Please wait a minute...
浙江大学学报(工学版)
Journal of ZheJiang University (Engineering Science)  2019, Vol. 53 Issue (9): 1826-1834    DOI: 10.3785/j.issn.1008-973X.2019.09.022
Environmental Engineering     
Lignite pyrolysis and oxy-fuel combustion characteristics under N2 and CO2 atmospheres
Shi-quan SHAN1(),Zhi-jun ZHOU1,*(),Jian-ping KUANG2,Yu ZHANG2,Ke-fa CEN1
1. State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
2. Ningxia Shenyao Technology Co. Ltd, Yinchuan 751411, China
Download: HTML     PDF(1391KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

A pyrolysis experiment was carried out in a tubular furnace using Ximeng lignite under N2 and CO2 atmospheres at the temperature between 600 °C and 1000 °C, in order to investigate the characteristics of lignite pyrolysis and oxy-fuel combustion under different atmospheres and to obtain their relationship. Further oxy-lignite combustion experiments under O2/N2 and O2/CO2 atmospheres were performed to investigate the oxy-lignite combustion characteristics under different reaction temperatures (from 600 °C to 1 000 °C) and different oxygen concentrations (from 21% to 60%). The effects of CO2 gasification on oxy-fuel combustion were explored based on the results of lignite pyrolysis. Results show that the Ximeng lignite gasification starts at 700 °C under CO2 atmosphere and the CO2 gasification is enhanced with the increase of temperature. CO2 mainly affects coal pyrolysis and combustion through gasification reaction at high temperature; the presence of gasification reaction after 700 °C can promote the oxy-fuel combustion process. For oxy-fuel combustion under O2/CO2 atmosphere, when the oxygen concentration is 30%, the temperature below 800 °C has greater effect on CO oxidation, while the temperature above 800 °C has greater effect on CO2 gasification. Moreover, there is little difference in the combustion time between two atmospheres of O2/CO2 and O2/N2 with the same oxygen concentration.

Key words： oxy-fuel combustion      lignite      pyrolysis      tubular furnace      combustion atmosphere      CO2 gasification     
Received: 22 July 2018      Published: 12 September 2019
CLC:  TK 16  
Corresponding Authors: Zhi-jun ZHOU     E-mail: shiquan1204@zju.edu.cn;zhouzj@zju.edu.cn
Service
E-mail this article
Add to my bookshelf
Add to citation manager
E-mail Alert
RSS
Articles by authors
Shi-quan SHAN
Zhi-jun ZHOU
Jian-ping KUANG
Yu ZHANG
Ke-fa CEN
Cite this article:

Shi-quan SHAN,Zhi-jun ZHOU,Jian-ping KUANG,Yu ZHANG,Ke-fa CEN. Lignite pyrolysis and oxy-fuel combustion characteristics under N2 and CO2 atmospheres. Journal of ZheJiang University (Engineering Science), 2019, 53(9): 1826-1834.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2019.09.022     OR     http://www.zjujournals.com/eng/Y2019/V53/I9/1826


褐煤在N2及CO2气氛下的热解与富氧燃烧特性

为了掌握不同气氛下褐煤热解与富氧燃烧的特性以及其之间的联系，在管式炉反应器上利用锡盟褐煤在N2和CO2气氛以及600~1 000 °C条件下进行热解. 进一步对其在O2/N2以及O2/CO2气氛下进行富氧燃烧实验，考察不同反应温度(600~1 000 °C)以及不同氧气体积分数(21%~60%)条件下的富氧燃烧特性，结合热解实验结果探究CO2气化反应对富氧燃烧的影响. 结果表明，CO2气氛中锡盟褐煤在700 °C时开始CO2气化反应，随温度增加气化反应增强，CO2主要通过高温区的气化反应来影响煤热解及燃烧，700 °C以上气化反应能促进富氧燃烧进程. 对于O2/CO2气氛的富氧燃烧，当氧气体积分数为30%时，在800 °C以下温度对CO氧化反应影响更大，而在800 °C以上温度对CO2气化反应影响更大. 当氧气体积分数相同时，O2/N2以及O2/CO2气氛下褐煤富氧燃烧反应时间差异不大.


关键词： 富氧燃烧,  褐煤,  热解,  管式炉,  燃烧气氛,  CO2气化 
Fig.1 Schematic diagram of tubular furnace experiment system for pyrolysis and oxy-fuel combustion
煤种 工业分析 wB / % 元素分析 wB / %
M A V FC C H N S O
　　注：1）表中数据为空气干燥基.
锡盟褐煤 20.20 14.01 31.20 34.59 45.69 2.84 0.63 0.75 15.88
Tab.1 Proximate and ultimate analysis of Ximeng lignite
Fig.2 TG and DTG profiles of lignite pyrolysis under N2 and CO2 atmospheres
气氛 θS/°C θmax/°C Δθ0.5/°C (dw/dt)max D/(10?7 %·min?1·°C?3)
N2 259.04 442.54 192 ?2.582 40 1.173 28
CO2 285.16 438.16 219 ?2.669 26 0.975 50
Tab.2 Pyrolysis characteristic parameters of lignite under N2 and CO2 atmospheres
反应 θ/°C E/(kJ·mol?1) ρ
N2热解 259.04~442.54 63.42 0.990 7
CO2热解 285.16~438.16 74.83 0.991 0
CO2气化 720.16~900.00 249.11 0.980 0
Tab.3 Kinetic parameters of lignite pyrolysis and gasification
Fig.3 Gases yield during lignite pyrolysis process
Fig.4 CO generation ratio of oxy-lignite combustion with different oxygen concentrations under O2/CO2 and O2/N2 atmospheres
Fig.5 Reaction time and maximum reaction rate of oxy-lignite combustion with different oxygen concentrations under O2/CO2 and O2/N2 atmospheres
Fig.6 Variation trend of n21 in oxy-lignite combustion under different oxygen concentrations
Fig.7 CO generation ratio of lignite combustion with different temperatures under O2/CO2 (φ(O2)=30%) and O2/N2 (φ(O2)=21%) atmospheres
Fig.8 Reaction time and maximum reaction rate of lignite combustion with different temperatures under typical oxy-fuel and air atmospheres
Fig.9 Variation trend of n21 in oxy-lignite combustion under different temperatures
[1]   NEMITALLAH M A, HABIB M A, BADR H M, et al Oxy-fuel combustion technology: current status, applications, and trends[J]. International Journal of Energy Research, 2017, 41 (12): 1670- 1708
doi: 10.1002/er.v41.12
[2]   郑楚光, 赵永椿, 郭欣 中国富氧燃烧技术研发进展[J]. 中国电机工程学报, 2014, 34 (23): 3856- 3864
ZHENG Chu-guang, ZHAO Yong-chun, GUO Xin Research and development of oxy-fuel combustion in China[J]. Proceedings of the CSEE, 2014, 34 (23): 3856- 3864
[3]   周志军, 涂艳伟, 游卓, 等 O2/CO2气氛下石油焦富氧燃烧特性研究 [J]. 热力发电, 2013, 42 (9): 45- 48
ZHOU Zhi-jun, TU Yan-wei, You Zhuo, et al Oxy-fuel combustion characteristics of petroleum coke in O2/CO2 atmosphere [J]. Thermal Power Generation, 2013, 42 (9): 45- 48
doi: 10.3969/j.issn.1002-3364.2013.09.045
[4]   吴迪, 邹春, 蔡磊, 等 CO2的物理化学属性对于煤粉富氧燃烧着火的影响 [J]. 燃烧科学与技术, 2016, 22 (6): 558- 562
WU Di, ZOU Chun, CAI Lei, et al Effect of physical and chemical properties of CO2 on ignition of coal particle in O2/CO2 atmosphere [J]. Journal of Combustion Science and Technology, 2016, 22 (6): 558- 562
[5]   段伦博, 赵长遂, 周骛, 等 CO2气氛对烟煤热解过程的影响 [J]. 中国电机工程学报, 2010, (2): 62- 66
DUAN Lun-bo, ZHAO Chang-sui, ZHOU Wu, et al Effect of CO2 atmosphere on the pyrolysis process of bituminous coal [J]. Proceedings of the CSEE, 2010, (2): 62- 66
[6]   高松平, 赵建涛, 王志青, 等 CO2对褐煤热解行为的影响 [J]. 燃料化学学报, 2013, 41 (3): 257- 264
GAO Song-ping, ZHAO Jian-tao, WANG Zhi-qing, et al Effect of CO2 on pyrolysis behaviors of lignite [J]. Journal of Fuel Chemistry and Technology, 2013, 41 (3): 257- 264
doi: 10.3969/j.issn.0253-2409.2013.03.001
[7]   周志军, 姜旭东, 周俊虎, 等 煤粉富氧燃烧着火模式判断和动力学参数分析[J]. 浙江大学学报: 工学版, 2012, 46 (3): 482- 488
ZHOU Zhi-jun, JIANG Xu-dong, ZHOU Jun-hu, et al Ignition model and kinetic parameters analysis of oxygen-enriched combustion of pulverized coal[J]. Journal of Zhejiang University: Engineering Science, 2012, 46 (3): 482- 488
[8]   刘倩, 钟文琪, 苏伟, 等 基于热重-质谱联用的煤粉富氧燃烧动力学及污染物生成特性[J]. 化工学报, 2018, 69 (1): 523- 530
LIU Qian, ZHONG Wen-qi, SU Wei, et al Oxy-coal combustion kinetics and formation characteristics of pollutants based on TG-MS analysis[J]. CIESC Journal, 2018, 69 (1): 523- 530
[9]   胡昕, 周志军, 王智化, 等 利用热分析法研究CO2对褐煤富氧燃烧特性的影响 [J]. 热力发电, 2013, 42 (3): 15- 19
HU xin, ZHOU Zhi-jun, WANG Zhi-hua, et al Thermogravimetry based analysis on the influence of CO2 on oxy-fuel combustion characteristics of lignite [J]. Thermal Power Generation, 2013, 42 (3): 15- 19
doi: 10.3969/j.issn.1002-3364.2013.03.015
[10]   何先辉, 顾明言, 李红, 等 O2/CO2气氛下煤粉燃烧NO排放特性 [J]. 燃烧科学与技术, 2017, 23 (6): 554- 559
HE Xian-hui, GU Ming-yan, LI Hong, et al NO emission characteristics of pulverized coal combustion in O2/CO2 atmosphere [J]. Journal of Combustion Science and Technology, 2017, 23 (6): 554- 559
[11]   王勇, 黄晓宏, 卢兴, 等 富氧燃烧条件下燃煤NOx排放的实验研究 [J]. 环境工程学报, 2016, 10 (7): 3751- 3755
WANG Yong, HUANG Xiao-hong, LU Xing, et al Experimental study of NOx emissions from coal combustion under oxy-fuel conditions [J]. Chinese Journal of Environmental Engineering, 2016, 10 (7): 3751- 3755
doi: 10.12030/j.cjee.201501239
[12]   WANG C, ZHANG X, LIU Y, et al Pyrolysis and combustion characteristics of coals in oxy-fuel combustion[J]. Applied Energy, 2012, 97: 264- 273
doi: 10.1016/j.apenergy.2012.02.011
[13]   KOSOWSKA-GOLACHOWSKA M Thermal analysis and kinetics of coal during oxy-fuel combustion[J]. Journal of Thermal Science, 2017, 26 (4): 355- 361
doi: 10.1007/s11630-017-0949-0
[14]   RATHNAM R K, WALL T F, MOGHTADERI B. Reactivity of pulverized coals and their chars in oxyfuel (O2/CO2) and air (O2/N2) conditions [C] // 3rd Oxyfuel Combustion Conference. Ponferrada: International Energy Agency, 2013.
[15]   RATHNAM R K. Pulverized coal combustibility in simulated oxy-fuel (O2/CO2) and air (O2/N2) conditions [D]. Newcastle: The University of Newcastle, 2012.
[16]   YUZBASI N S, SELCUK N Air and oxy-fuel combustion characteristics of biomass/lignite blends in TGA-FTIR[J]. Fuel Processing Technology, 2011, 92 (5): 1101- 1108
doi: 10.1016/j.fuproc.2011.01.005
[17]   魏砾宏, 李润东, 李爱民, 等 煤粉热解特性实验研究[J]. 中国电机工程学报, 2008, 28 (26): 53- 58
WEI Li-hong, LI Run-dong, LI Ai-min, et al Thermo gravimetric analysis on the pyrolysis characteristics of pulverized coal[J]. Proceedings of the CSEE, 2008, 28 (26): 53- 58
doi: 10.3321/j.issn:0258-8013.2008.26.010
[18]   JAMIL K, HAYASHI J, LI C Z Pyrolysis of a Victorian brown coal and gasification of nascent char in CO2 atmosphere in a wire-mesh reactor [J]. Fuel, 2004, 83 (7/8): 833- 843
doi: 10.1016/j.fuel.2003.09.017
[19]   郝成浩, 朱生华, 白永辉, 等 CO2气氛对胜利褐煤热解过程的影响 [J]. 燃料化学学报, 2017, 45 (3): 272- 278
HAO Cheng-hao, ZHU Sheng-hua, BAI Yong-hui, et al Effect of CO2 on pyrolysis behavior of Shengli lignite [J]. Journal of Fuel Chemistry and Technology, 2017, 45 (3): 272- 278
doi: 10.3969/j.issn.0253-2409.2017.03.003
[20]   ARENILLAS A, RUBIERA F, PIS J J Simultaneous thermogravimetric-mass spectrometric study on the pyrolysis behaviour of different rank coals[J]. Journal of Analytical and Applied Pyrolysis, 1999, 50 (1): 31- 46
doi: 10.1016/S0165-2370(99)00024-8
[21]   MOLINA A, SHADDIX C R Ignition and devolatilization of pulverized bituminous coal particles during oxygen/carbon dioxide coal combustion[J]. Proceedings of the combustion institute, 2007, 31 (2): 1905- 1912
doi: 10.1016/j.proci.2006.08.102
[22]   陶子宸, 王长安, 王鹏乾, 等 低挥发分半焦富氧燃烧扩散效应研究[J]. 西安交通大学学报, 2018, 52 (9): 160- 166
TAO Zi-chen, WANG Chang-an, WANG Peng-qian, et al Study on the diffusional effects of oxy-fuel combustion of low volatile semicoke[J]. Journal of Xi’an Jiaotong University, 2018, 52 (9): 160- 166
[23]   BEJARANO P A, LEVENDIS Y A Single-coal-particle combustion in O2/N2 and O2/CO2 environments [J]. Combustion and flame, 2008, 153 (1/2): 270- 287
doi: 10.1016/j.combustflame.2007.10.022
[24]   RATHNAM R K, ELLIOTT L K, WALL T F, et al Differences in reactivity of pulverised coal in air (O2/N2) and oxy-fuel (O2/CO2) conditions [J]. Fuel Processing Technology, 2009, 90 (6): 797- 802
doi: 10.1016/j.fuproc.2009.02.009
[25]   ENGIN B, ATAKUL H Air and oxy-fuel combustion kinetics of low rank lignites[J]. Journal of the Energy Institute, 2016, 91: 311- 322
[26]   雷鸣, 王春波, 黄星智. CO2气化反应对O2/CO2气氛中煤焦燃烧特性影响[J]. 煤炭学报, 2015, 40(增2): 511-516.
LEI Ming, WANG Chun-bo, HUANG Xing-zhi. Effect of CO2 gasification on the combustion characteristics of char under O2/CO2 atmosphere[J]. Journal of China Coal Society, 2015, 40(Suppl. 2): 511-516.
[1] Hua-mei YANG,Jing LI,Xi-hua DU. Pyrolysis and product analysis of lignin monomer model compounds[J]. Journal of ZheJiang University (Engineering Science), 2021, 55(5): 976-983.
[2] Kai ZHU,Yun-he WANG,Xue-wei QIN,Ya-dong HUANG,Qiang WANG,Ke WU. Effect of heating rate on asphalt combustion and gaseous products release characteristics[J]. Journal of ZheJiang University (Engineering Science), 2020, 54(9): 1805-1811.
[3] Xiao-jie LI,Jian-meng CEN,Zhi-xiang XIA,Meng-xiang FANG,Tao WANG,Qin-hui WANG,Zhong-yang LUO. Pressurized pyrolysis characteristics of pine sawdust and coal[J]. Journal of ZheJiang University (Engineering Science), 2019, 53(7): 1298-1305.
[4] LIU Jia-jia, CEN Jian-meng, FANG Meng-xiang, CHEN Quan-lin. Direct Current discharge characteristics under different gas compositions at high temperature[J]. Journal of ZheJiang University (Engineering Science), 2018, 52(5): 971-979.
[5] CHEN Ling hong, CHEN Xiang, WU Jian, WU Yan yan. Quantitative analysis of gaseous products evolved by coal combustion using TGFTIRMS technique[J]. Journal of ZheJiang University (Engineering Science), 2016, 50(5): 961-969.
[6] LI Jian, LIU Meng, DUAN Yu feng, XU Chao. Physicochemical analysis on hydrothermal upgrading of sewage sludge with lignite for solid fuel[J]. Journal of ZheJiang University (Engineering Science), 2016, 50(2): 327-332.
[7] NI Ming jiang, ZHAO Le, FANG Meng xiang, LI Min, LI Chao,WANG Qin hui, LUO Zhong yang. Influence of catalyst on coal pyrolysis during CH4 atmosphere[J]. Journal of ZheJiang University (Engineering Science), 2016, 50(2): 320-326.
[8] SONG Zu wei, ZHONG Zhao ping, ZHANG Bo, Lv Zi ting, DING Kuan. Experimental study on catalytic co pyrolysis of corn stalk and polypropylene[J]. Journal of ZheJiang University (Engineering Science), 2016, 50(2): 333-340.
[9] SUN Qiang, ZHANG Yan wei, LI Qian, WANG Zhi hua, GE Li chao, ZHOU Zhi jun, CHEN Ke fa. Physical and chemical characteristics and gasification reactivity of lignite fast pyrolysis char[J]. Journal of ZheJiang University (Engineering Science), 2016, 50(11): 2045-2051.
[10] WANG Gang, ZHENG Hai feng, YIN Hong, YUAN Shen feng, CHEN Zhi rong. Pyrolysis of 1-chloro-1,1 difluoroethane to vinylidene fluoride[J]. Journal of ZheJiang University (Engineering Science), 2015, 49(9): 1812-1816.
[11] PAN Zhi-juan, HUANG Qun-xing, Moussa-Mallaye Alhadj-Mallah, WANG Jun, CHI Yong, YAN Jian-hua.
Effect of active carbon on microwave pyrolysis characteristics of petroleum sludge
[J]. Journal of ZheJiang University (Engineering Science), 2015, 49(6): 1166-1172.
[12] MA Jian, XIE Yang, LUO Qi-yuan, XU Cang-su. Performance of diesel engine running on diesel fuel and its blends with refined biomass fast pyrolysis bio-oil[J]. Journal of ZheJiang University (Engineering Science), 2015, 49(4): 632-637.
[13] GE Li-chao, ZHANG Yan-wei, WANG Zhi-hua, ZHOU Jun-hu, CEN Ke-fa. Influence of microwave irradiation treatment on gasification characteristics of typical Chinese lignite[J]. Journal of ZheJiang University (Engineering Science), 2014, 48(4): 653-659.
[14] YOU Zhuo, WANG Zhi-hua, ZHOU Zhi-jun, HU Xin, ZHU Yan-qun, ZHOU Jun-hu, CEN Ke-fa. Numerical simulation of NOx emission from a 1 000 MW boiler retrofitted to oxy-fuel combustion[J]. Journal of ZheJiang University (Engineering Science), 2014, 48(11): 2080-2086.
[15] DING Kuan, ZHONG Zhao-ping, ZHANG Bo, LIU Zhi-chao. Catalytic pyrolysis of scrap tire to produce valuable liquid products using purified attapulgite[J]. Journal of ZheJiang University (Engineering Science), 2014, 48(11): 2053-2060.