Reduction of cold-start emissions using electrically-heated catalyst (EHC) technology was the focus of this work. Comprehensive emission measurements of CO, CO2,NOx, and total hydrocarbons (THC) are reported for a spark-ignited engine operated on baseline gasoline and compressed natural gas (CNG). Electric heating times of 0, 20, and 40 s with and without secondary air injection were investigated. The 40-second electric catalyst heating with secondary air injection scenario yielded the greatest catalyst system (EHC+OEM three-way catalyst) conversion efficiencies for THC, CO, and NOx for gasoline and natural gas fueling. Electric catalyst heating coupled with secondary air injection significantly improved THC and CO emissions for gasoline fueling. THC oxidation was difficult for CNG fueling due to the high content of nonreactive methane in the fuel. The independence of NOx emissions on heating time was demonstrated for all fueling cases.

U.S. Environmental Protection Agency Report, 1995, “National Air Pollutant Trends, 1900–1994,” EPA-454/R-95-011, Research Triangle Park, NC.
Summers, J. C., and Silver, R. G., 1992, “Catalyst Technologies to Meet Future Emission Requirements for Light-Duty Vehicles,” Catalytic Control of Air Pollution—Mobile and Stationary Sources, R. G. Silver, J. E. Sawyer, and J. C. Summers, eds., American Chemical Society, Washington, D.C., pp. 3–10.
Laing, P. M., 1994, “Development of an Alternator-Powered Electrically-Heated Catalyst System,” SAE Paper No. 941042, LEV/ULEV Emission Technologies, Society of Automotive Engineers, Warrendale, PA, pp. 137–144.
Whittenberger, W. A., and Kubsh, J. E., 1990, “Recent Developments in Electrically Heated Metal Monoliths,” Recent Trends in Automotive Emissions Control, Society of Automotive Engineers, Inc., Warrendale, PA, SAE Paper No. 900503, pp. 61–70.
Gottberg, I., Rydquist, J. E., Backlund, O., Wallman, S., Maus, W., Bruck, R., and Swars, H., 1991, “New Potential Exhaust Gas Aftertreatment Technologies for ‘Clean Car’ Legislation,” SAE Paper No. 910840.
Kaiser, F. W., Maus, W., Swars, H., and Bruck, R., 1993, “Optimization of an Electrically-Heated Catalytic Converter System Calculations and Application,” SAE Paper No. 932722.
Brunson, G., Kubsh, J. E., and Whittenberger, W. A., 1993, “Combining Heated and Unheated Core Functions for Improved Cold Start Emissions Performance,” SAE Paper No. 932722.
Hellman, K. H., Piotrowski, G. K., and Schaefer, R. M., 1994, “Evaluation of Specialized Methane Catalytic Converters on a CNG-Fueled Vehicle,” LEV/ULEV Emission Technologies, Society of Automotive Engineers, Inc., Warrendale, PA, February, SAE Paper No. 940473, pp. 67–86.
Coppage, G. N., 1996, “Cold-Start Emissions Reduction in a Bi-Fuel Spark Ignited Engine Using an Electrically-Heated Catalyst,” Master’s thesis, University of Alabama, Tuscaloosa, AL.
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