A new simplified method for estimating film mass transfer and surface diffusion coefficients from batch adsorption kinetic data

Abstract

A new simplified method is presented for estimating the film mass transfer and the surface diffusion coefficients from batch adsorption kinetic data without solving partial differential equations. The film mass transfer coefficient is determined from the initial adsorption rate which is estimated by fitting the kinetic data in the early adsorption stage to the early-stage kinetic equation. The surface diffusion coefficient is related to the late-stage adsorption rate constant which is estimated by fitting the late-stage kinetic data to the late-stage kinetic equation. The method is applied to four different adsorption systems in the literature. The predicted kinetics obtained with the estimated film mass transfer and surface diffusion coefficients shows a reasonable agreement with the experimental kinetics.