EFFECT OF HYDROTHERMAL AGING OVER A COMMERCIAL DOC
ON NO2 PRODUCTION AND SUBSEQUENT SCR EFFICIENCY |
Tae Joong Wang |
Doosan Infracore |
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ABSTRACT |
In this study, the effect of hydrothermal aging over a commercial diesel oxidation catalyst (DOC) on
deterioration in nitrogen dioxide (NO2) production activity has been experimentally investigated based on a micro-reactor
DOC experiment. Through this experimental result, the NO2 to nitrogen oxides (NOx) ratio at DOC outlet has been
mathematically expressed as a function of DOC temperature according to various aging conditions. The current study reveals
that the catalyst aging temperature is a more dominant factor than the aging duration in terms of the decrease in NO2
production performance through DOC. The DOC sample hydrothermally aged for 25 h at 750 °C has displayed the lowest NO2
to NOx ratio compared to the samples aged for 25 ~ 100 h at 650 °C. Also, in this study, the impact of hydrothermal aging
of a DOC on the selective catalytic reduction (SCR) efficiency in a ‘DOC + SCR’ aftertreatment system was predicted by
using transient SCR simulations. To validate the SCR simulation, this study has conducted a dynamometer test of a non-road
heavy-duty diesel engine with employing a commercial ‘DOC + SCR’ system on the exhaust line. The current study has
quantitatively estimated the effect of the variation in NO2 to NOx ratio due to the hydrothermal aging of DOC on the NOx
removal efficiency of SCR. |
Key Words:
Diesel engine, Exhaust aftertreatment system, Diesel oxidation catalyst, Selective catalytic reduction,
Hydrothermal aging |
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