Catalytic combustion of coal mine ventilation air methane

Abstract

Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive mine methane, and approximately 70% of all coal mining related emissions are from underground ventilation air. Hence, research and development on mine methane capture, mitigation and utilisation should focus on methane emitted in ventilation air. To develop more efficient, cost effective technology for the mitigation and utilisation of mine ventilation air methane, this paper introduces the monolith catalyst bed reactor, which has better characteristics for power generation applications than fixed bed and fluidised bed reactors. This is due to its very low pressure drop at elevated mass throughputs, high geometrical area, and high mechanical strength and high resistance to dust. This paper briefly reviews methane catalytic combustion basics, and mainly presents experimental results on simulated ventilation air methane (VAM) catalytic combustion performance of four catalysts tested at different temperature, pressure and CH 4 concentrations. The experimental results show that determination of major operational parameters including temperature is very important for designing large-scale combustors to achieve high methane conversion rate. The major operational parameters determined in the experimental rig would be a reference for the design. In general, a preheated air temperature of ≥450 °C is required for the most effective of the four tested catalysts.