Copper-catalyzed VOCs formation and combustion control during pyrolysis of waste polyester-imide enameled wires

The emission of volatile organic compounds (VOCs) during the pyrolysis of waste enameled wires poses a significant challenge to green and sustainable recycling. This study systematically investigates the formation mechanisms and mitigation strategies for VOCs during the pyrolysis of waste polyester-imide enameled wires, with a focus on the catalytic role of copper. Combining thermogravimetric analysis, PY-GC/MS, and density functional theory (DFT) calculations, we demonstrate that VOCs emissions primarily occur between 500-700 °C, generating alkanes, alkenes, and aromatic compounds. DFT reveals that copper modifies the electronic structure of the organic film, reducing the HOMO-LUMO energy gap and significantly accelerating pyrolysis reactivity, thereby promoting aromatic compound formation. To address this issue, an optimized combustion strategy (600 °C, excess air ratio of 1.10, furnace pressure of -0.04 MPa) was developed, which achieved a 95 % reduction in VOCs emissions compared to conventional pyrolysis. Mechanistic studies confirm that combustion effectively oxidizes most VOCs into CO₂ and H₂O, leaving only trace aldehyde residues. These findings not only elucidate the catalytic pathways of copper in VOCs formation but also provide a practical and efficient approach for VOCs suppression, advancing the development of environmentally friendly recycling technologies for electronic waste.