Experimental isobaric vapor–liquid equilibrium for ternary system of sec -butyl alcohol + sec -butyl acetate + N , N -dimethyl formamide at 101.3 kPa

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary systems sec-butyl alcohol + dimethyl sulfoxide (DMSO), sec-butyl acetate + DMSO and the ternary system sec-butyl alcohol + sec-butyl acetate + DMSO at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the binary experimental data was made by Herington method, Wisniak's L–W method and a point to point method of Van Ness test described by Fredenslund et al. And the thermodynamic consistency of the ternary system was checked by Van Ness test. The VLE data for the binary systems were correlated with the NRTL, Wilson and UNIQUAC activity coefficient models. And the binary and ternary VLE data predicted by the obtained binary interaction parameters agree well with the experimental data. The experimental results show that the relative volatility between sec-butyl alcohol and sec-butyl acetate is changed obviously when the mass ratio of DMSO to the pseudo-azeotrope mixture is 6:5. And DMSO is a promising extractive agent for the separation of the mixture of sec-butyl alcohol and sec-butyl acetate in extractive distillation.