This is an excerpt from EERE Network News, a weekly electronic newsletter.
Reports Note Benefits and Limitations of Using Biofuels
New reports from a variety of sources are reaching mixed conclusions about biofuels, although overall the outlook is positive. The Worldwatch Institute published a report in June that says biofuels supplied 1 percent of the global transport fuel market last year, with production doubling since 2001. The report concludes that biofuels are poised for strong growth and could provide 37 percent of U.S. transport fuel by 2030. Although the report warns of potential agricultural and ecological risks from large-scale use of biofuels, it also notes that the long-term potential of biofuels is in the use of non-food feedstock that include agricultural, municipal, and forestry wastes as well as fast-growing, cellulose-rich energy crops such as switchgrass. See the Worldwatch Institute press release, which links to the report.
At the same time, a study from the University of Minnesota concludes that although corn ethanol yields a net energy benefit, the benefit is much greater for biodiesel. Corn ethanol delivers 25 percent more energy than is used in its production, says the study, while biodiesel from soybeans generates 93 percent more energy than is used in its production. The study also notes the limitations of both fuels: if all of the corn produced in the United States were converted to ethanol, it would replace only 12 percent of our gasoline use, while the entire soybean crop could only replace 6 percent of our diesel fuel. Like the Worldwatch Institute, the University of Minnesota researchers look to non-food plants that can grow on marginal lands with minimal input of fertilizers and pesticides as the best hope for biofuels. The study was published online by the Proceedings of the National Academy of Sciences (PNAS) on July 12th. See the University of Minnesota press release and the abstract on the PNAS Web site.
Finally, a new report from the U.S. Department of Agriculture (USDA) examines the feasibility of producing ethanol from sugar, a process used heavily in Brazil. The report concludes that it is economically feasible to produce ethanol from molasses, but it may be difficult to find a large enough molasses supply in one area to support an ethanol plant. Producing ethanol from sugar cane, sugar beets, or raw or refined sugar is questionable, however, since it costs twice as much as producing ethanol from corn. See the USDA report (PDF 367 KB). Download Adobe Reader.