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News and Trends
http://biofuelsdigest.com/blog2/2009/02/19/german-researchers-identify-new-enzyment-to-convert-xylose-to-ethanol-in-a-single-step-eliminates-costly-two-step-process-for-cellulosic-ethanol/ Plant biomass is usually pretreated and broken down (saccharified) into a mixture of simple sugars (also called "monosaccharides") before fermentation into ethanol. The yeast, Saccharomyces cerevisiae is the more popular microorganism for fermentation of the monosaccharide mixture. The problem with ethanol fermentation by S. cerevisiae is that the yeast only utilizes the glucose (the six-carbon sugar) in the monosaccharide mixture. Other non-glucose monosaccharides (such as the five-carbon sugar, xylose), can potentially be converted to ethanol, but these are left unconverted by S. cerevisiae. Strategies for the utilization of unconverted xylose to ethanol by novel or improved strains of S. cerevisiae could help increase cellulose ethanol yields. Until recently, however, molecular biology attempts to insert xylose-conversion enzymes into S. cerevisiae have reportedly been not very successful. German scientists (from the Institute of Molecular Biosciences, Goethe-University Frankfurt) recently reported the successful cloning and expression of a "highly active new kind of xylose isomerase from the anaerobic bacterium Clostridium phytofermentans in S. cerevisiae". Their findings are reported in the journal, Applied and Environmental Microbiology (URL above). By having a strain of S. cerevisiae which can convert both glucose and xylose into ethanol, the product yield could increase and the production cost of cellulose ethanol could decrease.. The Biofuels Digest website reports that the Calcutta Tramways Company (CTC) has shifted to the use of B20 (20% blend) biodiesel for its fleet of buses. Environmental considerations are seen as the main reason for the shift. According to CTC Managing Director, P. K. Chattopadhyay, January field trials revealed a 35% improvement in smoke value. This means that the B20 biodiesel mixed emitted 35% less air pollutants compared to conventional petroleum diesel. An agreement for the regular procurement of biodiesel has been signed between the CTC and the Emami Biotech Group, at a price which will save CTC about US $1,000 a month..
http://www.genencor.com/cms/connect/genencor/media_relations/news/archive/2009/gen_pressrelease_436_en.htm http://biofuelsdigest.com/blog2/2009/02/26/genencor-launches-next-gen-enzyme-package-will-reduce-cost-of-cellulosic-ethanol-production/ In the production of cellulose ethanol from plant biomass, the cellulose in the plant matter is broken down into simple sugars, so that microorganisms can convert these sugars into ethanol. This breakdown step (also known as "saccharification" or "hydrolysis") is usually achieved by the addition of cellulose-degrading enzymes, called "cellulases". The cost of cellulase enzymes is considered to be one of the factors contributing to the high production cost of cellulose ethanol. This factor is also considered as one of the reasons why full commercial-scale production of cellulose ethanol has not yet completely taken off. Recently, Genencor (a global biotechnology company) launched a new class of enzyme (called "Accelerase 1500"), which can reportedly help reduce the cost of cellulose ethanol production. "Accelerase 1500" is an improved enzyme product with higher activity which can translate to "higher ethanol yields and effective operation in a wider variety of processes." The cellulase enzymes in the product are obtained by a fermentation process using a genetically modified microbial strain of Trichoderma reesei..
http://biofuelsdigest.com/blog2/2009/02/20/reuters-publishes-table-of-cellulosic-ethanol-plants-in-operation-planned-finds-311-mgy-in-planned-ce-capacity/ A list of cellulose-ethanol production plants in the United States (classified into "operating, pilot-scale", "commercial scale, under development" and "pilot scale, under development") has been published by Reuters UK. (No commercial scale operating plant has been listed yet). As of February 2009, five commercial scale operating pilot-scale plants (with ethanol production capacities ranging from 0.02 Mgy to 1.5 Mgy) are listed. (Mgy= million gallons per year). Verenium Corporation and KL Energy Corporation had the highest production capacities at the pilot scale level (1.4 Mgy and 1.5 Mgy, respectively). The range of feedstocks include: corn stover, corn cobs, wood and bagasse. Nineteen companies are listed under "commercial scale, under development". The production capacities of the commercial plants under development were in the range between 12 Mgy and 36 Mgy, and the feedstocks include wood biomass (3 plants), rice hull, corn stover and sweet sorghum. Twenty pilot-scale plants which are under development are also listed.. Energy Crops and Feedstocks for Biofuels Production
http://www.undeerc.org/news/newsitem.aspx?id=331 The Energy and Environmental Research Center (EERC) at the University of North Dakota (United States) has received a research grant amounting to US$1 million "to evaluate renewable oil refining technologies for commercial production of diesel, jet, and other fuels and chemicals from North Dakota oilseed crops." One of the viable North Dakota crops that is being considered for biofuel development is a drought tolerant plant called "crambe" (Crambe abyssinica) which produces a non-edible oil. The project (in collaboration with the Tesoro Company) is funded by the North Dakota Industrial Commission (NDIC) and the United States Department of Defense. Crambe oil can be considered a "second generation biofuel feedstock" because it is not food-based feedstock, and it also requires very little agricultural inputs (i.e., water, fertilizer) for cultivation. Related information on Crambe: http://edis.ifas.ufl.edu/pdffiles/AG/AG32700.pdf A report from the Institute of Food and Agricultural Sciences, University of Florida (United States) looks into the potential of giant reedgrass (Arundo donax) as biofuel feedstock. Arundo which is often regarded as a "noxious and invasive weed" is being investigated as a bioenergy crop. It is also known as "Spanish cane". Arundo donax is said to be a "C3 perennial grass", grows as dense clumps to heights between 5 feet to 20 feet. Stems are about one-half to one inch in diameter, and are hollow resembling bamboo. Arundo has a reported High Heating Value (HHV) of about 8,000 BTUs (British Thermal Unit(s) per pound. Processing of giant reedgrass into biofuel may involve gasification and subsequent conversion to "synthetic biofuels" or conversion into cellulose-ethanol by sequential treatments involving pretreatment, saccharification and fermentation. Related information on giant reed grass Biofuels Processing
http://news.uns.purdue.edu/x/2009a/090223BuckmasterShredding.html Pretreatment of lignocellulosic biomass for cellulose ethanol production requires that material be reduced to small sizes, so that the cellulose molecules are more accessible for processing. The method of size reduction ("chopping or shredding") has been found to have some effect on cellulose accessibility and the quantity of energy input. This could also ultimately affect the cost of cellulose ethanol production. Dennis Buckmaster, Associate Professor of Agricultural and Biological Engineering at Purdue University (United States) reports that shredding (rather than chopping) corn stover allows better access of cellulose and consumes 40% less energy. According to Buckmaster, "shredding corn stalks increases the surface area of the plant material. Since stalks can be shredded along the grain of the plants, like splitting a log with an axe, it takes less energy." The complete results of the study are published in the Transactions of the ASABE (American Society of Agricultural and Biological Engineers) (URL above).. Biofuels Policy and Economics
http://www.agric.wa.gov.au/content/SUST/BIOFUEL/CSIRO_WA_Biofuels_LCA_report.pdf The Australian Commonwealth Scientific and Industrial Research Organization (CSIRO) recently released a report on the results of a life cycle assessment (LCA) of environmental outcomes and greenhouse gas (GHG) emissions in Western Australia. LCA is a technique that help evaluate/assess environmental and other related impacts on a product, process or service. This can be achieved by (1) conducting an inventory of raw material inputs, product outputs, discharge of environmental pollutants, and energy flows, (2) evaluating the material and energy flows to analyze potential environmental impacts, and (3) interpreting the results to aid in decision-making. Some highlights of the study are: (1) biofuels based on E10 (10% ethanol blend) and B5 (5% biodiesel blend) can achieve "greenhouse gas savings" equivalent to 6% reduction in GHG emissions for the transport sector in Western Australia, (2) electricity production from the ethanol plant (through the utilization of biogas from anaerobic treatment of factory waste streams) contributed significantly to GHG reduction, (3) biofuel ethanol has a net positive energy yield equivalent to 9.7 units of useable energy produced for every unit of fossil energy used in the ethanol production process. The complete LCA report can be accessed at the website Department of Agriculture and Food, Western Australia (URL above). Related information on Life Cycle Analysis |
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