Bilingual Tech Mapping for Pulp Paper Guideline - Asosiasi Pulp ...

C. SOx Gas Control
SOx gases can be controlled by using Flue Gas
Desulphurization (FGD) wet method or dry method (Table
5.6). FGD wet type is more widely used, use absorbent
(absorbent) slurry solution containing compounds such as
Na, Ca, or Mg. Lime CaCO3 most widely used because it is
relatively inexpensive price, and produce CaSO4 (gypsum).
Absorption with alkali was developed to eliminate major
problems associated with lime, namely precipitation and
blockage of the scrubbing tower. Dual alkali using two
reagents and the two processes are repeated to remove
SO2 Na2SO3 or NaOH solution to neutralize role of SO2 in
absorber column. Because Na2SO3 and Na2SO4 is soluble
in water, no precipitation occurred in the scrubber. With this
system cause water pollution problems, besides the alkali
NaOH is much more expensive than lime. There are four
sub-processes in this system, namely:
• Preliminary processing of the gas flow pre-scrubber
• absorption of SO2 by Na2SO3 solution
• cleaning Na2SO4
• regeneration through the addition of Na2CO3 Na2SO3
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