Petroleum products distillation ranges

Figure 1.1 illustrates the diversity of products derived from petroleum classified according to their distillation ranges and number of carbon atoms. From one crude to another, the proportions of the recovered fractions vary widely. A good illustration is the gasoline fraction (one of the most economically attractive) a crude from Qatar gives about 37 per cent by volume whereas a Boscan crude oil only yields 4.5%. 

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). 

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. 

Gas-to-liquids (GTL) is the chemical conversion of natural gas into petroleum products. Gas-to-liquid plants use Fischer-Tropsch technology, which first converts natural gas into a synthesis gas, which is then fed into the Fischer-Tropsch reactor in the presence of a catalyst, producing a paraffin wax that is hydro-cracked to products (see also Chapter 7). Distillate is the primary product, ranging from 50% to 70% of the total yield. 

Over the years, the refinery has produced a range of petroleum products including liquid petroleum gas, gasoline, chemicals, solvents, distillate fuels, gas oils, lubricating oils, greases, asphalt products, and bunker fuels. The primary products of the refinery are currendy gasoline, jet fuel, and diesel. Minor products include coke, sulfur, naphtha, and fuel oil. The refinery processes approximately 200,000 barrels... 

The impact of the release of liquid products on the environment can, in part, be predicted from knowledge of the properties of the released liquid. Each part of an ocular liquid product from petroleum has its own set of unique analytical characteristics (Speight, 1999, 2002). Since these are well documented, there is no need for repetition here. The decision is to include the properties of the lowest-boiling liquid product (naphtha) and a high-boiling liquid product (fuel oil). For the properties of each product (as determined by analysis) a reasonable estimate can be made of other liquid products, but the relationship may not be linear and is subject to the type of crude oil and the distillation range of the product. 

The data produced by the nucrocarbon test (ASTM D4530, IP 398) are equivalent to those by the Conradson carbon residue method (ASTM D-189 IP 13). However, this nucrocarbon test method offers better control of test conditions and requires a smaller sample. Up to 12 samples can be run simultaneously. This test method is applicable to petroleum and to petroleum products that partially decompose on distillation at atmospheric pressure and is applicable to a variety of samples that generate a range of yields (0.01% w/w to 30% w/w) of thermal coke. 

The basic method of distillation (ASTM D-86) is one of the oldest methods in use because the distillation characteristics of hydrocarbons have an important effect on safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of petroleum and derived products during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors. Several methods are available to define the distillation characteristics of petroleum and its various petroleum products. In addition to these physical methods, other test methods based on gas chromatography are also used to derive the boiling point distribution of a sample (ASTM D-2887, ASTM D-3710, ASTM D-5307, ASTM D-6352). 

Distillation, as a means of determining the boiling range (hence the volatility) of petroleum and petroleum products, has been in use since the beginning of the petroleum industry and is an important aspect of product specifications. 

One method (ASTM D-1160) is probably the best known and most widely used of the methods for distillation of higher-boiUng petroleum products and uses vacuum distillation. The method is applicable to samples that can be at least partially volatilized at temperature up to 400°C (752°F) and pressure in the range of 1-50 mmHg. The distillation temperature at vacuum is converted to atmospheric equivalent temperatures. 

Crude oil contains a wide range of hydrocarbons and other compounds containing sulfur, nitrogen, etc. In the refinery, petroleum is distilled into various fractions. Depending on the desired final products, these fractions are further processed and then blended to yield a wide variety of products. 

The most comrson use for these cycles is the separation of normal and isoparaffins in a variety of petroleum fractions. Distillation is not practical for these separations because the boiling ranges of the two products overlap. The feedstock most often contains several caibon numbers and can range from about C3 to CIS The adsorbent used is 5A molecular sieve, whose 0.5 nm pones ndmit normal paraffins and exclude isoparaffins. 

Cyclohexane is a petroleum product obtained by distilling C4- 400°F boiling range naphthas, followed by fractionation and superfractionation also formed by catalytic hydrogenation of benzene. It is used extensively as a solvent for lacquers and resins, as a paint and varnish remover, and in the manufacture of adipic acid, benzene, cyclohexanol, and cyclohexanone. 

Refers to any of a wide range of petroleum products produced by distillation, as distinct from bottoms, cracked stock, and natural gas liquids. In fuels, a term referring specifically to those products in the mid-boiling range, which include kerosene, turbo fuel, and heating oil-also called middle distillates and distillate fuels. In lubricating oils, a term applied to the various fractions separated under vacuum in a distillation tower for further processing (lube distillate). 

Kaplan et al. [124] report on techniques, including IRMS, used to identify the source of hydrocarbon products, including light (naphtha) and middle distillate (kerosene-diesel) products in the C3-C25 hydrocarbon range. The refined petroleum products analyzed included petrol, specialty solvents, kerosene, jet fuels, and diesel fuels. According to the authors, the technique described has successfully been used in environmental cases throughout the United States. 

Raoult s Law. When subsurface NAPL-phase contamination exists, it is rarely in the form of a single compound. Distilled petroleum products, for instance, contain a great number of constituent compounds with widely ranging properties. In order to help determine the composition of vapor from a multicompound NAPL-phase contaminant, Raoult s law is used, which may be written as follows ... 

Qiemical and Petrochemical Industries. Distillation is one of the fundamental unit operations of chemical engineering and is an integral part of many chemical manufacturing processes. Modern industrial chemistry in the twentieth century was based on the numerous products obtainable from petrochemicals, especially when thermal and catalytic cracking is applied. Industrial distillations are performed in lai e, vertical distillation towers that are a common sight at chemical and petrochemical plants and petroleum refineries. These range from about 2 to 36 feet in diameter and 20 to 200 feet or more in height Chemical reaction and separation can be combined in a process called reactive distillation, where the removal of a volatile product is used to shift the equilibrium toward completion. 

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