Study of the Composition of Aromatic Hydrocarbons in Naphtha Fractions of Oils from Western Siberian Fields

STUDY OF THE COMPOSITION OF AROMATIC HYDROCARBONS IN NAPHTHA FRACTIONS OF OILS FROM WEST SIBERIAN FIELDS

S. I. Khoroshko, V. A. Kuznetsova, N. V. Usheva

(Presented by the Scientific-Methodological Seminar of the organic departments of the Faculty of Chemical Technology)

With each passing year, the output and assortment of products obtained from petroleum feedstock increase. For the most rational use of petroleum fractions, and for elucidating the geochemical conditions of oil formation and their metamorphism, it is necessary to know the composition and structure of petroleum hydrocarbons.

In the present work, aromatic concentrates isolated from the naphtha fraction \(150—200^\circ\text{C}\) of four oils from West Siberian fields were studied. The aromatic hydrocarbons were isolated by liquid-adsorption chromatography on ASM-grade silica gel [1].

Determination of the individual composition of the aromatic hydrocarbons was carried out by gas chromatography on a “Khrom-2” chromatograph with a flame-ionization detector. For the analysis, a copper capillary column with squalane was used, 100 m long and 0.5 mm in diameter; the carrier gas was nitrogen. The analysis was performed at a temperature of \(100^\circ\text{C}\), found experimentally. Qualitative identification of the components was performed by the method of standards, on the basis of literature data on retention characteristics and the order of elution of aromatic hydrocarbons [2], and on the basis of graphical dependences for the order of elution of alkylbenzenes [3].

Quantitative interpretation of the chromatograms was carried out by the method of internal normalization. On the basis of experimental data, correction coefficients were calculated. The presence of hydrocarbons detected by the GLC method was confirmed by spectral-analysis data. The results of qualitative and quantitative analyses of the aromatized naphtha fraction are given in the table.

As can be seen from the table, all the samples studied have a similar qualitative composition. It was established that some components under the selected analytical conditions are not separated—9, 11, 19, 26 (table), which is associated with the close boiling points of the indicated hydrocarbons and, in addition, with insufficient efficiency of the capillary column.

The hydrocarbons detected have an unbranched chain, with the exception of four groups with a tertiary carbon atom. The maximum number of hydrocarbon atoms making up one chain, as well as the greatest number of substituents in the benzene ring, is four. In quantitative composition, all the samples studied differ only slightly.

Table 1

Individual composition of aromatic hydrocarbons in the ligroin fraction of oils

Conclusions

1. Samples of ligroin fractions, 150–200°C, from the oils of the Ozernoe, Klyuchevskoe, Luginetskoe, and Samotlor fields were studied.

2. Thirty-four aromatic hydrocarbons were identified, and their quantitative composition was calculated.

References

1. Szynage P., Jedrychowska M. Konf. Chem. und chem. Verarb Erdöls und Erdgas, Budapest, 1965. Budapest 637–649, 1968.

2. Miyake H., Mitooka M., Matsumoto T., 38, No. 7, 1062–1071, 1965 Bull. Chem. Soc. Japan.

3. Sidorov R. I., Denisenko A. N., Lebedeva V. I. Journal of Analytical Chemistry. Vol. XXVI, issue 2, 1971, 388–392.