286. COAL AND THE EROEI OF CORN ETHANOL
The EROEI of corn (maize) ethanol is one of the "hot button" issues of peak oil, and a source of endless debate. On one side, you've got the partisans of David Pimental who say corn ethanol has an EROEI less than 1, and thus takes more energy to make than it actually contains. On the other side, you've got folks citing a variety studies showing Pimental to be in error.
This debate crops up again and again, and in fact, we had a little outbreak in the comments of this blog the other day.
The topic is boring in the extreme, and guaranteed to give you a migraine headache, so let's save ourselves a lot of time and misery by short-circuiting the entire fruitless argument.
My thesis: The poor EROEI of corn ethanol doesn't matter if you use a cheap, non-liquid form of energy (like coal) to do the distilling and synthesize the fertilizer etc. If you proceed that way, then ethanol can be regarded as a form of "coal liquefaction", and the low EROEI doesn't matter. The question is whether coal liquefaction via ethanol is more cost effective than coal liquefaction via other routes.
It turns out that this is exactly where the future of corn ethanol is going -- a fact I learned from Robert Rapier. Robert is a chemical engineer working in the oil industry, and has an outstanding new blog (R-SQUARED) which I will be adding to the POD sidebar. He is definitely the source to turn to for the best information on biofuels. In a great post on the future of grain ethanol, he describes a number of work-arounds for low EROEI and covers the coal strategy:
The final option is one that most environmentalists probably will not embrace. However, it is the one most likely to take place in the short-term. The natural gas input into ethanol production is a serious long-term threat to economic viability. Since natural gas is a fossil fuel, and supplies are diminishing, it will put upward pressure on the price of ethanol over time. However, if the energy inputs could be produced from coal, ethanol prices would be insulated from escalating natural gas prices. This might also end the EROI debate. I have heard the argument go something like this. "If I have 1 BTU of coal, who cares if I only get back 0.8 BTUs of ethanol? I converted the BTUs into a readily usable liquid form." This argument may be valid from both an economic and EROI point of view, but it ignores the fact that coal is still an inherently dirty energy source. If coal remains abundant and cheap, coal economics will beat natural gas economics, but coal will increase the rate at which we put carbon dioxide into the atmosphere. If we come up with a viable method of sequestering the carbon dioxide produced at the power plant, then we might finally have a viable economic solution (although we are still using up a non-sustainable fuel in the process).SourceRobert also happened to find this article from the Christian Science Monitor which describes how coal-based ethanol is catching on in Iowa. From the article:
Late last year in Goldfield, Iowa, a refinery began pumping out a stream of ethanol, which supporters call the clean, renewable fuel of the future.Cleaner options in the same vein include using nuclear or solar process heat.
There's just one twist: The plant is burning 300 tons of coal a day to turn corn into ethanol - the first US plant of its kind to use coal instead of cleaner natural gas.
An hour south of Goldfield, another coal-fired ethanol plant is under construction in Nevada, Iowa. At least three other such refineries are being built in Montana, North Dakota, and Minnesota.Source
-- by JD