Desalting of Crude Oils

Crude Oil Desalting Services

Intertek provides desalting services using a two-stage electrical (AC) desalter that can be operated in co-current or counter-current mode. It can also be operated as a single-stage desalter or two parallel single-stage desalters.

Salts in crude oil feedstocks can cause severe problems, including corrosion by acids formed by chloride salt decomposition in fractionator overhead equipment, fouling of heat exchangers by salt deposition, and poisoning of catalysts in down-stream units. The salt in the crude oil is picked up either in the reservoirs or during transportation. The crude oil can also contain suspended solids, such as sand, clay, and iron oxide particles. Typically the crude oil is desalted before being charged to the distillation train.

The Desalter operates at the following design conditions:

• Operating pressure - 100-140 psig
• Charge rate - 14 gph
• Process water rate - 5 to 15 vol% of feed
• Dmulsifier chmical rate - 1-2 quarts/M barrels
• Mixing valve pressure drop - 5 to 20 psi

By varying the process water injection rate, the transformer voltage (max 6.5 kV), the demulsifying rate, and the operating temperature then optimum conditions can be determined for any type of crude.