Liquid glycerol: Experimental densities at pressures of up to 25 MPa, and some derived thermodynamic properties

Abstract

In spite of the importance of glycerol in industry, only limited consistent information on its pVT data seems to be available in the literature. In this work, the density of glycerol (1,2,3-propanetriol) was measured within the temperature range 298.15–348.15K and over the pressure range from atmospheric pressure up to 25.0MPa by means of a vibrating tube densimeter. The estimated combined standard uncertainty of measurements is 0.86kg·m−3. The experimental pVT values of this study combined with selected values from the literature covering the ranges of T=(278–373)K and of p=(0.1–200)MPa were fitted using the Goharshadi–Morsali–Abbaspour equation of state (GMA EoS). The measured density in this work correlates with deviations of ±0.05% (less than 0.5kg·m−3) and in the range ±0.1% with the overall results. From the GMA EoS, the mechanical coefficients as thermal expansivity, isothermal compressibility and internal pressure were calculated. Vapour pressures selected from the literature covering the temperature range between the triple point and the normal boiling point were correlated with the Wagner equation. This equation was used in conjunction with the Clapeyron equation to calculate the molar enthalpies of vapourisation from the triple point to the normal boiling point.