Richardson Carl, Machalek Tom, Miller Scott, Dene Chuck, Chang Ramsay
URS Corporation, Austin, Texas 78729, USA.
J Air Waste Manag Assoc. 2002 Aug;52(8):941-7. doi: 10.1080/10473289.2002.10470835.
The speciation of Hg in coal-fired flue gas can be important in determining the ultimate Hg emissions as well as potential control options for the utility. The effects of NOx control processes, such as selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR), on Hg speciation are not well understood but may impact emissions of Hg. EPRI has investigated the reactions of Hg in flue gas at conditions expected for some NOx control processes. This paper describes the methodology used to investigate these reactions in actual flue gas at several power plants. Results have indicated that some commercial SCR catalysts are capable of oxidizing elemental Hg in flue gas obtained from the inlets of SCR or air heater units. Results are affected by various flue gas and operating parameters. The effect of flue gas composition, including the presence of NH3, has been evaluated. The influence of NH3 on fly ash Hg reactions also is being investigated.
煤燃烧烟气中汞的形态对于确定最终汞排放量以及公用事业的潜在控制方案可能很重要。氮氧化物控制工艺（如选择性催化还原（SCR）和选择性非催化还原（SNCR））对汞形态的影响尚未得到充分了解，但可能会影响汞的排放。电力研究协会（EPRI）已经研究了在一些氮氧化物控制工艺预期的条件下，汞在烟气中的反应。本文描述了用于在几家发电厂的实际烟气中研究这些反应的方法。结果表明，一些商用SCR催化剂能够氧化从SCR或空气预热器装置入口获得的烟气中的元素汞。结果受到各种烟气和运行参数的影响。已经评估了烟气成分（包括NH₃的存在）的影响。NH₃对飞灰汞反应的影响也正在研究中。
