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New Exhaust Catalyst Emission Control Systems for Nonroad SI Class I Engines
Technical Paper
2009-01-1900
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The U.S. Environmental Protection Agency has completed a program to demonstrate the feasibility of using integrated catalyst-muffler exhaust systems for nonroad spark ignition gasoline Class I engines (sub-19 kW, less than 225 cc). Integrated catalyst-muffler systems were developed for 4 different Class I engine families. Passive secondary air-injection systems were used with most of the systems to provide an exhaust feed-gas composition that was slightly rich of stoichiometry when used in conjunction with unmodified “Phase 2” carburetor A/F ratio calibrations. Catalyst sizing, PGM loading, and secondary-air venturi design were selected to limit CO oxidation and the typically resultant high heat rejection at high load operating points while still providing good NOx and HC emission control. Infrared thermal imaging was used to assess heat rejection at the EPA A-cycle operational points and during simulated hot soaks for selected configurations. Emissions of NOx+HC were reduced by approximately 35 to 65% at low hours and approximately 35 to 50% for configurations tested at near the end of the 125-hour regulatory useful life.
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Citation
McDonald, J. and Olson, B., "New Exhaust Catalyst Emission Control Systems for Nonroad SI Class I Engines," SAE Technical Paper 2009-01-1900, 2009, https://doi.org/10.4271/2009-01-1900.Also In
References
- Control of Emissions from Nonroad Spark-Ignition Engines and Equipment, U.S. Federal Register 72 96 Friday May 18 2007
- Code U.S. of Federal Regulations, Title 40, Part 90, Subpart E, Appendix A
- Yamaki et al.
- Sandefur et al.
- Gracyalny et al.
- EPA Technical Study on the Safety of Emission Controls for Nonroad Spark-Ignition Engines < 50 Horsepower