Harnessing feedstock diversity for sustainable aviation fuel production

Relying on a single feedstock for Sustainable Aviation Fuel (SAF) production is not a realistic option because the amount of SAF needed for the aviation sector to meet the growing number of mandates and targets around the world is likely to require contributions from all feedstocks and multiple process routes.

Until now, the main focus has been on hydroprocessed esters and fatty acids (HEFA) from used cooking oil, but there is a limited amount of this feedstock, with around 80% of the feedstock used in the EU coming from imports. Although regions including the US, Europe, and the UK have led the way with mandates and incentives for SAF production, attracting feedstocks from around the world, as other regions inevitably bring in their own goals, the reliance on importing feedstocks is a major threat to meeting SAF targets. Relying too heavily on HEFA and importing feedstocks is not a long-term solution. Quite simply, the status quo is flawed.

Diversification of feedstocks is vital for the resilience of the biofuels industry. Relying on a single type of feedstock may leave fuel suppliers vulnerable to market volatility and supply chain disruptions in an emerging market. Fuel suppliers are the obligated parties under mandates in the EU and UK, and they are expected to deliver against SAF targets in regions, like the USA, Japan and a growing list of others. By incorporating a variety of feedstocks, both fuel suppliers and countries can take control of their destiny and secure the SAF they need from domestic feedstocks.

However, there is a solution that can use a wide range of feedstocks, available globally, to unlock domestic SAF production at scale and ensure countries can produce the SAF they need.

Feedstock diversity to unlock SAF at scale

The Fischer-Tropsch (FT) process is based on a syngas platform and is an ASTM-approved route to produce synthetic SAF blendstocks. Syngas is a mixture of carbon monoxide (CO) and hydrogen (H2) and the FT process builds the hydrocarbon chains needed for SAF. Syngas can be produced from a huge range of feedstocks, such as municipal solid waste (MSW), waste biomass, and captured carbon dioxide (CO2) emissions (when combined with H2). Companies such as Johnson Matthey (JM) are leading the way in delivering syngas technology and the versatility provided by the FT route to SAF.

FT CANS, a step-change improvement in FT technology

The FT CANS™ technology developed by Johnson Matthey and bp represents a significant advancement in FT technology. The combination of reactor design and innovative catalyst offers several technical benefits that enhance the efficiency and scalability of the FT process:

The FT CANS technology utilises a modular reactor design that reduces the amount of catalyst required, lowering capital costs by approximately 50% versus traditional fixed-bed FT. Modularity also allows for easy scalability, enabling plant sizes to match available feedstock quantities. Our largest announced project to date has an expected capacity of 13,000 barrels per day once operational.

Heat management is critical in the highly exothermic FT process. The FT CANS reactor features a unique configuration that enhances heat transfer and control, meaning the technology boasts a high conversion rate, with CO conversion efficiencies exceeding 90%.4 This high conversion rate is achieved through an innovative radial flow design that maximises contact between the syngas and the catalyst facilitating efficient mass transfer, allowing for higher productivity and selectivity towards desired hydrocarbon products.

Conclusion

Processing eligible feedstocks for SAF production can reduce greenhouse gas emissions and provide economic benefits. According to estimates by the International Air Transport Association (IATA), using SAF can lead to an over 80% reduction in net carbon emissions over the full life cycle compared to fossil-derived jet fuel. Adopting diverse feedstocks for fuel production offers a long-term solution for creating synthetic fuels and meeting the increasing SAF targets globally.

Overall, harnessing feedstock diversity is a critical accelerator to produce synthetic fuels at scale, and the syngas-based FT CANS technology can play a crucial role in delivering this ambition. As the industry evolves, collaboration between governments, industry stakeholders, and research institutions will be key to unlocking the full potential of feedstock diversity for SAF.