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Which type of corrosion is most likely to occur in hydroprocess reactor effluent streams in units producing alkaline sour water?
Suggested Answer: B
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From API RP 571 and RP 932-B:
''In hydroprocessing reactor effluent systems, the most common corrosion mechanism is ammonium bisulfide (NHHS) corrosion, which forms in the presence of hydrogen sulfide and ammonia.''
''NHHS attacks carbon steel aggressively under turbulent flow and at low pH.''
Correct answer is B -- ammonium bisulfide corrosion.
12 comments · newest first
LY
Lyda
27 days ago
A) Amine could be a contender too, but I feel B) is more likely.
PE
Peggy
1 month ago
I’m leaning towards C) Caustic. It’s highly corrosive in those conditions.
EU
Eugene
1 month ago
I think B) Ammonium bisulfide is the right choice. It’s common in sour water.
MA
Madonna
1 month ago
Surprised to see ammonium bisulfide as a top contender!
AB
Abel
2 months ago
Wait, I thought caustic was the main issue?
JA
Janey
2 months ago
I’m not so sure about that, could be A) Amine too.
SH
Sharan
2 months ago
Definitely agree with that!
TH
Theodora
2 months ago
I think it's B) Ammonium bisulfide.
TA
Tamesha
2 months ago
Amine corrosion seems less likely here, but I’m not confident about the others. I wish I had reviewed more before the exam!
FL
Florinda
2 months ago
I feel like caustic corrosion was mentioned in a similar practice question, but I can't recall the specifics.
IL
Ilda
3 months ago
I think ammonium bisulfide could be a strong candidate since we discussed it in relation to sour water treatment in class.
LA
Laurel
3 months ago
I remember studying about corrosion types, but I’m not entirely sure which one is most common in alkaline sour water.