A Detailed View On The Desalting Of Crude Oil In Refineries

Crude oil, which is introduced to a massive refinery processing setup comprises of numerous undesirable impurities, some of these are inorganic salts, sand, drilling mud, corrosion byproduct, and polymer. The main purpose of refinery desalter operation is to eliminate all kinds undesirable impurities, particularly different varieties of salt and water, which are generated from the crude oil before the distillation process takes place. The amount of salt-content in the crude oil can differ a lot based on the source from which the crude oil was extracted from. When a combination of different crude oil from numerous sources are processed in the refinery system, the salt content will vary in terms of overall percentage.

The most common concerns of the impurities that are found in crude oil include —

1. Inorganic salts present can be easily decomposed in the crude oil heaters and exchangers. That is why the hydrogen chloride gas produced gets converted to liquid HCl acid at overhead system of the distillation column, might be the cause for a serious equipment corrosion.
   
   
2. To prevent any instances of corrosion due to the presence of salts in the crude oil, corrosion control should be implemented. That being said, the byproduct coming out from the corrosion control of oil field machinery and equipment comprises of particulate iron sulfide and oxide. Precipitation of these materials may cause the blocking of the heat exchanger trains and heater tubes. Furthermore, these materials may cause corrosion to any surface level they have been impacted by precipitation.
   
   
3. The silt/sand might be the reason to cause major damage due to erosion or abrasion of pumps and pipelines.
   
   
4. If calcium naphthanate (found in the crude unit residue stream) is not removed at the right time, that can result in the low-grade coke production and the deactivation of catalyst of the FCC unit.

Benefits of Crude Oil Desalting

• Enhanced crude throughput
  
  
• Less blocking, coking of heat exchanger
  
  
• Lower amounts of corrosion in pipelines, exchanger, and fractionators
  
  
• Improved corrosion control in CDU overhead
  
  
• Lower amount of erosion by solids in exchanger, control valves, and pumps
  
  
• Significant saving of oil from oil waste slopes

Desalting Process

For the complete desalting process, these are the most important steps that one needs to follow —

• Dilution water dispersion as well as injection
  
  
• Emusification of the diluted water present in oil
  
  
• Spreading of the emulsion
  
  
• Electrostatic coalescence
  
  
• Settling of water droplets

Consider this article and make use of the best desalter electrical grid for the process.

Author: The author is a blogger and the article is about desalter operation.

About This Author

desalters Joined: December 23rd, 2018