Corn Ethanol: Hero or Hype?

Image Gallery Up to your ears in ethanol hype? Before you choose E85 at the pump, consider the complicated issues behind this biofuel. ISTOCKPHOTO/BILL GROVE

Ethanol is ethyl alcohol, sometimes called “grain alcohol.” It’s made by fermenting the sugar and starch in the corn into alcohol, which is then separated from the water by distillation.

In the United States, most ethanol is produced from corn. You’re likely to encounter ethanol as a fuel additive or as E10 (10 percent ethanol, 90 percent gasoline), on which any modern vehicle with a gas engine can run. Full-fledged ethanol fuel — E85 (85 percent ethanol, 15 percent gasoline) — has limited, although increasing, availability and requires a car with a “flex-fuel” engine. Unlike gasoline, ethanol is renewable, and it causes less tailpipe emissions.

Why isn’t corn ethanol the answer?

As gas prices and concerns about global warming skyrocket, demand for ethanol continues to grow. But increased use of corn and other grains to produce ethanol is one of several factors pushing up the price of food made from these crops (including meat from animals fed with grains).

Lester Brown, president of the Earth Policy Institute, who has studied these issues for decades, describes this as the beginning of a great tragedy. “The United States, in a misguided effort to reduce its oil insecurity by converting grain into fuel for cars, is generating global food insecurity on a scale never seen before,” he says.

Other issues relative to corn ethanol include:

• In current engines, E85 provides about 30 percent less fuel economy than gasoline.
• Ethanol cannot be transported through existing pipelines because it is corrosive and easily absorbs water. It must be delivered by trucks, barges and rail cars, which produces more pollution.
• Converting remaining prairie, forests and rainforests into cropland will release CO2 and add to the problems of global warming. (Experts debate the extent of this concern.)
• Even if all current U.S. corn production went to biofuels, we could offset just 12 percent of our current gasoline use, according to a 2006 study from the University of Minnesota.
• Expanding ethanol production could diminish and pollute local water supplies.
• The numbers are debated among scientists, but it appears that, at best, the energy produced by corn ethanol is only slightly more than the energy required to make it.