The plastic cycle in Germany: analysis of flows, stocks and potential environmental impacts from 1980 to 2023

This work integrated Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) to evaluate polymer flows and their environmental impacts within Germany’s waste management system. MFA was used to quantify the magnitude and distribution of major polymers, namely HDPE, LDPE, PP, PET, PVC, and PS, across collection streams and end-of life(EOL) treatments over the period 1980-2023. The methodology revealed the predominance of polyolefins and the distinct environmental relevance of PET and PVC. Polymer flows for year 2023 were subsequently translated into potential environmental impacts through LCA, which assessed midpoint indicators as global warming potential, acidification, eutrophication, and toxicity. MFA model showed a steady increase in plastic in-use stock and in waste generation. LCA results highlighted that the environmental burden of EOL options is influenced by the treatment-specific impacts and the scale of polymer flows, estimated by the MFA model. Incineration with energy recovery, while offering energy substitution, showed the highest burdens due to the release of combustion gases. Landfilling presented long-term risks, as eutrophication and resource loss related to potential leachate leakage. Recycling emerged as the most sustainable strategy, with mechanical recycling demonstrating significant avoided impacts through the substitution of virgin polymer. The recycling of PET, HDPE, and LDPE provided substantial climate benefits, aligning with EU circular economy goals, but challenges remain for polymers as PVC. The study underscored the decisive role of MFA in interpreting LCA results and revealed limitations linked to database aggregation, system simplification, and data uncertainty. Policy implications suggested expanding recycling capacities, improving data quality, and balancing the role of recycling and energy recovery. The research provided insights to support more sustainable plastic waste management strategies in line with circular economy objectives.