Coal mine gas is a problematic phenomenon associated with pit coal mining since it is able to form explosive mixtures together with air.

The main component of coal mine gas is methane (25 – 60%), which develops during the geochemical conversion of organic substances into coal (carbonization). Coal mine gas is present both as liberated gas in fissures faults and pores and as adsorbed gas on the inner surface of the coal and neighbouring rock.

Combustion of coal mine gas in gas engines is practical for several reasons:an environmental and safety problem is effectively resolved while an otherwise lost source of energy can be economically utilizedat the same time.