by Paul R. Hollrah
May 01, 2007 01:44 PM EST
With each passing day, the push to substitute renewable energy sources for non-renewable sources, e.g. fossil fuels, begins more and more to resemble the global warming hysteria that recently won Al Gore an Academy Award. But before we all jump onto the most celebrated of renewable energy bandwagons, ethanol fuels, there are some basic things about ethanol that everyone should know.
So what is ethanol? Otherwise known as ethyl alcohol, or grain alcohol, ethanol is a slightly toxic, colorless, flammable liquid produced by fermentation. It is found in alcoholic beverages and is commonly referred to as alcohol.
Fermented beverages are usually classified by the foodstuff from which they are made. Beer is made from cereal grains and other starchy materials, while wines and ciders are made from fruit juices. Most beers contain from 3-5% ethanol; wines contain from 8-12% ethanol; while other fortified alcoholic beverages contain up to 25% ethanol, by volume.Distilled beverages, containing ethanol percentages up to 100% (pure grain alcohol) are made by distilling fermented beverages.
Categories of distilled beverages include whiskeys, distilled from fermented cereal grains; brandies, distilled from fermented fruit juices; and rum, distilled from fermented molasses or sugarcane. Vodka, made from fermented grain or potatoes, tequila, and other spirits, rarely have a taste associated with the starting material.
Moonshine, the most storied homemade ethanol, is made by fermenting a sugar source, usually corn, to produce ethanol and then separating the alcohol from the fermented mixture (the mash) through distillation: cooking the mash to produce ethanol vapors and then converting the vapors to liquid by cooling, as in a copper coil.
The downside to homemade ethanol is that methanol, and other highly toxic alcohols, can occur naturally in distilled spirits, resulting in the potential for death or blindness when consumed.
Home distillation of ethanol for commercial resale is still illegal in the United States, although the fermentation of beer and wine was legalized in 1978. Nevertheless, home distillation of ethanol is growing in popularity, with instructions, materials, and support available on the Internet.
However, the largest single use of ethanol is as a motor fuel or fuel additive. As the Wikipedia Encyclopedia notes, “As early as prohibition, there have been stories of moonshiners using their product as a powerful fuel in their automobiles… The sport of stock car racing got its start when moonshiners would modify their automobiles to outrun federal government revenue agents.”
Today, the world’s largest ethanol production industry is in Brazil, where a major automotive innovation has been the flex fuel engine… capable of running on pure ethanol, all gasoline, or any combination of both, depending on relative price fluctuations in gasoline and ethanol.
Brazil’s success in ethanol conversion was only possible because of the country’s efficient sugar cane industry. Sugar cane not only has a greater concentration of natural sugar (about 30% more than corn) but is also easier to process.
In the United States, the primary ethanol feedstock is corn. Approximately 2.8 gallons of ethanol can be produced from a bushel of corn. However, ethanol produced by grain fermentation and distillation always contains a small amount of water: at least 4.4%. This amount of water cannot be removed by further distillation; and while the product may be eminently suitable for human consumption, the presence of the water makes the ethanol unusable as engine fuel unless purified (dried) by other processes.
Critics say that the principal problem with the use of ethanol as an automotive fuel is that the energy-returned-on-energy-invested (EROEI) for ethanol made from corn is approximately 1: 1. In other words, it takes roughly as much energy (for planting and harvesting, natural gas based fertilizers, transportation, and processing) to create a gallon of ethanol as a gallon of ethanol produces when used as a motor fuel.
Ethanol advocates reject that notion outright, suggesting that the EROEI models fail to include the energy reducing byproducts of ethanol production, such as utilizing corn stalks as fuel in the distillation process. In addition, they suggest that waste mash from the distillation process can be used as a supplement in cattle feed and that the waste material subsequently produced by the cattle can then be used as a replacement for natural gas-based fertilizers.
According to the Renewable Fuels Association, 107 grain biorefineries in the U.S. have a production capacity of 5.1 billion gallons of ethanol per year, while an additional 56 plants, now under construction, can add 3.8 billion gallons of new capacity in the next 18 months. This is compared to U.S. gasoline demand currently at 150 billion gallons per year.
Clearly, ethanol as a motor fuel has a lot of hurdles to clear before it can ever be seen as a major factor in the motor fuel market. For example, the United States does not have enough cropland to grow the corn necessary to supply the motor fuel market. And, in a food-starved world, do we really want to dedicate that much arable land to the production of ethanol?
And finally, if we produce automobiles to run on pure ethanol, as opposed to gasoline-ethanol blends, what’s to stop our kids from drinking our tanks dry as opposed to driving them dry? Locking gas caps, anyone?
