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News and Trendshttp://web.mit.edu/newsoffice/2009/prinn-greenhouse-tt0311.html http://www.agu.org/pubs/crossref/2009/2008JD011162.shtml (may require paid subscription for full access) International scientists from the Massachusetts Institute of Technology (MIT), the Scripps Institution of Oceanography (United States) and other institutions report that a widely used pest control fumigant, sulfuryl fluoride, "has the potential to contribute significantly to future greenhouse warming". However, since it has not yet reached alarming levels, there is still time to consider strategies for intervention. Sulfuryl fluoride is reported to be a widely-used fumigant which replaced the phased-out methyl bromide. Ron Prinn, co-author and director of the Center for Global Change Science (at the Massachusetts Institute of Technology), mentions that sulfuryl fluoride is "about 4,800 times more potent a heat-trapping gas than carbon dioxide" and has a lifetime of about 36 years. While the fumigation industry is a big industry, and is necessary to "preserve buildings and food supply", identifying the greenhouse risks of the chemical would give the industry "a chance to find other substitutes at a time when that's still a relatively easy change to implement". Related information on greenhouse gases and global warming potential http://www.eia.doe.gov/bookshelf/brochures/greenhouse/Chapter1.htm
http://www.bioenergy.novozymes.com/files/documents/2009-03043-01.pdf Danish biotechnology solutions provider, Novozymes, recently launched two of its latest class of enzymes designed to further improve the cost competitiveness of cellulose ethanol production. The first enzyme (called "CellicTM CTec") is a "specially designed cellulase complex" that converts cellulose in the plant biomass to glucose (the 6-carbon sugar which is subsequently fermented to ethanol). The second enzyme (called "CellicTM HTec") is a hemicellulase which converts the hemicellulose components of the plant biomass into another fermentable 5-carbon sugar, xylose. Xylose can also be converted into ethanol by xylose-fermenting microorganisms. The cellulase complex is reported to be lower in cost, and can be applied to cellulose at lower dosages. The new generation enzymes are seen to "propel the cellulosic ethanol industry towards commercial viability"..
http://www3.interscience.wiley.com/cgi-bin/fulltext/121647166/HTMLSTART?CRETRY=1&SRETRY=0 Scientists from the University of Nebraska (United States) report that "corn-ethanol systems have substantially greater potential to mitigate greenhouse gas (GHG) emissions and reduce dependence on imported petroleum for transportation fuels than reported previously". Their findings, which appear in the Journal of Industrial Ecology, attempted to study the impacts of improved technologies in corn ethanol production on "environmental performance metrics", using life cycle assessment (LCA). The results showed that corn-ethanol can achieve between 48% and 59% reduction in GHG relative to petroleum-based transport fuels; this is about two to three times higher than previously estimated. According to the researchers, "the effectiveness of corn ethanol in reducing emissions could be even higher, depending on the technology used and the way the corn, ethanol and by-products are handled". For example, a "closed-loop bio-refinery" with an anaerobic digestion system reduces GHG emissions by 67%. The scientists concluded that improved technologies can move corn ethanol "closer to the hypothetical estimates for cellulosic ethanol".. Energy Crops and Feedstocks for Biofuels Productionhttp://cleantech.com/news/3820/indonesia-chooses-seaweed-biofuel The Indonesian Ministry of Fishery and Marine Resources is undertaking a joint collaboration with the Korea Institute of Industrial Technology, in an effort to harness its ample seaweed resources for biodiesel production. A "Geladine" variety of seaweed that is cultivated in Maluku, East Belitung and Lombok areas in Indonesia is being considered as feedstock for biodiesel production. According to Indonesian officials, South Korea has the processing technology for the conversion of seaweed into biodiesel, but it does not have the feedstock. The Cleantech website reports that the South Korean Government "signed a deal to lease 25,000 hectares (61,750 acres) of Indonesian coastal waters to grow seaweed for biofuel".. Biofuels Processing
http://aem.asm.org/cgi/content/abstract/75/4/907 The yeast, Saccharomyces cerevisiae, is the popular microorganism used for biofuel ethanol fermentation. In the production of cellulose ethanol, the yeast is added to a sugar mixture obtained after the breakdown of lignocellulosic plant biomass (by pretreatment and saccharification). Sugar mixtures from pretreated and saccharified lignocellulosic biomass often contains glucose (a 6-carbon sugar, or a "hexose") , and xylose/arabinose (both 5-carbon sugars, or "pentoses"). Generally, the yeast only utilizes the glucose in the sugar mixture for ethanol production. The pentoses (xylose and arabinose) are often left unutilized. One of the challenges for cost-effective cellulose ethanol production is the development of a S. cereviseae strain which can convert not only the hexoses (glucose) into ethanol, but also the pentoses (xylose and arabinose). In some way, a "sugar omnivore" can be considered a good ethanol-fermenting yeast. Recently, scientists from the Delft University of Technology (Netherlands) reported the use of evolutionary engineering to develop a strain of S. cerevisiae that is capable of fermenting mixtures of glucose, xylose, and arabinose with a high ethanol yield (0.43 gram per gram of total sugar). The conversion was achieved without the formation of undesirable side products, such as xylitol and arabinitol. The strategy involved "a regimen consisting of repeated batch cultivation with repeated cycles of consecutive growth in three media with different compositions (glucose, xylose, and arabinose; xylose and arabinose; and only arabinose)". The regimen allowed rapid selection of an evolved strain (IMS0010), exhibiting improved specific rates of consumption of xylose and arabinose. Details of their work are published in the journal, Applied and Environmental Microbiology (URL above).. Biofuels Policy and Economics
http://www.thebioenergysite.com/news/3201/new-alliance-appeals-to-world-bank The Global Renewable Fuels Alliance (GRFA) is a global federation of 29 member countries representing more than 60 percent of the world's renewable energy production. It was formally created in February 2009. Its main objectives are (1) to promote "the expanded use of renewable fuels throughout the world through the advocacy of sound public policy and responsible research", and (2) to produce renewable fuels "with the smallest possible ecological footprint" through the "development of new technology and best practices". At the recent National Ethanol Conference in San Antonio, Texas, the GRFA called on the World Bank to make investments in biofuels infrastructure in developing countries a top priority. According to the World Bank, many developing countries have "substantial agricultural bases and are well positioned to grow highly productive energy crops".. http://www.ers.usda.gov/AmberWaves/march09/Features/Biofuels.htm A feature article from the online version of "Amber Waves" (a magazine of the United States Department of Agriculture Economics Research Service, USDA-ERS) describes scenarios on how the agricultural landscape can change with increased cultivation of corn and other bioenergy crops for biofuel production. The Energy Independence and Security Act (EISA) of 2007 (United States) contains provisions for a Renewable Fuel Standard (RFS) mandating an increase in the supply of alternative fuel sources by requiring fuel producers to use at least 36 billion gallons of biofuel by 2022. This includes 15 billion gallons of "conventional" (i.e. "corn") ethanol by 2015, and 21 billion gallons of non-corn ethanol by 2022. Among the impacts are: (1) expanded crop acreage due to the federal mandate, including shifts in cropping patterns and livestock production due to higher prices for corn and other grain crops, (2) the "extent of agricultural land in production and intensity of input use increases the potential for environmental degradation", (3) environmental impacts of increased biofuel cultivation may be mitigated by research for improvement of crop productivity and conversion efficiency, as well as conservation practices like no-till and buffer strips. Access to the full article is available at the online version of Amber Waves (URL above).. |
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