Demulsifiers functions

Alkoxylated phenol formaldehyde resins are a well-known class of demulsifier, and the emulsion coalescence data in Table III confirm that Thin Film Spreading Agents, which belong to this class, can also function as chemical demulsifiers. When water in... 

Given time, water which exists as discrete droplets in finished fuel may coalesce into larger drops and settle by gravity from the fuel. Demulsifiers or dehazers can accelerate this process by functioning as a site for attraction of dispersed water. 

Upon adsorption, demulsifier/dehazer compounds function to break the oil or surfactant layer thus releasing the contained water. Once free, the water can then coalesce into larger drops and be removed from the fuel. 

Figure 7.9 Total oil recovery for demulsifiers A and B as a function of addition rate. Demulsifier B is effective at a much lower addition rate, but rag layer formation affects the recovery, resulting in a narrow range of effective concentration. Demulsifer A requires a higher addition rate, but is not as susceptible to overtreatment.

Figure 19. Comparison of electroacoustic analysis and dewatering efficiency of the mixed demulsifier as a function of the apparent spreading rate.

Recently, we have shown that sulfonated PHP can act as a demulsifier for highly stable emulsions like crud and water-in-crude oil emulsions. The mechanism of demulsification is that sulfonated PHP removes selectively surface active species in the emulsion, causing destabilization. At the same time, it also adsorbs metal ions, thus achieving two functions at the same time. As a result, these materials are called demulsifier adsorbers. In highly stable emulsions where neither electric field nor demulsifier adsorbers are effective, the combination of these two methods appears to create synergy for separation. 

FIG. 9 Film capacitance of crude oil/EOR system as a function of time the first kind of mechanism of film rupture. Oil phase 30% Shengli deasphaltene oil/n-Cio aqueous phase 0.1 mol/L NaOH + 0.15 mol/L NaCl + 5 ppm demulsifier. 

The frequency distribution of diameters is the most widely used way of presenting population size data. It contains useful information which aids the prediction of emulsion kinetic behavior e.g., sedimentation and diffusion are functions of droplet size. Also, one can follow flie evolution of the DSD as a function of time, the shift towards fewer/larger droplets being evidence of droplet-depletion mechanisms, such as coalescence and Ostwald ripening. From the distribution, the kinetic coefficients can be calculated, allowing prediction of how the DSD will develop (e.g., 48, 55). This is described in detail by Dukhin et al.. Chapter 4, this volume. Figure 11 shows how the addition of a demulsifier can destabilize an emulsion and bring about emulsion resolution. The example is a water-in-crude oil emulsion, the demulsifier a phenolic resin alkoxy-late. 

Figure 6 Examples of separation as function of time. Oil 1 with 20% water cut Demulsifier B.

Metallic sulfonates, such as sodium sulfonate, are often used as emulsifiers in both water-in-oil and oil-in-water emulsions. Other emulsifiers used include ethylene oxide condensation products and derivatives of polyhydroxy alcohols such as sorbitol and sulfosuccinates for water-in-oil emulsions. For oil-in-water emulsions, soaps of fatty acids, rosins, or naphthenic acids are often used as emulsifiers. In either application, the role of emulsifiers is to change the interfacial tension at the water and oil interface. In cases where emulsification with water is undesirable, demulsifiers are used. Frequently, the demulsifiers are heavy metal soaps, such as alkaline earth sulfonates. These surfactants function by lowering emulsion stability. 

Thus, multifunctional multipolymeric surfactant-thickener mixtures generated from the FRRPP process are proposed to be used in the recovery of oil from subterranean sources from waterflooding operations. The idea is to simply add the surfactant into the water in the injection well and enhanced production of oil (at least three times the rate compared to waterflooding) can be realized in the production wells. Surfactant-thickener mixtures can also be recycled and can function as demulsifiers, which add to the viability of the oil recovery operation. 

In this set of bottle test data, the water and solids content (BSW) of the separated oil phase has been evaluated as a function of distance from the separated water. The od at the surface (75-100) is in all cases water and solids free. The practical average is identical in all cases because during field testing it is often not possible to extract the entire oil phase for BSW testing. It is the most important part of the sample nearest die water phase (often about 10%) that is not analysed. Without detailed BSW data for the oil, these three demulsifiers would be presumed to have identical performance while in fact, demulsifier 1 has a significant amount of the oil which does not meet the 0.5% BSW pipeline specification. 

Figure 3. Comparison of the water in oil product and rag layer formation as a function of addition rate for demulsifiers A and B. Rag layer formation at high dosages is characteristic of overtreatment.

Uses Emulsifier for sol. oils wetting agent corrosion inhibitor in water-diluted emulsions gellant for naphthenic and paraffinic oils Demulsifier 3837 [Clariant/Functional Chems.j Chem. Descrip. Polymer... 

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