Recovery of chemicals and energy through thermo-chemical processing of plastic waste

Abstract

To mitigate the various socioeconomic/environmental consequences associated with plastic waste, it is crucial to adopt strategic measures aimed at source reduction. In this regard, the thermo-chemical approach is a promising technical option to realize this objective within the framework of the circular economy. Such approach involves transforming plastic waste into chemicals/fuels, which contributes to the build-up of a more sustainable and resource-efficient platform. Precise control over yield and selectivity towards target chemicals (monomers, light olefins, and benzene, toluene, ethylbenzene, and xylene isomers (BTEXs)) and fuels (transportation fuels and syngas) is achievable by manipulating operating parameters for the thermo-chemical platform despite the possibly marked influence of the waste composition on product distribution. This review aims to delineate a technically viable pathway of the thermo-chemical approach with the discussion on the physico-chemical properties and compositional characteristics of plastics, technical alternatives for their recycling, and the associated environmental risks (improper disposal practices including mismanagement, landfilling, and incineration). This review helps open a new path for the development of a strategic technical approach within thermo-chemical processing to integrate different facets of plastic waste recycling. Thus, it will contribute to the realization of a closed-loop circular economy within the plastic value chain by focusing on thermo-chemical recycling of plastic waste.