Predicting the Multipollutant Performance of Utility SCR Systems
Predicting the Multipollutant Performance of Utility SCR Systems
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DOI：
10.1021/ie9020599
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发表时间：
2010-06
影响因子：
4.2
通讯作者：
S. Niksa;A. Sibley
中科院分区：
文献类型：
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作者：
S. Niksa;A. Sibley
该分析涉及催化剂材料组合物和双峰孔径特征，以直接、定量的方式与沿着实用选择性催化还原（SCR）反应器同时进行NO还原、Hg0氧化和SO3产生的反应性相关。SCR整料维持两个化学上不同的区域。在入口区域，强烈的NH3吸附使氯化和硫酸化表面位点的覆盖率最小化，因此NO还原抑制Hg0和SO2氧化。然而，一旦NH3被消耗，氯化的表面覆盖率激增数量级，并且Hg0氧化速率迅速增加，即使气相中的HCl浓度保持均匀。氨抑制还消除了SCR入口处的快速膜传质促进Hg0氧化的益处。在许多情况下，在Hg0开始氧化之后不久，Hg0氧化速率就受到膜传输的限制，使得没有催化剂内表面积被利用。改变孔径尺寸的方法
This analysis relates catalyst material composition and bimodal pore size characteristics in a direct, quantitative way to the reactivities for simultaneous NO reduction, Hg0 oxidation, and SO3 production along utility selective catalytic reduction (SCR) reactors. SCR monoliths sustain two chemically distinct regions. In the inlet region, strong NH3 adsorption minimizes the coverage of chlorinated and sulfated surface sites, so NO reduction inhibits Hg0 and SO2 oxidation. Once the NH3 has been consumed, however, the chlorinated surface coverage surges by orders of magnitude, and the Hg0 oxidation rate rapidly increases, even while the HCl concentration in the gas phase remains uniform. Ammonia inhibition also eliminates the benefit of the rapid film mass transfer at the SCR inlet from promoting Hg0 oxidation. In many cases, the Hg0 oxidation rate becomes limited by film transport soon after the Hg0 begins to oxidize, so that none of the catalyst internal surface area is utilized. Shifting the pore size di...