Argonne study shows corn ethanol reduces carbon

LEMONT - A study conducted by researchers at the U.S. Department of Energy's Argonne National Laboratory reveals the use of corn ethanol is reducing the carbon footprint and diminishing greenhouse gases.

The study, recently published in Biofuels Bioproducts and Biorefining, analyzes corn ethanol production in the U.S. from 2005 to 2019, when production more than quadrupled. Scientists assessed corn ethanol's greenhouse gas emission intensity (sometimes known as carbon intensity, or CI) during that period, finding a 23% reduction in CI.

"The corn ethanol production pathway - both in terms of corn farming and biorefineries - has evolved greatly since 2005," said Argonne analyst Uisung Lee, first author of the study. Lee pointed out that the study relied on comprehensive statistics of corn farming from the U.S. Department of Agriculture and of corn ethanol production from industry benchmark data.

Hoyoung Kwon, a co-author, stated that U.S. corn grain yields improved by 15%, reaching 168 bushels per acre despite fertilizer inputs remaining constant, resulting in a decreased intensity in fertilizer input per bushel of corn harvested: reductions of 7% in nitrogen use and 18% in potash use.

With the increased total volume and the reduced CI values of corn ethanol between 2005 and 2019, corn ethanol has resulted in a total greenhouse gas reduction of more than 500 million tons between 2005 and 2019, said May Wu, another co-author.