scholarly journals Rheological properties and flow behaviour of wax-stabilized water-in-oil emulsions

2021 ◽  
Author(s):  
Samira Haj-Shafiei
Keyword(s):  
Rheological Properties ◽  
Initial Temperature ◽  
Rheological Behaviour ◽  
Flow Behaviour ◽  
Paraffin Wax ◽  
Oscillatory Rheology ◽  
Initial Deposition ◽  
Oil Emulsions ◽  
Light Mineral ◽  
Glycerol Monooleate

The objective of this study was to characterize the flow and rheological behaviour of model wax-stabilized water-in-oil (W/O) emulsions consisting of light mineral oil, paraffin wax and glycerol monooleate as the oil phase and water as the dispersed aqueous phase. An[sic] laboratory-scale benchtop flowloop system was used to explore the flow behaviour of the emulsions' oil phase (oil, paraffin wax and surfactant). The key contribution from this work was that the higher initial temperature gradient (40°C compared to 19°C) experienced by the rapidly-cooled oil led to more initial deposition on the flowloop inner wall. The rheological properties of W/O emulsions with different water cuts (10-50wt%) were also studied. Rotational, oscillatory rheology and creep compliance and recovery were characterized on emulsions aged up to 28 days. Overall, the results demonstrated that emulsion composition, and age could significantly influence an emulsion's flow behaviour and rheological properties.

scholarly journals Rheological properties and flow behaviour of wax-stabilized water-in-oil emulsions

2021 ◽  
Author(s):  
Samira Haj-Shafiei
Keyword(s):  
Rheological Properties ◽  
Initial Temperature ◽  
Rheological Behaviour ◽  
Flow Behaviour ◽  
Paraffin Wax ◽  
Oscillatory Rheology ◽  
Initial Deposition ◽  
Oil Emulsions ◽  
Light Mineral ◽  
Glycerol Monooleate

The objective of this study was to characterize the flow and rheological behaviour of model wax-stabilized water-in-oil (W/O) emulsions consisting of light mineral oil, paraffin wax and glycerol monooleate as the oil phase and water as the dispersed aqueous phase. An[sic] laboratory-scale benchtop flowloop system was used to explore the flow behaviour of the emulsions' oil phase (oil, paraffin wax and surfactant). The key contribution from this work was that the higher initial temperature gradient (40°C compared to 19°C) experienced by the rapidly-cooled oil led to more initial deposition on the flowloop inner wall. The rheological properties of W/O emulsions with different water cuts (10-50wt%) were also studied. Rotational, oscillatory rheology and creep compliance and recovery were characterized on emulsions aged up to 28 days. Overall, the results demonstrated that emulsion composition, and age could significantly influence an emulsion's flow behaviour and rheological properties.

scholarly journals Relationships Between Fat Crystal Characteristics and Emulsion Stability in Water in Oil Systems

2021 ◽  
Author(s):  
Shane Mason Hodge
Keyword(s):  
Polarized Light ◽  
Model System ◽  
Paraffin Wax ◽  
Crystal Habit ◽  
X Ray Diffraction ◽  
State Transformation ◽  
Solid State Transformation ◽  
Experimental Protocols ◽  
Oil Emulsions ◽  
Light Mineral

Investigations were made into the stabilization of water in oil emulsions using crystalline particles of paraffin wax and fully hydrogenated canola and cottonseed oils. A model system was studied to develop a methodology of study and provide a benchmark for a subsequent study of a real-world system. The model system involved the use of light mineral oil, purified water, paraffin wax and glycerol monooleate emulsifier. The wax was crystallized prior to and following emulsification. Prepared emulsion samples were monitored for sedimentation and flocculation behaviour. Measurements of coalescence were obtained by pulsed field gradient NMR. Formation of the solid crystalline wax phase following emulsification resulted in emulsions more stable to flocculation and coalescence than samples containing the same amount of wax crystallized prior to emulsification. Analysis of emulsion samples with polarized light microscopy showed the wax crystals were associated with the water droplet interfaces rather than dispersed freely within the continuous oil phase. Another investigation employed similar experimental protocols but incorporated food-grade materials. Two different solid fats were used, chosen for their differing polymorphic (crystal habit) behaviour. Solid crystals of canola stearine (ß-tending) and cottonseed stearine (ß-tending) were compared in their abilities to stabilize emulsions at levels of addition between 0 and 2%. Each type of fat was incorporated into the emulsion in a pre-crystallized state, or while melted and crystallized following emulsification. Cottonseed stearine was found to be in the ß polymorph when quickly crystallized following emulsification from 45⁰ to 5⁰C over 6 minutes. Further calorimetric and X-ray diffraction investigations revealed this crystallization behaviour was a result of a solid-state transformation via an imperfectly formed ß̕ intermediate. With respect to the post-crystallized emulsions, where the polymorphism of the two fats were both in the ß-form, the canola stearine provided better stabilization against coalescence than the cottonseed stearine. This observation coincided with a stronger energy of interfacial attachment for crystallized canola than for cottonseed as calculated from measurements of contact angle and interfacial tension. With the pre-crystallized system, incorporation of cottonseed stearine resulted in reduced sedimentation and coalescence compared to samples containing pre-crystallized canola stearine. This difference was attributed to the presence of fine shards of ß̕-form crystals. The system that imparted the highest degree of overall stability incorporated the use of canola stearine srystallized following emulsification.

scholarly journals Flow behaviour of water-in-oil emulsions stabilized by wax crystals

2021 ◽  
Author(s):  
Roomana Aafaqi
Keyword(s):  
Crude Oil ◽  
Pipe Wall ◽  
Rheological Behaviour ◽  
Flow Behaviour ◽  
Large Temperature ◽  
Gelation Temperature ◽  
Emulsion Flow ◽  
Oil Emulsions ◽  
Polyglycerol Polyricinoleate ◽  
Wax Crystals

The large temperature gradients experienced by crude oil emulsions in pipelines found in colder environments can lead to the precipitation, deposition and build-up of wax-like species from the crude oil onto the pipe wall that result in flow assurance problems. The objective of this thesis was to understand the rheological behaviour of model water-in-oil emulsions stabilized by wax crystals. The microstructure, phase transitions and rheology of model emulsions constisting of water, mineral oil, parrafin wax and the emulsifier polyglycerol polyricinoleate (PgPr) were investigated. Changes in emulsion flow begaviour (steady state and dynamic) as a function of composition, termperature and passage through a laboratory-scale flowloop were investigated, with these parameters significantly affecting shear flow, yield stress and viscoelasticity. The gelation temperature of wax-containing ('waxy') oil was slightly lower than that of its equivalent emulsion due to differences in the structure of the gelled emulsion network. Overall, this study successfully showed that there exist significant differences in the microstructure and flow behaviour of model crude oil emulsions when wax and a dispersed aqueous phase are present.

scholarly journals Relationships Between Fat Crystal Characteristics and Emulsion Stability in Water in Oil Systems

2021 ◽  
Author(s):  
Shane Mason Hodge
Keyword(s):  
Polarized Light ◽  
Model System ◽  
Paraffin Wax ◽  
Crystal Habit ◽  
X Ray Diffraction ◽  
State Transformation ◽  
Solid State Transformation ◽  
Experimental Protocols ◽  
Oil Emulsions ◽  
Light Mineral

Investigations were made into the stabilization of water in oil emulsions using crystalline particles of paraffin wax and fully hydrogenated canola and cottonseed oils. A model system was studied to develop a methodology of study and provide a benchmark for a subsequent study of a real-world system. The model system involved the use of light mineral oil, purified water, paraffin wax and glycerol monooleate emulsifier. The wax was crystallized prior to and following emulsification. Prepared emulsion samples were monitored for sedimentation and flocculation behaviour. Measurements of coalescence were obtained by pulsed field gradient NMR. Formation of the solid crystalline wax phase following emulsification resulted in emulsions more stable to flocculation and coalescence than samples containing the same amount of wax crystallized prior to emulsification. Analysis of emulsion samples with polarized light microscopy showed the wax crystals were associated with the water droplet interfaces rather than dispersed freely within the continuous oil phase. Another investigation employed similar experimental protocols but incorporated food-grade materials. Two different solid fats were used, chosen for their differing polymorphic (crystal habit) behaviour. Solid crystals of canola stearine (ß-tending) and cottonseed stearine (ß-tending) were compared in their abilities to stabilize emulsions at levels of addition between 0 and 2%. Each type of fat was incorporated into the emulsion in a pre-crystallized state, or while melted and crystallized following emulsification. Cottonseed stearine was found to be in the ß polymorph when quickly crystallized following emulsification from 45⁰ to 5⁰C over 6 minutes. Further calorimetric and X-ray diffraction investigations revealed this crystallization behaviour was a result of a solid-state transformation via an imperfectly formed ß̕ intermediate. With respect to the post-crystallized emulsions, where the polymorphism of the two fats were both in the ß-form, the canola stearine provided better stabilization against coalescence than the cottonseed stearine. This observation coincided with a stronger energy of interfacial attachment for crystallized canola than for cottonseed as calculated from measurements of contact angle and interfacial tension. With the pre-crystallized system, incorporation of cottonseed stearine resulted in reduced sedimentation and coalescence compared to samples containing pre-crystallized canola stearine. This difference was attributed to the presence of fine shards of ß̕-form crystals. The system that imparted the highest degree of overall stability incorporated the use of canola stearine srystallized following emulsification.

scholarly journals Flow behaviour of water-in-oil emulsions stabilized by wax crystals

2021 ◽  
Author(s):  
Roomana Aafaqi
Keyword(s):  
Crude Oil ◽  
Pipe Wall ◽  
Rheological Behaviour ◽  
Flow Behaviour ◽  
Large Temperature ◽  
Gelation Temperature ◽  
Emulsion Flow ◽  
Oil Emulsions ◽  
Polyglycerol Polyricinoleate ◽  
Wax Crystals

The large temperature gradients experienced by crude oil emulsions in pipelines found in colder environments can lead to the precipitation, deposition and build-up of wax-like species from the crude oil onto the pipe wall that result in flow assurance problems. The objective of this thesis was to understand the rheological behaviour of model water-in-oil emulsions stabilized by wax crystals. The microstructure, phase transitions and rheology of model emulsions constisting of water, mineral oil, parrafin wax and the emulsifier polyglycerol polyricinoleate (PgPr) were investigated. Changes in emulsion flow begaviour (steady state and dynamic) as a function of composition, termperature and passage through a laboratory-scale flowloop were investigated, with these parameters significantly affecting shear flow, yield stress and viscoelasticity. The gelation temperature of wax-containing ('waxy') oil was slightly lower than that of its equivalent emulsion due to differences in the structure of the gelled emulsion network. Overall, this study successfully showed that there exist significant differences in the microstructure and flow behaviour of model crude oil emulsions when wax and a dispersed aqueous phase are present.

Comparative Analysis of the Rheological Behaviour of Irvingia Gabonensis Ogbono and Foreign Polymer for Bentonite Formulated Mud.

2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
David Ekuma ◽  
Ikechukwu Okafor ◽  
Innocent Nweze
Keyword(s):  
Rheological Properties ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Research Work ◽  
Rheological Behaviour ◽  
Oil And Gas Industry ◽  
Drilling Mud ◽  
Gas Industry ◽  
Local Product ◽  
Irvingia Gabonensis

Abstract Drilling fluid are complex fluids consisting of several additives. These additives are added to enhance and control the rheological properties (such as viscosity, gel strength and yield point) of the mud. These properties are controlled for effective drilling of a well. This research work is focused on determining the rheological behavior of drilling mud using industry-based polymer and Irvingia Gabonensis (ogbono) as viscosifiers. Water based muds were formulated from the aforementioned locally sourced viscosifier and that of the conventional used viscosifier (Carboxylmetyl cellulose, CMC). Laboratory tests were carried out on the different muds formulated and their rheological properties (such as yield stress, shear stress, plastic viscosity and shear rate) are evaluated. The concentration of the viscosifiers were varied. The expected outcome of the research work aims at lowering the total drilling cost by reducing the importation of foreign polymer which promotes the development of local content in the oil and gas industry. The research compares the rheology of mud samples and the effect of varying the concentration (2g, 4g, 6g, 8g, and 10g) of both CMC and Ogbono and determining the changes in their rheological properties. The total volume of each mud sample is equivalent to 350ml which represent one barrel (42gal) in the lab. From the result, at concentration of 2g, the ogbono mud has a better rheology than the CMC mud, but at a concentration above 2g, CMC mud shows a better rheology than ogbono mud, that is, as the concentration of CMC is increased, the rheological properties of the mud increased while as the concentration of ogbono is increased the rheological properties decreased. The viscosity of the drilling fluid produced from the ogbono were lower than that of CMC, it could be used together with another local product such as cassava starch, offor or to further improve the rheology and then be a substitute to the conventional viscosifiers.

scholarly journals Rheological properties of emulsions stabilized by green banana (Musa cavendishii) pulp fitted by power law model

2009 ◽  
Vol 52 (6) ◽  
pp. 1541-1553 ◽  
Author(s):  
Dayane Rosalyn Izidoro ◽  
Agnes de Paula Scheer ◽  
Maria-Rita Sierakowsk
Keyword(s):  
Response Surface Methodology ◽  
Rheological Properties ◽  
Response Surface ◽  
Power Law ◽  
Cone Angle ◽  
Rheological Behaviour ◽  
Quadratic Model ◽  
Soy Oil ◽  
Power Law Model ◽  
Green Banana

In this work, the rheological behaviour of emulsions (mayonnaises) stabilized by green banana pulp using the response surface methodology was studied. In addition, the emulsions stability was investigated. Five formulations were developed, according to design for constrained surfaces and mixtures, with the proportion, respectively: water/soy oil/green banana pulp: F1 (0.10/0.20/0.70), F2 (0.20/0.20/0.60), F3 (0.10/0.25/0.65), F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625) .Emulsions rheological properties were performed with a rotational Haake Rheostress 600 rheometer and a cone and plate geometry sensor (60-mm diameter, 2º cone angle), using a gap distance of 1mm. The emulsions showed pseudoplastic behaviour and were adequately described by the Power Law model. The rheological responses were influenced by the difference in green banana pulp proportions and also by the temperatures (10 and 25ºC). The formulations with high pulp content (F1 and F3) presented higher shear stress and apparent viscosity. Response surface methodology, described by the quadratic model,showed that the consistency coefficient (K) increased with the interaction between green banana pulp and soy oil concentration and the water fraction contributed to the flow behaviour index increase for all emulsions samples. Analysis of variance showed that the second-order model had not significant lack-of-fit and a significant F-value, indicating that quadratic model fitted well into the experimental data. The emulsions that presented better stability were the formulations F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625).

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