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 βL·ae 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 ae 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 ae are in good agreement with the calculation based on the new model. It is therefore possible to separate the product βL·ae into liquid phase mass transfer coefficient βL and effective interfacial area ae.

Research highlights
► A new model for the prediction of mass transfer performance is presented.
► The model combines hydraulics and mass transfer in one physical concept.
► It allows calculation of liquid side mass transfer for all kinds of random packings.