Miscellaneous Refinery Corrosion Problems

Many miscellaneous corrosion problems in refinery and petrochemical plants involve metal contact with strong acids, such as sulfuric used in alkylation and acid washing, hydrofluoric in alkylation, nitric from ammonia oxidation, and so on. 

Corrosion prevention by chemicals is not ordinarily practical in refinery work for acids that are either concentrated or strong. However, dilute acid streams often may be rendered non-corrosive by use of inexpensive neutralizers and/or filming inhibitors. Examples include the mixed condensate composed of water and hydrocarbon liquids from dehydrogenation of ethyl benzene to styrene in the presence of steam, various acidic wash streams, etc. 

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