Coupled variation of pressure and temperature for methane adsorption in coal seam under three initial pressures

The methane adsorption test of coal under three initial pressures of 0.50MPa,0.75MPa and 1.00MPa was carried out using the coal bed adsorption simulation test system, and the change law of CH4 gas pressure and coal bed temperature under three initial pressures was studied. The distribution law of methane gas pressure and coal seam temperature on the inner plane of coal seam and the coupling relationship between them are studied by interpolating and plotting the collected data with MATLAB software. The results show that the methane pressure decreases with time, the coal seam temperature increases with time, and there is no linear correlation between the decrease of pressure and the increase of temperature. When coal is adsorbed, the pressure and temperature in the central region are lower, and the temperature in the region with high pressure is also higher, and the distribution of pressure and temperature is synchronized. The higher the initial pressure, the higher the temperature of the coal seam, the more methane adsorbed by the coal, but the strength of the adsorption capacity of the coal can not be measured simply by the amplitude of the pressure drop. The research content can be used as the basis for further investigation of methane occurrence rule in coal seam and evaluation of methane adsorption capacity of coal.