Liquid−Liquid Equilibrium Data for Systems Containing Vegetable Oils, Anhydrous Ethanol, and Hexane at (313.15, 318.15, and 328.15) K

Abstract

The aim of this work was to determine liquid−liquid equilibrium data for systems of interest in ethyl ester (biodiesel) production. The following systems were investigated: refined soybean oil + anhydrous ethanol + hexane at (313.15 ± 0.1) K and (328.25 ± 0.1) K, refined canola oil + anhydrous ethanol + hexane at (313.25 ± 0.1) K and (328.15 ± 0.1) K, and refined palm oil + anhydrous ethanol + hexane at (318.15 ± 0.1) K and (328.25 ± 0.1) K. The instrumental technique of near-infrared spectroscopy allied to multivariate calibration (in this work, this union was denominated “NIR method”) was used for quantification of the phase compositions. The NIR method presented an appropriate experimental accuracy for quantifying equilibrium data at higher temperatures. Good reliability of the phase compositions was confirmed from values of global mass balance deviations ranging from (0.06 to 0.16) %. The experimental data were correlated using the NRTL model with an average global deviation of 0.83 %.

Measurement, correlation and prediction of isothermal vapor–liquid equilibria of different systems containing vegetable oils

“…In contrast to methanol, ethanol molecules are less polar due to the longer hydrocarbon part attached to the alcohol group and at the same time they are able to form cyclic tetramers and thus retain a higher percentage of their hydrogen bonding even in unpolar solvents. The observed miscibility gaps for alcohols can be used for the separation of fatty compounds (for example deacidification of vegetable oils, biodiesel purification and solvent recover processes) by liquid-liquid extraction, as discussed already in previous works of our research group [31,44,[53][54][55].…”

Liquid–liquid equilibrium of binary and ternary systems composed by palm oil or palm oil fractions with methanol/ethanol and water

“…In this work, a ij = 0.3 was used for the correlation of liquid-liquid equilibrium data. Thus, in this work, there are four adjustable parameters for each pair of substances [26,27]. These parameters can be estimated with experimental data by using the procedure below.…”

Liquid–Liquid Equilibrium for Ethanolysis Systems of Fish Oil

“…A ij and B ij represent the interaction energy between compounds i and j and α ij is a nonrandomness parameter that derives from the local composition assumption. The parameter estimation was based on the minimization of the following objective function by using the Simplex Nelder Mead method: [9] where D is the number of data sets (number of studied temperatures for each system), M is the number of tie-lines in each data set, N is the number of components, the superscripts EP and OP refer to ethanol rich phase and oil rich phase respectively, and the superscripts exp and calc refer to the experimental and calculated values of the liquid-phase concentration. A similar procedure as proposed by Reyes-Labarta et al 22 has been followed in the minimization procedure to calculate the equilibrium concentrations.…”