Process Intensification in a HIGEE with Split Packing

Abstract

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 SO2 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.