Exhaust particles of modern gasoline vehicles: A laboratory and an on-road study

• Published in: Atmospheric environment (1994) Vol. 97; pp. 262 - 270
• Main Authors: Karjalainen, Panu, Pirjola, Liisa, Heikkilä, Juha, Lähde, Tero, Tzamkiozis, Theodoros, Ntziachristos, Leonidas, Keskinen, Jorma, Rönkkö, Topi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2014; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Automobiles; Automotive engineering; Emission analysis; Emissions control; Exact sciences and technology; Exhaust; Exhaust particles; Gasoline; Gasoline direct injection; Morphology; Nucleation; Particle emissions; Pollution; Pollution sources. Measurement results; Roads; Soot; Transports; Particle emissions; Exhaust particles; Nucleation; Gasoline direct injection; Soot; Laboratory study; Combustion residue; Carbonaceous materials; Volatility; Gasoline engine; Motor vehicle; Particle size distribution; Morphology; Aerosols; Air pollution; Exhaust gas; Road traffic; Emission measure; Field study; Direct injection; Particle number
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2014.08.025

Vehicle technology development and upcoming particle emission limits have increased the need for detailed analyses of particle emissions of vehicles using gasoline direct injection (GDI) techniques. In this paper the particle emission characteristics of modern GDI passenger cars were studied in a laboratory and on the road, with the focus on exhaust particle number emissions, size distributions, volatility and morphology. Both during acceleration and steady conditions the number size distribution of nonvolatile exhaust particles consisted of two modes, one with mean particle size below 30 nm and the other with mean particle size approximately 70 nm. Results indicate that both of these particles modes consisted of soot but with different morphologies. Both in laboratory and on the road, significant emissions of exhaust particles were observed also during decelerations conducted by engine braking. These particles are most likely originating from lubricant oil ash components. The semivolatile nucleation particles were observed in the laboratory experiments at high engine load conditions. Thus, in general, the study indicates that a modern gasoline vehicle can emit four distinctive types of exhaust particles. The differences in particle characteristics and formation should be taken into account in the development of emission control strategies and technologies and, on the other hand, in the assessment of the impact of particle emissions on environment and human health. [Display omitted] •Four types of exhaust particles were observed in the exhaust of GDI vehicles.•Nonvolatile particle size distribution consisted of two modes.•GDI vehicles emitted particles also during engine braking conditions.•Semivolatile nucleation particles were in the exhaust at high load conditions.•Particle emissions were in real-world qualitatively similar as in the laboratory.