Activity Coefficient Model Fitting for Binary Mixtures

A model fitting for Activity Coefficients of Binary Mixtures given Vapor-Liquid Equilibrium (VLE) Data

NOTE: Requires Optimization toolbox for the wilson.m, nrtl.m, margules2suffix.m and margules4suffix.m to work

It includes the 2-parameter models Margules, Van Laar, and Wilson for the excess Gibbs' energy, and consequently, for the activity coefficients. VLE data for a binary mixture must be available. They are stored in the variables:

x1-equilibirum liquid mol. frac of component 1

y1-equilibirum vapor mol. frac of component 1

P-system pressure

Before running the wilson.m, van laar.m, and margules.m, make sure these variables are loaded. The saturation pressures of the pure species must also be provided. The programs will calculate model parameters, the root mean-square for performace comparison, and then plots the system pressure base on the model and compared with the given experimental data. The equations used for both programs are all based on the ones presented by Smith, Van Ness, Abbott, and Swihart in their book "Introduction to Chemical Engineering Thermodynamics (8th ed.)." The sample problem in the documentation also came from this book.

For the UNIQUAC, provide the structural and binary interaction parameters, as well as the Antoine Coefficients for the two components. The equations used are from Prausnitz, Lichtenthaler, and Gomes de Azevedo in their book "Molecular Thermodynamics for Fluid-Phase Equilibria (3rd ed)."