Study of nitrogen bases of crude oils by mass-spectrometry

Study of nitrogen bases of crude oils by mass-spectrometry

Nitrogen bases of crude oils 173 Eb%q~NCr~ 1. R. M. MASAGUTOV, Alyumosilikatnyye katalizstory i izmeneniye ikh svo'mtv pri krekinge nefteproduktov (...

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Nitrogen bases of crude oils

173

Eb%q~NCr~ 1. R. M. MASAGUTOV, Alyumosilikatnyye katalizstory i izmeneniye ikh svo'mtv pri krekinge nefteproduktov (Aluminosilicate Catalysts and Variation of their Behaviour in Cracking of Petroleum Products), p. 133, ~himiya, Moscos 1 9 7 5 2. N. N. BEZINGER, M. A. ABDURAKHMANOV and G. D. GAL'PERN, Neftekhimiya 1, N o . 4, 5 8 9 , 1961 3. I. U. NUMANOV and I. M. NASYROV, Geteroatomnyye komponenty neftei Tadzhikskoi depressii (Hetero-cyelic Oil Components of the Tajik Region), p. 97, Dushanbe, Donish, 1973 4. V. M. BEMBEL', G. A. SAFONOV, N. P. GERASIMOVA, L. A. T8OI, A. N. PLYUSNIN and Yu. P. ZELENTSOV, Neftekhimlya 18, 304, 1978 5. V. S. AKSENOV, V. I. TITOV and V. F. KAM'YANOV, Khimiya getorotsiklicheskikh soyedinenii, No. 2, 147, 1979 6. A. MORGAN, J. Chem. Soc., 2448, 1931 7. L. M. KUL'BERG, Sintezy organicheskikh reaktivov dlya neftekhimicheskogo sinteza (Synthesis of Organic Reagents for Petrochemical Synthesis). p. 95, Goskhimizdat Moscow, 1947 8. F. UI,MANN, ~ber I)inaphtacridine, Ber., Bd. 36, 1027, 1903 9. L. G. YUDIN, A. N. KOST, Yu. A. BERLIN and A. E. S1T[SHOV, Zh. obshch, khimii 27, 3021, 1957

Petrol. Chem. U.S.S.R. Vol. 21, ]¢o. 3, pp. 173--180, 1981

Prin~edin Poland

0081-6458/81105017~08507.50/0 1982 Pergamon Press Led.

STUDY OF NITROGEN BASES OF CRUDE OILS BY MASS-SPECTROMETRY* I. V. Go~corr~ov, N. I. ZmT.'~sov and A. S. LaZAREV West Siberian Scientific Research Institute for Geological Exploration of Oils

(Received 20 O~ober 1980)

A G R i T number of studies by Soviet and foreign scientists [1-4] deal w i t h nitrogen bases of petroleum origin [1-4]. This interest is, on the one hand, explained by the effect of nitrogen bases on processes of oil processing and, on the other, by their negative effect on the quality of oil products. However, most studies were carried out using samples of nitrogen bases, which had been separated from petroleum fractions and various oil products. Development of group analysis of nitrogen compounds of oil [4-7] and their mass-spectrometry [8, 9] gave an impetus to investigating nitrogen compounds of crude oils of the Soviet Union. * Neftekhimiya 21, No. 5, 748-753, 1981.

174

I . v . C-OI~CHAROVet al.

A knowledge of the composition of nitrogen bases and regularities of distribution in various oils and oil products is of considerable practical interest since it enables effective methods of oil refining to be outlined and the quality of oil products improved. Ftu'thcrmore, information on the composition of nitrogen bases of crude oils is of interest from the point of view of their origin. The prospect offered by this approach aml lhc need tbr a detailed investigation of non-hydrocarbon oil components were lmderlined forty years ago [9]. Using various physical and chemical methods [10,11] we examined nitrogen bases (NB) obtained from oils and oil products of West Siberia. Being :~ continuation of investigations of non-hydrocarbon oil components, tiffs study deals with the composition of nitrogen bases separated from crude oils using mass-spectrometry. EXPERIMENTAL

For this investigation we selected samples from regions which differ markedly both in the composition of oils and conditions of occurrence. Table 1 shows some data on oils examined. 10~o HCI solution was used for separating nitrogen bases. TABLE 1. SOME CHARACTERISTICSOF THE OILS EXA~NED Drilling range, m

Content, wt. % asphalAO x g/cm3 tenes ~tot~l lO-S

44 77 26 70 98 5 64 6

870-898 1931-1937 2115-2123 2133-2137 2110-2120 2105-2117 2895-2854 2990-3000

0. 942 I 0. 898 0-853 [ 0. 845 0. 879 (~871 I 0. 842 [ 0. 797 I

0.95 2.7 0-89 0"71 1.07 1.47 0-26 1.3

0.20 0"27 0-13 0.13 0.17 0.10 0.10 0.10

13'0 33"0 40"4 132" 1 40"4 80"6 5"5 17'0

12

1180-1200

0.978

5-8

0-61

12"9

2349-2376

0.812 i

!~O.

Field region West Siberia. Russiaal Fedorov Samotlor

Salym Kalinov Central Asia Kichik-Bel' West Siberia Kuymnba

of well

P~

t, °C

of stratum 17 58 71 79 72 69 128 109

17"0

The group composition of NB concentrates was determined using low resolution mass-spectrometry, l~ass-spectra were obtained using an ionizing stress energy of 15 eV and a M A T - I l l mass-spectrometer. Samples were introduced to the ionic source via a system of direct inlet and heated from 20 to 300°C in 20 rain. The entire gas current (thermogram) was recorded using a full gas current detector of mass-spectrometers with an energy of

Nitrogen bases of crude oils

1~{~

o

o E~

J

I

ei

I

176

I.V. G o ~ c ~ o v

et al.

ionizing electrons of 20 eV. B y integration of mass-spectra obtained at differenl temperatures group composition and moleclflar weight distribution (M~VD) were determined. Peak intensities of molecular ions, relativo sensitivities of which are equal to one for all compound groups with isohar masses, wet( selected as analytical characteristics. Summing up mass-spectra, considering isotope superposition, plotting curves of M ~ and pseudo-molecular weight distribution, an ES-1040 computer was used to calculate group composition and deterrmne the average length of alkyl substituents. Each concentrate of nitrogen buses was analysed 2-3 times. Variations of results of parallel determinations when calculatfilg group composition were less than 15% rel. An optimum number of massspectra were selected on the thermogram using nitrogen bases of l~us~ian oil. It. appeared that deviations of results of determining group composition were under l~°fo when obtaining five and more mass-spectra in various parts of the thermogram. 6-12 Spectra were usually obtained, according to the t y p e of sample. These methods were used to determine the relative content of compounds with isobar homologuos series of molecular ions which differ in hydrogen lmsatm'ation. Table $ shows results of deternfining the group composition of ~ of various oils. Classification in "quinoline", "acridine", etc. series was made conditionally since several isobar homologous series were combined in each series with an identical degree of hydrogen unsaturation, which eamlot be separated using a low resolution device. However, in order t,, make comparison with results in the literature easier, we (lid not dcviat,. from the clussification adopted in Soviet literature [12,13]. Studies have been published in recent years which show that it is possibl,, in principle, to obtain further infi)rmation from low resolutio~,~ mass-spectr~-~. A description is given [14] of a method used for determiniHg the mm~ber and length of substituents in organic compound molecules in COlnpt~sit(~ mixtures. With an energy ()i' 12 -18 eV the intensit3 of mol(,(.ttlar ions of N]:; is comp~ratively high and ~t the salm~ t.ime this energy is sl~fficient for separating long :~lkyl substit(~ents from the nucleus. Theretbre, the distribution of ])ea~ks of pseudo-molectllar ions under these conditio~,~s together with ti~(, distribution of molecular ions may be used h)r evalm~ting the average mm~ber of carb(m atoms in the !lueie:~is an(l the average length of a!ks'l substituent.,;. RESULTS

It follows from TaMe 1 that the content of nitrogt~ai bases in oils is i ~ dependent of the depth of occurence of oils and of ch~racteristics such t~ density and contents of asphalt-resin components. It is also remarkable that the content of nitrogen bases is not affected by the overall content o f nitrogen in oil. Considerable variations are observed in the content of nitrogen bases in oils of one of the deposits (Samotlar oil).

Nitrogen bases of crude oils

177

According to results of Table 2, the group composition of nitrogen bases of the oils examined vary within very wide limits, since oils of very different composition and origin were selected. A general feature of all the samples is the fact that alkyl quinolines and alkyl acridines predominate in practically all of them. However, in oil samples of Kuyumba and Kichik-Bel' deposits almost half of the total of all bases is due to them, while in oils of Kalinov and Russian deposits their predominance is not so clearly expressed. The predominance of compounds of quinoline and acridine series, the low content of pyridines and the complete absence of anilines from the oils examined is in agreement with results in the literature [7, 12, 15], where similar distribution of I~B is indicated in straight-run fractions and residues. mole %

a

b

'4~

6 q

,

I ~

c

d q

12 114 18 18 20 22 2q 12 lq 16 18"20 Number of carbon afoms

22 2q

Curves of pseudomolecular-weight (1) and molecular-weight (2) distribution of oils of Samotlor (a, b) and Russian (0, d) deposits: No. of well: a--70; b--26; a, b, c--quinolines; d-- acridines. It is significant that low-molecular weight nitrogen bases, mainly quinolines are contained in high properties in very ancient oils (Kuyumba). They contain a minimum amount of acridine. It could be assumed that this is caused by c atagenetic processes aimed at forming low molecular weight compounds. This assumption, however, is not confirmed by a comparison of West Siberian oils, among which oils of Russian and Salym deposits stand out in oil composition. Salym oils occurring under highly rigid thermolJaric conditions contain almost twice as much acridine as oils of Russian deposits,

178

I. V. GONCHAI~OV et al.

where temperature is lower by ll0°C. The opposite view [ll] on the high heat-stability of acridines is not confirmed. Table 2 shows that acridin~ ~ content did not increase in oil ibllowing the action of heat. The content (d" c y c l e - a n d dicyclopyridines showed a marked increase. A similar effect--aJ~ increase in the proportion of cyclopyridine structures in nitrogen bases. products of coking and (tracking b y the action of heat, was also observed by other scientists [l~-17J. This is, probably, the eonseqttence of the breakdown of asphalt-resin substances contMning the main mass of nitrogen i.~ the form of high-molecldar weight nitrogen compounds. It is typical that the molecular-weight distribution of N:B formed after thermal degradatio, remains practically the same as in the initial oil. When selecting samples is was expected that marked differences in the composition of nitrogen bases would be observed for oils of the K u y u m b , and Kichik-Bel' deposits, the age of which (as regards surrounding ibrmations) exceeds halfa milliard years. However, it follows from the Table that compared with other samples, there are more common features than differences betwee~ these two samples. They are mainly distinguished b y a very high content of alkylquinolines. Therefore, it is not the age of the container-rock or temperatare in the bed that determine the qualitative and quantitative composition of nitrogen bases of oils. It is the environmental-ecological conditions of sedimentation [18] which, probably, have a decisive influence over the composition of nitrogen bases. The effect of lithotogy and mineral composition of surrouding rock is not clear. Their effect is emphasized by the proximity of the composition of K u y u m b a and Kichik-Bel' oils which, in spite of the enormous differel~cin age, are the only ones of all the oils examined that are deposited in carbonate; collectors. I f these two factors are not t~ken into account., it is fairly difficu!t to explain the difference in the composition of nitrogen bases of Samotlor oils taken from different wells of the same deposit. The age, originM org,ni(matter and conditions of deposits remain constant; however, within tht~ deposit rock composition varies which probably affects the qualitatiw • ~ls well as quantitative composition of l~_itrogen bases. It fClows from Tabh~ 2 that irL oils of wells 5 and 70 the content of pyridine structures and Nkyl quinolines is increased. At the same time oils with low yields ()f nitrogen bases (wells 98 and 26) contain acridine in somewhat higher proportions. Differences between N~B t)f the oils are more apparent when analysing eta'yes of MWD and pseudo-molccula.r weight distribution. Oils with a high cont~.d of nitrogen bases incorporate a larger proportion of compounds with h,ng alkyl substituents, which is clear from Fig. a and b. The problem of the effect of water-oil contact (WOC) on the content and composition of nitrogen bases remains open. It is generally known that i~ the zcme of WOO vigorous processes of transformation of oils take pbw(,. Si,~('( water its(if c~a~:¢)t re~ct with hydrocat'bons, the rote of water is most

Nitrogen bases of crude oils

17~

p r o b a b l y t o f o r m a f a v o u r a b l e m e d i u m for micro-organisms using oil as a source o f carbon. N i t r o g e n - - b a s e compounds are o n l y live. I t is n o t clear w h e t h e r t h e consequence o f biochemical reactions on WOC will be d e n i t r a tion o f oil, or on t h e c o n t r a r y , a n increase in nitrogen content? I t is possible, however, t h a t with r e t e n t i o n o f an overall nitrogen balance the s t r u c t u r a l g r o u p composition o f n i t r o g e n compounds changes. I t is possible t h a t it is precisely processes of biodegradation described b y a n u m b e r o f a u t h o r s in c o n n e c t i o n w i t h Russian deposits [1-9] which explain t h e u n u s u a l l y high c o n t e n t o f pseudo-molecular ions in spectra of their nitrogen bases (Fig. v a n d d).

SUMMARY

1. ]Y[ass-spectrometry was used to analyse n i t r o g e n bases isolated f r o m crude oils o f various deposits in t h e U.S.S.R. 2. I t was established t h a t c o m p o u n d s of quinoline a n d acridine series r e p r e s e n t a large p a r t o f c o n c e n t r a t e s o f nitrogen bases; pyridine is c o n t a i n e d in m u c h smaller quantities. 3. The overall c o n t e n t o f nitrogen bases a n d t h e i r s t r u c t u r a l - g r o u p c o m position varies within wide limits b o t h in oils o f different deposits a n d i n oils o f t h e same deposit.

1. R. A. KHEIY[L'NITSK~, Ye. S. BRODSKII and K. A. KLYIYFEY, Khimiya i teklmologiya topliv i n~sel, No. 2, 56, 1962 2. Ye. V. GUSINS~YA, Avtoref. na soiskaniye uch. st. kand. khim. nauk. Tomsk Polytechnic, 1976 3. M~KAY, J. F. WEBER and D. R. LATHAM, Analyt. Chem. 48, 891, 1976 4. N. N. BEZlNGER and G. D. GAL'PERIN, In: 1. Metody analiza organicheskikh soyedinenii ncfti, ikh smesei i proizvodnykh (I. Methods of Analysis of Organic Oil Compounds, their Mixtures and Derivatives). p. 141, Izd, AN SSSR, Moscow, 1960 5. N. N. BEZINGER, {L D. GAL'PERN and M. A. ABDURAKHMANOV, Zh. analit. khimii, No. 1, 91, 1961 6. N. N. BEZINGER, M. A. ABDURAKHMANOV and G. D. GAL'PERN, Neftekhimiya 1, 149, 1961 7. N. N. BENZINGER and M. A. ABDURAKHMANOV, Neftekhimiya 1, 589, 1961 8. R. A. ]~HMEL'NITSKT[~ Avtoref. na soiskaniye uch. st. dokt. khim. nauk. Moscow 9. G. I). GAL'PERN and I. A. MUSAYEV, Zh. prikl, khimii. 12, 563, 1939 10. Yu. P. ~SROV, I. V. GONCHAROV, I. V. KULACHENKO, A. N. PLYUSNIN, M. M. PUGOV]KIN and O. N. VYLEZHANIN, Neftekhimiya 17, 796, 1977 11. V. A. YERSHOV, N. I. ZHIL'TSOV and N. M. KOTIKOVA, sb. Problemy neff i igaza Tyumeni. No. 39, 15, 1978 12. V. G. BEN'KOVSKT[~ A. Ya. B~EKOYA and N. S. LYUBOPYTOVA, Neftekhimiya 14, 891, 1974 13. Ye. S. BRODSKII, V. S. STOPSKII, N. Y. RAZUMOV and Ye. V. GUSINSKAYA, Neftekhiraiya 15, 464, 1975

A. N. PAUKKUet al.

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14. Ire. S. BRODSKII, Zh. Analit. khimii 31, 2236, 1976 15. A. Ya. BAIKOVA,V. G. BEN'KOVSKIIand N. A. ALEKSEYEVA,Khimiya i tekhnol. topliv i ma~l, No. 5, 28, 1980 16. A. Ya. BAIKOVA, V. G. BEN'KOVSKII, Yu. N. POPOV, E. A. KRUGLOV and N. S. LYUBOPI"rOVA, Neftekhimiy~ 16, 304, 1976 17. A. Ya. BAIKOVA, V. G. BEN'KOVSKII, Yu. N. POPOV, E. A. KRUGLOV, A. N. STEKHUN and N. S. LYUBOPYTOVA, Neftekhimiya 15, 606, 1975 18. V. V. IVANOSOVA and R. S. SAKHIDGAREYEV, sb. Problemy nefti i gaza TYumeni, No. 31, 9~ 1976 19. O. A. AREF'YEV, V. M. MAKUSHIN'A and A. A. PETROV, Izv. AN SSSR, Ser. geol. No. 4, 124, 1980

Petrol. Chem. U.S.8.R. Vol. 21, No. 3, pp. 180-188, 1981

Printed in Poland

OO81~/81/0f,0180-0450'LS0/0 © 1982 Psrpmon Prsss Ltd.

COMPLEX FORMATION BETWEEN POLAR C @ M ] ~ M ~ I ~ OF ASPHAL~RES]~; SUBSTANCES OF 0 I L AND META/.~ OF VARLABLE VALENCY* A. N. PAUKKU, I. A. POSADOV, D. A. RozENT~', N. V. S m o ~ , F. K. YEGOROV,and S. YA. LAZA~EV Leningrad Technological Institut~

(Received 16 July 1980) CONDENSED ~-conjugated naphthene-aromatic fragments containing heterocycles form the basis of the molecular structure of polar components of resin-asphalthene substances of oil (RASO) [1], which determines their applicability in the synthesis of organo-metallic complex compounds--potential catalysts of redox process(s. I[1 this study it was found possible to obtain complex compounds of iron, titanium and vanadium with products of fractionation of RASO functioni~g as ligands; spectroscopic methods were also used to investigate the structure of complexes obt~)Jl~(~d. Synthesis was carried out using be~zene sohttions of metal chlorides with additiolz of solutio~s of RASO components in benzene while stirring rapidly in argon. Polar components of malthene and asphalthene fractions of compositions previously described [1] were used as ligands. I f complex-forming properties of the polar components separated are eh~racterized by metal conten.t in the complexes obtained, as shown by results * :Neftekhlmiya 21, No. 5, 762-764, 1981,