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1.
Zhaoqin Wang Haibo Huang Elvira Gonzalez de Mejia Qian Li Vijay Singh 《Cereal Chemistry》2016,93(4):344-351
In the dry‐grind ethanol process, distillers dried grains with solubles (DDGS) is the main coproduct, which is primarily used as an ingredient in ruminant animal diets. Increasing the value of DDGS will improve the profitability of the dry‐grind ethanol process. One way to increase DDGS value is to use pigmented maize as the feedstock for ethanol production. Pigmented maize is rich in anthocyanin content, and the anthocyanin imparts red, blue, and purple color to the grain. It is reported that anthocyanin would be absorbed by yeast cell walls during the fermentation process. The effects of anthocyanin on fermentation characteristics in the dry‐grind process are not known. In this study, the effects of anthocyanin in conventional (conventional starch hydrolyzing enzymes) and modified (granular starch hydrolyzing enzymes [GSHE]) dry‐grind processes were evaluated. The modified process using GSHE replaced high‐temperature liquefaction. The ethanol conversion efficiencies of pigmented maize were comparable to that of yellow dent corn in both conventional (78.4 ± 0.5% for blue maize, 74.3 ± 0.4% for red maize, 81.2 ± 1.0% for purple maize, and 75.1 ± 0.2% for yellow dent corn) and modified dry‐grind processes using GSHE (83.8 ± 0.8% for blue maize, 81.1 ± 0.3% for red maize, 93.5 ± 0.8% for purple maize, and 85.6 ± 0.1% for yellow dent corn). Total anthocyanin content in DDGS from the modified process was 1.4, 1.9, and 2.4 times of that from the conventional process for purple, red, and blue maize samples, respectively. These results indicated that pigmented maize rich in anthocyanin did not negatively affect the fermentation characteristics of the dry‐grind process and that there was a potential to use pigmented maize in the dry‐grind process, especially when using GSHE. 相似文献
2.
Ping Wang Vijay Singh Hua Xue David B. Johnston Kent D. Rausch M. E. Tumbleson 《Cereal Chemistry》2007,84(1):10-14
In a conventional dry‐grind corn process, starch is converted into dextrins using liquefaction enzymes at high temperatures (90–120°C) during a liquefaction step. Dextrins are hydrolyzed into sugars using saccharification enzymes during a simultaneous saccharification and fermentation (SSF) step. Recently, a raw starch hydrolyzing enzyme (RSH), Stargen 001, was developed that converts starch into dextrins at low temperatures (<48°C) and hydrolyzes dextrins into sugars during SSF. In this study, a dry‐grind corn process using RSH enzyme was compared with two combinations (DG1 and DG2) of commercial liquefaction and saccharification enzymes. Dry‐grind corn processes for all enzyme treatments were performed at the same process conditions except for the liquefaction step. For RSH and DG1 and DG2 treatments, ethanol concentrations at 72 hr of fermentation were 14.1–14.2% (v/v). All three enzyme treatments resulted in comparable ethanol conversion efficiencies, ethanol yields, and DDGS yields. Sugar profiles for the RSH treatment were different from DG1 and DG2 treatments, especially for glucose. During SSF, the highest glucose concentration for RSH treatment was 7% (w/v), whereas for DG1 and DG2 treatments, glucose concentrations had maximum of 19% (w/v). Glycerol concentrations were 0.5% (w/v) for RSH treatment and 0.8% (w/v) for DG1 and DG2 treatments. 相似文献
3.
Ping Wang Vijay Singh Li Xu David B. Johnston Kent D. Rausch M. E. Tumbleson 《Cereal Chemistry》2005,82(6):734-738
A new low temperature liquefaction and saccharification enzyme STARGEN 001 (Genencor International, Palo Alto, CA) with high granular starch hydrolyzing activity was used in enzymatic dry‐grind corn process to improve recovery of germ and pericarp fiber before fermentation. Enzymatic dry‐grind corn process was compared with conventional dry‐grind corn process using STARGEN 001 with same process parameters of dry solid content, pH, temperature, enzyme and yeast usage, and time. Sugar, ethanol, glycerol and organic acid profiles, fermentation rate, ethanol and coproducts yields were investigated. Final ethanol concentration of enzymatic dry‐grind corn process was 15.5 ± 0.2% (v/v), which was 9.2% higher than conventional process. Fermentation rate was also higher for enzymatic dry‐grind corn process. Ethanol yields of enzymatic and conventional dry‐grind corn processes were 0.395 ± 0.006 and 0.417 ± 0.002 L/kg (2.65 ± 0.04 and 2.80 ± 0.01 gal/bu), respectively. Three additional coproducts, germ 8.0 ± 0.4% (db), pericarp fiber 7.7 ± 0.4% (db), and endosperm fiber 5.2 ± 0.6% (db) were produced in addition to DDGS with enzymatic dry‐grind corn process. DDGS generated from enzymatic dry‐grind corn process was 66% less than conventional process. 相似文献
4.
Ping Wang David B. Johnston Kent D. Rausch Shelly J. Schmidt M. E. Tumbleson Vijay Singh 《Cereal Chemistry》2009,86(3):319-322
The dry grind process using granular starch hydrolyzing enzymes (GSHE) saves energy. The amount 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. Two specific proteases, an exoprotease and an endoprotease, were evaluated in the dry grind process using GSHE (GSH process). The effect of protease and urea addition on GSH process was also evaluated. Addition of these proteases resulted in higher ethanol concentrations (mean increase of 0.3–1.8 v/v) and lower distillers' dried grains with solubles (DDGS) yields (mean decrease of 1.3–8.0% db) compared with the control (no protease addition). As protease levels and GSHE increased, ethanol concentrations increased and DDGS yields decreased. Protease addition reduced the required GSHE dose. Final mean ethanol concentrations without urea (15.2% v/v) were higher than with urea (15.0% v/v) in GSH process across all protease treatments. 相似文献
5.
Ganti S. Murthy Vijay Singh David B. Johnston Kent D. Rausch M. E. Tumbleson 《Cereal Chemistry》2006,83(5):455-459
New corn fractionation technologies that produce higher value coproducts from dry‐grind processing have been developed. Wet fractionation technologies involve a short soaking of corn followed by milling to recover germ and pericarp fiber in an aqueous medium before fermentation of degermed defibered slurry. In dry fractionation technologies, a dry degerm defiber (3D) process (similar to conventional corn dry‐milling) is used to separate germ and pericarp fiber before fermentation of the endosperm fraction. The effect of dry and wet fractionation technologies on the fermentation rates and ethanol yields were studied and compared with the conventional dry‐grind process. The wet process had the highest fermentation rate. The endosperm fraction obtained from 3D process had lowest fermentation rate and highest residual sugars at the end of fermentation. Strategies to improve the fermentation characteristics of endosperm fraction from 3D process were evaluated using two saccharification and fermentation processes. The endosperm fraction obtained from 3D process was liquefied by enzymatic hydrolysis and fermented using either separate saccharification (SS) and fermentation or simultaneous saccharification and fermentation (SSF). Corn germ soak water and B‐vitamins were added during fermentation to study the effect of micronutrient addition. Ethanol and sugar profiles were measured using HPLC. The endosperm fraction fermented using SSF produced higher ethanol yields than SS. Addition of B‐vitamins and germ soak water during SSF improved fermentation of 3D process and resulted in 2.6 and 2.3% (v/v) higher ethanol concentrations and fermentation rates compared with 3D process treatment with no addition of micronutrients. 相似文献
6.
Amit Arora Bruce S. Dien Ronald L. Belyea Ping Wang Vijay Singh M. E. Tumbleson Kent D. Rausch 《Cereal Chemistry》2010,87(2):100-103
In dry‐grind corn processing, the whole kernel is fermented to produce ethanol and distillers dried grains with solubles (DDGS); the E‐Mill process was developed to generate coproducts in addition to DDGS. Compositions of thin stillage and wet grains obtained from the E‐Mill process will be different from the dry‐grind process. Knowledge of thin stillage compositions will provide information to improve coproducts from both processes. Laboratory dry‐grind and E‐Mill processes that used granular starch hydrolyzing enzymes (GSHE) were compared and process yields determined. Two methods, centrifugation and screening, were used to produce thin stillage and wet grains from the laboratory processes. Compositions of process streams were determined. In the dry‐grind process using GSHE, solids contents of beer, whole stillage, and wet grains were higher compared to the same fractions from the E‐Mill process using GSHE. Solids contents of mash for both processes were similar. Total solids, soluble solids, and ash contents of thin stillage were similar for the two processes. Fat content of thin stillage from E‐Mill was lower than that from the dry‐grind process; protein content of E‐Mill thin stillage was higher than that from dry‐grind thin stillage. Removal of germ and fiber before fermentation changed composition of thin stillage from the E‐Mill process. The screening method produced higher thin stillage and lower wet grains yields than using a centrifugation method. The screening method was less time consuming but resulted in limited wet grains material for additional analyses or processing. The centrifugation method of thin stillage separation removed more solids from thin stillage than the screening method. 相似文献
7.
Esha Khullar Erik D. Sall Kent D. Rausch M. E. Tumbleson Vijay Singh 《Cereal Chemistry》2009,86(6):616-622
Different corn types were used to compare ethanol production from the conventional dry‐grind process to wet or dry fractionation processes. High oil, dent corn with high starch extractability, dent corn with low starch extractability and waxy corn were selected. In the conventional process, corn was ground using a hammer mill; water was added to produce slurry which was fermented. In the wet fractionation process, corn was soaked in water; germ and pericarp fiber were removed before fermentation. In the dry fractionation process, corn was tempered, degerminated, and passed through a roller mill. Germ and pericarp fiber were separated from the endosperm. Due to removal of germ and pericarp fiber in the fractionation methods, more corn was used in the wet (10%) and dry (15%) fractionation processes than in the conventional process. Water was added to endosperm and the resulting slurry was fermented. Oil, protein, and residual starch in germ were analyzed. Pericarp fiber was analyzed for residual starch and neutral detergent fiber (NDF) content. Analysis of variance and Fisher's least significant difference test were used to compare means of final ethanol concentrations as well as germ and pericarp fiber yields. The wet fractionation process had the highest final ethanol concentrations (15.7% v/v) compared with dry fractionation (15.0% v/v) and conventional process (14.1% v/v). Higher ethanol concentrations were observed in fractionation processes compared to the conventional process due to higher fermentable substrate per batch available as a result of germ and pericarp fiber removal. Germ and pericarp yields were 7.47 and 6.03% for the wet fractionation process and 7.19 and 6.22% for the dry fractionation process, respectively. Germ obtained from the wet fractionation process had higher oil content (34% db) compared with the dry fractionation method (11% db). Residual starch content in the germ fraction was 16% for wet fractionation and 44% for dry fractionation. Residual starch in the pericarp fiber fraction was lower for the wet fractionation process (19.9%) compared with dry fractionation (23.7%). 相似文献
8.
To improve fractionation efficiency in modified dry grind corn processes, we evaluated the effectiveness of protease treatment in reducing residual starch in endosperm fiber. Three schemes of protease treatment were conducted in three processes: 1) enzymatic milling or E‐Mill, 2) dry fractionation with raw starch fermentation or dry RS, and 3) dry fractionation with conventional fermentation or dry conv. Kinetics of free amino nitrogen production were similar in both dry and wet fractionation (E‐Mill), indicating that proteolysis was effective in all three schemes. At the end of fermentation, endosperm fiber was recovered and its residual starch measured. Using protease treatment, residual starch in the endosperm fiber was reduced by 1.9% w/w (22% relative reduction) in dry conv and 1.7% w/w (8% relative reduction) in dry RS, while no reduction was observed in the E‐Mill process. Protease treatment increased ethanol production rates early in fermentation (≤24 hr) but final ethanol concentrations were unaffected in both dry RS and E‐Mill. In dry conv, the addition of protease resulted in a decline in final ethanol concentration by 0.3% v/v, as well as a higher variability in liquefaction product concentration (higher standard deviations in the glucose and maltose yields). Protease treatment can be used effectively to enhance modified dry grind processes. 相似文献
9.
Vijay Singh David B. Johnston Kalpana Naidu Kent D. Rausch Ronald L. Belyea M. E. Tumbleson 《Cereal Chemistry》2005,82(2):187-190
Three different modified dry‐grind corn processes, quick germ (QG), quick germ and quick fiber (QGQF), and enzymatic milling (E‐Mill) were compared with the conventional dry‐grind corn process for fermentation characteristics and distillers dried grains with solubles (DDGS) composition. Significant effects were observed on fermentation characteristics and DDGS composition with these modified dry‐grind processes. The QG, QGQF, and E‐Mill processes increased ethanol concentration by 8–27% relative to the conventional dry‐grind process. These process modifications reduced the fiber content of DDGS from 11 to 2% and increased the protein content of DDGS from 28 to 58%. 相似文献
10.
Optimization of simultaneous saccharification and fermentation for the production of ethanol from lignocellulosic biomass 总被引：4，自引：0，他引：4
Simultaneous saccharification and fermentation (SSF) of alkaline hydrogen peroxide pretreated Antigonum leptopus (Linn) leaves to ethanol was optimized using cellulase from Trichoderma reesei QM-9414 (Celluclast from Novo) and Saccharomyces cerevisiae NRRL-Y-132 cells. Response surface methodology (RSM) and a three-level four-variable design were employed to evaluate the effects of SSF process variables such as cellulase concentration (20-100 FPU/g of substrate), substrate concentration (5-15% w/v), incubation time (24-72 h), and temperature (35-45 degrees C) on ethanol production efficiency. Cellulase and substrate concentrations were found to be the most significant variables. The optimum conditions arrived at are as follows: cellulase = 100 FPU/g of substrate, substrate = 15% (w/v), incubation time = 57.2 h, and temperature = 38.5 degrees C. At these conditions, the predicted ethanol yield was 3.02% (w/v) and the actual experimental value was 3.0% (w/v). 相似文献
11.
Vijay Singh Christopher J. Batie George W. Aux Kent D. Rausch Carl Miller 《Cereal Chemistry》2006,83(4):317-320
An amylase corn has been developed that produces an α‐amylase enzyme that is activated in the presence of water at elevated temperatures (>70°C). Amylase corn in the dry‐grind process was evaluated and compared with the performance of exogenous amylases used in dry‐grind processing. Amylase corn (1–10% by weight) was added to dent corn (of the same genetic background as the amylase corn) as treatments and resulting samples were evaluated for dry‐grind ethanol fermentation using 150‐g and 3‐kg laboratory procedures. Ethanol concentrations during fermentation were compared with the control treatment (0% amylase corn addition or 100% dent corn) which was processed with a conventional amount of exogenous α‐amylase enzymes used in the dry‐grind corn process. The 1% amylase corn treatment (adding 1% amylase corn to dent corn) was sufficient to liquefy starch into dextrins. Following fermentation, ethanol concentrations from the 1% amylase corn treatment were similar to that of the control. Peak and breakdown viscosities of liquefied slurries for all amylase corn treatments were significantly higher than the control treatment. In contrast, final viscosities of liquefied slurries for all amylase corn treatments were lower than those of the control. Protein, fat, ash, and crude fiber contents of DDGS samples from the 3% amylase corn treatment and control were similar. 相似文献
12.
Bruce S. Dien David B. Johnston Kevin B. Hicks Michael A. Cotta Vijay Singh 《Cereal Chemistry》2005,82(5):616-620
A modified dry‐grind corn process has been developed that allows recovery of both pericarp and endosperm fibers as coproducts at the front end of the process before fermentation. The modified process is called enzymatic milling (E‐Mill) dry‐grind process. In a conventional dry‐grind corn process, only the starch component of the corn kernel is converted into ethanol. Additional ethanol can be produced from corn if the fiber component can also be converted into ethanol. In this study, pericarp and endosperm fibers recovered in the E‐Mill dry‐grind process were evaluated as a potential ethanol feedstock. Both fractions were tested for fermentability and potential ethanol yield. Total ethanol yield recovered from corn by fermenting starch, pericarp, and endosperm fibers was also determined. Results show that endosperm fiber produced 20.5% more ethanol than pericarp fiber on a g/100 g of fiber basis. Total ethanol yield obtained by fermenting starch and both fiber fractions was 0.370 L/kg compared with ethanol yield of 0.334 L/kg obtained by fermenting starch alone. 相似文献
13.
Ganti S. Murthy Devon E. Townsend Gavin L. Meerdink Gerald L. Bargren Mike E. Tumbleson Vijay Singh 《Cereal Chemistry》2005,82(3):302-304
Aflatoxins, like all mycotoxins, are toxic fungal metabolites that can have adverse health effects on animals and human beings. Aflatoxins are a major concern for the dry‐grind corn processing industry as it is believed that aflatoxins affect yeast and reduce its efficacy in producing ethanol. In the present study, aflatoxin B1 (100, 200, 350, or 775 ppb) was added to mycotoxin‐free corn and laboratory‐scale fermentations were conducted. No effect of aflatoxin B1 was observed on the fermentation rates or final ethanol concentrations. Mean ethanol concentration in the fermenter was 14.01–14.51% (v/v) at 60 hr for all the treatments. In the dry‐grind ethanol process, 55% of aflatoxin B1 was detected in wet grains and 45% in thin stillage. 相似文献
14.
Haibo Huang Wei Liu Vijay Singh Mary‐Grace C. Danao Steven R. Eckhoff 《Cereal Chemistry》2012,89(4):217-221
Efficiently utilizing the nongrain portion of the corn plant as ruminant food and the grain for ethanol will allow the optimization of both food and fuel production. Corn and corn stover could be more effectively used if they were harvested earlier before dry down. Corn harvested at different moisture contents (MCs) may exhibit different processing characteristics for the ethanol industry, because of differences in physical and chemical properties. Therefore, the objective of this study was to investigate the effect of corn harvest MC on dry‐grind fermentation characteristics and dried distillers grains with solubles (DDGS) composition. Pioneer hybrid 32D78 was harvested at seven different dates from August 21 to November 23, 2009, with harvest MCs ranging from 73 to 21% (wb). The corn samples with different harvest MCs were evaluated by a conventional dry‐grind process. Final ethanol concentration from the corn with harvest MC of 54% (kernel dent stage) was 17.9% (v/v), which was significantly higher (0.5–1.2 percentage points) than the mature corn with lower harvest MCs (P < 0.05). Ethanol conversion efficiencies for the corn with harvest MCs of 73 and 54% (wb) were 98.5 and 93.2%, respectively, whereas ethanol conversion efficiencies for the corn with lower harvest MCs were significantly lower (P < 0.05), ranging between 83.2 and 88.3%. For DDGS composition, with corn harvest MC decreasing from 73 to 21% (wb), the residual starch concentration increased from 7.7 to 15.2%, the crude protein concentration decreased from 29.4 to 24.9%, and the neutral detergent fiber concentration decreased from 26.6 to 20.6%. 相似文献
15.
Divya Ramchandran Ping Wang Bruce Dien Wei Liu Michael A. Cotta Vijay Singh 《Cereal Chemistry》2015,92(2):218-223
Ethanol fermentation of dry‐fractionated grits (corn endosperm pieces) containing different levels of germ was studied with the dry‐grind process. Partial removal of the germ fraction allows for marketing the germ fraction and potentially more efficient fermentation. Grits obtained from a dry‐milling plant were mixed with different amounts of germ (2, 5, 7, and 10% germ of the total sample) and compared with control grits (0% germ). Fermentation rates of germ‐supplemented grits (2, 5, 7, and 10% germ) were faster than control grits (0% germ). Addition of 2% germ was sufficient to achieve a high ethanol concentration (19.06% v/v) compared with control grits (18.18% v/v). Fermentation of dry‐fractionated grits (92, 95, and 97% grits) obtained from a commercial facility was also compared with ground whole corn (control). Fermentation rates were slower and final ethanol concentrations were lower for commercial grits than the control sample. However, in a final experiment, commercial grits were subjected to raw starch hydrolyzing (RSH) enzyme, resulting in higher ethanol concentrations (20.22, 19.90, and 19.49% v/v for 92, 95, and 97% grits, respectively) compared with the whole corn control (18.64% v/v). Therefore, high ethanol concentrations can be achieved with dry‐fractionated grits provided the inclusion of a certain amount of germ and the use of RSH enzyme for controlled starch hydrolysis. 相似文献
16.
A high‐tannin sorghum cultivar with 3.96% tannin content was used to study the effects of germination on its ethanol fermentation performance in a laboratory dry‐grind process. High‐tannin sorghum sample was germinated for 3 and 4 days. Original and germinated samples were analyzed for tannin, starch, protein, free amino nitrogen (FAN), and glucose content. Endosperm structures and flour pasting properties of germinated and nongerminated sorghum samples were examined using a scanning electron microscope (SEM) and rapid visco analyzer (RVA). Germination reduced tannin content from 3.96% to negligible levels. The free fermentable sugars (glucose, maltose, and maltotriose) in the germinated samples were significantly higher than those in the nongerminated control. Judged by the starch (starch plus dextrin) and free amino nitrogen contents in the mashed samples, germination improved degree of hydrolysis for starch by 13–20% and for protein by 5‐ to 10‐fold during mashing. Germination significantly shortened the required fermentation time for ethanol production by 24–36 hr, increased ethanol fermentation efficiency by 2.6–4.0%, and reduced the residual starch content in the distillers dried grain with solubles (DDGS) compared to the nongerminated control. Ethanol yield for the 3‐day germinated samples was 2.75 gallons/bushel, which was 3.1% higher than the 2.67 gallons for the nongerminated control. Ethanol yield for the 4‐day germinated sorghum was 2.63 gallons/bushel due to excessive loss of starch during germination. 相似文献
17.
The effects of fermentation temperature and dissolved solids concentration adjusted by changing mashing water-to-grain ratios on wheat fermentation efficiencies, fermentation times, final ethanol concentrations, and ethanol production rates were studied by using response surface methodology. Final ethanol concentrations in fermentors depended primarily on mash specific gravities. Predictably, increases in fermentation temperatures dramatically reduced fermentation times and thereby shortened fermentation cycles. The highest ethanol production rates were achieved with a high fermentation temperature of 30°C and a low water-to-grain ratio of 2.0. At these settings, an ethanol concentration of 13.6% (v/v) was attained with a fermentation time of 54 hr and an ethanol production rate of 2.45 mL of ethanol/L/hr. Optimization of operating conditions suggested in the current study will provide existing fuel alcohol plants with increased productivity without alteration of plant equipment or process flow. 相似文献
18.
The objective of this study was to establish methods for determining the content and components of residual starch in distiller's dried grains with solubles (DDGS), a coproduct from dry‐grind corn ethanol production. Four DDGS prepared in our laboratory and one DDGS obtained from a commercial ethanol manufacturer were used for the study. Quantitative analysis of total residual sugar (TRS) in DDGS was performed by determining d ‐glucose produced by enzymatic hydrolysis of oligosaccharides and residual starch remaining in hexane‐defatted DDGS after being dispersed in 90% DMSO. The TRS consisted of free glucose, oligosaccharides, and residual starch. The commercial manufacturer's DDGS contained more TRS (15.8%, w/w db) than the laboratory‐processed DDGS (2.4–2.9%, w/w db). The content of residual starch remaining in the commercial DDGS (5.5% w/w db) was also larger than the laboratory‐processed DDGS (1.9–2.5% w/w db). Analyses of molecular weight distribution showed that the residual starch in DDGS consisted of short‐chain amylose and amylopectin, respectively, as the major and minor components. The short‐chain amylose molecules constituted 86.5–94.1% of the residual starch. The major population of the short‐chain amyloses had an average degree of polymerization (DP) of 85, closely resembling the length of enzyme‐resistant fragments of amylose‐lipid complexes. 相似文献
19.
以菊芋粉为原料同步糖化发酵生产燃料乙醇 总被引：3，自引：1，他引：3
利用粟酒裂殖酵母（Schizosaccharomyces pombe）能发酵菊芋未水解糖液高产乙醇的特点提出了以菊芋粉为原料,同步糖化发酵生产燃料乙醇的新工艺。在摇瓶中考察了原料预处理方法、原料浓度和初始pH值对乙醇发酵的影响,进而在5 L发酵罐中考察了未调控pH值和恒定pH值与通气情况对乙醇发酵的影响。结果表明：该菌株最适pH值为4.0;100目筛分的菊芋粉发酵效果良好,115℃灭菌处理优于121℃,在此条件下,菊芋粉浓度200 g/L时,乙醇产量达到66.58 g/L,理论转化率为85.88%;发酵液pH值下降对乙醇发酵没有影响,通入适量氧气会导致乙醇产量的下降,这表明粟酒裂殖酵母进行乙醇发酵时不需要供氧;通入氮气保持厌氧环境不能显著提高乙醇产量,不通气进行乙醇发酵也达到高的转化率,因此在工业生产中,不必保持厌氧发酵环境。在此基础上,对菊芋粉补料发酵进行了试验,补料至菊芋粉终浓度为300 g/L,发酵终点乙醇浓度为94.81 g/L,理论转化率为81.54%。这些研究工作,为以菊芋为原料的燃料乙醇工业化生产提供技术依据。 相似文献
20.
M. R. Wilkins R. L. Belyea V. Singh P. Buriak M. A. Wallig M. E. Tumbleson K. D. Rausch 《Cereal Chemistry》2006,83(2):121-126
In dry‐grind processing to produce ethanol from corn, unfermented solids are removed from ethanol by distillation and dried to produce distillers dried grains with solubles (DDGS), an animal food. Fouling of thin stillage evaporators has been identified as an important energy consumption issue in dry‐grind facilities. Using an annular fouling apparatus, four batches of thin stillage were analyzed to determine repeatability of fouling rate and induction period measurements. Dry solids, protein and ash concentrations, and pH were correlated to fouling rate and induction period to determine how variation in thin stillage from the same dry‐grind facility affects these fouling parameters. Effects of increasing Reynolds number (Re) in the laminar region on fouling rate, induction period, and fouling deposit protein and ash concentrations were also determined. Repeatability of fouling rate measurements was similar to other studies (CV < 7.0%) but repeatability of induction period measurements was high relative to other studies (CV < 88.7%). Fouling rate increased with increasing dry solids concentration. Thin stillage at Re = 440 had shorter induction periods and greater fouling rates than at Re = 880. Fouling deposits collected from Re = 440 tests had similar protein concentrations and lower ash concentrations compared with deposits from Re = 880 tests. 相似文献