Producing ethanol & biodiesel from corn not worth the energy

By Susan S. Lang -- Cornell University News Service

ITHACA, N.Y. -- Turning plants such as corn, soybeans and sunflowers into fuel uses much more energy than the resulting ethanol or biodiesel generates, according to a new Cornell University and University of California-Berkeley study.

"There is just no energy benefit to using plant biomass for liquid fuel," says David Pimentel, professor of ecology and agriculture at Cornell. "These strategies are not sustainable."

Pimentel and Tad W. Patzek, professor of civil and environmental engineering at Berkeley, conducted a detailed analysis of 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. Their report is published in Natural Resources Research (Vol. 14:1, 65-76).

In terms of energy output compared with energy input for ethanol production, the study found that:

--Corn requires 29 percent more fossil energy than the fuel produced.

--Switch grass requires 45 percent more fossil energy than the fuel produced.

--Wood biomass requires 57 percent more fossil energy than the fuel produced.

more

http://worldnewstrust.org/modules/AMS/article.php?storyid=1872

decompose and ferment into methane gas without any extra energy!

How stupid are we for not ramping up an alternative energy program on both Hemp and Algae, while simultaneously pushing conservation and pushing public transportation?

even if it is not economically feasible it may be our only choice if the oil supply is cut off. It's better to have an expensive fuel than none at all.

They weren't looking at costs.

However, they were comparing fossil fueled needed vs the energy produced. Problem is, almost all proponents of bio-sourced fuels look into using the whole plant. Ie: when you produce ethanol from corn, burn the otherwise wasted husks and stalks for heat. Thus the plant itself fuels some of its own production.

Corn is also a poor example to highlight, as proponents are looking at far more productive species, such as hemp or algaes.

Wonder who paid Cornel for this study?

at a Peak Oil conference in NYC in October. He made a very convincing case that ethanol production is a net loss of energy, when considering inputs such as fertilizer and farm machinery. In any case, it's no panacea.

who claims on the web to be an 'expert" from a better school then Cornell. Have you ever been to Ithaca? Worse then Pittsburgh.

The fundamental hole in the Pimentel-Patzek study is that they assume the classic "petroleum refinery centric chemical engineering" model of Olaf Hougen (the "founder" of the academic discipline of chemical engineering).

Traditional "petroleum refinery centric chemical engineering" minimizes "residence time" in the process equipment. It does this by the use of high temperatures and high pressures to carry out the processes. That may work for "cracking" asphalt into octane. But - it is not what you use for "biochemical" processes --- like fermentation and digestion.

"Biochemical" processes --- fermentation and digestion --- are carried out at approximately "room temperature" conditions (50 - 100 degrees F, atmospheric pressure). Cheaper process equipment, cheaper process conditions.

That's the magic of biofuels.

Don't believe everything on the internet -- I claim to have a doctorate in chemical engineering -- but "who knows?"

Do their processes just use less energy? Just wondering.

to see where the funding for this study came from, of course, it's a pay only journal, so ... but was able to look about for other criticism on this article:

"The NREL study of 1998 say's virtually the opposite (see page 59):
http://www.nrel.gov/docs/legosti/fy98/24089.pdf

Biodiesel has a Net Energy gain of 3.2
Ethanol has a Net Energy gain of 1.34

Both of these values have been significantly improved upon since that study was published.

What to believe? Here's a fact for you from Prof. Patzek's own website - he is the Director of the UC Oil Consortium, which get's up to $120k/yer from each company in the program. How unbiased do you think he is now?
http://petroleum.berkeley.edu/ucoil.html

If you actually read his paper (p.66 of Natural Resources Research, vol 14, no. 1) and look at the numbers he uses, you will find that he concludes that it takes 271 gallons of ethanol equivalent of energy to produce 914 gallons of ethanol. That is actually 3.4 times more output than input (this includes ALL energy inputs, even the energy of Labor!!).
http://petroleum.berkeley.edu/papers/Biofuels/uc_scientist_says_ethanol_uses_m.htm

GET THE FACTS!"

http://www.greencarcongress.com/2005/07/fuel_to_the_fir.html


hmm. who to believe? :shrug:


dp

If anyone thinks the oil empire wouldn't pay for and publicize "studies" that claim that other forms of energy are "not economically feasible" or otherwise "not feasible", they are not living in the real world.

I say, let's try the other forms of energy ANYWAY!

Why assume you're going to use petroleum fuels to run the farm machinery? Why assume consumption of petroleum-derived insecticides and petro-fueled fertilizer production?

Why not assume instead that you're going to burn ethanol or biodiesel to run the equipment? Then there would be zero consumption of petroleum, just sunlight --> fuel.

If corn cost *that* much to produce, we wouldn't be feeding it to livestock.

It sounds like this research was funded by the petroleum industry. I don't think it's likely to survive close examination.

rec'd