Water treatment 1

[oilgasandwater]

Hey Folks,

How are you all doing ? I'm looking at a water purification procedure for the water coming out of wellheads.

Teh idea is to pass them through a process, bring down the total ppm of dissolved solids.

I have a pilot set up, with some foam packings put into chambers. I trickled down water from above and pupmped air with a normal centrifugal pump from the bottom. The air scrubs through the impure water and this air goes up and condenses into the adjacent chamber. The pm seems to be comign down considerably.

Now, im looking at putting up a commercial level equipment. Any process dieas how I oculd improve this process system ? In terms of material to be used to construct the new set up ? (SS , or plastic material),, and any other processes similar to the one I mentioned >> Any ideas ?? Thanks for reading

 

[quark]

Scrubbing removes suspended solids (and also separates oil from water in your case) and not dissolved solids. Scrubber manufacturers can help you in this regard. Google on Pall and raschig rings. You can get them in wide variety of MOC.

 

[oilgasandwater]

Oh, thankyou Quark.

That was nice information.

 

[25362]

In addition, when speaking of suspended solids, desanders of wellhead water based on small hydrocyclones have been in use. Google around for desanders.

 

[Okui]

yeah it has been used. but there was one installation in one of the platform in my company that actually failed after a few months...

 

[unclesyd]

You might want to look at the technology from Newalta, courtesy of unotec, if you want an off the shelf process.

http://www.newalta.com/default.asp?FolderID=2219

 

[Unotec]

Thanks unclesyd, I was about to ask "What's wrong with centrifuging?" I've been able to flock and remove particles down to five microns in the past. Centrifuging has a few tricks, but to remove solids and separate water and oil, comes in handy and inexpensive.

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[Zapster]

What's wrong with centrifuging?
If there are emulsions (especially colloidal emulsions), you will find that centrifugation does not work as advertised by many centrifuge manufacturers.

 

[Unotec]

I agree Zapster, but if you have a coloidal emulsion, treat it before hand and then coagulate and flock it you can actually remove most of the particles.
It would be wise to put a filter afterwards if more polishing is required.

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[Zapster]

If you first break the emulsion, you can remove solids down to the sub micron size with centrifugation. Without breaking the emulsions, you are limited in what you can do; perhaps that is where unotec was limited to 5 microns. The original post did not specifically state that there were problems with emulsions; however, if a standard separator based on stokes law will not work with produced water, there may be an emulsion issue.

See

http://en.wikipedia.org/wiki/API_oil-water_separator

for a description standard industry separators.

 

[Unotec]

Let me add a little to your post Zapster.
You are right that once the emulsion is broken you can remove down to sub micron with simple centrifugation. However, more often than not, a chemical treatment will be required (coag+floc).
The reason for this is that the apparent weight of coloidal particles is very often lower than the weight of the water carrying them.
Oh, and for the record, I could not go below 5 microns due to the limited centrifuging capacity. The emulsion had been broken and coag+floc used, but the throughput required was too much for the unit and I could not get a second one.

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[oilgasandwater]

Thankyou all for the great discussion and inputs !

 

[Unotec]

Let us know what happened at the end

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[scoho83]

He was asking about dissolved solids, which as pointed out earlier, centrifuges will have no impact. He is adding air to the system, which is oxidizing the TSS to form percipitates. I think he is wondering about about the contactor design. The packing issues suggestions are great, but I think we missed his other question about Mater'ls of construction. FRP has been used for "Air Stripper" in water treatment, so I would assume, if temps allow it, it could be used here as well.