Skipochka S.I., Palamarchuk T.A., Prokhorets L.V., Kurinniy V.P. Study of the thermodynamic parameters influence on the phase state of methane in coal
- Details
- Parent Category: Geo-Technical Mechanics, 2022
- Category: Geo-Technical Mechanics, 2022, Issue 161
Geoteh. meh. 2022, 161, 138-146
https://doi.org/10.15407/geotm2022.161.138
STUDY OF THE THERMODYNAMIC PARAMETERS INFLUENCE ON THE PHASE STATE OF METHANE IN COAL
1Skipochka S.I., 1Palamarchuk T.A., 1ProkhoretsL.V., 2Kurinniy V.P.
1Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, 2National Technical University “Dnipro Polytechnic”
UDC 622.023.623:622.411.332
Language: English
Abstract. The subject of research presented in the article is the processes that occur in the coal during change of its thermodynamic parameters. The aim of this research is to study the influence of pressure, temperature and binding energy of methane molecules on its distribution in coal. The analysis and generalization of the results conducted by the authors as well as referenced experimental and theoretical studies conducted by means of broad lines nuclear magnetic resonance method at high gas pressure as well as by means of spin echo method, physical and mathematical modeling are stated in the paper. The study of the influence of thermodynamic conditions change on the phase components of methane in coal has been further developed. The influence of pressure, temperature and binding energy of methane molecules on its distribution in coal has been studied. The redistribution of methane content between phases during pressure change has been studied. The nonlinear dependence of free and adsorbed methane on pressure that takes into account the relaxation time is established. The contribution of adsorbed and free methane varies with pressure change but proportion holds, which at low pressure is expressed by the Henry equation. At high pressure the Langmuir equation should be applied. It was established that the value of the methane phase components contribution to the total methane capacity significantly depends on the temperature. At low temperature, the amount of methane in coal could reach high values and it its value is determined mainly by adsorbed and dissolved methane content. As the temperature rises, the amount of methane contained in the coal decreases sharply - methane predominates as a free gas. It was found that at temperature value T = 300 K the solid solution contains a small amount of methane. Given that the solid state diffusion coefficient is very small, the contribution of methane to solid solution could be neglected in case of mine disasters. As the temperature increases from 300 K up to 350 K, the partial pressure of methane in the solid solution increases nearly in order of magnitude, so the gasdynamic situation in mines becomes more dangerous. According to the research results, the values of the desorption energy change for methane molecules and molar energy of methane desorption from the adsorbed state depending on the free methane pressure at T = 300 K are obtained, which allows estimation of the adsorbed methane amount.
Keywords: coal mine, gasdynamic phenomena, phase state, thermodynamic parameters.
REFERENCES:
1. Skipochka, S.I., Palamarchuk, T.A. and Prokhorets, L.V. (2020), “Methane content of the coal seam taking into account the contribution of the adsorbed methane component”, Abstracts of X International Scientific and Practical Conference “Trends in the development of modern scientific thought”, Vancouver, Canada, pp. 742-745.
2. Skipochka, S., Palamarchuk, T. and Prokhorets, L. (2021), “Theoretical estimation of methane’s phase components volumes in coal seams”, E3S Web of Conferences «Essays of Mining Science and Practice 2021», no 00064.
3. Skipochka, S.I. and Palamarchuk, T.A. (2015), “Estimation of the methane phase components contribution to the gas content of coal seams ”, Geotekhnichna mekhanika, no.120, pp. 245-255.
4. Vasilkovskiy, V.A. and Chesnokova, O.V. (2018), “Effect of methane pressure on its distribution in coals”, Visti Donetskogo girnychogo instytutu, no. 2(43), pp. 30–37. https://doi.org/10.31474/1999-981x-2018-2-30-37
5. Alekseyev, A.D., Vasilenko, T.A., Kirillov, A.K., Molchanov, A.N., Troitskii, G.A. and Pichka, T.V. (2012), “Distribution of methane over phase states in coal depending on pressure”, Naukovi pratsi UkrNDMI NAN Ukrainy, no. 10, pp. 401–412.
6. Alekseyev, A.D., Vasilenko, T.A., Kirillov, A.K., Molchanov, A.N., Troitskii, G.A., Vishniakov, A.V. and Pichka, T.V. (2011), “The content of free and sorbed methane in the structure of anthracite at various pressures”, Phizika I tekhnika vysokikh davlenii, vol. 21, no. 3, pp. 126–133.
7. Alekseyev, A.D., Ulyanova, Ye.V. and Vasilenko, T.A. (2005), “Possibilities of NMR in the study of fossil coals”, Uspekhiphizicheskikhnauk, vol.175, no. 1, pp. 1217–1232.
8. Alekseyev, A.D., Vasilenko, T.A., Kirillov, A.K., Molchanov, A.N. and Troitskii, G.A. (2009), “Use of NMR methods in the study of methane mobility in the pore volume of fossil coal”, Phizika I tekhnika vysokikh davlenii, vol.19, no. 4, pp. 117–128.
9. Johnson, C. S. Waugh, J.R. and Waugh, J.S. (1961), “Nuclear Relaxation in Gases: Mixtures of Methane and Oxygen”, J. Chem. Phys., no. 35, pp. 2020–2024. https://doi.org/10.1063/1.1732204
10. Vasilenko, T.A. (2006), “Effect of pressure and temperature on the amount of methane in coal”, Phiziko-tekhnicheskiye problemy gornogo proizvodstva, no. 9 (31), pp. 89–96.
11. Polevshchikov, G. Ya., Nepeina, G.S. and Tsuran, Ye.M. (2016), “Influence of temperature and additional pressure of inert gas on the sorption methane capacity of coals”, Vestnik KuzGTU, no. 1, pp. 51–57.
12. Landau, L.D. and Liphshits, Ye.M. (1976), Statisticheskaya phizika Chast 1. T.5. [Statistical physics. Part I. Vol. 5.],Nauka, Moscow, Russia.
About authors:
Skipochka Serhii Ivanovych, Doctor of Technical Sciences (D.Sc.), Professor, Head of Laboratory of physics and geomechanical monitoring of rocks massif, Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Palamarchuk Tetiana Andriivna., Doctor of Technical Sciences (D.Sc.), Leading Researcher in Rock Mechanics Department, Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Prokhorets Liliia Victorivna, Candidate of Technical Sciences (Ph.D.), Senior Researcher in Laboratory of physics and geomechanical monitoring of rocks mass, Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
Kurinnyi Volodymyr Pavlovych, Doctor of Technical Sciences (D.Sc.), Professor, Professor of Physics Department, National Technical University “Dnipro Polytechnic” (NTU "DP"), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.
| File | Description | File size |
|---|---|---|
 Skipochka S.I., Palamarchuk T.A., Prokhorets L.V., Kurinniy V.P. Study of the thermodynamic parameters influence on the phase state of methane in coal.pdf | 798 kB |