Isolation of non-hydrocarbon components of petroleum and petroleum distillates by complex formation with TiCl4

150

1. V. GO,CHAnCY and V. L. KULACHENKO

SUMMARY

1. A study was made of the interaction of diethylsulphide, dipropyldisulphide, diphenylsulphide, butylthiophans, benzthiophen, dibenzothiophen, quinoline and indole with aluminium chloride within the temperature' range of 21 to 1000°. All hetero-atomic compounds studied in hydrocarbon media at a temperature lower than 71 ° form complexes with aluminium chloride. 2. During the interaction of dipheaylsulphide with aluminium chloride thianthrene, polyphenylsulphides and benzene are formed. 3. It was established that butylthiophens undergo partial isomerizatioIl and indole undergoes trimerization by the ~ction of aluminium chloride. REFERENCES 1. G. L. RYZHOVA, V. P. NEI~HOROSHEV and Yu. G. SLIZHOV, Neftokhimiya 17, 910, 1977 2. Ye. N. GUR'YANOVA, I. P. GOL'DSHTEIN and I. P. ROMM, Donoraktseptornaya svyaz' (Donor-Accepter Bond). Khimiya, Moscow, 1973 3. A. V. GRill and T. P. TOLSTAYA, Izv. YN SSSR, ser. khim., 2572, 1970 4. V. Ye. MAZAYEV and M. A. KORSHUNOV, Neftekhimiya 11, 587, 1971 5. Auth. Cert. U.S.S.R. 509619; 24.06.1974. Otkr., izobr., prom. obr. i toy. znaki, I~o. 13, 1976 6. A. L. R Y Z H O V A ,

Y e . A. K R U L I K O V S K A Y A ,

A . G. D R A N A Y E V A ,

V. P. N E i ~ S

and A. V. BELIN, Tez. dokl. 14 nauch, ses. pc khimii i tekhnologii organicheskikh soyedinenii sery i sernistykh neftei (Proceedings of 14 Scientific Sessions Concerning the Chemistry and Technology of Organic Compounds of Sulphur and Sulphur Petroleum). Zinatne, Riga, 1976

Petrol. Chem. U.S.R,R. Vol. 20, lqo 3, pp. 150-165, 1980

Printed in Poland

0031-6458/80/040150-06507.5010 © 1981PergamonPress Ltd.

ISOLATION OF NON-HYDROCARBON COMPONENTS OF PETROLEUM AND PETROLEUM DISTILLATES BY COMPLEX FORMATION WITH TiCI4* I. V. GO~C~AROVand V. L. KULACHENKO West Siberian Scientific Research Institute of Geological Explora.tion of Petroleum, Tyumen

{Received 13 February 1979) CoMPT.Ex-formation with metal salts is a widely known method used for the removal of sulphur compounds from petroleum and petroleum products [1] and is applied both in laboratory practice and in industry [2]. * lqeftekhimiya 20. No. 4, 603-606, 1980.

Isolation of non-hydrocarbon components of petroleum

151

Several studies have been carried out in recent years concerning the possibility of isolating from petroleum and petroleum products low molecular weight hetero-atomic compounds [3], resinous asphalthene substances and nitrous bases [4] by complex-formation with titanium tetrachloride TiC14 which, compared with other complex-forming agents has a number of advantages. The degree of recovery of various alkylphenols with TiCl~ from petroleum products has previously been quantitatirely evaluated [5]. As the removal of hetero-atomic components has a marked effect on the quality of petroleum products, it was interesting to evaluate the degree of recovery of TiC14 of different classes of hetero-atomic compound from basic distillates obtained by industrial processing of petroleum. EXPERIMENTAL

A commercial mixture of West Siberian petroleums (Samotler-66~/o, Ust-Balyk-18.9°/o, Pravdinsk-15.1%) and distillates and tar oil obtained from them under industrial conditions were investigated. A given amount of II, I I I IV distillates and vacuum gas oil were dissolved in petroleum ethers and tar oil and petroleum in a mixture of petroleum ether and benzene (2 : 1) were transferred into a round-bottomed flask provided with a stirrer and TIC14 added. Middle distillate fractions were used without solvent. Since oxygen-, nitrogen- and sulphur-containing compounds form complexes with TiC14 basically of 1 : 1 composition and sulphur content in petroleum products is usually higher than the total of nitrogen and oxygen, the amount of complexforming agent was taken in excess, using 3 Ti atoms for 1 S atom. TiC14 fractions were treated at room temperature. Insoluble complexes formed were separated by centrifuging. The residue was neutralized with 5% NaOH solution, then washed with water, dried by filtration and the solvent distilled. In all petroleum products contents were determined as follows: S ~ l - - b u r n i n g in flask according to Shoenherr, Ssulph - - b y potentiometric titration (iodatometry) b l ~ l - - b y modified Kjeldahl method, Nbas--potentiometric titration in acetic medium. Results are shown in Table 1. Complexes were washed with hexane, the solvent distilled i n vacuo a n d decomposed with a 20% alkaline solution. The upper layer was extracted using chloroform and the lower one was neutralized by a 20~/o acid solution and also extracted with chloroform. All chloroform extracts were joined, dried with sodium sulphate and the solvent distilled. The final distillation was carried out i n vacuo at a temperature of 40-50 °. Stot~l, Nbas and ~tolal contents were determined in the concentrates obtained by this method (Table 2). Results indicate (Table 1) that compounds containing nitrogen are fully extracted from all distillates, remaining only in petroleum and tar oil. These results show satisfactory agreement with data previously described [7], in-

]. V. Go~,~c~A~ov a n d V. L. I ~ u L ) , c ~ E l ~ o

52

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i

'

T F-

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O

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i

i-- ! .... ~

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-

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I

_ .........

. . . . . . . . . .

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.2 N

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Isolation of non-hydrocarbon components of petroleum

153

dicating the formation of TiClt compounds insoluble in hydrocarbons with nitriles, indole and pyridine, quinoline and other nitrogen bases. The low~ sensitivity of analysis hinders the determination of overall nitrogen content in petroleum products purified using titanium tetrachloride in proportions lower than 0.01~/o. The Nbas/N~ml ratio was therefore calculated for initial fractions and concentrates (Table 2). I f neutral nitrogen compounds are extracted less satisfactorily than basic ones, this ratio should b e higher for concentrate than for a corrresponding fraction. Table 2 shows that there is no marked difference in the ratios of basic nitrogen to the overall substance for concentrates and fractions. TABLE

2.

CHARACTERISTICS

OF

COlqCENTRATES . OF

S,ot,, I Concentrate

HETERO-ATOMIC

N,o,,,I Nb.,o

~basie

Ntotal

Ntotal

Yield %

Petroleum Fraction, °C 140-240 155-290 180-360 Vacuum gas oil Distillate II III IV tar oil

COMPOUNDS

(eonc.)

(frae.) 0"31

11"0

5.7

0.43

1.22

0"35

0.5 1.6 1.8 5.0

7-8 7.5 7"1 7-2

0"30 0.31 0"33 @55

0"90 bOO 1.10 1.52

0"33 0.31 0.30 0.36

0.30 0-34

4.9 5-2 7.2 19.0

5"8 4.6 3"4 1"3

0"58 0"76 0"78 O'68

1-60 2.07 2"20 1.70

0"36 0"37 0"36 0"40

0.33 0.34 0-34 0.30

Table 1 shows the degree of extraction of sulphur compounds according to fractions. Results indicate that with an increase in the boiling point o f fractions, the degree of recovery decreases and is about 10°//o for tar oil. A reduction in the tendency to complex-formation for sulphur compounds with an increase in boiling point has been indicated previously [1]. It is significant that sulphides were recovered the most ceompletely of all the sulphur compounds. However, in contrast with nitrogen compounds, 100% recovery of sulphides from fractions of b.p. higher than 240 °, could not be achieved. This is, probably, due to the fact that sulphides form less strong complexes with TiC14 than corresponding amines [8]. Furthermore, it was shown [6] ' that alkyl- and cycloalkylsulphides having a branched substituent in the a-position and aromatic sulphides (diphenylsulphide type) do not produce insoluble complexes with TiCI4. Compounds of thiophen series form even less strong complexes than sulphides but, according to the authors' view [9], the is due to 3 :pal-hybridization of electrons of the sulphur atom. Thiophens are therefore recovered less satisfactorily than sulphides, which is confirmed b y results obtained (Table 1). It should be noted that in addition to N- and S-containing compounds~.

]54

I . V . GONCHAROVand V. L. KULACHENKO

0-containing compounds are also recovered by complex-formation with TiC14 from petroleum distillates. As however, no reliable method is available for the direct determination of oxygen in petroleum products, one cannot talk of the degree of dxtraction of oxygen compounds. However, we have previously shown the existence in the concentrate of hetero-atomic compounds, isolated from a 140-240 ° fraction [3], phenols and ketones. It is generally known t h a t O-containing compounds are basically in resinous substances which cause a deterioration in the colour of petroleum products. Therefore, the value of • was determined for petroleum distillates (the percentage of light trarlsmission before and after treatment with TiCla) (Table 1). Light transmission was determined using a photoelectrocolorimeter--a FEK-56M nephelometer ().max 400 n n l ) for solutior~s in n-heptane ( 1 : 5 ) relation to the solvent. Removal of resinous substallces using TiCl 4 improves r. I f for a 180-360 ° fl'action ~ increases 1-5-fold (Table 1), for distillate IV it increases 12.8-fold, which is due to an increase in the content of resinous substances in high-boiling fractions and their removal after treatment with TIC14. SUMMARY

1. Various hetero-atomic petroleum components were isolated from petroleum distillates and residual asphalt using titanium tetrachloride. 2. Nitrogen compounds, both basic and neutral are recovered completely from petroleum distillates of b.p. up to 511 °. From residual asphalt nitrogen bases are recovered to the extent of 87~o , while neutral nitrogen compounds, to the extent of 74O/o. From petroleum the percentage of recovery was 88 and 83 °/o, respectively. 3. Sulphur compounds are only removed completely using fractions of b.p. up to 241 ° and removal suddenly decreases with an incsease in the boiling point of distillates. Sulphides are most completely recovered among sulphur-containing compounds. REFERENCES

1. I. U. NUMANOVand I. I. NASYROV, Geteroatomnyyo komponenty noftei Tadzhikskoi depressii (Hetero-atomie Components of Petroleum in the Tajik Region). Donish, Dushanbe, 1973 2. V. A. GRUZE and D. R. STEVENS, Tekhnologiy~t perer~botki nefti (Technology of Processing Petroleum). Khimiya, Leningrad, 1964 3. I. V. GONCHAROV, Yu. P. TUROV, N. P. YELETSKII and A. N. PLYUSNIN, Neftekhlm i y a 16, 150, 1976 4. A. N. PLYUSNIN, V. I. BEMBEL', T. A. SAGACHENKOand T. V. MAIKOVA, Neftekhimiya 16, 275, 1976 5. I. V. (]ONCHAROV and V. I. KULACHENKO,Neftekhimiy~ 18, 816, 1978 6. Ye. N. GUR'YANOVA, V. G. SPIRKIN and Ya. B. CH~RT]KOV, Neftekhimiya 9, 597, 1969

Isolation and study of polycyelic naphthenes

155

7. Ya. B. GOROSHCHENKO,Khimiya titana (Chemistry of Titanium). Naukova dumka, Kiev, 1970 8. Ye. N. GUR'YAN0VA, I. P. GOL'DSHTEIN and Ye. N. KHARLAMOVA, Zh. obshch. khimii 38, 1974, 1968 9. Ye. N. GUR'YAN0VA, I. P. GOL'DSHTEIN and Ye. N. KHARLAMOV, Sb. Khimiya seraorganicheskikh soyedinenii soderzhashchikhsya v neftyakh i nefteproduktakh (Chemistry of Organosulphur Compounds Contained in Petroleum and Petroleum Products). 4, Khimiy~, 1964

Petrol. Chem. U.S.R.R. Vol. 20, 1~o 3, pp. 155-161, 1980 Printed in Poland

0031-6458/80/050155--07507.50/0 1981 Pergamon Press Ltd.

ISOLATION AND STUDY OF POLYCYCLIC NAPHTHENES FROM HIGH-BOILING PETROLEUM FRACTIONS* S. R. SERGIYE~XO, A. A. POLYAKOVA,A. A. A I D O G D Y Y E V , ~J~E. I. TALALAYEV, B. G. NiYAzov and L, O. KOGA~ Institute of Chemistry, Turkm. S.S.I~. Academy of Sciences, Ashkhabad AU-Union Scientific Research Institute for Processing Petroleum (Received 13 Jun6 1979)

DEVELOMPMENT of methods of differentiation and investigation of this multiple group of hydrocarbons is of particular interest for petroleum deposits of the Eastern shore of the Caspian Sea, rich in high-boiling naphthene-paraffin hydrocarbon content. There is now reliable information available about the concentration distribution of the high-boiling part of petroleum in groups of hydrocarbons such a unbranched and slightly branched paraflinic hydrocarbons, monocycloparaElns and isoprenoid hydrocarbons. Comparatively few studies have been carried out of polycyclic, particularly condensed naphthenic hydrocarbons of hybride structure. The use of mass-spectrometry made it possible to determine the content of paraffinic and naphthenic hydrocarbons of different cyclic properties. Howeves, the greater the differentiatiop. according to the type of molecular structure of these complex mixtures, the higher and the more reliable the effectiveness of all modern methods of investigating high-boiling hydrocarbon mixtures. Reseasch into effective method of separating complex hydrocarbon mixtures and complexes systems of investigating high-boiling petroleum fractions therefore continue to represent an urgent problem. A system was developed for more complete separation of saturated high * Neftekhimiya 20. No. 5, 643-648, 1980.