Liquid–Liquid Equilibrium for Ternary Systems of 1-Octene + Oxygenated Compounds + Propylene Carbonate: Phase Equilibrium Measurement and Correlation

The production of C8 linear α-olefins via Fischer–Tropsch (F-T) synthesis represents a promising alternative approach. However, purifying α-olefins from F-T synthesis oil presents considerable technical challenges, particularly with respect to the removal of oxygenated compounds. In this work, propylene carbonate (PC) was used as extractant, and 1-pentanol, n-valeraldehyde, 2-hexanone, and ethyl acetate were selected as representative substances of oxygenated compounds. Liquid–liquid equilibrium (LLE) for the binary system of 1-octene + PC, and the ternary systems of 1-octene + 1-pentanol + PC, 1-octene + n-valeraldehyde + PC, 1-octene + 2-hexanone + PC, and 1-octene + ethyl acetate + PC were measured at 298.15, 303.15, and 313.15 K under 101.3 kPa using a jacketed equilibrium cell. The phase diagrams for the ternary systems were classified as Treybal’s Type I behavior. The distribution coefficient (D) and selectivity (S) were calculated to investigate the efficiency of PC as an extractant. Moreover, the temperature dependencies of D and S were investigated in this study. The experimental LLE data were correlated using the NRTL and UNIQUAC models with the interaction parameters optimized. The RMSD values between the experimental and calculated data indicate that these models can accurately correlate the experimental data for the study systems.