Sustainable Aviation Fuels from Low-Carbon Ethanol Production
Share of corn ethanol to jet GHG emissions by source, including both corn-to-ethanol and ethanol-to-jet processes (the chart does not include 13.4 g CO2e/MJ jet credits from distillers’ grains with solubles). Image courtesy of Argonne National Laboratory
Not all of the challenge of reducing transportation-related greenhouse gas (GHG) emissions is found at the end of automobile tailpipes. The aviation sector currently accounts for more than ten percent of U.S. transportation-related GHG emissions. To address this issue, the White House recently announced a Sustainable Aviation Fuel (SAF) Grand Challenge to generate at least 3 billion gallons of SAF by 2030 and, by 2050, sufficient SAF to meet 100% of U.S. aviation fuel demand, currently projected to be around 35 billion gallons annually.
The technology needed for SAF production already exists, including ethanol-to-jet (ETJ) conversion technologies. To assess whether and how the ETJ pathway may reach the net-zero emission target, Argonne scientists performed a life cycle analysis of corn to ethanol and then to jet fuel, using the Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET)® model developed at Argonne. The GREET simulation covers the entire ETJ pathway, including corn farming, corn ethanol refining, jet fuel upgrading, and fuel transportation and consumption.
Overall, the analysis reveals there is great potential to produce SAF with potentially zero or negative GHG emissions, through a combination of cleaner production technologies and sustainable farming practices. More R&D, incentives, and coordinated efforts would be needed to speed up the deployment of these technologies. Read more about this research, supported by the the U.S. Department of Energy Bioenergy Technologies Office, in the “Sustainable Aviation Fuels from Low-Carbon Ethanol Production” story on the Bioprose: Bioenergy R&D Blog.