Individual Hydrocarbon Composition of Gasolines from Oils of Fields in the Tomsk Region
Abstract Generated abstract
This paper examines the individual hydrocarbon composition of gasoline fractions boiling up to 150°C from oils of the Luginetskoye and Olenye fields in the Tomsk Region. Fractions obtained by precision rectification were analyzed by gas liquid chromatography on a capillary column, with additional adsorption separation for the 125 to 150°C fraction. The study identified 134 hydrocarbons and found that the gasolines from both fields are similar in composition, dominated by paraffinic and naphthenic hydrocarbons. Paraffins constitute about 55 to 61 percent, naphthenes about 33 to 37 percent, with cyclopentane derivatives prevailing over cyclohexane derivatives, while aromatic hydrocarbons are present at low levels, about 3.4 to 6.26 percent.
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INDIVIDUAL HYDROCARBON COMPOSITION OF GASOLINES FROM OILS OF FIELDS IN THE TOMSK REGION
N. M. SMOLYANINOVA, S. I. KHOROSHKO, A. I. POPOV
(Presented by the Scientific-Methodological Seminar of the Organic Departments)
The study of the individual hydrocarbon composition of gasoline fractions of oils is an important component of the detailed study of oils from newly discovered fields in Western Siberia.
We have carried out a study of the individual hydrocarbon composition of fractions boiling up to 150°C of oils from the Luginetskoe and Olen’e fields.
The individual composition of the gasolines was determined by gas–liquid chromatography according to the method of E. K. Bryanskaya et al.^1 For the analysis, fractions b.p.—110°C, 110–125°C, and 125–150°C were used, obtained on a precision rectification column with an efficiency of 20 theoretical plates.
The analysis was performed on a Khrom-2 chromatograph with a flame-ionization detector. The column was a copper capillary 100 m long and 0.5 mm in internal diameter; the stationary phase was squalane; the carrier gas was nitrogen. The instrument column operated under isothermal conditions; the temperature was maintained with an accuracy of ±0.1–0.5°C.
For more complete separation, all fractions were subjected to chromatography at two temperatures: 30 and 80°C for the b.p.—110°C fraction; 50 and 80°C for the 110–125°C fraction; and 80 and 106°C for the 125–150°C fraction. The 125–150°C fraction was first separated by adsorption on silica gel into aromatic and paraffin–naphthenic portions, which were then analyzed by the indicated method.
In identifying the peaks on the chromatogram, we were guided by the order of elution of the hydrocarbons, which is constant for the given stationary phase and thermostatting temperature.
In all, 134 hydrocarbons were identified in the fraction from b.p. to 150°C. For brevity of presentation, the table gives the quantitative content of only individual groups of hydrocarbons. As can be seen from the table, the gasoline fractions of both fields are identical in individual hydrocarbon composition. The content of paraffinic hydrocarbons is 55–61%; within them, representatives of normal and isomeric structure occur in approximately equal amounts. The isoparaffins are represented mainly by mono- and disubstituted compounds, 18–23 and 6–10 wt.% per fraction, respectively. Isoalkanes with a quaternary carbon atom are present in small amounts (0.6–0.9% per fraction).
^1 E. K. Bryanskaya, Z. K. Olenina, Al. A. Petrov, Analysis of straight-run gasolines by the GLC method using capillary columns. In: Methods for the Analysis of Organic Compounds of Petroleum, Their Mixtures and Derivatives. Moscow, “Nauka,” 1969, No. 7.
Table 1
Composition of the b.p.–150°C fraction of oils from the Luginetskoye and Olenye fields
according to GLC data
| Hydrocarbons | Luginetskoye, well 154 | Luginetskoye, well 155 | Olenye, well 121 |
|---|---|---|---|
| Paraffinic | |||
| n-structure | 27,60 | 28,30 | 28,10 |
| iso-structure: monosubstituted | 23,01 | 22,00 | 18,17 |
| iso-structure: disubstituted | 10,06 | 6,36 | 7,89 |
| iso-structure: trisubstituted | 0,68 | 0,58 | 0,93 |
| Total: | 61,35 | 57,24 | 55,09 |
| Naphthenic, five-membered | |||
| With one substituent in the ring | 5,30 | 9,18 | 7,81 |
| With two substituents in the ring | 8,99 | 9,09 | 8,63 |
| With three substituents in the ring | 5,95 | 3,92 | 5,01 |
| With four substituents in the ring | 1,01 | 0,73 | 1,09 |
| Total: | 21,25 | 22,92 | 22,54 |
| Six-membered: | |||
| With one substituent in the ring | 4,68 | 9,35 | 8,80 |
| With two substituents in the ring | 5,50 | 3,64 | 3,85 |
| With three substituents in the ring | 1,52 | 1,01 | 1,43 |
| With four substituents in the ring | 0,04 | 0,01 | 0,02 |
| Total: | 11,74 | 14,01 | 14,10 |
| Aromatic | 3,40 | 4,38 | 6,26 |
| Unidentified | 2,26 | 1,45 | 2,01 |
Naphthenic hydrocarbons account for 33–37% of the fraction; moreover, the amount of cyclopentane hydrocarbons in the fraction studied is twice that of cyclohexane hydrocarbons. The contents of mono-, di-, and trisubstituted cycloalkanes are approximately the same.
This regularity distinguishes the oil samples studied from the previously investigated oils of the Tomsk fields.
It should be noted that gasolines up to 150°C are distinguished by a very low content of aromatic hydrocarbons, the amount of which is 6,26% in the Olenye oil and 3,40–4,38% in the Luginetskoye oil.
Conclusions
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The individual hydrocarbon composition of gasoline fractions from oils of the Olenye and Luginetskoye fields has been studied.
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It has been established that paraffin–naphthenic hydrocarbons predominate in the gasolines studied, while the aromatic content is low.