Sulfuric acid reaction causing foam?

[SimonWilhelm]

We are operating an ammonia scrubber using sulfuric acid, that cleans the air from pig stables and we periodically experience an unwanted foam production. The foam is white and quite "firm". The water is sprayed out using nozzles, at high pressure.

Has anyone experienced a similar problem in scrubbers using sulfuric acid?

Does anyone have a clue of what could be causing the foam production?

Is an anti foaming agent the best solution?

/Simon

 

[60degrees]

No experience in pig stable ventilation.
Might be that on some point the concentration of you sulfuric acid is so low that fungi or bacteria are let loose on your scrubber. The ammonium sulfate, which is formed in your scrubber is also part of nutrition salts for yeasts. Additional, you can´t tell what organic compounds are also solved into your scrubber. All that could be food for microbes.
Have you experienced the formation of biofilms or black floating things?

What´s the excact concentration of the sulphuric acid?

Kind regards,

Neal

 

[Chance17]

I am aware of seasonal variations in carbonate content of RAW used for scrubbing. Carbonates + H2SO4 = Foam
Possible?????

 

[ash9144]

Can you describe your scrubber? Packed bed, trayed, open spray chamber, etc?

 

[SimonWilhelm]

The system is kept at pH = 2 at all time resulting in an ~0,01 M solution

The biofilm formation is very low, andwe generally don't experience clogging.

Although we replace the water priodically we always have a thick ammonium sulfate sludge in the bottom of the scrubber. At one point foam seemed to be created when fresh water was added, furthermore the problem was worse when the system was just started up. Could the ammount of ammonium sulfate created over time prevent the foam from being created?

it's a spraytower design. We do not want packing material as it tends to clog up because of the dust from the stables.

The nozzles are fullcone and spray upwards

Temperature varries a lot from winter to summmer, as it is placed outside.

 

[globalrenewables]

hi.

i work for Global renewables and we also use ammonia scrubbers. these scrubbers foam very badly on an hourly basis and take alot of time to drain and re-fill. is there a solution to this or anything i can try to stop it foaming.

we use sulfuric acid 98%, and rain water. the ph is usually about 4.5, and temperature about 20 to 30'c. i think its an open spray chamber scrubber.

ive noticed if the ph level drops to 3 this causes more foaming action, and i am investigating if too much acid is being introduced in one go. but foaming has been known when the ph gets to 7.5 also. so im a little stuck!

any help would be appreciated. dave.