One‐sided single‐pellet technique for adsorption and intraparticle diffusion

Abstract

The one-sided single-pellet dynamic technique introduced in this article is shown to be a very effective and simple method for the analysis of adsorption and difision in porous solids. Moment expressions are presented for reversible and irreversible adsorption processes. Since the adsorption equilibrium constant is the only unknown parameter in the first moment expression, this parameter can be evaluated from a single set of pulse-response experiments. This technique to evaluate the adsorption equilibrium constant is illustrated using ethylbromide as tracer. It is also shown that for a very strongly adsorbing tracer, such as 1,d-dichloroethane in soil, modiJied moment expressions derived with a semiinfinite boundary condition are necessary unless a criterion developed in this work is satisfied.