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Volumetric–Densimetric Measurements of the Adsorption Equilibria of Binary Gas Mixtures

“…Standard procedures for activation have been described by a number of authors, e.g. Rouquerol et al (1999), Keller et al (1999) and Staudt (2000). The so-called helium volume of the sorbent sample should also be known.…”

“…The valves to the adsorption chamber are then opened allowing the helium gas to expand and to be partly adsorbed or absorbed in the sorbent material sample. This process may last milliseconds, minutes or --in the case of highly activated carbon --hours or days (Keller and Staudt 2004). After thermodynamic equilibrium has been attained, i.e.…”

“…We have experienced very rapid adsorption processes where equilibrium was attained within a few minutes, but also very slow ones which took days and even weeks to complete. One such example of the latter situation occurred with the penetration of helium into porous materials (Keller and Staudt 2004). Hence, it is a matter of practice to choose proper values of ∆Ω and ∆t according to the nature and behaviour of the adsorption system and the accuracy of the data needed.…”

“…Also, as it is still not possible to calculate accurate co-adsorption equilibria data ab initio, nor even from the adsorption data for the pure components and the (normally scarce) information regarding the sorbent material, there was a growing need for experimental methods to measure these quantities. Several methods are now available (Keller and Staudt 2004). The intention behind this paper is to inform the reader interested in the experimental determination of co-adsorption equilibria of binary gas mixtures on porous solids, such as activated carbons or zeolites, of a new measurement method which does not need a gas chromatograph.…”

“…the liquid triple state of the pure fluids (Keller and Staudt 2004). Combining the mass balances [equation (4)] with equations (5), (11), (16) and (18), we obtain two linear equations for that can easily be solved to yield: The partial densities of the sorptive gas are given by equations (11) and (11a), and the total masses of gas originally supplied by either equation (5) or (6).…”