Comparative techno-economic assessment of CO2-based SAF pathways: Fischer-Tropsch, methanol-to-jet and ethanol-to-jet across three global regions: EU, USA and Middle East

Aviation accounts for around 2.4% of global CO 2 emissions, and demand is expected to grow significantly by 2050. Although sustainable aviation fuels (SAFs) are considered a key mitigation strategy, comparative techno-economic insights across different production pathways and regions remain limited. This study provides a harmonized techno-economic assessment (TEA) of three power-to-liquid (PtL) routes for e-kerosene production: Fischer-Tropsch synthesis (FTS); methanol-to-jet (MtJ), with two variants: syngas-based via reverse water–gas shift (MtJ-1) and direct CO 2 hydrogenation (MtJ-2); and ethanol-to-jet (EtJ) via direct CO 2 gas fermentation. All pathways were modelled in Aspen Plus V14® with subsequent upgrading to kerosene-range hydrocarbons and a custom TEA tool was used for techno-economic evaluation. Regional scenarios were assessed for Europe, the USA and the Middle East. The results show that electrolysis accounts for 55–80% of capital expenditure, rendering hydrogen production a decisive cost driver. Net production costs (NPCs) range from 2.8 to 8.2 USD per kg of SAF across all pathways and regions, exceeding the cost of fossil Jet A-1 fuel (approximately 1 USD per kg) by at least a factor of three. MtJ-2 consistently emerges as the most cost-efficient pathway, with NPCs of around 2.8–5.3 USD per kg, while FTS performs worst due to extensive tail gas recycling loops and low single-pass CO conversion. EtJ exhibits intermediate performance, but faces uncertainties linked to large-scale gas fermentation. The carbon and energy efficiencies confirm this trend, at 56–63% and 48–54% respectively for alcohol-based routes versus 42% and 50% for FTS.