城市生活垃圾焚烧体系化学热力学平衡分析

Incineration has been widely applied over the past decade for disposal of municipal solid wastes (MSWs) in China. However, high chlorine content in MSW results in two major problems: high temperature corrosion and the emission of dioxins. In this paper, thermodynamic equilibrium calculations were performed to reveal the formation and transformation of chlorine-containing compounds during thermal conversion process of PVC and MSWs under different conditions. Calculations were also applied to the reactions between Ca-based sorbents and chlorine-containing compounds. The results showed that HCl was the main chlorine containing product for PVC. For MSWs, organic and inorganic chlorine can transform into HCl gas completely when temperature was over 600 ℃. Ca-based sorbents was effective on the HCl removal for PVC but ineffective for MSWs at the temperature of normal incineration conditions. Therefore, a new chlorine-removal process was proposed, which can remove chlorine and restrain dioxin emission simultaneously.