From Concept to Commercialization: NREL’s Sustainable Aviation Fuels Program

by Zia Abdullah (National Renewable Energy Laboratory) The National Renewable Energy Laboratory supports the U.S. DOE Bioenergy Technologies Office with fundamental and applied research, development, and deployment (RD&D) designed to advance technologies to produce biobased energy, fuels, chemicals and products from initial conception to demonstration stages.

NREL’s program is organized along six science and technology (S&T) research platforms, focused on pretreatment and biological conversion of biomass feed; catalytic conversion of biomass feed or intermediate streams; coproduct polymers and bioproducts production; lignin valorization; waste gas valorization; and algae biofuels and bioproducts. Supporting these S&T platforms is a crosscutting strategic and sustainability analysis platform, which provides process economics and sustainability metrics to help inform S&T research priorities. Projects in each S&T platform are integrated into feedstock–to-product “pathways” that support the DOE sustainable aviation fuel (SAF) and materials and chemicals CO2 reduction goals. The technology pathways are deployed through the market impact platform in collaboration with industry partners and other stakeholders.

Commercial aircraft being sold today will likely still be in operation for the next 30 years. Our program, therefore, targets development of SAF, which is completely fungible and drop-in to the existing commercial aviation fueling systems, as per ASTM 7566. Our approach is to make SAF blendstocks that comprise only those molecule classes, (cyclo-alkanes, n-alkanes, iso-alkanes, and aromatics) and that already exist in Jet-A, therefore resulting in a fully fungible fuel that meets the safety, performance, and operability requirements as per ASTM D4054 and ASTM D1655, and can be seamlessly used with existing infrastructure and airplanes.

The U.S. has approximately 100 billion gallons per year of petroleum hydrotreater and 85 billion gallons of fluid catalytic cracking capacity. A significant portion of these refinery assets may be underutilized if light-duty transportation undergoes significant electrification, and gasoline demand eventually starts reducing. Leveraging these petroleum refinery assets may significantly reduce capital costs for SAF production. Partnering with the petroleum industry may also allow an incremental transition to renewables by blending fossil and renewable streams. Refinery integration will also allow utilization of existing personnel skills in safety, equipment operation, fuel finishing, quality assurance and quality control, fuel blending, fuel branding and industry knowhow.

In addition to the nearer-term DOE Funding Opportunity Announcement projects with industry partners, NREL has very promising earlier-stage technologies in the pipeline, including algae to SAF and coproducts, lignin deconstruction and upgrading to SAF, syngas upgrading to SAF or high-octane blendstocks, carboxylic acids to SAF, and also multiple routes that can use renewable electricity and CO2 to produce intermediates for upgrading to SAF. Each of these technologies will eventually be licensed to industry partners for deployment to meet the administration’s goals to produce at least 3 billion gallons of SAF by 2030, and to completely decarbonize U.S. commercial aviation by producing 35 billion gallons of SAF by 2050. READ MORE