Deliverable Capacity of Methane: Required Material Property Levels for the Ideal “Holy Grail” Adsorbent

The Langmuir isotherm is used to determine the properties of a theoretical “holy grail” adsorbent that can meet the US Department of Energy’s methane storage target of 0.5 g/g and 266 v/v. For a storage tank operating between 5 and 65 bar, the adsorbent requires a maximum adsorption capacity of 0.8388 g/g, a binding affinity of 0.05547 bar^-1, and a material density of 377 g/L. For a tank operating between 5 and 80 bar, the binding affinity should be 0.05 bar^-1, with the same capacity and density. The Langmuir isotherm is also applied to calculate the necessary adsorbent properties, including the number of adsorption sites and binding energies, to achieve the volumetric storage target of 266 v/v based on the material’s density.