Experimental study on NO emission and burnout characteristics during semi-coke preheating combustion

Lü Zhao-min; XIONG Xiao-he; YU Shi-lin; TAN Hou-zhang; XIANG Bai-xiang; HUANG Jun

Volume 48 Issue 5

May 2020

Turn off MathJax

Article Contents

Article Navigation > Journal of Fuel Chemistry and Technology > 2020 > 48(5): 543-550

Lü Zhao-min, XIONG Xiao-he, YU Shi-lin, TAN Hou-zhang, XIANG Bai-xiang, HUANG Jun. Experimental study on NO emission and burnout characteristics during semi-coke preheating combustion[J]. Journal of Fuel Chemistry and Technology, 2020, 48(5): 543-550.

Citation:

Lü Zhao-min, XIONG Xiao-he, YU Shi-lin, TAN Hou-zhang, XIANG Bai-xiang, HUANG Jun. Experimental study on NO emission and burnout characteristics during semi-coke preheating combustion[J]. Journal of Fuel Chemistry and Technology, 2020, 48(5): 543-550.

Citation:

Lü Zhao-min, XIONG Xiao-he, YU Shi-lin, TAN Hou-zhang, XIANG Bai-xiang, HUANG Jun. Experimental study on NO emission and burnout characteristics during semi-coke preheating combustion[J]. Journal of Fuel Chemistry and Technology, 2020, 48(5): 543-550.

PDF( 968 KB)

Experimental study on NO emission and burnout characteristics during semi-coke preheating combustion

1.
MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
2.
Shenhua Guohua(Beijing) Electric Power Research Institute Co. LTD, Beijing 100025, China

Funds:

the National Key Research and Development Program of China 2018YFB0604203

More Information

Corresponding author: TAN Hou-zhang, E-mail:hzt@xjtu.edu.cn, mx1029@stu.xjtu.edu.cn
Received Date: 2020-03-31
Rev Recd Date: 2020-05-05

Available Online: 2021-01-23

Publish Date: 2020-05-10

Abstract

Abstract

To explore the De-NO_x potential of the semi-coke preheating combustion technique at higher preheating temperatures(>1000 ℃), the effects of preheating temperature(600-1400 ℃), combustion temperature(1200-1400 ℃) and excess air coefficient(α=0.6-1.4) on the NO emission and burnout of semi-coke combustion were studied on a two-stage drop-tube furnace. The results show that higher preheating temperature can reduce both NO emissions and carbon content in fly ash. Besides, under the fuel-rich conditions, the reduction of NO caused by increasing preheating temperature is larger than that under the fuel-lean conditions. When the preheating temperature increases from 800 to 1400 ℃, there is a maximum NO reduction of 74%(α=0.6), which is much higher than that of 20.6%(α=1.4) under fuel-lean conditions. On the contrast, under fuel-rich conditions, the decrease of carbon content in fly ash caused by increasing preheating temperature is smaller than that under fuel-lean conditions. Under fuel-lean conditions, the maximum decrease of fly ash carbon content is 26.8% (α=1.4), which is higher than that of 15.95% (α=0.6) under fuel-rich conditions. About the effect of combustion temperature on the NO emission, it is found that there is a critical excess air coefficient. When the excess air coefficient is higher than the critical value, the NO emissions increase as the combustion temperature increases. However, when the excess air coefficient is lower than the critical value, the trend is opposite.
- preheating,
- NO,
- semi-coke,
- burnout,
- excess air factor

FullText(HTML)

References(40)

References

[1]	张金刚, 孙志刚, 郭强, 王兴军, 于广锁, 刘海峰, 王辅臣.神府煤热解的结构变化及煤焦加氢反应性研究[J].燃料化学学报, 2017, 45(2):129-137. doi: 10.3969/j.issn.0253-2409.2017.02.001 ZHANG Jin-gang, SUN Zhi-gang, GUO Qiang, WANG Xing-jun, YU Guang-suo, LIU Hai-feng, WANG Fu-chen. Structural changes of Shenfu coal pyrolysis and the reactivity of coal char hydrogenation[J]. J Fuel Chem Technol, 2017, 45(2):129-137. doi: 10.3969/j.issn.0253-2409.2017.02.001
[2]	潘生杰, 陈建玉, 范飞, 李鹏飞.低阶煤分质利用转化路线的现状分析及展望[J].洁净煤技术, 2017, 23(5):7-12. doi: 10.13226/j.issn.1006-6772.2017.05.002 PAN Sheng-jie, CHEN Jian-yu, FAN Fei, LI Peng-fei. Status analysis and prospect of the conversion path of low-rank coal mass utilization[J]. Clean Coal Technol, 2017, 23(5):7-12. doi: 10.13226/j.issn.1006-6772.2017.05.002
[3]	SONG Y H, POHL J H, BEÉR J M, SAROFIM A F. Nitric oxide formation during pulverized coal combustion[J]. Combust Sci Technol, 1982, 28(1/2):31-40. http://d.old.wanfangdata.com.cn/NSTLHY/NSTL_HYCC0212629879/
[4]	YANG Y, LU X, WANG Q. Investigation on the co-combustion of low calorific oil shale and its semi-coke by using thermogravimetric analysis[J]. Energy Convers Manage, 2017, 136:99-107. doi: 10.1016/j.enconman.2017.01.006
[5]	刘家利, 郭孟狮, 李炎. 135 MW机组锅炉掺烧半焦试验及经济性分析[J].洁净煤技术, 2017, 23(2):86-91. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201702017.htm LIU Jia-li, GUO Meng-shi, LI Yan. Test and economic analysis of 135 MW unit boiler mixed with semi-coke[J]. Clean Coal Technol, 2017, 23(2):86-91. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201702017.htm
[6]	杨忠灿, 王志超, 李炎, 贾晓艳.电站煤粉锅炉掺烧兰炭试验研究[J].锅炉技术, 2017, 48(3):31-36. doi: 10.3969/j.issn.1672-4763.2017.03.007 YANG Zhong-can, WANG Zhi-chao, LI Yan, JIA Xiao-yan. Experimental study on coal-fired pulverized coal fired boiler mixed with blue charcoal[J]. Boiler Technol, 2017, 48(3):31-36. doi: 10.3969/j.issn.1672-4763.2017.03.007
[7]	黎贤达. 300MW锅炉半焦煤粉掺混的燃烧过程及NO_x排放的数值模拟[D].哈尔滨: 哈尔滨工业大学, 2019. https://kns.cnki.net/KCMS/detail/detail.aspx?dbcode=CMFD&dbname=CMFD202001&filename=1019690631.nh&v=MTEyOTViUElSOGVYMUx1eFlTN0RoMVQzcVRyV00xRnJDVVI3cWZZZWRxRnl6bFZidlBWRjI2RjdXeEh0ZlBycEU= LI Xian-da. Numerical simulation of combustion process and NO_x emissions of 300MW boiler semi-coking coal powder blending[D]. Harbin: Harbin Institute of Technology, 2019. https://kns.cnki.net/KCMS/detail/detail.aspx?dbcode=CMFD&dbname=CMFD202001&filename=1019690631.nh&v=MTEyOTViUElSOGVYMUx1eFlTN0RoMVQzcVRyV00xRnJDVVI3cWZZZWRxRnl6bFZidlBWRjI2RjdXeEh0ZlBycEU=
[8]	李慧, 杨石, 周建明.半焦空气分级燃烧降低NO_x排放的实验研究[J].洁净煤技术. LI Hui, YANG Shi, ZHOU Jian-ming. Experimental study on semi-coke air staged combustion to reduce NO_x emissions[J]. Clean Coal Technol.
[9]	REN Q, BAO S. Combustion characteristics of ultrafine gasified semi-char in circulating fluidized bed[J]. Can J Chem Eng, 2016, 94(9):1676-1682. doi: 10.1002/cjce.22562
[10]	YAO Y, ZHU J G, LU Q G. Experimental study on nitrogen transformation in combustion of pulverized semi-coke preheated in a circulating fluidized bed[J]. Energy Fuels, 2015, 29(6):3985-3991. doi: 10.1021/acs.energyfuels.5b00791
[11]	巩志强.低阶煤热解半焦的燃烧特性和NO_x排放特性试验研究[D].北京: 中国科学院研究生院(工程热物理研究所), 2016. http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y3107155 GONG Zhi-qiang. Experimental study on combustion characteristics and NO_x emission characteristics of low-rank coal pyrolysis semi-coke[D]. Beijing: Graduate School of Chinese Academy of Sciences(Institute of Engineering Thermophysics), 2016. http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y3107155
[12]	么遥.细粉半焦预热燃烧及NO_x生成特性实验研究[D].北京: 中国科学院研究生院(工程热物理研究所), 2016. http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y3107158 YAO Yao. Experimental study on preheating combustion of fine powder semi-coke and NO_x formation characteristics[D]. Beijing: Graduate School of the Chinese Academy of Sciences(Institute of Engineering Thermophysics), 2016. http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y3107158
[13]	RABOVITSER J, BRYAN B, KNIGHT R, NESTER S, WOHADLO S, TUMANOVSKY A G, TOLCHINSKY E N, VERBOVETSKY E H, LISAUSKAS R, BEITTEL R. Development and testing of a novel coal preheating technology for NO_x reduction from pulverized coal-fired boilers[J]. Gas, 2003, 1(2):4. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=CC029566011
[14]	BRYAN B, NESTER S, RABOVITSER J, WOHADLO S. Methane de-NO_x for Utility PC Boilers[R]. Des Plaines: Inst Gas Technol, 2005. 10.2172/834746
[15]	GLARBORG P, JENSEN A, JOHNSSON J E. Fuel nitrogen conversion in solid fuel fired systems[J]. Prog Energy Combust Sci, 2003, 29(2):89-113. doi: 10.1016/S0360-1285(02)00031-X
[16]	WU Z, OHTSUKA Y. Nitrogen distribution in a fixed bed pyrolysis of coals with different ranks:Formation and source of N₂[J]. Energy Fuels, 1997, 11(2):477-482. doi: 10.1021/ef9601226
[17]	KAMBARA S, TAKARADA T, YAMAMOTO Y, KATO K. Relation between functional forms of coal nitrogen and formation of nitrogen oxide(NO_x) precursors during rapid pyrolysis[J]. Energy Fuels, 1993, 7(6):1013-1020. doi: 10.1021/ef00042a045
[18]	熊伯春, 杨卫娟, 王智化, 黄镇宇, 刘建忠, 岑可法.煤的超高温热解与气化特性的热重实验研究[J].煤炭转化, 2016, 39(4):15-20. doi: 10.3969/j.issn.1004-4248.2016.04.004 XIONG Bo-chun, YANG Wei-juan, WANG Zhi-hua, HUANG Zhen-yu, LIU Jian-zhong, CEN Ke-fa. Thermogravimetric experimental study on ultrahigh temperature pyrolysis and gasification characteristics of coal[J]. Coal Convers, 2016, 39(4):15-20. doi: 10.3969/j.issn.1004-4248.2016.04.004
[19]	NAOTO, TSUBOUCHI. Formation of molecular nitrogen and hydrogen sulfide during high-temperature pyrolysis of coals[J]. Asia-Pac J Chem Eng, 2015, 10:154-162. doi: 10.1002/apj.1858
[20]	TANIGUCHI M, KAMIKAWA Y, TATSUMI T, YAMAMOTO K. Staged combustion properties for pulverized coals at high temperature[J]. Combust Flame, 2011, 158(11):2261-2271. doi: 10.1016/j.combustflame.2011.04.005
[21]	SONG Y H, BEER J M, SAROFIM A F. Oxidation and devolatilization of nitrogen in coal char[J]. Combust Sci Technol, 1982, 28(5/6):177-183. doi: 10.1080-00102208208952554/
[22]	ZENG C, WU H, HAYASHI J I, LI C Z. Effects of thermal pretreatment in helium on the pyrolysis behaviour of Loy Yang brown coal[J]. Fuel, 2005, 84(12/13):1586-1592. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=98723441f68aadf796337e9325fc8dc8
[23]	JENKINS R G, NANDI S P, WALKER JR P L. Reactivity of heat-treated coals in air at 500 C[J]. Fuel, 1973, 52(4):288-293. doi: 10.1016/0016-2361(73)90059-8
[24]	KHAN MR. Significance of char active surface area for appraising the reactivity of low-and high-temperature chars[J]. Fuel, 1987, 66(12):1626-1634. doi: 10.1016/0016-2361(87)90353-X
[25]	VAN HEEK K, MÜHLEN H J. Effect of coal and char properties on gasification[J]. Fuel Process Technol, 1987, 15:113-133. doi: 10.1016/0378-3820(87)90039-7
[26]	LIU C, HUI S, PAN S, ZOU H, ZHANG G, WANG D. Experimental investigation on NO_x reduction potential of gas-fired coal preheating technology[J]. Energy Fuels, 2014, 28(9):6089-6097. doi: 10.1021/ef501175v
[27]	SPLIETHOFF H, GREUL U, RÜDIGER H, HEIN K R. Basic effects on NO_x emissions in air staging and reburning at a bench-scale test facility[J]. Fuel 1996, 75(5):560-564. doi: 10.1016/0016-2361(95)00281-2
[28]	TANIGUCHI M, KAMIKAWA Y, OKAZAKI T, YAMAMOTO K, ORITA H J C. A role of hydrocarbon reaction for NO_x formation and reduction in fuel-rich pulverized coal combustion[J]. Combust Flame, 2010, 157(8):1456-1466. doi: 10.1016/j.combustflame.2010.04.009
[29]	BAI W, HAO L, LEI D, HU L, CHE D. Air-staged combustion characteristics of pulverized coal under high temperature and strong reducing atmosphere conditions[J]. Energy Fuels, 2014, 28(3):1820-1828. doi: 10.1021/ef402305h
[30]	TAKAGI H, ISODA T, KUSAKABE K, MOROOKA S. Effects of coal structures on denitrogenation during flash pyrolysis[J]. Energy fuels, 1999, 13(4):934-940. doi: 10.1021/ef990010p
[31]	JENSEN L S, JANNERUP H E, GLARBORG P, JENSEN A, DAM-JOHANSEN K. Experimental investigation of NO from pulverized char combustion[J]. Proc Combust Inst, 2000, 28(2):2271-2278. doi: 10.1016/S0082-0784(00)80637-2
[32]	MOLINA A, EDDINGS E, PERSHING D, SAROFIM A. Char nitrogen conversion:Implications to emissions from coal-fired utility boilers[J]. Prog Energy Combust Sci, 2000, 26(4/6):507-531. doi: 10.1016/S0360-1285(00)00010-1
[33]	陈萍, 顾明言, 陈金超, 陈雪, 卢坤.中度气化煤焦异相还原NO机理[J].燃料化学学报, 2018, 46(8):918-924. doi: 10.3969/j.issn.0253-2409.2018.08.003 CHEN Ping, GU Ming-yan, CHEN Jin-chao, CHEN Xue, LU Kun. NO mechanism of heterogeneous reduction of moderately gasified coal char[J]. J Fuel Chem Technol, 2018, 46(8):918-924. doi: 10.3969/j.issn.0253-2409.2018.08.003
[34]	AIHARA T, MATSUOKA K, KYOTANI T, TOMITA A. Mechanism of N₂ formation during coal char oxidation[J]. Proc Combust Inst, 2013, 28(2):2189-2195. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=CC028008572
[35]	ASHMAN P J, HAYNES B S, BUCKLEY A N, NELSON P F. The fate of char-nitrogen in low-temperature oxidation[J]. Symp (Int) Combust, 1998, 27(2):3069-3075. doi: 10.1016/S0082-0784(98)80168-9
[36]	THOMAS K M. The release of nitrogen oxides during char combustion[J]. Fuel, 1997, 76(6):457-473. doi: 10.1016/S0016-2361(97)00008-2
[37]	AARNA I, SUUBERG E M. A review of the kinetics of the nitric oxide-carbon reaction[J]. Fuel, 1997, 76(6):475-491. doi: 10.1016/S0016-2361(96)00212-8
[38]	CHAN L, SAROFIM A, BEER J. Kinetics of the NO carbon reaction at fluidized bed combustor conditions[J]. Combust Flame, 1983, 52:37-45. doi: 10.1016/0010-2180(83)90119-0
[39]	ALZUETA M U, GLARBORG P, DAM-JOHANSEN K. Low temperature interactions between hydrocarbons and nitric oxide:An experimental study[J]. Combust Flame, 1997, 109(1/2):25-36. doi: 10.1016-S0010-2180(96)00146-0/
[40]	FAN W, LI Y, GUO Q, CHEN C, WANG Y. Coal-nitrogen release and NO_x evolution in the oxidant-staged combustion of coal[J]. Energy, 2017, 125:417-426. doi: 10.1016/j.energy.2017.02.130