Environmental Engineering Reference
In-Depth Information
50%
protector
solution
Wash twice to be
weak basic at RT
by three times
volume of
1~1.5% sodium
carbonate
aqueous solution
to product
Wash to be
neutral at RT by
three times
volume of
sodium chloride
saturated
solution to
product
Wash by three times
volume of water to
product, and then
wash by three times
volume of sodium
chloride saturated
solution to product
Add
anhydrous
magnesium
sulfate for
drying
Nitration reactor with a
segregator
Slowly add n-butanol into a
solution containing protector and
nitric acid under agitation,
separate off water by the
segregator out of the reactor.
Product
Product
Product
Waste
water
Waste
water
Waste
water
Product
Waste
liquid
Product
Waste water tank
Cool down, treat waste acid,
recover protector
Filter off magnesium
sulfate and
rectification, collect
fractions around
boiling point of ±1°C,
drying and storage
Fig. 5.7
Preparation process of n-butyl nitrate
method and there are safety risks in the process of production [
12
]. The writer
prepared n-butyl nitrate by direct continuous nitration method by dilute nitric acid
in protecting agent. The preparation process
flow is shown in Fig.
5.7
.
As shown in Fig.
5.7
, the differences between the preparation of n-butyl nitrate
and the other monobasic alcohol nitrates are evident: (1) The nitration process for
the other nitrate esters, such as methyl nitrate, is the continuous nitration-distillation
method, while for n-butyl nitrate, the process is the re
fl
ux and water segregator
method; (2) In the washing process, n-butyl nitrate is washed by saturated sodium
chloride solution because its density is close to that of water.
The key device in the preparation of n-butyl nitrate is the water segregator,
which is seldom used in chemistry. The segregator is particularly designed in
application of the preparation of n-butyl nitrate based on the requirements and
working condition. The production facilities of n-butyl nitrate are shown in Fig.
5.8
.
The volume of the nitration reactor is about 110 L equipped with an explosion
proof motor, a cycloidal reducer, mechanical seals, an anchor agitator, a tempera-
ture sensor, a pressure gauge, three feeding holes with different size, a segregator
with a glass mirror, 1,000 mm condenser, and a jacket of heat transfer oil. The
system also includes a temperature controller, an agitation controller, and a washing
vessel. By application of the production unit, the yield of n-butyl nitrate is up to
95.7 % with the purity of 98.88 %.
fl
