A Techno-Economic, Environmental and Social Life Cycle Assessments of Sustainable Aviation Fuel production via the Alcohol-to-Jet process – A UK Case Study

This study presents a multi-dimensional (techno-economic, environmental, and social life cycle) assessment of sustainable aviation fuel production via the alcohol-to-jet pathway using lignocellulosic wheat straw and UK as a case study. A self-sufficient, integrated biorefinery was modelled in Aspen Plus®, incorporating in situ hydrogen and oxygen generation, enzyme production, co-product recovery (bio-naphtha, biodiesel), and waste-to-energy cogeneration. A techno-economic analysis was performed through discounted cash flow modelling, while environmental and social impacts were evaluated using ISO 14040/44-compliant life cycle assessment and PSILCA-based social life cycle assessment. Thermodynamic results indicate overall biomass-to-product conversion efficiency of 11% with 68% SAF selectivity, with >90% residue valorisation through a 66 MW Rankine-cycle cogeneration unit, enabling full internal energy supply and 48 MW of net electricity export. The economic analysis estimates capital and operating costs of £475 M and £193 M, with annual co-product revenues of £140 M. The Minimum Jet Fuel Selling Price ranges between £0.75 - £4.53/kg, strongly dependent on policy incentives and equity structure. Environmental assessment results show up to 80% greenhouse gas reduction compared to fossil jet comparator, while S-LCA highlights road transport and SAF production as the highest social risk sectors, with “fair salary” as the most critical indicator. Sensitivity and Monte Carlo analyses identify feedstock, enzymes, and utilities as dominant economic drivers, while scale-up from 1,000 to 4,000 t/day reduces MJSP substantially. Overall, the AtJ pathway demonstrates high SAF selectivity >70% and resource integration, offering strong potential for aviation decarbonisation under supportive policy and regulatory frameworks.