What Causes the Formation of Water-in-Oil Emulsions?

2001 ◽  
Vol 2001 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Mervin F. Fingas ◽  
Ben Fieldhouse ◽  
James Lane ◽  
Joseph V. Mullin
Keyword(s):  
Chemical Composition ◽  
Shear Rate ◽  
Resin Content ◽  
Stable Emulsion ◽  
Oil Viscosity ◽  
The Past ◽  
Asphaltene Content ◽  
Oil Emulsions ◽  
The Stability ◽  
Unstable Emulsion

ABSTRACT The results of studies conducted over the past 6 years to characterize why water-in-oil emulsions form are summarized. It is shown that water droplets are held in oil by a combination of viscous and interfacial forces. The stability of an emulsion is very important in understanding its formation because stability is the endpoint or measurement of the entire process. Emulsions can be grouped into three categories: stable, unstable, and mesostable. Each has distinct physical properties. For example, the viscosity of a stable emulsion at a shear rate of I reciprocal second is at least three orders-of-magnitude greater than that of the starting oil. An unstable emulsion usually has a viscosity no more than two orders-of-magnitude greater than that of the starting oil. The zero-shear-rate viscosity is at least six orders-of-magnitude greater than the starting oil for a stable emulsion. For an unstable emulsion, it is usually less than two or three orders-of-magnitude greater than the viscosity of the starting oil. and finally, a stable emulsion has a significant elasticity, whereas an unstable emulsion does not. The stability of emulsions has been studied by examining their asphaltene content and their resin content. Results are reported showing that asphaltenes and resins are responsible for stability. It is noted that, given the correct chemical composition, primarily asphaltenes, sea energy is needed. The properties of the starting oil are the important factor in determining what type of water-in-oil state is produced. Composition and property ranges are given for the starting oil to form each of the water-in-oil states. Important property factors are the asphaltene content, resin content, and starting oil viscosity.

Emulsification of Water and Pyrolysis Oil by Sorbitol Derivative Surfactants

2014 ◽  
Vol 633-634 ◽  
pp. 537-540 ◽  
Author(s):  
Prakorn Kittipoomwong ◽  
Monpilai Narasingha
Keyword(s):  
Surfactant Concentration ◽  
Pyrolysis Oil ◽  
Stable Emulsion ◽  
Sorbitan Monooleate ◽  
Oil Emulsion ◽  
Hydrophilic Lipophilic Balance ◽  
Average Water ◽  
Span 80 ◽  
Oil Emulsions ◽  
The Stability

Effects of sorbitol derivative surfactants on the stability of pyrolysis oil emulsion prepared from plastic waste were experimentally investigated. The water-pyrolysis oil mixture emulsified by Sorbitan monooleate (Span 80) surfactant is more stable than the water-in-oil emulsions prepared by other Sorbitol derivative surfactants which have lower hydrophilic-lipophilic balance (HLB) numbers. The Span 80 concentration of 1.5% by volume was found to produce the most stable emulsion and the smallest average water droplet. This optimal surfactant concentration is the same as critical micelle concentration.

scholarly journals The Effect of Weighting Materials on the Rheological Properties of Iraqi and Commercial Bentonite in Direct Emulsion

2021 ◽  
Vol 54 (1F) ◽  
pp. 110-121
Author(s):  
Amel Habeeb Assi
Keyword(s):  
Rheological Properties ◽  
Oil Shale ◽  
Drilling Fluid ◽  
Methyl Cellulose ◽  
Stable Emulsion ◽  
Emulsifying Agent ◽  
Oil Emulsions ◽  
The Stability ◽  
Filtration Properties

Numerous drilling additives and materials are used continuously because they are necessary to support and give the required properties of the drilling fluid so that to ensure the stability of the borehole. This paper aspires to evaluate the rheological properties of bentonite (montmorillonite) Trefawey as an alternative to using commercial bentonite. Monitoring and evaluating of the rheological and filtration properties were prepared. This exertion aims to focus on the effect of hematite, and barite on the rheological properties of the three aforementioned bentonite types. An improvement in the rheological properties of bentonite (montmorillonite). Trefawey was observed after adding the previous heavy materials. Hematite has by some means better ability to improve rheological properties compared to other heavy materials. The emulsifying agent used was Carboxyl Methyl Cellulose (HOCH2COONA), as it has provided excellent results parallel to the lignite. The rheological properties of bentonite (montmorillonite) Trefawey are enhanced by doubling the amount of carboxyl methyl cellulose (HOCH2COONA). The results have proved that the use of weighting materials and emulsifying agent affected the rheological properties of bentonite (montmorillonite) Trefawey in a direct emulsion. The results have shown that it is more appropriate to use carboxyl methyl cellulose as an emulsifying agent to prepare a direct emulsion than bentonite (montmorillonite) Trefawey due to its excellent effect in improving the rheological properties of bentonite (montmorillonite) Trefawey. And it can be said that this effort has succeeded in studying two effects simultaneously. In other words, both heavy substances and emulsifying agent have effects on bentonite (montmorillonite) Trefawey, in order to obtain a stable emulsion and a clearer view of the behavior of Iraqi bentonite. The above effort has focused on making bentonite (montmorillonite) Trefawey suitable for the nature of geological layers such as oil shale, limestone and sandstone. This means preparing drilling fluid using bentonite (montmorillonite) Trefawey to drill the above structures. The study has concluded that it is better to use bentonite (montmorillonite) Trefawey in preparing direct oil emulsions as a stable and successful alternative of imported bentonite.

WATER-IN-OIL EMULSIONS: HOW THEY ARE FORMED AND BROKEN

1995 ◽  
Vol 1995 (1) ◽  
pp. 829-830 ◽  
Author(s):  
Merv Fingas ◽  
Ben Fieldhouse ◽  
Joe Mullin
Keyword(s):  
Shear Rate ◽  
Water Content ◽  
Analytical Methods ◽  
Commercial Products ◽  
Visual Appearance ◽  
Closed Systems ◽  
Oil Emulsions ◽  
The Stability

ABSTRACT Studies on the formation of emulsions were summarized, and analytical methods used to determine the final results of the emulsion breaking process were evaluated. These include visual appearance, viscosity, zero-shear-rate viscosity, elasticity, water content, and conductivity. All but the latter two are useful for determining the stability of an emulsion. The development of four new tests was reviewed. These test the effectiveness of emulsion breakers in open and closed systems and emulsion preventers in open and closed systems. Results of testing on commercial products are presented.

Pemanfaatan Metil Ester Sulfonat pada Pembuatan Deterjen Cair

2016 ◽  
Vol 7 (14) ◽  
pp. 143-155
Author(s):  
Eldha Sampepana ◽  
Suroto Hadi Saputra
Keyword(s):  
Fatty Acids ◽  
Methyl Ester ◽  
Linear Alkylbenzene Sulfonate ◽  
Emulsion Stability ◽  
Alcohol Sulfate ◽  
Stable Emulsion ◽  
Linear Alkylbenzene ◽  
Alkylbenzene Sulfonate ◽  
The Stability ◽  
The Right

In the manufacture of detergents still using surfactants (which serves as an emulsifier) of crude oil in the form of the AS. (alcohol sulfate) and LAS (linear alkylbenzene sulfonate), where this type of surfactant cannot be degraded by microorganisms when discharged into the environment, causing environmental pollution. Methyl ester sulfonate surfactant is an anionic surfactant which has a composition of C16 - C18 fatty acids are capable of acting against nature deterjensinya, while the C12 - C14 fatty acids contribute to the foaming effect. The purpose of this study was to look for the formulation of methyl ester sulfonate (MES) the right to produce a good detergent by using materials such as methyl ester sulfonate surfactant self-made, methyl ester sulfonate and sodium lauryl market Ester Sulfate (SLS) with a concentration of 15 %, 20 % and 25 %. Detergent results of the study have high detergency ( net ) compared with the detergency of detergent commercial, have a stable emulsion stability, the stability of the foam/foam detergent power made from methyl ester sulfonate surfactant produces less foam, compared with a detergent made from SLS and surfactant SNI 06-4075-1996 standards.

Stability and Folding of the Unusually Stable Hemoglobin from Synechocystis is Subtly Optimized and Dependent on the Key Heme Pocket Residues.

2020 ◽  
Vol 27 ◽  
Author(s):  
Sheetal Uppal ◽  
Mohd. Asim Khan ◽  
Suman Kundu
Keyword(s):  
Molten Globule ◽  
Life Forms ◽  
Model System ◽  
Heme Pocket ◽  
The Past ◽  
Specific Manner ◽  
Delivery Vehicles ◽  
The Stability ◽  
Key Residues ◽  
Synechocystis Sp

Aims: The aim of our study is to understand the biophysical traits that govern the stability and folding of Synechocystis hemoglobin, a unique cyanobacterial globin that displays unusual traits not observed in any of the other globins discovered so far. Background: For the past few decades, classical hemoglobins such as vertebrate hemoglobin and myoglobin have been extensively studied to unravel the stability and folding mechanisms of hemoglobins. However, the expanding wealth of hemoglobins identified in all life forms with novel properties, like heme coordination chemistry and globin fold, have added complexity and challenges to the understanding of hemoglobin stability, which has not been adequately addressed. Here, we explored the unique truncated and hexacoordinate hemoglobin from the freshwater cyanobacterium Synechocystis sp. PCC 6803 known as “Synechocystis hemoglobin (SynHb)”. The “three histidines” linkages to heme are novel to this cyanobacterial hemoglobin. Objective: Mutational studies were employed to decipher the residues within the heme pocket that dictate the stability and folding of SynHb. Methods: Site-directed mutants of SynHb were generated and analyzed using a repertoire of spectroscopic and calorimetric tools. Result: The results revealed that the heme was stably associated to the protein under all denaturing conditions with His117 playing the anchoring role. The studies also highlighted the possibility of existence of a “molten globule” like intermediate at acidic pH in this exceptionally thermostable globin. His117 and other key residues in the heme pocket play an indispensable role in imparting significant polypeptide stability. Conclusion: Synechocystis hemoglobin presents an important model system for investigations of protein folding and stability in general. The heme pocket residues influenced the folding and stability of SynHb in a very subtle and specific manner and may have been optimized to make this Hb the most stable known as of date. Other: The knowledge gained hereby about the influence of heme pocket amino acid side chains on stability and expression is currently being utilized to improve the stability of recombinant human Hbs for efficient use as oxygen delivery vehicles.

scholarly journals Copper Phyllosilicates-Derived Catalysts in the Production of Alcohols from Hydrogenation of Carboxylates, Carboxylic Acids, Carbonates, Formyls, and CO2: A Review

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 255
Author(s):  
Dien-Thien To ◽  
Yu-Chuan Lin
Keyword(s):  
Carboxylic Acids ◽  
Catalytic Performance ◽  
Spatial Effect ◽  
Synthesis Methods ◽  
The Past ◽  
Surface Areas ◽  
Preparation Conditions ◽  
Remedial Actions ◽  
The Stability ◽  
Size Interaction

Copper phyllosilicates-derived catalysts (CuPS-cats) have been intensively explored in the past two decades due to their promising activity in carbonyls hydrogenation. However, CuPS-cats have not been completely reviewed. This paper focuses on the aspects concerning CuPS-cats from synthesis methods, effects of preparation conditions, and dopant to catalytic applications of CuPS-cats. The applications of CuPS-cats include the hydrogenation of carboxylates, carboxylic acids, carbonates, formyls, and CO2 to their respective alcohols. Besides, important factors such as the Cu dispersion, Cu+ and Cu0 surface areas, particles size, interaction between Cu and supports and dopants, morphologies, and spatial effect on catalytic performance of CuPS-cats are discussed. The deactivation and remedial actions to improve the stability of CuPS-cats are summarized. It ends up with the challenges and prospective by using this type of catalyst.

scholarly journals Thermodynamic and Energy Efficiency Analysis of a Domestic Refrigerator Using Al2O3 Nano-Refrigerant

2021 ◽  
Vol 13 (10) ◽  
pp. 5659
Author(s):  
Farhood Sarrafzadeh Javadi ◽  
Rahman Saidur
Keyword(s):  
Temperature Gradient ◽  
Technological Changes ◽  
Nanoparticle Concentration ◽  
Evaporator Temperature ◽  
Domestic Refrigerator ◽  
The Past ◽  
Nano Lubricant ◽  
The Stability ◽  
Energy Efficiency Analysis ◽  
Al2o3 Nanofluid

Refrigeration systems have experienced massive technological changes in the past 50 years. Nanotechnology can lead to a promising technological leap in the refrigeration industry. Nano-refrigerant still remains unknown because of the complexity of the phase change process of the mixture including refrigerant, lubricant, and nanoparticle. In this study, the stability of Al2O3 nanofluid and the performance of a nano-refrigerant-based domestic refrigerator have been experimentally investigated, with the focus on the thermodynamic and energy approaches. It was found that by increasing the nanoparticle concentration, the stability of nano-lubricant was decreased and evaporator temperature gradient was increased. The average of the temperature gradient increment in the evaporator was 20.2% in case of using 0.1%-Al2O3. The results showed that the energy consumption of the refrigerator reduced around 2.69% when 0.1%-Al2O3 nanoparticle was added to the system.

scholarly journals Water confined in solutions of biological relevance

2020 ◽  
Vol 92 (10) ◽  
pp. 1563-1574
Author(s):  
Marie-Claire Bellissent-Funel
Keyword(s):  
Aqueous Solutions ◽  
Bulk Water ◽  
Biological Macromolecules ◽  
Organic Solutes ◽  
Confined Water ◽  
The Past ◽  
Structure And Dynamics ◽  
Biological Relevance ◽  
The Stability

AbstractIn many relevant situations, water is not in its bulk form but instead attached to some substrates or filling some cavities. We shall call water in the latter environment confined water as opposed to bulk water. It is known that the confined water is essential for the stability and the function of biological macromolecules. In this paper, we provide a review of the experimental and computational advances over the past decades concerning the understanding of the structure and dynamics of water confined in aqueous solutions of biological relevance. Examples involving water in solution of organic solutes (cryoprotectants such as dimethylsulfoxide (DMSO), sugars such as trehalose) are provided.

Future Directions in Surface Electromyography

Biofeedback ◽  
2010 ◽  
Vol 38 (2) ◽  
pp. 78-82 ◽  
Author(s):  
John G. Arena
Keyword(s):  
Surface Electromyography ◽  
Ambulatory Monitoring ◽  
Future Directions ◽  
The Past ◽  
Psychophysiological Assessment ◽  
The Future ◽  
The Stability

Abstract The use of surface electromyography (SEMG) has increased exponentially in the past four decades. SEMG is one of the most widespread measures employed today in psychophysiological assessment and one of three primary biofeedback modalities. This article briefly outlines three areas that the author believes are important for SEMG to address if it is to continue to flourish in the future: applications in telehealth, the use of telemetry and ambulatory monitoring, and studies on the stability or reliability of surface electromyography.

Stability Considerations in Downward Miscible Displacements

1964 ◽  
Vol 4 (04) ◽  
pp. 356-362 ◽  
Author(s):  
J.M. Dumore
Keyword(s):  
Transition Zone ◽  
Viscous Fingering ◽  
Favorable Effect ◽  
Homogeneous Layer ◽  
Oil Viscosity ◽  
Critical Rate ◽  
Miscible Displacements ◽  
Viscous Fingers ◽  
The Stability ◽  
Definition Of

Abstract If, in a vertical, downward miscible displacement, the transition zone between the displacing and displaced fluids is neglected, a criterion for stable displacement can be obtained by considering a small hypothetical protrusion of one of the fluids into the other. This criterion leads to the definition of the well-known critical rate, uc = kg ??/?µ. The consideration is further extended by taking into account the transition zone that develops as a result of diffusion and mixing. A generalization of the previous criterion leads to the definition of another characteristic rate, the stable rate, which in actual miscible drives will be less than the critical rate. In such drives, the entire transition zone is stable at rates less than the stable rate. At rates between the stable and critical rates, the displacement is only partly stable, i.e. part of the transition zone adjacent to the displaced fluid is in an unstable position. From that part of the transition zone viscous fingers will develop. At rates greater than the critical rate the entire displacement is unstable and viscous fingers will develop more strongly. Results of laboratory experiments are in agreement with the expected behavior based on the theoretically deduced stability of the displacement. INTRODUCTION The simplest form of miscible drive in an oil-bearing formation is the injection of a fluid that is completely miscible* with the oil under reservoir conditions. In general, such a fluid, a solvent for example, is less dense and less viscous than the oil present in the formation. If it is injected into a horizontal homogeneous layer, gravitational forces will lead to the formation of a gravity tongue of solvent in the upper part of the layer and the adverse solvent-oil viscosity ratio will cause viscous fingers to develop. If, however, the solvent is injected up-structure into a dipping layer, gravity has a favorable effect, because it tends to keep the less dense solvent up-structure. Tongue formation and viscous fingering are consequently reduced and it is even possible that they will be suppressed completely. Viscous fingering and gravity tonguing are the consequences of the instability of the displacement. A stable displacement cannot result in growing viscous fingers and/or growing gravity tongues. Since large amounts of oil can be bypassed if there is viscous fingering and/or gravity tonguing, the stability of a miscible drive is very important with respect to the recovery efficiency of the drive. The stability is of particular importance in miscible-slug drives, as it determines how quickly the miscible slug between the displaced and displacing fluids will be distorted and broken up, after which the drive is no longer completely miscible. Stability is thus a most important factor in determining the success of a miscible drive, and it is considered that the aspects of stability considered in this paper will make a useful contribution to existing theories. Consideration is given only to vertical downward displacements, in which no gravity tongues can develop and which are therefore simpler than downward displacements in sloping layers.

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