What is the purpose of a desalting unit in refining?

The purpose of a desalting unit in refining is primarily to remove salts, water, and impurities from crude oil. This step is essential because crude oil often contains a variety of contaminants, including dissolved salts and water, which can lead to issues during refining processes.

When crude oil is heated in the distillation unit, salts can cause corrosion, scaling, and fouling of equipment, negatively impacting operational efficiency and safety. Water can also lead to emulsion problems and can hinder the separation of various components during the refining process.

By first treating crude oil in a desalting unit, the refining process is improved. The removal of these impurities ensures that the downstream processes, such as distillation, are more effective and result in higher quality petroleum products. Thus, the desalting unit plays a crucial role by enhancing the overall efficiency and reliability of the refining operations.