3.Al-Based Metal-Organic Framework MFM-300 and MIL-160 for SO2 Capture: A Molecular Simulation Study

Abstract

SO2 emission from fossil fuels combustion in the environment has led to various environmental and health hazards drawing the significant attention of the world to control. SO2 capture through metal-organic frameworks (MOFs) as adsorbent is a promising environmental technology to eliminate the emission of SO2. Many factors have been identified that influence the activity of SO2 separations for flue gases by MOFs, but the precise mechanisms of selectivity underlying the interactions between host and guest molecules are still unclear. Moreover, the role of H2O in flue gases needs to be considered since it is an essential factor in practical engineering applications. In this work, the MOFs of MIL-160 and MFM-300 are selected to capture SO2 from flue gases with various components, which have been experimentally demonstrated to have great feature in flue gas desulfurization. Force-field-based grand canonical Monte Carlo (GCMC) simulations combined with density functional theory (DFT) are employed to predict the strength of host/guest interactions and the adsorption isotherms for all guests in flue gas in MIL-160 and MFM-300. The results show that MIL-160 has an outstanding SO2/CO2 selectivity up to 220 (298 K, 1bar), compared to MFM-300 with 53. CO2 and SO2 binding furanyl groups in MIL-160 are stronger than binding hydroxyl groups in MFM-300. We also found that the increasing weakens the performance of SO2 capture due to the predominant H2O adsorption in the separation process.