The most expensive part of making sustainable aviation fuel is usually the plant. Circularity Fuels, a startup out of DCVC's entrepreneur-in-residence program, is betting it can shrink that plant down to the size of a shipping container and drop it on a dairy farm. The company's first pilot converted raw manure biogas from a California dairy into synthetic jet fuel components, and it did so, according to the company, at one-hundredth the capital cost of a conventional methane reformer [American Biogas Council]. For an industry where SAF can cost three to five times more than conventional jet fuel, that's the kind of number that gets investors to write checks.
Stephen Beaton, the company's founder and CEO, spent years as a scientist at the National Renewable Energy Laboratory and the U.S. Air Force Petroleum Office, which gave him a front-row seat to the military's intense interest in secure, drop-in fuels [DCVC, retrieved 2026]. His company's approach is a two-step hardware play. First, a compact, electrified "Ouro" reactor reforms biogas,a mix of methane and carbon dioxide,into syngas. Then, a second "Aion" reactor uses a Fischer-Tropsch process to assemble that syngas into a liquid hydrocarbon mixture ready for refining into jet fuel [Circularity Fuels, retrieved 2024]. The entire system is designed to be modular and skid-mounted, operating at the individual farm scale without needing to pipe biogas to a central facility [iGrowNews].
The diamond-shaped wedge
Before it powers a single airplane, Circularity Fuels' technology is making diamonds. The company's initial, and somewhat surprising, market is lab-grown diamond manufacturers. These facilities use chemical vapor deposition, which requires a stream of high-purity methane. Circularity's Ouro reactor can take waste carbon streams, including exhaust from other industrial processes, and reform them into that methane, selling it at a lower cost than purified fossil methane [DCVC, retrieved 2026]. It's a clever wedge: the market is smaller but more immediately valuable per molecule, letting the company prove its core reforming technology and generate early revenue while navigating the longer, more complex certification path for aviation fuel. As Beaton told TechCrunch, they'll make diamonds before powering jet planes [TechCrunch, Feb 2025].
The unit economics of manure
The fundamental bet is that distributed, small-scale production can beat centralized mega-plants on capital efficiency. A traditional biogas-to-SAF plant requires massive upfront investment for gas purification, pipeline connections, and large-scale reactors. Circularity's claim is that its modular, AI-controlled reactors can be mass-produced and deployed directly at the source of the waste, radically cutting those infrastructure costs. The company projects its commercial systems could achieve capital costs of less than $100,000 per barrel-per-day of installed capacity at scale [Renewable Energy Magazine, June 2026]. To put that in perspective, they claim this would be roughly one-fifth the cost of European SAF plants currently on the drawing board [BusinessWire, June 2026].
The early validation comes from a dairy in California's Central Valley, where a pilot unit successfully processed raw biogas from a manure storage facility into syngas [SAF Investor]. The next step is integrating the second reactor to produce the final liquid fuel blend, a milestone the company says it has now achieved in a lab setting [BusinessWire, June 2026].
The team and the tailwinds
Circularity Fuels is a classic deep-tech build. Beaton emerged from DCVC's entrepreneur-in-residence program, a structure the venture firm uses to incubate capital-intensive hardware bets [Waste360]. The backing reflects a mix of venture capital and government grant funding, with investors and partners including DCVC, MCJ Collective, the National Science Foundation, ARPA-E, and the California Energy Commission [PitchBook]. The team is hiring for mechanical and chemical engineering roles, signaling a move toward hardware development and scaling [LinkedIn, retrieved 2026].
| Founder / Leader | Role | Background |
|---|---|---|
| Dr. Stephen Beaton | CEO & Co-founder | Former scientist at NREL and U.S. Air Force Petroleum Office; emerged from DCVC's EIR program [DCVC, retrieved 2026] [Pollution Online] |
The regulatory and commercial winds are favorable. The U.S. Sustainable Aviation Fuel Grand Challenge aims to supply enough SAF to meet 100% of aviation fuel demand by 2050. Airlines are desperate for drop-in solutions that don't require new engines or infrastructure. And dairy farms, under increasing pressure to manage methane emissions, have a waste product they're often paid to dispose of. Turning that liability into a revenue stream for fuel production is a powerful narrative.
Where the chemistry gets hard
For all the promise, the path from pilot to profit is lined with chemical engineering challenges. The company's published claims are ambitious, and third-party validation of its cost and efficiency numbers at commercial scale is still pending. The Fischer-Tropsch process, while well-understood, is notoriously finicky and energy-intensive. Making it work economically in a container-sized unit is the core technical hurdle. Furthermore, the diamond market provides a useful beachhead, but it's a niche. The real volume,and the real test,is in aviation, a sector with unforgiving fuel specifications and safety certifications.
- Scale-up risk. Moving from a pilot reactor to a mass-manufactured, reliable field unit is the classic valley of death for hardware startups. A reactor that works in the controlled environment of a lab can behave differently on a farm.
- Feedstock consistency. Biogas composition can vary significantly from farm to farm and even day to day. The AI control system's ability to handle this variability while maintaining output quality and efficiency is untested at scale.
- The incumbent. Circularity isn't just competing against other startups like Infinium or Greenlyte. Its ultimate competitor is the existing fossil fuel supply chain, which has had a century to optimize for cost and reliability. The startup's reactor must beat the delivered price of conventional jet fuel, a moving target that currently enjoys massive scale and subsidy advantages.
The company's most plausible answer is its focus on modularity and capital cost. If it can truly deploy capacity for $100,000 per barrel-per-day, it changes the financing and risk model entirely, allowing for incremental build-out rather than billion-dollar bets.
The next twelve months
The immediate roadmap involves moving from an end-to-end lab demonstration to a field demonstration that integrates both reactors at a farm site. Securing offtake agreements with a fuel refiner or an airline would be a significant signal. The company will also likely need to raise a substantial Series A round to fund the manufacturing line for its first commercial reactor units. Given the investor lineup and the pressing need for SAF solutions, that round seems more a question of when than if.
Doing some back-of-the-envelope math: if a single reactor module truly costs $100,000 and produces one barrel of fuel per day, a small 100-barrel-per-day installation (serving a cluster of farms) would represent a $10 million capital outlay. At that scale, it starts to look like a tractable project for a farm cooperative or a dedicated fuel developer, rather than a national infrastructure program. The unit that must be beaten isn't another startup's reactor; it's the sprawling, pipeline-fed refinery complex that has supplied the world's jets for decades. Circularity Fuels is betting that a thousand small, smart containers can outmaneuver a few giant monuments to steel.