船舶尾气中NO臭氧氧化研究——反应温度和尾气中碳氢化合物含量的影响  

Experimental study on oxidation of NO in ship exhaust by O_3——The effect of reaction temperature and C_2H_4 content

作　　者：胡文佳[1] 杨国华[1] 周江华[1] 于春令[1] 

机构地区：[1]宁波大学海运学院,浙江宁波315211

出　　处：《中国科技论文在线》2008年第5期341-346,共6页

基　　金：浙江省自然科学基金项目(Y504013)

摘　　要：用管式反应器试验研究了反应温度和[O3]/[NO]对臭氧氧化NO的影响。结果表明,O3/N2/O2体系在常温、200℃和275℃下均不发生反应,N2不能被O3氧化;在O3/NO/N2/O2体系中,NO主要氧化为NO2,当[O3]/[NO]=1,反应温度分别为常温和200℃时,NO氧化率都达到100%,而在275℃时,NO氧化率只有72%,表明反应温度影响显著,原因主要与较高温度下O3分解加快有关。O3在不同温度下的分解试验发现,O3在常温下分解很慢;200℃时分解加快,在反应器中停留9s时,O3的分解率为59%,而275℃时分解更快,在反应器中停留9s时,O3的分解率为80%。NO的氧化率与[O3]/[NO]成线形相关,C2H4对NO氧化成NO2有促进作用。在[O3]/[NO]=0.6,反应温度分别为常温、200℃和275℃时,加入400×10-6C2H4,NO氧化率率由61%、62.6%和38.5%分别提高到63.8%、63%和41%。C2H4的促进机理,可能是O3与C2H4发生一系列反应生成强氧化性的过氧自由基CH3O2和HO2,这些自由基参与了NO的氧化反应。The experiments were carried out in a tube reactor located in a tube furnace to investigate the influences of reaction temperature and [O3]/[NO] molar ratio on the oxidation of NO by O3. Results showed that no reaction was detected in O3/N2/O2 system at ambient temperature, 200 ℃ and 275 ℃,which confirms that N2 can not be oxidized by ozone to form nitrogen-oxides. In the O3/NO/N2/O2 system, NO was mainly oxidized to NO2. Almost 100% of NO was oxidized at both ambient temperature and 200 ℃, but only 72% at 275 ℃, under the same [O3]/[NO] ratio of 1. It indicates that the reaction temperature has a considerable influence on NO oxidation, i.e., faster decomposition of O3 occurs at higher temperature. The further tests show that decomposition rate of O3 was nearly zero at ambient temperature, but increased to 59% and 80% at 200 ℃ and 275 ℃ respectively, withresident time of 9 seconds in the tube reactor. In addition, the NO oxidation rate increased linearly with the increase of [O3]/[NO] ratio, and the introduction of C2H4 facilitates the conversion of NO to NO2. The addition of 400×10-6 C2H4 increased the yield rate of NO2 from 61%, 62.6% and 38.5% at ambient temperature, 200 ℃ and 275 ℃ respectively to 63.8%, 63% and 41% under the same [O3]/[NO] ratio of 0.6. It seems that the reactions between C2H4 and O3 produced some strong oxidative radicals such as CH3O2 and HO2, which could oxidize NO to NO2.

关 键 词：环境工程学 脱硝 反应温度 乙烯 臭氧 

分 类 号：X701[环境科学与工程—环境工程]