1. 4thInternational Conference on "Advances in Energy Research"
Heterogeneous Catalysis for Biodiesel
Synthesis and Valorization of Glycerol
Presented by
Dheerendra Singh
Under the guidance of
Prof. Sanjay M. Mahajani
Prof. Anuradda Ganesh

2. Introduction
 Biodiesel is a mixture of fatty acid methyl esters (FAME)
 Transesterification of vegetable oils in presence of NaOH/KOH as catalyst
 Heterogeneous catalysts have an added advantage i. e. ease of separation
ZnO & PbO on zeolite are promising catalysts for producing biodiesel using jatropha oil.
Catalysts are characterized by XRD, BET, TEM, SEM and TPD/TPR.
The leaching of metal ions is minimized with zeolite as support material.
 Glycerol is obtained as a by-product (~10 wt %) in biodiesel production
 Mono-glyceride and Glycerol carbonate are synthesized by esterification and
transesterification of glycerol.
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3. General schematic of reactions considered in the present
work
Vegetable oil + Methanol
Biodiesel
+
Glycerol
Glycerol
Fatty acid
DMC
Mono-glyceride
Urea
Glycerol carbonate
+
Methanol
Glycerol carbonate
+
NH3
Urea
+ Methanol
NH3
+
CO2
DMC +
NH3
Urea
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4. Methodology
Batch
Reactor
Materials:
Jatropha oil and sunflower oil for Biodiesel
Synthesis and oleic acid for esterification of
glycerol
Catalyst Preparation:
 Precipitation
 HIP Method1
 Modified citrate technique2
Schematic of continuous packed bed reactor
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5. Catalyst Characterization
MgO (2 2 2)
MgO (3 1 1)
MgO (2 2 0)
MgO
MgO (2 0 0)
MgO (1 1 1)
1. X-Ray Diffraction
ZnO (1 0 3)
ZnO (1 1 0)
ZnO (1 0 2)
ZnO (1 0 1)
ZnO (1 0 0)
ZnO/ZSM5
ZnO (0 0 2)
Intensity (a.u.)
PbO/ZSM5
ZSM5
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
2
 Two separate phases (ZnO and Zeolite) are observed
 The average crystallite size of ZnO is estimated with the help of Scherrer equation
and is found to be 22.15 nm.
 Intensity of PbO in PbO/ZSM-5 very small
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6. 2. Scanning electron microscopy (SEM)
SEM imaging of the catalyst ZnO/zeolite, PbO/zeolite and MgO
The shape of zeolite (support) particles were non-uniform and the particle size
distribution was large with size varying from 50 to 300 nm.
 MgO catalyst has porous texture with uniform particle size of 20 nm.
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7. Counts
Counts
3. Transmission electron microscopy (TEM)
2
14
16
18
20
22
Particle size (nm)
24
26
3
4
5
6
Particle size (nm)
7
TEM imaging of the catalyst ZnO/zeolite, PbO/zeolite and MgO
 ZnO particle size varies from 14 nm to 26 nm and the average particle size is 19.54 nm
 The particle size of PbO varies from 2.9 nm to 6.8 nm with an average particle size of 4.2 nm
 Particle size of MgO is ~ 20 nm.

8. 1. Biodiesel synthesis
100
90
Performance Evaluation of 3ZnO/ZSM-5 catalyst
in batch and continuous reactors
Wt % of components
80
The conversion of jatropha oil and the yield of
biodiesel using ZnO/zeolite and PbO/zeolite are
found to be approximately 100 % and 93.8 % at
70
60
50
Wt% MG
Wt% FFA
Wt% DG
Wt% TG
Wt % BD
40
30
20
10
0
optimum reaction conditions.
0
10
20
30
40
50
60
Time (min)
[Oil (Jatropha): Methanol 1:30, Temperature 200 C, Catalyst loading 0.50 wt %, RPM 500]
90
Zn/Pb (ppm)
Not detected
>1238.15
920.575
614.033
127.523
PbO powder
Zn leaching (ppm)
Sample
Blank (perchloric acid)
ZnO powder
ZnO/γ-alumina
ZnO/α-alumina
ZnO/ZSM-5
90
80
Comparison of Zn/Pb leaching on different supports
100
80
70
70
60
60
TG conversion
50
Zn leaching
40
50
40
30
30
>3400
20
20
PbO/γ-alumina
>464
10
10
PbO/β-zeolite
9.29
0
0
0
50
100
150
200
250
300
Time (hr)
[4] Singh et al. (under review)
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[Reaction temperature, 200°C; methanol: jatropha oil molar ratio, 6:1]
% TG conversion
100

9. 4. Thermal program method
ZSM-5
TPD of ZSM-5
and ZnO/ZSM-5
0
100
200
300
400
500
600
700
800
TCD Signal
Metal support interaction
ZnO/ZSM-5
900
30 % PbO/ZSM-5
0
25 % PbO/ZSM-5
100
200
300
400
500
o
TPR of PbO
supported catalyst
Temperature ( C)
25 % PbO/Alumina
PbO
0
100
200
300
400
500
600
o
Temperature C
700
800
900
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600

10. 2. Esterification of oleic acid with glycerol
 Mono-glyceride is a good surfactant and has a wide range of applications as emulsifier
in food, pharmaceutical, and cosmetic industries.
 Reaction can take place even in the absence of catalyst but zeolite alone does not show
any catalytic activity. ZnO supported on zeolite shows a significant rise in the reaction rate
Product can be formed through parallel or series reaction pathway
O
OH
O
OH +
R
O
O
C
C
R
O
C
O C
OH
Glycerol
OH
Oleic acid
R
O
C
O
R
MG
,
OH
R +
n H2O
O
,
DG
R
C
O
OH
OH
O
O
C
R
O
TG
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11. 100
Esterification of glycerol with oleic acid
90
80
Conversion %
70
 Esterification of oleic acid exhibited selectivity
60
50
without catalyst
40
with zeolite
30
as high as 70-80 % for mono-glyceride in the
2.0 wt % ZnO
20
2 wt % ZnO Zeolite
10
conversion range 60-90 %.
Amberlyst 35
0
0
100
200
Time (min)
 The results indicate that the zeolite supported
400
100
catalyst is equally active as ZnO powder.
90
Both mono-and di-glyceride concentrations
80
70
Selectivity %
increase with time
300
60
50
40
30
20
10
0
15
[5] Singh et al. (2013)
25
35
without catalyst (MG)
ZnO/Zeolite (MG)
ZnO (DG)
with zeolite (TG)
amberlyst 35 (MG)
45
55
65
conversion %OA
with zeolite (MG)
Without catalyst (DG)
ZnO/Zeolite (DG)
ZnO (TG)
amberlyst 35 (DG)
75
85
95
ZnO (MG)
with Zeolite (DG)
without cat (TG)
ZnO/Zeolite (TG)
Amberlyst 35 (TG)
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(Gly:OA mole ratio 4:1; Reaction temperature 150 °C; zeolite, Amberlyst 35 and ZnO loading 2.0 wt % each)

12. 3. Synthesis of glycerol carbonate (GC)
 Glycerol carbonate has wide usage in adhesive, surfactant, and elastomer production
The conventional method for GC synthesis is by direct carbonation of glycerol with
phosgene or carbon monoxide and oxygen
 Green way: with Glycerol and Di-methyl Carbonate (DMC) or with Glycerol and Urea
O
NH2
OH
HO
OH
+
H2N
Catalyst
-NH3
O
Glycerol
NH2
OH
HO
Catalyst
-NH3
O
O
Urea
O
O
OH
Glycerol carbonate
O
O
O
H3C
OH
CH3 + HO
O
O
Dimethyl carbonate
Catalyst
OH
-CH3OH
H3C
O
Glycerol
HO
O
OH
Catalyst
-CH3OH
O
O
OH
Glycerol carbonate
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13. 80
Synthesis of glycerol carbonate
With Urea
and Glycerol
 Without catalyst, glycerol conversion was
39 % after 6 hr.
Glycerol conversion %
70
60
50
40
30
With out catalyst
20
ZnO
10
 Catalytic performance of MgO is better
MgO
0
0
than ZnO
1
2
3
Time (hr)
4
5
6
(Reaction condition: Temp 140oC, cat. loading
0.5 wt %, Urea: glycerol mol ratio 1.4:1)
 No by-product formed in the reaction
100
 Another value added product, Glycidol
is formed in the reaction.
 There is observed dependency of
selectivity for GC on molar feed ratio of
DMC to glycerol
90
80
Conversion % Glycerol
With DMC
and Glycerol
70
60
50
40
150 C
30
160 C
20
170 C
10
180 C
0
0
1
2
Time (hr)
3
4
5
(DMC : glycerol molar ratio 4:1, catalyst (MgO) loading 0.5 wt % )
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14. 4. Synthesis of DMC from methanol and urea
 Di-methyl carbonate (DMC) is an important, environmentally benign building block
and is widely used in industry. (2009, world production capacity was 1.8 x 1014 lit/day)
 Conventionally DMC was manufactured from phosgene and methanol.
 Synthesis of DMC using urea and methanol is an attractive alternative route
(1)
Slow step thus
need cat.
(2)
(3)
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15. Synthesis of DMC
Time (hr)
1
2
4
6
DMC yield
0.63
0.83
1.08
2.14
MC yield
86
86.27
87
87
(Reaction temp 180 oC, Methanol/Urea 15, (ZnO/ZSM5) catalyst loading 1 wt %)
18 g molecular sieve with (Si/Al 2.5, acidic Zeolite) was
used to absorb the ammonia formed during the reaction.
Amberlyst
36
A maximum 6.7 % yield of DMC was obtained in this case.
Glass beads
(4 mm)
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16. Conclusion
 ZnO/zeolite, PbO/zeolite catalysts have exhibited good performance in biodiesel synthesis
using vegetable oils
 Glycerol obtained as a byproduct can be used further in many useful reactions.
Mono-glyceride can be synthesized by esterification of glycerol with fatty acid.
 Esterification of oleic acid showed selectivity as high as 70-80 % for mono-glyceride in
the conversion range 60-90 %.
The performance of MgO in the synthesis of glycerol carbonate via urea glycerol and
DMC glycerol route is better than ZnO.
A maximum of 6.7 % yield of DMC was obtained in the reaction of urea and
methanol, which may further increase by continuous and efficient removal of ammonia.
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17. References
[1] Lu, W., Lu, G., Luo, Y. and Chen, A. (2002) A novel preparation method of ZnO/MCM-41 for hydrogenation of
methyl benzoate, Journal of Molecular Catalysis A: Chemical, 188(1), pp. 225–231.
[2] Chen, L., Sun, X., Liu, Y. and Li, Y. (2004) Preparation and characterization of porous MgO and NiO/MgO nano
composites, Applied Catalysis A: General, 265, pp. 123–128.
[3] Mahajani, S. M., Ganesh, A., Singh, D. K. and Gupta, P. D. (2010) Heterogeneous acid catalyst for producing
biodiesel from vegetable oils and process for the preparation thereof, Indian Patent Application No 2134/MUM/2010.
[4] Singh, D., Bhoi, R., Ganesh, A. and Mahajani, S. M. (2013) Synthesis of Biodiesel from vegetable oil Using
supported metal oxide catalyst. Applied catalysis A: General, under review
[5] Singh, D., Patidar, P., Ganesh, A. and Mahajani, S. M. (2013) Esterification of oleic acid with glycerol in the
presence of supported zinc oxide as catalyst, Industrial and Engineering Chemistry Research, 52 (42), pp.14776-14786
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18. Thank you
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