ABSTRACT
Crude oil desalting is the first separation unit encountered by crude oil as it enters a petroleum refinery. One of the most important reasons for desalting the crude oil it to remove chloride salts that could lead to corrosion during downstream processing. Another important reason for desalting the crude oil is to limit formation of solid deposits in downstream units. Desalting is carried out by mixing the crude oil with 3–10 vol% water at temperatures from 90–150 °C. There is crude oil desalter technology that uses both AC and DC fields to provide high dewatering efficiency at lower temperatures than possible with single-field technology. Heavy naphthenic crudes form more stable emulsions than most other crude oils, and desalters usually operate at lower efficiencies when handling them. In extreme cases, crude oil desalting technology cannot achieve water and solids separation to below 0.5 wt%, and different technology must be considered to reduce the water and solids content in the oil.
