Catalytic conversion of cellulose into hydrocarbon fuel components

Article abstract of DOI:10.1134/S0965544113060145

The results of catalytic processing of cellulose to hydrocarbon fuel component are presented. Nanoscale Mo,Fe(III) catalytic systems have been formed from organic solutions of mono and bimetallic complex compounds on the surface of the substrate. Tetralin, an analogue of naphthenoaromatic compounds of crude oil and its refining products, has been used as a hydrogen donor. The effect of the precursor nature and catalyst activation method on the parameter of the process has been investigated. It has been shown that the cellulose conversion reaches 97-98% under optimal conditions, yielding up to 90% of liquid hydrocar- bons with the exhaustive deoxygenation. It has been found that the most efficient method of preliminary activation of both active components and cellulose is ultrasonic treatment leading to an increase of the rate of cellulose conversion into hydrocarbons. Pleiades Publishing, Ltd., 2013.

Full text of DOI:10.1134/S0965544113060145

ISSN 0965ꢀ5441, Petroleum Chemistry, 2013, Vol. 53, No. 6, pp. 367–373. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © M.V. Tsodikov, M.V. Chudakova, A.V. Chistyakov, Yu.V. Maksimov, 2013, published in Neftekhimiya, 2013, Vol. 53, No. 6, pp. 414–420.
Catalytic Conversion of Cellulose
into Hydrocarbon Fuel Components
M. V. Tsodikova, M. V. Chudakovaa, A. V. Chistyakova, and Yu. V. Maksimovb
a Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskii pr. 29, Moscow, 119991 Russia
eꢀmail: tsodikov@ips.ac.ru
b Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, Moscow, 119991 Russia
Received March 5, 2013
Abstract—The results of catalytic processing of cellulose to hydrocarbon fuel component are presented.
Nanoscale Mo,Fe(III) catalytic systems have been formed from organic solutions of monoꢀ and bimetallic
complex compounds on the surface of the substrate. Tetralin, an analogue of naphthenoaromatic compounds
of crude oil and its refining products, has been used as a hydrogen donor. The effect of the precursor nature
and catalyst activation method on the parameter of the process has been investigated. It has been shown that
the cellulose conversion reaches 97–98% under optimal conditions, yielding up to 90% of liquid hydrocarꢀ
bons with the exhaustive deoxygenation. It has been found that the most efficient method of preliminary actiꢀ
vation of both active components and cellulose is ultrasonic treatment leading to an increase of the rate of
cellulose conversion into hydrocarbons.
Keywords: cellulose, deoxygenation, fuel components, nanoscale catalytic systems
DOI: 10.1134/S0965544113060145
Plant raw materials, primarily wood, hold much viding the efficient proceeding of the hydrofining and
promise as feedstock for the chemical and fuel indusꢀ hydrocracking processes are the most effective [4].
try; therefore, the investigation of the catalytic converꢀ
Curran et al. [5] showed that the processes develꢀ
sion of the dominant wood component cellulose into
oped for liquidꢀphase hydrogenation of coals in a solꢀ
carbonaceous fuel components is of great importance.
vent (hydrogen donor) medium can be used for the
However the groupꢀtype composition of cellulose
liquefaction of cellulose. In contrast to coal, biomass
makes it difficult to dissolve for the purpose of further
is characterized by relatively a high H/C ratio (1.7 for
processing and does not allow a high degree of deoxyꢀ
cellulose versus 0.7 for bituminous coal) and a very
genation to be achieved.
high oxygen content, which substantially decreases its
In countries having large renewable biomass calorific capacity. In this connection, the main probꢀ
resources, process for the thermochemical and lem of the cellulose conversion to hydrocarbons is to
miocrobiological conversion of the biomass into alcoꢀ provide deep deoxygenation along with the cracking of
hols and liquid and gaseous fuels are currently being C–C bonds.
developed and implemented [1].
As a hydrogen donor, various solvents with labile
The chemical processing of celluloseꢀcontaining C–H bonds can be used, since they relatively easy to
raw materials is mainly based on multistep processes of dehydrogenate under the liquefaction conditions,
hydrolysis oriented to production of polyols and, to a enhancing their solvating power. One of the most
lesser degree, hydrocarbons [2, 3].
effective solvents (hydrogen donors) is tetralin, which
is a prototype of naphthenoaromatic compounds of
crude oil and its processing products . Compounds
with a higher boiling point from this group (cresols)
are less active as hydrogen donors, but their mixtures
with tetralin exhibit synergism: the mixture of equal
parts of tetralin and cresol has a higher donating ability
than each individual component [6].
It was found that melts of mixtures of alkali metal
formates with an alkali ensure effective liquefaction of
wood even at atmospheric pressure. The maximum
yield of oils (15 wt %) is achieved in the case of wood
liquefaction by an HCO2Na/KOH melt at 480°С,
with the oxygen content in the products being 12.6 wt %.
The liquid products obtained so can be converted into
hydrocarbon mixtures similar to gasoline with the use
In this study, we investigated the catalytic converꢀ
of the catalytic hydrofining and cracking processes sion of cellulose nased on the previously developed
developed for petroleum feedstock. In this case, process of hydrogenation liquefaction of the organic
bifunctional catalysts that combine components proꢀ matter of brown coal in which nanoscale catalytic sysꢀ
367

368
TSODIKOV et al.
tems are formed immediately on the surface of the 10°/min, 270°C, Tinj = 250°C,
substrate [7, 8]. split ratio.
Pinj = 2.2 bar, 1/300
Elemental analysis was performed by laser ionizaꢀ
tion mass spectrometry on an EMALꢀ2 instrument.
The source of laser radiation was an IZꢀ25 laser with
the active medium of neodymiumꢀdoped yttrium
oxide.
EXPERIMENTAL
Ammonium molybdate (NH4)6Mo7O24
trial iron acetylacetonate Fe(CH3COCH=C(CH3)O)3
and the bimetallic complex [Mo72Fe30O252(CH3COO)12
{Mo2O7(H2O)}2{H2Mo2O8(H2O)}(H2O)91] 150H2O
synthesized for the purpose were used as the precursors of
bimetallic catalysts. These compounds were deposited on
the surface of microcrystalline cellulose of the BZNCꢀ
1000 brand by impregnation with the active component
ratio of Mo/Fe = 2/5. Thus, three samples of catalyst were
prepared: two from mixtures of the complexes taken in difꢀ
ferent ratios (0.50Fe + 1Mo (samp. 1) and 0.22 Fe + 1 Mo
(samp. 2)) and one [0.22 Fe + 1 Mo] from the heteromeꢀ
tallic complex (samp. 3). The moisture capacity of the iniꢀ
tial cellulose was determined by absorption of an aqueous
·
4H2O, indusꢀ
,
13
1H and C NMR Fourierꢀtransform spectra were
obtained on a Bruker MSLꢀ300 spectrometer with an
operating frequency of 300 MHz at 24°C. The samples
·
for investigation were prepared as solutions in CCl4
with addition of CDCl3. The chemical shift was calcuꢀ
lated from signal of residual protons of chloroform
7.25 ppm.
IR spectra were recorded in the transmission mode
on a Bruker IFSꢀ66 v/s Fourierꢀtransform spectromeꢀ
ter in the region of 400–4000 cm–1 (50 scans, 1–2 cm–1
resolution). The samples were prepared in the form of
film obtained from a cellulose oil solution in CCl4
applied onto a KBr plate. The spectrum of the film
obtained was recorded in the transmission mode.
alcohol solution (VEtOH
: VH O = 1 : 2), its value was
2
2.39 cm3/g.
Mössbauer spectra were recorded on Haldor and
Wissel electrodynamic spectrometers (Germany).
γ
Iron acetylacetonate after recrystallization in aceꢀ
tone/hexane = 1/6 mixture and drying in “Fisher’s
pistol” over P2O5 was dissolved in a calculated volume
The
ꢀradiation source was 57Co in a matrix of
metallic rhodium with an activity up to 1.1 GBq. The
chemical shifts were determined relative to center of
of ethanol at 40
nium molybdate dissolved in distilled water at 75–
80 was added by portions with vigorous stirring to
°С. The calculated amount of ammoꢀ
lines of
tra were processed by standard programs of calculation
and simulation for Mössbauer transition 3/2 1/2
α
ꢀFe magnetic hyperfine structure. The specꢀ
°С
the solution obtained. In this case, the amount of
water taken for dissolving molybdate was two times
that of ethanol taken for dissolving iron acetylacetoꢀ
nate. The prepared aqueous alcohol solution containꢀ
ing Fe and Mo was thoroughly mixed, deposited on
→
.
The main programs of the leastꢀsquares method
(LSM) were LOREN program created in UNIX operꢀ
ational system and WINNORMOS. The complex
treatment of the Mössbauer spectra was performed
with the use of LRT and Wissoft2003 programs. The
Mössbauer spectra in the 16–300 K temperature
interval were obtained using a Janis helium cryostat
(model CCSꢀ850) with a Lake Shore Cryotronics
temperature controller (model 332). The accuracy of
the temperature maintenance was at least 0.1 K.
cellulose at 40–45
ature for 24 h and in vacuum oven for 4 h at 50
°С, and dried in air at room temperꢀ
°С.
The heterometallic complex was dissolved in absoꢀ
lute ethanol and then deposited on cellulose as
described above.
Cellulose with the active components deposited
was mixed with tetralin in the 1/1 ratio. The catalytic
conversion of cellulose was performed in a rotary
Analysis for C/H was performed according to a
standard procedure on an CHNSꢀO EA1108 elemenꢀ
tal analyzer.
autoclave of 0.5 L volume at 300–450°C at a hydrogen
pressure of 80–120 atm for 2 h.
The С1–С5 hydrocarbon gases were analyzed on a
Kristallꢀ4000 chromatograph (FID, He 70 cm3/min;
RESULTS AND DISCUSSION
1200
°
С;
P
1.65 MPa, HPꢀPLOT/AI2O3, 50
m
×
As is seen from Table 1, cellulose in the hydrogen
donor medium easily converts into a solution of celluꢀ
lose oil in tetralin. The cellulose conversion during
hydrogenation in the tetralin medium without a cataꢀ
lyst is 86% (entry 1). The deposition of a small amount
0.32 mm). CO, СО2, and Н2 were determined on the
Kristallꢀ4000 chromatograph as well (TCD, Ar (speꢀ
cial purity grade), SKT column, 150
30 mL/min).
×
0.4 cm, 130°C,
Liquid organic products (cellulose oil) of the reacꢀ of the catalyst (up to 1.5 wt %) leads to an increase in
tion were identified by gas chromatography–mass conversion of the cellulose organic mass to 98%. It is
spectrometry on a DelsiꢀNermag Automassꢀ150 for the first time that the fraction of light hydrocarbons
instrument with an MSD 6973 (Agilent) detector), boiling below 120
EI = 70 eV, 1 L sample volume, columns: HPꢀ5MS, clopentanes and alkylcyclohexanes is detected on
0.32 50, Df = 0.52, 50 Moꢀcontaining catalytic systems. The complete
(5 min), 10о/min, 270°C, Fe
inj = 250°C, 1 mL/min constant flow, 1/(100–200) composition of the light fraction is presented in
split ratio; CPSilꢀ5, 0.15 25, Df = 1.2, 50 (8 min), Table 2.
°С and mainly consisting of alkylcyꢀ
µ
×
°C
⎯
T
×
°C
PETROLEUM CHEMISTRY Vol. 53
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CATALYTIC CONVERSION OF CELLULOSE
369
Table 1. Conversion and yield of products of cellulose hydrogenation in the presence of Fe, MOꢀcontaining catalysts
Product yield, wt %
Catalyst composition, Conversion,
No.
wt %
%
gas
cellulose oil
65.5
fraction to 120
0
°
C
solid residue
14.3
1
2
Without catalyst
Sample 1
85.7
20.3
0.50 Feꢀ1 Mo1)
98.5
97.5
97.9
24.0
23.3
17.0
72.6
73.7
81.0
1.9
0.5
0
1.5
2.5
2.1
3
Sample 2
0.22 Feꢀ1 Mo 1)
Sample 3
0.22 Feꢀ1Mo 2)
4
1)
Conditions:
T
= 400
24
°
C,
2
P
= 100 atm; solvent, tetralin. the active components deposited from a mixture of monometallic complexes
oper.
2)
(NH ) Mo O Þ 4H O and Fe(CH COCH=C(CH )O) ; the active components deposited from the heterometallic complex.
4 6
7
3
3
3
Table 2. Composition of the light fraction of hydrocarbons boiling off to 120°C obtained in run 2 (see Table 1)
Hydrocarbons
Cyclopentene
Content, wt %
Cyclopentene
Content, wt %
5.47
4.10
4.46
4.87
2.69
7.64
5.47
21.87
Methylcyclopentene
Dimethylcyclopentene
Ethylcyclopentene
Methylꢀethylcyclopentene
Heptene
10.94
11.35
4.51
5.69
2.87
2.60
2.05
3.42
Pentadiene
Hexane
Hexenes
Hexadiene
Cyclohexane
Methylcyclohexane
Methylcyclopentane
Heptadiene
Octenes
Octadienes
The main gaseous products of cellulose conversion the test without catalyst, thereby indicating a high
degree of deoxygenation of the initial cellulose.
on all the catalysts are CO and СО2 (Table 3). Their
proportion in gaseous products is 80–90 wt % even in
A gas chromatography–mass spectrometric analyꢀ
sis of the liquid product (with boiling temperature
>220°C) showed the presence of alkyl derivatives of
tetralin (their content ~5–8%) and nonvolatile comꢀ
pounds.
Table 3. Composition and yield (mol %) of gas generated by
cellulose hydrogenation (
T
= 400
°
C)
Run no.
1
2
3
4
To determine the dependence of the yield of celluꢀ
lose oil and its composition on the process temperaꢀ
ture in the range of 300–430°С, a set of experiments in
C1
C2
4.90
4.40
0.20
2.32
0.49
0.35
0.09
17.24
70.01
3.73
4.32
0.09
1.46
0.27
0.13
0.04
6.59
83.37
3.25
6.35
0.57
2.52
0.65
0.44
0.40
35.20
50.62
3.53
7.13
0.30
2.78
0.67
0.47
0.38
9.15
75.59
the presence of the most effective catalyst 0.5 Fe +
1 Mo (sample 1) was performed (Table 4). As is seen,
the decrease of temperature significantly reduces the
cellulose conversion and, correspondingly, the yield of
liquid products. At the same time, an increase in the
process temperature leads to a monotonic increase in
the amount of the hydrocarbon components of the gas.
However, the composition of the gaseous fraction
remains unchanged (Table 5). The analysis of the liqꢀ
C2=
C3
C3=
C4
C4=
CO
CO2
uid products obtained at 300°С and 350°С showed
that they do not contain the light fraction. Nonetheꢀ
less, the deoxygenation estimated by the yield of carꢀ
PETROLEUM CHEMISTRY Vol. 53
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370
TSODIKOV et al.
Table 4. Dependence of cellulose conversion and product
composition on temperature (0.50Fe–1Mo cat.) (sample 1)
observed. Besides the maximal yield of cellulose oil
containing the light fraction of alkylcyclic hydrocarꢀ
bons was observed at this temperature.
The effective method for increasing the reactivity
of solid organic substrates is mechanical treatment of
various kinds facilitating the change of structure and
the formation of defects [10, 11].
Product yield, wt %
Process
Converꢀ
temperaꢀ
sion, %
solid
residue
ture,
°
C
gas
cellulose oil
The action of ultrasound of even a small power on
cellulose causes structural changes and enhances the
solubility and, hence, reactivity of cellulose [12].
In this connection with the aim to intensify the
destruction of the cellulose polymer chains the initial
matrix was subjected to mechanical treatment in a
planetary mill for 2 h and sonication (25 kHz, 10 min)
followed by hydrogenating liquefaction (sample 4).
The results of tests are presented in Table 7. As is seen,
during the 0.5ꢀh ultrasonic treatment of cellulose with
the deposited catalyst (sample 4) followed by hydrogeꢀ
nation, the degree of conversion of cellulose reaches
more than 95% at a total yield of the oil of ~74 wt %.
This result is compared with the results of optimal test
presented above in Table 1; however, the time of the
hydrogenating liquefaction of cellulose preliminary
treated by ultrasound is in four times shorter. The fracꢀ
tion of light hydrocarbons is formed under these conꢀ
ditions as in the case of test 2.
Thus, the ultrasonication of the initial cellulose
with the (0.22 Fe + 1 Mo) catalyst (samp. 4) signifiꢀ
cantly intensifies the hydrogenating liquefaction withꢀ
out changing the process selectivity.
The mechanical treatment action (samp. 5) in conꢀ
trast to sonication (Table 7) negatively affects the celꢀ
lulose hydrogenation selectivity, which is apparently
associated with the deformation distortions of its polyꢀ
mer chains. In this case the selectivity substantially
changes: the yield of the gaseous products increases,
the conversion degree and the cellulose oil yield
decrease.
300
34.7
65.5
98.5
22.8
20.7
24.0
11.9
44.7
65.3
34.5
1.5
350
400
72.6 + 1.9
fraction to
120
°
C
430
97.8
28.9
68.9
2.1
Table 5. Composition of gaseous products generated by celꢀ
lulose hydrogenation (sample 1)
Cellulose
conversion
products
Cellulose hydrogenation temperature, °C
300°C
350°C
400°C
430°C
C1
0.28
0.18
0.01
0.05
0.03
0.16
0.04
10.41
88.83
2.01
2.25
0.05
0.76
0.15
0.15
0.04
8.5
3.73
4.32
0.09
1.46
0.27
0.13
0.04
6.59
83.36
6.63
6.85
0.55
3.40
0.50
3.27
0.08
6.63
72.11
C2
C2=
C3
C3=
C4
C4=
CO
CO2
86.10
To determine the composition of cellulose and celꢀ
lulose oil in the presence of 0.22 Fe + 1 Mo catalyst
(samp. 1), the C/H analysis of the products was perꢀ
formed. It was found that the hydrogen and carbon
bon oxides and water was almost complete at 300°C
(Table 6).
Based the results of the experiment, we can conꢀ contents in the initial cellulose are 6.6. and 42.6%,
clude that the optimal temperature of hydrogenating respectively, and the carbon (C) and hydrogen conꢀ
liquefaction of cellulose is 400°С when a high converꢀ tents in the highꢀboiling organic residue increase to
sion and almost exhaustive deoxygenation are 88.5 and 8.7%, indicating a high proportion of aroꢀ
Table 6. Oxygen balance during cellulose hydrogenation on the 0.5Fe–1 Mo catalyst (sample 1) at different temperatures
Cellulose hydrogenation temperature, °C
Product composition
300
350
400
430
1. Fed
– cellulose
– water
– CO
0.49
0.28
0.01
0.15
0.44
0.54
0.32
0.01
0.19
0.52
1.00
0.67
0.02
0.31
1.00
0.72
0.44
0.02
0.24
0.70
2. Withdrawn
– CO2
Σ
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CATALYTIC CONVERSION OF CELLULOSE
371
Table 7. Dependence of the yield of cellulose conversion products in the presence of the 0.5Fe + 1Mo catalyst upon the
mode of pretreatment (hydrogenation conditions:
T
= 400
°
C;
Poper. = 100 atm; solvent, tetralin)
Product yield, wt %
Reaction Conversion,
No.
Treatment mode
time, h
%
gas
heavy oil
light oil
solid residue
Sample 4 Ultrasound
0.5
2.0
95.6
91.4
21.2
30.0
74.5
61.4
1.8
0
4.4
8.5
Sample 5 Mechanochemistry
matic cycles in the products of hydrogenation. Nitroꢀ active sites of the surface. Thus, it may be concluded
gen, sulfur, metalꢀcontaining catalytic components that Fe(III) ions during cycle opening of the complex
and trace elements were found in the solid residue isoꢀ are spatially distant from the Mo ions, forming the
lated; N and S were not detected in the products of oxide cluster structure of their own. The conclusion
hydrogenation.
To more exactly determine the product composiꢀ
tion of cellulose hydrogenation, the cellulose oil
obtained was analyzed with the use of H and C
NMR techniques. Based on the data obtained, we can
conclude that the resulting cellulose oil consists of
aromatic compounds, mainly substituted bicyclic and
tricyclic hydrocarbons (1Н 6.5–9 ppm; 13C 120–
about the formation of the spinel cluster structure is
confirmed by the spectra of 0.22 Fe + 1 Mo/sample
(samp. 2), with is active in catalysis (Figs. 1b, 1c).
1
13
This sample is distinguished by the formation of
quite large (d ~ 6–8 nm) clusters of nonstoichiometric
magnetite, which are characterized by two systems of
magnetic HFS from the Aꢀ and Bꢀpositions of iron
ions in the inverted spinel structure. The relative proꢀ
140 ppm). The signals of aliphatic hydrocarbons
portion of these clusters is ~ 26% at
Т = 300 K. Along
13
1Н 0.5–6 ppm; C 10–35 ppm) show that there are
with this there is a doublet of highꢀspin Fe3+ ions
(
saturated hydrocarbon chains with 16 C atoms (up to
40%) in the mixture of products that complicates the
identification and attribution of these hydrocarbons to
exact classes of compounds, i.e. they can be both free
alkanes and alkyl substituents in the aromatic comꢀ
pounds. This conclusion completely agrees with the
IR data.
which are characterized by smaller clusters of the same
spinel (
lows from the fact that during measurement at
15 K, the fraction of “paramagnetic” doublet
d ~ 2–4 nm) in the spectrum at 300 K. It folꢀ
Т
=
I
, rel. units
The IR spectra of the cellulose oil show the presꢀ
ence of saturated linear hydrocarbons (1350–
1180 cm–1) and aromatic hydrocarbons (diꢀ, triꢀ,
tetraꢀsubstituted) (1600, 3017, 3055, 780 cm–1) withꢀ
out the monosubstituted ones . There are also carboxꢀ
ylate groups (–Ph–C(O)OH) (1705 cm–1) and probaꢀ
bly ether bonds (Ph–O–Ph) in the aromatic cycles of
the products. It is noteworthy that there are no signals
corresponding to oxygenꢀcontaining compounds in
NMR spectra, but they are displayed in the IR specꢀ
trum, suggesting the presence of compounds of this
class in the cellulose oil, although their content is low
and does not exceed 0.5 wt %.
The samples of cellulose with the deposited mixꢀ
ture of monometallic complexes of iron and molybdeꢀ
num (0.22 Fe + 1 Mo catalyst/cellulose) (samp. 2)
before and after hydrogenation were studied by Mössꢀ
bauer spectroscopy, as well as the most active catalyst
(sample 4) preliminary treated by ultrasonication
before hydrogenation (Fig. 1, Table 8).
1.000
0.998
(а)
1.00
0.98
(b)
(c)
1.000
0.992
0.984
1.00
0.98
0.96
(d)
–10
–5
0
5
10
, mm/s
Spectrum 1a exhibits a “paramagnetic” doublet
probably corresponding to small superparamagnetic
clusters of iron oxide with the structure of inverted
spinel and a broadened monoline from the undecomꢀ
posed Fe(acac)3 complex . It follows that during the
deposition of iron acetylacetonate onto the surface of
activated cellulose, more than half of the initial
amount of the complex decomposes reacting with
V
Mössbauer spectra at
T = 300 and 15 K of 0.22Fe + 1Mo
catalyst/cellulose before and after catalysis: (a) before
catalysis, 300 K; (b) the same system after catalysis, 300 K;
(c) the same system after catalysis, 15 K; (d) the same sysꢀ
tem after preliminary sonication and after catalysis, 300 K.
PETROLEUM CHEMISTRY Vol. 53
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372
TSODIKOV et al.
Table 8. Mössbauer parameters of 0.22 Fe + 1 Mo catalyst/cellulose before and after catalysis
δ
Δ
Hin
A
Catalyst
0.22 Fe + 1 Mo
(before catalysis)
T
, K
Componen
0.03 mm/s
0.5 T
5%
300
300
Fe3+(monoline)
Fe3+(paramagnetic)
Fe3+(paramagnetic)
Fe2+(paramagnetic)
0.30
0.29
–
–
–
43
57
0.82
0.22 Fe + 1 Mo
(after catalysis)
0.38
0.94
0.31
0.76
0.74
1.91
0.02
0.04
–
62
12
10
16
–
Fe3O4 + (A) magnetic
δ
48.7
45.5
Fe3O4 + (B) magnetic
δ
0.22 Fe + 1 Mo
(after catalysis)
15
Fe3+(paramagnetic)
Fe2+(paramagnetic)
0.51
1.10
0.38
1.10
0.77
2.20
0.00
0.00
–
20
16
40
24
–
Fe3O4 + (A) magnetic
δ
49.0
47.4
Fe3O4 + (B) magnetic
δ
0.22 Fe + 1 Mo
(Sonication, after catalysis)
300
Fe3+(paramagnetic)
Fe2+(paramagnetic)
0.37
1.02
0.72
1.35
–
–
55
45
decreases from 60% (
Т
= 300 K) to 20% (
Т
= 15 K).
On both catalytic systems the active structure of
In this case the fraction of resonance absorption from catalysts is probably formed with participation of small
the magneticꢀordered clusters of spinel increases proꢀ superparamagnetic clusters of iron oxide with the
portionally. The “paramagnetic” Fe2+ ion with a relaꢀ spinel structure and “paramagnetic” Fe(II) ions localꢀ
tive content of ~ 15% formed via electron transfer on ized in defectꢀcontaining areas of activated cellulose.
the Fe(III) ion from electronꢀdonor sites of the actiꢀ
The results obtained show that the process used for
vated cellulose surface; ionized anionic vacancies can
the hydrogenating liquefaction of brown coal [7, 8] is
serve as such sites. Regarding the sample subjected to
quite efficient in cellulose deoxygenation and formaꢀ
ultrasonic treatment (Fig. 1d), magneticꢀordered
tion of higher hydrocarbons free of heteroatoms (S, N)
clusters of spinel are not formed in it according to the
which, as a rule, are always present during the processꢀ
Mössbauer data. There are only “paramagnetic” Fe3+
ing of conventional carbonaceous raw materials
(crude oil, coal). Highly dispersed catalytic systems
formed on the cellulose surface exhibit polyfunctional
properties, enhancing the processes of C–C bond
cracking and [C–O] bond deoxygenation with СО2
release. These properties of catalysts are manifested in
and Fe2+ ions in the catalytically active sample,
wherein the relative amount of Fe3+ is already 45%.
The presence of Fe3+ ions in a highꢀspin state characꢀ
terizes relatively small clusters of iron oxide with the
spinel structure again, whereas the formation of larger
clusters of spinel was most likely inhibited in the presꢀ
an increase of the cellulose conversion in the presence
ence of greater amount of the structure defects generꢀ
of the catalytic systems as compared with that
ated at the sonication stage. All this had a favorable
obtained during the uncatalyzed liquefaction of celluꢀ
effect on the catalytic properties of the system.
lose in the tetralin medium. Another important funcꢀ
According to the data of Table 1, the cellulose conꢀ
version degree and the composition of the reaction
products remain almost the same as with the use of
both the 0.22Fe + 1Mo catalysts obtained by deposiꢀ
tion from the mixture of monometallic complexes
(samp. 2) and the catalyst in which the active compoꢀ
nents were deposited on cellulose from the heteromeꢀ
tallic complex (samp. 3). The only difference is the
that the application of the heterometallic precursor
leads to the formation of a small amount of the light
fraction. The Mössbauer data also indicate that the
nature of active sites on the two catalysts is almost
unchanged. Although the heterocomplex (samp. 3) in
contrast to the sample 2 catalyst indeed does not
tion of the catalytic systems is regeneration of tetralin,
which donates hydrogen for saturating the cellulose
cracking products.
During the liquidꢀphase hydrogen transfer in the
absence of catalyst systems, tetralin irreversibly transꢀ
forms into naphthalene.
Thus, the catalytic cycle of the process under conꢀ
sideration lies in the reactions of C–C bond cracking
and cellulose deoxygenation with the liquidꢀphase
hydrogen transfer from tetralin to the forming subꢀ
strates with the continuous regeneration of tetralin on
catalytically active sites.
Thermocatalytic cleavage of cellulose in the presꢀ
decompose after deposition on the active matrix of ence of the deposited catalytic systems without tetralin
cellulose, the spectra obtained at = 300 and 15 K for leads only to gas formation and buildup of consolidaꢀ
samples 2 and 3 almost coincide after the catalysis. tion products [13]. It is likely that the role of tetralin as
Т
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2013

CATALYTIC CONVERSION OF CELLULOSE
2. B. N. Kuznetsov, Ross. Khim. Zh. 47, 83 (2003).
373
it was previously found during the brown coal hydroꢀ
genation consists in the dissolving of unsaturated
organic products of cellulose cracking and liquidꢀ
phase hydrogen transfer to these products, wherein
hydrogen hinders the formation of consolidation
products [8].
3. D. Fengel and G. Wegener, Wood: Chemistry, Ultraꢀ
structure, Reactions (Walter de Gruyter, Berlin, 1984).
4. B. N. Kuznetsov, Soros. Obraz. Zh., No. 12, 47 (1996).
5. G. P. Curran, R. T. Struck, and E. R. Gorin, Ind. Eng.
Chem. Process. Des. Dev. 6, 166 (1967).
The celluloseꢀderived hydrocarbon oil can be used
as a purified feedstock for manufacturing a broad
range of highꢀpurity hydrocarbons for various purꢀ
poses.
6. R. F. Probstein, and R. F. Hicks, Synthetic Fuels
(McGrawꢀHill, New York, 1982).
7. M. V.Tsodikov, Yu. V. Maksimov, O. G. Ellert, et al.,
Khim. Tverd. Topl. (Moscow), No. 4, 96 (1989).
8. M. V. Tsodikov, Yu. V. Maksimov, G. A. Teplyakova,
et al., Khim. Tverd. Topl. (Moscow), No. 4, 89 (1991).
ACKNOWLEDGMENTS
9. A. Müller, S. Talismanov, P. Kögerler, et al., J. Cluster
This work was supported by the Russian Foundaꢀ
tion for Basic Research, project nos. 12ꢀ03ꢀ00489, 12ꢀ
03ꢀ33062, and 13ꢀ03ꢀ12034, President’s Council on
grants for support of young scientists, project no. MKꢀ
2151.2012.3, and leading scientific schools, project
no. NShꢀ5232.2012.3.
The authors thank M. B. Smirnov for assistance in
interpreting the NMR data and G. N. Bondarenko for
assistance in IR determination of the composition of
cellulose oil.
Sci. 16, 391 (2005).
10. I. V. Avgushevich, T. M. Bronovets, and G. S. Golovin,
Standard Coal Testing Methods (NTK Trek, Moscow,
2008) [in Russian].
11. T. M. Khrenkova, Doctoral Dissertation in Chemistry
(Moscow, 1983) [in Russian].
12. V. V. Molchanov and R. A. Buyanov, Usp. Khim. 69
,
476 (2000).
13. M. G. Sul’man, V. G. Matveeva, E. M. Sul’man, et al.,
Kinet. Katal. 39, 635 (1998).
14. M. Chistyakov, M. Gubanov, M. Chudakova, et al., in
Proceedings of Synfuelꢀ2012 Conference, (Munich,
2012).
REFERENCES
1. D. T. Boyles, Bioenergy: Technology, Thermodynamics
and Costs (Ellis Horwood, Chichester, 1984).
Translated by K. Aleksanyan
PETROLEUM CHEMISTRY Vol. 53
No. 6
2013