Simplied model to predict methane emission from longwall panel based on methane emission rate

The structure of coal contains both micropores and macropores in which the methane remains as free gas and adsorbed phase. These two phases keep equilibrium and can exchange each other if the balanceable conditions are destroyed because of coal extraction. Then the migration of methane begins in coal seam. Many factors, both geological and mining technological, control the process of methane migration in the coal seam, therefore directly influence the amount of methane entering into the coal working. The methane emission rate on the coalface in a longwall panel may be an important integrative embodiment of all these facters above. Based on this basic parameter, a prediction model is built to predict the amount of methane emission from the longwall panel. This model has been used in several coalmines in China and its accuracy satisfies the need of the mine ventilation management and methane conteol.