AcresUSA.com links

Corn Use for Ethanol

By Dr. Harold Willis

For the last several years, the possibility of using corn to produce a vehicle fuel — ethanol — has generated much excite­ment among politicians and the agribusiness industry. Can growing our own fuel really free the U.S. from importing so much foreign oil?

Ethanol is just the chemist’s name for what is often called ethyl alcohol or grain alcohol. It can and has been produced from many sources for thousands of years: fruits, grains, pota­toes and sugar cane, for example. It has usually been made for human consumption in the form of beer, wines, vodka, whiskey and many others. Corn grain is just one convenient source.

Corn being processed into ethanol.

All that is needed is an organic material (or biomass) con­taining a source of sugar (starch and cellulose can be changed into sugar). Certain yeasts can transform (ferment) sugar into alcohol. When corn is used, the left-over solids, called distiller’s grain, can be used as livestock feed, and wastewater (high in nitrogen) can be used as a fertilizer.

With recent price increases in petroleum, interest in biofu­els has greatly increased, with scores of ethanol plants going up, especially in corn belt states. As long as the base price for oil is high enough, ethanol production can be profitable, but in late 2008, the petroleum price nose-dived, and many ethanol plants went out of business. During the brief heyday of corn ethanol production (especially 2007-2008), the demand for corn was so high, with as much as 25 to 30% of the U.S. harvest used for ethanol, that livestock feeders had trouble obtaining corn, driv­ing prices as high as $4 a bushel. Corn farmers loved that and increased their corn acreage (even plowing up land set aside for conservation), but it all caused considerable economic disrup­tion. Critics questioned the wisdom of diverting a food crop to fuel when malnutrition and starvation are worldwide problems.

But besides the uncertain economic aspects of ethanol pro­duction, there are several other drawbacks. For one, the use of corn as a fuel source is hardly worthwhile, ecologically speak­ing. Depending on whose figures you use, growing and distill­ing corn may or may not take more energy than the ethanol pro­duces when it is burned as fuel. You have to include the energy used to plant and harvest the crop, and to make the fertilizer, herbicide and pesticides that most corn farmers use (all of those products are usually made from and with petroleum or natural gas). Then the distillation process also uses a lot of fossil fuel.

Also, when ethanol is used as a vehicle fuel, it does not give as many miles per gallon as gasoline (only about 66% as many), so ethanol is blended with gasoline (another reason for this is that engines require special modification to burn pure ethanol). Burning ethanol does produce less carbon dioxide (CO2) than an equal amount of gasoline, but if the use of petroleum in corn growing and distillation is added in, corn ethanol isn’t a great help in fighting climate change.

Many critics of corn ethanol are hoping that the commercial production of ethanol from other sources of biomass, such as switchgrass, sugar beets, crop wastes, lumbering wastes, city leaves, garbage, and so on, will supplant the use of corn, These alternate sources would likely be more economical than using corn, but if some of the crops (switchgrass and other dryland plants) require tilling thousands of acres of marginal farmland, prairies and deserts, the ecological destruction and dust-bowl conditions could be devastating.

Although corn-based fuel may not turn out to be such a great thing, ethanol from other sources, as well as biodiesel made from oil seed crops (especially soybeans), waste vegetable oils and even single-celled algae may eventually help to alleviate the future shortage of petroleum.

Source: How to Grow Top Quality Corn

, , ,