Demulsification chemical methods

Although, many other methods (e.g. electrostatic separation, heating, centrifugation, etc.) may be used to separate the oil and water phases, chemical demulsification is the most inexpensive and widely used technique to resolve crude oil emulsions. The demulsifiers are oil-soluble water-dispersible non-ionic polymeric... 

Two principal approaches for the demulsification of the loaded emulsion are chemical and physical treatments. Chemical treatment involves the addition of a demulsifier to the emulsion. This method seems to be very effective. However, the added demulsifier will change the properties of the membrane phase and thus inhibits its reuse. In addition, the recovery of the demulsifier by distillation is rather expensive. Therefore, chemical treatment is usually not suitable for breaking emulsion liquid membrane, although few examples of chemical demulsification have been reported for certain liquid membrane systems [88]. 

Coalescence of the large water and oil droplets with their respective continuous phases in the coalescer To date, chemical or physical treatment is the method used for demulsification. 

In practice considerable difficulties are encountered in selecting both demulsifiers and demulsification methods. Thermal, electric and chemical demulsification methods are listed in [241]. The latter is discussed very briefly and includes commonly known conditions 1) choice of demulsifier and its optimum concentration 2) effective stirring at a certain temperature 3) optimum period of time to allow the phases to separate and to obtain a clear-cut boundary between the phases. Besides, 2 examples of rather well-known formulations are given, which... 

Chemical demulsification by adding surfactant demulsifiers is still one of the most frequently applied industrial method to break the crude oil emulsions (Sjdblom et al., 2001)-This process can be very difficult and non-efficient to demulsify W/O emulsions of heavy viscous crude oils, and it takes a long time. 

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