Development of Next-Generation NOx Reduction System for Diesel Exhaust Emission

Ohashi, Noboru; Nakatani, Koichiro; Asanuma, Takamitsu; Fukuma, Takao; Matsubara, Hiroyuki; Sobue, Yuichi; Watanabe, Minoru

doi:10.4271/2008-01-0065

Cited by 22 publications

(8 citation statements)

References 14 publications

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“…SO 3 is stored in the rear part of the catalyst. When stored O 2 is totally consumed (Figure 10d), there is high availability of H 2 and SO 2 /H 2 S can no longer be oxidized into SO 3 and SO 2 , respectively. Subsequently, H 2 S is released at the outlet of the catalyst.…”

Section: Lean/rich Desulfation Mechanism Explanationmentioning

confidence: 99%

“…Eventually, the catalyst is saturated with NO x , leading to significant decrease in NO x removal efficiency after a few minutes of normal operation. Therefore, the engine is operated in rich mode for a few seconds, in order to remove the stored NO x from the catalyst's surface and subsequently to reduce the released NO x mainly into N 2 and secondarily into N 2 O and NH 3 . The interested reader may find in the literature several experimental studies on the performance of the NSR catalyst as well as simulation studies and kinetic models.…”

Section: Introductionmentioning

confidence: 99%

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Modeling of the desulfation process in NO_x storage and reduction catalysts

et al. 2016

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One of the major challenges for the NOx Storage and Reduction Catalysts technology used in automotive exhaust remains the sulfur susceptibility, which calls for efficient desulfation strategies. The sulfation and desulfation processes are systematically studied via measurements and mathematical modeling of the physicochemical processes. The role of oxygen storage which influences the reducing agents availability for desulfation is explained and a respective reaction model is presented. The bulk oxygen storage component appears to be involved in sulfur storage, which further emphasizes the importance of oxygen–sulfur storage interactions. Next, the observed release of sulfur species under lean mode is discussed along with a proposed reaction mechanism which involves SO2 formation via O2 reaction with elemental sulfur on the surface. The parameters of the complex reaction model are calibrated in order to reproduce the observed trends at least in a qualitative manner. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2117–2127, 2017

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Section: Lean/rich Desulfation Mechanism Explanationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling of the desulfation process in NO_x storage and reduction catalysts

et al. 2016

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“…Precious metal dispersion is greatly enhanced, resulting in reduced usage and improved performance (36). Components are added to the LNT to inhibit sulfate formation (37), and desulfation temperatures for new formulations are coming down as well, to the 600ºC range (from 700-750ºC) without compromising high-temperature performance (38). Figure 11.…”

Section: Hc-based Denoxmentioning

confidence: 99%

Diesel Emission Control in Review

Johnson

2008

SAE Int. J. Fuels Lubr.

207

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This summary covers representative developments from 2008 in diesel regulations, engine technology, and NOx, particulate matter (PM), and hydrocarbon (HC) control. Europe is finalizing the Euro VI heavy-duty (HD) regulations for 2013 with the intent of technologically harmonizing with the US. A new particle number standard will be adopted. California is considering tightening the light-duty fleet average to US Tier 2 Bin 2 levels, and CO 2 mandates are emerging in Europe for LD, and in the US for all vehicles. LD engine technology is focused on downsizing to deliver lower CO 2 emissions, enabled by advances in boost and EGR (exhaust gas recirculation). Emerging concepts are shown for attaining Bin 2 emission levels. HD engines will make deNOx systems optional for even the tightest NOx standards, but deNOx systems enable much lower fuel consumption levels and will likely be used. NOx control is centered on SCR (selective catalytic reduction) for diverse applications. Focus is on cold operation, system optimization, and catalyst durability. LNT (lean NOx trap) performance is advancing and precious metal cost content is decreasing. Desulfation is enhanced, and new compositions are emerging based on alumina and ceria. LNCs (lean NOx catalysts or HC-SCR) developments are updated. Diesel particulate filter (DPF) technology is in a state of optimization and cost reduction. New DPF regeneration strategies are described as well as the new learnings on the fundamentals of soot/catalyst interaction and the impact of DPF pore structure. Finally an update on diesel oxidation catalysts (DOCs) is provided showing potential solutions for advanced combustion strategies.

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“…One of the maintenancefree solutions that do not require additional catalyst power is the DPNR system. Its efficiency of 99% NO x reduction has been confirmed in D1 simulation tests for power generators [Parthiban and Jain 2019, Ohashi et al 2008].…”

Section: Introductionmentioning

confidence: 96%

Effect of Diesel Fuel Temperature on the Nitrogen Oxides Emission from a Compression-Ignition Engine

Czechlowski

2020

J. Ecol. Eng.

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The research aimed at analysing the influence of the diesel oil temperature on the NO x emission level. The tests were carried out on a test stand equipped with a 9.5 kW multi-fuel compression-ignition engine. The setup constitutes an experimental cogeneration unit discharging the produced energy into the power grid. The measurements were carried out under the D1 test procedure provided by ISO 8178-4 for testing engines operating at a constant speed. As a result of statistical analysis of the results obtained, significant differences were found in the u specific values of the nitrogen oxides emission gained for particular phases of D1 tests, when the engine was fed with diesel fuel of different temperatures. The results obtained confirmed the possibility of limiting the specific emission of NO x only when the engine is running at 75% of its nominal torque. An increase in the NO x emissions was recorded for the remaining loads.

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Development of Next-Generation NOx Reduction System for Diesel Exhaust Emission

Cited by 22 publications

References 14 publications

Modeling of the desulfation process in NO_x storage and reduction catalysts

Modeling of the desulfation process in NO_x storage and reduction catalysts

Diesel Emission Control in Review

Effect of Diesel Fuel Temperature on the Nitrogen Oxides Emission from a Compression-Ignition Engine

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Development of Next-Generation NOx Reduction System for Diesel Exhaust Emission

Cited by 22 publications

References 14 publications

Modeling of the desulfation process in NOx storage and reduction catalysts

Modeling of the desulfation process in NOx storage and reduction catalysts

Diesel Emission Control in Review

Effect of Diesel Fuel Temperature on the Nitrogen Oxides Emission from a Compression-Ignition Engine

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Product

Resources

About

Modeling of the desulfation process in NO_x storage and reduction catalysts

Modeling of the desulfation process in NO_x storage and reduction catalysts