Spatial Differentiation of Carbon Mitigation Potential and Economic Viability of Corn-Straw-Based SAF Production in China Through a Synergy Framework

Sustainable aviation fuels (SAFs) are critical for aviation decarbonization, yet feedstock supply-side trade-offs, including spatial variability and straw return to soil, are often overlooked. This study integrates energy and ecological assessments via lifecycle assessment to evaluate carbon mitigation and economic feasibility of corn-straw-based SAF in China using aqueous phase reforming (APR), hydrothermal liquefaction (HTL), and gasification–Fischer–Tropsch (FT) synthesis. HTL shows the highest mitigation efficiency (61.4%) and greatest potential, and is therefore optimal. Spatially, mitigation potential is highly heterogeneous, concentrated in northeastern and northern China, while some western and southern provinces show low or negative mitigation under FT synthesis. A 20%/80% straw allocation to SAF and soil retention yields 55.0 Mt CO2-eq annually, 29.6 Mt of additional mitigation from fuel substitution and 25.4 Mt of maintained soil carbon sequestration. Economically, with carbon credits, HTL is cost-competitive with fossil jet fuel in all provinces, saving 241–1730 yuan/t (≈36–260 USD/t), highest in Inner Mongolia, Xinjiang, Heilongjiang, Liaoning, and Ningxia (1510–1730 yuan/t). FT synthesis has reached cost parity in some provinces, whereas APR remains unviable, costing 1700–3210 yuan/t (≈255–482 USD/t) more than fossil jet fuel. These findings support regional SAF deployment and China’s carbon neutrality goals.