Mineral Gas Combustion Heat as a Function of Methane Concentration
|Methane concentration in mine gas (%)||30||40||50||60||70||80||90|
|Combustion heat (MJ/kg)||10.5||14.3||17.8||21.3||24.7||28.5||32.1|
In most cases, the concentration of methane in mine gas is up to 35–40% vol. To be used as fuel gas, mine gas must have a lower calorific value of at least 16.0 MJ/m³, which corresponds to a CH4 content of 46% vol.
A similar situation (inability to use the gas directly as fuel gas due to its extremely low calorific value) arises for associated petroleum gas with a high nitrogen content (in some cases up to 90% vol.).
Grasys membrane units can treat mine gas as well as associated petroleum gas with high nitrogen content for use as fuel for GTPPs, GRPPs and boiler houses.