Adsorption of methane on three Sichuan Basin shales at 318 K, 338 K, and 358 K has been investigated experimentally. The adsorption equilibrium isotherm data were fitted with Langmuir, DR and DA model. A thermodynamic model on heat of adsorption (Q_st), considering the non-ideality of gas and the adsorbed phase specific volume, was developed for adsorption fields of methane and shales. The other thermodynamic properties, included specific heat capacity of adsorbed phase (c_p,a), entropy (s_a) and enthalpy (h_a) of adsorbed phase, were also evaluated on basis of the developed heat of adsorption model. The calculated isosteric heat of adsorption shows a temperature independent feature at lower surface loading while a negative temperature dependence at higher surface loading. Specific heat capacity of adsorbed phase (c_pa) values increases with temperature, pressure and adsorption amount. The change of c_pa value with temperature are higher at lower pressure and adsorption amount. The entropy and enthalpy of adsorbed phase decreases with the increase of methane adsorption, and the entropy change is larger at lower temperature suggesting lower temperature is conducive to formed ordered arrangement of CH₄ molecules.

实验研究了甲烷在 318 K、338 K 和 358 K 下在四川盆地的三个页岩上的吸附。吸附平衡等温线数据符合 Langmuir、DR 和 DA 模型。针对甲烷和页岩的吸附场，建立了考虑气体非理想性和吸附相比容的吸附热热力学模型（Q _st）。其他热力学性质，包括吸附相的比热容 ( c _p,a )、熵 ( s _a ) 和焓 ( h _{a )}) 的吸附相，也根据开发的吸附热模型进行了评估。计算的等量吸附热在较低表面负载下显示出与温度无关的特征，而在较高表面负载下显示出负温度依赖性。吸附相的比热容 ( c _pa ) 值随温度、压力和吸附量而增加。在较低的压力和吸附量下，c _pa值随温度的变化较大。吸附相的熵和焓随着甲烷吸附量的增加而减小，且在较低温度下熵变较大，表明较低温度有利于CH ₄分子的有序排列。