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1.
Belyea RL Clevenger TE Singh V Tumbleson ME Rausch KD 《Applied biochemistry and biotechnology》2006,134(2):113-128
The dry-grind corn process is one of two technologies used to convert corn into ethanol. In his process, all kernel components
are processed through several sequential steps, including fermentation. Only one coproduct (distillers’ dried grains with
solubles [DDGS]) is available for marketing. DDGS provide income to offset costs of processing; issues that affect marketing
have implications in the economic viability of dry-grind plants. Two issues relate to elements in DDGS: high concentrations
and excessive variation. Data on element concentrations in dry-grind processing streams could be helpful in addressing these
concerns. The objective of this study was to determine element concentrations in primary process streams from dry-grind plants.
Samples of corn, ground corn, beer, wet grains, syrup, and DDGS were obtained from nine dry-grind plants, and element concentrations
were determinined. The concentrations of most elements in corn were not different among processing plants and were similar
to published data. However, for the processing streams, there were differences in several element concentrations among processing
plants. The concentrations of most elements in beer were about three times those of corn, due to the disappearance of starch
during fermentation. Syrup had the highest element concentrations. Variations in element contents of DDGS and parent streams
were due to processing conditions and not corn. Appropriate processing of thin stillage (the parent stream of syrup) could
reduce the element content of DDGS. 相似文献
2.
Distillers’ dried grains with solubles (DDGS) and corn gluten feed (CGF) are major coproducts of ethanol production from corn
dry grind and wet milling facilities, respectively. These coproducts contain important nutrients and high levels of phytates.
The phytates in these products cannot be digested by nonruminant animals; consequently, large quantities of phytate phosphorus
(P) are deposited into the soil with the animal wastes which potentially could cause P pollution in soil and underground water
resources. To reduce phytates in DDGS and CGF, a phytase from Aspergillus niger, PhyA, was investigated regarding its capability to catalyze the hydrolysis of phytates in light steep water (LSW) and whole
stillage (WS). LSW and WS streams are the intermediate streams in the production of CGF and DDGS, respectively, and contribute
to most of the P in these streams. Enzyme loadings with activity of 0.1, 1, 2, and 4 FTU/g substrate and temperatures of 35
and 45 °C were investigated regarding their influences on the degree of hydrolysis. The analysis of the hydrolyzate suggested
to a sequentially degradation of phytates to lower order myo-inositol phosphate isomers. Approximately 90% phytate P of LSW
and 66% phytate P of WS were released, suggesting myo-inositol monophosphate as the end product. The maximum amount of released
P was 4.52 ± 0.03 mg/g LSW and 0.86 ± 0.01 mg/g WS. 相似文献
3.
Elankovan Ponnampalam D. Bernie Steele Deborah Burgdorf Darold McCalla 《Applied biochemistry and biotechnology》2004,115(1-3):837-842
Ethanol fermentations were conducted using both whole corn, and corn with 100% of the germ, and a portion (∼74%) of the fiber
removed. Ethanol production increased 11% in the germ and fiber-removed corn vs the whole corn. The protein content of distiller's
dried grains and solubles increased from 30 to 36%, and phosphate levels were 60% lower in corn with germ and fiber removed
vs whole corn. Removal of germ and fiber prior to fermentation allows higher starch loading and results in increased ethanol
production. The integration of germ and fiber removal in the dry-grind ethanol industry could increase capacity and add valuable
coproducts, resulting in increased productivity and profits. 相似文献
4.
Taylor F Mcaloon AJ Craig JC Yang P Wahjudi J Eckhoff SR 《Applied biochemistry and biotechnology》2001,94(1):41-49
The Quick-Germ process developed at the University of Illinois at Urbana-Champaign is a way to obtain corn oil, but with lower
capital costs than the traditional wet-milling process. Quick-Germ has the potential to increase the coproduct credits and
profitability of the existing dry-grind fuel ethanol process, but the fermentability of the corn remaining after oil recovery
has not been tested. Therefore, a series of pilot scale (50 L) fermentations was carefully controlled and monitored with unique
methods for standard inoculation and automatic sampling. It was found that the concentration of suspended solids was significantly
reduced in the Quick-Germ fermentations. When compared at the same concentration of fermentable sugars, the fermentation rate
and yield were not statistically different from controls. When Quick-Germ was integrated into a state-of-the-art dry-grind
fuel ethanol process, computer simulation and cost models indicated savings of approx $0.01/L of ethanol ($0.04/gal) with
the Quick-Germ process. Additional savings associated with the lower suspended solids could not be quantified and were not
included. However, the savings are sensitive to the price of corn oil.
Mention of brand or firm name does not constitute an endorsement by the U.S. Department of Agriculture over others of a similar
nature not mentioned. 相似文献
5.
Hominy feed is a low value ($83.7/metric ton) coproduct of the corn dry milling process that accounts for nearly 35% of the
starting corn quantity. The average composition of hominy feed on a dry basis is 56.9% starch, 25.2% neutral detergent fiber,
11.1% protein, and 5.3% fat. Starch in hominy feed can be fermented to ethanol thus increasing its levels of protein and fat.
The increase in protein and fat percentages may increase the market competitiveness and price of hominy feed. Hydrolysis and
fermentation were performed on nine hominy feed samples collected from three corn dry milling plants in the USA. The original
hominy feed samples and postfermentation solids were analyzed for starch, protein, fat, and fiber content. Compared to the
original hominy feed, the percentage increase in protein, fat and fiber in postfermentation solids of nine samples ranged
from 10.4 to 21.3, 6.78 to 10.6, and 12.6 to 28.7% (dry basis), respectively. Ethanol yields varied from 271.7 to 380.2 l/metric
ton for the nine hominy feed samples. These results indicate that the value of hominy feed as an animal feedstock can potentially
be increased with fermentation and can produce more profit per metric ton than currently being derived by its sale as a low
protein feed ingredient. 相似文献
6.
To increase the value of coproducts from corn ethanol fermentation and soybean aqueous processing, distiller??s dried grains with solubles (DDGS) and soybean cotyledon fiber were used as the substrates for solid state fermentation (SSF) to improve feed digestibility. Aspergillus oryzae, Trichoderma reesei, and Phanerochaete chrysosporium were chosen as they produce desirable enzymes and are widely used in SSF for feed. The results showed that the cellulase and xylanase activities were significantly increased after 7?days of fermentation, and cellulose and hemicellulose degradation was also greatly increased. When soybean fiber was used as SSF substrate, the maximum activities of the cellulase and xylanase were 10.3 and 84.2?IU/g substrate (dry weight basis) after SSF treatment, respectively. However, the enzyme activities were relatively low in DDGS, and the growth of the three fungi was poor. The fungi grew better when soybean cotyledon fiber was added to DDGS, and cellulase and xylanase activity increased with the increase of soybean fiber content. Porosity was identified as an important factor for SSF because the addition of inert soybean hull alone improved the fungi growth significantly. These data suggest that the nutritional value of DDGS and soybean cotyledon fiber as monogastric animal feed could be greatly enhanced by SSF treatment. 相似文献
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9.
Hossein Noureddini Jongwon Byun Ta-Jen Yu 《Applied biochemistry and biotechnology》2009,159(2):553-567
Distillers’ grains and corn fiber are the coproducts of the corn dry grind and wet milling industries, respectively. Availability
of distillers’ grains and corn fiber at the ethanol plant and their high levels of lignocellulosic material make these coproducts
attractive feedstocks for conversion to ethanol. In this study, dilute sulfuric acid hydrolysis of these coproducts was investigated
in a multistage scheme. After the completion of each pretreatment stage, the liquid substrate was separated and reused in
the succeeding pretreatment stage with a fresh substrate. The substrate from each stage was also subjected to enzyme hydrolysis
in a separate experiment. The sulfuric acid concentration and the substrate loading were maintained at 1.0 vol% and 15.0 wt.%,
respectively, and the temperature was maintained at 120 °C in all the experiments. Experiments were also performed to study
the effect of removing oil from the samples prior to the pretreatment. The highest concentration of monomeric sugars (MS)
was observed when three stages of pretreatment were followed by the enzyme reaction. The enzyme hydrolysis of the three-stage
pretreated dried distillers’ grains and corn fiber yielded 122.6 ± 5.8 and 184.5 ± 4.1 mg/mL of MS, respectively. The formation
of inhibitory products was also monitored. 相似文献
10.
Melvin P. Tucker Nicholas J. Nagle Edward W. Jennings Kelly N. Ibsen Andy Aden Quang A. Nguyen Kyoung H. Kim Sally L. Noll 《Applied biochemistry and biotechnology》2004,115(1-3):1139-1159
Over the past three decades ethanol production in the United States has increased more than 10-fold, to approx 2.9 billion
gal/yr (mid-2003), with ethanol production expected to reach 5 billion gal/yr by 2005. The simultaneous coproduction of 7
million t/yr of distiller's grain (DG) may potentially drive down the price of DG as a cattle feed supplement. The sale of
residual DG for animal feed is an important part of corn dry-grind ethanol production economics; therefore, dry-grind ethanol
producers are seeking ways to improve the quality of DG to increase market penetration and help stabilize prices. One possible
improvement is to increase the protein content of DG by converting the residual starch and fiber into ethanol. We have developed
methods for steam explosion, SO2, and dilute-sulfuric acid pretreatment of DG for evaluation as a feedstock for ethanol production. The highest soluble sugar
yields (∼77% of available carbohydrate) were obtained by pretreatment of DG at 140°C for 20 min with 3.27 wt% H2SO4. Fermentation protocols for pretreated DG were developed at the bench scale and scaled to a working volume of 809 L for production
of hydrolyzed distiller's grain (HDG) for feeding trials. The pretreated DG was fermented with Saccharomyces cerevisiae D5A, with ethanol yields of 73% of theoretical from available glucans. The HDG was air-dried and used for turkey-feeding trials.
The inclusion of HDG into turkey poult (as a model non-ruminant animal) diets at 5 and 10% levels, replacing corn and soybean
meal, showed weight gains in the birds similar to controls, whereas 15 and 20% inclusion levels showed slight decreases (−6%)
in weight gain. At the conclusion of the trial, no negative effects on internal organs or morphology, and no mortality among
the poults, was found. The high protein levels (58–61%) available in HDG show promising economics for incorporation of this
process into corn dry-grind ethanol plants. 相似文献
11.
Ximenes EA Dien BS Ladisch MR Mosier N Cotta MA Li XL 《Applied biochemistry and biotechnology》2007,137(1-12):171-183
Distillers dried grain with solubles (DDGS) is the major coproduct produced at a dry grind ethanol facility. Currently, it is sold primarily as a ruminant animal feed. DDGS is low cost and relatively high in protein and fiber contents. In this study, DDGS was investigated as carbon source for extracellular hydrolytic enzyme production. Two filamentous fungi, noted for their high cellulolytic and hemicellulolytic enzyme titers, were grown on DDGS: Trichoderma reesei Rut C-30 and Asper gillus niger NRRL 2001. DDGS was either used as delivered from the plant (untreated) or after being pretreated with hot water. Both microorganisms secreted a broad range of enzymes when grown on DDGS. Higher xylanase titers were obtained when cultured on hot water DDGS compared with growth on untreated DDGS. Maximum xylanase titers were produced in 4 d for A. niger and 8 d for T. reesei in shake flask cultures. Larger amounts of enzymes were produced in bioreactors (5 L) either equipped with Rushton (for T. reesei) or updraft marine impellers (A. niger). Initial production titers were lower for bioreactor than for flask cultures, especially for T. reesei cultures. Improvement of enzyme titers were obtained using fed-batch feeding schemes. 相似文献
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13.
Amit Kumar Jay B. Cameron Peter C. Flynn 《Applied biochemistry and biotechnology》2005,121(1-3):47-58
Issues of traffic congestion and community acceptance limit the size of biomass-processing plants based on truck delivery
to about 2 million (M) dry t/yr or less. In this study, the cost of ethanol from an ethanol fermentation plant processing
2 M dry t/yr of corn stover supplied by truck is compared with that of larger plants in the range of 4–38 M dry t/yr supplied
by a combination of trucks plus pipelines. For corn stover, a biomass source with a low yield per gross hectare, the cost
of ethanol from larger plants is always higher. For wood chips from the boreal forest, a biomass source with a relatively
high yield per gross hectare, a plant processing 14–38 M dry t/yr produces ethanol at a 13% reduction in cost compared with
a plant producing 2 M dry t/yr supplied by truck. Processing of value-added products, such as chemicals from lignin, would
be enabled by larger-scale plants. 相似文献
14.
Exposure to anhydrous ammonia has been suggested as a pretreatment for corn milling. Batches of corn were exposed to ammonia
under controlled conditions. The amounts of ammonia absorbed and reacted with the corn were measured. The amounts were not
more than are needed as nutritional supplement for yeast fermentation to ethanol. Loosening of the hull was observed qualitatively,
and subsequent shearing in a disk mill followed by steeping for 2, 4, 6, or 8h showed that germ could be recovered at higher
yield and after a shorter steeping time compared to untreated control batches. Quality of oil was not affected by treatment
with ammonia.
Mention of brand or firm name does not constitute an endorsement by the U.S. Department of Agriculture above others of a similar
nature not mentioned. 相似文献
15.
Ball Milling Pretreatment of Corn Stover for Enhancing the Efficiency of Enzymatic Hydrolysis 总被引:2,自引:0,他引:2
Zengxiang Lin He Huang Hongman Zhang Lin Zhang Lishi Yan Jingwen Chen 《Applied biochemistry and biotechnology》2010,162(7):1872-1880
Ethanol can be produced from lignocellulosic biomass with the usage of ball milling pretreatment followed by enzymatic hydrolysis
and fermentation. The sugar yields from lignocellulosic feed stocks are critical parameters for ethanol production process.
The research results from this paper indicated that the yields of glucose and xylose were improved by adding any of the following
dilute chemical reagents: H2SO4, HCl, HNO3, CH3COOH, HCOOH, H3PO4, and NaOH, KOH, Ca(OH)2, NH3·H2O in the ball milling pretreatment of corn stover. The optimal enzymatic hydrolysis efficiencies were obtained under the conditions
of ball milling in the alkali medium that was due to delignification. The data also demonstrated that ball milling pretreatment
was a robust process. From the microscope image of ball milling-pretreated corn stover, it could be observed that the particle
size of material was decreased and the fiber structure was more loosely organized. Meanwhile, the results indicate that the
treatment effect of wet milling is better than that of dry milling. The optimum parameters for the milling process were ball
speed of 350 r/min, solid/liquid ratio of 1:10, raw material particle size with 0.5 mm, and number of balls of 20 (steel ball,
Φ = 10 mm), grinding for 30 min. In comparison with water milling process, alkaline milling treatment could increase the enzymatic
hydrolysis efficiency of corn stover by 110%; and through the digestion process with the combination of xylanase and cellulase
mixture, the hydrolysis efficiency could increase by 160%. 相似文献
16.
《Chemie in Unserer Zeit》2017,51(3):198-209
Propylene oxide (PO) is one of the most important intermediates for the chemical industry. It is used for the manufacture of materials such as insulating foams, solvents, deicing fluids among others and has, thus, become essential for our modern life. The first industrial production route for PO and today still the most important one is the so called chlorhydrine process. With the renouncement of chlorine, the SM‐PO and MTBE‐PO processes provide more environmentally friendly routes for the production of PO. However, Styrene and MTBE are obtained as secondary coproducts. The economic feasibility of these processes is determined not only by PO. It is also influenced by the demand of the coproducts. The CU‐PO process has been developed as a coproduct‐free variant of the SM‐PO process. The development of the highly selective catalyst titansilicalit‐1 (TS‐1) together with the vast expansion of the availability of hydrogen peroxide paved the way for the industrial realization of the coproduct‐free HPPO technology at various sites worldwide. Excellent yields and selectivities and water as an environmentally friendly byproduct characterize this new process for the production of PO. The application of homogeneous catalysts or the direct synthesis using air/oxygen and propylene are only of academic importance so far. 相似文献
17.
Nghiem NP Montanti J Johnston DB Drapcho C 《Applied biochemistry and biotechnology》2011,164(8):1390-1404
A process was developed to fractionate and isolate the hemicellulose B component of corn fiber generated by corn wet milling.
The process consisted of pretreatment by soaking in aqueous ammonia followed by enzymatic cellulose hydrolysis, during which
the hemicellulose B was solubilized by cleavage into xylo-oligosaccharides and subsequently recovered by precipitation with
ethanol. The pretreatment step resulted in high retention of major sugars and improvement of subsequent enzymatic hydrolysis.
The recovered hemicellulose B was hydrolyzed by a cocktail of enzymes that consisted of β-glucosidase, pectinase, xylanase,
and ferulic acid esterase (FAE). Xylanase alone was ineffective, demonstrating yields of less than 2% of xylose and arabinose.
The greatest xylose and arabinose yields, 44% and 53%, respectively, were obtained by the combination of pectinase and FAE.
A mass balance accounted for 87% of the initially present glucan, 91% of the xylan, and 90% of the arabinan. The developed
process offered a means for production of corn fiber gum as a value-added co-product and C5 sugars, which could be converted
to other valuable co-products through fermentation in a corn wet-milling biorefinery. 相似文献
18.
Rajagopalan S Ponnampalam E McCalla D Stowers M 《Applied biochemistry and biotechnology》2005,120(1):37-50
An Aspen Plus™ modeling platform was developed to evaluate the performance of the conversion process of degermed defibered
corn (DDC) to ethanol in 15- and 40-million gallons per year (MGPY) dry mill ethanol plants. Upstream corn milling equipment
in conventional dry mill ethanol plants was replaced with germ and fiber separation equipment. DDC with higher starch content
was fed to the existing saccharification and fermentation units, resulting in higher ethanol productivity than with regular
corn. The results of the DDC models were compared with those of conventional dry mill ethanol process models. A simple financial
analysis that included capital and operating costs, revenues, earnings, and return on investment was created to evaluate each
model comparatively. Case studies were performed on 15- and 40-MGPY base case models with two DDC process designs and DDC
with a mechanical oil extraction process. 相似文献
19.
Ellen I. Burnes John Hagen Dennis Wichelns Kristen Callens 《Applied biochemistry and biotechnology》2004,113(1-3):95-110
In this article, we estimate the costs of using alternative feedstocks to produce ethanol in a 40 million-gal facility in
California’s San Joaquin Valley. Feedstocks include corn imported from Midwestern states and locally grown agricultural products
such as corn, grapes, raisins, oranges, and other tree fruits. The estimated feedstock costs per gallon of ethanol include
$0.92 for Midwestern corn, $1.21 for locally grown corn, $6.79 for grapes, $3.36 for raisins, $3.92 for citrus, and $1.42
for other tree fruit. Adjusting for coproduct values lowers the estimated net feedstock costs to $0.67/gal of ethanol for
Midwestern corn, $0.96 for locally grown corn, $6.53 for grapes, and $3.30 for raisins. We also examine the potential increases
in net revenue to raisin producers, made possible by having an alternative outlet available for selling surplus raisins. 相似文献
20.
Flodman HR Boyer EJ Muthukumarappan A Noureddini H 《Applied biochemistry and biotechnology》2012,166(4):1070-1081
The feasibility of using coproducts from dry grind corn ethanol production as a substrate for the production of soluble fiber
was examined. Acid- and base-catalyzed hydrolysis experiments were performed using sulfuric acid and sodium hydroxide to partially
hydrolyze hemicellulose content of whole stillage, a precursor to distillers' grains, to soluble fiber. The influences of
temperature, reaction time, and hydrolyzing agent concentration on the formation of soluble fiber were studied. Soluble fiber
was recovered by precipitation in a 95% ethanol solution. Results indicate that appreciable quantities of soluble fiber may
be extracted using either acid- or base-catalyzed reactions. The highest yield of soluble fibers was 13.2 g per 100 g-db of
treated whole stillage using one weight percent sodium hydroxide at 80oC for 1 h. HPLC analysis was used to quantify the amount
of monomeric sugars which were formed during the hydrolysis procedures. 相似文献