- Email: [email protected]
Lower carboxylic acids of West Siberian crude oil
40
S. V. CHERNYAVSKAYA e t
aL
16. N. S. NAMETKIN, L. P. K()LESNIKOVA, T. G. BAIKOVA, A. A. BABYLOVA, L. K. 9RUMYANTSEVA and G. V. MOROZOVA, N.eftekhimiya 19, 127, 1979 17. Preobrazovaniye neftei mikroorganizmami (Transformation of Oils by Micro-organisms), Tr. VNIGRI, 281, 8, 15, Leningrad, 1970 18. S.I. KUZNETSOV, M. V. IVANOV and N. N. LYALIKOVA, Vvedeniye v geologicheskuyu mikrobiologiyu (Introduction to Geological Microbiology), p. 73, Izd. AN SSSR, Moscow, 1962
19. L. I. VLADIMIROVA, In: Geokhimicheskiye metody poiskov nefti i gaza na Russkoi platforme (Geochemical Methods of Research into Oil and Gas in Russian Deposits), p. 54, Saratov, 1980 20. V. A. YERSHOV, N. I. ZHIL'TSOV and T. F. ZAKHAROVA, In: Problemy nefti i gaza Tyumenl eProblems Concerning Tyumen Petroleum and Gas). issue 47, p. 50, Tujmen, 1980
]Petrol. Chem. U.S.S.R. Vol. 23, No. I 0 pp. 40-47, 1983 Primcd in Poland
9
0031-6458183 $10.00+.00 1984 Pcrgamon Press Ltd.
LOWER CARBOXYLIC ACIDS OF WEST SIBERIAN CRUDE OIL* S. V. CttERNYAVSKAYA, T. A. FIL1MONOVA and V. F. KAM'YANOV Institute of Petroleum Chemistry, U.S.S.R. Academy of Sciences (Received 18 Au,qust 1981)
IN SPilE o f many years' studies and the industrial value of peiroleum acids, the composition and structure of these crude oil components are still little understood. Over 60 individual fatty, napfithenic and aromatic acids have been identified qualitatively in crude oils [1], however, quantitative information about these substances is restricted to overall content and in a few c a s e s - g r o u p composition and even more r a r e l y - t o the concentration and distribution of alkanoic acids in petroleum. The main reasons why aC!ds are so neglected are the difficulties of separating and determining quantitatively the individual !aeterocompounds of petroleum. Our intensive studies of the lower petroleum acid, involved the use of reactive gas chromatography, and the rapid catalytic deoxygenation of the material and subsequent analysis of reaction products by highly effective capillary G L C by methods previously described [2]. This method has not applied to the stud) of crude oil oxygen compounds although it was used very effectively for the quantitative determination of a large number of individual sulphur compounds in petroleum fractions [3] and appeared to have potential for the analysis of phenols [4, 5] and other natural heterocompounds. * Neftekhimi~)a 23, No. 1, 137-142, 1983.
Lower carboxylie acids of West Siberian crude oil
4t
Z_e
17,
IZ
Z! ZO !
,Z
I]
tO
9 Ill
ee
8
5
b IZ 611 13 7 z!
Ig
H
Chromatographic curves of products of deoxygenation of acids (a) and light petroleum hydrocarbons (b) from a Soviet petroleum deposit: I-2-methylpentane; 2-3-methylpentane; 3 - n-hexane; 4 - methylcyclopentane; 5 - benzene; 6 - cyclohexane; 7 - 2-methylhexane; 8 - 3methylhexane; 9-n-heptane; lO-methylcyc.lohexane; //--toluene; 12-2-methylheptane;
13-3-methylheptane; 14-n-octane; 15-2,6-dimethylheptane; 16-2,5-dimethylheptane;
17-
3,5-dimethylheptane; 18-p-xylene; 19-m-xylene; 2 0 - 2-methyloctane; 21-3-methyloctane;
22-n.nonane.
-42
S ; V; CItERNY,,~VSI~AYA
al.
et
EXPERIMENTAL
Carboxylic acids were recovered from an anhydrous sample of lower chalky West Siberian crude oil (Soviet deposit, Tomsk region; its characteristics have already been reported [6]) by a traditional method, which involved the extraction of all acidic substances with 1 ~o aqueous-alcoholic solution of alkali at room temperature, phenols Were liberated from the alkaline extract with 5~o:solution of sodium bicarbonate and extracted into petroleum ether. Acidification with hydrochloric acid to a p H of 1-2 and repeated extraction with ether, yielded the organic TABLE l . G R O U P COMPOSITION OF LIGftT ItYDROCARBONS AND PRODUCTS OF DEOXYGENATION OF .ACIDS FROM ~VES'I- SIBERIAN OIL, 't.t,'t.~o PER TOTAL OF C 6 - C 9
Componnd
C6
[
C7
[
COMPOUNDS OF
Cs
-
b.p.
u e "to
150~
C9
YC6-C9
2"34 4-48 6-82 2"21 5-10 7"31
28-22 30.89 59.11 21.40 18.18 39.58 1.31 lOO.OO
Petroleum hydroc0rbons n-Paraffins lsoparaffins X of paraffins Alkylcyclopentanes A lkylcyclohexancs S of naphthenes Alkylbenzenes Total
10-51 : 10"49 2l'e0 6.01 2"80 8"81 0-08 29 "89
8"71 7-44 16"15 7-17 5'55 12"72 0"41 29"28
6.66 8;48 15'14 6'01 4-73 10"74 0.82 26.70
14.13
Products of deoxygenation of petroleum acids n-Paraffins lsoparaffins -Yof paraffins Alkylcyclopentanes Alkylcyclohexanes X of naphthenes Alkylbenzcnes Total
3"57 ] 0'60 4.17 0'22 0"36 0"58 0"14 4"89 :
!6"10 :4"63 10.73 ~1,91 ,I-54 3.45 .0-57 14.75
9"72 10-20 19.92 2.18 3.20 5.38 4.01 . 29-31
16-10 29-16 45 "26 1.20
4.59 5"79 51.05
35.49 44.59 80.08 6.75 7.48 14.23 4.72 100.00
acids. The acids (0.23 w L ~ on'crud+ bii),were esterified with" cli-azomethane. Methyl esters were hydrogcrio'lysed in acontinubus micro-rdactor (eval~orator ofa'.'Khrom-41" gas chromatograph [2]), containing 2 g finely granulated (0-5-1.0' ram) industrial nicke! catalyst (skeletal nickel) at a temperature of 250~ and a hydrogen pressure of 0-1 MPa through a flow divider (1:500). The hydrogenolysate wag passed through a stainless steel capillary column (50 m x0.25 m m ) c o a t e d with squalane and thermostatically controlled at 50~ where it was separated and the components w e r e detected using a flame-ionization detector. A light petroleum spirit I B P - 150~'C from the same petroleum was analysed under the same conditions, but in the absence of catalyst. Chromatographic curves of light petroleum hydrocarbons and products of deoxygenation of acids are shown in the Figure.
Lower carboxylic acids of West Siberian crude oil
43"
TABLE 2. DISTRIBUTION OF ALIPtlATIC IIYDROCARBONS (a) AND PRODUCTS OF DEOX~fGI~NATION "OF ACIDS ( b ) FROM A SOVIET PETROLEUM DEPOSIT ( W t . ~ o OF THE TOTAL OF ISOMERS)
Compound
a
j
b
2-Mcthylpentane 3-Methylpentane 2,2-Dimr 2,3-Dimethylbutane X iso-C6
1oo.o
1o6.o
2-Methylhexane 3-MethsIhexane 3-Ethylpentane 2,2-Dimcthylpentane 2,3-Dimcthylpentane 2,4-Dimethylpentane 3,3-Dimethylpentane 2,2,3-Trimethylbutane , S iso-C7
31 "5 46"4 0"7 1"5 14"9 4'0 0'5 0'5 100'0
33"9 50"1 0 0"4 12"7 1"7 0"5 0"5 100"0
39"7 25 "5 12"0 1"1 0'8 3"5 3"9 4"7 0"8 1"4
43 '4 35"3 15"8 0 0"4 1"8 0"8 0"9 0 0"2
61 "2 63"3 34"8 . 36-7 0"8 I 0 3.2 0
i
2-Methylpentane 3-Methylpentane 4-Methylpentane 3-Ethylhexane 2,2-Dimethylhexane 2,3-Dmethylhexane 2,4-Dimethylhexane 2,5-Dimethylhexane 3,3-Dimethylhexane 3,4-Dimethylhexane
Compound
[
a
b
1
2-Methyl-3-ethylpentane [ 1-7 3-Metbyl-3-ethylpentane 0"2 2,2,3-Trimethylpentane 0-7 2,2,4-Trimethylpentane [ 0-6 2,3,3-Trimethylpentane 0"5 2,3,4-Trimethylpentane 2-8 X iso-Cs 100-0. I
2-Methyloctane 3-Methyloctane 4-Methyloctane 3-Ethylpentane 4-Ethylpentane 2,2-Dimcthylpentane 2,3-Dimethylheptane 2,4-D!methylheptane 2,5-Dimethylheptane 2,6-Dimethylheptane 3,3-Dimethylheptane 3,4-Dimethylheptane 3,5-Dimethylh:ptane 2-Mcthyl-4-ethylhexan~ 2,3,5-Trimethylhexa ne -,~ iso-C9
1"1 0 0 0
0.4 100"0
] 19.2 23-4 [ 20"8 26-4 5"4 12-4 1-1 ,1"7 0-7 ; 0.9 0"9 [ 0-2 i 8'9 11-1 I 6.0 1-6 6"7 5.1 21-2 13.3 0-4 0"l 1-1 0'6 3-3 3.1 1"6 0 2.7 0.1 100-0 100.0
RESULTS
Previous work has demonstrated a correspondence between the concentration of fatty acids and hydrocarbons with similar carbon skeletons in petroleums rock extracts: Thus the concentratiort of isoprenane acids vary in parallel with concentr,itions of corresponding isoprenane hydrocarbons [7], whereas the distribution o f linear fatty acids more closely parallels that of n-paraffins, containing one fewer Icarbon atom per molecule. This relationship is particularly characteristic of recent oils [8] and rock extracts [1, 9]. Regularities which reflect the interdependence of petroleum acids and hydrocarbons were only established for comparatively high molecular weight components, where linear and isoprenoid compounds often predominate but most other isomers are absent or not recorded by existing methods. Light petroleum fractions contain most theoretically possible hydrocarbon isomers, their concentrations are readily determined by capillary GLC. A number of low-molecular weight isomeric hzdr 0carbons were identified among the deoxygenation products of petroleum acids that
44
S.V.
CilERNYAVSKAYA e l al.
TABLE 3. DISTRIBUTION OF cYcLIc ItYDROCARBONS (a) AND PRODUC'IS OF DEOXYGENATI'ON Ol ACIDS (b) FROM SOVIET PETROLEUM DEPOSI'IS (Wt. ~o OF ~'HE TOTAL OF ISOMERS)
Compound Ethylcyclopentane
l,I-Dimethylcyclopentane
trans.l,2-Dimethylcyclopentane cis.l,2-Dimethylcyclopentane trans.1,3-Dimethylcyclopentane cis-l,3-Dimethylcyclopentane X of C7 eycl0pentanes n-Propylcyclopentane lsopropylcyclopentane trans-I -Methyl-2-ethylcyelopentane
trans-l-Methyl-3-ethylcyclopentane cis-I -Methyl-3-ethylcyclopentanc l,l,2-Trimethylcyclopenta,ne l,l,3-Trimeth.ylcycl0pentane
trans; trans-l,2,3-Trimethylcyclopentane trans, cis-l,2,3-Trimethyleyclopenta.ne trans, trans-l,2,4-Trimethyleyelopentane 1,2,4-Trimethylcyclopentane(cis, trans-+ cis, cis) X of Ca eyclopentanes
trans.l-Methyl-2-propylcyclopentane l ,l -Dimethyl-3-ethylcyclopentane
trans, trans-l,2-Dimethyl-3-ethyleyclopentane trans, cis-1,2-Dimeth)l-3-ethylcyelopentane cis, trans-l,2-Dimethyl-3-r trans, cis-1,4-Dimethyl-2-ethylcyclopentane tram, trans-1,4-Dimethyl-2-ethylcyclopentane Unidentified Ca cyclopentanes Z" of C9 cyclopentanes Ethylcyclohexane l,l-Dimethylcyclohexane trans-1,2-Dimet hyleyclohexane cis-1,2-Dimet hylcyclohexane
trans-1,3-Dimethylcyclohexane cls-l,3-Dimethylcyclohexane trans-1,4-Dimethyleyclohexane cis-l,4-Dimethyleyclohexane r of Ca eyclohexanes
cis-I -Methyl-3-ethylcyclohexane l,l,3-Trimetbylcyclohexane 1,1,4-Trimethylcyclohexane
trans, trans-l,2,3-Trimethylc~clohexane trans, cis-l,2,4-Trimethyleyclohexane trans, trans-1,2,4-Trimetl~ylcyclohexane trans, cis-1,3,5-Trimethyleyclohexane cis, cis-l,3,5-Trimethylcyclohexane Unidentified (29 eyclohexanes
a
b
22.6 4"9 35"8 4-0 13-9 18-8 100-0 8-2 2-2 22"1 13.3 14"8 4"3 12-3 7"0 I-2 12-3 2-3 100"0 28"1 13"1 8"6 8"1
19"4 3"7 31 "4 3"7 17"8 24"0 100"0 11"0 2"8
5:4
11"9 9"6 11"0 5"5 14"7 7"8 2"3 17"9 5"5 100-0 27.5 13-3 9"2 8-3 5.0 14-2
14"5 II'8 10"4 I00'0 24"I 4"7 17-5 1"7 6'6
I00"0 "26"2 4"I 13"I 3"I 6"2
33.0 9.7 2.7 100.0 7"8 15"7 6'9 7"0 7"1 2-0 2"4 6"7 44"1
32.9 10-6 3.8 iO0.O 10-7 ,14"2 6-1 14"4 16.3 4-4 3-9 7"0 23.1
11-7 10-8
Lower caxboxylic acids of West Siberian crude oil Compound of C9 cydohexancs Ethylbcnzene o-Xylene nl-Xylene p-Xylene Z"of Cs alkylbenzenes
45
a
b
io00
1130.0 16.2 22.9 9 47-9 13-0 I00.0
17"1 30.5 41"5 11-0 1130-0
we examined however, tile reaction products and native h~rdrocarbons of the same oil were not identical neither were their ratios (Tables I-3). Hydrogenolysis products of the acids of Soviet oil were characterized by a much larger proportion of aliphatic and a smaller proportion of naphthenie compounds, when compared with native hydrocarbons (Table 1). The concentration of acids of all structural types rapidly increases with increasing carbon number whereas the paraffins and naphthenic hydrocarbons showed the opposite trend. Under the conditions of hydrogenolysis studied at least 80% benzene rings underwent hydrogenation, whereas only about 20% hexamethylene rings were I aromatized [2]. The concentrations of alkylcyclohexanes found in the products of deoxygenation are accordingly too high, compared with proportions of cyclohexanoic acids in crude oil. With this: reservation the cyclopentane structures are seen to predominate over cyclohexane structures, this distribution is preserved in the light petroleum fractions of Mesozoic otis of West Siberia and is, apparently, also typical of acids. Furthermore, the concentration of lower arene structures in the petroleum studied is much higher among natural acids than among native hydrocarbons. The higher the overall concentration ot paraffins in light petroleum spirits, the higher was the proportion of n-paraffins and monomethyl alkanes amongst the isoalkanes [10]. Similarly, the products from deoxygenation of lower acids are more aliphatic than are the native hydrocarbons of the same oil, they contain a high proportion of n- and monomethyl alkanes amongst the constituent isoalkanes {Table 2). The ratios of isomeric monomethylparaffins and more branched aliphatic structures among the products from deoxygenation of acids and native hydrocarbons are very similar. The skeletal aikanes from deoxygenation of petroleum acids like the native hydrocarbons of the crude oil are similar in structure and characterized by the alkanes already mentioned and supplemented by 2,3- and 2,6-dimethylalkanes. These results indicate that carboxyl groups in petroleum acids appear largely in terminal positions in aliphatic chains; otherwise, hydrogenolysis of the carboxyl .groups should result in a noticeable increase in relative concentration of branched alkanes. Quantitative ratios of structurally identical acids and native naphthenic hydro.carbons (Table 3) are fairly similar. Among the low-boiling alicyclic hydrocarbons of petroleum thermodynamically more stable isomers predominate [11], the structure ~of the alkanes resulting from hydrogenolysis of the lower naphthenic acids of this \ ~crude oil appear to follow the same rule.
4.6
S. V. CtlERNYAVSKAYA e t aL
"
The proportions of isomeric xylenes formed during.de0xygenation of the separated acids differ markedly from the ratios o f the equivalent native arenes, noticeable is the increased concentration of the m-isomer at the expense of the o-is'omer (Table 3). These results confirm a close similarity between the distribution of natural petroleum hydrocarbons and carboxylic acids. The lower acids and light petroleum hydrocarbons include amongst their number a variety of skeletal variations w]dlst the proportions are similar. Isomeric variation among the petroleun'~ acids is restricted by the end-of-chain location of tlie carboxyl group. The isomeric cofnposition o f high-bgiling hydroc~rbons and acids is much more limited, previous "workers [i] have established similar (rends. The main differences between distributions of acids arid hydrocarbons from the same petroleum are Observed in their group comp.osition but not in their isomer distribution, tiie variation in group composition is higlflighted by the variation in the relative contents of aliphati c, ajigyclic and aromatic structur,is i n each. Class o f compound, Changes in the group composition of petroleunl acids 9are proportional to the ch,'inges in the hydrocarbon group composition of petroleum. SUMMARY
1. Capillary gasqi~luid chromatography revealed composition' of'products o f catalytic dr of low-molecular weight acids f r o m crude oils of Soviet deposits. The lower p'etroleum acids have structures similar to those o f the hydro9carbons oi~.!ight petroleum spirits. These structures would be equivalent to the ,theoretieal!y possible isomers coming from acids with the earl~oxyl group lhai,aly in terminal positions. The quantitative distribution of isomeric acids arid hydrocarbons conf0rms to the same mechanisms. 2. Petroleum'acids are characterized by a highei" content of aliphatic and aromatic structures, but a lower content of alicycl!c structures than the corresponding hydrocarbons of light petroleum spirits from the same oil. REFERENCES
1. W. K. SEIFERT, Carboxylic Acids in Petroleum and Sediments. Fortschr. der Chem. org. Naturst., vol. 32, Springer Verlag, Wien-New York, 1975 2. S. "~:. C H E R N Y A V S K A Y A , T. A. FILIMONOVA and V. F. KAM'~'ANOV, Ncftckhimiya 22, 1982 3. It. T. RALL, C.J. THO,MI:'SON, tl. J. COLEMAN and R. L. HOPKINS, Sulfur Compounds in Crude Oil. US Bur. Mines Bull., Wash., 659,:187, 1972 4. Yu. E. LILLE and Kh. A. KUNDEL', In: Gazovaya.khromat0grafiya (Gas Chromatography), issue 3, pp. 42-48, NIITEKhim., Moscow, 1965 5. I. R. KLESMENT, In: Gazovaya khromatografiya, issue 4, pp. 102-110, NIITEKhim., Moscow, 1966 6. A. K. LEBEDEV, L. V. GORBUNOVA and V. F. KAM'YANOV, Neftekhimyia 20, 6, 918-926, 1980 7. A. G. DOUGLAS, K. DOURAGItI-ZADEH, G. EGLINTON, J. R. MAXWELL and J. N. RAMSAY, In: Adv. in Org. Geochemistry, 1966 (eds. G. D. ltobson and G. C. Speers). p. 315, Pergamon Press,Oxford, 1970
Cyclanes of.naphthal/me crude oil
-47
- 8. J . E . COOPER and E. E~ IIRAY,-Ge0chim. Cosrnochim. Acta 27, 11, 1113-1127,;1963 9 9. K. A. KVENVOLDENi Nature 209, 4.921,573, !966 :: .~10. V: F. KAM'YANOV, Dis. na soiskaniye uch. st. kand. khirn, nauk, IKh AN TSSR, Ashkhabad, 1971 11. AI. A. Pi~TROV~ Khimi:;'a naftenov, p. 388, Nauka, Moscow, 1971
0031~458/83 S I0.00+.00" ~) 1984 pergamon Press Lt,J.
Petrol. Chem. U.S.S.R. Vol. 23, No. 1, pp. 47-52, 1983 Printed in Poland
CYCLANES OF NAPHTHALANE CRUDE OIL::' E. K~L KURASHOVA, YE. S. BRODSKII, I. A. MUSAYEV, A. M. KRAPIVIN, L. S. YE~I',IAKOVA and P. I. SANIN A. V. Topchiyev Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences ,
(Receh'ed
12
May
1982)
IN a previous study [1] concerning the chemical composition of naphthalane crude oi! in connection with explaining active and natural products related ratios of componefits of this oil main' attention was given to investigating hydrocarbons of isoprenoid, st'eraiioid and triterpenoid types. ~, Mass and N M R spectroscopy using ~aC nucleiwere applied in this study t o the examination o f the structure of the cyclanes in naphthalane crude oil. Saturated h y d r o c a r b o n s Were eluted by n-hexane from naphthalane crUde oil "adsorbed on ASK silica gel. These hydrocarbons which are essentially cyclanes were fractionally distilled at 0.133 Pa. Cyclane fractions b.p. 180~ ~ 250~ ~ "350~ ~ 400~176 450~176 and a residue boiling higher than 525~ were 9dbtaih'ed. ' 9t ' Mass spectra t were obtained from a MKh-1303 mass-spectrometer at 50 eV, (ionisation chamber 250~ admission system (cylinder) 200-250~ Characteristic ion groups [2] were separated mass-spectr0metrically, and the structural-group composition and characteristics of the compounds were established
[31. Paraftinic hydrocarbons were practically absent from the crude oil and from the cyclane concentrates. The crude oil cyclanes (Table 1) consist of hydrocarbons containing one to eight rings per molecule, the main part (87.5 70)ctimpriscd mono-, bi-, tri- and tetracyclic hydrocarbons; bicyclic (29-8 70) and tricyclic (24.2 ~ hydro147-151, 1983. Mass spectra were obtained by V. G. l'ebedevskaya, for which the authors are grateful.
* Neftekhimiya 23, No. 2,
S. V. CHERNYAVSKAYA e t
aL
16. N. S. NAMETKIN, L. P. K()LESNIKOVA, T. G. BAIKOVA, A. A. BABYLOVA, L. K. 9RUMYANTSEVA and G. V. MOROZOVA, N.eftekhimiya 19, 127, 1979 17. Preobrazovaniye neftei mikroorganizmami (Transformation of Oils by Micro-organisms), Tr. VNIGRI, 281, 8, 15, Leningrad, 1970 18. S.I. KUZNETSOV, M. V. IVANOV and N. N. LYALIKOVA, Vvedeniye v geologicheskuyu mikrobiologiyu (Introduction to Geological Microbiology), p. 73, Izd. AN SSSR, Moscow, 1962
19. L. I. VLADIMIROVA, In: Geokhimicheskiye metody poiskov nefti i gaza na Russkoi platforme (Geochemical Methods of Research into Oil and Gas in Russian Deposits), p. 54, Saratov, 1980 20. V. A. YERSHOV, N. I. ZHIL'TSOV and T. F. ZAKHAROVA, In: Problemy nefti i gaza Tyumenl eProblems Concerning Tyumen Petroleum and Gas). issue 47, p. 50, Tujmen, 1980
]Petrol. Chem. U.S.S.R. Vol. 23, No. I 0 pp. 40-47, 1983 Primcd in Poland
9
0031-6458183 $10.00+.00 1984 Pcrgamon Press Ltd.
LOWER CARBOXYLIC ACIDS OF WEST SIBERIAN CRUDE OIL* S. V. CttERNYAVSKAYA, T. A. FIL1MONOVA and V. F. KAM'YANOV Institute of Petroleum Chemistry, U.S.S.R. Academy of Sciences (Received 18 Au,qust 1981)
IN SPilE o f many years' studies and the industrial value of peiroleum acids, the composition and structure of these crude oil components are still little understood. Over 60 individual fatty, napfithenic and aromatic acids have been identified qualitatively in crude oils [1], however, quantitative information about these substances is restricted to overall content and in a few c a s e s - g r o u p composition and even more r a r e l y - t o the concentration and distribution of alkanoic acids in petroleum. The main reasons why aC!ds are so neglected are the difficulties of separating and determining quantitatively the individual !aeterocompounds of petroleum. Our intensive studies of the lower petroleum acid, involved the use of reactive gas chromatography, and the rapid catalytic deoxygenation of the material and subsequent analysis of reaction products by highly effective capillary G L C by methods previously described [2]. This method has not applied to the stud) of crude oil oxygen compounds although it was used very effectively for the quantitative determination of a large number of individual sulphur compounds in petroleum fractions [3] and appeared to have potential for the analysis of phenols [4, 5] and other natural heterocompounds. * Neftekhimi~)a 23, No. 1, 137-142, 1983.
Lower carboxylie acids of West Siberian crude oil
4t
Z_e
17,
IZ
Z! ZO !
,Z
I]
tO
9 Ill
ee
8
5
b IZ 611 13 7 z!
Ig
H
Chromatographic curves of products of deoxygenation of acids (a) and light petroleum hydrocarbons (b) from a Soviet petroleum deposit: I-2-methylpentane; 2-3-methylpentane; 3 - n-hexane; 4 - methylcyclopentane; 5 - benzene; 6 - cyclohexane; 7 - 2-methylhexane; 8 - 3methylhexane; 9-n-heptane; lO-methylcyc.lohexane; //--toluene; 12-2-methylheptane;
13-3-methylheptane; 14-n-octane; 15-2,6-dimethylheptane; 16-2,5-dimethylheptane;
17-
3,5-dimethylheptane; 18-p-xylene; 19-m-xylene; 2 0 - 2-methyloctane; 21-3-methyloctane;
22-n.nonane.
-42
S ; V; CItERNY,,~VSI~AYA
al.
et
EXPERIMENTAL
Carboxylic acids were recovered from an anhydrous sample of lower chalky West Siberian crude oil (Soviet deposit, Tomsk region; its characteristics have already been reported [6]) by a traditional method, which involved the extraction of all acidic substances with 1 ~o aqueous-alcoholic solution of alkali at room temperature, phenols Were liberated from the alkaline extract with 5~o:solution of sodium bicarbonate and extracted into petroleum ether. Acidification with hydrochloric acid to a p H of 1-2 and repeated extraction with ether, yielded the organic TABLE l . G R O U P COMPOSITION OF LIGftT ItYDROCARBONS AND PRODUCTS OF DEOXYGENATION OF .ACIDS FROM ~VES'I- SIBERIAN OIL, 't.t,'t.~o PER TOTAL OF C 6 - C 9
Componnd
C6
[
C7
[
COMPOUNDS OF
Cs
-
b.p.
u e "to
150~
C9
YC6-C9
2"34 4-48 6-82 2"21 5-10 7"31
28-22 30.89 59.11 21.40 18.18 39.58 1.31 lOO.OO
Petroleum hydroc0rbons n-Paraffins lsoparaffins X of paraffins Alkylcyclopentanes A lkylcyclohexancs S of naphthenes Alkylbenzenes Total
10-51 : 10"49 2l'e0 6.01 2"80 8"81 0-08 29 "89
8"71 7-44 16"15 7-17 5'55 12"72 0"41 29"28
6.66 8;48 15'14 6'01 4-73 10"74 0.82 26.70
14.13
Products of deoxygenation of petroleum acids n-Paraffins lsoparaffins -Yof paraffins Alkylcyclopentanes Alkylcyclohexanes X of naphthenes Alkylbenzcnes Total
3"57 ] 0'60 4.17 0'22 0"36 0"58 0"14 4"89 :
!6"10 :4"63 10.73 ~1,91 ,I-54 3.45 .0-57 14.75
9"72 10-20 19.92 2.18 3.20 5.38 4.01 . 29-31
16-10 29-16 45 "26 1.20
4.59 5"79 51.05
35.49 44.59 80.08 6.75 7.48 14.23 4.72 100.00
acids. The acids (0.23 w L ~ on'crud+ bii),were esterified with" cli-azomethane. Methyl esters were hydrogcrio'lysed in acontinubus micro-rdactor (eval~orator ofa'.'Khrom-41" gas chromatograph [2]), containing 2 g finely granulated (0-5-1.0' ram) industrial nicke! catalyst (skeletal nickel) at a temperature of 250~ and a hydrogen pressure of 0-1 MPa through a flow divider (1:500). The hydrogenolysate wag passed through a stainless steel capillary column (50 m x0.25 m m ) c o a t e d with squalane and thermostatically controlled at 50~ where it was separated and the components w e r e detected using a flame-ionization detector. A light petroleum spirit I B P - 150~'C from the same petroleum was analysed under the same conditions, but in the absence of catalyst. Chromatographic curves of light petroleum hydrocarbons and products of deoxygenation of acids are shown in the Figure.
Lower carboxylic acids of West Siberian crude oil
43"
TABLE 2. DISTRIBUTION OF ALIPtlATIC IIYDROCARBONS (a) AND PRODUCTS OF DEOX~fGI~NATION "OF ACIDS ( b ) FROM A SOVIET PETROLEUM DEPOSIT ( W t . ~ o OF THE TOTAL OF ISOMERS)
Compound
a
j
b
2-Mcthylpentane 3-Methylpentane 2,2-Dimr 2,3-Dimethylbutane X iso-C6
1oo.o
1o6.o
2-Methylhexane 3-MethsIhexane 3-Ethylpentane 2,2-Dimcthylpentane 2,3-Dimcthylpentane 2,4-Dimethylpentane 3,3-Dimethylpentane 2,2,3-Trimethylbutane , S iso-C7
31 "5 46"4 0"7 1"5 14"9 4'0 0'5 0'5 100'0
33"9 50"1 0 0"4 12"7 1"7 0"5 0"5 100"0
39"7 25 "5 12"0 1"1 0'8 3"5 3"9 4"7 0"8 1"4
43 '4 35"3 15"8 0 0"4 1"8 0"8 0"9 0 0"2
61 "2 63"3 34"8 . 36-7 0"8 I 0 3.2 0
i
2-Methylpentane 3-Methylpentane 4-Methylpentane 3-Ethylhexane 2,2-Dimethylhexane 2,3-Dmethylhexane 2,4-Dimethylhexane 2,5-Dimethylhexane 3,3-Dimethylhexane 3,4-Dimethylhexane
Compound
[
a
b
1
2-Methyl-3-ethylpentane [ 1-7 3-Metbyl-3-ethylpentane 0"2 2,2,3-Trimethylpentane 0-7 2,2,4-Trimethylpentane [ 0-6 2,3,3-Trimethylpentane 0"5 2,3,4-Trimethylpentane 2-8 X iso-Cs 100-0. I
2-Methyloctane 3-Methyloctane 4-Methyloctane 3-Ethylpentane 4-Ethylpentane 2,2-Dimcthylpentane 2,3-Dimethylheptane 2,4-D!methylheptane 2,5-Dimethylheptane 2,6-Dimethylheptane 3,3-Dimethylheptane 3,4-Dimethylheptane 3,5-Dimethylh:ptane 2-Mcthyl-4-ethylhexan~ 2,3,5-Trimethylhexa ne -,~ iso-C9
1"1 0 0 0
0.4 100"0
] 19.2 23-4 [ 20"8 26-4 5"4 12-4 1-1 ,1"7 0-7 ; 0.9 0"9 [ 0-2 i 8'9 11-1 I 6.0 1-6 6"7 5.1 21-2 13.3 0-4 0"l 1-1 0'6 3-3 3.1 1"6 0 2.7 0.1 100-0 100.0
RESULTS
Previous work has demonstrated a correspondence between the concentration of fatty acids and hydrocarbons with similar carbon skeletons in petroleums rock extracts: Thus the concentratiort of isoprenane acids vary in parallel with concentr,itions of corresponding isoprenane hydrocarbons [7], whereas the distribution o f linear fatty acids more closely parallels that of n-paraffins, containing one fewer Icarbon atom per molecule. This relationship is particularly characteristic of recent oils [8] and rock extracts [1, 9]. Regularities which reflect the interdependence of petroleum acids and hydrocarbons were only established for comparatively high molecular weight components, where linear and isoprenoid compounds often predominate but most other isomers are absent or not recorded by existing methods. Light petroleum fractions contain most theoretically possible hydrocarbon isomers, their concentrations are readily determined by capillary GLC. A number of low-molecular weight isomeric hzdr 0carbons were identified among the deoxygenation products of petroleum acids that
44
S.V.
CilERNYAVSKAYA e l al.
TABLE 3. DISTRIBUTION OF cYcLIc ItYDROCARBONS (a) AND PRODUC'IS OF DEOXYGENATI'ON Ol ACIDS (b) FROM SOVIET PETROLEUM DEPOSI'IS (Wt. ~o OF ~'HE TOTAL OF ISOMERS)
Compound Ethylcyclopentane
l,I-Dimethylcyclopentane
trans.l,2-Dimethylcyclopentane cis.l,2-Dimethylcyclopentane trans.1,3-Dimethylcyclopentane cis-l,3-Dimethylcyclopentane X of C7 eycl0pentanes n-Propylcyclopentane lsopropylcyclopentane trans-I -Methyl-2-ethylcyelopentane
trans-l-Methyl-3-ethylcyclopentane cis-I -Methyl-3-ethylcyclopentanc l,l,2-Trimethylcyclopenta,ne l,l,3-Trimeth.ylcycl0pentane
trans; trans-l,2,3-Trimethylcyclopentane trans, cis-l,2,3-Trimethyleyclopenta.ne trans, trans-l,2,4-Trimethyleyelopentane 1,2,4-Trimethylcyclopentane(cis, trans-+ cis, cis) X of Ca eyclopentanes
trans.l-Methyl-2-propylcyclopentane l ,l -Dimethyl-3-ethylcyclopentane
trans, trans-l,2-Dimethyl-3-ethyleyclopentane trans, cis-1,2-Dimeth)l-3-ethylcyelopentane cis, trans-l,2-Dimethyl-3-r trans, cis-1,4-Dimethyl-2-ethylcyclopentane tram, trans-1,4-Dimethyl-2-ethylcyclopentane Unidentified Ca cyclopentanes Z" of C9 cyclopentanes Ethylcyclohexane l,l-Dimethylcyclohexane trans-1,2-Dimet hyleyclohexane cis-1,2-Dimet hylcyclohexane
trans-1,3-Dimethylcyclohexane cls-l,3-Dimethylcyclohexane trans-1,4-Dimethyleyclohexane cis-l,4-Dimethyleyclohexane r of Ca eyclohexanes
cis-I -Methyl-3-ethylcyclohexane l,l,3-Trimetbylcyclohexane 1,1,4-Trimethylcyclohexane
trans, trans-l,2,3-Trimethylc~clohexane trans, cis-l,2,4-Trimethyleyclohexane trans, trans-1,2,4-Trimetl~ylcyclohexane trans, cis-1,3,5-Trimethyleyclohexane cis, cis-l,3,5-Trimethylcyclohexane Unidentified (29 eyclohexanes
a
b
22.6 4"9 35"8 4-0 13-9 18-8 100-0 8-2 2-2 22"1 13.3 14"8 4"3 12-3 7"0 I-2 12-3 2-3 100"0 28"1 13"1 8"6 8"1
19"4 3"7 31 "4 3"7 17"8 24"0 100"0 11"0 2"8
5:4
11"9 9"6 11"0 5"5 14"7 7"8 2"3 17"9 5"5 100-0 27.5 13-3 9"2 8-3 5.0 14-2
14"5 II'8 10"4 I00'0 24"I 4"7 17-5 1"7 6'6
I00"0 "26"2 4"I 13"I 3"I 6"2
33.0 9.7 2.7 100.0 7"8 15"7 6'9 7"0 7"1 2-0 2"4 6"7 44"1
32.9 10-6 3.8 iO0.O 10-7 ,14"2 6-1 14"4 16.3 4-4 3-9 7"0 23.1
11-7 10-8
Lower caxboxylic acids of West Siberian crude oil Compound of C9 cydohexancs Ethylbcnzene o-Xylene nl-Xylene p-Xylene Z"of Cs alkylbenzenes
45
a
b
io00
1130.0 16.2 22.9 9 47-9 13-0 I00.0
17"1 30.5 41"5 11-0 1130-0
we examined however, tile reaction products and native h~rdrocarbons of the same oil were not identical neither were their ratios (Tables I-3). Hydrogenolysis products of the acids of Soviet oil were characterized by a much larger proportion of aliphatic and a smaller proportion of naphthenie compounds, when compared with native hydrocarbons (Table 1). The concentration of acids of all structural types rapidly increases with increasing carbon number whereas the paraffins and naphthenic hydrocarbons showed the opposite trend. Under the conditions of hydrogenolysis studied at least 80% benzene rings underwent hydrogenation, whereas only about 20% hexamethylene rings were I aromatized [2]. The concentrations of alkylcyclohexanes found in the products of deoxygenation are accordingly too high, compared with proportions of cyclohexanoic acids in crude oil. With this: reservation the cyclopentane structures are seen to predominate over cyclohexane structures, this distribution is preserved in the light petroleum fractions of Mesozoic otis of West Siberia and is, apparently, also typical of acids. Furthermore, the concentration of lower arene structures in the petroleum studied is much higher among natural acids than among native hydrocarbons. The higher the overall concentration ot paraffins in light petroleum spirits, the higher was the proportion of n-paraffins and monomethyl alkanes amongst the isoalkanes [10]. Similarly, the products from deoxygenation of lower acids are more aliphatic than are the native hydrocarbons of the same oil, they contain a high proportion of n- and monomethyl alkanes amongst the constituent isoalkanes {Table 2). The ratios of isomeric monomethylparaffins and more branched aliphatic structures among the products from deoxygenation of acids and native hydrocarbons are very similar. The skeletal aikanes from deoxygenation of petroleum acids like the native hydrocarbons of the crude oil are similar in structure and characterized by the alkanes already mentioned and supplemented by 2,3- and 2,6-dimethylalkanes. These results indicate that carboxyl groups in petroleum acids appear largely in terminal positions in aliphatic chains; otherwise, hydrogenolysis of the carboxyl .groups should result in a noticeable increase in relative concentration of branched alkanes. Quantitative ratios of structurally identical acids and native naphthenic hydro.carbons (Table 3) are fairly similar. Among the low-boiling alicyclic hydrocarbons of petroleum thermodynamically more stable isomers predominate [11], the structure ~of the alkanes resulting from hydrogenolysis of the lower naphthenic acids of this \ ~crude oil appear to follow the same rule.
4.6
S. V. CtlERNYAVSKAYA e t aL
"
The proportions of isomeric xylenes formed during.de0xygenation of the separated acids differ markedly from the ratios o f the equivalent native arenes, noticeable is the increased concentration of the m-isomer at the expense of the o-is'omer (Table 3). These results confirm a close similarity between the distribution of natural petroleum hydrocarbons and carboxylic acids. The lower acids and light petroleum hydrocarbons include amongst their number a variety of skeletal variations w]dlst the proportions are similar. Isomeric variation among the petroleun'~ acids is restricted by the end-of-chain location of tlie carboxyl group. The isomeric cofnposition o f high-bgiling hydroc~rbons and acids is much more limited, previous "workers [i] have established similar (rends. The main differences between distributions of acids arid hydrocarbons from the same petroleum are Observed in their group comp.osition but not in their isomer distribution, tiie variation in group composition is higlflighted by the variation in the relative contents of aliphati c, ajigyclic and aromatic structur,is i n each. Class o f compound, Changes in the group composition of petroleunl acids 9are proportional to the ch,'inges in the hydrocarbon group composition of petroleum. SUMMARY
1. Capillary gasqi~luid chromatography revealed composition' of'products o f catalytic dr of low-molecular weight acids f r o m crude oils of Soviet deposits. The lower p'etroleum acids have structures similar to those o f the hydro9carbons oi~.!ight petroleum spirits. These structures would be equivalent to the ,theoretieal!y possible isomers coming from acids with the earl~oxyl group lhai,aly in terminal positions. The quantitative distribution of isomeric acids arid hydrocarbons conf0rms to the same mechanisms. 2. Petroleum'acids are characterized by a highei" content of aliphatic and aromatic structures, but a lower content of alicycl!c structures than the corresponding hydrocarbons of light petroleum spirits from the same oil. REFERENCES
1. W. K. SEIFERT, Carboxylic Acids in Petroleum and Sediments. Fortschr. der Chem. org. Naturst., vol. 32, Springer Verlag, Wien-New York, 1975 2. S. "~:. C H E R N Y A V S K A Y A , T. A. FILIMONOVA and V. F. KAM'~'ANOV, Ncftckhimiya 22, 1982 3. It. T. RALL, C.J. THO,MI:'SON, tl. J. COLEMAN and R. L. HOPKINS, Sulfur Compounds in Crude Oil. US Bur. Mines Bull., Wash., 659,:187, 1972 4. Yu. E. LILLE and Kh. A. KUNDEL', In: Gazovaya.khromat0grafiya (Gas Chromatography), issue 3, pp. 42-48, NIITEKhim., Moscow, 1965 5. I. R. KLESMENT, In: Gazovaya khromatografiya, issue 4, pp. 102-110, NIITEKhim., Moscow, 1966 6. A. K. LEBEDEV, L. V. GORBUNOVA and V. F. KAM'YANOV, Neftekhimyia 20, 6, 918-926, 1980 7. A. G. DOUGLAS, K. DOURAGItI-ZADEH, G. EGLINTON, J. R. MAXWELL and J. N. RAMSAY, In: Adv. in Org. Geochemistry, 1966 (eds. G. D. ltobson and G. C. Speers). p. 315, Pergamon Press,Oxford, 1970
Cyclanes of.naphthal/me crude oil
-47
- 8. J . E . COOPER and E. E~ IIRAY,-Ge0chim. Cosrnochim. Acta 27, 11, 1113-1127,;1963 9 9. K. A. KVENVOLDENi Nature 209, 4.921,573, !966 :: .~10. V: F. KAM'YANOV, Dis. na soiskaniye uch. st. kand. khirn, nauk, IKh AN TSSR, Ashkhabad, 1971 11. AI. A. Pi~TROV~ Khimi:;'a naftenov, p. 388, Nauka, Moscow, 1971
0031~458/83 S I0.00+.00" ~) 1984 pergamon Press Lt,J.
Petrol. Chem. U.S.S.R. Vol. 23, No. 1, pp. 47-52, 1983 Printed in Poland
CYCLANES OF NAPHTHALANE CRUDE OIL::' E. K~L KURASHOVA, YE. S. BRODSKII, I. A. MUSAYEV, A. M. KRAPIVIN, L. S. YE~I',IAKOVA and P. I. SANIN A. V. Topchiyev Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences ,
(Receh'ed
12
May
1982)
IN a previous study [1] concerning the chemical composition of naphthalane crude oi! in connection with explaining active and natural products related ratios of componefits of this oil main' attention was given to investigating hydrocarbons of isoprenoid, st'eraiioid and triterpenoid types. ~, Mass and N M R spectroscopy using ~aC nucleiwere applied in this study t o the examination o f the structure of the cyclanes in naphthalane crude oil. Saturated h y d r o c a r b o n s Were eluted by n-hexane from naphthalane crUde oil "adsorbed on ASK silica gel. These hydrocarbons which are essentially cyclanes were fractionally distilled at 0.133 Pa. Cyclane fractions b.p. 180~ ~ 250~ ~ "350~ ~ 400~176 450~176 and a residue boiling higher than 525~ were 9dbtaih'ed. ' 9t ' Mass spectra t were obtained from a MKh-1303 mass-spectrometer at 50 eV, (ionisation chamber 250~ admission system (cylinder) 200-250~ Characteristic ion groups [2] were separated mass-spectr0metrically, and the structural-group composition and characteristics of the compounds were established
[31. Paraftinic hydrocarbons were practically absent from the crude oil and from the cyclane concentrates. The crude oil cyclanes (Table 1) consist of hydrocarbons containing one to eight rings per molecule, the main part (87.5 70)ctimpriscd mono-, bi-, tri- and tetracyclic hydrocarbons; bicyclic (29-8 70) and tricyclic (24.2 ~ hydro147-151, 1983. Mass spectra were obtained by V. G. l'ebedevskaya, for which the authors are grateful.
* Neftekhimiya 23, No. 2,