High CO2 H2S TEG Dehydration MOC

[SJones]

Colleagues,

We plan to dehydrate the regenerated gas from an amine unit. The gas will be substantially CO2 and H2S. Typical materials of construction for TEG dehydration units are 316L/316L clad. If anyone is operating high acid gas dehydration units - have you found 316L to be an acceptable material selection, or have you upgraded the material in design or had to upgrade because of corrosion problems in operation? Any experiences would be valuable information. Many thanks.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[grampi1]

If the TEG unit operates properly, CS would be fine in the abosrber and piping, since the TEG absorbs the water and prevents water wetting. Water wetting will occur in the upper part of the still. Here 316L or 304L is the standard upgrade and will be needed with high levels of acid gas.

 

[shoffman83]

I agree with Grampi that CS would be fine if things operate correctly. (realize that I am not addressing the upstream scrubber in this statement that normally proceeds a TEG contactor).

However, in a high C02 Environ (98%, 3% H2S), I have seen two contactors made from 304L SS operating with no significant losses or others signs of corrosion (pitting, etc) operating for 20+ years.

Scott Hoffman
Mustang Engineering

 

[dcasto]

Use the 304 SS, we replaced our TEG regenerators every year with CS.