Environmental Engineering Reference
In-Depth Information
Fig. 4.1
Diagram of the experimental setup that combines O
3
oxidation with a wet scrubber
Ta b l e 4. 1
Properties of the gases used in the experiments
Gas
Concentration
Volume/Pressure
Producer
N
2
High pure (99.999%)
40 L/15.0 MPa
Jingong Gas, Hangzhou
O
2
High pure (99.999%)
40 L/15.0 MPa
Jingong Gas, Hangzhou
NO/N
2
1.2%
8 L/9.5 MPa
Xinsiji Gas, Hangzhou
SO
2
/N
2
1.2%
8 L/9.5 MPa
Xinsiji Gas, Hangzhou
NO
2
/N
2
1.2%
8 L/9.5 MPa
Xinsiji Gas, Hangzhou
HCl/N
2
1.2%
8 L/9.5 MPa
Xinsiji Gas, Hangzhou
4.3 Effect of pH Value on NO
2
Removal
As mentioned above, NO
2
in the gas bottle was employed as an oxidation product
when the molar ratio O
3
/NO was 1 in the experiments. Given the inevitability of
NO in the NO
2
gas from the bottle, the NO
2
gas employed actually comprised
300±5 ppm NO
2
and around 10 ppm NO, with the gas phase balance controlled by
Eqs. (4.2) and (4.3). This means that aside from NO
2
and NO, a little N
2
O
3
and
N
2
O
4
exist in the gas phase. The EQUIL model of CHEMKIN 4.7 was employed
before the experiments to calculate the balanced composition of the employed 300
ppm NO
x
.
K
←
⎯→
NO+NO
2
N
2
O
3
(4.2)
1
K
←
⎯→
NO
2
+NO
2
N
2
O
4
(4.3)
2
Fig. 4.2 shows the balanced compositions of NO
x
at different ORs (i.e., the
molar ratio of NO
2
to NO
x
). The figure also shows that NO and NO
2
are the main
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