Molecular Dynamics Simulation of PAHs Generated from Rubber Pyrolysis

The rapid expansion of the automotive industry has posed challenges for the waster tire rubber sector. Pyrolysis, as a prominent method for waster rubber treatment, inevitably produces polycyclic aromatic hydrocarbons (PAHs), which serve as precursors to dioxins and exhibit high toxicity. This study utilizes molecular dynamics simulations to investigate the thermal decomposition of rubber macromolecules and the subsequent formation of PAHs. Initially, an overall simulation of the pyrolysis process is conducted to analyze the evolution of pyrolysis products. The pyrolysis of rubber involves sequential decomposition and polymerization, with the evolutionary analysis of the decomposition products with various numbers of carbon atoms used to validate this process. Subsequently, the factors influencing PAH formation are examined and assessed. Temperature elevation enhances rubber pyrolysis, while the maturity of PAH molecules is linked to oxygen levels. The introduction of hydrogen or hydroxyl groups can partially impede PAH generation. This investigation elucidates the mechanisms governing PAH generation during rubber pyrolysis, with the goal of aiding in the effective regulation of PAHs in waster rubber pyrolysis.