Deactivation of TWC as a Function of Oil Ash Accumulation - A Parameter Study

Franz, J.; Schmidt, J.; Schoen, Christof; Harperscheid, Manfred; Eckhoff, S.; Roesch, Martin; Leyrer, J.

doi:10.4271/2005-01-1097

Cited by 18 publications

(6 citation statements)

References 7 publications

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“…the one based on thermal degradation and the other one based on fouling and/or poisoning of the reactive sites. In this case study, as the registered operating temperatures resulted not particularly high (even at stoichiometric regime) and far from those generally acknowledged as critical due to thermal deactivation phenomena [2][3], the attention has been focused only on poisoning and fouling phenomena caused by the deposition of the soot produced by lubricant vapours and droplets combustion. The interest towards this potential issue is mandatory, because of the porous conformation of the OPC and of its trapping ability for particles, which could easily give rise to fouling phenomena.…”

Section: -3mentioning

confidence: 99%

“…It is well known that normal oil consumption in an internal combustion engine can negatively affect the right functioning of the three-way catalyst (TWC, from now on) after a long running period, thus determining a significant increase of gaseous emissions [1][2][3]. This aspect is well verified in the typical case of distributed generating plants or cogenerative systems, which could be the base of several energy arrangements, such as a smart-grid or micro-grids, in a near future.…”

Section: Introductionmentioning

confidence: 99%

“…The main reason for which the oil burning produces ashes depends on its chemical composition and, above all, on the presence of contained additives. The latter are fundamental to improve the overall performances in terms of friction reduction (thus improving engine overall efficiency) and anti-wear characteristics [1][2][4][5][6]. Also, they improve resistance to acid or corrosive attacks derived from combustion (especially from sulphuric and nitric acid) and reduce the tendency to foam and deposits formation (through dispersants and detergents) [2,[5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…The latter are fundamental to improve the overall performances in terms of friction reduction (thus improving engine overall efficiency) and anti-wear characteristics [1][2][4][5][6]. Also, they improve resistance to acid or corrosive attacks derived from combustion (especially from sulphuric and nitric acid) and reduce the tendency to foam and deposits formation (through dispersants and detergents) [2,[5][6][7]. However, most of these useful additives contain metals, such as Zinc (Zn), Calcium (Ca), Magnesium (Mg), Molybdenum (Mo), and other compounds, based on Phosphorus (P) and Sulphur (S), which, in case of partial combustion of oil droplets or in presence of heavy vapours inside the engine, can reach the catalytic surface and deposit on it, occluding most of its active sites, hence dramatically reducing its efficiency [1][2][3]8].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Oil Consumption over an Innovative Exhaust After-Treatment System Suitable For Cogeneration Plants

Grimaldi¹,

Capaldi²

2022

International Conference on Energy Harvesting, Storage, and Transfer

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In the following Paper, the behaviour of an innovative exhaust after-treatment system, suitable for internal combustion engines (ICE) powerplants working at stoichiometric conditions, is discussed in respect to its resistance to oil and ash contamination. This system is based on an unconventional double-stage system made up of a first oxidative filter followed by a three-way catalyst, which has been constructed, developed and tested at STEMS-CNR (the Italian National Research Council). The prototype has shown very interesting performances in terms of overall reduction of exhaust emissions even after a long exposure to lubricant contamination, maintaining a high efficiency during all its lifetime. Moreover, the effective service of this solution resulted prolonged if compared to standard after-treatment systems such a conventional three-way catalyst, as the latter greatly suffers the presence of partially burned oil produced by engines at the escape, especially after a very long running period. Catalyst failure is very common in ICE cogenerative and distributed plants making this prototype an important means to reduce emissions during the entire lifespan of cogenerative and distributed generation systems, which will be soon applied into smartgrids as energetic support of residential units and as recharger for electric vehicles.

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Section: -3mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Oil Consumption over an Innovative Exhaust After-Treatment System Suitable For Cogeneration Plants

Grimaldi¹,

Capaldi²

2022

International Conference on Energy Harvesting, Storage, and Transfer

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“…The influence of oil ash accumulation on the deactivation of three-way automotive exhaust gas purification catalysts (TWCs) after different times of operation was studied by means of XRF on samples that were taken from every centimeter of the bulk catalyst brick [53]. The phosphorus content and the calcium content versus catalyst length of six road-aged catalysts are compared in Fig.…”

Section: Macroscopic Element Distribution Profiles In the Centimeter mentioning

confidence: 99%

Bulk Chemical Composition

Albers¹

2008

Handbook of Heterogeneous Catalysis

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where P 1 is the initial weight of the fresh sample after sieving, P 2 the weight of the tested sample after sieving and P 3 the weight of fines.3.1.4.3.1 Grains or Powders Conventional catalyst attrition testing has been used for years to provide refiners with a relative measure of catalyst attrition resistance (commonly referred to as ''hardness''). Some tests use a high-velocity stream of gas to cause attrition of the catalyst. The major attrition test uses an air jet device. This apparatus measures the creation of 0-20-µm particles formed by particle-to-particle collisions in a high-velocity air jet. This measurement best represents the tendency of the catalyst to undergo attrition due to high jet velocities inside a fluid bed reactor.For quantification of the results of attrition tests, Grace Davison has specified the DI (Davison Index), which is measured using a jet-cup technique. In some tests, a small-scale plant which simulates the commercial plant is used. The amount of attrition measured in all these tests is very dependent on the exact procedure used. Reproducibility among laboratories is likely to be possible only if precise details of the method are given.In essence, the attrition test results are not scalable as a good indicator of unit retention performance. Attrition Resistance of Coated MonolithsWashcoated catalyst supports suffer from several disadvantages in use. In service, the supports are exposed to a flow of gases that often contain dusts or particulate matter, which can cause abrasion of the active layer. Adhesiveness of CoatingsApart from high dust exposure, a high surface area coating can flake off from the underlying ceramic or metallic support when the support is exposed to temperature cycles because the wash coat and the underlying ceramic material often have different thermal expansion coefficients.Several techniques have been developed by individual producers for testing the adhesiveness of a catalytic wash coat on a metallic or ceramic support. A simple example is to scratch with a specially designed tip of a needle at constant force on a plain part of a wash coat. The result should be a microscopically clear cut and no flake-off. A slightly more complicated test is the DIN EN ISO 2409 Cross Cutting, which also shows the adhesiveness of coatings on the carrier surface. The adhesiveness is determined by cutting in the varnish surface at a distance of 2 mm (1 mm in case of a layer less than 60 µm thick) in parallel lines down to the carrier surface and repeating this process after rotating the specimen by 90 • so that the cuts cross.The results are classified into different characteristic values (GT 0-5) by comparison with standard images of increasingly damaged coatings stating the adhesive loss on the test surface as a percentage. However, because the morphology of most of the monolith catalysts is characterized by a very fine fin structure, the cross cutting test needs to be performed on an equally treated separate plain model piece.Other methods such as those that are used in th...

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Charakterisierung von Katalysatoren

Albers¹

2006

Chemie Ingenieur Technik

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Vorgestellt werden Beispiele der Nutzung geeigneter Methodenkombinationen, um bestimmte Fragestellungen bei der Charakterisierung typischer Katalysatortypen zu klären. Zudem wird anhand eines aktuellen Beispiels aus der Brennstoffzellenkatalyse die Verknüpfung von Informationen aus heutzutage laborüblichen Methoden mit Techniken der Grundlagenforschung angesprochen. Dabei geht es um die Bestimmung der Adsorptionseigenschaften geträgerter Platin‐Nanopartikel und der Platzbesetzung durch atomaren Wasserstoff unter realistischen Bedingungen.

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Deactivation of TWC as a Function of Oil Ash Accumulation - A Parameter Study

Cited by 18 publications

References 7 publications

Effect of Oil Consumption over an Innovative Exhaust After-Treatment System Suitable For Cogeneration Plants

Effect of Oil Consumption over an Innovative Exhaust After-Treatment System Suitable For Cogeneration Plants

Bulk Chemical Composition

Charakterisierung von Katalysatoren

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