High-pressure density measurements for choline chloride: Urea deep eutectic solvent and its aqueous mixtures at T = (298.15 to 323.15) K and up to 50 MPa

New measurements are reported for the densities of choline chloride: urea (REL) deep eutectic solvent and its aqueous mixtures over the temperature range (298.15 to 323.15) K and pressures up to 50 MPa. The experimental data were used to derive other properties such as isothermal compressibility, isobaric expansivity and excess molar volume. A Tait-type equation was used to correlate accurately the high-pressure density data to temperature, T, pressure, P, and composition, x. The excess molar volumes of {REL (1) + H2O (2)} mixtures were also investigated and represented as a function of all three variables, T, P, x, using an empirical equation. Results indicate that the correlations used in this work can be satisfactorily used to predict the densities of the studied systems at different conditions of temperature, pressure and composition.

► The high-pressure densities of Reline and its aqueous solutions were measured.
► The pressure studied was (0.1 to 50) MPa.
► The temperature studied was (298.15 to 323.15) K.
► The measured data were reported as functions of temperature and composition.
► The measured data were represented satisfactorily by the applied correlations.