• Replacing incineration with waste-to-kerosene improves most environmental impacts. • Trade-offs include higher climate change and toxicity impacts in waste-to-fuel systems. • Waste-to-kerosene can meet near-term SAF demand, but a small share in the long term. • Scaling waste-derived aviation fuels depends on policy support and system constraints. This study presents an integrated modeling framework to assess the capacity of modern urban waste management systems (WMSs) to contribute to sustainable aviation fuel (SAF) production through gasification and Fischer–Tropsch (FT) synthesis. While SAF deployment is central to aviation decarbonization strategies, the system-level implications of integrating waste-to-SAF pathways within existing WMSs remain insufficiently explored. A detailed Aspen Plus® simulation of the FT process was embedded in a machine-learning surrogate model and coupled with a prospective life-cycle assessment of a full WMS, enabling the joint evaluation of process-level design choices, system-level environmental trade-offs, and SAF supply potential. The proposed waste-to-SAF FT configuration was developed as an alternative to incineration and compared with a gasification-to-electricity pathway. Results show that the FT-based configuration improves environmental performance relative to incineration across most impact categories, although climate change impacts increase by 14.7 %. Compared to gasification for electricity generation, the FT route exhibits comparable overall performance but higher impacts in climate change and ecotoxicity. Using Madrid as a case study, the model quantified the contribution of WMSs to SAF supply under evolving European Union blending mandates. At a 50 % blend with conventional jet fuel, waste-based SAF could fully meet the mandated demand for early-stage deployment, whereas under a 70 % blending target it would cover only 2.3 % of the projected requirement by 2050. While scalability is limited by resource availability and investment requirements, localized SAF production offers strategic value for aviation decarbonization through waste valorization. The model provides a decision-support tool for integrating waste, energy, and climate policies in the context of ReFuelEU Aviation.
Martínez-Ramón et al. (Sun,) studied this question.