Implications of chemical recycling of plastic waste for climate change impacts: A critical review

Chemical recycling systems have been reported to enhance the environmental performance of plastic waste management. Life cycle assessment (LCA) has been extensively employed to evaluate the potential environmental benefits of chemical recycling compared with other recycling systems. However, a disparity exists between the outcomes of environmental assessments and the anticipated environmental benefits of chemical recycling. Moreover, few reviews have discussed the findings of these comparable studies. Therefore, herein, we aim to analyze the climate change implications of chemical recycling and further discuss whether it can achieve climate benefits by conducting a critical review of the scientific literature on plastic waste recycling based on the LCA methodology. The review demonstrates that a substantial range of variability in climate change impacts is evident, spanning -3.3 to 137.6 kg CO2 eq./kg. Besides, high variability is observed for climate benefits compared with energy recovery, ranging from -6.8 to 68.1 kg CO2 eq./kg. In addition, multiple factors contributing to inconsistent results, such as various recycling technologies, waste composition, and functional units, are analyzed in depth to provide an overview and insights for potential stakeholders. Furthermore, we identify gaps in current research and outline potential directions for future studies, providing guidance for further research.