The Effects of Catalytic Converter Location and Palladium Loading on Tailpipe Emissions

Zammit, Michael; Wuttke, Jeffrey; Ravindran, Pramod; Aaltonen, Steven

doi:10.4271/2012-01-1247

Cited by 8 publications

(4 citation statements)

References 12 publications

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“…We illustrate the construction of the substitution curve model for the TWC. Data were collected for PGM loading in 24 TWCs, described in the technical literature. ,− Loadings were normalized on the basis of engine displacement to a common engine size of 2.5 L.…”

Section: Methodsmentioning

confidence: 99%

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Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals

Zhang

Everson

Wallington

et al. 2016

Environ. Sci. Technol.

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Platinum-group metals (PGMs) are technological and economic enablers of many industrial processes. This important role, coupled with their limited geographic availability, has led to PGMs being labeled as "critical materials". Studies of future PGM flows have focused on trends within material flows or macroeconomic indicators. We complement the previous work by introducing a novel technoeconomic model of substitution among PGMs within the automotive sector (the largest user of PGMs) reflecting the rational response of firms to changing prices. The results from the model support previous conclusions that PGM use is likely to grow, in some cases strongly, by 2030 (approximately 45% for Pd and 5% for Pt), driven by the increasing sales of automobiles. The model also indicates that PGM-demand growth will be significantly influenced by the future Pt-to-Pd price ratio, with swings of Pt and Pd demand of as much as 25% if the future price ratio shifts higher or lower even if it stays within the historic range. Fortunately, automotive catalysts are one of the more effectively recycled metals. As such, with proper policy support, recycling can serve to meet some of this growing demand.

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Section: Methodsmentioning

confidence: 99%

“…Data were collected for PGM loading in 24 TWCs described in the technical literature. (40,(46)(47)(48)(49)(50)(51)(52) Loadings were normalized based on engine displacement to a common engine size of 2.5 liters.…”

Section: Overall Model Framework a Model Of Aggregate Automotive Pgm Usementioning

confidence: 99%

Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals

Zhang

Everson

Wallington

et al. 2016

Environ. Sci. Technol.

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show abstract

“…In an entirely different approach to evaluating cost and emissions, Zammit, et al [81] changed the distance from the engine of a close-coupled TWC and measured the emissions. They made estimates of the increased PGM loadings to offset the increased distance while keeping the emissions the same: $0.95 to $1.28 per cm, for palladium at $800/oz.…”

Section: Three-way Catalystsmentioning

confidence: 99%

Vehicular Emissions in Review

Johnson¹

2013

SAE Int. J. Engines

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This review paper summarizes major developments in vehicular emissions regulations and technologies (light-duty, heavy-duty, gasoline, diesel) in 2012. First, the paper covers the key regulatory developments in the field, including finalized criteria pollutant tightening in California; and in Europe, the development of real-world driving emissions (RDE) standards. The US finalized LD (light-duty) greenhouse gas (GHG) regulation for 2017-25. The paper then gives a brief, high-level overview of key developments in LD and HD engine technology, covering both gasoline and diesel. Marked improvements in engine efficiency are summarized for gasoline and diesel engines to meet both the emerging NOx and GHG regulations. HD engines are just starting to demonstrate 50% brake thermal efficiency. NOx control technologies are then summarized, including SCR (selective catalytic reduction) with ammonia, and hydrocarbon-based approaches. Emphasis is on low-temperature deNOx, durability, and cost reduction. PM (particulate matter) reduction technologies are evolving around SCR integration and the behavior of soot and ash deposits. Next, DOC (diesel oxidation catalyst) developments are summarized. They mainly involve better understanding of aging and substitution of base metals oxides for precious metal. The paper then discusses some key developments in gasoline emission controls, focusing on new coated GPF (gasoline particulate filter) understanding. Advanced three-way catalysts improve with layered coating technology, and with improved understanding on engine calibration.

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“…The secondary air injection at exhaust manifold aids oxidation of CO and HC and exothermic oxidation reaction increases the temperature of exhaust gas, resulting in fast light-off of catalyst [19]. Close coupled catalyst is a good solution for reducing the light off time [20]. However, due to the close proximity of the converter from the engine exhaust manifold, it is subjected to a high temperature of around 800°C throughout the operation of the engine.…”

Section: Introductionmentioning

confidence: 99%

Temperature analysis of dynamic catalytic convertor system with pre-catalyst in a multi cylinder spark ignition engine to reduce light-off time

Mahadeven¹,

Sendilvelan²

2017

IJHT

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The objective of the present work is to reduce the light-off time of the catalyst and at the same time reduce the thermal degradation and ageing of the catalyst to the minimum possible extent by adopting an approach with Dynamic Catalytic Converter System (DCCS). In this approach, the catalytic converter is kept very close to the exhaust manifold during cold start of the vehicle and once it attains the light-off temperature the converter is moved to a far away position as any other conventional converter thereby reducing damages caused due to overheating. The emission tests were conducted in a four-cylinder spark ignition engine with DCCS at different positions from the engine outlet manifold and also with pre-catalysts of 40% volume of the main catalytic converter. It was established that considerable reduction in the light off time was achieved by using DCCS and light-off time was further reduced by using pre-catalysts as compared to the conventional catalytic converter. The CO light-off time of main catalytic converter reduced 60% with DCCS with PC (40%) and the corresponding reduction for HC light-off time is 57% compared to main catalytic converter without DCCS.

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The Effects of Catalytic Converter Location and Palladium Loading on Tailpipe Emissions

Cited by 8 publications

References 12 publications

Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals

Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals

Vehicular Emissions in Review

Temperature analysis of dynamic catalytic convertor system with pre-catalyst in a multi cylinder spark ignition engine to reduce light-off time

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