1. Catalytic fluid-solid reactions

In heterogeneous catalysis reactions, the reactants present in a fluid react on the active surface of a porous solid catalyst. The products of the reaction flow from the catalytic surface back into the fluid. Completion of the reaction involves several steps in series: diffusion through the boundary layer surrounding the solid grains (external transfer), diffusion within the porous solid (internal transfer), adsorption/desorption at the surface, and the chemical reaction itself, in the adsorbed phase. The heat of reaction diffuses simultaneously outside and inside the solid. It is the most difficult of these serial steps that imposes its speed (see article [46] in this treatise). The essential results are summarized below. The notations are similar to those of these authors, although the indices are slightly different, given...