Environmental Engineering Reference
In-Depth Information
P
c-J
: 13 GPa
Hit (impact) sensitivity: 0
8 % (drop weight of 10 kg, characteristic drop height of
-
50 cm)
Heat or vacuum stability: At 300
°
C, the half-life of nitromethane is 30 days, it
decomposes completely at 350
400
°
C slowly, and its autocatalytic decomposition
-
at above 400
C generates explosion detonation.
At room temperature, the 8th detonator can detonate nitromethane, and the
minimum shock energy to detonate nitromethane is 8
°
9 GPa. With the increase of
temperature, explosion detonation sensitivity increases and the critical diameter
decreases, but the explosion velocity is reduced, and the explosion velocity is
6,380 m/s at 4
-
18m/s
C. At 25
°
C,
D
D
=
D
T
¼
3
:
964
0
:
°
C, the maximum
stable explosion velocity of nitromethane is 6,320 m/s.
4.3.1.3 Applications of Nitromethane
Nitromethane is active chemically, can have many chemical reactions as a chemical
reagent or synthesis intermediate. It also can be used as solvents for cellulose
nitrate, cellulose acetate, cellulose acetate, vinyl resin, polyacrylate coating, bees-
wax, etc.; base or other materials can be added into nitromethane for generate
explosives; when nitromethane is mixed with strong oxidant hydrogen peroxide or
N
2
O
4
, it can be used as liquid rocket propellants and fuel; nitromethane can also be
used in medicine, dyes, insecticides, fungicides, stabilizers and surfactants.
4.3.1.4 Preparation of Nitromethane
Nitro Methane is the simplest nitro aliphatic compound with strong explosion
properties, thus, it is a very important liquid explosive. Nitromethane can be pro-
duced directly through methane gas phase nitration [
24
,
25
]. In the methane direct
method, methane gas as a raw material reacts with nitric acid at 300
500
°
C
-
through gasi
cation reaction followed by rough separation and distillation to obtain
nitromethane. The advantage of this process is the wide sources of raw materials,
and its disadvantage is that rich gas resources and relatively good production
facilities are needed to build the production line, which has certain restrictions on
the practice and poor selectivity. Because nature gas purity is not high, many
byproducts will be produced. In addition to the methane direct method, tmethods to
prepare nitromethane include nitrite slat substitution method [
26
], sodium nitrite
halogenated alkyl method [
27
],
uxing nucleophilic displacement between
dimethyl sulfate and sodium nitrite [
28
]. Liquid methane and its derivatives can be
liquid-nitrated at about 200
re
fl
°
C, in which the nitration rate depends on the con-
centration of nitric acid and the reaction temperature. With nitric oxide as catalyst,
special attention should be paid to controlling the explosion limit concentration of
nitric oxide and hydrocarbons. The main reactions are:
