Mousse emulsion

Some special problems arise at sea. When crude oil is spilled on the ocean, a slick is formed which spreads out from the source with a rate that depends on the oil viscosity. With sufficient energy an O/W emulsion may be formed, which helps disperse oil into the water column and away from sensitive shorelines. Otherwise, the oil may pick up water to form a water-in-oil emulsion, or mousse ( chocolate mousse ). These mousse emulsions can have high water contents and have very high viscosities, with weathering they can become semi-solid and considerably more difficult to handle, very much like the rag-layer emulsions referred to above. The presence of mechanically strong films makes it hard to get demulsifiers into these emulsions, so they are hard to break. See Chapter 9. 

Motionless Mixer Mousse Emulsion Multiple Emulsion... 

Finally, many kinds of emulsions pose difficult problems wherever they may occur. For example, crude oil when spilled on the ocean tends to become emulsified in the form of chocolate mousse emulsions, so named for their color and semisolid consistency. These water-in-oil emulsions with high water content tend to be quite stable due to the strong stabilizing films that are present. Mousse emulsions increase the quantity of pollutant and are usually very much more viscous than the oil itself. 

A graphic and important example is furnished by the oil spill chocolate mousse emulsions formed when crude oil spills into seawater. These water-in-oil emulsions have high water contents that may exceed 74% and reach = 0.80 or more without inverting. As their common name implies, these mousse emulsions not only ha e viscosities that are much higher than the original crude oil but can become semisolid. With increasing time after a spill, these emulsions weather (the oil becomes depleted in its lower boiling fractions), and apparently the emulsions become more stable, more solidlike, and considerably more difficult to handle and break. 

Chocolate Mousse Emulsion A name frequently used to refer to the water-in-oil emulsions having a high water content that are formed when crude oils are spilled on the oceans. The name reflects the color and very viscous consistency of these emulsions. It has also been applied to other petroleum emulsions of similar appearance. 

One important area of petroleum emulsions that is not addressed concerns the water-in-oil mousse emulsions created from oil spills at sea. This topic is covered in detail in a hook hy J. R. Payne and C. R. Phillips entitled Petroleum Spills in the Marine Environment The Chemistry and Formation ofWater-in-Oil Emulsions and Tar Balls Lewis Publishers Chelsea, MI, 1985. 

Dispersal is usually aimed at creating an O/W emulsion so that the dispersed oil drops can settle out as described earlier. Emulsification of the oil also accelerates microbial degradation of the oil owing to its increased surface area. To achieve O/W emulsification, the dispersant (emulsifying agent) needs to be added within about the first 12 - 24 h after a spill, otherwise a maximum viscosity mousse emulsion will have formed making it extremely difficult to get the dispersant into the oil [79, 84]. Nevertheless, dispersants are commonly used in oil spill treatment. 

In many surface separation processes, three distinct phases or process streams will occur a product stream (either oil or water), a waste (tailings) stream and an interface emulsion stream, which may contain emulsified oil and/or water. The interface emulsion (also termed cuff layer, pad layer or rag layer emulsion) can be the most troublesome, in terms of process operation, and the most complex and intractable, in terms of treatment. Such emulsions can have high solid contents and are frequently very viscous (see also mousse emulsions in Section 9.5). 

Water or sewage treatment emulsions, oil spill mousse emulsions... 

Figure 11. Illustration of possible structures in the interface in a water-in-oil mousse emulsion. Some possibilities are, from left to right, stabilized by asphaltenes, by surfactants and waxes, by both, and unstabilized. (From Mackay [147]. Copyright 1987 Environment Canada, Ottawa, ON.)...

Chocolate Mousse Emulsion. A name frequently used to refer to the... 

The composition of water-in-oil emulsions varies from 30% to 80% water. These are extremely stable. After several days, they form chocolate mousse emulsions, which are annoyingly unresponsive to oxidation, adsorption, dispersion, combustion, and even sinking. The most effective method for mousse emulsions is physical removal. Mousse contains roughly 80% water, so after a 40 to 50% loss of light-ends through evaporation, a spill of 200,000 barrels oil can form 400,000 to 500,000 barrels of mousse. 

At first, authorities decided against using dispersants in sensitive areas and along the coastal fringe. Meanwhile, the spill formed a highly stable water-in-oil emulsion ( chocolate mousse ). On the open sea, the French Navy applied both dilute and concentrated dispersants, but good dispersion was hard to achieve because in some places the mousse emulsion was several centimeters thick. If dispersants been dropped from the air at the source of the spill - in days instead of weeks - the formation of mousse emulsion might have been prevented. 

About 650 metric tons of chalk was applied in an effort to sink the oil. But after one month at sea, the oil was so viscous that the chalk just sat of top of it. Rubber powder made from ground-up tires was applied absorb the oil absorption. The French Navy used water hoses to spread most of the powder. Some was applied manually from small fishing boats. Because it stayed on top of the oil, the mbber powder had little effect wave action wasn t strong enough to mix it into the oil, most of which was trapped inside the chocolate mousse emulsion. 

---