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.