Search

Isobaric vapor–liquid equilibrium (VLE) for the binary system N , N -dimethyl formamide (DMF) + N , N -dimethyl acetamide (DMAC) and the quaternary system sec -butyl alcohol (SBA) + sec -butyl acetate (SBAC) + DMF + DMAC were determined at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the experimental data was checked by Van Ness point test. The binary VLE data were correlated with the NRTL, UNIQUAC and Wilson activity coefficient models respectively. And the VLE data of the quaternary system predicted by the correlated binary interaction parameters agree well with the experimental data. And the mixture of DMF (3) and DMAC (4) can eliminate the pseudo-azeotrope of sec -butyl alcohol (1) + sec -butyl acetate (2). Thus, the mixture of DMF and DMAC is appropriate for separation of the pseudo-azotrope of SBA and SBAC by extractive distillation.

Isobaric vapor–liquid equilibrium (VLE) data for the quaternary system sec-butyl alcohol + sec-butyl acetate + N, N-dimethyl formamide (DMF) + dimethyl sulfoxide (DMSO) and the constituent binary system DMF + DMSO were determined at 101.3 kPa with a modified Othmer still. The measured experimental data of binary and quaternary systems were certified to be thermodynamically consistent according to the Van Ness method. And the experimental binary data were correlated by Wilson, NRTL and UNIQUAC activity coefficient models. The rest of binary interaction parameters have been obtained in our previous work. Then, the binary and quaternary vapor–liquid equilibrium were predicted by the models with the correlated parameters. The results show that the three models yield a good prediction for the binary and quaternary systems. But NRTL model performed better than the other two models in predicting VLE of the quaternary system.

Isobaric vapor–liquid equilibrium (VLE) data for the systems of methyl acetate + dimethyl sulfoxide (DMSO), methanol + DMSO and methyl acetate + methanol + DMSO were determined with a modified Othmer still at 101.3 kPa. And all experimental VLE data have passed the Herington and Van Ness thermodynamic consistency tests. The experimental binary VLE data were correlated by NRTL, Wilson and UNIQUAC models and the binary interaction parameters were obtained. And the VLE data predicted by the obtained parameters agree well with the experimental data. The binary azeotrope of methyl acetate and methanol is eliminated when the mole ratio of DMSO to the binary azeotrope is approximately 1.5:1. Therefore, DMSO is a promising extractive agent for the separation of the binary azeotrope of methanol and methyl acetate in extractive distillation.

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary systems sec-butyl alcohol + N,N-dimethyl acetamide (DMAC), sec-butyl acetate + DMAC and the ternary system sec-butyl alcohol + sec-butyl acetate + DMAC at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the binary experimental data was made by Herington method and McDermott–Ellis method. And the thermodynamic consistency test for the ternary experimental data was made by McDermott–Ellis method. The binary VLE data were correlated with the NRTL, Wilson and UNIQUAC activity coefficient models. The obtained binary interaction parameters were used to predict the binary and ternary VLE data. The results indicate that the calculated values of vapor phase mole fraction and boiling temperature by the NRTL, Wilson and UNIQUAC models agree well with the experimental data. And the binary pseudo-azeotrope of sec-butyl alcohol and sec-butyl acetate was eliminated when the mass ratio of DMAC to the pseudo-azeotrope mixture is 6:5. Thus, DMAC is an appropriate solvent for separation of the mixture of sec-butyl alcohol and sec-butyl acetate in extractive distillation.

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.