Researchers analyzed the financial and environmental costs and benefits of four biofuels crops used to produce sustainable aviation fuels in the U.S. They found that each feedstock — corn stover, energy sorghum, miscanthus or switchgrass — performed best in a specific region of the rainfed United States. Their study will help growers and policymakers select the feedstocks most suited to meeting goals like reducing production costs, lowering greenhouse gas emissions and building soil carbon stocks. 

The U.S. currently consumes 23 billion gallons of jet fuel per year, and aviation fuel accounts for roughly 13% of domestic transportation carbon dioxide emissions, the researchers report in their analysis in the journal Environmental Science and Technology. So far, only a few million gallons of sustainable aviation fuels are produced in the U.S., but a national initiative, the Sustainable Aviation Fuel Grand Challenge, aims to expand production to 3 billion gallons by 2030 and 35 billion gallons by 2050 while achieving a 50% reduction in life-cycle greenhouse gas emissions intensity compared with conventional fuel. 

The mix of bioenergy crop feedstocks that will be produced to meet this challenge, their relative costs and carbon intensities will depend on how the goals of the policy are specified, said Madhu Khanna, a professor of agricultural and consumer economics at the University of Illinois Urbana-Champaign and the director of the U. of I. Institute for Sustainability, Energy and Environment. Khanna led the study with Xinxin Fan, a postdoctoral researcher at iSEE.

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