Optimization of activity coefficient models to describe vapor–liquid equilibrium of (alcohol + water) mixtures using a particle swarm algorithm

A method to model the vapor–liquid phase based on a particle swarm algorithm is developed in this study. Two activity coefficient models (UNIQUAC and NRTL) were optimized with particle swarm optimization (PSO), and used to describe the isobaric vapor–liquid equilibrium of fifteen binary mixtures containing alcohol + water. The results were compared with the Levenberg–Marquardt algorithm, and show that the PSO algorithm is a good method to correlate and predict the vapor–liquid equilibrium of this type of system.