Comparative life cycle assessment of plastic waste management technologies: Environmental performance of pyrolysis, mechanical recycling, chemical recycling and open burning.

Sustainable management of plastic waste is critical for advancing circular material flows and reducing dependence on fossil resources. However, comparative environmental assessments across treatment technologies remain limited, particularly in developing regions where informal disposal practices persist. This study presents a life cycle assessment (LCA) framework comparing four plastic waste treatment pathways: mechanical recycling, pyrolysis-based plastic-to-fuel (PTF) conversion, chemical recycling for monomer recovery, and open burning. Using primary operational data from an industrial-scale PTF facility with literature-validated parameters for comparative scenarios, we applied ReCiPe 2016 Midpoint (H) method to quantify environmental impacts, with emphasis on global warming potential (GWP). Monomer recovery exhibited lowest net GWP (9443 kg CO₂ eq per ton of plastic waste) due to credits from displacing virgin polymer production, representing approximately 20% lower emissions than mechanical recycling (11,830 kg CO₂ eq/t) and 31% lower emissions than PTF conversion (13,700 kg CO₂ eq/t). Open burning, still common in informal systems, generated catastrophic emissions exceeding 3.2 million kg CO₂ eq per ton, approximately 230-340 times higher than engineered alternatives. For the engineered treatment pathways, transportation was the dominant contributor to total GWP (60-73%), suggesting that infrastructure decentralization and improved collection logistics may deliver larger benefits than process-level efficiency improvements. Monte Carlo uncertainty analysis confirmed robust comparative rankings, with coefficients of variation below 15% for all scenarios. These findings support integrated waste management strategies that combine mechanical and chemical recycling based on feedstock quality, and inform policy priorities for regions transitioning from informal to formal waste management. The framework provides a transferable method for context-specific assessment of plastic waste treatment options.