×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Chlorinated Water from Chlorination Unit content White deposite.

Chlorinated Water from Chlorination Unit content White deposite.

Chlorinated Water from Chlorination Unit content White deposite.

(OP)
Hi,

Please anyone has any information about this problem:
In an offshore oilfield we are using sea water to feed Chlorination Unit to Produce Sodium Hypochlorit to inject to suction of Sea Water Intake Pumps (SWIP).

We have found a white deposite in the produced Hypochlorit that is highly soluable in diluted HCL solution, and I believe it is CACO3. The concentration of Cl2 is OK but we have to make Acid Wash with an Inhibited Solution of 3-5% HCL very often.


Anyone has been facing this problem before?
Why do we have this deposite? What is This deposite?
And how can we prevent the formation of this deposite?!

Many thanks for your help!

Mehran

RE: Chlorinated Water from Chlorination Unit content White deposite.

I suspect your using electrolysis to create the sodium hyperchlorate - if so, then the fracturing of calcium carbonate and other calcium containing chemical compositions in the water will create precipitates of calcium - normally on the electrode surface, but also free in the water.

You need to filter the water following electrolysis to remove the precipitate - and probably need to clean the electrode failry often to prevent large build up on the plates, which then falls off from agitation of the water within the cell.

This can be difficult to filter, as the acidity of the solution makes the calcium soluble - then when you dilute, the precipitate forms due to change in the pH. So the solution will probably be to create the dilution and filter it as opposed to the direct sodium hyperchlorit solution.

RE: Chlorinated Water from Chlorination Unit content White deposite.

(OP)
Hi Muggle,

Many thanks for your reply.
It is exactly correct, we are using electrolysis.

Do you have any idea how can we prevent fracturing of Calcium Carbonate and other calcium containing chemical composition?

This is abnormal, because I have been in another oilfield that was using the same process to produce Sodium Hypochlorite by electrolysis, but I never faced with such a problem there!

Thank you very much for your help.


Mehran

RE: Chlorinated Water from Chlorination Unit content White deposite.

The fracturing depends on several factors - but primarily - it's the amount of applied current. If your running too high a current - then you need to reduce it to stop the fracturing of the carbonates - sodium hyperchlorit does not take more then about 20amps to get a good production - if running higher - this may be main problem.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources