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News and Trends
http://www.csiro.au/files/files/pvib.pdf A recent publication by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) reports that "important biosecurity issues are being ignored in the global push to develop new non-food crops for biofuels and industrial/pharmaceutical uses." The publication entitled, Biosecurity in the New Bioeconomy, highlights the findings of a summit (with the same title), held in Canberra, Australia in November 2009. According to the report, key biosecurity issues associated with the exponential rise of non-food crops are: (1) potential invasiveness of new crops, (2) effects of abandoned plantings of trial crops, and (3) pests/diseases and pest management. Ignoring these biosecurity issues could compromise conventional agriculture. Awareness of these issues is important, so that countries can make informed decisions for addressing potential biosecurity risks, through appropriate revisions in biofuel policy legislation. Among the highlights of the report are: (1) Science has a role "in developing and regulating sustainable crop-based biofuels so its recommendations are relevant to a wide international audience including farmers, industry, researchers and policy makers", (2) There is a "need for a global vision for future agricultural development around biofuels and international standards and certification for the industry to avoid repeating the environmental harm previous agricultural ‘revolutions' have caused", (3) "Developing countries will need assistance to develop best management practices, protect their environment and undertake risk assessments." The full report can be downloaded at the CSIRO website (URL above)..
Researchers from the National Center for Agricultural Utilization Research of the Agricultural Research Service (ARS), United States Department of Agriculture (USDA), report some latest findings in their research on ethanol production from wheat straw. They found two pretreatment methods which did not produce compounds known as "fermentation inhibitors" and were effective in increasing ethanol yields. These pretreatments were the addition of alkaline peroxide and lime. Pretreatment is one of the first steps in the conversion of lignocellulosic biomass to ethanol. It removes the lignin wrapping around the biomass, to expose the hemi-cellulose fibers. The exposed fibers can then be degraded into simple sugars for ethanol fermentation. Conventional pretreatments using acid or alkali often produce compounds which inhibit the ethanol fermentation step ("fermentation inhibitors", such as furfural). Alkaline peroxide and lime pretreatments were successfully done without the production of such inhibitors. Ethanol yields for alkaline peroxide and lime pretreatments were 93 gallons per ton of wheat straw and 83 gallons per ton of wheat straw, respectively. The scientists also report some progress in the analysis of bacterial contamination during ethanol fermentation. According to USDA-ARS microbiologist, Ken Bischoff, "chronic infections can reduce ethanol yields from 2 to 4 percent, which is a lot at a plant that produces 100 million gallons of ethanol a year." A shake-flask model for simulatng bacterial contamination during ethanol fermentation was developed, which can be used for helping the ethanol industry find strategies to control bacterial contamination in their ethanol fermentation plants. Related information: Modelling of bacterial contamination during ethanol fermentation http://ddr.nal.usda.gov/bitstream/10113/29908/1/IND44187615.pdf Energy Crops and Feedstocks for Biofuels Production
http://www.ars.usda.gov/is/pr/2010/100422.htm MultiCalculator download site: http://www.ars.usda.gov/Services/docs.htm?docid=19206 A special calculation program has been developed at the Agricultural Research Service (ARS), United States Department of Agriculture (USDA), which can help farmers estimate crop yields based on available water in semi-arid regions. Called the MultiCalculator, three downloadable spreadsheet programs can calculate non-irrigated crop yield and irrigated water requirement, given the inputs such as crop type, location, and expected average precipitation during the growing season. The "yield calculator" can be used for 18 crops, including cereal grains, seed legumes, oilseeds and forages. If corn is the chosen crop, the ethanol yield can also be estimated. The calculation program can be downloaded at the USDA-ARS website (URL above). Biofuels Processing
http://www.ns.umich.edu/htdocs/releases/story.php?id=7645 The University of Michigan (UM, United States) website reports that their scientists at the Chemical Engineering Department are working on a research project for the production of biofuels from algae, using a high pressure hydrothermal process. Algae-based biofuels are said to be "carbon neutral" because the amount of carbon dioxide released during its combustion is balanced by the amount of carbon dioxide captured during the algal cultivation. According to the UM press release, the "pressure-cooker method", "bucks the trend in algae-to-fuel processing", because even non-oleagenous (non-oil-bearing) algae can be used, and it also eliminates the drying process. The method involves the heating of the algae with water at "300 degrees" under high pressure, for about 30 minutes to one hour. The research team is taking "a broad and deep look at this process" looking at ways for the resulting crude biofuel mixure (after "pressure cooking") to have (1) increased the energy density by application of catalysts, (2) better flow properties, and (3) reduced sulfur and nitrogen content..
http://www.biotechnologyforbiofuels.com/content/pdf/1754-6834-3-8.pdf Scientists from the Eastern Regional Research Center of the Agricultural Research Service (ARS), United States Department of Agriculture (USDA), report a process for the production of ethanol from winter barley. Winter barley is reported as a starchy feedstock for ethanol production, which is not food-based. However, in addition to starch, it also has a high content of beta-glucans (polysaccharides of glucose), which increases its viscosity (and therefore increases production cost), when processed into ethanol. The ARS scientists developed a process which can overcome the viscosity problem caused by beta-glucans, and at the same time, produce ethanol. Called the "EDGE" process (enhanced dry grinding enzymatic process), winter barely is first size-reduced (by dry grinding in a Wiley mill), and then mixed with deionized water. The slurry is then added with four enzymes: (1) beta-glucanases, (2) beta-glucosidase, (3) alpha-amylase, and (4) glucoamylase. The first two enzymes breakdown the glucans into their component sugars (glucose), while the last two enzymes convert the starch component (in the winter barley), also into glucose. The sugar mixture is finally fermented to ethanol. The scientists report that ethanol can be produced at a concentration of 15% (by volume) from 30% of dry solids. The residue after ethanol processing (called "distillers dry grains, DDG), was also found to be a suitable ruminant or mono-gastric animal feed. The full report is published in the open access journal, Biotechnology for Biofuels (URL above)..
http://www.technologyreview.com/energy/24663/ http://www.sciencemag.org/cgi/content/abstract/sci;327/5969/1110?maxtoshow=&hits=10 The Technology Review website reports a novel process for transport fuel production from waste biomass by University of Wisconsin scientists (in the United States). "Unwanted by-products (levulinic acid and formic acid) from the breaking of cellulose down into sugar" are the starting materials for the developed thermochemical process. Unlike conventional biological methods for biofuel production, the "Wisconsin process" is reported to have the following advantages: (1) easier to control (since it is a chemical process), and (2) the carbon-dioxide created during its production can be easily captured. The process can be briefly described as follows: The (levulinic and formic) acids in the waste biomass are combined to form gamma-valerolactone, an industrial chemical. Catalysts made of silica and alumina then help convert this to a gas called butene, which is easily converted to liquid hydrocarbon fuels, including gasoline and jet fuel. The high pressure stream of carbon dioxide can be "captured and stored," according to the researchers. There are efforts to make the process cost-competitive.. |
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