ABSTRACT
The critical temperature of CO2 is 31.06 °C and the critical pressure is 7.39 MPa (Xue et al. 2004; Yang et al. 2008). In the storage process, the injection is usually in a supercritical state. Its critical density is 0.448 g/cm3 and it is the highest above common supercritical solvent. The coal seam volume expansion, contraction, pore structure changes and other phenomena are usually caused with the process of injecting and storing CO2, while the process of coal seam adsorption and desorption on CH4 is changed. The coal-related natures influenced by the supercritical CO2 are studied through experiment including the singlephase adsorption experiment on CO2 and CH4 at
1 INTRODUCTION
Gas disaster has severely restricted the green development of the coal industry, and mine gas control has come to the point of imminent. Therefore, the occurrence of coal mine gas accident can be reduced or even eliminated, and a new clean, efficient energy can be gotten if the method of coalbed methane mining is optimized and improved with plan and purpose.
