Liquid–Liquid Equilibrium for the Ternary System 2-Methyl-1-propanol + 3-Methyl-1-butanol + Water at (298.15, 323.15, and 348.15) K

Liquid–liquid equilibrium (LLE) data for the ternary system 2-methyl-1-propanol + 3-methyl-1-butanol + water have been measured at (298.15, 323.15, and 348.15) K, respectively, under atmospheric pressure in this article. The Othmer–Tobias and Bachman equations were used to check the reliability of the obtained tie-line data. In addition, both NRTL (nonrandom two-liquid) and UNIQUAC (universal quasichemical) activity coefficient models were applied to the ternary system, and the relevant interaction parameters were regressed with the experimental data. The predicted values by both methods were compared with the measured experimental data. The consistency of the two models was excellent, with a better prediction by the NRTL model with a parameter α of 0.3. The obtained interaction parameters of both models can be used in the calculation of the liquid–liquid phase equilibrium of aqueous solution comprising 2-methyl-1-propanol and 3-methyl-1-butanol as well as for the design and optimization of the related separation process.