Pursuing the End-of-Life Tire Circularity: An Outlook toward the Production of Secondary Raw Materials from Tire Pyrolysis Oil

Pyrolysisis perceived as the missing link between themanagementof end-of-life tires (ELTs) and the tire industry because it strikesdirectly in the transition from a linear to a circular economy modeland toward the defossilization of diverse economic sectors. Tire pyrolysisoil (TPO) is one of the most valuable and interesting fractions derivedfrom the pyrolysis of ELTs. It contains valuable chemicals including,among others, benzene, toluene, ethylbenzene, and xylene, as wellas limonene, which are some of the building blocks of the petrochemicalindustry. Within the circular economy framework, traditional practicessuch as the direct use of TPO in combustion systems seem to exhibita low circularity degree. Instead, the production of secondary rawmaterials that can be reused for multiple purposes associated withthe petrochemical industry is getting special attention. Based onthe above, this work aims at reviewing different pathways currentlyexplored in the scientific community to produce various value-addedproducts from TPO. Due to the similarity of its properties with thoseof petroleum streams, the coprocessing of TPO using existing unitsin conventional refineries exhibits a massive potential. In this manner,the properties of the derived products can be fine-tuned accordingto the hydrocarbons and petrochemical market requirements. As such,discussed are the advantages, recent progress, and challenges in theimplementation of conventional refinery practices such as distillation,fluid catalytic cracking (FCC), hydroprocessing, and steam crackingfor TPO post-treatment. These processes are seen as the path to integrateTPO in the current hydrocarbon/petrochemical market.

Automated summary

Pyrolysis is seen as a crucial step in the transition from a linear to a circular economy and the defossilization of various economic sectors. Tire pyrolysis oil (TPO), derived from the pyrolysis of end-of-life tires, contains valuable chemicals that are building blocks of the petrochemical industry. This study reviews different pathways for producing value-added products from TPO and focuses on implementing conventional refinery practices such as distillation, fluid catalytic cracking (FCC), hydroprocessing, and steam cracking for TPO post-treatment.