Process Intensification in a HIGEE with Split Packing

Process intensification in rotating packed beds has attracted attention. The intensification is due to the large specific surface area of the packing and high liquid- and gas-side mass-transfer coefficients. Recent studies indicate that the slip velocity between the gas and the liquid in a rotating bed is in the same range as in conventional packed columns. Hence, the intensification is limited to a higher surface area of the packing if the resistance for mass transfer is on the gas side. To overcome this limitation, we proposed a rotating packed bed with split packing to promote the slip velocity as high as 30 m/s. To assess its efficacy, we have measured the mass-transfer coefficients on the gas side using the absorption of SO 2 from air into aqueous NaOH solution and the one on the liquid side by the stripping of oxygen from water into nitrogen. The volumetric mass-transfer coefficients on the gas side and the liquid side, respectively, were in the ranges 35−280× and 25−250× compared to those of packed columns. Correlations for the local mass-transfer coefficients have been presented. The studies indicate a volume reduction of the units by 2 orders of magnitude is feasible.