Hybrid Recycling of Polyvinyl Chloride and Polyethylene Terephthalate: A Life Cycle and Technoeconomic Assessment

With global plastic waste accumulation growing, effective recycling approaches are in increasing demand. We propose a recycling system capable of recovering polyvinyl chloride (PVC), diisononyl phthalate (DINP), and polyethylene terephthalate (PET) from mixed waste consisting of tarpaulins and wire harnesses. The system combines selective dissolution (SD) to extract PVC and DINP and enzymatic hydrolysis to reduce PET to monomers terephthalic acid and ethylene glycol, which are then repolymerized. Life cycle assessment shows that recycled PVC (r-PVC) has lower environmental impacts than virgin PVC in several categories, including acidification (15% lower), ozone depletion (91% lower), land use (99% lower), and freshwater eutrophication (29% lower). Despite these improvements, r-PVC underperforms in key metrics such as climate change (75% higher), energy demand (37% higher), and carcinogenic toxicity (1103% higher). Steam production for distillation is the primary contributor to most impact categories followed by residual PVC waste treatment and electricity demand. Results also show that recycled PET underperforms in 24 of 25 impact categories with ozone depletion being the only improvement relative to virgin PET. The primary contributor is the physically allocated impact from the SD subprocess used to separate and recover the PVC and PET individually, indicating that reductions in this subprocess are necessary for environmental sustainability. Scenario analyses show that ameliorating these impacts depends on sustainable steam sourcing and alternative waste disposal practices for PVC. Technoeconomic analysis reveals that the valorization process cannot achieve price parity with virgin PVC primarily due to high wire harness feedstock procurement. Although the system currently lacks environmental and economic sustainability under current design, operating, and pricing strategies, this study offers opportunities for process optimization and establishes a foundational methodology for developing hybrid plastic recycling systems.