Study of Vanadium Distribution in ITC Fractions of Oils from Western Siberian Fields
Abstract Generated abstract
This study examines the content and distribution of vanadium in true boiling point fractions of Western Siberian crude oils, motivated by its geochemical significance and its adverse effects in refining and high-temperature fuel use. Vanadium was quantitatively determined by neutron activation analysis in fractions of typical 1975 and 1980 oils, Var-Egan oil, and twenty-degree fractions of Samotlor oil subjected to gamma irradiation. The results indicate that vanadium occurs in all studied fractions, with a nonuniform distribution and a stepwise increase in fractions boiling at about 200 to 380°C, while the highest concentrations are associated with residual fractions, likely through resin-asphaltene substances. Gamma irradiation altered vanadium distribution in Samotlor fractions in a dose-dependent manner, suggesting that some vanadium-associated petroleum compounds are sensitive to gamma radiation.
Full Text
Study of Vanadium Distribution in TBP Fractions of Oils from Western Siberian Fields
G. N. Aleshin, L. G. Glukhov, G. M. Ryzhova, V. N. Semenov
(Submitted by the scientific-methodological seminar of the organic departments of the Chemical-Technological Faculty)
Of all the trace elements contained in petroleum, vanadium is of the greatest interest. This is explained by the fact that it is a constant component of petroleum ash and is also widespread in bitumens, shales, hard coals, and peats [1, 14].
The quantitative content of vanadium and of a number of other trace elements in petroleum is accepted in modern geochemistry as a criterion for determining its age [5, 6], and can also be used as an assessment for the genetic classification of petroleum in certain regions of its production [14].
The presence of vanadium in catalytic-cracking feedstock leads to its deposition on the catalyst, which lowers the activity and selectivity of the latter. This leads to a decrease in gasoline yield and an increase in coke and gas [2, 3].
Table 1
Characteristics of typical oils and oils from the Samotlor and Var-Yeganskoye fields
| Oil | Density, g/cm³ | Ash content, wt % | Molecular weight | Kinematic viscosity | Asphaltene content, wt % | Sulfur content, wt % | Silica-gel resins content, wt % |
|---|---|---|---|---|---|---|---|
| Samotlor field | 0.8525 | 0.017 | 213 | 7.39 | 0.71 | 0.95 | 8.53 |
| Typical, 1975 | 0.8473 | 0.029 | 186 | 7.07 | 0.80 | 0.88 | 5.90 |
| Typical, 1980 | 0.8512 | 0.028 | 190 | 3.74 | 0.60 | 0.66 | 7.00 |
| Var-Yeganskoye field | 0.8552 | 0.016 | 208 | 9.73 | 0.90 | 0.47 | 6.70 |
The content of this element in heavy residual fuels promotes high-temperature corrosion of equipment, observed at temperatures above 600°C. Thus, working and guide blades of gas turbines are subject to considerable vanadium corrosion.
turbines [4, 8]. The industrial extraction of vanadium from heavy petroleum fractions, in which the bulk of it is concentrated, is also of interest.
The purpose of the present study, carried out at the Department of Chemical Technology of Fuels, was to examine the vanadium content and to identify the regularities of its distribution in crude oils and TBP fractions of oils from Western Siberian fields. The objects of the study were typical oils from 1975 and 1980, as well as oils from the Samotlor and Var-Egan fields, the characteristics of which are given in Table 1.
Table 2
Vanadium content in TBP fractions of typical oils from 1975 and 1980 and in oil from the Var-Egan field
| Typical oil, 1975: temperature limits of fraction collection, °C | Typical oil, 1975: vanadium content in fractions, wt. %, ×10^-3 | Typical oil, 1980: temperature limits of fraction collection, °C | Typical oil, 1980: vanadium content in fractions, wt. %, ×10^-3 | Oil from the Var-Egan field: temperature limits of fraction collection, °C | Oil from the Var-Egan field: vanadium content in fractions, wt. %, ×10^-3 |
|---|---|---|---|---|---|
| 75—97 | 0,012 | 55—77 | 0,038 | 34—65 | 0,028 |
| 97—116 | 0,019 | 77—95 | 0,0407 | 65—80 | 0,058 |
| 116—133 | 0,059 | 95—111 | 0,047 | 80—92 | 0,102 |
| 133—150 | 0,133 | 111—124 | 0,090 | 92—110 | 0,184 |
| 150—167 | 0,023 | 124—142 | 0,145 | 110—130 | 0,558 |
| 167—182 | 0,018 | 142—158 | 0,136 | 130—144 | 0,067 |
| 182—199 | 0,028 | 158—174 | 0,148 | 144—159 | 0,109 |
| 199—214 | 0,213 | 174—192 | 0,107 | 159—175 | 0,323 |
| 214—230 | 0,314 | 192—207 | 0,342 | 175—193 | 0,165 |
| 230—246 | — | 207—225 | 0,372 | 193—210 | 0,281 |
| 246—263 | 0,135 | 225—240 | 0,308 | 210—230 | 0,685 |
| 263—280 | 240—258 | 0,318 | 230—250 | 0,875 | |
| 280—298 | 0,292 | 258—280 | 0,326 | 250—269 | 0,614 |
| 298—315 | 0,258 | 280—298 | 0,282 | 269—284 | 0,605 |
| 315—334 | 0,391 | 298—312 | — | 284—299 | 1,792 |
| 334—353 | 0,154 | 312—329 | 0,338 | 299—317 | 0,706 |
| 353—373 | 0,328 | 329—343 | 0,256 | 317—334 | 1,186 |
| 373—392 | 0,351 | 343—363 | 0,341 | 334—353 | — |
| 392—411 | 0,235 | 363—380 | — | 353—370 | 0,655 |
| 411—430 | — | 380—402 | — | 370—390 | 0,480 |
| 430—450 | 0,258 | 402—420 | 0,209 | 390—408 | 2,265 |
| — | — | 420—438 | 0,267 | 408—425 | 1,520 |
| — | — | 438—454 | 0,205 | 425—445 | 3,365 |
| — | — | 454—472 | 0,108 | 445—465 | — |
| — | — | 472—490 | — | 465—480 | — |
| — | — | 490—500 | 0,206 | — | — |
| Residue | 1,25 | Residue | 1,390 | — | — |
Quantitative determination of vanadium in oils and TBP fractions was carried out by the neutron-activation method in the radioactivation-analysis sector of the YaFEA Research Institute at TPI [13]. The results obtained are given in Table 2.
It is seen from Table 2 that vanadium is present in all fractions of the oils studied. This confirms the numerous facts indicating that vanadium is not an accidental impurity in oil. The presence of vanadium in all TBP fractions can be explained by the volatility of the oil compounds with which vanadium is associated.
The distribution of vanadium among the TBP fractions is nonuniform. They are characterized by an abrupt increase in its content in the temperature interval 200–380°C. It may be assumed that these may be vanadyl compounds. Since from \(1/2\) to \(1/3\) of the volatile vanadium compounds are found in gas oil not only in the form of compounds of the metal-porphyrin complex, but also in the form of vanadyl compounds [9].
It should also be noted that the TBP fractions of the Var-Eganskoye field contain considerably less vanadium than the TBP fractions of typical oils of 1975–1980.
The maximum vanadium content during TBP distillation of oils occurs in the residual fractions, which may be explained by its concentration by resin-asphaltene substances [7, 11, 12].
A study was conducted of the vanadium content in twenty-degree fractions of Samotlor oil previously subjected to irradiation with \(\gamma\)-quanta. The irradiation dose varied in the interval \(10^{-6}\)—\(10^{-8}\) rad. The results are given in Table 3.
Table 3
Vanadium content in twenty-degree fractions of Samotlor oil
| Temperature limits for fraction collection, °C | Vanadium content, g/ml · \(10^{-6}\) | Vanadium content, g/ml · \(10^{-6}\) | Vanadium content, g/ml · \(10^{-6}\) | Vanadium content, g/ml · \(10^{-6}\) |
|---|---|---|---|---|
| Unirradiated oil | Oil irradiated to a dose of 1 rad: \(1{,}6 \cdot 10^{-6}\) | Oil irradiated to a dose of 1 rad: \(1{,}92 \cdot 10^{-7}\) | Oil irradiated to a dose of 1 rad: \(1{,}06 \cdot 10^{-8}\) | |
| 100—120 | 1,24 | 2,17 | 2,31 | 2,54 |
| 140—160 | 1,21 | 1,71 | 0,78 | 1,79 |
| 180—200 | 0,24 | 0,45 | 0,63 | 0,27 |
| 220—240 | 0,49 | 0,29 | 0,76 | 0,88 |
| 260—280 | 0,68 | 0,98 | 1,91 | 3,26 |
| 300—320 | 1,45 | 2,31 | 2,82 | 5,46 |
| 340—360 | 0,17 | 0,73 | 0,59 | 1,58 |
The data of Table 3 show that \(\gamma\)-radiation affects the distribution of vanadium in the twenty-degree fractions of Samotlor oil. As the dose increases, an increase in the content of the microelement in them is observed. This indicates the sensitivity to \(\gamma\)-quanta of a certain part of the oil compounds associated with vanadium [10].
Conclusions
- The vanadium content was determined in the TBP fractions of typical oils of 1975—1980, oil from the Var-Eganskoye field, and in
twenty-degree fractions of Samotlor oil preliminarily irradiated with γ-quanta.
-
Vanadium is present in all ITC fractions.
-
A stepwise increase is observed in the vanadium content in ITC fractions boiling within the temperature range 200–380°C.
-
Gamma radiation affects the distribution of vanadium in 20°C fractions of Samotlor oil. It depends on the magnitude of the dose.
LITERATURE
-
D. I. Zulfugarly. Geochemical study of caustobioliths. Scientific Notes of Azerbaijan University. Chemical Sciences Series, No. 4, 1967, pp. 27–35.
-
R. M. Masagutov, B. F. Borzov, R. A. Danilova. Poisoning by metals and aging of cracking catalysts. Moscow, TsNIITENeftekhim, 1968.
-
R. M. Masagutov, G. A. Berg, R. A. Danilova. Influence of vanadium on the quality of an aluminosilicate catalyst and the indices of catalytic cracking. Chemistry and Technology of Fuels and Oils, Moscow, 1967, No. 9, pp. 14–16.
-
K. I. Ivanov, K. E. Zeger, A. A. Luzhetskii. On quality requirements for high-sulfur fuel oils. In: Problems in the Processing of High-Sulfur Oils. Moscow, “Khimiya,” 1966, pp. 239–244.
-
A. I. Bogomolov. Principal directions in the development of research on oils and petroleum geochemistry. Proceedings of the IX conference of workers of laboratories of geochemical organizations. Issue 6, 1965.
-
G. N. Blankova, B. N. Bochkarev. Neutron-activation analysis of microelements of oils with semiconductor gamma spectrometry. In: New Methods and Devices of Nuclear Geophysics. Novosibirsk, “Nauka,” 1970.
-
D. I. Zulfugarly. Study of the content of microelements in individual oil fractions. Scientific Notes of Azerbaijan University. Chemical Sciences Series, 1966, No. 4, pp. 41–44.
-
K. I. Ivanov, K. E. Zeger. On the quality and composition of liquid boiler fuels. Moscow, “Khimiya,” 1961.
-
Ya. B. Chertkov. Non-hydrocarbon compounds in petroleum products. Moscow, “Khimiya,” 1964.
-
A. V. Kotova, V. G. Benkovskii, V. B. Bulgakov. Destruction of metal-porphyrin complexes under the action of gamma radiation on oil and petroleum products. Chemistry and Technology of Fuels and Oils, 1966, No. 8, pp. 22–24.
-
D. I. Zulfugarly. Paragenesis of heterogeneous and organic components of oil. Scientific Notes of Azerbaijan University. Chemical Sciences Series, 1966, No. 3, pp. 18–22.
-
S. P. Sergienko. High-molecular compounds of oil. Moscow, “Gostoptekhizdat,” 1959.
-
R. A. Kuznetsov. Activation analysis. Moscow, “Atomizdat,” 1967.
-
D. I. Zulfugarly. Distribution of microelements in caustobioliths, organisms, sedimentary rocks, and formation waters. Baku, Azerbaijan University Press, 1960.