Environmental Engineering Reference
In-Depth Information
Incorporated with Ozone Oxidization and Alkali Solution Adsorption
Ta b l e 5. 5
Comparison of investments and running costs of various technologies
Pulverized
coal reburning
Project
Unit
OFA
SNCR
SCR
WFGD
mg/(N·m
3
)
NO
x
emission
560
400-560
480-560
40-160
800
mg/(N·m
3
)
SO
2
emission
2000
2000
2000
2000
100
NO
x
removal
%
30
30-50
30-40
80-95
No
SO
2
removal
%
no
no
no
no
95
Hg removal
%
no
no
no
ˉ
No
280
Investment
yuan/kW
15-20
20-30
50-170
200
Operating costs
Point/(kW
h)
0
0.8
0.4
2-4.3
1.5
WFGD basis
Project
WFGD
Electron beam
reburning+SNCR
O
3
+OFA
O
3
+reburning
NO
x
emission
800
640-720
160
160
250
SO
2
emission
100
400
100
100
2,000
NO
x
removal
No
10-20
80
80
68.75
SO
2
removal
95
80
95
95
No
Hg removal
No
no
85
85
No
280
Investment
600
120
70
90-100
Operating costs
1.5
0.76
0.3
0.2
0.5
Note: The initial emission concentration of NO
x
and SO
2
is 800 and 2000 mg/(Nm
3
), respectively
Both O
3
oxidization and e-beam technologies belong to the electro-catalytic
category. However, e-beam discharges in the entire flue gas. The inactive N
2
and
CO
2
in flue gas consume a lot of energy. However, O
3
only discharges a small
dosage of oxygen or air. Therefore, both the discharge efficiency and electrode
lifespan in O
3
generation are superior to those in the electron-beam preparation.
The energy consumption of the electron beam levels at 6.3 W/(Nm
3
) when
achieving the same NO
x
emission levels released by the Chengdu Thermal Power
Plant in China. On the contrary, O
3
oxidation only consumes 0.83 - 0.96
W/(Nm
3
), saving more than 80% power consumption
[9]
, compared with the
aforementioned e-beam method. Definitely, ozone oxidation combined with OFA
or reburning, coupled with WFGD system, is approved as a promising
cost-effective multi-pollutants removal method.
5.4 Summary
This chapter is attentively employed to present an engineering design of a
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