Effect of honeycomb inserts on axial mixing in bubble columns

The axial mixing characteristics of a pilot-scale column were investigated with the objective of identifying means to mitigate the extent of axial mixing that adversely affects its performance. The effect of using honeycomb inserts on column hydrodynamics was thus investigated under a wide range of operating conditions. The experimental results, obtained using the dynamic response method, were analysed using three axial mixing models. The use of honeycomb inserts was found to increase the interfacial area of contact by up to 120% but the axial dispersion coefficient is adversely impacted. The higher axial dispersion coefficient obtained at higher superficial liquid velocities should, however, be balanced against the benefits resulting from the larger interfacial areas and the ability to use columns of smaller diameters.