Optimizing in-situ capture of Cl and C through HCl acidification and crystal formation in PVC-based cable pyrolysis

13X zeolite-calcium oxide (CaO) composite capture agent application in the pyrolysis recovery of polyvinyl chloride (PVC)-based waste cables was investigated in this research to elucidate the agent's efficiency in capturing chlorine (Cl) and carbon (C) during pyrolysis. The 13X zeolite-CaO mixture is subjected to separate pyrolysis of the PVC-based cable outer sheath in experimental furnaces of simulated solar-powered and thermogravimetry. Subsequently, a range of spectroscopic techniques are employed to quantitatively analyze the gaseous and solid products resulting from the pyrolysis process. Through X-ray fluorescence, total carbon, and other analyses, the research outcomes demonstrated that the capture agent exhibits superior Cl and C capture performance compared to using a single agent for plastic pyrolysis. The yield of Cl element in the solid residue has increased significantly by 130-140% under the presence of optimized composite capture agent. By determining the dynamic changes of gaseous and solid products during the cable outer sheath pyrolysis, the influence of the capture agent on the redistribution and transformation mechanisms of Cl and C elements was identified, and it was found that contaminating volatiles were well immobilized in the solid residue. This research provides a new solution for efficient Cl and C capture in the pyrolysis recovery of waste cables and determines the fixation and transformation mechanisms of Cl and C elements by the composite capture agent, indicating a potential for feasible and sustainable resource utilization of waste cables.