Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

A systematic study on the phase behavior of saturated ethyl esters with supercritical CO2 is presented. High pressure phase behavior measurements for the systems CO2/ethyl decanoate, CO2/ethyl dodecanoate, CO2/ethyl tetradecanoate and CO2/ethyl hexadecanoate were conducted in a static synthetic view cell in the temperature range 308 to 358 K. Phase transition pressures were measured in the range 5.86 to 23.01 MPa for ethyl ester mass fractions in the range 0.0174 to 0.657 and complement existing literature data. Throughout the temperature and compositional range measured, which encompassed the liquid phase, mixture critical region and vapor phase, an increase in temperature leads to an increase in phase transition pressure with no temperature inversions or three phase regions observed. Additionally, an increase in hydrocarbon backbone length leads to an ever-increasing phase transition pressure, suggestion fractionation of ethyl esters according to molecular mass with supercritical CO2 is possible. Finally, the measured and previously published CO2/ethyl ester data were successfully correlated with a modified Chrastil models and the MT model. While these models can not easily be used predictively and depend on the data sets used for correlation, these are simple and easy methods that can be used to interpolate data.