Experiment and simulation study of CO2 solubility in dimethyl carbonate, 1-octyl-3-methylimidazolium tetrafluoroborate and their mixtures

CO 2 capture with solvent-based process is known as a promising technology for controlling the global warming. In this work, the constant-volume method was used to investigate CO 2 solubility in DMC, ionic liquid of [Omim][BF 4 ], and their mixtures from 298.15 to 328.15 K under pressures up to about 3 MPa. The COSMO-RS model was used to predict the Henry's constants and the vapor pressures of DMC in the mixtures. The experimental results showed the CO 2 solubility in [Omim][BF 4 ] is higher than DMC at 318.15–328.15 K and adding [Omim][BF 4 ] into DMC can decrease the viscosity compared to the pure [Omim][BF 4 ]. Besides, the COSMO-RS simulation results showed the Henry's constants in the mixtures increases with the decreasing mass ratio of [Omim][BF 4 ] which are consistent with experimental values and the vapor pressures of DMC in the mixtures decreases with the increasing mass ratio of [Omim][BF 4 ]. Moreover, the activation energy ( Ea ) predicted from viscosity showed the higher viscosity mean the larger Ea and the larger Ea indicate the higher CO 2 solubility in these solvents. Finally, the mixtures of DMC and [Omim][BF 4 ] may be used as promising physical solvents to capture CO 2 with high partial pressures, which combine the advantages of organic solvents and ionic liquids.