Molecular simulations adsorption of hydrogen sulfide, carbon dioxide, methane and nitrogen and separation of binary mixtures (H2S/CH4), (CO2/CH4) into NUM-3a metal–organic frameworks

In this work, the adsorption of hydrogen sulfide, carbon dioxide, methane and nitrogen and separation of their binary mixtures (H2S/CH4), (CO2/CH4) by NUM-3a were studied using Grand Canonical Monte Carlo molecular simulations (GCMC). The adsorption isotherms of pure gases on the studied MOF were simulated at 298k.Comparison with experimental results showed that the simulated adsorption isotherms of hydrogen sulfide, carbon dioxide, methane and nitrogen on NUM-3a agreed well with the experimental. The obtained results indicated that the adsorption of H2S is higher than carbon dioxide, methane and nitrogen. As well as, the simulated adsorption selectivity’s NUM-3a for the CO2/CH4, H2S/CH4 were in the order H2S/CH4 CO2/CH4. NUM-3a had higher selectivity for H2S, CO2 over CH4 showing that this MOF can be good adsorbents for separation of H2S, CO2 from CH4. Furthermore, the preferred site of adsorption for hydrogen sulfide, carbon dioxide, methane and nitrogen on the NUM-3a were also investigated.