Hau, Jorge L.
Shell Projects and Technology, Shell Global Solutions (U.S.), Inc., Houston, TX
Pages: 18 Published: Jan 2013
Metallic materials used to manufacture equipment for the petroleum refining industry are subjected to a wide variety of potential damage mechanisms, the most common being corrosion and environmental stress corrosion cracking. Safe operation of oil refineries depends on understanding these degradation mechanisms, making the proper material selection, devising corrosion control, inspection programs for earlier detection of problems, and monitoring material performance. This chapter divides corrosion into wet and dry, as applicable to particular refining processes. Wet corrosion occurs in the presence of electrolytes. Stress corrosion cracking mechanisms are associated with wet corrosion processes and the most common ones, affecting metals and alloys used in oil refineries, are described. Dry corrosion affects large areas of refineries; it does not require the presence of water. Dry corrosion also includes oxidation, carburization, and metal dusting, but the most relevant for oil refining is attributed to the presence of sulfur, naphthenic acids, or both. Although they are rather old recognized corrosion mechanisms, the phenomena have not yet been fully comprehended, in particular the complex interaction between these two corrosion processes and the influence of the many factors that seem to play an important role. Some discussion is offered in this respect, based on own research results and experience gained by having been involved in many analyses of failures in oil refineries. Damage mechanisms other than corrosion are also described in their connection with particular refining processes.
Corrosion in oil refining, crude unit overhead corrosion, wet H, 2, S corrosion and cracking, ammonium bisulfide, stress corrosion cracking, sulfidic corrosion, naphthenic acids, high-temperature hydrogen attack, material degradation mechanisms
Paper ID: MNL5820131212917