(718b) 3D CFD Simulation of Two-Phase Flow in a Rotating Packed Bed (RPB) for CO2 Capture: Sensitivity of Pressure Drop and Liquid Pool to Operating Conditions

Carbon capture processes are very investment intensive, so this is a major driver for technical innovation. Process intensification in the field of gas-liquid contacting may lead to the downsizing of one order of magnitude (if not more) of the structured packing volume required to contact the fumes and the solvent in charge of extracting CO2. Rotating packed beds (RPB) appear to be one of the promising process intensification technologies [1] as it increases both mass transfer and mixing efficiency.

The aim of this study is to contribute to the understanding of the complex two-phase flow in a RPB in order to improve the design of CO2 capture facilities to reduce greenhouse gas emissions, in particular from industrial combustion flue gases.

Steady 3D CFD (Computational Fluid Dynamics) simulations were carried out using ANSYS^® FLUENT^® with a two-phase liquid-gas Eulerian approach. The packing is modeled as an isotropic porous bed zone. The liquid phase is assumed to be described as mono-sized droplets using an Euler-Euler modelling.

The previously developed CFD model [2] seems to reproduce properly the global features of the flow. Nevertheless, the range of the operating conditions has to be extended. In this work, the rotation speed (w), as well as the liquid mass flow rate (Q_L) and physical properties were varied to investigate the sensitivity of flow field, pressure drop and liquid pool at the bottom of the RPB (Figures 1 and 2).

Besides, different geometries were also compared.

References

[1] “Mass Transfer in a Rotating Packed Bed: A Critical Review”, Z. Wang, T. Yang, Z. Liu, S. Wang, Y. Gao, M. Wu, Chemical Engineering & Processing: Process Intensification, 139, 2019.

[2] P. Béard, V. Penin, P. Alix, "Towards 3D CFD simulation of two-phase flow in a rotating packed bed (RPB) for CO2 capture”, CHISA (International Congress of Chemical and Process Engineering), virtually, 2021.