孔隙形状对煤中CO2和CH4吸附与扩散影响的分子模拟OA

To clarify the micro dynamic mechanism of competitive adsorption and diffusion of CH4 and CO2 in long-flame coal,the long-flame coal models with different shapes of nano pores were established based on solid-state nuclear magnetic resonance experiments.The influences of pore shape and CH4-to-CO2molar ratio on the competitive adsorption and diffusion characteristics of CH4 and CO2 in long-flame coal were discussed using molecular simulation method.The research results indicate that under the same conditions,the adsorp-tion capacity of CH4 and CO2 in pores of different shapes,from strong to weak,is as follows:narrow slit pores,square pores,and circular pores.The maximum adsorption capacity of narrow slit pores for CH4 and CO2 is about three times that of circular pores.Both high con-centration CO2 and high adsorption pressure have adverse effects on the competitive adsorption.In long-flame coal,the diffusion ability of CH4 is much stronger than that of CO2,and the diffusion ability in different shaped pores,from strong to weak,is as follows:narrow slit pores,circular pores,and square pores.The research results provide a theoretical basis for the enhanced extraction of coalbed meth-ane and geological storage of carbon dioxide.