Emerging regulations require an examination of corn ethanol’s greenhouse gas emissions on a life cycle basis, including emissions from energy consumed at the plant level. However, comprehensive survey data of the industry’s average performance dates back to 2001, prior to the industry’s expansion phase. Responding to the need for updated data, we conducted a survey to collect energy and processing data for average dry mill ethanol produced during 2008. The study finds that the average liter of anhydrous corn ethanol produced during 2008 requires 28% less thermal energy than 2001 ethanol: 7.18 MJ/l compared to 10 MJ/l. Also, 2008 ethanol requires 32% less electricity: 0.195 kWh/l compared to 0.287 kWh/l, but anhydrous ethanol yields from corn are 5.3% higher and total 0.416 l/kg compared to 0.395 l/kg. Findings also suggest that older plants installed energy efficiency retrofits.
Corn ethanol yieldEthanol energy balanceEthanol life cycle