ABSTRACT
Studies on gas solubility were initiated long before development of physical chemistry as a separate branch. In 1803, one of the principal laws in this branch, the Henry law, was discovered. However, fulfillment of ideal gas solubility laws for real gases is most likely an exclusion rather than a rule, and somewhat satisfactory correlation between experimental and calculated data is observed only for noninteracting substances at low concentrations. The effect of solvent origin on solubility is especially complex. In 1948, A.I. Brodsky wrote: "In the most cases, gas solubility strictly depends on the solvent origin... The question about the solvent origin effect on solubility is complicated and still not quantitatively solved. This is associated with the absence of quite clear and general ideas about intermolecular forces acting in solutions and defining solubility, and the absence of total theory of liquids" [1]. In recent 50 years, despite occurrence of some experimental works on the study of real gas solubility and generalizing theoretical creations, the situation did not generally change: "Comparison of various gases solubility under the same conditions does not allow setting any simple, general regularity yet" [2]. This is because at present, any universal theory of solutions is absent [3], though some successful steps were made in this direction. The following achievements should be mentioned here: Hildebrand's theory of regular solutions [4], works by Pierotti [5], Deals and Derr [6], a series of developments by Prausnitz et aL [7], development of various calculation forms of Gibbs-Duhem equations, VanLaare, Margules, Wilson formulae, NRTL, UNIFAC, UNIQUAC, etc. Remember that basically, these equations, designed for calculation of component activities in the system (y°)9 are also applied to calculation of extraction processes.
