In November 2025, a plant in Soperton, Georgia began producing jet fuel from ethanol — the world’s first commercial-scale facility to do so. The plant, operated by LanzaJet, a company in which LanzaTech holds majority ownership, uses an alcohol-to-jet (ATJ) process that converts ethanol fermented from waste industrial gases into synthetic paraffinic kerosene — a drop-in sustainable aviation fuel certified under ASTM D7566, the standard that governs fuels approved for use in commercial aircraft. The ethanol feedstock can come from agricultural residues, municipal solid waste, or industrial carbon emissions. The resulting fuel reduces aviation lifecycle emissions by up to 85 percent compared to conventional jet fuel derived from petroleum.
The Georgia plant represents a milestone in a decade-long effort to make sustainable aviation fuel not just chemically possible but commercially real. Aviation accounts for approximately 2.5 percent of global CO₂ emissions — a relatively modest fraction of total greenhouse gas emissions but a disproportionately challenging one to decarbonize, because flight depends on energy-dense liquid fuels that cannot easily be replaced by batteries or direct electrification at the scale of long-haul commercial aviation. Drop-in SAF — fuel that is chemically similar enough to conventional jet fuel to work in existing aircraft, engines, and fueling infrastructure without modification — is the most practically achievable path to reducing aviation’s climate footprint without waiting for fleet replacement or engine redesign.
Why Synthetic Biology Matters for SAF
Sustainable aviation fuel can be produced through several pathways. Hydroprocessed esters and fatty acids (HEFA) converts fats, oils, and greases — from used cooking oil, animal fats, or purpose-grown oilseed crops — into jet fuel using hydrogen and catalysis. HEFA accounts for the large majority of SAF produced today. Its limitation is feedstock: the supply of waste fats and oils is finite, and purpose-grown oilseed crops compete with food production and land use.
Microbial and synthetic biology pathways address this limitation by using feedstocks that are effectively unlimited or that derive value from waste: waste industrial gases, agricultural residues, municipal solid waste, captured CO₂, or low-value biomass. LanzaTech’s core process ferments CO-rich waste gases from steel mills and industrial facilities using a bacterium called Clostridium autoethanogenum, which metabolizes the carbon monoxide into ethanol. That ethanol is then converted to jet fuel through LanzaJet’s ATJ process — alcohol dehydration to ethylene, oligomerization to the right carbon chain length, and hydrogenation to saturate the double bonds. The end product is chemically indistinguishable from conventional jet fuel in its combustion properties.
Other microbial routes target different molecules. Gevo produces isobutanol from fermentation of agricultural sugars, then converts it through a similar chemical processing chain to jet fuel. Viridos, formerly Sapphire Energy, engineers microalgae to produce hydrocarbons directly. Joule Unlimited developed cyanobacteria engineered to produce fuels directly from CO₂ and sunlight. Each approach differs in feedstock, microbial chassis, metabolic pathway, and downstream processing — but all share the characteristic of using engineered biology to produce molecules that fall within aviation fuel specifications.
The ASTM Certification Framework
One aspect of SAF commercialization that receives less attention than production technology is the regulatory certification framework — and it is crucial. ASTM D7566 defines the standard for aviation turbine fuel containing synthesized hydrocarbons, and it specifies not just the chemical properties of acceptable fuels but the approved production pathways, feedstocks, and blending limits. A new production pathway — including a new microbial fermentation route — must be certified through an exhaustive process before the resulting fuel can be used commercially. This process typically takes five to seven years and requires extensive documentation of fuel chemical composition, materials compatibility, thermal stability, and combustion properties.
LanzaJet’s ATJ pathway received ASTM approval in 2018 after years of testing and validation. The Freedom Pines plant in Georgia is the first to produce fuel from this pathway at commercial scale, generating ASTM-certified synthetic paraffinic kerosene and renewable diesel. The certification represents not just a technical achievement but a regulatory infrastructure achievement — establishing the precedent and the pathway documentation that future microbial SAF producers using related chemistry can reference.
The Policy Pull
The commercial case for microbial SAF is being strengthened by regulatory mandates that create guaranteed market demand. The European Union’s ReFuelEU Aviation regulation, which entered into force in January 2024, requires aviation fuel suppliers to blend a minimum of 2 percent SAF at EU airports by 2025, rising to 6 percent by 2030, 20 percent by 2035, and 70 percent by 2050. The U.S. Sustainable Aviation Fuel Grand Challenge, supported by the Inflation Reduction Act’s SAF tax credits, targets 3 billion gallons of SAF per year by 2030. The UK has its own mandate structure, as do Japan, Singapore, and other aviation-significant economies.
These mandates are creating commercial pull that pure technology push has not been able to generate: airlines that need to comply with blending requirements are willing to pay premiums for certified SAF, and investors are willing to fund commercial plants because the demand is guaranteed rather than speculative. LanzaTech’s 30-million-gallon-per-year waste-based ethanol-to-SAF facilities in the UK and EU, announced as high-priority commercial projects in early 2025, are being built into this policy environment.
The Scale and Cost Challenge
Commercial aviation consumes approximately 100 billion gallons of jet fuel per year globally. Current SAF production is measured in hundreds of millions of gallons — less than 1 percent of demand. The challenge of scaling microbial SAF production to meaningful fractions of that demand within the timeframe that climate targets require is immense.
The feedstock supply chain is one constraint: LanzaTech’s industrial gas fermentation is limited to geographic proximity to steel mills and industrial facilities with CO-rich emissions. Agricultural waste fermentation pathways are limited by biomass collection logistics. Each feedstock type has a finite supply curve. The cost premium of SAF over conventional jet fuel — typically two to five times the petroleum-derived equivalent — remains a significant barrier to voluntary adoption beyond mandate compliance, though the IRA tax credits of $1.25 to $1.75 per gallon for qualifying SAF narrow that gap substantially for U.S.-produced fuel.
Metabolic engineering continues to improve the efficiency of microbial fuel production. Higher titers — the concentration of product a microorganism produces per unit volume — reduce fermentation costs directly. Better selectivity — producing the specific carbon chain lengths and structures that fall within jet fuel specifications without requiring extensive downstream purification — reduces processing costs. CRISPR-based strain engineering is accelerating the pace of these improvements by enabling precise, targeted modifications to metabolic pathways that previously required years of conventional strain evolution.
Why It Matters
Aviation’s climate challenge is structural. Commercial aircraft operate for 25 to 30 years, and the aircraft flying today will still be in service in 2050. There is no near-term pathway to electric commercial aviation for long-haul routes. Drop-in SAF from microbial production is the most credible available technology for meaningful near-term emissions reduction in this sector without requiring fleet replacement or infrastructure overhaul. The LanzaJet Freedom Pines plant demonstrates that the biology, chemistry, and engineering of this pathway work at commercial scale. The policy environment is creating the demand. The remaining challenge is cost and scale — and those are engineering and capital allocation problems that accelerating manufacturing deployment, not fundamental scientific barriers, can address.
Closing Human Dimension
The fuel that powers a transatlantic flight is, at its chemical level, a collection of hydrocarbon molecules of specific lengths and structures. Whether those molecules were assembled by petroleum geology over millions of years or by engineered microorganisms fermenting waste industrial gases over hours is invisible to the aircraft’s engines and to the passengers who board. The difference is in the carbon cycle: petroleum molecules release ancient carbon that has been sequestered for geological time; microbially produced SAF recycles carbon that was already in the atmosphere. For the traveler who does not want to give up the connections that flight enables but cares about the atmosphere that makes them possible, microbial SAF is the kind of solution that changes the terms of the tradeoff without asking anyone to stop flying.
Sources
1. LanzaTech / SEC Filing. “LanzaTech Reports Third Quarter 2025 Financial Results — First Commercial Ethanol-to-Jet Plant Operational.” November 2025. https://www.sec.gov/Archives/edgar/data/0001843724/000162828025053237/ex991lnzapressrelease_9302.htm
2. LanzaTech / SEC Filing. “LanzaTech Reaches 53% Non-Controlling Ownership Milestone in LanzaJet.” December 2025. https://www.sec.gov/Archives/edgar/data/0001843724/000162828025058573/ex991_lanzajetshareholde.htm
3. LanzaTech / SEC Filing. “LanzaJet’s 10 million gallon per year SAF facility completed construction.” Q1 2024 earnings. https://www.sec.gov/Archives/edgar/data/0001843724/000162828024021942/a1q24lnzaearningsrelease.htm
4. LanzaTech / SEC Filing. “LanzaTech Announces LanzaX Spin-Out and Synthetic Biology Strategy.” January 2025. https://www.sec.gov/Archives/edgar/data/0001843724/000162828025002081/lnzapressrelease-jan2120.htm
5. European Union. “ReFuelEU Aviation Regulation.” Official Journal of the European Union (2023). https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32023R2405
6. U.S. Department of Energy. “SAF Grand Challenge Roadmap.” https://www.energy.gov/sites/default/files/2022-09/SAF%20Grand%20Challenge%20Roadmap_09-2022_0.pdf
7. ASTM International. “D7566 Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons.” https://www.astm.org/d7566-23a.html
Idea generated by Grok. Article expanded with Grok, substantially rewritten with Claude Sonnet 4.6. Published at artificialideas.org.
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