It depends on many factors below;
1. Velocity
2. Amount and type of liquid HC
3. Temperature
4. NH3 & H2S (and HCl) partial pressure
5. NH4HS concentration
6. Wash water treatment/ Water quality
7. Dew point control
8. pH
9. Materials
10. Others
Normally the recommended materials may be upgraded according to the severity.
CS < (316 SS) < 2205 DSS < Alloy 825 < Alloy 625 < Titanium or Alloy C276
Please find the following references.
1. API RP 932-B, Design, Materials, Fabrication, Operation, and Inspection Guidelines for Corrosion Control in Hydroprocessing Reactor Effluent Air Cooler (REAC) Systems, 2004
2. API Technical Publication 938-C, Use of DSS in the Oil Refinery Industry, 2005
3. API RP 571 Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, 2003
4. R.L. Piehl, Survey: Air Cooler Corrosion, Hydrocarbon Processing, p169-170, July 1975 and
Survey of Corrosion in Hydrocracker Effluent Air Coolers, Materials Performance, Vol 15 (1), January 1976, pp 15-20
5. E.F. Ehmke, Air Cooler Corrosion, Hydrocarbon Processing, p172-175, July 1975
6. B.N. Greene, Materials of Construction, p149-151, Chemical Engineering, Oct.1998
7. C.A. Shargay, et al., Corrosion in Hydroprocessing Units, NACE, 1996
8. A. Shingh, et al., Corrosion of Reactor Effluent Air Coolers, Corrosion Paper #97490, NACE, 1997
9. J. Turner, Design of Hydroprocessing Effluent Water Wash Systems, Corrosion Paper #98593, NACE, 1998
10. C.A. Shargay, et al., Ammonium Salt Corrosion in Hydrotreating Unit Stripper Column Overhead System, Corrosion Paper #99392, NACE, 1999
11. C.A. Shargay, et al., Design Considerations to Minimize Ammonium Chloride Corrosion in Hydrotreater Reactors, Corrosion Paper #01543, NACE, 2001
12. N. Sakai, et al., Hydrogen Absorption in Wet NH4HS Environment, Corrosion Paper #00681, NACE, 2000
13. H. Iwawaki, et al., Hydrogen Absorption in Non-Acidic H2S Environment, Corrosion Paper #96602, NACE, 1996
14. G.W. Wilks, et al., Unusual Aspects of Corrosion Failures in Refinery Hydrotreater Units, Corrosion Paper #00702, NACE, 2000
15. C.A. Shargay, et al., Cost Comparison of Materials Options for Hydroprocessing Effluent Equipment and Piping, Corrosion Paper #96600, NACE, 1996
16. P.R. Petersen, et al., Impact of Ammonia Chloride Salt Deposition of Refinery Operations., Corrosion Paper #01540, NACE, 2001
17. B.E. Hopkinson, et al., Material Upgrading History of An HDS Complex, Corrosion Paper #96599, NACE, 1996
18. J. Gutzeit, Effect of Organic Chloride Contamination of crude Oil on Refinery Corrosion, Corrosion Paper #00694, NACE, 2000
19. A. Bagdasarian, Crude Unit Corrosion and Corrosion Control, Corrosion Paper #96615, NACE, 1996
20. API STD 661, 2001
21. Materials Considerations/ Concerns and Corrosion Control, American Company Manual, 1998
22. Corrosion/2003 Minutes, NACE Task 205X, 2003
23. A.J. Bagdasarian, et al., Chloride SCC of ASS in Hydroprocessing Units, Corrosion Paper #97501, NACE, 1997
24. James Turrner, Design of Hydroprocessing Effluent Water Wash Systems, Corrosion Paper #98593, NACE, 1998
25. R.R. Williamson, Chloride Corrosion and Fouling in Naphtha Hydrotreating Units, UOP, AlChE Spring National Meeting, Orlando, Florida, Mar. 18-20, 1990
26. D.G. Damin and J. D. McCoy, Prevention of Corrosion in Hydrodesulfurizer Air Coolers and Condensers, Materials Performance, Vol 17 (12), December 1978, pp 23-26 (see also Corrosion Paper # 78131, NACE, 1978).
27. B.V. Johnson, H.J. Choi, and A.S. Green, Effects of Liquid Wall Shear Stress on CO2 Corrosion of X-52 C-Steel in Simulated Oilfield Production Environments", Corrosion Paper #91573, NACE, 1991
28. C. Scherrer, M. Durrieu, and G. Jarno, "Distillate and Resid Hydroprocessing: Coping with High Concentrations of Ammonium Bisulfide in the Process Water", Materials Performance, Vol 19 (11), November 1980, pp 25-31 (see also Corrosion Paper # 79027, NACE, 1979).
29.
Thomas Eun