I found this and was, to say the least, quite surprised. I had always thought this was a much much better alternative to gasoline if it could be implemented on a large scale.
Quote:
Switching from gasoline to ethanol — touted as a green alternative at the pump — may create dirtier air, causing slightly more smog-related deaths, a new study says.
"It's not green in terms of air pollution," said study author Mark Jacobson, a Stanford University civil and environmental engineering professor. "If you want to use ethanol, fine, but don't do it based on health grounds. It's no better than gasoline, apparently slightly worse."
The science behind why ethanol might increase smog is complicated, but according to Jacobson, part of the explanation is that ethanol produces more hydrocarbons than gasoline. And ozone is the product of hydrocarbons and nitrogen oxide cooking in the sun.
Also, the ethanol produces longer-lasting chemicals that eventually turn into hydrocarbons that can travel farther. "You are really spreading out pollution over a larger area," he said.
And finally, while ethanol produces less nitrogen oxide, that can actually be a negative in some very smoggy places. When an area like Los Angeles reaches a certain high level of nitrogen oxide, that excess chemical begins eating up spare ozone, Jacobson said.
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Fascinating stuff really.
http://www.usatoday.com/tech/science...ol-study_N.htm