A lengthy report recently released by USDA concludes that corn-based ethanol emits 43% lower greenhouse gas emissions than gasoline. The report, “A Life-Cycle Analysis of the Greenhouse Gas Emissions of Corn-Based Ethanol,” measured these sources on an “energy equivalent basis” to arrive at these conclusions.
That’s significant, as the report states: “a biofuel must have a life-cycle greenhouse gas profile of at least 20% lower than that of the fossil fuel it replaces to qualify as a renewable fuel under the RFS2.”
That equation factors in more efficient farming methods and more intense conservation practices such as reduced tillage, cover crops and variable-rate nitrogen applications. Steffen Mueller, economist with the University of Illinois at Chicago Energy Resources Center, argues that better farmer practices have in turn made ethanol production increasingly more efficient.
“The report provides a sound incorporation of the recent energy efficiency improvements achieved by corn ethanol plants, many of which were driven by the incentives provided by the RFS2,” he says. “Corn ethnol today now mirrors the environmental benefits of advance biofuels.”
Mueller has been sharing the findings of his research with other countries as well as in the U.S.
“Several [regions] like the EU and Japan require a greenhouse gas reduction of 50% to qualify corn ethanol blends into their fuel supply – this is without considering international land use assessments in recognition of the uncertainties surrounding this science,” he says. “[The recent] USDA report shows that the average U.S. produced corn ethanol easily meets these international requirements, which documents the competitive advantage of this fuel in green markets abroad.”
About 2.76 gallons of ethanol can be produced from a bushel of corn, according to the report.