Sulphur Species Corrosivity in Refinery Feed Stock

Abstract:

High temperature sulphide corrosion and equipment failures have been reported in several crude and condensate processing facilities of petroleum refineries. Affected materials were carbon and low alloy steels operated in temperatures ranging from 200 to 300°C.These failures were attributed to specific sulphur species and were not anticipated by corrosion prediction tools used for their material selection. The corrosion mechanisms of these species are not fully understood. This paper presents Takreer Research Centre (TRC) research work for isolating the active sulphur species responsible for the corrosion. Two condensate samples were first analysed for total sulphur, hydrogen sulphide (H₂S), Mercaptans (RSH) and other impurities. Using Gas Chromatograph with Sulphur Chemilumenesence Detector (SCD), it was possible to identify Mercaptans and sulphides from the process samples. Laboratory corrosivity testing of condensate sample using carbon steel and low alloy steel coupons at 275°C indicated that the corrosion rate was mainly related to the Mercaptans species within the Total Sulphur. The results concluded that specific dissociation temperature of respective Mercaptans is a useful tool in predicting the possibility and extent of corrosion and its vulnerable process loop.

• Periodical: Solid State Phenomena (Volume 227)
• Pages: 213-216
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.227.213
• Online since: January 2015
• Authors: Mabruk I. Suleiman*
• Keywords: Condensate, Corrosivity Indexing, Mercaptans, Sulphidation, Sulphur Speciation

References

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[2] A.S. Couper, High Temperature Mercaptan Corrosion of Steels', Corros., 19 (1963) 396-401.

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[5] NACE publication 34103. Overview of sulphidic corrosion in petroleum refining. 2004: 7-9.