Stability and demulsification of petroleum emulsions
Petroleum is predominantly recovered in form of W/O-emulsions which are stabilized by petroleum resins and asphaltenes, colloidal disperse components of petroleum. Both of these substances are polydisperse, resoluble, oleophilic micellar colloids, ocurring in dilutions in spherical form. In concentrated solutions, however, they form larger, inter-micellar structures. These structures generally form with the enrichment of resins and asphaltenes at oil/water interfaces.
Petroleum emulsions are stabilized by “thick films” according to Gibbs which are composed from different petroleum-internal tensides and have a Gibb’s elasticity. The more the interfacial activities of the components differ from each other, the higher is the elasticity module of the multi-component films.
We found optically anisotropic interface films in petroleum emulsions. The observed structure-formation in interface films of emulsions which are mostly stabilized by petroleum resins, increases continuuously with raising temperature. Even isolated petroleum resins in volume-phases show such a structure-formation. Lyotropic, liquid-crystalline mesophases develop. This proves that the “enhanced emulsion stability” according to Friberg is valid for petroleum resins as multi-component systems as well.
The demulsification of emulsions after addition of demulsifiers as a result of a shift of the balance lyophilic-lyophobic is being discussed.
Key wordsPetroleum emulsions emulsion stability demulsification liquid crystals interfacial films
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- 2.Speight JG (1980) The Chemistry and Technology of Petroleum. Marcel Dekker New York, Basel, Chapt 7Google Scholar
- 3.Neumann HJ (1967) Habilitationsschrift BraunschweigGoogle Scholar
- 4.Neumann HJ (1970) Erdöl Kohle-Erdgas-Petrochem 23:496–499Google Scholar
- 5.Gibbs JW (1928) Collected works Vol 1 Yale Univ PressGoogle Scholar
- 9.Haardt HJ (1973) Diss BraunschweigGoogle Scholar
- 10.Durmosch MR (1977) Diss BraunschweigGoogle Scholar
- 11.Neumann HJ, Rahimian I, Paczynska-Lahme B (1992) Bitumen 54:54–56Google Scholar
- 12.Hoechst AG (1987) The effective way of separating water from oil and oil from waterGoogle Scholar