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Technology of
Single Stage process for removing H2S from gas streams and converting it to
innocuous elemental sulfur on liquid Redox (Reduction-Oxidation) reaction
H2S
is a toxic, corrosive & odorous compound
HYDROGEN SULFIDE …
• When
dissolved in water, forms an acidic solution, which can be very corrosive to
pipelines and equipment.
•
When
burned, forms sulfur dioxide (SO2) which is a precursor to acid rain. SO2 is
itself the subject of regulatory concern.
• Is
strong poison for most of industrial catalysis and deadly poison
Direct Removing H2S from Gas Streams
There are 3 main methods of removing H2S:
•
Liquid & Solid H2S Scavengers such as Triazines & Iron sponge
•
Liquid Redox processes employ aqueous-based solutions containing metal ions,
usually iron,which are capable of transferring electrons in reduction-dation (redox)
reactions
•
Cluse systems
SULFIRAN
Is a Liquid
Redox Process
SULFIRAN process …
•
Is a
Special Technology Developed by RIPI(Research Institute of Petroleum
Industry)
•
Has a
99+% H2S Removal Efficiency
•
Using
Iron Chelate Catalyst Licensed by RIPI
•
Is High
Flexible and Can be Used on a Wide Variety of H2S Containing Gases
•
Has a
Catalyst which Continuously Regenerated in an Oxidizer
•
In the absorber, H2S is absorbed into the slightly alkaline, aqueous
RIPI Catalyst:
H2S(g) + H2O(liq) H2S
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•
Then the H2S ionizes to bisulfide(HS- ):
H2S(liq) <==> HS- +
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•
which finally bisulfide is oxidized to sulfur by reducing the iron
ion from the ferric( Fe+++ ) to the ferrous( Fe++
) state
HS- + 2 Fe+++ <==> S°(soild)+
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Overall Reactions
The overall
reaction is an isothermal reaction:
To maintain the above reactions
some chemical additions required:
•
Caustic for maintaining the pH
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Replacement of chelated iron lost in the sulfur removal process
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Replacement of degraded chelating agents
Comparison Table
SULFIRAN Semi Commercial Unit at FAJR-E-JAM Gas Refinery
Based on
the results obtained in the laboratory & pilot plant, RIPI has been designed
and constructing a semi commercial unit at Fajr-E-Jam gas refinery with
following
specifications:
•
Capacity: 450,000 SCFD
•
Feed : A portion of Amine tail gas containing Max 2%
wt H2S
•
Catalyst: Iron Chelate 2000 PPM Licenced by RIPI
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H2S in outlet gas: Nil
Summary
• The
SULFIRAN technology is applicable to all types of gas streams including :
Air, sour gas, CO2, amine acid gas, biogas, landfill gas, refinery, fuel
gas, etc.
•
In cases of sulfur recovery from .2 up to 20 TPD ,SULFIRAN
is the Best
Choice in economical &technical view of point
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The liquid catalyst adapts easily to variations in flow and concentration.
Flexible operation allows 100% turndown in gas flow and H2S
concentrations.
So Units require minimal operator attention
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