Chemical Reaction Engineering

Abstract

The models used to describe fixed bed catalytic reactors are classified in two broad categories: pseudo-homogeneous and heterogeneous models. In the former the conditions on the catalyst are considered to equal those in the fluid phase; in the latter this restriction is removed. The pseudo-homogeneous category contains the ideal one-dimensional model, the one-dimensional model with effective axial transport, and the two-dimensional models with axial and radial gradients. Particular emphasis is placed on such problems as parametric sensitivity, runaway, and instabilities induced by axial mixing. In the heterogeneous category attention is given to the effect of transport phenomena around and inside the catalyst particle on the behavior of the reactor. Finally, a new, general two-dimensional heterogeneous model is set up and compared with previously discussed models.