煤中多组分混合气体竞争吸附研究现状及工程应用

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

煤对气体的吸附特性是煤岩瓦斯动力灾害防治、提高煤层气采收率(ECBM)等研究的基础。煤层气中不仅含有CH 4,同时含有CO、CO 2、H 2S以及其他烷烃类气体。在注气开采煤层气和煤层主动式瓦斯压力测定等工程中,不同气体由于吸附能力的差异会发生竞争吸附行为。首先,分析了煤中气体竞争吸附的机理,对比分析煤基质中多组分气体吸附平衡预测模型,并探讨了竞争吸附的影响因素、吸附膨胀特性以及吸附动力学行为。其次,结合现有研究阐述了CO 2-ECBM过程中的煤层渗透率降低、衍生的突出灾害风险以及超临界CO 2吸附等问题。最后,对煤中多组分气体吸附平衡预测模型、煤岩动力灾害防治、ECBM及PSA变压分离技术等工程应用进行了探讨。

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 CH 4,but also CO,CO 2,H 2S 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 CO 2-ECBM,the derived outburst disaster risk and the supercritical CO 2 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.