Sustainable polyvinyl chloride recycling and bioethanol production via CO2-assisted pyrolysis

Summary The improper disposal of polyvinyl chloride (PVC) through landfilling or incineration can lead to serious environmental contamination due to chlorinated compounds. Hence, we propose an integrated process for PVC pyrolysis and bioethanol production to address these environmental issues. In the first stage of pyrolysis, PVC is dechlorinated to produce hydrogen chloride (HCl) and PVC residues. The generated HCl was used for pretreatment in the bioethanol process. In the second stage, the biomass residue after pretreatment is co-pyrolyzed with PVC residue at 720°C in a CO₂ environment. The gas-phase reaction of CO₂ and volatiles stemming from the two residues directly led to the enhanced generation of carbon monoxide (CO). Moreover, bioethanol, syngas, oil, and char were obtained. Thus, this process offers eco-friendly PVC treatment, the utilization of biomass residues, and increased syngas production. Therefore, this process contributes to resource circulation through eco-friendly waste treatment and additional value realized from the co-products.