Vapor–liquid equilibrium data for the 2-methoxy-2-methylpropane (MTBE)–ethanol, MTBE–ethanol–calcium chloride, and MTBE–ethanol–copper chloride

Abstract

Isobaric vapor–liquid equilibrium data were measured for the methyl tert-butyl ether (MTBE)–ethanol, MTBE–ethanol–calcium chloride, and MTBE–ethanol–copper chloride at an atmospheric pressure of 702 mmHg using a modified Malanowski equilibrium still. The experimental data of the salt-free system were compared with those predicted by the ASOG, original UNIFAC, and UNIFAC–Dortmund methods of prediction, which predicted the bubble-point temperatures with root-mean-square deviations (RMSD) of: 1.30, 0.16, and 0.38K, respectively. The RMSD values of the vapor-phase compositions given by these models were: 0.0197, 0.0049, and 0.007, respectively. The experimental data of the salt-free system were also correlated by the Wilson, NRTL, and UNIQUAC models. The calculated data using both the Wilson and NRTL models were in good agreement with the experimental results. The salts used in this study, calcium chloride and copper chloride, resulted in salting-out the MTBE and shifting the azeotropic point from 94.0 to 96.0 mol% MTBE. The experimental data of the salt-saturated systems were compared with those predicted by the Tan–Wilson equation and the results were in good agreement with the experimental data.