| Abstract
| - Global kinetics for the oxidation of diesel fuel (DF), propylene (C3H6), CO, H2, and NO were determinedover a commercial diesel oxidation catalyst (DOC) with simulated diesel exhaust between 200 and 415 °Cover a wide concentration range intended to represent engine exhaust from both conventional and premixedcompression ignition (PCI) combustion. Total hydrocarbons in the exhaust were represented as a combinationof propylene, to represent partially oxidized fuel species, and diesel fuel, to represent unburned fuel. Anintegral reactor with high space velocity capability (up to 2 million h-1) was used to generate low and moderateconversion data for the rate-generation process. Mass transport properties of DF were determined based onthe experimental data. First-order concentration dependency for all of the reactants involved in the DF, C3H6,CO, and H2 oxidation reactions adequately captured the experimental behavior. An overall inhibition termincluding only the effects of CO and NO was found to be adequate for these reactions over the range ofconditions examined for this study. For the NO oxidation reaction, the rate was found to be first order withrespect to NO and 0.5 with respect to O2. The inhibition term for this reaction was found to be a function ofDF and NO. Modeling approaches and optimization strategies similar to our previous work were employedfor the entire rate-generation process. These rate expressions were first validated against light-off curvesgenerated with the same laboratory reactor operating at realistic space velocities and subsequently validatedagainst light-off curves generated on a full-size DOC mounted on a 1.7 L Isuzu diesel engine using bothconventional and PCI combustion strategies.
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