Progress on waste plastics gasification process: a review of operating conditions, reactors and catalysts for clean syngas production and tar abatement: A review of operating conditions, reactors and catalysts for clean syngas production and tar abatement

With the continuous increase in global plastic production and the associated challenges in managing plastic and waste plastic, this review provides an overview of the plastic waste issue and explores gasification as a potential solution. The main objective of gasification is to convert selectively waste plastics into synthesis gas (syngas). It is important to highlight that the composition and potential applications of the resulting syngas are largely dependent on the gasifying agent employed. Specifically, steam or oxygen gasification typically yields hydrogen-rich syngas suitable for synthesis processes, whereas air gasification predominantly produces syngas for energy generation. Nonetheless, the applicability of the produced syngas is often constrained by the presence of various contaminants. Among these, the high tar content represents one of the principal limitations of the gasification process. This review examines the impact of key operational parameters and the utilization of various catalysts in the reduction of tar during the gasification of plastics. The results from over 100 experimental trials are summarised, providing a thorough synthesis of recent advancements in the field. Furthermore, the principal gasification strategies and technologies relevant to plastics and plastic waste are explored in detail.