ON THE MECHANISM OF CO2 ABSORPTION AND DESORPTION

Recent work by Thomas et al. (1982) showed a significant difference in mass transfer rates between absorption and desorption for a CO2-water system in a film flow, and attributed the phenomena to density-driven convection. Our experiment with a flat-surface stirred cell shows no enhancement of oxygen absorption in simultaneous absorption with CO2 under a turbulent flow condition. Also, a comparison of liquid velocities measured extremely close to the gas-liquid interface with a laser doppler anemometer reveals negligible difference between absorption of air and that of CO2. These results indicate that there is practically no detectable density-driven convection in CO2 absorption.