Demulsifier formulations

Work on the characterization of oil-field emulsions coupled with chemical characterization of commercially available demulsifier formulations has shown that physical processes (temperature, pumping, and dispersed water size distribution) can be at least as important as the chemical effects associated with demulsifiers themselves in determining demulsifier effectiveness [468,469].In fact, there are so many variables involved in industrial demulsification that, to a large degree, demulsifier selection and performance evaluation are still conducted using simple test procedures developed for use in the plant or field. These tests, usually bottle or centrifuge tests, can be good indicators of performance trends, and are usually carried out for selected suites of commercial demulsifier formulations. 

The choice of chemical is usually based on trial-and-error procedures hence, demulsifier technology is more of an art than a science. In most cases a combination of chemicals is used in the demulsifier formulation to achieve both efficient flocculation and coalescence. The type of demulsifiers and their effect on interfacial area are among the important factors that influence the coalescence process. Time-dependent interfacial tensions have been shown to be sensitive to these factors, and the relation between time-dependent interfacial tensions and the adsorption of surfactants at the oil-aqueous interface was considered by a number of researchers (27, 31-36). From studies of the time-dependent tensions at the interface between organic solvents and aqueous solutions of different surfactants, Joos and coworkers (33—36) concluded that the adsorption process of the surfactants at the liquid-liquid interface was not only diffusion controlled but that adsorption barriers and surfactant molecule reorientation were important mecha-... 

This formulation is designed as a complete treatment, providing improved atomization and combustion, sludge dispersancy, demulsifi-cation of water from oil, prevention of bacterial slimes at the water-oil interface, reduced cold-end corrosion, and less fuel system deposits. 

Heat can be used to break some emulsions Changing the pH of the water can often break an emulsion The presence of acid-forming and sulfate-reducing microorganisms may enhance the formation of emulsions treat the fuel with a microbiocide Formulate fuels with a demulsifier to inhibit emulsion formation Ensure that surfactant compounds and additives... 

Texstim B741 is a nonionic surfactant which performs as a "self-demulsifying" detergent. This is extremely useful in truckwash applications. In most oil/water separators, the formulation "split" the oil and water into two phases without further treatment. The oil phase can then be skimmed off for recovery or disposal and not be sent to the sewage treatment plant. 

Selection of a suitable chemical emulsion breaker and dosage is crucial. A particular demulsifier may be effective and efficient for one emulsion yet entirely unsatisfactory for another. Contemporary demulsifiers are formulated with polymeric chains of ethylene and propylene oxides of alcohol, alkyl phenols, amino compounds, and resinous materials that have hydroxy acceptor groups. Each of these polymers is carefully formulated to yield a molecule with a particular affinity for water. Demulsifier dosage is also important excessive demulsifier addition can inhibit the efficiency of emulsion breakdown. 

It is often said that the skill of formulating a demulsifier is a black art , selection of an effective product relying on a trial and error approach, supplemented by the selector s knowledge of what worked before. The test procedure requires the production of an emulsion under reproducible conditions. The rate of water coalescence is taken as a measure of the effectiveness of the product. 

HartopoU P art Chem. Ltd.] Polyoxy-alkylene glycol dispersant demulsifier, emulsifier, rinse aid, defoamer for windshield washer fluids, emulsion polymerization, industrial formulations, household prods. 

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... 

A fairly large number of demulsifying/dispersing formulations have been created for application to marine oil spills [54, 85-87]. They are usually designed to promote O/W emulsion formation and tend to be moderately hydrophilic. Many such formulations are mixtures of non-ionic and anionic surfactants formulated to achieve a target hydrophile-hpophUe balance (HLB) of about 10 [85, 87-90]. 

The choice of demulsifiers is not an easy process as there are thousands of patents published on various formulations. 

Staiss et al. (288) have summarized the developments in chemical demulsifiers and their effeetive dosages used until 1991. They indieated then that the most recent developments in poly(ester amines) at very low dosages were most efficacious for crude oils (Table 4). Table 5 extends this development to eneompass some of the demulsifiers used by research groups globally to date. Table 5 summarizes some of the chosen ehemistries or produets used in published studies on demulsifieation of a variety of erude W/0 emulsions world wide. Aerosol OT is still used today in formulations and is one of the few demulsifiers approved by the Norwegian environmental authorities (284). Aerosol OT still appears to be sueeessful in demulsify-ing eonventional crude emulsions. However, it easily partitions into the water phase and eannot be available for a long time. 

For these reasons the basic understanding of crude oil and bitumen emulsions and demulsification has received considerable attention. Advances in the knowledge of the physicochemical-mechanical structure of the stable emulsions and their films are being made in our laboratory and elsewhere. The films response to demulsifiers are studied in order to understand the detailed mechanisms of demulsification. This knowledge will provide a more scientific basis for formulating products. The knowledge of surfactant chemistry, the behavior in solutions, the behavior at interfaces, and interactions with the crude-oil solvent base involve a wide interplay of complex processes in designing formulations. 

Uses Monomer for creation of new polymer backbones and in formulating high performance acrylic latexes, plastic and rubber modifiers, coatings, adhesives, polyol modifiers, oil field demulsifiers, textile finishes, vise, modifiers, reactive chems. 

Storage Sensitive to moisture store in cool, dry place store under nitrogen keep tightly closed Uses Monomer for creation of new polymer backbones and in formulating high performance acrylic latexes, plastic and rubber modifiers, coatings, adhesives, polyol modifiers, oil field demulsifiers, textile finishes vise, modifiers, reactive chems. Manuf./Distrib. ABCR http //www.abcr.de, Aldrich http //www.sigma-aldrich.com, TCI Am. http //www.tciamerica. com... 

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