Removal of Dioxins in Flue Gas from Waste Incinerators by Catalytic Oxidative Process
Ichiro Ninomiya*, Kazue Ueda*, Kazumasa Tanaka**,Abstract
Removal of dioxins in flue gas from waste incinerators by catalytic oxidative process was investigated. Mono-chlorobenzene (MCB) was used as a model-compound of dioxins in order to study the kinetics of catalytic decomposition. The decomposition of MCB is a first order reaction with respect to the concentration of MCB and the reaction rate was 1.4 times higher at 200*C[Celsius degeree] than at 170*C[Celsius degeree]. The durability test of the catalyst using the real flue gas from a municipal waste incinerator was performed. Dioxins were completely decomposed at the initial stage, and the decomposition efficiency of dioxins after 16,500 hours was still 95% in TEQ. The influences of reaction temperature and linear velocity on the decomposition of dioxins were clarified. The high decomposition rate of dioxins was maintained in the temperature range of 170-240*C[Celsius degeree]. The decomposition reaction of dioxins was well interpreted by the theoretical calculations based on the mixing diffusion model.
Key words: dioxins, catalyst, decomposition, mono-chlorobenzene, durability test