CO2 Solubility in 1-ethyl-3-methylimidazolium trifluoromethylsulfonate Using the Monte Carlo Simulation

The liquid structure, volumetric properties, and solubility of CO2 in ionic liquid of 1- ethyl-3-methylimidazolium trifluoromethylsulfonate [EMIM][CF3SO3] were investigated using the Monte Carlo simulation method. Force field parameters used for the species [EMIM],+ CF3SO3 -, and CO2 were taken from those reported in the literature. The Monte Carlo simulation method was used for an isothermal-isobaric ensemble and also NPTGibbs ensemble using the Metropolis acceptance rules at 298 K. The results showed that predicted density of pure IL is in good agreement with the experimental data. The centre of mass RDF’s for cation-cation, anion-anion, and anion-cation of pure IL which show the characteristic ordering of fluids with long-range columbic interaction were plotted. Also, the site-site RDF’s between different H atoms of imidazolium ring of [EMIM]+ and F and O atoms in CF3SO3 - in pure IL which proves the hydrogen bond formation between H5 atom of the ring and O atoms of the anions were obtained. In addition, SDF’s of the anions around the cation as well as the cation around the anions were presented. Solubility of CO2 in the IL was determined at 298 K and different partial pressures of 0.5, 1.0, and 2.0 atm. The centre of mass RDF’s for CO2 about the ions of the IL show thatcarbon dioxide is more highly distribute about anions than cations which shows more important effect of anion on solubility of carbon dioxide than that of cation. SDF’s of CO2 about the ions were presented which show that CO2 are mostly distribute near O atoms of the anion and also above and below of the imidazolium ring.

Keywords:

Ionic Liquids , 1-ethyl-3-methylimidazolium , trifluoromethylsulfonate , Carbon dioxide , Monte Carlo Simulation