Volumetric behavior of ethyl acetate, ethyl octanoate, ethyl laurate, ethyl linoleate, and fish oil ethyl esters in the presence of supercritical CO2

The volumetric behavior of ethyl esters and fish oil ethyl esters in the presence of supercritical CO2 was studied with a newly designed flow apparatus. Pure esters studied were ethyl acetate (C2), ethyl octanoate (C8), ethyl laurate (C12) and ethyl linoleate (C18:2). Fish oil ethyl esters were derived from esterification with ethanol. Conditions were CO2 at 313.2 K over the pressure range of 0.1-25 MPa and over the full range of single phase compositions. The density data were interpreted in terms of swelling factors, V-mix/V-ester. It was found that the swelling factors over the full range of compositions at a given pressure could be made to collapse into a single curve by using weight fraction instead of mole fraction. Further, the Soave-Redlich-Kwong equation of state was found to provide prediction of the swelling factors to within 3.0% average error or correlation to within 1.1% average error. Supercritical CO2 + fish oil mixtures were found to show the same swelling behavior as supercritical CO2 + ethyl esters. (C) 1998 Elsevier Science B.V.