Theoretical prediction of thermal diffusion in water-methanol, water-ethanol, and water isopropanol mixtures using the PC-SAFT equation of state

In this paper, by combining the PC-SAFT equation of state ( EOS) to the thermal diffusion models for non-associating mixtures, the theoretical prediction of thermal diffusion has been carried out for associating fluid mixtures including water-methanol, water-ethanol, and water-isopropanol. At first, the parameters of the PC-SAFT for water-methanol, water-ethanol, and water-isopropanol mixtures are optimized. Then, by comparing the predictive and experimental values of density and residual partial molar enthalpy in water-methanol, water-ethanol, and water-isopropanol mixtures, we demonstrate the capability of PC-SAFT EOS to reproduce reliable thermodynamic properties in these mixtures with a low to moderate water concentration. Finally, with the thermodynamic properties from the PC-SAFT, several thermal diffusion models available in the literature are extended to binary water-alcohol mixtures including water-methanol, water-ethanol, and water-isopropanol. The Firoozabadi model combined with the PC-SAFT EOS has shown an effective capability for predicting mixtures with a low to moderate water concentration.