479
and possible way out would be to combine both the units which produce glycerol
carbonate and can consume the by-product ammonia. Li et al. also proposed that in
order to selectively prepare cyclic carbonates by using diols and urea, it could be
seen that catalysts having both acidic and basic properties are much favourable
[137]. Shanbhag et al. showed that catalysts with optimum acid-base sites can
deliver remarkable results for glycerol carbonylation reaction [126]. According to
Marakatti et al., Lewis acid sites along with their conjugate bases are reasons for
better catalytic activity for the synthesis of glycerol carbonate. A bunch of study
reported by Lingaiah et al. on glycerol carbonylation also stated the fact about the
presence of Lewis acid-base pair for selective synthesis of glycerol carbonate.
Chemical equilibrium calculations demonstrated that elevated temperature and
reduced pressure facilitate the glycerol carbonylation reaction with urea [105].
From ecological and energy point of view, this synthetic route is the most advantageous involving biobased reactants and notably not involving any organic solvents.
5 Catalytic Esterification of Glycerol
The esterification of glycerol is another widely studied pathway to convert glycerol
into value-added chemicals. Esterification of glycerol with an acetyl source results
in mono-, di- and tri-acetyl esters which are commonly termed as monoacetin
Table 3 Performance of some catalysts in glycerol carbonylation with urea as reported in literature
Catalyst
Temperature
(°C)
Time
(h)
Conversion
(%)
Selectivity
(%)
GC yield
(%)
Reference
SW21
140
4
52.1
95.3
49.7
[128]
Zr-P
140
3
80
100
80
[127]
Au/Fe 2 O 3
150
4
80
48
38.4
[139]
2.5% Au/
Nb 2 O 5
150
4
66
32
21
[139]
Zn/MCM-41
(im)
145
5
75
98
73
[123]
Sm 0.66 TPA
140
4
49.5
85.4
42.3
[125]
Zn 1 TPA
140
4
69.2
99.7
68.8
[140]
Co 3 O 4 /ZnO
145
4
69
97
66.9
[129]
15% WO 3 /TiO 2 140
4
100
73
73
[136]
Ta 0.4 TPA
140
4
71
100
71
[132]
Sn(OH) 2
140
4
87
85
74
[135]
ZnAlO
140
4
91
70
64
[133]
Cu-Mn
140
6
91
99
90
[134]
Zn-Y
150
3
94.6
98
92.7
[130]
ZnSn(OH) 6
165
5
98.0
99.6
97.6
[131]
La 2 O 3
140
4
68.9
98.1
67.6
[124]
Zn 2 SnCoPre- 600
155
4
96
99.6
95.6
[126]
Catalytic Conversion of Biomass-Derived Glycerol to Value-Added Chemicals
and possible way out would be to combine both the units which produce glycerol
carbonate and can consume the by-product ammonia. Li et al. also proposed that in
order to selectively prepare cyclic carbonates by using diols and urea, it could be
seen that catalysts having both acidic and basic properties are much favourable
[137]. Shanbhag et al. showed that catalysts with optimum acid-base sites can
deliver remarkable results for glycerol carbonylation reaction [126]. According to
Marakatti et al., Lewis acid sites along with their conjugate bases are reasons for
better catalytic activity for the synthesis of glycerol carbonate. A bunch of study
reported by Lingaiah et al. on glycerol carbonylation also stated the fact about the
presence of Lewis acid-base pair for selective synthesis of glycerol carbonate.
Chemical equilibrium calculations demonstrated that elevated temperature and
reduced pressure facilitate the glycerol carbonylation reaction with urea [105].
From ecological and energy point of view, this synthetic route is the most advantageous involving biobased reactants and notably not involving any organic solvents.
5 Catalytic Esterification of Glycerol
The esterification of glycerol is another widely studied pathway to convert glycerol
into value-added chemicals. Esterification of glycerol with an acetyl source results
in mono-, di- and tri-acetyl esters which are commonly termed as monoacetin
Table 3 Performance of some catalysts in glycerol carbonylation with urea as reported in literature
Catalyst
Temperature
(°C)
Time
(h)
Conversion
(%)
Selectivity
(%)
GC yield
(%)
Reference
SW21
140
4
52.1
95.3
49.7
[128]
Zr-P
140
3
80
100
80
[127]
Au/Fe 2 O 3
150
4
80
48
38.4
[139]
2.5% Au/
Nb 2 O 5
150
4
66
32
21
[139]
Zn/MCM-41
(im)
145
5
75
98
73
[123]
Sm 0.66 TPA
140
4
49.5
85.4
42.3
[125]
Zn 1 TPA
140
4
69.2
99.7
68.8
[140]
Co 3 O 4 /ZnO
145
4
69
97
66.9
[129]
15% WO 3 /TiO 2 140
4
100
73
73
[136]
Ta 0.4 TPA
140
4
71
100
71
[132]
Sn(OH) 2
140
4
87
85
74
[135]
ZnAlO
140
4
91
70
64
[133]
Cu-Mn
140
6
91
99
90
[134]
Zn-Y
150
3
94.6
98
92.7
[130]
ZnSn(OH) 6
165
5
98.0
99.6
97.6
[131]
La 2 O 3
140
4
68.9
98.1
67.6
[124]
Zn 2 SnCoPre- 600
155
4
96
99.6
95.6
[126]
Catalytic Conversion of Biomass-Derived Glycerol to Value-Added Chemicals