Presto Albert A, Granite Evan J
National Energy Technology Laboratory, United States Department of Energy, P.O. Box 10940, MS 58-103A, Pittsburgh, Pennsylvania 15236-0940, USA.
Environ Sci Technol. 2006 Sep 15;40(18):5601-9. doi: 10.1021/es060504i.
Methods for removing mercury from flue gas have received increased attention because of recent limitations placed on mercury emissions from coal-fired utility boilers by the U. S. Environmental Protection Agency and various states. A promising method for mercury removal is catalytic oxidation of elemental mercury (Hg0) to oxidized mercury (Hg2+), followed by wet flue gas desulfurization (FGD). FGD cannot remove Hg0, but easily removes Hg2+ because of its solubility in water. To date, research has focused on three broad catalyst areas: selective catalytic reduction catalysts, carbon-based materials, and metals and metal oxides. We review published results for each type of catalyst and also present a discussion on the possible reaction mechanisms in each case. One of the major sources of uncertainty in understanding catalytic mercury oxidation is a lack of knowledge of the reaction mechanisms and kinetics. Thus, we propose that future research in this area should focus on two major aspects: determining the reaction mechanism and kinetics and searching for more cost-effective catalyst and support materials.
由于美国环境保护署及各州近期对燃煤公用事业锅炉的汞排放加以限制，烟道气脱汞方法已受到更多关注。一种很有前景的脱汞方法是将元素汞（Hg0）催化氧化为氧化汞（Hg2+），随后进行湿法烟气脱硫（FGD）。FGD无法脱除Hg0，但由于Hg2+在水中的溶解性，它能轻易脱除Hg2+。迄今为止，研究集中在三大类催化剂领域：选择性催化还原催化剂、碳基材料以及金属和金属氧化物。我们综述了每种催化剂已发表的研究结果，并对每种情况下可能的反应机理进行了讨论。理解催化汞氧化过程中不确定性的主要来源之一是缺乏对反应机理和动力学的了解。因此，我们建议该领域未来的研究应集中在两个主要方面：确定反应机理和动力学，以及寻找更具成本效益的催化剂和载体材料。
