Kinetics of high‐temperature carbon gasification reaction

A simple technique is developed and is used to measure simultaneously the overall rate and the depth of the reaction zone in the porous solid. It is shown that by using some simple models, one may calculate the intrinsic rate constant and the pore diffusivity from the overall rate and the penetration depth. Models which allow for a varying pore diffusivity according to a linear porosity profile are presented, and have been shown more satisfactory than the constant diffusivity models of Thiele and of Zeldovich when applied to the high temperature carbon‐carbon dioxide reaction.