Desalter
Desalting
All crude oil contains salt, predominantly chlorides. Chloride salts can combine with water to form hydrochloric acid in atmospheric distillation unit overhead systems causing significant equipment damage and processing upsets. Chlorides and other salts will also deposit on heat exchanger surfaces reducing energy efficiency and increasing equipment repairs and cleaning.
Salt must be removed from crude oil prior to processing. Crude oil is pumped from storage tanks and preheated by exchanging heat with atmospheric distillation product streams to approximately 250˚F (120˚C). Inorganic salts are removed by emulsifying crude oil with water and separating them in a desalter. Salts are dissolved in water and brine is removed using an electrostatic field and sent to the waste water treatment.
