Petroleum boiling point

The allylic oxidation of the sesquiterpenoid (+)-valencene has been performed using f-BuOOH as the oxidant and BiCl3 as catalyst. Nootkatone was the major product, isolated in 35% yield by flash chromatography (ethyl acetate - light petroleum, boiling point 40-60 °C) (Scheme 17) [87, 88]. 

Finely ground seeds of Castilloa elastica (3550 g) are percolated with sufficient light petroleum (boiling point 60°-80°C) to ensure removal of all the fat. The mart is dried with a current of air and percolated with chloroform until no further color is obtained with alkaline m-dinitrobenzene. The percolate is evaporated under reduced pressure, the residue triturated with dry ether (750 ml) and filtered. The residue (69.75 g) is washed with dry ether, dried, and some of the washed residue (20 g) is dissolved in a benzene-chloroform mixture (50 ml), comprising one part benzene to two parts chloroform by volume, and is absorbed on to a column of alumina (7x32 cm), previously deactivated with 10% acetic acid [hereinafter referred to as Column (I)] and eluted with the same solvent mixture. 

Light petroleum, boiling point 40°C, can also be used. 

Sulfur in Petroleum Boiling Points, Freezing Points, Densities, and Refractive Indices of Some Sulfur Compounds. 

The procedure applies to stabilized, i.e., debutanized, crudes, but can be applied to any petroleum mixture with the exception of liquefied petroleum gas, very light naphtha, and those fractions having boiling points over 400°C. 

D 2887, applies to products and petroleum fractions whose final boiling points are equal to or below 538°C (1000°F), and have boiling points above 38°C (100°F). The results obtained are equivalent to those obtained from the TBP distillation, ASTM D 2892. 

D 3710, applies to products and petroleum fractions whose final boiling points are equal to or less than 260°C (500°F). 

To extend the applicability of the characterization factor to the complex mixtures of hydrocarbons found in petroleum fractions, it was necessary to introduce the concept of a mean average boiling point temperature to a petroleum cut. This is calculated from the distillation curves, either ASTM or TBP. The volume average boiling point (VABP) is derived from the cut point temperatures for 10, 20, 50, 80 or 90% for the sample in question. In the above formula, VABP replaces the boiling point for the pure component. 

As the boiling points increase, the cuts become more and more complex and the analytical means must be adapted to the degree of complexity. Tables 3.4 and 3.5 describe the most widely used petroleum product separation scheme and the analyses that are most generally applied. 

One has seen that the number of individual components in a hydrocarbon cut increases rapidly with its boiling point. It is thereby out of the question to resolve such a cut to its individual components instead of the analysis by family given by mass spectrometry, one may prefer a distribution by type of carbon. This can be done by infrared absorption spectrometry which also has other applications in the petroleum industry. Another distribution is possible which describes a cut in tei ns of a set of structural patterns using nuclear magnetic resonance of hydrogen (or carbon) this can thus describe the average molecule in the fraction under study. 

The current calculation methods are based on the hypothesis that each mixture whose properties are sought can be characterized by a set of pure components and petroleum fractions of a narrow boiling point range and by a composition expressed in mass fractions. 

We will use the term petroleum fraction to designate a mixture of hydrocarbons whose boiling points fall within a narrow temperature range, typically as follows ... 

It is common that a mixture of hydrocarbons whose boiling points are far enough apart petroleum cut) is characterized by a distillation curve and an average standard specific gravity. It is then necessary to calculate the standard specific gravity of each fraction composing the cut by using the relation below [4.8] ... 

The molecular weight can be also estimated for petroleum fractions whose boiling point is not known precisely starting with a relation using the viscosities at 100 and 210°F ... 

This factor is the intermediate parameter employed in numerous calculational methods. For petroleum cuts obtained by distillation from the same crude oil, the Watson factor is generally constant when the boiling points are above 200°C. 

As seen in Chapter 2, mixtures of hydrocarbons and petroleum fractions are analyzed in the laboratory using precise standards published by ASTM (American Society for Testing and Materials) and incorporated for the most part into international (ISO), European (EN) and national (NF) collections. We wiil recall below the methods utilizing a classification by boiling point ... 

Maxwell and Bonnel (1955) proposed a method to calculate the vapor pressure of pure hydrocarbons or petroleum fractions whose normal boiling point and specific gravity are known. It is iterative if the boiling point is greater than 366.5 K ... 

Petroleum solvents are relatively light petroleum cuts, in the C4 to C14 range, and have numerous applications in industry and agriculture. Their use is often related to their tendency to evaporate consequently, they are classified as a function of their boiling points. 

Naphthas constitute a special category of petroleum solvents whose boiling points correspond to the class of white-spirits (see paragraph 6.1). 

Crude petroleum is fractionated into around fifty cuts having a very narrow distillation intervals which allows them to be considered as ficticious pure hydrocarbons whose boiling points are equal to the arithmetic average of the initial and final boiling points, = (T, + Ty)/2, the other physical characteristics being average properties measured for each cut. 

The most important source of helium is the natural gas from certain petroleum wells in the United States and Canada. This gas may contain as much as 8 % of helium. Because helium has a lower boiling point Table 12.1) than any other gas, it is readily obtained by cooling natural gas to a temperature at which all the other gases are liquid (77 K) almost pure helium can then be pumped off. The yearly production in this way may be many millions of m of gas. but something like 10 m per year is still wasted. 

If the substance is found to be far too soluble in one solvent and much too insoluble in another solvent to allow of satisfactory recrystallisation, mixed solvents or solvent pairs may frequently be used with excellent results. The two solvents must, of course, be completely miscible. Recrystallisation from mixed solvents is carried out near the boiling point of the solvent. The compound is dissolved in the solvent in which it is very soluble, and the hot solvent, in which the substance is only sparingly soluble, is added cautiously until a slight turbidity is produced. The turbidity is then just cleared by the addition of a small quantity of the first solvent and the mixture is allowed to cool to room temperature crystals will separate. Pairs of liquids which may be used include alcohol and water alcohol and benzene benzene and petroleum ether acetone and petroleum ether glacial acetic acid and water. 

Selection of solvents. The choice of solvent will naturally depend in the first place upon the solubility relations of the substance. If this is already in solution, for example, as an extract, it is usually evaporated to dryness under reduced pressure and then dissolved in a suitable medium the solution must be dilute since crystallisation in the column must be avoided. The solvents generally employed possess boiling points between 40° and 85°. The most widely used medium is light petroleum (b.p. not above 80°) others are cycZohexane, carbon disulphide, benzene, chloroform, carbon tetrachloride, methylene chloride, ethyl acetate, ethyl alcohol, acetone, ether and acetic acid. 

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. 

Vacuum Distillation. Vacuum distUlation evolved as the need arose to separate the less volatile products, such as lubricating oUs, from petroleum without subjecting these higher boiling materials to cracking conditions. The boiling point of the heaviest cut obtainable at atmospheric pressure (101.3 kPa = 760 mm Hg) is limited by the temperature (ca 350°C) at which the residue starts to decompose or crack. It is at this point that distUlation in a vacuum pipe stUl is initiated. 

Methylphenol. y -Cresol is produced synthetically from toluene. Toluene is chlorinated and the resulting chlorotoluene is hydrolyzed to a mixture of methylphenols. Purification by distillation gives a mixture of 3-methylphenol and 4-methylphenol since they have nearly identical boiling points. Reaction of this mixture with isobutylene under acid catalysis forms 2,6-di-/ f2 -butyl-4-methylphenol and 2,4-di-/ f2 -butyl-5-methylphenol, which can then be separated by fractional distillation and debutylated to give the corresponding 3- and 4-methylphenols. A mixture of 3- and 4-methylphenols is also derived from petroleum cmde and coal tars. 

In the fire codes, the atmospheric boiling point is an important physical property used to classify the degree of hazardousness of a Hquid. If a mixture of Hquids is heated, it starts to bod at some temperature but continues to rise ia temperature over a boiling temperature range. Because the mixture does not have a definite boiling poiat, the NFPA fire codes define a comparable value of boiling poiat for the purposes of classifying Hquids. For petroleum mixture, it is based on the 10% poiat of a distillation performed ia accordance with ASTM D86, Standard Method of Test for Distillation of Petroleum Products. 

The second category differs from those discussed above in that it relates, in the main, to those situations for which no data or only characterizing data exist. In such cases, this small set of characterizing data or, in its absence, stmcture data are used to estimate a set of parameters of the type requited by point generation routines. One notable specific example of this type of facihty is the creation of data sets for petroleum boiling fractions from information on average boiling point and density. 

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