Mineyev S.P.,Prusova A.A.,Yanzhula A.S.,Gulay A.A.,Ryzhova S.A. Physics of methane desorption from a disturbed coal-bed zone

Details

Parent Category: Geo-Technical Mechanics, 2015

Category: Geo-Technical Mechanics, 2015, Issue 125

Geoteh. meh. 2015, 125, 70-81

PHYSICS OF METHANE DESORPTION FROM A DISTURBED COAL-BED ZONE

¹Mineyev S.P., ¹Prusova A.A., ²Yanzhula A.S., ²Gulay A.A., ³Ryzhova S.A.
¹IGTM NAS of Ukraine, ²PJSC «CG «Pokrovskoe», ³IGTM NAS of Ukraine

UDC 622.411.332:533.587

Abstract. On the basis of molecular mechanics, a model of a process of methane desorption from a disturbed coal-bed zone was created with taking into account intermolecular and sorption interactions in the system "methane-coal". The model is based on the Peys-Deytiner theory, which most fully connects parameters of the coal molecular structure with the coal diffusibility, and takes into account local interactions between the gas molecules and segments of coal structural chain. The problem of methane desorption in a disturbed coal-bed zone was reduced to a problem of methane diffusion in a coal fragment; the problem is described by an equation of diffusion in spherical coordinates with a coefficient of diffusion with taking into account intermolecular interactions and energy of methane-desorption activation in coal. As a result of solving the equation of diffusion by method of Fourier correlation, a ratio was obtained which specified a change of desorbing-methane concentration in the disturbed coal-bed zone with taking into account parameters of the coal fragments’ disturbance and packing. The calculations made helped building graphic dependences between in-time changes of desorbing-methane concentration and energy of activated conformational transformations in the disturbed coal microstructure ( к а Е ). Approximating functions describing average regularity of changing retained-methane concentration in outburst-prone coal were specified. The analysis of the results showed that desorption was more intensive at high energies of activated conformational transformations in a coal bed. Smoothing time makes 8 hours for к а Е max and 11 hours for к а Е min. That is, at high energies of activated conformational transformations in a coal microstructure, smoothing of desorbing-methane concentration is quicker. And, if an investigated interval of time makes not more than 10 hours, then physics of changed retained-methane concentration can be described by an exponential function, and in case of more than 10 hours - by a logarithmic function.
Keywords: Keywords: disturbed coal bed, methane, intermolecular interactions, desorption, diffusion, activating energy.

REFERENCES

1. Mineev, S.P., Prusova, A.A. and Kornilov, M.G. (2007), Aktivatsiya desorbtsiyi metana v ugolnikh plastakh [Activating desorption of methane in coal beds], Veber, Dnepropetrovsk, UA 2. Saranchuk, V.E., Iruni, A.T. and Kovalyev, K.E. (1988), Nadmolekularnaya organizatsiya, struktura I svoystva uglya [Over-molecular organization, structure and properties of coal], Naukova dumka, Kiev, SU.
3. Godunov, S. K. (1979), Uravneniya matematicheskoy fiziki [Equalizations of mathematical physics], Nauka, Moscow, SU.
4. Kovaleva, E.B. and Solovyova, I.A. (2001), ” About possibility of the use physics of mechanical descriptions of coal for the estimation of ability of coal beds to metane return”, available at: http: // www.seminar-1.narod.ru/sem10/d10.htm. Мoskow, IPKON RAN, 2001. p. 6- Seminar IPKON RAN
5. Olhovichenko, A.I. (1982), Prognoz vybrosoopasnosti ugolnikh plastov [Prognosis of emission danger of coal beds], Nedra, Moskow, SU.
6. HyperChem Release 5.0 for Windows Reference Manual (1996) -Canada: Hypercube.

 About the authors:

Mineev Sergei Pavlovich, Doctor of Technical Sciences (D.Sc.), Professor, Head of Department of Pressure Dinamic Control in Rocks of the N.S. Polyakov Institute of Geotechnical Mechanics National Academy Science of Ukraine (IGTM NAS of Ukraine), This email address is being protected from spambots. You need JavaScript enabled to view it.

Prusova Alla Andreevna, Candidate of Technical Sciences (Ph.D), Senior Reseacher

Yanzhula Aleksey Sergeevich, Master of Science, Chief Engineer of «Colliery Group, «Pokrovskoe», Krasnoarmeysk

Gulay Aleksey Alexandrovich, Master of Science, Deputy Chief Engineer of «Colliery Group, «Pokrovskoe», Krasnoarmeysk

Rizhova Svetlana Alekseevna, Master of Science

• < Prev
• Next >