Pyrolytic decomposition of waste plastic automotive accessories, derived from actual vehicles at the end of their life cycle

Abstract The management of end-of-life vehicles (ELVs) represents a crucial challenge in western world. In recent years, the automotive industry has increasingly substituted metal parts with lightweight and insulating plastic materials. As a consequence, conventional management methods for ELVs, such as compression and heat casting, have become less effective due to the increasing presence of heterogeneous polymer mixtures. This shift highlights the need to investigate alternative and sustainable recycling strategies. For this reason, this work examines pyrolysis as a sustainable approach for the recycling of real plastic components derived from ELVs, while previous studies have primarily focused on automotive solid residue or pure polymers. Prior to pyrolysis, the characterization of the automotive plastic waste (APW) samples took place via a comparative evaluation of FT-IR, DSC and pyrolysis products analysis. The results showed that the APW samples comprised PP, PE, ABS, PU, PMMA, PC, PA-6 as main polymers along with fillers and additives, always present in commercial products. The multiple types of plastics evident in APW is the main reason of retarded thermochemical processes for recycling of this demanding feedstock, while pyrolysis can additionally be employed as a molecular fingerprinting analytical tool for the characterization of multi-component systems. The common pyrolysis enables the recovery of monomers from some plastics, including caprolactam from PA-6, styrene from PS and ABS, bisphenol-A from PC and MMA from PMMA, while pyrolysis of polyolefin-based plastic parts yields hydrocarbons, such as alkanes and alkenes in the diesel range, with potential valorization as fuel precursors.