Isobaric Vapor–Liquid Equilibrium Data for Water (1) + 2‑Methyl-propan-1-ol (2), 2‑Methyl-propan-1-ol (1) + Pyridine (2), and Water (1) + 2‑Methyl-propan-1-ol (2) + Pyridine (3) Systems

In this work, isobaric vapor–liquid equilibrium (VLE) measurements were conducted for the binary systems of water (1) + 2-methyl-propan-1-ol (2) and 2-methyl-propan-1-ol (1) + pyridine (2) at approximately 50, 80, and 100 kPa using a dynamic equilibrium apparatus. The water (1) + 2-methyl-propan-1-ol (2) system was found to be partially miscible for some intermediate compositions and exhibited azeotropic behavior, while a maximum boiling azeotrope was observed for the 2-methyl-propan-1-ol (1) + pyridine (2) system at 51 kPa and approximately x1 = 0.23. Ternary VLE measurements were also conducted for the water (1) + 2-methyl-propan-1-ol (2) + pyridine (3) system at 101.3 kPa. The binary VLE data were modeled using the γ–Φ approach with the Nonrandom Two-Liquid and Universal Quasi-Chemical activity coefficient models and the virial equation of state. The measured data were found to be thermodynamically consistent using the point-type and infinite dilution tests. Ternary VLE data were predicted from the regressed binary interaction parameters and show satisfactory comparison to the experimentally determined VLE data.