应用脉冲放电等离子体氧化NO、SO_2的影响因素

Factors Influencing the Oxidation of NO and SO_2 by Pulsed Discharge Plasma

在典型的脉冲放电烟气脱硫、脱硝工艺中,NO和SO2主要通过氧化反应转化为相应的高价氨盐化合物脱除,因此如何促进污染物的氧化反应是该技术的关键问题之一。为此,采用丙烯作为添加剂,研究了脉冲频率、烟气中水蒸气的体积分数、注入丙烯的体积分数、SO2等对NO的氧化产物的影响。实验结果表明:烟气中不存在SO2时,NO氧化的主要产物是NO2,且NO2生成的选择性随脉冲频率的上升、水蒸气体积分数的增大而下降,随注入丙烯体积分数的增大而增大。综合考虑到脱硝能耗,丙烯按1倍NOx的体积分数注入烟气为佳;烟气中存在SO2时,NO氧化生成的NO2可以生成硝酸盐,NO2生成的选择性较低,因此SO2可以促进氮氧化物的脱除。

NO and SO2 were mainly oxidized to their corresponding ammonium compounds in the typical pulse discharge de-NOx/de-SO2 processes, so how to＂ enhance the oxidation of NO/SO2 is very important in waste gas treatment containing NO/SO2. The influence of factors such as the pulse frequency, the volume content of water vapor and Ca H6 and the existence of SO2 in flue gas on the oxidation products of NO was studied. Experimental results re vealed that NO was mainly oxidized to NO2 when SO2 does not exist in flue gas, and the production quantity of NO2 decreased with the increasing pulse frequency and water vapor content, but increased with the injection quantity of C3H6. Considering the energy cost, C3H6 had better to be added into the flue gas according to about the same concentration of NOx ; the production quantity of NO2 was low when SO2 existed in flue gas. The reason is that NO2 , the oxidation product of NO, could be converted to its ammonium nitrate. So SO2 and its ammonium aerosol could enhance the removal efficiency of NOx.