IDEAS home Printed from https://ideas.repec.org/a/gam/jeners/v13y2020i24p6618-d462517.html
   My bibliography  Save this article

Macromolecular Structure Controlling Micro Mechanical Properties of Vitrinite and Inertinite in Tectonically Deformed Coals—A Case Study in Fengfeng Coal Mine of Taihangshan Fault Zone (North China)

Author

Listed:
  • Anmin Wang

    (Department of Energy Geology, College of Geoscience & Surveying Engineering, China University of Mining & Technology, Beijing 100083, China
    Shandong Key Laboratory of Depositional Mineralization & Sedimentary Mineral, Shandong University of Science and Technology, Qingdao 266510, China)

  • Daiyong Cao

    (Department of Energy Geology, College of Geoscience & Surveying Engineering, China University of Mining & Technology, Beijing 100083, China)

  • Yingchun Wei

    (Department of Energy Geology, College of Geoscience & Surveying Engineering, China University of Mining & Technology, Beijing 100083, China)

  • Zhifei Liu

    (Department of Energy Geology, College of Geoscience & Surveying Engineering, China University of Mining & Technology, Beijing 100083, China)

Abstract

In order to study the evolution of the mechanical properties and macromolecular structures in different macerals of tectonically deformed coal (TDC), vitrinite and inertinite samples were handpicked from six block TDCs in the same coal seam with an increasing deformation degree (unaltered, cataclastic, porphyroclast, scaly and powdery coal). The micro mechanical properties were tested by the nanoindentation experiment and the macromolecular structures were measured using 13 C nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The results show that the range of hardness and elastic modulus of inertinite is 0.373–1.517 GPa and 4.339–12.158 GPa, respectively, which is significantly higher than that of vitrinite with values of 0.278–0.456 GPa and 4.857–7.810 GPa, respectively. From unaltered coal to powdery coal, the hardness of vitrinite and inertinite gradually decreases, with the difference between these macerals becomes smaller and the elastic modulus of vitrinite shows an increasing trend, while that of inertinite was more variable. Both the NMR and FITR results reveal that the macromolecular structure of inertinite has similar structural transitions as vitrinite. As the degree of deformation increases, the aliphatic side chains become shorter and the aromaticity is increasing. Macromolecular alterations caused by tectonic stress is expected to produce defects in the TDCs, therefore there should be more interspacing among the macromolecular groups for the extrusion of macromolecules caused by the indenter of the nanoindentation experiment, thereby reducing the hardness. The elastic modulus of coal is believed to be related to intermolecular forces, which are positively correlated to the dipole moment. By calculating the dipole moments of the typical aromatic molecular structures with aliphatic side chains, the detachment of the aliphatic side chains and the growth of benzene rings can both increase the dipole moment, which can promote elastic modulus. In addition, the increasing number of benzene rings can create more π-π bonds between the molecules, which can lead to an increase in the intermolecular forces, further increasing the elastic modulus.

Suggested Citation

  • Anmin Wang & Daiyong Cao & Yingchun Wei & Zhifei Liu, 2020. "Macromolecular Structure Controlling Micro Mechanical Properties of Vitrinite and Inertinite in Tectonically Deformed Coals—A Case Study in Fengfeng Coal Mine of Taihangshan Fault Zone (North China)," Energies, MDPI, vol. 13(24), pages 1-23, December.
    • Handle: RePEc:gam:jeners:v:13:y:2020:i:24:p:6618-:d:462517
    as

    Download full text from publisher

    File URL: https://www.mdpi.com/1996-1073/13/24/6618/pdf
    Download Restriction: no
    File URL: https://www.mdpi.com/1996-1073/13/24/6618/
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Katarzyna Godyń & Barbara Dutka & Monika Chuchro & Mariusz Młynarczuk, 2020. "Synergy of Parameters Determining the Optimal Properties of Coal as a Natural Sorbent," Energies, MDPI, vol. 13(8), pages 1-17, April.
    2. Qiang Chen & Jin Jing & Jun Liu & Jianhui Long & Sheng Zhang, 2019. "Productivity Evaluation of Coalbed Methane Well with Geophysical Logging-Derived Tectonically Deformed Coal," Energies, MDPI, vol. 12(18), pages 1-15, September.
    3. Jun Lu & Yun Wang & Jingyi Chen, 2018. "Detection of Tectonically Deformed Coal Using Model-Based Joint Inversion of Multi-Component Seismic Data," Energies, MDPI, vol. 11(4), pages 1-17, April.
    4. Xin Wang & Tongjun Chen & Hui Xu, 2020. "Thickness Distribution Prediction for Tectonically Deformed Coal with a Deep Belief Network: A Case Study," Energies, MDPI, vol. 13(5), pages 1-14, March.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Meng Zhao & Anmin Wang & Daiyong Cao & Yingchun Wei & Liqi Ding, 2022. "Differences in Macromolecular Structure Evolution during the Pyrolysis of Vitrinite and Inertinite Based on In Situ FTIR and XRD Measurements," Energies, MDPI, vol. 15(15), pages 1-18, July.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Zhihui Liu & Yongfei Yang & Yingwen Li & Jiaxue Li, 2021. "In Situ Deformation Analysis of a Fracture in Coal under Cyclic Loading and Unloading," Energies, MDPI, vol. 14(20), pages 1-16, October.
    2. Xin Wang & Tongjun Chen & Hui Xu, 2020. "Thickness Distribution Prediction for Tectonically Deformed Coal with a Deep Belief Network: A Case Study," Energies, MDPI, vol. 13(5), pages 1-14, March.
    3. Katarzyna Godyń & Barbara Dutka, 2022. "Preliminary Studies of Slag and Ash from Incinerated Municipal Waste for Prospective Applications," Energies, MDPI, vol. 16(1), pages 1-26, December.
    4. Yang, Weifei & Xiao, Changlai & Zhang, Zhihao & Liang, Xiujuan, 2022. "Identification of the formation temperature field of the southern Songliao Basin, China based on a deep belief network," Renewable Energy, Elsevier, vol. 182(C), pages 32-42.
    5. Liang Sun & Suping Peng & Dengke He, 2018. "A Novel Static Correction Approach for Eliminating the Effect of Geophones—A Case Study in Coal Reservoirs, Ordos Basin, China," Energies, MDPI, vol. 11(12), pages 1-12, November.
    6. Qiang Chen & Jin Jing & Jun Liu & Jianhui Long & Sheng Zhang, 2019. "Productivity Evaluation of Coalbed Methane Well with Geophysical Logging-Derived Tectonically Deformed Coal," Energies, MDPI, vol. 12(18), pages 1-15, September.
    7. Xiaobo Lin & Pingsong Zhang & Fanbin Meng & Chang Liu, 2022. "A Coal Seam Thickness Prediction Model Based on CPSAC and WOA–LS-SVM: A Case Study on the ZJ Mine in the Huainan Coalfield," Energies, MDPI, vol. 15(19), pages 1-19, October.
    8. Xiong Song & Tongjun Chen & Dengliang Zhang, 2023. "The Acoustic Characteristics of Tectonically Deformed Coal in Huaibei Coalfield," Energies, MDPI, vol. 16(13), pages 1-15, July.
    9. Marta Skiba & Barbara Dutka & Mariusz Młynarczuk, 2021. "MLP-Based Model for Estimation of Methane Seam Pressure," Energies, MDPI, vol. 14(22), pages 1-12, November.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:gam:jeners:v:13:y:2020:i:24:p:6618-:d:462517. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: MDPI Indexing Manager (email available below). General contact details of provider: https://www.mdpi.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.