Role of the catalysis sphere in the chain-radical process of hydrocarbon pyrolysis

The effect of the catalysis sphere (i.e., the sphere with an increased concentration of radicals around the catalyst granules) on hydrocarbon pyrolysis is analyzed. The values of the radii of the spheres, the lifetimes of radicals in the sphere, and the diffusion time of molecules to the surface are estimated. The applicability of the reaction area concept to these processes is discussed. Requirements for the optimum spatial arrangement of the catalyst in the volume of the reactor are justified.