Structural characteristics and pyrolysis behavior of low-rank coal with different vitrinite/inertinite ratio

被引:0
|
作者
Wang X. [1 ]
Wang S. [1 ]
Chen H. [1 ]
Zhao Y. [1 ]
Sha J. [1 ]
Li K. [1 ]
机构
[1] School of Geosciences and Surveying Engineering, China University of Mining and Technology-Beijing, Beijing
关键词
different vitrinite/inertinite ratio; low-rank coal; pyrolysis behavior; structural characteristics;
D O I
10.13199/j.cnki.cst.2021-1023
中图分类号
学科分类号
摘要
Pyrolysis is the basis of clean coal technologies such as coal liquefaction and gasification, especially for the low-rank coal. To further investigate the pyrolysis characteristics of low-rank coals, a series of different vitrinite/inertinite ratio ZJZ, MTH, and DT coals (V/I: 0.1, 0.76, and 1.76 respectively) are used as the research objects. The chemical structure of the sample was analyzed with Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction technology (XRD). The pyrolysis process and gas release behavior of coal samples at 30−900 °C was checked by TG-MS. The results show that the chemical structure content of low-rank coals with different V/I is quite different. Compared with the inertinite-rich ZJZ coals, the vitrinite-rich coals have relatively rich aliphatic structures, long aliphatic chains, and oxygen functional groups. Especially for DT coal, it has more C-O content. The corresponding aromatic structure content decreases with the increase of the mirror-inert ratio. With the increase of V/I in the coal, the aromatic layer spacing d002, the ratio of the aromatic layer size to the aromatic layer stacking height (La/Lc) increase, and Lc, La and the number of stacking layers (N) decrease. The weight loss ratio of DT, MTH, and ZJZ coal during pyrolysis is 36.4%, 32.2%, and 28.9% respectively. As the V/I decreases, the final pyrolysis gaseous product yield and the maximum pyrolysis rate decrease accordingly. During the pyrolysis process, the small molecular gas, such as H2, H2O, CH4, CO, CO2, are released; In addition, the content of released gas is closely related to the maceral composition. The mass of small molecules produced by inertinite-rich coal is almost lower than that produced by vitrinite-rich coal. Because the vitrinite in coal contains more aliphatic structures, and the polycondensation capacity between the aromatic layers is stronger, the free radicals fragment are easily formed during the thermal process and then combined into gas. © 2023 China Coal Society. All Rights Reserved.
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页码:294 / 301
页数:7
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共 33 条
  • [1] XIA Wencheng, XIE Guangyuan, PENG Yaoli, Recent advances in beneficiation for low rank coals[J], Powder Technology, 277, (2015)
  • [2] STACH E M, MACKOWSKY M Th, TEICHMULLER M, Et al., Stach's Text Book of Coal Petrology, (1982)
  • [3] PAJAK Janusz, SOCHA Lukasz, Effects of Pressure on Hydrogen Transfer from Tetralin to Coal Macerals[J], Energy & Fuels, 19, 2, (2005)
  • [4] WANG Peizhen, YU Chen, XUE Zihan, Et al., Transfer learning based identification model for macerals of exinite in coal[J], Coal Science and Technology, 50, 1, (2022)
  • [5] DUXBURY J., Prediction of coal pyrolysis yields by maceral separation[J], Journal of Analytical and Applied Pyrolysis, 40-41, 1, (1997)
  • [6] WANG Pengfei, JIN Lijun, LIU Jiahe, Et al., Analysis of coal tar derived from pyrolysis at different atmospheres[J], Fuel, 104, (2013)
  • [7] ZHAO Yunpeng, HU Haoquan, JIN Lijun, Et al., Pyrolysis Behavi- or of Weakly Reductive Coals from Northwest China[J], Energy & Fuels, 23, 2, (2009)
  • [8] WU Dun, ZHANG Wenyong, FU Biao, Et al., Chemical structure and gas products of different rank coals during pyrolysis[J], Journal of Thermal Analysis and Calorimetry, 136, 5, (2019)
  • [9] ZHU Xuedong, ZHU Zibin, Fundamental study on the pyrolysis of coals I. effect of atmosphere and temperature on pyrolysis[J], Journal of East China University of Science and Technology, 24, 1, (1998)
  • [10] XIE Qiang, LIANG Dingcheng, TIAN Meng, Et al., Influence of he ating rate on structure of chars derived from pyrolysis of Shenmu coal[J], Journal of Fuel Chemistry and Technology, 43, 7, (2015)