Modeling dynamic phenomena in 3-way catalytic converters

Mathematical modeling of 3-way catalytic converter (3WCC) operation is incr easingly employed in automotive catalyst and converter systems optimization . The majority of the models employed in this direction employ a 'quasi-ste ady' approach in the reaction kinetics computations. This approach is usefu l in predicting real-world performance of the catalyst. However, certain im provements, that are produced by the application of specially tuned redox o scillations, can not be predicted. This paper presents an approach embodyin g certain types of dynamic phenomena into an existing 3-WCC quasi-steady mo del. The dynamic model developed according to this approach is validated ag ainst literature data and results from experimental investigations. It is c onfirmed, that the catalyst behavior under dynamic exhaust composition cond itions significantly differs from what is predicted under the quasi-steady- state assumption. More specifically, oxygen storage and the transient chara cter 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 be yond the scope of traditional 3WCC models. (C) 1999 Elsevier Science Ltd. A ll rights reserved.