Prediction of molar volume and partial molar volume for CO2/ionic liquid systems with heterosegmented statistical associating fluid theory

To design ionic liquids (ILs) as effective liquid absorbents for CO2 separation from flue or synthesis gases, it is necessary to know the properties and phase equilibria of the CO2/IL systems. The molar volumes of CO2/IL mixtures are predicted with the heterosegmented statistical associating fluid theory equation of state. The comparison with the available experimental data shows that the model can be used to predict reliably the molar volumes of CO2/IL mixtures from 293 to 413 K and pressures up to 160 bar. In addition, the partial molar volume of CO2 in CO2/IL mixtures and the partial molar volume of CO2 at infinite dilution in an IL are also predicted.

► Heterosegmented SAFT with transferable parameters is used to model CO2/IL systems. ► Molar volumes of these systems are well predicted from 293 to 413 K and up to 160 bar. ► Partial molar volumes of CO2 in these mixtures are also predicted.