Formation of PCDD/Fs in Artificial Solid Waste Incineration in a Laboratory-Scale Fluidized-Bed Reactor: Influence of Contents and Forms of Chlorine Sources in High-Temperature Combustion

The formation of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) has been examined to investigate the influence of organic and inorganic chlorine sources and their contents in municipal solid waste incineration. A laboratory-scale fluidized-bed reactor with electric heating was used to control combustion condition identically. Combustion temperature was set to 900 °C, and the amount of air supplied was twice as much as the amount of theoretical air. Artificial wastes containing organic (polyvinyl chloride, PVC) or inorganic (NaCl) sources of chlorine at several levels and copper chloride (CuCl 2 ·2H 2 O) as a catalyst were prepared to define the waste composition and make it constant. The experimental setup had been carefully planned to suppress the effects of experimental conditions except the waste composition. Results of combustion experiments revealed that no PCDD/Fs were detected in the absence of Cl sources and copper chloride, but PCDD/Fs formation was recognized in the cases with Cl and a catalyst. In our experimental conditions, both organic and inorganic chlorines affect PCDD/Fs formation obviously. As Cl content in the waste was increased, CO concentration in flue gas became higher, and more PCDD/Fs were formed in both series of experiments with PVC or NaCl. It seems that combustion conditions indicated by CO concentration are strongly related to PCDD/Fs formation during incineration. It cannot be said that there is a significant difference between the effects of PVC and NaCl on PCDD/Fs formation in the artificial solid waste incineration.