Refutation of Anti-Ethanol Research by Cornell Scientist
Here is the research that nearly destroyed consumer confidence in Ethanol as an alternative to petroleum with my comments in braces [ ] ....
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Ethanol fuel from corn faulted as 'unsustainable subsidized food burning' in analysis by Cornell scientist
FOR RELEASE: Aug. 6, 2001
Contact: Roger Segelken
Office: 607-255-9736
E-Mail:
hrs2@cornell.edu
ITHACA, N.Y. -- Neither increases in government subsidies to corn-based ethanol fuel nor hikes in the price of petroleum can overcome what one Cornell University agricultural scientist calls a fundamental input-yield problem: It takes more energy to make ethanol from grain than the combustion of ethanol produces.
At a time when ethanol-gasoline mixtures (gasohol) are touted as the American answer to fossil fuel shortages by corn producers, food processors and some lawmakers, Cornell's David Pimentel takes a longer range view.
"Abusing our precious croplands to grow corn for an energy-inefficient process that yields low-grade automobile fuel amounts to unsustainable, subsidized food burning," says the Cornell professor in the College of Agriculture and Life Sciences. Pimentel, who chaired a U.S. Department of Energy panel that investigated the energetics, economics and environmental aspects of ethanol production several years ago, subsequently conducted a detailed analysis of the corn-to-car fuel process. His findings will be published in September, 2001 in the forthcoming Encyclopedia of Physical Sciences and Technology .
Among his findings are:
o An acre of U.S. corn yields about 7,110 pounds of corn for processing into 328 gallons of ethanol. But planting, growing and harvesting that much corn requires about 140 gallons of fossil fuels and costs $347 per acre, according to Pimentel's analysis. Thus, even before corn is converted to ethanol, the feedstock costs $1.05 per gallon of ethanol.
[The same acre of land produces 64,000 pounds of plant fiber, cellulose, hemicellulose, and lignin which can be converted to fermentable sugars to produce far more ethanol than just from corn starch.]
o The energy economics get worse at the processing plants, where the grain is crushed and fermented. As many as three distillation steps are needed to separate the 8 percent ethanol from the 92 percent water. Additional treatment and energy are required to produce the 99.8 percent pure ethanol for mixing with gasoline. o Adding up the energy costs of corn production and its conversion to ethanol, 131,000 BTUs are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 77,000 BTU. "Put another way," Pimentel says, "about 70 percent more energy is required to produce ethanol than the energy that actually is in ethanol. Every time you make 1 gallon of ethanol, there is a net energy loss of 54,000 BTU."
[Ethanol of 180 proof, or 90% ethanol mixed with 10% water, is an excellent automotive fuel. It has slightly lower energy content compared to gasoline, but it will clean your engine of soot and residue from other petroleum-based fuels, and your engine will last 2-3 times longer. However US and Canadian laws say that ethanol must be denatured, or rendered unfit for human consumption to be sold as automotive fuel, or else extra taxes upwards of $22 per liter are applied. Denaturing ethanol is usually accomplished by mixing in 15% gasoline. Distilled ethanol up to 99.8 percent pure is needed if one intends to mix it with gasoline. The water must be removed because while water mixes with ethanol, and ethanol mixes with gasoline, water does not mix with gasoline. Removing the water to achieve such extreme purity by distillation, just so that 15% gasoline can be mixed in, is extremely wasteful of energy. Changing the law to allow non-denatured ethanol to be used as fuel without extra taxes being applied would be the best solution. If not then distillation can be avoided by using hygroscopic materials that absorb water, or by using polyvinyl alcohol membranes that remove water by osmosis, while consuming little or no energy, albeit in a more time consuming manner. ]
o Ethanol from corn costs about $1.74 per gallon to produce, compared with about 95 cents to produce a gallon of gasoline. "That helps explain why fossil fuels -- not ethanol -- are used to produce ethanol," Pimentel says. "The growers and processors can't afford to burn ethanol to make ethanol. U.S. drivers couldn't afford it, either, if it weren't for government subsidies to artificially lower the price."
[ Using all the methods available, one can achieve at least a 25% net energy gain. These methods include using cellulose as a feedstock, acid and enzyme hydrolysis to reduce them to sugars, and saving energy on the distillation end by either changing the law, or by using low-energy water separation methods.]
o Most economic analyses of corn-to-ethanol production overlook the costs of environmental damages, which Pimentel says should add another 23 cents per gallon. "Corn production in the U.S. erodes soil about 12 times faster than the soil can be reformed, and irrigating corn mines groundwater 25 percent faster than the natural recharge rate of ground water. The environmental system in which corn is being produced is being rapidly degraded. Corn should not be considered a renewable resource for ethanol energy production, especially when human food is being converted into ethanol."
[ Corn should be eaten as food. Non-food crops can be used to produce ethanol, such as grasses, softwood & hardwood lumber residues & sawdust, even recycled cardboard. ]
o The approximately $1 billion a year in current federal and state subsidies (mainly to large corporations) for ethanol production are not the only costs to consumers, the Cornell scientist observes. Subsidized corn results in higher prices for meat, milk and eggs because about 70 percent of corn grain is fed to livestock and poultry in the United States Increasing ethanol production would further inflate corn prices, Pimentel says, noting: "In addition to paying tax dollars for ethanol subsidies, consumers would be paying significantly higher food prices in the marketplace."
[There are plenty of alternatives to corn, as noted above.]
Nickels and dimes aside, some drivers still would rather see their cars fueled by farms in the Midwest than by oil wells in the Middle East, Pimentel acknowledges, so he calculated the amount of corn needed to power an automobile:
o The average U.S. automobile, traveling 10,000 miles a year on pure ethanol (not a gasoline-ethanol mix) would need about 852 gallons of the corn-based fuel. This would take 11 acres to grow, based on net ethanol production. This is the same amount of cropland required to feed seven Americans.
o If all the automobiles in the United States were fueled with 100 percent ethanol, a total of about 97 percent of U.S. land area would be needed to grow the corn feedstock. Corn would cover nearly the total land area of the United States.
[ If cellulose were used widely to produce ethanol, rather than just corn starch, then a 10-fold reduction in the amount of land area needed would be immediately realized. At the same time a diversification of feedstocks would be available, not just corn, but all plant types, whether food crops or non-food grasses and other biomass. Furthermore 93% of cars on the road have only one person riding in them. Reducing the mass of these cars by 7-fold would proportionally increase their fuel economy by the same amount. Taken together these two factors could reduce the land area needed to 1/70th of that estimated by the Cornell scientist.]
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In addition to my own comments, and in a detailed analysis of Pimentel's research, Dr. Michael S. Graboski of the Colorado School of Mines says Pimentel's findings are based on out-of-date statistics and are contradicted by a recent US Department of Agriculture (USDA) study.
