- Researchers from the University of Illinois Urbana-Champaign found that corn stover, energy sorghum, miscanthus, and switchgrass each perform best in specific rainfed regions of the US for sustainable aviation fuel production.
- The Sustainable Aviation Fuel Grand Challenge aims to boost SAF production to 3 billion gallons by 2030 and 35 billion gallons by 2050, reducing greenhouse gas emissions by 50% compared to conventional fuels.
- Choosing regionally optimal biofuel crops can help reduce production costs, lower greenhouse gas emissions, and increase soil carbon stocks, supporting national and international climate goals.
Researchers have pinpointed the best biofuel crops for sustainable aviation fuel (SAF) across different US regions. This study, led by the University of Illinois Urbana-Champaign, evaluated four key biofuel crops: corn stover, energy sorghum, miscanthus, and switchgrass. Each crop performs optimally in specific rainfed areas of the United States.
The findings, published in *Environmental Science and Technology*, aim to assist growers and policymakers in selecting suitable feedstocks. These choices help reduce production costs, lower greenhouse gas emissions, and increase soil carbon stocks.
The US consumes 23 billion gallons of jet fuel annually, contributing about 13% of the country’s transportation-related carbon dioxide emissions. Despite limited SAF production in the US—just a few million gallons annually—a national initiative, the Sustainable Aviation Fuel Grand Challenge, seeks to change this. The initiative aims to produce 3 billion gallons of SAF by 2030 and 35 billion gallons by 2050. It also aims for a 50% reduction in life-cycle greenhouse gas emissions intensity compared to conventional fuels.
“The mix of bioenergy crop feedstocks will depend on policy goals,” said Madhu Khanna, professor of agricultural and consumer economics at the University of Illinois Urbana-Champaign. Khanna also directs the Institute for Sustainability, Energy, and Environment (iSEE). She led the study with Xinxin Fan, a postdoctoral researcher at iSEE.
Corn stover, a byproduct of corn harvesting, includes stalks, leaves, and husks left after corn harvest. Energy sorghum, a fast-growing crop, thrives in dry conditions. Miscanthus, a tall, perennial grass, efficiently converts sunlight into biomass. Switchgrass, another perennial grass, grows well on marginal lands unsuitable for food crops.
The study’s regional approach ensures that each crop grows where it performs best. For example, corn stover performs well in the Midwest, where corn is abundant. Energy sorghum suits the southern plains, where it withstands heat and drought. Miscanthus and switchgrass thrive in the central and eastern US due to their high yield and adaptability.
Selecting the suitable feedstock for each region optimises production efficiency and reduces the overall environmental impact of SAF production. This regional optimisation balances economic and ecological benefits.
The Sustainable Aviation Fuel Grand Challenge involves multiple stakeholders, including government agencies, private companies, and research institutions. The initiative is part of a broader strategy to decarbonise the aviation sector, aligning with national and international climate goals.
SAF can come from various feedstocks, including agricultural residues, dedicated energy crops, and waste materials. Each feedstock has different costs and carbon intensities, making the right mix crucial for meeting production and emission targets.
The study provides valuable insights into the regional suitability of biofuel crops for SAF. It highlights the importance of matching crops to their optimal growing conditions. This approach helps achieve cost-effective and environmentally sustainable aviation fuel production. The findings support the goals of the Sustainable Aviation Fuel Grand Challenge, paving the way for a greener aviation industry.