Diesel fuel naphthenes

The properties of straight run diesel fuels depend on both nature of the crude oil and selected distillation range. Thus the paraffinic crudes give cuts of satisfactory cetane number but poorer cold characteristics the opposite will be observed with naphthenic or aromatic crudes. The increasing demand for diesel fuel could lead the refiner to increase the distillation end point, but that will result in a deterioration of the cloud point. It is generally accepted that a weight gain in yield of 0.5% could increase the cloud point by 1°C. The compromise between quantity and quality is particularly difficult to reconcile. 

The level of injector fouling is most often illustrated in terms of residual flow (RF) expressed as a percentage of the flow under new conditions for a given needle lift. An RF on the order of 20% for a lift of 0.1 mm is a good compromise. This level may not be achieved with certain aromatic or naphthenic diesel fuels. The best recourse is then detergent additive addition. 

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. 

In the case of diesel fuel, an important property that defines the fuel quality is the cetane number (CN). Fuels with low-CN have poor ignition quality (i.e. knocking, noise, PM emissions) and make starting the engine difficult on cold days.6,7 It is well known that CN is lowest for PAHs and highest for w-paraffins.8,9 In normal paraffins, CN increases with the number of carbon atoms in the molecule. For naphthenic compounds and iso-paraffins the CN falls between those of aromatics and w-paraffins. In iso-paraffins, the CN decreases as the degree of branching increases.10... 

Diesel fuel is produced by distilling raw oil, which is extracted from bedrock. Diesel is a fossil fuel, consisting of hydrocarbons with between 9 and 27 carbon atoms in a chain, as well as a smaller amount of sulfur, nitrogen, oxygen and metal compounds. It is a general properly of hydrocarbons that the autoignition temperature is higher for more volatile hydrocaibons. The hydrocarbons present in the diesel fuels include alkanes, naphthenes, olefins and aromatics. 

Sulfur (total) compounds, mercaptans, naphthenic acids from diesel fuel natural clinoptilolite [258]... 

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. 

Motor fuels, solvents, toluene for explosives, etc. Illuminating oil, diesel fuel, gas adsorption oils. Heating fuels, diesel fuel, cracking stock, naphthenic acid which may be converted to lubricating oil additives, paint driers, fungicides, etc. 

Diesel fuel no. 1 is a straight-run middle distillate with a boiling range consistent with that of kerosene. It contains branched-chain alkanes (paraffins), cycloalkanes (naphthenes), aromatics, and mixed aromatic... 

The chemical composition of diesel fuel is extremely complex, with an enormous number of compounds normally present (Table 8.2). For this reason, it usually is not practical to analyze diesel fuel for individual compounds but it is often advantageous to define the compounds present as broad classifications of compound types, such as aromatics, paraffins, naphthenes and olefins. 

Kinetic modeling of diesel autothermal reforming is extremely complicated. Diesel fuel consists of a complex variable mixture of hundreds of hydrocarbon compounds containing paraffins, isoparaffins, naphthenes, aromatics, and olefins. To simplify the model, a steady-state power law rate expression for the diesel reforming over each type of catalyst used in this study was developed. A linearized least-squares method of data analysis was used to determine the power law parameters from a series of diesel ATR experiments. The power law rate model for diesel autothermal reaction may be written as ... 

Diesel fuel is a complex mixture of hydrocarbons which includes paraffins, naphthenes, and aromatics, and at low temperatures, phase separation can occur causing engine failure. The temperature, Tps, at which phase separation occurs is called the cloud point and is determined under standard conditions of cooling, e.g., l°C/min. Long chain polymer additives at as low as 0.1% can lower the cloud point, Tps, by several degrees. 

Naphthenic acids occur ia a wide boiling range of cmde oil fractions, with acid content increa sing with boiling point to a maximum ia the gas oil fraction (ca 325°C). Jet fuel, kerosene, and diesel fractions are the source of most commercial naphthenic acid. The acid number of the naphthenic acids decreases as heavier petroleum fractions are isolated, ranging from 255 mg KOH/g for acids recovered from kerosene and 170 from diesel, to 108 from heavy fuel oil (19). The amount of unsaturation as indicated by iodine number also increases in the high molecular weight acids recovered from heavier distillation cuts. 

Identifying the paraffin, olefin, naphthene, and aromatic content of fuel good for gasoline not as accurate for jet, diesel, and other mid-distillates... 

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