Determination and Correlation of Liquid-Liquid Equilibrium Data for the Ternary System of DMF-CHCl_3-H_2O

The study on liquid-liquid equilibrium(LLE) is important for N,N-dimethylformamide(DMF) recovery from wastewater by extraction.In order to achieve the basic data for further study,the LLE experiments of DMF-chloroform-water ternary system at 30℃,35℃,40℃ and atmospheric pressure were carried out in an equilibrium cell.The equilibrium concentrations 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 model parameters were estimated by the simplex method.The active coefficients in the LLE equations were calculated by the NRTL and UNIQUAC models,and the calculated LLE data of DMF-chloroform-water ternary system were compared with the experimental data.Based on the NRTL and UNIQUAC models,the calculated equilibrium compositions of the studied ternary system are in good agreement with the experimental data.The total mean absolute deviations of NRTL and UNIQUAC models are 0.0032 and 0.0033,respectively,and the total mean relative deviations of them are 2.60% and 2.97%,respectively.