dThe use of near-critical CO2 and propane for the removal of chemicals-pollutants, undesirable or valuable products-from fatty oils is studied. The process conditions are discussed, on the basis of phase equilibrium predictions from a group contribution equation of state. The extension of the equation to cover systems with large differences in molecular size requires the use of revised parameters. With the new parameters, a good correlation of phase equilibrium data for all of the binaries involved in the process was achieved. Distribution coefficients of different chemicals between the oil and solvent phases were predicted, and optimum process conditions were explored. The extraction with propane requires the operation above the lower critical endpoint temperature of the binary fatty oil-propane system, to have liquid-liquid or liquid near-critical fluid phase immiscibility. The process analysis indicates that there are optimum operating pressures that minimize solvent requirements and fatty oil losses in the extract.