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Steady-state particulate loading experiments were conducted on an advanced production catalyzed particulate filter (CPF), both with and without a diesel oxidation catalyst (DOC). A heavy-duty diesel engine was used for this study with the experiments conducted at 20, 40, 60 and 75 % of full load (1120 Nm) at rated speed (2100 rpm). The data obtained from these experiments were used and are necessary for calibrating the MTU 1-D 2-Layer CPF model. These experimental and modeling results were compared to previous research conducted at MTU that used the same engine but an earlier development version of the combination of DOC and CPF. The motivation for the comparison of the two systems was to determine whether the reformulated production catalysts performed as good or better than the early development catalysts. The results were compared to understand the filtration and oxidation differences between the two DOC+CPF and the CPF-only aftertreatment systems.

Active regeneration experiments were performed on a Cummins 2007 aftertreatment system by hydrocarbon dosing with injection of diesel fuel downstream of the turbocharger. The main objective was to characterize the thermal oxidation rate as a function of temperature and particulate matter (PM) loading of the catalyzed particulate filter (CPF). Partial regeneration tests were carried out to ensure measureable masses are retained in the CPF in order to model the oxidation kinetics. The CPF was subsequently re-loaded to determine the effects of partial regeneration during post-loading. A methodology for gathering particulate data for analysis and determination of thermal oxidation in a CPF system operating in the engine exhaust was developed. Durations of the active regeneration experiments were estimated using previous active regeneration work by Singh et al. 2006 [1] and were adjusted as the experiments progressed using a lumped oxidation model [2, 3].

A 2007 Cummins ISL 8.9L direct-injection common rail diesel engine rated at 272 kW (365 hp) was used to load the filter to 2.2 g/L and passively oxidize particulate matter (PM) within a 2007 OEM aftertreatment system consisting of a diesel oxidation catalyst (DOC) and catalyzed particulate filter (CPF). Having a better understanding of the passive NO₂ oxidation kinetics of PM within the CPF allows for reducing the frequency of active regenerations (hydrocarbon injection) and the associated fuel penalties. Being able to model the passive oxidation of accumulated PM in the CPF is critical to creating accurate state estimation strategies. The MTU 1-D CPF model will be used to simulate data collected from this study to examine differences in the PM oxidation kinetics when soy methyl ester (SME) biodiesel is used as the source of fuel for the engine.

Active regeneration experiments were carried out on a production 2007 Cummins 8.9L ISL engine and associated diesel oxidation catalyst (DOC) and catalyzed particulate filter (CPF) aftertreatment system. The effects of SME biodiesel blends were investigated to determine the particulate matter (PM) oxidation reaction rates for active regeneration. The experimental data from this study will also be used to calibrate the MTU-1D CPF model [1]. The experiments covered a range of CPF inlet temperatures using ULSD, B10, and B20 blends of biodiesel. The majority of the tests were performed at a CPF PM loading of 2.2 g/L with in-cylinder dosing, although 4.1 g/L and a post-turbo dosing injector were also investigated. The PM reaction rate was shown to increase with increasing percent biodiesel in the test fuel as well as increasing CPF temperature.