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Catalyst Development for Stoichiometric and Lean Bum Natural Gas Engines
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Event:
SAE Brasil '94
Language:
English
Abstract
The exhaust emissions from stoichiometric gas engines contain CO, Hydrocarbons and NOx besides CO2 and H2O. The Hydrocarbon emissions consist mostly of unburnt methane. Conventional Pt and Rh based three-way catalysts show a good performance for the conversion of CO and NOx at stoichiometric exhaust gas composition, but methane passes almost unconverted through the catalytic converter. At rich exhaust gas composition (Lambda = 0.995) higher conversion rates are achieved for methane, but the efficiency is still not satisfactory for instationary applications.
Therefore specific catalyst formulations based on Pd were developed. Model gas reactor and first engine evaluation results are presented. The model gas data indicate that with Pd/Rh catalysts both a wider lambda window and a methane conversion of more than 90% can be achieved.
Furthermore catalysts for lean burn applications were investigated. In this case the NOx emissions play only a minor role, but the CO and methane emission levels are important. CO is easily oxidised even at temperatures below 250°C. For methane oxidation high temperatures (> 500°C) are needed with conventional catalysts, these temperatures usually do not occur in the exhaust gas of lean-burn gas engines. For this application therefore different washcoat compositions were tested, which in combination especially with Pd gave catalysts that show a good performance even at low temperatures.
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Authors
Topic
Citation
Gluck, K., Löx, E., Schafer-Sindlinger, A., Kreuzer, T. et al., "Catalyst Development for Stoichiometric and Lean Bum Natural Gas Engines," SAE Technical Paper 942419, 1994, https://doi.org/10.4271/942419.Also In
References
- Lowi, A. Jr. Carter W.P.L SAE-Paper No. 900710 1990
- Carter W.P.L. “Ozone Reactivity Analysis of Emissions from Motor Vehicles” Air Pollution Research Center, University of California Riverside July 1989
- Heintz A. Reinhardt G. “Chemie und Umwelt” 1991 Friedr. Vieweg & Sohn Publishers Braunschweig/Wiesbaden
- Lox E. Engler B.H. Koberstein E. SAE-Paper No. 910841 1991
- Cornetti G.M. Singer M. Filippi F. “CNG Low Emitting Engines for Italian City Buses” Symposium on the Use of Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG) and Liquefied Petroleum Gas (LPG) as Fuel for Internal Combustion Engines Kiev (Ukrainian SSR) 23-26 September 1991
- IVECO Engineering TNO Research Degussa AG
- Sakai T. Choi B. Chul Osuga R. Ko Y. SAE-Paper No. 912599 1991
- van der Weide J. Seppen J.J. “Natural Gas Vehicles, Environmental mental Balances” “Natural Gas Vehicles: An EEC Overview” Thermie Seminar: “Natural Gas as Fuel in Public Transportation” 13- 15 May 1992 Milan
- van Ling J. TNO Research “CNG Engines for Urban Bus Applications and their Impact on the Environment” Conference Natural Gas and Public Transport Ravenna 2 October 1992
- Degussa AG
- Cullis C.F. Willat B.M. J. Catal. 83 267 285 1983
- oh S.H. Mitchell P.J. Siewert R.M. J. Catal. 132 287 301 1991
- Otto K. Langmuir 5 1364 1369 1989
- Briot P. Primet M. Appl. Catal. 68 301 314 1991