This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Nanoparticle Growth During Dilution and Cooling of Diesel Exhaust: Experimental Investigation and Theoretical Assessment
Technical Paper
2000-01-0515
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SAE 2000 World Congress
Language:
English
Abstract
Nanoparticle formation during exhaust sampling and dilution has been examined using a two-stage micro-dilution system to sample the exhaust from a modern, medium-duty diesel engine. Growth rates of nanoparticles at different exhaust dilution ratios and temperatures have been determined by monitoring the evolution of particle size distributions in the first stage of the dilution system. Two methods, graphical and analytical, are described to determine particle growth rate. Extrapolation of size distribution down to 1 nm in diameter has been demonstrated using the graphical method. The average growth rate of nanoparticles is calculated using the analytical method. The growth rate ranges from 6 nm/sec to 24 nm/sec, except at a dilution ratio of 40 and primary dilution temperature of 48 °C where the growth rate drops to 2 nm /sec. This condition seems to represent a threshold for growth. Observed nucleation and growth patterns are consistent with predictions of a simple physical model. It assumes that nanoparticles form initially by nucleation of sulfuric acid-water droplets. This is followed by growth by absorption of additional acid and water as well as hydrocarbons into the growing droplets. The model indicates that there is not enough sulfuric acid vapor in the exhaust to explain observed growth. Hydrocarbons absorbing into the concentrated acid solution must also play a role. However, sulfuric acid is the trigger for initial particle formation. Growth is influenced by particle surface area. Existing particles, especially soot agglomerates may strongly suppress growth. Thus, as carbon emissions from engines are reduced, nanoparticle formation and growth becomes more likely unless emissions of sulfuric acid and hydrocarbons are correspondingly reduced.
Recommended Content
Authors
Topic
Citation
Khalek, I., Kittelson, D., and Brear, F., "Nanoparticle Growth During Dilution and Cooling of Diesel Exhaust: Experimental Investigation and Theoretical Assessment," SAE Technical Paper 2000-01-0515, 2000, https://doi.org/10.4271/2000-01-0515.Also In
References
- 3 rd International ETH-Workshop on Nanoparticle Measurement Zurich, Swtizerland 1999
- Bagley, S. T. Baumgard K.J. Gratz L.D. Johnson J.H. Leddy D.G. 1996 Characterization of Fuel and Aftertreatment Device Effects on Diesel Emissions Health Effects Institute Research Report No. 76 88
- Bagan, J. Study of Particle Size Distributions Emitted by a Diese Engine” SAE Paper No. 1999-01-1141 1999
- Abdul-Khalek, I. S. Kittelson D. B. Graskow B. R. Wei Q. Brear F. 1998 Diesel Exhaust Particle Size: Measurement Issues and Trends SAE paper number 98P-353
- Kruger, M. et al. 1997 Influence of Exhaust Gas Aftertreatment on Particulate Characteristics of Vehicle Diesel Engines Research Report of the Forschungsvereinigung Verbrennungskraftmaschinen e.V. (FVV), MTZ Motortechnische Zeitschrift 58 27 30
- Abdul-Khalek, I. S. Kittelson D. B. Brear F. 1998 Diesel Trap Performance: Particle Size Measurements and Trends SAE Tech. Pap. Ser. No. 982599
- Abdul-Khalek, I.S. Kittelson D.B. Brear F. 1999 Influence of Dilution Conditions on Diesel Exhaust Particle Size Distribution Measurements SAE Paper No. 1999-01-1142
- 1999
- Kittelson, D. B. et al. 1988 Characterization of Diesel Particles in the Atmosphere Coordinating Research Council AP-2 Project Group Final Report Kittelson, D. B. et al. 1988 Characterization of Diesel Particles in the Atmosphere Coordinating Research Council AP-2 Project Group Final Report
- Weingartner, E. et al. 1997 Aerosol Emission in a Road Tunnel Atmosph. Environ. 31 3 451 462
- Harrison, R. M. et al. 1996 Airborne Particulate Matter in the United Kingdom Third Report of the Quality of Urban Air Review Group University of Birmingham Birmingham, UK 176
- Whitby, K. T. et al. 1975 Characterization of California Aerosols - 1 Size Distributions of Freeway Aerosol. Atmosph. Environ. 9 463 482
- Wilson, W. E. et al. 1977 General Motors Sulfate Dispersion Experiment: Summary of EPA Measurements JAPCA 27 1 46 51
- Baumgard, K. “The effect of Fuel and Engine Design on Diesel Exhaust Particle Size Distributions” Michigan Technological University 1995
- Abdul-Khalek, I.S. Kittelson D.B. Brear F. “The Influence of Dilution Conditions on Diesel Exhaust Particle Size Distribution Measurements,” SAE Paper No. 1999-01-1142 1999
- Abdul-Khalek, I.S. “Influence of Dilution Conditions on Diesel Exhaust Nanoparticle Emissions: Experimental Investigation and Theoretical Assessment” University of Minnesota 1999
- Mirabel, P. Katz J.L. “Binary homogeneous nucleation as a mechanism for the formation of aerosols” J. Chem. Phys. 60 3 1138 1144 1974
- Friedlander S. K “Smoke Dust and Haze” Wiley and Sons 1977
- McMurry P.H. Wilson J. C. “Growth Laws For the formation of secondary Ambient Aerosols: Implications for Chemical Conversion Mechanisms” Atmos. Env. 1982
- Seinfield J H Atmospheric Chemistry and Physics of Air Pollution John Wiley and Sons 1986
- Bagely, S.T. Baumgard K.J. Gratz L.D. Johnson J.H. Leddy D.G. Characterization of Fuel and Aftertreatment Device Effects on Diesel Emissions” Health Effect Institute, Research Report Number 76 September 1996
- Johnson, J.E. “Hydrocarbons Oxidation in A Diesel Catalytic Converter” University of Minnesota 1993
- Ayers G. P. Gillett R.W. Gras J.L. “On the Vapor Pressure of Sulfuric Acid” Geoph. Res. Lett. 7 433 436 1980
- Hinds, C.W. “Aerosol Technology, Properties, Behavior, and Measurement of Airborne Particles” J. Wiley and Sons, Inc 133 1982