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Can biofuels be sustainable?
August 20, 2008With oil prices skyrocketing, the search is on for efficient and sustainable biofuels. Research published this month in Agronomy Journal examines one biofuel crop contender: corn stover.
Corn stover is made up of the leaves and stalks of corn plants that are left in the field after harvesting the edible corn grain. Corn stover could supply as much as 25% of the biofuel crop needed by 2030.
Scientists with the USDA-ARS Agroecosystem Unit located at the University of Nebraska examined the long-term sustainability of using corn stover as a biofuel crop.
When corn stover is not harvested as a biofuel crop, it can be left on the fields to restore vital nutrients to the soil. Full-scale harvesting of corn stover may deplete the soil.
Researchers measured the soil organic carbon levels and residue production over 14 years in fields planted continuously with corn, continuously with soybeans, and with a rotation of corn and soybeans. Organic carbon rates were found to stay steady or even increase in all three field types.
Gary Varvel and Wally Wilhelm, who conducted the study, said "These results suggest that a portion of corn stover could be harvested for biofuel production without reducing soil organic carbon levels in high yielding systems. However, since this study did not study the direct impact of stover removal, that aspect remains to be evaluated."
Research into the effects of residue removal on soil organic carbon levels in several different cropping systems is ongoing at this and several other USDA-ARS locations throughout the U.S. Much of this research is under the auspices of a multi-location CRIS project within ARS called REAP (Renewable Energy Assessment Project).
American Society of Agronomy
When corn stover is not harvested as a biofuel crop, it can be left on the fields to restore vital nutrients to the soil. Full-scale harvesting of corn stover may deplete the soil.
Researchers measured the soil organic carbon levels and residue production over 14 years in fields planted continuously with corn, continuously with soybeans, and with a rotation of corn and soybeans. Organic carbon rates were found to stay steady or even increase in all three field types.
Gary Varvel and Wally Wilhelm, who conducted the study, said "These results suggest that a portion of corn stover could be harvested for biofuel production without reducing soil organic carbon levels in high yielding systems. However, since this study did not study the direct impact of stover removal, that aspect remains to be evaluated."
Research into the effects of residue removal on soil organic carbon levels in several different cropping systems is ongoing at this and several other USDA-ARS locations throughout the U.S. Much of this research is under the auspices of a multi-location CRIS project within ARS called REAP (Renewable Energy Assessment Project).
American Society of Agronomy
Corn Stover Current Events and Corn Stover News RSSReport examines hidden costs of energy production and use
A new report from the National Research Council examines and, when possible, estimates "hidden" costs of energy production and use -- such as the damage air pollution imposes on human health -- that are not reflected in market prices of coal, oil, other energy sources, or the electricity and gasoline produced from them.
Study shows more corn for biofuels would hurt water
More of the fertilizers and pesticides used to grow corn would find their way into nearby water sources if ethanol demands lead to planting more acres in corn, according to a Purdue University study.
Technology is key for biofuel success
To make the conversion of biomass to biofuels more cost-effective, new technologies are essential, according to Dr. Richard Hess from the Idaho National Laboratory in Idaho Falls in the US and his team.
GEN reports on alternative feedstocks for ethanol production
Scientists say they are forging ahead in developing replacements for petrochemical fuels that will be cost-competitive and renewable while having a minimal impact on the environment, reports Genetic Engineering & Biotechnology News (GEN).
Plastic that grows on trees, part two
Some researchers hope to turn plants into a renewable, nonpolluting replacement for crude oil. To achieve this, scientists have to learn how to convert plant biomass into a building block for plastics and fuels cheaply and efficiently.
Shredding corn silage could produce more ethanol at less cost
A Purdue University researcher has found a way to get more bang for fewer bucks when it comes to processing cellulosic material to make ethanol.
Biofuels can provide viable, sustainable solution to reducing petroleum dependence
An in-depth study by Sandia National Laboratories and General Motors Corp. has found that plant and forestry waste and dedicated energy crops could sustainably replace nearly a third of gasoline use by the year 2030.
Two-step chemical process turns raw biomass into biofuel
Taking a chemical approach, researchers at the University of Wisconsin-Madison have developed a two-step method to convert the cellulose in raw biomass into a promising biofuel.
Process can cut the cost of making cellulosic biofuels
A patented Michigan State University process to pretreat corn-crop waste before conversion into ethanol means extra nutrients don't have to be added, cutting the cost of making biofuels from cellulose.
Managing Carbon Loss
As the United States continues to develop alternative energy methods and push towards energy independence, cellulosic-based ethanol has emerged as one of the most commercially viable technologies.
More Corn Stover Current Events and Corn Stover News Articles
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21st Century Guide to Energy Crops and Biofuels, Agricultural Residue, Corn and Wheat Stover, Rice Straw, Oil Seeds, Switchgrass, Feedstocks, Sugars, Biorefineries, Ethanol, Syngas (Two CD-ROM Set) by U.S. Government (Author) This up-to-date and comprehensive electronic book on two CD-ROMs presents an incredible and totally revised collection of important documents and publications about biofuels, biomass energy, and biodiesel, with practical information for producers and users of these exciting alternative fuels of the future. There is information on the use of energy crops and agricultural residue, including corn and wheat stover, rice straw, oil seeds, switchgrass, and more. Encyclopedic coverage of every aspect of biofuels is included, with coverage of biopower, ethanol and methanol, hydrogen, methane, Fischer-Tropsch diesel, plant materials, and much more. It includes material on E85 ethanol programs with practical information for start-ups and entrepreneurs, including sources of funding and help. Federal... |
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Candy Jelly Kabobs (24 Individually wrapped Kabobs) by Alberts 24 Jelly Halloween Kabobs. Each kabob has a witch, skull, pumpkin, and candy corn. The perfect treat for Halloween. Like cooking meat on the grill except you get tasty Halloween treats:) |
![Steam activation of chars produced from oat hulls and corn stover [An article from: Bioresource Technology]](http://ecx.images-amazon.com/images/I/512SA5QAAFL._SL160_.jpg) |
Steam activation of chars produced from oat hulls and corn stover [An article from: Bioresource Technology] by M. Fan (Author), W. Marshall (Author), D. Daugaard (Author), R. Brown (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Oat hulls and corn stover were used to produce chars at approximately 500 ^oC. The carbon concentrations of oat hull char and corn stover chars produced were 72.3 and 68.0 wt.%, respectively. Both activation burn-off and Brunauer-Emmett-Teller (BET) surface area appear to exhibit a linear relationship with respect to activation time of oat hulls. As to corn stover activated carbons, there is no linear relationship between activation time and BET surface area. However, activation burn-off of and activation time... |
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Carbonic acid enhancement of hydrolysis in aqueous pretreatment of corn stover [An article from: Bioresource Technology] by G. Peter van Walsum (Author), H. Shi (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Carbonic acid and liquid hot water pretreatments were applied to corn stover. Temperatures ranged from 180 to 220 ^oC; reaction times varied between 2 and 32 min and prereaction carbon dioxide pressure was either 0 or 800 psig. Over the range of reaction conditions tested, it was found that the presence of carbonic acid had an effect of increasing the concentrations of xylose and furan compounds in the hydrolysate that was significant at above the 99% confidence level. Thus there appears to be an increase in... |
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Specific energy requirement for compacting corn stover [An article from: Bioresource Technology] by S. Mani (Author), L.G. Tabil (Author), S. Sokhansanj (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Corn stover is a major crop residue for biomass conversion to produce chemicals and fuels. One of the problems associated with the supply of corn stover to conversion plants is the delivery of feedstock at a low cost. Corn stover has low bulk density and it is difficult to handle. In this study, chopped corn stover samples were compacted in a piston cylinder under three pressure levels (5, 10, 15MPa) and at three moisture content levels (5%, 10%, 15% (wb)) to produce briquettes. The total energy requirement to... |
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Optimization of pH controlled liquid hot water pretreatment of corn stover [An article from: Bioresource Technology] by N. Mosier (Author), R. Hendrickson (Author), N. Ho (Author), M. Sedlak (Author), Ladis (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Controlled pH, liquid hot water pretreatment of corn stover has been optimized for enzyme digestibility with respect to processing temperature and time. This processing technology does not require the addition of chemicals such as sulfuric acid, lime, or ammonia that add cost to the process because these chemicals must be neutralized or recovered in addition to the significant expense of the chemicals themselves. Second, an optimized controlled pH, liquid hot water pretreatment process maximizes the solubilization... |
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Lime pretreatment and enzymatic hydrolysis of corn stover [An article from: Bioresource Technology] by S. Kim (Author), M.T. Holtzapple (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Corn stover was pretreated with an excess of calcium hydroxide (0.5g Ca(OH)"2/g raw biomass) in non-oxidative and oxidative conditions at 25, 35, 45, and 55^oC. The optimal condition is 55^oC for 4weeks with aeration. Glucan (91.3%) and xylan (51.8%) were converted to glucose and xylose respectively, when the treated corn stover was enzymatically hydrolyzed with 15 FPU/g cellulose. Only 0.073g Ca(OH)"2 was consumed per g of raw corn stover. Of the initial lignin, 87.5% was maximally removed. Almost all acetyl... |
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Fractionation of corn stover by hot-water and aqueous ammonia treatment [An article from: Bioresource Technology] by T.H. Kim (Author), Y.Y. Lee (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The efficiency of biomass utilization can be significantly improved by fractionation of biomass. A two-stage percolation process was investigated for pretreatment and fractionation of corn stover. The two-stage process is composed of hot water treatment followed by treatment with aqueous ammonia, both applied in a flow-through (percolation) reactor. The first stage processing is intended for hemicellulose removal whereas the second stage is intended for delignification. The pretreated material was nearly pure... |
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Optimization of the ammonia fiber explosion (AFEX) treatment parameters for enzymatic hydrolysis of corn stover [An article from: Bioresource Technology] by F. Teymouri (Author), L. Laureano-Perez (Author), H. Alizadeh (Author), Dale (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: |
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Delignification kinetics of corn stover in lime pretreatment [An article from: Bioresource Technology] by S. Kim (Author), M.T. Holtzapple (Author) This digital document is a journal article from Bioresource Technology, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Corn stover was pretreated with excess calcium hydroxide (0.5g Ca(OH)"2/g raw biomass) in non-oxidative and oxidative conditions at 25, 35, 45, and 55^oC. The delignification kinetic model of corn stover used three first-order reactions with following forms: W"L=0.09.exp(-~.t)+0.28.exp(-k"2.t)+0.63.exp(-k"3.t) in non-oxidative pretreatment; W"L=0.16.exp(-~.t)+0.27.exp(-k"2.t)+0.57.exp(-k"3.t) in oxidative pretreatment. The first term corresponds to the initial phase, which is essentially infinite at the time scale... |
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