Abstract
In this paper, THM model and coal molecular model are established to study the gas adsorption and desorption behavior in coal seam at different injection pressures. The results show that, the total energy decreases during the adsorption process and increases in the desorption process. CO2 has a stronger adsorption capacity which is in a dominant position in the competition adsorption process, while N2 is in a weak position. The order of the diffusion coefficient is N2>CH4(CH4–N2) > CH4(CH4–CO2) > CO2. The diffusion coefficient does not necessarily increase with the increase of injection pressure. At the same injection pressure, the relative concentration of CH4 in the CH4–CO2 system is greater than that in the CH4–N2 system, and injection of CO2 to promote CH4 desorption is significantly better than the injection of N2. With the increase of injection pressure, the average relative concentration of CH4/CO2/N2 in the vacuum layer increased. The optimal injection pressure for N2 injection to promote CH4 desorption is 2 MPa, and the reasonable injection pressure for CO2 injection is 1–3 MPa.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
