High Yield Oil from Catalytic Pyrolysis of Polyethylene Terephthalate Using Natural Zeolite: A Review

Abstract

Polyethylene terephthalate (PET) waste has emerged as a critical environmental issue due to its widespread use, particularly in food and beverage packaging. Catalytic pyrolysis with natural zeolite presents a promising approach to convert PET into valuable benzene-rich oil, providing a sustainable pathway for plastic waste management. However, significant challenges persist, notably the generation of acidic byproducts such as terephthalic acid, which may lead to reactor blockages and catalyst deactivation. This review explores the role of natural zeolite catalysts in enhancing PET pyrolysis, facilitating the breakdown of PET into shorter-chain hydrocarbons, and improving oil yield and quality. Various modifications of natural zeolite, including activation, acid treatment, and metal impregnation, are assessed for their effects on catalytic performance. The review further examines mechanistic insights into the reaction pathways, including C–C bond scission, decarboxylation, and aromatization, supported by the acidic sites within zeolite. A bibliometric analysis of studies from 2014 to 2024 identifies research trends and existing gaps in PET pyrolysis, underscoring the need for innovative catalyst designs to reduce energy demands and mitigate unwanted byproducts. Recommendations are also provided for optimizing reaction conditions, including temperature, residence time, and catalyst composition, to enable scalable and energy-efficient PET pyrolysis processes. These findings emphasize the significant potential of natural zeolite as a cost-effective catalyst in transforming PET waste into alternative fuels, contributing to both environmental sustainability and advancements in waste-to-energy catalysis