Prediction of Vapor–Liquid Equilibria of the Levulinic Acid + Water + Ethyl Acetate Ternary Mixture via Monte Carlo Simulations

Abstract Vapor–liquid equilibria data for the levulinic acid, water, and ethyl acetate ternary mixture have been predicted via Gibbs ensemble Monte Carlo simulations in the isothermal isobaric ensemble at 101.325 kPa and temperatures from 370.15 to 400.15 K. We find that as the temperature increases from 370.15 to 400.15 K, mole fractions of ethyl acetate and water in the liquid phase decrease, enriching the liquid phase with levulinic acid. The trend in partition coefficient (K) values is Kwater > Kethyl acetate > Klevulinic acid, and Klevulinic acid is significantly lower than unity, indicating preference for the liquid phase for levulinic acid, corresponding to the highest values of Gibbs free energy of transfer from liquid to vapor phase. The liquid structure has been analyzed using the site–site intermolecular RDFs, which show that the purity of levulinic acid increases with temperature. Further, the extent of hydrogen bonding between levulinic acid and ethyl acetate via H9–carbonyl oxygen of ethyl acetate (O1) interactions is decreasing with an increase in temperature and is lowest at 400.15 K, attributed to a decrease in the mole fraction of ethyl acetate in the liquid phase (as ethyl acetate vaporizes along with water) and increasing purity of levulinic acid.