Gas-liquid Mass Transfer Enhancement in a Surface Aeration Stirred Slurry Reactors

This paper postulates four possible mechanisms for the enhancement of gas-liquid (G-L) mass transfer in slurry reactors: (1) hydrodynamic effect, (2) shuttling, (3) stabilization of bubbles, and (4) reaction enhancement. Mass transfer and reactivity experiments using two different slurry systems and two different Pd-catalysed reactions, i.e., oxidation of glucose (aqueous phase) and hydrogenation of a-methyl styrene (organic phase), with both hydrophobic carbon and hydrophilic silica catalyst supports, were performed in a laboratory scale surface aeration reactor with a flat gas-liquid interface. Physical and reaction enhancement have been distinguished successfully. The experimental results show that the level of catalyst support hydrophobicity has a strong influence on the rate of mass transfer.