Determination and correlation of liquid-liquid equilibrium data for the dichloromethane plus water plus N,N-dimethylacetamide plus NaCl system

The (liquid + liquid) equilibrium (LLE) data for the quaternary system dichloromethane (DCM)+ water + N,N-dimethylacetamide (DMAC) + NaCl have been determined at (298.15 and 308.15)K and atmospheric pressure. The experimental data were correlated by using Othmer-Tobias equation, and all the linear correlation coefficients were approximate to 1. Both NRTL and UNIQUAC models were adopted to correlate the LLE data, the model parameters were regressed by nonlinear least-squares method, then the LLE data of the quaternary system were calculated. The comparison between calculated and experimental data shows good agreement. The results show that the enlargement of two-phase region occurred with an increase of salt concentration in initial aqueous phase, and adding salt to the system is beneficial to increase the selectivity of solvent. (C) 2015 Elsevier B.V. All rights reserved.