Influence of SO3 on mercury removal with activated carbon: Full-scale results
Influence of SO3 on mercury removal with activated carbon: Full-scale results
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DOI：
10.1016/j.fuproc.2009.08.019
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发表时间：
2009-11
影响因子：
7.5
通讯作者：
S. Sjostrom;M. Dillon;B. Donnelly;J. Bustard;G. Filippelli;Rob Glesmann;Tom Orscheln;S. Wahlert;R. Chang;Andrew O'Palko
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文献类型：
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作者：
S. Sjostrom;M. Dillon;B. Donnelly;J. Bustard;G. Filippelli;Rob Glesmann;Tom Orscheln;S. Wahlert;R. Chang;Andrew O'Palko
注入活性碳被认为是燃料发电厂控制汞的最具成本效益的选择之一。然而，大约30%的燃用PRB煤的地点使用SO3进行烟气调节。烟气中SO3的存在会降低活性碳对汞的捕获量，有时会显著减少。对于采用这种配置的机组，克服SO3调节造成的活性碳性能限制对于使这些工厂能够经济高效地满足即将出台的汞排放法规至关重要。阿莫林的Labadie 2号机组燃烧PRB煤，并使用SO3来增强静电除尘器(ESP)中的颗粒捕获。2005年至2007年在拉巴迪进行了全尺寸的吸着剂注入试验。在SO3注入浓度从0到10.7ppm的范围内，测试了六种脱硫剂。在两个喷射位置(空气预热器(APH)入口和出口)评价了脱硫剂的性能。自然汞在飞灰上的捕获率通常不到15%。当汞吸附剂被注入空气预热器的下游时，SO3浓度导致汞捕获率从85%(不注入SO3)下降到17%(SO3注入设置为10.7ppm)。汞脱色剂在空气预热器上游注入时效果更好。在关闭SO3系统的情况下，在APH出口注入5.1磅/MMacf的溴化碳时，汞的脱除率为75%，而在入口注入时，汞的脱除率为95%。试验结果表明，在SO3系统开启的情况下，出口处的喷射率约为30%，进口处的喷射率为58%。评估ADA-ES专利现场研磨工艺的测试表明，注入4lb/mMacf的研磨活性碳可实现85%的汞捕获率，而使用原碳实现相同的去除要求为10lb/mMacf，这意味着活性碳消耗减少了60%。在这些测试中，没有观察到不透明度、APH和ESP性能的变化，或者其他植物平衡效应。
Activated carbon injection is considered one of the most cost-effective options for mercury control at PRB-fired power plants. However, roughly 30% of sites firing PRB coal use SO3for flue gas conditioning. The presence of SO3in flue gas can decrease mercury capture by activated carbon, sometimes dramatically. Overcoming activated carbon performance limitations caused by SO3conditioning for units with this configuration is essential to enable these plants to cost-effectively meet pending mercury emission regulations. Ameren's Labadie Unit 2 fires PRB coal and uses SO3to enhance particulate capture in the electrostatic precipitator (ESP). Full-scale sorbent injection tests at Labadie were conducted from 2005–2007. Six sorbents were tested at SO3injection concentrations ranging from 0 to 10.7ppm. Sorbent performance was evaluated at two injection locations (the air preheater (APH) inlet and outlet). Native mercury capture on fly ash was typically less than 15%. When the mercury sorbents were injected downstream of the air preheater, the SO3concentration resulted in a decrease in mercury capture from 85% (no SO3injection) to 17% (SO3injection set at 10.7ppm). Mercury sorbents were more effective when injected upstream of the air preheater. With the SO3system off, mercury removal increased from 75% when injecting 5.1lb/MMacf of brominated carbon at the APH outlet, compared to 95% when injecting at the inlet. With the SO3system on, test results indicated an increase from about 30% injecting at the outlet to 58% injecting at the inlet. Tests evaluating the ADA-ES patented onsite milling process showed that 85% mercury capture was achieved injecting 4lb/MMacf of milled activated carbon compared to a requirement of 10lb/MMacf to achieve the same removal using as-received carbon, representing a 60% reduction in activated carbon consumption. No changes in opacity, APH and ESP performance, or other balance-of-plant effects were observed in these tests.