Individual Hydrocarbon Composition Research Articles

Carbon isotope variations in n-alkanes and isoprenoids of whole oils

Carbon isotope analysis of oils and source rock bitumens has been performed mainly on distillate cuts or whole fractions (i.e. saturated and aromatic hydrocarbons and NSO compounds). Until recently, previous studies on the carbon isotope composition of individual hydrocarbons has been restricted by the problem of balancing adequate resolution of individual compounds and obtaining enough material for good analysis. Previous studies on the carbon isotopic variations of individual hydrocarbons have used packed column gas chromatography to collect enough of each individual compound for analysis, or more recently combined with an interface to a mass spectrometer for immediate analysis after separation. In both techniques, resolution is insufficient for accurate measurement and, while the former technique, is also time-consuming. As a result of the development of a new isotope ratio-gas chromatograph combination in which capillary columns are used for improved resolution, both analytical problems have been removed. Experimental results obtained with this instrument (VG Isogas Isochrom II) show that there are clear differences in the carbon isotope composition of n-alkanes and acyclic isoprenoids in oils. In addition, differences in the isotope composition of these compound types appear to be related to source and maturity variations. Examples from a selection of oils are presented and discussed.

Production of unleaded gasoline in gas condensate fields

This paper discusses gas condensate processing, the process of which consists of stepwise vaporization of the gasoline fraction in horizontal vaporizer tanks at a temperature of 100-120 C. The individual hydrocarbon composition of an experimental sample of unleaded automotive gasoline recovered from gas condensate in a small-scale unit is presented and test results on this gasoline by qualification test methods are given. A specification has been developed for gas-condensate automotive gasoline (AG-76); the product is intended for use in automotive vehicles and tractors currently operated on A-76 gasoline.

Individual composition of hydrocarbons in naphthas from secondary processes

1. A method of analysis has been developed for the individual hydrocarbon composition of the IBP-150°C fraction of catalytically cracked naphtha, based on a combination of methods including fractional distillation, liquid fluorescent chromatography, and gas chromatography. 2. Methods for identification have been proposed; when these are used along with literature data on retention indices, it has been found possible to identify 243 components classed as paraffinic, naphthenic, olefinic, and aromatic hydrocarbons. For the cycloolefinic and diolefinic hydrocarbons, retention indices have been calculated for the first time.

Determination of the individual hydrocarbon composition of tartary petroleums Communication 9. Gasoline and ligroine from the Shugurov oil field

1. The gasoline and ligroine from the oil of Shugurov No. 5 well, which arises from Carboniferous carbonate deposits of the Namurian stratum, were studied. 2. The data obtained for the individual hydrocarbon compositions of this gasoline and ligroine are compared with the data for gasoline and ligroine from the Shugurov oil of the No. 10 well, which arises from the Carboniferous carbonate deposits of the Tournaisian stratum.

Carbon Isotope Composition of Individual Hydrocarbons from Italian Natural Gases

SINCE the fundamental paper by Craig1 on the geochemistry of the stable carbon isotopes, much work has been done on the determination of carbon isotope distribution in different materials.

Determination of the individual-hydrocarbon composition of gas condensates from Ukrainian deposits Communication 1. Average gas condensate from the shebelinko deposits

1.1 With the aid of the combined method for the investigation of the individual-hydrocarbon compositions of straight-run fractions an analysis was made of one sample of average gas condensate from the Shebelinko deposits in the Ukraine, which are confined to the upper Carboniferous and lower Permian formations. 2. In the gasoline fractions of the condensate all possible normal and branched paraffins from C2 to c10 were found. Among cyclopentane hydrocarbons, cyclopentane itself and some of its closest homologs, with a predominance of methylcyclopentane, were found. Among cyclohexane hydrocarbons (up to 205°) all possible isomers from C6 to C10 were found (mono-, di-, tri-, tetra-, and gem-substituted hydrocarbons). Among aromatic hydrocarbons benzene, toluene, and di-, tri-, and tetra-substituted benzenes were found. 3.1 The high content of cyclohexane and aromatic hydrocarbons in the gas condensate from the Shebelinko deposit will lead to an increase in the resources of the petrochemical industry for the manufacture of synthetic materials, in particular caprolactam.

Determination of the individual hydrocarbon composition of gasolines of tartary petroleums

Determination of the individual hydrocarbon composition of gasolines of tartary petroleums

Determination of the individual hydrocarbon composition of tartary petroleums

1. It was shown that the ligroin contained 26 aromatic, 26 cyclohexane, and 3 normal paraffin hydrocarbons. 2. The individual composition of the ligroin from Shurugin petroleum differs from that of the ligroins of Devonian petroleums in the relatively large content of cyclopentanes and of isoparaffins.

Determination of individual hydrocarbon composition of tatar crudes

1. The individual and group hydrocarbon composition of the 1502-200° ligroln of Bavly crude has been investigated; thereby 23 aromatic and 26 hydroaromatic hydrocarbons have been detected, and their contents have been determined by a Raman spectrum method. 2. The total quantity of pentamethylene and paraffinic hydrocarbons has been calculated on the basis of specific refraction of the narrow fractions.

Chemical composition of cracked gasolines from naphthenic crude

1. An investigation has been made on the individual hydrocarbon composition of three samples of carcked gasoline fractions boiling up to 60‡ and of the aromatic hydrocarbons of the 60–175‡ fractions of those same samples, which were produced from naphthenic-base crudes. 2. The data obtained attest to the high concentrations of hydrocarbons in the head fractions of cracked gasolines which can serve as raw material for petrochemical synthesis. 3. The concentrations of aromatic hydrocarbons such as pseudocumene, toluene, ethylbenzene, m-xylene, and p-xylene in the catalytically cracked gasoline considerably exceed their concentrations in the thermally cracked gasolines. 4. The data which have been presented show differences in the chemical composition of the gasolines investigated, in connection with differences in the chemical composition of the initial feedstock and the processing methods.

Investigation of the composition of the 150?250� fraction of emben petroleum

1. An attempt was made to extend the combined method for the investigation of gasolines to the investigation of the 150–250° fraction of Emben petroleum from the Koschagyl deposits. It was shown that this fraction contains 12.6% of aromatic and 13.0% of cyclohexane hydrocarbons. The individual hydrocarbon composition of the aromatic part was established to the extent of 48% and 29 hydrocarbons were found. 2. For the aromatic and cyclohexane hydrocarbons boiling over the above-indicated range It is possible to establish their quantitative distribution into groups according to the arrangement of the side chains in the benzene nucleus or in the cyclohexane ring, and in the case of polynuclear hydrocarbons, according to the way in which the rings are joined. In. this way we succeeded in establishing the composition of the aromatic part to the extent of 70%, and that of the cyclohexane part to the extent of 46%. 3. In the paraffln-naphthene part we succeeded in establishing only the presence of naphthenes with geminate side chains. li]3.|Data are given on the distribution of naphthenes over the narrow fractions of the paraffln-naphthene part; these are based on a study of the densities, refractive indices, and aniline points of these fractions.

Determination of the individual hydrocarbon composition of gasolines from Tatariia petroleums

1. It was shown that Minnibaev, Bavlin, and Romashkin gasolines, which originate from coeval devonian petroleums, are close in individual hydrocarbon composition. 2. Minnibaev and Romashkin gasolines, being derived from petroleums of the same Romashkin depost, are similar with respect to the approximate equality of the contents of normal and branched paraffins; in this respect they differ from Bavlin and Tuimazin petroleums, in which normal paraffins predominate to some extent over isoparaffins.

Determination of the hydrocarbon composition of gasolines obtained from petroleums of the Tatar Republic I. Gasolines of the Bavlin and Romashkino petroleum deposits

1. The combination method of examination of the individual hydrocarbon composition of straight-run gasolines was applied to the analysis of two samples of gasoline with an end boiling point of 150° from the Bavlin and Romashkino oil deposits of the Tatar Republich located in the first horizon of the Devonian (Pashtsk series). 2. It was shown that the chemical characters of the investigated gasolines of petroleums of the same age from one and the same level are identical, apart from slight fluctuations in the content of paraffinic hydrocarbons of normal and iso structure. 3. Of the paraffinic normal hydrocarbons, all of the possible hydrocarbons from propane through nonane were found in the investigated gasolines. Of the naphthenic hydrocarbons, we found cyclopentane, cyclohexane and some of their immediate homologs with predominance of methyleyelopentane and methylcyclohexane. The ratio between the quantities of cyclopentane and cyclohexane hydrocarbons is 0.74 for Bavlin gasoline and 0.68 for Romashkino gasoline. Aromatic hydrocarbons were represented by benzene, toluene, ethylbenzene and o-, m- and p-xylenes. In both of the gasolines the amounts of individual aromatics increased in the order: p- and o-xylenes, ethylbenzene and benzene, m-xylene, toluene. 4. The low octane numbers of gasolines from petroleums of the eastern regions of the USSR are due to the high content of normal paraffins and also (apparently) to the remarkably small proportion in these isoparaffins of highly branched hydrocarbons with high octane numbers. 5. The method of examination of gasolines developed in the Institute of Organic Chemistry and the Institute of Physics of the Academy of Sciences, USSR was successfully employed for investigation of gasolines from the sulfur-containing petroleums of the Tatar Republic (the crudes contained 1.2–1.7%sulfur and the gasolines 0.02–0.03% sulfur).

Determination of the individual hydrocarbon composition of gasolines by the combination method. Commnication 3. Surakhangasolines

1. With the aid of the combination method for the investigation of the individual hydrocarbon composition of gasolines, two gasoline samples, from first-grade and oil grade Surakhan petroleums respectively, have been analyzed. 2. The individual composition of the gasoline derived from first grade Surakhan petroleum has been accounted for quantitatively to the extent of 77.8%, and the gasoline from the oil-grade petroleum has been accounted for to the extent of 84.0%. Altogether, 47 hydrocarbons have been determined quantitatively in the two gasolines.

Determination of the individual hydrocarbon composition of gasolines by the combination method. Communication 2. Two gasolines from Kazanbuiak petroleums

1. With the aid of the combination method for the investigation of the individual hydrocarbon composition of straight-run gasolines, a study has been made of gasoline fractions derived from two petroleums originating from two horizons at Kazanbulak. In the fractions boiling below 150° more than 70 individual hydrocarbons have been detected qualitatively. It was found possible to account quantitatively for 55% of one of the gasolines and for 40% of the other. 2. It has been shown that, in spite of the closeness of the strata from which these petroleums were obtained, the chemical nature of the hydrocarbons forming their gasoline fractions diffes very greatly.

Determination of the individual hydrocarbon composition of gasoline by the combination method communication 4. Gasoline from tuimazin petroleum

1. By the aid of the combination method of investigating the individual hydrocarbon composition of straight -run gasolines, the analysis has been carried out of a gasoline having an upper boiling limit of 150° derived from a sample of a low-sulfur Tuimazin petroleum (Devonian level). 2. The individual hydrocarbon composition of the Tuimazin gasoline has been accounted for quantitatively to the extent of 87.9% (by weight on the whole gasoline). The total losses were about 6%. 3. It has been found that normal paraffins predominate in this essentially paraffin gasoline from Tuimazin petroleum Among the cyclopentanes, methylcyclopentane is present in the greatest amount. Among the cyclohexanes, methyl-, 1,3-dimethyl-, and 1,1,3-trimethyl-cyclohexanes are present in the greatest amounts. Among the aromatic hydrocarbons, toluene and m-xylene are present in the greatest amounts.

Determination of the composition of the individual hydrocarbons of gasolines by the combination method

1. Gasoline with an end boiling point of 150°, obtained from low-sulfur Emba petroleum (Koschagyl), was analyzed with the help of the combination method of investigation of the individual hydrocarbons of straight-run gasolines. 2. The individual hydrocarbon composition of gasoline from Emba petroleum was established to the extent of 81.1 weight-% of the total gasoline. Total losses were approx. 8%. 3. It was found that the investigated gasoline from Emba petroleum was naphthenic. Among the paraffinic hydrocarbons the branched-chain compounds predominate. Among the cyclopentanic hydrocarbons the chief representative is methylcyclopentane, and a series of hydrocarbons is present with two and three side chains. The cyclohexanic hydrocarbons present in largest quantity are methylcyclohexane, 1,3-dimethylcyclohexane and 1,1,3-trimethylcyclohexane, m-Xylene predominates among the aromatic hydrocarbons.