January 23, 2009

Corn-based ethanol emits an average 51 percent less greenhouse gas than gasoline, according to a new study by University of Nebraska-Lincoln.

The study marks another page in the chronicle of the battle between the two fuel sources.

"Critics claim that corn ethanol has only a small net energy yield and little potential for direct reductions in greenhouse gas emissions compared to use of gasoline," said UNL agronomist and research team member Ken Cassman in a news release issued Thursday.

"This is the first peer-reviewed study to document that these claims are not correct."

For every unit of energy it takes to make ethanol, 1.5 to 1.8 units of energy are produced as ethanol - earlier studies pegged the ratio at 1-1.2, Cassman said.

Old studies do not account for greater efficiencies in crop production, ethanol manufacturing and byproduct distribution, he added.

Factoring in energy use, greenhouse gases from crop production, ethanol conversion, byproduct use, and transportation, the study also found that 10-19 gallons of ethanol are produced for every gallon of petroleum used in the entire corn-ethanol production life cycle.