Global trends and strategic pathways for waste plastics depolymerization in the circular economy

Abstract

The global plastic waste crisis underscores the urgent need for sustainable recycling, with chemical depolymerisation emerging as a cornerstone of the circular economy. This study maps global research trends and strategic pathways for waste plastic depolymerisation, revealing exponential growth since 2016, dominated by China and the U.S., with Europe leading in citation impact. Research has focused on polyethylene terephthalate (PET) via glycolysis, hydrolysis, and enzymatic methods; however, it neglects polyolefins, which are dominant in waste streams, exposing a critical mismatch. Emerging hybrid technologies, such as microwave-assisted and enzymatic-catalytic approaches, show promise but struggle with scalability and cost. Sustainability is gaining attention; however, weak Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) frameworks impede progress. Three main research domains have emerged, namely fundamental mechanisms, polymer-specific solutions, and sustainable innovation. Strategic directions include shifting the focus to polyolefins, integrating hybrid methods, and embedding LCA/TEA standards supported by policies such as polyolefin recycling subsidies and UN Treaty-backed collaborations. These insights offer researchers, funders, and policymakers a roadmap to align depolymerisation research with circular economy goals, advancing scalable and equitable solutions to the challenge of plastic waste.