Catalyst Technologies for Future Automotive Emission Systems

Williamson, W. B.; Summers, James; Skowron, John F.

doi:10.4271/880103

Cited by 19 publications

(2 citation statements)

References 12 publications

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“…These results are in agreement with previous finding of Hoebink et al, [15] and Granger, et al, [16]. 4) illustrate the effect of gas space velocity in the range of (17.69 -44.23 s -1 ) on the conversion of exhaust gas at temperature (673 K) for commercial monolith catalyst and for 0.4wt%Pd loading catalyst.It can be noticed from this figure that the conversion of the exhaust gas components decreases with increasing gas velocity, owing to decrease in the residence time (decreasing contact time of the feed reactant) with the catalyst inside reactor, such trends are in agreement with the observation of previous finding of Williaamson et al, [17], Tomasic et al, [18] and Fabiano et al, [19]. From these figures, it can be seen that the conversion of NO reduction using Pd loading catalyst is higher than those obtained by commercial catalysts.…”

Section: Results and Discussion Effect Of Operating Variable On Monol...supporting

confidence: 92%

Investigation the Activity of Pd Loading on Commercial Monolithic Catalyst in Automobile Exhaust Gases

Abdul K .Mohammed,

R. Rauof,

Hussain Khalaf

2013

ETJ

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Catalytic monolith reactors have numerous applications in industrial processes and as technical devices, so the focus is set specially on automotive catalytic converters.The present work aimed to study the experimental performance of monolith reactor on the oxidation and reduction of exhaust gas (NO, CO, and HC) which emitted from gasoline generator. Commercial and modified commercial ceramic monolith catalyst was used in the present work. The modified commercial catalyst was obtained by loaded Pd metal .A laboratory unit was constructed for this purpose where a versatile stainless steel monolith reactor of 0.02 m inside diameter and 0.2 m height was used.The catalytic performance of the catalysts was studied in the following operating conditions, in a border range of gas space velocity(17.69 -44.23s -1) , reaction temperature(373 -673 K), bed length(0.075 -0.15 m) and at atmospheric pressure and constant air/fuel ratio (14.6).The results show that the conversion of NO, CO and HC are slightly changed with the bed length . The conversion of exhaust gas reactant enhances in presence of water, increases with the increasing reaction temperature and decreases with increasing gas space velocity. Monolithic catalyst which loaded with 0.4% Pd gives high conversion compared with an commercial catalyst (unloaded) for the HC oxidation reaction more than CO oxidation and NO reduction.

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Section: Results and Discussion Effect Of Operating Variable On Monol...supporting

confidence: 92%

Investigation the Activity of Pd Loading on Commercial Monolithic Catalyst in Automobile Exhaust Gases

Abdul K .Mohammed,

R. Rauof,

Hussain Khalaf

2013

ETJ

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“…These oxides are found to have O 2 storage capabilities and enhance catalytic activity, especially at low temperatures. Although OSC increases with the increase of CeO 2 content in the washcoat [ 50 ] , instabilities of structure at elevated temperatures are correlated with the thermal sintering of the noble metals. OSC of cerium oxides is affected by temperature [51] and the conjunction of other oxides, like…”

Section: S T O R a G E C O M P O N E N T Smentioning

confidence: 99%

Development and application of a computer aided engineering methodology supporting the design optimization of automotive exhaust treatment systems

Konstantas¹

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O p t i m i z a t i o n o f A u t o m o t i v e E x h a u s t T r e a t m e n t S y s t e m sTHESIS submitted in partial fulfillment of the requirements for the degree of D o c t o r o f P h i l o s o p h y i n M e c h a n i c a l E n g i n e e r i n g of the D e p a r t m e n t o f M e c h a n i c a l a n d I n d u s t r i a l E n g i n e e r i n g -3 - Since the core of almost every automotive exhaust aftertreatment system is some kind of catalytic converter, intensive research activity is devoted to the various scientific and technical aspects of catalytic technology. These aspects vary from practical research on new materials and novel techniques to improve catalyst microstructure, to theoretical contributions of detailed descriptions of chemical phenomena inside the converters and proposals of mechanistic reaction schemes.Nevertheless, the extremely high efficiencies that are expected from any modern catalyst cannot be attained without simultaneously optimizing aftertreatment device performance, engine design and the control system that drives the whole system. Thus, from a mechanical engineer's point of view, the exhaust treatment complexity is expressed as a strong interaction between these three fields: powertrain operation, engine management characteristics and exhaust treatment device operation.In general, the composition of exhaust gas depends on the engine type, the operating point of the engine, the ambient temperature, the transmission system and miscellaneous characteristics of each system. Thus, the engine management holds a key role in the behavior of the catalytic converter, since it affects both its input as well as the temperature range under which it operates. Moreover, exhaust line design, involving exhaust manifold heat capacity, insulated pipes and positioning of the devices, is strongly connected with the catalytic converter operation. Furthermore, catalysts with the same chemical composition may behave quite differently, depending on the actual procedures that were employed during catalyst preparation.The complexity of the automotive exhaust treatment systems quickly became apparent in the industry. Mathematical modeling tools are continuously developed, in order to complement the experimental efforts and provide guidance for areas that needed improvement. In the last 30 years, many models have appeared in the literature [2] . Their approaches and their scope were diverse, but in general they were rather focused on the individual devices than on the whole aftertreatment system. -6 -Specifically for the catalytic converter modeling: most kinetic studies so far resulted in models that are valid for the specific combination of engine and catalyst status at that moment (usually fresh catalysts). Although valuable for a specific engineering problem, such modeling results could only partially be extended in different systems, and only with great caution. Indeed, successful extension of the results of a specific case to another one is rare in the literature [1] . As a characteristic example...

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