Effect of slug flow on dextran ultrafiltration in ceramic membrane process

The ceramic membrane process has been encountered with a problem of high energy consuming owing to that high crossflow velocities are necessary for the concentration polarization and membrane fouling control. On the other hand, the external loop airlift reactor is widely used in the field of chemical engineering. Thus, the application of air sparging in dextran ultrafiltration with ceramic membrane process is studied at different gas flow rates (Q_G). 87% increase in permeation flux was achieved while filtering 2 g·L^-1 dextran (2×10⁶) solution with the airlift crossflow operation of QG=400 L·h^-1. Hydrodynamics of the gas-liquid two-phase flow was characterized and the flux enhancement mechanism in the case of slug flow in tubular ceramic membrane was discussed.