Experimental Study on Demercurization Performance of Wet Flue Gas Desulfurization System

✍ Scribed by Jingjing Bao; Linjun Yang; Jinpei Yan

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 122 KB
• Volume: 27
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.200990376

✦ Synopsis

The demercurization performance of wet flue gas desulfurization (WFGD) system was investigated by measuring mercury concentrations at the inlet and outlet of WFGD system with a QM201H mercury analyzer. The selected desulfurizer included NH 3 •H 2 O, NaOH, Na 2 CO 3 , Ca(OH) 2 and CaCO 3 . The influences of adding oxidant and coagulant such as KMnO 4 , Fenton reagent, K 2 S 2 O 8 /CuSO 4 and Na 2 S into desulfurization solutions were also studied. The results show that elemental mercury is the main component of gaseous mercury in coal-fired flue gas, and the proportion of oxidized mercury is less than 36%. Oxidized mercury could be removed by WFGD system efficiently, and the removal efficiency could amount to 81.1%-92.6%. However, the concentration of elemental mercury slightly increased at the outlet of WFGD as a result of its insolubility and re-emission. Therefore, the removal efficiency of gaseous mercury is only 13.3%-18.3%. The mercury removal efficiency of WFGD system increased with increasing the liquid-gas ratio. In addition, adding KMnO 4 , Fenton reagent, K 2 S 2 O 8 /CuSO 4 and Na 2 S into desulfurization solutions could increase the mercury removal efficiency obviously. Various additives have different effects, and Na 2 S is demonstrated to be the most efficient, in which a mercury removal efficiency of 67.2% can be reached.