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LIU Jikun,REN Bang,WANG Cuixia. Pore structure characteristics of middle and low rank coals and their influence on gas desorption characteristics[J]. Coal Science and Technology,2022,50(12):153−161. DOI: 10.13199/j.cnki.cst.2021–0775
Citation: LIU Jikun,REN Bang,WANG Cuixia. Pore structure characteristics of middle and low rank coals and their influence on gas desorption characteristics[J]. Coal Science and Technology,2022,50(12):153−161. DOI: 10.13199/j.cnki.cst.2021–0775

Pore structure characteristics of middle and low rank coals and their influence on gas desorption characteristics

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National Natural Science Foundation of China (51404188)

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  • Received Date: November 19, 2021
  • Available Online: March 08, 2023
  • The pore structure of coal is an important factor affecting gas storage and migration. In order to further study the gas desorption characteristics of low and medium metamorphic coals, 6 sets of coal samples from the Fukang mining area were selected for mercury intrusion and gas desorption experiment. Mercury intrusion and extrusion curves of coal samples were drawed, the pore structure characteristics of each pore segment were counted, the gas desorption curve was drawed, and the pore morphology, pore volume, pore specific surface area and volume fractal dimension of coal and their influence on the gas desorption capacity and desorption rate were analyzed. The results show that there are different proportions of open pores in coal samples. Macropores are mainly composed of open pores, the middle and small pores are mainly composed of semi-closed pores, and the micropores are mainly composed of closed pores. In addiction, the total pore volume are mainly contributed by micropores and macropores, and micropores contributes the most to the total specific surface area. By drawing the gas desorption curve and the desorption rate scatter diagram, it is found that the gas desorption amount increases rapidly with the desorption time and then tends to a stable value, and then the fitting finds that the gas desorption curve of middle and low rank coal can be expressed by 1/Q=m/t0.75+n, the degree of fitting is above 0.995, wheremis a parameter related to the gas desorption rate,nis a parameter related to the desorption volume constant,and the coefficient of 0.75 may be related to the degree of coal metamorphism, and the desorption curves with different degrees of metamorphism can be analyzed in the later stage. And the desorption rate decreases exponentially with the desorption time. Fitting the pore structure characteristics of different pore sizes with the desorption characteristic parameters, it is found that the gas in the macropores is preferentially desorbed in the initial stage of desorption. As the pore size decreases, the priority rate gradually decreases. The fractal dimension of mesopores and macropores is between 2.879 1−2.991 5, which has obvious fractal characteristics. It is proposed that the initial desorption velocity and fractal dimension show a significant positive correlation. The relationship betweennvalue and fractal dimension is not obvious.

  • [1]
    谢和平,吴立新,郑德志. 2025年中国能源消费及煤炭需求预测[J]. 煤炭学报,2019,44(7):1949−1960.

    XIE Heping,WU Lixin,ZHENG Dezhi. Prediction on the energy consumption and coal demand of China in 2025[J]. Journal of China Coal Society,2019,44(7):1949−1960.
    [2]
    杨 明,柳 磊,张学博,等. 不同阶煤孔隙结构与流体特性的核磁共振试验研究[J]. 中国安全科学学报,2021,31(1):81−88.

    YANG Ming,LIU Lei,ZHANG Xuebo,et al. Nuclear magnetic resonance experimental study on pore structure and fluid characteristics of coal at different ranks[J]. China Safety Science Journal,2021,31(1):81−88.
    [3]
    郝建峰,梁 冰,孙维吉,等. 考虑吸附/解吸热效应的含瓦斯煤热–流-固耦合模型及数值模拟[J]. 采矿与安全工程学报,2020,37(6):1282−1290.

    HAO Jianfeng,LIANG Bing,SUN Weiji,et al. Gassy coal thermal-hydraulic-mechanical coupling model and numerical simulation considering adsorption/desorption thermal effect[J]. Journal of Mining and Safety Engineering,2020,37(6):1282−1290.
    [4]
    高 尚,王 亮,高 杰,等. 基于分形理论的不同变质程度硬煤孔隙结构试验研究[J]. 煤炭科学技术,2018,46(8):93−100.

    GAO Shang,WANG Liang,GAO Jie,et al. Experimental study on pore structures of hard coal with different metamorphic grade based on fractal theory[J]. Coal Science and Technology,2018,46(8):93−100.
    [5]
    李 冰,刘见宝,任建刚,等. 水力冲孔对煤微观孔隙和结构成分影响的试验研究[J]. 煤炭科学技术,2021,49(8):131−138.

    LI Bing,LIU Jianbao,REN Jiangang,et al. Experimental study of influence of hydraulic punching on microscopic pores and structural components of coal[J]. Coal Science and Technology,2021,49(8):131−138.
    [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]
    杨昌永,常会珍,邵显华,等. 扫描电镜下不同煤体结构煤微孔隙特征研究[J]. 煤炭科学技术,2019,47(12):194−200.

    YANG Changyong,CHANG Huizhen,SHAO Xianhua,et al. Study on micro-pore characteristics of structural coal in different coal bodies under scanning electron microscopy[J]. Coal Science and Technology,2019,47(12):194−200.
    [8]
    李 伟,要惠芳,刘鸿福,等. 基于显微CT的不同煤体结构煤三维孔隙精细表征[J]. 煤炭学报,2014,39(6):1127−1132.

    LI Wei,YAO Huifang,LIU Hongfu,et al. Advanced characterization of three-dimensional pores in coals with different coal-body structure by micro-CT[J]. Journal of China Coal Society,2014,39(6):1127−1132.
    [9]
    聂百胜,王科迪,樊 堉,等. 基于小角X射线散射技术计算不同孔形的煤孔隙特征比较研究[J]. 矿业科学学报,2020,5(3):284−290.

    NIE Baisheng,WANG Kedi,FAN Yu,et al. The comparative study on calculation of coal pore characteristics of different pore shapes based SAXS[J]. Journal of Mining Science and Technology,2020,5(3):284−290.
    [10]
    FAN Chaojun,ELSWORTH Derek,LI Sheng,et al. Ther- mo-hydro-mechanical-chemical couplings controlling CH4 production and CO2 sequestration in enhanced coalbed methane recovery[J]. Energy,2019,173:1054−1077.
    [11]
    张召召,潘结南,李 猛,等. 基于压汞和低温氮吸附联合试验的不同变质程度煤全孔隙结构特征研究[J]. 煤矿安全,2018,49(4):25−29.

    ZHANG Zhaozhao,PAN Jienan,LI Meng,et al. TOTAL pore structure characteristics of coal with different metamorphic degree based on joint experiment of mercury intrusion and low temperature nitrogen adsorption[J]. Safety in Coal Mines,2018,49(4):25−29.
    [12]
    王 杰,赵 东,蔡婷婷,等. 结合孔隙结构分析热蒸汽对煤体瓦斯解吸的影响[J]. 矿业研究与开发,2021,41(5):113−117.

    WANG Jie,ZHAO Dong,CAI Tingting,et al. Analysis on the influence of hot steam on coal gas desorption combined with pore structure[J]. Mining Research and Development,2021,41(5):113−117.
    [13]
    范家文,刘 健. 煤体解吸甲烷规律及解吸后微结构特征研究[J]. 煤炭工程,2021,53(2):147−152.

    FAN Jiawen,LIU Jiang. Law of methane desorption in coal and microstructure characteristics of coal after desorption[J]. Coal Engineering,2021,53(2):147−152.
    [14]
    尹金辉. 温度对煤样罐内煤体瓦斯解吸的影响[J]. 能源与环保,2020,42(8):19−22.

    YIN Jinhui. Influence of temperature acts on gas desorption of coal mass in coal sample tank[J]. China Energy and Environmental Protection,2020,42(8):19−22.
    [15]
    陆 壮,王 亮,聂 雷,等. 不同变质程度煤体瓦斯解吸迟滞特征实验研究[J]. 西安科技大学学报,2020,40(1):88−95.

    LU Zhuang,WANG Liang,NIE Lei,et al. Experimental study of methane desorption hysteresis characteristics of coal with different metamorphic degrees[J]. Journal of Xi’an University of Science and Technology,2020,40(1):88−95.
    [16]
    许耀波,朱玉双. 高阶煤的孔隙结构特征及其对煤层气解吸的影响[J]. 天然气地球科学,2020,31(1):84−92.

    XU Yaobo,ZHU Yushuang. Pore structure characteristics of high rank coal and its effect on CBM desorption[J]. Natural Gas Geoscience,2020,31(1):84−92.
    [17]
    张书林,刘永茜,孟 涛. 不同矿化度水对煤的甲烷解吸影响的试验研究[J]. 煤炭科学技术,2021,49(7):110−117.

    ZHANG Shulin,LIU Yongqian,MENG Tao. Experimental study on influence of water with different salinity on methane desorption performance of coal seam[J]. Coal Science and Technology,2021,49(7):110−117.
    [18]
    琚宜文. 构造煤结构演化与储层物性特征及其作用机理[D]. 徐州: 中国矿业大学, 2002: 23–30.

    JU Yiwen. Structural evolution of structural coal, physical characteristics of reservoirs and their mechanism[D]. Xuzhou: China University of Mining and Technology, 2002: 23–30.
    [19]
    XOJIOT B B. 煤与瓦斯突出[M]. 北京: 中国煤炭出版社, 1966: 19–28.
    [20]
    王 欣,齐 梅,胡永乐,等. 高压压汞法结合分形理论分析页岩孔隙结构[J]. 大庆石油地质与开发,2015,34(2):165−169.

    WANG Xin,QI Mei,HU Yongle,et al. Analysis of shale pore structure by high pressure mercury injection combined with fractal theory[J]. Daqing Petroleum Geology and Development,2015,34(2):165−169.
    [21]
    孟 然. 软煤体孔隙结构及其瓦斯吸附特性研究[D]. 西安: 西安科技大学, 2016: 17–18.

    MENG Ran. Research on the pore structure of soft coal and its adsorption characteristics to CH4[D]. Xi’an: Xi’an University of Science and Technology, 2016: 17–18.
    [22]
    刘一楠,刘 勇,辛福东,等. 压汞实验对低阶煤表征的适用性分析及校正方法[J]. 煤田地质与勘探,2020,48(4):118−125.

    LIU Yinan,LIU Yong,XIN Fudong,et al. Applicability of mercury injection test to the characterization of low rank coal and its correction method[J]. Coal Geology & Exploration,2020,48(4):118−125.
    [23]
    LI Yonghua,LU Gaoqing,RUDOLPH Victor. Compressi-bility and fractal dimension of fine coal particles in relation to pore structure characterization using mercury porosimetry[J]. Particle& Particle Systems Characteri-zation,1999,16:25−31.
    [24]
    李希建,薛海腾,陈刘瑜,等. 贵州地区突出煤层微孔结构及对瓦斯流动特性的影响[J]. 煤炭科学技术,2020,48(10):67−74.

    LI Xijian,XUE Haiteng,CHEN Liuyu,et al. Micropore structure of outburst coal seam in Guizhou Area and its effect on gas flow[J]. Coal Science and Technology,2020,48(10):67−74.
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