everyone has already said corn and soy sucked for a fuel stock- ive actually gotten pretty mouthy about it... Jason ICQ#: 154998177 MSN: [EMAIL PROTECTED] ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <biofuel@sustainablelists.org> Sent: Wednesday, October 18, 2006 7:38 PM Subject: [Biofuel] recent study of bio fuel energetics; abstract
> Forwarding from another list. > > Darryl > > ====================================== > >>From the Cover > BIOLOGICAL SCIENCES / SOCIAL SCIENCES / ECOLOGY / SUSTAINABILITY > SCIENCE-SS > Environmental, economic, and energetic costs and benefits of biodiesel > and ethanol biofuels > > Jason Hill*,,,, Erik Nelson, David Tilman*,, Stephen Polasky*,, and > Douglas Tiffany > > Departments of *Ecology, Evolution, and Behavior and Applied > Economics, University of Minnesota, St. Paul, MN 55108; and Department > of Biology, St. Olaf College, Northfield, MN 55057 > > > > Negative environmental consequences of fossil fuels and concerns about > petroleum supplies have spurred the search for renewable > transportation biofuels. To be a viable alternative, a biofuel should > provide a net energy gain, have environmental benefits, be > economically competitive, and be producible in large quantities > without reducing food supplies. We use these criteria to evaluate, > through life-cycle accounting, ethanol from corn grain and biodiesel > from soybeans. Ethanol yields 25% more energy than the energy invested > in its production, whereas biodiesel yields 93% more. Compared with > ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the > agricultural nitrogen, phosphorus, and pesticide pollutants, > respectively, per net energy gain. Relative to the fossil fuels they > displace, greenhouse gas emissions are reduced 12% by the production > and combustion of ethanol and 41% by biodiesel. Biodiesel also > releases less air pollutants per net energy gain than ethanol. These > advantages of biodiesel over ethanol come from lower agricultural > inputs and more efficient conversion of feedstocks to fuel. Neither > biofuel can replace much petroleum without impacting food supplies. > Even dedicating all U.S. corn and soybean production to biofuels would > meet only 12% of gasoline demand and 6% of diesel demand. Until recent > increases in petroleum prices, high production costs made biofuels > unprofitable without subsidies. Biodiesel provides sufficient > environmental advantages to merit subsidy. Transportation biofuels > such as synfuel hydrocarbons or cellulosic ethanol, if produced from > low-input biomass grown on agriculturally marginal land or from waste > biomass, could provide much greater supplies and environmental > benefits than food-based biofuels. > > > corn | soybean | life-cycle accounting | agriculture | fossil fuel > > > > -------------------------------------------------------------------------------- > Contributed by David Tilman, June 2, 2006 > Author contributions: J.H., D. Tilman, and S.P. designed > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (50,000 > messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.408 / Virus Database: 268.13.5/482 - Release Date: 10/18/2006 > > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.5/482 - Release Date: 10/18/2006 _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
