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

Economou, I. G., The Petroleum Institute
Karakatsani, E. K., Institute of Physical Chemistry National Center for Scientific Research “Demokritos”
Peters, C. J., Petroleum Institute
Witkamp, G., Delft University of Technology, Faculty of Design, Engineering and Production, Laboratory for Process Equipment

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.


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).