A more general structural model which includes the induction time for gas—solid reactions—I. Nonporous solids

This paper presents a more general structural model for gas—solid reactions which include the induction time. The work was done by introducing the concept of “surface activation” and carrying out a very tedious derivation. For simple geometries such as infinite slabs, long cylinders, and spheres, we obtained the following relationship between the conversion and time: where with The quantity σ2g which incorporates both structural and kinetic parameters is the characterization of the system. When σ2g approaches zero, the overall rate is controlled by the chemical reaction. When σ2g is large, the overall rate is controlled solely by the diffusion of the gaseous reactant within the grain.