PHASE EQUILIBRIA STUDY OF SYSTEMS COMPOSED OF MACAUBA PULP OIL (Acrocomia aculeata), FREE FATTY ACIDS, AND HYDROUS ETHANOL AT 25ºC

The deacidification of vegetable oil by liquid-liquid extraction is based on the difference in solubility of the free fatty acids and triacylglycerols in the solvent. In the present study, the determination of the ternary phase diagram of the liquid-liquid equilibrium for a pseudo-ternary mixture of solvent (ethanol and water), neutral oil (triacylglycerols) and free fatty acids was performed. It is important to highlight that the macauba pulp oil sample used did not pass through any kind of treatment such as degumming or neutralization. Therefore, the free fatty acids in the sample are resulted from natural degradation of the macauba oil. Despite of that, the results were similar to those found in other studies with purified macauba oil or other sources of triacylglycerols with the addition of oleic acid. The experimental data were correlated by NRTL model and the global deviation between experimental and calculated concentrations was 2.74%.