Effects of Oil-Derived Contaminants on Emissions from TWC-Equipped Vehicles

Darr, Stephan; Choksi, R. A.; Hubbard, Carolyn P.; Johnson, M. D.; McCabe, Robert W.

doi:10.4271/2000-01-1881

Cited by 31 publications

(20 citation statements)

References 11 publications

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“…One of the unresolved questions for the practical applications of this technology is the potential impact on TWC reactivity, and how the impact compares with commercially available lubricant additives, such as ZDDP. From prior studies, it is well-known that ZDDP contributes to the deactivation of TWCs through normal oil consumption in engines [1][2][3][4][5][6][7][8][9]. Vehicle manufacturers must then design the emissions control systems to tolerate some level of Zn and P deactivation over the lifetime of the vehicle such that it still meets emission standards at the end of full useful life.…”

Section: Discussionmentioning

confidence: 99%

“…With high effectiveness in wear protection, zinc dialkyl dithiophosphate (ZDDP) is the most common anti-wear additive used in the automotive industry. The major drawback of ZDDP is that it can form ash during combustion and poison emissions control catalysts [1][2][3][4][5][6][7][8][9][10][11]. Thus, there is significant interest in developing a new lubricant additive that is ashless, has less impact on engine emissions control catalysts, and reduces friction and wear.…”

Section: Introductionmentioning

confidence: 99%

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Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts

et al. 2016

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Abstract:As alternative lubricant anti-wear additives are sought to reduce friction and improve overall fuel economy, it is important that these additives are also compatible with current emissions control catalysts. In the present work, an oil-miscible phosphorous-containing ionic liquid (IL), trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate ([P 66614 ][DEHP]), is evaluated for its impact on three-way catalysts (TWC) and benchmarked against the industry standard zinc-dialkyl-dithio-phosphate (ZDDP). The TWCs are aged in different scenarios: neat gasoline (no-additive, or NA), gasoline+ZDDP, and gasoline+IL. The aged samples, along with the as-received TWC, are characterized through various analytical techniques including catalyst reactivity evaluation in a bench-flow reactor. The temperatures of 50% conversion (T50) for the ZDDP-aged TWCs increased by 30, 24, and 25˝C for NO, CO, and C 3 H 6 , respectively, compared to the no-additive case. Although the IL-aged TWC also increased in T50 for CO and C 3 H 6 , it was notably less than ZDDP, 7 and 9˝C, respectively. Additionally, the IL-aged samples had higher water-gas-shift reactivity and oxygen storage capacity than the ZDDP-aged TWC. Characterization of the aged samples indicated the predominant presence of CePO 4 in the ZDDP-aged TWC aged by ZDDP, while its formation was retarded in the case of IL where higher levels of AlPO 4 is observed. Thus, results in this work indicate that the phosphonium-phosphate IL potentially has less adverse impact on TWC than ZDDP.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts

et al. 2016

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“…Because the lubricant with the highest S levels also had the highest levels of P, it can be concluded that the P in the lubricant also had a minimal impact on the regulated gas-phase emissions over the mileage accumulation and test conditions of the present study. Because previous studies have shown that lubricant P can have adverse effects on regulated gas-phase emissions, [21][22][23] it is possible that P effects would be stronger for higher mileages or for higher lubricant P contents.…”

Section: Steady-state Idle and 50-mph Cruise Resultsmentioning

confidence: 99%

“…The phosphorus (P) levels also are included in Table 2 because previous studies have shown that P from lubricants also can have adverse effects on emissions performance. [21][22][23] (1) This lubricant had a synthetic, zero-S PAO base with an ashless, zero-S antiwear and antioxidant additive. This oil was designed to provide a zero-S baseline condition with adequate engine protection (actual lubricant S level ϭ 0.01%).…”

Section: Lubricants and Gasolinementioning

confidence: 99%

Impact of Engine Lubricant Properties on Regulated Gaseous Emissions of 2000-2001 Model-Year Gasoline Vehicles

Durbin

Sauer

Pisano

et al. 2004

Journal of the Air & Waste Management Association

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The impact of the sulfur (S) content in lubricating oil was evaluated for four ultra-low-emission vehicles and two super-ultra-low-emission vehicles, all with low mileage. The S content in the lube oils ranged from 0.01 to 0.76%, while the S content of the gasoline was fixed at 0.2 ppmw. Vehicles were configured with aged catalysts and tested over the Federal Test Procedure, at idle and at 50-mph cruise conditions. In all testing modes, variations in the S level of the lubricant did not significantly affect the regulated gas-phase tailpipe emissions. In addition to the regulated gas-phase emissions, a key element of the research was measuring the engine-out sulfur dioxide (SO 2 ) in near-real-time. This research used a new methodology based on a differential optical absorption spectrometer (DOAS) to measure SO 2 from the lubricants used in this study. With the DOAS, the contribution of SO 2 emissions for the highest-S lubricant was found to range from less than 1 to 6 ppm on a gasoline S equivalent basis over the range of vehicles and test cycles used. The development and operation of the DOAS is discussed in this paper. INTRODUCTIONOver the years, gasoline sulfur (S) levels have declined as a result of both federal and state regulations. A number of studies have measured the impact of fuel S levels on gas-phase exhaust emissions for gasoline vehicles. 1-14 Additional reductions in S content are anticipated to meet the new U.S. Environmental Protection Agency (EPA) requirements of average S levels of 30 ppm and the California requirements of average S levels of 15 ppm.As S levels are reduced in gasoline, it has been suggested that the issue of lubricant S levels and other properties be further investigated. 15 In a recent study of 1-, 30-, and 100-ppm S level fuels, it was found that the familiar

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“…The sampling spot size was ¾2 µm. Ten to fifteen scans with exposure times of 30 s each were accumulated for each spectrum, which were calibrated using the F 2g mode of silicon at 521 cm 1 . The laser power reaching the sample was less than 5 mW.…”

Section: Methodsmentioning

confidence: 99%

Principal component analysis of Raman spectra from phosphorus-poisoned automotive exhaust-gas catalysts

O׳Neill

2005

J. Raman Spectrosc.

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Raman spectra from real-world, phosphorus-poisoned automotive catalysts can be remarkably complicated, owing to the fact that factors such as variable driving conditions, catalyst formulations, and oil and fuel additives can contribute to the formation of a huge variety of compounds. To classify the Raman spectra from many catalysts without necessarily identifying all phosphorus contaminants, principal component analysis was performed. Examination of the scores in the PC1-PC2 plane showed that samples with similar spectra are grouped together while dissimilar ones are spaced apart from one another. The score plot also confirmed that the strongest peaks of orthophosphates generally lie close to one another. Examination of the loadings revealed that CePO 4 , and possibly Ca 10 (OH) 2 (PO 4 ) 6 and BaSO 4 , are among the major components present in the spectra. CePO 4 is readily observed in many of the spectra, but Ca 10 (OH) 2 (PO 4 ) 6 is not, showing that principal component analysis was useful in uncovering possible spectral constituents difficult to unambiguously assign from the original spectra. The spectra can be adequately reproduced using eight principal components, which means that a much smaller set of numbers can be used to represent the spectra instead of typical wavenumber-intensity data.

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Effects of Oil-Derived Contaminants on Emissions from TWC-Equipped Vehicles

Cited by 31 publications

References 11 publications

Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts

Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts

Impact of Engine Lubricant Properties on Regulated Gaseous Emissions of 2000-2001 Model-Year Gasoline Vehicles

Principal component analysis of Raman spectra from phosphorus-poisoned automotive exhaust-gas catalysts

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