Power Generation on Mine Gas

Problems are encountered after the closure of a coal mine, since gas may continue to be emitted from the cracks and crevices created in the ground by mining activities. The resulting drop in gas pressure leads to the desorption of the adsorbed gas. The mine gas escapes into the atmosphere through the ventilation pipes remaining in many shafts. It also migrates into the environment through the overlying rock, since it is impossible to seal a disused pit to make it completely gastight. This methanous gas is released into the atmosphere in a cold state.

The potential danger due to the diffuse emission of this mine gas and its main constituent methane (25 to 60 percent) is reduced by efficiently using it for power generation. The gas can be used to replace conventional fuels, preventing the emission of methane into the atmosphere. The use of Power / CHPC stations for the generation of electrical energy from mine gas is an established practice, and will continue to grow in importance in the future due to the free availability of fuels, the fact that problematic cold flaring is no longer necessary, and that in many instances the heat generated can also be used directly.

Not only in Germany, but also in the UK, in Poland and soon in China, MWM delivers engine technology for mine gas utilization. Especially in Poland, our highly efficient and robust engines form the cores of many projects. Worldwide MWM developed the first engines to run on mine gas with only 25% methane, the rest of the gas being mostly carbon dioxide and nitrogen. Nonetheless these engines run at their full power output, as if fuelled with regular natural gas. In the Polish mining town of Pniowek, two MWM gensets, type TCG 2032 V16, generate more than seven megawatt electricity, simultaneously providing more than five megs of cooling energy, in order to cater to optimum conditions at the coal face, both for miners and machines.