Study on the Regeneration Path of ZnO Desulfurizer and the Formation Mechanism of Zinc Sulfate
WANG Yuxiao1, YANG Chao2, KOU Jiawei1, SONG Xinrui3, ZHAO Yu3, FAN Huiling1
1. College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan 030024, China;
2. College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
3. College of Chemistry, Taiyuan University of Technology, Taiyuan 030024, China
Abstract：The thermal oxidation regeneration of desulfurizer refers to the process of converting metal sulfides into metal oxides in an oxygen-containing atmosphere while releasing sulfur dioxide(SO2). However, the reaction process of zinc oxide (ZnO) regeneration products has not been systematically studied theoretically, and the main reaction pathway is still unclear. Through the regeneration experiment of ZnO desulfurizer and X-ray photoelectron spectroscopy (XPS) test results, it could be seen that the regenerated solid product of ZnO desulfurizer not only contains ZnO, but also zinc sulfate (ZnSO4), and the formation of zinc sulfate seriously affects the regeneration performance of ZnO desulfurizer. The possible reaction pathways of the regeneration of ZnO desulfurizer and the formation of zinc sulfate at 600 ℃ in oxygen-containing atmosphere were further studied by density functional theory (DFT) method, and the evolution mechanism was analyzed in detail. The results showed that oxygen dissociation adsorption on ZnS(110) surface provided oxygen source for the regeneration process of ZnO desulfurizer. In addition, it was clear that the regenerated products ZnO and gaseous SO2 were mainly obtained by further decomposition of zinc sulfite produced by the reaction of ZnS with oxygen. The by-product zinc sulfate was mainly formed by the further oxidation of zinc sulfite formed by the reaction of ZnS with oxygen during the regeneration of ZnO desulfurizer. Both of them had the same rate-determining step energy barrier of 156.7 kJ/mol. However, the decomposition of zinc sulfite to produce ZnO and gaseous SO2 had a lower energy barrier span (29.7 kJ/mol), so it was easier to produce ZnO and gaseous SO2 during the regeneration of ZnO desulfurizer, rather than zinc sulfate.
WANG Yuxiao,YANG Chao,KOU Jiawei et al. Study on the Regeneration Path of ZnO Desulfurizer and the Formation Mechanism of Zinc Sulfate[J]. Chemical Reaction Engineering and Technology, 2025, 41(3): 370-381.
