Wednesday, February 04, 2009

U. of Minnesota study says corn ethanol takes heavier toll on environment, health than gasoline

A University of Minnesota study has found that corn ethanol can be worse than gasoline for health and the environment. "The study, released Monday, is the first one to estimate the economic costs to human health and well-being from three different fuels -- gasoline, corn-based ethanol and cellulosic (plant-based) ethanol," reports Tom Meersman of the Minneapolis Star Tribune. "Scientists and economists looked at life-cycle emissions of growing, harvesting, producing and burning different fuels, and concluded that ethanol made from switchgrass and other plant materials is far better than either corn ethanol or gasoline.

The environmental impact of the three fuels is measured by the amount of greenhouse gases that are emitted in the production of the fuel. The health impact is measure by the amount of fine particulate matter released through the burning of fossil fuels. The study determined that the environmental and health cost of making gasoline is about 71 cents per gallon. Corn ethanol's final costs is said to be within a range of 72 cents to $1.45 per gallon. Cellulosic ethanol is the cheapest option, at 19 to 32 cents per gallon, depending on the technology and type of plants used in the process.

According to the study, "Much of the variance is because of a lack of consensus on the economic values of both climate stabilization and human health. While this affects the dollar value of cost estimates, it does not change the relative ranking among fuel alternatives." The environmental impact of corn ethanol varies because of the different biorefinery heat sources. When natural gas is used, the level of greenhouse gas released from corn-ethanol manufacturing drops. Inversely, the use of coal as a heat source increases the amount of greenhouse-gas emissions and fine particulate matter. The study notes, "Corn ethanol fares poorly relative to alternatives because it requires, per unit of fuel produced, more fossil fuel and fertilizer inputs."

The results of the study are not good news for the corn-ethanol industry, which has faced setbacks from fluctuation in demand as well as unstable corn prices. But Mark Hamerlinck, communications director for the Minnesota Corn Growers Association, told the STrib, "I'm stifling a yawn. It would be news if the university had anything positive to say about corn ethanol. It's how they make a living over there." There is hope for the industry. The study adds that, "Environmental costs per unit of ethanol decline with higher biomass yield, lower fertilizer and fuel inputs into biomass production, and improvements in biomass to biofuel conversion efficiency." (Read more)

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