THERMAL SCIENCE

International Scientific Journal

STUDY OF FRACTAL BASED OXYGEN ADSORPTION EXPERIMENT OF POROUS COAL

ABSTRACT
Coal is China’s main energy source and fuel. Coal spontaneous combustion is one of the most prominent issues that threaten the production safety of coal mining, storage, and transportation. In order to explore the factors affecting coal spontaneous combustion, we investigated the pore structure characteristics of the coal based on the fractal theory, through the low temperature liquid nitrogen adsorption experiment of coal. The fractal dimension of the coal sample was calculated, and the oxygen adsorption quantity of the same coal sample was obtained by using the physical adsorption experiment of coal. Experimental and fitting results showed that coal sample has obvious surface fractal dimension features and pore structure fractal features. Fractal dimension expressed coal oxygen adsorption well. In the meantime, the coal samples with lower fractal dimension, higher temperature, smaller porosity usually have less oxygen adsorption quantity. This research cannot only enrich the study of oxygen adsorption in porous media such as coal, but also help to understand its spontaneous combustion mechanism in depth, thereby reducing the occurrence of spontaneous combustion disasters.
KEYWORDS
PAPER SUBMITTED: 2020-10-08
PAPER REVISED: 2020-12-25
PAPER ACCEPTED: 2020-12-28
PUBLISHED ONLINE: 2021-02-06
DOI REFERENCE: https://doi.org/10.2298/TSCI201008062L
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 1, PAGES [517 - 527]
REFERENCES
  1. Wang, J.B., Status and development of coal spontaneous combustion prevention technology, Inner Mongolia Coal Economy, 19 (2008), pp. 103-104
  2. Shang, X.J., et al. Mineral Composition, Pore Structure, and Mechanical Characteristics of Pyroxene Granite Exposed to Heat Treatments, Minerals, 9 (2019), pp. 553
  3. Chen, X., Teng, F., Zhao, J.K., Experimental study of the effect of particle size on the oxidation heating process of coal, Journal of Henan Polytechnic University (Natural Science), 38 (2019), 4, pp. 25-31
  4. Wang, F.Z., et al, Study on Influence of Coal Composition and Structure on Spontaneous Combustion Tendency, Coal Technology, 38 (2019), 8, pp. 75-77
  5. Wang, Z.Y, et al., Experimental study of pore structure and fractal characteristics of pulverized intact coal and tectonic coal by low temperature nitrogen adsorption, Powder Technology, 350 (2019), pp. 15-25
  6. Shang, X.J., et al., Fractal Analysis for Heat Extraction in Geothermal system, Thermal Science, 21 (2017), S1, pp. S25-S31
  7. Tan, X. H., Zhang, L.H., Analysis of permeability for transient two-phase flow in fractal porous media, Journal of Applied Physics, 115 (2014), 11, pp. 1-6
  8. Yong Y., et al., Direct simulation of the influence of the pore structure on the diffusion process in porous media, Computers & Mathematics with Applications, 67 (2014), 02, pp. 412-423
  9. Zhang, S., et al, A comprehensive analysis of the seepage characters of non-Newtonian fluids in fractal porous media, Journal of Porous Media, 17 (2014), 12, pp. 1031-1044
  10. Li, Y., et al, Classification and fractal characteristics of coal rock fragments under uniaxial cyclic loading conditions, Arabian Journal of Geosciences, 11 (2018), 9, pp. 201
  11. Liu, X.F., Nie B.S., Fractal characteristics of coal samples utilizing image analysis and gas adsorption, Fuel, 182 (2016), oct.15, pp. 314-322
  12. Xu, Y., et al, Effects of surface roughness and derivation of scaling laws on gas transport in coal using a fractal-based lattice Boltzmann method, Fuel, 259 (2020), pp. 116229X
  13. Zhu, J., et al, The relationship between oxygen consumption rate and temperature during coal spontaneous combustion, Safety Science, 50 (2012), 4, pp. 842-845
  14. Liang, P.P., et al, Safety in Coal Mines, Experimental Study on Influence of Moisture Content on Oxidation Spontaneous Combustion Characteristics of Long-flame Coal, Safety in Coal Mines, 49 (2018), 11, pp. 49-53
  15. Wang, D.M., et al., Test method for the propensity of coal to spontaneous combustion, Procedia Earth & Planetary Science, 1 (2009), 1, pp. 20-26
  16. Lv, X. et al. A numerical study on oxygen adsorption in porous media of coal rock based on fractal geometry. Royal Society Open Science, 7 (2020), 2, pp. 1-12
  17. Shang, X.J., et al., Analytical Solutions of Fractal-Hydro-Thermal Model for Twophase Flow in Thermal Stimulation Enhanced Coalbed Methane Recovery, Thermal Science, 23 (2019), 3A, pp. 1345-1353
  18. Ju, Y.W., et al, Structural Evolution of Nano- scale Pores of Tectonic Coals in Southern North China and Its Mechanism, Acta Geologica Sinica, 2 (2005), pp. 269-285
  19. Shuang, S., et al, Exploring effect of water immersion on the structure and low-temperature oxidation of coal: A case study of Shendong long flame coal, China, Fuel, 234 (2018), DEC.15, pp. 732-737
  20. Qi, Y.M., Qian G.Y., Coal spontaneous combustion tendency chromatographic oxygen absorption identification method and its application, Coal, 2 (1996), pp. 5-9
  21. Omais, B., et al, A novel analytical approach for oxygen speciation in coal-derived liquids, Fuel, 104 (2013), FEB., pp. 805-812
  22. Sun, W.J., et al, Fractal characterization and methane adsorption features of coal particles taken from shallow and deep coalmine layers, Fuel, 155 (2015), pp.7-13
  23. Yu, L.B., Liang, X.Y., Numerical simulation of physical adsorption oxygen in the process of coal spontaneous combustion, Journal of China University of Metrology, 27 (2016), 3, pp. 276-280
  24. Mandelbrot, B.B., Wheeler, J.A., The Fractal Geometry of Nature, American Journal of Physics, 51 (1983), 3, pp. 286
  25. Zhang, X.Y., Experimental Study on the Changes of Oxygen in Coal during Coal Heating Process, Ph. D. thesis, Taiyuan University of Technology, Tai Yuan, China, 2016

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence