433g Pattern Formation and Chaotic Dynamics In a Model of Simultaneous Oxidation and Reduction In Three-Way Catalytic Converters

Martin Kohout¹, Milan Kubicek², Milos Marek³, and Igor Schreiber¹. (1) Department of Chemical Engineering, Institute of Chemical Technology, Prague, Technicka 5, Prague 6, 16628, Czech Republic, (2) Department of Mathematics, Prague Institute of Chemical Technology, Technicka 5, Prague 6, 16628, Czech Republic, (3) Department of Chemical Engineering, Prague Institute of Chemical Technology, Technicka 5, Prague 6, 16628, Czech Republic

Dynamical behavior of reaction-transport processes in a detailed model of three-way catalytic converter, where catalytic oxidation of carbon monoxide and hydrocarbons occurs simultaneously with reduction of nitrogen oxides possesses several sources of kinetic rather than thermokinetic autocatalysis and can support sustained oscillations and patterns.

The instabilities are provided by kinetics of certain subnetworks found by a reaction network analysis. First, bifurcation analysis is applied to identify basic dynamical modes in a spatially homogeneous reactor. Then the kinetic subnetwork is coupled with transport by diffusion and convection. Reaction-transport processes are assumed to occur in a tubular cross-flow reactor, where reactants are supplied at the inlet as well as along the reactor. We examine whether and how spatiotemporal structures such as spatially nonhomogeneous steady states and travelling waves are produced. Furthermore we find that the system displays a wide variety of chaotic spatiotemporal patterns, which are examined in detail.

References

1. M. Marek, M. Schejbal, P. Kočí, V. Nevoral, M. Kubíček, O. Hadač and I. Schreiber, Chaos, 16, 037107 (2006).

2. M. Kohout, I. Schreiber and M. Kubíček, Comp. & Chem. Eng., 26, 517 (2002).