Burnt Gas Characteristics in Catalytic Combustion of Methane/Air Mixture

Abstract

Burnt gas from a catalytic combustion of methane/air mixture was studied experimentally. Palladium catalyst supported on a cordierite honeycomb monolith was used. Methane/air mixture, which was pre-heated to 530K, was introduced into the honeycomb monolith. In the case of lean mixture, occurrence of the catalytic combustion was confirmed. When the equivalence ratio of the mixture was greater than stoichiometry, a blue flame appeared after the honeycomb monolith in addition to the cat-alytic combustion. To clarify the characteristics of burnt gas from the catalytic combustion, burnt gases were sampled by a quartz probe, and were analyzed using a fourier transform infrared spectrophotome-ter (FTIR). In addition, low level NO and hot-O₂ in the burnt gases were detected using a laser-induced fluorescence (LIF). When the blue flame appeared after the honeycomb monolith, CO was detected from the burnt gas. And its concentration decreased around the blue flame. The NO emission level of the cat-alytic combustion was the highest when the equivalence ratio of the mixture was about 0.4.