Assessing technological pathways for a circular PET management in Switzerland, integrating MFA, LCA, and TEA

This study compares two approaches to inform decision-making on reducing the environmental impacts of the polyethylene terephthalate (PET) management system in Switzerland. The first analysis combines life cycle assessment (LCA) and techno-economic analysis (TEA) to inform process design for six end-of-life (EOL) technologies: incineration, mechanical recycling, three depolymerisation routes, and incineration with carbon capture and storage (CCS). The second analysis has a broader scope, evaluating PET waste distribution across these pathways to minimise environmental impacts and costs of this sector in Switzerland, under a cradle-to-grave boundary that accounts for virgin PET production, with collection and quality constraints. Initial results show that recycling pathways (mechanical and depolymerisation) achieve the greatest reductions in climate change impact through avoided virgin PET production. Incineration with CCS reduces climate change impacts at higher costs and with burden shifting toward other impact categories, such as water use and fossil and nuclear energy use. At the system scale, a parameterised framework explores different collection rates and technology shares within the treatment mix to map the full solution space. Three strategies emerge, balancing total costs and environmental impacts. Maximising separate collection combined with mechanical recycling delivers the largest impacts reductions at no additional cost. Integrating depolymerisation further reduces impacts for textiles and contaminated packaging streams, at diminishing returns. CCS addresses residual flows but only proves environmentally effective under a low-carbon electricity mix, at significantly higher costs. Technological improvements alone are insufficient to meet Switzerland's climate targets. Reducing PET demand remains essential to achieve substantial environmental benefits.