[Plant-education] Re: bioethanol

David R. Hershey via plant-ed%40net.bio.net (by dh321 At excite.com)
Sat Jan 6 00:08:04 EST 2007

Tad Patzek of the University of California, Berkeley, and David
Pimental of Cornell University have published detailed analyses that
indicate that bioethanol production requires more energy as fossil fuel
than present in the bioethanol.

The National Corn Growers Association has analyses from consultants and
federal government scientists that show a net gain in energy for corn
bioethanol production.

I find Patzek and Pimental's analyses much more believable. If corn
ethanol production yielded more energy than it required, the corn
ethanol industry would be able to run all their fertilizer and
pesticide factories, farm machinery and ethanol production facilties on
bioethanol rather than fossil fuels and still have a net production of
ethanol. I have never heard this even being attempted on a pilot
project basis.

Large U.S. government subsidies for the corn bioethanol industry are
attractive politically for several reasons. They create jobs in farm
states. They make it appear that the government is doing something to
counter global warming. They make it appear that the government is
working to reduce dependence on foreign oil.


Patzek, T.W. 2006. Thermodynamics of the corn-ethanol biofuel cycle.
updated web version of Critical Reviews in Plant Sciences 23: 519-567

National Corn Growers Association. The Truth About Ethanol -
Addressing the Myths of the Pimentel/Patzek Study

Google search for ethanol boondoogle

David Alan Walker wrote:
> Agricultural food production in the UK is reckoned to be about the most
> efficient (yields per acre) in the 'Western World'. Yet, if all of the sums
> are done, it turns out that there is no net energy gain. It is, in fact, "a
> very inefficient way of turning oil in to potatoes". Where does this leave
> bioethanol production from conventional and unconventional crops?
> Clearly many of the inputs are about the same but then there is the
> additional, inescapable energy cost of distillation. O.K., distillation
> processes are more energy efficient than they were a few decades ago but,
> in the end, there is no way round the laws of physics. Does any one have
> itemised details of the energy inputs involved ?
> Many thanks,
> David

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