Environmental Engineering Reference
In-Depth Information
equivalents to 4 equivalents, the amount of water is drastically reduced while the
ethyl acetate loss will be reduced and the waste liquid is also dropped signi
cantly.
It can be expected that, if 1,000 g of DNPOH is produced, the amount of generated
waste is 14.26 kg; the cost of raw materials and waste handling can be reduced to
$8.59 (reduced by 56 %). In the production, if nitroethane is used as a starting
material instead of 2-nitropropanol, two different electrolytic pathways to synthe-
size DNPOH have been designed as shown in Figs.
4.4
and
4.5
.
After many years of development, the U.S. Department of Defense-funded
project WP-1460 [
67
] was made a signi
cant progress. In 2007, Idaho National
Laboratory completed a continuous process of electrochemical synthesis of the key
intermediate 2,2-nitroethyl potassium (KDNE) of DNPOH in the laboratory [
68
]
from nitroethane. It was believed that the electrochemical process to produce
DNPOH could reduce more than 92 % of the waste, carbide or nickel alloy rods
was used as electrodes instead of silver rods according to the U.S. patent [
69
]. With
different voltages, anode oxidizes inactive chemical intermediates (such as ferro-
cyanide ion) into active intermediates or oxidant (such as iron cyanide ion). Oxi-
dants and nitro compounds react with nitrite ions to form a gem-dinitro product.
Anode can oxidize ferrous cyanide continuously to produce lively iron cyanide
ions, thus to provide enough iron cyanide ions for reaction. The scheme of synthesis
is shown in Fig.
4.6
.
In the technical report of 2011 [
67
], Alexander Paraskos et al. on the basis of
synthetic route in a small test, ampli
ed and completed the pilot test of KDNE. The
results con
rmed that, in the pilot test of KDNE electrochemical synthesis, [Fe
(CN)
6
]
3
−
/
4
−
is an excellent
reaction medium,
leading very good operating
NO
2
NO
2
NaOH
CH
2
O
OH
NaOH
NO
2
OH
Nitroethane
2-nitro-Propanol
NO
2
O
2
N
anode
oxidating
NO
2
anode
oxidating
NO
2
OH
+NO
2
O
2
N
OH
OH
Fig. 4.4 Electrochemical synthesis route 1 of DNPOH
NO
2
NO
2
NO
2
NaOH
anode
oxidating
anod
e
oxidating
+NO
2
-
anode
oxidating
NO
2
NO
2
NO
2
NO
2
O
2
N
NO
2
NaOH
CH
2
O
OH
