Thermodynamic and kinetic studies for synthesis of glycerol carbonate from glycerol and diethyl carbonate over Ce–NiO catalyst

Article abstract of DOI:10.1007/s11696-018-0518-3

Abstract: The present work aimed to investigate the law of the conversion of glycerol with diethyl carbonate (DEC) over the highly efficient Ce–NiO catalyst prepared by co-precipitation method. The thermodynamic and kinetics parameters of this reaction for glycerol carbonate synthesis were studied. The reaction equilibrium constants were investigated experimentally in the temperature region of 338–358?K, and the standard molar properties (at 298?K) were obtained (△H⁰= 115.71?kJ?mol^?1, △G⁰= 13.523?kJ?mol^?1, △S⁰= 0.343?kJ?mol^?1). Effects of various experimental conditions including stirring speed, reaction temperature, catalyst amount, reactant mole ratio on the reaction kinetics were also studied. Different order kinetic equations were used to simulate law of the transesterification process. The result shows a three-order equation of glycerol (two orders) and DEC (one order) was more appropriate to interpret the law of glycerol transesterification with diethyl carbonate. The activation energy of this reaction was obtained with 87.90?kJ?mol^?1. Finally, the microstructure and physicochemical properties of the Ce–NiO samples were studied by XRD, SEM, TEM, and CO₂-TPD. Graphical abstract: One-pot catalytic conversion of glycerol into glycerol carbonate over Ce–NiO catalyst.[Figure not available: see fulltext.].

Full text of DOI:10.1007/s11696-018-0518-3

Chemical Papers
https://doi.org/10.1007/s11696-018-0518-3
ORIGINAL PAPER
Thermodynamic and kinetic studies for synthesis of glycerol carbonate
from glycerol and diethyl carbonate over Ce–NiO catalyst
Jiahui Zhang1 · Yuanfeng Wu1 · Xianghai Song1 · Siquan Xu1 · Shuai Li1 · Yanli Zhu1 · Lijing Gao1 · Jin Zhang1 ·
Guomin Xiao1
Received: 17 April 2018 / Accepted: 25 May 2018
© Institute of Chemistry, Slovak Academy of Sciences 2018
Abstract
The present work aimed to investigate the law of the conversion of glycerol with diethyl carbonate (DEC) over the highly
efcient Ce–NiO catalyst prepared by co-precipitation method. The thermodynamic and kinetics parameters of this reac-
tion for glycerol carbonate synthesis were studied. The reaction equilibrium constants were investigated experimentally in
the temperature region of 338–358 K, and the standard molar properties (at 298 K) were obtained (△H0=115.71 kJ mol−1,
△G0=13.523 kJ mol−1, △S0=0.343 kJ mol−1). Efects of various experimental conditions including stirring speed, reaction
temperature, catalyst amount, reactant mole ratio on the reaction kinetics were also studied. Diferent order kinetic equa-
tions were used to simulate law of the transesterifcation process. The result shows a three-order equation of glycerol (two
orders) and DEC (one order) was more appropriate to interpret the law of glycerol transesterifcation with diethyl carbonate.
The activation energy of this reaction was obtained with 87.90 kJ mol−1. Finally, the microstructure and physicochemical
properties of the Ce–NiO samples were studied by XRD, SEM, TEM, and CO2-TPD.
Graphical abstract One-pot catalytic conversion of glycerol into glycerol carbonate over Ce–NiO catalyst.
Keywords Thermodynamic · Kinetic · Glycerol · Glycerol carbonate · Ce–NiO
List of symbols
ꢀ
Reaction order of glycerol
ꢀ
Reaction order of diethyl carbonate
cA Initial concentration of glycerol (mol L−1)
0
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s11696-018-0518-3) contains
supplementary material, which is available to authorized users.
cB Initial concentration of diethyl carbonate (mol L−1)
0
cA Concentration of glycerol after time t (mol L−1)
cB Concentration of diethyl carbonate after time t
(mol L−1)
* Guomin Xiao
xiaogm426@gmail.com
cC Concentration of glycerol carbonate after time t
(mol L−1)
1
School of Chemistry and Chemical Engineering, Southeast
University, Nanjing 211189, China
Vol.:(0123456789)
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Chemical Papers
cD Concentration of ethanol after time t (mol L−1)
this respect, Álvarez and his co-others have studied the pro-
cess abundantly. For example, Álvarez et al. (2010, 2012a,
b) used hydrotalcite derived materials, supported hydrotal-
cites and hydrotalcite-like compounds as basic catalysts for
efcient production of GC from glycerol transesterifcation
and DEC, respectively. Importantly, the transesterifcation
process could be obviously enhanced by the basic catalysts
(Esteban et al. 2015a; Yadav and Chandan 2014). It has been
reported that pure ceria as a basic catalyst is not very reac-
tive in transesterifcation reactions, but it can be used as the
efcient component to improve the basicity of solid basic
catalyst (Nasreen et al. 2016; Wong et al. 2015).
ꢀ
k
t
Mole ratio of cA to cB
0
0
Rate constant
Reaction time (h)
KC Equilibrium constant
xG Equilibrium conversion of glycerol (%)
Conversion of glycerol (%)
x
Introduction
Nowadays, the rapid expansion in biodiesel production
has caused an oversupply of glycerol (Lamers et al. 2011;
Quispe et al. 2013), which is expected to food the world
market (Dieuzeide and Amadeo 2010; Liu et al. 2016). Con-
sequently, conversion of glycerol into highly valued-added
chemicals is of great importance to promote the develop-
ment of biodiesel industry (Hakim et al. 2013). Up to now,
numerous pathways have been developed for efcient pro-
duction of glycerol derivatives with the glycerol as the start-
ing raw (Dibenedetto et al. 2011; Nakagawa and Tomishige
2011; Vlad et al. 2013). Glycerol carbonate (GC) as the one
of the possible products has been explored and applied as
novel solvent, surfactant, carries in batteries, chemical inter-
mediates and monomer due to its excellent physicochemical
properties (high boiling point, low toxicity and biodegrada-
bility) (Diaz-Alvarez et al. 2011; Lertlukkanasuk et al. 2013;
Sonnati et al. 2013; Sun et al. 2014).
It is no doubt that to investigate thermodynamics and
kinetics of the transesterifcation reaction is signifcant for
further improvement of the glycerol conversion. Thermody-
namic and kinetic studies of the Acetalization of Glycerol
with Acetaldehyde respectively was investigated by Esteban
et al. (2015b), Faria et al. (2013) and Nanda et al. (2014).
Besides, kinetic model for hydrogenolysis of glycerol was
also studied with the use of Cu/MgO as catalyst (Pandhare
et al. 2017). In addition, a kinetic model was also developed
for simulating the process of glycerol esterifcation (Molin-
ero et al. 2013). Although kinetic model for GC synthesis
with the use of the dimethyl carbonate (Esteban et al. 2015a,
b, c) and ethylene carbonate (Esteban et al. 2016) as car-
bonyl agents were explored, the developed models cannot
completely value all the transesterifcation process. As a
result, a new model needs to be developed for valuation of
the glycerol transesterifcation with DEC.
According to the literatures, synthesis of GC from glyc-
erol needs use of various carbonyl agents, respectively
(Aresta et al. 2006; George et al. 2009; Hu et al. 2010; Kim
et al. 2014; Lee et al. 2014). The use of COCl2 and CO as
carbonyl source is undesired due to the toxicity and process-
ing difculty in industries (Nemirowsky 1885). When urea
was used as carbonyl source, the newly formed ammonia
needs to be removed intermittently from the reactor and the
subsequent process is also relatively difcult (Li et al. 2013;
Zhang and He 2014). Although CO2 coupling with glycerol
is interesting for academic and industrial viewpoint, this
reaction is thermodynamically limited in conversion of glyc-
erol (Aresta et al. 2006; Li et al. 2015). On the other hand,
glycerol transesterifcation with organic carbonates has been
reported abundantly, of which glycerol transesterifcation
with DMC have been explored by Esteban et al. (2015a, b, c)
and Ochoa-Gómez et al. (2009), respectively. Besides, some
cyclic carbonates such as ethylene carbonate, propylene
and butylene carbonate have also been used as the carbonyl
sources for glycerol carbonate synthesis (Choi et al. 2013;
Climent et al. 2010). Nevertheless, most of the synthetic
paths for glycerol transesterifcation resulted in generation
of alcohols or glycols together with GC. However, when
glycerol reacts with diethyl carbonate, only two molecules
of newly formed ethanol are considered as side product. In
Hence, this work aims to study thermodynamics and
kinetic model of glycerol and DEC catalyzed by the highly
active Ce–NiO catalyst. A series of Ce and Ni bimetal sam-
ples were prepared by co-precipitation method. The char-
acteristics of the bimetal catalysts were studied by various
technologies such as XRD, SEM, TEM, and CO2-TPD (Sup-
porting information). The efects of various reaction condi-
tions (Ce/Ni ratio, reaction temperature, catalyst amount,
glycerol/DEC mole ratio, and reaction time) on the catalytic
performance were investigated in detail.
Results and discussion
Characterization of catalysts
XRD patterns of the bimetal Ce–NiO catalysts with difer-
ent compositions and treated at 673 K for 5 h are shown in
Fig. 1. XRD patterns indicated that the crystal structure of
CeO2 was associated with the cubic phase (JCPDS 65-2975)
(Zou et al. 2015). The 2θ at 37.24, 43.29, 62.86 correspond
to the (003), (012), (104) planes of NiO (JCPDS 22-1189)
respectively. The intensity of NiO crystallite difraction
peak gradually decreases with the increase of Ce content,
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sizes (Table 1). The selected area electron difraction pat-
terns of 0.2CeNiO sample were shown in Fig. 2e. All the
difraction spots related to the bimetal sample are generally
distributed on circles. Moreover, the circles associated with
the micro-difraction of CeO2 and NiO are continuous in line
with results of XRD (Fig. 1). The chemical composition of
Ce–NiO was investigated as shown in Fig. 2h. Only three
kinds of the studied element (O, Ce, Ni) were detected in the
bimetal sample, indicating other elements were removed in
the catalyst synthesis.
CO2-TPD profles of these catalysts are determined in
range of 373–1073 K (Fig. 3a). According to the literature
(Kondawar et al. 2015), CO2-TPD profles can be generally
divided into three regions: the weak (323–473 K), moder-
ate (473–673 K) and strong (> 673 K) basic sites, which
were associated with OH− groups, metal-O groups and
O2− groups, respectively (Wang et al. 2011). It can be seen
from Fig. 3a, only a small CO2 desorption peak area for
monometal oxides (NiO and CeO2) was observed. How-
ever, desorption peak area corresponding to strong basic
sites obviously grows larger for the bimetal samples. This
result may be due to the substitution of Ce4+ by Ni2+ in
the CeO2 lattices which induces the generation of oxygen
vacancy (Indran et al. 2014). CO2-TPD curves have been
decomposed with the symmetrical peaks as shown in Fig.
S2 (the peak area can be regard as the relative concentra-
tion of basic sites). The integral result illustrated in Fig. 3b
exhibited the amount of the total and strong basic sites, was
enhanced continuously to the peak values (x=0.8), and then
decreased (x=1.0) with increase in Ce/Ni ratio, which indi-
cated that only a certain amount of Ce4+ can be substituted
by Ni2+ in the CeO2 lattices.
Fig. 1 XRD patterns of NiO, CeO2, and xCeNiO (x=0.2, 0.4, 0.6,
0.8, 10) samples
indicating the enlargement of Ce element could promote the
dispersion of NiO particles (Xu et al. 2006). Scherrer for-
mula was used for calculation of the mean crystal sizes of
NiO and CeO2 particles and the result was listed in Table 1.
When the Ce/Ni ratio increases from 0.2 to 1.0, the average
crystal sizes of CeO2 gradually decrease, while that of NiO
frst increases from 6.4 to 10.3 nm and then decreases to
6.2 nm, which was attributed to the existence of diferent
interactions between Ce and Ni inside the solid (Fang et al.
2012).
To further validate the interaction inside Ce–NiO, low
scan XRD patterns of the bimetal samples were investigated
in 2θ range 25°–35° for CeO2 and 35°–45° for NiO, respec-
tively. The (1 1 1) plain of ceria shifts to higher difraction
angle compared with that of pure CeO2 (Fig. S1a), while
no shift in the position of the difraction peaks (NiO) was
observed (Fig. S1b). This was associated with the replace-
ment of Ce4+ by Ni2+ inside the CeO2 lattices which resulted
in asymmetry in the crystal structure (Xu et al. 2006). There-
fore, a tentative model of Ce–NiO was proposed in Scheme
S1.
Catalyst screening
To achieve the optimal performance of Ce–NiO on glycerol
transesterifcation with DEC, Ce–NiO catalysts with difer-
ent atomic ratios were studied as follows.
Figure 2 shows the microstructure and particle size distri-
bution of the Ce–NiO catalysts. The microstructure of pure
CeO2 (Fig. 2a) was lamellae in shape (Farias et al. 2015).
While there appeared the foam-like structure after addition
of Ce element in the catalyst synthesis (Fig. 2c), which can
be further confrmed by Padmanathan and Selladurai (2013).
As Fig. 2d, e, g, h shows, the crystalline size (5–9 nm) of the
bimetal oxides is smaller than that of fresh NiO (8–15 nm),
agreeing well with the calculated result of the mean crystal
The efect of Ce/Ni ratio on the glycerol transesterif-
cation was investigated in Fig. 4. When the pure NiO was
employed for enhancement of glycerol conversion, a small
glycerol conversion (17.3%) was observed. Interestingly, the
conversion of glycerol grows larger for the bimetal sample,
which implied this reaction could be accelerated by strong
basic sites (Fig. 3). Nevertheless, glycerol conversion gradu-
ally decreases from maximum (76.95%, x=0.2) to 66.51%,
with the increase of Ce/Ni ratio, suggesting conversion
Table 1 Mean crystallite size
Catalyst
NiO
CeO2
0.2CeNiO
0.4CeNiO
0.6CeNiO
0.8CeNiO
1.0CeNiO
of NiO and CeO2 inside the
bimetal catalysts
DNiO (nm)
10.4
–
–
8.5
6.4
3.8
6.9
4.6
10.3
4.8
7.8
5.0
6.2
5.2
DCeO (nm)
2
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Fig. 2 FESEM images of a CeO2, b NiO, c 0.2CeNiO catalysts. TEM images of d NiO; e, f, i 0.2CeNiO catalysts. Crystal size dispersion charts
of g NiO, h 0.2CeNiO catalysts
of glycerol was not only related to the strong basic sites.
Importantly, at Ce/Ni ratio of 0.2, the bimetal catalyst was
main consist of the well dispersed NiO species. Hence, the
well-dispersed NiO species also plays an important role in
promotion of glycerol transesterifcation.
all the experiments were prolonged for 6 h until the meas-
ured results of the glycerol conversion and GC selectiv-
ity versus time were observed without any change. The
equilibrium compositions at different temperatures are
listed in Table 2.
The equilibrium constant (KC) for glycerol conversion
was calculated based on the Eq. (1) and the result was given
in Table 2:
Thermodynamic results
Thermodynamic investigation of the glycerol transesteri-
fication reaction was performed in a 50-mL bath reactor
in a temperature range of 338–358 K. In this series of
experiments, a high initial mole ratio of DEC to glycerol
(3:1) was adopted, and the catalyst amount was fixed at
5 wt% of glycerol. To confirm the reaction equilibrium,
cC ⋅ c2D
KC =
.
(1)
cA ⋅ cB
It can be seen from Table 2, with the increase in the reac-
tion temperature, the value of KC increases continuously,
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Chemical Papers
Fig. 3 a CO2-TPD profles and b basic sites concentration of the bimetal Ce–NiO catalysts
The thermodynamic properties such as entropy and
enthalpy of glycerol transesterifcation can be calculated
according to the Eq. (2) by plotting the experimental values
of Ln KC versus 1/T (K−1):
ΔS0 ΔH0 1
Ln KC =
−
,
(2)
R
R T
where ΔS0 is the standard entropy at 298 K (kJ mol−1 K−1),
ΔH0 is the standard enthalpy at 298 K (kJ mol−1), R is the
universal gas constant (J mol−1 K−1) and T is the reaction
temperature (K). The liner fitting of experimental data
(Fig. 5) according to Eq. (2) gives
Ln KC = −13918∕T+41.
(3)
According to Eqs. (2) and (3), entropy change (ΔH0) and
enthalpy change (ΔS0) were found to be 115.71 kJ mol−1
and 0.343 kJ mol−1 K−1 from the slope and the intercept,
respectively. The standard state Gibbs free energy change
(ΔG0) can be calculated based on the standard state entropy
change and enthalpy change with the use of Eq. (4):
Fig. 4 Efects of Ce/Ni atomic ratio on catalytic activity of glycerol
transesterifcation glycerol 4.6 g (0.05 mol), DEC 11.8 g (0.10 mol),
reaction temperature 353 K, reaction time 6 h, and 5 wt% catalyst of
glycerol. Reproduced with permission (Wu et al. 2017). Copyright
2017, ELSEVIER Publications
ΔG0 = ΔH0 − TΔS0.
(4)
indicating the endothermicity of the reaction. That is to say,
elevation in the reaction temperature can achieve a high
equilibrium conversion of glycerol.
As a result, the value of ΔG0 was obtained to
be 13.523 kJ mol−1. This result indicates glycerol
Table 2 Experimental data of
Temperature
cB
cA
cB
cA
cC
cD
KC
0.940
2.623
2.821
6.608
10.484
xG
0
0
equilibrium and equilibrium
constant
338
343
348
353
358
6.592
6.592
6.592
6.592
6.592
2.197
2.197
2.197
2.197
2.197
5.478
5.198
5.178
4.947
4.832
1.082
0.801
0.781
0.549
0.434
1.117
1.398
1.418
1.650
1.765
2.234
2.795
2.836
3.299
3.530
0.5080
0.6357
0.6449
0.7502
0.8026
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Chemical Papers
In the present work, various experimental conditions
including stirring speed, catalyst loading, temperature, reac-
tion time, reactant molar ratio were investigated in detail.
Efects of various reaction conditions
To study the efect of mass transfer resistance on the glycerol
conversion, a series of experimental were performed at dif-
ferent stirring speeds (200, 300, 400, 700 rpm). The result
was shown in Fig. 6. When the stirring speed was above
400 rpm, the conversion of glycerol maintained a constant,
which implies the mass transfer resistance was negligible
above 400 rpm. Therefore, the following experiments were
conducted at a stirring speed of 400 rpm.
Reaction temperature was usually considered as an
important parameter of chemical reaction, which determined
the extent of reaction and product distribution. It can be seen
from Fig. 7a. The conversion of glycerol was continuously
promoted with the reaction temperature increase from 343
to 368 K. However, the GC selectivity exhibited an opposite
Fig. 5 Plot of Ln KC vs. 1/T (K−1
)
transesterifcation with diethyl carbonate cannot occur at
the standard state.
Kinetic studies
Proposed mechanism
For glycerol transesterifcation, many literatures have been
reported that these reactions were promoted in the presence
of base catalyst. Therefore, we proposed a mechanism for
glycerol transesterifcation with DEC over a heterogeneous
basic catalyst as elucidated in Scheme 1.
1. Adsorbed DEC reacted with glycerol to give intermedi-
ate I (step 1).
2. Intermediate I lose ethoxy group to form Intermediate
II (step 2).
3. Intermediate II underwent intramolecular nucleophilic
substitution to form intermediate III (step 3).
4. Intermediate III lose the other ethoxy group to form
glycerol carbonate (step 4).
Fig. 6 Efect of stirring speed: glycerol 4.6 g (0.05 mol), DEC 11.8 g
(0.1 mol), reaction time 6 h, 5 wt% catalyst of glycerol at 353 K
Scheme 1 A proposed mechanism for synthesis of GC from glycerol and DEC
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Fig. 7 a Efect of reaction temperature. b Efect of reactant mole ratio. c Efect of reaction time. d Efect of catalyst amount. The optimized reac-
tion conditions: glycerol 4.6 g, DEC 11.8 g, reaction time 6 h, 5 wt% catalyst of glycerol, 353 K
change with a sudden decrease above 358 K, which was due
to the decarbonylation of newly formed GC that produced a
large number of glycidol. Therefore, to obtain the relatively
pure product of GC, 353 K can be considered as the opti-
mized temperature for glycerol transesterifcation with DEC.
Figure 7b displays the result of glycerol conversion versus
reactant mole ratio. The conversion of glycerol increases
continuously from 78.43% (6 h) to 83.36% (6 h), when glyc-
erol/DEC mole ratio varies from 1:2 to 1:4. However, the rel-
ative increment of glycerol conversion had a drop tendency
with the rise in DEC amount. When the reactant mole ratio
was fxed at 1:3, the relative increment of glycerol conver-
sion of 2.07% (6 h) was higher than that of other ratios in
promotion of glycerol conversion. Hence, the glycerol/DEC
mole ratio of 1:3 could be considered as the optimal mole
ratio for glycerol conversion.
time (Fig. 7c). The conversion of glycerol was continuously
facilitated as reaction time extended to 10 h, and maximized
to 97.35%, and then showed a decrease. However, the GC
selectivity presented an obvious and sudden drop after 6 h
and minimized to 64.74% (12 h), which suggested a large
number of glycidols (GD) were produced from the newly
formed GC decarbonylation with the reaction prolongation.
Therefore, considering the factors of the product purity and
energy consumption, 6 h was considered as the optimal reac-
tion time.
The efect of catalyst amount on GC synthesis was given in
Fig. 7d. When the catalyst amount varied from 1 to 6% wt of
glycerol, the conversion of glycerol frst increased consistently
from 73.49 to 81.62% then decreased to 77.94%. Besides, the
largest glycerol conversion was achieved in the presence of 5%
wt catalyst of glycerol. This phenomenon can be interpreted
that the appropriate active sites for this reaction were benef-
cial for achievement of a higher glycerol conversion, while
The efect of reaction time on glycerol transesterifcation
with DEC was investigated through lengthening reaction
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(12)
excessive active sites could suppress the desorption rate of
newly formed GC from the catalyst surface, leading to a low
glycerol conversion. Thus, a decrease in conversion of glycerol
was obtained after the catalyst amount above 5%.
Case III (α = 0, β = 1)
[
]
1
Ln
= kt.
ꢀ − x
Hence, to study the law of glycerol transesterifcation cata-
lyzed by the bimetal Ce and Ni catalyst, a series of experi-
ments were performed in the temperature range of 338–358 K,
under optimal conditions (400 rpm, 5 wt% catalyst of glycerol,
glycerol/DEC ratio of 1:3, 5 h reaction time) and the conver-
sion of glycerol was detected per hour as presented in Fig. S3.
Case IV (α = 1, β = 1)
[
]
1
ꢀ − x
Ln
= kcA t.
0
(13)
ꢀ − 1
(1 − x)ꢀ
Case V (α = 2, β = 0)
x
= kcA t.
(14)
(15)
0
1 − x
Kinetic model
Case VI (α = 0, β = 2)
In present work, the reaction kinetic equations were developed
by Alok and Fernando (2007) and Patil et al. (2011), which
were further developed as follows:
x
= kcA t.
0
(ꢀ − x)ꢀ
Case VII (α = 2, β = 1)
A + B ⇌ C + 2D,
(5)
[
(
)]
(1 − x)ꢀ
ꢀ − x
where A, B, C, D represent the glycerol, diethyl carbonate,
glycerol carbonate, ethanol, respectively.
1
x
1
+
ꢀ − 1 1 − x ꢀ − 1
Ln
= kc2A t.
(16)
0
The general rate equation for Eq. (5) is
Case VIII (α = 1, β = 2)
dcA
[
(
)]
−
= kcꢀAcꢁB,
(6)
(1 − x)ꢀ
ꢀ − x
1
x
1
dt
−
ꢀ − 1 (x − ꢀ)ꢀ ꢀ − 1
Ln
= kc2A t.
(17)
0
where cA∕t is the consumption of reactant A per unit time,
k is a rate constant, cA(cB) is the concentration of A (B) after
time t, ꢀ (ꢀ) is the order of reactant A (B). In addition,
The theoretical rate of glycerol transesterifcation was
ftted based on the measured rates at diferent tempera-
tures (Fig. 8a). The values of k at diferent temperatures
were calculated using linear regression method according
to Eq. (16) and the results are listed in Table 3. Besides,
the experimental data was also fitted with the use of
Eqs. (10)–(15), (17), respectively, and the results were
shown in Fig. S4. Compared with other equations, Eq. (16)
achieved the highest determining coefcient of Arrhenius
equation. Therefore, (α = 2, β = 1) was very close to the
real reaction orders of glycerol transesterifcation with
DEC.
cA = c (1 − x),
A0
(7)
/
ꢀ = cB cA ,
(8)
0
0
where cA (cB ) is the initial concentration of A (B), x is the
0
0
conversion of glycerol, and ꢀ is the initial concentration ratio
of glycerol to DEC. According to Eqs. (7) and (8), Eq. (6)
can be further transformed as
dx
= kcAꢀ+ꢁ−1(1 − x)ꢀ(ꢂ − x)ꢁ.
(9)
According to the diferent rate of the reaction (k), the
activation energy (Ea) can be calculated by the Arrhenius
equation,
0
dt
To explore the law of glycerol transesterifcation with DEC,
eight diferent cases were considered in the present work,
which included (α=0, β=0), (α=1, β=0), (α=0, β=1),
(α=1, β=1), (α=2, β=0), (α=0, β=2), (α=2, β=1), (α=1,
β=2). With respect to each case, defnite integrals of Eqs. (9)
were performed in the integral interval of (0, 0) to (x, t). All the
derived linear equations were presented as follows:
Case I (α=0, β=0)
(
)
Ea
k = kr exp
−
,
(18)
RT
where kr is the pre-exponential factor for Eq. (18). Ea is the
activation energy of formation of glycerol carbonate from
glycerol and diethyl carbonate. Besides, the value of Ea can
be calculated according to the slope of linear logarithm
equation derived from Eq. (18) and the curve was plotted in
Fig. 8b. From the curve, the value of Ea was obtained with
87.90 kJ mol−1.
c x = kt.
A0
(10)
Case II (α=1, β=0)
[
]
1
Ln
= kt.
(11)
1 − x
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Chemical Papers
Fig. 8 a Experimental and theoretical curves and b kinetic model parameter ln k vs. 1/T
Acknowledgements This work was fnancially supported by National
Natural Science Foundation of china (nos. 21276050, 21676054,
21406034), Natural Science foundation of Jiangsu (no. BK20161415),
Fundamental Research Funds for the central Universities (nos.
2242018K40041, 3207045414, 3207045101, 3207045426), Key Labo-
ratory Open Fund of Jiangsu Province (JSBEM201409).
Table 3 Kinetic parameter (k)
and the determining coefcient
(R2)
Tempera-
ture (K)
k
R2
338
343
348
353
358
0.0108
0.0189
0.0190
0.0426
0.0645
0.8598
0.9511
0.9647
0.9979
0.9975
References
Alok KS, Fernando SD (2007) Reaction kinetics of soybean oil transes-
terifcation using heterogeneous metal oxide catalysts. Chem Eng
Technol 30:1716–1720. https://doi.org/10.1002/ceat.200700274
Alvarez MG, Segarra AM, Contreras S, Sueiras JE, Medina F, Figueras
F (2010) Enhanced use of renewable resources: transesterifcation
of glycerol catalyzed by hydrotalcite-like compounds. Chem Eng
J 161:340–345. https://doi.org/10.1016/j.cej.2009.12.036
Álvarez MG, Chimentão RJ, Figueras F, Medina F (2012a) Tunable
basic and textural properties of hydrotalcite derived materials for
transesterifcation of glycerol. Appl Clay Sci 58:16–24. https://
doi.org/10.1016/j.clay.2012.02.004
Conclusions
Glycerol transesterifcation with diethyl carbonate to pro-
duce glycerol carbonate catalyzed by the bimetal solid
base catalyst was investigated in a batch reactor. The ther-
modynamic equilibrium constant was calculated in the
temperature region of 338–358 K. The standard proper-
Álvarez MG, Plíšková M, Segarra AM, Medina F, Figueras F (2012b)
Synthesis of glycerol carbonates by transesterifcation of glycerol
in a continuous system using supported hydrotalcites as catalysts.
Appl Catal B 113–114:212–220. https://doi.org/10.1016/j.apcat
b.2011.11.040
ties of the reaction at 298 K are △H0= 115.71 kJ mol−1
,
△G0= 13.523 kJ mol−1, △S0= 0.343 kJ mol−1, respec-
tively. Efects of diferent parameters such as temperature,
catalyst amount, reactant molar ratio, and reaction time
were investigated in detail. The result shows a three-order
kinetic equation of glycerol (two orders) and DEC (one
order) was more appropriate to simulate the law of glyc-
erol transesterifcation with diethyl carbonate. The activa-
tion energy for glycerol carbonate synthesis was calculated
to be 87.90 kJ mol−1. The simulated results were in well
correspondence with the experimental data. Therefore, this
achieved model can further be applied to predict the reac-
tor performance for glycerol transestrifcation. Besides, the
optimized reaction conditions can be regarded as a base for
achievement of a higher glycerol carbonate yield.
Aresta M, Dibenedetto A, Nocito F, Pastore C (2006) A study on the
carboxylation of glycerol to glycerol carbonate with carbon diox-
ide: the role of the catalyst, solvent and reaction conditions. J
Mol Catal A Chem 257:149–153. https://doi.org/10.1016/j.molca
ta.2006.05.021
Choi JS, Simanjuntaka FSH, Oh JY, Lee KI, Lee SD, Cheong M,
Kim HS, Lee H (2013) Ionic-liquid-catalyzed decarboxylation of
glycerol carbonate to glycidol. J Catal 297:248–255. https://doi.
org/10.1016/j.jcat.2012.10.015
Climent MJ, Corma A, De Frutos P, Iborra S, Noy M, Velty A, Con-
cepción P (2010) Chemicals from biomass: synthesis of glycerol
carbonate by transesterification and carbonylation with urea
with hydrotalcite catalysts. The role of acid–base pairs. J Catal
269:140–149. https://doi.org/10.1016/j.jcat.2009.11.001
1 3

Chemical Papers
Diaz-Alvarez AE, Francos J, Lastra-Barreira B, Crochet P, Cadierno
V (2011) Glycerol and derived solvents: new sustainable reaction
media for organic synthesis. Chem Commun 47:6208–6227. https
://doi.org/10.1039/C1CC10620A
Kondawar SE, Potdar AS, Rode CV (2015) Solvent-free carbonyla-
tion of glycerol with urea using metal loaded MCM-41 cata-
lysts. RSC Adv 5:16452–16460. https://doi.org/10.1039/C4RA1
1590B
Dibenedetto A, Angelini A, Aresta M, Ethiraj J, Fragale C, Nocito F
(2011) Converting wastes into added value products: from glyc-
erol to glycerol carbonate, glycidol and epichlorohydrin using
environmentally friendly synthetic routes. Tetrahedron 67:1308–
1313. https://doi.org/10.1016/j.tet.2010.11.070
Lamers P, Hamelinck C, Junginger M, Faaij A (2011) International bio-
energy trade—a review of past developments in the liquid biofuel
market. Renew Sustain Energy Rev 15:2655–2676. https://doi.
org/10.1016/j.rser.2011.01.022
Lee SD, Park MS, Kim DW, Kim I, Park DW (2014) Catalytic perfor-
mance of ion-exchanged montmorillonite with quaternary ammo-
nium salts for the glycerolysis of urea. Catal Today 232:127–133.
https://doi.org/10.1016/j.cattod.2013.10.009
Dieuzeide ML, Amadeo N (2010) Thermodynamic analysis of glyc-
erol steam reforming. Chem Eng Technol 33:89–96. https://doi.
org/10.1002/ceat.200900260
Esteban J, Domínguez E, Ladero M, Garcia-Ochoa F (2015a) Kinet-
ics of the production of glycerol carbonate by transesterifcation
of glycerol with dimethyl and ethylene carbonate using potas-
sium methoxide, a highly active catalyst. Fuel Process Technol
138:243–251. https://doi.org/10.1016/j.fuproc.2015.06.012
Esteban J, Fuente E, Blanco A, Ladero M, Garcia-Ochoa F (2015b)
Phenomenological kinetic model of the synthesis of glycerol car-
bonate assisted by focused beam refectance measurements. Chem
Eng J 260:434–443. https://doi.org/10.1016/j.cej.2014.09.039
Esteban J, Ladero M, García-Ochoa F (2015c) Kinetic modelling of
the solventless synthesis of solketal with a sulphonic ion exchange
resin. Chem Eng J 269:194–202. https://doi.org/10.1016/j.
cej.2015.01.107
Lertlukkanasuk N, Phiyanalinmat S, Kiatkittipong W, Arpornwichanop
A, Aiouache F, Assabumrungrat S (2013) Reactive distillation for
synthesis of glycerol carbonate via glycerolysis of urea. Chem Eng
Process 70:103–109. https://doi.org/10.1016/j.cep.2013.05.001
Li H, Gao D, Gao P, Wang F, Zhao N, Xiao F, Wei W, Sun Y (2013)
The synthesis of glycerol carbonate from glycerol and CO2 over
La2O2CO3–ZnO catalysts. Catal Sci Technol 3:2801–2809. https
://doi.org/10.1039/C3CY00335C
Li H, Jiao X, Li L, Zhao N, Xiao F, Wei W, Sun Y, Zhang B (2015)
Synthesis of glycerol carbonate by direct carbonylation of glyc-
erol with CO2 over solid catalysts derived from Zn/Al/La and Zn/
Al/La/M (M = Li, Mg and Zr) hydrotalcites. Catal Sci Technol
5:989–1005. https://doi.org/10.1039/C4CY01237B
Esteban J, Ladero M, Fuente E, Blanco Á, García-Ochoa F (2016)
Experimental and modelling approach to the catalytic coproduc-
tion of glycerol carbonate and ethylene glycol as a means to val-
orise glycerol. J Taiwan Inst Chem Eng 63:89–100. https://doi.
org/10.1016/j.jtice.2016.03.031
Liu J, Daoutidis P, Yang B (2016) Process design and optimization for
etherifcation of glycerol with isobutene. Chem Eng Sci 144:326–
335. https://doi.org/10.1016/j.ces.2016.01.055
Molinero L, Ladero M, Tamayo JJ, Esteban J, García-Ochoa F (2013)
Thermal esterification of cinnamic and p-methoxycinnamic
acids with glycerol to cinnamate glycerides in solventless
media: a kinetic model. Chem Eng J 225:710–719. https://doi.
org/10.1016/j.cej.2013.04.016
Fang W, Pirez C, Capron M, Paul S, Raja T, Dhepe PL, Dumeignil
F, Jalowiecki-Duhamel L (2012) Ce–Ni mixed oxide as efcient
catalyst for H2 production and nanofbrous carbon material from
ethanol in the presence of water. RSC Adv 2:9626–9634. https://
doi.org/10.1039/C2RA21701E
Nakagawa Y, Tomishige K (2011) Catalyst development for the
hydrogenolysis of biomass-derived chemicals to value-added
ones. Catal Surv Asia 15:111–116. https://doi.org/10.1007/s1056
3-011-9114-z
Faria RPV, Pereira CSM, Silva VMTM, Loureiro JM, Rodrigues AE
(2013) Glycerol valorization as biofuel: thermodynamic and
kinetic study of the acetalization of glycerol with acetaldehyde.
Ind Eng Chem Res 52:1538–1547. https://doi.org/10.1021/ie302
935w
Nanda MR, Yuan Z, Qin W, Ghaziaskar HS, Poirier MA, Xu CC (2014)
Thermodynamic and kinetic studies of a catalytic process to con-
vert glycerol into solketal as an oxygenated fuel additive. Fuel
117:470–477. https://doi.org/10.1016/j.fuel.2013.09.066
Nasreen S, Liu H, Qureshi LA, Sissou Z, Lukic I, Skala D (2016)
Cerium–manganese oxide as catalyst for transesterifcation of
soybean oil with subcritical methanol. Fuel Process Technol
148:76–84. https://doi.org/10.1016/j.fuproc.2016.02.035
Nemirowsky J (1885) Ueber die Einwirkung von Chlorkohlenoxyd auf
Glycolchlorhydrin. Journal für Praktische Chemie 3:173–175.
https://doi.org/10.1002/prac.18850310115
Farias AFF, Moura KF, Souza JKD, Lima RO, Nascimento JDSS,
Cutrim AA, Longo E, Araujo AS, Carvalho-Filho JR, Souza AG,
Santos IMG (2015) Biodiesel obtained by ethylic transesterif-
cation using CuO, ZnO and CeO2 supported on bentonite. Fuel
160:357–365. https://doi.org/10.1016/j.fuel.2015.07.102
George J, Patel Y, Pillai SM, Munshi P (2009) Methanol assisted
selective formation of 1,2-glycerol carbonate from glycerol and
carbon dioxide using nBu2SnO as a catalyst. J Mol Catal A Chem
304:1–7. https://doi.org/10.1016/j.molcata.2009.01.010
Hakim L, Yaakob Z, Ismail M, Daud W, Sari R (2013) Hydro-
gen production by steam reforming of glycerol over Ni/Ce/Cu
hydroxyapatite-supported catalysts. Chem Pap 67:703–712. https
://doi.org/10.2478/s11696-013-0368-y
Ochoa-Gómez JR, Gómez-Jiménez-Aberasturi O, Maestro-Madurga
B, Pesquera-Rodríguez A, Ramírez-López C, Lorenzo-Ibarreta L,
Torrecilla-Soria J, Villarán-Velasco MC (2009) Synthesis of glyc-
erol carbonate from glycerol and dimethyl carbonate by transester-
ifcation: catalyst screening and reaction optimization. Appl Catal
A 366:315–324. https://doi.org/10.1016/j.apcata.2009.07.020
Padmanathan N, Selladurai S (2013) Electrochemical capacitance of
porous NiO–CeO2 binary oxide synthesized via sol–gel technique
for supercapacitor. Ionics 20:409–420. https://doi.org/10.1007/
s11581-013-0989-8
Hu J, Li J, Gu Y, Guan Z, Mo W, Ni Y, Li T, Li G (2010) Oxida-
tive carbonylation of glycerol to glycerol carbonate catalyzed
by PdCl2(phen)/KI. Appl Catal A 386:188–193. https://doi.
org/10.1016/j.apcata.2010.07.059
Indran VP, Syuhada Zuhaimi NA, Deraman MA, Maniam GP, Yusof
MM, Yun Hin TY, Ab. Rahim MH (2014) An accelerated route
of glycerol carbonate formation from glycerol using waste boiler
ash as catalyst. RSC Adv 4:25257–25267. https://doi.org/10.1039/
C4RA02910K
Pandhare NN, Pudi SM, Mondal S, Pareta K, Kumar M, Biswas P
(2017) Development of kinetic model for hydrogenolysis of glyc-
erol over Cu/MgO catalyst in a slurry reactor. Ind Eng Chem Res
57:101–110. https://doi.org/10.1021/acs.iecr.7b03684
Kim DW, Park KA, Kim MJ, Kang DH, Yang JG, Park DW (2014)
Synthesis of glycerol carbonate from urea and glycerol using
polymer-supported metal containing ionic liquid catalysts. Appl
Catal A 473:31–40. https://doi.org/10.1016/j.apcata.2013.12.032
Patil P, Gude VG, Pinappu S, Deng S (2011) Transesterifcation kinet-
ics of Camelina sativa oil on metal oxide catalysts under conven-
tional and microwave heating conditions. Chem Eng J 168:1296–
1300. https://doi.org/10.1016/j.cej.2011.02.030
1 3

Chemical Papers
Quispe CAG, Coronado CJR, Carvalho JA Jr (2013) Glycerol: pro-
duction, consumption, prices, characterization and new trends in
combustion. Renew Sustain Energy Rev 27:475–493. https://doi.
org/10.1016/j.rser.2013.06.017
CaO–CeO2 mixed oxide catalysts. Fuel 162:288–293. https://doi.
org/10.1016/j.fuel.2015.09.012
Wu YF, Song XH, Cai FF, Xiao GM (2017) Synthesis of glycerol car-
bonate from glycerol and diethyl carbonate over Ce–NiO catalyst:
the role of multiphase Ni. J Alloy Compd 720:360–368. https://
doi.org/10.1016/j.jallcom.2017.05.292
Sonnati MO, Amigoni S, Tafn de Givenchy EP, Darmanin T, Choulet
O, Guittard F (2013) Glycerol carbonate as a versatile building
block for tomorrow: synthesis, reactivity, properties and applica-
tions. Green Chem 15:283–306. https://doi.org/10.1039/C2GC3
6525A
Xu S, Yan X, Wang X (2006) Catalytic performances of NiO–CeO2 for
the reforming of methane with CO2 and O2. Fuel 85:2243–2247.
https://doi.org/10.1016/j.fuel.2006.03.022
Sun Y, Tong X, Wu Z, Liu J, Yan Y, Xue S (2014) A sustainable prepa-
ration of glycerol carbonate from glycerol and urea catalyzed by
hydrotalcite-like solid catalysts. Energy Technol 2:263–268. https
://doi.org/10.1002/ente.201300135
Yadav GD, Chandan PA (2014) A green process for glycerol val-
orization to glycerol carbonate over heterogeneous hydrotalcite
catalyst. Catal Today 237:47–53. https://doi.org/10.1016/j.catto
d.2014.01.043
Vlad E, Bildea CS, Bozga G (2013) Robust optimal design of an glyc-
erol etherifcation process. Chem Eng Technol 36:251–258. https
://doi.org/10.1002/ceat.201200274
Zhang J, He D (2014) Lanthanum-based mixed oxides for the synthesis
of glycerol carbonate from glycerol and urea. React Kinet Mech
Catal 113:375–392. https://doi.org/10.1007/s11144-014-0739-6
Zou W, Ge C, Lu M, Wu S, Wang Y, Sun J, Pu Y, Tang C, Gao F, Dong
L (2015) Engineering the NiO/CeO2 interface to enhance the cata-
lytic performance for CO oxidation. RSC Adv 5:98335–98343.
https://doi.org/10.1039/C5RA20466F
Wang L, Ma Y, Wang Y, Liu S, Deng Y (2011) Efcient synthesis of
glycerol carbonate from glycerol and urea with lanthanum oxide
as a solid base catalyst. Catal Commun 12:1458–1462. https://doi.
org/10.1016/j.catcom.2011.05.027
Wong YC, Tan YP, Taufq-Yap YH, Ramli I, Tee HS (2015) Bio-
diesel production via transesterifcation of palm oil by using
1 3