Robust SCR Design Against Environmental Impacts

Jacques, Jason; Pauly, Thomas; Zammit, Michael; Ahari, Homayoun; Smith, Michael A.

doi:10.4271/2016-01-0954

Cited by 9 publications

(7 citation statements)

References 18 publications

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“…There were many studies that investigate the factors which impact NOx emission and NH 3 slip, especially the temperature influence, as well as the functions of ASC [24][25][26]. In these experiments, the SCR temperature during NRTC is kept within a 250 • C to 400 • C range in most of the real application conditions.…”

Section: System Emission Results With Different Scr Size Conceptsmentioning

confidence: 99%

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

2020

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Urea-Selective Catalytic Reduction (SCR) is widely used to reduce nitrogen oxide (NOx) emissions. This paper presents a comprehensive experimental research work on aftertreatment emissions of NOx and ammonia (NH3) slip for three aftertreatment concepts by introducing the SCR sizing strategy on a 6-cylinder mid-range non-exhaust gas recirculation (EGR) diesel engine to meet China non-road Stage IV regulation limits. It can be observed that the three concepts could meet the regulation limits for NOx emissions and NH3 slip by selecting the appropriate length. There is little effect on emission results during a non-road transient cycle (NRTC) when the aftertreatment inlet/outlet with insulation and without insulation and the emission results on both strategies could meet non-road China Stage IV regulation limits. It is recommended to select Concept 2 which could meet regulation requirements considering multiple factors in the SCR sizing strategy. Substrate impact and NH3/NOx molar ratio (ANR) impact are investigated based on Concept 2. The results show that by applying the SCR substrate aftertreatment with a cell density of 600 cpsi, NOx conversion capability is stronger than that with cell density 400 cpsi for the same SCR size. Current dosing strategy is capable and recommended ANR is 0.9–1.1 if considering dosing strategy optimization. The methodology in this study provides an effective guidance and reference for future aftertreatment SCR sizing strategies in real applications.

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Section: System Emission Results With Different Scr Size Conceptsmentioning

confidence: 99%

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

2020

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“…The cold start wetting impact is simulated by soaking catalysts in ammonium water at different alkalinities. The ammonium water is diluted with deionized water until the pH value reaches 9 and 12, respectively . Then, 1 g of the Cu-SSZ-13 catalyst is soaked in 50 mL of the as-prepared solution or pure AdBlue for 24 h. After that, the catalyst is dried at 100 °C for 12 h. The catalyst deactivated by AdBlue and diluted ammonium water is named as follows: Si/Al- x -AdBlue and Si/Al- x -pH = y , respectively, with y denoting the pH value of the solution.…”

Section: Methodsmentioning

confidence: 99%

“…However, in order to satisfy the requirements for improving the SCR activity during the cold start process, the injection temperature of liquid urea decreases significantly and becomes even lower than its vaporization temperature. As a result, the liquid urea may impact and consequently soak the SCR catalyst . Even worse, the dissolution of NH 3 into liquid water increases the alkalinity of the solution, which may result in a profound alkaline deactivation to the catalyst.…”

Section: Introductionmentioning

confidence: 99%

Cold Start Wetting Effect on the Catalytic Property and Hydrothermal Stability of a Cu-SSZ-13 Catalyst for NH₃-SCR

Fan

Ming

Chen

et al. 2020

Ind. Eng. Chem. Res.

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The cold start wetting effect on Cu-SSZ-13 has been simulated via soaking catalysts with various Si/Al ratios in ammonium water at disparate pH levels. It is found that a mild treatment (pH = 9) has little effect on the selective catalytic reduction of NO x with NH 3 performance of Cu-SSZ-13. However, on increasing the pH to 12, the deNO x activity and resistant ability to hydrothermal aging decrease obviously. Such a decrease could be attributed to the desilication phenomenon during the soaking process, which results in a number of effects including extraction of Cu 2+ ions from the exchange sites, decrease in acidity, and damage to the zeolite structure. Meanwhile, the alkaline treatment exhibits distinct impacts on the physicochemical properties of Cu-SSZ-13 with different Si/Al ratios. The low Si/Al ratio catalyst (Si/Al-6) is insusceptible to desilication because of a higher content of the AlO 4 − structure and extra-framework Al (Al ef ), which could hamper the desilication.

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“…Optimization of structures, morphology, exchange processes for the introduction of active components as well as the macroporosity of the layers are, e.g., approaches for increasing the efficiency of zeolitic catalysts. Thus, new zeolite structure types are being proposed for application [22,23].…”

Section: Enhancement Of Catalytic Componentsmentioning

confidence: 99%

Minimizing Real Driving Emissions of Heavy‐Duty Vehicles – Exhaust Systems and Legislation

2019

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Despite of generally improving air quality, many European urban areas fail to comply with current immission rules. Therefore, in the automotive sector including commercial vehicles tighter limits and test procedures for real driving emissions are in discussion or have already been adopted. For the commercial vehicle sector corresponding regulations are discussed as well as challenges and measures to meet the upcoming more stringent requirements.

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Robust SCR Design Against Environmental Impacts

Cited by 9 publications

References 18 publications

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

Cold Start Wetting Effect on the Catalytic Property and Hydrothermal Stability of a Cu-SSZ-13 Catalyst for NH₃-SCR

Minimizing Real Driving Emissions of Heavy‐Duty Vehicles – Exhaust Systems and Legislation

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Robust SCR Design Against Environmental Impacts

Cited by 9 publications

References 18 publications

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

Experimental Research on Aftertreatment SCR Sizing Strategy for a Nonroad Mid–Range Diesel Engine

Cold Start Wetting Effect on the Catalytic Property and Hydrothermal Stability of a Cu-SSZ-13 Catalyst for NH3-SCR

Minimizing Real Driving Emissions of Heavy‐Duty Vehicles – Exhaust Systems and Legislation

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Cold Start Wetting Effect on the Catalytic Property and Hydrothermal Stability of a Cu-SSZ-13 Catalyst for NH₃-SCR