300MW燃煤机组烟气控制装置对气态汞去除效果

利用美国EPA OH法对烟气中不同形态汞的气态汞进行测试,研究300 MW锅炉的袋式除尘、静电除尘和湿法烟气脱硫对气态汞的去除效果。研究结果表明,静电除尘器对气态汞的去除效率仅为32.50%,对颗粒态汞的去除效率达76.88%,而使用袋式除尘器对气态汞的去除效率可达44.33%,可脱除99.92%以上的颗粒态汞;应用湿法烟气脱硫对二价汞的去除率可达49.03%。通过对粉煤灰、炉渣和脱硫石膏等燃煤副产物汞含量分析发现,脱硫石膏中汞的含量最高达0.77 mg/kg,汞及其环境毒性是燃煤副产物安全利用时需要注意一个主要问题。

Removal of gaseous mercury for pollution control systems of two sets of 300 MW coal-fired units

Mercury speciation analysis was carried out based on US EPA Ontario Hydro Method (OHM), gaseous mercury removal performance of fabric filter (FF), electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) of two sets of 300 MW coal-fired units were analyzed.The test results showed the gaseous mercury removal efficiency of 32.50% and particulate mercury removal efficiency of 76.88% for ESP.While mercury removal efficiency of 44.33% and 99.92% attained for FF for gaseous mercury and particulate mercury, respectively.For wet FGD, the removal efficiency of 49.03% for oxide mercury was achieved.Mercury concentration of fly ash, bottom ash, and desulfurization gypsum were determined, and results showed that as high as 0.77 mg/kg for desulfurization gypsum attained, and mercury and its toxicity of coal combustion product had to be considered on its utilization.