Sustainable thermochemical plastic valorization towards a circular economy: a critical review

In response to the historic resolution endorsed by the United Nations (UN) to end plastic pollution, completely mitigating ubiquitous plastic pollution would be challenging if substantial advancements are not made towards sustainable plastic management. Therefore, this review aims to provide valuable insights into practical technical routes for plastic pollution mitigation, aligning with the goals of the UN treaty on plastic pollution. This review discusses current technological advancements and proposes innovative solutions for achieving a circular plastic economy. Compared with traditional incineration and mechanical approaches, advanced thermochemical approaches and multifunctional catalytic techniques are the most promising approaches for plastic pollution mitigation owing to their higher economic feasibility and environmental benefits. Machine learning-guided valorizations of plastic waste into value-added products are promising and feasible routes for efficiently optimizing plastic valorization systems and accurately designing high-performance catalysts. Finally, this review offers an outlook and a roadmap on the valorization and innovation of plastic waste for achieving energy and environmental sustainability, which are also beneficial in achieving several UN sustainable development goals, Environmental, Social and Governance, and carbon neutrality.