An internal circulation rotating packed bed for green chemical engineering: structure optimization of liquid lifter

The internal circulation rotating packed beds (IN-RPBs) have been widely used in multiphase systems. However, its key component's liquid lifter suffers from the liquid lifting rate (Q_L), limiting the micro-mixing and mass transfer efficiency. In this study, the fluid motion inside the conventional lifter was theoretically analyzed. Based on the above theoretical analysis, a new impeller-equipped lifter was innovatively designed for the IN-RPB to enhance Q_L. Experiment results showed that Q_L was increased by 100% at 1400 r/min within the impeller-equipped lifter. Numerical simulations demonstrated that the flow field was altered in the impeller-equipped lifter, promoting the generation of vortices, thereby increasing the Q_L. Mass transfer experiments demonstrated that the structure optimization of the lifter led to a 60% increase in the gas-liquid volumetric mass transfer coefficient (k_La). This study provides a basis for the industrialization of the IN-RPB with an impeller-equipped lifter.