Emulsions bitumen

Bitumen emulsions are emulsions in which the dispersed phase (discontinuous phase) is bitumen and the water or aqueous solution is the continuous phase. 

The suspension of bitumen particles is achieved by charging their surface with the same electric charge after the addition of the emulsifier, or emulsifying agent, during the emulsification process. 

Apart from the above three basic ingredients, a bitumen emulsion may contain, in minute amounts, one or more of the following stabilisers, break control agents, acidity regulators, coating improvers or anti-stripping agents. 

When a modified bitumen emulsion is to be produced, polymer is also added. 

In an unmodified bituminous emulsion, the proportion by mass of bitumen, water, emulsifier and other additives typically range within the values 40%-70% bitumen, 58%-28% water, 0.5%-1.5% emulsifier and less than 1% other additives. 

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The standard NF T 65-011 distinguishes the bitumen emulsions by their ionic nature (anionic or cationic), their stability with respect to agglomerates and weight content of base binder. There are 20 grades of emulsions. 

Loading levels above about 8 N/mm for short term and 4N/mm for an indefinite period are, therefore, not recommended for bitumen emulsion-modified cementitious floors. 

Polyalkylene polyamine salts are prepared by contacting polyamines with organic or inorganic acids. The polyamines have a molecular weight of at least 1000 Dalton and ranging up to the limits of water solubility [1185]. In a process of demulsification of the aqueous phase of the broken bitumen emulsions, the pH is adjusted to deactivate the demulsifier so that the water may be used in subsequent in situ hot water or steam floods of the tar sand formation. 

D. R. McCoy. Demulsification of bitumen emulsions using polyalkyl-ene polyamine salts. Patent CA 1220151,1987. 

Shellperm A process for rendering sandy soils impermeable to water by pumping in a bitumen emulsion with a coagulant which is effective after a predetermined period. Used in the construction of dams. 

Stockpiles of milled peat are prevented from self heating and ignition by sprayed application of bitumen emulsion to form a 2-2.5 mm protective permeable film [1], The mechanism of self heating and ignition first involves aerobic microbiological processes, then chemical transformation of iron-containing minerals in the peat into pyrophoric iron compounds which later ignite the peat mound [2],... 

F. Leal Calderon, J. Bibette, and F. Guimberteau Method for Preparing Concentrated and Calibrated Emulsions in a Highly Viscous Phase, in Particular Bitumen Emulsions. US Patent 6602917 (1998). 

One kind of surface emulsion that is desirable is the Orinoco bitumen emulsion produced from in situ steam stimulation and recovery in the Orinoco River deposit in Venezuela. This emulsion is reformulated into Orimulsion , an O/W emulsion, containing about 30% fresh water and a stabilizing surfactant (typically about 0.1 percent each of monoethanolamine and an alcohol ethoxylate) [588,759,760], The O/W emulsion has a viscosity of about 450 mPa-s (30 °C, 100 s-1) compared with the original bitumen viscosity of about 10000 mPa-s [760,761], This emulsion can be used as an alternative fuel for power-generating plants. Being water-continuous the emulsion is easily handled and transported, but otherwise behaves similarly to fuel oil. 

Emulsions are dispersions of one fluid into another. Both oil-in-water and water-in-oil emulsions are encountered. Foams are similar to emulsions, but the dispersed phase is a gas. Emulsions are everywhere some examples of products that are based on emulsions are salad dressings, mayonnaise, egg yolk, milk, margarine, cream, ice cream, waterborne paints and bitumen. Emulsions are generally not stable, so they need to be stabilized against coalescence. One can use surfactants for that, or polymers, such as proteins and polysaccharides, or particles. 

Eilers 49, 50) proposed the following empirical equation to fit his data on polydisperse bitumen emulsions ... 

The non-Newtonian nature of emulsion-solids mixtures depends on the nature of the pure emulsions. Addition of solids to a highly shear-thinning emulsion also results in a shearthinning mixture. However, addition of solids to a fairly Newtonian bitumen emulsion results in a more complex mixture that can exhibit different non-Newtonian behaviors at different shear stress or shear rate. 

In some cases, minimal effort is required for the demulsification process. For example, in field tests, adequate separation of a bitumen emulsion could be achieved without the use of demulsifiers by raising the temperature of the emulsion to 190 T and providing 24 to 48 h of residence time in quiescent storage tanks. However, proper selection of demulsification chemicals is essential when treating the emulsions in conventional equipment on a continuous-flow basis. 

Energy. Thermal. The addition of heat promotes the treatment process. First, it reduces the viscosity of the oil. This effect is especially instrumental in the handling and treatment of heavy crude oils or bitumen emulsions. Second, it weakens or ruptures the film between the oil and water droplets by expanding the water present. Last, heat increases the difference in densities of the fluids and thereby tends to reduce the settling time. 

Emulsions offer a possible method of getting an otherwise viscous material to penetrate a fine formation. Asphalt emulsions have been used for this purpose [23]. For an emulsion to act as an effective grout, the emulsion must break down at the proper time and place, so that the grout phase of the emulsion is deposited. Triggering the breakdown may become involved and expensive and tends to nullify the major advantage of bitumen emulsions, which is low initial cost. 

Several industrial systems involve emulsions, of which the following are worthy of mention. Food emulsions include mayonnaise, salad creams, deserts, and beverages, while personal care and cosmetics emulsions include hand creams, lotions, hair sprays, and sunscreens. Agrochemical emulsions include self-emulsifiable oils that produce emulsions on dilution with water, emulsion concentrates with water as the continuous phase, and crop oil sprays. Pharmaceutical emulsions include anaesthetics (O/W emulsions), hpid emulsions, and double and multiple emulsions, while paints may involve emulsions of alkyd resins and latex. Some dry-cleaning formulations may contain water droplets emulsified in the dry cleaning oil that is necessary to remove soils and clays, while bitumen emulsions are prepared stable in their containers but coalesce to form a uniform fihn of bitumen when apphed with road chippings. In the oil industry, many crude oils (e.g.. North sea oil) contain water droplets that must be removed by coalescence followed by separation. In oil slick dispersion, the oil spilled from tankers must be emulsified and then separated, while the emulsification of waste oils is an important process for pollution control. 

Duomeen . [Al Akzo Chem. BV] Alkyl propane diamines or salts chemical intomediate, corrosion inhibitor, fuel oil additive, flotation agent used in metals, textiles, plastics, herbicides, paints, bitumen emulsions epoxy curing i ent... 

Depending on the application, relatively hard distillation bitumen, oxidation bitumen, or high-vacuum bitumen (hard bitumen) are used for physically drying bitumen paints. Waterborne bitumen paints and thick coatings (bitumen emulsions) are produced from moderately hard distillation bitumen. 

One and two-component waterproofing thick coatings, based on destination or polymer bitumen (bitumen emulsions), have become an increasing importance for the protection of buildings in wet-duty areas like cellar, bathrooms e.g. 

In the case of anionic two-component bitumen emulsions, the second component consists of a cement powder that braks the emulsion during the potlife time (time of application) and reacts with the water in excess of the emulsion. 

Durand, G. Poirier, J.-E. Chappat, M. Aqueous bitumen emulsions containing encapsulated demulsifi-cation agents for controlled bitumen addition to paving materials. EP 864611, 1998. 

Many emulsion-based formulations also contain solid particles. Typical examples are food products, such as margarine and salad dressing or petroleum products, such as crude oil emulsions or bitumen emulsions. 

In 1985, the transportation and the combustion research teams at INTEVEP combined their efforts and a preliminary round of combustion tests was carried out (10,11). By 1986, it was established that the bitumen emulsion could be used as an efficient fuel (60, 61). 

Additionally, the manufacturing of bitumen emulsions required four times less investment than deep conversion into synthetic crude. 

There are several hypotheses concerning the source of the water in bitumen emulsion stability. The most common says that the emulsion is stabilized by the asphalthene fraction of the bitumen. The following experiment (1) clearly shows that, although the stabilizers may come from the asphalthene fraction, it is not the whole asphalthene fraction that is responsible for the emulsion stability. 

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