A major technical hurdle in the race toward 100% sustainable aviation fuel may have just been narrowed.
Universal Fuel Technologies (Unifuel) said independent testing by Washington State University has validated its Flexiforming technology as a way to convert HEFA-derived naphtha into synthetic aromatic kerosene. When blended with paraffinic SAF, the resulting fuel can meet key performance requirements associated with conventional jet fuel.
The university tested a blend made up of 16% Flexiforming-produced aromatic SAF and 84% HEFA-derived paraffinic SAF. According to Unifuel, the results showed that the fuel performed comparably to conventional jet fuel across critical properties.
That matters because HEFA (Hydroprocessed Esters and Fatty Acids), currently the most widely used SAF production pathway, produces only paraffinic fuel components. Conventional jet fuel, however, also contains 8% to 25% aromatic molecules, which are important for engine and fuel system performance. Under current ASTM rules, SAF generally still has to be blended with fossil jet fuel to supply those aromatic properties.
Unifuel’s approach addresses that gap by upgrading HEFA naphtha, a byproduct that can account for up to 20% of HEFA output and is often considered relatively low value.
The fuel was evaluated by Washington State University’s Bioproducts, Sciences, and Engineering Laboratory through ASTM-authorized screening tests. According to the company, the blend met all critical jet fuel properties tested at that stage, including density, viscosity, freeze point and flash point. The reported freeze point of -43.5°C, along with low-temperature viscosity and heating value results, suggested performance comparable to—or potentially better than—conventional jet fuel under demanding aviation conditions.
Unifuel CEO Alexei Beltyukov said the validation supports a practical route for HEFA producers to improve both their yields and the economics of SAF production by converting an existing byproduct into a valuable aromatic component, rather than relying on ongoing blending with fossil jet fuel.
Washington State University researchers also underscored the importance of the development. Dr. Joshua Heyne, director of the Bioproducts, Sciences and Engineering Lab, said Flexiforming addresses one of today’s key SAF limitations by enabling the production of a fully synthetic fuel with both the paraffinic and aromatic components needed for drop-in equivalency with conventional kerosene. Harrison Yang, research assistant professor at the lab, added that the tested blend demonstrated excellent performance across all measured parameters.
The potential reach of the technology goes beyond HEFA. Unifuel says the same concept could apply to Fischer-Tropsch (FT) and ethanol-to-jet (ETJ) pathways, both of which also tend to produce paraffinic outputs and may generate naphtha byproducts that could be upgraded.
The company presents Flexiforming as a low-capital, bolt-on solution that producers can integrate into existing infrastructure rather than replacing entire plants or relying on complicated external blending arrangements.
Co-founder Denis Pchelintsev described aromatics as the missing piece in the move toward fully synthetic aviation turbine fuel, saying the results suggest that those molecules can be produced reliably from byproducts that SAF producers already generate.
Unifuel is also advancing its ethanol-to-jet technology through the qualification process. In August last year, the company’s ETJ SAF produced via Flexiforming was accepted into the ASTM D4054 Clearinghouse, an important step in the technical evaluation pathway required before new aviation fuels can reach commercial use.
Together, the developments suggest that the industry may be edging closer to a future in which fully synthetic, fossil-free drop-in jet fuel becomes technically and commercially viable.
