Reactive mixing in rotating packed beds: On the packing’s role and mixing modeling

Abstract

Rotating packed beds (RPBs) are some of the most promising modular and intensified apparatuses for continuous mixing of large liquid streams. In this study, the influence of packing depth, liquid distribution, and volumetric ratio on mixing processes are for the first time investigated in detail. It is shown that the packing seems to be more important at low volumetric ratios and an overlapping liquid distribution, but less important – or even interfering with fast mixing – at higher volumetric ratios and an opposite liquid distribution. Based on these findings, a promising novel type of HiGee equipment is suggested, that is particularly suitable for fast mixing at high volumetric ratios. Additionally, the linear and the exponential approaches of the incorporation model, as well as of the Interaction-by-Exchange-with-the-Mean (IEM) model, are investigated for their suitability to accurately describe the mixing process. On the basis of revised kinetics for the Dushman reaction, micromixing time parameters in the order of 10−1 ms to 101 ms are obtained for the investigated operating conditions.