High-pressure adsorption equilibrium of CO₂, CH₄, and CO on an impregnated activated carbon

An impregnated activated carbon (I-AC) has been characterized using SEM, EDS, and nitrogen adsorption for micropore structure analysis. A detailed experimental study has been made of the adsorption of pure methane, carbon dioxide, and carbon monoxide at various temperatures [(298 to 318) K] and pressures up to 24 bar. Multitemperature isotherms were modeled using the Toth equation to obtain useful thermodynamic properties including Henrys law constants and isosteric heats of adsorption. Compared with other activated carbon materials, this impregnated carbon has a decreased surface area and more heterogeneous sites on the surface. CO appears to undergo chemisorption in the impregnated carbon, as indicated by a hysteresis loop upon desorption. The effect becomes more pronounced with increasing temperature.