Phase equilibria of phenol + tetrahydrofuran + water system and its thermodynamic description

The vapour-liquid equilibrium at 101.32 kPa and the solid-liquid equilibrium were measured for the binary system phenol + tetrahydrofuran. In the ternary system phenol + tetrahydrofuran + water, liquid-liquid and solid-liquid equilibrium data were experimentally determined. Data on VLE, LLE and the heats of mixing were correlated simultaneously for each of the following binary subsystems: tetrahydrofuran + water, phenol + water and phenol + tetrahydrofuran. For this purpose, modified Wilson and NRTL equations were used. The ternary system shows a strong temperature dependence of the LLE which involves closed-loop curves of limited miscibility. The ternary LLE data were correlated with the modified Wilson and NRTL equations with a ternary correction that had to be applied to reach an adequate thermodynamic description.