介质阻挡放电中气体成分对NOx脱除的影响

利用介质阻挡放电(DBD)产生低温等离子体进行烟气的脱硝实验,研究了在乙烯存在的条件下,温度和其他烟气成分对NO_x脱除率的影响。结果表明:随着温度的升高,NO脱除速率增快;模拟烟气中加入CO₂,在能量密度较低时,CO₂作为电负性分子会降低自由基的生成,导致NO的脱除率降低,随着能量密度的升高,CO₂对NO脱除的影响减小;模拟烟气中加入水后可以产生更多的OH、HO₂等自由基,促进NO的氧化;SO₂的加入会与自由基O反应,使初始反应中O与C₂H₄的反应速率减弱,从而影响了NO的氧化速率,但O₃、HO₂等强氧化自由基会优先与NO反应,因此SO₂的加入不会影响NO最终的脱除率。

Effect of gas composition on NOx removal in dielectric barrier discharge reactor

The experiment for removal of NO_x in flue gas by non-thermal plasma generated in dielectric barrier discharge(DBD)was conducted to study the influence of temperature and gas composition of gas containing-ethylene on the removal.The results show that rate of NO removal is accelerated by increase of temperature.Under lower energy density,addition of electronegative molecule CO₂ into simulation gas leads to efficiency reduction of NO removal because of decrease of radical generated,but the effect will be weakened with increasing energy density.The water addition in simulation gas can result in formation of more free radicals such as OH and HO₂ which can promote oxidation of NO.However,if SO₂ is also added which can react with O radical,on one hand,the reaction rate of O and C₂H₄ in the initial stage can be reduced,which makes NO oxidation decrease.On the other hand,free radicals O₃ and HO₂ with strong oxidation ability can react with NO prior to SO₂.So,addition of SO₂ has no influence on NO removal.