Investigation of diesel ash particulate matter: A scanning electron microscope and transmission electron microscope study

Liati, Anthi; Eggenschwiler, Panayotis Dimopoulos; Müller, E.; Schreiber, Daniel; Aguirre, Myriam H.

doi:10.1016/j.atmosenv.2011.10.035

Cited by 93 publications

(43 citation statements)

References 10 publications

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“…Most likely, Ptsintering in large particles took place inside the DPF after detachment from the DOC. The presence of Pt particles in ash deposits within DPFs has been described in previous studies (e.g., Liati et al 2012). Detachment of Pt particles from the DOC may be a procedure contributing to its aging and needs to be followed up in detail.…”

Section: Sem Imaging Of Ash Depositionsmentioning

confidence: 78%

Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

et al. 2012

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Investigation of soot and ash particulate matter deposited in diesel particulate filters (DPFs) operating with biofuel (B100) and diesel (pure diesel: B0 and diesel 80 /biofuel 20 blend: B20) by means of optical microscopy, scanning electron microscopy, and high resolution transmission electron microscopy (HRTEM) reveals the following: the rapeseed methyl ester biofuel used for this study contributes to ash production, mainly of Ca-Sand P-bearing compounds ranging in size between 50 and 300 nm. Smaller ash particles are less common and build aggregates. Ash is deposited on the inlet DPF surface, the inlet channel walls, and in B100-DPF at the plugged ends of inlet channels. The presence of Fe-Cr-Ni fragments, down to tens of nanometers in size within the ash is attributed to engine wear. Pt particles (50-400 nm large) within the ash indicate that the diesel oxidation catalyst (DOC) upstream of the DPF shows aging effects. Radial cracks on the coating layer of the DOC confirm this assumption. The B100-DPF contains significantly less soot than B20 and B0. Based on the generally accepted view that soot reactivity correlates with the nanostructure of its primary particles, the length and curvature of graphene sheets from biofuel-and diesel-derived soot were measured and computed on the basis of HRTEM images. The results show that biofuel-derived soot can be more easily oxidized than diesel soot, not only during early formation but also during and after considerable particle growth. Differences in the graphene sheet separation distance, degree of crystalline order and size of primary soot particles between the two fuel types are in line with this inference.

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Section: Sem Imaging Of Ash Depositionsmentioning

confidence: 78%

Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

et al. 2012

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“…The probable reason for this correlation might be the generation of these metals from the household dust and cooking activities [28]. At outdoor, Fe, Ni, Zn, Al, and Mn were correlated to each other in PM 0.5-1.0 and Cr, Cu, Ni, Fe, Zn, Al and Mn were correlated in PM 0.25-0.5 , the probable reason of this correlation might be a common source of combustion from diesel vehicles [25].…”

Section: Source Identificationmentioning

confidence: 90%

Chemical characterization of sub-micron particles in indoor and outdoor air at two different microenvironments in the western part of India

Masih¹,

Nair²,

Gautam

et al. 2019

SN Appl. Sci.

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In this study, the concentration of sub-micron particulate matter (PM) and its associated metals concentration have been discussed. Monitoring of sub-micron particulate matter has been made by using Leland legacy sample pump with five-stage Sioutas Cascade Impactor. Total, 150 samples from urban and sub urban areas of western part of India were analysed using ICP-OES. For PM 1.0-2.5 , PM 0.50-1.0 and PM 0.25-0.50 the average mass concentration ranged from 28.33 to 38.86 µg m −3 , 30.46 to 39.44 µg m −3 , 25.43 to 46.30 µg m −3 for indoor environment, while outdoor environment concentrations ranged from 23.15 to 54.01 µg m −3 , 22.38 to 36.20 µg m −3 , 22.32 to 44.30 µg m −3 , respectively. On the other hand, in sub urban area, the average mass concentrations ranged from 23.15 to 69.44 µg m −3 , 27.72 to 51.73 µg m −3 , 17.72 to 54.01 µg m −3 for indoor environment, while for outdoor environment, the average mass concentrations ranged from 30.86 to 77.16 µg m −3 , 23.15 to 54.01 µg m −3 , 24.25 to 46.30 µg m −3 for PM 1.0-2.5 , PM 0.50-1.0 and PM 0.25-0.50 , respectively. Among all eight toxic metals, Al and Fe were found to be abundant. Human health risk factor also being calculated which showed that these metals were threat to human life. The sources of the sub-micron particulate matter associated metals in outdoor air were found to be the emissions from industries, vehicular activities, and dust from construction sites and in indoor it was mostly from cooking, cleaning and other human activities.

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“…Liati et al demonstrated that the maximum penetration depth of ash particles inside the filter wall is only ∼80 µm, and the ash cake deposition begins at the end of ash deep‐bed deposition, so the permeability of the filter wall surface layer is approximately equal to the permeability of the ash cake layer when ash deep‐bed deposition reaches saturation. Assuming that permeability of the filter wall is unchanged along the direction of penetration depth, flow resistance of the filter wall during ash cake deposition can be approximately derived as Equation according to Darcy's law and the pressure drop model of the clean filter wall.…”

Section: Physical Model and Mathematical Model Of Ash Deposition On Tmentioning

confidence: 99%

Failure recognition of the diesel particulate filter based on catastrophe theory

et al. 2016

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In order to effectively recognize the failure behaviour of the diesel particulate filter (DPF), a failure cusp catastrophe model of a porous medium filter in DPF was established using catastrophe theory and diffeomorphism transformation based on the flow resistance model of a porous medium filter with ash deposition. Then, critical points and singular points of the failure cusp catastrophe model were solved and the discriminant of the DPF failure cusp catastrophic model was obtained, which was used to recognize the failure behaviour of the DPF. Finally, failure or critical state details of DPF were acquired via calculation examples, and recognition results of the DPF failure behaviour were verified on the engine bench test. Recognition results of the failure state are consistent with the experimental ones, which confirms the validity of failure recognition based on the failure cusp catastrophe model of DPF, and provides a theoretical basis and reference for research on the failure prediction and diagnosis, as well as the anti-failure, of DPF.Keywords: catastrophe theory, diesel particulate filter, ash deposition, failure, recognition INTRODUCTION D iesel particulate filters (DPF) whose core component is a porous medium filter have been shown to significantly reduce particulate matter (PM) emissions from diesel engines. Further application of diesel particulate filters in automobiles is restricted due to the short life of the porous medium filter. Therefore, how to improve its durability and service life has become an urgent problem. To address this, the failure mechanism of the porous medium filter of DPF requires in-depth study.A key factor responsible for the failure of porous medium filters is pore blockage, which directly results from ash deposition in the channels of the filter. In the past 30 years, most studies have concentrated on the filter structure, capture performance, flow field characteristics, motion and deposition laws of particles and ashes, regeneration characteristics, and blockage of filter channels, [1,2] but research on diesel particulate filter failure is rare. Researchers have carried out theoretical and experimental studies on the ash deposition and pore clogging of porous medium filters, and have optimized their structure in order to extend their service life. Among experimental studies, a vehicle experimental study on the road loading a DPF found that ash comprises > 80 % of the sediment inside the filter.[3] The ash deposition process of DPF on heavy-duty diesel vehicles, physical and chemical properties of ash particles in channels of the porous medium filter, properties of the ash layer, and its effects on the capture performance and the regeneration characteristics of DPF were experimentally studied. [4][5][6] A rapid assessment method of DPF aging based on ash deposition was established. [7] For theoretical studies, a prediction model of exhaust back pressure in the DPF was established by Heibel and Bhargava based on the ash deposition and the regeneration characteristics.[8] To in...

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Investigation of diesel ash particulate matter: A scanning electron microscope and transmission electron microscope study

Cited by 93 publications

References 10 publications

Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

Chemical characterization of sub-micron particles in indoor and outdoor air at two different microenvironments in the western part of India

Failure recognition of the diesel particulate filter based on catastrophe theory

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