Chemical Engineering Journal
Igor Belot;David Vidal;Robert Greiner;Martin Votsmeier;Robert E. Hayes;Fran?ois Bertrand
The impact of catalyst distribution within the porous wall of a coated gasoline particulate filter on its catalytic performance is investigated. Sections of catalyzed filter wall with different amounts of washcoat and different levels of uniformity are digitally reconstructed from tomography data. A coupled problem involving the exhaust gas flow and the transport and reaction of a dilute species in the reconstructed structures is solved using the lattice Boltzmann method. The resulting model is verified and its accuracy is assessed for first-order reactions and those with inhibition kinetics. Computed washcoat effectiveness values agree well with the Thiele modulus theory. Improvements in catalytic conversion and washcoat effectiveness of uniform washcoat distribution are observed with increased washcoat loading. These effects are quantified and the benefits are found to be limited to the transitional regime. The uniform washcoat distribution is shown to be beneficial for both filtration and conversion performance.