Paraffins sulfur derivatives

Black oil should be a pure petroleum product free from fatty oils, fatty acids, resins, soaps, or other nonhydrocarbons. Sediment and sludge, insoluble in paraffin naphtha, should not exceed 12% when determined by the methods of the American Association of State Highway Officials. The product should be a distilled or fractionated oil, and should contain no oil-well water or residue therefrom. The product should be free of or contain no more than traces of naphthenic acids, naphthenes, mercaptans, soluble sulfide, and volatile sulfur derivatives. The oil should flow freely from the tank car at temperatures above 32 F. 

Ci uuc oil—complex, naturally occurring fluid mixture of petroleum hydrocarbons, yellow to black in color, and also containing small amounts of oxygen, nitrogen, and sulfur derivatives and other impurities. Crude oil was formed by the action of bacteria, heat, and pressure on ancient plant and animal remains, and is usually found in layers of porous rock such as limestone or sandstone, capped by an impervious layer of shale or clay that traps the oil (see reservoir). Crude oil varies in appearance and hydrocarbon composition depending on the locality where it occurs, some crudes being predominately naphthenic, some paraffinic, and others asphaltic. Crude is refined to yield petroleum products. See distillation, hydrocarbon, sour crude, sweet crude, asphalt, naphthene, paraffin. 

Table 8 shows that the naphthas produced by the EDS process have higher concentrations of cycloparaffins and phenols than do petroleum-derived naphthas, whereas the normal paraffins are present in much lower concentrations. The sulfur and nitrogen concentrations in coal naphthas are high compared to those in petroleum naphthas. 

The term naphthenic acid, as commonly used in the petroleum industry, refers collectively to all of the carboxyUc acids present in cmde oil. Naphthenic acids [1338-24-5] are classified as monobasic carboxyUc acids of the general formula RCOOH, where R represents the naphthene moiety consisting of cyclopentane and cyclohexane derivatives. Naphthenic acids are composed predorninandy of aLkyl-substituted cycloaUphatic carboxyUc acids, with smaller amounts of acycHc aUphatic (paraffinic or fatty) acids. Aromatic, olefinic, hydroxy, and dibasic acids are considered to be minor components. Commercial naphthenic acids also contain varying amounts of unsaponifiable hydrocarbons, phenoHc compounds, sulfur compounds, and water. The complex mixture of acids is derived from straight-mn distillates of petroleum, mosdy from kerosene and diesel fractions (see Petroleum). 

Impurities can sometimes be removed by conversion to derivatives under conditions where the major component does not react or reacts much more slowly. For example, normal (straight-chain) paraffins can be freed from unsaturated and branched-chain components by taking advantage of the greater reactivity of the latter with chlorosulfonic acid or bromine. Similarly, the preferential nitration of aromatic hydrocarbons can be used to remove e.g. benzene or toluene from cyclohexane by shaking for several hours with a mixture of concentrated nitric acid (25%), sulfuric acid (58%), and water (17%). 

The kinetics of hydrocracking reactions has been studied with real feedstocks and apparent kinetic equations have been proposed. First-order kinetics with activation energy close to 50 kcal/gmol was derived for VGO. The reactions declines as metal removal > olefin saturation > sulfur removal > nitrogen removal > saturation of rings > cracking of naphthenes > cracking of paraffins [102],... 

Manufacture of these explosives received great impetus in Germany and France during World War I, probably on account of the lack of nitrogen compounds. Composition The chief constituent, 60-80 per cent, is a chlorate or perchlorate of ammonium, sodium, or potassium. The other ingredients are combustible products such as charcoal, sulfur, aluminum powder, or mixtures of vegetahle meals uitro derivatives of benzene, toluene, naphthalene, phenol and as de-sensitizers solid hydrocarbons (paraffin) and castor oil may he added. The addition of the nitro compounds serves to improve the propagation. 

Derivation Finely ground cinchona bark mixed with lime is extracted with hot, high-boiling paraffin oil. The solution is filtered, shaken with dilute sulfuric acid, and the latter neutralized while still hot with sodium carbonate on cooling, quinine sulfate crystallizes out. The sulfate is then treated with ammonia, the alkaloid being obtained. 

Derivation Benzene is alkylated with dodecene, to which it attaches itself in any secondary position the resulting dodecylbenzene is sulfonated with sulfuric acid and neutralized with caustic soda. For ABS (branched-chain alkyl) the dodecene is usually a propylene tetramer, made by catalytic polymerization of propylene. For LAS (straight-chain alkyl), the dodecene may be removed from kerosene or crudes by molecular sieve, may be formed by Ziegler polymerization of ethylene, or by cracking wax paraffins to a-olefins. 

The sulfur content of petroleum containing these compounds is usually quite low but it can be as high as 6% of the total. The more stable oxygen derivatives of hydrocarbons, such as the paraffinic acids, ketones, and phenols (Eq. 18.7), also occur in crude oils. 

The early investigators, by repeated fractional distillation, were able to determine that crude petroleum consisted principally of hydrocarbons. Ultimate analyses had shown that relatively small proportions of sulfur, nitrogen, and oxygen were usually present, probably in the form of derivatives. They were able to identify a number of hydrocarbon types such as paraffins, cycloparaffins, and aromatics, and even to isolate some members of these series in a qualitative way. The state of the art was very well summed up by Hoefer (1888) (65) when he wrote in his book Das Erdol as follows It should be pointed out that up to the present no complete quantitative analysis has been carried out on any crude petroleum, that we must be content rather to discover which are the principal types of hydrocarbons present, which predominate and, qualitatively, to identify the individual members of such series. ... 

For the removal of aromatics in particular and to some extent also for the removal of sulfur and nitrogen heterocycles, further treatments are dependent on the nature of the crude from which the raw distillates are derived. A major difference is in the treatment required to reduce the aromatics. Aromatics can be removed from raw distillates which contain a sufficient proportion of paraffinic chains by a solvent extraction process, whereas distillates with a high proportion of naphthenic rings and too low a content of paraffinic chains do not respond to selective extraction by a solvent. 

Instead of the use of sulfuryl chloride, SO2 and CI2, which combine to give sulfuryl chloride, can be employed for vapor-phase reactions. When the ratio of SO2 to CI2 is adjusted, it is feasible to produce sulfonic or chlorosulfonic acid derivatives of saturated paraffins in liquid-phase reactions. According to Lockwood and Richmond, a premixed stream of sulfur dioxide and chlorine can be used for the countercurrent photochlorination of white oil (petroleum fraction, sp gr, 0.8033 bp, 283-324 C) at about 50°C. The product, after hydrolysis with 30 per cent sodium hydroxide, yields an aqueous solution of the sodium salt of a sulfonic or chlorosulfonic acid. An increase in the ratio of SO2 to CI2 greatly increases the yield of solubilized product. When a 3 1 ratio is used, the product contains very little chlorine and has good wetting and detergent characteristics. ... 

The product from the reformer will be blended with the products from the alkylation units to make gasoline. These alkylation units are the units that process the gas fraction of the crude oil. These units use a catalyst to combine olefins, paraffins, or aromatics to form a high-octane product to blend into gasoline. There are two types of alkylation units that derive their name from the catalyst used sulfuric acid and hydrofluoric acid. 

BTL diesel is a renewable fuel of excellent quality, compared to both fossil-derived diesel and first-generation biodiesel produced via the transesterification of vegetable oils. BTL synthetic fuel consists mainly of linear paraffinic hydrocarbons with almost zero aromatics and sulfur compounds. The physical properties of BTL diesel presented in Table 18.6 (Rantanen et al., 2005) demonstrate its very high cetane number that can reach up to 75, much higher than conventional diesel. The big advantage of BTL diesel is that it is directly usable today in the transportation sector and furthermore it may be suitable for future fuel cell vehicles via on-board reforming since it is free of sulfur. 

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