Combined Characterization of Scanning Electron Microscopy, Pore and Crack Analysis System, and Gas Adsorption on Pore Structure of Coal with Different Volatilization
-
摘要: 为了定量表征煤的孔隙结构，研究煤孔隙特征与吸附性能的内在联系，采用低温液氮吸附法（LP-N2GA）、CO2吸附法、扫描电镜（SEM）和孔隙-裂隙分析系统（PCAS）对6种不同变质程度煤样进行孔隙相关分析.煤样孔隙分布相似时，煤样对N2和CO2的吸附能力、孔隙率的近似概率密度和孔隙面积（中孔）与煤的挥发分呈负相关，煤样孔隙的分形维数与煤的挥发分呈正相关.煤样的孔隙分布差异较大时，煤样对N2和CO2的最大吸附容量与孔隙分布有关.建立了煤纳米孔结构的联合表征模式，该表征模式能够更有效地研究和分析煤中的孔隙，包括孔隙数目、孔隙面积、孔隙周长、平均形状因子、孔隙率、分形维数和孔径分布，将SEM-PCAS与气体吸附方法相结合对煤的孔隙结构进行定量联合表征的模式是可行的.Abstract: The coal nanopore structure's common characterization pattern is established by the LP-N2GA method, CO2 adsorption method, SEM-PCAS, and the pore characteristics of six coals with different metamorphic degrees are analyzed. The characterization model enables us to study and analyze the pores in coal more effectively, including pore number, pore area, pore perimeter, average shape factor, porosity, fractal dimension, and pore size distribution. When the pore distribution of coal samples is similar, the adsorption capacity of coal for N2 and CO2, the approximate probability density of porosity and pore area (mesopore) of coal samples are negatively correlated with the volatile matter of coal, and the fractal dimension of the pore of coal samples is positively correlated with the volatile matter of coal. When the pore distribution of coal samples is quite different, the maximum adsorption capacity of N2 and CO2 is related to the pore distribution. The combination of SEM-PCAS and gas adsorption technology facilitates the understanding of the pore characteristics of coal. The research results have specific guiding significance for coal mine gas control.
-
图 5 六种煤样CO2和N2的最大吸附量
Fig. 5. Maximum adsorption volumes of CO2 and N2 for six coal samples
图 6 六种煤样的孔径分布(CO2吸附实验)
Fig. 6. Pore size distribution of the samples (CO2 adsorption experiment)
图 7 1号煤样SEM原始图像和PCAS处理后图像
Fig. 7. No.1 coal sample SEM original image and PCAS processed image
图 8 2号煤样SEM原始图像和PCAS处理后图像
Fig. 8. No.2 coal sample SEM original image and PCAS processed image
图 9 3号煤样SEM原始图像和PCAS处理后图像
Fig. 9. No.3 coal sample SEM original image and PCAS processed image
图 10 4号煤样SEM原始图像和PCAS处理后图像
Fig. 10. No.4 coal sample SEM original image and PCAS processed image
图 11 5号煤样SEM原始图像和PCAS处理后图像
Fig. 11. No.5 coal sample SEM original image and PCAS processed image
图 12 6号煤样SEM原始图像和PCAS处理后图像
Fig. 12. No.6 coal sample SEM original image and PCAS processed image
图 14 煤样孔隙面积的近似概率密度函数
Fig. 14. Approximate probability density function of pore area of the coal sample
图 15 孔隙形状因子随孔隙面积的近似函数
Fig. 15. Approximate function of pore form factor with pore area
表 1 测试煤样的基本信息
Table 1. Necessary information on the tested coal samples
样品编号 煤阶 煤样工业分析 Mad (%) Aad (%) Vdaf (%) FCad (%) 1 无烟煤 1.51 28.36 7.70 62.98 2 低挥发性烟煤 1.83 16.61 11.29 70.78 3 低挥发性烟煤 0.66 14.24 11.73 73.54 4 低挥发性烟煤 0.66 8.20 18.57 72.74 5 中挥发性烟煤 0.81 14.9 28.05 56.59 6 高挥发性烟煤 4.77 3.30 32.24 60.81 
下载: 导出CSV
表 2 测试煤样的基本信息
Table 2. Necessary information on test coal samples
样品编号 孔隙数 平均面积/像素 平均周长/像素 平均形状因子 分形维数 孔隙率(%) 1 1 382 109.12 33.73 0.588 1 1.308 9 13.13 2 493 170.81 46.55 0.589 1 1.296 2 7.33 3 1 391 63.71 31.27 0.584 5 1.288 3 7.71 4 1 266 40.74 27.31 0.603 7 1.344 1 4.49 5 343 44.79 33.75 0.577 1 1.407 0 1.34 6 958 51.43 30.93 0.606 8 1.277 4 4.29
下载: 导出CSV
表 3 3、4、5号煤样的实验结果
Table 3. Experimental results of 3, 4 and 5 coal samples
样品编号 N2的最大吸附量（cm3/g, @STP） CO2的最大吸附量（cm3/g, @STP） 孔隙率（%） 分形维数 中孔面积的近似概率密度 
下载: 导出CSV
-
Adeyilola, A., Nordeng, S., Hu, Q., 2022. Porosity and Pore Networks in Tight Dolostone-Mudstone Reservoirs: Insights from the Devonian Three Forks Formation, Williston Basin, USA. Journal of Earth Science, 33(2): 462-481. https://doi.org/10.1007/s12583-021-1458-3 Cai, Y., Liu, D., Pan, Z., et al., 2013. Pore Structure and Its Impact on CH4 Adsorption Capacity and Flow Capability of Bituminous and Subbituminous Coals from Northeast China. Fuel, 103: 258-268. https://doi.org/10.1016/j.fuel.2012.06.055 Cui, J.Y., Zhang, W.Y., Xie, B.L., et al., 2019. Collapsibility and Microscopic Mechanism of Intact Loess at Different Depths in Xining Area. Chinese Journal of Geotechnical Engineering, 41(S2): 249-252 (in Chinese with English abstract). Dai, L., Sun, H., Zhao, B., et al., 2019. Experimental Study of the Impact of Gas Adsorption on Coal and Gas Outburst Dynamic Effects. Process Safety and Environmental Protection, 128: 158-166. https://doi.org/10.1016/j.psep.2019.05.020 Kang, Z. Q., Li, X., Li, W., et al., 2018. Experimental Investigation of Methane Adsorption/Desorption Behavior in Coals with Different Coal-Body Structure and Its Revelation. Journal of China Coal Society, 43(5): 1400-1407 (in Chinese with English abstract). Lei, H., Cody, G.D., Hatcher, P.G., et al., 1994. Imaging the Microstructure of Low Rank Coals. Fuel, 73(2): 199-203. https://doi.org/10.1016/0016-2361(94)90114-7 Li, M., Jiang, B., Qin, Y., et al., 2017. Analysis of Mineral Effect on Coal Pore Structure of Tectonically Deformed Coal. Journal of China Coal Society, 42(3): 726-731 (in Chinese with English abstract). Li, W., Yao, H. F., Liu, H. F., et al., 2014. Advanced Characterization of Three-Dimensional Pores in Coals with Different Coal-Body Structure by Micro-CT. Journal of China Coal Society, 39(6): 1127-1132 (in Chinese with English abstract). Li, X. C., Li, Z. B., Zhang, L., et al., 2019. Pore Strucure Characterization of Various Rank Coal and Its Effect on Gas Desorption and Diffusion. Journal of China Coal Society, 44(S1): 142-156 (in Chinese with English abstract). Li, X. C., Lu, W. D., Meng, Y. Y., et al., 2018. Effects of Microscopic Pore Structure and Coal Composition on Coal Resistivity. Journal of Mining & Safety Engineering, 35(1): 221-228 (in Chinese with English abstract). Li, Y., Zhang, Y. G., Zhang, L., et al., 2019. Characterization on Pore Structure of Tectonic Coals Based on the Method of Mercury Intrusion, Carbon Dioxide Adsorption and Nitrogen Adsorption. Journal of China Coal Society, 44(4): 1188-1196 (in Chinese with English abstract). Lin, H. F., Wei, W. B., Li, S. G., et al., 2016. Experiment Study on Pore Structure of Low Rank Coal Affected to Gas Adsorption Features. Coal Science and Technology, 44(6): 127-133 (in Chinese with English abstract). Lin, J., Ren, T., Cheng, Y., et al., 2021. Laboratory Quantification of Coal Permeability Reduction Effect during Carbon Dioxide Injection Process. Process Safety and Environmental Protection, 148: 36-38. https://doi.org/148.10.1016/j.psep.2021.01.038 Liu, C., Xu, Q., Shi, B., et al., 2018. Digital Image Recognition Method of Rock Particle and Pore System and Its Application. Chinese Journal of Geotechnical Engineering, 40(5): 925-931 (in Chinese with English abstract). Liu, X. F., Song, D. Z., He, X. Q., et al., 2018. Effect of Microstructure on Methane Adsorption Characteristics of Soft and Hard Coal. Journal of China University of Mining & Technology, 47(1): 155-161 (in Chinese with English abstract). Liu, X., Song, D., He, X., et al., 2019a. Nanopore Structure of Deep-Burial Coals Explored by AFM. Fuel, 246: 9-17. https://doi.org/10.1016/j.fuel.2019.02.090 Liu, X. F., Nie, B. S., Wang, W. X., et al., 2019b. The Use of AFM in Quantitative Analysis of Pore Characteristics in Coal and Coal-Bearing Shale. Marine and Petroleum Geology, 105: 331-337. https://doi.org/10.1016/j.marpetgeo.2019.04.021 Mahamud, M.M., Menéndez, J.M., Álvarez, A., et al., 2019. Fractal Analysis of CO2 and N2 Adsorption Data to Assess Textural Changes during Char Gasification. Fuel Processing Technology, 189: 15-27. https://doi.org/10.1016/j.fuproc.2019.02.019 Mastalerz, M., He, L. L., Melnichenko, Y. B., et al., 2012. Porosity of Coal and Shale: Insights from Gas Adsorption and SANS/USANS Techniques. Energy & Fuels, 26(Jul. /Aug. ): 5109-5120. Meng, Z.P., Liu, S.S., Wang, B.Y., et al., 2015. Adsorption Capacity and Its Pore Structure of Coals with Different Coal Body Structure. Journal of China Coal Society, 40(8): 1865-1870 (in Chinese with English abstract). Nie, B., Yang, L., Meng, J., et al., 2015. Pore Structure Characterization of Different Rank Coals Using Gas Adsorption and Scanning Electron Microscopy. Fuel, 158: 908-917. https://doi.org/10.1016/j.fuel.2015.06.050 Nie, B.S., Lun, J.Y., Wang, K.D., et al., 2018. Characteristics of Nanometer Pore Structure in Coal Reservoir. Earth Science, 43(5): 1755-1762 (in Chinese with English abstract). Okolo, G.N., Everson, R.C., Neomagus, H.W., et al., 2015. Comparing the Porosity and Surface Areas of Coal as Measured by Gas Adsorption, Mercury Intrusion and SAXS Techniques. Fuel, 141: 293-304. https://doi.org/10.1016/j.fuel.2014.10.046 Pan, J., Peng, C., Wan, X., et al., 2017. Pore Structure Characteristics of Coal-Bearing Organic Shale in Yuzhou Coalfield, China Using Low Pressure N2 Adsorption and FESEM Methods. Journal of Petroleum Science & Engineering, 153: 234-243. https://doi.org/10.1016/j.petrol.2017.03.043 Pan, J., Zhu, H., Hou, Q., et al., 2015. Macromolecular and Pore Structures of Chinese Tectonically Deformed Coal Studied by Atomic Force Microscopy. Fuel, 139: 94-101. https://doi.org/10.1016/j.fuel.2014.08.039 Ren, H.K., Wang, A.M., Li, C.F., et al., 2017. Study on Porosity Characteristics of Low-Rank Coal Reservoirs Based on Nuclear Magnetic Resonance Technology. Coal Science and Technology, 45(4): 143-148 (in Chinese with English abstract). Song, D.Y., He, K.K., Ji, X.F., et al., 2018. Fine Characterization of Pores and Fractures in Coal Based on a CT Scan. Natural Gas Industry, 38(3): 41-49 (in Chinese with English abstract). Song, X.X., Tang, Y.G., Li, W., et al., 2014. Pore Structure in Tectonically Deformed Coals by Small Angle X-Ray Scattering. Journal of China Coal Society, 39(4): 719-724 (in Chinese with English abstract). Tang, X., Li, J. H., 2021. Transmission Electron Microscopy: New Advances and Applications for Earth and Planetary Sciences. Earth Science, 46(4): 1374-1415 (in Chinese with English abstract). Tian, H., Zhang, S. C., Liu, S. B., et al., 2016. The Dual Influence of Shale Composition and Pore Size on Adsorption Gas Storage Mechanism of Organic-Rich Shale. Natural Gas Geoscience, 27(3): 494-502 (in Chinese with English abstract). Wang, K., Lou, Z., Guan, L. H., et al., 2020. Experimental Study on the Performance of Drilling Fluid for Coal Seam Methane Drainage Boreholes. Process Safety and Environmental Protection, 138(Prepublish): 246-255. Wang, X. J., Jin, J. P., Guo, Y. Q., et al., 2021. The Characteristics of Gas Hydrate Accumulation and Quantitative Estimation in the North Slope of South China Sea. Earth Science, 46(3): 1038-1057 (in Chinese with English abstract). Wang, Y., Pu, J., Wang, L., et al., 2016. Characterization of Typical 3D Pore Networks of Jiulaodong Formation Shale Using Nano-Transmission X-Ray Microscopy. Fuel, 170: 84-91. https://doi.org/10.1016/j.fuel.2015.11.086 Xie, S.B., Yao, Y.B., Chen, J.Y., et al., 2015. Research of Micro-Pore Structure in Coal Reservoir Using Low-Field NMR. Journal of China Coal Society, 40(S1): 170-176 (in Chinese with English abstract). Xin, F., Xu, H., Tang, D., et al., 2020. An Improved Method to Determine Accurate Porosity of Low-Rank Coals by Nuclear Magnetic Resonance. Fuel Processing Technology, 205: 106435. https://doi.org/10.1016/j.fuproc.2020.106435. Yan, G. Y., Wei, C. T., Song, Y., et al., 2018. Quantitative Characterization of Shale Pore Structure Based on Ar-SEM and PCAS. Earth Science, 43(5): 1602-1610 (in Chinese with English abstract). Yang, F., Ning, Z. F., Wang, Q., et al., 2014. Fractal Characteristics of Nanopore in Shales. Natural Gas Geoscience, 25(4): 618-623 (in Chinese with English abstract). Zhou, S., Liu, D., Cai, Y., et al., 2017. Effects of the Coalification Jump on the Petrophysical Properties of Lignite, Subbituminous and High-Volatile Bituminous Coals. Fuel, 199(1): 219-228. https://doi.org/10.1016/j.fuel.2017.02.092. Zla, B., Dl, A., Yc, A., et al., 2017. Multi-Scale Quantitative Characterization of 3-D Pore-Fracture Networks in Bituminous and Anthracite Coals Using FIB-SEM Tomography and X-Ray μ-CT Science Direct. Fuel, 209: 43-53. https://doi.org/10.1016/j.fuel.2017.07.088 Zou, M. J., Wei, C. T., Zhang, M., et al., 2013. Classifying Coal Pores and Estimating Reservoir Parameters by Nuclear Magnetic Resonance and Mercury Intrusion Porosimetry. Energy Fuels, 27(7): 3699-3708. https://doi.org/10.1021/ef400421u 崔靖俞, 张吾渝, 解邦龙, 等, 2019. 西宁地区不同深度原状黄土湿陷性及微观机理研究. 岩土工程学报, 41(S2): 249-252. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2019S2063.htm 康志勤, 李翔, 李伟, 等, 2018. 煤体结构与甲烷吸附/解吸规律相关性实验研究及启示. 煤炭学报, 43(5): 1400-1407. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201805025.htm 李明, 姜波, 秦勇, 等, 2017. 构造煤中矿物质对孔隙结构的影响研究. 煤炭学报, 42(3): 726-731. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201703024.htm 李伟, 要惠芳, 刘鸿福, 等, 2014. 基于显微CT的不同煤体结构煤三维孔隙精细表征. 煤炭学报, 39(6): 1127-1132. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201406022.htm 李祥春, 李忠备, 张良, 等, 2019. 不同煤阶煤样孔隙结构表征及其对瓦斯解吸扩散的影响. 煤炭学报, 44(S1): 142-156. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2019S1016.htm 李祥春, 陆卫东, 孟洋洋, 等, 2018. 微观孔隙结构和煤的成分对煤样电阻率的影响. 采矿与安全工程学报, 35(1): 221-228. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201801033.htm 李阳, 张玉贵, 张浪, 等, 2019. 基于压汞, 低温N2吸附和CO2吸附的构造煤孔隙结构表征. 煤炭学报, 44(4): 1188-1196. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201904025.htm 林海飞, 蔚文斌, 李树刚, 等, 2016. 低阶煤孔隙结构对瓦斯吸附特性影响的试验研究. 煤炭科学技术, 44(6): 127-133. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201606021.htm 刘春, 许强, 施斌, 等, 2018. 岩石颗粒与孔隙系统数字图像识别方法及应用. 岩土工程学报, 40(5): 925-931. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201805022.htm 柳先锋, 宋大钊, 何学秋, 等, 2018. 微结构对软硬煤瓦斯吸附特性的影响. 中国矿业大学学报, 47(1): 155-161. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201801020.htm 孟召平, 刘珊珊, 王保玉, 等, 2015. 不同煤体结构煤的吸附性能及其孔隙结构特征. 煤炭学报, 40(8): 1865-1870. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201508022.htm 聂百胜, 伦嘉云, 王科迪, 等, 2018. 煤储层纳米孔隙结构及其瓦斯扩散特征. 地球科学, 43(5): 1755-1762. doi: 10.3799/dqkx.2018.427 任会康, 王安民, 李昌峰, 等, 2017. 基于核磁共振技术的低阶煤储层孔隙特征研究. 煤炭科学技术, 45(4): 143-148. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201704025.htm 宋党育, 何凯凯, 吉小峰, 等, 2018. 基于CT扫描的煤中孔裂隙精细表征. 天然气工业, 38(3): 41-49. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201803007.htm 宋晓夏, 唐跃刚, 李伟, 等, 2014. 基于小角X射线散射构造煤孔隙结构的研究. 煤炭学报, 39(4): 719-724. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201404021.htm 唐旭, 李金华, 2021. 透射电子显微镜技术新进展及其在地球和行星科学研究中的应用. 地球科学, 46(4): 1374-1415. doi: 10.3799/dqkx.2020.387 田华, 张水昌, 柳少波, 等, 2016. 富有机质页岩成分与孔隙结构对吸附气赋存的控制作用. 天然气地球科学, 27(3): 494-502. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201603013.htm 王秀娟, 靳佳澎, 郭依群, 等, 2021. 南海北部天然气水合物富集特征及定量评价. 地球科学, 46(3): 1038-1057. doi: 10.3799/dqkx.2020.321 谢松彬, 姚艳斌, 陈基瑜, 等, 2015. 煤储层微小孔孔隙结构的低场核磁共振研究. 煤炭学报, 40(S1): 170-176. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2015S1026.htm 闫高原, 韦重韬, 宋昱, 等, 2018. 基于Ar-SEM及PCAS页岩孔隙结构定量表征. 地球科学, 43(5): 1602-1610. doi: 10.3799/dqkx.2017.525 杨峰, 宁正福, 王庆, 等, 2014. 页岩纳米孔隙分形特征. 天然气地球科学, 25(4): 618-623. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201404019.htm -
点击查看大图
图(15) / 表(3)
计量
- 文章访问数: 1311
- HTML全文浏览量: 614
- PDF下载量: 123
- 被引次数: 0
