Plastic-to-jet conversion of plastic waste: A critical review of pyrolysis oil characteristics and aviation fuel compliance

The global aviation sector is under increasing pressure to decarbonize, while plastic waste continues to accumulate worldwide. Converting waste plastics into sustainable aviation fuel (SAF) precursors through pyrolysis and catalytic upgrading, namely the plastic-to-jet (PTJ) route, offers a potential pathway to couple plastic-waste valorization with aviation-fuel decarbonization. However, plastic-derived pyrolysis oils cannot satisfy SAF-relevant requirements directly. This review critically evaluates recent progress in plastic pyrolysis and systematically maps the major fuel-quality gaps between plastic-derived oils and ASTM D7566/D1655-relevant aviation-fuel requirements. Key parameters, including carbon-number distribution, hydrocarbon composition, oxygen content, chlorine, sulphur and nitrogen impurities, olefins and gum formation, and physical properties, are discussed. The roles of feedstock type, pyrolysis temperature, catalyst type and loading, fractional distillation, and hydrotreating are analyzed in relation to SAF-oriented product regulation, with particular attention given to the trade-offs involved in these strategies. Engineering, techno-economic, and life-cycle considerations are also included to discuss the practical feasibility of PTJ pathways. This review emphasizes that PTJ development is not a single-step conversion process, but a multi-strategy optimization process aimed at satisfying multiple SAF-relevant specifications simultaneously. This process requires a careful balance between fuel-quality improvement and the associated trade-offs in yield, hydrogen demand, energy consumption, process complexity, economic cost, and environmental impact. This review provides a specification-driven basis for assessing the feasibility of PTJ pathways and guiding their development toward SAF-compliant products.