HPImpact: Debate continues over ethanol use vs. actual energy savings
Hydrocarbon Processing September 2005. p. 1
ProQuest database
Section:
HPImpact
Publication title: Hydrocarbon Processing. Houston: Sep 2005. pg. 1
Source type:
Periodical
Abstract (Document Summary)
Studies from two major universities claim that the amount of energy produced by ethanol
or biodiesel fuels is in fact less than the energy used to make the fuels. This indicates that
ethanol and biodiesel fuels are not sustainable since they are not renewable or
economical.
Full Text (362 words)
Copyright Euromoney Institutional Investor PLC Sep 2005
WENDY WEIRAUCH, MANAGING EDITOR
Comments? Write:
WW@HydrocarbonProcessing.com
Turning plants such as corn, soybeans and sunflowers into fuel uses much more energy
than what the resulting ethanol or biodiesel generates, according to a new Cornell
University and University of California-Berkeley study.
The detailed analysis examines the energy input-yield ratios of producing ethanol from
corn, switch grass and wood biomass as well as for producing biodiesel from soybean
and sunflower plants. The research was conducted by David Pimentel, professor of
ecology and agriculture at Cornell, and Tad W. Patzek, professor of civil and
environmental engineering at Berkeley.
"There is just no energy benefit to using plant biomass for liquid fuel," according to Dr.
Pimentel. "These strategies are not sustainable."
In terms of energy output compared with energy input for ethanol production, the study
found that:Corn requires 29% more fossil energy than the fuel produced. Switch grass
requires 45% more fossil energy than the fuel produced. Wood biomass requires 57%
more fossil energy than the fuel produced.
Examining energy output compared with the energy input for biodiesel production, the
study found that:Soybean plants require 27% more fossil energy than the fuel produced.
Sunflower plants require 118% more fossil energy than the fuel produced.
In assessing inputs, the researchers considered such factors as the energy used in
producing the crop (including production of pesticides and fertilizer, running farm
machinery and irrigating, grinding and transporting the crop) and in fermenting/ distilling
the ethanol from the water mix.
Although Dr. Pimentel advocates the use of burning biomass to produce thermal energy
(to heat homes, for example), he disputes the use of biomass for liquid fuel. "The
government spends more than $3 billion a year to subsidize ethanol production when it
does not provide a net energy balance or gain, is not a renewable energy source nor an
economical fuel. Further, its production and use contribute to air, water and soil pollution
and global warming," he says.
Ethanol producers dispute Dr. Pimentel's and Dr. Patzek's findings, saying that the data
are outdated and don't take into account profits, which offset costs. In addition, the
National Corn Growers Association observes that "their study may have a hidden
political agenda." HP