Phase Equilibrium Measurements and Thermodynamic Modeling of the Systems (CO2 + Ethyl Levulinate) and (CO2 + Levulinic Acid)

Abstract

This work reports phase equilibrium measurements and thermodynamic modeling of the binary systems (CO2 + ethyl levulinate) and (CO2 + levulinic acid). Each composition was carried out in a high-pressure variable-volume view cell at temperatures ranging from 303.15 to 353.15 K and with CO2 mole fraction ranging from 0.4002 to 0.9751 for the system (CO2 + ethyl levulinate) and from 0.4083 to 0.9930 for the system (CO2 + levulinic acid). Under these conditions, only vapor–liquid phase transitions were observed. The experimental data were modeled with the Peng–Robinson cubic equation of state with the Boston–Mathias alpha function (PR-BM) and using the van der Waals quadratic mixing rule. The results showed that the experimental data of the system (CO2 + ethyl levulinate) were adequately represented by the thermodynamic model with a unique set of binary interaction parameters, which were fitted from all isotherms. Whereas the experimental data of the system (CO2 + levulinic acid) were only adequately represen...