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.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    New Exhaust Catalyst Emission Control Systems for Nonroad SI Class I Engines


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    Powertrains, Fuels and Lubricants Meeting ; 2009



    Publication date :

    2009-06-15




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    New exhaust catalyst emission control systems for nonroad spark ignition class 1 engines

    McDonald,J. / Olson,B.A. / Environmental Protection Agency,EPA,US | Automotive engineering | 2009


    Demonstration of Advanced Emission Controls for Nonroad SI Class II Engines

    Olson, Brian / McDonald, Joseph / Murawski, Marc | SAE Technical Papers | 2009



    Demonstration of advanced emission controls for nonroad spark ignition class II engines

    McDonald,J. / Olson,B. / Murawski,M. et al. | Automotive engineering | 2009


    Evaluation of durable emission controls for large nonroad si engines

    Ulmet,V. / White,J.J. / Stout,A. et al. | Automotive engineering | 2002