Modeling gas solubilities in imidazolium based ionic liquids with the [Tf2N] anion using the GC-EoS

• The GC-EoS is extended to model gas solubilities in ionic liquids.
• Imidazolium-based ionic liquids with the [Tf2N] anion are considered.
• CO2, CO, H2, CH4, and C2H6 are the gases evaluated in this work.
• The GC-EoS repulsive term is calculated based on ILs density data.
• The predictive model is successful for non-ideal systems and can also predict LLE.

The group contribution equation of state (GC-EoS) is extended to model gas solubilities in the homologous 1-alkyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl) imide family. The gases considered in this work are CO2, CO, H2, CH4, and C2H6. The model parameters were estimated on the basis of 1400 experimental data points in the temperature range of 278–460 K and pressures up to 160 bars. A correlation is also presented to calculate the critical diameter, a characteristic parameter of the GC-EoS repulsive term, as a function of the ionic liquid molar volume. Density data is most often available for ionic liquids; hence, the correlation provides a predictive method for ionic liquids not included in the parameterization process. The new parameters were then used to predict the phase behavior of binary mixtures containing different solutes (including C3H8, C4H10, and C6H14) and ionic liquids with different chain lengths than those used in the parameterization process.

Figure optionsDownload as PowerPoint slide