Liquid–liquid equilibrium data for ternary aqueous mixtures containing 1-pentanol and 2-methyl-1-propanol at (298.15, 323.15, and 348.15) K

• LLE tie-line data for 2-methyl-1-propanol + 1-pentanol + water have been measured.
• The influence of temperature on phase behaviors for the studied system was detected.
• The NRTL and UNIQUAC models have been used to correlate the experimental data given.
• The NRTL and UNIQUAC interaction parameters were obtained.
• A good agreement has been observed between the calculated and experimental data.

Liquid–liquid equilibrium (LLE) tie-line data of ternary aqueous mixtures containing 1-pentanol and 2-methyl-1-propanol were reported separately at T = (298.15, 323.15 and 348.15) K under normal pressure in this article. Meanwhile, a type II LLE phase diagram for the investigated system at each constant temperature was given and the effect of temperature on LLE phase behavior was discussed. The well-known Othmer–Tobias, Bachman and Hand correlations were used to test the reliability of the experimental data. In addition, both the NRTL (α = 0.2) and UNIQUAC models were applied to correlate the measured data to obtain the binary interaction parameters between each pair of components valid for the range of temperature studied. All of the root-mean-square deviation (RMSD) between the measured and calculated data was less than 0.0056. The results of this study can be used to design and optimize the liquid–liquid separation process of aqueous solution containing 2-methyl-1-propanol and 1-pentanol.