Abstract
A Hydrocarbon is supplied to a diesel oxidation catalyst installed in an upstream of the diesel particulate filter for burning particulate matter deposited on the diesel particulate filter. In this study, we developed a thermal fluid numerical computation fluid dynamics code including a chemical reaction rate model which shows the influence of a hydrocarbon concentration and a type on the oxidation reaction of a hydrocarbon on a diesel oxidation catalyst. First, oxidation characteristics of four types of hydrocarbon fuels (Decane, Hexadecane, Eicosane, and 1-Methylnaphthalene) were investigated using a straight flow substrate carrying a platinum palladium catalyst. 1-methylnaphthalene greatly deteriorated the oxidizing ability, but there was no significant difference in the three kinds of alkane fuels. The difference of these oxidation characteristics could be reproduced by constructing a sub model expressing the difference between the adsorption characteristics of each hydrocarbon fuel and the oxidation inhibition effect due to adsorption. Further, the oxidation characteristics of the zeolite-containing catalyst were evaluated. As a result of the evaluation, the oxidation characteristics of the decane of the linear hydrocarbon did not change when compared with the catalyst which did not contain the zeolite, but the oxidation characteristics of the aromatic hydrocarbon 1-methylnaphthalene deteriorated. It was assumed that the zeolite had high adsorption capacity of 1-methylnaphthalene and a further inhibition of a reaction by adsorption was accelerated.
