臭氧对船舶废气中氮氧化物的氧化试验研究

A Study on NO Oxidation by Ozone of Ship Exhaust

用管式反应器试验研究了反应温度、[O3]/[NO]对臭氧氧化NO的影响。结果表明,O3/N2/O2体系在常温、200℃、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,只有1～6（10-6）其他氮氧化物生成,如N2O and N2O3。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,其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9 s时,O3的分解率为59%,而275℃时分解更快,在反应器中停留9 s时,O3的分解率为80%。试验结果还表明,NO氧化率与[O3]/[NO]成线性关系。

A study is carried out to see the effects of reaction temperatures and [-O3 ]/[-NO] molar ratios on NO oxidation by ozone in a tube reactor. Test results indicate that no reaction is detected in O3/N2/O2 system at the temperatures of normal, 200℃ or 275℃. N2 can not be oxidized by ozone. In O3/NO/N2/O2 system, NO is mainly oxidized to NO2 with 1～6 （ 10^-6 ） other nitrogen-oxides, such as N2O and N2O3. When [-O3 ]/[-NO] ratio equals 1, 100% NO is oxidized at temperatures of normal and 200 ℃ and 72% at 275 ℃, which proves that reaction temperature has a considerable effect on NO oxidation due to the faster decomposition of O3 at higher temperature. The further tests show that decomposition of 03 is very slow at normal temperature and is faster at 200 ℃ （59G） and 275 ℃ （80G） after 9 seconds in tube reactor. The rate of NO oxidation increases linearly with [-O3]/[-NO] ratio.