5 replies to this topic

[Abm]

Im Working In a Double Stage Sour Water Stripping Unit. Stage 01 column Removes NH3 At 7kg/cm2 Pressure and stage 02 column Removes H2S at 1kg/cm2 pressure.
Why This Pressure Difference?
What Chemistry is Behind this?
Kindly Clarify.

[Bobby Strain]

Here is your answer.

 

http://www.eptq.com/...9d-e0e5c70ebcd5

 

Bobby

[Abm]

Thank You for the response but it doesnt explain why there is a operating pressure difference in columns..

[Sharma Varun]

Im Working In a Double Stage Sour Water Stripping Unit. Stage 01 column Removes NH3 At 7kg/cm2 Pressure and stage 02 column Removes H2S at 1kg/cm2 pressure.
Why This Pressure Difference?
What Chemistry is Behind this?
Kindly Clarify.

Usually its opposite of what u r saying, stage-1 is operating at higher pressures & strips H2S, Stage-2 operates at lower pressure & strips H2S.

[Abm]

Sorry For The Error.
Stage 01 Removes H2S at 7 Kg/cm2 Pressure and Stage 02 Removes NH3 At 1.1Kg/cm2 Pressure.
My Question Is On What Basis This Pressure Difference is maintained Between the stripping Column

[gegio1960]

I don't exactly understand the reason of your question, anyway...

the final scope of this kind of plants is the separate stripping of the 2 components

H2S is stripped easier than NH3 and this fact determines the order of stripping: H2S is stripped at higher pressure and 7 barg is the optimum pressure level.

to obtain very low H2S and NH3 content in the final stripped water, you shall operate the 2nd stage at the lowest pressure achievable (usually around 0.8-1 barg, imposed by the operating pressure of the downstream plant for the Sour Gases, normally a Claus).

with these simple concepts and a visit to an existing plant with this configuration, I've designed 3 of these plants during my process engineer life.

good luck!