Process integration of ammonia-assisted and biomass-based pathways for hybrid sustainable aviation fuel production: Techno-economic and life-cycle assessment under national-scale constraints

Sustainable aviation fuel (SAF) is a key option for reducing greenhouse gas (GHG) emissions, but achieving both deep decarbonization and cost competitiveness remains challenging. This study proposed a hybrid SAF production system integrating ammonia-assisted and biomass-based pathways. In the ammonia-assisted pathway, green ammonia serves as a hydrogen carrier, while carbon is supplied by CO 2 captured from petrochemical complexes. A biomass-based pathway is developed via chemical looping gasification of underutilized woody biomass. A national-scale case study for the Republic of Korea is conducted using process modeling, techno-economic analysis and life-cycle assessment. The ammonia-assisted pathway shows strong GHG reduction but exceeds the current SAF market price range (1870–2600 US$/tonne SAF). Integrating the biomass-based pathway reduces the blended SAF cost to within this range when its share increases from 21% to 43%. Increasing the ammonia-assisted share from 57% to 79% achieves over 20% additional life-cycle CO 2 reduction. The results demonstrate that process integration enables effective trade-off management under limited biomass availability.