Isobaric vapor-liquid equilibria of chloroform plus ethanol and chloroform plus ethanol plus calcium chloride at 94.0 kPa

Vapor-liquid equilibrium data of chloroform + ethanol and chloroform + ethanol + CaCl2 (at saturation) were measured at a pressure of 94.0 kPa, using a modified Malanowski equilibrium still. The salt investigated in this work, i.e. CaCl2, exhibits a slight salting-out effect on chloroform. The experimental results of the salt-free binary were compared with those predicted by ASOG, original UNIFAC, and modified UNIFAC models which predicted the bubble point temperatures with a root-mean-square-deviation (RMSD) of: 0.40, 0.55, and 1.48 K, respectively. RMSD values of the vapor-phase composition given by these models were: 0.020, 0.019 and 0.039 mole fraction, respectively. On the other hand, the experimental data of the salt-containing system were compared with those predicted by Wilson-Tan and NRTL-Tan models for the effect of the electrolyte on the phase behavior of the system under study which has an azeotrope around x(1) = 0.93. Both models showed similar capability in predicting the bubble-point temperatures and vapor-phase compositions: temperatures were predicted by both models with an RMSD of about 0.4 K whereas the RMSD values of the vapor-phase mole fractions, predicted by these models, were 0.026 and 0.022, respectively. (C) 1997 Elsevier Science B.V.