Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Effect of CaO Addition on HCl Removal during PVC Pyrolysis: characterization and analysis of products.


ABSTRACT
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.