Chemical composition of extracts from Polish bituminous coal

Petrol. Chem. U . S . S . R . Vol. 23, No. 3, pp, 149-156, 1983 Printed in Poland

9 .

0031=6-1.58183 $ 1 0 . 0 0 + . 0 0 9 1985 Pergamon Press Ltd.

CtlEMICAL C O M P O S I T I O N OF EXTRACTS F R O M P O L I S H B I T U M I N O U S COAL* D. BODZEK, V. KiSELEV, I. B. USIIAKOVA,V. G. ZAIKIN and P. I. SANllq InstitUte of Petroleum and Coal Chemistry, Polish Academy of Selenccs, Gliwice A. V. Topchlyev Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences (Received9 December 1981)

TttE limited availability or complete absence of petroleum and gas in some countries of the world and the concurrent increase in their cost and increased "demand uP0n ' energy resources resulted in research into methods converting coal t o cnglne fuels. 'Study of the chemical structure of coal will thus complement the development Of new methods for the chemical processing of coal, liquid products. Although studies in this field l~ave continued for many years there remain a number of problems which are still unexplained [I]. Recent 9 have indicated the chemical structure of coal to consist of two main elements: a macromolecular three-dimensional network with molecular compounds 9 .the pores of this network [2]. Coal extracts containing the molecular components of coal were obtained and examined in the Institute of Petroleum and Coal of the Polish Academy of Sciences [3]. Investigations. suggest that the proportion of organic matter extracted from coal at room temperature and at ambient pressure reaches 30 wt. ~o. The extracted material consists of compounds with molecular weights below 800 [4]. The donoracceptor electron bond of molecular components with macromolecular network of coal forms the basis ofthe-chenaical structural model of coal developed [3]. Investigation of the hydrocarbon components of coal are dealt with in this paper. A highly volatile bituminous coal A from the Jankovice deposit (Silesia) with the following petrographic structure (wt. ~): Vitrain Sporinite Reslnlte 9Semil'uslnhe Fusinite Macrlnlte M[crinlte

73.2 5.8 1.4 9-0 3"6 1.8 5.3

yielded au extract for compositional study. * Ncftckhimiya 23, No. 4, 478--~84, i983. 149

D.'~BODZEK et al.

150

Coal (air-dry, crushed to <0.4 mm) was extracted with organic solvents, or solvent mixtures with different electron-donor and electron-acceptor properties [3, 5]. An extract obtained with a benzene]ethanol mixture (7 : 3) contains the highest TABLE 1. CIIARACTERISTICS OF COAL AND ITS EXTRACT*

Components, wt. ~o Moisture Ash Volatile product Elementary composition C

Coal9

Coal extract

4"34 4'02 39'05 82"3

Components, wt. ~ It N S

o*

82"4

Coal 5"4 1"6 0"6 I0"0

Yield

Coal extract 7"4 1"2 0'6 8"3 4"5

* Analytical results and extract ~,'ield are given o n conversion to organic mass ofcoal. I From the difference.

94mount of hoxane soluble hydrocarbons (calculated on carbon). Extracii0n was conducted at room temperature and with mechanical stirring. Treatment with fresh benzene/ethanol was repeated three times. Table ] shows the yield and analysis of t he extract. The extract was separated by the scheme given below: Extract fractionation scheme Coal extract Benzene[ Insoluble product '

I

Pyridine Preasphalthenes 9Pyridine insoluble

Soluble product Partial evaporation of benzene I Iexane I Hcxane soluble

~ I. Naphthene-paraffin part J-/ Aromatic hydrocarbons

Asphalthenes

,t Resins '

Table 2 shows yields of individual components separated from the extract using various solvents. The first fraction, separated 9 hexane, was examined in more detail. Elemental analysis was conducted in a device made by Laboratorny Pristoje (~.S.S.R.) type CHN-1 where a sample was burnt in oxygen in the presence of CuO and CoaO.~ catalysts. The sulphur content was determined by combustion Of a sample in oxygen in the presence of a platinum catalyst. Nitrogen content was determined by the modified Dumas method. The amount of..oxygen was calculated

Extracts from Polish bituminous coal

151

by difference. Results of elemental 'analysis of a hexane fraction (wt. ,?/~)are as follows: C

83"4

It 9"1

N

S

0"2 0"3

O* 6"9

(Hewlett-Packard osmometer (model 302B) in benzene at 35 ~ to 50"C with a concentration of 0.I to 60 g/kg. The average molar mass of the hexane fraction was 290). TABLE 2. COMPOSITION OF COAL'EXTRACT,.XVT. ~oo

Vraetlon

Hexane fraction Pre-asphalthenes (extraction agents: benzene and pyridlne) Asphalthenes (extraction agents: hexane and benzene) Product insoluble in pyridine

23 45

1.03 9.03

23

1.03

1

0"04

The naphthenic-paraffinic portion separated from tile hexane Iracnon was studied in more detail. The naphthenie-paraffinic hydrocarbon was separated from a hexane fraction by precipitation with h-pentane, asphalthenes (15.1 y~) were removed by adsorption chromatography on silica gel ( A S M - r e s i n ) (39.6~) and aromatic hydrocarbons (35'8 ~ were segregated. TABLE 3. QUALITATIVE COMPOSITION OF First term of the homologous series

C, H2,_, AROMATIC HYDRocARBoNS OF AN EXTRACT

Experimental number of carbon atoms determined

10

CgHa

I0, 11

12

CIoHs

10, 11, 13, ! 4, 15, 17, 18

14

9CtzHlo

Possible structures" Indene, dihydronaphthalene, octahydro. phenanthrene Naphthalene, azulene, hexahydroanthracene

15, 16, 18, 19

16 18 20

CxzHs Ci4Hxo

16, 17, 18 14, 15, 16, 17, 18

Cl4Hs

14,15, 17, 18

22 24 26

CI6HIo

CIsHz2 CIaHto 9

"18, 19 18, 20, 21 18, 19

28

C2oHt2

21

* From the difference;

. ._

Diphenyl, acenaphthene, tetrahydrophenanthrene Acenaphthylene, diphenylene, fluorene Anthracene, phenanthrene Meat hanophenanthrene, phenylnaphthalene Pyrene, fluoranthene, dihydronaphthacene Tetracene, chrysene, tetraphene .~ Benzo(g, h, /)fluoranthene, phenylphenanthrenc Benzypyrene, perylene, naphthofluorene

152

D. BODZKKet

al.

The qualitative composition of the aromatic hydrocarbon fraction was determined by high resolution MS. Varian MATTll mass-spectrometer, direct introduction of sample at temperatures from ambient to 250~ Spectra were recorded twice*; once with a resolution of about 15,000 at 70 eV, to dete/'mine accurate masses, and once 'at lo~v resolution at 13 eV to determine the approximate content of components with molecular ions of the highest intensity. Table 3 shows analytical results. Aromatic hydrocarbons of homologous series C.H2._.. : C.H2._12 (naphthalene, azulene, hexahydroanthracone), C~H2._14 (diphenyl, acenaphthene, tetrahydrophenanthrene), C~H2.-2o (methanophenanthrene, phenyh~taphthalene) are present in the highest proportion. Possible structures of the hydrocarbons identified are as follows:

Cl

Cs

Z-'I2

Z=14

Z -18

~

~

C3~ C 6

~

C0----C4

~

C1

C3~C~

~/

~C~

Z --20

C2 ~

C

l~ C 2

33 Aromatic hydrocarbon types corresponding to 10 homologous series (CnH2n-1o to C.H2._2B) were generally identified. The hydrocarbons contained two to five

* Spectra were obtained in the MS laboratory of the University in Gdansk.

Extracts from Polish bituminous coal

1~3

condensed aromatic rings in the molecule and the maximum number of saturated carbon atoms forming alk2r or naphthene-alkyl chains, is eight. The proportion of saturated hydrocarbons was 9.4 70. Hydrocarbon composition was determined by gas-liquid chromatography. (LCM-7a chromatograph with copper capillary column (33 In) coated With Apiezone L, hydrogen carrier-gas, inlet pressure 0.2 MPa, programmed from 140~ to 280~ Normal paraffins and isoprenanes were identified. The quantitative content of hydrocarbons identified was calculated from peak areas on the gas-liquid chromatogram, corresponding to these hydrocarbons. The "peak" area on the gas-liquid chromatogram, corresponding to naphthenes eluted from the capillary column ~'as also measured. Polycyclic hydrocarbons were identified using an LKV-2091 chromatomassspectrometer (molecular separator and ionization chamber at 250 ~, ionizing voltage 70 eV, emission current 50 ttM) using a copper column 30 m x0.25 mm coated with Apiezone L, helium was the carrier-gas and the mass-spectrometer itself-the detector. Table 4 shows the. composition of the paraffinic-naPhthenic part of the extract. Normal paraffins in the carbon number range (C16-C3o), isoparaffins, including isoprenanes and naphthenes were found in the naphthenic-Paraffinic part of the extract. Three isopi'enanes-2,6,10-trimethylpentadecane (Cla), 2,6,10,14-tetramethylpentadecane (C~9, pristane) and 2,6,10,14-tetramethylhexadecane (C2o, TABLE 4.

COMPOSITION OF TIlE PARAI:I?INIC-NAPHTtlIrNIC PART OF THE EXTRACT~ WT.~o t

Fraction Naphthenic-para ffinic Hexanoic Extract Organic mass of coal

Naphthe- [ n-Parafnoparaffi-nie [ fins 100 9.4 2.2 0-1

35"0 3.3 0.8 0.036

Isoparaftlns Naphthcnes isopreisopretotal total nanes nanes 11.6 3.2 53.4 14.8 1-1 0.3 5.0 1"4 0-2 0.07 1.2 0.2 0.009 0.003 0.054 0.009

phytane) were identified by comparison with authentic hydrocarbons. Previous work [6] described the synthesis and properties of isoprenanes. The concentrate contained n-paraffins 35 70, isoparaffins 11"67o and isoprenanes-3"27o. The content of isoprenanes calculated on extract (0"0770) is much lower than in petroleums (0"5-3"070). Pristane is found in the highest proportion-827o, phytane-13 70 and 2,5,10-trimethylpentadecane-in about 5 70 (the overall amount of isoprenanes being 10070). Naphthenes (53 70) form over half the naphthenic-paraffinic fraction some 915 70 of these are tetra- and pentacyclic hydrocarbons. GC/MS was used to detect iso-campestane (C28, ergostane stereomer). Its concentration at 0"0870 is low calculated on hydrocarbon concentrate or one ten thousandth part of a per cent calculated on the whole carbon extract. Triterpanes were identified using as standard

.154

_: D. BoDzr2z et aL

a trite?pane concentrate separated from Surakhan petrolemn, in which a number of hopanes in the carbon number range (C29-Ca2) were identified b y GC]MS [7]. 18 Triterpanes were identified in the carbon number range (C27-Cs4) (17ctH hopane series): tris-norhopane C27 and two of its isomers, three C29 adiantane isomers, three Ca o hopane isomers, three Ca i homohopane isomers, a mixture of homohopane and triterpane (Ca2) and two triterpane isomers (Ca2, Ca3 and Ca4). Formulae for steranes and triterpanes are as follows:

Steranes tt 9

.CII3..

ttopanes

.

:

12.

.

.

role t91

.

..

... tg[-----~20

' m / e 149, t51

ergostane( campestane )

~*"'///

X=H-adiantane; X=CH3-hopane; X=C2Hs-homohopane; X = C a H T - C 6 H i a - h o p a n e homologoues, C27-trisnorhopane (has stituents at C22).

no

sub-

TABLE 5. DISTRIBUTION OF TRITERPANES 1N A ItYDROCARBON CONCEN'TRATE~ ~o OF EXTRACT

Isomer 2

Tritcrpanes

Adiantahes C:9 Hopanes Cao

2

Homohopanes

rrisnorhopanes C27

Isomer

Triterpanes

13"0 8"6I0"0

0.6

D.6

1-7

0.5

0.6

1"7

9 C31

Ca: Caa Ca4.

12.2 0.8 9.4 8"0

12-2 0.5 8 "3 6"6

I

I

4.7 ---

Table 5 shows the distribution of triterpanes in the naphthenic-paraffinie part o f the extract; their content calculated on the hexane fraction is 1"4 wt. ~o. The overall content of triterpanes in the extract is 0.2 w t . ~ (same order as in petroleums). If ~e assume the overall proportion of triterpanes to be 100 ~o, the content of indivii dual forms of hopane series varies within the range of 0.5 to 13 Yo. The histogram of triterpanes of the extract obtained from coal is shown in the Figure.

Extracts from Polish bittimlnohs coal

\

135

TZ7

%

iO

T31+~Z

5

T3z Timc. Histogram of triterpanes of a coal extract. T27-T3~ - triterpanes in the carbon number range (C27-C~).. SUMMARY

I. The composition 'of saturated and aromatic hydrocarbons-constituents of a bituminous coal extract (Silesia)-were examined. 2. The extract contained precursor hydrocarbons in the range C~6"C30 and included normal paraffins; C18, C~9 and C2o isoprenanes; C28 sterane (isocampestane) and eighteen (C27-C34) triterpanes, namely C27 trisnorhopane and two o f its isomers, three C29 adiantane isomers, three C3o hopane isomers, three C31homohopane isomers and two triterpane isomers (C3z, C33 and C3~). The extract contained 0.2 Yotriterpanes. The triterpanes identified in the extract were representatives of 17c~H hopane, typical of petroleum hydrocarbons, 3. The extract contained aromatic hydrocarbons with 2 t o 5 condensed rings in the molecule (homologous series ranging from CnHz,_ ~o to CnH2"_28).Homologues of naphthalene, acenaphthene, diphenyl, anthracene (phenanthrene, phenylnaphthalene and methanophenanthrene) were present in the largest proportion. The maximum number of carbon atoms in aromatic hydrocarbon substituents was 8. REFERENCES

I. R. M. DAVIDSON, Report No. ICTIS/TR 08. Intern. energy agency. Technical Information Service, London, 1980 2. A. MARZEC, Molecular Structure of Coal, Chemla Stosowana 25, 31 381-390, 1981 3. A. MARZEC, M. JUZWA, K. BETLF_..Iand M. SOBKOWIAK, Fuel Proc. Technology 2, I, 35, 1979

-156

M. YA. GOUBE8.GRITSeta!.

4. D. BODZEC and A. MARZEC, Fuel 60, 1, 47, 1981 5. u GUTMANN, The Donor-accepter Approach to Molecular Interactions, Plenum Press, New York,,1978 6. I. B. USHAKO'VA,L. M. ROZENBERG,I. S. GENEKHand P. I. SAN'IN, Neftekhimiya8, 5, 651, 1968 7. I. B. USHAKO'VA,"V. G. ZAIKIN, I. S. GENEKH, B. A. SMIRNOV and P. I. SANIN, Neftekhimiya 15, 5, 635, 1975

Petrol. Chem. U.S.S.R. Vol. 23, No. 3, pp. 156-159, 1983 Printed in Poland

0031-6458183 $10.00 + . 0 0 1985 Pergamon Press Ltd.

INHIBITION IN COMBINED LIQUID-PHASE PHOTOCHEMICAL OXIDATION OF BENZ(a)PYRENE AND SOME POLYCYCLIC ARENES* M. YA. GOOBERGRITS,L. P. PAALMEand P. S. JACQUIGNONE Institute of Chemisti'y,Estonian Academyof Sciences Institute of the ChemistryOf Natural Compo'unds,NTsNI, France (Received 22 March 1982)

OXIDATION OF benz(a)pyrene ([BP]-tHr m a i n carcinogenic component formed by the action of heat on petroleum and oil products and entering the biosphere in waste water and industrial waste) seldom takes place in isolation. It usually occurs in the presence of other associated biologically active substances interacting with them. Similar interactions have been studied previously [1], the cooxidation of BP and mixtures with phenols, some biologically active substances of plants, with certain polyarenes (PA)-p~rene, phenanthren% anthracene (and-some derivatives of the last named), by initiated UV radiation in a broad wave range, i.e. under conditions simulating oxidative breakdown of carcinogenic impurities in the surrounding atmosphere. The pattern and the extent of the effect we are interested in is demonstrated to be determined by the structure and reactivity of molecules associated with BP and their relative concentration. The effects of inhibition of the oxidation of BP are characterized in this study by polycyclic arches of more complex structure, the by-products of the stronger action of heat on organic fuels-pyrene, fluoranthene and dibenzo-derivatives on the basis of a formal-kinetic evaluation of these PrOCesses. A list of PAs co-oxidized in this study with BP is tabulated. T h e kinetic experiment was c0fiducted using known methods [2-4] for the photo-initiated oxidation of model dibenzopyrenes * Neftekhimiya23, No. 4, 530-532) 1983.