Abstract
Sustainable aviation fuel (SAF) is a key pathway for mitigating greenhouse gas emissions in aviation, yet its large-scale deployment is constrained by high energy demand and production costs. Among available conversion routes, the hydroprocessed esters and fatty acids (HEFA) pathway is the most commercially mature, but it requires substantial hydrogen input and high-temperature heat, affecting both economic and environmental performance. This study presents a decision-support framework for SAF production via integrated biorefineries, using rapeseed oil extraction coupled with HEFA conversion as a case study. Detailed process simulations are combined with energy integration and mixed-integer linear programming optimization to enable system-level analysis. Material integration strategies include internal hydrogen generation via glycerol steam reforming and valorization of rapeseed meal through gasification for syngas production. Heat integration considers cross-process heat recovery and the application of high-temperature heat pumps to reduce external energy demand. The results demonstrate that coordinated optimization of heat and material flows significantly improves energy efficiency and reduces reliance on fossil utilities. The framework provides a practical tool for identifying economically and environmentally robust SAF production pathways by integrating feedstock conversion, co-product utilization, and utility optimization. These findings support strategic decision-making for next-generation biorefineries and strengthen circular economy principles in sustainable aviation fuel production.