The routes differ in how they build an intermediate. Fats and oils are deoxygenated and isomerised, wet waste is liquefied into a biocrude, plastic and tire oils are hydrocracked, biomass is gasified and rebuilt over a Fischer-Tropsch catalyst, sugars are joined by aldol condensation, and carbon dioxide is reduced to carbon monoxide or hydrogenated. They converge on a shared finishing step that trims the product to kerosene range. A palm-oil-mill-effluent process cleans its feedstock by adsorption, then hydrotreats and isomerises it. Algal biocrude from continuous hydrothermal liquefaction has been hydrotreated to a jet cut at about 22.7% by weight. Corn-stover fast pyrolysis reaches a competitive selling price but overshoots the specification's final-boiling-point limit, so it blends at up to 10%. The shared back end is why the feedstocks compete for the same upgrading capacity.
The premium is real, and the oil price moves it more than SAF does
2 / 8
SAF averaged about 2,872 a tonne in 2026, roughly 2.5 times conventional jet, adding an estimated 4.3 billion to airline fuel costs. The multiple is not stable. Argus reported the narrowest gap between SAF and jet since it began tracking prices, with SAF oversupply meeting fossil jet prices lifted by the Middle East conflict, and in March 2026 western European SAF traded near $2,500 a tonne with its premium falling for the same reason.
Strategy
Certification is where the commercial effort concentrates
3 / 8
The clearest commercial move in the field is a standards approval, and the licensing clusters around it. Methanol-to-jet cleared ASTM in July 2026. Honeywell UOP's eFining methanol-to-jet process was licensed to Verso Energy across seven planned sites in France, Finland and the United States, Topsoe markets its own methanol-to-jet route, and Axens completed a methanol-to-jet offer by buying Air Liquide's methanol-to-olefins portfolio. The effort is going into certified pathways and the licences around them, not into new chemistry.
Research
The certified routes all make the same narrow molecule
4 / 8
The certified pathways turn out iso- and n-alkanes and almost nothing else. Jet fuel also needs cyclic molecules, naphthenes and aromatics, to swell fuel-system seals, and the paraffinic routes make too few of them, which is why synthetic blendstock is capped at 50% in conventional jet fuel. Three lines of work are trying to make the missing classes. Hydrodeoxygenation of lignin oil yields jet-range naphthenes and aromatics. Ethylbenzene made from waste polystyrene restores seal swell and could lift the blend ceiling. A distilled-tall-oil route has produced all four hydrocarbon classes with aromatics above 80% and passed seal-swell testing. So the routes compete on cost and certification, and the product itself is not where they differ.
Market
Public money, not the passenger, carries much of the premium in Europe
5 / 8
EU ETS support for 2025 SAF uptake came to about 5.2 million allowances worth roughly €430 million, spread across 130 operators, on top of a €135 million incentive from zero-rating SAF on ETS routes: about €565 million against just over 530,000 tonnes of fuel claimed. The support is retrospective, paid for fuel already claimed, and it subsidises uptake rather than capacity. It is also the clearest case of the state acting as the buyer of the premium while the mandate is still being met from existing waste-lipid supply.
Strategy
Value is settling with the process owners, not the plant owners
6 / 8
Licensing revenue arrives at award, whether or not the plant ever runs at nameplate, while the developer carries the demand risk. KBR licensed its PureSAF technology for a plant on Jurong Island, for Kazakhstan's first SAF project, and for what is billed as Northern Europe's largest SAF and e-SAF plant, in Latvia. Axens licensed its HEFA technology for facilities in Africa and the Caribbean. Topsoe and Sasol returned to licensing after closing their production venture, signing a technology and engineering agreement for a $6.1 billion project in Uzbekistan. The scarce asset is a certified pathway, and the companies that own one are selling access rather than building.
Research
Methanol joins the biomass and power routes
7 / 8
Methanol can be made from biomass-derived syngas or from captured carbon dioxide and hydrogen, so one certified pathway now draws on both the collected-matter and the electricity economies. ASTM added methanol to the alcohol-to-jet annex of its synthetic-fuel specification in July 2026.
Market
A corporate SAF claim rests on a registry rulebook, not on fuel in the tank
8 / 8
Book-and-claim decouples the environmental attribute from the molecule: a SAF certificate equals one tonne of neat certified SAF and carries the right to claim scope 1 and scope 3 reductions once retired in a registry. The channel is growing — IATA, Airbus and Accenture put corporate purchases at 1.0 to 1.9 million tonnes by 2030, from about 323,000 tonnes in 2024.
Every route ends with a paraffinic cut that has to be branched to stay liquid at altitude, and that is where the filings concentrate. Sinopec's ZSM-48 catalyst family lists Fischer-Tropsch wax, cracked tail oil, bio-jet feedstock and C5-C6 isomerisation feed as its charge, so one catalyst line serves the output of quite different front ends because the molecule arriving at that reactor is the same. The claims compete on crystal size and acidity rather than on feedstock: ellipsoidal ZSM-48 grains below 700 nm with a surface area above 200 m²/g, a Pt-Ir-Pd trimetallic on a phosphorus-modified SAPO-11/ZSM-5 composite aimed explicitly at bio-aviation kerosene, and a ZSM-22/ZSM-48 composite carrying 0.2-0.4 wt% platinum in 4-8 nm particles to steer the cut into the C8-C16 range.
Signals to watch
Freeze point and density pull against each other, and one filer claims the ratio window
TotalEnergies claims a composition instead of a process: at least 90% paraffins, a freeze point of -40°C or below under ASTM D7566-21, and a density of at least 755 kg/m³, held by requiring the mass ratio of iso-paraffins in each carbon number to n-paraffins in the one below it to fall between 14 and 18 across C14 to C17. The reason a ratio band gets claimed rather than a molecule is that branching lowers freeze point and density together. Density is what limits how much of the fuel can go into a tank of conventional jet, so the commercial prize is blend headroom, and the patent is an attempt to buy some inside the specification.
Signals to watch
Two filers are building the missing molecule class into the fuel itself
Chevron Phillips takes bio-ethylene through oligomerisation to C16-plus paraffins, and in one version separates the C6-C8 cut, reforms it to aromatics, optionally hydrogenates those to cycloparaffins, then blends the paraffin, aromatic and cycloparaffin streams in chosen proportions. A Korean group does the same split starting from alcohols: alcohol-to-olefin, co-oligomerisation to jet-range heavy olefins, then one stream aromatised into jet-range aromatics and cycloalkanes and one hydrogenated into linear and branched paraffins, the two blended to the finished fuel.
Signals to watch
The byproduct becomes the product
In the Chevron Phillips scheme the first oligomerisation yields C4-C8 alpha-olefins plus a decene mixture, and the decenes are the fraction without a natural jet market. The filings recover it two ways: reacting the decenes with a C6-plus olefin over a second catalyst, boron trifluoride with a protic promoter or a chemically modified solid oxide, or metathesising them with a C8-minus olefin, in both cases reaching a C16 olefin that is then hydrogenated to paraffins. The yield problem in alcohol-to-jet is the molecular weight distribution, and the fix is chemistry on the light end rather than a bigger reactor.
Signals to watch
Feedstock preparation has become the process engineering
Neste's filings treat phosphorus as the decisive impurity. Lipophilic phosphorus compounds above 2 wppm survive degumming and bleaching, deactivate the catalyst and plug reactors through salt precipitation, so the method measures them by solid-phase extraction or flash chromatography and picks the pretreatment from the result. The companion sets the operating target: cut lipophilic phosphorus below 2 wppm, preferably 1.5, before hydrotreating, isomerising or hydrocracking.
Signals to watch
Wet waste gets two different front ends
Firefly Green Fuels works on digested sewage cake at 15-40 wt% solids, liquefying it at 300-350°C and 180-220 bar, then hydrotreating and hydrocracking at 360-450°C and 10-20 MPa over nickel-tungsten on silica-alumina. The product averages about 11.5 carbons, and the patent claims aromatics tunable below 20 wt% so the blend can be balanced between soot reduction and the seal swelling that aromatics prevent.
Signals to watch
Fischer-Tropsch's downstream is already specified in detail
UOP's sequence hydrocracks the Fischer-Tropsch oil, splits off a kerosene cut and a C19-plus unconverted tail, dewaxes the kerosene, and recycles the tail back to hydrocracking; a second arrangement dewaxes first and combines the two effluents. Dewaxing runs on noble metals on AEL or MRE molecular sieves at 315-400°C and 300-1000 psig hydrogen partial pressure. The plant shape behind a small integrated demonstration is therefore a hydrocracker, a dewaxing reactor and a recycle loop, and the recycle ratio is what sets the yield.
Signals to watch
Engine makers are specifying the fuel through the combustor
Rolls-Royce's family does not wait for a better molecule. A lean-burn staged combustor is paired with a fuel-oil heat exchanger that drops fuel viscosity at combustor entry to 0.58 mm²/s or below at cruise, written for fuel containing up to 100% SAF, because the FT-derived product is thin and gives poor pump lubricity. Nozzle subsets are split in ratios from 1:2 to 1:5, and the claims are stated as emissions ratios against fossil kerosene: non-volatile particulate index below 1 at take-off, climb and idle, and below 0.2 for lean cruise against take-off, with a 10-70% average particulate reduction measured between 85% and 30% thrust. One filing goes further and claims a module that reads the fuel's characteristics and resets the pilot-to-main staging ratio to suit.
Signals to watch
The retrofit everyone is buying has little patent surface
The filings that say co-processing build a train. Chevron slurries solid biomass with hydrogen and a slurry hydrocracking catalyst, coprocesses that effluent with fats, oils and greases over a hydrotreating catalyst, then hydroisomerises the result. Petrobras does feed a renewable stream into existing hardware, sending C10-C14 methyl esters from metathesis to co-processing with fossil jet in an existing hydroprocessing unit.
Signals to watch
The only capacity with money and a date is a revamp
The one project in this period with an investment decision taken is a modification to a unit BPCL already runs. Topsoe will license kerosene hydrotreating into the Mumbai refinery, where a 4,000 metric ton per day hydrotreater takes 5% used cooking oil alongside conventional feed; the decision is taken, the revamp is under way, and commissioning is targeted for the end of 2026.
Signals to watch
The licensor ends up holding the asset, and the sums committed are small
LanzaJet's financing is the clearest statement of who carries the risk in a first-of-a-kind plant. The announcement was at least $20 million for Freedom Pines. The filings behind it show up to 25 million of senior secured notes, 10 million drawn at the first close on 14 October, first-priority liens on substantially all assets including intellectual property, a minimum return of 1.2 to 1.3 times principal on certain repayments depending on timing, and a warrant structure that lets LanzaTech reach 66.7% ownership and voting power, with the same terms set out in a second reading of the filing.
Signals to watch
The subsidy is written for the first plant
India's package is being assembled around viability gap funding for first-of-a-kind production plants, rationalisation of GST and excise, concessional finance, and feedstock support tied to verified origin and quality, all inside a forthcoming National SAF Policy. Uttar Pradesh has approved its own manufacturing promotion policy aimed at pulling in private investment and green jobs. Illinois supported the Phillips 66 arrangement through the Invest in Illinois Act.
Signals to watch
The funded constraint has moved to collection and verification
Grinda won up to KRW 3 billion over three years of government R&D money to industrialise collection and pretreatment across a network it puts at more than 3,000 sites. SGS took an award at the India SAF Conclave for testing, inspection, verification and traceability across the fuel chain. Neela Biotech raised £2.1 million of pre-seed to trial a microbial route that runs inside anaerobic digestion plants that already exist.
Signals to watch
Patent effort is going into the route that is already built
The filings concentrated on carbon efficiency and catalyst life in fats, oils and greases. Chevron claims a Linde Type A zeolite with an acid site concentration of about 2.6 to 3.0 mol/l, against an industry belief that stability requires 1.8 or below, to selectively hydrocrack the scantily branched paraffins that raise viscosity and would otherwise push SAF yield into renewable diesel. A second Chevron family converts fatty acid glycerol esters over a metal oxide catalyst into an intermediate carrying at least 70% of its oxygen in ketone groups, then fractionates and hydrodeoxygenates to hit the flash point, freeze point and viscosity limits.
Signals to watch
The quiet engineering is about feedstock impurities and how fuel gets allocated
Pongamia is the clearest case of work that exists in filings and barely in public discussion. J-Oil Mills purifies the oil to an absorbance of 0.215 or below at 330 nm before hydrogenation, or goes through a methyl ester first, to improve hydrogenation efficiency for HVO and SAF. A specification written around the absorbance of an impurity is what a feedstock looks like when it is available in principle and awkward in a reactor. Nothing published in this period describes the crop commercially.
Innovation activity
Conversion Technologies
This week's conversion news is dominated by one shape of project: SAF made inside hardware a refinery already owns.
Innovation activity
Policy & Commercial Deployment
This week's documents are almost entirely about who absorbs the cost of sustainable aviation fuel, and the answer being assembled differs sharply by jurisdiction.
Innovation activity
Feedstock Supply
This area covers the front end of the fuel chain: where the carbon comes from, who can grow or collect it, and whether its sustainability can be proved. Three feedstock lines carry most of the work, and they are at very different stages.
Innovation activity
Cross-Cutting Assessment
This area is the field's accounting layer. Its documents do three jobs: they estimate what a pathway costs to build and run, they estimate the greenhouse gas saving it delivers against fossil kerosene, and they track the price spread that decides whether any of it gets financed. The reviews and readiness assessments extend that to the whole portfolio. The purpose is to rank pathways before capital is committed.