Experimental study on premixed methane-air catalytic combustion in rectangular micro channel

Abstract

The catalytic combustion process of pre-mixed methane-air in a rectangular micro channel was studied experimentally. Infrared thermal imager and flue gas analyzer were used to measure the temperature distribution of the outer wall and main components of exhaust gas respectively. Flammability limits of premixed methane-air in catalytic and non-catalytic micro channel were obtained by changing flow rates of methane, and the effects of equivalence ratio, inlet velocity and channel height on combustion characteristics were analyzed. Results showed that the flammability limits improved significantly when platinum was added into the micro channel. The highest centerline temperature of the outer wall was obtained at an equivalent ratio of 0.9 at the same inlet velocity with or without catalyst in the micro channel. Addition of catalyst in the channel not only gave a uniform temperature distribution on the outer wall of the channel but also improved methane conversion. With the increase of inlet velocity, the centerline temperature of the outer wall increased and the highest points of the temperature shifted to downstream of the channel gradually. Combustion intensity in the channel increased with the increase of channel height at the same inlet velocity.