Demonstration of SCR on a Diesel Particulate Filter System on a Heavy Duty Application

Conway, Raymond; Chatterjee, Sougato; Naseri, Mojghan; Aydin, Ceren

doi:10.4271/2015-01-1033

Cited by 16 publications

(6 citation statements)

References 3 publications

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“…For example, DOC can be combined to reduce the amount of N 2 O generated from the reaction of HCs and NO x adsorbed on PNA, 134 and an ozone generator or heating element can be added to improve NO x conversion on downstream SCR catalyst. 135,136 Frankly, more and more related patents attend to devise layered or zoned monolith catalysts being able to reduce NO x and to oxidize other contaminants (HCs, CO, NH 3 , etc.) simultaneously, as do basic researches.…”

Section: Pna Integration Into Exhaust After-treatment Systemsmentioning

confidence: 99%

“…The second configuration is the separation of a PNA and an SCR catalyst, including an independent PNA unit or a combined DOC/PNA unit located upstream from the urea dosing unit and the SCR unit (Figure b). , For such multiunit system, most inventors have been devoted to address realistic issues related to the presence of PNA. For example, DOC can be combined to reduce the amount of N 2 O generated from the reaction of HCs and NO x adsorbed on PNA, and an ozone generator or heating element can be added to improve NO x conversion on downstream SCR catalyst. , …”

Section: Pna Integration Into Exhaust After-treatment Systemsmentioning

confidence: 99%

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Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Liu

Chen

et al. 2023

Environ. Sci. Technol.

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It remains a major challenge to abate efficiently the harmful nitrogen oxides (NO x ) in low-temperature diesel exhausts emitted during the cold-start period of engine operation. Passive NO x adsorbers (PNA), which could temporarily capture NO x at low temperatures (below 200 °C) and release the stored NO x at higher temperatures (normally 250–450 °C) to downstream selective catalytic reduction unit for complete abatement, hold promise to mitigate cold-start NO x emissions. In this review, recent advances in material design, mechanism understanding, and system integration are summarized for PNA based on palladium-exchanged zeolites. First, we discuss the choices of parent zeolite, Pd precursor, and synthetic method for the synthesis of Pd-zeolites with atomic Pd dispersions, and review the effect of hydrothermal aging on the properties and PNA performance of Pd-zeolites. Then, we show how different experimental and theoretical methodologies can be integrated to gain mechanistic insights into the nature of Pd active sites, the NO x storage/release chemistry, as well as the interactions between Pd and typical components/poisons in engine exhausts. This review also gathers several novel designs of PNA integration into modern exhaust after-treatment systems for practical application. At the end, we discuss the major challenges, as well as important implications, for the further development and real application of Pd-zeolite-based PNA in cold-start NO x mitigation.

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Section: Pna Integration Into Exhaust After-treatment Systemsmentioning

confidence: 99%

Section: Pna Integration Into Exhaust After-treatment Systemsmentioning

confidence: 99%

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Liu

Chen

et al. 2023

Environ. Sci. Technol.

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“…The heavy-duty diesel engine produces significant nitrogen oxide (NOx) and particulate matter (PM) emissions that negatively affect human health [1][2][3][4][5]. For this reason, the global automotive industry is required to reduce NOx emissions from their products, and it is anticipated that future standards will require exhaust after-treatment research to solve the NOx emission problem [2].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

Wardana

2020

Catalysts

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Heavy-duty diesel engines in highway use account for more than 40% of total particulate and nitrogen oxide (NOx) emissions around the world. Selective catalytic reduction (SCR) is a method with effective results to reduce this problem. This research deals with problems in the urea evaporation process and ammonia gas distribution in an SCR system. The studied system used two types of urea injectors to elucidate the quality of ammonia uniformity in the SCR system, and a 12,000-cc heavy-duty diesel engine was used for experimentation to reduce NOx in the system. The uniformity of the generated quantities of ammonia was sampled at the catalyst inlet using a gas sensor. The ammonia samples from the two types of urea injectors were compared in experimental and simulation results, where the simulation conditions were based on experimental parameters and were performed using the commercial CFD (computational fluid dynamics) code of STAR-CCM+. This study produces temperatures of 371 to 374 °C to assist the vaporization phenomena of two injectors, the gas pattern informs the distributions of ammonia in the system, and the high ammonia quantity from the I-type urea injector and high quality of ammonia uniformity from the L-type urea injector can produce different results for NOx reduction efficiency quality after the catalyst process. The investigations showed the performance of two types of injectors and catalysts in the SCR system in a heavy-duty diesel engine.

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“…Diesel engines are commonly used for public transportation on-road and off-road applications. Growth production of the diesel engine is very significant year to year [1]. The diesel engine is used for commercial and passenger vehicle [2][3] [4].…”

Section: Introductionmentioning

confidence: 99%

“…The emission rules have reached the pollution limit of the EURO VI and the US TIER 2 regulation [1][5] [6]. The ammonia in the Selective Catalytic Reduction (SCR) as the main solution to control specific emissions from the engine.…”

Section: Introductionmentioning

confidence: 99%

A study effects of injection pressure and wall temperature on the mixing process of NOx and NH3 in Selective Catalytic Reduction system

Wardana

2020

J. Mechatron. Electr. Power Veh. Technol.

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Diesel engines are commonly used for public transportation on-road and off-road applications. Growth production of the diesel engine is very significant from year to year. Nitride Oxide (NOx) from diesel engine was one of the major sources of air pollution. Selective Catalytic Reduction (SCR) has been successfully used to reduce NOx from a diesel engine with a chemical reaction from ammonia (NH3). The mixing reaction between NOx and NH3 reaction can produce steam (H2O) and Nitrogen (N2). However, ammonia uniformity pattern usually not homogenization and the ammonia was difficult to mix with NOx. The constant air flows incomplete to assist the spray injector to spread NH3 to all corners of SCR. The impact study of turbulent phenomena and standard k-epsilon Low-Reynolds Number model to the mixing process in the SCR system using STARCCM+. The simulation studies are conducted under different pressure (4 to 6 bars), the injection rate (0.04 g/s) and temperature (338 K – 553 K) and the high pressure and high velocity magnitude creating turbulent swirl flow. The ammonia decomposition process and mixing process with NOx were investigated using a box with optical access. The simulation and numerical study results validated using back pressure value and the distribution of NOx concentration value from the catalyst outlet. The wall temperature will increase the urea evaporation to generate ammonia and gas pressure will increase the mixing process and chemical process in the SCR system. These reactions enable to optimize the SCR system technology which eventually able to reduce the NOx quantity from a diesel engine.

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Demonstration of SCR on a Diesel Particulate Filter System on a Heavy Duty Application

Cited by 16 publications

References 3 publications

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

A study effects of injection pressure and wall temperature on the mixing process of NOx and NH3 in Selective Catalytic Reduction system

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Demonstration of SCR on a Diesel Particulate Filter System on a Heavy Duty Application

Cited by 16 publications

References 3 publications

Cold-Start NOx Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Cold-Start NOx Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

A study effects of injection pressure and wall temperature on the mixing process of NOx and NH3 in Selective Catalytic Reduction system

Contact Info

Product

Resources

About

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration