Experimental Study the Influence of Bromine、Iron on Particulate Mercury Formation

Br、Fe has a significant impact on particular Hg (Hg_p) formation in the flue gas. This paper conducted burning experiments for two kinds of coals blending with KBr, CaBr₂, Fe₂O₃ and KBr with Fe₂O₃ together in the high-temperature electrically heated reactor. The addition ratio of KBr, CaBr₂ was 0.1%、0.3%、0.5%, combustion temperature was 1250℃. The fly ash samples of different combustion condition were collected, and the Hg content in fly ash was measured. The result shows that: the Hg content in ash and particulate Hg ratio increase with increased KBr, CaBr₂ addition ratio. At the same addition ratio, adding CaBr₂ led to slight higher Hg_p formation than adding KBr. The influences of Fe₂O₃ addition on Hg_p formation are different for the two coals. The generation of Hg_p for coal 1 increases linearly with the increase of Fe₂O₃, however the generation of Hg_p for coal 2 has no significant promotion with Fe₂O₃ addition. But at KBr additions, Hg_p formation is also promoted by Fe₂O₃ addition for coal 2.