H2S separation from biogas by adsorption on functionalized MIL-47-X (X = -OH and -OCH3): A simulation study

Monte Carlo molecular simulations in grand canonical ensemble were performed to study the H2S, CO2 and CH4 adsorption and separation on the MIL-47 and the functionalized MIL-47-X (X = -OH and -OCH3). The preferred situation for the adsorption of gas molecules on the studied MOFs was also investigated. The calculated adsorption isotherms of CO2 on the MIL-47 agreed well with the experimental uptakes. Furthermore, the simulated adsorption selectivities of three MOFs for the CO2/CH4, H2S/CH4 and H2S/CO2 mixtures were in the order H2S/ CH4 > H2S/CO2 > CO2/CH4. These MOFs had higher selectivity for H2S over CH4 indicating that they can be good adsorbents for the H2S separation. The probability distribution of the adsorbed molecules showed that the guest molecules were more localized near the metal centers and functional groups.