Sorption of methane in a series of Zn-based MOFs studied by PHSC equation of state

Adsorption and storage of gaseous methane as a clean fuel for cars has always attracted the attention of researchers. One of the most famous porous absorbents which has been used for separation and storage of several gases is called metal organic framework (MOF). These kinds of absorbents have been intensely studied in recent years. In this study, the experimental data related to methane adsorption on and desorption from five absorbents, namely, MOF-5, MOF-177, MOF-200, MOF-205 and MOF-210 have been adopted. Then, the methane sorption has been modeled by applying Perturbed Hard Sphere Chain Equation of State (PHSC EoS). PHSC equation of state has three molecular-based parameters, r, σ and ɛ; which are the number of segments per molecule, the hard-sphere diameter and the non-bonded interaction energy, respectively. These three parameters have been calculated using the group contribution (GC) method. The amount of methane uptake in the adsorbents has been obtained through gas-absorbents phase equilibrium calculations at temperature 298 K and various pressures up to 90 × 105 Pa. Finally, results have been compared with the experimental data to show the precision of PHSC equation of state in predicting the methane sorption trend.