Materials for Crude Tower Top Section

[Xeros]

Hi,
I'm Xeros,

Crude has MgCl & CaCl and potential HCl is high.
So, i'm to apply "Monel claddig" for Crude Tower Top Section.

Howevere, Someone said to me that Monel is not suitable if ammonia is injected to pH control at Crude Tower overhead. The reason is that the stress corrosion cracking could be occur to Monel by injected Ammonia in abnormal operation.

is this right?

Generally, i have known that ammonia stress corrosion cracking could be occured to copper alloy. Monel is Nickel based alloy but has lots of copper (about 30%).

Could incoloy 825 be applied if above matter is true?

I think that incoloy 825 has a good resistance for hydrochloric acid and no problem for ammonia stress corrosion cracking.

Regards,

 

[0707]

Ammonia is prone to copper content of Monel.
As would be expected from its high copper content, ammonia environments rapidly attack Monel. Corrosion does occur at the boundary where the crystals of nickel and copper join. Corrosion in Monel is seen by a blue colour in its surface by Cupric Nitrate (Copper Nitrate) Cu(NO3)2·nH2O.


luis

 

[25362]

In order to keep using carbon steel, is two-stage desalting possible ? What about a minimum injection of NaOH solution downstream ?