Detailed Chemical Composition and Particle Size Assessment of Diesel Engine Exhaust

Kweon, Chol-Bum; Foster, David E.; Schauer, James J.; Okada, Shusuke

doi:10.4271/2002-01-2670

Cited by 56 publications

(38 citation statements)

References 8 publications

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“…The highest value of VF is obtained in the case of diesel (low) fueling and the lowest is for diesel (high) fueling. Higher volatile organic fractions (VOFs) and soluble organic fractions (SOFs) for diesel fueling under low to medium loads compared to high loads are already reported (Kweon et al 2002(Kweon et al , 2003Ning et al 2004;Lapuerta et al 2007). The TGA results obtained here for diesel PM therefore agree well with these previous studies.…”

Section: Tgamentioning

confidence: 99%

“…According to Kweon et al (2002Kweon et al ( , 2003) the premixed combustion is a primary controlling factor for the particle-phase organic compounds in diesel PM. As the stoichiometric A/F ratio decreases with the introduction of gaseous fuels in the engine, theoretically richer mixture are in existence in dual fueling condition than diesel (high load) condition.…”

Section: Volatile Fraction (Vf)mentioning

confidence: 99%

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Characterization of Exhaust Particulates from a Dual Fuel Engine by TGA, XPS, and Raman Techniques

Mustafi

Raine

James

2010

Aerosol Science and Technology

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Particulate matter (PM) emitted from a dual fuel engine is characterized using thermogravimetry, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Thermogravimetric analysis (TGA) provides the mass fractions of elemental carbon and volatile materials in PM; XPS provides the possible chemical compositions in the topmost layer of PM surface and Raman analysis provides the possible structure of the carbon presented in PM. Dual fuel engine uses both liquid (diesel) and gaseous fuels simultaneously to produce mechanical power and can be switched to only diesel fueling under load. The dual fuel engine is operated with natural gas and simulated biogases (laboratory prepared) and results are compared between the dual fueling and diesel fueling under the same engine operating conditions. Significantly higher volatile fractions in PM are obtained for dual fueling compared to diesel fueling complementing the gravimetric results. The maximum contribution of the graphitic carbon or aliphatic carbon such as hydrocarbons and paraffins (C C or C C) are found in the topmost atomic layers of both the diesel and dual fuel PM samples. The other chemical states are found to be the carbon-oxygen functional groups indicating significant oxidation behavior in the PM surface. Lesser aromatic content is noticed in the case of dual fuel PM than diesel PM. The carbon in dual fuel PM is found to be more amorphous compared to diesel PM. These characterizations provide us new information how the PM from a diesel engine can be different from that from a dual fuel engine.

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Section: Tgamentioning

confidence: 99%

Section: Volatile Fraction (Vf)mentioning

confidence: 99%

Characterization of Exhaust Particulates from a Dual Fuel Engine by TGA, XPS, and Raman Techniques

Mustafi

Raine

James

2010

Aerosol Science and Technology

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“…The protocols regarding engine bench setup, operation, sampling/measurement, and detailed particle characterization and chemical composition of the exposure system have been substantially described in previous publications (Kweon et al 2002(Kweon et al , 2003. Briefly, a research single-cylinder 4-cycle diesel engine, adapted from an in-line six-cylinder Cummins N14-series, was utilized in this study.…”

Section: Diesel Exhaust Exposurementioning

confidence: 99%

Tachykinin substance P signaling involved in diesel exhaust-induced bronchopulmonary neurogenic inflammation in rats

Wong

Sun

Keith

et al. 2003

Archives of Toxicology

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This study characterizes the molecular neurotoxicity of diesel exhaust (DE) on the tachykinin substance P (SP) signaling system in the lungs. A total of 96 female Fischer 344/NH rats (approximately 175 g, approximately 4 weeks old) were randomly assigned to eight groups in a 2 x4 factorial design: capsaicin versus non-capsaicin (vehicle) pretreatment, and filtered room air versus two exposure levels of DE with diesel engine room control. The rats were exposed nose-only to room air or low (35.3 micro g/m(3)) and high concentrations (669.3 micro g/m(3)) particulates directly from a Cummins N14 research engine at 75% throttle for 4 h/day, 5 days/week, for 3 weeks. The findings showed that exposure to DE dose-dependently induced bronchopulmonary neurogenic inflammation, both in capsaicin- and vehicle-pretreated rats, as measured by plasma extravasation, edema, and inflammatory cells. DE inhalation affected the SP signaling processes, including stored SP depletion and the gene/protein overexpression for neurokinin-1 receptor. DE also significantly reduced the activity of neutral endopeptidase, a main degradation enzyme for SP. Consequently, these changes may be regarded as critical factors that switched neurogenic pulmonary responses from their protective functions to a detrimental role that perpetuates lung inflammation. These changes may possibly be associated with the mass concentration of DE particles due to their physico-chemical characteristics. Moreover, capsaicin-pretreated rats had more sensitivity to these levels of DE exposure due to stimulation of bronchopulmonary C-fibers. However, the effects of capsaicin treatment were not consistent and apparent in this study. Taken together, our findings suggest that neurokininergic mechanisms may possibly be involved in DE-induced lung inflammation, but that bronchopulmonary C-fibers did not dominate DE-induced inflammatory abnormalities.

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“…Assuming most engine emissions are comprised of similar constituents, the mass of each may be summed together to formulate a chemically reconstructed mass (Kweon et al 2002;Zielinska et al 2004;Schauer et al 2008). Measuring the EC and organic carbon (OC) fractions of low concentrations of PM is possible through the thermal optical method (TOM), a NIOSH-based measurement (Birch and Cary 1996;Warner et al 2003;Kweon et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Comparison of Strategies for the Measurement of Mass Emissions from Diesel Engines Emitting Ultra-Low Levels of Particulate Matter

Liu

Vasys

Dettmann

et al. 2009

Aerosol Science and Technology

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Regulatory methods for the measurement of particulate matter (PM) mass emissions have traditionally been gravimetric. Modern diesel engines equipped with aftertreatment systems, especially Diesel Particulate Filters (DPFs), however, emit much smaller amounts of particulate matter as compared to traditional diesel engines and emit particulate matter with variable compositions. These changes have led to difficulties in measuring PM emissions rates from modern diesel engines using gravimetric methods. Issues associated with diesel PM mass measurement, such as the semi-volatile nature of PM, the interactions with components in the dilution air such as water and ammonia, and the possibility of sampling artifacts, have counteracted a singular focus on mass measurements. These inherent problems may warrant some alternative approaches to characterizing emissions, using methods related to mass and impacts of emissions that can be more accurately defined. The present study provides a comparison and relative precision of several alternative mass measurement methods employed to measure the mass emissions of particulate matter from diesel engines with low and ultra-low levels of emissions. The methods of measurement reviewed in this study include two gravimetrically based methods, a chemically reconstructed mass method, and an integrated particle size distribution (IPSD) method. The mass measurements were consistent at low emission levels but the chemical speciation and IPSD methods achieved closer agreement and were more precise at ultra-low emission levels. Although mass measurement is a NIST-traceable quantity, alternative methods may present a new paradigm that better characterizes engine emissions in an atmospherically relevant manner.

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Detailed Chemical Composition and Particle Size Assessment of Diesel Engine Exhaust

Cited by 56 publications

References 8 publications

Characterization of Exhaust Particulates from a Dual Fuel Engine by TGA, XPS, and Raman Techniques

Characterization of Exhaust Particulates from a Dual Fuel Engine by TGA, XPS, and Raman Techniques

Tachykinin substance P signaling involved in diesel exhaust-induced bronchopulmonary neurogenic inflammation in rats

Comparison of Strategies for the Measurement of Mass Emissions from Diesel Engines Emitting Ultra-Low Levels of Particulate Matter

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