Abstract:
In order to further clarify the adsorption thermodynamic characteristics of CH
4 and CO
2 in coal, the giant canonical ensemble Monte Carlo method was used to simulate the adsorption behavior of CH
4 and CO
2 in coal at different temperatures and different moisture content. The results show that the adsorption capacity of CH4 and CO
2 in coal molecules decreases with the increasing temperature and moisture content. By comparing the adsorption amounts of the two components, it is found that both high temperature and the presence of water molecules are not conducive to displace CH
4 by CO
2; the average adsorption heat of CH
4 is negatively correlated with temperature and water content, and average adsorption heat of CO
2 has a negative correlation with temperature and a positive correlation with water content. Water molecules are more inclined to react with CO2; the overall adsorption potential of CH
4 and CO
2 is negatively correlated with temperature and moisture content. When the pressure is low, the adsorption potential of CO2 increases slightly with the increasing of temperature; the adsorption entropy of CH
4 and CO
2 increases with the increasing of temperature and decreases with the increasing of moisture content. The influence of water on CO
2 is stronger than CH
4. When two components are injected, the existence of water molecules makes the whole system more stable, which is not conducive to CH
4 output.