Effects of surface-active substances on gas holdup and gas-liquid mass transfer in bubble column

Abstract

The effects of surfactants and antifoam agent on the gas holdup ε, the liquid-phase mass transfer coefficient kLand the volumetric liquid-phase mass transfer coefficient kLa in a bubble column were studied experimentally. An addition of surfactants such as n-alcohols to water increases ε and decreases kL, and an addition of antifoam agent to water decreases ε, kLand kLa. However, the degree of reduction of kLvalue by an addition of surfactant to water is lower for bubble swarms in a bubble column than that for a single bubble in stagnant liquid. Based on these observations, the previous model for estimating kLof a single bubble in aqueous solutions of surface-active substance is modified so as to be applicable to the estimation of kLfor bubble swarms in a bubble column. © 1985, The Society of Chemical Engineers, Japan. All rights reserved.