MINNEAPOLIS, July 11 (UPI) -- The first comprehensive U.S. analysis of the life cycles of soybean biodiesel and corn grain ethanol shows biodiesel performs better than corn ethanol.
The University of Minnesota study suggests soybean biodiesel has much less of an impact on the environment and a much higher net energy benefit than does corn ethanol, but neither can do much to meet U.S. energy demand.
Researchers tracked the energy used for growing corn and soybeans and converting the crops into biofuels. They also looked at how much fertilizer and pesticide corn and soybeans required and how much greenhouse gases and nitrogen, phosphorus and pesticide pollutants each released into the environment.
The research suggests both corn grain ethanol and soybean biodiesel produce more energy than is needed to grow and convert them into biofuels. That refutes studies claiming the biofuels require more energy to produce than they provide.
But researchers say they found the amount of energy each returns differs greatly: Soybean biodiesel returns 93 percent more energy than is used to produce it, while corn grain ethanol currently provides 25 percent more energy.
The study is detailed in the Proceedings of the National Academy of Sciences.
