Experimental Study on Demercurization Performance of Wet Flue Gas Desulfurization System
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_2O, NaOH, Na_2CO_3, Ca(OH)_2 and CaCO_3. The influences of adding oxidant and coagulant such as KMnO_4, Fenton reagent, K_2S_2O_8/CuSO_4 and Na_2S 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_2S_2O_8/CuSO_4 and Na_2S into desulfurization solutions could increase the mercury removal efficiency obviously. Various additives have different effects, and Na_2S is demonstrated to be the most efficient, in which a mercury removal efficiency of 67.2% can be reached.
作 者： BAO, Jingjing YANG, Linjun YAN, Jinpei 作者单位： School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China 刊 名： 中国化学（英文版） SCI 英文刊名： CHINESE JOURNAL OF CHEMISTRY 年，卷(期)： 2009 27(11) 分类号： O6 关键词： wet flue gas desulfurization system mercury valence state of mercury removal additive oxidant