Prediction of phase equilibria and transport properties in carbon-dioxide expanded solvents by molecular simulation

Abstract

Abstract We review our recent work on the calculations of the phase equilibrium and transport properties in carbon-dioxide (CO2) expanded liquids (CXLs) via Monte Carlo and molecular dynamics (MD) simulations. Gibbs ensemble Monte Carlo simulations were performed to determine the volume expansion, the pressure–composition and pressure–density phase diagrams for CO2 expanded acetonitrile, acetone, methanol, ethanol, acetic acid, toluene and 1-octene. MD simulations were conducted to compute the translational diffusion coefficients, rotational correlation times and shear viscosities in CO2 expanded acetonitrile. Potential parameters for the pure component together with standard mixing rules were used to describe the interactions between the mixture components. A good agreement between simulation results and available experimental data is achieved. The simulation results for the volume expansion, the pressure–composition and pressure–density phase diagrams were in some cases superior to the Peng–Robinson (PR) equation of state correlations, showing the ability of molecular simulation to predict CXL properties for their use as solvent media in engineering processes. Keywords: Molecular-dynamics simulationMonte-Carlo-simulationCO2-expanded liquidsVapor-liquid-equilibria