Stefaan Gouhie - Ametek CSI
Throughout the world, field-erected storage tanks are commonly used for the temporary storage of large volumes of molten sulphur. Unfortunately, tank life can be significantly limited by corrosion, especially in the vapor space above the normal liquid level. Several corrosion mechanisms are possible and will be reviewed. Most likely, corrosion results from the deposition of solid sulphur and formation of trace quantities of liquid water at cool metal surfaces. This combination leads to the formation of iron sulphide which, in addition to resulting in tank damage, is pyrophoric. If iron sulphide is suddenly exposed to oxygen, it can also ignite a sulphur fire within the storage tank. The best way to mitigate corrosion is to prevent the formation of solid sulphur on the tank wall/roof. Conventional heating technologies, such as internal coils, are effective in keeping the sulphur in molten state but do not maintain a sufficiently high tank wall temperature in the vapor space. By employing a distributed external heating system, the tank wall and roof temperatures as well as vapor space temperatures can be maintained at temperatures above the sulphur freezing point, thereby eliminating the primary corrosion mechanism. This paper will review potential corrosion mechanisms and operational data which illustrate the importance of engineered heating systems.
Stefaan Gouhie is on a mission to help refiners solve heat related plugging and corrosion issues in the DCU and SRU. As a mechanical engineer, he joined CSI Ametek as Business Development Director to give dedicated support to the European refiners and chemical plants. After 4 years in the Sulphur industry with numerous site visits and hands-on installations, he has developed an expertise in good heating practices. Prior to joining CSI, Stefaan was part of the delayed coking family while working for a pressure vessel manufacturer.