Gas Dissolution Process with Chemical Reaction of a Spherical Rising Gas Bubble. 2nd Report. Numerical Analysis for Dissolution Process of a CO2 Bubbles in Strong Alkaline Solution.

Abstract

Gas dissolution process with chemical reaction of a spherical rising gas bubble was investigated numerically. We numerically estimated drag coefficients and Sherwood number of the Stagnant Cap Model by directly solving the Navier-Stokes equation and the convection-diffusion equation when a carbon dioxide bubble dissolves in strong alkaeine solution with chemical reactions. In this analysis, we assume that the chemical equilibrium does not attain near the bubble is and include the chemical reaction term in the convection-diffusion equation. We compared the results with the measured rising speed and dissolution rate. The results reveal that the experimental and numerical results are in good agreement and the dissolution rate with the chemical reactions can be estimated even when the chemical equilibrium does not attain near the bubble. We also observed that the behavior of the bubble returns to that of a fluid sphere after it is closed to that of a solid particle when the concentration of sodium hydroxide is as high as 1 mol/1.