Study on the Effect of H2S on the Adsorption of CH4, N2, and CO2 by Anthracite

In order to study the effect of H2S on gas adsorption in a coal seam, the adsorption characteristics of single-component CO2, CH4, N2, and H2S and multicomponent H2S mixed with CO2, CH4, and N2 by anthracite were simulated by using the Grand Canonical Ensemble Monte Carlo (GCMC) method. The results show that the adsorption capacity of CO2, CH4, N2, and H2S in anthracite decreases with increasing temperature and increases with increasing pressure. The isothermal adsorption curves of CO2, CH4, N2, and H2S and different proportions of H2S/CH4, H2S/N2, and H2S/CO2 are highly consistent with the Langmuir equation, and the R2 is above 0.99. Under different temperature and pressure conditions, the adsorption capacity of H2S and CO2 is stronger than that of coal for N2 and CH4, and the adsorption capacity difference is about 3 mmol/g. There is competitive adsorption among H2S, CO2, CH4, and N2, and H2S has a superior adsorption property. When H2S and other gases exist at the same time, the adsorption capacities of CH4, N2, and CO2 are reduced by 48–60%, 81–91%, and 51–66%, respectively.