Development of SCR on High Porosity Substrates for Heavy Duty and Off-Road Applications

Pless, Jason D.; Naseri, Mojghan; Klink, Wassim; Spreitzer, Glen; Chatterjee, Sougato; Markatou, Penelope

doi:10.4271/2014-01-1521

Cited by 12 publications

(4 citation statements)

References 6 publications

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“…For the downstream flow through SCR catalysts, work is continuing to demonstrate that high NO x reduction can be achieved by placing a high amount of active catalytic material on highly porous and high cell density flow through substrates [6,7,8]. In the current study, results are being presented from the evaluation of combinations of a cold start catalyst plus SCR-DPF unit with downstream high porosity SCR catalysts to achieve high NO x conversions.…”

Section: Introductionmentioning

confidence: 89%

Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines

Naseri

Aydin

Mulla

et al. 2015

SAE Int. J. Engines

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To meet NO x emission requirements and regulations for heavy duty diesel engines, selective catalytic reduction (SCR) has been demonstrated to be an effective solution. With increasing demand for improved fuel economy there is a desire to improve the NO x emission reduction of the SCR system, thus allowing for higher engine out NO x emissions. Such requirements will challenge the current aftertreatment designs, which consist of DOC, catalyzed soot filter (CSF) and SCR units. One approach is to replace the CSF with a diesel particulate filter coated with SCR (SCR-DPF) while keeping the flow-through SCR downstream. The downstream SCR can also be improved by using a highly porous flow-through substrate coated with higher washcoat loadings than those typically used on standard substrates today. This design will not only allow for improvement of NO x conversion at low temperature since the SCR-DPF unit will be closer to turbo out, but also an increased number of SCR active sites can be placed in the overall system without increasing the packing size in a typical 2010/13 system and thus provide high NO x conversion. For the SCR-DPF technology, high porosity filters are needed to enable the use of the higher catalytic loadings necessary to get good performance and durability. These highly porous filters need to have very good thermo mechanical properties to enable them to survive the active regeneration events over the life of the system. Also, a novel catalyst known as diesel Cold Start Concept (dCSC™) ABSTRACT Selective Catalytic Reduction (SCR) systems have been demonstrated as effective solutions for controlling NO x emissions from Heavy Duty diesel engines. Future HD diesel engines are being designed for higher engine out NO x to improve fuel economy, while discussions are in progress for tightening NO x emissions from HD engines post 2020. This will require increasingly higher NO x conversions across the emission control system and will challenge the current aftertreatment designs. Typical 2010/2013 Heavy Duty systems include a diesel oxidation catalyst (DOC) along with a catalyzed diesel particulate filter (CDPF) in addition to the SCR sub-assembly. For future aftertreatment designs, advanced technologies such as cold start concept (dCSC™) catalyst, SCR coated on filter (SCRF ® hereafter referred to as SCR-DPF) and SCR coated on high porous flow through substrates can be utilized to achieve high NO x conversions, in combination with improved control strategies.The objective of this work is to evaluate different advanced emission control system options in order to meet future high NO x conversions.First, high performance NO x control system architecture was designed by using a combination of dCSC catalyst, SCR-DPF filter system and high performance SCR on high porosity substrates. In this architecture, dCSC technology stores NO x during cold start when system is cold for any SCR reaction and then releases when the system warms up to allow NO x reduction across the SCR-DPF filter. The SCR-DPF filter enables lower t...

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Section: Introductionmentioning

confidence: 89%

Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines

Naseri

Aydin

Mulla

et al. 2015

SAE Int. J. Engines

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“…Cu-zeolite was claimed to perform well on NOx emissions and could become a good candidate for the next generation SCR technology, especially for applications that require high thermal durability [13][14][15]. It was demonstrated that higher performance was achieved by using highly loaded high porosity and high cell density substrates could enable significant a volume reduction for future heavy duty and off-road diesel aftertreatment systems [16]. The thermal SCR performance degradation was validated and many researchers have studied the SCR catalyst aging impact factors and proposed aging specifications according to real duty cycle applications when developing SCR in aftertreatment systems [17][18][19][20][21][22].…”

Section: Introductionmentioning

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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“…17 Second, there have been many research studies and developments to improve the geometrical characteristics of the SCR substrates. [18][19][20][21][22] One of the key technical directions is to increase the cell density of the SCR substrate to 900 cells/in 2 , while 400 cells/in 2 is the commercial mainstream value utilized at present. 18,20 A high-cell-density substrate can easily provide more active catalytic sites, which enables the exhaust gas to have more deNO x reaction opportunities.…”

Section: Introductionmentioning

confidence: 99%

Simulation study on improving the selective catalytic reduction efficiency by using the temperature rise in a non-road transient cycle

Wang¹,

Kim²,

Ahn³

2016

Proceedings of the Institution of Mechanical Engineers, Part D:

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In this study, the transient nitrogen oxide reduction performance of a urea selective catalytic reduction system installed on a non-road diesel engine was tested on an engine dynamometer bench over a scheduled non-road transient cycle mode. Based on the measurement results, the characteristics of the transient selective catalytic reduction behaviours of nitrogen oxide reduction were evaluated. Also, in this study, the effects of several thermal management strategies for improving the selective catalytic reduction efficiency was investigated by transient selective catalytic reduction simulations. The kinetic parameters of the current simulation code for selective catalytic reduction were calibrated and validated by comparison with the measurement data. As a result of this study, it was found that a thermal management strategy utilizing a partial temperature rise in the transient time domain can be an efficient approach for improving the transient selective catalytic reduction efficiency, in comparison with the temperature rise over the entire cycle period. Furthermore, this study can provide some guideline data for the magnitude and the duration of the temperature rise required to obtain the target selective catalytic reduction efficiency over the non-road transient cycle mode. In the last part of this study, the impact of the variation in the space velocity on the transient selective catalytic reduction efficiency was assessed using transient selective catalytic reduction simulations.

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Development of SCR on High Porosity Substrates for Heavy Duty and Off-Road Applications

Cited by 12 publications

References 6 publications

Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines

Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines

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

Simulation study on improving the selective catalytic reduction efficiency by using the temperature rise in a non-road transient cycle

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Development of SCR on High Porosity Substrates for Heavy Duty and Off-Road Applications

Cited by 12 publications

References 6 publications

Development of Emission Control Systems to Enable High NOx Conversion on Heavy Duty Diesel Engines

Development of Emission Control Systems to Enable High NOx Conversion on Heavy Duty Diesel Engines

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

Simulation study on improving the selective catalytic reduction efficiency by using the temperature rise in a non-road transient cycle

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Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines

Development of Emission Control Systems to Enable High NO_x Conversion on Heavy Duty Diesel Engines