Influence of temperature and pressure on the density and speed of sound of N-ethyl-2-hydroxyethylammonium propionate ionic liquid

Abstract

The alkanolammonium ILs are protic ionic liquids (PILs) with low cost of preparation, simple synthesis and purification methodologies and low toxicity. The knowledge of high-pressure density and speed of sound are fundamental properties either to understand the nature of molecular interactions, structure and packing effects or to determine other thermodynamic properties useful in chemical and industrial processes. Herein, the density, up to 35 MPa along isotherms ranging from (298.15 to 343.15) K, and the speed of sound up to 20 MPa, along isotherms in the range (303.15 to 353.15) K, are reported for the N-ethyl-2-hydroxyethylammonium propionate, [E2HEA][Pr] PIL. The experimental pVT data were further correlated with the Goharshadi–Morsali–Abbaspour equation of state (GMA EoS) with average absolute deviation (%AARD) of 0.03%. From GMA EoS the thermal expansivity and isothermal compressibility were determined. The speed of sound was correlated with Sun equation with %AARD = 0.08%. The isentropic and molar compressibilities were also calculated from the density and speed of sound.