N2O5 Formation Mechanism during the Ozone-Based Low-Temperature Oxidation deNOx Process

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• 作者：Fawei Lin ; Zhihua Wang ; Qiang Ma ; Yong He ; Ronald Whiddon ; Yanqun Zhu ; Jianzhong Liu
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：June 16, 2016
• 年：2016
• 卷：30
• 期：6
• 页码：5101-5107
• 全文大小：570K
• 年卷期：0
• ISSN：1520-5029

文摘

With advantage of the solubility improving from NO into a higher valence state of nitrogen oxides, especially N₂O₅, the ozone-based low-temperature oxidation deNO_x process was investigated, especially the N₂O₅ formation mechanism. The temperature ranging from 60 to 150 °C and O₃/NO ratios and residence time changing were investigated by a well-designed experiment. N₂O₅ was detected by Fourier transform infrared spectroscopy (FTIR). A 24-step mechanism was also proposed, specially for describing the formation of N₂O₅. Results demonstrated that the formation of N₂O₅ was greatly influenced by the temperature and residence time. N₂O₅ could be formed at relatively low temperatures, such as 60–80 °C, within 3–5 s when O₃/NO > 1.0. There was no N₂O₅ detected when the temperature was higher than 130 °C as a result of the decomposition of NO₃. The proposed mechanism could give a good prediction of the experimental results with kinetic simulation. To speed up the N₂O₅ formation process and reduce the O₃ dosage and O₃ slip, a type of MnO_x-based catalyst was developed. Results showed that the MnO_x-loaded spherical alumina catalyst had obviously a positive effect on the formation of N₂O₅, with more than 90% NO converted into N₂O₅ at 80 °C within 0.24 s and O₃/NO = 1.5, with less than 15 ppm of O₃ leftover.