Chemical Engineering Science, Vol.54, No.20, 4567-4578, 1999
Modeling dynamic phenomena in 3-way catalytic converters
Mathematical modeling of 3-way catalytic converter (3WCC) operation is increasingly employed in automotive catalyst and converter systems optimization. The majority of the models employed in this direction employ a 'quasi-steady' approach in the reaction kinetics computations. This approach is useful in predicting real-world performance of the catalyst. However, certain improvements, that are produced by the application of specially tuned redox oscillations, can not be predicted. This paper presents an approach embodying certain types of dynamic phenomena into an existing 3-WCC quasi-steady model. The dynamic model developed according to this approach is validated against literature data and results from experimental investigations. It is confirmed, that the catalyst behavior under dynamic exhaust composition conditions significantly differs from what is predicted under the quasi-steady-state assumption. More specifically, oxygen storage and the transient character of water gas shift reaction are shown to affect dynamic behavior. The results of this investigation encourage further application of mathematical modeling in areas like lambda control strategy optimization, which lied beyond the scope of traditional 3WCC models.