100
Chapter 5 · The Coproduct of Oleochemistry - Glycerol
5
The monotelomer is particularly interesting
for application in detergents. By hydrogenation
of the monotelomer, glycerol monooctylether
is formed, which can be used as emulsifier or
surfactant. Telomerization is a homogeneously
catalyzed reaction that takes place under very
mild reaction conditions. In a continuously operated miniplant, almost complete recycling of the
homogeneous palladium catalyst and control of
the selectivity to the monotelomer was achieved.
5.4 Glycerol Acetals and Ketals
Aldehydes form acetals with di- or polyols (glycerol, for instance), whereas ketones form ketals,
respectively. The corresponding products have a
wide range of applications:
5 Acetals and ketals of glycerol have long been
used in the synthesis of active ingredients.
h-GTBE can be used as an oxygen-containing
diesel fuel additive, which significantly reduces
particle emissions. Due to the branched alkyl
chains, h-GTBE can also be used in gasolines
as an “octane booster” to replace the less advantageous methyl tertiary butyl ether (MTBE).
Synthesis takes place in the presence of acidic
homogeneous catalysts such as p-toluenesulfonic
acid or sulfuric acid. The process has now been
optimized on a miniplant scale so that only
the desired h-GTBE leaves the plant, while the
m-GTBE is extractively separated and returned
to the reactor for further reaction with isobutene.
5.3.4 Glycerol Alkenyl Ether
An atom economic method for the synthesis
of unsaturated glycerol ether is the palladiumcatalyzed telomerization of glycerol with the petrochemical 1,3-butadiene to glycerol octadienyl
ether (. Fig. 5.10). In this reaction, two butadiene
molecules combine to form a C 8 chain and add to
the hydroxyl groups of the glycerol.
OH
HO
HO
+ n
O
OH
OH
O
OH
OH
O
OH
O
O
O
O
[Pd]
. Fig. 5.10 Telomerization of glycerol with butadiene
to glycerol octadienyl ether
OH
OH
OH
+ n
OH
OH
O
O
OH
OH
O
OH
O
O
O
O
+
+
+
[H + ]
m-GTBE
h-GTBE
OH
O
O
. Fig. 5.9 Synthesis of glycerol tertiary butyl ether (GTBE)
Chapter 5 · The Coproduct of Oleochemistry - Glycerol
5
The monotelomer is particularly interesting
for application in detergents. By hydrogenation
of the monotelomer, glycerol monooctylether
is formed, which can be used as emulsifier or
surfactant. Telomerization is a homogeneously
catalyzed reaction that takes place under very
mild reaction conditions. In a continuously operated miniplant, almost complete recycling of the
homogeneous palladium catalyst and control of
the selectivity to the monotelomer was achieved.
5.4 Glycerol Acetals and Ketals
Aldehydes form acetals with di- or polyols (glycerol, for instance), whereas ketones form ketals,
respectively. The corresponding products have a
wide range of applications:
5 Acetals and ketals of glycerol have long been
used in the synthesis of active ingredients.
h-GTBE can be used as an oxygen-containing
diesel fuel additive, which significantly reduces
particle emissions. Due to the branched alkyl
chains, h-GTBE can also be used in gasolines
as an “octane booster” to replace the less advantageous methyl tertiary butyl ether (MTBE).
Synthesis takes place in the presence of acidic
homogeneous catalysts such as p-toluenesulfonic
acid or sulfuric acid. The process has now been
optimized on a miniplant scale so that only
the desired h-GTBE leaves the plant, while the
m-GTBE is extractively separated and returned
to the reactor for further reaction with isobutene.
5.3.4 Glycerol Alkenyl Ether
An atom economic method for the synthesis
of unsaturated glycerol ether is the palladiumcatalyzed telomerization of glycerol with the petrochemical 1,3-butadiene to glycerol octadienyl
ether (. Fig. 5.10). In this reaction, two butadiene
molecules combine to form a C 8 chain and add to
the hydroxyl groups of the glycerol.
OH
HO
HO
+ n
O
OH
OH
O
OH
OH
O
OH
O
O
O
O
[Pd]
. Fig. 5.10 Telomerization of glycerol with butadiene
to glycerol octadienyl ether
OH
OH
OH
+ n
OH
OH
O
O
OH
OH
O
OH
O
O
O
O
+
+
+
[H + ]
m-GTBE
h-GTBE
OH
O
O
. Fig. 5.9 Synthesis of glycerol tertiary butyl ether (GTBE)