Correlation of solid—liquid and vapor—liquid equilibrium data for polynuclear aromatic compounds

Abstract

Solid—liquid equilibrium (SLE) data were measured for five solutes in cis-decalin from ambient temperature to the melting point of the solutes. These SLE data plus our previous data for the same solutes in tetralin were used to determine experimental activity coefficients and interaction parameters using the UNIQUAC model. This set of interaction parameters gave a good representation of the experimental SLE data but were not satisfactory generally for predicting vapor—liquid equilibria for these systems. However, in an alternative approach, the solid solubility data and one vapor—liquid equilibrium point for each isotherm from previous work were used to determine another set of binary interaction parameters in the UNIQUAC model using a gradient-based search technique. The calculated values of parameters were used then to predict the vapor—liquid equilibrium for that system. It was found that the solid solubility and one vapor—liquid equilibrium data point were sufficient to predict the vapor—liquid equilibrium curve for the binary systems studied. Finally, all the solid solubility and vapor—liquid equilibrium data were combined to determine global parameters for the ten binary systems using the UNIQUAC model.