Civil Engineering Reference
In-Depth Information
Degas Relief Valve
Degassing
Separator
Reactor Vessel
Venturi Injector
Backpressure
Control Valve
Fig. 9-14.
GDT
process equipment (Courtesy of GDT Process)
Off-Gas Treatment
For some aeration systems, the off-gas may need to be treated before being released
to the atmosphere. A recent survey of packed tower installations found that of the
seven respondents, none were required to employ off-gas destruction. However, two
respondents were planning to install off-gas treatment in the near future—one to com-
ply with regulatory requirements and the other because of public perception.
15
Such
treatment can add significant capital costs and operation and maintenance costs.
For a known airflow rate, the mass balance on the emissions rate of a compound
(in pounds per hour) is calculated based on the following formula:
emissions rate (lb / hr)
(
C
C
)
Q
K
in
out
L
where
C
in
influent concentration of the compound,
g/L
C
out
effluent concentration of the compound,
g/L
