+1 vote

Iron Scale problem in MEG regeneration system

asked Mar 26, 2014 in Process by RichS29 (4,320 points)
In MEG regeneration section of the plant has deposition of iron scales. Could some one help identify the issues?
commented Mar 26, 2014 by odadmin (21,030 points)
I am assuming your MEG systems is used for natural gas dehydration. Does it contain carbon dioxide and hydrogen sulfide and how much? What is your operating temperatures, solution pH, equipment metallurgy looks like?
commented Mar 26, 2014 by RichS29 (4,320 points)
Produced gas has CO2 and ppm leves of H2S.

1 Answer

+1 vote
answered Mar 26, 2014 by odadmin (21,030 points)

Generally, scale deposition can takes place due to dissolved iron from corrosion. This will reduce heat exchangers performance, plug valves, etc. Scale type will vary with type of contaminants present in the Gas.

CO2 - CO2 dominated corrosion will have iron carbonate scales. These scales typically deposit on hot surfaces (heat exchangers) and on packing in contactor towers.

H2S - If H2S if present with CO2, iron sulfide films deposit instead of iron carbonate. Similar scaling issues are found.

Follwing are the typical Mitigation Methods:

  • pH modification
  • Internal coating
  • Corrosion resistant alloys
  • Corrosion Iinhibition