Best available technology options for the mitigation of environmental impacts in waste plastics

Abstract The best available technology (BAT) for waste plastics relies on their components and the right technology employed, while the quality of waste plastics depends on the original plastics and the source separation processes simultaneously. In this study, the quality of waste plastics and the potential recycling processes, including recycling granulation, pyrolysis to oil, Green-RDF and incineration technology, were co-related from the economic and technical perspective. A database was established for waste plastic components, considering factors such as plastic fraction, waste composition, moisture content, and impurity rate. The corresponding environmental impacts for the typical resource processes were assessed by life cycle analysis (LCA) and cost–benefit analysis combined. It was found that around 23% ± 1% of waste plastics in residual waste had the resource potential if the stricter classification criteria of plastic wastes were adopted, such as the components, moisture content less than 5% or 8% and impurity rate less than 8%. Pyrolysis to oil had the best environmental benefits in GWP100, reaching -1,683.51 kg CO 2 equivalent (CO 2 -eq), determined as the best method for high-value plastics, and incineration depicted poor environmental benefits for low-value plastics. The net income of recycling granulation for middle-value waste plastics would achieve 1383 ± 35 yuan/ton through cost–benefit analysis, which represented the optimal economic benefits. CO 2 emissions for waste plastics could be mitigated around 29.74% by matching BATs compared to the current management system, which would provide policymakers with proper recommendations in terms of the adaptability of waste plastic sources and technologies.