Molecular structures and comparative analysis of macerals of vitrinite and inertinite for Qinghua coal, Ningxia

doi:10.16085/j.issn.1000-6613.2020-0286

Abstract

Abstract:

The macerals of Qinghua coal in Ningxia were separated by density gradient centrifugation to obtain vitrinite and inertinite. The physical properties of different macerals were characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), solid ¹³C nuclear magnetic resonance (¹³C NMR), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) technology. Further, based on the statistical average molecular structure approximation combined with molecular modeling calculations, the molecular structures of vitrinite and inertinite for Qinghua coal can be expressed as C₂₆₉H₁₉₆N₄O₁₃S and C₂₅₅H₁₇₉N₃O₁₄S, respectively. Through the verification of FTIR and ¹³C NMR spectra, the molecular structure of different macerals was described. The molecular models and structural parameters of two macerals were compared and analyzed systematically, and it found that the aromatic carbon percentage of vitrinite and inertinite were 51.95 and 62.16, respectively. In the vitrinite model, the number of aromatic carbon structure is less, the fatty carbon structure is rich, the unsaturation is smaller, and the reduction degree is the largest. While in the inertinite model, the number of aromatic carbon structure is the largest, the number of fatty carbon structure is small, the unsaturation is the largest, and the degree of coalification is high. Furthermore, the vitrinite is the main component of raw coal because of its high content. The content of inertinite is low and the condensation degree of macromolecular structure is high, which is distributed in the matrix of vitrinite.

Key words: coal, macerals, model, computer simulation, kinetics

摘要：

使用密度梯度离心法对宁夏庆华煤的显微组分进行分离，获得煤的镜质组和惰质组。通过元素分析、X射线光电子能谱（XPS）、固体¹³C核磁共振（¹³C NMR）技术、傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）技术等表征手段对不同显微组分进行物性表征。进一步基于统计平均的分子结构近似结合分子模拟计算，确定庆华煤镜质组和惰质组显微组分的分子结构可分别表示为C₂₆₉H₁₉₆N₄O₁₃S和C₂₅₅H₁₇₉N₃O₁₄S。通过FTIR光谱与¹³C NMR光谱验证，从而实现了不同显微组分的分子结构描述。对两种显微组分的分子模型和结构参数进行了系统对比分析，发现镜质组的芳碳百分数为51.95，惰质组的芳碳百分数为62.16。镜质组模型中芳碳结构数目较少，脂肪碳结构丰富，不饱和度较小，还原度最大。惰质组模型中芳碳结构数量最大，脂肪碳结构数目少，不饱和度最大，煤化程度高。镜质组在原煤中含量高，是原煤的主要组成。惰质组的含量少且大分子结构缩合度高，分布在镜质组构成的基体中。

关键词: 煤, 显微组分, 模型, 计算机模拟, 动力学

CLC Number:

TQ530

Qiang WANG, Ning MAO, Yan YANG, Jinpeng ZHANG, Hongcun BAI. Molecular structures and comparative analysis of macerals of vitrinite and inertinite for Qinghua coal, Ningxia[J]. Chemical Industry and Engineering Progress, 2020, 39(S2): 142-151.

王强, 毛宁, 杨妍, 张金鹏, 白红存. 宁夏庆华煤镜质组和惰质组显微组分的分子结构及对比分析[J]. 化工进展, 2020, 39(S2): 142-151.

Figures/Tables 12

样品	工业分析（质量分数）/%				岩相分析（质量分数）/%				R_max
样品	M_ad^①	A_ad^②	V_daf^③	FC_d^④	镜质组	惰质组	壳质组	矿物质	R_max
QH	0.86	10.81	19.70	71.62	88.4	7.8	0.0	3.8	1.38%

样品	元素分析（质量分数，干燥无灰基）/%					原子比				A_ad/%
样品	C	H	O	N	S	H/C	O/C	N/C	S/C	A_ad/%
镜质组	86.62	5.25	5.47	1.59	1.07	0.7273	0.0474	0.0157	0.0046	4.10
惰质组	86.24	5.02	6.49	1.37	0.88	0.6985	0.0564	0.0136	0.0038	7.58

样品	f_a^①	$f a c$ ^②	$f a'$ ^③	$f a H$ ^④	$f a N$ ^⑤	$f a P$ ^⑥	$f a S$ ^⑦	$f a B$ ^⑧	f_al^⑨	$f a 1 *$ ^⑩	$f a 1 H$ ^?	$f a 1 O$ ^?
镜质组	64.97	13.00	51.95	34.44	17.51	1.24	7.30	8.97	35.03	10.91	19.19	4.93
惰质组	76.43	14.27	62.16	44.75	17.41	0.87	4.30	12.24	23.57	9.05	9.61	4.91

样品	f_a^①	$f a c$ ^②	$f a'$ ^③	$f a H$ ^④	$f a N$ ^⑤	$f a P$ ^⑥	$f a S$ ^⑦	$f a B$ ^⑧	f_al^⑨	$f a 1 *$ ^⑩	$f a 1 H$ ^?	$f a 1 O$ ^?
镜质组	64.97	13.00	51.95	34.44	17.51	1.24	7.30	8.97	35.03	10.91	19.19	4.93
惰质组	76.43	14.27	62.16	44.75	17.41	0.87	4.30	12.24	23.57	9.05	9.61	4.91

芳环类型	芳环数目		芳环类型	芳环数目
芳环类型	镜质组	惰质组	芳环类型	镜质组	惰质组
	3	2		2	1
	1	1		1	1
	1	1		1	1
	3	6		1	0
	3	5		0	1
	2	2

样品	分子式	分子质量/g·mol^-1	芳碳C_ar/个	脂肪碳C_a/个	X_BP	$f a'$ /%	δ	n_CB	n_aT	n_C	n_aT/n_C	B/%
镜质组	C₂₆₉H₁₉₆O₁₃N₄S	3720	173	96	0.173	51.95	9.27	17.64	13.01	7.23	1.80	28.89
惰质组	C₂₅₅H₁₇₉O₁₄N₃S	3536	195	60	0.20	62.16	9.41	17.51	12.81	7.21	1.78	27.34

样品	分子式	分子质量/g·mol^-1	芳碳C_ar/个	脂肪碳C_a/个	X_BP	$f a'$ /%	δ	n_CB	n_aT	n_C	n_aT/n_C	B/%
镜质组	C₂₆₉H₁₉₆O₁₃N₄S	3720	173	96	0.173	51.95	9.27	17.64	13.01	7.23	1.80	28.89
惰质组	C₂₅₅H₁₇₉O₁₄N₃S	3536	195	60	0.20	62.16	9.41	17.51	12.81	7.21	1.78	27.34

References 47

1	WANG Keying, WU Meng, SUN Yongping, et al. Resource abundance, industrial structure, and regional carbon emissions efficiency in China[J]. Resources Policy, 2019, 60: 203-214.
2	SONG Malin, WANG Jianlin, ZHAO Jiajia. Coal endowment, resource curse, and high coal-consuming industries location: analysis based on large-scale data[J]. Resources, Conservation and Recycling, 2018, 129: 333-344.
3	ZHANG Lei, HE Chaonan, YANG Anquan, et al. Modeling and implication of coal physical input-output table in China—based on clean coal concept[J]. Resources, Conservation and Recycling, 2018, 129: 355-365.
4	MATHEWS Jonathan P, CHAFFEE Alan L. The molecular representations of coal—a review[J]. Fuel, 2012, 96: 1-14.
5	崔馨, 严煌, 赵培涛. 煤分子结构模型构建及分析方法综述[J]. 中国矿业大学学报, 2019, 48(4): 704-717.
	CUI Xin, YAN Hang, ZHAO Peitao. A review on the model construction and analytical methods of coal molecular structure[J]. Journal of China University of Mining & Technology, 2019, 48(4): 704-717.
6	MATHEWS Jonathan P, DUIN Adri C T VAN, CHAFFEE Alan L. The utility of coal molecular models[J]. Fuel Processing Technology, 2011, 92(4): 718-728.
7	LIU Jiaxun, JIANG Yuanzhen, YAO Wang, et al. Molecular characterization of Henan anthracite coal[J]. Energy & Fuels, 2019, 33(7): 6215-6225.
8	WANG Jieping, LI Guangyue, GUO Rui, et al. Theoretical and experimental insight into coal structure: establishing a chemical model for Yuzhou lignite[J]. Energy & Fuels, 2016, 31(1): 124-132.
9	LIN Hualin, LI Kejian, ZHANG Xuwen, et al. Structure characterization and model construction of Indonesian brown coal[J]. Energy & Fuels, 2015, 30(5): 3809-3814.
10	柏静儒, 陈嘉彬, 李坤, 等. 印尼油砂沥青组成及化学结构分析[J]. 化工进展, 2019, 38(7): 3117-3125.
	BAI Jingru, CHEN Jiabin, LI Kun, et al. Analysis of composition and chemical structure of Indonesian oil sands bitumen[J]. Chemical Industry and Engineering Progress, 2019, 38(7): 3117-3125.
11	YAN Guochao, REN Gang, BAI Longjian, et al. Molecular model construction and evaluation of Jincheng anthracite[J]. ACS Omega, 2020, 5(19): 10663-10670.
12	FAN Zheyong, CHEN Wei, VIERIMAA Ville, et al. Efficient molecular dynamics simulations with many-body potentials on graphics processing units[J]. Computer Physics Communications, 2017, 218: 10-16.
13	Fidel CASTRO-MARCANO, LOBODIN Vladislav V, RODGERS Ryan P, et al. A molecular model for Illinois No. 6 argonne premium coal: moving toward capturing the continuum structure[J]. Fuel, 2012, 95: 35-49.
14	SALMON Elodie, DUIN Adri C VAN.T, LORANT François,et al. Early maturation processes in coal. Part 2: reactive dynamics simulations using the ReaxFF reactive force field on Morwell brown coal structures[J]. Organic Geochemistry, 2009, 40(12): 1195-1209.
15	CHEN Bo, DIAO Zhijun, LU Haiyun. Using the ReaxFF reactive force field for molecular dynamics simulations of the spontaneous combustion of lignite with the hatcher lignite model[J]. Fuel, 2014, 116: 7-13.
16	ZHENG Mo, LI Xiaoxia, WANG Meijun, et al. Dynamic profiles of tar products during Naomaohu coal pyrolysis revealed by large-scale reactive molecular dynamic simulation[J]. Fuel, 2019, 253: 910-920.
17	XU Fang, PAN Shuo, LIU Chunguang, et al. Construction and evaluation of chemical structure model of Huolinhe lignite using molecular modeling[J]. RSC Advances, 2017, 7(66): 41512-41519.
18	XU Fang, LIU Hui, WANG Qing, et al. Study of non-isothermal pyrolysis mechanism of lignite using ReaxFF molecular dynamics simulations[J]. Fuel, 2019, 256: 115884.
19	HONG Dikun, GUO Xin. Molecular dynamics simulations of Zhundong coal pyrolysis using reactive force field[J]. Fuel, 2017, 210: 58-66.
20	GAO Mingjie, LI Xiaoxia, GUO Li. Pyrolysis simulations of Fugu coal by large-scale ReaxFF molecular dynamics[J]. Fuel Processing Technology, 2018, 178: 197-205.
21	GAO Mingjie, LI Xiaoxia, REN Chunxing, et al. Construction of a multicomponent molecular model of Fugu coal for ReaxFF-MD pyrolysis simulation[J]. Energy & Fuels, 2019, 33(4): 2848-2858.
22	周星宇, 曾凡桂, 相建华, 等. 马脊梁镜煤有机质大分子模型构建及分子模拟[J]. 化工学报, 2019, 70: 1-14.
	ZHOU Xingyu, ZENG Fangui, XIANG Jianhua, et al. Macromolecular model construction and molecular simulation of organic matter in Majiliang vitrain[J]. CIESC Journal, 2019, 70: 1-14.
23	FENG Wei, LI Zhuangmei, GAO Hongfeng, et al. Understanding the molecular structure of HSW coal at atomic level: a comprehensive characterization from combined experimental and computational study[J]. Green Energy & Environment, 2020, doi: 10.1016/j.gee.2020.03.013.
24	DUIN Adri CT VAN, DASGUPTA Siddharth, LORANT Francois, et al. ReaxFF: a reactive force field for hydrocarbons[J]. The Journal of Physical Chemistry A, 2001, 105(41): 9396-9409.
25	CHENOWETH Kimberly, DUIN Adri CT VAN, GODDARD William A. ReaxFF reactive force field for molecular dynamics simulations of hydrocarbon oxidation[J]. The Journal of Physical Chemistry A, 2008, 112(5): 1040-1053.
26	DUIN Adri C T VAN, GODDARD William A, SCHOOT H VAN, et al. ReaxFF 2017[C]. SCM, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands, .
27	FRISCH M J, TRUCKS G W, SCHLEGEL H B, et al. Gaussian 09[C]. Gaussian, Inc, Pittsburgh P A, 2009.
28	李壮楣, 王艳美, 李平, 等. 宁东红石湾煤大分子模型构建及量子化学计算[J]. 化工学报, 2018, 69(5): 2208-2216.
	LI Zhuangmei, WANG Yanmei, LI Ping, et al. Macromolecule model construction and quantum chemical calculation of Ningdong Hongshiwan coal[J]. CIESC Journal, 2018, 69(5): 2208-2216.
29	久利马里耶夫. 煤结构-化学指数分类与应用[M]. 聂书岭, 马凤云, 译. 北京: 化学工业出版社, 2013: 33.
	Giulimareyev. Coal structure-chemical index classification and application[M]. NIE Shuling, MA Fengyun, trans. Beijing: Chemical Industry Press, 2013: 33.
30	FENG Li, ZHAO Guangyao, ZHAO Yingya, et al. Construction of the molecular structure model of the Shengli lignite using TG-GC/MS and FTIR spectrometry data[J]. Fuel, 2017, 203: 924-931.
31	LIU Xianfeng, SONG Dazhao, HE Xueqiu, et al. Insight into the macromolecular structural differences between hard coal and deformed soft coal[J]. Fuel, 2019, 245: 188-197.
32	HE Xueqiu, LIU Xianfeng, NIE Baisheng, et al. FTIR and Raman spectroscopy characterization of functional groups in various rank coals[J]. Fuel, 2017, 206: 555-563.
33	段春婷, 刘均庆, 徐文强, 等. 三种不同原料中间相沥青的性质表征[J]. 化工进展, 2018, 37(1): 189-194.
	DUAN Chunting, LIU Junqing, XU Wenqiang, et al. Characterization of mesophase pitches made from three different raw materials[J]. Chemical Industry and Engineering Progress, 2018, 37(1): 189-194.
34	KELEMEN S R, AFEWORKI M, GORBATY M L,et al. Characterization of organically bound oxygen forms in lignites, peats, and pyrolyzed peats by X-ray photoelectron spectroscopy (XPS) and solid-state ¹³C NMR methods[J]. Energy & Fuels, 2002, 16(6): 1450-1462.
35	LI Zhanku, WEI Xianyong, YAN Honglei, et al. Insight into the structural features of Zhaotong lignite using multiple techniques[J]. Fuel, 2015, 153: 176-182.
36	WANG Yugao, WEI Xianyong, WANG Shengkang, et al. Structural evaluation of Xiaolongtan lignite by direct characterization and pyrolytic analysis[J]. Fuel Processing Technology, 2016, 144: 248-254.
37	杜鸿飞, 段钰锋, 佘敏. 高硫石油焦热解过程及硫形态的变化特性[J]. 化工进展, 2016, 35(8): 2420-2425.
	DU Hongfei, DUAN Yufeng, SHE Min. Research on pyrolysis process of high sulfur petroleum coke and the changes of sulfur species[J]. Chemical Industry and Engineering Progress, 2016, 35(8): 2420-2425.
38	SUPALUKNARI S, LARKINS F P, REDLICH P, et al. Determination of aromaticities and other structural features of Australian coals using solid state ¹³C NMR and FTIR spectroscopies[J]. Fuel Processing Technology, 1989, 23(1): 47-61.
39	王擎, 王智超, 贾春霞, 等. 基于固体 ¹³C 核磁共振技术对油砂沥青质结构的研究[J]. 化工进展, 2014, 33(6): 1392-1396.
	WANG Qiang, WANG Zhichao, JIA Chunxia, et al. Study on structural features of oil sands with solid state ¹³C NMR[J]. Chemical Industry and Engineering Progress, 2014, 33(6): 1392-1396.
40	CUI Xin, YAN Huang, ZHAO Peitao, et al. Modeling of molecular and properties of anthracite base on structural accuracy identification methods[J]. Journal of Molecular Structure, 2019, 1183: 313-323.
41	谢克昌. 煤的结构与反应[M]. 北京: 科学出版社, 2002: 88.
	XIE Kechang. Coal structure and its reactivity[M]. Beijing: Science Press, 2002: 88.
42	冯炜, 高红凤, 王贵, 等. 枣泉煤分子模型构建及热解的分子模拟[J]. 化工学报, 2019, 70(4): 1522-1531.
	FENG Wei, GAO Hongfeng, WANG Gui, et al. Molecular model and pyrolysis simulation of Zaoquan coal[J]. CIESC Journal, 2019, 70(4): 1522-1531.
43	SHI Kaiyi, GUI Xiahui, TAO Xiuxiang, et al. Macromolecular structural unit construction of Fushun nitric-acid-oxidized coal[J]. Energy & Fuels, 2015, 29(6): 3566-3572.
44	XIANG Jianhua, ZENG Fangui, LI Bin, et al. Construction of macromolecular structural model of anthracite from Chengzhuang coal mine and its molecular simulation[J]. Journal of Fuel Chemistry and Technology, 2013, 41(4): 391-400.
45	XIANG Jianhua, ZENG Fangui, LIANG Huzhen, et al. Model construction of the macromolecular structure of Yanzhou coal and its molecular simulation[J]. Journal of Fuel Chemistry and Technology, 2011, 39(7): 481-488.
46	MENG Junqing, ZHONG Ruquan, LI Shichao, et al. Molecular model construction and study of gas adsorption of Zhaozhuang coal[J]. Energy & Fuels, 2018, 32(9): 9727-9737.
47	WANG Jie, HE Yaqun, LI Hong, et al. The molecular structure of Inner Mongolia lignite utilizing XRD, solid state ¹³C NMR, HRTEM and XPS techniques[J]. Fuel, 2017, 203: 764-773.

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