Computational investigation of solid sorbent carbon dioxide capture in a fluidized bed reactor

• Hydrodynamics and species concentration are non-uniform in the adsorption reactor.
• Adsorption reactions mainly take place in the bottom bubbling fluidized bed.
• CO2 capture efficiency decreases with increasing the initial CO2 content and gas velocity.
• High reaction temperature and large sorbent circulation rate are preferable to CO2 capture.

This paper presents a computational investigation of the hydrodynamics and the reaction behavior in a fluidized-bed CO2 capture reactor. Integrating CO2 adsorption kinetics with the two fluid model, a multiphase flow and reaction model is established. Computational fluid dynamics analyses are performed, and the influences of various operating conditions are evaluated. The results indicate that velocity, volume fraction and species concentration of the gas and particle phase are significantly nonuniform inside the fluidized-bed reactor. Adsorption reaction mainly takes place in the bottom bubbling fluidized bed. CO2 capture efficiency decreases with increasing the initial CO2 content in the flue gas. A low gas velocity of 0.13–0.16 m/s leads to a higher CO2 capture efficiency. High reaction temperatures and large sorbent circulation rates are beneficial to CO2 removal in the current reactor.

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