Fundamental, technical and environmental overviews of plastic chemical recycling

The accumulation of plastic waste is a severe environmental challenge worldwide. Although mechanical recycling methods are in place for plastics such as polyethylene terephthalate (PET), the physical and chemical properties are significantly compromised after a number of cycles, and they eventually reach end-of-life and end up in landfill. Chemical recycling is a collection of emerging innovative technologies that transform plastic waste into base chemicals, monomers and feedstocks. This approach complements mechanical recycling, bridging the gap between waste management and the petrochemical industry. However, with regard to the seven types of recyclable plastic, there is currently no clear overview of the suitable techniques. Therefore, we aim to provide a critical perspective on the suitability of different chemical processes towards recycling different types of plastic, by combining fundamental knowledge and research advancements in recent years, with an emphasis on assessing their environmental and economic impacts. Finally, based on the development status, we will highlight the current challenges and future opportunities in implementing chemical recycling technologies to meet the sustainability requirement of a climate-neutral circular economy. We review the fundamental knowledge and research advancements in chemically recycling different types of plastic, and highlight the current challenges and future opportunities in implementing these technologies to meet climate-neutral targets.