EPA details emissions from ethanol facilities
Carcinogens went undetected
By Janet Kubat Willette
CHICAGO -- More than 30 different compounds are being emitted from ethanol plant smokestacks, some of which are classified as carcinogens, according to EPA officials.
But that doesn't mean there is an immediate threat to human health, the officials cautioned in a conference call held last week after a meeting in Chicago with 75 representatives from 46 Midwest ethanol plants.
Volatile organic compounds detected in dryer exhaust include ethanol, methanol, acrolein, acetaldehyde, formaldehyde, lactic acid and acetic acid, according to the EPA. Acrolein and acetaldehyde are cancer-causing, said Steve Rothblatt, acting director of air and radiation division for EPA Region 5.
The emissions went undetected for so long because ethanol and methanol were assumed to be the only emissions from the ethanol production process, Rothblatt said.
It was only after studies were done at Gopher State Ethanol in St. Paul following odor complaints that the other compounds were discovered, said Tom Skinner, EPA Region 5 administrator. That's been in the last 18 months.
Since then, tests have been done at four other dry milling facilities in Minnesota and Indiana. Those tests contained similar compounds.
"It isn't about who knew what when," said Jim Warner, director of the Minnesota Pollution Control Agency majors and remediation division. "It's now that we have the information, what is the best way to address the issue."
Most of the discussion has focused on thermal oxidizers. This control technology can be installed in as little as six months, Rothblatt said. Other possible solutions include re-routing emissions and process variations.
Emission solutions will be unique to each plant, Skinner said.
"We want to work individually with these plants because they're not all the same," he said.
Monte Shaw, spokesman for the Renewable Fuels Association, said the ethanol industry is committed to dealing with the emissions issue in the short term.
"We want to make any necessary changes quickly and move on," he said.
Not all plants will be required to make changes, Shaw said. The emissions from wet milling plants haven't been cited. Other plants already have thermal oxidizers.
"With any type of manufacturing you're going to have certain emissions," he said. "This is a manufacturing process. I just hope there's some perspective."
Neither MPCA nor RFA officials were able to say how the cancer-causing emissions resulted from a process where corn is fermented into ethanol, but most of the emissions are released in the drying process.