Environmental Engineering Reference
In-Depth Information
500
500
400
400
300
300
200
CO
200
100
100
0
0
EODQN
2&2
ć
2&2
ć
2&2
ć
Blank O
3
/CO=0.86 O
3
/CO=3.5 O
3
/CO=3.5
100 °C 100 °C 300 °C
Fig. 3.17
CO concentration variations with the temperature and ratio of O
3
to CO
3.4 Competitive Reaction Mechanism Between Different
Pollutants
3.4.1 Reaction Competition Between NO and SO
2
with Ozone
For the simultaneous removal of NO
x
and SO
2
, SO
2
inevitably exists during the
NO oxidation process because of flue gas always containing high SO
2
content.
The SO
2
influence on the NO oxidation should be investigated. As mentioned
previously in the subsection 3.3.3, in the flue gas with ozone, SO
2
may also be
oxidized into SO
3
by ozone or O radical. Reacting with the moisture in the flue
gas, SO
3
then transforms into H
2
SO
4
, which increases the duct corrosion. Again,
the SO
2
oxidation increases greatly the ozone consumption. The oxidation of SO
2
is essentially redundant because more than 95% of SO
2
in flue gas can be
effectively removed by the WFGD system. Fortunately, the experimental results
presented previously in the subsection 3.3.3 (see Fig. 3.14 and its discussion) have
disclosed that the existence of SO
2
has little effect on the NO conversion. This
observation implies weak reaction between O
3
and SO
2
. Therefore, SO
2
in the flue
gas affects slightly the total O
3
consumption in a simultaneous multi-pollutants
removal system.
Search WWH ::
Custom Search