Potential Theory of Multicomponent Adsorption

✍ Scribed by Alexander A. Shapiro; Erling H. Stenby

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 247 KB
• Volume: 201
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1998.5424

✦ Synopsis

assumed that adsorbate is a homogeneous fluid possessing We develop a theory of multicomponent adsorption on the basis an effective density and a fugacity, which differs from a of the potential concept originally suggested by Polanyi. The mixfugacity of the bulk phase by a value of the so-called adsorpture is considered as a heterogeneous substance segregated in the tion potential. Several ways of introducing the adsorbate external field emitted by the adsorbent. The same standard equafugacities into the potential theory and several density corretion of state, with no additional fitting parameters, is used for lations have been proposed ( ).

the segregated and for the bulk phases. With this approach, few A major disadvantage of the assumption about adsorbate parameters are needed to correlate pure component adsorption homogeneity is, in our opinion, that this assumption breaks isotherms. These parameters may be used to predict adsorption equilibria of multicomponent mixtures without additional adjust-the connection of the adsorbate behavior with the behavior ment. A connection between the potential theory and the spreading of the corresponding bulk fluid. This necessitates the intropressure concept is established, and problems of the theory consisduction of additional fitting parameters into the equation tency are studied. Numerical algorithms are suggested for evaluaof state for adsorbate, and the number of these parameters tion of the segregated state of the mixture in the potential field of increases to a large extent for multicomponent mixtures. adsorption forces. Comparison with experimental data shows good Even using a large number of parameters is not of much use agreement and high degree of predictability of the theory develfor nontrivially behaving mixtures, for example, for hydrooped.