- 12:30 PM
83a

Diffusion and Reaction in Catalytic Monolith Washcoat - Modeling Approaches

Milos Marek1, Petr Koci1, Jan Stepanek1, Vladimir Novak1, and Milan Kubicek2. (1) Department of Chemical Engineering, Institute of Chemical Technology, Prague, Technicka 5, Prague, CZ16628, Czech Republic, (2) Department of Mathematics, Institute of Chemical Technology, Prague, Technicka 5, Prague, CZ16628, Czech Republic

To model properly the effects of varying washcoat thickness, distribution of noble metals and other catalyst components on ignition phenomena and conversion a detailed description of processes inside the catalytic washcoat layer is necessary. In this contribution we first discuss the spatially 2D (1D+1D) model of entire monolith with effective internal diffusion. Then we describe detailed, spatially 3D model using digital reconstruction of a section of porous catalytic washcoat on a micro- and nano-scale. We briefly describe suitable numerical procedures for solution of such models and coupling of the models on different levels. We illustrate the methodology on examples of oxidation catalyst and NOx storage & reduction catalyst.

References:

P. Koci, F. Stepanek, M. Kubicek, M. Marek: Modelling of micro/nano-scale concentration and temperature gradients in porous supported catalysts, Chemical Engineering Science 62, (2007), 5380-5385. DOI:10.1016/j.ces.2006.12.033

M. Marek, Z. Grof, P. Koci, M. Kohout, J. Kosek, F. Stepanek: Multiscale modelling of transport, reaction and phase change in heterogeneous media, Journal of Chemical Engineering of Japan 40, (2007), 879-889. DOI:10.1252/jcej.07WE044

P. Koci, M. Kubicek, M. Marek: Modelling of TWC monolith converters with microkinetics and diffusion in the washcoat, Ind. Eng. Chem. Res. 43, (2004), 4503-4510. DOI:10.1021/ie034137k

A. Guethenke, D. Chatterjee, M. Weibel, B. Krutzsch, P. Koci, M. Marek, I. Nova and E. Tronconi: Current status of modeling lean exhaust gas aftertreatment catalysts, in "Advances in Chemical Engineering vol. 33: Automotive Emission Control", pp. 103-211, ed. G. B. Marin, ISBN: 978-0-12-373900-1, Elsevier 2007. DOI:10.1016/S0065-2377(07)33003-2

T. Stary, O. Solcova, P. Schneider and M. Marek: Effective diffusivities and pore-transport characteristics of washcoated ceramic monolith for automotive catalytic converter, Chemical Engineering Science 61, (2006), 5934-5943. DOI:10.1016/j.ces.2006.05.014

www.vscht.cz/monolith



Web Page: www.vscht.cz/monolith