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Mechanism of NO reduction and regeneration in ammonia reburning process |
CHEN Jing-yi, YANG Wei-juan, SHI Peng-sheng, ZHU Xiao-yu, HE Yong, WANG Zhi-hua |
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China |
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Abstract Aiming at the application background of ammonia reburning technology, the chemical reaction kinetics simulation of ammonia reburning was conducted under NO/O2/H2O/N2 atmosphere in the PFR reactor model by using Chemkin software. The effects on reburning performance were investigated and revealed of temperature (1173~1573K), oxygen concentration (0~4%) and reburning ratio (1%~30%) by Zhang mechanism of ammonia reactions. The results showed that the denitration efficiency of ammonia reburning was remarkable in the range of the study range. The efficiencies could touch over 97% and it retained more than 80% in the temperature window of 1350~1469K. It was founded by an analyse from the perspective of reaction paths that the process of ammonia reburning comprised of the NO reduction region, equilibrium region and NO regeneration region. The NO regeneration region appeared visibly when the oxygen concentration was higher than 1.5%. Moverover the higher the oxygen concentration, the greater the rebound of NO and the higher the final NO concentration. The reburning ratio was preferable in the range of 10%±3% balancing between the denitration efficiency and the unreacted ammonia.
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Received: 07 November 2023
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[1] 刘怀平,尹海滨,熊尚超,等.水泥炉窑中低温催化脱硝技术中试性能[J].中国环境科学, 2021,41(7):3169-3175. Liu H P, Yin H B, Xiong S C, et al. A pilot scale study of low-temperature De-NOx in cement furnace[J]. China Environmental Science, 2021,41(7):3169-3175. [2] 黎宝林,李明玉,刘海豪,等.络合-氧化-还原耦合方法脱除烟气中NOx的研究[J].中国环境科学, 2014,34(5):1125-1130. Li B L, Li M Y, LIU H H, et al. Removal of NOx in flue gas by complexation-oxidation-reduction coupling method[J]. China Environmental Science, 2014,34(5):1125-1130. [3] 乔彤,刘长红,柳志刚,等.载体平衡离子对MnOx/ZSM-5催化NH3-SCR性能影响[J].中国环境科学, 2021,41(7):3176-3183. Qiao T, Liu C H, Liu Z G, et al. The effect of equilibrium ion on the NH3-SCR performance of MnOx/ZSM-5catalysts[J]. China Environmental Science, 2021,41(7):3176-3183. [4] Javed M Tayyeb, Irfan Naseem, Gibbs B M. Control of combustion-generated nitrogen oxides by selective non-catalytic reduction[J]. Journal of environmental management, 2007,83(3):251-289. [5] 路涛,贾双燕,李晓芸.关于烟气脱硝的SNCR工艺及其技术经济分析[J].现代电力, 2004,21(1):17-22. Lu T, Jia S Y, Li Xi Y. Techno-economic analysis for process and application of SNCR[J]. Modern Electric Power, 2004,21(1):17-22. [6] 原奇鑫,赵立正,翟刚,等.NH3选择性非催化还原脱硝影响因素[J].燃烧科学与技术, 2017,23(4):378-382. Yuan Q X, Zhao L Z, Zhai G, et al. Impact factors of selective non-catalytic reduction denitration by NH3[J]. Journal of Combustion Science and Technology, 2017,23(4):378-382. [7] Rahman Z, Wang X B, Zhang J Y, et al. Kinetic study and optimization on SNCR process in pressurized oxycombustion[J]. Journal of the Energy Institute, 2021,94:63-271. [8] Chen J, Fan W D, Wu X F, et al. Effects of O2/CO/CO2 on NH3reducing NO at 1073-1773K in different flow reactors:The effect of O2[J]. Fuel, 2021,283:119335. [9] 周俊虎,杨卫娟,周志军,等.选择非催化还原过程中的N2O生成与排放[J].中国电机工程学报, 2005,25(13):91-95. Zhou J H, Yang W J, Zhou Z J, et al. Nitrous oxide formation and emission in selective non-catalytic reduction process[J]. Proceedings of the CSEE, 2005,25(13):91-95. [10] 王智化,周昊,周俊虎,等.不同温度下炉内喷射氨水脱除NOx的模拟与试验研究[J].燃料化学学报, 2004,32(1):48-53. Wang Z H, Zhou H, Zhou J H, et al. Modeling and experimental study on NOx reduction in furnace with ammonia injection[J]. Journal of Fuel Chemistry and Technology, 2004,32(1):48-53. [11] 熊志波,韩奎华,高攀,等.生物质再燃脱除NO的特性[J].中国环境科学, 2011,31(3):361-366. Xiong Z B, Han K H, Gao P, et al. Experimental study of NO reduction by biomass reburning[J]. China Environmental Science, 2011,31(3):361-366. [12] 沈伯雄,孙幸福.天然气先进再燃区脱硝效率影响因素的实验与模拟研究[J].中国电机工程学报, 2005,25(5):148-151,165. Shen B X, Sun X F. Study on the parameters that influence the efficiency of DENOx in advanced natural gas reburningared by experimentaland kinetic model[J]. Proceedings of the CSEE, 2005,25(5):148-151,165. [13] 高攀,路春美,韩奎华,等.天然气/液化气先进再燃脱硝特性研究[J].煤炭学报, 2007,32(11):1191-1195. Gao P, Lu C M, Han K H, et al. NO reduction performance of natural gas and petroleum gas advanced reburning[J]. Journal of China Coal Society, 2007,32(11):1191-1195. [14] Zhang L Y, Wei X L, Zhang Z X, et al. Modeling De-NOx by injection ammonia in high temperature zone of cement precalciner[J]. Journal of Thermal Science, 2021,30(2):636-643. [15] Zhang X, Moosakutty SP, Rajan RP, et al. Combustion chemistry of ammonia/hydrogen mixtures:Jet-stirred reactor measurements and comprehensive kinetic modeling[J]. Combustion and Flame, 2021,234:111653. [16] Mei B, Ma S, Zhang Y, et al. Exploration on laminar flame propagation of ammonia and syngas mixtures up to 10atm[J]. Combustion and Flame, 2020,220:368-377. [17] Han X, Wang Z, He Y, et al. Experimental and kinetic modeling study of laminar burning velocities of NH3/syngas/air premixed flames[J]. Combustion and Flame, 2020,213:1-13. [18] Okafor EC, Naito Y, Colson S, et al. Experimental and numerical study of the laminar burning velocity of CH4-NH3-air premixed flames[J]. Combustion and Flame, 2018,187:185-198. [19] Shrestha KP, Lhuillier C, Barbosa AA, et al. An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature[J]. Proceedings of the Combustion Institute, 2020,38(2):2163-2174. [20] Shrestha KP, Seidel L, Zeuch T, et al. Detailed kinetic mechanism for the oxidation of ammonia including the formation and reduction of nitrogen oxides[J]. Energy and Fuels, 2018,32(10):10202-10217. [21] Han X, Wang Z, He Y, et al. The temperature dependence of the laminar burning velocity and superadiabatic flame temperature phenomenon for NH3/air flames[J]. Combustion and Flame, 2020,217:314-320. [22] Takizawa K, Takahashi A, Tokuhashi K, et al. Burning velocity measurements of nitrogen-containing compounds[J]. Journal of Hazardous Materials, 2007,155(1):144-152. [23] Akihiro Hayakawa, Takashi Goto, Rentaro Mimoto, et al. Laminar burning velocity and Markstein length of ammonia/air premixed flames at various pressures[J]. Fuel, 2015,159:98-106. [24] Mei B, Zhang X, Ma S, et al. Experimental and kinetic modeling investigation on the laminar flame propagation of ammonia under oxygen enrichment and elevated pressure conditions[J]. Combustion and Flame, 2019,210(C):236-246. [25] Kasuya F, Glarborg P, Johnsson J E, et al. The thermal DeNOx process:Influence of partial pressures and temperature[J]. Chemical Engineering Science, 1995,50(9):1455-1466. [26] 沈伯雄,刘亭,韩永富.选择性非催化还原脱除氮氧化物的影响因素分析[J].中国电机工程学报, 2008,28(23):53-59. Shen B X, Liu T, Han Y F. Analysis on impact factors for removal of NOx with selective non-catalytic reduction[J]. Proceedings of the CSEE, 2008,28(23):53-59. [27] 吕洪坤.选择性非催化还原与先进再燃技术的实验及机理研究[D].杭州:浙江大学, 2009. Lü H K. Experimental and mechanism study on selective non-catalytic reduction and advanced reburning[D]. Hangzhou:Zhejiang University, 2009. [28] Ren Q Q, Chi H Y, Gao J, et al. Experimental study and mechanism analysis of NO formation during volatile-N model compounds combustion in H2O/CO2 atmosphere[J]. Fuel, 2020,273:117722. |
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