Study of Hg0 removal characteristics on Fe2O3 with H2S

A series of elemental mercury removal experiments were performed at different temperatures to explore the elemental mercury oxidation efficiency on α-Fe 2 O 3 and γ-Fe 2 O 3 in the presence of H 2 S. Our experimental results indicated that the α-Fe 2 O 3 and γ-Fe 2 O 3 similarly played important roles in removing elemental mercury. The reaction temperature around 230   °C is a critical turning point in effectively capturing elemental mercury, above which the Hg 0 removal efficiency would decrease. According to our previous researches, H 2 S will preferentially adsorb on the Fe 2 O 3 surface, forming active sulfur sites to react with Hg 0 . In this paper, we analyzed the contrastive samples before and after removing Hg 0 to further investigate the probable products by the Hg 0 re-release experiments, as well as thermogravimetry–differential scanning calorimeter (TG–DSC) and X-ray photoelectron spectroscopy (XPS) analysis. The test results of morphological characterization showed that mercury compounds and new substances generated in the Fe 2 O 3 samples after adsorbing Hg 0 . At the same time, the detection results showed that Hg 2+ , sulfur, S 2− , S − and Fe 2+ had appeared, which demonstrated the probable mercury products, and the H 2 S pre-adsorption and Hg 0 oxidation could be confirmed as well by the different groups of comparative tests. In conclusion, our experimental results are in good agreement with our previous experiments and computational results.