Stories tagged greenhouse gas

Aug
07
2006

Corn field: Corn is used to produce ethanol fuels, such as E85.  Photo courtesy killermart, Flickr Creative Commons.
Corn field: Corn is used to produce ethanol fuels, such as E85. Photo courtesy killermart, Flickr Creative Commons.
Biofuels are fuels that are derived from recently living organisms, such as corn or soybeans, or their byproducts, such as manure from cows. A recent study at the University of Minnesota examined the total life-cycle cost of all of the energy used for growing corn and soybeans and converting these crops into biofuels to determine what biofuel has the highest energy benefit and the least impact on the environment.
Corn grain ethanol vs. soybean biodisel
Two types of biofuels are becoming more visible as we look for alternatives to petroleum because of increasing gas prices: soybean biodisel and corn grain ethanol, such as E85. The study showed that both corn grain ethanol and soybean biodiesel produce more energy than is needed to grow the crops and convert them into biofuels. However, the amount of energy each fuel returns differs greatly. Soybean biodiesel returns 93 percent more energy than is used to produce it, while corn grain ethanol currently provides only 25 percent more energy than is used to produce it.
The study also compared the amount of greenhouse gases each biofuel released into the environment when used. Soybean biodiesel produces 41% less greenhouse gas emissions than diesel fuel while corn grain ethanol produces 12% less greenhouse gas emissions than gasoline.
Not a silver bullet
The researchers conducting this study caution that neither biofuel is ready to replace petroleum. Even if all current U.S. corn and soybean production were dedicated to biofuels production, it would still only meet 12 percent of gasoline demand and 6 percent of diesel demand, and we still need to produce these crops for food. Biofuels are steps in the right direction, however, and can be a piece of the overall puzzle needed to be put together to solve our energy needs.