Liquid-liquid Equilibrium in Systems Containing Olive Oil, Free Fatty Acids, Ethanol and Water

Abstract

This paper reports experimental data and the thermodynamic modeling of the liquid-liquid equilibrium systems with triacylglycerols, free fatty acids (obtained from olive oil), ethanol and water. The experimental data were fitted using the UNIQUAC model, in which absolute deviation of 1.28 % and root mean square deviation of 2.10 % between experimental and calculated mass fraction of the components in each phase were obtained. The results from this study can be complementary to investigations of more complex liquid-liquid equilibrium of systems containing diacylglycerols and monoacylglcerols of olive oil in hydroalcoholic solutions, once such systems will mostly also contain triacylglycerols and free fatty acids on its composition. Diacylglycerols are obtained from different reaction processes and can be purified by liquid-liquid extraction at mild conditions of temperature and pressure, what justifies the experimental and theoretical approach made in this work.

Extraction of Free Fatty Acid Mixtures from Rice Bran Oil by Aqueous Renewable Alcohols: Liquid-liquid Equilibrium Diagram and Number of Equilibrium Stages

“…However, they measured the data without variation of FFA contents in the RBO so that complete LLE diagrams could not be constructed although the solvent-to-RBO ratios had been varied during the measurement. Lima, et al [44] studied LLE of olive oil-FFA-ethanol-water using FFA derived from olive oil. However, most of their data involved only three of the four components studied and, in the quaternary system, the concentrations of FFA and olive oil were lumped into one group.…”

On the Importance of Choosing the Best Minimization Algorithm for the Determination of Ternary Diffusion Coefficients by the Taylor Dispersion Method

“…Nowadays, this analysis is normally performed by averaging the results obtained by fitting 2–4 experimental outputs obtained with different α 1 values. In both cases, traditional least-square methods, such as the well-known Levenberg–Marquardt algorithm, are normally adopted to find the minimum of the objective function. − Even if the effect of using local versus global solvers in parameter estimation analysis is a well-known topic for several kinds of applications, − no specific studies are present in the literature that deal with the choice of the best minimization algorithm, which could give place to the determination of the real global minimum of the objective function with a single-parameter estimation analysis on multiple experimental datasets, for diffusivity measurements obtained by the Taylor dispersion method. For this reason, in this work, we have chosen a specific experimental system and performed Taylor measurements.…”