Optimising next-generation sustainable aviation fuel

The UK aviation industry has committed to achieving net zero emissions by 2050. While lighter, more efficiently powered aircraft are being developed, current aircraft, which will remain in operation until the 2030s, need to be less reliant on unsustainable fossil fuels.

Up to 70% of global emissions from the aviation industry can be reduced if fossil fuels are replaced by SAF derived from feedstocks that include waste. However, many of the existing solutions for SAF production, primarily developed in the US, have not been compatible with the renewable feedstocks available in the UK.

The FASTACEJET project, led by CPI and supported by the University of Nottingham, Drochaid Research Services and the University of Sheffield, aims to develop affordable and high-quality next-generation SAF. In contrast to some of the fuels available on the market, this SAF will be derived from feedstocks that neither compete with food production nor lead to deforestation, with minimal freshwater and land requirements. Funding from the HVMC via Innovate UK for the Aerospace Technology Institute (ATI) has been provided to help de-risk and accelerate the commercialisation of the novel technology. 

The FASTACEJET project will focus on two viable processes – the FASTJET and ACEJET pathways – to produce SAF. The FASTJET pathway produces fatty acids via a two-stage fermentation process – chemolithotrophic fermentation of H2 and CO2 for the production of an intermediate organic acid that becomes the feedstock for the subsequent fermentation of oleaginous yeast.

The ACEJET pathway produces an aldehyde as a platform chemical from waste or surplus H2 and CO2 in chemolithotrophic fermentation. Both fermentation products are then upgraded to SAF products by chemo-catalytic processes. The project will optimise both pathways – which have already demonstrated feasibility at lab-scale – to create fuel samples to evaluate physico-chemical properties and their suitability as aviation fuel, together with more detailed techno-economic modelling of the processes.

CPI will coordinate all activities with subcontractors, secure funding and provide access to its state-of-the-art facilities. Besides bringing vital scientific and engineering expertise to this project, CPI will offer capabilities in gas fermentation at its open-access facility.

This facility has both process and safety controls, ensuring the composition of the gas mix is optimal for the growth of the microorganism under study and, importantly, also maintained within the defined safe operating window. The facility is being successfully operated using CO2, hydrogen and air mixtures as feedstock, supporting existing customer projects.

Yvonne Armitage, Biotechnology Business Unit Director at CPI, said: “I am delighted that CPI is leading such an exciting collaborative project to help solve major challenges in the aviation industry. The outcomes of this project could help us produce commercially viable and greener SAF to help meet net zero targets.”

Dr Grant Dench, at Drochaid Research Centre, added: “Drochaid Research Services Ltd is glad to bring extensive experience and expertise in catalytic processes to support CPI and the University of Nottingham on the development of these technologies aiming to support the net zero aviation strategy and contribute to the UK’s transition towards a low carbon future.”