What is desalting of crude oil?

Desalting is the first refining process applied to crude oil. The process removes salt, water and solid particles that would otherwise lead to operational problems during refining such as corrosion, fouling of equipment, or poisoning of catalysts.

What is dehydration and desalting of crude?

Desalting of Crude oil means the removal of the dissolved salt in the crude oil and increasing the grade of the crude oil. Crude oil dehydration is the process of removing the water present in crude oil to meet the purchaser’s limit.

What is crude oil distillation unit?

The crude oil distillation unit (CDU) is the first processing unit in virtually all petroleum refineries. The CDU distills the incoming crude oil into various fractions of different boiling ranges, each of which are then processed further in the other refinery processing units.

Why dehydration and desalting of crude oil is required?

Clean, dehydrated oil flows from the top of the vessel. Depending on the salt specifications, a combination of dehydrator followed by a desalting unit may be required. The role played by adding chemicals to break crude oil-emulsions is very influential in waste formation.

Why is crude desalting important?

The purpose of crude oil desalting is to remove these undesirable impurities, especially salts and water, from the crude oil prior to distillation. The salt content in the crude oil varies depending on source of the crude oil.

What is the principle of desalting?

Desalting occurs when buffer salts and other small molecules are removed from a sample in exchange for water (with the resin being pre-equilibrated in water). Buffer exchange occurs when the buffer salts in a sample are exchanged for those in another buffer.

Why is desalting of crude necessary?

The purpose of a desalting system is to reduce the salt content of the treated oil to acceptable levels. When the salinity of the produced brine is not too high, merely ensuring that there is a low fraction of water in the oil can reduce salt content.

What is the desalting process explain double stage desalting?

In the two-stage desalting system, as shown in Figure 4, dilution water is added in the second stage and all, or part, of the disposed water in the second stage is recycled and used as the dilution water for the first desalting stage.

What is crude oil used for?

The largest share of crude is used for energy carriers that can be combined into gasoline, jet fuel, diesel, and heating oils. Heavier products are used to make tar, asphalt, paraffin wax, and lubricating oils.

Why is crude oil distillation necessary?

The primary purpose of the crude oil distillation unit is to perform the initial separation of crude oil into intermediate products which undergo further processing in downstream units to improve their qualities according to market standard.

Why is crude oil desalting necessary?

Crude oil introduced to refinery processing contains many undesirable impurities, such as sand, inorganic salts, drilling mud, polymer, corrosion byproduct, etc. The purpose of crude oil desalting is to remove these undesirable impurities, especially salts and water, from the crude oil prior to distillation.

How is desalting of crude done?

Crude oil to be desalted is heated to a temperature of 100-150 °C and mixed with 4-10% fresh water, which dilutes the salt. The mixture is then pumped into a settling tank where the salt water separates from the oil and is drawn off.

What is crude oil desalting?

Crude Oil Desalting Principles of Crude Oil Desalting Desalting is an integral part of refinery crude oil processing and can be the key to controlling pipestill corrosion, heat exchanger fouling, furnace tube coking, and process water disposal.

What is the objective of desalting?

The objective of desalting process is to remove chloride salts and other minerals from the crude oil by water-washing. Depending on the desired salt content in the desalted crude oil, a one- or two-step process could be applied.

How is crude oil processed?

The process starts by mixing the raw crude oil with an appropriate amount of washing water also known as dilution water. The washing water as a volume percent of the crude oil processed could oscillate between 3 and 10%, depending on the API gravity of the crude oil – the heavier the crude oil, the more the water required [ 2 ].

What is electrostatic desalting?

Electrostatic desalting is used to remove salts and particulates from crude oil. The crude oilbrine mixture is contacted with wash water using a mix valve just upstream of the desalter vessel.