What Is A Diesel Particulate Filter

Diesel fuel Particulate Filter

Diesel particulate filters (DPFs) combined with a DOC, which can trap a groovy number of PM from the combustion chamber that are then oxidized by the noble metallic Pt catalyst to regenerate the DPF, is a high-efficiency engineering science for decision-making PM emissions.

From: Metal Oxides in Free energy Technologies , 2018

Principle and pattern of emission control systems

Masaaki Okubo , Takuya Kuwahara , in New Technologies for Emission Control in Marine Diesel Engines, 2020

Regeneration methods of diesel particulate filter

DPF regenerations are classified into continuous and intermittent regeneration methods. A reverse jet menstruation is ane of the DPF regeneration techniques and represents intermittent regeneration. As an example, a high-temperature dust collector called Cerallec System is equipped with a honeycomb ceramic filter developed past NGK Insulators, Ltd., Japan, for marine diesel engines [nineteen]. A schematic diagram of this system is shown inFig. 3.4.ten. The system is developed for a marine diesel engine. The heatproof temperature of the ceramic filter is 900°C. In this system, PM in the diesel exhaust gas is accumulated in the ceramic filter past monitoring the pressure level difference of the filter. Its PM removal efficiency is 97%. When the pressure level difference reaches a threshold value, compressed air is reversely injected into the filter. PM is detached from the filter past injection and collected in a dust box. This process is regularly and automatically performed. The pulse jet method is a way of injecting high-speed and intermediate-pulse air to the surface of the filter from the within upper region of the filter.

Catalysts (Atomic number 26, Cu, or Ce) are utilized for promoting DPF regeneration at the exhaust gas temperature of 300–400°C. This method is utilized together with DPF regeneration using an electric heater. In DPF regeneration by postinjection, the temperature of DPF is increased past supplying fuel to oxidation catalysts coating DPF in oxidation reactions. Compared with O_ii, free radicals are more constructive in soot oxidation at low temperatures. CRT (continuous regeneration trap), which is developed by Johnson Matthey, United kingdom, is an instance system that uses free radical reactions. It uses NO₂ to generate free radicals. The technology of CRT is explained after in Subsection iii.5.3 related to Fig. three.5.13.

The catalyst method is a continuous regeneration method and consists of two processes. In the offset process, NO in the raw exhaust gas is converted into NO₂ with an oxidation goad installed upstream of a DPF. In the second process, soot (carbon, C) accumulated in the DPF is oxidized into CO or CO_ii with generated NO₂, and the DPF is regenerated. Although reactions can be achieved at a lower temperature of 280°C than the normal soot burning temperature of 600°C, they crave the ultralow sulfur concentrations (< 50 ppm) [26] because of the catalyst deposition by sulfur and sufficient NO_x (NO_x/PM ratio should exist 20 at minimum and more than twoscore is preferable) condition [27]. For complimentary radical utilization, some techniques using catalysts and NTP have also been proposed and developed.

DPF regeneration using electric heaters, which is an intermittent method, is widely used in automobiles. Soot starts to burn spontaneously at 600°C. DPF regeneration takes more than than 10 min at 600°C and several minutes at > 700°C. The exhaust gas temperature is typically 500–600°C in an operation at the highest power output; thus, information technology is seldom possible to regenerate a DPF by heating during merely ordinal engine functioning. Electrical heating is relatively easy to command DPF regeneration. DPF regeneration using electric heaters requires an electrical ability of 10 kW at minimum for an frazzle gas flow charge per unit of 1500 50/min, which corresponds to an idling exhaust gas flow from a 5-50 diesel fuel engine [28]. It requires a higher heating power for the operations with big engine loads. In automobiles, to reduce the electrical power consumption, DPF regeneration techniques accept been developed using catalysts or enhancing the exhaust gas temperature in combustion and/or with oestrus insulation. In marine diesel engines, power consumption would exist much larger with the electric heating method; thus, advanced technologies are needed.

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Performance examples of emission control systems

Masaaki Okubo , Takuya Kuwahara , in New Technologies for Emission Control in Marine Diesel fuel Engines, 2020

four.five.1 Diesel particulate filter regeneration

Diesel particulate filter (DPF) regeneration corresponds to the PM removal deposited inside it. The technology to be done is important to realize a clean diesel fuel engine. The principle is explained in Chapter three. DPF regeneration using plasma-induced ozone injection is explained hither based on Ref. [39] in Chapter three. Fig. four.5.1 shows a schematic of the experimental apparatus for DPF regeneration using ozone injection. The engine that is used for the investigation is a diesel engine generator (maximum load = two kW, deportation = 219 mL, unmarried cylinder blazon, and rotation rate = 3600 rpm; YDG200VS-6E, YANMAR Co., Ltd.) that uses gas oil or light diesel oil (sulfur concentration = 7 ppm) every bit fuel. During the experiment, the menstruation rate of the exhaust gas is maintained at 300 NL/min, where N ways the standard state (0°C and 101.325 kPa), and a load in the form of a 1-kW electrical heater is connected to the power output terminal. Before the experiment, the engine is warmed upwards for one h with the exhaust gas emitted through menstruum channel i. Immediately after warming upwardly, the experiment is performed by switching the exhaust flow via a valve from menses channel 1 to flow aqueduct 2, in which a SiC DPF (bore = 50 mm, length = lxxx mm, cell density = 300 cpsi ≈ 46.5 cells/cm², wall thickness = 12 mil ≈ 0.three mm, and textile: SiC, TYK Corporation) is placed. The PM is initially captured in the DPF for some time. And so, without stopping the engine, O_three generated by a plasma-induced ozonizer (surface discharge type, OZS–HC–70/W, Masuda Research Inc.) is injected at the inlet of the DPF for the regeneration. DPF regeneration is evaluated by measuring the force per unit area differences. Table 4.5.1 shows the experimental weather condition of the flow charge per unit of the supplied O_ii for the ozonizer, the mass flow rates, and concentrations of O₃. The ozone is produced by supplying O₂ of 99.6% purity from a gas cylinder to the ozonizer with an input power of 370 W. The ozonizer produces and emits O₃ every bit a mixture of O₃ and O₂. An ozone injection tube is installed at the middle of the cross section of the flow aqueduct and 35 mm in front of the DPF inlet against the exhaust gas flow. O₃ is injected into the DPF appliance in a direction reverse to the exhaust gas flow. The PM drove is gear up to 1–two h; the DPF regeneration is set to 2–5.5 h; and the O_three injection charge per unit is 25.viii–34.8 g(O_iii)/h (the O_three concentration after injection is 658–873 ppm). During PM collection, the injected flow rate of air is maintained equal to that of O₃ during DPF regeneration.

Table 4.5.1. Experimental status.

Volumetric period rate of supplied O_ii	L/min	five	8	10
Mass menses rate of O₃	one thousand/h	25.viii	32.9	34.8
Concentration of O₃ at outlet of ozonizer	%	iv.10	iii.25	ii.74
Concentration of O₃ later injection	ppm	658	831	873

The engine load is prepare to one.0 kW (50% of the maximum output power) for all the experimental trials. The pressures at the inlet and outlet of the DPF are measured using pressure sensors (amplifier AP-C40, sensor head AP-44, KEYENCE Co.). The force per unit area difference betwixt the inlet and outlet channels is adamant from the measured pressures. The pressure sensor has ii resolutions—0.02 and 0.1 kPa—for dissimilar pressure ranges. A resolution of 0.02 kPa is used at both the inlet and the outlet when Δp ≤ 14 kPa, whereas 0.1 kPa is used at the inlet and 0.02 kPa is used at the outlet when Δp > 14 kPa. In add-on, the frazzle gas temperatures upstream and downstream of the DPF are measured using thermocouples (type K) connected to a recorder (NR-g, KEYENCE Co.). Gas components such as NO, NO_x (=NO + NO₂), CO, CO_ii, O₂, and hydrocarbons (HCs) upstream and downstream of the DPF are besides analyzed using gas analyzers (PG-240, Horiba, Ltd., Japan and VMS-100F, Shimadzu Co., Japan). The pressure and temperature measurements and the gas sampling are taken at specified points, namely, 95 mm from the DPF inlet pipe and 145 mm from the outlet pipage.

When the pressure difference returns to the initial value before the PM drove, the DPF is considered to have been completely regenerated, in other words, complete DPF regeneration has been achieved. Information technology should be noted that the DPF and flow channel are covered with thermal insulation cloth to minimize the effect of variations at ambient temperature. The mass of the collected and oxidized PM is determined by measuring the mass of the DPF using an electromagnetic force balance (PFII-3000, Shinko Denshi Co., Ltd., measurement accurateness = x mg) after information technology is gradually cooled to betwixt 18 and 19°C.

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Diesel aftertreatment integration and matching

Qianfan Xin , in Diesel fuel Engine System Design, 2013

8.1.5 Diesel particulate filter (DPF) performance

Achieving high filtration efficiency and depression flow restriction with pocket-size dimensions and low costs is a challenging task in DPF design. The exhaust restriction at the turbine outlet refers to the pressure drop through all the aftertreatment components plus the exhaust pipes. Frazzle restriction depends on hardware blueprint and the catamenia restriction characteristics of the components. The pressure drop of the DPF increases every bit the soot and the ash accumulate in the filter. It as well varies with the amount of soot deposits in the filter earlier and after the DPF regeneration. Exhaust brake likewise can be regulated by using an exhaust back-pressure valve, such every bit a flap valve installed at the turbine outlet. Closing the back-pressure valve reduces the exhaust flow rate or may help engine braking. Exhaust restriction has a big impact on turbocharged engine performance.

DPF technologies are reviewed and summarized in 3 comprehensive books by Majewski and Khair (2006), Johnson (2007b), and Eastwood (2008). There is no demand to elaborate on them here. The literature on DPF research areas is organized as follows:

•

The DPF selection for retrofitting vehicles is discussed by Mayer et al. (2001). DPF design effects were studied by Konstandopoulos et al. (1999, 2005b), Nikitidis et al. (2001), Merkel et al. (2001), Konstandopoulos and Kladopoulou (2004), Soeger et al. (2005), Yamaguchi et al. (2005), and Ido et al. (2005).

•

DPF full general performance was studied past Khair (2003), Khair and McKinnon (1999), Toorisaka et al. (2004), Herrmuth et al. (2004), Cutler (2004), and Kapetanovic et al. (2009).

•

DPF pressure driblet was researched by Taoka et al. (2001), Konstandopoulos et al. (2001b), Stratakis et al. (2002), Konstandopoulos (2003), Cunningham et al. (2007), and Ohyama et al. (2008).

•

DPF regeneration performance was experimentally investigated by Tan et al. (1996), Gantawar et al. (1997), Park et al. (1998), Bouchez and Dementhon (2000), Salvat et al. (2000), Gieshoff et al. (2001), Locker et al. (2002), Hiranuma et al. (2003), Flörchinger et al. (2004), Mayer et al. (2005), Kong et al. (2005), Ogyu et al. (2007), and Ootake et al. (2007).

•

DPF regeneration control algorithms were developed by Brewbaker and Nieuwstadt (2002), Nieuwstadt and Trudell (2004), Birkby et al. (2006), and Bencherif et al. (2009).

•

DPF modeling has been carried out mainly by the following groups:

➢: A group of researchers primarily at Aerosol & Particle Technology Laboratory in Greece (review papers by Konstandopoulos et al., 2000, 2005a; Konstandopoulos and Kostoglou, 1999, 2004; Masoudi et al., 2001; Konstandopoulos et al., 2001a, 2002, 2003a, 2003b, 2004; Kladopoulou et al., 2003).
➢: A group of researchers at Michigan Technological University (Huynh et al., 2003; Kladopoulou et al., 2003; Singh et al., 2005; Mohammed et al., 2006a, 2006b; Premchand et al., 2007).
➢: A group of researchers at General Motors and the University of Wisconsin–Madison (Kapparos et al., 2005; Strzelec et al., 2006; England et al., 2006; He, 2007; Rutland et al., 2007; Gurupatham and He, 2008; Singh et al., 2009).
➢: A group of researchers at Gamma Technologies for the software GT-Power (Tang et al., 2007, 2008; Wahiduzzaman et al., 2007).
➢: Other sources (Rumminger et al., 2001; Millet et al., 2002; Kandylas and Koltsakis, 2002; Liu and Miller, 2002; Guo and Zhang, 2005a, 2005b; York et al., 2005, 2009; Reader et al., 2006; Yi, 2006; Bouteiller et al., 2007; Cunningham and Meckl, 2007; Chiatti et al., 2008; Subramaniam et al., 2009).

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Engine Exhaust Emissions

A.J. Martyr , Chiliad.A. Plint , in Engine Testing (Fourth Edition), 2012

Diesel Particulate Filter (DPF)

A DPF, by the nature of its office, increases exhaust back-pressure as the particles are captured inside its matrix. The in-vehicle method of cleaning the filter is chosen "regeneration" and may be carried out passively or actively. Passive regeneration requires the unit of measurement'due south internals to be at a high enough temperature during regular utilise to "burn off" the deposits, usually a minimum of 350 °C.

Active regeneration is triggered when the exhaust back-pressure across the DPF is sensed to have reached a showtime disquisitional betoken, whereupon the ECU initiates a fuel injection routine designed to increase the exhaust temperature in the DPF to over 600 °C in order to oxidize the particulate deposits.

Failure of DPF by "bottleneck", usually caused by a end–start, short journeying, operating bike that prevents the agile regeneration cycle from completing, is becoming a mutual cause of complaint by some rider car and delivery van drivers.

Simulating partial blocking levels and the bottleneck failure mode within an engine test cell has proved problematic and time consuming, since the rate of particulate eolith is quite wearisome from an engine running legislative cycles and any acceleration of the process requires a modified control map in the ECU. This has led to the evolution of DPF test benches such every bit that produced by Cambustion (http://www.cambustion.com) and shown diagrammatically in Figure 16.nine.

The chief operational features of this fully automated unit are that the diesel is burned under controlled, stable atmospheric condition and is unaffected past the DPF'southward dorsum-pressure. The charge per unit of soot degradation can be controlled by adjusting the air menstruation rates, which allows for repeatable DPF loading conditions. Systems such every bit this are designed to measure filtration efficiency and to regenerate the DPF under operator-controlled conditions, making the test methodology cheaper and faster than using an engine in a test cell.

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Sustainable Built Environment & Sustainable Manufacturing

J. He , ... J. Xu , in Encyclopedia of Sustainable Technologies, 2017

Diesel particulate filter

DPF is the process designed to capture diesel PM or soot physically produced from diesel fuel engine. It has go one of the most effective technologies for control emissions of diesel fuel soot with the filtration efficiency of exceeding 90%, and it shows good thermal and mechanical immovability. Particles are normally removed due to deposition mechanisms. The exhaust gas flows through filter, which consists of a fine pore ceramic construction and porous wall inside, during which the PM and soot are then deposited and collected.

DPF can accumulate PM in considerable book speedily, which would finally cause excessively high pressure drib of exhaust in filter and may harm engine operation. Therefore, filter regeneration (remove particulates from filters) is required to provide enough collection capacity for soot retainment. Information technology can exist performed either periodically (after PM has been accumulated in predetermined amount), or continuously during the period of filter performance. In vehicle's command system, it commonly performs periodically.

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Compressor for exhaust treatment of not-road vehicles

R. Sachs , W. Asal , in 8th International Conference on Compressors and their Systems, 2013

Abstruse

Diesel fuel particulate filter systems are practical to run across emission standards for engines in not-road mobile machinery. A burner with an air supply unit can ensure the regeneration of the filter without machine stoppages. A low price unit with a constant performance and a low menstruum pulsation is therefore needed: a and so-called COR®-compressor (1) consisting of 2 axial rotors with a trochoidal shaped gearing is proposed. The rotor material of this dry running positive displacement machine needs to combine a high geometrical accuracy with a practiced tribological behaviour. Hence plastic rotors are utilised which are produced using a two-component thermoset injection moulding process.

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Science and Technology in Catalysis 2006

Shin'ichi Matsumoto , in Studies in Surface Science and Catalysis, 2007

3.4 Application of NSR catalyst to diesel engines

The Diesel Particulate Filter (DPF) and oxidation catalysts have been developed for reducing HC, CO and PM in the exhaust of diesel engines. However, they cannot reduce NO _x in the same as TWCs because of the oxygen-rich condition of diesel exhaust.

To reduce PM, a new DPF system was developed with an optimized pore structure [29]. In addition, the DPF was coated with NSR catalyst material in order to reduce NO_x simultaneously. This new system is called DPNR (Diesel fuel Particulate-NO_x Reduction system). Based on the accustomed NO_x reduction mechanism of the NSR catalyst, it is known that NO_ten and oxygen are stored as the nitrate of NO_x storage materials under lean conditions. An alkaline or alkali earth compound used as a NO_x storage cloth lowers the oxidizing temperature of PM under the oxygen stream [37]. On the other hand, the stored NO_x is reduced to Northward₂ past HC and other reducing agents under rich weather. At the same time, the trapped PM can exist burned out by NO_x desorbed from the NO_xstorage materials. The DPNR arrangement, along with new diesel fuel combustion technology that enables the performance of a diesel engine in the rich operating status, is capable of removing both NO_x and PM simultaneously from the frazzle stream [37].

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Using 3D CFD to model exhaust fuel dosing device (fuel vaporizer) and oxidation of hydrocarbon

W.U.A. Leong , ... J. Scott , in Internal Combustion Engines: Improving Performance, Fuel Economy and Emissions: IMechE, London, 29–xxx November 2011, 2011

3.one Clarification of the examination case

Information technology is evident that DPF soot regeneration efficiency is linked to the gas temperature distribution at the entry of the DPF. In full general, a uniformly distributed temperature field at the front face of the DPF results in loftier soot conversion across the DPF. In addition, a compatible temperature field too avoids the creation of thermal daze which is the common cause of DPF failure. Although the HC distribution is critical for the exothermic reactions, information technology is much easier to measure gas temperature in a laboratory environment. For this reason, gas temperature measured by thermocouples volition be used for the correlation report.

The design used for the correlation is based on a stage 5 exhaust/aftertreatment system for passenger vehicles equipped with a two.0 Fifty turbo-diesel fuel engine, meet Figure 2 . The aftertreatment arrangement consists of a shut-coupled diesel oxidation catalyst (Medico), a diesel exothermic goad (DEC) and a catalytic Diesel Particulate Filter (cDPF). Both DEC and cDPF are packed into a single canister with a modest gap between them.

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Horizons in Sustainable Industrial Chemistry and Catalysis

Tahrizi Andana , ... Raffaele Pirone , in Studies in Surface Science and Catalysis, 2019

1.2 Active Versus Passive DPF Regeneration

The trouble with DPF high operating temperature could be overcome by using catalytic DPF. Washcoating additional catalytic layers on the inner wall of the filter may help improve the reaction conversion at a lower temperature. Cerium dioxide (CeO_two), but known every bit "ceria," has been the most investigated fabric for the catalytic layer. Ceria is broadly renowned for its early on application for the Iii-Way Goad (TWC) that benefits from ceria'southward and then-chosen "redox properties" [18–22]. The ability of ceria to undergo rapid reduction and oxidation might ensure a good mobility of oxygen species within ceria-soot interface. In the early development of catalytic DPF, the cleanup, or regeneration process, was assumed to be carried out, for the virtually part, by oxygen, as the molecule makes up nigh 10%–15% of the exhaust gas. This scheme is known as "active" regeneration because "active" participation of oxygen from bulk phase to catalyst-soot interface is required [15,sixteen,23]. Previous investigations take demonstrated that the number of contact points between ceria and soot plays a decisive role in minimizing the reaction temperature [24–26]. Therefore, in the active regeneration scheme, the goad must not simply be intrinsically active toward the reaction but likewise be geometrically unconstrained when establishing an intimate contact with soot.

The loftier air-to-fuel ratio in diesel engine results non only in lower exhaust gas temperatures, compared to those in gasoline engine, but also in more NO₁₀. This is a major advantage to the regeneration process as NO_two is a stronger oxidant than oxygen. The gas is so strongly oxidizing the contact between catalyst and soot becomes less important. The presence of NO_two in the reaction tin assist lower the reaction temperature, even down to 250–300°C [27,28]. This scheme is called "passive" DPF regeneration, equally it demands less energy and less involvement of oxygen [15,16]. However, NO_two is less abundant in the exhaust gas than NO, thus raising the need of an oxidation catalyst. In 1990, Johnson Matthey patented the Continuously Regenerating Trap (CRT) filter configuration [29], which is used in a series of platinum-based DOC (16.i), as the catalyst to NO oxidation reaction, and uncatalyzed DPF (16.2), where soot oxidation reaction takes place.

(16.1) $NO + 0.5 O_{ii} \overset{Pt}{\to} {NO}_{2}$

(16.2) ${NO}_{two} + C \to NO + {CO}_{2}$

Johnson Matthey has also patented the more avant-garde version of CRT called CCRT (Catalyzed Continuously Regenerating Trap) that widens the operating window of the filter equally the DPF is washcoated with a catalytic layer that is active toward NO oxidation reaction. Some unreacted NO in the first compartment (Doctor) can be further re-oxidized to NO₂ in the now-catalyzed DPF (CDPF) that subsequently reacts with more soot trapped in the filter. Driven by the prohibitive cost of platinum-group metals (PGMs), enough of researches are focusing on formulating non-noble metallic catalysts for NO_x-assisted soot oxidation.

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12th International Symposium on Process Systems Engineering and 25th European Symposium on Estimator Aided Procedure Engineering

Andreas Åberg , ... Jakob K. Huusom , in Figurer Aided Chemical Applied science, 2015

iii.1.2 Diesel Particulate Filter Model

The wall-catamenia DPF has the geometry of a catalytic converter, merely with plugged contrary ends of adjacent channels. Unfiltered exhaust gases enter the inlet channels and laissez passer through the porous substrate layer orthogonal to the inlet flow direction, before it exits through the outlet channel. During DPF operation, a deposit layer of soot volition build upwards on the substrate layer, leading to an increasing pressure drop over time. The model was developed around a single inlet/outlet channel and involves quasi-steady country equations of mass, momentum, and free energy for the exhaust gases along with dynamic equations for particle mass and temperature for the filter substrate. A schematic view of a single inlet/outlet channel can exist seen in Fig. 3a. The model tracks the changes in concentration of NO, NO₂, O₂, CO, and CO_ii, and uses the filter substrate temperature to compute reaction speed for the kinetics. The kinetics are based on the piece of work of (A. Messerer et al., 2006). The inputs and outputs to and from the model are: exhaust mass catamenia rate, inlet gas composition (NO, NO₂, O₂, CO, and CO_ii), gas temperature, and outlet pressure.

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