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The isobaric vapor–liquid equilibrium (VLE) data at 101.3kPa for (1,3-propanediol(PG) + 1,3-butanediol(BD)), (1,3-PG+2,3-BD) and (1,3-BD+2,3-BD) and for the ternary system of (1,3-PG+1,3-BD+2,3-BD) have been measured. The thermodynamic properties of the non-ideal vapor phase have been considered with the EOS equation. The liquid activity coefficients have been calculated with Wilson, NRTL and UNIQUAC equations, and the binary interaction parameters were regressed by these models. The vapor composition of VLE data were calculated by the optimum parameter group and generated a good consistency to experimental values. Based on all the preceding results, a two-column distillation process was designed. [ABSTRACT FROM AUTHOR]

A study on separation of system (1,2-ethanediol (1,2-EG) + 1,3-butanediol (1,3-BD) + 1,3-propanediol (1,3-PG)) was conducted in the article. Vapor-liquid equilibria (VLE) behaviors of systems (1,2-EG + 1,3-BD), (1,2-EG +1,3-PG), (1,2-EG + 1,3-BD + 1,3-PG) were studied at 101.3 kPa. A two-column (column C1 and column C2) sequence distillation process at normal pressure was designed and optimized to separate the ternary mixture. The results have shown Wilson model is the most appropriate one to describe the ternary system; product amounts of 1,2-EG, 1,3-BD, and 1,3-PG can be up to 0.970, 0.945, and 0.980, respectively, under optimized conditions. [ABSTRACT FROM AUTHOR]

A polymer–salt aqueous two-phase system based on polyethylene glycol and sulfates was applied to explore the partition behavior of spiramycin. Binodal curves were measured by the turbidimetric titration method. The influence of temperature, salt concentration, and pH on the distribution behavior was investigated in detail by determining the partition coefficient and extraction efficiency. As pH and salt concentration increase, the partition coefficients increase accordingly. It was found that pH displays a significant influence on the partition behavior. The partition coefficient and extraction efficiency can reach 42.46 and 97.8%, respectively, at pH 9.0 and 15.80% (w/w) salt concentration. [ABSTRACT FROM AUTHOR]

To separate spiramycin from the crude sample of bitespiramycin, the optimal extraction conditions in single stage extraction had been obtained as follows: the temperature was 30-40°C, the concentration of phosphate solution was 0.3-0.4 wt.%, and the volumetric ratio of ester/aqueous was 2-3. A three-stage counter-current extraction technique had been utilized to improve extraction efficiency. The removal rate of spiramycin and the retention rate of bitespiramycin were as high as 79.14% and 92.41%, respectively. A theoretical model of three-stage counter-current extraction was introduced to calculate the results of the extraction and fitted the experimental data with satisfactory accuracy. [ABSTRACT FROM PUBLISHER]

The isobaric vapor-liquid equilibrium data for distillation have been measured for three binary systems of (1,2-butanediol(BD)+1,4-BD), (1,2-BD+2,3-BD), and (1,4-BD+2,3-BD) and for the ternary system of (1,2+BD+1,4-BD+2,3-BD) at 101.3 kPa. The thermodynamic properties of the vapor phase have been calculated with the Hayden-O’Connell equation in consideration of nonideality. The liquid activity coefficients have been satisfactorily correlated with the Wilson, NRTL and UNIQUAC models. The corresponding binary interaction parameters of the three models were calculated. Based on all the preceding results, a two-column distillation process was designed to obtain the required products with purity of 98% for industrial use. [ABSTRACT FROM AUTHOR]