Alkanes from petroleum

NPE). Dehydrogenation of -alkanes from petroleum (C9H20) is the source of the linear nonene. They still have 13% of the production for the major household surfactant market. 

Most of the alkanes from petroleum are used to produce energy by combustion, but a few percent are converted to industrially useful compounds by controlled reaction with oxygen or chlorine. The alkanes are inert to attack by most chemical reagents and will react with oxygen and halogens only under the special conditions of radical initiated reactions. 

Jovancicevic B, Polic P, Vrvic M, Sheeder G, Teschner T, Wehner H (2003) Transformations of n-alkanes from petroleum pollutants in alluvial ground waters. Environ Chem Lett 1, 73-81. 

Isomerization (rearrangement) of hydrocarbons is of substantial practical importance. Straight-chain alkanes obtained from petroleum... 

The principal sources of feedstocks in the United States are the decant oils from petroleum refining operations. These are clarified heavy distillates from the catalytic cracking of gas oils. About 95% of U.S. feedstock use is decant oil. Another source of feedstock is ethylene process tars obtained as the heavy byproducts from the production of ethylene by steam cracking of alkanes, naphthas, and gas oils. There is a wide use of these feedstocks in European production. European and Asian operations also use significant quantities of coal tars, creosote oils, and anthracene oils, the distillates from the high temperature coking of coal. European feedstock sources are 50% decant oils and 50% ethylene tars and creosote oils. 

Paraffin waxes are also considered of mineral origin and are obtained from petroleum. The petroleum is distilled and the white colour of the wax is obtained by acid washing and purification. It has a typical melting point between about 47 °C and 64 °C. Its uses include candle making, casting and as a solidifier/stabilizer. The wax is composed of C20 C36 n-alkanes (40 90%), isoalkanes and cycloalkanes. 

DDT converts in part to p,p -DDE over time in the environment, especially in sediments [151, 171]. An example of the total aliphatic extract of a sediment from the Los Angeles Bight contaminated with p,p -DDE is shown in Fig. 11. The TIC trace shows a major UCM and the minor resolved peaks are normal alkanes (primarily from higher plant wax), with mature 17a(H),21/ (H)-hopanes (from petroleum residues as is the UCM). The mass spectrum ofp,p -DDE is shown in Fig. 12a, registering the molecular ion cluster at m/z 316-320. DDE is detected in the m/z 246 fragmentogram (Fig. lid), appearing as a small peak in the TIC trace and DDT is not detectable in this sample. 

The 0x0 process is used to convert the C4 fraction to C5 derivatives. Synthesis gas is catalytically reacted with 1-butene to give pentanal which can be hydrogenated to 1-pentanol ( -amyl alcohol), giving a route to C5 compounds in larger amounts than what would be available from C5 alkanes in petroleum. 

The transition from petroleum to light alkanes as direct chemical feedstocks is stiU in progress. 

Benzene, naphthalene, toluene, and the xylenes are naturally occurring compounds obtained from coal tar. Industrial synthetic methods, called catalytic reforming, utilize alkanes and cycloalkanes isolated from petroleum. Thus, cyclohexane is dehydrogenated (aromatization), and n-hexane(cycli> zation) and methylcyclopentane(isomerization) are converted to benzene. Aromatization is the reverse of catalytic hydrogenation and, in the laboratory, the same catalysts—Pt, Pd, and Ni—can be used. The stability of the aromatic ring favors dehydrogenation. 

The principal source of alkanes is petroleum and natural gas, which contain only the more volatile alkanes. Therefore, low molecular weight alkanes, e.g. methane and small amounts of ethane, propane and other higher alkanes can be obtained directly from natural gas. Another fossil fuel, coal, is a potential second source of alkanes. Usually alkanes are obtained through refinement or hydrogenation of petroleum and coal. 

The problem of availability of suitable paraffinic feedstocks of low cost, which represent a potentially wide range of molecular weight, will soon be rectified. Linear alkanes of high purity will be available from petroleum on a large scale, as is evident from recent announcements by both chemical and petroleum companies of plans to build normal paraffin extraction plants (2, J, 8). 

FRICDCL AND SHARKBY Alkanes from Coal, Petroleum, and Gas 33... 

There are very few data available on alkane isomers above C7 for comparison of petroleum or any other natural product. Some analyses, however, are available for the Cs isomers from alkanes from crude oils. Predicted results from the Fischer-Tropsch equation with / = 0.1 are given in Table II along with analyses of Cs alkanes from two crude oils (2, 4). A very definite exception to the predicted values appears in Table I, namely, the predominance of 2-methylheptane over 3-methylheptane. This observation is contrary to the prediction of the equation. According to scheme B (1) other Ck analyses from crudes made available to the author by M. J, O Neal show the same predominance cf the 2-methyl isomers. A total of four Ch analyses available for comparison represent crudes from western and southwestern United States. As mentioned in (8), 11 out of 14 analyses through the Ct s showed the reversal the three that did not have the predicted reversal also came from the Southwest. It would be of interest to have analyses of Cs s in crudes from other parts of the world in order to study this reversal. For Cn alkanes only partial analyses are available they are Ponca City, Okla. crude (4) and a commercial mixture... 

The data recently published by Ouchi and Imuta (15) on a chloroform extract of Yubari coal also indicates similarities to petroleum. Branching is greater at the low carbon numbers and drops off at higher carbon numbers as in crudes (II) and Fischer-Tropsch product (17). The other similarity to crude oil is noted in the odd-even alternation of normal alkanes from Cm to C25 with the odd carbon number alkanes predominating. 

First reported from petroleum in 1963 (268, 269), acyclic isoprenoid alkanes have now been identified in crude oils from three continents (270-273), and in one crude oil all 12 isoprenoid hydrocarbons from C14 to C25 as well as head-to-tail conformations, have been found... 

Gas fraction, boiling point up to 40°, contains normal and branched alkanes from Cj to C5. Natural gas is mainly methane and ethane. Bottled gas (liquefied petroleum gas) is mainly propane and butane. 

The economies of the highly industrialized nations of the world are based in large part on energy and chemicals produced from petroleum. Although the most important and versatile intermediates for conversion of petroleum to chemicals are compounds with double or triple bonds, it also is possible to prepare many valuable substances by substitution reactions of alkanes. In such substitutions, a hydrogen is removed from a carbon chain and another atom or group of atoms becomes attached in its place. 

Manganese(III) acetate is poorly reactive with saturated hydrocarbons.514 However, oxidation of adamantane by Mn(OAc)3 in trifluoroacetic acid gives relatively high yields of 1-adamantyl trifluoroacetate, showing a preferential attack at tertiary C—H bonds.515 Oxidation of n-alkanes by air in the presence of manganese catalysts constitutes the basis for an industrial process for the manufacture of synthetic fatty acids from n-alkanes of petroleum origin, which has been commercially developed in the Soviet Union.516... 

Alkanes are abundantly and cheaply available from petroleum oil and natural gas. Their utilization is, therefore, of great practical interest and the activation and functionalization of C-H bonds of alkanes is an important, promising route for future synthesis of functional materials. It is, however, difficult to achieve the functionalization of alkanes because they are unreactive, owing to the low reactivity of alkane C-H bonds. 

Ci6 and Up Alkanes with more than 16 carbon atoms are most often used as lubricating and heating oils. These are sometimes called mineral oils because they come from petroleum, which was once considered a mineral. 

Alkanes are derived mostly from petroleum and petroleum by-products. Petroleum, often called crude oil, is pumped from wells that reach into pockets containing the remains of prehistoric plants. The principal constituents of crude oil are alkanes, some aromatics, and some undesirable compounds containing sulfur and nitrogen. The composition of petroleum and the amounts of contaminants vary from one source to another, and a refinery must be carefully adjusted to process a particular type of crude oil. Because of their different qualities, different prices are paid for light Arabian crude, West Texas crude, and other classes of crude petroleum. 

Mixtures of alkanes obtained from petroleum, natural gas and coal can be used as fuel. 

Benzene can also be produced from petroleum hydrocarbons by aromatization. Alkanes can be dehydrogenated to produce benzene and its derivatives by heating them over catalysts. 

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