ABSTRACT
The chemical engineering required to develop and design a reactor ranges from the trivial to the complex and on any scale of difficulty the design of a heterogeneous catalytic reactor would come close to or at the top. The key properties required by a catalyst are: high activity; high selectivity; long life. The simplest model of a catalyst is that of a porous solid with a large internal surface. The design and development of a catalyst is concerned with increasing the number of active sites and changing the structure to minimise the resistance of the pore system to diffusion. The purpose of the catalyst is to promote the useful step and suppress the reaction that proceeds without catalysis. The obvious arrangement of a catalyst bed is to place the catalyst inside a vertical right cylinder with gas flow down the bed keeping the catalyst in the vessel with a holding-down grid to prevent attrition of the top layers.
