Impact of structured packing on bubble column mass transfer charasteristics - Part 1. Backmixing in the liquid phase

Axial liquid phase dispersion coefficient in a concurrent up-flow bubble co lumn packed with Sulzer structured packing (SMV 16) was measured by means o f the stationary method in a region between the homogeneous and heterogeneo us hydrodynamic regimes. Column had a 0.14 cm ID and 1.885 m total packing length. Tap water was used as liquid phase and oxygen as gas phase. KCl was used as a tracer. For comparison experiments were also performed in the sa me column but without packing. The gas holdup was determined simultaneously . An increase in the measured E-L values with the gas velocity was observed in both packed and non-packed columns, while the liquid flow rate only sli ghtly raised the axial dispersion coefficient when the column was packed. T he presence of structured packing reduced the liquid axial dispersion coeff icient for nearly 50% at low gas velocities, whereas there was only 20% red uction found at higher velocities.