The critical properties of binary mixtures containing carbon dioxide: Krichevskii parameter and related thermodynamic properties

The values of Krichevskii parameter are given, which are calculated using the data on critical lines for binary CO2 + solute mixtures (n-alkanes, alcohols, refrigerants, inert gases, water, diatomic gases, and other organic compounds), and detailed comparison is made with the results of other researchers obtained using different measuring techniques. In this review, special attention is given to the investigation of the thermodynamic (partial molar properties, Henry’s constant, distribution coefficient, solubility, and others) and structural (direct and total correlation integrals, size of clusters) properties of infinitely dilute solutions (IDS) of CO2 + solute in the vicinity of the critical point (CP) of pure solvent (CO2), for which purpose the values of Krichevskii parameter and the properties of pure solvent are used. The procedure is given of estimating the effect of small impurities on the accuracy of determination of the critical parameters of pure substances. The importance of critical lines (pattern and qualitative form) and of the Krichevskii parameter in the investigation of the scaling behavior (renormalization of the critical behavior) of thermodynamic functions of IDS in the vicinity of the CP of pure CO2 is discussed in detail. The boundaries are determined of regions in the T-x and Δρ-x planes, in which the renormalization is observed of the critical behavior of weakly divergent (isochoric heat capacity) and highly divergent (isobaric heat capacity and isothermal compressibility) properties in CO2 + solute mixtures.