Sort:Industry News Release time:2020-04-09 673Views
Why should crude oil undergo electrical desalination and electrical dehydration devices? What is the role?
The salty water content of crude oil causes great harm to crude oil storage and transportation, processing, product quality and equipment, mainly:
1. Increase equipment load and power, heat energy, cooling water consumption.
2. Crude oil that affects the normal operation of the distillation tower has too much water, the water vaporizes, and the volume of the gas phase increases greatly, resulting in an increase in the pressure drop in the distillation tower and an excessive gas velocity, which is likely to cause operational accidents such as tower flushing.
3. Salts in crude oil that affect heat transfer and block pipelines. As water evaporates, salt forms salt scales on the walls of heat exchangers and furnace tubes, reducing heat transfer efficiency, increasing flow resistance, and leading to blocked pipelines when severe , Burning through the pipe wall and causing an accident.
4. Corrosion equipment CaCl2 and MgCl2 can be hydrolyzed to generate highly corrosive HCl, especially in the presence of moisture in low temperature equipment, hydrochloric acid is formed, and the corrosion is more serious. When processing sulfur-containing crude oil, sulfur-containing compounds will decompose H2S and have a corrosive effect on the equipment, but the generated corrosive FeS attached to the metal surface can partially protect the metal. However, when HCl is present at the same time, HCl can react with FeS to destroy the protective layer, and the released H2S will further react with iron, intensifying corrosion.
5. Affecting product quality Metals in salts enter heavy distillate oil or residual oil, poisoning the catalyst, affecting the quality of secondary processing raw materials and product quality. Therefore, after the crude oil enters the refinery, it must be desalted and dehydrated first, so that the water content reaches 0.1% to 0.2% and the salt content is less than 5mg / l. For oil refineries with residual oil hydrogenation or heavy oil catalytic cracking process, the crude oil salt content is required to be<3mg / l.