Abstract: | A general criterion is developed for testing the relative importance of intraparticle and external, concentration and temperature gradients on the observed rates, for reactions catalyzed by porous solids. The criterion is applicable to any multiple reaction system and to reactions conforming to any rate law. The applicability of such criteria is extended to reaction systems with highly nonlinear temperature and concentration dependence, by taking into-account the higher order terms in the Taylor expansion of the rate expressions in the derivation. |