Plastics are one of the world’s greatest industrial innovations. Nevertheless, the sheer scale of their production and the poor disposal practices have led to a dramatic increase in plastic waste (PW) and, consequently, to serious environmental sustainability problems. Chemical recycling (CR) is an emerging theme in PW management, which has the potential to contribute to a low-carbon, resource-efficient and sustainable economy. Among CR processes, hydrocracking (HDC) is one of the most promising technologies for the conversion of PW into high-quality liquid fuels and other value-added chemical products. Contrary to other thermal and catalytic routes, it allows, in a single stage, the breakdown of heavy polymer molecules into much lighter molecules in the gaseous and liquid ranges and the reduction, by hydrogenation reactions, of the olefin and aromatic contents in the products. In addition, the HDC process includes the excellent ability for handling troublesome heteroatoms and the reduction of the coke precursors responsible for catalyst deactivation. This chapter presents the current state of the art of the application of HDC technology to convert PW into high-added-value products. First, the most common PW management strategies, especially the CR ones, are considered for comparative purposes. Then, an overview of the typical HDC mechanism, the type of catalytic systems and process operating conditions (temperature, H2 pressure, time and reactor type) are discussed.
