Chapter 1 - Prediction and correlation of physical properties including transport and interfacial properties with the PC-SAFT equation of state

Abstract

This chapter discusses thermodynamic properties and phase equilibria using equations of states. Focus is thereby placed on the perturbed-chain statistical associating fluid theory (PC-SAFT) as a representative for physically-based equations of state. It is a model that is suitable for nonspherical molecules and hydrogen-bonding species or mixtures. Thermodynamic models are regularly used in process simulations to provide properties like enthalpies, densities, pressures, coexisting compositions of mixtures, chemical potentials for chemical equilibria. With modern equations of state, it is also possible to predict interfacial tensions, adsorption isotherms, or contact angles using density functional theory or density gradient theory. Moreover, transport coefficients, such as shear viscosity, thermal conductivity, and diffusion coefficients can be correlated or predicted using excess entropy scaling approaches. This chapter is also concerned with determining meaningful model parameters. The predictive capability of the model, once pure-component and binary interaction parameters were adjusted to a given set of thermodynamic properties, for predicting further properties relevant for a flowsheet simulation is discussed. Group-contribution approaches are presented to address the frequently encountered case of absent experimental data for parameter adjustment.