Numerical studies for the CO₂ capture process in a fluidized-bed absorber

The dry sorbent carbon dioxide capture technology is an efficient method to remove CO₂ from flue gases. In this work, a multiphase hydrodynamic model with a sorption reaction of CO₂ is developed and a two-dimensional computational fluid dynamics (CFD) simulation is carried out. The potassium carbonates are used as dry sorbents. A revised multi-scale interphase drag coefficient model is incorporated into the two-fluid model to consider the influence of clusters. The non-uniform distribution of the solid concentration and CO₂ concentration is captured in the reactor. The core-annular regime can be found in the reactor. Predicted results are in good agreement with experimental results. The effects of operating conditions and parameters on the CO₂ removal are evaluated. Simulated results indicate that reducing the inlet gas velocity can prolong the residence time of sorbents and enhance the overall CO₂ removal. Improving the particle size and solid inventory will lead to an increase of CO₂ removal to some extent.