Study of Hg and SO3 behavior in flue gas of oxy-fuel combustion system
Study of Hg and SO3 behavior in flue gas of oxy-fuel combustion system
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DOI：
10.1016/j.ijggc.2011.05.017
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发表时间：
2011-07
影响因子：
3.9
通讯作者：
Y. Mitsui;Noriyuki Imada;H. Kikkawa;Atsushi Katagawa
中科院分区：
文献类型：
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作者：
Y. Mitsui;Noriyuki Imada;H. Kikkawa;Atsushi Katagawa
为了减少燃煤发电厂的CO2排放量，一直在开发氧燃料燃烧系统。在富氧燃烧系统中，烟气中的汞会对CO2净化和压缩装置造成腐蚀。烟气中的SO 3对富氧燃烧系统的设备和管道也有腐蚀作用。因此，需要去除Hg和SO 3。Babcock-Hitachi使用1.5MWth燃烧和空气质量控制系统（AQCS）测试设施进行测试，该测试设施包括氧气供应单元，熔炉，选择性催化还原（SCR）催化剂，清洁能源换热器（CER），干式静电除尘器（DESP），烟气再循环系统，湿法烟气脱硫（WFGD）和CO2压缩和净化单元（CPU）。在空气和富氧燃料燃烧的两种情况下，通过在DESP上游安装CER并降低DESP入口处的气体温度，可以改善整个DESP的Hg去除，并且DESP出口处的SO 3浓度可以降低到小于1 ppm。Hg没有溶解在从CO2压缩机回收的排水中，并且可能被吸附在CO2压缩机的内部。这表明需要在CO2压缩机的上游位置去除汞，以防止压缩机腐蚀。
Oxy-fuel combustion systems have been under development to reduce CO2emissions from coal-fired power plants. In oxy-fuel combustion system, Hg in the flue gas causes corrosion in CO2purification and compression units. Also, SO3in the flue gas corrodes the equipment and ducts of oxy-fuel combustion system. Therefore, Hg and SO3need to be removed. Babcock-Hitachi conducted tests using a 1.5MWth Combustion & Air Quality Control System (AQCS) test facility which consists of oxygen supply unit, furnace, Selective Catalytic Reduction (SCR) catalyst, Clean Energy Recuperator (CER), Dry Electrostatic Precipitator (DESP), flue gas recirculation system, Wet Flue Gas Desulfurization (WFGD), and CO2Compression and Purification Unit (CPU). In both cases of air and oxy-fuel combustion, the Hg removal across the DESP could be improved, and SO3concentration at the DESP outlet could be reduced to less than 1ppm by installing a CER upstream of the DESP and reducing the gas temperature at the DESP inlet. Hg was not dissolved in the drain recovered from CO2compressor, and may be adsorbed at an inner part of CO2compressor. This indicated that Hg needs to be removed at a location upstream of the CO2compressor to prevent corrosion of the compressor.