Research status and engineering application of competitive adsorption of multicomponent mixed gases in coal

Abstract

Adsorption characteristics of gases in coal are the basis of research on prevention and control of dynamic disasters of methane in coal mine and ECBM engineering.Coalbed methane contains not only CH4, but also CO, CO2, H2S and other alkanes.Furthermore, in the projects of enhanced coalbed methane recovery by gas injection and pressure measurement by gas injection actively of coal seam, competitive adsorption behavior occurs due to the difference adsorption capacity of different gases in coal.First, the mechanism of competitive adsorption of gas in coal was analyzed.The multi-component gas adsorption equilibrium prediction model in coal porous media was compared and analyzed.The influencing factors, characteristics of adsorption swelling and adsorption dynamic behavior of competitive adsorption were discussed.Second, the phenomenon of permeability decay caused by the swelling deformation in the process of CO2-ECBM, the derived outburst disaster risk and the supercritical CO2 adsorption were discussed.Finally, the adsorption equilibrium prediction model of multicomponent gases in coal, the engineering application of coal-rock dynamic disaster prevention, ECBM and PSA technology were discussed.

Keywords

• coal
• multicomponent gas mixture
• competitive adsorption
• research status
• engineering application