ABSTRACT
Supercritical fluid technology has allowed significant improvements in several industrial processes and there are still many opportunities for further applications in new emergent areas. To optimize the conditions at which supercritical fluid processes take place, a precise characterization of this region is needed; however, the particular behavior and singularities observed in the properties of compounds and their mixtures in the near-critical region makes the study of this region a challenge from any modeling and experimental approaches. This chapter focuses on fundamentals of the supercritical fluids. It deals the singularities found in the critical region of fluids as a consequence of the inhomogeneities in the density (and composition for the case of mixtures) and how to take them into account in a modeling approach. The theory is illustrated with the incorporation of a crossover term, based on renormalization theory,
into a molecular-based equation of state (soft-SAFT) and applied to some experimental systems.
