Investigation of Synthetic and Analytic Methods for Measuring Phase Equilibria in the Hexafluoropropylene + Methylcyclohexane System

Abstract

Isothermal vapor–liquid equilibrium data for the binary system 1,1,2,3,3,3-hexafluoro-1-propene + methylcyclohexane are presented over a temperature range of (273–313) K. Both static-synthetic and static-analytic techniques were employed. For the synthesis of binary mixtures using the synthetic technique, gravimetric, volumetric, and manometric methods were performed. Total composition data (T-P-z) were converted to phase equilibrium data (T-P-x-y) using the phase densities and the volume of the equilibrium cell. The uncertainties in the measured variables were estimated using methods outlined by the National Institute of Standards and Technology. The Peng-Robinson equation of state and the Wong-Sandler mixing rule were utilized to model the data, with the Gibbs excess energy for the mixing rule being determined using the Non-Random-Two-Liquid activity coefficient model.