(373a) The Separation of Sulfide in Polluted Air from Molecular Simulation

The air pollution is serious problem to affect life and environment especial toxic gases. In this work, we employed molecular simulation method to study the separation capacity of nano microporous materials removing sulfide in polluted air. The studies show that the life-threatening concentration of hydrogen sulfide (H₂S) or sulfur dioxide (SO₂) is just higher than 100 ppm in air. There are 89 kinds of nano porous materials including MOFs and COFs were evaluated to capture H₂S and SO₂ from ratio of 79% nitrogen (N₂) and 21% oxygen (O₂) using grand canonical Monte Carlo (GCMC) simulation. The processes of pressure swing adsorption (PSA) and temperature swing adsorption (TSA) were simulated to obtain the selectivity, working capacity and selection parameter. The results show that UiO-66, ZIF-71, ZIF-69 and ZIF-97 are good adsorbents for separation of H₂S. Their selectivity and loading of H₂S are higher than 300 and 0.01 mmol/g, respectively; the working capacity of PSA is almost 0.06 mmol/g from 1 bar increasing to 10 bar; and the working capacity of TSA is about 0.008 mmol/g from 348 K decreasing to 298 K. For the separation of SO₂ the good candidates are UiO-66, ZIF-71, ZIF-69, MIL-100, Zn-DOBDC, ZnBDC, IRMOF-11and MIL-140B which have the higher selectivity of 500 and the loading of 0.06 mmol/g. Their working capacity of PSA and TSA is almost 0.2 mmol/g and 0.05 mmol/g at same condition as H₂S, respectively. At the same time the diffusivity of gases was investigated in good adsorbents with concentration changes of N₂ through molecular dynamics (MD) simulation. The diffusions of sulfide have no obviously change with decreasing of N₂. Our works provides useful computational insights for the separation of sulfide in governance of polluted air.