Modeling and simulation of nitrogen oxides adsorption in fluidized bed reactors

Abstract

NOx adsorption in a fluidized bed reactor was investigated by both experiment and simulation. In the experiment, NOx adsorption was tested at different temperatures, inlet NO concentrations and gas velocities. The experimental breakthrough curves were then used to tune the model, which consists of three mass balance equations for solid phase, gas in the dense phase and gas in the bubble phase, respectively. Adsorption isotherms were obtained separately from the fixed bed adsorption experiment with the same catalyst. Bed expansion was obtained experimentally in a fluidized bed with the same catalyst particles. The model showed good agreement with the experimental breakthrough curves and was used to simulate NOx concentration profiles in each phase along the reactor height. Simulation results showed that the NOx adsorption performance in fluidized beds could be improved by reducing particle size and the superficial gas velocity. The model was also applied to investigate the NOx adsorption performance in the adsorption zone of an internal circulating fluidized bed deNOx reactor.