Simultaneous liquid–liquid and vapour–liquid equilibria predictions of selected oxygenated aromatic molecules in mixtures with alkanes, alcohols, water, using the polar GC-PC-SAFT

International audiencePhase equilibria of oxygen-bearing aromatic compounds, hydrocarbons and water mixtures are of essential interest in many processes using feeds originating from biomass. The strong non-ideal thermodynamic behavior of these systems sometimes results in immiscibility with both water and alkanes.To address this problem, the GC-PPC-SAFT equation of state [Tamouza et al., 2004; Nguyen-Huynh et al., 2008a] is extended to some selected components: phenol, alkyl-phenols, alkyl-benzoates, benzaldehyde and anisole. However, as in these multifunctional compounds, the proximity of polar functional groups may result in a lack of transferability of the parameters from the monofunctional homologous species, some parameters have been adapted in view of physical arguments. Next, liquid–vapour and liquid–liquid equilibria of mixtures with n-alkanes were evaluated, using a predictive method for the binary interaction parameters (kij) [Nguyen-Huynh et al., 2008b]. Finally, mixtures with other associating compounds, as alcohols and water have also been considered.In all cases, both correlations and predictions are qualitatively and quantitatively satisfactory. The relative deviations obtained on bubble pressure of vapor–liquid equilibria are 4–8%, that is comparable to those obtained on previously investigated systems