Experimental Investigation and Correlation of Liquid-Side Mass Transfer in Pilot-Scale Rotating Packed Beds

Mass transfer in rotating packed beds (RPBs) is intensified by centrifugal force compared to conventional columns. The resulting significant reductions of equipment size may be advantageous, e.g., for off-shore applications or retrofits. Volumetric liquid-side mass transfer coefficients k_La_e are one of the key parameters for modeling. A database of k_La_e for pilot scale RPBs, i.e., with radial bed lengths significantly greater than 100 mm, was compiled from the literature and supplemented by own water deoxygenation experiments. Available correlations for k_La_e, which are based on lab-scale RPBs mostly with bed lengths below 60 mm, could not adequately describe the data. Hence, a new correlation was developed, which is capable of describing the majority of the data within ±30%. The correlation incorporates effects of liquid as well as gas flow rate and captures the local maximum in separation efficiency, which was observed at intermediate centrifugal accelerations.