High pressure phase behaviour of the CO2 + 1-decanol + n-dodecane system

The phase behaviour of three (1-decanol + n-dodecane)-mixtures in the presence of supercritical CO2 was investigated. Phase equilibrium measurements were conducted at temperatures ranging between 308 K and 348 K, with solute mass fractions ranging between 0.017 and 0.621. The experimental data emphasize the dominant influence of n-dodecane in the solute mixture. It has been proposed that the presence of n-dodecane interrupts the formation of alcohol multimers and thus significantly improves the solubility of 1-decanol in supercritical CO2. The ternary system also displays a slight cosolvency effect. The experimental data was used to determine solute-solute binary interaction parameters for the RK-Aspen model in Aspen Plus®. Addition of these interaction parameters improved the correlative capability of the equation of state allowing for future improved process modelling of systems involving these components.