Phase behavior of soybean oil, castor oil and their fatty acid ethyl esters in carbon dioxide at high pressures

This work provides experimental phase equilibrium data of binary and ternary systems involving carbon dioxide (CO2), ethanol, soybean oil, castor oil and their fatty acid ethyl esters. Here the oils and their fatty acid ethyl esters were treated as pseudo components. The experiments were carried out in a high-pressure variable-volume view cell in the temperature range of 13–70 °C, for carbon dioxide overall composition ranging from 5 to 45 wt.% and pressures up to 270 bar. The Peng–Robinson and statistical associating fluid theory (SAFT) equations of state were used to represent the experimental data, and results show that for fatty acid esters both models provide satisfactory representation of experimental data, while for the vegetable oils the SAFT demonstrated superior performance compared to the Peng–Robinson equations of state (EoS).