Phase equilibria involved in extractive distillation of dipropyl ether + 1-propyl alcohol using 2-ethoxyethanol as entrainer

Consistent vapour–liquid equilibrium data at 101.3 kPa have been determined for the ternary system dipropyl ether + 1-propyl alcohol + 2-ethoxyethanol and two constituent binary systems: dipropyl ether + 2-ethoxyethanol and 1-propyl alcohol + 2-ethoxyethanol. The dipropyl ether + 2-ethoxyethanol system shows positive deviations from ideal behaviour and 1-propyl alcohol + 2-ethoxyethanol system exhibits no deviation from ideal behaviour. The activity coefficients and the boiling points were correlated with their compositions by the Wilson, NRTL and UNIQUAC equations. It is shown that the models allow a very good prediction of the phase equilibria of the ternary system using the pertinent parameters of the binary systems. The parameters obtained from binary data were utilized to predict the phase behaviour of the ternary system. The results showed a good agreement with the experimental values. Moreover, the entrainer capabilities of 2-ethoxyethanol were compared with 1-pentanol, butyl propionate and N,N-dimethylformamide, concluding that N,N-dimethylformamide is the best entrainer.