Chemical Recycling of End-of-Life Tires Using Catalytic Pyrolysis: Effects of Catalysts and Process Conditions toward the Production of a Highly Aromatic Pyrolysis Oil.

End-of-life tires (ELTs) represent both an environmental challenge and an opportunity as an untapped resource for materials and energy recovery. This work demonstrates the catalytic pyrolysis of ELTs using equilibrium FCC catalysts with varying metal contamination levels and ZSM-5 catalyst additives to produce highly aromatic oils with considerable promise for direct application. The investigation employed a systematic approach, screening catalysts in a batch reactor followed by validation in a continuous process development unit. The produced oils were characterized by quantitative methods to determine aromatic hydrocarbon yields and catalyst selectivity. Results showed strong agreement between the two setups with equilibrium FCC catalysts achieving 48 wt % oil yields containing up to 87 wt % aromatic hydrocarbons. Ni contamination on the catalyst shifted selectivity from monoaromatic to polyaromatic hydrocarbons and increased the overall aromaticity, rendering the oil attractive as a feedstock to produce carbon black and as a source of BTX and aromatic fuel additives.