Ethanol always not as green as some believe
Ethanol not always as green as some believe
mongabay.com
February 16, 2007
Ethanol is generally not as green as some people believe says Bruce Dale, Michigan State University professor of chemical engineering and materials science.
Speaking at the American Association for the Advancement of Science annual meeting in San Francisco, Dale says that while corn ethanol produces less greenhouse gases than gasoline, it can cause other detrimental environmental effects if not carefully managed.
“Biofuels can provide large environmental benefits when compared to gasoline or petroleum diesel,” said Dale. “But if we’re going to fully realize the environmental potential of biofuels, we need to plan carefully. For example, producing ethanol from corn grain can release large amounts of nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide, into the environment. It’s possible to minimize nitrous oxide emissions and significantly improve the greenhouse gas profile of ethanol, but we need to be aware of and deal squarely with this issue.”
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Dale said that the use of cover crops — such as rye grass during the winter — can reduce greenhouse gas emissions significantly, while rasiging levels of organic nutrients in the soil. He also notes that harvesting corn stalks or the cover crop to make cellulosic ethanol can cut nitrous oxide emissions and reduce the use of gasoline usually used for corn production.
“We need to carefully consider and intelligently manage the entire ethanol production system for long- term sustainability — not just focus on pieces of the system,” Dale said. “Ethanol is and will be a critical part of reducing our national dependence on oil for liquid fuels. Production technology for both corn and cellulosic ethanol is advancing rapidly. So it’s essential that we understand how to improve all portions of the system for maximum environmental benefits.”
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