Experimental research on adsorption characteristics of N 2 , CH 4 , and CO 2 in coal under different temperatures and gas pressures

Abstract The coal deformation was induced by the gas adsorption of N 2 , CH 4 , and CO 2 . However, the differences between different gas adsorption performances and the deformation mechanism of coal need to be further studied. In this study, the experiments were conducted using self‐developed equipment to reveal the adsorption characteristics of different gases. The results showed that the gas adsorption capacity followed the sequence of CO 2 > CH 4 > N 2 . The gas adsorption capacity was negatively correlated with temperature. The maximum decrease in adsorption capacity (23.70%) was N 2 . The gas adsorption capacity was positively correlated with gas pressure. The maximum increase in gas adsorption capacity (232.79%) was N 2 . Correspondingly, the coal deformation of CO 2 was the largest, and that of N 2 was the smallest. The maximum decrease in deformation (31.09%) was CO 2 during the temperature increase. The initial coal deformation rates of N 2 , CH 4 , and CO 2 were 0.060, 0.091, and 0.042 mm·h −1 , respectively. The maximum increase of deformation (234.65%) was CH 4 with the gas pressure increase. The initial coal deformation rates of N 2 , CH 4 , and CO 2 were 0.024, 0.045, and 0.016 mm·h −1 , respectively. This work guided further clarifying the mechanism of different gases' adsorption capacity and coal deformation.