Johnson Matthey revolutionising SAF with HyCOgen

opinion

by Fayaz Hussain

November 18, 2024

The efficient use of a diverse range of feedstocks is crucial for advancing sustainable aviation fuel (SAF) technologies, writes Paul Ticehurst, MD, HyCOgen and FT Liquids at Johnson Matthey. Beyond first- and second-generation biofuels, e-fuels from captured CO2 and electrolytic (green) hydrogen are seen as a long-term solution. Johnson Matthey’s (JM) HyCOgen technology is optimised to produce syngas for e-fuels in combination with Fischer-Tropsch (FT) CANS technology, but it also hides a secret identity. It can supercharge SAF production enabling plants to boost SAF productivity to over 250%.

Syngas production

Syngas, a mixture of hydrogen and carbon monoxide, is a crucial intermediate for synthesising SAF, and can be derived from a variety of feedstocks, including biomass, municipal solid waste, and even captured CO2 and H2. Syngas generation technology has been proven at scale around the world with more than 50 plants using waste gasification to produce syngas as a fuel for energy production. The ability to use a versatile range of feedstocks is pivotal for the scalability and sustainability of SAF production.

Typical syngas production via gasification produces both hydrogen and carbon monoxide, but not in the correct ratio to feed an FT reactor, gasification also produces CO2. Often a water gas shift (WGS) reactor is employed to produce the additional hydrogen, but this also converts valuable CO into CO2 which must be removed from the process before FT synthesis, effectively acting as a carbon leak and reducing the overall carbon efficiency of the process. Figure 1 shows this base case for production of syngas and SAF. Water gas shift is used to balance the mix of H2, CO and CO2. It is followed by CO2 removal before the syngas enters the Fischer-Tropsch (FT) reactor and the products are upgraded to produce SAF.

Turbocharging productivity

One method to avoid this leakage of valuable carbon from SAF feedstocks is to dispense with the WGS process altogether and simply feed in additional hydrogen to achieve the required ratio. Operating the process in this manner can significantly increase SAF output compared to the base case but even this still leaves a portion of the valuable carbon behind. In Figure 2, adding hydrogen into the process can increase the overall liquid product yield by around 60%, effectively turbocharging the process.

Supercharging SAF production

HyCOgen technology can use the CO2 produced during SAF manufacturing and with the addition of hydrogen convert it into syngas. This not only prevents what could otherwise be waste CO2 from potentially being released into the atmosphere but also transforms it into a valuable syngas feedstock for further fuel production. This capability can significantly enhance economic viability of hybrid SAF plants, able to produce SAF from both bio-feedstocks and via power-to-liquid. By utilising the captured CO2, hybrid SAF plants can increase their SAF output by a further 90%, to over 250% (Figure 3). This supercharged SAF productivity is achieved without the need for additional feedstocks.

Pathway to e-fuels and economic benefits

HyCOgen technology offers a pathway to unlocking production of power-to-liquid fuels without the need for building a separate PtL plant. If HyCOgen is fed with electrolytic (green) hydrogen, it effectively creates hybrid SAF plants, able to produce both second generation bio-SAF and e-SAF. By supercharging these plants, HyCOgen and FT CANS maximise utilisation of valuable feedstocks and offer full integration of the production process. This approach not only enhances the overall efficiency but also accelerates the transition to e-fuels.

The integration of HyCOgen technology in hybrid SAF plants provides multiple benefits. Economically, the increased productivity and resource efficiency translate to lower production costs and higher profit margins. Capturing and using the carbon dioxide to create additional fuel provides an option that can avoid CO2 being released into the atmosphere.

Additional circularity benefits

When generating electrolytic hydrogen, oxygen is produced as a by-product. This oxygen could be used to fuel the gasification process, further enhancing the overall efficiency and integration of the system. This symbiotic relationship between hydrogen production and syngas creation can contribute to the optimised performance of hybrid SAF plants.

Furthermore, by adding HyCOgen into the flowsheet, the water it produces could be used to feed the electrolyser, further reducing the freshwater requirements and waste streams of the SAF plant.

Using HyCOgen and FT to balance intermittent renewables

When integrating HyCOgen in hybrid SAF plants, the co-produced FT naphtha could be recycled alongside FT tails gas back into the HyCOgen process to make additional syngas. This naphtha can effectively be utilised as a chemical battery to balance out intermittency in renewable electricity used in the electrolysis process.

FT CANS Technology: Complementing HyCOgen technology

FT CANS technology, jointly developed by JM and bp, represents a significant advancement in the FT process. The FT CANS reactor design utilises a modular approach that reduces the amount of catalyst required, lowering capital and operational costs while enhancing scalability. It features an innovative configuration for better heat management and efficient mass transfer, resulting in high CO conversion efficiencies exceeding 90%.

The granularity and scalability of the FT CANS technology means it is ideally suited to complement HyCOgen deployment in hybrid SAF plants to maximise feedstock utilisation. The FT CANS reactors can be precisely scaled, to make full use of carbon in the feedstock and minimise carbon leakage in the SAF production process.

Ultimately, the combination of HyCOgen and FT CANS technologies offers a robust pathway to SAF, utilising a wide range of feedstocks and optimising the overall production process to reach carbon efficiencies, after upgrading, exceeding 98%.

Compliance with e-SAF legislation

The FT CANS technology qualifies as an ASTM approved route to aviation fuel containing synthesized hydrocarbons. With sub-mandates for power-to-liquids SAF being introduced in the UK and EU, leveraging HyCOgen alongside FT CANS in a hybrid SAF plant offers a means to co-produce 2nd-generation bio-SAF and e-SAF in the same facility, meeting the needs of the mandates while avoiding the need for stand-alone e-fuels facilities. By utilising approved carbon sources and integrating advanced CO2 capture and conversion techniques, JM ensures that its technology aligns with current and future regulatory frameworks.

Conclusion

JM’s HyCOgen technology is set to revolutionise syngas production and hybrid SAF plants. By efficiently converting captured CO2 into syngas and integrating electrolytic hydrogen, this technology supercharges SAF productivity. The ability to produce both regular SAF and e-SAF within the same plant, combined with compliance with broader SAF legislation around the world, positions HyCOgen and FT CANS as key technologies in the future of SAF. The increased productivity and carbon efficiency offered by this technology not only enhance the economic viability of SAF production but also contributes to the future of air travel.

About the author:

Paul Ticehurst is MD for HyCOgen and FT Liquids with Johnson Matthey, based in London. Paul has over 25 years of experience developing process-based projects, working throughout Europe and US. At Johnson Matthey, he has commercial responsibility for the Fischer-Tropsch CANS technology jointly licenced with bp and the Reverse Water Gas Shift technology, HyCOgen. He is a chartered chemical engineer, holds a bachelor’s degree in chemical engineering with minerals engineering from the University of Birmingham and an MBA from Kingston University.