Modeling the density and the second-order thermodynamic derivative properties of imidazolium-, cyano-based ionic liquids using the SAFT-γ EoS

Abstract

The knowledge of the thermophysical properties is essential to develop industrial processes involving ionic liquids (ILs). In the present research, the SAFT-γ group contribution (GC) technique is performed to estimate the density and the second-order thermodynamic derivative properties of some imidazolium-, cyano-based ILs (with either [SCN], [DCA], [TCM] or [TCB] anions). The density and the second-order derivatives including isothermal and isentropic compressibility coefficients, thermal expansion and thermal pressure coefficients, isochoric and isobaric heat capacities, and speed of sound are determined for the mentioned ionic liquids within a temperature range of 262–412 K and at pressures up to 200 MPa. The SAFT-γ predictions of the density and the second-order derivatives are compared with some accessible experimental data. The results demonstrate that the SAFT-γ equation can estimate the thermophysical properties of the studied ILs with good accuracy.