Ethanol producers tout themselves as part of the solution to air pollution because their product helps make gasoline burn cleaner. But EPA says ethanol plants themselves could be an important source of air pollutants.

This comes as Congress is considering tripling the amount of ethanol used in gasoline, in part as a political boon to midwestern corn farmers.

An EPA spokesman says tests by the federal agency and state regulators at a number of ethanol plants found emissions of volatile organic compounds (VOCs) and carbon monoxide that were many times greater than companies had reported. Organic compounds included three chemicals ranked as hazardous air pollutants: acetaldehyde, formaldehyde, and acrolein, he tells C&EN.

"We expect that this circumstance is not unique to the tested facilities but rather is common to most, if not all, ethanol facilities," says a recent letter from EPA's Midwestern office, which is based in Chicago. The missive invited ethanol producers to a meeting last week to discuss their air emissions. EPA subsequently canceled the meeting and rescheduled it for early June.

Monte Shaw, spokesman for the Renewable Fuels Association, an ethanol industry group, says makers of the alcohol were not aware of the emissions and have yet to see the data that triggered EPA's concern. "Nobody knew it was going on," he says.

"This is not going to be an insurmountable problem," Shaw continues. Controlling emissions will cost ethanol makers, but it will not impact capacity or expansion of the industry, he says.

Meanwhile, the Senate and House of Representatives are working out their differences on an energy bill that may increase ethanol sales. The Senate version of the bill calls for boosting ethanol use in gasoline to 5 billion gal per year by 2012.

Chemical & Engineering News
Copyright © 2002 American Chemical Society