Modeling the absorption mass transfer in a foaming device regarding changes in the concentration of absorbable gases in liquid

Abstract

A physical and mathematical model of the absorption mass transfer in a foaming device between a liquid and a gas—vapor mixture has been developed. The model accounts for the changes in temperature and chemical composition of the liquid phase of a foam layer in dynamics and kinetics of the entire absorption process. In this model, it is assumed that the absorption processes mostly occur in bubbles as they are formed in apertures of the gas distribution grid of a foaming device. The calculations of heat and mass transfer between water and a mixture of moist air and carbon dioxide as well as a mixture of moist air and sulfur dioxide are performed. It has been demonstrated that the intensity of the extraction of absorbable gas components from a gas—vapor mixture is limited by their concentration in an absorbing liquid. A decrease in the degree of extraction of absorbable components with an increase of the volumetric flow rate of the absorbable gas is confirmed by the calculations. This decrease is due to the effect that the increase in the concentration of the absorbable components has on the absorption intensity. The effect is especially pronounced for poorly soluble gases. The results of the calculations performed with the proposed model demonstrate that the efficiency of carbon dioxide extraction with water increases with an increase in its initial concentration. These results are in good agreement with the experimental data.