Enhancement effect of Ce addition on Mn3O4/diatomite sorbent for moderate-temperature flue gas desulfurization

Abstract

To improve the performance of single manganese oxide (MnOx) for moderate-temperature flue gas desulfurization, a series of cerium (Ce) modified Mn3O4/diatomite sorbents with different Ce/Mn molar ratios are prepared by the sol–gel method. Results show that the desulfurization performance of single Mn-based sorbents is significantly enhanced by the addition of CeO2. The strong redox couples are formed between CeO2 and Mn3O4 to further improve the desulfurization activity of sorbents. Moreover, the agglomeration of active component on the surface of carrier is restrained by the designed CeO2-Mn3O4 binary oxides with a micro-reticulated framework to provide more active sites, which is conducive to improving the utilization of active component. The M2C2D6 sorbent is verified as the most outstanding sorbent with the desulfurization efficiency of 96 %, sulfur capacity of 221 mg-SO2/g-sorbent and breakthrough time of 251 min. To master the reaction path and control the types of products, the mechanism of desulfurization-regeneration of M2C2D6 is systematically elaborated by the combination of thermodynamic calculation and product calibration. The above results further prove the effectiveness of Ce doping in the enhancement of desulfurization performance of single Mn-based sorbents for moderate-temperature flue gas desulfurization.