Poet cellulosic ethanol shows negative GHG emissions

By | July 15, 2010
Ethanol produced by Project Liberty, Poet LLC's first planned commercial cellulosic ethanol plant, will reduce carbon emissions by 111 percent over gasoline, an independent lifecycle analysis shows, offsetting more greenhouse gas (GHG) emissions than it produces.

Jeff Broin, CEO of Poet, presented the results at a news conference held during the Fuel Ethanol Workshop & Expo in St. Louis. A life-cycle analysis tracks the emissions of ethanol production from "field to tank." including emissions from planting and harvest, feedstock transportation, conversion to ethanol, waste products, coproducts and transportation of the ethanol. It also includes U.S. EPA calculations for changes in land use and effects on agriculture inputs. The analysis, compiled by Michigan-based Air Improvement Resource Inc., highlights characteristics of Poet's process leading to this large emissions reduction, including the fact that the waste streams will be fed to two anaerobic digesters to create biogas for power and process heat.

The analysis found that all the inputs into Project Liberty will emit 41.8 grams of CO2 equivalent units per megajoule of energy produced. The biogas exported as a coproduct will offset 49.8 grams CO2 per megajoule. EPA estimates for land use and agriculture changes offset an additional 1.7 grams CO2 per megajoule, bringing Project Liberty's total emissions to -9.7 grams CO2 per megajoule. EPA's standard for gasoline emissions is 92.9 grams CO2 per megajoule.