Environmental performance analysis on resource multiple life-cycle recycling system: Evidence from waste pet bottles in China

Resource multiple-life-cycle (MLC) recycling process is a complex system with closed-loop and open-loop recycling interwoven with each other, which has recieved vast attention in recent years. Resource MLC recycling has a cascading effect, one recycling process will have an impact on the next cycle, and ultimately affect the overall environmental performance of the social system. Policies will affect the flow of resource MLC recycling. How to maximize the emission reduction effect of resource MLC recycling through policy design is still under exploration. Employing MLC recycling of China's waste PET bottles as an example, this paper constructs an environmental performance accounting method based on MLCA, and simulates the overall impact of various policies such as implementing deposit system, promoting recycled materials, strenghtening environmental regulation and enhancing regeneration technology on the recycling system of PET bottles. The combined policy scenario is constructed by selecting advantageous strategies that can effectively give full play to the strengths of each policy scenario. From 2020 to 2040, the environmental performance loss value of the combined policy scenario will be 52.52% of the baseline scenario without policy support, and the cumulative emission reductions of wastewater, waste gas and solid waste will be 0.98, 3.61 and 341.39 million tonnes respectively, which can help China to achieve emission reduction targets set out in each five-year plan. In order to realize the combined policy scenario, it is suggested that the life cycle assessment (LCA) should be replaced by multiple life cycle assessment (MLCA), the effect of resource saving and environmental emission reduction in the recycling process should be accounted as accurately as possible, a top-level management organization of natural resources across multiple departments should be established as soon as possible, with the goal of maximizing the comprehensive environmental and economic benefits of MLC processes.