Experimental Study Of Additives On NO Removal By Dielectric Barrier-corona Discharge Coupling Method

In recent years,the problem of air pollution is becoming increasingly serious,of which excessive emissions of nitrogen oxides bring great harm to the entire ecological environment and human health.Therefore,the control of nitrogen oxides is the key issue to be solved urgently.The experiment of NO removal was investigated on a self-designed dielectric barrier-corona discharge coupling device.Firstly,urea and ammonia were introduced into the system,and the effects of these additives on NO removal were discussed in different gas components.Based on that conditions,a solid compound of sodium(CH3COONa,Na2CO3,NaOH)was further added to the urea-added system,while effects of different sodium additives on the removal of NO by urea and effects of various factors(O2 volume fraction,NO initial concentration,gas volume flow,CO2 concentration,H2O)on NO removal were investigated.Meanwhile the conversion products and mechanism of each additive were discussed.The results showed as follows:(1)In the atmosphere of NO/O2/N2,NO/O2/CO2/N2,NO/O2/CO2/H2O/N2,O2,CO2,and H2O all have inhibitory effects on NO removal,but the addition of urea and ammonia can weaken this inhibition effect to varying degress and improve the NO removal rate,and the role of ammonia was significantly higher than urea.When the gas components was 500 ppmNO+3%O2+10%CO2+0.1%H2O+N2,the addition of urea can achieve about 50%-60%removal rate of NO,while ammonia can make the NO removal rate reach 80%,In addition,the CO was produced and increased with the increasing of the dosage of urea(2)The addition of a small amount of sodium additives could significantly improve the NO removal rate which increased with the increasing content of sodium additives.Meanwhile the amount of CO production was also effectively inhibited.Various sodium additives could promote the NO removal of urea under the same dosage.The NO removal was affected by the sodium additive in accordance with the order of NaOH>Na2CO3>CH3COONa.In addition,O2 volume fraction,NO initial concentration,gas volume flow,CO2 concentration and H2O all have inhibitory effects on NO removal,but the introduction of sodium additives can greatly weaken this inhibitory effect and improve the NO removal rate.In the atmosphere of 500 ppmNO+3%O2+10%CO2+0.1%H2O+N2,when the added sodium carbonate and sodium hydroxide and urea mass ratio was 10:10,the NO removal efficiency reach more than 85%under two kinds of sodium additives.