The Development and In-Field Demonstration of Highly Durable SCR Catalyst Systems

Walker, Andrew P.; Blakeman, Philip G.; Ilkenhans, Thomas; Magnusson, B.; McDonald, Alex C.; Kleijwegt, Peter; Stunnenberg, F.; Sánchez, Mauricio

doi:10.4271/2004-01-1289

Cited by 18 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering the inverse relationship between the NO X emission and fuel consumption in diesel engines, the urea‐SCR system is the only technology that solves the dilemma of the trade‐off between these two performance parameters . It is possible for a Euro V engine utilizing the urea‐SCR system to reduce fuel consumption by 6 % and its operating cost by 5 to 7 % compared to the Euro III engine technology, without changing the engine structure . Furthermore, numerous studies have demonstrated good high mileage durability and low engine heat rejection of the urea‐SCR system .…”

Section: Introductionmentioning

confidence: 99%

“…[5] It is possible for a Euro V engine utilizing the urea-SCR system to reduce fuel consumption by 6 % and its operating cost by 5 to 7 % compared to the Euro III engine technology, without changing the engine structure. [9] Furthermore, numerous studies have demonstrated good high mileage durability and low engine heat rejection of the urea-SCR system. [10] With the push of global commercial vehicle energy conservation and emission reduction, the urea-SCR system combined with a NO to NO 2 catalyst and closed-loop control strategy will be hoping to obtain further recognition in the market.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental investigation on the urea injection and mixing module for improving the performance of urea‐SCR in diesel engines

Liu

2017

Can J Chem Eng

View full text Add to dashboard Cite

In a urea selective catalytic reduction (urea‐SCR) system for diesel engines, the atomization, evaporation, and mixing conditions of urea water solution (UWS) play a crucial role for NOX conversion and ammonia slip in the SCR process. In this paper, a series of novel mixing modules were proposed to improve UWS evaporation, mixing, and distribution for NOX reduction in the SCR system. Experimental investigations were conducted on the performances of the existing and developed mixing modules under various engine test conditions, including particle size test, NOX conversion efficiency, flow bench tests, etc. To determine ammonia slip, the urea and ammonia distribution patterns were constructed and the non‐uniformity index was then calculated. Compared with the baseline (without mixing module) and existing mixing module, the NOX conversion efficiency of the SCR system with a developed mixing module is improved by 37.7 and 14.1 % at maximum, respectively. Furthermore, ammonia slip and distribution are ameliorated significantly with low‐pressure drops simultaneously. Among the mixing modules, Concept 3 design exhibits superior performance under the engine test conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental investigation on the urea injection and mixing module for improving the performance of urea‐SCR in diesel engines

Liu

2017

Can J Chem Eng

View full text Add to dashboard Cite

show abstract

“…This system provides a reduction of up to 92% in NO x emissions along with a reduction of up to 70% in PM levels. Additionally a catalyst for ammonia slip control was used keeping the ammonia slip levels below 10 ppm [22].…”

Section: Selective Catalytic Reduction (Scr)mentioning

confidence: 99%

Optimization of Selective-Type Aftertreatment Systems in Diesel Engines

Lourenço¹,

Almeida²,

Glovaski³

2015

Anais Do XXIII Simpósio Internacional De Engenharia Automotiva

View full text Add to dashboard Cite

Diesel engine technology has been driven by stringent regulation. To fulfill this demands emission control systems are constantly improving. In this context exhaust gas aftertreatment development assumes an important role however the in-cylinder emissions control is fundamental to comply with future legislations.Among the aftertreatment systems applied to reduce diesel engines combustion products the Selective Catalytic Reduction (SCR), which converts nitrogen oxides, (NO x ) into nitrogen N 2 and water H 2 O via dosing a chemical reducing agent containing ammonia in the exhaust system is an already proven solution for most medium and heavy duty Diesel (MDD and HDD) applications.The current work aims to compare the behavior of different urea and formamide-based reducing agents using a selective catalytic reduction aftertreatment system (ATS) when it comes to NO x reduction. Another purpose of this study in addition to studying the NO x reduction is also to understand the effects or side-effects in other gases like carbon monoxide (CO), carbon dioxide (CO 2 ), hydrocarbon (HC), oxygen (O 2 ), ammonia (NH 3 ) and to discuss in detail the potential of using this alternative reducing agents to comply with EURO VI standards and optimized SCR systems towards increasing their efficiency.Regarding the SCR catalyst system as to NO x reduction it is possible to say that urea-based mixtures are the most efficient ones but on the other hand are also those that present higher values of ammonia slip. The formamide-based mixtures do not present efficiency as significant as the urea-based mixtures but the ammonia slip levels produced by those mixtures are virtually none.With regard to CO and HC emissions the formamide-based mixtures have presented significant increase on the emissions of those two gases while in the urea-based mixtures the values have remained virtually unchanged.

show abstract

“…In accordance with the requirement of the regulations regarding real-world emissions measurement (BEPB&BAQTS, 2013), market fuel from the certified refueling stations was used and the fuel quality complied with China III or China IV standard (see Table S1). The difference is mostly sulfur content (< 350 ppm for China III and < 50 ppm for China IV), which should be applicable to SCR devices (Walker et al, 2004;Jiang et al, 2010). All drivers were instructed to maintain their usual driving behaviors during the test trips.…”

Section: Methodsmentioning

confidence: 99%

Investigating Real-World Emissions of China’s Heavy-Duty Diesel Trucks: Can SCR Effectively Mitigate NOx Emissions for Highway Trucks?

Zhang

et al. 2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

The Euro IV emission standards for heavy-duty diesel vehicles require a substantial reduction in NO x emissions, spurring the introduction of selective catalytic reduction (SCR) systems. However, previous studies have found unsatisfactory control of NO x emissions for SCR-equipped urban buses, which has raised concern among policy-makers and researchers regarding the capability of SCR adopted by heavy-duty diesel trucks (HDDTs) in real-world applications. This study tested sixteen HDDTs in China between 2010 and 2014, including six SCR-equipped Euro IV HDDTs using a portable emissions measurement system (PEMS). On-road emission measurement results show no significant difference in NO x emissions between Euro II and Euro III HDDTs. In contrast, we observed a substantial reduction in real-world NO x emissions, as low as 25.4 g kg-fuel -1 , for six SCR-equipped HDDTs (Euro IV) compared with those without SCR systems (Euro II and Euro III), providing an overall reduction of ~50%. However, real-world brake-specific NO x emission factors for the SCRequipped HDDTs were higher by ~45% than the lab test limit of 3.5 g kWh -1 due to off-cycle NO x emissions, indicating the importance of introducing real-world emission test requirements for HDDTs. Due to the introduction of SCR systems, distinctive impacts from real-world operating conditions are observed for HDDTs. For example, fuel-based NO x emission factors steadily decrease as the vehicle speed increases due to higher exhaust temperatures, which improve the efficiency of SCR systems.

show abstract

The Development and In-Field Demonstration of Highly Durable SCR Catalyst Systems

Cited by 18 publications

References 0 publications

Experimental investigation on the urea injection and mixing module for improving the performance of urea‐SCR in diesel engines

Experimental investigation on the urea injection and mixing module for improving the performance of urea‐SCR in diesel engines

Optimization of Selective-Type Aftertreatment Systems in Diesel Engines

Investigating Real-World Emissions of China’s Heavy-Duty Diesel Trucks: Can SCR Effectively Mitigate NOx Emissions for Highway Trucks?

Contact Info

Product

Resources

About