Corrosion Reasons of Overhead Circulation System of Atmospheric Tower for Processing Crude Oil with High Acid Value

Aiming at a phenomenon that the corrosion of the overhead circulation of atmospheric tower for processing crude oil with high acid value in some petrochemical corporation was aggravated, the corrosion media in top cycle oil and overhead condensed water of atmospheric tower were analyzed. At the same time, the corrosion products in heat exchanger and filter of the overhead circulation of atmospheric tower were analyzed by XRD and EDS. The experimental results indicate that hydrogen chloride and hydrogen sulfide were the main causes of corrosion. The decomposition of naphthenic acid into carbon dioxide at high temperature, the mild acidity of the top cycle oil in atmospheric tower and the existence of small molecular carboxylic acid were the important causes of corrosion.