Three-component mixtures extractive, diagrams

As a consequence of these restrictions, separation of binaiy mixtures by extractive distillation corresponds to onfy two possible three-component distillation region diagrams, depending on whether the binary mixture is pinched or close-boiling (DRD 001), or forms a minimumboiling azeotrope (DRD 003). The addition of high-boiling solvents... 

Diagrams of Extractive Reversibie Distiiiation for Three-Component Mixtures 97... 

Diagrams of Extractive Reversible Distillation for Three-Component Mixtures... 

Extraction involves the use of systems composed of at least three substances, and although for the most part the insoluble phases are chemically very different, generally all three components appear at least to some extent in both phases. A number of different phase diagrams and computational techniques have been devised to determine the equilibrium compositions in ternary mixtures. In what follows, A and B are pure, substantially insoluble liquids, and C is the distributed solvent. Mixtures to be separated by extraction are composed of A and C, and B is the extracting solvent. 

When both components of a binary gas or vapor mixture are separately adsorbed to roughly the same extent, the amount of either one adsorbed from the mixture will be affected by the presence of the other. Since such systems are composed of three components when the adsorbent is included, the equilibrium data are conveniently shown in the maimer used for ternary liquid equilibria in Chap. 10. For this purpose it is convenient to consider the solid adsorbent as being analogous to liquid solvent in extraction operations. However, adsorption is greatly influenced by both temperature and pressure, unlike liquid solubility, which is scarcely affected by pressure under ordinary circumstances. Equilibrium diagrams are consequently best plotted at constant temperature and constant total pressure, and they are therefore simultaneously isotherms and isobars. 

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