| With the increasing threaten of global warming, carbon dioxide is widely accepted as the main greenhouse gas. The carbon capture and storage (CCS) technologies is considered as a promising method to achieve the goal of reduction in CO2emissions. Nowadays more and more research groups devoted to developing new CO2capture technologies. But relatively few have gained any measure of acceptance from an industrial viewpoint. Ionic liquids (ILs) are commonly defined as liquids which are composed entirely of ions with a melting point near the room temperature. Because of its unique characteristics, i.e., wide liquid range, thermal stability, negligible vapor pressure, tunable physico-chemical character and high CO2solubility, ionic liquids is considered to be a better choice for CO2capture. However there are still much uncertainties about the ionic liquids when used as a solvent for CO2capture. Fortunately with the rapid progressing of computer technologies, molecular simulation method is considered as a excellent method to solve these problems.In this work, molecular dynamic simulation method and monte carlo simulation method were used in combination. CO2solubilities in [Bmim][PF6],[Bmim][BF4],[Bmim][Ac],[Bmim][Tf2N] were measured, respectively, at temperature of283.15K,298.15K,323.15K, and348.15K and pressure range from1MPa to2MPa. Gas solubilities were determined from equilibrium stage data. Present and literature data were fitted to determine group segment numbers and interaction energy parameters between groups.The agreement between data and calculater solubilities were found generally good for ionic liquid with1-alkyl-3-methylimidazolium cation and [PF6],[BF4],[Ac] and[Tf2N] anions. Otherwise by means of comparing RDF between solute and ions, we find that when dissolving in ionic liquids, anions paly a more important role than cations.Moreover, we also calculated the solubilities of CO2in small molecular organic solvent as complementary data. |
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