As a novel energy recovery process from waste polyvinyl chloride(PVC), we have proposed a process consisting of a steam pyrolyzer for PVC, where steam decomposition of calcium chloride is also performed, a neutralizer for hydrogen chloride neutralized with alkali contained in waste glass and a char combustor. In this work, mass and heat balance studies to see how much energy can be recovered from waste PVC were carried out for PVC based wallpaper and pipe material. Experiments were performed to obtain sufficient conditions for decomposing calcium chloride in the char. In the pyrolyzer lower temperature pyrolysis was found favorable to prevent calcium chloride formation. However, thermodynamic equilibrium calculation showed that higher temperature was encouraging steam decomposition of calcium chloride, which is crucial to remove all chlorine from residual char so that it can be burned without producing much toxic byproducts. Based on these experiments and calculations the appropriate design for the process was made as a two-stage pyrolyzer consisting of low temperature pyrolysis at 573K and high temperature char treatment at 1073K followed by a neutralizer and a char combustor.
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