Life cycle assessment of corn stover-based Fischer–Tropsch sustainable aviation fuel in Portugal: Environmental hotspots and greenhouse gas reduction potential

Aviation remains one of the most challenging sectors to decarbonize due to its reliance on high-energy-density liquid fuels and the limited availability of near-term alternatives to fossil-derived jet fuel. This study applies an ISO 14040/14044-compliant life cycle assessment, implemented in GREET model, to evaluate sustainable aviation fuel produced from corn stover via gasification and Fischer–Tropsch synthesis under Portuguese conditions. The functional unit is 1 MJ of Fischer–Tropsch jet fuel at the refinery gate, using a cradle-to-gate boundary. Portugal-specific parameters, namely the electricity mix and weighted average road transport distance, were incorporated, while default GREET data were retained for conversion processes where regional inventories were unavailable. The pathway showed a global warming potential of 0.015 kg CO2-eq/MJ, corresponding to an 83% reduction relative to the conventional aviation fuel comparator of 0.089 kg CO 2 -eq/MJ. The conversion stage was the main environmental hotspot, contributing approximately 70%–80% of the assessed impacts, depending on the category. The results indicate that SAF produced via gasification-Fischer–Tropsch using corn stover may contribute to aviation decarbonization in Portugal, although its performance remains dependent on conversion efficiency, electricity carbon intensity, logistics and residue-management assumptions.