In diesel fuel

These developments will reduce the total emissions of SO2 but the effect will remain limited. The reduction in sulfur levels in diesel fuel from 0.2 to 0.05% Is admitted to reduce yearly emissions of SO2 in France to only 10 to 12%. 

Influence of the sulfur content in diesel fuel on particulate emissions as a, function of the catalytic converter inlet temperature. 

Finally it is likely that attention will be focused on emissions of polynuclear aromatics (PNA) in diesel fuels. Currently the analytical techniques for these materials in exhaust systems are not very accurate and will need appreciable improvement. In conventional diesel fuels, emissions of PNA thought to be carcinogenic do not exceed however, a few micrograms per km, that is a car will have to be driven for several years and cover at least 100,000 km to emit one gram of benzopyrene for example These already very low levels can be divided by four if deeply hydrotreated diesel fuels are used. 

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. 

Methanol is more soluble in aromatic than paraffinic hydrocarbons. Thus varying gasoline compositions can affect fuel blends. At room temperature, the solubiUty of methanol in gasoline is very limited in the presence of water. Generally, cosolvents are added to methanol—gasoline blends to enhance water tolerance. Methanol is practically insoluble in diesel fuel. 

Sulfur. Sulfur in diesel fuel should be kept below set limits for both environmental and operational reasons. Operationally, high levels of sulfur can lead to high levels of corrosion and engine wear owing to emissions of SO that can react with condensed water during start-up to form sulfuric acids. From an environmental perspective, sulfur bums to SO2 and SO, the exact spHt being a function of temperature and time in the combustion chamber. 

Corrosion Inhibitors. The corrosion inhibitors used in diesel fuel ate generally similar to those used in gasoline and, like the latter, produce an effect primarily by surface action. If amine additives ate used for detergency, these may provide some corrosion protection as well. 

Detergent Additives. Diesel engine deposits ate most troublesome in the fuel dehvery system, ie, the fuel pump and both fuel side and combustion side of the injectors. Small clearances and high pressures mean that even small amounts of deposits have the potential to cause maldistribution and poor atomization in the combustion chamber. The same types of additives used in gasoline ate used in diesel fuel. Low molecular weight amines can also provide some corrosion inhibition as well as some color stabilization. Whereas detergents have been shown to be effective in certain tests, the benefit in widespread use is not fully agreed upon (77). 

European countries, including the UK, and covers about 5% of the total European diesel market. It contains less than 5 vol%. of mono-ring aromatics and less than 0.1 vol%. of di- and higher-ring aromatics. Eurthermore it is low in sulfur. Both EC and SEC methods have been developed for the rapid analysis of aromatics in diesel fuel. 

Different approaches utilizing multidimensional EC or SEC systems have been reported for the analysis of middle distillates in diesel fuel. A method, based on the EC separation of paraffins and naphthenes by means of a micro-particulate, organic gel column has been described (23, 24). The complete system contained up to four different EC columns, a number of column-switching valves and a dielectric constant detector. However, the EC column for the separation of paraffins and naphthenes, which is an essential part of the system, is no longer commercially available. 

Figure 14.16 Typical cliromatograms of LC (a) and SFC (b) analysis of aromatics in diesel fuel. Peak identification is as follows 1, total saturates 2, total aromatics 3, mono-aromatics 4, higher-ring aromatics.

Trucks line North Capitol Street in Washington, D.C., as they convoy toward the U.S. Capitol on February 22, 2000. Hundreds of trucks entered the district to protest a steep rise in diesel fuel prices. (Corbis Corporation)... 

The demand for environment-friendly fuels requires the removal of organosulfur compounds present in crade-oil fractions. SO2 or SO3 contribute to the formation of acid rain and have an effect on pollution control devices [9]. Very stringent environmental regulations will limit the sulfur levels in diesel fuels in EU to less than 10 ppm by the end of 2010 [10]. The conventional sulfur-compound... 

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. 

Henricsson, S. and Westerholm, R., Liquid chromatographic method for analysing the colour marker Solvent Yellow 124, N-ethyl-N-[2-(l-isobutoxy-ethoxy)ethyl](4-phenylazophenyl)amine, in diesel fuels, ]. Chromatogr. A, 723, 395, 1996. 

Santana, R.C. et alv Evaluation of different reaction strategies for the improvement of cetane number in diesel fuels, Fuel, 85,643,2006. 

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... 

Aromatic compounds, 13 108-109 13 680. See also Aromatics acylation of, 12 173-181 amination of, 12 184 arylation of, 12 170-171 Cycloalkylation of, 12 169 in diesel fuel, 12 425 formylation of, 12 178 Friedel-Crafts acylation of, 12 174 Friedel-Crafts alkylation of, 12 164 nitration of, 12 182-183 oxidative coupling of, 19 654 sulfonation of, 12 181 sulfonation reagents for, 23 521-524 Aromatic-containing polymers, sulfonation of, 23 535-536... 

Carbon residue, in diesel fuel, 22 424 Carbon selenides, 22 87 Carbon sources, for fermentation, 22 25 Carbon steels, 23 291-297 cold working, 23 295-296 heat treatment of, 23 296 hot working, 23 294-295 microstructure and grain size of, 23 293-294 properties of, 23 292—293 residual elements in, 23 296-297 wrought, 23 296... 

Defoamers, 3 236-254 9 23 applications, 3 245-249 commercial sources, 3 240, 241t components, 3 237-240 defoaming theory, 3 241-245 economic aspects, 3 249-250 health and safety factors, 3 251-252 in paper manufacture, 13 118 in polymer colloids, 20 386 silica in, 22 376 surface tension, 8 244t test methods, 3 250-251 Defoaming, 3 240-242 Defoaming (antifoaming) agents, 25 in diesel fuel, 12 428 in food, 12 63-64... 

E. Resasco, Fuel, 85, 643 (2006). Evaluation of Different Reaction Strategies for the Improvement of Cetane Number in Diesel Fuels. 

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