Model for the prediction of liquid phase mass transfer of random packed columns for gas-liquid systems

The following work presents a new, generally applicable model for description of the mass transfer in the liquid phase for packed columns filled with random dumped non-perforated and lattice-type packing with size between 12 and 90 mm for gas-liquid systems in operating range up to flooding point. The new equation for evaluation of the volumetric mass transfer coefficient in the liquid phase beta(L).a(e) was derived on the basis of the assumption that liquid flows down in packed bed mainly in the form of droplets and that effective interfacial area a(e) depends on hold-up in packed bed. The relation between the fluid dynamics and the mass transfer is shown based on the channel model with a partly open structure. The experimentally derived values for the effective mass transfer area in different types of random packings a(e) are in good agreement with the calculation based on the new model. It is therefore possible to separate the product beta(L).a(e) into liquid phase mass transfer coefficient beta(L) and effective interfacial area a(e). (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.