Selective Catalytic Reduction on Filter Performance Testing on
Non-road Diesel Engine 2021-01-5054
High-efficiency lean-burn compression ignition engines are expected to continue
to play an important role as a power source for non-road mobile machinery. The
challenge for these engines is that they suffer both high levels of nitrogen
oxide (NOx) and particulate matter (PM) emissions, and the
simultaneous reduction of these particular emissions is difficult due to the
trade-off relationship between NOx and PM. Consequently, achieving
the most stringent emission limits requires efficient exhaust aftertreatment.
Traditionally, NOx and PM have been controlled by separate
aftertreatment devices. However, such sequential system configurations have
several disadvantages, such as a large volume of the aftertreatment system. The
compact design of a selective catalytic reduction (SCR)-coated diesel
particulate filters (DPF), referred to as selective catalytic reduction on
filter (FSCR), allows the reduction in aftertreatment system volume and mass.
Another advantage is that the SCR can be placed closer to the engine to improve
SCR temperature behavior. The major challenge of the FSCR technology is the
interaction between the SCR and DPF functions. The present study examines the
operation of a state-of-the-art combined particulate filter and SCR catalyst
device as a part of an exhaust aftertreatment system on a high-speed non-road
diesel engine. Unlike previous studies, the goal was a complete ammonia
(NH3) slip-free operation. The main objective was to investigate
how the SCR properties—NOx conversion and NH3 slip—change
when the filter fills up with soot. In this context, tests with clean FSCR and
with soot-loaded FSCR were conducted at varying urea dosing. The soot-loaded
FSCR, compared with a clean one, showed a slightly (4-6%) lower NOx
reduction and higher (1-4 ppm) NH3 slip under identical operating
conditions. The results also indicated a decrease in NH3 storage
capacity upon soot loading. Finally, a supplementary flow-through SCR catalyst
was added downstream of the FSCR, and tests with FSCR only versus FSCR + SCR
were performed. Adding the second SCR allowed for higher urea dosing without
NH3 slip and, consequently, higher (+23%) NOx
conversions.
Citation: Spoof-Tuomi, K., Niemi, S., Ovaska, T., Nilsson, O. et al., "Selective Catalytic Reduction on Filter Performance Testing on Non-road Diesel Engine," SAE Technical Paper 2021-01-5054, 2021, https://doi.org/10.4271/2021-01-5054. Download Citation
Author(s):
Kirsi Spoof-Tuomi, Seppo Niemi, Teemu Ovaska, Olav Nilsson, Sonja Heikkilä, Krister Ekman
Affiliated:
University of Vaasa, Turku University of Applied Sciences
Pages: 12
Event:
Automotive Technical Papers
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Selective catalytic reduction
Diesel particulate filters
Particulate matter (PM)
Diesel / compression ignition engines
Particulate filters
Nitrogen oxides
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