How AIRMADE^® SAF Compares to Other SAF Pathways

SAF is not a one-size-fits-all solution; it encompasses a variety of production methods and feedstocks, each with its unique benefits and challenges. Biofuel derived from used cooking oil (or other lipids), referred to as Hydroprocessed Esters and Fatty Acids (HEFA), is currently a prevalent form of SAF. Production of SAF from energy crops such as corn via alcohol-to-jet pathway (ATJ) is considered to be the next technology in the pipeline in some regions. For HEFA SAF, feedstock scarcity is a real concern: the International Energy Agency (IEA) warns of an impending supply shortage for biodiesel, renewable diesel, and biojet fuel producers from 2022 to 2027. Energy crops-based SAFs are under less pressure from the feedstock availability perspective, but those pathways might not be available or can be challenging to develop in some regions, and certain scalability limits also exist. Given the projected growth in demand for air travel and increasing pressure on the industry to reduce its GHG emissions, there is an urgent need for SAF diversification and innovation to ensure robust and reliable supply. Using municipal solid waste (MSW) and non-food crops as feedstocks is also gaining interest. However, SAF made directly from CO₂ (aka power-to-liquids/PtL or e-SAF) is expected to deliver the deepest GHG reductions. It has the potential to be one of the most globally scalable options, and commercial projects are now beginning to emerge. 

The use of SAF has been gradually increasing, with a notable expansion in airports adopting it and airlines incorporating it into their operations—a sign of the aviation industry's commitment to reducing its carbon footprint and striving to achieve net-zero emissions by 2050. 

To meet 2050 net zero targets, 449 billion liters of SAF will be required in 2050, with e-SAF made from CO₂ projected to play a critical role in meeting the aviation sector demand and climate targets. According to IATA, of potential GHG emissions reductions from using SAF (based on ICAO’s LTAG SAF availability scenarios) replacing 80-90% of conventional aviation fuel with SAF would result in a 62% reduction in global aviation CO₂ emissions by 2050. This would require about 40% to be PtL SAF made with gaseous CO₂ as a feedstock.

Our AIRMADE® SAF is a pioneering approach, utilizing captured carbon dioxide and clean hydrogen as primary feedstocks and converting it into a 100% drop-in fuel via a single-step CO₂-to-hydrocarbons conversion process. Our method encompasses a proprietary streamlined process that differs from traditional e-fuel production methods, such as the Fischer-Tropsch process that relies on reverse water gas shift (RWGS). AIRMADE^® SAF stands out due to its innovative single-step process for converting CO₂ to hydrocarbons and 100% drop-in fuel capabilities, enabling direct replacement of conventional jet fuel without modifications to aircraft—boosting efficiency and lowering carbon intensity.

SAF is produced using renewable feedstocks such as waste oils, agricultural residues and other non-petroleum-based resources that constitute alternatives to fossil fuels and reduce the carbon intensity of the fuel.

There are several regulatorily-approved SAF production pathways, each defined in terms of their feedstock, chemical conversion process and composition of the resulting synthetic blending component. ASTM—the international standard-setting body responsible for approving SAF pathways to be safely used in commercial aviation—developed a pathway-naming convention that describes each pathway using the same terms but is not always consistent with the terms applied. There are currently eight ASTM-approved pathways, but the three pathways that are currently in use are:

The other five pathways are currently not producing SAF. They include Hydroprocessed Fermented Sugars to Synthetic Isoparaffins (HFS-SIP), which involve the microbial conversion of sugars to a jet fuel blending component.  FT-SPK with Aromatics (FT-SPK/A) is similar to the FT-SPK process but with a process modification that adds aromatic components to the jet fuel blending component. Catalytic Hydrothermolysis Synthesized Kerosene (CH-SKA or CHJ) uses supercritical water as a catalyst to convert the same feedstocks as HEFA into a liquid crude, which, after upgrading results in a fully formulated jet fuel containing aromatics. Hydrocarbon-Hydroprocessed Esters and Fatty Acids (HC-HEFA-SPK) convert unique algal oil containing saturated hydrocarbons in addition to lipids using the HEFA process into an SPK blending component. The most recently approved pathway, Alcohol to Jet with Aromatics (ATJ-SKA), converts alcohols into fully-formulated jet fuel containing aromatics using a modified version of the ATJ-SPK process.

Our pathway belongs to the e-fuels family but it is different from the FT process described above as it converts clean hydrogen and captured CO₂ into a liquid drop-in SAF without using an FT reactor. Hydrogen is produced through the electrolysis of water, which is then combined with captured CO₂ and converted in a one-step process to a liquid crude fuel. The liquid is upgraded to produce a fully formulated e-SAF that does not require blending. The reliance on captured CO₂ and renewable electricity, coupled with a higher efficiency process, positions the production process to become scalable and deployed anywhere in the world. AIRMADE^® SAF is expected to deliver GHG reductions of over 90% compared to conventional jet fuel on a full lifecycle basis.

One of the primary differentiators of AIRMADE^® SAF is its production method, which hinges on a streamlined and more efficient process than the traditional Fischer-Tropsch process—the process that’s typically associated with PtL and has been largely unchanged since its development in 1925. AIRMADE^® SAF is also a fully formulated drop-in SAF because it includes two key components that comprise jet fuel: aromatics and paraffins.

AIRMADE^® SAF process begins with capturing CO₂, which currently comes from industrial biogenic sources. This CO₂ is then combined with green hydrogen produced using renewable electricity. The chemical reaction within a proprietary Carbon Conversion Reactor that combines the feedstocks yields reactor liquid, which comprises alcohols, alkanes and water. This mixture is then distilled to separate these components, and the alkanes are used to produce the paraffins, one of the main components in SAF.

This process stands out for its potential to achieve greater energy efficiency compared to FT.  We also utilize only biogenic CO₂ from existing sources, which means we can take emissions that otherwise would have been emitted into the atmosphere and transform it into sustainable aviation fuel (SAF) instead while reducing the aviation sector's reliance on fossil fuels.

The environmental benefit of AIRMADE^® SAF, among other e-SAFs, could be significant, offering one of the highest greenhouse gas (GHG) emission reductions of any SAF pathways currently available. Significant reductions in carbon intensity through e-SAF pathways are attractive to the aviation industry, especially considering the challenges in lowering emissions in the sector with limited decarbonization alternatives. Our aviation partners include JetBlue, Virgin Atlantic, Air Canada and Boom Supersonic, amongst other undisclosed partners, that are interested in purchasing AIRMADE^® SAF. The United States Air Force used unblended AIRMADE^® SAF made from CO₂ on an unmanned test flight (and we currently have an R&D contract with the U.S. Defense Innovation Unit) in 2022, marking the beginning of radically transforming the industry's environmental footprint.

In addition to its environmental benefits, AIRMADE^® SAF is designed to be a drop-in fuel, meaning it does not require blending with fossil fuels and can be used without the need for new infrastructure or modifications to existing aircraft engines (note that ASTM rules currently do not allow 100% drop-in fuels and all SAFs are required to be blended with conventional jet fuel up to 50%). This means that AIRMADE^® SAF can be easier for the aviation industry to uptake. 

According to a recent IEA report, e-fuels are on track to become big players starting in 2030, especially as electrolyzer technology gets better and cheaper. AIR COMPANY is among the industry leaders innovating in the e-SAF space.

With a focus on continuous innovation and strategic collaborations, AIRMADE^® SAF is not just a product; it's a vision for cleaner skies and a more sustainable world. At AIR COMPANY, we're working toward a greener, more sustainable future. Stay tuned—we're almost there.