PCDD/Fs Formation Behavior in Model Waste Incineration

Abstract

Combustion experiments in a laboratory-scale fluidized bed reactor were performed to elucidate the effects of combustion temperature on PCDD/Fs formation during incineration of model wastes with polyvinyl chloride or sodium chloride as a chlorine source and copper chloride as a catalyst. Each temperature of primary and secondary combustion zones in the reactor was set independently to 700,800,and 900C using external electric heaters. The PCDD/Fs concentration is reduced as the temperature of the secondary combustion zone increase. It is effective to keep the temperature of the secondary combustion zone high enough to reduce their release during the waste incineration. On the other hand, as the temperature of the primary combustion zone rises, the PCDD/Fs concentration also increases. This result is probably related to the devolatilization rate of the solid waste in the primary combustion zone. The temperature decrease slows the devolatilization rate and promotes mixing of oxygen and volatile matters from the solid waste. This contributes to completing combustion reactions, resulting in reducing the PCDD/Fs concentration.