Comparison of One- and Two-Dimensional Models of Plate Reactors

This Demonstration compares three mathematical models of a plate chemical reactor in which an adiabatic reaction takes place. The fluid containing the reactants flows in the channel between two parallel plates; the distance between the plates is much smaller than their width or length. The models assume a steady-state condition with constant material properties. The first model is one-dimensional; it considers only horizontal convective transport. The others are two-dimensional models that consider horizontal convection and vertical diffusion as well; they differ only in the horizontal fluid velocity profiles: one is laminar flow and the other is plug flow.

There is no significant difference in the results of the average (cup) temperature or conversion of the one-dimensional and the two-dimensional plug flow models. However, these models overestimate both the average conversion and average temperature change of reactants for both endothermic and exothermic reactions.

The models show significant differences in both predicted temperature and conversion across the vertical direction. The changes are larger in slower (higher activation energy) reactions, and more noticeable near the center where the velocity of the two-dimensional model with laminar flow approaches the maximum velocity. Here the conversion is lowest; therefore, the temperature of the laminar flow model is lower than the other models in exothermic reactions and higher in endothermic reactions, whereas the conversion in the laminar flow model is always lower in both types of reactions.