Determination of ternary vlle by p(x 1,x 2) measurements

Abstract

For determination of VLE and LLE of ternary systems showing a misciblity gap the static method of p(x 1,x 2) measurements at constant temperature has been applied. The apparatus used is similar to that described by Gibbs and Van Ness. Measurements have been carried out for the system ethanol/water/cyclohexane at 303.15 K. For data reduction Barker's method has been chosen. The excess Gibbs energy is represented by a NRTL-equation with an added ternary term. Because this mixture behaves strongly non-ideal a representation of the data was not possible for the entire range of composition with one set of parameters. Therefore, data reduction had to be carried out separately for limited regions. Thus, a fairly good representation of both VLE and LLE could be achieved.