Liquid−Liquid Equilibrium Data for Fatty Systems Containing Refined Rice Bran Oil, Oleic Acid, Anhydrous Ethanol, and Hexane

Abstract

The objective of this work was to determine liquid−liquid equilibrium data for fatty systems of interest in the extraction/refining process of vegetable oils and in the biodiesel production. The following systems were investigated: refined rice bran oil + anhydrous ethanol + hexane at (298.15 ± 0.2) K and (313.15 ± 0.2) K and refined rice bran oil + commercial oleic acid + anhydrous ethanol + hexane at (298.15 ± 0.2) K with mass fractions of (5.08, 7.98, 10.65, and 15.09) % of fatty acid in oil. The instrumental technique of near-infrared spectroscopy allied to multivariate calibration (in this work, termed “NIR method”) was used for quantification of the phase compositions. For the pseudoternary system, the relative deviations for global mass balance were (0.10 and 0.11) % for the temperature of (298.15 and 313.15) K, respectively. For the pseudoquaternary systems, the relative deviations for global mass balance varied in the range from (0.15 to 0.31) %. The experimental data were correlated using the NRTL model with overall deviations lower than 1.15 %. We can conclude that the NIR method is highly accurate, and the low deviations obtained indicate the good quality of the equilibrium data.