Study On Simultaneous Desulfurization And Denitrification By Dielectric Barrier Coupled Corona Discharge

Coal plays an important role in China's primary energy consumption,and a large number of pollutants?NOx,SO₂,CO₂,trace heavy metals,et al.?will be produced in the process of coal combustion.These substances cause serious pollution and great harm to the atmospheric environment,human health and ecosystem.In order to reduce the secondary pollution and effectively remove NOx and SO₂,many technologies have been put into scientific research and industrial application.in which low-temperature plasma method,as a comprehensive multi-disciplinary technology,has attracted more and more attention and is considered to be the most potential technology in flue gas treatment.Based on the comprehensive investigation of the characteristics of low-temperature plasma discharge,the dielectric barrier coupled corona discharge device was designed and established.In the experiment,the effects of O₂,CO₂,H₂O content,input current,flue gas flow and other factors on the removal rate of NO and SO₂ were investigated firstly,and the competition relationship between free radicals in the process of desulfurization and denitrification alone and at the same time was compared and analyzed.At the same time,on the premise of adding Ethanolamine,the influence of the above factors on the efficiency of simultaneous desulfurization and denitrification was investigated,and the removal path of NO was deduced by on-line mass spectrometer analysis.The experimental results show that:?1?In the process of plasma desulfurization and denitrification,the increase of O₂ and CO₂content has obvious inhibition on the removal of NO,but has little effect on the removal of SO₂.The addition of H₂O will inhibit the removal of NO and slightly promote the removal rate of SO₂.When NO and SO₂ coexist,the velocity of electrons will be reduced and the number of high energy electrons will be reduced,which will inhibit the removal of each other.At the same time,increasing the initial concentration of SO₂ is not conducive to the removal of NO,but the change of the initial concentration of NO has little effect on the removal rate of SO₂.The increase of input current is beneficial to the improvement of pollutant removal rate.?2?When NO and SO₂ coexist in the same system,the addition of Ethanolamine can not only effectively absorb SO₂ in flue gas,but also enter into the discharge reactor with carrier gas.During the discharge,a large number of active oxidation radicals are generated,which react fully with NO,so as to significantly improve the removal rate of NO.After the introduction of Ethanolamine,the inhibition effect of O₂ on NO removal can be eliminated obviously.Even if the content of O₂ is increased to 12%,the NO removal rate can reach about 90%;Because the amount of Ethanolamine is limited,the inhibition effect of CO₂can not be eliminated completely,and the NO removal rate will gradually decrease with the absorption reaction of CO₂ and Ethanolamine,and tend to be stable,but it is still higher than that without Ethanolamine under the same condition.The inhibition of NO removal by H₂O,initial concentration of pollutants and flue gas flow was weakened;In this process,Ethanolamine can quickly absorb SO₂ in the system in a short period of time,and it is almost unaffected by other gas components.The SO₂ removal rate is as high as 95%.