Phase behavior of β- d galactose pentaacetate–carbon dioxide binary system

• Published in: Fluid phase equilibria 2006-01, Vol.239 (2), p.172-177
• Main Authors: Dilek, Cerag, Manke, Charles W., Gulari, Esin
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Phase equilibria; Solubility; Sugar acetate; Supercritical carbon dioxide; β- d Galactose pentaacetate
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2005.11.013

Phase behavior of β- d galactose pentaacetate–carbon dioxide binary system is investigated by dew-point and bubble-point measurements conducted in a high pressure variable volume sapphire cell. The phase envelope for solutions of β- d galactose pentaacetate in supercritical CO 2 is obtained for β- d galactose pentaacetate concentrations between 2 and 26 wt%, and for the temperature range of 308–323 K. The system exhibits lower critical solution temperature (LCST) behavior and high solubility of β- d galactose pentaacetate is observed. The densities of the system are also measured, and liquid-like densities (near 1 g/cm 3) are observed for single-phase solutions of β- d galactose pentaacetate in supercritical CO 2 at concentrations of 18 wt% and higher. Viscosity is measured for solutions of 18 and 25 wt% β- d galactose pentaacetate in the single-phase region at 313 K and 17 MPa and the viscosity values, 0.095 and 0.103 cp, respectively, are similar in magnitude to the viscosity of pure carbon dioxide.