Modeling and optimization of the moving granular bed for combined hot gas desulfurization and dust removal

The development of the moving granular bed process for combined removal of particulates and gaseous pollutants is an attractive engineering solution for hot gas cleanup due to its advantages of process compactness and lower cost in comparison to separated process steps. The key to achieve the best performance of the combined process is to match the different unit operations. This work aims to simulate the cross-flow moving granular bed for combined hot gas desulfurization with dust removal and to realize the process optimization. Based on the hydrodynamics equations, particulate collecting equations and desulfurization equations, a mathematical model was established to simulate the performance of the combined process. The simulating results show that the combined process has advantages to improve the desulfurization efficiency and the sorbent conversion in comparison with the single desulfurization process because deposited dust may influence the gas flow pattern in the bed. The method based on the analyzing operating curves was proposed for the reactor design and the optimization of operating variables. The appropriate parameters can be determined according to an operating characteristic diagram given by the model.