A new approach to in-situ determination of roadside particle emission factors of individual vehicles under conventional driving conditions

Abstract A method for continuous on-road measurements of particle number emissions for both diesel- and petrol-fuelled vehicles is presented. The setup allows the determination of particle number emission factors on an individual vehicle basis by the simultaneous measurement of CO2 and particle concentrations. As an alternative to previous measurements on the kerbside, the sample is taken directly in the street, with the advantage of sampling in-situ within the exhaust plumes of passing vehicles, allowing the separation of the individual high-concentration plumes. The method was tested in two experiments that were conducted in the Gothenburg area. In the first study, which was performed at an urban roadside, we were able to determine particle emission factors from individual vehicles in a common car fleet passing the measurement site. The obtained emission factors were of the same order of magnitude (between 1.4 × 1012 and 1.8 × 1014 particles km−1) as values published in the recent literature for light duty vehicles. An additional on-road experiment was conducted at a rural road with four light duty reference vehicles (three of them petrol-powered and one diesel-powered) at driving speeds of 50 and 70 km h−1, realised with different engine speeds. The results of the traffic emission studies show that the method is applicable provided that instruments with an adequate dynamic range are used and that the traffic is not too dense. In addition, the variability in particle emissions for a specified driving condition was estimated.

[1]  Scott C Herndon,et al.  Characterization of urban pollutant emission fluxes and ambient concentration distributions using a mobile laboratory with rapid response instrumentation. , 2005, Faraday discussions.

[2]  A novel method for determination of size resolved, submicrometer particle traffic emission factors. , 2005, Environmental science & technology.

[3]  E. R. Jayaratne,et al.  The Use of Carbon Dioxide as a Tracer in the Determination of Particle Number Emissions from Heavy-Duty Diesel Vehicles , 2005 .

[4]  M. Andreae,et al.  Emission of trace gases and aerosols from biomass burning , 2001 .

[5]  Efthimios Zervas,et al.  CO2 benefit from the increasing percentage of diesel passenger cars in Sweden , 2007 .

[6]  Tom Wenzel,et al.  Some issues in the statistical analysis of vehicle emissions , 2000 .

[7]  L. Morawska,et al.  Quantification of particle number emission factors for motor vehicles from on-road measurements. , 2005, Environmental science & technology.

[8]  Liisa Pirjola,et al.  Emissions of fine particles, NOx, and CO from on-road vehicles in Finland , 2005 .

[9]  Roy M. Harrison,et al.  Sources and concentration of nanoparticles (<10 nm diameter) in the urban atmosphere , 2001 .

[10]  Christian John,et al.  COMPARISON OF EMISSION FACTORS FOR ROAD TRAFFIC FROM A TUNNEL STUDY (GUBRIST TUNNEL, SWITZERLAND) AND FROM EMISSION MODELING , 1999 .

[11]  G Carter,et al.  A Method for Measuring Particle Number Emissions from Vehicles Driving on the Road , 2002, Environmental technology.

[12]  Martin Mohr,et al.  Comprehensive particle characterization of modern gasoline and diesel passenger cars at low ambient temperatures , 2005 .

[13]  Ü. Rannik,et al.  Relaxed Eddy Accumulation System for Size-Resolved Aerosol Particle Flux Measurements , 2004 .

[14]  K. Donaldson,et al.  Increased inflammation and altered macrophage chemotactic responses caused by two ultrafine particle types , 2004, Occupational and Environmental Medicine.

[15]  G. Oberdörster,et al.  Nanotoxicology: An Emerging Discipline Evolving from Studies of Ultrafine Particles , 2005, Environmental health perspectives.

[16]  P Ahlvik,et al.  ENVIRONMENTAL AND HEALTH IMPACT FROM MODERN CARS , 2002 .

[17]  C. Goodfellow,et al.  A Study of the Size, Number and Mass Distribution of the Automotive ParticulateEmissions from European Light Duty Vehicles , 1998 .

[18]  Christer Johansson,et al.  Spatial & temporal variations of PM10 and particle number concentrations in urban air , 2007, Environmental monitoring and assessment.

[19]  G. Bishop,et al.  Development of a High-Speed Ultraviolet Spectrometer for Remote Sensing of Mobile Source Nitric Oxide Emissions. , 1999, Journal of the Air & Waste Management Association.

[20]  David J. Williams,et al.  Modelling of Motor Vehicle Fuel Consumption and Emissions Using a Power-Based Model , 2000 .

[21]  D. Dockery,et al.  An association between air pollution and mortality in six U.S. cities. , 1993, The New England journal of medicine.

[22]  Philip K. Hopke,et al.  Modeling Source Contributions to Submicron Particle Number Concentrations Measured in Rochester, New York , 2007 .

[23]  John Whipp,et al.  Electrical and Electronic Systems , 1990 .

[24]  J L Sullivan,et al.  CO2 emission benefit of diesel (versus gasoline) powered vehicles. , 2004, Environmental science & technology.

[25]  B. Brunekreef,et al.  Epidemiological evidence of effects of coarse airborne particles on health , 2005, European Respiratory Journal.

[26]  M. L. Laucks,et al.  Aerosol Technology Properties, Behavior, and Measurement of Airborne Particles , 2000 .

[27]  M. Maricq.  Chemical characterization of particulate emissions from diesel engines: A review , 2007 .

[28]  E. R. Jayaratne,et al.  Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel. , 2005, The Science of the total environment.

[29]  Martin Mohr,et al.  Particle emissions from diesel passenger cars equipped with a particle trap in comparison to other technologies. , 2006, Environmental science & technology.

[30]  Roy M. Harrison,et al.  Estimation of the emission factors of particle number and mass fractions from traffic at a site where mean vehicle speeds vary over short distances , 2006 .