Comparison of Water and Butanol Based CPCs for Examining Diesel Combustion Aerosols

Franklin, Luke; Bika, Anil Singh; Watts, Winthrop F.; Kittelson, David B.

doi:10.1080/02786826.2010.482112

Cited by 15 publications

(11 citation statements)

References 22 publications

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“…This 212 difference could be due to CPC sensitivity to particle composition that depends on the 213 condensing fluid (i.e., water versus butanol), or due to other differences in CPC design. 29 Emission factor-weighted particle size distributions were used to derive a characteristic 223 particle number emission profile for each truck category. Measured size distributions for each 224 truck were weighted by corresponding FMPS-derived PN emission factors.…”

Section: Results and Discussion 165mentioning

confidence: 99%

Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland

Preble

Dallmann

Kreisberg

et al. 2015

Environ. Sci. Technol.

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Effects of fleet modernization and use of diesel particle filters (DPF) and selective catalytic reduction (SCR) on heavy-duty diesel truck emissions were studied at the Port of Oakland in California. Nitrogen oxides (NOx), black carbon (BC), particle number (PN), and size distributions were measured in the exhaust plumes of ∼1400 drayage trucks. Average NOx, BC, and PN emission factors for newer engines (2010-2013 model years) equipped with both DPF and SCR were 69 ± 15%, 92 ± 32%, and 66 ± 35% lower, respectively, than 2004-2006 engines without these technologies. Intentional oxidation of NO to NO2 for DPF regeneration increased tailpipe NO2 emissions, especially from older (1994-2006) engines with retrofit DPFs. Increased deployment of advanced controls has further skewed emission factor distributions; a small number of trucks emit a disproportionately large fraction of total BC and NOx. The fraction of DPF-equipped drayage trucks increased from 2 to 99% and the median engine age decreased from 11 to 6 years between 2009 and 2013. Over this period, fleet-average BC and NOx emission factors decreased by 76 ± 22% and 53 ± 8%, respectively. Emission changes occurred rapidly compared to what would have been observed due to natural (i.e., unforced) turnover of the Port truck fleet. These results provide a preview of more widespread emission changes expected statewide and nationally in the coming years.

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Section: Results and Discussion 165mentioning

confidence: 99%

Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland

Preble

Dallmann

Kreisberg

et al. 2015

Environ. Sci. Technol.

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“…Note that the water-based particle counters without a sheath flow design, as those used in Los Angeles, have been shown to underestimate vehicle-emitted PNCs, particularly for particles o20 nm. 49 In Los Angeles, higher relative humidity was associated with higher PNCs. 45 Also, traffic speeds were considerably distinct between studies.…”

Section: Traffic Effectsmentioning

confidence: 98%

Ultrafine particle levels at an international port of entry between the US and Mexico: Exposure implications for users, workers, and neighbors

Olvera

Lopez

Guerrero

et al. 2013

J Expo Sci Environ Epidemiol

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Exposure to diesel-emitted particles has been linked to increased cancer risk and cardiopulmonary diseases. Because of their size (<100 nm), exposure to ultrafine particles (UFPs) emitted from heavy-duty diesel vehicles (HDDV) might result in greater health risks than those associated with larger particles. Seasonal UFP levels at the International Bridge of the Americas, which connects the US and Mexico and has high HDDV traffic demands, were characterized. Hourly average UFP concentrations ranged between 1.7 × 10(3)/cc and 2.9 × 10(5)/cc with a mean of 3.5 × 10(4)/cc. Wind speeds <2 m s(-1) and temperatures <15 °C were associated with particle number concentrations above normal conditions. The presence of HDDV had the strongest impact on local UFP levels. Varying particle size distributions were associated with south- and northbound HDDV traffic. Peak exposure occurred on weekday afternoons. Although in winter, high exposure episodes were also observed in the morning. Particle number concentrations were estimated to reach background levels at 400 m away from traffic. The populations exposed to UFP above background levels include law enforcement officers, street vendors, private commuters, and commercial vehicle drivers as well as neighbors on both sides of the border, including a church and several schools.

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“…Shading represents the standard deviation. ambient air, freeway tunnel, and laboratory-generated particles (Biswas et al, 2005;Franklin et al, 2010;Iida et al, 2008;Kupc et al, 2013). The application of this single scaling factor across all the particle sizes is an approximation, as the particle morphology likely differs for different particle sizes.…”

Section: Development and Validation Of A Source-independent Correctiomentioning

confidence: 98%

A source-independent empirical correction procedure for the fast mobility and engine exhaust particle sizers

Zimmerman

Jeong

Wang

et al. 2015

Atmospheric Environment

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h i g h l i g h t sAccuracy of high time resolution particle sizers is affected by particle morphology. These instruments also under-size particles larger than 80 nm. We provide a source-independent correction protocol to address this issue. The correction protocol ensures agreement within 20% of a reference instrument. Keywords: EEPS FMPS SMPS Morphology Vehicle emissions Particle size distributions a b s t r a c tThe TSI Fast Mobility Particle Sizer (FMPS) and Engine Exhaust Particle Sizer (EEPS) provide size distributions for 6e560 nm particles with a time resolution suitable for characterizing transient particle sources; however, the accuracy of these instruments can be source dependent, due to influences of particle morphology. The aim of this study was to develop a source-independent correction protocol for the FMPS and EEPS. The correction protocol consists of: (1) broadening the >80 nm size range of the distribution to account for under-sizing by the FMPS and EEPS; (2) applying an existing correction protocol in the 8e93 nm size range; and (3) dividing each size bin by the ratio of total concentration measured by the FMPS or EEPS and a water-based Condensation Particle Counter (CPC) as a surrogate scaling factor to account for particle morphology. Efficacy of the correction protocol was assessed for three sources: urban ambient air, diluted gasoline direct injection engine exhaust, and diluted diesel engine exhaust. Linear regression against a reference instrument, the Scanning Mobility Particle Sizer (SMPS), before and after applying the correction protocol demonstrated that the correction ensured agreement within 20%.

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Comparison of Water and Butanol Based CPCs for Examining Diesel Combustion Aerosols

Cited by 15 publications

References 22 publications

Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland

Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland

Ultrafine particle levels at an international port of entry between the US and Mexico: Exposure implications for users, workers, and neighbors

A source-independent empirical correction procedure for the fast mobility and engine exhaust particle sizers

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