Solar thermal catalysis for sustainable and efficient polyester upcycling

Summary

Although the extraction of value-added products from end-of-life plastics brings significant environmental and economic returns, the current recycling technologies are limited by their low efficiency and high energy consumption. Here, we propose an efficient solar thermal catalysis to recycle various polyesters into high value-added monomer derivatives with low energy consumption and carbon emissions. Compared with the traditional thermal catalysis of homogeneous heating, the solar thermal process exhibits a unique localized solar heating effect, forming a temperature gradient from the solar absorber to the bulk solution. This effect allows a lower depolymerization temperature (150°C), but the recycling efficiency is increased by threefold, unattainable by thermal catalysis. Furthermore, the solar thermal process can reduce energy consumption by 3.7 GJ and CO₂ emissions by 0.4 tons per ton of polyester treated compared with the thermal catalysis. Therefore, solar thermal catalysis opens an efficient, high-profit, and eco-friendly way to reuse waste plastics.