Comparison Between Two-Stage Waste Combustion with HCl Recovery and Conventional Incineration Plants

A comparison is made between a two-stage combustion process for high polyvinyl chloride (PVC) solid waste with HCl recovery and a conventional solid waste incineration plant from the perspective of plant performance and environmental impact, mainly considering HCl emission. The work reported here is an energy efficiency optimization analysis using a process simulation program (PROSIM). Results are presented for various process temperatures and for waste-derived fuels with varying amounts of a typical PVC. The two-stage process has a theoretic thermal efficiency of approximately 36.8%, depending on the pyrolysis temperature, PVC content in the solid waste, and moisture content. HCl recovery can be above 90% at pyrolysis temperatures above 310°C combined with low HCl emissions. A design case for a conventional waste incineration plant has been calculated with thermal efficiency of 33.4% for comparison with the suggested new process.