Reductive Upcycling of Polyolefins, Polyesters and Mixed Plastic Wastes to Valuable Chemicals: Bridging Chemical Catalysis With Plastic Waste Management

The unmatched applications of plastic commodities are evident from the enormous plastic production, reaching over 400 million tons per year in recent times. Contrastingly, the lack of proper management leads to a large accumulation of plastic waste, majorly including polyolefins and polyesters. Conventional management methods possess significant drawbacks like cost-ineffectiveness and greenhouse gas emissions. Over the last decade, chemical processes have shown promising potential for plastic management but only hold a 0.1% share in plastic recycling. The catalytic processes offer excellent protocols to obtain high-value liquid fuels, waxes, and chemicals from plastic waste. This review presents an elaborate discussion on the state of the art in the reductive upcycling of polyolefins, polyesters, and mixed plastic waste. The review initially discusses the alarming statistics of plastics and conventional approaches followed by an introduction to chemical processes. Further, various recently reported catalytic upcycling strategies have been elaborated in detail followed by catalyst deactivation, technoeconomic analysis, and life cycle assessment to obtain a deeper understanding of the current state of this research field. Finally, a detailed summary of the current state of plastic management along with the existing challenges and countermeasures is discussed to open new avenues in plastic waste management research.