Elucidating dechlorination of waste polyvinyl chloride under high-temperature catalytic hydrothermal treatment

This study focused on evaluating the reduction of chlorine content in waste polyvinyl chloride (WPVC) through high-temperature catalytic hydrothermal treatment (HTT). Catalytic HTT experiments were carried out to evaluate the effect of noble metal catalysts (Ru/C, Pt/C, and Pd/C), residence time (0.5, 1, 2, and, 4 h), reaction temperature (300, 325, and 350 degrees C), and catalyst loading (0, 5, and 10 wt%). The findings indicated that dechlorination efficiency can be achieved by 99.01% at 350 degrees C and 1 h, with 10 wt% Pd/C loading. Based on chlorine balance, the chlorine content of the solid phase significantly decreased from 568.8 to 5.64 g kg(-1) at the same condition. The catalytic HTT solid residue ash has low chlorine content under most operational conditions. These results suggest that catalytic HTT is an effective method to dechlorinate WPVC as a high-halogenated waste plastic in order to reduce its harmful effect on the environment.