Acenaphthene and fluorene hydrogenation on industrial aluminum oxide catalysts in a flow system

Article abstract of DOI:10.1134/S0965544114020029

Hydrogenation of the tricyclic aromatic hydrocarbons acenaphthene and fluorene on industrial aluminum oxide catalysts in a flow system has been studied. It has been found that total these hydrocarbons are exhaustively hydrogenated in the presence of a nickel-chromium catalyst at 200°C and a pressure of 100 atm to give isomer mixtures of the corresponding perhydroaromatic hydrocarbons decahydroacenaphthene and dodecahydrofluorene. The liquid products obtained can be of interest as components of hydrocarbon fuels with increased density. Certain conformational features of the stereoisomers obtained have been considered. It has been assumed that some spatial isomers of decahydroacenaphthene have six-membered rings in the boat conformation.

Full text of DOI:10.1134/S0965544114020029

ISSN 0965ꢀ5441, Petroleum Chemistry, 2014, Vol. 54, No. 2, pp. 100–104. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © E.I. Bagrii, M.V. Tsodikov, 2014, published in Neftekhimiya, 2014, Vol. 54, No. 2, pp. 101–105.
Acenaphthene and Fluorene Hydrogenation on Industrial Aluminum
Oxide Catalysts in a Flow System
E. I. Bagrii and M. V. Tsodikov
Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia
eꢀmail: bagrii@ips.ac.ru
Received October 10, 2013
Abstract—Hydrogenation of the tricyclic aromatic hydrocarbons acenaphthene and fluorene on industrial
aluminum oxide catalysts in a flow system has been studied. It has been found that total these hydrocarbons
are exhaustively hydrogenated in the presence of a nickel–chromium catalyst at 200°C and a pressure of
100 atm to give isomer mixtures of the corresponding perhydroaromatic hydrocarbons decahydroacenaphꢀ
thene and dodecahydrofluorene. The liquid products obtained can be of interest as components of hydrocarꢀ
bon fuels with increased density. Certain conformational features of the stereoisomers obtained have been
considered. It has been assumed that some spatial isomers of decahydroacenaphthene have sixꢀmembered
rings in the boat conformation.
Keywords: solid polycyclic aromatic hydrocarbons, acenaphthene, fluorene, hydrogenation, industrial aluꢀ
mina catalysts, perhydroacenaphthene, perhydrofluorene, spatial isomer structure, coal tar, liquid compoꢀ
nents of hydrocarbon fuels
DOI: 10.1134/S0965544114020029
Polycyclic saturated hydrocarbons are valuable hydrocarbons acenaphthene and fluorene contained
components of hydrocarbon fuels with increased denꢀ in coal tar, a byproduct of coke production.
sity and, hence, a higher volumetric calorific value.
For example, the highꢀenergy fuels RJꢀ4 and JPꢀ10
designed for use in aircrafts with a limited volume of
fuel tanks are based on hydrogenated dimers of cycloꢀ
pentadiene and methylcyclopentadienes. A further
progress in this area was made with the use of unique acenaphthene (AN) of 98% purity (mp 91–92
natural sources, gas condensates containing alkyldiaꢀ bp 277.5
; density, 1.029 (99°C); flash point, 158
mondoids, higher cyclic homologues of the adamanꢀ fire point, 162
EXPERIMENTAL
The reactant chemicals were technicalꢀgrade
°
C
;
;
°
C
°C
°
C) with a sulfur content of 0.3–0.4%
tane hydrocarbon series, namely, alkyldiamantanes and biphenyl, diphenylene oxide, as methylnaphthaꢀ
and alkyltriamantanes. Highꢀenergy fuels such as RFꢀ lenes as impurities and reagentꢀgrade fluorene (FL) of
1 and RFꢀ3 were designed on their basis [1].
99.5% purity, mp 115°C. Hydrogenation was carried
out in a modified standard laboratory flow unit and a
pilot flow unit both consisting of a feed tank, a pump,
a coil heater, a reactor, a condenser, a separator, a filꢀ
ter, a hydrogen pressure and flow rate control system,
and a process control panel. The units were provided
with external heating of the feed tank and feedstock
solutions, the feed pump head, and all the pipelines
before the reactor. Feedstock from the tank was
pumped to the heater. A hydrogen supply line was conꢀ
nected to the feed line before the heater. After the
heater, the mixture of hydrogen and feedstock was fed
to the top (bottom) of the reactor. Reaction products
and hydrogenꢀcontaining gas were sent from the reacꢀ
tor to the condenser, and condensed liquid hydrogeꢀ
nation products and gases were separated in the gas
separator. The liquid products were periodically
A process for preparing alkyladamantanes by
isomerization of hydrogenated tricyclic aromatic
hydrocarbons under conditions of heterogeneous
catalysis on solid alumina and aluminosilicate cataꢀ
lysts was designed at the Topchiev Institute of Petroꢀ
chemical Synthesis [2, 3]. Along with the use as fuel
components, adamantane derivatives are of interest as
valuable chemicals, a variety of pharmaceuticals, and
other products important for the national economy.
The first step of this process is the hydrogenation of
appropriate aromatic hydrocarbons to obtain satuꢀ
rated polycyclic hydrocarbons. Along with petroleum
fractions, cokemaking byproducts which have found
limited application are a source of aromatic hydrocarꢀ
bons and other valuable chemicals.
In this paper, we present the results of study of the bypassed to the receiver marinated under a pressure
hydrogenation in a flow system of tricyclic aromatic close to the atmospheric one.
100

ACENAPHTHENE AND FLUORENE HYDROGENATION
101
Table 1. Results of acenaphthene hydrogenation in a cyclohexane solution (weight ratio is 1 : 18) on the nickel catalyst at
80 atm
Isomers PHAN, wt %
Solution space
Temperature,
°
C
Run time, h
Total
velocity, h–1
1
2
3
4
150
150
150
200
200
200
200
200
1.5
0.5
0.5
0.5
1.0
1.5
2.0
2.0
4.5
4
2
40
20
45
32
22
30
23
2
4
3
48
22
47
61
61
59
70
93
4
100
96
5
14
4
40
4
96
4
100
100
100
100
98
1.5
1
2
5
4
13
7
1
4
4.5
2
3
The hydrogenation of acenaphthene was studied molecules to give decahydroacenaphthene (perhyꢀ
both in both its pure form (in melt) and solution. droacenaphthene, PHAN (III) in the second step. In
Cyclohexane, a mixture trimethylcyclohexanes, the the presence of the nickel–molybdenum–alumina
crude perhydronaphthalene fraction, and still bottoms catalyst, the hydrogenation of acenaphthene at a temꢀ
remaining after distilling crude perhydroacenaphꢀ perature of 250–300°C and a pressure of 30–100 atm
thene off were used as a solvent. The best results were proceeds quite selectively to give mainly tetrahyꢀ
obtained with the use of the trimethylcyclohexane droacenaphthene (II). Under optimal conditions, the
(TMCH) mixture prepared preliminarily by hydrogeꢀ AN conversion reaches 95–100%.
nating the industrial mesitylene fraction. The hydroꢀ
genation process was studied at 150–300 and a
The results obtained in the experiments with the
industrial catalyst APꢀ56 showed that the catalyst also
does not exhibit a sufficiently high activity: the degree
of AN hydrogenation under the given conditions
°C
hydrogen pressure of 30–100 atm. The catalysts used
in the study were the commercial platinum–alumina
catalyst APꢀ56 an industrial nickel catalyst, and the
nickel–molybdenum–alumina catalyst manufactured
at the Pikalevo integrated alumina plant according to
the Topchiev Institute’s method.
(
150–200°C) was no more than 30%, with THAN
being the main product. The industrial nickel catalyst
appeared to be the most efficient, the 100% conversion
of the reactant hydrocarbon was attained to give excluꢀ
sively decahydroacenaphthene in the hydrogenation
of AN in a cyclohexane or trimehylcyclohexanes soluꢀ
tion over this catalyst. Table 1 presents the conditions
of the process and the results of some of the most repꢀ
resentative experiments.
The data in Table 1 show that the conditions of the
process have a considerable effect on both its progress
and the product composition. In the optimal temperꢀ
ature range of 150–200°C, the complete hydrogenaꢀ
tion of AN to PHAN is achieved at all the space velocꢀ
ities studied, with the degradation products being
RESULTS AND DISCUSSION
Hydrogenation of Acenaphthene
Autoclave hydrogenation of acenaphthene (I) was
studied by many investigators, including that on oxide
catalysts [4]. Running the hydrogenation in a flow sysꢀ
tem is fraught with additional difficulties due to the
solid state of the material, although these difficulties
have been overcome by means by selecting and using a
suitable solvent.
The acenaphthene hydrogenation process in a flow actually absent, which appear at higher temperatures,
system on a fixed catalyst bed proceeds stepwise, a as found in addition experiments. Changes in the proꢀ
manner that is especially clear under mild process cess conditions considerably affect the PHAN isomer
conditions. The aromatic hydrocarbon molecule adds composition (Table 2). For example, an increase in the
two hydrogen molecules to give tetrahydroacenaphꢀ space velocity, especially, at a lower temperature facilꢀ
thene (THAN) (II) in the first step and three more itates the predominant formation of one of the isoꢀ
PETROLEUM CHEMISTRY Vol. 54
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102
BAGRII, TSODIKOV
mers, isomer 4, which, being instable, isomerizes to another stationary phase [5] and agree with the data
given by Grosse et al. [6].
more stable isomers 1 and 3 with an increase in the catꢀ
alyst contact time or temperature. The product comꢀ
pounds were identified by elemental analysis and mass
spectra data. The spatial structure of the isomers, some
To determine the spatial structures of the PHAN
stereoisomers and their chromatographic elution
order from column, were used the results of the
conformational features of the PHAN molecule strucꢀ detailed comprehensive stereochemical analysis of
PHAN isomers by Shabanova [5].
ture, and chromatographic parameters of the PHAN
isomers are also given in Table 2. The boiling points of
the stereoisomers were calculated from the relative
chromatographic retention times on Apiezon L; they
The stereochemistry of perhydroacenaphthene has
some specific features that are worth noting. Theoretꢀ
ically, decahydroacenaphthene can have six stereoisoꢀ
differ somewhat from the published data obtained on mers:
trans
trans
trans
,
cis
trans
trans
,
cis
cis
trans
,
trans
trans
cis
,
trans
cis
cis
,
cis
cis
,
,
,
,
,
,
,
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
cisꢀ
IIIꢀA
IIIꢀB
IIIꢀC
IIIꢀD
IIIꢀE
IIIꢀF
It might seem that the structure of individual 25.2%; cis,trans,trans (IIIꢀB), 3.4%; and cis,cis,cis
PHAN stereoisomers, their thermodynamic stability,
and the elution order from chromatographic column
with a nonpolar phase would be determined on the
basis of the structures of isomers of their nearest bicyꢀ
clic analogs, methyldecalin derivatives (methylbicyꢀ
clo[4.4.0]decanes), whose stereochemistry had been
studied in [7–9]. Thus, it was found that among 2ꢀsubꢀ
(IIIꢀF), 2.3%. The trans,trans,cisꢀisomer (IIIꢀD)
seems to exist only theoretically. Comparison of these
results with published data on the thermodynamic staꢀ
bility and on the elution order of PHAN stereoisomers
made it possible to determine the structure and chroꢀ
matographic characteristics of the PHAN stereoisoꢀ
mers obtained in hydrogenation, which are given in
Table 2.
stututed methyldecalins, the isomer with the trans
ꢀ
junction of the sixꢀmembered cycles, namely,
trans,transꢀ2ꢀmethyldecalin, is the most stable therꢀ
modynamically, its content in the equilibrium mixture
Of no less of interest are the conformations of units
making the tricyclic structure of perhydroacenaphꢀ
thene. The presence of the additional cycle in the
decalin structure, which rigidly joins the sixꢀmemꢀ
bered rings, considerably impedes conformational
transitions in PHAN isomer molecules. This results in
the situation when stabilization of the sixꢀmembered
cycle in the “boat” conformation is significantly
favored. In this case, the existence of several conformꢀ
ers with approximately equal strain energies is possible
at 160°C is more than 80% of total 2ꢀsubstututed
methyldecalin derivatives. In the case dimethylbicyꢀ
clo[4.4.0]decanes as compounds that are the closest in
structure to PHAN isomers,, the isomers having the
transꢀdecalin configuration also considerably prevails
at equilibrium (usually their content is more than
90%) among all the 2,Xꢀdimethylated derivatives. It
might be assumed that the most stable PHAN isomers,
i.e., isomers 1 and 3, making in total more than 90% in
the PHAN mixture close to equilibrium also have the
transꢀjunction of the sixꢀmembered cycles.
for some stereoisomers. Thus, isomers with the trans
decalin moiety—trans,trans,trans and cis,cis,trans
ꢀ
—
have rather limited possibilities to form conformers
and mainly exist as the conformers shown below,
whereas isomers with the cisꢀdecalin unit, for examꢀ
ple, the trans,cis,cisꢀ and cis,cis,cisꢀPHAN isomers,
can have several conformations with a nearly equal
strain of the fiveꢀmembered cycle, in which one or
both of sixꢀmembered ring will be in the boat conforꢀ
At the same time, it was unambiguously found [5]
that the most thermodynamically stable PHAN isoꢀ
mer is the trans,cis,cisꢀisomer (IIIꢀE), i.e., the isomer
having the cisꢀconfiguration of the decalin moiety of
the molecule; in equilibrium at 613 K, its content
was 38.7%. The equilibrium concentrations of other
stereoisomers are arranged in the following order:
trans,trans,trans (IIIꢀA), 30.4%; cis,cis,trans (IIIꢀC), mation (Scheme 2).
PETROLEUM CHEMISTRY Vol. 54
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ACENAPHTHENE AND FLUORENE HYDROGENATION
103
Table 2. Characterization of perhydroacenaphthene (tricyclo[7.2.1.05.12]dodecane) isomers
Name
1,3,5ꢀTMCH
RRT*
Bp,
°
C
Bp, K [5]
Conformation
1.0
4.3
136–141
235
–
499
503
507
513
–
PHAN, isomers:
1
2
3
4
trans
cis trans
trans cis
cis cis
,
trans
,
trans
5.0
239
,
,
,
trans
5.9
243
,
cis + cis
,
cis
,
trans
7.0
246
,
,
cis
Tetrahydroacenaphthene
Acenaphthene
19.0
36.0
252
–
–
278
–
Relative retention time, Apiezon L, 200
°C.
trans
,
trans
,
trans
ꢀ
cis,
cis
,
trans
ꢀ
trans
,
cis,
cisꢀ
cis, cis, cisꢀ
IIIꢀA
IIIꢀC
IIIꢀE
IIIꢀF
Scheme. Preferred conformations of some PHAN isomers.
However, one of the sixꢀmembered cycles of the 1.5002. Thus, perhydroacenaphthene and perhydrofꢀ
third isomer with the transꢀjunction of the decalin luorene correspond to keroseneꢀcut hydrocarbons in
moiety, namely, cis,trans,transꢀPHAN (IIIꢀB), should their physicochemical characteristics. They can be
also have a slightly deformed boat conformation.
The isomer composition of perhydroacenaphthene
prepared by AN hydrogenation has a considerably
effect on its physicochemical parameters and, hence,
performance characteristics of the product. For examꢀ
ple, cis,cis,cisꢀPHAN at room temperature is a solid,
whereas an isomer mixture containing 75% of this isoꢀ
used as components of hydrocarbon fuels with an
increased density.
Thus, in this study we have determined the condiꢀ
tions and processing parameters for the process of
acenaphthene and fluorene hydrogenation on indusꢀ
trial alumina catalysts to allow the process to be run in
the continuous mode to produce their fully hydrogeꢀ
nated derivatives with a desired isomer composition.
The catalyst activity loss remained unchanged during
the time on stream of 200 h.
mer has the pour point of 15°C (density of
0.950 g/cm3, a refractive index n n2D0 1.4995).
Based on the results of the study, we can propose an
area of focus in the integrated use of coal by chemical
processing the liquid products of coke byproducts
plants, which represent valuable chemical and energyꢀ
generation feedstock that has not found wide practical
use to date. It is evident that extending the range of
feedstock resources by involving other components of
coal tar and petroleum fractions with a high amount of
polycyclic aromatic hydrocarbons will help somewhat
to resolve the solubility problem, although it will be
necessary to modify the catalysts in the line of
enhancement of their stability to catalytic poisons
present in tar and to adjust the processing conditions.
Hydrogenation of Fluorene
Under conditions similar to those for acenaphꢀ
thene hydrogenation
(150–160°C, 100 atm,
fluorene WHSV 0.08
−
0.12 h–1), fluorene is exhausꢀ
tively hydrogenated to dodecahydrofluorene to give
three stereoisomers, of which one having the highest
boiling point makes 70−80% of the total mixture. Most
likely, it is the cis,syn,cisꢀPHFL isomer. Perhydrofluoꢀ
rene (tricyclo[7.3.1.05.13]tridecane) is a transparent,
colorless or slightly yellowish liquid with an odor charꢀ
acteristic of naphthene hydrocarbons, bp 132
(12 mm Hg) or 254–258 (760 mm Hg), pour point
below –60 (at a certain isomer composition), denꢀ
sity of 0.945
°C
°C
°C
The authors are greatly indebted to the staff memꢀ
−
0.950 g/cm3, and refractive index of bers of the petroleum chemistry laboratory (head,
PETROLEUM CHEMISTRY Vol. 54
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104
BAGRII, TSODIKOV
2. E. I. Bagrii and P. I. Sanin, USSR Inventor’s Certificate
ate No. 239302; Byull. Izobret., No. 25, 241 (1971).
Prof. P.I. Sanin) and hydrogenation laboratory (head,
Cand. Sci. (TecTech.) Ya.R. Katzobashvili) at the
Topchiev Institute: A.R. BrunꢀTsekhovoi, E.Kh. Kuꢀ
rashova, T.N. Dolgopolova, M.N. Dzyubina,
Yu.A. Lozovoi, V.N. Solov’ev, T.Yu. Frid, D.M. Oleiꢀ
nik, Yu.Ya. Goldfarb, S.S. Kurdyumov, P.M. Erusalꢀ
imskii, N.S. Ananchenko, A.P. Istomin, and others
who took part in the experiments.
Development and validation of the technology of
hydrogenation of solid polycyclic hydrocarbons to liqꢀ
uid fuels on the pilot scale and production of an
enlarged batch of the product were performed on a
petrochemical plant. The energy characteristics of
fuels were obtained at the level of those of JPꢀ10.
3. E. I. Bagrii and P. I. Sanin, US Patent No. 3 637 876
(1972); FR Patent No. 7 011 712; GB Patent
No. 1256202 (1971); JP Patent No. 755646.
4. M. M. Dashevskii, Acenaphthenes (Khimiya, Moscow,
1966) [in Russian].
5. A. S. Shabanova, Candidate’s Dissertation in Chemisꢀ
try (Samara, 2000) [in Russian].
6. V. Grosse, G. M. Mavity, and M. J. Mattox, Ind. Eng.
Chem. 38, 1040 (1946).
7. E. I. Bagrii, I. A. Musaev, E. Kh. Kurashova, et al.,
Neftekhimiya
8. L. N. Stukanova, T. N. Shan’gina, and Al. A. Petrov,
Neftekhimiya , 196 (1969).
8, 818 (1968).
9
REFERENCES
9. I. A. Musaev, V. N. Novikova, E. Kh. Kurashova, and
P. I. Sanin, Neftekhimiya 15, 190 (1975).
1. H. S. Chung, C. S. H. Chen, R. A. Kremer, et al.,
Energy Fuels 13, 641 (1999).
Translated by S. Lebedev
PETROLEUM CHEMISTRY Vol. 54
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2014