Emulsions economic effect

Solvent Extraction. Solvent extraction has widespread appHcation for uranium recovery from ores. In contrast to ion exchange, which is a batch process, solvent extraction can be operated in a continuous countercurrent-fiow manner. However, solvent extraction has a large disadvantage, owing to incomplete phase separation because of solubihty and the formation of emulsions. These effects, as well as solvent losses, result in financial losses and a potential pollution problem inherent in the disposal of spent leach solutions. For leach solutions with a concentration greater than 1 g U/L, solvent extraction is preferred. For low grade solutions with <1 g U/L and carbonate leach solutions, ion exchange is preferred (23). Solvent extraction has not proven economically useful for carbonate solutions. 

Solvent extraction carried out in conventional contactors like mixer-settlers and columns has certain limitations, including (a) controlling optimum dispersion and coalescence, (b) purifying both phases to ensure that stable emulsions are avoided (c) temperature control within a narrow band (d) high entrained solvent losses and related environmental and process economic effects and (e) large equipment dimensions and energy requirements when the density differential or selectivity is low. 

Demulsification with electrostatic fields appears to be the most effective and economic way for breaking of W/0 emulsion in ELM processes 190, 91]. Electrostatic coalescence is a technique widely used to separate dispersed aqueous droplets from nonconducting oils. Since this type of technique is strictly a physical process, it is most suitable for breaking emulsion liquid membranes to recover the oil membrane phase for reuse. 

Overall, horizontal vessels arc more economical for normal oil and gas separation, particularly where there may be problems with emulsions, foam or high gas-oil ratios. Vertical vessels work more effectively in either low or very high GOR applications, such as scrubbers. 

Despite these generalizations, the reduction or elimination of coagulum is usually best accomplished by a "systems approach", i.e., a consideration of latex properties to be achieved in the emulsion polymerization, the economics of the polymerization process, and the deliberate design of the reactor system for that particular polymerization system. Each polymerization system must be considered as a separate system and treated as such. The most effective approach to reduce or eliminate the formation of coagulum is to determine the mechanism by which it is formed and... 

Emulsion polymerization is one of the major processes for the production of industrial polymers. It represents a sizable application for surface active agents, although manufacturers tend to minimize their use because of economic and environmental considerations (surfactants are usually more expensive compared to monomers and are mostly left in the liquor) and because of the negative effects on the final properties of the polymers and of their coalesced films. 

Injecting 0.5 PV of 2.5% Kern River oil-in-water emulsion into a sandpack made from Kern River sand reduced the permeability from 1624 to 397 md, a reduction of 76%. This is a significant result since injection of 0.5 pore volume of a steam-swept zone is economically viable should a field test be performed. An additional 0.5 PV of the emulsion was injected, lowering the permeability to 226 md. The stability of the block under steamflooding conditions was tested by injecting saturated steam at 150 C. After steam injection, the permeability was 406 md—still a 75% reduction in effective permeability (see Table VI). 

The emulsification properties of the crude oil must be determined. Some crude oils can be emulsified with surfactant mixtures, others with caustic. Some crudes, such as Hasley Canyon (Table III), are difficult to emulsify. Experiments can be performed to determine if in situ emulsification is feasible, or if an emulsion must be injected. If in situ emulsification is feasible, loss of chemicals to reservoir rock is a problem to be addressed. If in situ emulsification is employed in conjunction with steam, it must be determined if chemicals are most effective when injected with the flowing steam or when chemical/steam injections are alternated. Relative permeabilities of the injected fluids should be determined. All of this information is needed to calculate the economics of scale-up to a specific field situation. 

To bring all these parameters to an acceptable compromise is not easy, even for a single purpose finish. But usually several types of finishes are combined for economical reasons mostly in one bath (only one application and drying process). This is often the hardest challenge of chemical finishing. First, all components of the finish bath must be compatible. Precipitations of anionic with cationic products have to be avoided. The emulsion stability of different products may be reduced by product interactions. More difficult is often the second hurdle, the compatibility of the primary and secondary effects of the different types of finishes that are being combined ... 

Within oil-field emulsion breaking, the economics usually favor minimal heat input because light ends are not lost to the gas phase and fuel-gas consumption is minimized. Other significant effects caused by the addition of heat are an increased tendency toward scale deposition on fire tubes, an increased potential for corrosion in treating vessels, and a tendency to render asphaltenes insoluble (because of loss of light aromatic components), which may produce an interface pad problem. 

Economic pipeline transport of viscous crudes as concentrated oil-inwater emulsions has been demonstrated in at least two commercial pipelines. The present study was undertaken to learn more about the rheological characteristics of concentrated emulsions and the effect of such variables as emulsion formulation and preparation techniques, aging,and crude oil viscosity on emulsion properties. 

The bimodal distribution feature may be attained in different ways, the most simple being the mixing of two streams with different stirring conditions. However, it is probably not the most economical, and may not be the safest one. In effect, since the final location of the emulsion is very near the inversion line, the extra stirring of one part of the emulsion might end up in inversion instead of in smaller drops. The curved path may be a more appropriate way to attain a bimodal emulsion, since the final condition... 

Chem. Descrip. Disp. of a hydrophobic wax in min. oil with silicone Uses Defoamer, emulsifier for water-based systems, flat and semigloss emulsion paints, aq. adhesives, caulks, and sealants Features High efficiency economical long term effectiveness exc. stability, shelf life no VOC... 

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