GAS-LIQUID MASS-TRANSFER IN GAS-LIQUID-LIQUID DISPERSIONS

Gas-liquid mass transfer measurements by dynamic absorption in a stirr ed auto-clave have been performed successively in various single liqui d phases and in liquid-liquid mixtures. Data were interpreted through a pseudo-homogeneous model based on Danckwerts surface renewal theory and on continuous liquid-liquid equilibrium due to very fast liquid ma ss transfer. As a major result, the volumetric mass transfer coefficie nt k(1)a is clearly increased when adding a dispersed organic phase, w ith a clear maximum at 3 to 4% of organic volume fraction. Higher enha ncement (up to 70%) was performed at high stirring speed and with hydr ogen better than with carbon monoxide as the dissolving gas. (C) 1997 Elsevier Science Ltd.