Corrosion and its control in petroleum refineries - a review

Corrosion has always been one of the major problems in oil refineries. Although crude oils consist predominantly of non-corrosive hydrocarbons, they contain varying amounts of potentially-corrosive impurities. In addition, refinery processes use chemicals known to be corrosive. In this article, corrosion problems in a refinery environment are discussed under two categories: low-temperature corrosion and high-temperature corrosion. The causes of low-temperature corrosion in a refinery are the presence of hydrochloric acid, hydrogen sulphide, oxygen, oxides of sulphur, amines, or cyanides. High-temperature corrosion in refineries is caused by sulphur compounds, naphthenic acids, or hydrogen gas. The control measures for these corrosion problems are discussed in the light of recent literatures. Corrosion monitoring of refinery equipment and optimizing control measures are discussed separately. (Author)