Study on carbon dioxide capture in circulating fluidized bed reactors

The dry sorbent technology for carbon dioxide capture is a common and efficient method to remove CO₂ from flue gases. On the basis of two-fluid model, the energy minimization multi-scale (EMMS) model is present by considering the effect of clusters to calculate the inter-phase drag coefficient. The potassium carbonate pellets are used as dry sorbents. Combined with chemical reaction kinetics theory, the reaction model is present for the process of sorption reaction of CO₂. The simulation based on the experiment by YI et al. is performed in circulating fluidized bed absorbor for carbon dioxide capture process. The predicted results are in a better agreement with experimental results by EMMS method. The simulation results also give the distribution characteristics of solid concentration, CO₂ concentration and solid temperature. The effects of water vapor content, reactor height and operating pressure on CO₂ removal are investigated. The results indicate that CO₂ removal will be enhanced with increasing the water vapor content and reactor height, and decreasing the operating pressure.