Fractions of petroleum

Vaseline A trade name for soft paraffin. Yellow and white semi-solid, partly translucent mixtures of hydrocarbons of the paraffin series ranging from CijHji to C2oH42- Obtained from the high-boiling fractions of petroleum... 

The feedstocks used ia the production of petroleum resias are obtaiaed mainly from the low pressure vapor-phase cracking (steam cracking) and subsequent fractionation of petroleum distillates ranging from light naphthas to gas oil fractions, which typically boil ia the 20—450°C range (16). Obtaiaed from this process are feedstreams composed of atiphatic, aromatic, and cycloatiphatic olefins and diolefins, which are subsequently polymerized to yield resias of various compositioas and physical properties. Typically, feedstocks are divided iato atiphatic, cycloatiphatic, and aromatic streams. Table 2 illustrates the predominant olefinic hydrocarbons obtained from steam cracking processes for petroleum resia synthesis (18). 

The gasoline automobile is developed by German engineer Karl Friedrich Benz. Before this, gasoline was an unwanted fraction of petroleum that caused many house fires because of its tendency to explode when placed in kerosene lamps. 

Methylbenzenes occur in small quantities in naphtha and higher boiling fractions of petroleum. Those presently of commercial importance are toluene, o-xylene, p-xylene, and to a much lesser extent m-xylene. 

Petroleum, a complex mixture of many different hydrocarbons, is the main source of alkanes. Petroleum can be processed into various fractions by boiling a mixture in huge distilling towers. Each fraction contains alkanes with a relatively narrow range of molar masses. Table lists these major fractions of petroleum and some of their uses. As the table shows, these compounds are the principal sources of energy in our society. 

Table 9-1 Major Fractions of Petroleum and Their Uses...

Useful Surfactants from Polar Fractions of Petroleum and Shale Oil... 

Result The recovery of different fractions of petroleum distillate under atmospheric pressure was more than under reduced pressure because at lower pressure the vapour pressure of lighter molecule of crude oil increased so that they were siphoned out from the system without being condensed. Whereas a combination of distillation of lighter fraction under normal atmospheric pressure followed by the distillation of heavier contents under reduced pressure showed an improvement in the recovery of petroleum products. Recovery of distillates was still more when crude oil was first sonicated and then distilled under normal and reduced pressures. The viscosity of distillate increased with sonication whereas there was a decrease in value of density. 

VRDS Isomax [Vacuum residua desulphurization] A hydrodesulfurization process adapted for processing the residues from the vacuum distillation of the least volatile fraction of petroleum. An extension of the RDS Isomax process, developed and piloted by Chevron Research Company in the early 1970s. In 1988, one unit was under construction and one was being engineered. 

There are numerous refining methods employed to extract the fractions of petroleum liquids and gases. A particular refinery process design is normally dependent on the raw feedstock characteristics (e.g., crude oil and produced gas natural specifications) and the market demands (e.g., aviation or automotive gasolines), which it intends to meet. 

Instead of 2-methylbutane, a low-boiling fraction of petroleum ether (bp 30-37°C), but not pure pentane, can be used (cf. Note 2). 

Distillation is a common method for the fractionation of petroleum that is used in the laboratory as well as in refineries. The technique of distillation has been practiced for many centuries, and the stills that have been employed have taken many forms (Speight, 1999). Distillation is the first and the most fundamental step in the refining process (after the crude oil has been cleaned and any remnants of brine removed) (Bland and Davidson, 1967 Speight, 1999, and references cited therein Speight and Ozum, 2002, and references cited therein), which is often referred to as the primary refining process. Distillation involves the separation of the various hydrocarbon compounds that occur naturally in a crude oil into a number of different fractions (a fraction is often referred to as a cut). 

Fractionation of petroleum by volatility, informative as it might be, does not give any indication of the physical nature of petroleum. This is more often achieved by subdivision of the petroleum into bulk fractions that are separated by a variety of solvent and adsorption methods. 

Many of the gaseous and liquid constituents of the lower-boiling fractions of petroleum and also those in petroleum products fall into the class of chemicals that have one or more of the following characteristics, considered to be hazardous by the EPA. 

Atmospheric equivaient boiiing point (AEBP) a mathematical method of estimating the boiling point at atmospheric pressure of nonvolatile fractions of petroleum. 

Cut point the boiling-temperature division between distillation fractions of petroleum. 

Deasphaltened oil the fraction of petroleum after the asphaltenes have been removed. 

Fractionating column a column arranged to separate various fractions of petroleum by a single distillation which may be tapped at different points along its length to separate various fractions in the order of their boiling points. 

Kerosene (kerosine) a fraction of petroleum that was initially sought as an illuminant in lamps a precursor to diesel fuel with a distillation range that generally falls within the limits of 150 and 300°C main uses are as a jet engine fuel, an illuminant, for heating purposes, and as a fuel for certain types of internal combustion engines. 

Maltenes that fraction of petroleum that is soluble in, for example, pentane or heptane deasphaltened oil q.v.y, also the term arbitrarily assigned to the pentane-soluble portion of petroleum that is relatively high boiling (>300°C, 760 mm) see also Petrolenes. 

Naphtha a generic term applied to refined, partly refined, or unrefined petroleum products and liquid products of natural gas, the majority of which distills below 240° C (464°F) the volatile fraction of petroleum which is used as a solvent or as a precursor to gasoline. 

The density of crude oil is on the order of 0.85 g/cm, so if the sea surface is calm, an oil spill will initially form a slick. The slick is subject to physical processes, such as advection and turbulence, causing it to move vertically and/or horizontally. Advection tends to lead to dispersal or, if land is nearby, shoreline stranding. Turbulence promotes the formation of emulsions, called chocolate mousse, which can be transformed via weathering into tarballs. The lower-molecular-weight compounds tend to evaporate or dissolve. Some fractions of petroleum have solubilities in seawater on the order of tens of milligrams per liter. Some are also photochemically oxidized. 

Gasoline The fraction of petroleum that has a boiling point less than 180°C. Most of the compounds are low-molecular-weight, straight-chain hydrocarbons. 

Vegetable oils have the potential to substitute a fraction of petroleum distillates and petroleum-based petrochemicals in the near future. Vegetable oil fuels are not petroleum-competitive fuels because they are more expensive than petroleum fuels. However, with recent increases in petroleum prices and uncertainties concerning petroleum availability, there is renewed interest in using vegetable oils, called biodiesel, in diesel engines. 

Source Constituent in paraffin fraction of petroleum. Dodecane may be present in stormwater runoff from asphalted roadways and general use of petroleum oils and tars (quoted, Verschueren). 

Fuel oil is any liquid petroleum product that is burned in a furnace for the generation of heat, or used in an engine for the generation of power, except oils having a flash point below 100°F and oil burned in cotton or wool burners. The oil may be a distillated fraction of petroleum, a residuum from refinery operations, a crude petroleum, or a blend of two or more of these. 

The distillate manufacturing processes of diesel fuel oils, such as fuel oil 1-D and fuel oil 2-D, are similar to those of fuel oil no. 1 and fuel oil no. 2, respectively (lARC 1989). Fuel oil no. 1-D is manufactured from a straight-run distillate process. Diesel fuel oil (1-D, 2-D) is defined as the fraction of petroleum that distills after kerosene (Air Force 1989). Fuel oil no. 2-D is also made from mixing of straight-run and catalytically cracked distillates (LARC 1989). 

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