Emulsions water specific gravity

Interface control has the advantage of being easily adjustable to handle unexpected changes in oil or water specific gravity or flowrates. However, in heavy oil applications or where large amounts of emulsion or paraffin arc anticipated, it may be difficult to sense the interface. In such a case, bucket and weir control is recommended. 

We have an emulsion of oil in water that we need to separate. The oil droplets have a mean diameter of lO " m, and the specific gravity Of the oil is 0.91. Applying a sedimentation centrifuge to effect the separation at a spedd of 5,000 rpm, and assuming that the distance of a droplet to the axis of rotation is 0.1 m, determine the droplet s radial settling velocity. 

Aboveground separators are typically large tanks whose function is to slow down the flow of the incoming water this allows gravity separation of the less dense gasoline emulsions.19,41 Separators are composed of two or more chambers. The first chamber is used for the deposition of settleable solids, and the second is used for the separation of liquids of dissimilar specific gravities and the removal of the lighter liquid. 

Fig. 7—Heating oil-water emulsion towers tie specific gravities of both liquids. But S.G difference may increase or decrease, depending upon crude oil characteristics.

The copolymers were patented by Wiley, Scott, and Seymour in the early 1940s. A typical formulation for emulsion copolymerization contains vinylidene (85 g), vinyl chloride (15 g). methylhydroxypropylcellulose (0.05 g), lauroyl peroxide (0.3 g) and water (200 g), More than 95 per cent of these monomers are converted to copolymer when this aqueous suspension is agitated in an oxygen-free atmosphere for 40 hrs at 60°C. The glass transition temperature of the homopolymer is — 17°C. It has a specific gravity of 1.875 and a solubility parameter of 9.8. 

An even more difficult processing condition arises with heavy bituminous oils which always carry much sand, clay, and silt of coarse and small particle sizes which stabilize the oil-water emulsions even more. The bituminous oils have specific gravities of 0.9-1.4 and have high viscosities thus they cannot be separated from the water or solids present by settling or by using the most efficient centrifuges. 

Diluting these emulsions of heavy oils with light solvents—e.g., kerosene, solvent naphtha, benzene, etc.—reduces the specific gravity of the oil phase of the emulsions below that of water and lowers the vis-... 

Heavy solvents (high specific gravity) are undesirable in most cases because it is hard to stabilize the emulsion when the EC is mixed with water. If the specific gravity of the solvent is near that of water, the setting tendency of the emulsion is decreased. The terms top creaming and bottom creaming are used to describe emulsions in which the insecticide-containing solvent has risen to the top or settled to the bottom of the emulsion. Other... 

Although the solvent extraction of a metal occurs by reaction with an extractant that is essentially insoluble in water, h is seldntu practical to use pure extractant as the solvent phase. The pare extractants are usually very viscous and may have specific gravities nenr 1 so ibet both mixing and separating phases may be difficult. They are intrinsically surface active and tend to form emulsions with water. To avoid these problems and to provide flexibility with respect to phase ratios and the hydraulics of liquid-liquid contacting, one uses a diluent, which is often the major component in the organic phase. 

Dispersions of pol5Tetrafluoroethylene are colloidal emulsions of small pol mier particles (<0.25 pm) in water which are negatively charged. They contain relatively high concentrations of PTFE, which increases their specific gravity. An estimate of solids content can be obtained from the specific gravity (Table 5.12). 

Evaporation, dissolution, photooxidation, and the formation of viscous water-in-oil emulsions increase the density of oil on the sea surface. The change in oil density through time is facilitated by the incorporation of particulate matter and the agglomeration of oil particulate mixtures. The sorption of hydrocarbons to particulate matter creates a high specific gravity mixture more than twice that of seawater alone (1.025 g cm" ), which promotes its sedimentation. 

This test method determines the specific gravity and density of bituminous binders, apart from bitumen emulsions, at 25°C 0.2°C using capillary-stoppered pycnometers. The method may be performed at other temperatures, but when doing so, the density values of the water or other liquid used should be determined. 

The specific gravity should be far enough removed from that of water to permit satisfactory settling without the formation of an emulsion. 

Small amounts of solids in produced water may or may not create problems in water treating depending on the particle micron size and its relative attraction to the dispersed oil. If the physical characteristics and electronic charge of such solids result in an attraction to the dispersed oil droplets, the solid particles can attach to the dispersed oil droplets to stabilize emulsions, thereby preventing coalescence and separation of the oil phase. The combined specific gravity of the resulting oil/solid droplet can be approximately equal to that of the produced water, and gravity separation becomes difficult if not impossible. 

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