Chemical and Physical Properties of Ultrafine Diesel Exhaust Particles Sampled Downstream of a Catalytic Trap

• Published in: Environmental science & technology Vol. 40; no. 17; pp. 5502 - 5507
• Main Authors: Grose, Melissa, Sakurai, Hiromu, Savstrom, Jake, Stolzenburg, Mark R, Watts, Winthrop F, Morgan, Christopher G, Murray, Ian P, Twigg, Martyn V, Kittelson, David B, McMurry, Peter H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.09.2006
• Subjects: Air Pollutants; Airborne particulates; Applied sciences; Atmospheric pollution; Catalysis; Diesel engines; Exact sciences and technology; Nanoparticles; Particle Size; Physical properties; Pollution; Pollution sources. Measurement results; Simulation; Sulfur content; Transports; Vehicle Emissions; Gravimetric analysis; Catalytic muffler; Hygroscopicity; Chemical analysis; Nanoparticle; Volatility; Diesel engine; Motor vehicle; Ultrafine particle; Pollutant emission; Heavy truck; Particle size distribution; Catalytic converter; Aerosols; Exhaust gas; Road traffic
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es052267+

The chemical and physical properties of exhaust particles produced by a Caterpillar 3176 C-12 heavy duty diesel engine equipped with a catalytic trap (CRT) are reported. The engine was operated at 600 Nm and 1500 rpm, using fuels containing 15 and 49 ppm sulfur. A two-stage dilution tunnel designed to simulate the reactions that occur when hot combustion products mix with cooler atmospheric air was used. Particle size distributions were measured using a scanning mobility particle sizer (SMPS) and nano-scanning mobility particle sizer (nano SMPS); a nano-micro-orifice uniform deposit impactor (nano MOUDI) collected size-resolved samples for gravimetric and chemical analysis. A nanometer tandem differential mobility analyzer (nano TDMA) was used to measure the volatility and hygroscopicity of 4−15 nm particles. These measure ments confirm that the particles consisted primarily of sulfates.