Phase Diagrams in Chemical Engineering: Application to Distillation and Solvent Extraction

Christophe Coquelet (1) , Deresh Ramjugernath (2)

1 CEP/Fontainebleau
2 Thermodynamics Research Unit

A phase diagram in physical chemistry and chemical engineering is a graphical representation showing distinct phases which are in thermodynamic equilibrium. Since these equilibrium relationships are dependent on the pressure, temperature, and composition of the system, a phase diagram provides a graphical visualization of the effects of these system variables on the equilbrium behavior between the phases. Phase diagrams are essential in the understanding and development of separation processes, especially in the choice and design of separation unit operations, e.g. knowledge about high pressure phase equilibria is essential not just in chemical processes and separation operations, but is also important for the simulation of petroleum reservoirs, the transportation of petroleum fluids, as well as in the refrigeration industry. In order to utilize the knowledge of phase behavior it is important to represent or correlate the phase information via the most accurate thermodynamic models. Thermodynamic models enable a mathematical representation of the phase diagram which ensures comprehensive and reproducible production of phase diagrams. The measurement of phase equilibrium data is necessary to develop and refine thermodynamic models, as well as to adjust them by fitting or correlating their parameters to experimental data. Generally the measurement of phase equilibria is undertaken using two categories of experimental techniques, viz. synthetic and analytic methods. The choice of the technique depends on the type of data to be determined, the range of temperatures and pressures, the precision required, and also the order of magnitude of the phase concentrations expected.

Mots clés: Phas diagrams; distillation; Solvent extraction

Domaines: Génie des procédés

Christophe Coquelet, Deresh Ramjugernath. Phase Diagrams in Chemical Engineering: Application to Distillation and Solvent Extraction. Zeeshan Nawaz and Shahid Naveed. Advances in Chemical Engineering, Intech, 23 p., 2012, 978-953-51-0392-9. ⟨10.5772/33632⟩. ⟨hal-00877007⟩