Tadayuki Ishimi*, Hisao Yamaguchi*, Satoshi Kuroishi*, Kazuhiro Higashimura* and Chikara Yoneda*

*KUBOTA Corporation

+ Correspondence should be addressed to Tadayuki Ishimi:
KUBOTA Corporation
(1-1-1 Hama, Amagasaki, Hiyogo 661 Japan)

Abstract

For a municipal solid waste incinerator, it is crucial to establish design and operation methods to perform complete combustion of flue gas, which is essential for reducing the generation of micro-pollutants such as dioxins. Accordingly, influential factors and degree of effect on gaseous combustion need to be identified. However, the individual effect of each factor is hardly ever evaluated because actual waste combustion is composed of extremely complicated phenomena occurring simultaneously: drying, gaseous combustion and solid combustion of waste whose characteristics also vary considerably with time. The purpose of this work, therefore, is to recognize the degree of effect of each factor influencing gaseous combustion by using bench-scale test equipment modeling the secondary combustion chamber of an actual incinerator. Carbon monoxide (CO) gas, considered an indicator for complete combustion, is employed as unburned gas for the tests. The variation of CO concentration is measured under various combustion conditions including temperature, O2 concentration and retention time. Then, the Arrhenius-type rate equation of CO is obtained from the measured data by determining the parameters of the equation. In addition, by applying the rate equation to an actual incinerator, the combustion conditions are evaluated.

Key words: municipal solid waste incinerator, dioxins, secondary combustion, carbon monoxide, rate equation