Abstract:
In order to study the gas adsorption pattern and mechanism of coal particles under different axial compression conditions, the gas adsorption patterns of three coal samples with different degrees of metamorphism under different temperatures, gas pressures, and axial compression conditions were studied experimentally by self-developed adsorption experimental system which can control temperature, gas pressure, and axial compression, and the mechanism of the influence of axial compression on gas adsorption of coal particles was discussed. It is shown that the adsorption capacity does not vary monotonically with the increase of axial compression at different gas pressures at the same temperature but decreases and then increases with the increase of axial compression at higher gas pressure and decreases with the increase of axial compression at lower gas pressure. Gas pressure and axial compression change the pore structure of coal and thus affect the adsorption characteristics of coal. With the increase of axial compression, there are three stages of pore structure change of coal-pore compression stage, pore transformation stage, and pore compaction stage, corresponding to three stages of adsorption capacity change.