Experimental and modeling study of the adsorption of supercritical methaneon a high surface activated carbon

The adsorption of methane on an activated carbon of high surface was measur ed in the range of 233-333 K and 0-10 MPa. The isotherms showed a considera bly different feature than that measured on low surface carbon. A maximum a ppeared on isotherms at relatively low temperatures. All the experimental i sotherms were well modeled by the Langmuir-Freundlich equation. The differe nce between the measured and the so-called absolute adsorption was properly accounted for in modeling. An assumption of monolayer adsorbate adsorbed w as included in the model. The layer volume evaluated was consistent with th e pore volume of adsorbent reported by CO2 adsorption. The intermolecular d istance in the adsorbed phase was evaluated from a model parameter. This in termolecular distance was compared with that in the free sate, which reveal ed a basic picture of the physical state of the adsorbed phase at above-cri tical temperatures.