High-resolution dynamic material flow analysis to elucidate plastic flows in waste management systems

With the transition toward a circular plastic economy, detailed knowledge of individual waste streams is required to assess their potential for recycling. This work presents a dynamic probabilistic material flow analysis (DPMFA) model for assessing plastic flows across all life-cycle stages, with high granularity at the end-of-life stage. The model is parameterized for eight types of plastic polymers in Japan between 1990 and 2023, including 47 product categories, 17 waste collection pathways, and 10 sorting systems. In 2023, post-consumer waste accounts for 70% of mechanical recycling inflows, with 77% originating from the packaging sector. While data limitations prevent explicit modeling of secondary material use, existing evidence shows that recycled plastics are often downcycled to lower-quality applications or transferred to different sectors, such as the conversion of agricultural plastics to flooring. Insights from the model enable evaluation of the quantity, separability, and recyclability of individual flows, supporting prioritization of waste flows for future collection and recycling.