In an exciting breakthrough for sustainable aviation, Circularity Fuels has successfully demonstrated the world’s first end-to-end conversion of raw agricultural biogas into sustainable aviation fuel (SAF). This ambitious pilot, which took place over six months in California, highlights a promising new path for combating the environmental challenges associated with traditional jet fuel.
The pilot utilized biogas sourced directly from a dairy farm’s manure digester, ultimately producing a drop-in jet fuel that meets the stringent ASTM D7566 Annex A1 specifications. Demonstrating extraordinary economic potential, the pilot’s projections suggested that the commercial capital costs could be less than $100,000 per barrel-per-day of installed capacity at commercial scale, roughly one-fifth of what similar SAF plants currently under construction in Europe would cost.
The timing for such innovation couldn’t be more crucial. The aviation industry has been facing mounting pressure due to the instability in crude oil markets driven by international geopolitics. With soaring prices impacting both airlines and travelers, SAF serves as a domestically produced alternative. However, it currently accounts for less than 1% of the global supply and is predominantly derived from used cooking oil, a feedstock burdened by competitive scalability and energy security concerns, as much of the oil is imported from countries like China.
Agricultural biogas emerges as a game-changing feedstock for SAF, largely due to the fact that it represents a waste product; capturing this resource allows for a more sustainable approach. The dairy farm featured in this pilot program, housing over 5,000 cattle, currently vents its biogas—a potent greenhouse gas—into the atmosphere, exacerbating climate change. Circularity Fuels’ innovative system monetizes this methane directly on-site, creating a pathway for producing SAF without the hefty costs typically associated with carbon dioxide removal.
Throughout the pilot, Circularity’s system operated efficiently on raw biogas, consisting of approximately 65% methane and 35% CO₂, resulting in finished jet fuel. The technology incorporates two crucial reactors: the electrified Ouro bi-reforming reactor and the compact Aion Fischer-Tropsch synthesis reactor. Both reactors are modular and skid-mounted, making them well-suited to the distributed scales at which biogas is generated.
Transforming Waste into Jet Fuel
This pilot program stands out as the first of its kind to convert raw dairy biogas into ASTM D7566 Annex A1 (FT-SPK) jet fuel using an integrated, modular system. The Ouro reactor achieved impressive results, with over 98% methane conversion and over 90% CO₂ conversion, tackling what has been a significant barrier in the industry. The resultant fuel can be blended with conventional Jet-A fuel up to a 50% mix, facilitating usage in commercial aircraft today.
Remarkably, this process yields a negative carbon intensity score of -350.7 gCO₂e/MJ. This figure is derived from the feedstock’s ability to consume methane that would otherwise contribute to global warming. In essence, using this innovative technology is akin to removing approximately 100 pounds of CO₂e from the atmosphere for every gallon of fuel produced.
Voices from the Industry
Dr. Stephen Beaton, the Founder and CEO of Circularity Fuels, expressed the significance of this achievement by saying:
“The hard part of this industry was never designing a theoretical plant that could make SAF. It was proving you could do it continuously, from real biogas, at a cost that pencils. We’ve now done that.”
Craig Hartman of Hartman Engineering emphasized the revolution this technology brings to dairy operations, explaining:
“Circularity is the first team I’ve seen take raw biogas straight from a digester and turn it into finished jet fuel on-site. That changes the conversation for every dairy operator we work with.”
This biogas-fueled aviation fuel allows Circularity to offer competitive pricing compared to fossil fuels, even as a pioneering commercial plant. Moreover, it qualifies for various federal and state biofuel incentives. Programs like the EPA’s Renewable Fuel Standard and California’s carbon-negative LCFS pathway pave the way for SAF derived from biogas to reach commercial volumes.
Building upon the success of this pilot, Circularity Fuels is gearing up for its first commercial-scale deployment. The company aims to break ground on its inaugural site in 2027, targeting agricultural biogas resources throughout the United States, Latin America, and Europe.
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Discover more about Circularity Fuels and its groundbreaking achievement in converting raw dairy biogas to jet fuel in their official announcement here.