Macrokinetics of Chemical Processes on Porous Catalysts Having Regard to Anomalous Diffusion

Abstract

An analysis of the macrokinetics of chemical processes is undertaken on the condition that mass transfer is determined by anomalous diffusion of the reagents. In such a case the “reaction–diffusion” equation is written in the form of an equation with partial fractional derivatives. It is shown that in the internal diffusion region the rate of the process depends exponentially on the rate constant of the chemical reaction. Here, in contrast to the classical case of ordinary diffusion, the effective activation energy is defined as E _k /γ, where 0 < γ < 2 and E _k determines the activation energy of the chemical reaction. The classical case corresponds to γ = 2.