More information on ethanol (CH3-CH2-OH):

Melting Point 156 K
Boiling Point 352 K
Density 789 kg m-3
Specific latent heat of vaporisation 839 * 10-3 l/J kg-1
Specific heat capacity 2500 J kg-1 K-1
Viscosity 1.20 * 10-3 N s m-2

Pure ethanol burns nicely with a blue flame in air to produce water and carbon dioxide.
CH3-CH2-OH + 3 O2 --> 2 CO2 + 3 H2O

physical characteristics from

Ethanol is made by converting corn starch into a sugar form through a fermentation process. Actually many crops can produce the necessary starches that make up ethanol.

Throughout the United States, there is a big government push for ethanol. Most of the big agricultural states already have ethanol initiatives in effect. The federal government already requires that only "clean" gasoline to be sold in areas with high pollution.

Why ethanol is important:

  • Reduces dependence on foreign oil
  • Fuels burn cleaner, meaning cleaner air
  • Completely renewable
  • Revitalizes American farming

Ethanol is a very good thing for rural America. As demand for corn flattened in the last decades, government initiatives promoting ethanol boosted corn prices again. Making ethanol and using ethanol both are environmentally-healthy. Plus, foreign cartels such as OPEC have less power in controlling United States energy usage.

Why ethanol is bad:

Transporting and adding ethanol to gasoline isn't free from costs. California, which is suffering quite an energy crunch lately, recently asked President Bush to discontinue federal requirements for cleaner fuels. California officials estimate removing ethanol requirements would reduce gas prices by 5 ¢ a gallon.

Despite this, ethanol use is getting bigger all the time. It's definitely a fuel for the future: environmentally and economically.

Environmentalists Are Re-thinking Ethanol

The sustainable living / renewable energy branch of Environmentalism has long listed ethanol as one of the many viable alternatives to fossil fuel, the others list members typically being wind, solar, hydrogen, fusion, and perhaps biomass.

The purpose of this write-up is not to re-hash the debate over whether there is at the moment a viable alternative to fossil fuel. The point is to make you aware that based on recent science, environmentalists should no longer consider ethanol to be a viable alternative.

Surprised? I was. Read on.

My Source

This write-up is based on peer reviewed research by a scientist who is manifestly "pro-Environment". He is not, so far as I can tell, funded by or supportive of the fossil fuel industry or any other parties that might have an anti-Environmentalist axe to grind.

The most recent research I've found was published in the Sept., 2001 issue of the prestigious, peer reviewed Encyclopedia of Physical Sciences and Technology. The study is by David Pimentel, a Professor Emeritus at the College of Agriculture and Life Sciences at Cornell University in Ithaca, NY, USA. I haven't found the study itself on the Internet, and the Encyclopedia itself costs over $3000 a copy, but you can read the press release for the study at

Ethanol fuel from corn faulted as 'unsustainable subsidized food burning' in analysis by Cornell scientist

The essential finding, from the press release:
Neither increases in government subsidies to corn-based ethanol fuel nor hikes in the price of petroleum can overcome...a fundamental input-yield problem: It takes more energy to make ethanol from grain than the combustion of ethanol produces.
For those of you who think ethanol would be desirable even if it isn't economical, remember that the argument here isn't that it's more expensive than fossil fuels, it's that ethanol is not economically viable on its own terms. It would require a net investment of energy from non-ethanol sources to produce ethanol. Using a gas-ethanol mix only dilutes the problem; the net energy contribution of ethanol to the mix is still negative.

And even if we solved the input-yield problem, the press release continues:

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:
  • 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.
  • 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.
You can read an earlier, peer reviewed study by Pimentel (BioScience -- Vol. 44, No. 8, September 1994) with essentially the same conclusions, thanks to the cheerful folks at (page down to the section titled "Ethanol"). This study, called Renewable Energy: Economic and Environmental Issues, while optimistic about many other renewable energy approaches, calmly and dispassionately dismantles the myth of ethanol (emphasis added):
The expended to produce 1 liter of ethanol from corn is 10,200 kcal, but note that 1 liter of ethanol has an energy value of only 5130 kcal. Thus, there is an energy imbalance causing a net energy loss.
These current ethanol techniques, which a recent U.S. energy bill just blessed with massive support, are not even close to having a positive net energy yield. Pimentel goes on to evaluate various ways ethanol can be made at a lower energy cost, including a promising, but still experimental, membrane technology that reduces the energy input cost from 10,200 to 6,200 kcal. Nevertheless, "the energy budget remains negative".

Even if the energy budget problem were to be solved, according to Pimentel, there are other fundamental problems with ethanol, including the environmental costs of intensive corn farming, the non-nutritive components of the sewage produced by the fermentation and refining processes, and the tailpipe emissions from burning ethanol in conventional combustion engines. He concludes: "Ethanol produced from corn clearly is not a renewable energy source. Its production adds to the depletion of agricultural resources and raises ethical questions at a time when food supplies must increase to meet the basic needs of the rapidly growing world population."

Is Pimentel Alone in His Conclusions?

Pimentel is citing not just his own research, but others as well, read the study for the list. He is published in peer reviewed journals, meaning his peers may or may not agree with him, but they agree that his research is scientific.

And some well-known lobbying groups with impeccable environmental credentials have quietly supported his view. There are many examples; if you have time to spare, search the Congressional Record or the science section of a major newspaper. For now, just one example from the Web: On April 8, 2002, Environmental Defense wrote to the National Highway Traffic Safety Administration, a major US government regulatory body,

"...a fleet (of dual-fuel cars) is of no value without a broader business case for economically viable non-petroleum fuels. In spite of massive subsidies, to the domestic ethanol industry in particular, such a business case is nowhere close to being established."
The ethanol industry has, of course, responded to Pimentel's early studies. For example, the American Coalition for Ethanol (ACE), conveniently at, cites a 1995 U.S. Department of Agriculture (USDA) study available at This study finds a net positive energy balance by making more optimistic assumptions about farming techniques, discounting the energy costs to build capital equipment and plants, etc. This study is also peer reviewed, so it's hard to evaluate these conflicting assumptions, but I can say that the Agriculture Department study is underwhelming: it finds an energy balance of 1.24, meaning you'd have to burn the energy equivalent of 4 liters of ethanol to produce 5 liters of ethanol. I'm guessing that Pimentel is aware of this USDA study, and has every incentive to give ethanol the benefit of the doubt. Yet Pimentel still concluded in 2001 that the net energy balance is negative.

Corn-based Ethanol is Probably a Bust

When scientists disagree about how much benefit a new technology promises, that's one thing. When scientists can't agree if a technology with a known track record even has a benefit or not, it is safe to conclude that technology is not ready for prime time.

At this point let me insert my standard disclaimer with regards to technology: sure, it's possible that future research could solve all these ethanol problems: the next generation of refining technology could solve the energy budget problem and produce less sewage; combustion engines and emissions controls designed specifically for ethanol or gas/ethanol could ameliorate or even solve the tailpipe problem; revolutionary new agriculture techniques could one day generate high, sustainable yields on less land, or we might find a way to make ethanol from "waste" biomass instead of growing corn.

...Or, the Taelons might arrive and solve all our energy problems! The universe is a big place; Taelons aren't that much less likely than all these other solutions emerging in time for ethanol to save the planet.

But to say that the current approach, growing corn for ethanol, is one of those prêt à porter technologies held back only by inertia, addiction to fossil fuels, or evil big business, is just not true. Probably, the only reason ethanol-containing fuel is currently available in a very small scale in the U.S. at anything like a reasonable price is because cheaper fossil fuels are used to harvest, refine, and dilute the ethanol, and massive subsidies for ethanol production (on top of the traditional subsidies for corn production) hide the true cost of the process. Indeed, I would argue that corn ethanol is mostly propaganda pushed by immense agri-business concerns such as Archer Daniels Midland (ADM) who benefit financially as well as by appearing to be Green.

Under any current or foreseeable technology, corn ethanol is probably a bust.

Ethanol is the alcohol that is found in beverages and is produced as a by-product of fermentation of yeast and sugar. It is colorless and tastless - many high proof beverages are often called 'smooth' or said to go down like water (another colorless and tasteless beverage). This sugar is often part of some grain, thus the term 'grain alcohol'. To an animal (including the poor yeast that were killed as part of producing it), alcohol is a poison and the body does everything it can to make it less of one.

The first step in metabolizing ethanol is found in the stomach and is the enzyme 'alcohol dehydrogenase'. An interesting point with this enzyme is that it differs between the sexes - the same enzyme found in men is on the order of 70%-80% more effective than that in women. This difference also becomes more pronounced in young women and men over the age of 50. Frequent drinking also reduces the body's supply of this enzyme.

Alcohol dehydrogenase (often called just 'ADH') coverts ethanol to acetaldehyde - which is even more toxic than ethanol. This is then converted into acetate and various other compounds. While ADH is named after alcohol, this enzyme also processes other compounds too, such as: retinol, steroids, and fatty acids. There are actually 9 forms of this enzyme within the body - each composed of two parts (each part may be one of three chains - alpha, beta, or gamma -- 32 = 9). Furthermore, this enzyme works on a wide range of alcohols too, which can be a problem. When processing methanol, ADH converts it to formaldehyde which then damages various proteins - especially those in the retina leading to blindness. It should be noted that the treatment for several types of poisoning related to the post metabolic product (methanol, anti-freeze, and others) created by ADH is to drink lots of ethanol which is handled first by ADH, thus using up all of the ADH and allowing the not quite so poisonous compound to be flushed from the system.

As most people know, eating food along with drinking reduces the impact of the ethanol. This is because the sphincters in the stomach is closed to digest the food and gives the enzyme more time to work on the ethanol before it is passed to the intestines where the remaining ethanol will be rapidly absorbed by the body.

Once the ethanol gets into the blood stream, there are two interesting places for it to go. The first is the brain. Within the brain, ethanol acts as a stimulant and a depressant, becoming more of a depressant as the level of ethanol increases. The 'buzz' is from an increased activity in the pleasure center of the brain (similar to cocaine). Furthermore, ethanol reduces activity in the anxiety centers of the brain which leads to calming, and reduced anxiety (much akin to Valium). Yet another effect upon the brain is in the serotonin (a neurotransmitter) system similar to Prozac which reduces depression and increases self-confidence. It should be noted that these effects in the brain are addictive and lead to alcoholism. Higher levels of ethanol interferes with the brain in many areas - from reduced control over muscles (clumsy, coordination, and slurring of speech) to the formation of memories. Driving in this state of mind is drunk driving, and between the reduced control of muscles and other interferance, can be very dangerous to the driver, passengers, other drivers and people on the sidewalk. Even higher levels of ethanol cause parts of the brain to shut down and is known as alcohol poisoning.

The other interesting place in the body is that of the liver. The liver's purpose in life is to break down poisons. A healthy liver in a young adult male will take on the order of one hour to process a drink - it will take longer in a young woman. Drinking faster than the liver can process the alcohol leads to getting drunk. Realize that the liver can only do so much work - other chemicals that are metabolized in the liver such as anti-histamines and other drugs will result in something not getting done. This can either reduce the effectiveness of the drug (such as antibiotics), damage the liver (as with anti-histamines and Tylenol), or even more serious effects (see Don't mix acetaminophen with alcohol).

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