Circular plastic economy for sustainable development: current advances and future perspectives

Abstract

More than 8 billion tonnes of plastic have been produced globally since 1950, with almost 80% of the plastic generated annually turning into waste. This plastic waste represents a significant environmental challenge and reflects a major economic loss. Catalytic methods capable of transforming plastic waste into valuable chemicals and fuels offer the opportunity to turn plastic pollution into a viable resource, promoting a circular plastic economy that is crucial for achieving sustainability in energy sectors. This review examines the latest research advancements in catalytic processes for recycling plastic waste into chemicals and fuels. These technologies are emerging as potential solutions in the search for a sustainable circular plastic economy and energy markets, offering alternatives that incineration and mechanical recycling have largely failed to deliver. Various catalytic processes are comprehensively accessed, including pyrolysis, hydrocracking, chemolysis, hydrogenolysis, photocatalysis, electrocatalysis, biocatalysis, and metathesis, which efficiently convert plastic waste into valuable chemical building blocks, fuels, and other high-value products. These technologies not only address the environmental issues associated with plastic pollution but also contribute to resource recovery and energy sustainability with potential to produce low-carbon fuels, chemicals and building blocks to enhance plastic circularity. Moreover, this review addresses the current challenges and future research directions essential for accelerating the transition towards sustainable circular plastic economy. It offers a comprehensive evaluation of catalytic recycling technologies, including pyrolysis, hydrocracking, chemical depolymerisation, and metathesis, with a focus on mitigating Scope 3 Emissions and fostering sustainable energy solutions. The objective is to promote the advancement of catalytic technologies, recognizing the potential of catalysis to enhance economic efficiency and capitalize on the conversion of plastic waste into high value chemical feedstocks and energy. The review highlights recent developments in catalytic processes, including catalysts, plastic feedstocks, reaction parameters, and their impact on product distribution and yield. While the gasification method is briefly mentioned, this review does not cover thermosetting plastics, physical recycling, or non-catalytic processes such as thermal recycling, mechanical recycling, or incineration.