CFD simulation of gas pressure drop in porous packing for rotating packed beds (RPB) CO2 absorbers

Abstract

Rotating packed bed (RPB) is a promising technology which can be used to intensify mass transfer in absorption processes. A better understanding of fluid dynamics is crucial to fill the gap in fundamental knowledge. Raising awareness on new technology and creating rules for process design and control are also very important. The experimental investigation of fluid in rotating beds is a very complex and difficult issue. What is more, the knowledge of the phase behavior in an RPB device is still insufficient. Therefore, an CFD (computational fluid dynamics) simulation is proposed as a tool for the study of gas phase flow inside porous packing. This study presents a three-dimensional numerical model for two fluid models: k-ε and RNG k-ε, for predicting dry pressure drop. The obtained simulation outcome was compared with the experimental results. The experimental dry pressure drop for porous packing was investigated for rotational speed in the range from 150 rpm to 1500 rpm and compared to the results from the CFD model. The comparison between the experimental and simulation results indicates very good consistency for the entire range of the rotational speed of interest. CFD modelling is recognised as an adequate tool leading to the better understanding of gas phase behaviour inside an RPB, filling an essential gap in our knowledge of the hydrodynamics of rotating packing, which allows to improve the design and performance of the process in RPB in terms of minimizing energy and material consumption.