改性粉煤灰基烟气脱汞吸附剂氧化性能分析

Oxidation capability of modified fly ash based adsorbent for mercury in coal-fired flue gas

为提高粉煤灰基吸附剂对单质汞的氧化性能,分别用NaBr、NaCl溶液对粉煤灰基烟气脱汞吸附剂进行浸渍改性,分析了改性前后吸附剂的物理性能,并研究了改性溶液浓度和烟气温度对Hg0氧化率的影响。结果表明:用浓度为5%的NaBr溶液改性得到的吸附剂对汞的氧化率为79.43%,饱和吸附量约为1 700ng/g,使用寿命约为480h。烟气温度对Hg0的氧化吸附影响显著,最佳温度范围为100～200℃。

Fly ash based adsorbent is dipping modified by NaCl or NaBr solution and the purpose is to improve their oxidation capability.Adsorption experiments of vapor-phase elemental mercury are performed in a laboratory-scale fixed-bed reactor.Physical properties of the adsorbent before and after modification are measured and the influences of the solution concentration and flue gas temperature on mercury oxidation rate are studied.The results show that when NaBr solution concentration is 5%,the mercury oxidation rate can reach 79.43%.The saturation adsorption quantity of absorbent 5%-NaBr is 1 700 ng/g and the service life is about 480 hours.Flue gas temperature played an important role in mercury oxidation and the best temperature ranged from 100 to 200 ℃.