Info Kcv
FIGURE 5.9 Critical micelle concentrations of technical grade alcohol ethoxylates and alkyl polyglucosides as a function of degree of polymerization of the head group T 21 1 C . FIGURE 5.9 Critical micelle concentrations of technical grade alcohol ethoxylates and alkyl polyglucosides as a function of degree of polymerization of the head group T 21 1 C . increasing m indicative of the increasing hydrophilicity of the surfactant monomer. Moreover, the steric repulsion between the surfactant head...
Firp
Universidad de Los Andes M rida, Venezuela Science and Technology Trondheim, Norway Investigaciones Cient ficas Barcelona, Spain Chemistry and Colloid Science Wageningen University Wageningen, Netherlands Statoil R amp D Center Trondheim, Norway University of Petroleum Beijing, China
Info Bmr
25 50 75 100 125 150 175 200 Area cm2 25 50 75 100 125 150 175 200 Area cm2 FIGURE 12.20 Interfacial pressure isotherms of films formed between water and oil containing different ratios of asphaltenes and resins or asphaltenes and demulsifiers. However, the concentration needed to achieve the same effects is considerably lower when demulsifiers are used instead of resins. Demulsifier A has a quite small influence on a film of asphaltenes. From film studies above one can conclude that the best...
Info Kdr
0 20 40 60 80 100 120 140 160 Area cm2 FIGURE 12.21 Interfacial pressure isotherms of films formed between water containing different types of particles and an oil phase of pure decane. may dissolve under the influence of compression. An increased inhibitor concentration reduces the interfacial pressure, but has no influence on the film behavior. The reduced pressure is probably due to a more complete cover of inhibitor at the interface. That is, fewer components from the asphaltene fraction...
Generalized Formulation
In real systems that additionally contain electrolytes and alcohols, the number of degrees of freedom is appalling. However, the extensive research work carried out to rationalize the observed findings has shown that the formulation effect can be gathered in a single parameter, either theoretical such as Winsor's R ratio of interaction energies 2,3 or experimental such as Shinoda's phase inversion temperature PIT 14 , whose value command the phase behavior. This generalized formulation has been...
Modeling of Catastrophic Inversion
Catastrophic inversion is triggered by the addition of too much internal phase to an emulsion submitted to stirring. Main features involve the possibility of two states O W and W O , sudden jump, irreversibility, hysteresis, divergence, all characteristic of the so-called cusp catastrophe 105 . An even better match can be provided by a higher order catastrophe model, so-called butterfly 106 , which accounts for the HLD, WOR, and surfactant concentration effects on both the phase behavior at...
Theoretical Background
There are six known mechanisms of ultrasound interaction with a dispersed system Here we give only short qualitative descriptions omitting complicated mathematical models. Viscous losses of the acoustic energy occur due to the shear waves generated by the particle oscillating in the acoustic pressure field. These shear waves appear because of the difference in the densities of the particles and medium. This density contrast causes the particle motion with respect to the medium. As a result, the...
Hydraulic Behavior In A Horizontal Separator
The gas liquid and liquid liquid systems will result in two relatively separated flow systems in pipelines or separators, due to the density differences. Between the two fluids a dynamic interface will form, stratified or annular in pipelines and stratified in separators. The characteristics of such flow systems may be developing flows, entrance flows, co-current flow transition, etc. and the full dynamic interaction between the phases is important. The gas and liquid flows with rather high...
Kinetic and Thermodynamic Stability in Macroemulsions and MiniEmulsions
The majority of emulsion technology problems relate to the stabilization and destabilization of emulsions 29,164-169 . Despite the existence of many fundamental studies related to the stability of emulsions, the extreme variability and complexity of the systems involved in any specific application often pushes the oil industry to achieve technologically applicable results without developing a detailed understanding of the fundamental processes. Nevertheless, since in most cases technological...
Local Supersaturation Nanoparticle Formation
Minehan and Messing 22 contacted solutions of partially hydrolyzed tetraethoxysilane in ethanol with aqueous NH4OH solutions. Local supersaturation produced spontaneous emulsification in the aqueous phase. The drops were subsequently gelled to yield silica particles, which in some cases had diameters of order 100 nm. In recent years there has been considerable interest in using nanoparticles NPs of biodegradable polymers such as polylactide and poly D,L-lactide-co-glycolide for drug delivery...
Properties Of Bitumen Emulsions
Properties of bitumen emulsions for roads are specified in many standards. Each country usually has a national standard, although there are many similarities among the different countries. It is obvious that the national standardization bodies have to some extent copied each other. In Europe a harmonized standard will soon be launched which will make all national standards in Europe obsolete. Examples of standards on bitumen emulsions are ASTM D-977 in the U.S.A., EN 13808 in Europe and JIS K...
Local Supersaturation General Considerations
As indicated previously, the alternate to spontaneous emulsification caused by mechanical instabilities is formation of droplets in regions of local supersaturation produced by diffusion. That diffusion is responsible for emulsification in some systems has long been recognized, as discussed by Davies and Rideal 1 , who described it as diffusion and stranding. Ruschak and Miller 16 presented an analysis which clarified how and when regions of local supersaturation could develop. They started...
Stability and Rupture of Bilayer Black Films
The Newton black foam films, the Newton black emulsion films, and the bilayer lipid membranes BLM are bilayers of amphiphile molecules. Their stability in respect to rupture and their permeability can be considered from a unified point of view 102,103 . Figure 3.27 represents schematically the generally accepted molecular model of such bilayers. The description of the fluctuation formation of microscopically small holes responsible for the bilayer stability and permeability can be based on both...
breaking and adhesion
The main purpose of bitumen in asphalt is to act as a glue to bind the stones together. The emulsification of bitumen should be considered as a way of transportation of the binder bitumen to the right place between the stones in the asphalt. Once the bitumen is in the right place it should separate from the water followed by wetting the stone surface and gluing the stones together. We may call this process the breaking of the emulsion although in reality it consists of a number of different...
REFERENCES Ikm
1. Flanigan, D.A. Stolhand, J.E. Scribner, M.E. Shimoda, E. Droplet Size Analysis A New Tool for Improving Oilfield Separations. 63rd Ann. Tech. Conf. Exhib. Soc. Petr. Eng., Houston 1988, SPE 18204. 2. Geankoplis, C.J. Transport Processes and Unit Operations. Prentice Hall New Jersey, 1983. 3. Cussler, E.L. Diffusion. Mass Transfer in Fluid Systems. 2nd edition. Cambridge University Press Cambridge, 1997. 4. Jeelani, S.A.K. Hartland, S. Effect of dispersion properties on the separation of...
REFERENCES Dlo
1. Davis, H. T. Colloids and Surfaces, A Physicochemical and Engineering Aspects, 1994, 91, 9-24. 2. Israelachvili, J. N. Intermolecular and Surface Forces, Academic Press Ltd, London, 1992. 3. Shinoda, K. Friberg, S. Emulsions and Solubilization, Wiley, New York, 1986. 4. Wadle, A. Tesmann, H. Leonhard, M. F rster, T. Phase inversion in emulsions, in Surfactants in Cosmetics, Rieger, M. M. Rhein, L. D., eds, Marcel Dekker Inc, New York, Basel, 1997, 207-224. 5. Kabalnov, A. Wennerstr m, H....
REFERENCES Kkt
1. K.J. Lissant. J. Colloid. Interface Sci., 22 462, 1966. 2. H.M. Princen. J. Colloid Interface Sci., 71 55, 1979. 3. H. Kunieda, C. Solans, N. Shida and J.L. Parra. Colloids Surf. A, 24 225, 1987. 4. C. Solans, J.G. Dom nguez, J.L. Parra, J. Heuser and S.E. Friberg. Colloid Polym. Sci., 266 570, 1988. 5. C. Solans, R. Pons and H. Kunieda. In B.P. Binks ed. , Modern Aspects of Emulsion Science. Cambridge Royal Society of Chemistry, 1998, pp 367-394. 6. J.C. Ravey, M.J. St b and S. Sauvage....
Catastrophic Inversion
When the WOR is changed by addition of a phase under constant stirring, this results either in dilution or in an increase in internal phase content, the latter one being the only case of interest, with two subcases a change from normal morphology A or A- to abnormal one C or B- or vice versa. In both subcases the increase in internal phase content results in an increase in the number of drops which then tend to get closer and closer to each other until they finally touch with one another. It is...
Info Tpi
FIGURE 12.37 Illustration of the hydrodynamic radius Rh of a spherical particle with an overall negative surface charge. FIGURE 12.37 Illustration of the hydrodynamic radius Rh of a spherical particle with an overall negative surface charge. where wj s2D is a weighting function determined by the population in size range j. As real systems rarely, if ever, are truly monodisperse, numerical algorithms such as cumulant expansion Z-average 134 , CONTIN 135,136 , NNLS 137,138 etc. are required in...
Emulsifiers
Most types of emulsifier have been used for emulsification of bitumen. In the early days anionic emulsifiers were the most common, but since the 1950s cationic emulsifiers have taken over more and more. One of the advantages of cationic emulsifiers is their good adhesion to acidic stone materials like granite, which also are good construction materials in roads. Another advantage is the active breaking against the surface of acidic stones. The anionic emulsions have maintained some importance...
Characterization Of Naphthenic Acids In Crude Oils
The difference in behavior observed during the processing of acidic crudes mainly arises from the difference of the nature of the acids which is why it is expected that the isolation and characterization of naphthenic acids could be of prime importance for the prediction of the associated risks. The standard methods used to analyze naphthenic acids are discussed hereafter with a special interest to mass spectrometry. 13.2.1 Naphthenic Acids Quantification in Crude Oils There are several methods...
manufacturing and handling
Bitumen emulsions are generally of the oil-in-water type of emulsions thus most emulsifiers for bitumen emulsification are more soluble in the water phase than in the bitumen. Therefore it would be an advantage for the emulsification process if the emulsifier was added to the bitumen phase, since the migration of the emulsifier into the water phase will help the emulsification process. In the production of bitumen emulsions, however, the bitumen is usually at temperatures between 120 C and 180...
Perfection of Methods for Emulsion Stabilization Destabilization by Means of
Stability instability of an emulsion is caused by the coupling of coalescence and flocculation. Meanwhile, for emulsifiers or deemulsifiers the elaboration of their influence on the elementary act of coalescence only is mainly taken into account. The coupling of coalescence and flocculation is reflected in Equation 1.135 and one concludes that it follows the multiplicativity rule and not the additivity rule. This means that the total result of the application of a stabilizer destabilizer...
Mow 1
FIGURE 4.21 Transitional inversion produced by adding water in the case in which it results in a formulation change. that very slight variations in such corner paths produce huge variations in the resulting drop size after inversion. In most cases the mixed concomitant variations of formulation and WOR, and sometimes surfactant cosurfactant concentration, is not voluntary, but comes from the protocol. For instance, the addition of one phase can result in different effects which are likely to...
Info Qev
FIGURE 14.14 Stability of the emulsion formed of crude model oil Gu Dong 4 and distilled water a or 1.2 Na2CO3 water solution b , 60 C. in the asphaltene fraction react with Na2CO3 solution and form soap-like interfacially active components which accumulate at the oil water interface and form a rigid film around water droplets. Therefore, the film is able to prevent the coalescence of the droplets. The result also shows that the mechanical strength of the interfacial film can increase with the...
Iiqab
Institute of Physical Chemistry Bulgarian Academy of Sciences Sofia, Bulgaria Department of Chemical Engineering Norwegian University of Science and Technology Trondheim, Norway Dispersion Technology Inc. Bedford Hills, New York, USA University of Petroleum Beijing, China Department of Chemical Engineering Norwegian University of Science and Technology Trondheim, Norway Complex Flow Design AS Trondheim, Norway Champion Technologies Delden, Netherlands Department of Chemical Engineering...