Petroleum crude oil desalting process and unit

摘要

An improved method and process unit for desalting petroleum crude oils in which a portion of the stable emulsion layer which forms in the desalter vessel is withdrawn from the desalter and diluted with a liquid diluent, typically oil or water or both to destabilize the emulsion which is then separated into separate oil and water phases.

主权项

1. A crude oil desalting process which comprises:
(i) mixing a crude oil to be desalted with desalting water and passing the mixture of oil and water to a desalter vessel to form (a) a settled water layer containing salts dissolved from the oil in the lower portion of the vessel, (b) a settled supernatant, desalted oil layer in the upper portion of the vessel with (c) an intervening emulsion layer formed from the oil and the water, (ii) withdrawing a portion of the emulsion from the desalter vessel, (iii) mixing the withdrawn emulsion with a diluent liquid to destabilize the emulsion and form a diluted emulsion, wherein the diluent liquid comprises at least one of water and process water, and (iv) separating the diluted emulsion.