Lin Wenfeng, Zhang Bin, Hou Wenhui, Li Dawei, Yang Hongmin
School of Power Engineering, Nanjing Normal University, Nanjing 210042, China.
J Environ Sci (China). 2009;21(6):790-4. doi: 10.1016/s1001-0742(08)62342-6.
Although the approach using non-thermal plasma (NTP) for deNOx has been studied for over 15 years, how to achieve higher removal efficiency with lower cost is still a barrier for its industrial application. In order to investigate the impact of the argon additive on electron density, energy and nitric oxide reduction process in plasma, the spectrum of the dielectric barrier discharge at atmospheric pressure in a coaxial reactor was measured using the monochromater with high resolution. The comparative experiments for NO reduction were carried out simultaneously in N2/O2/NO plasma stream with and without argon, respectively. The nitrogen molecular spectrum which is attributed to the energy level transition (C3pi(u)-->B3pi(g)) was compared in the wavelength range 300-480 nm and the electron density and temperature were determined based on the relative intensities and Stark broadening width of spectral lines. The spectrum results indicated that the argon additive could enhance the intensity of emissive spectrum of plasma, thus the electron concentration as well as the energy was increased, and finally prompted the ionization rate to produce active N, O and O3. The results of NO reduction showed that NO conversion efficiency increased in the range of 10%-30% with 5% addition of argon in stream comparing with the condition without argon additive. This study will play a positive role in the industrial application of dielectric barrier discharge deNOx reactor.
尽管利用非热等离子体（NTP）进行脱硝的方法已研究了15年以上，但如何以更低成本实现更高的去除效率仍是其工业应用的一个障碍。为了研究氩气添加剂对等离子体中电子密度、能量及一氧化氮还原过程的影响，使用高分辨率单色仪测量了同轴反应器中大气压下介质阻挡放电的光谱。分别在含氩气和不含氩气的N2/O2/NO等离子体流中同时进行了NO还原的对比实验。在300 - 480 nm波长范围内比较了归因于能级跃迁（C3pi(u)-->B3pi(g)）的氮分子光谱，并根据谱线的相对强度和斯塔克展宽宽度确定了电子密度和温度。光谱结果表明，氩气添加剂可增强等离子体发射光谱的强度，从而提高电子浓度和能量，最终促使电离速率提高以产生活性N、O和O3。NO还原结果表明，与无氩气添加剂的情况相比，在气流中添加5%氩气时，NO转化效率提高了10% - 30%。本研究将对介质阻挡放电脱硝反应器的工业应用起到积极作用。
