Power and heat from coal mine gas
Coal mine gas is released from seams of coal during mining activities. We distinguish between four kinds of coal mine gas: Methane exhausted from unexplored coal beds (CBM), methane coming from active underground mining (CMM), methane exhausted from abandoned mines (AMM) and lean gas. Due to the high methane content of 30 to 95 %, especially CBM, CMM and AMM are suitable for the utilization in gas engines. Only lean gas cannot be used for energy generation, because of the low methane content of 0,2 - 1,5%.
By using coal mine gas with a methane content of up to 30 percent, methane, which is harmful to the environment, can be converted to energy.
The use of coal mine gas in a gas engine has two main advantages: First, methane is converted into CO2 by combustion. CO2 is up to 25 times less harmful to the environment. Second, up to 90 % of the energy bound in methane is converted into power and warmth.