The neutralization of acids in the crude unit overhead condensing system using ammonia or organic amine neutralizers is standard practice. These neutralizers can be misapplied or recycled with water streams routed to the crude unit desalters. As a result, corrosive chloride salts can form, causing severe fouling and corrosion of tower trays, overhead vapor lines, and condensers. Several techniques have proven effective in
mitigating these problems. They include crude oil desalting, caustic injection for overhead chloride control, water washing, filming amines and more recently, adding low base strength neutralizers to control corrosive salt formation. The proper chemistry, effective monitoring tools, and rapid response to upsets are needed for salt fouling and corrosion control. A detailed case history is presented highlighting application of these techniques. Elimination of lost production and increased
condenser life has resulted in reduced operating costs.
Keywords: crude distillation unit, filming inhibitor, amine neutralizer, ammonium chloride, amine-hydrochloride salts, salt fouling, crude oil desalting