ABSTRACT
The principal objective of this chapter is to present thermodynamic principles essential to understanding the supercritical fluid extraction (SCFE) technique and the interdependence of relevant process parameters. In addition, systematic calculation procedures and predictive thermodynamic models are reviewed for quantitative understanding of the process, selection of the process parameters, and design, operation and optimization of the SCFE systems. Knowledge of phase equilibrium behavior and generation of phase equilibrium data, such as solubility, distribution coefficient, and selectivity of separation of the extractables in the supercritical fluid (SCF) solvent, are required at the extraction and separation conditions. In order to fully appreciate the phase diagrams and theoretical developments presented in this chapter, the reader may require familiarity with the basic concepts of molecular thermodynamics. Nevertheless, for brevity, a quick glance at the trends of thermodynamic property variations will surely give some insight into the background principles. However, subsequent chapters have been written with the general reader in mind and the materials discussed therein may be understood without recourse to the advanced concepts presented in this chapter.
