Desalter Effluent Water Low pH

[DeeZee]

We are facing Desalter Effluent Water Low pH which is corroding the downstream valves and piping. Currently we have no caustic injection facility at CDU and we are controlling the pH by increasing the Stripped water pH. Now we are working on the caustic injection at CDU. We want to know that which location for the injection of caustic is best for controlling Effluent Water pH either before crude pump or after pre-heating train and before desalter. If any more best location u think-please advice us.

 

[whylie]

Hi DeeZee,

A good injection point could be upsream of the Effluent Water/Inlet Water heat exchanger,and work to maintain a PH(6-8.5),your PH meter,and sampling point can be after the cooler.

Regards,

 

[July]

We used to operate with 2 caustic injection points - 1 at the crude pump suction and the other in the preheat train before the desalter and didn't face problems.

 

[Falcon03]

Our caustic injection is located downstream of CRUDE desalters (booster pupms suction) and we never faced any problems.

 

[ponderer]

What kind of crude your CDU process?

I estimate it is some kind of sour
crude.

We never encounter low PH in our CDU.