NOx-separation
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| Products- Washer programme |
|
NOx separation from waste
air
Method of recovery of raw materials from waste gas without any
origin of waste |
|
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| 4. Example
of the use : 4.2.2 G-NOx-Process |
| During G-NOx process
a catalytic accelerated NO oxidation in gaseous phase takes place. The
drawn off air which has to be purified is also fed through a jet condensation
column into a column filled with small solid bodies where nitric acid
is produced in the washing circuit. The washing process has been designed
for an economic recovery with 80 – 90 % NOx separation efficiency.
NOx residual content in an amount of 1 000 ppm is in the air on the outlet
from nitric acid recovery stage. This air is fed into the adsorption stage
where catalytic oxidation of NO to NO2 takes place on a molecular sieve
and activated carbon mixture and at the same time NO2 is adsorbed in catalytic
way. In continuous processes it is necessary that adsorption stage be
in redundant execution. The adsorber filled with NO2 can be regenerated
with hot air. The produced NO2- concentrated gas is fed into a washing
column. With this process it is also possible to produce an amount of
35 kg/h and 29.5 l/h respectively of 30%- nitric acid. |
| This process requires
the following operating cost: |
| Electric
power for using cold water, pumps and fans |
300 |
kW/d |
72,00 |
DM/d |
| Steam
2bar for regenerating air |
700 |
kg/d |
28,00 |
DM/d |
| In
total |
|
|
100,00 |
DM/d |
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| The produced nitric
acid can be utilized again in the pickling process circuit. The advantage
of this method consists in the fact that the produced nitric acid is not
contaminated by hydrogen peroxide and in addition to it a value of the
purified gas of less than 100 mg NOx/ml is attained in the adsorption
stage. The use of molecular sieve or activated charcoal is dependent on
treated NOx concentration. The flow of the process is evident from the
process flow sheet in Figure 2. |
|
| G-NOx process flow
sheet ( Figure 2) |
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|
NOx-separation
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