Application of the volterra integral equation to the mathematical modelling of adsorption kinetics under constant-volume/variable-concentration conditions

Abstract

Mathematical solutions of adsorption kinetics on porous solids are usually developed for constant or variable concentration conditions. From both a theoretical and practical point of view the comparison of the kinetic parameters (e.g. intracrystalline diffusion coefficients of microporous adsorption systems) obtained from the various methods is valuable. This paper presents a solution which provides a numerical calculation of the kinetic curves at variable boundary conditions, e.g. constant-volume/variable-concentration, based on the appropriate analytical solution of Fick's diffusion law at constant boundary conditions, e.g. constant concentration.