Sulfur Poisoning and Desulfation of the Lean NOx Trap

Li, J.; Theis, Joseph R.; Wang, Chun; Goralski, Christian T.; Kudla, Robert; Ura, Justin; Watkins, W.L.H.; Chattha, M. S.; Hurley, R. G.

doi:10.4271/2001-01-2503

Cited by 37 publications

(28 citation statements)

References 16 publications

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“…Three-way catalysts typically contain base metal promoters such as barium; 14,15 these materials are known to store NO X . 16 These materials also have a high affinity for sulfur, and sulfur has been shown to limit catalyst effectiveness; the largest effect is on NO X performance. 16,17,18,19 Catalyst function has been shown to recover when sulfur is purged through hot, rich operation such as that reached during the repeated WOT cycles used in the current study.…”

Section: Resultsmentioning

confidence: 99%

“…16 These materials also have a high affinity for sulfur, and sulfur has been shown to limit catalyst effectiveness; the largest effect is on NO X performance. 16,17,18,19 Catalyst function has been shown to recover when sulfur is purged through hot, rich operation such as that reached during the repeated WOT cycles used in the current study. 17,18,19 It may be that the vehicles' exposure to repeated WOT cycles resulted in continual improvement of NO X reduction.…”

Section: Resultsmentioning

confidence: 99%

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Effects of Mid-Level Ethanol Blends on Conventional Vehicle Emissions

Knoll¹,

West²,

Huff³

et al. 2009

SAE Technical Paper Series

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Tests were conducted during 2008 on 16 late-model, conventional vehicles (1999 through 2007) to determine short-term effects of mid-level ethanol blends on performance and emissions. Vehicle odometer readings ranged from 10,000 to 100,000 miles, and all vehicles conformed to federal emissions requirements for their federal certification level. The LA92 drive cycle, also known as the Unified Cycle, was used for testing as it was considered to more accurately represent real-world acceleration rates and speeds than the Federal Test Procedure (FTP) used for emissions certification testing. Test fuels were splash-blends of up to 20 volume percent ethanol with federal certification gasoline. Both regulated and unregulated air-toxic emissions were measured.For the aggregate 16-vehicle fleet, increasing ethanol content resulted in reductions in average composite emissions of both NMHC and CO and increases in average emissions of ethanol and aldehydes. Changes in average composite emissions of NMOG and NO X were not statistically significant. By segregating the vehicle fleet according to power-enrichment fueling strategy, a better understanding of ethanol fuel-effect on emissions was realized. Vehicles found to apply longterm fuel trim (LTFT) to power-enrichment fueling showed no statistically significant fuel effect on NMOG, NMHC, CO or NO X . For vehicles found to not apply LTFT to power-enrichment, statistically significant reductions in NMHC and CO were observed, as was a statistically significant increase in NO X emissions. Effects of ethanol on NMOG and NMHC emissions were found to also be influenced by power-to-weight ratio, while the effects on NO X emissions were found to be influenced by engine displacement.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effects of Mid-Level Ethanol Blends on Conventional Vehicle Emissions

Knoll¹,

West²,

Huff³

et al. 2009

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…The NO x storage capacity of the LNT, one of the most critical parameters for control design and calibration, varies dynamically. In particular, the trap is susceptible to sulfur poisoning [56] and the capacity of the trap is reduced as sulfates accumulate. In addition, ambient conditions and component-to-component variations can affect the LNT operation and lead to deteriorated performance.…”

Section: Aftertreatment Control and Adaptationmentioning

confidence: 99%

Automotive Powertrain Control - A Survey

Cook

Sun²,

Buckland

et al. 2008

Asian Journal of Control

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This paper surveys recent and historical publications on automotive powertrain control. Control-oriented models of gasoline and diesel engines and their aftertreatment systems are reviewed, and challenging control problems for conventional engines, hybrid vehicles and fuel cell powertrains are discussed. Fundamentals are revisited and advancements are highlighted. A comprehensive list of references is provided.

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“…Among these variables and functions, the following are considered to have significant impact on the performance and are most susceptible to uncertainties: * Trap capacity C LNT : As mentioned earlier, sulphur poisoning is the primary source of uncertainty [6]. Other factors, such as thermal degradation due to ageing, also change the capacity slowly over time.…”

Section: Remark 33mentioning

confidence: 99%

“…Second, the NO x storage capacity of the LNT, one of the most critical parameters for its control strategies, varies dynamically. In particular, the trap is susceptible to sulphur poisoning [6]. Sulphur di-oxide, a by-product of the combustion process for engines fuelled by gasoline with sulphur content, will compete with the nitrates for active storage sites.…”

Section: Introductionmentioning

confidence: 99%

Aftertreatment control and adaptation for automotive lean burn engines with HEGO sensors

Sun

Kim

Wang

2004

Adaptive Control & Signal

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Control of aftertreatment systems for lean burn technology engines represents a big challenge, due to the lack of on-board emission measurements and the sensitivity of the hardware components to ageing and sulphur poisoning. In this paper, we consider the control and adaptation of aftertreatment systems involving lean NO x trap (LNT). A phenomenological LNT model is presented to facilitate the model-based control and adaptation. A control strategy based on the LNT model and HEGO (heated exhaust gas oxygen) sensor feedback is discussed. A linear parametric model, which is derived by exploiting the physical properties of the LNT is used for adaptation of trap capacity and feedgas NO x emission models. The conditions under which parameter convergence will be achieved are derived for the proposed adaptive scheme. Simulation results for different scenarios are included to demonstrate the effectiveness of control and adaptation.

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Sulfur Poisoning and Desulfation of the Lean NOx Trap

Cited by 37 publications

References 16 publications

Effects of Mid-Level Ethanol Blends on Conventional Vehicle Emissions

Effects of Mid-Level Ethanol Blends on Conventional Vehicle Emissions

Automotive Powertrain Control - A Survey

Aftertreatment control and adaptation for automotive lean burn engines with HEGO sensors

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