Friday, June 29, 2012
Ethanol Does Pollute
I recently attended a lecture by a college professor about the dangers of climate change. During the presentation he praised the mechanic of the university airplane for converting it to use ethanol-based fuel. (He uses this airplane to fly to Alaska and back for his research.) Since the thrust of his presentation was reduction of CO2 in the atmosphere, it seemed strange that he should commend a switch to ethanol which is a hydrocarbon and also emits CO2 when burned. Using ethanol is about reducing dependence on foreign oil, not reducing CO2 in the atmosphere.
This may come as a surprise to some, but in this black-and-white world of environmental slogans many are led to believe that ethanol = good and gasoline = bad, as this presenter implied. After reviewing a number of sources, I found the below table on CO2 emissions and the energy per gallon for various substances. There is a more detailed explanation on the source website. The conclusion is that ethanol emits less CO2 per gallon, but also produces less energy per gallon. When you go through the calculations, it comes out that it emits at least 95% of CO2 as gasoline for an equivalent amount of energy to power your car or this airplane. Ethanol is not really a “cleaner” fuel in terms of CO2 for climate change modeling.
Now consider how much land area an oil well takes up compared to a cornfield and that use of gasoline does not affect the food supply. Is this another instance where we have not applied sufficient critical thinking before promoting a politically correct solution?