(28g) Modeling Carbon Dioxide - Imidazolium-Based Ionic Liquid Phase Equilibria with the Tpc-Psaft Equation of State

An equation of state (EoS) is developed to predict accurately the phase behavior of ionic liquid + CO2 systems based on the truncated Perturbed Chain Polar Statistical Associating Fluid Theory (tPC-PSAFT) EoS. This EoS accounts explicitly for the dipolar interactions between ionic liquid molecules, the quadrupolar interactions between CO2 molecules and the Lewis acid-base cross-association between the ionic liquid and the CO2 molecules. Physically meaningful model pure component parameters for ionic liquids are estimated based on literature data. All experimental vapor-liquid equilibrium data are correlated with a single linearly temperature-dependent binary interaction parameter. The ability of the model to describe accurately carbon dioxide solubility in various 1-alkyl-3-methylimidazolium-based ionic liquids with different alkyl chain length and different anion at pressures from 0 MPa to 100 MPa and carbon dioxide fractions from 0 mole % to 75 mole % is demonstrated. In all cases, good agreement with experimental data is obtained.

Reference

M.C. Kroon, E.K. Karakatsani, I.G. Economou, G.-J. Witkamp and C.J. Peters, ?Modeling of the Carbon Dioxide Solubility in Imidazolium-Based Ionic Liquids with the tPC-PSAFT Equation of State?, J. Phys. Chem. B, 110(18), 9262 - 9269 (2006).