Concentration in diesel fuel

The nature of these paraffins and their concentration in diesel fuel affect the three temperatures that characterize the cold behavior. The cloud point is the temperature at which crystals of paraffins appear when the temperature is lowered. The cold filter pluming point is defined as the temperature under which a suspension no ionger flows through a standard filter. Finally, the pour point is the temperature below which the diesel fuel no longer flows by simple gravity in a standard tube. These three temperatures are defined by regulations and the refiner has three types of additives to improve the quality of the diesel fuel of winter. 

Sulphur dioxide originates essentially from the combustion of gas oil and coal. Sources are, therefore, thermal power stations generating electricity, central or individual heating plants and industrial plants. Transport (cars, industrial vehicles) is not a significant source of sulphur dioxide, especially since in Europe the sulphur concentration in diesel fuel has been decreased from 0.20 to 0.05%. 

One of the major challenges in the petroleum industry today is the removal of sulfur compounds, especially refractive ones such as 4,6-dimethyldibenzo-thiophene (DMDBT), from petroleum fractions such as diesel to concentrations <5-10 ppm from the current values of 50-500 ppm. The current technology is hydrodesulfurization catalyzed by cobalt-nickel-molybdenum sulfides at high pressures. Reducing sulfur concentratios in diesel fuels below 5-10 ppm... 

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). 

Source Concentrations in 8 diesel fuels ranged from 0.026 to 40 mg/L with a mean value of 6.275 mg/L (Westerholm and Li, 1994). Lee et al. (1992) reported concentration ranges of 100-300 mg/L and 0.04-2 pg/L in diesel fuel and corresponding aqueous phase (distilled water), respectively. Schauer et al. (1999) reported anthracene in diesel fuel at a concentration of 5 pg/g and in a diesel-powered medium-duty truck exhaust at an emission rate of 12.5 pg/km. Anthracene was detected in a distilled water-soluble fraction of used motor oil at concentrations ranging from 1.1 to 1.3 pg/L (Chen et al., 1994). 

Schauer et al. (1999) reported dibenzofuran in diesel fuel at a concentration of 29 pg/g and in a diesel-powered medium-duty truck exhaust at an emission rate of 28.7 pg/km. 

Source Fluorene was detected in groundwater beneath a former coal gasification plant in Seattle, WA at a concentration of 140 pg/L (ASTR, 1995). Present in diesel fuel and corresponding... 

The paraffins in diesel fuel can vary in molecular weight, concentration, and crystallization temperature. For this reason, fuels with similar physical properties may behave differently at low temperatures. This difference in behavior can be related to the low-temperature properties of the fuel paraffins present. 

These results show that, in equimolar concentrations, naphthalene would not be considered as a strong inhibitor toward direct sulfur extraction (A Do) for PASCs. However, as discussed earlier, the content of di- and trinuclear aromatics in diesel fuels and gas oils can be as high as 20-30%, whereas the level of sulfur compounds in today s diesel fuels is only 0.2% sulfur, or about 1 wt% PASCs. So the competition for the active site by aromatic hydrocarbons is very strong. Their effect on the direct desulfurization route will lower the rate to about one-third of the noninhibited rate in the case of dibenzothiophene and would lower that of 4,6-DMDBT even more. 

The minimum fuel/air ratio for ignition is analogous to the lower limit of flammability. It is important in Diesel fuel combustion because partial oxidation will occur in local regions in which the concentration of fuel is less than the minimum or lower limit, but these regions will not ignite or inflame. Consequently, products of partial oxidation giving rise to odor, and possibly deposits, will appear in the exhaust. This is discussed in a subsequent section. 

This is approximately equivalent to 39.2 pg/mL x 100 = 3920 pg/mL of total diesel fuel in the sample extract. Therefore, the concentration of diesel fuel in the sample is ... 

In a fuel additive use for 2-ethylhexanol, the alcohol is reacted with nitric acid and the nitrate produced added in low concentrations to diesel fuel to improve ignition quality. Use of such a "cetane improver" allows the refiner greater flexibility in blending distillate into fuel such as aromatics, branched paraffins, and naphthenes. The "cetane improver" also helps meet sudden local increases in demand for diesel fuels by allowing refiners to upgrade stored heating oil to diesel fuel quality quickly and economically. 

The principle of the isotope dilution analysis (IDA) is described in Section 6.4. Due to its advantages as a definitive and accurate analytical method for the determination of element concentration via isotope ratio measurements, IDA is being increasingly applied in mass spectrometry, especially in ICP-MS and LA-ICP-MS as one of the most frequently used techniques. For example, the isotope dilution technique is employed in species analysis in biological systems, " e.g., for the determination of mercury species in tuna material,or in aquatic systems. Further applications of the isotope dilution technique are the determination of selenomethionine in human blood serum by capillary HPLC-ICP (ORC) MS ° or sulfur speciation in gas oil, diesel or heating fuel by LA-ICP-MS. Evans and co-workers have reported on the high accuracy analysis of sulfur in diesel fuel by IDA. ICP-SFMS has been employed for Si species analysis in biological or clinical samples and... 

Diesel Fuel Measurement - ASTM D3524 The ASTM D3524 gas chromatography test determines the concentration of diesel fuel in motor oils. 

Metal deactivators prevent the catalytic influence of the metals on reactions that can lead to its instability in diesel fuel. They are typically used in concentrations of up to 15 ppm. 

Dispersants disperse the formed insoluble products in diesel fuel, preventing them from clustering into aggregates large enough to plug fuel filters or injectors. Dispersants are typically used in concentrations of up to 100 ppm. 

It was shown that in the presence of oil-soluble surfactants, stable foams are formed at a certain water content in diesel fuel, and maximum stability is achieved at a relatively low aqueous phase concentration (1% - 2%) corresponding to the transition of the solubilised solution to an inverted emulsion [265] with increasing viscosity of the surfactant solutions in the diesel fuel, the foam stability increases substantially. These ideas can be used when considering foam formation in other petroleum products containing small amounts of water and natural surfactants. 

Jet and diesel fuel samples were spiked with known concentrations of manganese, copper, and iron and stored in dark bottles (20 jug/L spike). The element content was checked over a period of 25 days using calibration solutions prepared daily. The results obtained for manganese are reported in Fig. 11. While manganese content in diesel fuel samples remains constant during the timefi ame investigated, the element content in jet fuels drops dramatically after about two... 

In diesel fuels, sulfur compounds can be present as mercaptans, sulfides, disulfides, and heterocyclic compounds, such as thiophenes. Their combustion by-products can cause wear in diesel engines and increase the amount of deposits in the combustion chamber and on the pistons. Some typical sulfur concentrations reported in diesel fuels are given in Table 2. 

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