Sustainable production of alternative aviation fuel via thermolytic conversion of plastic waste: techno-economic analysis and life cycle assessment

This study proposes scalable process for producing alternative aviation fuel from plastic waste, particularly high-density polyethylene (HDPE), through pyrolysis. Prior to process design, HDPE pyrolysis experiments were conducted at 500, 600, and 700 °C to examine temperature effect on aviation fuel production. The aviation fuel yields were 24.0, 20.8, and 3.0 wt% at 500, 600, and 700 °C, respectively, indicating that 500 and 600 °C were most effective. Based on these findings, two aviation fuel production processes (AFP-500 and AFP-600) were developed, integrating pyrolysis at 500 and 600 °C with catalytic cracking. Notably, catalytic cracking was employed to convert wax produced during pyrolysis process. Simulation results showed that HDPE feed rate of 5000 kg h−1 yielded 1523 and 1159 kg h−1 of aviation fuel in AFP-500 and AFP-600, respectively. Techno-economic analysis (TEA) revealed that the levelized cost of production (LCOP) for AFP-500 and AFP-600 were 0.017 and 0.035 USD MJ−1, respectively, indicating that 500 °C is the optimal pyrolysis temperature. Additionally, the LCOP of AFP-500 is 40–77% lower than that of sustainable aviation fuels (SAFs). Life cycle assessment (LCA) results demonstrated net GHG emissions of 0.050 and 0.073 kgCO₂e MJ−1 for AFP-500 and AFP-600, 43% and 18% lower than fossil-based fuel. Eco-efficiency analysis (EEA) was performed to evaluate sustainability of aviation fuel production from HDPE via proposed processes. Aviation fuel produced from HDPE via AFP-500 exhibited the highest eco-efficiency compared with SAFs and that derived from AFP-600. These findings suggest that AFP-500 offers a viable pathway for producing alternative aviation fuel from HDPE.