Conversion of biological substrates to fuel components in the presence of industrial catalysts

Article abstract of DOI:10.1007/s11172-013-0111-4

Conditions were found under which the industrial aluminum-platinum catalyst AP-64 and the pilot zeolite system Pd-Zn/Al₂O₃/MFI (MFI is a high-silica ZSM-5 type zeolite) catalyze single-stage highly selective conversion of rapeseed oil and ethanol to either alkane or alkanearomatic fraction of hydrocarbons suitable as engine fuel components. The hydrocarbon chain grows with participation of ethylene, which is formed in the argon medium directly from the ethanol molecule. Under these conditions, hydrogenation of this alkene on intermetallic clusters arising during the long-term reductive preactivation is suppressed. The alcohol supplies not only ethylene but also hydrogen. In the presence of Pd-Zn/Al₂O₃/MFI, ethanol is converted to alkanes and aromatic hydrocarbons according to independent pathways. Joint processing of alcohols and rapeseed oil in the presence of the Pd-Zn/Al₂O₃/MFI catalyst system is an efficient and promising route to C₃-C₁₁ hydrocarbons in the absence of an external source of hydrogen.

Full text of DOI:10.1007/s11172-013-0111-4

Russian Chemical Bulletin, International Edition, Vol. 62, No. 3, pp. 820—829, March, 2013
820
Conversion of biological substrates to fuel components
in the presence of industrial catalysts*
M. V. Tsodikov,a A. V. Chistyakov,a M. A. Gubanov,a S. N. Khadzhiev,a A. E. Gekhman,b and I. I. Moiseevb
аA. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences,
29 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (495) 633 8520. Eꢀmail: chistyakov@ips.ac.ru
bN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (495) 954 1279
Conditions were found under which the industrial aluminum—platinum catalyst APꢀ64 and
the pilot zeolite system Pd—Zn/Al2O3/MFI (MFI is a highꢀsilica ZSMꢀ5 type zeolite) catalyze
singleꢀstage highly selective conversion of rapeseed oil and ethanol to either alkane or alkaneꢀ
aromatic fraction of hydrocarbons suitable as engine fuel components. The hydrocarbon chain
grows with participation of ethylene, which is formed in the argon medium directly from the
ethanol molecule. Under these conditions, hydrogenation of this alkene on intermetallic clusꢀ
ters arising during the longꢀterm reductive preactivation is suppressed. The alcohol supplies not
only ethylene but also hydrogen. In the presence of Pd—Zn/Al2O3/MFI, ethanol is converted
to alkanes and aromatic hydrocarbons according to independent pathways. Joint processing of
alcohols and rapeseed oil in the presence of the Pd—Zn/Al2O3/MFI catalyst system is an
efficient and promising route to C3—C11 hydrocarbons in the absence of an external source of
hydrogen.
Key words: heterogeneous catalysis, processing of biomass products, catalyst activaꢀ
tion, biofuel.
The search for economic routes for the production of
products, rapeseed oil, and their mixture to hydrocarbon
fuel components. The industrial aluminum—platinum catꢀ
alyst APꢀ64 and two pilot catalyst samples Pd—Zn/Al2O3/
MFI (MFI is highꢀsilica zeolite) based on a ZSMꢀ5 type
zeolite were used.
petrochemicals and engine fuel components from primary
biomass processing products is a topical challenge. In reꢀ
cent years, researchers´ attention has been drawn to the
chemistry of alcohols obtained by fermentation by plant
carbohydrates and lipids produced by diverse agricultural
crops, fungi and micro algae.1
Experimental
Previously, it was found2 that longꢀterm reduction of
the industrial aluminum—platinum catalyst changes conꢀ
siderably its properties. Indeed, ethanol is usually deꢀ
hydrated on the catalyst APꢀ64 to give ethylene and diꢀ
ethyl ether (DEE). However, in the presence of the same
catalyst preactivated by hydrogen for a long period, ethaꢀ
nol is converted, under argon atmosphere, to the C4—C12
alkane fraction, while higher alcohols C4 and C5 are mainly
converted to C8 and C10 alkanes.3,4
A number of publications5—8 describes the transforꢀ
mation of ethanol and vegetable oils to aromatic hydroꢀ
carbons in the presence of zeolite catalysts based on ZSMꢀ5.
The principal drawback of these catalysts is fast deactivaꢀ
tion caused by the formation of products of condensation.
This work reports the results of catalytic conversion of
ethanol, a model mixture of carbohydrate fermentation
Two study employed two types of industrial catalysts: the
aluminum—platinum catalyst APꢀ64 (0.6 wt % Pt on ꢀAl2O3,
specific surface area 200 m2 g–1, pore volume 0.65 cm3; TU
2177ꢀ021ꢀ04610600ꢀ2000) and the catalyst based on MFI,
a structural analog of ZSMꢀ5, with the ratio SiO2/Al2O3 = 37,
and ꢀAl2O3 modified with either 0.6 wt % Pd and 1 wt % Zn, or
with 0.6 wt. % Pd and 1.2 wt.% Zn (manufactured by the OJSC
Angarsk Plant of Catalysts and Organic Synthesis).9
The rapeseed oil of the brand name P (GOST 8988ꢀ2002)
manufactured by "Russian Seeds" company served as a raw maꢀ
terial. The fattyꢀacid composition of the oil transesterified with
methanol is presented below.
Component
Methyl stearate
Methyl oleate
Methyl gondoinate
Methyl erucate

Content in the oil (wt.%)
4.9
93.313
1.795
0.102
100.00
* Dedicated to Academician of the Russian Academy of Sciences
I. P. Beletskaya on the occasion of her anniversary.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 0819—0828, March, 2013.
1066ꢀ5285/13/6203ꢀ820 © 2013 Springer Science+Business Media, Inc.

Fuel from biomass on industrial catalysts
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
821
The procedure for determination of the fattyꢀacid composiꢀ
tion of rapeseed oil was reported previously.10
Ethanol (analytically pure grade, GOST 5964ꢀ93), propanꢀ
1ꢀol (chemically pure grade, TU 6ꢀ09ꢀ4344ꢀ87), butanꢀ1ꢀol (pure
grade, GOST 6006ꢀ78), and isoamyl alcohol (pure grade, GOST
5830ꢀ79) were used as received.
The conversion of bioꢀsubstrates in the presence of Pd—Zn/
Al2O3/MFI was studied on a PID Eng and Tech flow type fixed
bed microcatalytic setup.11
The activity of the APꢀ64 catalyst in the transformation of
bioꢀsubstrates was studied on an original flowꢀcirculation type
laboratory setup with a fixed catalyst bed, which ensured continꢀ
uous recycling of the reaction gases back to the reaction area.12
Immediately prior to experiments, both catalytic systems
were reduced in a hydrogen flow (30 L h–1) at 450 C and a
pressure of 50 atm.
Y (wt.%)
40
35
30
25
20
15
10
5
100 C
300 C
450 C
C1
C2
CO + CO2 C3+
Oxygenates
Fig. 1. Effect of the Pt/Al2O3 reduction temperature on the comꢀ
position of ethanol conversion products; Y is yield; C1, C2, and
C3+ are aliphatic hydrocarbons.
The reaction of rapeseed oil was studied in a hydrogen flow
in a molar excess with respect to the substrate (10 : 1), a temperꢀ
ature of 360—420 C, a pressure of 50 atm, and a substrate space
velocity of 0.6—2.4 h–1
.
The ethanol transformation was carried out in argon at
Dehydration of ethanol to give alkanes with longer
carbon skeleton was found for the first time in the presꢀ
ence of a mixture of intermetallic compound with an aluꢀ
minum—platinum or over fused iron catalyst;2,15 this
reaction was called reductive dehydration of ethanol
(RDE).
a pressure of 5 atm, a temperature of 330 C, and a substrate
space velocity of 0.6—2.4 h–1
.
The gaseous reaction products were analyzed by gas chroꢀ
matography in the onꢀline mode: the C1—C5 hydrocarbon gases
were analyzed on a Kristallꢀ4000М chromatograph (flame
ionization detector, a HPꢀPLOT/Al2O3 column) and CO, CO2,
and H2 were determined on a Kristallꢀ4000 chromatograph (heat
conductivity detector, an SKT column). Low CO concentraꢀ
tions (<0.4 vol.%) were determined by a Riken Keiki gas analyzꢀ
er with an IR cell (RIꢀ550A).
m C2H5OH
(n  3)
CnH2n+2 + H2O
(1)
Liquid organic reaction products in the aqueous and organic
phase were identified by GCꢀMS using MSD 6973 (Agelent) and
Automassꢀ150 (Delsi Nermag) instruments and HPꢀ5MS and
CPSilꢀ5 columns. Organic compounds were quantified by GLC
on a Varian 3600 instrument, a Chromtech SEꢀ30 column using
trifluoromethylbenzene as the internal standard for the organic
layer. The residual content of organic products in the aqueous
phase was found by the GC/MS from the integral signal ratio by
absolute calibration method.
The RDE reaction occurs in rather narrow temperaꢀ
ture and ethanol space velocity ranges, the optimal condiꢀ
tions being a temperature of 300—350 C and an ethanol
feed velocity of 0.5—0.9 h–1 (Fig. 2). A temperature deꢀ
crease below 300 C and increase in the feed space veloꢀ
city above 0.9 h–1 result in almost complete loss of selecꢀ
tivity of formation of C3—C12 alkanes.16
The yields of the major products of ethanol conversion
in the presence of APꢀ64 (330 C, 5 atm, Ar, substrate
space velocity 0.6 h–1) are presented below.
Results and Discussion
In a flow type reactor in the presence of the aluꢀ
minum—platinum catalyst in the temperature range
of 250—400 C, ethanol tends to be mainly dehydrated
to give ethylene and diethyl ether (DEE). The yield
of ethane is negligibly low under these conditions.13,14
However, hydrogen pretreatment of APꢀ64 even at
moderate temperature markedly changes the catalyst
selectivity. Indeed, in the presence of the H2ꢀpretreatꢀ
ed catalyst at 100 C, ethanol is mainly converted over
a period of 2 h to gaseous products: C1—C4 alkanes, CO,
and CO2 in an overall yield of 75 wt.% (Fig. 1). In the
presence of a catalyst preꢀreduced for 12—14 h, the route
of ethanol conversion under inert gas at 450—500 C
changes even more noticeably. After this longꢀterm reꢀ
ducing treatment, the yield of methane decreases and the
yield of C3—C12 alkanes increases (see Fig. 1).
C (wt.%)
35
30
25
20
15
10
5
C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 Alkane
Fig. 2. Composition of the C3—C12 alkane fraction obtained
during ethanol conversion in the presence of APꢀ64 at 330 C,
5 atm of Ar, substrate space velocity of 0.6 h–1
.

822
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
Tsodikov et al.
Product
Water
H2
CO
CO2
CH4
C2H6
Oxygenates
C3—C12 alkanes
Yield (wt.%)
22.10
0.08
The formation of a minor amount of alkanes with odd
numbers of carbon atoms can be due to secondary crackꢀ
ing of hydrocarbon reaction products.
A XAFS study of the structure of the catalyst APꢀ64
after longꢀterm reduction demonstrated that Pt2Al clusꢀ
ters are formed on the catalyst surface. The Xꢀray absorpꢀ
tion spectra coincide to a high accuracy with the spectra
of Pt2Al synthesized from the elements.16,17
4.91
12.39
6.15
21.03
2.88
30.46
The temperatureꢀprogrammed desorption of ammoꢀ
nia revealed the presence of strong Brønsted acid sites.16
The industrial aluminum—platinum catalyst subjected
to longꢀterm preactivation shows high activity in ethanol
dehydration followed by carbon chain growth and mild
hydrogenation of C=C bonds of oligomerization prodꢀ
ucts. Among important advantages of this catalyst is subꢀ
stantial retardation of C—C bond cleavage processes on
this catalyst as compared with processes that occur on the
same catalyst preꢀreduced for a short time. In the latter
case, ethanol is mainly converted to ethane.
In the presence of the industrial aluminum—platinum
catalyst subjected to longꢀterm reductive pretreatment,
the reaction pathway changes not only for ethanol but also
for fatty acid triglycerides (FATG). FATG are converted
to an alkane fraction (Fig. 3), the IR spectra of which do
not show absorption bands for CO (1200 cm–1) or CO2
(1750 cm–1) groups. Thus, in the presence of the alumiꢀ
num—platinum catalyst, rapeseed oil is completely conꢀ
verted to alkanes and water.
Gaseous products contain large amounts of carbon oxꢀ
ides and C1 and C2 alkanes. Liquid products contain, along
with alkanes, minor amounts (totally 1%) of cycloꢀ
alkanes, olefins, and aromatic hydrocarbons. Oxygenates
mainly comprise diethyl ether and also acetaldehyde, ethyl
acetate, and traces of butanol and hexanol. Hydrogen
needed for the formation of alkanes according to Eq. (1) is
generated, most likely, directly in the following catalytic
reactions:
C2H5OH
CH4 + CO + H2,
2 CO + 4 H2,
(2)
(3)
(4)
(5)
(6)
C2H5OH + H2O
C2H5OH
CH3CHO + H2,
CH3CHOOC2H5 + 2 H2,
CO2 + H2.
2 C2H5OH
CO + H2O
The C16 and C17 alkanes (total yield 80 wt.%) are
formed upon the reduction and decarboxylation of the
acyl groups of the oil. Apart from these major products,
other alkanes are formed, their composition being repreꢀ
sented by a continuous broad spectrum (see Fig. 3). These
alkanes are likely to arise upon hydrocracking of the priꢀ
mary products. The carbon chains of the major compoꢀ
nents of the alkane fraction are either equal to or one
carbon shorter than the alkyl chain length of the fatty acid
of the initial oil. Apparently, the major pathways of oil
conversion are hydrogenation and decarboxylation of the
FATG acid groups:
The intermolecular hydride transfer between the priꢀ
mary products of ethanol conversion may also occur.
In the presence of the aluminum—platinum catalyst,
the gaseous reaction products were found to contain
0.08 wt.% of hydrogen despite the intense hydrogen transꢀ
fer in the reaction system.
Hydrocarbons with even numbers of carbon atoms preꢀ
dominate (<70 wt.%) in the alkane fraction (see Fig. 2).
The effect of potential intermediates on the alkane yield
indicates that the hydrocarbon chain grows at the expence
of diethyl ether and ethylene.16 All the available data can
be interpreted within the framework of Scheme 1, which
includes oligomerization of the intermediate ethylene folꢀ
lowed by hydrogenation of the resulting olefins on platiꢀ
num sites12,16 (see Fig. 2).
CnH2nCOO— + H2
Cn+1H2n+2 + H2O,
(7)
(8)
CnH2nCOO— + H2
CnH2n+2 + CO2.
Scheme 1
Since the gaseous reaction products contain only tracꢀ
es of carbon oxides, they have evidently been hydrogenated
during catalysis to methane, which is formed in a 1.5 wt.%
yield.
The reaction products were also found to include
C23—C28 alkanes containing more carbon atoms than the
fatty acids in the initial oil. The total yield of C23—C28
alkanes was 5 wt.%, which suggests that a glycerol fragꢀ
ment has been incorporated into the intermediates formed
from acyl groups.
AS are the acid sites of the support, s is the molecule sorbed on the
catalyst surface.

Fuel from biomass on industrial catalysts
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
823
Y (wt.%)
30
64.27
25
20
15
10
5
1 2 3 4
5 6 7 8 9 10 1112 13 14 15 16 1718 19 20 21 22 2324 25 26 27 282930 31 n
Fig. 3. Yield of the alkane products of rapeseed oil conversion; n is the number of carbon atoms in the alkane.
Consider the data on the variation of the aluminum—
platinum catalyst activity during operation. The alumiꢀ
num—platinum catalyst without reductive pretreatment
reaches the stable performance equal to that of the preꢀ
treated catalyst after 28 h (Fig. 4).
During the first 28 h, the aluminum—platinum cataꢀ
lyst not only exhibits high hydrogenating activity but also
cracks the C—C bonds and isomerizes the alkanes formed.
However, methanation is not very intensive, the maxiꢀ
mum yield of light C1—C3 alkanes being 21 wt.%. At
420 C, the yields of both light and branched alkanes deꢀ
crease after 28 h; the system reaches stable operation in
which the yield of the target C4—C25+ fraction is mainꢀ
tained at 85—90 wt.% in relation to the weight of carbon
passed and the content of iso structures is 2—3 wt.%. The
yield of gaseous hydrocarbons does not exceed 5—6 wt.%;
the predominant components among these are methane
and ethane the content of which per carbon atom roughly
corresponds to the theoretical amount of carbon obtained
by decarboxylation of the fatty acids fed in the reactor.
This selectivity is retained for the subsequent 22 h. The
formation of heavy C23+ alkanes occurs throughout the
whole experiment and becomes noticeably more proꢀ
nounced after the catalyst has operated for the first 28 h
(see Fig. 4). The amount of C3 hydrocarbons is 70% lower
than the number of stoichiometric C atoms in the glycerol
C (wt.%)
Y (wt.%)
40
80
35
30
25
20
15
10
5
70
60
2
50
5
40
3
30
20
10
1
4
10
20
30
40
50
t/h
Fig. 4. Variation dynamics of the yields of rapeseed oil conversion products in longꢀtime run on APꢀ64 without preactivation (420 C,
space velocity of 0.6 h–1, 50 atm of H2): alkanes C1—C3 (1), C4—C16 (2), C17 (3), C18+ (4), iso structures (5).

824
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
Tsodikov et al.
Table 1. Comparative data on ethanol conversion in the presꢀ
ence of Pd(0.6%)—Zn(1%)/MFI and Pd(0.6%)—Zn(1.2%)/MFI
catalysts (initial Ar pressure 5 atm, 330 C, ethanol space velocꢀ
moiety of FATG. This fact also indicates the possibility of
intramolecular condensation of hydrocarbon parts of
FATG with participation of the glycerol moiety.
ity 0.6 h—1
)
These results indicate that the industrial aluminum—
platinum catalyst efficiently produces a newꢀgeneration
biodiesel in one step and markedly reduces the loss of
valuable carbon stock of both glycerol and acid moieties,
which is inherent in operation of other catalysts.1,18,19 The
discovered new properties of the aluminum—platinum
catalyst may considerably enhance the efficiency of bioꢀ
substrate conversion to valuable fuel components.
The pilot samples of the Pd—Zn/Al2O3/MFI catalyst
proved themselves promising for obtaining hydrocarbons in
high yields from ethanol and rapeseed oil. They are based
on a structural analog of ZSMꢀ5 developed for the conversion
of dimethyl ether or dimethyl ether—methanol mixture to
gasoline. The hydrocarbon yield on this catalyst is very high,
although the selectivity of this system differs appreciably
from that for the aluminum—platinum catalyst,20 aroꢀ
matic compounds being predominant reaction products.
In the presence of the two samples of the Pd—Zn/
Al2O3/MFI catalyst, ethanol is converted almost comꢀ
pletely. The major product is C3—C12 alkaneꢀaromatic
hydrocarbon fraction, which is formed in 70—83 wt.%
yield in relation to the carbon passed (Table 1).
Parameter
Pd(0.6%)—
Zn(1%)/MFI
Pd(0.6%)—
Zn(1.2%)/MFI
Ethanol conversion (%)
Yield (wt.%)
Hydrocarbons
Water
Composition of hydrocarbon
products (wt.%)
С1
>99
>99
61.2
38.8
60.9
39.1
0.64
11.98
3.94
0.27
26.72
2.03
С2
С2=
Aliphatic C3—C7
hydrocarbons
Aromatic C6—C12
hydrocarbons
Composition of the aliphatic
C3—C7 fraction
С3
С4
С5
С6
С7
45.87
28.06
37.57
42.92
34.07
33.07
21.72
7.82
45.47
29.91
9.60
10.12
4.90
3.32
Thus, palladium and zinc modification of a ZSMꢀ5
type zeolite substantially decreases the yield of olefins comꢀ
pared with the yield of the products of ethanol conversion
cstalyzed by either nonꢀmodified HꢀZSMꢀ5 or that with
supported metals.21—24
A comparison of the results with the results for
Pd—Zn/Al2O3 (see Ref. 25) shows a considerable increase
in the total yield of the target hydrocarbon fraction,
C3—C12, from 50 to 83%. Furthermore, the zeolite cataꢀ
lyst shows selectivity toward the formation of alkanes and
aromatic hydrocarbons, whereas the aluminaꢀsupported
Pd—Zn catalyst predominantly produces the alkaneꢀoleꢀ
fin fraction.25
Composition of the aromatic
C6—C12 fraction
Benzene
Toluene
Ethylbenzene
Xylenes
Trimethylbenzene
Ethylmethylbenzene
Diethylbenzene
Dimethylethylbenzene
Methylnaphthalene
Dimethylnaphthalene
1.16
16.73
7.46
24.36
9.83
24.34
10.15
2.31
0.97
28.61
7.52
35.83
5.08
10.98
4.83
2.89
3.66
0.00
3.30
0.97
Hydrogen formation:
(n + 3) С2H4
An increase in the zinc content in the catalyst by
0.2 wt.% results in much higher yield of ethane and aroꢀ
matics (see Table 1). The increase in the ethane content is
correlated with the decrease in the yield of the C3—C7
aliphatic hydrocarbons from 46 to 28% and increase in the
yield of aromatics (see Table 1). The reaction proceeds in
an inert medium; therefore, hydrogen needed for the forꢀ
mation of alkanes is for the most part supplied, in all
probability, by aromatization of the intermediates formed
from ethanol.22,26 The increase in the yield of the aromatꢀ
ic fraction is accompanied by enhanced formation of hyꢀ
drogen and, as a consequence, by increased contribution
of ethylene to ethane hydrogenation.
+ 3 H2,
(9)
(n + 10) C2H4
+ 6 H2,
(10)
С2H5OH
CH4 + CO + H2,
(11)
(12)
CO + H2O
CO2 + H2.
Apparently, ethylene is the key intermediate responsiꢀ
ble for the carbon chain buildup.22,26 Hence, hydrogen
formation and consumption in the system can be described
by Eqs (9)—(12) and (13), respectively.
Hydrogen consumption:
n C2H4 + H2
C2nH4n+2
.
(13)

Fuel from biomass on industrial catalysts
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
825
Table 2. Balance of hydrogen redistribution during the conversion of 0.7 moles of ethanol in the
presence of a zeolite catalyst containing Pd(0.6%)—Zn(1%)
Hydrogen formation*
Hydrogen consumption**
Hydrogen m/mmol
Hydrogen donor (D)
Hydrogen evolution,
m/mmol
acceptor (A)
A
H2
D
H2
Benzene
Toluene
Ethylbenzene
Xylenes
Trimethylbenzene
Ethylmethylbenzene
Diethylbenzene
Dimethylethylbenzene
Methylnaphthalene
Carbon monoxide
0.96
13.73
4.54
17.82
5.28
13.08
6.88
1.97
2.87
41.18
13.61
53.46
15.85
39.24
20.64
5.90
Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Hydrogen
—
6.75
66.51
66.59
34.53
25.07
8.13
3.87
0.71
—
6.75
66.51
66.59
34.53
25.07
8.13
3.87
0.71
—
2.05
3.12
12.30
3.12
—
—
—
* Totally 208.18 mmoles of H2 are evolved.
** Totally 212.6 mmol H2 are consumed.
The hydrogen amount liberated upon the formation of
aromatic hydrocarbons present in the reaction products
calculated in terms of the proposed model is consistent
with the amount of hydrogen spent for the formation of
the alkane fraction (Tables 2 and 3). In the presence of
the Pd(0.6%)—Zn(1.2%) catalyst, the amount of hydroꢀ
gen formed is 25 mol.% greater than for the Pd(0.6%)—
Zn(1%) sample.
The Pd—Zn/Al2O3/MFI catalyst efficiently accelerꢀ
ates the transformation of ethanol to valuable fuel comꢀ
ponents. The yield of the alkaneꢀaromatic fraction is much
higher than in the presence of analogous nonꢀzeolite cataꢀ
lysts. When the catalyst contacts with the reaction mixture
for 48 h, no detectable loss of activity or selectivity occurs,
which was the case for analogous catalysts.21—24,26 The
catalyst stability to surface carbon deposition attests to its
high activity in hydrogen transfer reaction. Therefore, the
Pd—Zn/Al2O3/MFI catalyst may be expected to be also
efficient in the processing of heavier bioꢀsubstrates such as
vegetable oils. During hydrogen preactivation, clusters of
the intermetallic compound Pd0.5Zn0.5 are formed on the
zeolite surface.27
In the presence of metalꢀcontaining zeolite catalysts
(pentasil), FATG are destroyed to give a broad spectrum
Table 3. Balance of hydrogen redistribution during the conversion of 0.7 moles of ethanol in the
presence of a zeolite catalyst containing Pd(0.6%)—Zn(1.2%)
Hydrogen formation*
Hydrogen consumption**
Hydrogen m/mmol
Hydrogen donor (D)
Hydrogen evolution,
m/mmol
acceptor (A)
A
H2
D
H2
Benzene
Toluene
Ethylbenzene
Xylenes
Trimethylbenzene
Ethylmethylbenzene
Diethylbenzene
Dimethylethylbenzene
Methylnaphthalene
Dimethylnaphthalene
1.08
15.42
5.10
20.02
5.93
14.69
7.73
2.21
3.24
46.27
15.30
60.06
17.80
44.08
23.19
6.64
Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Hydrogen
—
2.88
152.69
54.35
26.36
9.29
6.27
2.61
1.07
—
2.88
152.69
51.35
24.36
9.29
5.27
2.61
1.07
—
3.51
2.30
21.03
13.82
—
—
—
* Totally 251.43 mmoles of H2 are evolved.
** Totally 249.52 mmol H2 are consumed.

826
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
Tsodikov et al.
Table 4. Composition of the products of rapeseed oil conversion under optimal conditions: 420 C, 2.4 h–1 (I) and
230 C, 1.2 h–1 (II)
Products
Content (wt.%)
II
Products
Content (wt.%)
I
I
II
С1
С2
C2=
C3
C3=
isoꢀC4
nꢀС4
C4=
isoꢀС5
nꢀC5
С5=
2,3ꢀDimethylbutane
isoꢀC6
nꢀC6
1.04
4.83
0.32
10.79
0.75
5.88
2.19
1.81
4.52
1.46
1.12
0.45
0.94
0.72
6.56
0.54
4.89
0.18
11.71
0.37
9.50
5.30
1.49
9.91
2.60
0.66
1.09
2.04
3.40
7.04
Toluene
18.42
4.81
13.06
3.15
0.94
5.93
1.40
1.01
1.61
0.96
1.16
1.40
2.55
0.21
100.00
16.92
3.79
9.24
2.23
0.00
4.16
0.80
0.61
0.00
0.00
0.00
0.63
0.58
0.33
100.00
Ethylbenzene
oꢀXylene, pꢀxylene
mꢀXylene
Propylbenzene
Ethylmethylbenzene
1,2,3ꢀTrimethylbenzene
Methylphenylethylen
1,2ꢀDiethylbenzene
ꢀPhenylꢀꢀethylethylene
Naphthalene
ꢀMethylnaphthalene
СО
СО2
Benzene

of products, aromatics being the predominant compoꢀ
nents,5—7 although this process tends to give methane in
a high yield and the catalyst systems are rapidly deactivated.
Study of the conversion of rapeseed oil in the presence
of Pd—Zn/Al2O3/MFI identified two optimal modes that
provided the highest yields of the target alkaneꢀaromatic
fraction: space velocity of 2.4 h–1 at 420 C or space velocꢀ
ity of 1.2 h–1 at 360 C. In the former case, the highest
yield of the target aromatic hydrocarbon fraction was
obtained (79 wt.%), while in the latter case, the highest
yield of C3—C6 aliphatic hydrocarbons was achieved
(48 wt.%, Table 4).
The conversion of the oil does not give aliphatic hydroꢀ
carbons with more than six carbon atoms (n). The reacꢀ
tions give mainly C4—C8 hydrocarbons (62 wt.%), those
with n > 6 being aromatic (see Table 4), which is attributꢀ
able to the shapeꢀselectivity effect of the catalyst.28 The
lack of temperature effect on the formation of aromatic
hydrocarbons suggests that the cyclization occurs by soꢀ
called "hydrocarbon pool" mechanism described in relaꢀ
tion to the preparation of identical alkaneꢀaromatic fracꢀ
tion from methanol and ethanol.29 According to this mechꢀ
anism, dehydration and C—C bond cleavage of ethanol
give separate fragments of [CHх] radicals, which are conꢀ
densed in the zeolite pores to give aromatic hydrocarbons
with predominant yield of toluene and xylenes. The forꢀ
mation of aromatic hydrocarbons is accompanied by evoꢀ
lution of H2, and ethanol oxygen mainly goes to a water
molecule.29
During conversion of fatty acid triglycerides, decarbꢀ
oxylation of the acid moiety at 360 C is of low intensity,
as the yield of carbon monoꢀ and dioxide is less than oneꢀ
tenth of the theoretically possible yield. An increase in the
temperature to 420 C considerably intensifies the formaꢀ
tion of CO, its yield being 1/3 of the theoretically possiꢀ
ble value (see Table 5).
Oxygen present in the FATG molecule goes for most
part into water, which is indicative of a great contribution
of hydrogenation of C—O bonds (see Table 6).
In the early stages of FATG conversion, decarbonylaꢀ
tion and decarboxylation of the acid moieties may take
place followed by reduction of the resulting carbon oxides
to methane. However, the total yield of methane and
carbon oxide is 20 mol.% at 360 C and 50 mol.% at 420 C
Table 5. Carbon content in acid groups and glycerol moiety
(mmol) that were passed through a catalyst bed during the
experiment under different reaction conditions: 420 C,
2.4 h–1 (I) and 360 C, 1.2 h–1 (II)
Parameter
I
II
Carbon content, mmolꢀat. C
In glycerol
67.61
67.61
135.22
35.03
35.03
70.06
In carboxyl group

Recovered C, mmol
From СН4
12.40
61.39
140.40
17.40
0.91
3.09
29.92
73.22
1.91
From С2Н6
From С3Н8
From СО
The contribution of decarbonylation and decarboxylaꢀ
tion of the acid groups of fatty acid triglycerides of rapeꢀ
seed oil to the conversion of the glycerol moiety was estiꢀ
mated from the balance of carbon and oxygen introduced
in the reaction and recovered (Tables 5 and 6).
From СО2
0.69

232.5
108.83

Fuel from biomass on industrial catalysts
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
827
Table 6. Oxygen content in ester groups (mmol)
that were passed through a catalyst bed during the
experiment under different reaction conditions:
420 C, 2.4 h–1 (I) and 360 C, 1.2 h–1 (II)
attests to a secondary cracking of alkanes, because at eleꢀ
vated temperature (420 C), an increase in the yield of
propane is accompanied by a decrease in the content of
aliphatic hydrocarbons.
The FATG conversion products predominantly conꢀ
tain alkylaromatic compounds that could have resulted
from condensation, in zeolite pores, of CHx hydrocarbon
fragments arising upon cracking of the initial aliphatic
chains of fatty acids.
It is known that zincꢀcontaining active components
are highly active in the conversion of alkanes29 and oleꢀ
fins30 to alkylaromatic compounds. Presumably, the conꢀ
densation of the carbon products of cracking according to
the hydrocarbon pool mechanism occurs particularly on
zinc active components.
The shapeꢀselectivity effect of the zeolite support is
manifested in the fact that the major product fraction
C4—C8 does not contain liquid alkanes heavier than C6.
The content of branched alkanes reaches 80%.
During the ethanol conversion catalyzed by Pd—Zn/
Al2O3/MFI, the system produces much more hydrogen
than in the case of APꢀ64. In order to achieve higher
energy efficiency, experiments on combined conversion of
rapeseed oil together with alcohol were performed; this
reaction was expected to occur in an inert medium withꢀ
out consumption of hydrogen.
The catalytic tests were conducted using a mixture of
alcohols rather than pure ethanol, this mixture modeling
the biomass fermentation products and consisting of
ethanol (80%), propanol (5%), butanol (5%), and isoamyl
alcohol (10%). The substrate composition included rapeꢀ
seed oil (25%) + alcohol mixture (75%). The component
ratio was chosen so as to ensure a threefold excess of H2
produced from ethanol. The 100% conversion of the subꢀ
strates was confirmed by IR and 1H and 13C NMR data.
The yields of the major products of joint conversion of
rapeseed oil (25 vol.%) and alcohol mixture (75 vol.%) in
the presence of Pd—Zn/Al2O3/MFI (420 C, 5 atm, Ar,
substrate space velocity of 1.2 h–1) are presented below.
Parameter
I
II
Fed
135.23
70.06
Recovered
О in Н2О
О in СО
О in СО2

115.38
17.40
1.81
66.68
1.91
1.38
69.97
134.59
of the theoretically possible value. The amount of the obꢀ
tained propane is twice as high as the amount that could
have formed from the glycerol introduced in the system.
Evidently, in the presence of Pd—Zn/Al2O3/MFI, reꢀ
duction (hydrogenation) of C—O bonds and the subseꢀ
quent cracking of the resulting carbon fragments occurs
more intensively, while at higher temperature, the contriꢀ
bution of decarbonylation and decarboxylation increases.
Stability testing of the Pd—Zn/Al2O3/MFI catalyst
demonstrated that almost complete conversion of rapeꢀ
seed oil and the high selectivity with respect to the target
alkaneꢀaromatic fraction are retained for 50 h (Fig. 5).
It can be concluded that the conversion of rapeseed
oil catalyzed by Pd—Zn/Al2O3/MFI is a complex proꢀ
cess consisting of reactions that take place on metal and
oxide sites.
The glycerol moiety of FATG is apparently converted
completely to the propane fraction. The products obtained
with this catalyst contain more C3 hydrocarbons than
could be expected if they were formed from glycerol. This
Y (wt.%)
4
3
50
40
30
20
10
Product
Water
Yield (wt.%)
30.88
CO + CO2
CH4
00.45
00.73
C2H6
01.49
C2H4
00.87
C3—C6 alkanes
C3—C6 olefins
C6—C11 aromatics
10.49
06.46
48.63
2
1
The combined conversion of ethanol and rapeseed oil
affords much more olefins and aromatic hydrocarbons than
separate conversion of either of the substrates (Table 9
and Fig. 6). The yield of light hydrocarbons remains at
<5 wt.%, despite the elevated temperature (420 C), whereꢀ
as in the case of conversion of ethanol alone at 330 C, the
yield of C1—C2 hydrocarbons is 8—18 wt.%. The decrease
10
20
30
40
50
t/h
Fig. 5. Yields of the major products of rapeseed oil conversions
during the endurance testing of the Pd—Zn/Al2O3/MFI catalyst
at 360 C and rapeseed oil feed space velocity of 1.2 h–1: alkanes
C2 (1), C3 (2), C4—C6 (3), aromatic hydrocarbons (4); t is the
catalyst operation time.

828
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
Tsodikov et al.
C (wt.%)
hydrogen. The combined processing of alcohols and rapeꢀ
seed oil on the Pd—Zn/Al2O3/MFI catalyst system is an
effective and promising method for the preparation of
C3—C11 hydrocarbons without an external source of
hydrogen.
25
20
15
10
5
This work was financially supported by the Russian
Foundation for Basic Research (Projects No. 12ꢀ03ꢀ00489
and No. 12ꢀ03ꢀ33062), The Council for Grants at Russian
Federation President (State Support Program for Leading
Scientific Schools of the RF and Young Ph.Ds, Projects
NShꢀ5232.2012.3 and MKꢀ2151.2012.3), and by
the Ministry of Education and Science (State Contract
No. 14.516.11.0070).
C3
C3= C4
C4= C5
C5= C6
C6=
Fig. 6. Composition of aliphatic hydrocarbons resulting from
joint conversion of rapeseed oil (25 vol.%) and alcohol mixture
(75 vol.%) catalyzed by Pd—Zn/Al2O3/MFI (420 C, 5 atm of
Ar, substrate space velocity 1.2 h–1).
References
in the yield of gases following the addition of the heavier
substrate to ethanol was also observed previously for crossꢀ
condensation of glycerol and ethanol during their joint
processing catalyzed by Re—Wꢀ, Re—Taꢀ, Cuꢀ, and Gaꢀ
containing systems.20,27
Among the aromatic products, toluene, xylenes, and
trimethylbenzene are the major components; small amount
of methylnaphthalene is also present (Fig. 7).
Thus, modified industrial aluminum—platinum cataꢀ
lyst and pilot samples of the Pd—Zn catalyst based on
a ZSMꢀ5 type zeolite are able to selectively convert the bioꢀ
mass processing intermediates to alkanes and alkaneꢀaroꢀ
matic mixtures suitable as engine fuel components. Alꢀ
kanes and arenes are formed from ethylene and diethyl
ether produced from ethanol. The hydrocarbon chain
growth and aromatization take place on cluster intermeꢀ
tallic sites in argon under conditions where the ethylene
hydrogenation is suppressed. The clusters are formed durꢀ
ing the longꢀterm reductive preactivation and participate
in hydrogen transfer. Ethanol is not only a substrate giving
rise to the alkane or aromatic molecule but also a source of
1. I. I. Moiseev, Teor. Eksp. Khim., 2010, 46, 360 [Theor. Exp.
Chem. (Engl. Transl.), 2010, 46].
2. M. V. Tsodikov, V. Ya. Kugel´, F. A. Yandieva, G. A. Kliger,
L. S. Glebov, A. I. Mikaya, V. G. Zaikin, E. V. Slivinskii,
N. A. Plate, A. E. Gekhman, I. I. Moiseev, Kinet. Catal.,
2004, 45, 1 [Kinet. Catal. (Engl. Transl.), 2004, 45, 1].
3. RF Inventor´s Certificate 2220941, Byul. izobret. [Invent.
Bull.], 2004, No. 16 (in Russian).
4. RF Inventor´s Certificate 2220940 RF, Byul. izobret. [Invent.
Bull.], 2004, No. 10 (in Russian).
5. Y. S. Prasad, N. N. Bakhshi, Appl. Catal., 1985, 18, 71.
6. US Pat. 4300009, Chem. Abstrs, 1981, 10, 150109.
7. A. G. Dedov, A. S. Loktev, L. Kh. Kunashev, M. N. Karꢀ
tasheva, V. S. Bogatyrev, I. I. Moiseev, Khim. Tekhnol.
[Chem. Engin.], 2002, 8, 15 (in Russian).
8. W. Charusiri, W. Yongchareon, T. Vitidsant, Korean J. Chem.
Eng., 2006, 23, 349.
9. RF Inventor´s Certificate 2248341 RF, Byul. izobret., 2003,
No. 8(in Russian)..
10. M. V. Tsodikov, A. V. Chistyakov, M. A. Gubanov, V. Yu.
Murzin, Z. M. Bukina, N. V. Kolesnichenko, S. N. Khadꢀ
zhiev, Neftekhimiya, 2013, 53, 50 [Petroleum Chem.
(Engl. Transl.), 2013, 53, 46].
11. http://www.pidengtech.com/thereference.html.
12. A. Chistyakov, M. Tsodikov, M. Chudakova, A. Gekhman,
I. Moiseev, Chem. Eng. Trans., 2011, 24, 175.
13. A. C. Basagiannis, P. Panagiotopoulou, X. E. Verykios, Top
Catal., 2008, 51, 12.
14. A. Erdohelyi, J. Rasko, T. Kecskes, M. Tooth, M. Domok,
K. Baan, Catal. Today, 2006, 116, 367.
15. M. V. Tsodikov, F. A. Yandieva, V. Ya. Kugel, A. V. Chisꢀ
tyakov, A. E. Gekhman, I. I. Moiseev, Catal. Lett., 2008,
1, 25.
16. F. A. Yandieva, M. V. Tsodikov, A. V. Chistyakov, V. Ya.
Kugel´, Ya. V. Zubavichus, A. A. Veligzhanov, L. E. Kitaev,
V. V. Yushchenko, A. E. Gekhman, I. I. Moiseev, Kinet.
Catal., 2010, 51, 1 [Kinet. Catal. (Engl. Transl.), 2010,
51, 548].
17. T. Chattopadhyay, K. Schubert, J. LessꢀCommon Met., 1976,
45, 79.
18. J. Hancsuk, S. Magyar, A. Hollu, Chem. Eng. Trans., 2007,
11, 41.
С (wt.%)
30
20
10
1
2
3
4
5
6
7
8
9
Hydroꢀ
carbon
Fig. 7. Composition of aromatic hydrocarbons resulting from
joint conversion of rapeseed oil (25 vol.%) and alcohol mixture
(75 vol.%) catalyzed by Pd—Zn/Al2O3/MFI (420 C, 5 atm of
Ar, substrate space velocity 1.2 h–1): benzene (1), toluene (2),
oꢀ and pꢀxylenes (3), mꢀxylenes (4), ethylbenzene (5), trimethylꢀ
benzene (6), phenylpropylene (7), tetramethylbenzene (8),
methylnaphthalene (9).

Fuel from biomass on industrial catalysts
Russ.Chem.Bull., Int.Ed., Vol. 62, No. 3, March, 2013
829
19. A. S. Berenblyum, V. Ya. Danyushevskii, E. A. Katsman,
T. A. Podoplelova, V. R. Flid, Neftekhimiya, 2010, 50, 317
[Petroleum Chem. (Engl. Transl.), 2010, 50, 305].
26. E. Derouane, J. B. Nagy, P. Dejaifve, J. H. van Hoff,
B. Spekrnan, C. Vedrine, C. Naccache, J. Catal., 1978,
53, 40.
20. A. V. Chistyakov, V. Yu. Murzin, M. A. Gubanov, M. V.
Chudakova, F. A. Yandieva, M. V. Tsodikov, Book Abstr., IX
Int. Conf. "Mechanisms of Catalytic Reactions" (St.ꢀPetersꢀ
burg, October 22—25, 2012), St.ꢀPetersburg, 2012, OYꢀIVꢀ4.
21. K. Inoue, M. Inaba, I. Takahara, K. Murat, Catal. Lett.,
2010, 136, 19.
27. A. V. Chistyakov, V. Yu. Murzin, M. V. Chudakova, M. A.
Gubanov, S. A. Nikolaev, V. V. Kriventsov, M. V. Tsodikov,
Ross. Nauch. Konf. "Klasterꢀ2012" [Russ. Sci. Conf. "Clusterꢀ
2012"] (Novosibirsk, June 17—22, 2012), Novosibirsk, 2012,
133 (in Russian).
28. Kh. M. Minachev, V. I. Garanin, Ya. I. Isakov, Russ. Chem.
Rev., 1966, 35, 903 [Kh. M. Minachev, V. I. Garanin, Ya. I.
Isakov, Uspekhi khimii, 1966, 35, 2151].
22. R. Johansson, S. L. Hruby, J. RassꢀHansen, C. H. Chrisꢀ
tensen, Catal. Lett., 2009, 127, 6.
23. C. W. Ingram, R. J. Lancashire, Catal. Lett., 1995, 31, 395.
24. A. T. Aguayo, A. G. Gayubo, A. Atutxa, M. Olazar, J. Bilꢀ
bao, Ind. Eng. Chem. Res., 2002, 41, 4216.
29. M. Seiler, W. Wang, A. Buchholz, M. Hunger, Catal. Lett.,
2003, 88, 187.
30. J. C. Slater, J. Chem. Phys., 1964, 41, 3199.
25. A. V. Chistyakov, M. V. Tsodikov, V. Yu. Murzin, F. A.
Yandieva, Ya. V. Zubavichus, N. Yu. Kozitsyna, A. E. Gekhꢀ
man, V. V. Kriventsov, I. I. Moiseev, Kinet. Catal., 2011, 52,
266 [Kinet. Catal. (Engl. Transl.), 2011, 52, 258].
Received December 17, 2012;
in revised form February 11, 2013