The adsorption of hydrogen sulfide in calcite pores: A molecular simulation study

The adsorption of hydrogen sulfide in gas reservoir cores is important to natural gas industry for predicting the sulfur content. Here, the adsorption of hydrogen sulfide in the calcite pore is investigated using molecular simulations. The results show that the absolute adsorption amount of H₂S increases with the increasing of the pressure. However, the absolute adsorption amount decreases with the increasing of temperature. The adsorption capacity of H₂S on the calcite surface can be well described by the combination of Langmuir equation and Clausius-Clapeyron equation. In order to investigate the effect of hydrogen bond on adsorption, a method of computing the hydrogen bond of H₂S is proposed. The number of the average hydrogen bond per H₂S molecules increases with the increasing of pressure. Furthermore, the existence of calcite surface will affect the distribution of hydrogen bond. This will order the structures of H₂S molecules near the calcite surface and break the hydrogen bonds.