Predicting Absorption Equilibria of Mixtures: Comparison of Potential Theory and Ideal Adsorption Solution Theory

摘要

The Dubinin-Radushkevich (DR) Equation has been used successfully to correlate and predict pure-component adsorption equilibria for a variety of vapors on microporous, carbonaceous adsorbents. Two methods are examined to apply the predictive advantages of the DR Equation to describe multicomponent adsorption equilibria: (1) the method of Grant and Manes, and (2) the method of Myers and Prausnitz. These methods are equivalent whenever the Gibbs adsorption isotherm is satisfied. The DR Equation for mixtures has the 'correct' limits whenever more than one component is adsorbed. The thermodynamic theory of mixtures is used to determine if pure-component isotherm data is consistent with the Gibbs adsorption isotherm.