How Much Fuel Does it Take to Make Ethanol Fuel?
January 10th, 2006
Daily News columnist Bill Hammond, commenting on Pataki’s State of the State address, picks up the critique that the governor’s proposal to increase the use of ethanol fuel in New York State was really intended to “pander to Iowa farmers.”
To prove the absurdity of the proposal, he cites a study by Cornell University’s David Pimentel, an ecologist, in which he states that “turning plants such as corn, soybeans and sunflowers into fuel uses much more energy than the resulting ethanol or biodiesel generates.”
The study is also cited to show ethanol as an unsustainable option to fossil fuels at The Oil Drum: New York City, a blog that focuses on NYC’s oil dependency.
But posts on the blog’s large comment section dispute the Pimentel study and one commentator points out a report published by the United States Department of Agriculture (pdf). In this report, the authors compare many studies on the subject – including their own – and find that more studies weigh in ethanol’s favor. (The commentator links to a colorful presentation on the report, in which page 16 plots the studies on a graph.)
The Rocky Mountain Institute, an energy policy nonprofit that focuses on market-based solutions, also finds fault with the Pimentel study. They say he only focuses on one method to make ethanol, which is the least efficient of three possible ways.
The oil blog has a link to a good piece by Danny Hakim for The New York Times that takes a much broader look at the governor’s proposal.
By Mike Muller on January 10, 2006, 5:38 pmIn category: Environment, Health, Tech, Transportation | 3 Comments »



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January 10th, 2006 at 10:36 pm
Mike,
It does take more fuel to make ethanol — especially corn ethanol — than the ethanol returns. (Note I said “fuel” and not “energy.”)
Fuel and energy are not the same. All fuel is energy, but not all energy is in the form of a useable fuel.
As the USDA reports says, making corn ethanol probably returns more energy than it consumes. Unfortunately, what the USDA doesn’t make obvious is that the excess energy is locked in a waste product of fermentation and distillation called distiller’s grains (DG). (Each pound of DG contains about 9600 Btu.)
Unfortunately, the energy in that DG is only useable on a micro level to livestock farmers in the immediate vicinity. On a macroscale of hundreds or thousands of ethanol plants across the country, the waste DG would start to pile up and ethanol plants would soon look like old coal mines surrounded by slag heaps, except the slag heaps around ethanol plants would be piles of distiller’s grain that no one woudl know what to do with.
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The critical fuel that corn-based ethanol consumes is natural gas.
Few realize it, but growing corn is utterly dependent on nitrogen fertilizers made from natural gas. Take away nitrogen fertilizers and corn ethanol production would soon stop.
And there is a huge problem with using those nitrogen fertilizers: Because the demand for natural gas is rapidly outstripping domestic supplies, more and more of that fertilizer is made overseas from foreign natural gas and imported into the U.S. I’ve even seen estimates from respected agricultural economists who expect that within five years we will have to import 100% of the nitrogen fertilizer our corn farmers must depend on — all of that fertilizer made overseas from foreign natural gas.
Do you think Governor Pataki thinks a dependence on imported nitrogen fertilizers made from foreign natural gas would be any better than our already ill-advised dependence on foreign oil?
April 28th, 2006 at 5:52 am
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May 16th, 2006 at 1:45 pm
As it was pointed out, there are quite a few lacunae in the Cornell University study…the basic issue appears to be that they have overestimated the energy needs at every step, which, according to the critics of the study, had resulted in a very skewed result
Be it may, I think a thorough review of the feedstock to be used for ethanol production is needed. Recent reports suggested new feedstock such as switchgrass…Is it possible that these feedstock could be be more economical, also because these are not otherwise used anywhere?
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