All Roads Leading to SAF
Reach the Global Target of 11 billion Liters of SAF in 2030, Choose Axens as a Trusted Partner!
On the road to SAF
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Introduction to SAF
What is SAF, its market perspectives, and how to produce it?
SAF processes review
Depending on local resources, various solutions can be adapted, ranging from integrating with existing assets to establishing greenfield plants. We provide a single point of contact throughout the execution, integrated guarantees, and process optimization to enhance profitability, enabling a smooth energy transition.
Axens Pathways
Vegan® is a flexible solution to produce renewable diesel and SAF through the hydrotreatment of a wide range of lipids. This technology allows producers to effectively address environmental regulations, sustainability targets, and secure energy diversification with drop-in premium-quality products.
Hydrotreatment section
Vegan® technology includes a hydrotreatment section to deoxygenate and remove contaminants from renewable lipids in the presence of hydrogen to produce linear paraffins.
Hydroisomerisation section
Vegan® technology includes a hydroisomerisation section to upgrade the linear paraffins produced in the previous step into real drop-in middle distillate biofuels. The hydroisomerisation section can be tuned to produce different grades of jet fuel or diesel fuel, according to market needs, with the ability to produce anywhere from 0 to 100% of the middle distillate product as SAF.
Gasel® technology converts synthesis gas (H₂+CO) from various origins – biomass, captured carbon oxides – into a flexible slate of ultra-clean liquid fuels (XTL), including SAF. This Fischer-Tropsch (FT) route is commonly accepted as one of the most promising mid-term solutions for the production of alternative fuels and petrochemicals, including biomass-to-liquids (BTL) and efuels.
Syngas purification
If required, this step aims at ensuring a syngas purity suitable for the FT catalyst. It can treat syngas from any conventional acid gas removal process.
FT synthesis
The reaction takes place in a three-phase slurry bubble column (SBC) reactor where syngas is brought into contact with the solid FT catalyst to produce long-chained liquid hydrocarbons. The liquid products are recovered in Liquid/Solid and Gas/Liquid separators and sent to the upgrading section.
FT product upgrading
The raw FT liquid product is stabilised, hydrotreated (olefins and oxygenates), hydrocracked, and isomerised. The fully converted product is then separated, and it offers flexibility towards different production modes (max kerosene or max middle distillates/diesel with a small production of naphtha).
BioTfueL® technology unlocks SAF and advanced biofuels production from energy crops, agricultural, and forestry residues (including wood industry residues) via a thermochemical pathway. This technology is the most de-risked Gasification-FT chain in the market thanks to its successful operation of 2 large-scale demonstration plants in France. Axens is the single licensor for this proven and robust BTL chain. BioTfueL® offers the unique one-stop-shop concept of one-single guarantee from Biomass to SAF!
Pretreatment
Biomass is conditioned with drying and torrefaction. These steps homogenize feedstock quality, facilitate grinding, and increase storage stability and biomass energy density. Flexible process conditions allow adjustments due to changes in biomass quality and supply strategy.
Gasification
The applied Uhde entrained-flow gasification process with direct quench (PDQ) is a high pressure and high temperature partial oxidation converting carbonaceous material into tar-free syngas.
Syngas conditioning
Syngas is conditioned to FT requirement by adjusting the H₂/CO ratio via a water gas shift reaction, followed by acid gas removal and a final purification.
FT synthesis and upgrading
Gasel® technology uses CO & H2 building blocks to form long chains of liquid hydrocarbons. The reaction takes place in a 3-phase Slurry Bubble Column (SBC). The SBC allows perfect control of the high exothermicity and good homogeneity of the reaction. FT products are then upgraded toward the targeted products.
Movie on BioTfueL®️ technology
Futurol® converts lignocellulosic biomass from various origins into cellulosic ethanol (advanced bioethanol). This cellulosic ethanol can then be converted to SAF with the Jetanol™ (ATJ) process.
Pretreatment
An energy-efficient, single train, continuous technology was selected and optimized for converting biomass feedstock such as energy crops, agricultural, and wood residues to a standardized pretreated substrate, highly digestible, and with low moisture. High hemicellulose conversion is attained while product degradation is minimized.
Biocatalysts production
Inhibitors-resistant tailor-made biocatalysts (enzymes and yeasts) were designed, adapted, and improved to optimize process performances. Futurol® offers on-site enzyme production and yeast propagation using lignocellulosic substrate, which strongly contributes to ethanol production cost reduction.
Hydrolysis and fermentation
Enzymatic hydrolysis of biomass and co-fermentation of C₅ and C6 sugars take place simultaneously in the same vessel (‘one-pot’ process). This process configuration capitalizes on a synergy between biocatalysts and allows for both Capex and Opex minimization while achieving high ethanol yield through full conversion of C5 and C6 sugars.
Products recovery
State of the art distillation and dehydration allow recovery of advanced bioethanol suitable for biofuel applications or further processing in chemical production. Lignin and stillage are recovered and routed to energy production while water is recycled.
Jetanol™ is the process by which low-carbon ethanol (bioethanol and advanced bioethanol) is converted to SAF via different steps. This differentiating technology bundle approach utilizes commercially proven processes.
Dehydration step
Polymer-grade ethylene is produced by ethanol dehydration (Atol®).
Oligomerisation step
The Ethylene is then oligomerized into SAF utilizing stable catalysts which can be generated and/or on the fly changeout when required.
Upgrading step
A last step of hydrogenation is necessary to reduce the olefin content of the product to fulfill ASTM specifications for the final products.
Combining Futurol® and Jetanol™ processes provides the possibility of producing ultra-low CI – or even carbon-neutral, SAF from lignocellulosic biomass.
Find out more
Sustainable Aviation Fuels Brochure
Vegan® Commercial Bulletin
Gasel® Commercial Bulletin
Jetanol™ Commercial Bulletin
BioTfueL® Commercial Bulletin
Contact our experts
Yvon Bernard
David Schwalje