The influence mechanism of dynamic metamorphism on the evolution of micro-nano pore structure in tectonically deformed coal (TDC)
-
摘要: 【目的】 煤中微纳米孔隙结构是瓦斯的主要赋存空间之一，探讨动力变质影响下构造煤微纳米孔隙结构的演化机制，有助于深入理解煤与瓦斯突出机理。【方法】 综合利用CO2吸附实验、傅里叶变换红外光谱(FTIR)测试和分子动力学模拟研究宿州祁南矿72煤层发育的不同类型构造煤微纳米孔隙结构演化特征及机理。【结果和结论】 结果表明：随着构造变形增强，超微孔(0.3~0.7 nm)孔径整体向小孔径方向偏移，微纳米孔隙体积分形维数和比表面积分形维数增大，非均质性增大，孔隙结构复杂度升高；分子结构测试和分子动学模拟结果表明，脆性变形构造煤主要发生应力降解作用，煤分子结构中氢键、脂肪侧链和含氧官能团的断裂和解离促使分子结构活动性增强，并在构造应力作用下煤大分子结构初步被压缩；脆韧性和韧性变形构造煤可以发生显著的应力缩聚作用，煤中芳香结构发生旋转、折叠和重组等化学变化，形成排列更紧密的构造煤分子结构构型。因此，随着构造变形作用增强，煤大分子结构被不断压缩改变，分子结构间隙被分割，导致微纳米孔隙结构的形态和大小发生改变，孔隙复杂度升高，孔径整体向小孔径方向偏移。Abstract: Micro-nano pore structure is one of the main occurrence spaces of gas. Exploring the evolutionary mechanism of micro-nano pore in TDC under the influence of dynamic metamorphism can help to deepen the understanding of coal and gas outburst mechanisms. The evolutionary characteristics and mechanism of micro-nano pore structure of different types of TDCs developed in 72 coal seam of Qi'nan Coal Mine in Suzhou were studied by CO2 adsorption experiment, Fourier transform infrared spectroscopy (FTIR) test and molecular dynamics simulation. The results show that with the increase of tectonic deformation, the pore size of ultra-micropores (0.3 ~ 0.7 nm) shifts to the direction of small pore size, the fractal dimension of micro-nano pore volume and the fractal dimension of specific surface area increase, the heterogeneity increases, and the complexity of pore structure increases. The results of molecular structure test and molecular dynamics simulation indicate that brittle deformed coals mainly occur through stress degradation. The breaking and dissociation of hydrogen bonds, aliphatic side chains, and oxygen-containing functional groups in the coal molecular structure enhance the activity of the molecular structure, and under the action of tectonic stress, the coal macromolecular structure is initially compressed; The brittle-ductile and ductile deformed coals undergo significant stress condensation, and the aromatic structure in coal can undergo chemical changes such as rotation, folding, and recombination, forming a more tightly arranged molecular structure configuration of coal. Therefore, with the enhancement of tectonic deformation, the structure of coal macromolecules is continuously compressed and changed, and the gaps between molecular structures are divided, resulting in changes in the morphology and size of micro-nano pore structures, an increase in pore complexity, and an overall shift in pore size towards smaller pore sizes.
-
-
[1] 肖鹏，杜媛媛.构造煤微观结构对其吸附特性的影响实验[J].西安科技大学学报，2021，41(2)：237–245. XIAO Peng，DU Yuanyuan.Experiment on the influence of microstructure of tectonic coal on its adsorption characteristics[J].Journal of Xi’an University of Science and Technology，2021，41(2)：237–245.
[2] 孟召平，张昆，沈振.构造煤与原生结构煤中甲烷扩散性能差异性分析[J].煤田地质与勘探，2022，50(3)：102–109. MENG Zhaoping，ZHANG Kun，SHEN Zhen.Difference analysis of methane diffusion properties between tectonic coal and primary coal[J].Coal Geology & Exploration，2022，50(3)：102–109.
[3] 程远平，付建华，俞启香.中国煤矿瓦斯抽采技术的发展[J].采矿与安全工程学报，2009，26(2)：127–139. CHENG Yuanping，FU Jianhua，YU Qixiang.Development of gas extraction technology in coal mines of China[J].Journal of Mining & Safety Engineering，2009，26(2)：127–139.
[4] 李明.构造煤结构演化及成因机制[D].徐州：中国矿业大学，2013.LI Ming.Structure evolution and deformation mechanism of tectonically deformed coal[D].Xuzhou：China University of Mining and Technology，2013. [5] 张小东，张瑜，张硕，等.超临界CO2对高阶构造煤微观结构的影响机制[J].煤田地质与勘探，2023，51(5)：45–53.ZHANG Xiaodong，ZHANG Yu，ZHANG Shuo，et al.Influencing mechanisms of SC-CO2 extraction on the microstructures of high-rank tectonic coals[J].Coal Geology & Exploration，2023，51(5)：45–53. [6] 杨明，柳磊，刘佳佳，等.中阶煤孔隙结构的氮吸附-压汞-核磁共振联合表征研究[J].煤炭科学技术，2021，49(5)：67–74.YANG Ming，LIU Lei，LIU Jiajia，et al.Study on joint characterization of pore structure of middle-rank coal by nitrogen adsorption-mercury intrusion-NMR[J].Coal Science and Technology，2021，49(5)：67–74. [7] 张宁远，姚素平.脆性变形序列构造煤纳米孔隙和粗糙度的原子力显微镜研究[J].煤田地质与勘探，2022，50(5)：32–42. ZHANG Ningyuan，YAO Suping.Nanopore structure and surface roughness in brittle tectonically deformed coals explored by atomic force microscopy[J].Coal Geology & Exploration，2022，50(5)：32–42.
[8] EVERETT D H.Manual of symbols and terminology for physicochemical quantities and units，appendix Ⅱ：Definitions，terminology and symbols in colloid and surface chemistry[J].Pure and Applied Chemistry，1972，31(4)：577–638.
[9] 曹涛涛，宋之光，刘光祥，等.氮气吸附法—压汞法分析页岩孔隙、分形特征及其影响因素[J].油气地质与采收率，2016，23(2)：1–8.CAO Taotao，SONG Zhiguang，LIU Guangxiang，et al.Characteristics of shale pores，fractal dimension and their controlling factors determined by nitrogen adsorption and mercury injection methods[J].Petroleum Geology and Recovery Efficiency，2016，23(2)：1–8. [10] 王士路，张开仲，杜联营，等.构造煤微观孔隙结构形态学特征及定量分析[J].西安科技大学学报，2021，41(5)：862–871. WANG Shilu，ZHANG Kaizhong，DU Lianying，et al.Morphological characteristics of microscopic pore structure of tectonic coal and its quantitative analysis[J].Journal of Xi’an University of Science and Technology，2021，41(5)：862–871.
[11] 李阳.构造煤多尺度孔隙结构与瓦斯扩散分形特征[D].焦作：河南理工大学，2019.LI Yang.Fractal characteristics of multi-scale porestructure and gas diffusion in tectonic coal[D].Jiaozuo：Henan Polytechnic University，2019. [12] 张昆，孟召平，金毅，等.不同煤体结构煤的孔隙结构分形特征及其研究意义[J].煤炭科学技术，2023，51(10)：198–206. ZHANG Kun，MENG Zhaoping，JIN Yi，et al.Fractal characteristics of pore structures on different coal structures and its research significance[J].Coal Science and Technology，2023，51(10)：198–206.
[13] JU Yiwen，JIANG Bo，HOU Quanlin，et al.Relationship between nanoscale deformation of coal structure and metamorphic-deformed environments[J].Chinese Science Bulletin，2005，50(16)：1785–1796.
[14] JU Yiwen，SUN Ying，TAN Jingqiang，et al.The composition，pore structure characterization and deformation mechanism of coal-bearing shales from tectonically altered coalfields in Eastern China[J].Fuel，2018，234：626–642.
[15] 曹运兴，张玉贵，李凯琦，等.构造煤的动力变质作用及其演化规律[J].煤田地质与勘探，1996，24(4)：15–18. CAO Yunxing，ZHANG Yugui，LI Kaiqi，et al.Tectonic coal dynamometamorphism and evolutionary process[J].Coal Geology & Exploration，1996，24(4)：15–18.
[16] 李宗翔，张明乾，杨志斌，等.FTIR和XRD在断层构造煤结构分析中的应用[J].光谱学与光谱分析，2023，43(2)：657–664. LI Zongxiang，ZHANG Mingqian，YANG Zhibin，et al.Application of FTIR and XRD in coal structural analysis of fault tectonic[J].Spectroscopy and Spectral Analysis，2023，43(2)：657–664.
[17] 郭德勇，郭晓洁，刘庆军，等.烟煤级构造煤分子结构演化及动力变质作用研究[J].中国矿业大学学报，2019，48(5)：1036–1044. GUO Deyong，GUO Xiaojie，LIU Qingjun，et al.Study of molecular structure evolution and dynamic metamorphism of bituminous deformed coal[J].Journal of China University of Mining & Technology，2019，48(5)：1036–1044.
[18] 曹代勇，李小明，张守仁.构造应力对煤化作用的影响：应力降解机制与应力缩聚机制[J].中国科学(D辑：地球科学)，2006，36(1)：59–68.CAO Daiyong，LI Xiaoming，ZHANG Shouren.Influence of tectonic stress on coalification-stress degradation mechanism and stress polycondensation mechanism[J].Science in China (Series D (Earth Sciences))，2006，36(1)：59–68. [19] PAN Jienan，WANG Sen，JU Yiwen，et al.Quantitative study of the macromolecular structures of tectonically deformed coal using high-resolution transmission electron microscopy[J].Journal of Natural Gas Science and Engineering，2015，27：1852–1862.
[20] LI Yunbo，SONG Dangyu，LIU Shimin，et al.Characterization of ultramicropores and analysis of their evolution in tectonically deformed coals by low-pressure CO2 adsorption，XRD，and HRTEM techniques[J].Energy & Fuels，2020，34(8)：9436–9449.
[21] 张开仲.构造煤微观结构精细定量表征及瓦斯分形输运特性研究[D].徐州：中国矿业大学，2020.ZHANG Kaizhong.Quantitative characterization of tectonic coal microstructure and fractal gas transport characteristics[D].Xuzhou：China University of Mining and Technology，2020. [22] 董博，曹代勇，魏迎春，等.煤变质作用的构造物理化学机理实验研究进展[J].现代地质，2024，38(4)：892–909.DONG Bo，CAO Daiyong，WEI Yingchun，et al.Advancements in experimental studies on the tectonic physical-chemical mechanisms of coal metamorphism[J].Geoscience，2024，38(4)：892–909. [23] MEYERS R A.Coal structure[M].New York：Academic Press，1982
[24] 王陆超，汪吉林，李磊.徐宿地区构造特征及其演化[J].地质学刊，2011，35(3)：247–250.WANG Luchao，WANG Jilin，LI Lei.Tectonic characteristics and their evolution in Xu-Su area[J].Journal of Geology，2011，35(3)：247–250. [25] LIU Yu，ZHU Yanming，LI Wu，et al.Ultra micropores in macromolecular structure of subbituminous coal vitrinite[J].Fuel，2017，210：298–306.
[26] 琚宜文，姜波，侯泉林，等.构造煤结构-成因新分类及其地质意义[J].煤炭学报，2004，29(5)：513–517.JU Yiwen，JIANG Bo，HOU Quanlin，et al.The new structure-genetic classification system in tectonically deformed coals and its geological significance[J].Journal of China Coal Society，2004，29(5)：513–517. [27] LIU Hewu.Evolution of the hierarchical molecular structures of tectonically deformed coals：Insights from first-order Raman spectra[J].ACS Omega，2022，7(40)：35942–35950.
[28] JIANG Bo，QU Zhenghui，WANG G G X，et al.Effects of structural deformation on formation of coalbed methane reservoirs in Huaibei coalfield，China[J].International Journal of Coal Geology，2010，82(3/4)：175–183.
[29] 姜波，李明，宋昱，等.构造煤及其瓦斯地质意义[M].北京：科学出版社，2020. [30] GROEN J C，PEFFER L A A，PÉREZ-RAMıREZ J.Pore size determination in modified micro- and mesoporous materials.Pitfalls and limitations in gas adsorption data analysis[J].Microporous and Mesoporous Materials，2003，60(1/2/3)：1–17.
[31] 李明，姜波，秦勇，等.构造煤中矿物质对孔隙结构的影响研究[J].煤炭学报，2017，42(3)：726–731. LI Ming，JIANG Bo，QIN Yong，et al.Analysis of mineral effect on coal pore structure of tectonically deformed coal[J].Journal of China Coal Society，2017，42(3)：726–731.
[32] WANG Fumin，LI Shaofen.Determination of the surface fractal dimension for porous media by capillary condensation[J].Industrial & Engineering Chemistry Research，1997，36(5)：1598–1602.
[33] LIU Hewu，JIANG Bo.Stress response of noncovalent bonds in molecular networks of tectonically deformed coals[J].Fuel，2019，255：115785.
[34] 宋昱.低中阶构造煤纳米孔及大分子结构演化机理[D].徐州：中国矿业大学，2019.SONG Yu.Evolution mechanism of nano-pore andmacromolecule in low and middle-ranktectonically deformed coals (TDCs[D].Xuzhou：China University of Mining and Technology，2019. [35] 贾廷贵，李璕，曲国娜，等.不同变质程度煤样化学结构特征FTIR表征[J].光谱学与光谱分析，2021，41(11)：3363–3369. JIA Tinggui，LI Xun，QU Guona，et al.FTIR characterization of chemical structures characteristics of coal samples with different metamorphic degrees[J].Spectroscopy and Spectral Analysis，2021，41(11)：3363–3369.
[36] NISHIOKA M，LARSEN J W.Association of aromatic structures in coals[J].Energy & Fuels，1990，4(1)：100–106.
[37] CHEN Yanyan，MASTALERZ M，SCHIMMELMANN A.Characterization of chemical functional groups in macerals across different coal ranks via micro-FTIR spectroscopy[J].International Journal of Coal Geology，2012，104：22–33.
[38] 范顺利，李云波，宋党育，等.不同变形机制下构造煤大分子结构演化机理[J].煤炭科学技术，2019，47(11)：239–246. FAN Shunli，LI Yunbo，SONG Dangyu，et al.Macromolecular structure evolution mechanism of tectonically deformed coal under different deformation mechanisms[J].Coal Science and Technology，2019，47(11)：239–246.
[39] 李霞，曾凡桂，王威，等.低中煤级煤结构演化的FTIR表征[J].煤炭学报，2015，40(12)：2900–2908.LI Xia，ZENG Fangui，WANG Wei，et al.FTIR characterization of structural evolution in low-middle rank coals[J].Journal of China Coal Society，2015，40(12)：2900–2908. [40] LIU Hewu，JIANG Bo，SONG Yu，et al.The tectonic stress–driving alteration and evolution of chemical structure for low- to medium-rank coals—By molecular simulation method[J].Arabian Journal of Geosciences，2019，12(23)：726.
计量
- 文章访问数: 39
- HTML全文浏览量: 17
- PDF下载量: 8
下载:
