Crude Oil Desalter/Dehydration

Howe-Baker's Approach To Desalter/Deydration Design

Howe-Baker uses the "basic engineering" approach for the design and specification of electrostatic desalters and dehydrators.  We believe that if the problem is well defined and the surrounding circumstances recognized, then the proper equipment, using the correct safety factor, can be specified. 

Figure 1figure1

One-stage Operation

Dehydration (Figure 1) – Single stage units are usually sufficient for dehydrating produced crudes. BS&W carryovers can range from trace to 1.0 volume percent, depending on crude type, operating temperature, inlet water content and other factors.  "Other factors" include production methods, chemical treatments, handling procedures. Etc.                

Desalting (Figure 2) – Adding water which is less saline that the water contained in the feedstock crude converts and hydrator into a desalter. 


Figure 2

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Typical single stage removals are illustrated in Figure 3.


Two-Stage Operation

Dehydration/Desalter (Figure 4) - First stage reduces B. S. & W. content so that water added for desalting can dilute more effectively.


Figure 4

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Desalter/Desalter (Figure 5) - Two stage desalting is required when 90-95% salt removal is not good enough. Process water is injected into the second stage and recycled back to the First. 98-99% salt removals can be expected for most crudes.


Three-Stage Operation

Dehydration/Desalter/Desalter (Figure 6) – This design is appropriate when feedstock BS&W are high (say 5-40 volume percent) and product salt content must be low (2 ptb). The dehydrator reduces the BS&W


Figure 6

Figure 7figure7

Desalter/Desalter/Desalter (Figure 7) - This design is rare but has been specified for applications on very heavy crudes and residua. When these oils are used as feedstock for cat crackers and turbine generators, very low sodium contents are required.



Last modified on Monday, 06 January 2014 23:08