【摘要】 采用沉降炉实验系统及燃煤烟气汞在线分析仪,试验研究了空气和O2/CO2气氛下,O2浓度、CaO和Fe2O3对煤样Hg排放的影响。从空气气氛切换至20%O2/CO2气氛时,褐煤烟气中气态单质汞(Hg0(g))浓度略降低,气态总汞(HgT(g))浓度略升高,烟煤则呈现相反趋势。O2/CO2气氛下,O2浓度为20%～25%时,烟煤的HgT(g)浓度变化不大,约19μg/m3;O2为30%时,HgT(g)浓度显著升高至23.2μg/m3;Hg0(g)浓度基本未受影响。CaO和Fe2O3可抑制Hg排放,且O2/CO2气氛下的效果优于空气气氛。CaO添加后可显著降低Hg0(g)浓度,同等O2浓度下,O2/CO2气氛更有利于HgT(g)的减排。Fe2O3加入后,HgT(g)浓度有所降低,O2浓度升高,Hg0(g)氧化随之增强。更多还原

【Abstract】 By using a sedimentation furnace test system and an on-line coal-fired flue gas Hg analyzer,experimentally studied was the influence of O2 concentration,CaO and Fe2O3 on coal sample Hg emissions in an air and O2/CO2 atmosphere.When a conversion is made from an air atmosphere to a 20% O2/CO2 concentration atmosphere,the gas-state single-substance mercury(Hg0(g))concentration in the flue gas produced by burning lignite will slightly decrease and the total gas-state mercury(HgT(g))will slightly increase while bituminous coal will exhibit a contrary tendency.In the O2/CO2 atmosphere,when O2 concentration ranges from 20% to 25%,HgT(g)concentration of the bituminous coal will change insignificantly,i.e.around 19 μg/m3.When O2 concentration is 30%,the HgT(g)concentration will conspicuously increase to 23.2 μg/m3 while the Hg0(g)concentration will basically not be affected.CaO and Fe2O3 can curb the Hg emissions and the effectiveness achieved in the O2/CO2 atmosphere is superior to that in an air atmosphere.After CaO has been added,the Hg0(g)concentration will decrease remarkably.At a same O2 concentration,the O2/CO2 atmosphere will be more favorable for the reduction of HgT(g)emissions.After Fe2O3 has been added,the HgT(g)concentration will somewhat decrease while the O2 concentration will increase,so that Hg0(g)oxidation will be enhanced accordingly.更多还原