The formation of stable and persistent emulsions and foams in contact hydrophilic materials, which then partition into the the production and refining of crude petroleum is a challenge aqueous droplets (10, 11). These desalter emulsions must which has defied broad and generic resolution for several decades. subsequently be broken down to recover the ''clean'' crude Rational and systematic approaches to demulsification have been oil. However, a considerable proportion of these emulsions slow to develop due to a lack of fundamental understanding of are very stable and lead to sludge generation (12). As the the molecular origins of emulsion stabilization and the full range EPA continues to redefine specific petroleum-derived comof factors which govern emulsion stability. Several studies have ponents which will be targeted as listed wastes, the need shown the importance of resins and asphaltenes, which have the to minimize the formation of petroleum emulsions and the ability to organize and form rigid films at the oil/water interface.
We have developed a molecular model in which we propose that impetus to develop new methods for effective treatment of the integrity of these films and thus their ability to stabilize waterthem have become more acute.
in-crude-oil emulsions are sensitive to a variety of crude solvency
Despite years of research, there is a lack of a fundamental parameters, such as aromaticity, resin-to-asphaltene ratio, and pounderstanding of the mechanisms governing the stability of lar functional group concentration. This model was tested by correoil-continuous emulsions. With crude oil emulsions, the imlating the stability of emulsions formed from a variety of crude portance in long-term stability of a rigid and protective film oils-Arab Berri (Extra Light), Arab Heavy, Alaska North Slope, surrounding the water droplets is clear (13-18). The deand San Joaquin Valley-in which the resin and asphaltene contailed properties of this film, together with a fundamental tents vary, as well as their specific characteristics. The results of knowledge of the chemistry of the interfacially active comthe elemental and functional group characterization of these ponents in the crude oil, are far from understood (19). Howcrudes and their fractions and the techniques utilized to obtain ever, studies have established the significance of components them were presented previously. Detailed quantitative protocols for gauging relative emulsion stability have been developed to such as asphaltenes and resins, which, because of their surfurther evaluate the proposed model by blending solvents of varyface-active and structure-forming properties, accumulate at ing aromaticity and by doping isolated resins from different crudes the interface and hence have pronounced effects on emulsion into solvent-modified crudes. Dramatic destabilization of emulstabilization and breaking (11,(13)(14)(15)(16)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31). Others have sions was accomplished by modifying the crude solvency in either also shown the importance of other components which may fashion. Simple physical and chemical techniques for minimizing be present in the crude such as waxes and inorganic solids emulsion formation such as basic crude blending and solvent- (8, 18, 19,24,(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42). The focus of this study will be on recycle schemes will also be discussed. แญง 1997 Academic Press the role of the asphaltenes and their interactions with the resins and surrounding crude medium in forming these interfacial films and the resultant effects on emulsion stability.