Rotating packed beds for post-combustion CO2 capture: Holistic process modeling and plant design
Babis Kantouros, Panagiotis Kazepidis, Αθανάσιος Ι. Παπαδόπουλος, Panos Seferlis
Abstract
• Custom Rotating Packed Bed model enables intensified CO 2 capture simulation. • Model validation achieves < 4 % deviation across 35 experimental cases. • Model tested on industrial capacity flue gas from quicklime plant. • Reported internal desorber behavior in RPBs for the first time. • Identified key indicators driving RPB design. Rotating Packed Beds (RPBs) are receiving attention for the intensification of solvent-based, post-combustion CO 2 capture processes. While accurate models are essential for scaling-up RPB systems, the few existing studies focus on standalone RPB absorbers and rarely on RPB desorbers or integrated flowsheets. In the latter cases model-based insights for equipment-internal, flow or transport phenomena have not yet been reported, whereas the existing equipment models focus on validation based on lab-scale infrastructure. This work develops and validates an RPB model for both absorption and desorption, which serves as a base for designing an integrated CO 2 capture process flowsheet using aqueous monoethanolamine (MEA) solution. The model is founded on first principles for steady-state conditions and employs two-film theory for mass transfer as well as a flexible thermodynamic representation. It captures the radial profiles of CO 2 loading, temperature, and pressure drop in the absorber and presents, for the first time, CO 2 desorption profiles in both gas and liquid phases. The model is validated against four experimental datasets, covering 24 absorption and 11 regeneration cases under varying operational conditions. The results show high accuracy, with average deviations up to 4%. Design and operational analyses are performed for an industrial capacity flue gas stream from a quicklime plant targeting recovery of 130 tn CO 2 /day. The analysis illustrates internal RPB process profiles in the integrated flowsheet and quantifies the impact of rotational speed, liquid-to-gas ratio, lean solution temperature, and inlet gas pressure on their dimensions. It also provides insights on the capture efficiency and regeneration energy.