An Overview of Ammonium Chloride (NH4Cl) Corrosion in the Refining Unit

Abstract

Ammonium chloride is a destructive agent of localized corrosion which poses devastating threat to refining structure integrity and the safety of the refinery processes. Ammonium chloride is an underdeposit corrosion commonly found in overhead equipment and piping for crude and hydroprocessing units. This form of insidious form of corrosion had caused severe fouling that posed negative impact on the operating reliability of various processing units. This review addresses the corrosion mechanism of ammonium chloride, affected materials and equipment, Environmental factors for its impact, thermodynamic behavior of a wet ammonium chloride system, some case studies of ammonium chloride and the preventive measures to mitigate its effect.