Temperature evolution in abandoned mines and the effect on gas adsorption properties of residual coal

Abandoned mines contain a large amount of residual coal and gas resources for development and utilization. In order to accurately establish the calculation model of gas reserves and lay a foundation for the exploitation of gas resources in abandoned mines, based on the analysis of temperature evolution of abandoned mines, gas adsorption experiments and molecular simulations were carried out at temperatures of 30, 60, 90, 120, 150 degrees C and five different adsorption equilibrium pressures (0.5 similar to 2.5 MPa). The test results show that the attenuation rates of gas adsorption at 30 similar to 60 degrees C, 60 similar to 90 degrees C, 90 similar to 120 degrees C, and 120 similar to 150 degrees C are 8.53%, 7.89%, 5.55%, and 1.55%, respectively. High temperature inhibits the increase of gas adsorption by residual coal, but its inhibition has a certain limit. At high adsorption equilibrium pressure, the initial adsorption rate increases with the rise of temperature. When the pressure is 2.5 MPa, the initial adsorption rates at 30, 60, and 90 degrees C is 1.25, 2.22, and 2.32 mlg(-1)min(-1), respectively. Temperature affects the gas adsorption characteristics of residual coal. Therefore, the influence of temperature should be considered when establishing the gas reserves model of abandoned mines.