SO_2对模拟燃煤烟气中汞形态分布影响的实验研究

Effect of sulfur dioxide on the speciation of mercury in flue gases

采用OntarioHydro方法作为检测方法 ,在小型模拟燃煤烟气Hg形态转化实验台上研究了烟气中SO2 浓度、HCl浓度、O2 浓度变化对燃煤烟气中Hg形态分布的影响 .结果表明 :在CO2 O2 N2 的烟气体系中 ,加入SO2 后 ,Hg的转化率略有增加 ,随反应温度升高Hg的转化率逐渐降低 ,较高的O2 浓度可以促进Hg的氧化 .加入HCl后 ,随反应温度的升高Hg的转化率升高 ,SO2 的存在会降低Hg的转化率 ,HCl的浓度越大 ,转化率越大 ,较高的O2 浓度也可以促进Hg的氧化 .

An experimental set-up was built, on which a bench-scale experimental was conducted to study the effects of SO_2 on the speciation distribution of mercury in simulated flue gases. The test method used here for mercury speciation was Ontario Hydro Method. The conclusions are as follows: In the CO_2-O_2-N_2-SO_2 system, conversion ratio of Hg^(2+) to total Hg became lower at higher reaction temperature, SO_2 could increase the conversion ratio of Hg^(2+) to total Hg and higher concentration of O_2 could enhance oxidation of Hg. In the CO_2-O_2-N_2-SO_2-HCl system, conversion ratio of Hg^(2+) to total Hg became higher at higher reaction temperature, but decreased at higher SO_2 concentration. The conversion ratio of Hg^(2+) to total Hg increased at higher HCl concentration and higher concentration of O_2 could enhance oxidation of Hg.