Liquid hydrogenation of maleic anhydride with Pd/C catalyst at low pressure and temperature in batch reactor

Article abstract of DOI:10.1166/jnn.2015.8349

Succinic acid (SA) produced from hydrogenation of maleic anhydride (MAN) is used widely in manufacturing of pharmaceuticals, agrochemicals, surfactants and detergent, green solvent and biodegradable plastic. In this study, we performed that liquid hydrogenation of MAN to SA with 5 wt% Pd supported on activated carbon (Pd/C) at low pressure and temperature. The synthesis of SA was performed in aqueous solution while varying temperature, pressure, catalytic amount and agitation speed. We confirmed that the composition of the products consisting of SA, maleic acid (MA), fumaric acid (FA) and malic acid (MLA) depends on the process. The catalytic characteristics were analyzed by TGA, TEM.

Full text of DOI:10.1166/jnn.2015.8349

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Nanoscience and Nanotechnology
Vol. 15, 290–294, 2015
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Liquid Hydrogenation of Maleic Anhydride with
Pd/C Catalyst at Low Pressure and
Temperature in Batch Reactor
Ji Sun Kim1ꢀ2, Jae Ho Baek1, Young Bok Ryu1,
Seong-Soo Hong2, and Man Sig Lee1ꢀ∗
1Green Technology Center, Korea Institute of Industrial Technology (KITECH), Ulsan 681-802, South Korea
2Department of Chemical Engineering, Pukyong National University, Busan 608-739, South Korea
Succinic acid (SA) produced from hydrogenation of maleic anhydride (MAN) is used widely in
manufacturing of pharmaceuticals, agrochemicals, surfactants and detergent, green solvent and
biodegradable plastic. In this study, we performed that liquid hydrogenation of MAN to SA with
5 wt% Pd supported on activated carbon (Pd/C) at low pressure and temperature. The synthesis of
SA was performed in aqueous solution while varying temperature, pressure, catalytic amount and
agitation speed. We confirmed that the composition of the products consisting of SA, maleic acid
(MA), fumaric acid (FA) and malic acid (MLA) depends on the process. The catalytic characteristics
Delivered by Publishing Technology to: Florida State University, College of Medicine
were analyzed by TGA, TEM.
IP: 69.73.17.154 On: Fri, 16 Oct 2015 10:54:47
Keywords: Pd/C, Hydrogenation, Succinic Acid, Batch Reactor.
Copyright: American Scientific Publishers
1. INTRODUCTION
SA is major interest as starting material for production
of important polymer. For example, polyurethanes and
poly(butylene terephalate) etc., which are mainly used for
synthesis of fibers, films, and adhesive. Hydrogenation of
MAN to SA can be catalyzed by transition metals in both
liquid and gas phase. But liquid phase hydrogenation is
preferred since gas phase hydrogenation is performed at
difficult reaction condition rather than liquid phase hydro-
genation. In liquid phase hydrogenation, distribution of
products consisting of SA, FA, MA, MLA varies according
to process parameter. High temperature and H2 pressure
are beneficial to the hydrogenation of MAN to tetrahydro-
furan, 1,4-butadiol via consecutive hydrogenation of MA
to SA.3 But, hydrogenation of MAN to SA is conducted
in the relatively low temperature and pressure when com-
pared to the tetrahydrofuran, 1,4-butadiol formation reac-
tion condition since the double bonds in MA molecules
are easy hydrogenated by H2. Many researcher reported
that Platinum metal, palladium, ruthemnium, rhodium etc.,
catalyst were found to be suitable for hydrogenation of
maleic acid.4–6
Green technology is becoming more of a driving force
in the chemical industry because of the current need to
decrease pollution caused by petrochemical processing
and the future need to replace the dwinding hydrocarbon
economy with a renewable, environmentally sound, car-
bohydrate econmy.1 Maleic anhydride (MAN) has been
considered as good green feed stock since MAN can
be produced at a low cost and a large scale. MAN
has high chemical reactivity because it has two car-
bonyl groups. So this material is product Succinic acid
(SA), 1,4-butadiol, tetrahyrofuran via catalytic hydro-
genation. Catalytic hydrogenation of maleic acid (MA)
produces important industrial chemicals, such as suc-
cinic acid (SA), ꢀ-butyrolacetone, tetrahydrofuran and
1,4-butanediol, which are widely used polymer and
pharmaceutical industries. From among the derivatives of
MA, SA is typically used in the manufacturing of pharma-
ceuticals, agrochemicals, surfactants and detergent, green
solvent, biodegradable plastic and major stock for pro-
duction of 1,4-butadiol, tetrahydrofuran.1ꢁ2 Furthermore,
In this study, liquid hydrogenation of MAN to SA
catalyzed nano size Pd/C of and intermediates were
∗Author to whom correspondence should be addressed.
290
J. Nanosci. Nanotechnol. 2015, Vol. 15, No. 1
1533-4880/2015/15/290/005
doi:10.1166/jnn.2015.8349

Kim et al.
Liquid Hydrogenation of Maleic Anhydride with Pd/C Catalyst at Low Pressure and Temperature in Batch Reactor
investigated in batch type reactor under mild condition.
Synthesis of SA performed in aqueous solution while vary-
ing temperature, pressure, catalytic amounts and agitation
speed. We confirmed liquid hydrogenation mechanism on
surface of nano size Pd/C catalyst. The Pd weight percent-
age of Pd/C catalyst was measured with a thermogravi-
metric analysis (TGA). The shape and dispersion of Pd
particle supported on activated carbon were examined by
transmission electron microscope (TEM).
100
90
80
70
60
50
40
30
20
10
0
2. EXPERIMENTAL DETAILS
2.1. Materials
0
100 200 300 400 500 600 700 800
Temperature
Maleic anhydride (MAN) were purchased from YCI Ind.
Pd/C catalyst (Pd contents 5%, water contents 50 wt%)
were purchased from N.E chemcat corp. Standard materi-
als of fumaric acid (FA), succinic acid (SA), maleic acid
(MA), malic acid (MLA) were purchased from Sigma-
Aldrich for analysis.
Figure 1. TGA results of Pd/C Before reaction After reaction.
Before reaction
After reaction
2.2. Synthesis of Succinic Acid
The hydrogenation of MAN was carried out in a 100 mL
capacity stainless steel autoclave fitted with a magnetically
driven impeller, which was used disk turbine type. The
autoclave was charged with the appointed MA, solvent,
and catalyst. First, reactor was purged with nitrogen to
remove oxygen. Then hydrogen from a cylinder was intro-
Figure 2. TEM images of Pd distribution on activated carbon (Before
and After Reaction).
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duced, and the pressure was raised to the desired value.
IP: 69.73.17.154 On: Fri, 16 Oct 2015 10:54:47
We performed hydrogenation of MAN, the reaction was
Copyright: American Scientific Publishers
5 wt% on activated carbon. Figure 2. provides TEM of
carried out at in the temperature, pressure, agitation spezed
5 wt% Pd/C. Before reaction, Pd particles are dispersed
uniformly on the support. And the average Pd particle size
was observed 10 to 20 nm by TEM. But, after reaction, Pd
particle has not good distribution. Some Pd particles were
sintered on the support.
ꢀ
range of 50–150 C, 3–15 bar and 200–900 rpm for a
150 min and the weight ratio of catalyst to maleic anhy-
dride was 1:100. At the end of reaction, the autoclave
was heated and cooled to 95 ꢀC and maintains 5 min
for filtration of catalyst through thermal filtration of prod-
ucts. We obtained SA by re-crystallization of separated
solution.
3.2. Effect of Reaction Temperature
The results distributed the reaction product on the hydro-
genation of MAN are shown in Figure 3 and Table I
2.3. Analysis of Products
The product was analyzed by HPLC (Agilent, HPLC
Series) equipped with UV detector with 210 nm of wave-
length and CAPCELL PAK C18-AQ (4ꢂ6×250 mm, 5 um)
column. 0.1 M NH4H2PO4 adjusted to 2.5 pH with H2PO4
was used as mobile phase at flow rate of 1 ml/min.
100
80
Succinic acid
Maleic acid
Fumaric acid
Malic acid
60
40
20
0
2.4. Catalyst Characteristics of Pd/C
The Pd weight percentage of Pd/C catalyst was measured
with a TGA (TA Ins., Q50). The shape and dispersion of
Pd particle supported on activated carbon were examined
by TEM (JEM- 2010, JEOL).
40
60
80
100
120
140
160
3. RESULTS AND DISCUSSION
3.1. Catalyst Characteristics of Pd/C
Reaction temperature (ºC)
Figure 1. shows the TGA results. We confirmed that the
catalyst contain water 46%. Pd was loaded contents of
Figure 3. Effect of reaction temperature by hydrogenation of MAN
to SA.
J. Nanosci. Nanotechnol. 15, 290–294, 2015
291

Liquid Hydrogenation of Maleic Anhydride with Pd/C Catalyst at Low Pressure and Temperature in Batch Reactor
Table I. Effect of reaction temperature. Table II. Effect of reaction pressure.
Kim et al.
Temp. (ꢀC)
SAa (%)
MAb
FAc
MLAd
Pressure (bar)
SAa (%)
MAb (ppm)
FAc
MLAd
50
70
90
110
130
150
97.38
99.16
99.66
99.85
99.68
99.48
–
–
2.5%
3.5 ppm
4.5 ppm
14.4 ppm
6.0 ppm
–
–
–
–
–
–
3
5
10
15
84.16
99.54
99.66
99.82
309
1.1
0.73
–
15.2%
11.7 ppm
4.5 ppm
6.6 ppm
–
–
–
–
0.73 ppm
–
–
–
Notes: aSA: Succinic acid; bMA: Maleic acid; cFA: Fumaric acid; dMAL: Malic
acid. ∗Reaction condition: MA38 wt%, 90 ꢀC, 150 min, 700 rpm, catalyst 1.0 wt%
by MA.
241 ppm
Notes: aSA: Succinic acid; bMA: Maleic acid; cFA: Fumaric acid; dMAL: Malic
acid. ∗Reaction conditions: MA38 wt%, 10 bar, 700 rpm, 150 min, catalysts
1.0 wt% by MA.
100
at different reaction temperature. Contents of SA at
different reaction temperature were 99.38, 99.16, 99.66,
99.85, 99.68 and 99.48%, respectively. The contents of
FA were decreased by an increase the reaction temper-
ature. Malic acid was obtained at 150 ꢀC for the first
time.
Succinic acid
Maleic acid
Fumaric acid
Malic acid
80
60
40
20
0
3.3. Effect of Reaction Pressure
The results distributed the reaction product on the hydro-
genation of MAN are shown in Figure 4 and Table II
at different reaction pressure. Contents of SA at different
reaction pressure were 84.16, 99.54, 99.66 and 99.82%,
respectively. We confirmed that the contents of SA were
increased by an increase the reaction pressure and con-
0.0
0.5
1.0
1.5
2.0
Catalytic amount (%)
Figure 5. Effect of reaction catalytic amounts by hydrogenation of
MAN to SA.
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tents of FA decreased by increase the reaction pressure.
IP: 69.73.17.154 On: Fri, 16 Oct 2015 10:54:47
In general liquid hydrogenation, it is known that the
Copyright: American Scientific Publishers
different catalytic amount. Contents of SA at different
catalytic amount were 99.97, 99.78, 99.62, 99.79, 99.66,
99.55 and 99.59%, respectively. We confirmed that high
contents of SA were observed in the range of all of the
reaction condition. According to this result, it can be con-
cluded that this reaction, the hydrogenation of MAN to
SA, is affected by other reaction step rather than chemical
reaction.
increasing solubility of hydrogen promotes the hydrogen
reaction. According to this results, it can be concluded that
increasing reaction pressure increases gas–liquid solubil-
ity. And it would be expected to give an improved mass
transfer at gas–liquid interface.
3.4. Effect of Catalytic Amounts
The results distributed the reaction product on the hydro-
genation of MAN are shown Figure 5. and Table III at
3.5. Effect of Agitation Speed
The results distributed the reaction product on the
hydrogenation of MAN are shown Figure 6 and Table IV
at different agitation speed. Contents of SA at different
agitation speed were 76.79, 71.96, 80.4, 99.66, 99.78 and
99.87%, respectively. We confirmed that the contents of
100
80
Succinic acid
Maleic acid
Fumaric acid
Malic acid
60
Table III. Effect of catalytic amount.
Catalytic amounts (wt%) SAa (%)
MAb
FAc
MLAd
40
20
0
0.1
0.3
0.5
0.7
1.0
2.0
99.97
99.78
99.62
99.79
99.66
99.59
45 ppm
20 ppm
7.8 ppm
9.52 ppm
–
–
–
–
–
–
–
–
–
–
0.73 ppm
57.3 ppm 10.9 ppm
4.5 ppm
0
2
4
6
8
10
12
14
16
Reaction pressure (bar)
Notes: aSA: Succinic acid; bMA: Maleic acid; cFA: Fumaric acid, dMAL: Malic
acid. ∗Reaction condition: MA38 wt%, 10 bar, 90 ꢀC, 150 min, 700 rpm.
Figure 4. Effect of reaction pressure by hydrogenation of MAN to SA.
292
J. Nanosci. Nanotechnol. 15, 290–294, 2015

Kim et al.
Liquid Hydrogenation of Maleic Anhydride with Pd/C Catalyst at Low Pressure and Temperature in Batch Reactor
100
80
60
40
20
0
Succinic acid
Maleic acid
Fumaric acid
Malic acid
SA
FA
MA
MLA
100 200 300 400 500 600 700 800 900 1000
Agitation speed (rpm)
Figure 8. Liquid hydrogenation of MAN on surface of Pd/C catalyst.
Figure 6. Effect of Agitation speed by hydrogenation of MAN to SA.
Hydrogenation and protonation are in progress at the same
time. We obtained high contents of SA in the products
because reaction rate of hydrogenation is faster than pro-
tonation. The adsorption rate of FA on the catalyst sur-
face is very slow, so MLA is obtained by hydration
of FA.8
Table IV. Effect of reaction agitation speed.
Agitation speed
SAa (%)
MAb
FAc
MLAd
200
600
700
800
900
76.79
80.40
99.66
99.78
99.87
3.67%
2.12%
0.73 ppm
19.3%
17.2%
4.5 ppm
–
–
–
–
–
–
3.7. Liquid Hydrogenation of MAN on
–
–
Surface of Pd/C Catalyst
3.7 ppm
From this result, the reaction route of MA hydrogenation
in surface of catalyst can be proposed as follows. When
polar solvent was used in the catalytic hydrogenation pro-
cess, the MA was easily dispersed in the solvent. And
Notes: aSA: Succinic acid; bMA: Maleic acid; cFA: Fumaric acid; dMAL: Malic
acid. ∗Reaction condition: MA38 wt%, 10 bar, 90 ꢀC, 150 min, catalyst 1.0 wt%
by MA.
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then, the diffusion of H occurred into reaction solution.
IP: 69.73.17.154 On: Fri, 16 Oct 2015 10:54:47 2
SA were increased by an increase agitation speed and
Copyright: American Scientific Publishers
In this study, the gas–liquid solubility accelerated by an
increase the agitation speed and reaction pressure. This
reaction step affected by agitation speed and reaction pres-
sure, increasing of which promote gas–liquid solubility.
And it would be expected to give an improved mass trans-
fer at gasliquid interface. If process parameter should be
same, mass transfer rate in hydrogenation of MAN will be
same. In this case, the size of catalyst is the most important
factor rather than process parameter such as reaction tem-
perature, pressure, catalytic amount and agitation speed.
Small-sized Pd/C had more surface active sites, giving
high catalytic activity in the liquid phase hydrogenation
of MA to SA. The reaction pathway catalyzed by Pd/C
catalysts is described in Figure 8.
contents of FA decreased by increase the agitation speed.
Base on the above finding, the agitation speed is an
important factor for increasing the gas–liquid solubility in
liquid hydrogenation.
3.6. Reaction Mechanism
We confirmed that SA end point of reaction and start-
ing point of reaction is similar. The contents of FA were
increased in initial time and then these were decreased.
After that, FA was not observed. As a result, it can be
concluded that FA is intermediates in SA product pro-
cess. Base on the above finding, the reaction mechanism
of MAN hydrogenation can be proposed as Figure 7.
Figure 7. Reaction mechanism of MAN hydrogenation.
J. Nanosci. Nanotechnol. 15, 290–294, 2015
293

Liquid Hydrogenation of Maleic Anhydride with Pd/C Catalyst at Low Pressure and Temperature in Batch Reactor
Kim et al.
4. CONCLUSION
temperature, pressure, catalytic amount and agitation
speed.
In this paper, liquid hydrogenation of MAN catalyzed
Pd/C and intermediates were studied in batch type reactor
under mild condition. The synthesis of SA was performed
in aqueous solution while varying temperature, pressure
and agitation speed. We confirmed that distribution of
product was different according to process parameters.
We confirmed that the contents of SA were increased
by an increase the reaction pressure and the contents
of FA decreased by increase the reaction pressure. The
optimum temperature is 130 ꢀC in the production for
high contents SA. Because, malic acid was obtained at
150 ꢀC for the first time. We confirmed that the con-
tents of SA were increased by an increase the reaction
pressure and agitation speed. From the result, we may
conclude that reaction pressure and agitation speed are
important factor for promoting mass transfer rate of gas–
liquid interface by increasing gas–liquid solubility in liq-
uid hydrogenation. If process parameter should be same,
mass transfer rate in hydrogenation of MAN will be
same. In this case, the size of catalyst is the most impor-
tant factor rather than process parameter such as reaction
Acknowledgment: This research was financially sup-
ported by Code No. (R0000495) from the Ministry of
Knowledge Economy (MKE) and Korea Institute for
Advancement of Technology (KIAT) through the Research
and Development for Regional Industry and Development
of process for production of succinic acid through Private
Finance Research Project.
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Received: 10 March 2013. Accepted: 10 April 2013.
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J. Nanosci. Nanotechnol. 15, 290–294, 2015