Diesel Engine Exhausts

HSG 187 Control of diesel engine exhaust emissions m the workplace... 

Petrol or LPG engine exhaust gas Diesel engine exhaust gas... 

Figure 8.14 Senipreparative class separation of a diesel engine exhaust sample. Column 25 cm x 7.9 mm, lO micrometer Porasil. Solvent gradient hexane to 5% methylene chloride over 5 min., linear gradient to 100% methylene chloride over 25 min., isocratic for 10 min., linear gradient to 100% acetonitrile over 10 min., Isocratic for 5 min., step change to tetrahydrofuran for 10 min.,...

NTP and both NH3- and HC-SCR was observed to be present under real diesel engine exhaust conditions [90],... 

Szanyi et al., using again in situ IR-TPD coupled skills, studied the effect of acid sites on the catalytic activities of a series of H+-modified Na-Y zeolites in the non-thermal plasma assisted NO reduction reaction using a simulated diesel engine exhaust gas mixture. The acid sites were formed by NH ion exchange and subsequent heat treatment of a NaY zeolite. The catalytic activities of these H+- modified NaY zeolites... 

Sequence plasma ON (low temperature) - plasma OFF (high temperature) in the presence of a mixture of HCs representative of diesel engine exhaust... 

Health Assessment Document for Diesel Engine Exhaust, EPA/600/8-90/057F, May 2002. 

Rajanikanth, B.S. and Ravi, V. (2002) Pulsed electrical discharges assisted by dielectric pellets/catalysts for diesel engine exhaust treatment, IEEE Trans. Diel. El. Insul. 9, 616-26. 

Mok, Y.S. and Huh, Y.J. (2005) Simultaneous removal of nitrogen oxides and particulate matters from diesel engine exhaust using dielectric barrier discharge and catalysis hybrid system, Plasma Chem. Plasma Process. 25, 625-39. 

One of the studies at the Fraunhofer Institute clearly indicated that the toxicity resulting from chronic inhalation of diesel engine exhaust was due to the particulate component of the exhaust and not the gases (21). Rats were exposed by inhalation over most of their life span to filtered or unfiltered diesel exhaust. Exposures were 19 h/day, 5 days/wk with soot concentrations of 4 mg/m3. All of the measures of toxicity determined, including decreases in body weight, alveolar clearance, and various measures of lung function, as well as the induction of lung tumors, were observed only In animals exposed to the unfiltered exhaust. 

In a study conducted at the Lovelace Inhalation Toxicology Research Institute (ITR1), rats were exposed for up to 30 months, 7 h/day, 5 days/wk, to diesel exhaust containing 0, 0.35, 3.5, or 7.1 mg soot/m3 of air. The diesel engine exhaust was generated as indicated in the section of this paperon "Physical/Chemical Characteristics of Diesel Soot." The lowest exposure concentration, 0.35 mg soot/m3, is directly relevant to some occupational exposures and is 10 to 100 times higher than any current or anticipated environmental exposures. Observations of the animals were made at 6-mo intervals and included measures of dosimetry (mg soot/g lung),... 

Figure 3. Accumulation of diesel soot in lungs exposed to diesel engine exhaust containing 0.35, 3.5, or 7.0 mg soot/m3. Lung burdens at the lower exposure concentration did not exceed 1.0 mg/g lung (Data from ref. 23).

Ishinishi, N. Koizumi, A. McClellan, R. 0. Stober, W. Carcinogenic and Mutagenic Effects of Diesel Engine Exhaust Elsevier Science Publishers, 1986. 

Source in diesel engine exhaust at a concentration of 0.9% of emitted hydrocarbons (quoted, Verschueren, 1983). Schauer et al. (1999) reported 2,3-dimethylpentane in a diesel-powered medium-duty truck exhaust at an emission rate of 720 pg/km. 

Source In diesel engine exhaust at a concentration of 1.2% of emitted hydrocarbons (quoted, Verschueren, 1983). 

Miscellaneous. Volatile nitrosamines can escape into the atmosphere from a variety of other sources. Automobile and diesel engine exhausts may contain N-nitroso compounds, including NDMA at trace levels (5). Nitrosodiethanolamine (NDEIA) is a likely air contaminant in machine shops which use cutting and grinding fluids contaminated with high concentrations of NDElA (10). Several herbicides, known to contain appreciable levels of volatile nitrosamines (9), are applied as aqueous sprays it is likely that worker exposure via inhalation may be appreciable. 

K. -W. Naujack, U. Mohr, and H. Ernst, Contribution of Polycyclic Aromatic Hydrocarbons and Nitro-Derivatives to the Carcinogenic Impact of Diesel Engine Exhaust Condensate Evaluated by Implantation into the Lungs of Rats, Cancer Lett., 37, 173-180 0 987). 

Schuetzle, D., and J. A. Frazier, Factors Influencing the Emission of Vapor and Particulate Phase Components from Diesel Engines, in Carcinogenic and Mutagenic Effects of Diesel Engine Exhaust (N. Ishinishi, A. Koizumi, R. O. McClellan, and W. Stober, Eds.), pp. 41-63, Elsevier, Amsterdam/New York, 1986. 

This paper describes the analysis of formic acid in diesel engine exhaust and mine air using ion chromatography (IC) and ion chromatography exclusion (ICE). 

Two ion chromatographic techniques were utilized to quantify formic acid in both diesel engine exhaust and mine air subjected to diesel emissions. A commonly used anion separation system utilizing a weak borate eluent adequately separated the acids of interest in diesel exhaust. It was, however, affected by the presence of strong acids during subsequent consecutive analyses. 

Results of analysis of formic acid in diesel engine exhaust subjected to various forms of post-combustion control, i.e., catalytic oxidation and water conditioning, indicate both a reduction of formic acid due to oxidation in the catalyst and dissolution in the water scrubber. In-mine analysis of formic acid at increasing distances from a source of diesel exhaust indicates that no significant change in concentration occurs. This finding contradicts a hypothesis that formaldehyde concentration decreases with increasing distance due to gas phase oxidation to formic acid. Surface reactions may, however, be important sinks for formaldehyde. 

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