3 replies to this topic

[Zauberberg]

Due to the nature of NH3 and H2S components, pH value of the effluent water from Sour Water Stripper is often higher than 10 (compared to pH=8 of sour water feed). Although SWS is working efficiently, high pH value (from residual NH3) causes unacceptable conditions in the wastewater treatment plant.

So, the question is: how to reduce the pH of effluent stream and have a complete stripping of H2S (which is the case now), at the same time?

I have an idea of SWS effluent acidification, but I do not know if this is applied somewhere in industrial practice. In such case, pH controller should take the information from SWS feed control valve (flow) and effluent pH (pH analyzer) and automatically adjust the amount of acidic neutralizer that is going to be injected downstream of the feed/effluent heat exchangers. Target pH should be maintained between 7 and 8.

- What type of acid should be used for such purpose?
- Does anyone of forum members have similar experiences, and how did you battle against these kind of problems?

Regards,

[indy]

There are a method for removing hydrogen sulfide from a gaseous stream by contacting the gaseous stream with a polyvalent metal chelate present in an aqueous alkaline scrubbing solution including the regeneration of the polyvalent metal chelate in an electrolytic cell and automatic control of the pH of said aqueous alkaline scrubbing solution at about 7 to 9.

go to


http://www.freepaten...om/4643886.html

regards


luismarques

[TPR]

Due to the nature of NH3 and H2S components, pH value of the effluent water from Sour Water Stripper is often higher than 10 (compared to pH=8 of sour water feed). Although SWS is working efficiently, high pH value (from residual NH3) causes unacceptable conditions in the wastewater treatment plant.

So, the question is: how to reduce the pH of effluent stream and have a complete stripping of H2S (which is the case now), at the same time?

I have an idea of SWS effluent acidification, but I do not know if this is applied somewhere in industrial practice. In such case, pH controller should take the information from SWS feed control valve (flow) and effluent pH (pH analyzer) and automatically adjust the amount of acidic neutralizer that is going to be injected downstream of the feed/effluent heat exchangers. Target pH should be maintained between 7 and 8.

- What type of acid should be used for such purpose?
- Does anyone of forum members have similar experiences, and how did you battle against these kind of problems?

Regards,

Hello Zauberberg,
Not sure if you have solved this one yet? See it was posted some time ago.
If so what did you do?
Else:
Our H2S stripper which produces sour water has the same problem.
We have use 50% dilute H2O2 as H2S neutraliser and it seems to have kept the pH below 8.
We add roughly 0.5% to 1% depending on the result which we test downstream of injection.
We have had some occasions of pH drift requiring adjusting and we used acetic acid to great effect and it is cheap and not that hazardous.
Probably no need to warn you on the use of N2O2.
DO NOT LOCK IT IN A PIPELINE!
The effluent water run down line should be locked open ended to avoid any exothermic expansions being enclosed.

On the topic of ammonia bisulphide, would you have experience with this in reactor effluent systems?
If so, please let me know since I have an issue I would like to bounce off some knowledgable people.
Thanks
Antony

[mufti]

does anyone knows about sour water stripper?

Thank You very much...

best regards

MUFTI CAHYANTO