Speed of sound and derived thermodynamic properties of glycerol

Abstract

A recent study published by the authors, where correlation methods are proposed to reproduce the density, vapour pressure, and viscosity of glycerol over wide ranges of temperature and pressure, here we present a similar methodology that was applied to the speed of sound in liquid glycerol. The speed of sound in liquid glycerol was calculated from the propagation time measured by using two 5 MHz ultrasonic transducers in through transmission mode, up to 20 MPa and at temperatures ranging from (303.15 to 373.15) K. The density, isothermal compressibility, and isobaric heat capacity were evaluated in the temperature range (298.15 to 348.15) K and pressures up to 100 MPa, from the measured speed of sound starting from the density and specific heat capacity data at 0.1 MPa available in literature, and using a computational method originally developed by Davis and Gordon. The derived density and speed of sound data made the molar compressibility calculation possible, from which a new method was developed for the speed of sound estimation for pressures up to 100 MPa. The proposed method provided speed of sound with high accuracy (AARD% = 0.2%).