Environmental Engineering Reference
In-Depth Information
5.3.1.4 Preparation of Glycol Dinitrate
The early preparation method of glycol dinitrate is to nitrate ethylene [
73
]. The
product includes
ʲ
type nitroethyl alcohol and glycol dinitrate.
CH
2
OH
CH
2
CH
2
CH
2
ONO
2
HNO
3
CH
2
NO
2
+2HNO
3
+
CH
2
NO
2
CH
2
NO
2
CH
2
ONO
2
In later method, glycol dinitrate can be directly obtained by dehydration in the
process of ethylene nitration.
CH
2
CH
2
CH
2
ONO
2
CH
2
ONO
2
HNO
3
H
2
SO
4
+2HNO
3
CH
2
ONO
CH
2
ONO
2
About 50
60 % ethylene is converted by the
first equation and the other 40
-
-
50 % is converted by the second reaction.
(1) Electrolytic ethylene method
This method [
74
] can be used to produce glycol dinitrate and diethylene glycol
dinitrate. Platinum wire mesh dipped in calcium nitrate-acetone solution is used as
an anode. The gaseous ethylene is continuously going through the solution. Back
the aluminum cathode, calcium nitrate-nitric acid solution is
filled. At anode, the
nitrate ions will be converted to free group of NO
3
, part of which will be reacted
with ethylene to form glycol dinitrate.
CH
2
ONO
2
CH
2
CH
2
+2 NO
3
CH
2
ONO
2
The interreaction among free groups of NO
3
will produce oxygen free groups,
which can be further reacted with NO
3
to form diethylene glycol dinitrate.
+H
2
O
2HNO
3
2NO
3
N
2
O
5
+[O]
2
NO
3
CH
2
ONO
2
CH
2
CH
2
CH
2
CH
2
+[O]
+
NO
3
O
2
CH
2
ONO
2
The anode solution will be neutralized by calcium hydroxide and acetone will be
removed by distillation. The main products are calcium nitrate and glycol dinitrate. The
calcium nitrate can be removed by
ltration. The
ltrate solution can be washed bywater
and treated for stability. After drying, the
nal product of glycol dinitrate can be obtained.
(2) Modern manufacturing technologies of glycol dinitrate [
73
,
75
78
]
-
It is well known that glycol dinitrate can be produced by nitration of glycol in a
mixed acid of nitric acid and sulphuric acid. The typical composition of the mixed
acid is 11.5
-
20 % H
2
O, 18
-
40 HNO
3
, and 45
-
68.5 % H
2
SO
4
. The appropriate
reaction temperature is 5
-
15
°
C. The nitration coef
cient is in the range of 12
-
24.
The conversion of glycol is up to 92
-
96 %. It is an exothermal reaction with
ʔ
H of
355.64 J/mol glycol.
