Ko Li Si, Pan Kuan Lun, Chang Moo Been
Graduate Institute of Environmental Engineering, National Central University, Taoyuan City, Taiwan.
Green Energy and Environment Institute, Industrial Technology Research Institute, Hsinchu City, Taiwan.
J Air Waste Manag Assoc. 2025 Jan;75(1):37-51. doi: 10.1080/10962247.2024.2416047. Epub 2024 Nov 4.
In addition to selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) which are available to remove NO from flue gas, oxidation method is receiving more and more attention because this method makes it possible to remove NO and SO from flue gas simultaneously by wet scrubbing. O as a strong oxidant has a high oxidation capacity and it can oxide NO to NO which has a higher water solubility compared with NO. However, it needs a long reaction time and the escape of unreacted ozone may cause secondary pollution. In this study, FeMnCo/AlO catalyst and FeMnCe/AlO catalyst were prepared and applied to enhance the deep oxidation of NO with ozone and reduce O slip. Effects of various operating parameters such as O/NO ratio, gas residence time, and operating temperature were evaluated, and the results demonstrate that NO began to generate when O/NO ratio was higher than 1.0 and increased with increasing O/NO ratio. Little residual O was formed in the presence of catalyst, while 350 ppm O was measured at the outlet gas when O/NO ratio was controlled at 2.0. The NO conversion efficiency increased with increasing gas residence time and operating temperature, and the highest NO conversion efficiency was achieved at 100°C. Furthermore, the conversion efficiency remained around 90% during 20 h operation over FeMnCe/AlO catalyst with an O/NO ratio of 1.73, a gas residence time of 1.2 s, and a temperature of 100°C. On the other hand, the NO conversion efficiency remained around 80% during 3 h operation over FeMnCo/AlO catalyst. Overall, FeMnCe/AlO catalyst reveals good potential for deep oxidation of NO by O and can be further developed as a viable catalyst for reducing NO emission from industries.: In this study, FeMnCo/AlO catalyst and FeMnCe/AlO catalyst were applied to enhance the deep oxidation of NO into NO with O. The catalysts can improve the conversion of NO into NO, shorten the reaction time and reduce the unreacted O slip, which are beneficial to reduce the size of the reactor required and cost of APCDs (air pollution control devices) in practical application. This method can make it possible to simultaneously remove NO and SO from flue gas by wet scrubbing for reducing NO emissions from industries, especially small and medium scaled industries, to meet increasingly stringent emission standards.
除了可用于从烟气中去除NO的选择性催化还原（SCR）和选择性非催化还原（SNCR）外，氧化法越来越受到关注，因为该方法可通过湿法洗涤同时从烟气中去除NO和SO。O作为一种强氧化剂具有很高的氧化能力，它可以将NO氧化为NO₂，与NO相比，NO₂具有更高的水溶性。然而，它需要较长的反应时间，并且未反应的臭氧逸出可能会造成二次污染。在本研究中，制备了FeMnCo/Al₂O₃催化剂和FeMnCe/Al₂O₃催化剂，并将其应用于强化NO与臭氧的深度氧化并减少O₃泄漏。评估了各种操作参数如O₃/NO比、气体停留时间和操作温度的影响，结果表明，当O₃/NO比高于1.0时开始生成NO₂，并随O₃/NO比的增加而增加。在催化剂存在下几乎没有形成残留的O₃，而当O₃/NO比控制在2.0时，在出口气体中测得350 ppm的O₃。NO转化率随气体停留时间和操作温度的增加而提高，在100°C时达到最高的NO转化率。此外，在FeMnCe/Al₂O₃催化剂上以O₃/NO比1.73、气体停留时间1.2 s和温度100°C运行20小时期间，转化效率保持在90%左右。另一方面，在FeMnCo/Al₂O₃催化剂上运行3小时期间，NO转化率保持在80%左右。总体而言，FeMnCe/Al₂O₃催化剂显示出通过O₃深度氧化NO的良好潜力，并且可以进一步开发成为一种可行的催化剂，用于减少工业中的NO排放。：在本研究中，应用FeMnCo/Al₂O₃催化剂和FeMnCe/Al₂O₃催化剂强化NO与O₃深度氧化为NO₂。这些催化剂可以提高NO转化为NO₂的转化率，缩短反应时间并减少未反应的O₃泄漏，这有利于在实际应用中减小所需反应器的尺寸和空气污染控制装置（APCDs）的成本。该方法可以通过湿法洗涤同时从烟气中去除NO和SO，以减少工业，特别是中小型工业的NO排放，从而满足日益严格的排放标准。
