EFFECTIVE DIFFUSIVITY OF A POROUS CATALYST WITH AND WITHOUT CHEMICAL REACTION

Abstract

The difference between the effective diffusivity of a cylindrical porous catalyst under reacting conditions, DeR, and non-reacting conditions, DeD, was studied experimentally and theoretically (on the basis of the pore model). It was concluded that the "local value"** of DeR substantially agrees with that of DeD. But the "apparent value" of DeR obtained experimentally was greatly affected by the non-uniformity of the catalyst pellet, that is, the local value of DeD was non-uniform. Especially when the reaction was carried out in the intraparticle diffusion limited region, DeR apparently became much smaller than DeD.