Microstructure evolution characteristics of Shengli lignite during combustion process
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摘要: 对胜利脱灰褐煤的燃烧反应性进行了测试,并利用FT-IR、XPS、XRD和Raman等对不同条件下的未反应残留物进行了表征,以分析胜利脱灰褐煤在燃烧过程中微结构演变特性。结果表明,在燃烧反应过程中,煤样的脂肪族官能团不断消耗,碳氧官能团和芳烃骨架的消耗与生成交替进行,褐煤表面C-C/C-H键合结构所占比例先增加后减少,碳-氧键合结构所占比例先减小后增加,未反应残留物的芳香度不断升高,褐煤的石墨缺陷指数先增加后降低,而脂肪族侧链指数则呈现先减少后增加的变化规律,表明随着燃烧反应进行对褐煤未反应残留物的石墨化程度逐渐提高,特别是在燃烧反应后期,石墨化程度显著提高。Abstract: The combustion of Shengli lignite demineralized with hydrochloric acid was carried and residues from different reaction conditions were obtained. The microstructural properties of the lignite and residues were examined by FT-IR, XRD, XPS and Raman, respectively. The results indicate that aliphatic functional groups were consumed during combustion, while oxygen-containing groups and aromatic structure were consumed and generated alternatively. The proportion of C-C/C-H structure decreased after increasing, while the content of carbon-oxygen structure was increased following decrease. The aromaticity of residues increased and ID/IG increased before decrease, while IS/IG decreased before increase. This indicated that graphitization transformation degree of lignite obviously increased during combustion, especially in the late stage of reaction.
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表 1 煤样的工业分析和元素分析
Table 1 Proximate analysis and ultimate of coal samples
Sample Proximate analysis wd/% Ultimate analysis wd/% A V FC C H N S+O* SL 13.92 33.37 52.71 66.90 4.16 1.03 27.90 SL+ 7.53 39.77 52.70 66.43 3.61 0.93 29.03 note: d: dried basis; A: ash content; V: volatile content; FC: fixed carbon; O*: by difference 表 2 煤样及煤灰中金属组分分布
Table 2 Percentage of metal components in coal samples and ash
Sample Coal based/Ash based w/% Al Na Ca Si Fe Mn K SL 2.40/35.50 0.58/8.59 0.41/6.08 3.11/46.09 0.11/0.69 0.08/1.18 0.06/0.88 SL+ 0.90/32.94 0.00/0.16 0.01/0.19 2.89/64.58 0.03/0.92 0.03/1.18 0.00/0.03 表 3 煤样及未反应残留物的晶体结构参数
Table 3 Crystalline structure parameters of SL+ and solid residues
Sample fa d002/nm Lc/nm La/nm N SL+-0 0.447 0.363 2 0.817 4 0.961 2 2.248 1 SL+-5 0.463 0.359 0 0.976 7 1.279 6 2.720 6 SL+-10 0.492 0.365 4 0.932 1 1.795 9 2.550 9 SL+-20 0.573 0.363 0 0.964 2 1.696 9 2.656 2 SL+-40 0.631 0.356 5 0.920 9 1.496 4 2.583 2 表 4 煤样及未反应残留物的Raman谱图拟合参数
Table 4 Raman spectra fitting parameters of SL+ and solid residues
Sample ID/IG ID/(ID+IG) IG/(ID+IG) (ID+IG)/Iall ID/I(GR+VR+VL) IS/IG SL+-0 0.897 0.473 0.527 0.486 1.216 0.419 SL+-5 0.918 0.479 0.521 0.539 1.670 0.385 SL+-10 1.607 0.616 0.384 0.615 2.845 0.343 SL+-20 1.335 0.571 0.428 0.513 1.591 0.418 SL+-40 0.964 0.491 0.509 0.480 1.174 0.464 -
[1] YANG X J, ZHANG C, TAN P, TANG T, YANG T, FANG Q Y, CHEN G. Properties of upgraded Shengli lignite and its behavior of gasfication[J]. Energy Fuels, 2014, 28(1):264-274. doi: 10.1021/ef401497a [2] 甘萍香. 褐煤、烟煤、无烟煤及其混煤的燃烧特性研究[D]. 昆明: 昆明理工大学, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10674-1013347090.htmGAN Xiang-ping. Study on characteristics of blended coal which formed by lignite, bituminous coal, anthracite[D]. Kunming:Kunming University of Science and Technology, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10674-1013347090.htm [3] 孙云, 王长安, 刘京燕, 车的福.混煤燃烧技术研究进展[J].电站系统工程, 2011, 27(2):1-3. http://www.wenkuxiazai.com/doc/c7236b1aa300a6c30c229f57.htmlSUN Yun, WANG Chang-an, LIU Jing-yan, CHE De-fu. Research process on blended coal combustion[J]. Power Sys Eng, 2011, 27(2):1-3. http://www.wenkuxiazai.com/doc/c7236b1aa300a6c30c229f57.html [4] 李春柱, 余江龙, 常丽萍.维多利亚褐煤科学进展[M].北京:化学工业出版社, 2009.LI Chun-zhu, YU Jiang-long, CHANG Li-ping. Advances in the Science of Victorian Brown Coal[M]. Beijing:Chemical Industry Press, 2009. [5] MEGARITIS A, MESSENBOCK R C. High-pressure pyrolysis and CO2 gasification of coal maceral concentrates conversion and char combustion reactivities[J]. Fuel, 1999, 78(8):871-882. doi: 10.1016/S0016-2361(99)00003-4 [6] MENDEZ L B, BORREGO A G, MARTINEZ T M R, MENENDEZ R. Influence of petrographic and mineral matter composition of coal particles on their combustion reactivity[J]. Fuel, 2003, 82:1875-1882. doi: 10.1016/S0016-2361(03)00190-X [7] RUBIERA T, ARENILLAS A, PEVIDA C, GAICIA R. Coal structure and reactivity changes induced by chemical demineralization[J]. Fuel Process Technol, 2002, 79(3):273-279. doi: 10.1016/S0378-3820(02)00185-6 [8] TEKELY P, NICOLE D, DELPUECH J J. Chemical structure changes in coals after low-temperature oxidation and demineralization by acid treatment as revealed by high resolusion solid state 13C NMR[J]. Fuel Process Technol, 1987, 15:225-231. http://www.sciencedirect.com/science/article/pii/0378382087900476 [9] ACMA H H, YAVUZ R, MERICBOYU A E, KUCUKBAYRAK S. Effect of mineral matter on the reactivity of lignite[J]. Thermochim Acta, 1999, 342:79-84. doi: 10.1016/S0040-6031(99)00209-9 [10] YURUM Y, ALTUNTAS N. Air oxidation of Beypazari lignite at 50℃, 100℃ and 150℃[J]. Fuel, 1998, 77(15):1809-1814. doi: 10.1016/S0016-2361(98)00067-2 [11] 严荣林, 钱国胤.煤的分子结构与煤氧化自燃的气体产物[J].煤炭学报, 1995, 20(S1):58-64. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb5s1.011&dbname=CJFD&dbcode=CJFQYAN Rong-lin, QIAN Guo-yin. Molecular structure of coal and gases produced by coal oxidation[J]. J Chin Coal Soc, 1995, 20(S1):58-64. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb5s1.011&dbname=CJFD&dbcode=CJFQ [12] 张国枢, 谢应明, 顾建明.煤炭自燃微观结构变化的红外光谱分析[J].煤炭学报, 2003, 28(5):473-476. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb200305006&dbname=CJFD&dbcode=CJFQZHANG Guo-shu, XIE Ying-ming, GU Jian-ming. Infrared spectral analysis of microstructure change during the coal spontaneous oxidation[J]. J Chin Coal Soc, 2003, 28(5):473-476. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb200305006&dbname=CJFD&dbcode=CJFQ [13] 董庆年, 陈学艺, 靳国强, 顾永达.红外发射光谱法原位研究褐煤的低温氧化过程[J].燃料化学学报, 1997, 25:333-338. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=rlhx704.009&dbname=CJFD&dbcode=CJFQDONG Qing-nian, CHEN Xue-yi, JIN Guo-qiang, GU Yong-da. Study of lignite oxidation at low temperature by FT-IR emission spectroscopy[J]. J Fuel Chem Technol, 1997, 25:333-338. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=rlhx704.009&dbname=CJFD&dbcode=CJFQ [14] 戴广龙.煤低温氧化过程中微晶结构变化规律研究[J].煤炭学报, 2011, 36:322-325. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb201102032&dbname=CJFD&dbcode=CJFQDAI Guang-long. Research on microcrystalline structure change regularity in the coal low temperature oxidation process[J]. J Chin Coal Soc, 2011, 36:322-325. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=mtxb201102032&dbname=CJFD&dbcode=CJFQ [15] SONG Y M, FENG W, LI N, LI Y, ZHI K D, TENG Y Y, HE R X, ZHOU H C, LIU Q S. Effects of demineralization on the Structure and Combustion Properties of Shengli Lignite[J]. Fuel, 2016, 183:659-667. doi: 10.1016/j.fuel.2016.06.109 [16] 宋银敏, 冯伟, 王云飞, 李娜, 班延鹏, 滕英跃, 智科端, 何润霞, 周华从, 刘全生.胜利褐煤燃烧中未反应残留物结构特性及铁的添加效应[J].燃料化学学报, 2016, 44(12):1447-1456. doi: 10.3969/j.issn.0253-2409.2016.12.006SONG Yin-min, FENG Wei, WANG Yun-fei, LI Na, BAN Yan-peng, TENG Ying-yue, ZHI Ke-duan, HE Run-xia, ZHOU Hua-cong, LIU Quan-sheng. Structure characteristics of unreacted residues in the processes of Shengli lignite combustion and effect of adding Fe components[J]. J Fuel Chem Technol, 2016, 44(12):1447-1456. doi: 10.3969/j.issn.0253-2409.2016.12.006 [17] LI Y, ZHOU C L, LI N, ZHI K D, SONG Y M, HE R X, TENG Y Y, LIU Q S. Production of high H2/CO syngas by steam gasification of Shengli lignite:catalytic effect of inherent minerals[J]. Energy Fuels, 2015, 29:4738-4746. doi: 10.1021/acs.energyfuels.5b00168 [18] 石金明, 向军, 胡松, 孙路石, 苏胜, 徐朝芬, 许凯.洗煤过程中煤结构的变化[J].化工学报, 2010, 61:3220-3227. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=hgsz201012027&dbname=CJFD&dbcode=CJFQSHI Jin-ming, XIANG Jun, HU Song, SUN Lu-shi, SU Sheng, XU Chao-fen, XU Kai. Change of coal structure during washing process[J]. J Chem Ind Eng, 2010, 61:3220-3227. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=hgsz201012027&dbname=CJFD&dbcode=CJFQ [19] SHINN J H. From coal to sigle stage and two stages products:A reactive model of coal structure[J]. Fuel, 1984, 63:1187-1196. doi: 10.1016/0016-2361(84)90422-8 [20] TONG J H, HAN X X, WANG S, JIANG X M. Evaluation of structural characteristics of Huadian oil shale kerogen using cirect techniques (solid-state 13C NMR, XPS, FT-IR, and XRD)[J]. Energy Fuels, 2011, 25:4006-4013. doi: 10.1021/ef200738p [21] WANG Y G, WEI X Y, XIE R L, LIU F J, LI P, ZONG Z M. Structural characterization of typical organic species in Jincheng No.15 anthracite[J]. Energy Fuels, 2015, 29:595-601. doi: 10.1021/ef502373p [22] LI Z K, WEI X Y, YAN H L, ZONG Z M. Insight into the structural features of Zhaotong lignite using multiple techniques[J]. Fuel, 2015, 153:176-182. doi: 10.1016/j.fuel.2015.02.117 [23] GENG W H, YASUTAKA K, TSUNENORI N, HIROKAZU T, AKIRA O. Analysis of hydrothermally-treated and weathered coals by X-ray photoelectron spectroscopy (XPS)[J]. Fuel, 2009, 88:644-649. doi: 10.1016/j.fuel.2008.09.025 [24] 常海洲, 王传格, 曾凡桂, 李军, 李文英, 谢克昌.不同还原程度煤显微组分组表面结构XPS对比分析[J].燃料化学学报, 2006, 34:389-394. doi: 10.3969/j.issn.0253-2409.2006.04.002CHANG Hai-zhou, WANG Chuan-ge, ZENG Fan-gui, LI Jun, LI Wen-ying, XIE Ke-chang. XPS comparative analysis of coal macerals with different reducibility[J]. J Fuel Chem Technol, 2006, 34:389-394. doi: 10.3969/j.issn.0253-2409.2006.04.002 [25] ANDREDA S M, ANDRE S M, ANTONIO C F V, EDUARDO O. Study of coal, char and coke fines structures and their proportions in the off-gas blast furnace samples by X-ray diffraction[J]. Fuel, 2013, 114:224-228. doi: 10.1016/j.fuel.2012.07.064 [26] OLUWADAYO O S, TOBIAS H, STEPHEN F F. Structural characterization of Nigerian coals by X-ray diffraction, Raman and FTIR spectroscopy[J]. Energy, 2010, 35(12):5347-5353. doi: 10.1016/j.energy.2010.07.025 [27] GUEDES A, VALENTIM B, PRIETO A C, NORONHA F. Raman spectroscopy of coal macerals and fluidized bed char morphotypes[J]. Fuel, 2012, 97:443-449. doi: 10.1016/j.fuel.2012.02.054 [28] LI X J, HAYASHI J, LI C Z. FT-Raman spectroscopic study of the evolution of char structure during the pyrolisis of a Victorian brown coal[J]. Fuel, 2006, 85:1700-1707. doi: 10.1016/j.fuel.2006.03.008 [29] 李美芬, 曾凡桂, 齐福辉, 孙蓓蕾.不同煤级煤的Raman谱特征及XRD结构参数的关系[J].光谱学与光谱分析, 2009, 29:2446-2449. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201503022.htmLI Mei-fen, ZENG Fan-gui, QI Fu-hui, SUN Bei-lei. Raman spectroscopic characteristics of different rank coals and the relation with XRD structural parameters[J]. Spectr Spect Anal, 2009, 29:2446-2449. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201503022.htm [30] 公旭中, 郭占成, 王志. Fe2O3对高变质程度脱灰煤热解反应性及半焦结构的影响[J].化工学报, 2009, 60(9):2321-2325. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=hgsz200909030&dbname=CJFD&dbcode=CJFQGONG Xu-zhong, GUO Zhan-cheng, WANG Zhi. Effects of Fe2O3 on pyrolysis reactivity of demineralized higher rank coal and its char structure[J]. J Chem Ind Eng, 2009, 60(9):2321-2325. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=hgsz200909030&dbname=CJFD&dbcode=CJFQ