ANALYSIS OF EFFECT OF GAS–LIQUID INTERFACIAL DISTURBANCE ON MASS TRANSFER PERFORMANCE

Abstract

In order to study the mass transfer phenomena for water vapor absorbed by triethylene glycol (TEG) solution and to elucidate effect of interfacial disturbance on absorption performance, the interfacial phenomena for water drop instilling on the surface of TEG solution and mass transfer process were observed and operated in this study. Besides liquid and gas flow rates, the interfacial disturbance can also affect the mass transfer performance in the absorption system with continuous liquid phase, and the advanced mass transfer phenomena must be discussed from the interface of matter. Therefore, the surface tensions of desiccant solutions were measured to analyze the disturbed phenomena of water drop instilling on the surface of TEG solution. Since the Marangoni-Index (MI) means the maximum surface tension difference on the surface of liquid layer, the values of MI were calculated and compared with the mass transfer performance of packed-bed absorber. Generally speaking, the interfacial disturbance, resulted from the surface tension difference, would promote the contacting area of gas and liquid phases. The observation of water drop instilling on surface of TEG solution found that the interfacial disturbance existed between water drop and TEG solution, and the interfacial instability was found in the peripheral region of the water drop. On the other hand, the values of MI were increased by the increased TEG concentrations, and it can be deduced that the surface tension effect should be significant in the higher concentration of TEG solution and the interfacial disturbance would be heavier above 95 wt.% TEG solutions. Finally, the absorption performance for 95 and 96 wt.% TEG solutions were much larger than that of 90 and 88.6 wt.% TEG solutions in the operation of packed-bed absorber.