2005 Volume 47 Issue 140 Pages 137-145
A high emphasis is placed on disposal of waste gas from various plants because of rise of environmental consciousness. A catalytic combustion deodorizer that has an advantage of low running cost is getting a lot of attention. Honeycomb is commonly used for catalytic combustion deodorizer. But, the measurement of temperature and concentration in the honeycomb is very difficult, because honeycomb is assembled with a lot of millimeter-sized channels. So, it is necessary to investigate the physical quantity by the numerical simulation and to understand the phenomenon in the honeycomb. This paper describes the results obtained by the numerical simulation for catalytic combustion of CH4/air mixtures on palladium catalyst in honeycomb used in deodorizer. The numerical model has the elementary reaction kinetics considering nine surface chemical species. The details of catalytic combustion in a channel, such as temperature and mole fraction in the gas phase, surface temperature, heat release rate and coverage at the catalyst, are obtained. Especially, the effects of inlet conditions such as inlet velocity, inlet temperature and fuel equivalence ratio on characteristics of catalytic combustion are examined, and the catalytic reaction mechanisms are made clear.