Figure 22
The schematic representation of adsorbed and free gas regions for methane adsorption in illite nanopore of \(W=4\) nm at 333.15 K and 10 MPa. The yellow area presents the adsorbed phase from our model, the orange area presents the adsorbed phase from SDR model with constant \({V}_{a}^{SDR{,}^{\ast }}\), the blue area depicts the adsorbed phase from SDR model with constant \({\rho }_{a}^{SDR{,}^{\ast \ast }}\) with corresponding \({V}_{a}^{SDR{,}^{\ast \ast }}\) at 10 MPa, and the green area depicts the free gas phase from our model. B, B*, and B** represent the boundaries of adsorbed phase from our model, SDR model with constant \({V}_{a}^{SDR,\ast }\), and SDR model with constant \({\rho }_{a}^{SDR{,}^{\ast \ast }}\), respectively. The heights of adsorbed and free gas phases from our model are depicted from \({\rho }_{a}={\int }_{A}^{B}\rho (z)dz/{z}_{AB}\) and \({\rho }_{b}\) from NIST Chemistry Webbook, respectively. The heights of adsorbed phase from SDR model with constant \({V}_{a}^{SDR{,}^{\ast }}\) and \({\rho }_{a}^{SDR{,}^{\ast \ast }}\) are depicted from \({\rho }_{a}^{\ast }={\int }_{A}^{{B}^{\ast }}\rho (z)dz/{z}_{A{B}^{\ast }}\) and \({\rho }_{a}^{\ast \ast }={\int }_{A}^{{B}^{\ast \ast }}\rho (z)dz/{z}_{A{B}^{\ast \ast }}\), respectively. The adsorbed phase density \({\rho }_{a}^{SDR{,}^{\ast }}\) from SDR model with constant \({V}_{a}^{SDR,\ast }\) is from Eq. (17), and \({\rho }_{a}^{SDR{,}^{\ast \ast }}=286.09381\) kg/m3 is from the SDR fitting with constant \({\rho }_{a}^{SDR{,}^{\ast \ast }}\).
