Reach the Global Target of 11 billion Liters of SAF in 2030, Choose Axens as a Trusted Partner!
On the road to SAF
Introduction to SAF
What is SAF, its market perspectives, and how to produce it?
& Market Price
Axens is uniquely positioned, providing de-risked technologies. The Fischer-Tropsch pathway was the first process to be certified in 2009, followed by the hydrotreatment of esters and fatty acids in 2011. The Alcohol to Jet (ATJ) process was certified in 2018 for SAF production.
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.
Vegan® technology includes a hydrotreatment section to deoxygenate and remove contaminants from renewable lipids in the presence of hydrogen to produce linear paraffins.
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.
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.
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!
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.
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 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.
Futurol® converts lignocellulosic biomass from various origins into cellulosic ethanol (advanced bioethanol). This cellulosic ethanol can then be converted to SAF with the Alcohol to Jet (ATJ) process.
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.
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.
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.
Alcohol to Jet is the process by which 1G or advanced bioethanol (2G) is converted to SAF via different steps. This differentiating technology bundle approach utilizes commercially proven processes with over 100 homogeneous and heterogeneous reference units.
First, polymer-grade ethylene is produced by ethanol dehydration (Atol®).
The ethylene is then oligomerised at close to ambient temperature with a high selectivity towards butenes, utilising a liquid phase, homogeneous Ziegler-type catalytic system based upon a transition metal derivative, nickel, activated by an alkylaluminium reduction compound. The catalytic system is called homogeneous because the reactants, the products, and the catalysts form a single liquid phase (Dimersol™).
The produced butenes and hexenes are converted into SAF via heterogeneous oligomerisation (Polynaphtha™), utilizing a robust, environmentally friendly and regenerable catalyst, which ensures long cycles and long catalyst life.
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 ATJ processes provides the possibility of producing ultra-low CI – or even carbon-neutral, advanced SAF from lignocellulosic biomass.