Density and viscosity of mixtures of glycerol acetates saturated with CO2 for the design of a supercritical fractionation column

Abstract

Supercritical CO2 technology has a great potential for the fractionation of glycerol acetates (mono, di, and triacetyl glycerol) according to the quality standards of the food and cosmeceutical sectors. The design of fractionation columns requires a robust thermodynamic model for phase-equilibrium and PVT predictions, as well as proper correlations for physical properties like viscosity. In this work, we measure volumetric and rheological properties of mixtures of glycerol acetates saturated with CO2 (up to 70 mol%) in the temperature range 298−323 K. The mixture molar volumes are between 75 mL/mol and 135 mL/mol, while the viscosities between 0.9 mPa.s and 20 mPa.s. Results show that assuming ideal solution behaviour to estimate the physical properties has a major impact on the design of the fractionation.