be avoided using dexmethylphenidate (dexMPH). This notwithstanding, maximal potentiated euphoria occurs following dexMPH-ethanol. C57BL/6 mice model dl-MPH-ethanol interactions: an otherwise depressive dose of ethanol synergistically increases dl-MPH stimulation; a substimulatory dose of dl-MPH potentiates a low, stimulatory dose of ethanol; ethanol elevates blood, brain, and urinary d-MPH concentrations while forming l-EPH. Integration of EPH preclinical neuropharmacology with clinical studies of MPH-ethanol interactions provides a translational approach toward advancement of ADHD personalized medicine and management of comorbid alcohol use disorder. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. Lignocellulosic ethanol: Technology design and its impact on process efficiency.

    Science.gov (United States)

    Paulova, Leona; Patakova, Petra; Branska, Barbora; Rychtera, Mojmir; Melzoch, Karel

    2015-11-01

    This review provides current information on the production of ethanol from lignocellulosic biomass, with the main focus on relationships between process design and efficiency, expressed as ethanol concentration, yield and productivity. In spite of unquestionable advantages of lignocellulosic biomass as a feedstock for ethanol production (availability, price, non-competitiveness with food, waste material), many technological bottlenecks hinder its wide industrial application and competitiveness with 1st generation ethanol production. Among the main technological challenges are the recalcitrant structure of the material, and thus the need for extensive pretreatment (usually physico-chemical followed by enzymatic hydrolysis) to yield fermentable sugars, and a relatively low concentration of monosaccharides in the medium that hinder the achievement of ethanol concentrations comparable with those obtained using 1st generation feedstocks (e.g. corn or molasses). The presence of both pentose and hexose sugars in the fermentation broth, the price of cellulolytic enzymes, and the presence of toxic compounds that can inhibit cellulolytic enzymes and microbial producers of ethanol are major issues. In this review, different process configurations of the main technological steps (enzymatic hydrolysis, fermentation of hexose/and or pentose sugars) are discussed and their efficiencies are compared. The main features, benefits and drawbacks of simultaneous saccharification and fermentation (SSF), simultaneous saccharification and fermentation with delayed inoculation (dSSF), consolidated bioprocesses (CBP) combining production of cellulolytic enzymes, hydrolysis of biomass and fermentation into one step, together with an approach combining utilization of both pentose and hexose sugars are discussed and compared with separate hydrolysis and fermentation (SHF) processes. The impact of individual technological steps on final process efficiency is emphasized and the potential for use

  2. 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.

  3. Biomass Supply Chain and Conversion Economics of Cellulosic Ethanol

    Science.gov (United States)

    Gonzalez, Ronalds W.

    2011-12-01

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

  4. Transesterification of waste vegetable oil under pulse sonication using ethanol, methanol and ethanol–methanol mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar, E-mail: gude@cee.msstate.edu

    2014-12-15

    Highlights: • Pulse sonication effect on transesterification of waste vegetable oil was studied. • Effects of ethanol, methanol, and alcohol mixtures on FAMEs yield were evaluated. • Effect of ultrasonic intensity, power density, and its output rates were evaluated. • Alcohol mixtures resulted in higher biodiesel yields due to better solubility. - Abstract: This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol–methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol–methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1–2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol–methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.

  5. Metabolic characterization and transformation of the non-dairy Lactococcus lactis strain KF147, for production of ethanol from xylose

    DEFF Research Database (Denmark)

    Petersen, Kia Vest; Liu, Jianming; Chen, Jun

    2017-01-01

    producing ethanol as the sole fermentation product with a high yield corresponding to 83% of the theoretical maximum. The results clearly indicate the great potential of using the more metabolically diverse non-dairy L. lactis strains for bio-production based on xylose containing feedstocks.......The non-dairy lactic acid bacterium Lactococcus lactis KF147 can utilize xylose as the sole energy source. To assess whether KF147 could serve as a platform organism for converting second generation sugars into useful chemicals, we characterized growth and product formation for KF147 when grown...... the arcA gene encoding the arginine deiminase. The fermentation product profile suggested two routes for xylose degradation, the phosphoketolase pathway and the pentose phosphate pathway. Inactivation of the phosphoketolase pathway redirected the entire flux through the pentose phosphate pathway whereas...

  6. Development of nanosized electrocatalysts for direct ethanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mohamedi, M. [Institut National de la Recherche Scientifique, Varennes, PQ (Canada). Centre de l' Energie, Materiaux et Telecommunications

    2008-07-01

    Fuel cells have been touted as a promising power supply for automotive, portable or stationary use. Although methanol is a strong contender as an alternative fuel, the extensive use of this toxic compound is not practical due to environmental hazards. Ethanol is a good substitute because it has a very positive environmental, health, and safety footprint with no major uncertainties or hazards. Ethanol is a hydrogen-rich liquid which has more energy density than methanol. The C-C bond has a determining effect on fuel cell efficiency and the theoretical energy yield. Therefore, a good electrocatalyst towards the complete oxidation of ethanol must activate the C-C bond breaking while avoiding the poisoning of the catalytic surface by carbon monoxide species that occurs with methanol oxidation. The objective of this study was to develop new catalyst nanoparticles of well-controlled shape, size, and composition with excellent stability and better electrocatalytic activity. This paper described the recent achievements regarding the development of a series of PtxSn100-x catalysts prepared by pulsed laser deposition (PLD). It reported on the effect of several deposition parameters on the structure and properties of the deposited catalysts. It also described how these deposition conditions affect the electrocatalytic response of the resulting materials toward ethanol oxidation. Some interesting periodic oscillations were observed at some catalysts during ethanol electrooxidation. 7 refs., 1 fig.

  7. ETHANOL PRECIPITATION OF GLYCOSYL HYDROLASES PRODUCED BY Trichoderma harzianum P49P11

    Directory of Open Access Journals (Sweden)

    M. A. Mariño

    2015-06-01

    Full Text Available AbstractThis study aimed to concentrate glycosyl hydrolases produced by Trichoderma harzianum P49P11 by ethanol precipitation. The variables tested besides ethanol concentration were temperature and pH. The precipitation with 90% (v/v ethanol at pH 5.0 recovered more than 98% of the xylanase activity, regard less of the temperature (5.0, 15.0, or 25.0 °C. The maximum recovery of cellulase activity as FPase was 77% by precipitation carried out at this same pH and ethanol concentration but at 5.0 °C. Therefore, ethanol precipitation can be considered to be an efficient technique for xylanase concentration and, to a certain extent, also for the cellulase complex.

  8. Very high gravity ethanol fermentation by flocculating yeast under redox potential-controlled conditions

    Directory of Open Access Journals (Sweden)

    Liu Chen-Guang

    2012-08-01

    Full Text Available Abstract Background Very high gravity (VHG fermentation using medium in excess of 250 g/L sugars for more than 15% (v ethanol can save energy consumption, not only for ethanol distillation, but also for distillage treatment; however, stuck fermentation with prolonged fermentation time and more sugars unfermented is the biggest challenge. Controlling redox potential (ORP during VHG fermentation benefits biomass accumulation and improvement of yeast cell viability that is affected by osmotic pressure and ethanol inhibition, enhancing ethanol productivity and yield, the most important techno-economic aspect of fuel ethanol production. Results Batch fermentation was performed under different ORP conditions using the flocculating yeast and media containing glucose of 201 ± 3.1, 252 ± 2.9 and 298 ± 3.8 g/L. Compared with ethanol fermentation by non-flocculating yeast, different ORP profiles were observed with the flocculating yeast due to the morphological change associated with the flocculation of yeast cells. When ORP was controlled at −100 mV, ethanol fermentation with the high gravity (HG media containing glucose of 201 ± 3.1 and 252 ± 2.9 g/L was completed at 32 and 56 h, respectively, producing 93.0 ± 1.3 and 120.0 ± 1.8 g/L ethanol, correspondingly. In contrast, there were 24.0 ± 0.4 and 17.0 ± 0.3 g/L glucose remained unfermented without ORP control. As high as 131.0 ± 1.8 g/L ethanol was produced at 72 h when ORP was controlled at −150 mV for the VHG fermentation with medium containing 298 ± 3.8 g/L glucose, since yeast cell viability was improved more significantly. Conclusions No lag phase was observed during ethanol fermentation with the flocculating yeast, and the implementation of ORP control improved ethanol productivity and yield. When ORP was controlled at −150 mV, more reducing power was available for yeast cells to survive, which in turn improved their viability and VHG

  9. Optimization studies for the bioconversion of Jerusalem artichoke tubers to ethanol and microbial biomass

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.; Cannell, E.

    1981-01-01

    A total of 8 yeast and other microbial cultures were grown in the extract derived from the tubers of Jerusalem artichoke (Helianthus tuberosus) and screened according to the following optimization criteria: rates and yields of ethanol production, rates and yields of biomass production, and percent of original sugars utilized during fermentation. Batch growth kinetic parameters were also determined for the cultures studied. Kluyveromyces marxianus UCD (FST) 55-82 had the highest specific growth rate, 0.41/h, with a high ethanol yield, 88% of theoretical.

  10. 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.

  11. 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).

  12. Xylose fermentation to biofuels (hydrogen and ethanol) by extreme thermophilic (70 C) mixed culture

    DEFF Research Database (Denmark)

    Chenxi, Zhao; Karakashev, Dimitar Borisov; Lu, W.

    2010-01-01

    -xylose corresponding to 55% of the theoretical hydrogen yield based on acetate metabolic pathway. An empirical model was established to reveal the quantitative effect of factors significant for biohydrogen (quadratic model) production and for bioethanol (linear model) production. Changes in hydrogen/ethanol yields...

  13. Enhanced ethanol production by fermentation of Gelidium amansii hydrolysate using a detoxification process and yeasts acclimated to high-salt concentration.

    Science.gov (United States)

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Yung; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-01

    A total monosaccharide concentration of 59.0 g/L, representing 80.1 % conversion of 73.6 g/L total fermentable sugars from 160 g dw/L G. amansii slurry was obtained by thermal acid hydrolysis and enzymatic hydrolysis. Subsequent adsorption treatment using 5 % activated carbon with an adsorption time of 2 min was used to prevent the inhibitory effect of 5-hydroxymethylfurfural (HMF) >5 g/L in the medium. Ethanol production decreased with increasing salt concentration using C. tropicalis KCTC 7212 non-acclimated or acclimated to a high concentration of salt. Salt concentration of 90 psu was the maximum concentration for cell growth and ethanol production. The levels of ethanol production by C. tropicalis non-acclimated or acclimated to 90 psu high-salt concentration were 13.8 g/L with a yield (YEtOH) of 0.23, and 26.7 g/L with YEtOH of 0.45, respectively.

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

    Science.gov (United States)

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

    2009-02-01

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

  15. Yield performance of brassica varieties under rainfed condition

    International Nuclear Information System (INIS)

    Hassan, M.Z.U.; Wahla, A.J.; Waqar, M.Q.

    2014-01-01

    A field study was conducted to evaluate crop growth and seed yield performance of Brassica varieties under Rainfed conditions. The varieties, included in the study, were BSA, Zafar-2000, Pakola, Con.1, Con.2, Abaseen, Rainbow, SPS-5, Bard-1, and KJ-119. KJ-119 (2500.0 KG/HA) among Brassica juncea L. varieties and Abaseen (2425.9 kg/ha) among Brassica napusL. Varieties produced with maximum seed yield as compared to rest of varieties. Significantly, minimum seed yield was observed in check variety BSA. The significant difference in seed yield of Brassica varieties, Abaseen and KJ 119, was attributed to improve yield components over other varieties. Maximum pods per plant and seeds per pod led these varieties to attain maximum yield. Inspite of weather variations existence during years 2007-09,the same varieties produced with maximum seed yield. (author)

  16. Catalytic Ethanol Dehydration over Different Acid-activated Montmorillonite Clays.

    Science.gov (United States)

    Krutpijit, Chadaporn; Jongsomjit, Bunjerd

    2016-01-01

    In the present study, the catalytic dehydration of ethanol to obtain ethylene over montmorillonite clays (MMT) with mineral acid activation including H2SO4 (SA-MMT), HCl (HA-MMT) and HNO3 (NA-MMT) was investigated at temperature range of 200 to 400°C. It revealed that HA-MMT exhibited the highest catalytic activity. Ethanol conversion and ethylene selectivity were found to increase with increased reaction temperature. At 400°C, the HA-MMT yielded 82% of ethanol conversion having 78% of ethylene yield. At lower temperature (i.e. 200 to 300°C), diethyl ether (DEE) was a major product. The highest activity obtained from HA-MMT can be attributed to an increase of weak acid sites and acid density by the activation of MMT with HCl. It can be also proven by various characterization techniques that in most case, the main structure of MMT did not alter by acid activation (excepted for NA-MMT). Upon the stability test for 72 h during the reaction, the MMT and HA-MMT showed only slight deactivation due to carbon deposition. Hence, the acid activation of MMT by HCl is promising to enhance the catalytic dehydration of ethanol.

  17. 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.

  18. Yeast selection for fuel ethanol production in Brazil.

    Science.gov (United States)

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

    2008-11-01

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

  19. 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

  20. Thermophilic ethanol fermentation from lignocellulose hydrolysate by genetically engineered Moorella thermoacetica.

    Science.gov (United States)

    Rahayu, Farida; Kawai, Yuto; Iwasaki, Yuki; Yoshida, Koichiro; Kita, Akihisa; Tajima, Takahisa; Kato, Junichi; Murakami, Katsuji; Hoshino, Tamotsu; Nakashimada, Yutaka

    2017-12-01

    A transformant of Moorella thermoacetica was constructed for thermophilic ethanol production from lignocellulosic biomass by deleting two phosphotransacetylase genes, pdul1 and pdul2, and introducing the native aldehyde dehydrogenase gene (aldh) controlled by the promoter from glyceraldehyde-3-phosphate dehydrogenase. The transformant showed tolerance to 540mM and fermented sugars including fructose, glucose, galactose and xylose to mainly ethanol. In a mixed-sugar medium of glucose and xylose, all of the sugars were consumed to produce ethanol at the yield of 1.9mol/mol-sugar. The transformant successfully fermented sugars in hydrolysate prepared through the acid hydrolysis of lignocellulose to ethanol, suggesting that this transformant can be used to ferment the sugars in lignocellulosic biomass for ethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 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.

  2. 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.

  3. Net energy value of maize ethanol as a response to different climate and soil conditions in the southeastern USA

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tomas; Garcia y Garcia, Axel; Paz, Joel O.; Hoogenboom, Gerrit [Department of Biological and Agricultural Engineering, 1109 Experiment Street, The University of Georgia, Griffin, GA 30223 (United States); Jones, James W. [Department of Agricultural and Biological Engineering, Frazier Rogers Hall, University of Florida, Gainesville, FL 32611 (United States)

    2009-08-15

    A recent increase in the demand for bio-ethanol has sparked maize production in the USA and other countries across the world. The net energy value (NEV), i.e. the energy output in ethanol and co-products after accounting for energy input requirements in the production chain of ethanol, is a measure of its sustainability. Grain yield of maize, which varies substantially across different climate and soil conditions, greatly impacts the ethanol NEV. The objectives of this study were to determine i) the NEV of ethanol produced from maize grown in four production regions in the southeastern USA and, ii) the specific impact of local soil variability under the same climate conditions within the four regions on the NEV of maize-ethanol. Maize yield was simulated with the Cropping System Model (CSM)-CERES-Maize model for soil and weather conditions, and management practices representing Bulloch, Floyd, Laurens and Mitchell counties, Georgia, USA. The calculation of ethanol NEV took into account the energy inputs and outputs of the entire ethanol production chain, and was based on the crop simulations. There were statistically significant differences in ethanol NEV among the counties, and within counties due to local soil variability. Differences in ethanol NEV among counties were partially due to different transportation distances. Based on the results of this study, it was concluded that maize-ethanol NEV can be increased by accounting for the soil and climate factors in the feedstock production and by locating ethanol-processing facilities in regions with soil and climate conditions that are favorable for ethanol-maize production. (author)

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Plant cell walls to ethanol.

    Science.gov (United States)

    Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation, and separation. Ultimately, it is desired to combine as man...

  9. ENERGY CHARACTERISTICS OF ETHANOL CHARACTERISTICS ...

    African Journals Online (AJOL)

    eobe

    CHARACTERISTICS OF ETHANOL-DIESEL MIX FOR AUTOMOTIVE. DIESEL ... diesel engine and the engine speed, torque, power and specific fuel consumption (sfc) were determine .... heated on an electric stove and stirred continuously.

  10. 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

  11. Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Rafaela de Fátima Ferreira [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Taipeiro, Elane de Fátima [Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Queiroz, Regina Helena Costa [Departamento de Análise Clínica - Toxicológica e Ciência de Alimentos - Faculdade de Ciências Farmacêuticas - USP, São Paulo, SP (Brazil); Chies, Agnaldo Bruno [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Cordellini, Sandra, E-mail: cordelli@ibb.unesp.br [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil)

    2014-03-15

    Stress and ethanol are both, independently, important cardiovascular risk factors. To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure.

  12. Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

    International Nuclear Information System (INIS)

    Baptista, Rafaela de Fátima Ferreira; Taipeiro, Elane de Fátima; Queiroz, Regina Helena Costa; Chies, Agnaldo Bruno; Cordellini, Sandra

    2014-01-01

    Stress and ethanol are both, independently, important cardiovascular risk factors. To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure

  13. 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...

  14. 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....

  15. 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.

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

    DEFF Research Database (Denmark)

    Szijarto, Nora; Kádár, Zsófia; Varga, Eniko

    2009-01-01

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

  18. Pulp and paper from oil palm fronds: Wavelet neural networks modeling of soda-ethanol pulping

    OpenAIRE

    Zarita Zainuddin; Wan Rosli Wan Daud; Pauline Ong; Amran Shafie

    2012-01-01

    Wavelet neural networks (WNNs) were used to investigate the influence of operational variables in the soda-ethanol pulping of oil palm fronds (viz. NaOH concentration (10-30%), ethanol concentration (15-75%), cooking temperature (150-190 ºC), and time (60-180 min)) on the resulting pulp and paper properties (viz. screened yield, kappa number, tensile index, and tear index). Performance assessments demonstrated the predictive capability of WNNs, in that the experimental results of the dependen...

  19. 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.

  20. 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.

  1. Ethanol effect on metabolic activity of the ethalogenic fungus Fusarium oxysporum.

    Science.gov (United States)

    Paschos, Thomas; Xiros, Charilaos; Christakopoulos, Paul

    2015-03-12

    Fusarium oxysporum is a filamentous fungus which has attracted a lot of scientific interest not only due to its ability to produce a variety of lignocellulolytic enzymes, but also because it is able to ferment both hexoses and pentoses to ethanol. Although this fungus has been studied a lot as a cell factory, regarding applications for the production of bioethanol and other high added value products, no systematic study has been performed concerning its ethanol tolerance levels. In aerobic conditions it was shown that both the biomass production and the specific growth rate were affected by the presence of ethanol. The maximum allowable ethanol concentration, above which cells could not grow, was predicted to be 72 g/L. Under limited aeration conditions the ethanol-producing capability of the cells was completely inhibited at 50 g/L ethanol. The lignocellulolytic enzymatic activities were affected to a lesser extent by the presence of ethanol, while the ethanol inhibitory effect appears to be more severe at elevated temperatures. Moreover, when the produced ethanol was partially removed from the broth, it led to an increase in fermenting ability of the fungus up to 22.5%. The addition of F. oxysporum's system was shown to increase the fermentation of pretreated wheat straw by 11%, in co-fermentation with Saccharomyces cerevisiae. The assessment of ethanol tolerance levels of F. oxysporum on aerobic growth, on lignocellulolytic activities and on fermentative performance confirmed its biotechnological potential for the production of bioethanol. The cellulolytic and xylanolytic enzymes of this fungus could be exploited within the biorefinery concept as their ethanol resistance is similar to that of the commercial enzymes broadly used in large scale fermentations and therefore, may substantially contribute to a rational design of a bioconversion process involving F. oxysporum. The SSCF experiments on liquefied wheat straw rich in hemicellulose indicated that the

  2. Fate of Fumonisin B1 in Naturally Contaminated Corn during Ethanol Fermentation

    OpenAIRE

    Bothast, R. J.; Bennett, G. A.; Vancauwenberge, J. E.; Richard, J. L.

    1992-01-01

    Two lots of corn naturally contaminated with fumonisin B1 (15 and 36 ppm) and a control lot (no fumonisin B1 detected) were used as substrates for ethanol production in replicate 8.5-liter yeast fermentations. Ethanol yields were 8.8% for both the control and low-fumonisin corn, while the high-fumonisin corn contained less starch and produced 7.2% ethanol. Little degradation of fumonisin occurred during fermentation, and most was recovered in the distillers' grains, thin stillage, and distill...

  3. Ethanol production from maize silage as lignocellulosic biomass in anaerobically digested and wet-oxidized manure

    DEFF Research Database (Denmark)

    Oleskowicz-Popiel, Piotr; Lisiecki, P.; Holm-Nielsen, J.B.

    2008-01-01

    was investigated using 2 1 bioreactors. Wet oxidation performed for 20 min at 121 degrees C was found as the most suitable pretreatment conditions for AD manure. High ammonia concentration and significant amount of macro- and micro-nutrients in the AD manure had a positive influence on the ethanol fermentation....... No extra nitrogen source was needed in the fermentation broth. It was shown that the AD manure could successfully substitute process water in SSF of pretreated lignocellulosic fibres. Theoretical ethanol yields of 82% were achieved, giving 30.8 kg ethanol per 100 kg dry mass of maize silage. (C) 2007...

  4. The Hydrocarbon Pool in Ethanol-to-Gasoline over HZSM-5 Catalysts

    DEFF Research Database (Denmark)

    Johansson, Roger; Hruby, S.L.; Hansen, Jeppe Rass

    2009-01-01

    It is shown that the conversion of ethanol-to-gasoline over an HZSM-5 catalyst yields essentially the same product distribution as for methanol-to-gasoline performed over the same catalyst. Interestingly, there is a significant difference between the identity of the hydrocarbon molecules trapped...... inside the HZSM-5 catalyst when ethanol is used as a feed instead of methanol. In particular, the hydrocarbon pool contains a significant amount of ethylsubstituted aromatics when ethanol is used as feedstock, but there remains only methyl-substituted aromatics in the product slate....

  5. 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

  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 and water adsorption in methanol-derived ZIF-71

    KAUST Repository

    Lively, Ryan P.; Dose, Michelle E.; Thompson, Joshua A.; McCool, Benjamin A.; Chance, Ronald R.; Koros, William J.

    2011-01-01

    A room temperature method for synthesizing zeolitic imidizolate framework 71 (ZIF-71) is described. The methanol-based synthesis results in >95% yields (based on Zn) and produces crystals with 70% greater surface area than reported earlier. Ethanol uptake into the ZIF compares favorably with a recent modeling-based study. Water uptake was significantly higher than model predictions. © The Royal Society of Chemistry 2011.

  8. Simultaneous saccharification and fermentation of alkaline-pretreated corn stover to ethanol using a recombinant yeast strain

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jing; Xia, Liming [Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2009-10-15

    Bio-ethanol converted from cheap and abundant lignocellulosic materials is a potential renewable resource to replace depleting fossil fuels. Simultaneous saccharification and fermentation (SSF) of alkaline-pretreated corn stover for the production of ethanol was investigated using a recombinant yeast strain Saccharomyces cerevisiae ZU-10. Low cellobiase activity in Trichoderma reesei cellulase resulted in cellobiose accumulation. Supplementing the simultaneous saccharification and fermentation system with cellobiase greatly reduced feedback inhibition caused by cellobiose to the cellulase reaction, thereby increased the ethanol yield. 12 h of enzymatic prehydrolysis at 50 C prior to simultaneous saccharification and fermentation was found to have a negative effect on the overall ethanol yield. Glucose and xylose produced from alkaline-pretreated corn stover could be co-fermented to ethanol effectively by S. cerevisiae ZU-10. An ethanol concentration of 27.8 g/L and the corresponding ethanol yield on carbohydrate in substrate of 0.350 g/g were achieved within 72 h at 33 C with 80 g/L of substrate and enzyme loadings of 20 filter paper activity units (FPU)/g substrate and 10 cellobiase units (CBU)/g substrate. The results are meaningful in co-conversion of cellulose and hemicellulose fraction of lignocellulosic materials to fuel ethanol. (author)

  9. From Ethanol to Salsolinol: Role of Ethanol Metabolites in the Effects of Ethanol

    Directory of Open Access Journals (Sweden)

    Alessandra T. Peana

    2016-01-01

    Full Text Available In spite of the global reputation of ethanol as the psychopharmacologically active ingredient of alcoholic drinks, the neurobiological basis of the central effects of ethanol still presents some dark sides due to a number of unanswered questions related to both its precise mechanism of action and its metabolism. Accordingly, ethanol represents the interesting example of a compound whose actions cannot be explained as simply due to the involvement of a single receptor/neurotransmitter, a scenario further complicated by the robust evidence that two main metabolites, acetaldehyde and salsolinol, exert many effects similar to those of their parent compound. The present review recapitulates, in a perspective manner, the major and most recent advances that in the last decades boosted a significant growth in the understanding on the role of ethanol metabolism, in particular, in the neurobiological basis of its central effects.

  10. 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.

  11. 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).

  12. Direct conversion of starch to ethanol using recombınant Saccharomyces cerevisiae containing glucoamylase gene

    Science.gov (United States)

    Purkan, P.; Baktir, A.; Puspaningsih, N. N. T.; Ni'mah, M.

    2017-09-01

    Saccharomyces cerevisiae is known for its high fermentative capacity, high ethanol yield and its high ethanol tolerance. The yeast is inability converting starch (relatively inexpensive substrate) into biofuel ethanol. Insertion of glucoamylase gene in yeast cell of Saccharomyces cerevisiae had been done to increase the yeast function in ethanol fermentation from starch. Transformation of yeast of S. cerevisiae with recombinant plasmid yEP-GLO1 carrying gene encoding glucoamylase (GLO1) produced the recombinant yeast which enable to degrade starch. Optimizing of bioconversion process of starch into ethanol by the yeast of recombinant Saccharomyces cerevisiae [yEP-GLO1] had been also done. Starch concentration which could be digested by recombinant yeast of S. cerevisiae [yEP-GLO1] was 10% (w/v). Bioconversion of starch having concentration 10% (b/v) using recombinant yeast of S. cerevisiae BY5207 [yEP-GLO1] could result ethanol as 20% (v/v) to alcoholmeter and 19,5% (v/v) to gas of chromatography. Otherwise, using recombinant yeast S. cerevisiae S. cerevisiae AS3324 [yEP-GLO1] resulted ethanol as 17% (v/v) to alcoholmeter and 17,5% (v/v) to gas of chromatography. The highest ethanol in starch bioconversion using both recombinant yeasts BY5207 and AS3324 could be resulted on 144 hours of fermentation time as well as in pH 5.

  13. Converting Eucalyptus biomass into ethanol: Financial and sensitivity analysis in a co-current dilute acid process. Part II

    International Nuclear Information System (INIS)

    Gonzalez, R.; Treasure, T.; Phillips, R.; Jameel, H.; Saloni, D.; Wright, J.; Abt, R.

    2011-01-01

    The technical and financial performance of high yield Eucalyptus biomass in a co-current dilute acid pretreatment followed by enzymatic hydrolysis process was simulated using WinGEMS registered and Excel registered . Average ethanol yield per dry Mg of Eucalyptus biomass was approximately 347.6 L of ethanol (with average carbohydrate content in the biomass around 66.1%) at a cost of 0.49 L -1 of ethanol, cash cost of ∝0.46 L -1 and CAPEX of 1.03 L -1 of ethanol. The main cost drivers are: biomass, enzyme, tax, fuel (gasoline), depreciation and labor. Profitability of the process is very sensitive to biomass cost, carbohydrate content (%) in biomass and enzyme cost. Biomass delivered cost was simulated and financially evaluated in Part I; here in Part II the conversion of this raw material into cellulosic ethanol using the dilute acid process is evaluated. (author)

  14. Impact of recycling stillage on conversion of dilute sulfuric acid pretreated corn stover to ethanol.

    Science.gov (United States)

    Mohagheghi, Ali; Schell, Daniel J

    2010-04-01

    Both the current corn starch to ethanol industry and the emerging lignocellulosic biofuels industry view recycling of spent fermentation broth or stillage as a method to reduce fresh water use. The objective of this study was to understand the impact of recycling stillage on conversion of corn stover to ethanol. Sugars in a dilute-acid pretreated corn stover hydrolysate were fermented to ethanol by the glucose-xylose fermenting bacteria Zymomonas mobilis 8b. Three serial fermentations were performed at two different initial sugar concentrations using either 10% or 25% of the stillage as makeup water for the next fermentation in the series. Serial fermentations were performed to achieve near steady state concentration of inhibitors and other compounds in the corn stover hydrolysate. Little impact on ethanol yields was seen at sugar concentrations equivalent to pretreated corn stover slurry at 15% (w/w) with 10% recycle of the stillage. However, ethanol yields became progressively poorer as the sugar concentration increased and fraction of the stillage recycled increased. At an equivalent corn stover slurry concentration of 20% with 25% recycled stillage the ethanol yield was only 5%. For this microorganism with dilute-acid pretreated corn stover, recycling a large fraction of the stillage had a significant negative impact on fermentation performance. Although this finding is of concern for biochemical-based lignocellulose conversion processes, other microorganism/pretreatment technology combinations will likely perform differently. (c) 2009 Wiley Periodicals, Inc.

  15. Direct bioconversion of brown algae into ethanol by thermophilic bacterium Defluviitalea phaphyphila.

    Science.gov (United States)

    Ji, Shi-Qi; Wang, Bing; Lu, Ming; Li, Fu-Li

    2016-01-01

    Brown algae are promising feedstocks for biofuel production with inherent advantages of no structural lignin, high growth rate, and no competition for land and fresh water. However, it is difficult for one microorganism to convert all components of brown algae with different oxidoreduction potentials to ethanol. Defluviitalea phaphyphila Alg1 is the first characterized thermophilic bacterium capable of direct utilization of brown algae. Defluviitalea phaphyphila Alg1 can simultaneously utilize mannitol, glucose, and alginate to produce ethanol, and high ethanol yields of 0.47 g/g-mannitol, 0.44 g/g-glucose, and 0.3 g/g-alginate were obtained. A rational redox balance system under obligate anaerobic condition in fermenting brown algae was revealed in D. phaphyphila Alg1 through genome and redox analysis. The excess reducing equivalents produced from mannitol metabolism were equilibrated by oxidizing forces from alginate assimilation. Furthermore, D. phaphyphila Alg1 can directly utilize unpretreated kelp powder, and 10 g/L of ethanol was accumulated within 72 h with an ethanol yield of 0.25 g/g-kelp. Microscopic observation further demonstrated the deconstruction process of brown algae cell by D. phaphyphila Alg1. The integrated biomass deconstruction system of D. phaphyphila Alg1, as well as its high ethanol yield, provided us an excellent alternative for brown algae bioconversion at elevated temperature.

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

    Science.gov (United States)

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

    2015-05-01

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

  17. 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

  18. Low temperature lignocellulose pretreatment: effects and interactions of pretreatment pH are critical for maximizing enzymatic monosaccharide yields from wheat straw

    DEFF Research Database (Denmark)

    Pedersen, Mads; Johansen, Katja S.; Meyer, Anne S.

    2011-01-01

    Background: The recent development of improved enzymes and pentose-using yeast for cellulosic ethanol processes calls for new attention to the lignocellulose pretreatment step. This study assessed the influence of pretreatment pH, temperature, and time, and their interactions on the enzymatic...... alkaline pretreatments. Alkaline pretreatments also solubilized most of the lignin. Conclusions: Pretreatment pH exerted significant effects and factor interactions on the enzymatic glucose and xylose releases. Quite extreme pH values were necessary with mild thermal pretreatment strategies (T...... glucose and xylose yields from mildly pretreated wheat straw in multivariate experimental designs of acid and alkaline pretreatments. Results: The pretreatment pH was the most significant factor affecting both the enzymatic glucose and xylose yields after mild thermal pretreatments at maximum 140 degrees...

  19. 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.

  20. Catalytic dehydration of ethanol for poly 13 C compounds synthesis

    International Nuclear Information System (INIS)

    Almasan, Valer; Marginean, Petru; Lazar, Mihaela; Tusa, Florina

    2003-01-01

    Classical methods for the synthesis of organic compounds are not very well applied in the case of 13 C labeled compounds. One of the principal demands is to find the best method to transform a small quantity of isotopic reagent with a very high yield. In this case to obtain 13 C 2 chloroethanol from 13 C 2 ethanol there are two synthesis steps: - catalytic dehydration of ethanol to ethylene; - ethylene double bounding saturation: either via ethylene oxide (30% yield) or in diluted solution of chlorine. For the first step of synthesis we choose the thermal dehydration over alumina catalyst at 400 deg C. There were tested 2 samples of g alumina with 255 m 2 /g and 355 m 2 /g with very good results. In the second step of the synthesis we used the chlorine addition to ethylene in very diluted water solution. We have built a reactor which combined the two steps of this synthesis method to produce 13 C 2 chloroethanol from 13 C 2 ethanol. The global yield of method was 42%. (authors)

  1. 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...

  2. 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.

  3. 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.

  4. Conversion of bagasse cellulose into ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Cuzens, J.E.

    1997-11-19

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

  5. 6 Grain Yield

    African Journals Online (AJOL)

    create a favourable environment for rice ... developing lines adaptable to many ... have stable, not too short crop duration with ..... Analysis of variance of the effect of site and season on maturity, grain yield and plant ..... and yield components.

  6. Ultrasonic pretreatment for enhanced saccharification and fermentation of ethanol production from corn

    Science.gov (United States)

    Montalbo-Lomboy, Melissa T.

    The 21st Century human lifestyle has become heavily dependent on hydrocarbon inputs. Energy demand and the global warming effects due to the burning of fossil fuels have continued to increase. Rising awareness of the negative environmental and economic impacts of hydrocarbon dependence has led to a resurgence of interest in renewable energy sources such as ethanol. Fuel ethanol is known to be a cleaner and renewable source of energy relative to gasoline. Many studies have agreed that fuel ethanol has reduced greenhouse gas (GHG) emissions and has larger overall energy benefits compared to gasoline. Currently, the majority of the fuel ethanol in the United States is produced from corn using dry-grind milling process. The typical dry-grind ethanol plant incorporates jet cooking using steam to cook the corn slurry as pretreatment for saccharification; an energy intensive step. In aiming to reduce energy usage, this study evaluated the use of ultrasonics as an alternative to jet cooking. Ultrasonic batch experiments were conducted using a Branson 2000 Series bench-scale ultrasonic unit operating at a frequency of 20 kHz and a maximum output of 2.2 kW. Corn slurry was sonicated at varying amplitudes from 192 to 320 mumpeak-to-peak(p-p) for 0-40 seconds. Enzyme stability was investigated by adding enzyme (STARGEN(TM)001) before and after sonication. Scanning electron micrograph (SEM) images and particle size distribution analysis showed a nearly 20-fold size reduction by disintegration of corn particles due to ultrasonication. The results also showed a 30% improvement in sugar release of sonicated samples relative to the control group (untreated). The efficiency exceeded 100% in terms of relative energy gain from the additional sugar released due to ultrasonication compared to the ultrasonic energy applied. Interestingly, enzymatic activity was enhanced when sonicated at low and medium power. This result suggested that ultrasonic energy did not denature the enzymes

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Edita Martini

    2011-05-01

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

  9. 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

  10. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  11. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  12. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  13. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

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

    Science.gov (United States)

    Udeh, Benard Anayo; Erkurt, Emrah Ahmet

    2017-01-01

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

  15. Synthesis and characterization of Co and Ni catalysts supported on alumina, synthesized from aluminum industry wastes and its use in the reforming reaction of ethanol, to hydrogen production

    International Nuclear Information System (INIS)

    Saborio Gonzalez, Maricruz

    2013-01-01

    Alumina was synthesized from aluminum anodizing process wastes through a process of mechanical and thermal treatment of calcination,1373 K with a heating rate of 5 K/min to 8h, obtaining a pure alumina of corundum type, a crystal size of 9.77 nm. This material is used as a microporous support and have elaborated Cobalt heterogeneous catalysts (CO 3 O 4 / Al 2 O 3 ) and Nickel (NiO/Al 2 O 3 ) which were calcined at different temperatures (573 K, 773 K, 973 K, 1173 K). From these is produced hydrogen by ethenol catalytic reforming. Two techniques were used for driving the mixture EtOH:H 2 O (1:3) of starting gas. A first technique has involved trawling through boiling of the mixture. High percentages were obtained of hydrogen but to a lesser reaction time, consuming all starting reagent, the most efficient catalyst has been the CO 2 O 3 / Al 2 O 3 calcined at 973K with a production of H 2 of 50% v/v as well as CH 4 and CO of 10%v/v. The second type of starting reagent carryover has been mild heating at 333 K and nitrogen sweep, with the following results 11% v/v H 2 , 12% v/v CH 4 and 7% v/v CO. Addition of ethanol conversion maximums of 76% and hydrogen yield of 29%, of the theoretical yield based on the ethanol consumed. (author) [es

  16. N-acetylcysteine increased rice yield

    OpenAIRE

    NOZULAIDI, MOHD; JAHAN, MD SARWAR; KHAIRI, MOHD; KHANDAKER, MOHAMMAD MONERUZZAMAN; NASHRIYAH, MAT; KHANIF, YUSOP MOHD

    2015-01-01

    N-acetylcysteine (NAC) biosynthesized reduced glutathione (GSH), which maintains redox homeostasis in plants under normal and stressful conditions. To justify the effects of NAC on rice production, we measured yield parameters, chlorophyll (Chl) content, minimum Chl fluorescence (Fo), maximum Chl fluorescence (Fm), quantum yield (Fv/Fm), net photosynthesis rate (Pn), photosynthetically active radiation (PAR), and relative water content (RWC). Four treatments, N1G0 (nitrogen (N) with no NAC), ...

  17. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  18. 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

  19. 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.

  20. Conversion of hemicelluloses and D-xylose into ethanol by the use of thermophilic anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    Ethanol is a CO{sub 2} neutral liquid fuel that can substitute the use of fossil fuels in the transportation sector, thereby reducing the CO{sub 2} emission to the atmosphere. CO{sub 2} emission is suspected to contribute significantly to the so-called greenhouse effect, the global heating. Substrates for production of ethanol must be cheap and plentiful. This can be met by the use of lignocellulosic biomass such as willow, wheat straw, hardwood and softwood. However, the complexity of these polymeric substrates and the presence of several types of carbohydrates (glucose, xylose, mannose, galactose, arabinose) require additional treatment to release the useful carbohydrates and ferment the major carbohydrates fractions. The costs related to the ethanol-production must be kept at a minimum to be price competitive compared to gasoline. Therefore all of the carbohydrates present in lignocellulose need to be converted into ethanol. Glucose can be fermented to ethanol by yeast strains such as Saccharomyces cerevisiae, which, however, is unable to ferment the other major carbohydrate fraction, D-xylose. Thermophilic anaerobic ethanol producing bacteria can be used for fermentation of the hemicelluloses fraction of lignocellulosic biomass. However, physiological studies of thermophilic anaerobic bacteria have shown that the ethanol yield decreases at increasing substrate concentration. The biochemical limitations causing this phenomenon are not known in detail. Physiological and biochemical studies of a newly characterized thermophilic anaerobic ethanol producing bacterium, Thermoanaerobacter mathranii, was performed. This study included extraction of intracellular metabolites and enzymes of the pentose phosphate pathway and glycolysis. These studies revealed several bottlenecks in the D-xylose metabolism. This knowledge makes way for physiological and genetic engineering of this strain to improve the ethanol yield and productivity at high concentration of D-xylose. (au)

  1. Computer optimization of cutting yield from multiple ripped boards

    Science.gov (United States)

    A.R. Stern; K.A. McDonald

    1978-01-01

    RIPYLD is a computer program that optimizes the cutting yield from multiple-ripped boards. Decisions are based on automatically collected defect information, cutting bill requirements, and sawing variables. The yield of clear cuttings from a board is calculated for every possible permutation of specified rip widths and both the maximum and minimum percent yield...

  2. Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting.

    Science.gov (United States)

    Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L

    2016-08-01

    This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple MR tissue parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization.

  3. 2G ethanol from the whole sugarcane lignocellulosic biomass.

    Science.gov (United States)

    Pereira, Sandra Cerqueira; Maehara, Larissa; Machado, Cristina Maria Monteiro; Farinas, Cristiane Sanchez

    2015-01-01

    In the sugarcane industry, large amounts of lignocellulosic residues are generated, which includes bagasse, straw, and tops. The use of the whole sugarcane lignocellulosic biomass for the production of second-generation (2G) ethanol can be a potential alternative to contribute to the economic viability of this process. Here, we conducted a systematic comparative study of the use of the lignocellulosic residues from the whole sugarcane lignocellulosic biomass (bagasse, straw, and tops) from commercial sugarcane varieties for the production of 2G ethanol. In addition, the feasibility of using a mixture of these residues from a selected variety was also investigated. The materials were pretreated with dilute acid and hydrolyzed with a commercial enzymatic preparation, after which the hydrolysates were fermented using an industrial strain of Saccharomyces cerevisiae. The susceptibility to enzymatic saccharification was higher for the tops, followed by straw and bagasse. Interestingly, the fermentability of the hydrolysates showed a different profile, with straw achieving the highest ethanol yields, followed by tops and bagasse. Using a mixture of the different sugarcane parts (bagasse-straw-tops, 1:1:1, in a dry-weight basis), it was possible to achieve a 55% higher enzymatic conversion and a 25% higher ethanol yield, compared to use of the bagasse alone. For the four commercial sugarcane varieties evaluated using the same experimental set of conditions, it was found that the variety of sugarcane was not a significant factor in the 2G ethanol production process. Assessment of use of the whole lignocellulosic sugarcane biomass clearly showed that 2G ethanol production could be significantly improved by the combined use of bagasse, straw, and tops, when compared to the use of bagasse alone. The lower susceptibility to saccharification of sugarcane bagasse, as well as the lower fermentability of its hydrolysates, can be compensated by using it in combination with straw

  4. Energy and greenhouse gas balances of cassava-based ethanol

    International Nuclear Information System (INIS)

    Le, Loan T.; Ierland, Ekko C. van; Zhu, Xueqin; Wesseler, Justus

    2013-01-01

    Biofuel production has been promoted to save fossil fuels and reduce greenhouse gas (GHG) emissions. However, there have been concerns about the potential of biofuel to improve energy efficiency and mitigate climate change. This paper investigates energy efficiency and GHG emission saving of cassava-based ethanol as energy for transportation. Energy and GHG balances are calculated for a functional unit of 1 km of road transportation using life-cycle assessment and considering effects of land use change (LUC). Based on a case study in Vietnam, the results show that the energy input for and GHG emissions from ethanol production are 0.93 MJ and 34.95 g carbon dioxide equivalent per megajoule of ethanol respectively. The use of E5 and E10 as a substitute for gasoline results in energy savings, provided that their fuel consumption in terms of liter per kilometer of transportation is not exceeding the consumption of gasoline per kilometer by more than 2.4% and 4.5% respectively. It will reduce GHG emissions, provided that the fuel consumption of E5 and E10 is not exceeding the consumption of gasoline per kilometer by more than 3.8% and 7.8% respectively. The quantitative effects depend on the efficiency in production and on the fuel efficiency of E5 and E10. The variations in results of energy input and GHG emissions in the ethanol production among studies are due to differences in coverage of effects of LUC, CO 2 photosynthesis of cassava, yields of cassava, energy efficiency in farming, and by-product analyses. -- Highlights: ► Cassava-based ethanol substitution for gasoline in form of E5 could save 1.4 MJ km −1 ► Ethanol substitution for gasoline in form of E5 reduces a CO 2 e emission of 156 g km −1 ► We examined changes in fuel efficiency of blends affecting energy and GHG balances. ► LUC and change in soil management lead to a CO 2 e emission of 942 g L −1 of ethanol. ► LUC effects, energy inputs, yields, and by-products explain results among

  5. Yield stress fluids slowly yield to analysis

    NARCIS (Netherlands)

    Bonn, D.; Denn, M.M.

    2009-01-01

    We are surrounded in everyday life by yield stress fluids: materials that behave as solids under small stresses but flow like liquids beyond a critical stress. For example, paint must flow under the brush, but remain fixed in a vertical film despite the force of gravity. Food products (such as

  6. Solid phase fermentation of Helianthus tuberosus for ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Baerwald, G.; Hamad, S.H.

    1989-01-01

    The direct fermentation of pure inulin and hammer mill crushed Helianthus tuberosus tubers (topinambur, Jerusalem artichoke) was studied using two heat-tolerant yeasts, namely Kluyveromyces marxianus and Candida kefyr. A Saccharomyces cerevisiae was included in the study so as to compare the yields of these two yeasts with that of a commercial distiller's yeast. The inulin fermentation was carried out in an 18-L bioreactor using the fed-batch and the batch-fermentation methods. The final ethanol concentration was 6.1% (L/L) which represents 82% of the theoretical yield. Commercial scale experiments with hammer mill crushed tubers gave yields lower than those found in the laboratory: 69% of the theoretical yield for direct fermentation without enzyme addition, and about 91% when cellolytic enzymes were added.

  7. Ethanol does not delay muscle recovery but decreases testosterone/cortisol ratio.

    Science.gov (United States)

    Haugvad, Anders; Haugvad, Lars; Hamarsland, Håvard; Paulsen, Gøran

    2014-11-01

    This study investigated the effects of ethanol consumption on recovery from traditional resistance exercise in recreationally trained individuals. Nine recreationally trained volunteers (eight males and one female, 26 ± 4 yr, 81 ± 4 kg) conducted four resistance exercise sessions and consumed a low (0.6 (females) and 0.7 (males) g · kg(-1) body mass) or a high dose (1.2 or 1.4 g · kg(-1) body mass) of ethanol 1-2.5 h after exercise on two occasions. The first session was for familiarization with the tests and exercises and was performed without ethanol consumption. As a control trial, alcohol-free drinks were consumed after the exercise session. The sequence of trials, with low and high ethanol doses and alcohol-free drinks (control), was randomized. Maximal voluntary contractions (MVC) (knee extension), electrically stimulated contractions (knee extension), squat jumps, and hand grip strength were assessed 10-15 min and 12 and 24 h after the ethanol/placebo drinks. In addition to a baseline sample, blood was collected 1, 12, and 24 h after the ethanol/placebo drinks. The exercise session comprised 4 × 8 repetition maximum of squats, leg presses, and knee extensions. MVC were reduced by 13%-15% immediately after the exercise sessions (P squat jump performance were recovered 24 h after ethanol drinks. MVC was not fully recovered at 24 h in the control trial. Compared with those in the control, cortisol increased and the free testosterone/cortisol ratio were reduced after the high ethanol dose (P < 0.01). Neither a low nor a high dose of ethanol adversely affected recovery of muscle function after resistance exercise in recreationally strength-trained individuals. However, the increased cortisol levels and reduced testosterone/cortisol ratio after the high ethanol dose could translate into long-term negative effects.

  8. Ethanol and High-Value Terpene Co-Production from Lignocellulosic Biomass of Cymbopogon flexuosus and Cymbopogon martinii.

    Directory of Open Access Journals (Sweden)

    Blake L Joyce

    Full Text Available Cymbopogon flexuosus, lemongrass, and C. martinii, palmarosa, are perennial grasses grown to produce essential oils for the fragrance industry. The objectives of this study were (1 to evaluate biomass and oil yields as a function of nitrogen and sulfur fertilization, and (2 to characterize their utility for lignocellulosic ethanol compared to Panicum virgatum (switchgrass. Mean biomass yields were 12.83 Mg lemongrass ha-1 and 15.11 Mg palmarosa ha-1 during the second harvest year resulting in theoretical biofuel yields of 2541 and 2569 L ethanol ha-1 respectively compared to reported 1749-3691 L ethanol ha-1 for switchgrass. Pretreated lemongrass yielded 198 mL ethanol (g biomass-1 and pretreated palmarosa yielded 170 mL ethanol (g biomass-1. Additionally, lemongrass yielded 85.7 kg essential oil ha-1 and palmarosa yielded 67.0 kg ha-1 with an estimated value of USD $857 and $1005 ha-1. These data suggest that dual-use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.

  9. Ethanol and High-Value Terpene Co-Production from Lignocellulosic Biomass of Cymbopogon flexuosus and Cymbopogon martinii.

    Science.gov (United States)

    Joyce, Blake L; Zheljazkov, Valtcho D; Sykes, Robert; Cantrell, Charles L; Hamilton, Choo; Mann, David G J; Rodriguez, Miguel; Mielenz, Jonathan R; Astatkie, Tess; Stewart, C Neal

    2015-01-01

    Cymbopogon flexuosus, lemongrass, and C. martinii, palmarosa, are perennial grasses grown to produce essential oils for the fragrance industry. The objectives of this study were (1) to evaluate biomass and oil yields as a function of nitrogen and sulfur fertilization, and (2) to characterize their utility for lignocellulosic ethanol compared to Panicum virgatum (switchgrass). Mean biomass yields were 12.83 Mg lemongrass ha-1 and 15.11 Mg palmarosa ha-1 during the second harvest year resulting in theoretical biofuel yields of 2541 and 2569 L ethanol ha-1 respectively compared to reported 1749-3691 L ethanol ha-1 for switchgrass. Pretreated lemongrass yielded 198 mL ethanol (g biomass)-1 and pretreated palmarosa yielded 170 mL ethanol (g biomass)-1. Additionally, lemongrass yielded 85.7 kg essential oil ha-1 and palmarosa yielded 67.0 kg ha-1 with an estimated value of USD $857 and $1005 ha-1. These data suggest that dual-use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.

  10. Introducing Textiles as Material of Construction of Ethanol Bioreactors

    Directory of Open Access Journals (Sweden)

    Osagie A. Osadolor

    2014-11-01

    Full Text Available The conventional materials for constructing bioreactors for ethanol production are stainless and cladded carbon steel because of the corrosive behaviour of the fermenting media. As an alternative and cheaper material of construction, a novel textile bioreactor was developed and examined. The textile, coated with several layers to withstand the pressure, resist the chemicals inside the reactor and to be gas-proof was welded to form a 30 L lab reactor. The reactor had excellent performance for fermentative production of bioethanol from sugar using baker’s yeast. Experiments with temperature and mixing as process parameters were performed. No bacterial contamination was observed. Bioethanol was produced for all conditions considered with the optimum fermentation time of 15 h and ethanol yield of 0.48 g/g sucrose. The need for mixing and temperature control can be eliminated. Using a textile bioreactor at room temperature of 22 °C without mixing required 2.5 times longer retention time to produce bioethanol than at 30 °C with mixing. This will reduce the fermentation investment cost by 26% for an ethanol plant with capacity of 100,000 m3 ethanol/y. Also, replacing one 1300 m3 stainless steel reactor with 1300 m3 of the textile bioreactor in this plant will reduce the fermentation investment cost by 19%.

  11. Feasibility assessment of whey-based ethanol facilities

    Energy Technology Data Exchange (ETDEWEB)

    Walker, L P; Pellerin, R A; Rao, A M; Hang, Y D; Kalter, R J; Boisvert, R N; Gabler, E C

    1985-07-01

    In the U.S., corn has been the principal commodity considered for conversion to ethanol. One alternative to using corn and other food crops is to utilize organic wastes, such as food processing waste. Cheese whey is one such waste that holds potential for conversion to ethanol. To ascertain the feasibility of using whey as a feedstock a series of regional studies were conducted by the authors. Results from these studies indicate that the transport of condensed whey to a central processing plant for conversion to ethanol is economically feasible. The energy balance for the plants considered can yield a positive or negative balance depending on whether an energy penalty is assigned for condensing the whey. A net energy gain of 23833 to 26921 kJ/l of ethanol was obtained if energy for whey condensing was not included and a net energy loss ranging from -279 to -686 kJ/l was obtained if whey condensing was included in the energy balance. Plants utilizing continuous fermentation technology showed positive energy balance with or without a penalty for the condensing of the whey.

  12. 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.

  13. Modeling maximum daily temperature using a varying coefficient regression model

    Science.gov (United States)

    Han Li; Xinwei Deng; Dong-Yum Kim; Eric P. Smith

    2014-01-01

    Relationships between stream water and air temperatures are often modeled using linear or nonlinear regression methods. Despite a strong relationship between water and air temperatures and a variety of models that are effective for data summarized on a weekly basis, such models did not yield consistently good predictions for summaries such as daily maximum temperature...

  14. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  15. Polymorphisms in monolignol biosynthetic genes are associated with biomass yield and agronomic traits in European maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Chen, Yongsheng; Zein, Imad; Brenner, Everton A

    2010-01-01

    Background Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes...