A structural model for gas—solid reactions with a moving boundary—IV. Langmuir—Hinshelwood kinetics

Abstract

The Langmuir—Hinshelwood type of kinetic expression has been incorporated into the “general structural model” for the reaction of a porous solid with a gas. Thus the system occupies the domain between the asymptotes corresponding to first-order and zeroth-order kinetics. The effect of the form of the rate expression is found to be the largest in the intermediate regime where both chemical reaction and diffusion play important roles in determining the overall rate. A “gas—solid reaction modulus” generalized for the Langmuir—Hinshelwood type of rate expression was developed to define the regimes of the different controlling mechanisms.