Local and global gas-liquid mass transfer in a micro-packed bed reactor utilizing a noninvasive colorimetric technique

Micro-packed bed reactor (mu PBR) presents great potential in the field of multiphase reactions due to the features of safety and high efficiency. However, the deeper cognition of mass transfer needs to be taken into consideration that is the foundation of reactor design. In this work, local and global gas-liquid mass transfer in the mu PBR were studied utilizing a noninvasive colorimetric technique. In reactor level, the qualitative and quantitative comparisons were conducted; in particle level, liquid flow and mass transfer textures were assessed for the first time. The diversities of local mass transfer characteristics from temporal and spatial dimensions were obtained, and the heterogeneity of local and global mass transfer was revealed. The predicted correlations of kLa in mu PBR with churn flow and pseudo-static flow were established with deviations generally within +/- 18%. This study contributes to improve the understanding of mass transfer and points out the process intensification direction of mu PBR.