Experimental kinetic studies on the effects of organic additives on ammonia-based selective non-catalytic reduction proc
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RESEARCH ARTICLE
Experimental kinetic studies on the effects of organic additives on ammonia-based selective non-catalytic reduction process Yangyang Guo 1 & Lei Luo 1 & Yang Zheng 1 & Tingyu Zhu 1,2 Received: 7 July 2020 / Accepted: 25 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The effect of organic components including ethanol, acetic acid, and benzene on ammonia-based selective non-catalytic reduction (SNCR) process has been investigated. Experiments were performed through a quartz tube reactor with simulated flue gas and conducted from 973 to 1373 K. The combustion and pyrolysis properties of organic components were carried out first, it was found that all the combustion processes were completed ahead of the pyrolysis, and the combustion and pyrolysis temperatures for benzene are the highest among the three organic components. Ethanol addition promoted the removal of NO in the temperature range of 973 to 1073 K, and the NO reaction temperature window was broadened, while NO removal was greatly inhibited under a higher temperature over 1100 K. With regard to the effect of addition of multiple organic components on NO removal, the combination of C2H6O and C2H4O2 significantly promoted this process, while the combination of C2H6O/C2H4O2 and C6H6 showed a negative effect on NO removal. The mechanism based on the radicals’ reaction has been illustrated, showing the competition of these reactions under different situations. Keywords SNCR reaction . Organic additives . Combustion and pyrolysis . NO reduction . Radicals . NO removal efficiency
Introduction Cement industry in China emits large amounts of NOx, causing serious environmental problems (Li et al. 2018). Much stricter legislations and standards have been promulgated to limit the NOx emissions (Cai et al. 2017; Chang and Wang 2010). Selective non-catalytic reduction (SNCR) technology has commonly been used in the cement industry for denitration, by injecting aqueous ammonia or urea into the emitted flue gas at 1120~1380 K to realize the reduction of NOx (Chen et al. 2016; Lee et al. 2008). Responsible Editor: Santiago V. Luis * Tingyu Zhu [email protected] 1
Beijing Engineering Research Centre of Process Pollution Control, Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
2
Center for Excellent in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
The SNCR technology requires less equipment space and is quite flexible to operate, while its reduction medium consumption is nearly 40% higher than that in the selective catalytic reduction (SCR) technology for the same amount of NOx reduction (Choi et al. 2015). Additionally the operating temperature window for SNCR is quite narrow; when the temperature is below 1120 K, the initiation reactions are too slow to provide any reduction, and w
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