Measurement and correlation of liquid-liquid equilibrium data for DMF-H_2O-CHCl_3 ternary system

The LLE experiments of N,N-dimethylformamide-chloroform-water ternary system at 293 k and atmospheric pressure were carried out in an equilibrium cell,to achieve the basic data for further study of N,N-dimethylformamide( DMF) recovery from wastewater by extraction. The equilibrium concentrations of each phase were determined by gas chromatography. The NRTL and UNIQUAC models were adopted to correlate the liquid-liquid equilibrium data of the studied system,and the simplex method was used to estimate model parameters. Finally,combined with phase equilibrium data of other temperature,phase equilibrium equation was obtained by regression of all the data. The results showed that the calculated equilibrium compositions of the studied ternary system were in good agreement with the experimental data. The total mean absolute deviations of NRTL and UNIQUAC models were0.0079 and 0.0076 respectively,the regression correlation coefficient of phase equilibrium equation was 0.98.