Progress and future challenges in passive NO adsorption over Pd/zeolite catalysts

2021 ◽  
Author(s):  
Guohua Jing ◽  
Johannes W. Schwank ◽  
Alexander J Hill ◽  
Huawang Zhao ◽  
Lei Ma ◽  
...  
Keyword(s):  
Cold Start ◽  
Zeolite Catalysts ◽  
Catalytic Converters ◽  
No Adsorption ◽  
Emission Standards ◽  
Future Challenges ◽  
Future Emission

Future emission standards are becoming increasingly stringent. Around 50% of targeted tailpipe emissions are emitted during the cold-start period, mainly due to the ineffectiveness of catalytic converters in the after-treatment...

High Performance Cooling and EGR Systems as a Contribution to Meeting Future Emission Standards

2008 ◽  
Vol 1 (1) ◽  
pp. 756-769 ◽  
Author(s):  
U. Krüger ◽  
S. Edwards ◽  
E. Pantow ◽  
R. Lutz ◽  
R. Dreisbach ◽  
...  
Keyword(s):  
High Performance ◽  
Emission Standards ◽  
Future Emission

A Proposed Diesel Powertrain to Meet Future Emission Standards and Achieve High Engine Efficiency

2019 ◽  
Author(s):  
Konstantinos Priftis ◽  
Apostolos Karvountzis Kontakiotis ◽  
Wolfgang Gstrein ◽  
Christoph Schuette
Keyword(s):  
Engine Efficiency ◽  
Emission Standards ◽  
Future Emission

Optimal design of catalytic converters for minimizing cold-start emissions

2004 ◽  
Vol 98 (3) ◽  
pp. 357-373 ◽  
Author(s):  
Karthik Ramanathan ◽  
David H. West ◽  
Vemuri Balakotaiah
Keyword(s):  
Optimal Design ◽  
Cold Start ◽  
Catalytic Converters

Reduction of cold start emissions with microwave heated catalytic converters

2019 ◽  
pp. 612-623 ◽  
Author(s):  
Viola Papetti ◽  
Panayotis Dimopoulos Eggenschwiler ◽  
Daniel Schreiber
Keyword(s):  
Cold Start ◽  
Catalytic Converters

A fleet-prediction oriented catalyst model for highly transient driving in cold and hot mode conditions

2012 ◽  
Vol 13 (5) ◽  
pp. 497-513 ◽  
Author(s):  
Martin Weilenmann ◽  
Dimitrios N Tsinoglou
Keyword(s):  
Real World ◽  
Catalytic Converter ◽  
Cold Start ◽  
Catalyst Design ◽  
Pollutant Emissions ◽  
Oxygen Storage ◽  
Catalytic Converters ◽  
Driving Cycles ◽  
Wide Range ◽  
Oxidation Catalytic Converter

Various models for simulating catalytic converters are given in the literature. They deal with a wide range of different aspects. In addition to the type of catalytic converter (three-way catalytic converter, diesel oxidation catalytic converter, etc.), the aspect of complexity versus accuracy and speed can be tackled using different approaches. Moreover, the desired use has an influence on the model structure: optimization of catalyst design or prediction of emissions from real-world traffic situations or optimization of air–fuel ratio control? The model described here has been developed to predict emissions in arbitrary real-world driving patterns, both for hot driving as well as for cold-start situations. As these tests mainly last over 30 minutes (real time), the calculation effort should be small. The model should be easy to parameterize, as it should be applicable to vehicles from traffic. A model with a reduced set of chemical reactions has been developed with a particular focus on the thermal balance for cold-start cycles. Its outputs are the pollutant emissions at the tailpipe if the emissions, exhaust mass flow and temperature from the engine are given. It is applied to three-way catalytic converters. It models the chemical phenomena almost entirely based on oxygen storage and release reactions, which dominate highly transient situations. The model has been validated against a large database of measured driving cycles, carried out using different types of cars. It presents an acceptable degree of correlation between simulated and experimental results.

Optimum Use of Noble Metal Catalysts in Catalytic Converters

2002 ◽  
Author(s):  
F. Lacin ◽  
M. Zhuang
Keyword(s):  
Noble Metal ◽  
Catalytic Converter ◽  
Cold Start ◽  
Metal Catalysts ◽  
Vapor Condensation ◽  
Metal Distribution ◽  
Catalytic Converters ◽  
Model Calculations ◽  
Noble Metal Catalysts ◽  
Off Time

The catalytic converter is an important device for the emission control from spark-ignition engines. Several concurrent physical/chemical processes such as convective heat transfer, gas phase chemical reactions, surface reactions, flow oscillations, water vapor condensation and diffusion mechanisms add complexity to modeling of flows inside catalytic converters. Under cold-start conditions, the fact that catalytic converters do not become operational during the initial operation allows a significant fraction of the overall pollutants to be emitted. In the present study, these complex transient phenomena have been examined using a previously validated numerical model.1 The numerical results suggest new material-dependent designs to improve both the transient conversion characteristics and the steady state conversion efficiency of catalytic converters. Moreover, from our model calculations, we have observed that for a given amount of the noble metal catalysts the light-off time and the monolith temperature are greatly affected by the noble-metal distribution along the honeycomb walls of a monolith. The results of the numerical simulations indicate that the light-off time is shortened by approximately 35% for CO, H2 and C3H6 when replacing a traditional homogeneous noble metal distribution by a simple, step-function distribution.2 The emissions of CO, H2 and C3H6 from the exhaust gas are, therefore, reduced without increasing the cost of noble metal catalysts used in converters. In order to avoid further deterioration of catalysts due to the thermal effects, an optimum noble metal distribution needs to be investigated with the understanding that the optimum noble metal distribution proposed has to be practical for the manufacturing. Since the main source of the exhaust emissions is generated during the cold-start period of the converter operation, the reduction of emissions shown in our model calculations is quite substantial.

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