Removal of HCl Produced by PVC's Pyrolyzation With CaO

This study investigates polyvinyl chloride (PVC) slow pyrolysis in a tubular furnace, focusing on hydrogen chloride (HCl) removal efficiency via calcium oxide (CaO) addition. Key parameters include temperature (500°C–550°C) and Ca/Cl molar ratios (optimized at 2:1). Solid residues from co‐pyrolysis were characterized by scanning electron microscopy (SEM)/energy‐dispersive x‐ray spectroscopy (EDS) and x‐ray diffractometry (XRD) for morphology and crystallinity. Liquid products were analyzed via Fourier‐transform infrared spectroscopy (FTIR), while gas compositions were determined using gas chromatography (GC). Results show that a 2:1 Ca/Cl ratio provides maximum reactive sites for HCl neutralization. Alkaline calcium chloride concentration peaked at 500°C, indicating optimal HCl removal efficiency at this temperature. Notably, HCl removal reached 93.4% at 550°C with a 2:1 Ca/Cl ratio. Tar and gas byproducts were characterized, though detailed compositional analysis was not emphasized. The findings establish a theoretical framework for HCl mitigation during PVC thermal recycling, highlighting CaO's role in neutralizing acidic chlorides. Temperature and CaO dosage directly influence removal efficiency, offering practical insights for industrial‐scale waste PVC processing. This work advances sustainable PVC recycling strategies by optimizing reaction conditions for reduced environmental and health risks.