(575ag) Multi-Mode Low-Dimensional Models for Real Time Simulation of Monolithic Catalytic Reactors

We present accurate low-dimensional models for real time simulation, control and optimization of monolithic catalytic converters used in automobile exhaust treatment. These are derived rigorously using the Liapunov-Schmidt (LS) technique of bifurcation theory and are expressed in terms of three concentration and two temperature modes. They include washcoat diffusional effects without using the concept of effectiveness factor and reduce to the classical two-phase models under steady-state conditions and when the washcoat thickness is very small. The models are validated by comparing the solutions with the exact solution of the detailed convection-diffusion-reaction equations. The usefulness of these new models is illustrated by simulating the transient behavior of the three-way converter and comparing the predictions with detailed solution. It is shown that these new models are robust and accurate with practically acceptable error, speed up the computations by orders of magnitude, and can be used with confidence for the real time simulation and control of monolithic and other catalytic reactors.