The U.S. Department of Energy Bioenergy Technologies Office (BETO) empowers energy companies and aviation stakeholders by supporting advances in research, development, and demonstration to overcome barriers to the widespread deployment of low-carbon sustainable aviation fuel (SAF).
SAF made from renewable biomass and waste resources has the potential to deliver the performance of petroleum-based jet fuel but with a fraction of its carbon footprint, giving airlines solid footing for decoupling greenhouse gas (GHG) emissions from flight.
The U.S. Department of Energy is working with the U.S. Department of Transportation, the U.S. Department of Agriculture, and other federal government agencies to develop a comprehensive strategy for scaling up new technologies to produce SAF on a commercial scale.
Learn more about this multi-agency strategy on the Sustainable Aviation Fuel Grand Challenge site.
Demand for jet fuel is expected to balloon over the next three decades. SAF can help meet goals for cutting GHG emissions from domestic and international aviation. Photo courtesy of iStock.
Sustainable Aviation Fuel: Safe, Reliable, Low Carbon
SAF is a biofuel used to power aircraft that has similar properties to conventional jet fuel but with a smaller carbon footprint. Depending on the feedstock and technologies used to produce it, SAF can reduce life cycle GHG emissions dramatically compared to conventional jet fuel. Some emerging SAF pathways even have a net-negative GHG footprint.
SAFs lower carbon intensity makes it an important solution for reducing aviation GHGs, which make up 9%–12% of U.S. transportation GHG emissions, according to the U.S. Environmental Protection Agency.
A Menu of Sustainable Feedstocks for Producing SAF
An estimated 1 billion dry tons of biomass can be collected sustainably each year in the United States, enough to produce 50–60 billion gallons of low-carbon biofuels. These resources include:
- Corn grain
- Oil seeds
- Algae
- Other fats, oils, and greases
- Agricultural residues
- Forestry residues
- Wood mill waste
- Municipal solid waste streams
- Wet wastes (manures, wastewater treatment sludge)
- Dedicated energy crops.
This vast resource contains enough feedstock to meet the projected fuel demand of the U.S. aviation industry, additional volumes of drop-in low carbon fuels for use in other modes of transportation, and produce high-value bioproducts and renewable chemicals.
SAF Benefits Beyond Lowering GHG Emissions
Growing, sourcing, and producing SAF from renewable and waste resources can create new economic opportunities in farming communities, improve the environment, and even boost aircraft performance.
Extra Revenue for Farmers
By growing biomass crops for SAF production, American farmers can earn more money during off seasons by providing feedstocks to this new market, while also securing benefits for their farms like reducing nutrient losses and improving soil quality.
Environmental Services
Biomass crops can control erosion and improve water quality and quantity. They can also increase biodiversity and store carbon in the soil, which can deliver on-farm benefits and environmental benefits across the country. Producing SAF from wet wastes, like manure and sewage sludge, reduces pollution pressure on watersheds, while also keeping potent methane gas—a key contributor to climate change—out of the atmosphere.
Improved Aircraft Performance
Many SAFs contain fewer aromatic components, which enables them to burn cleaner in aircraft engines. This means lower local emissions of harmful compounds around airports during take-off and landing. Aromatic components are also precursors to contrails, which can exacerbate the impacts of climate change.
Biofuels Production Supports American Jobs
The United States is the largest producer of biofuels in the world, which contributes to our domestic economy, creates jobs, and reduces GHG emissions.
Expanding domestic SAF production can help sustain the benefits of our biofuel industry and forge new economic benefits, creating and securing employment opportunities across the country. These include jobs in:
- Feedstock production in farming communities
- Construction for building cutting-edge biorefineries
- Manufacturing for operating SAF biorefineries and infrastructure
- Aviation, including countless pilots, crew members, maintenance workers, and other industry professionals.
BETO Research Brings More SAF to the Market
To meet U.S. and aviation climate goals, more production pathways and feedstocks are needed to meet the growing demand for SAF.
SAF can be made with a variety of technologies, which use physical, biological, and chemical reactions to break down biomass and waste resources and recombine them into energy-dense hydrocarbons. Like conventional jet fuel, the blend of hydrocarbons in SAF must be tuned to achieve key properties needed to support safe, reliable aircraft operation.
In partnership with biorefineries, aviation companies, and farmers, BETO-funded researchers are developing novel pathways for producing SAFs from renewable and waste feedstocks that meet strict fuel specifications for use in existing airplanes and infrastructure. BETO is working with laboratory and industry partners to develop new SAF pathways and fuel formulations in order to enable the testing and certification required to ensure these fuels are fully compatible with existing aircraft and infrastructure.
Emerging SAFs
- SAF from wet waste, National Renewable Energy Laboratory: Drawing on stores of carbon energy is cheap, widely available food waste, animal manure, and other wastes with high water content, SAF from wet waste is a carbon-negative fuel.
- Bio-based polycyclic alkane SAF, Los Alamos National Laboratory: If upgraded with ultraviolet light and catalysts, bio-acetone made from a range of biomass resources, like corn stover or bioenergy crops, can yield SAF with 12% more energy than conventional jet fuel.
- SAF from carbon-rich waste gases, Pacific Northwest National Laboratory: Waste carbon monoxide from industrial processes can be captured and upgraded with bacteria into ethanol for easy conversion into “alcohol-to-jet” SAF.
