A comparative study of liquid–liquid equilibria for aqueous mixtures of straight chain and branched chain carboxylic acids with methyl isobutyl carbinol

Publication date: Available online 10 December 2019Source: The Journal of Chemical ThermodynamicsAuthor(s): A. Ghanadzadeh Gilani, F. Amouzadeh, B. Ghalami-ChoobarAbstractLiquid-liquid equilibrium (LLE) data of the (water + butyric or 3-methylbutyric acids + methyl isobutyl carbinol) ternary systems were experimentally obtained at T = (298.2, 303.2, and 308.2) K and P = 0.1 MPa for the first time. Using solubility and tie-line measurements, the triangle phase diagrams were obtained and influence of the chemical structure of the acids on the LLE behaviour was studied. The first ternary aqueous system containing butyric acid and the alcohol displays type-1 LLE behaviour, while the second one including 3-methylbutyric acid exhibits type-2 phase diagram. The reliability of the experimental data was checked using the Othmer-Tobias and Hand correlation equations. The UNIQUAC and NRTL thermodynamic models were used to fit the experimental tie line data and values of the corresponding binary interaction parameters were determined. The binary model parameters were optimized by the MATLAB fminsearch function. According to the experimental tie-line data, distribution coefficients and separation factors were determined for the studied systems.

Source: The Journal of Chemical Thermodynamics - December 10, 2019 Category: Chemistry Source Type: research