Diesel-fuel smoke

Subchronic repeated exposure studies were also conducted by Callahan et al. (1986) who exposed mice and rats to DF2 smoke at a mean concentration of 2300 mg m for 15 or 60 min each day for 5 days week for up to 13 weeks. The only clinical sign was hypoactivity. Mild-to-moderate pulmonary congestion was seen compared with unexposed controls, with minimal inflammatory changes in the nasal turbinates and trachea. Lock et al. (1984) conducted a 13 week study in which male and female rats were exposed to diesel-fuel smoke for 4 h, twice a week for 13 weeks. Exposure concentrations were measured as 170, 870, and 1600 mg m . There were no signs and no mortality. Body weight decreased until the fourth exposure week, after which there were body weight gains. 

As with diesel-fuel smokes, a proportion of generated particulates are respirable, and the most... 

Jenkins, R.A., Manning, D.L., Maskatinec, M.P., Moneyhun, J.H., and Dalbey, W., Chemical characterization and toxicologic evaluation of airborne mixtures. Diesel fuel smoke particulate dosimetry in Sprague-Dawley rats, ORNL/TM-9195. AD-A142 914, Oak Ridge National Laboratory, Oak Ridge, TN, 1983. 

The reaction mechanism for these products is not clearly understood, but the introduction of organo-metallic compounds (barium or iron salts in colloidal suspension) has been shown to have a beneficiai action on the combustion of diesel fuel in engines and reduce smoke. However, these products cause deposits to form because they are used in relatively large proportions (on the order 0.6 to 0.8 weight %) to be effective. 

The high-surface-area TUD-1 can serve as an anchor for many catalysts. Si- or Al-Si-TUD-1 (24,25) can be used as a support for various noble metals (Pt, PtPd, Ir, etc.). This will provide catalysts suitable for the hydrogenation of olefins and aromatics. In the refining industry, one use is the hydrogenation of polynuclear aromatics ( PNAs ) in diesel fuel, which can lower the fuel s toxic properties. Also, jet fuel has an aromatics constraint, designed to lessen smoke formation. Cracked stocks (e.g., coker or visbreaker liquids) generally have undesirable olefins (especially a-olefins) that also need to be saturated prior to final processing. 

On the other hand, biodiesel is a good additive to diesel fuel, reducing smoke, particulate matter (PM) and CO emissions. Engines using E-diesel with 10%... 

Source Detected in groundwater beneath a former coal gasification plant in Seattle, WA at a concentration of 180 g/L (ASTR, 1995). Acenaphthene is present in tobacco smoke, asphalt, combustion of aromatic fuels containing pyridine (quoted, Verschueren, 1983). Acenaphthene was detected in asphalt fumes at an average concentration of 18.65 ng/m (Wang et al., 2001). Present in diesel fuel and corresponding aqueous phase (distilled water) at concentrations of 100 to 600 mg/L and 4 to 14 g/L, respectively (Lee et al, 1992). 

Acetone was detected in diesel fuel at a concentration of 22,000 pg/g (Schauer et al., 1999). Identified as an oxidative degradation product in the headspace of a used engine oil (10-30W) after 4,080 miles (Levermore et al., 2001). Acetone also was detected in automobile exhaust at concentrations ranging from 0.09 to 4.50 mg/m (Grimaldi et al, 1996) and in cigarette smoke at concentrations ranging from 498 to 869 mg/m (Euler et al., 1996). 

Liss-Suter D, Villaume JE, Goldstein FJ. 1978. A literature review - problem definition studies on selected toxic chemicals. Volume 8 Environmental aspects of diesel fuels and fog oils SGF no. 1 and SGF no. 2 and smoke screens generated from them. Philadelphia, PA Franklin Institute Research Laboratories. Final report. Contract no. DAMD 17-77-C-7020. ADAO56021. 

Highly aromatic, low- API diesel fuel can also enhance black smoke production. This is due to the fact that more fuel mass is injected per volume of fuel than would be from higher-°API fuel. Also, there are a variety of mechanical factors which can influence black smoke production such as poorly functioning injectors and air intake system problems. 

I. Smoke and Odor During Diesel Fuel Combustion... 

Diesel fuel with a high T-50, for example >575°F (>302°C), will tend to bum with more smoke, soot, and hydrocarbon odor than fuel with a lower T-50. This is basically due to the incomplete combustion and oxidation of a great number of high-boiling-point, high-carbon-content fuel components in a limited-oxygen-content environment. 

The new specifications not only limit the concentration of sulfur to 0.05% but also specify that the fuel should have the combustion properties of a 10% or lower aromatics-containing fuel and have a minimum cetane number of 40. Fuels that have more than 10% aromatics are now able to meet these specifications through additives (22). However, as smoke emission standards become more restrictive, the aromatics content of diesel fuels may have to be lowered to a true value of 10% or less. A very thorough review of the consequences of this potential problem has recently been written by Stanislaus and Cooper, which covers in detail aromatic hydrocarbon hydroprocessing kinetics, thermodynamics, catalyst compositions, and mechanisms (109). There is little need to repeat the details of that report... 

Additives, Diesel Fuel—Chemicals for reducing smoke emissions and for cold weather conditioning. 

Methanol bums without a visible flame, which is a safety concern, but which also demonstrates that methanol does not produce soot or smoke when combusted. This fact makes methanol a very attractive diesel engine fuel because, unlike diesel fuel, no fuel particulates are formed. Recent health effects studies suggest that particulate matter is a health hazard regardless of whether known... 

CDDs are released into the air in emissions from municipal solid waste and industrial incinerators. Exhaust from vehicles powered with leaded and unleaded gasoline and diesel fuel also release CDDs to the air. Other sources of CDDs in air include emissions from oil- or coal-fired power plants, burning of chlorinated compounds such as PCBs, and cigarette smoke. CDDs formed during combustion processes are associated with small particles in the air, such as ash. The larger particles will be deposited close to the emission source, while very small particles may be... 

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