PC-SAFT predictions of VLE and LLE of systems related to biodiesel production

Biodiesel has risen as a potential energy carrier and alternative biofuel. Understanding the phase equilibria of systems formed by alkyl esters of fatty acids and alcohols is of great interest to biodiesel industry. Predictive thermodynamic models are essential for process simulators used for plant design and optimization. The Perturbed Chain form of the Statistical Associating Fluid Theory (PC-SAFT) is used in this work to predict the thermophysical properties, vapor-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) of binary and ternary systems related to biodiesel processing. The PC-SAFT was able to accurately predict the VLE and LLE of mixtures involving different types of biodiesel. The phase behavior prediction for mixtures investigated in this work seems to be not greatly influenced by the dipole-dipole. Furthermore, the phase behavior of binary and ternary mixtures of biodiesel was successfully predicted using a transferable cross-association parameters approach.