Methods and Experimental Techniques to Research Solubility of Gases in Liquids
- PDF / 503,323 Bytes
- 8 Pages / 594 x 792 pts Page_size
- 67 Downloads / 143 Views
METHODS AND EXPERIMENTAL TECHNIQUES TO RESEARCH SOLUBILITY OF GASES IN LIQUIDS A. V. Valyakina, V. N. Valyakin, V. L. Bondarenko, and A. V. Borisenko
UDC 532.77–1, 544.344.2
Experimental methods for determining the limiting activity coefficients that are relevant in the approbation of theoretical approaches to solve the problem of gas solubility in a liquid are described. Traditional methods realized on a single installation are preferred in order to obtain consistent information. The necessity of additional purification of problem samples of the studied substances is demonstrated. A developed and created low-temperature laboratory column is presented, for which the degree of separation in cases with a coil and packed rectification section, as well as the relative fugacity of the pentane — fluorodichloroethane test mixture are found. Based on the conducted experiments, it can be concluded that it is possible to efficiently use both a coil and a packed column for the purification of substances and enhancement of the measuring effect, and the possibility of obtaining reliable data on limiting solubility from the experimental installation. The gravimetric static method for measuring the concentration of the components in binary mixtures is promising for the study of little-researched and rare substances and is applicable in combination with a small volume cell. Keywords: gas solubility in liquid, thermodynamic properties, experimental methods, binary mixtures, rectification column, diluted solutions.
In the simulation of various low-temperature technology and chemical production, when controlling harmful impurities in working fluids and coolants, it is often necessary to determine the solubility of a gas in a liquid. The laws of dilute solutions are usually applied to determine solubility. The nature of real dilute solutions is more complicated than the nature of regular solutions, and lots of data for non-stratifying systems are satisfactorily described (accurately within 1%) separately by different concentration dependences. At limiting dilution (the concentration of components in the liquid phase is X < 0.002–0.005, the molecules of the solute are surrounded by the solvent), this is Raoult’s law for the solvent and Henry’s law for the dissolved component. In the case of highly dilute solutions (X < 0.03) , a linear correction is added to the equations for calculating the parameters of the dissolved component. In dilute solutions (X < 0.2) , the parameters of both components are described by equations containing quadratic corrections to the laws of infinitely dilute solutions [1]. In real solutions, the deviation from ideal behavior is accounted for by a correction function — the activity coefficient γ , i.e., everything that distinguishes a solution from an ideal one (interactions between solvent mol-
ecules, the effect of hydration) is formally considered involving various correlations of experimental data (Margules, Redlich–Kister, and others). These equations should be considered, first of all, as a means for
Data Loading...
