Dissertations / Theses: 'Oil-in-water emulsion'

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Hu, Binjie. "Cross flow microfiltration of water in oil emulsion." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366591.

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Ligiero, Leticia. "Crude oil/water interface characterization and its relation to water-in-oil emulsion stability." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3048/document.

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La formation d’émulsions stables eau/huile lors des processus de récupération et de raffinage du pétrole peut impacter défavorablement l’efficacité de ces opérations. Bien que résines et asphaltènes soient généralement tenus pour responsables de la stabilité des émulsions, la composition exacte des molécules présentes à l’interface eau/huile est en réalité assez mal connue. L’identification de ces molécules et la connaissance de leur influence sur la propriété des interfaces est une étape nécessaire pour mieux prédire les problèmes de stabilité des émulsions dans l’industrie pétrolière. Cette thèse présente des résultats de caractérisation analytique par GPC-ICP-HRMS et FTMS du matériel interfacial (IM) extrait de quatre bruts différents et des espèces transférées dans la phase aqueuse lorsque ces bruts contactent l’eau, ainsi que des propriétés rhéologiques en cisaillement et en dilatation des interfaces eau/huile en présence de ces composés. Les bruts ont été choisis en raison de leur capacité à former des émulsions eau-dans-huile de stabilités différentes. Les mesures d’élasticité de cisaillement ont montré que la majorité des interfaces eau/huile étudiées formaient une structure élastique susceptible de fausser la mesure du module dilatationnel de Gibbs par la méthode d’analyse du profil de goutte. Néanmoins, nous montrons à l’aide de simulations numériques que le module apparent Eapp mesuré dans un tel cas est proche de la somme du module de Gibbs et du module de cisaillement (G) multiplié par 2 du réseau interfacial dès lors que G reste petit (G < 10 mN/m), ce qui est très souvent le cas puisque nous observons que le réseau interfacial formé se rompt lors des expériences de dilatation. Une équation phénoménologique a été développée permettant d’attribuer un temps de relaxation unique aux processus de relaxation qui ont lieu aux interfaces eau/huile, ce qui nous permet de classer les différents systèmes entre eux. Nous avons également étudié les IM extraits des bruts selon la technique chromatographique dite « wet silica method » récemment développée par Jarvis et al. (Energy Fuels, 2015). Les expériences de rhéologie interfaciale confirment que cette méthode permet d’extraire les composés les plus tensioactifs présents aux interfaces eau-brut. Les analyses chimiques montrent que les IM sont partiellement composés d’asphaltènes et suggèrent que les composés contenant du soufre jouent un rôle important dans la stabilité des émulsions. Enfin, nous avons trouvé que les composés hydrosolubles transférés du brut à l’eau ont un comportement bénéfique, dans le sens où leur présence rend les émulsions eau-dans-brut moins stables. L’analyse FTMS de ces composés montre qu’ils appartiennent aux classes d’hétéroatomes suivant : O2, O3, S1, OS et O2S2 et qu’une partie de ces composés appartient à la classe des asphaltènes
Crude oil recovery and refining operations rely on high consumption water processes, which may induce the formation of stable water-in-oil emulsions. Although asphaltenes and resins are known to influence the stability of crude oil emulsions, much is still unknown about the real composition of the w/o interfacial layer. Therefore, identifying these molecules and understanding their impact on the w/o interfacial properties are key points for better predicting emulsion problems in the petroleum industry. This thesis presents results on water/oil (w/o) interface characterization using shear and dilatational interfacial rheology as well as results on molecular characterization (GPC-ICP-HRMS and FTMS) of the crude oil interfacial material (IM) and of the amphiphilic crude oil species, which are transferred to the aqueous phase during the emulsification process. Four crude oils forming w/o emulsions of different stability were used in this study. Shear interfacial rheology experiments showed that most of the studied w/o interfaces were capable of forming an elastic interfacial network exhibiting shear elasticity G. A non-null G value interferes on drop deformation and thus on drop shape analysis (DSA) results. Nevertheless, the dilatational elasticity modulus measured by DSA (Eapp) was found to be representative of the sum of the Gibbs modulus plus 2 times G, as long as G  10 mN/m. This condition is generally satisfied since the asphaltene network is broken during dilatational experiments. Consequently, Eapp gives a good approximation of the real Gibbs modulus of the interface. A new phenomenological equation was proposed to fit the dilatational Eapp experimental data, allowing the assignment of a unique characteristic time to describe the w/o interfacial relaxation process and thus sample comparison. The IM of the crude oils was extracted using the “wet silica method” recently developed by Jarvis et al. (Energy Fuels, 2015). Results showed that this method collects the most-surface active compounds that adsorb in the time frame of the extraction procedure. Successive extractions collected species that were larger and less concentrated in the crude oil, but with higher adsorption energies. Molecular characterization revealed that the IM was partially composed of asphaltene compounds, and suggested that sulfur-containing compounds may play a major role in emulsion stability. Lastly, the oil-to-water transferred species were proven to impact the w/o interfacial properties and emulsion stability. Interestingly, concentrating these water-soluble species led to more efficient crude oil dehydration. FTMS analysis of the transferred species revealed that part of the compounds belonged to O2, O3, S1, OS and O2S2 heteroatom classes, and some of them have an asphaltene-type of molecules classification

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Barillaro, Filippo Carmelo. "Electrolytic demulsification of a dilute oil-in-water emulsion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0018/MQ45470.pdf.

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Seymour, Lisa. "A computer model of water-in-oil emulsion coagulation." Doctoral thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/17966.

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In this thesis, a stochastic computer model of water-in-oil emulsion coagulation, a two stage process of aggregation and coalescence, is presented. The theoretical basis of the model, including equations for the van der Waals, electrostatic and steric energy barriers between dissimilar droplets, is described. Many of these equations have been derived by the author. A chemical speciation study of the aqueous phase typically found in emulsion explosives is presented. A potentiometric investigation of the protonation equilibria of propionate, succinate and mono-methyl succinate in tetraethyl ammonium bromide, ammonium nitrate, sodium nitrate, potassium nitrate and calcium nitrate at 25°C and 3 mol/dm³ ionic strength was performed. Nuclear Magnetic Resonance titrations for succinate and propionate in varying concentrations of the same salts are also shown. A method of converting thermodynamic stability constants from one ionic strength to another using a modified form of the Pitzer equations is presented with a computer program which performs the conversion. A novel method of obtaining complexation constants from protonation constants in varying media is proposed. Using optical microscopy, creaming rates and laser particle sizing, the affects of changing surfactant concentration, salt concentration, pH and shearing time for emulsions of ammonium nitrate solution in heptane with CRILL 43 are shown. Equations are derived for converting creaming rate data to droplet size information and a computer program for converting Malvern light intensity data in the anomalous regime (typical of water-in-oil emulsions) to size distribution data is presented. The computer model is validated against experimental data from this work and the literature and is used to make stability predictions for systems for which no data exists. Further uses for the model are discussed.

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Walker, I. M. "The formation and evaluation of water-in-oil-in-water multiple emulsion systems." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371137.

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Islam, Sonia. "Investigation of oil adsorption capacity of granular organoclay media and the kinetics of oil removal from oil-in-water emulsions." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4979.

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Produced water, a byproduct of oil and gas production, includes almost 98% of all waste generated by oil and gas exploration and their production activities. This oil contaminated waste water has a great impact on our environment and is considered to be a high-cost liability. The Department of EnergyÃ¢ÂÂs Oil and Gas Environmental Program is concerned with the development of new and affordable technology to clean this produced water. Organically modified clays are proposed as a good option for removal of oil from produced water. Organoclay, incorporated into a treatment process shows promise of being a cost effective method of treatment to remove crude oil from brine either as a final treatment prior to brine disposal at sea or as a precursor to desalination. Organoclay also pre-polishes the waste water before further treatment. This research studies the efficacy of using organoclay to remove oil by measuring its adsorption capacity to remove the oil from a SAE 30 (Golden West Superior) motor oil-water emulsion. A kinetic model was developed to examine the time dependent behavior of the oil adsorbing characteristics of the organoclay and to investigate how closely the experimentally obtained data matches the kinetic model. It was found that organoclay is effective in removing various percentages of oil depending on the concentrations of a SAE 30 (Golden West Superior) motor oil-water emulsion. Moreover, it was found that the experimental data closely follow the kinetic behavior of the organoclay as shown by the kinetic model. Since this research is specific to a particular type of oil, SAE 30, further research is required for verifying the adsorption capacity of organoclay in other types of oils. Moreover, it is also recommended that the adsorption capacity of the organoclay, together with conventional adsorbent such as GAC (Granular Activated Carbon), be investigated to determine if there is any further improvement in the adsorption capacity. Lastly, a detailed investigation using the actual produced water from the oil field should be conducted to determine the efficacy of the organoclay system in removing oil from water produced in the field.

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Stoyel, Jason Alexander. "Fundamentals of drop coalescence in crude oil." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312176.

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VARGAS, KELLY MARGARITA COLMENARES. "OIL DISPLACEMENT IN MICRO MODELS OF POROUS MEDIA BY INJECTION OF OIL IN WATER EMULSION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35523@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
O processo de recuperação de óleo pelo deslocamento com água é o método mais utilizado na indústria de petróleo. No entanto, as altas razões de mobilidade e baixas eficiências de varrido tornam o processo menos eficiente. Uma alternativa usada para minimizar este efeito é a aplicação de tecnologias que atuam como agentes de controle de mobilidade. Dentre eles, e em particular a injeção de emulsões de óleo em água tem sido estudada com relativo sucesso como um método de recuperação avançada de óleo. Alguns estudos indicam melhor varredura do reservatório devido a uma redução da mobilidade da água em regiões do reservatório já varridas por água, mediante a aglomeração e bloqueio parcial dos poros mais permeáveis com gotas da fase dispersa da emulsão. Contudo, ainda não há compreensão plena dos mecanismos associados ao escoamento de emulsões em meios porosos, assim, uma análise e visualização na escala microscópica dos fenômenos envolvidos se faz essencial para a melhora do entendimento do escoamento de emulsões em um reservatório. Neste trabalho, experimentos de escoamento de emulsões foram conduzidos em um micromodelo de vidro, estrutura artificial que busca representar alguns aspectos principais de um meio poroso e proporciona uma adequada visualização do comportamento das faces ao longo do escoamento. Nos experimentos foram realizadas alterações na molhabilidade e variou-se a vazão volumétrica a fim de avaliar diferentes números de capilaridade no meio poroso. Dentro dos resultados mais significativos, foi evidenciado como a fase dispersa da emulsão é capaz de bloquear os poros e gargantas de poro alterando a distribuição dos fluidos no meio poroso, melhorando a eficiência de deslocamento na escala de poro e com isso o fator de recuperação final. Os resultados mostram que, a altos números de capilaridade as forças interfaciais são menos importantes ao reduzir o efeito de bloqueio pelas gotas da fase dispersa nos poros do micromodelo. Estes resultados fornecem um grande aprendizado ao permitir conhecer características do escoamento de emulsões no meio poroso para uma futura aplicação no campo.
The oil recovery process by water-flooding is the most used method in the oil industry. However, the high mobility ratios and low sweep efficiencies make the process less effective. A common alternative to minimize this effect is the application of technologies that act as mobility control agents. Among them and in particular the injection of oil in water emulsions has been studied with relative success as an Enhanced Oil Recovery (EOR) method. Several studies indicate a better reservoir sweep due to the water mobility reduction in regions already swept by water. This reduction can be associated with partial blockage of porous media throats by droplets of emulsion dispersed phase. Nevertheless, there is still no full understanding of the mechanisms associated to the flow of emulsions in porous media, thus, an analysis and visualization at the microscopic scale of the involved phenomena is essential for the improvement of the comprehension of the flow of emulsions in a reservoir. In this work, experimental tests related to the flow of emulsions in a glass micro-model were performed, artificial device that represents some principal features of a porous medium and provides a proper visualization of the phase behavior. In the experiments, the effect of the capillary number on the oil recovery factor and the relative influence of the wettability of the porous medium on the oil displacement process were studied. The results evidence how the oil droplets in the emulsion are capable of block the pores and the pore throats modifying the fluids distribution in the porous medium, improving the displacement efficiency at pore scale and consequently the final oil recovery factor. It was also observed that at high capillary numbers, the blocking caused by the capillary pressure needed to deform the droplet becomes less intense. These results provide a great learning by allowing to know the characteristics of the flow of emulsions in porous media for a future field application.

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Jimeno, Nieves. "Effect of demulsifiers on the separation of water-in-oil emulsion /." [S.l.] : [s.n.], 1987. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8347.

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Andre, Antonio Luzaiadio Buco. "Investigation of the stability and separation of water-in-oil emulsion." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2267.

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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: The study of water-in-oil emulsion stability and separation was carried out for this thesis. The main objectives were as follows: to rank crude oil samples in terms of creating stable emulsions; to assess the effect of the brine pH on emulsion stability; to investigate the influence of different organic acids on emulsion stability; and to determine the efficiency of an electric separator in removing water droplets from a flowing organic liquid. Seven crude oil samples from different sources such as A, C, H, M, P, U, and V were used to investigate the water-in-crude-oil emulsion. Two crude oil blends were also used. Brine solution comprising 4 wt% NaCl and 1 wt% CaCl2 was used. In this study the gravity settling, critical electric field (CEF) and centrifuge test methods were used to estimate the emulsion stability created by the crude oil and crude oil blend samples. The experiments were carried out at 60°C. In the gravity test method, the brine pH, stirring speed, stirring time and water-cut (the fraction of water in the emulsion) were changed in 2IV-1 factorial design. The parameters for the centrifuge and CEF test methods were selected on the basis of the gravity test method. The crude oil samples were ranked in terms of creating stable emulsion in the following order V, U, P, H, A, M and C. The crude oil blends created more stable emulsions than their respective constituents. The ranking order of the crude oil samples did not correlate to asphaltenes, resins, wax or total acid number (TAN). There was a good correlation between the test methods used. There was an increase and decrease in the brine pH when different crude oil samples were in contact with the brine. It is believed that the structure of the surfactants present in crude oil may explain the emulsion-forming characteristics of different crude oil deposits around the world. To account for the effect of organic acids on emulsion stability, different organic acids were used. In this case, a mixture of equal volumes of heptane and toluene (here referred to as heptol) was used as the model for crude oil. The brine solution composition was the same as the one used in the crude oil experiments. Equal volumes of heptol and brine were mixed for a period of time and then separated. The brine pH was changed from acidic to basic. In this regard, gas chromatography and liquid chromatography were used to analyse the concentration of the acids in the brine and heptol samples. It was found that the partitioning coefficient for acids containing a straight-chain hydrocarbon moiety decreased with an increase in molecular weight. However, the partitioning coefficient depended on the structure of the acid. The presence of a benzene ring in the organic acid increased the partitioning coefficient. Organic acids with rings created an interface layer when the heptol sample was mixed with basic brine solution. This confirmed that the emulsion of water and crude oil starts with the formation of a film, and it also provides insight into the formation of naphthenate soap. It is believed that the naphthenic acids that cause stable emulsions have rings. More organic acids should be tested. It is recommended that the interaction of asphaltenes, resins and naphthenic acids should be investigated at different pH levels, temperatures and pressures. The separation of water droplets from a flowing organic liquid was carried out using a direct current (d.c.) electric separator. The separator used centrifugal forces and a d.c. electric field to enhance the removal of water drops from a flowing organic liquid. For this, vegetable oil, crude oil blend and heptane were used as the continuous phase. The experiments were carried out at room temperature (for heptane and vegetable oil) and at 70°C (for vegetable oil and crude oil blend). The flow rate to the separator was kept constant. The separator removed water droplets from flowing organic liquids. A maximum of 97% (at 100 V)of water droplets was removed from the heptane liquid; a maximum of 28% (at 100 V) of water droplets was removed from the vegetable oil at 70°C and 5% (at 100 V) of water droplets was removed from the crude oil blend. The d.c. electric field enhanced the efficiency of the separator in removing water droplets. The break-up of the droplets is suspected to decrease the efficiency of the separator. This separator can easily be installed into existing process lines and does not require much space. However, further improvements are needed in the design of this separator. Emulsions created in the petroleum industries are quite complex to deal with. The identification of the structure of the components in crude oil is a matter that still has to be investigated. An improvement in the techniques may lead to a better understanding of the cause of the ultra-stable emulsion encountered in the petroleum and related industries.
AFRIKAANSE OPSOMMING: Die studie van die stabiliteit en skeiding van water-in-olie-emulsies is vir hierdie tesis uitgevoer. Die hoofdoelstellings was as volg: om ruolie-monsters in terme van die skepping van stabiele emulsies te klassifiseer; om die effek van die pekel-pH op emulsie-stabiliteit te assesseer; om die invloed van verskillende organiese sure op emulsie-stabiliteit te ondersoek; en om die doeltreffendheid van ’n elektriese skeier in die verwydering van waterdruppels uit ’n vloeiende organiese vloeistof te bepaal. Sewe ruolie-monsters uit verskillende bronne soos was A, C, H, M, P, U en V gebruik om die water-in-ruolie-emulsie te ondersoek. Twee ruolie-mengels is ook gebruik. ’n Pekeloplossing wat 4 wt% NaCl en 1 wt% CaCl2 bevat, is gebruik. In hierdie studie is die gravitasie-afsakkings-, kritieke elektriese veld- (KEV-) en sentrifuge-toetsmetodes gebruik om die emulsie-stabiliteit te beraam wat deur die ruolie- en ruolie-mengsel-monsters geskep is. Die eksperimente is teen 60°C uitgevoer. In die gravitasietoetsmetode is die pekel-pH, roertempo en watersnyding (die fraksie van water in die emulsie) is in ‘n 2IV-1-faktoriaalontwerp ondersoek. Die parameters vir die sentrifuge- en KEV-toetsmetodes is op grond van die gravitasietoetsmetode resultate gekies. Die ruolie-monsters is in terme van die skepping van ’n emulsie stabiliteit geklassifiseer in die volyende orde V, U, P, H, A, M, en C. Die rudie-menysels het meer stabiele emulsies gerorm as die respektiewe samestellende dele. Die rangorde van emulsie stabiliteit van die ruolie-monsters het nie met asfaltene, hars, waks of totale suurgetal gekorreleer nie. Daar was ’n goeie korrelasie tussen die toetsmetodes wat gebruik is. Daar was ’n toename of afname in die pekel-pH wanneer verskillende ruolie-monsters in kontak met die pekel was. Die aanname is dat die struktuur van die surfaktante wat in die ruolie teenwoordig is, die emulsievormende karaktereienskappe van verskillende ruolie-neerslae regoor die wêreld kan verklaar. Om die effek van organiese sure op emulsie-stabiliteit te verklaar, is verskillende organiese sure gebruik. In hierdie geval is ’n mengsel van gelyke hoeveelhede heptaan en tolueen (voortaan verwys na as heptol) as die model vir ruolie gebruik. Die pekeloplossing-samestelling was dieselfde as die een wat in die ruolie-eksperimente gebruik is. Gelyke hoeveelhede heptol en pekel is vir ’n tydperk gemeng en toe geskei. Die pekel-pH is van suurvormend tot basies verander. Gaschromatografie en vloeistofchromatografie is gebruik om die konsentrasie van die sure in die pekel- en heptoloplossings te analiseer. Daar is gevind dat die verdelingskoëffisiënt vir sure wat ’n reguitketting-koolwaterstofhelfte bevat met ’n toename in molekulêre gewig afneem. Die verdelingskoëffisiënt het egter van die struktuur van die suur afgehang. Die teenwoordigheid van ’n benseenring in die organiese suur het die verdelingskoëffisiënt verhoog. Organiese sure met ringe het ’n tussenvlaklaag geskep toe die heptolmonster met die basiese pekeloplossing gemeng is. Dit het bevestig dat die emulsie van water en ruolie met die vorming van ’n vlies begin, en gee ook insig in die vorming van naftenaatseep. Dit blyk dat die naftenaatsure wat stabiele emulsies veroorsaak, ringe het. Meer organiese sure moet getoets word. Daar word aanbeveel dat die interaksie van asfaltene, hars en naftenaatsure teen verskillende pH-vlakke, temperature en drukke getoets word. Die skeiding van waterdruppels uit ’n vloeiende organiese vloeistof is uitgevoer met behulp van ’n gelykstroom- elektriese skeier. Die skeier het sentrifugiese kragte en ’n wisselstroomelektriese veld gebruik om die verwydering van waterdruppels uit ’n vloeiende organiese vloeistof te verhoog. Hiervoor is plantolie, ’n ruoliemengsel en heptaan gebruik as die deurlopende fase. Die eksperimente is teen kamertemperatuur (vir heptaan en plantolie) en teen 70°C (vir plantolie en ruolie-mengsel) uitgevoer. Die vloeitempo na die skeier is konstant gehou. Die skeier het waterdruppels uit die vloeiende organiese vloeistowwe verwyder. N’ maksimum van 97% (by 100 V) van die water drupples is verweider van die heptaan vloeistof; a maksimum van 28% (by 100 V) van die water druppels was verweider van die plantolie by 70°C en 5% (by 100 V) van die water druppels was verweider van die rudie mengsel. Die gelykstroom- elektriese veld het die doeltreffendheid van die skeier om waterdruppels te verwyder, verhoog. Daar word vermoed dat die afbreek van die waterdruppels die doeltreffendheid van die skeier verlaag. Die skeier kan met gemak in bestaande proseslyne geïnstalleer word en benodig nie veel spasie nie. Verdere verbeterings is egter nodig ten opsigte van die ontwerp van hierdie skeier. Emulsies wat in die petroleumbedrywe geskep word, is kompleks om te hanteer. Die identifikasie van die struktuur van die komponente in ruolie verg verdere ondersoek. ’n Verbetering in hierdie tegnieke kan tot beter begrip lei van die oorsaak van die ultrastabiele emulsie wat in die petroleum- en verwante bedrywe aangetref word.

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Platt, Samantha Helen. "Breakage of water-in-oil emulsions using membranes as a coalescing aid." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301547.

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Jahaniaval, Firouz. "Effects of proteins and triacylglycerols on the physicochemical and functional properties of a double emulsion system (oil-in-water-in-oil emulsion)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ56283.pdf.

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Kennelly, Timothy Robert. "An investigation of the combustion of oil sand derived bitumen-in-water emulsions." Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/246.

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Dwindling conventional oil resources has caused exploration efforts to focus elsewhere. Bitumen from oil sands has emerged as one of the primary unconventional oil resources in use today. Quadrise Canada Corporation has harnessed this unconventional oil by developing their bitumen-in-water emulsion known as MSAR (Multi-Phase Superfine Atomized Residue). Fuel-in-water emulsions are linked to a combustion phenomenon known as micro-explosion, which are associated with an increase in combustion efficiency and decrease in harmful emissions. A study has been conducted of the MSAR fuel to help advance the optimization and modeling of its use in spray combustors so as to best harness the potential. Quantitative and qualitative data has been obtained during combustion experiments of the fuel that will attribute to this end. Additionally, a simplified statistical model is presented based on the governing equations to describe the atomization that occur as a result of micro-explosions of the MSAR fuel as well as a simple model to represent internal force needed for a micro-explosion to occur. The results of this study continue to reinforce the understanding that micro-explosions cannot be attributed to one overriding physical principal, but rather are th result from variations in turbulent, dynamic, and thermal forces.

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Huang, Xiaoqing. "Evaluation of hydrocolloid gums as stabilizers in oil/water emulsion, emulsion stability, interfacial activity and rheological properties." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0018/MQ55681.pdf.

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VILLALOBOS, EDUARDO MARTIN CABELLOS. "EMULSION FORMATION IN THE TWO-PHASE OIL-WATER FLOW THROUGH SMALL PASSAGES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16583@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
A produção de óleo diminui e a produção de água aumenta com o passar do tempo na vida de um reservatório. A mistura de óleo e água é geralmente produzida na forma de uma emulsão. A formação da emulsão começa no escoamento bifásico no interior do reservatório e sua estrutura muda na medida em que os líquidos escoam através de tubulações, bombas e válvulas até as instalações de superfície. Durante a produção, as gotas maiores da fase dispersa quebram-se mudando a distribuição do tamanho das gotas. É importante conhecer a distribuição de tamanho de gota da fase dispersa da emulsão a fim de projetar as unidades de separação e prever as quedas de pressão ao longo do escoamento. O objetivo do presente trabalho é o estudo do processo de quebra de gotas em capilares retos e válvulas agulha a fim de prever o tamanho das gotas resultantes em função das condições de escoamento. O principal desafio é entender como os diferentes parâmetros operacionais de escoamento afetam o processo de quebra. Duas bancadas experimentais foram utilizadas para o estudo do processo. Na primeira, foi realizada uma análise paramétrica de formação de emulsões em um escoamento laminar através de capilares retos. Os experimentos foram realizados utilizando duas seringas conectadas através de um capilar. A emulsão óleo-emágua foi forçada a uma passagem de ida e vinda através do capilar. O diâmetro médio de gota e a superfície específica da fase dispersa foram obtidos em função da vazão de injeção, taxa de cisalhamento, tempo de residência e trabalho dissipado na parede do capilar. Como esperado, o diâmetro médio da fase dispersa diminui com o aumento do tempo de cisalhamento atingindo um valor assintótico e possui uma grande dependência com a taxa de cisalhamento na parede do capilar. Na segunda bancada, foi realizada uma análise paramétrica de um escoamento turbulento de emulsão óleo-em-água através de uma válvula agulha. Os experimentos foram realizados utilizando uma bomba helicoidal para controlar a vazão através da válvula. O diâmetro médio de gota e a superfície específica da fase dispersa a montante e a jusante da válvula foram obtidos em função da queda de pressão, vazão e taxa de dissipação de energia na válvula. O diâmetro médio da fase dispersa diminui e a superfície específica aumenta com o aumento da queda de pressão na válvula agulha até atingir um valor assintótico.
Oil production decreases and water production increases as time goes by in the life of a hydrocarbon reservoir. The mixture of oil and water is usually produced as an emulsion. Emulsion formation starts in the two-phase flow inside the reservoir. The emulsion structure changes as it flows through pipes, pumps and valves up to the surface facilities. During all stages, large drops of the dispersed phase break up leading to smaller drops. It is important to know the droplet size distribution of the dispersed phase in order to design separation units and predict the pressure drop along the flow. The aim of the this work is to study the droplets break-up process that takes place in capillaries and in a needle valve in order to make predictions of the size of the resulting droplets that emerge from this process. The main challenge is to understand how the different operating flow parameters affect the break up process. In order to achieve this goal, two laboratory scale experimental set-ups have been used. In the first experiment, we conducted a parametric analysis of oil-water emulsion formation in laminar flow through straight capillaries. The experiments were carried out using two syringe pumps connected by a double-hubbed capillary pipe. The oil-water emulsion is forced back and forth through the pipe. The mean diameter and the specific surface area of the dispersed phase were obtained as a function of flow rate, shear rate, residence time and rate of energy dissipation at the capillary wall. As expected, keeping all other variables fixed, the dispersed phase mean diameter decreases with the shearing time, reaching an asymptotic value, which was a strong function of the shear rate at the capillary wall. Secondly, we conducted a parametric analysis of turbulent oil-in-water emulsion flow through a needle valve. The experiments were carried out using a helicoidal pump to control the flow rate through the needle valve. The mean diameter and the specific surface area of the dispersed phase upstream and downstream of the valve were obtained as a function of the pressure drop in the valve, flow rate, and rate energy dissipation of the flow. The dispersed phase mean diameter falls and the specific surface area rises with the pressure drop in the valve until reaching an asymptotic value.

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16

Grizio, Miranda. "Optimizing emulsion stability of high-oil pourable dressings using different stabilizers." Kansas State University, 2011. http://hdl.handle.net/2097/9202.

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Master of Science
Department of Food Science Institute
Fadi M. Aramouni
To find an optimal formulation of oil-in-water (O/W) emulsion pourable dressings containing 60% and 70% soybean oil, nine stabilizers common to the dressing industry were tested, each at three concentrations. The stabilizers tested were xanthan gum, propylene glycol alginate (PGA), a xanthan gum/guar gum/sodium alginate blend, a viscosifying modified corn starch, an emulsifying modified corn starch, microcrystalline cellulose (MCC), liquid salted egg yolks, liquid salted whole eggs, and dried egg whites (DEW). The emulsions were made with a laboratory high shear disperser and evaluated over 8 weeks by measurement of creaming in 100- mL graduated cylinders and by change in viscosity as measured by a Brookfield viscometer. The stabilizers and concentrations most effective at preventing separation and maintaining viscosity were MCC at 1%, 2%, and 3% in the 60% oil emulsion and 0.25% xanthan gum in the 70% oil emulsion. Average viscosities ranged from 3300 - 23,400 centipoise (cP). The emulsifying starch and dried egg whites were also effective at preventing creaming, but failed to maintain viscosity. The other ingredients showed some initial emulsion stability followed by either a gradual or sudden decrease in stabilization, as seen by decreasing viscosity and eventual separation.

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17

NUNEZ, VICTOR RAUL GUILLEN. "OIL DISPLACEMENT IN A POROUS MEDIA THROUGH INJECTION OF OIL-IN-WATER EMULSION: ANALYSIS OF LINEAR FLOW." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10663@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
AGÊNCIA NACIONAL DE PETRÓLEO
A injeção de emulsão é um método comum para melhorar o varrido do reservatório e manter-lo pressurizado. A eficiência de recuperação de óleo no caso de óleos pesados é limitada pela alta razão de mobilidade entre a água injetada e o óleo. Um método de reduzir o problema relativo µa alta razão de viscosidade é por injeção de soluções poliméricas. Porem, a interação líquido- rocha, os grandes volumes e o preço associado dos polímeros podem fazer esta técnica não aplicável em caso de campos gigantes. Diferentes métodos de recuperação avançada de óleo estão sendo desenvolvidos como alternativas µa injeção de polímeros. A injeção de dispersões, em particular a injeção de emulsões, têm sido tratadas com relativo sucesso como um método de recuperação avançada de óleo, mas as técnicas não são totalmente desenvolvidas ou compreendidas. O uso de cada método requer uma completa análise dos diferentes regimes de fluxo de emulsões dentro do espaço poroso de um reservatório. A maioria das análises de fluxo de emulsões em um meio poroso utiliza uma descrição macroscópica. Esta aproximãção é só valida para emulsões com o tamanho da fase dispersa muito menor do que o tamanho do poro. Se o tamanho de gota da fase dispersa é da mesma ordem de magnitude do tamanho de poro, as gotas podem aglomera-se e particularmente podem bloquear o fluxo através dos poros. Este regime de fluxo pode ser utilizado para controlar a mobilidade do líquido injetado, conduzindo a um fator de recuperação maior. Neste trabalho, experimentos de deslocamento de óleo foram executados em um corpo de prova de arenito. Os resultados mostram que a injeção de uma emulsão mudou o fator de recuperação de óleo, elevando este desde 40%, obtido só por injeção de água, ate um valor aproximado de 75%, seja em modo primario ou depois do influxo da água.
Water injection is a common method to improve the reservoir sweep and maintain its pressure. The e±ciency of oil recovery in the case of heavy oils is limited by the high mobility ratio between the injected water and oil. A method of reducing the problem related to the high viscosity ratio is by polymer solution injection. However, the liquid-rock interaction, the large volume and the associated cost of polymer may make this technique not applicable in the case of giant fields. Different enhanced oil recovery methods are being developed and studied as alternatives to polymer injection. Dispersion injection, in particular oil-water emulsion injection, has been tried with relative success as an enhanced oil recovery method, but the techniques are not fully developed or understood. The use of such methods requires a complete analysis of the different flow regimes of emulsions inside the porous space of a reservoir. Most analyses of flow of emulsion in a porous media use a macroscopic description. This approach is only valid for dilute emulsion which the size of the disperse phase is much smaller of the pore throat. If the drop size of the disperse phase is of the same order of magnitude of the pore size, the drops may agglomerate and partially block the flow through pores. This flow regime may be used to control the mobility of the injected liquid, leading to higher recovery factor. In this work, experiments of oil displacement were performed in a sandstone plug. The results show that injection of an emulsion changed the oil recovery factor, raising it from approximately 40%, obtained with water injection alone, to approximately 75%, whether in primary mode or after water flooding.

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18

Ojala, J. (Jonna). "Functionalized cellulose nanoparticles in the stabilization of oil-in-water emulsions:bio-based approach to chemical oil spill response." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526222417.

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Abstract Nanocellulose is a renewable, biodegradable, and easily available material that is considered as an attractive resource for many different value-added applications in the emerging bio-based economy. Its outstanding properties, such as strength, lightness, transparency, and good thermal insulation, have inspired research and product development around nanocellulose. The potential of nanocellulose to replace synthetic chemicals made from non-renewable sources, for example, is considered to be very promising. Chemical functionalization, that is, the modification of the cellulosic surface properties, is seen to be beneficial in applications such as those in which higher hydrophobicity is needed. In this thesis, the ability of cellulose nanoparticles to stabilize oil droplets in oil-in-water emulsions was studied. The aim of the study was to explore the possibility of developing a new type of "green" oil spill chemical from cellulose. Therefore, the cellulose was chemically modified in an aquatic environment with a sequential periodate oxidation and chlorite oxidation followed by reductive amination reaction, which increased the hydrophobicity of the produced nanocellulose. In addition, the use of deep-eutectic solvents in the preparation of modified (succinylated and carboxylated) and non-modified cellulose nanoparticles was studied. Chemical (kraft) pulp, dissolving pulp, and semi-chemical fine fibers were used as raw materials in this research. The results demonstrated that chemically modified cellulose nanoparticles work well as stabilizers for oil-water emulsions resulting in small, stable oil droplets and impeding creaming, which is a typical phenomenon for particle stabilized emulsions. The modification of cellulose nanoparticles improved their ability to partition at the oil-water interface, which enabled efficient and irreversible adsorption. It was found that because of their small size, the cellulose nanocrystals can be compressed more tightly onto the surface of the oil droplet, while longer and more flexible cellulose nanofibrils formed a web structure between the oil droplets. All cellulose nanoparticle-stabilized emulsions were stable against droplet coalescence, and even at low temperatures, they retained their droplet size and stability. Salinity, on the other hand, improved stability when CNCs from chemical pulp were used, but it negatively affected stability when nanocrystals from semichemical pulp were used
Tiivistelmä Uusiutuva, biohajoava ja helposti saatavilla oleva nanoselluloosa on merkittävä tulevaisuuden raaka-aine useissa erilaisissa käyttökohteissa. Sen ylivertaiset ominaisuudet, kuten lujuus, keveys, läpinäkyvyys ja lämmöneristävyys ovat olleet innoittamassa nanoselluloosan tutkimusta ja tuotekehitystä. Nanoselluloosan mahdollisuuksia ja käyttöä eri sovelluksissa korvaamaan esimerkiksi uusiutumattomista luonnonvaroista valmistettuja kemikaaleja, pidetään erittäin lupaavina. Kemiallisesta funktionalisoinnista eli selluloosan pintaominaisuuksien muokkauksesta nähdään olevan hyötyä, kun tavoitellaan nanoselluloosan toiminnallisuutta esimerkiksi hydrofobista luonnetta vaativissa sovelluksissa pinta-aktiivisen aineen tavoin. Tässä työssä tutkittiin erityisesti nanoselluloosapartikkeleiden kykyä stabiloida öljypisaroita dieselöljy-vesiemulsioissa. Tutkimuksen päämääränä oli selvittää mahdollisuutta kehittää uudentyyppistä, ”vihreää” öljyntorjuntakemikaalia selluloosasta. Tämän vuoksi selluloosaa muokattiin kemiallisesti vesiympäristössä yhdistetyllä hapetus- ja aminointikäsittelyllä, mikä lisäsi valmistetun nanoselluloosan hydrofobisuutta. Toisena käsittelyvaihtoehtona tutkittiin syväeutektisten liuottimien käyttöä sekä muokattujen (sukkinyloidut ja karboksyloidut) että muokkaamattomien nanoselluloosapartikkeleiden valmistuksessa. Raaka-aineina työssä käytettiin kemiallista sellumassaa, liukosellua sekä puolikemiallista hienokuitua. Työn tuloksena voidaan todeta, että nanoselluloosasta valmistetut kemiallisesti muokatut (funktionalisoidut) nanopartikkelit toimivat hyvin öljy-vesiemulsiossa estäen emulsion öljypisaroiden yhteensulautumista. Nanopartikkelit stabiloivat emulsiossa olevan öljyn hyvin pieniksi pisaroiksi hidastaen kermottumista eli emulsion yleistä faasierottumista. Nanoselluloosan funktionalisointi paransi sen kykyä hakeutua öljy-vesi rajapintaan, mahdollistaen tehokkaan ja palautumattoman adsorption. Havaittiin, että pienen kokonsa vuoksi selluloosananokiteet pystyivät pakkautumaan tiiviimmin öljyn pinnalle, kun taas selluloosananokuidut, jotka ovat pidempiä, muodostivat verkkomaisen rakenteen myös öljypisaroiden väliin. Suolan lisäys vaikutti emulsion stabiilisuuteen vaihtelevasti eri näytteiden välillä, kun taas kylmät olosuhteet poikkeuksetta paransivat stabiilisuutta

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19

CASTILLO, OSWALDO ÁNGEL FRANCISCO ROBLES. "EXPERIMENTAL ANALYSIS OF THE OIL-IN-WATER EMULSION FLOW THROUGH CONSTRICTED MICRO-CAPILLARIES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=17786@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
No método de injeção de água, o óleo no reservatório é varrido até os poços produtores através de frentes de deslocamento não uniformes, deixando óleo estagnado em grandes regiões do reservatório. Frentes uniformes de deslocamento e uma melhor varredura do reservatório podem ser obtidas diminuindo a razão de mobilidade entre a água e o óleo. Normalmente, esta diminuição é feita através da modificação da razão de viscosidade entre ambas as fases. No método de injeção de emulsões, o controle da mobilidade é alcançado bloqueando os poros ou caminhos gerados pela água com gotas da fase dispersa com diâmetro da mesma ordem ou maior do que o tamanho de poro. A aplicação de emulsões no controle da mobilidade e o efeito do bloqueio de poro podem ser desenvolvidos mediante a análise de diferentes regimes de escoamento de emulsões em meios porosos. Neste trabalho, o estudo do escoamento de emulsões em meios porosos foi realizado mediante duas abordagens experimentais utilizando um micro-capilar com garganta para modelar uma garganta conectando dois poros adjacentes. Na primeira abordagem experimental, quantificou-se a queda de pressão para diferentes vazões com emulsões de três tamanhos de gota e duas concentrações de óleo em dois capilares diferentes. Os resultados confirmam que a razão entre o diâmetro da garganta do capilar e o tamanho de gota influencia fortemente a relação vazão-queda de pressão. Os resultados mostram que, para baixos números de capilaridade, o escoamento de emulsões é dominado por efeitos capilares e leva a uma diminuição da mobilidade local. Na segunda montagem experimental, o sistema de micro-velocimetria por imagem de partículas ou u-PIV foi utilizado para medir campos de velocidade do escoamento através de micro-capilares com garganta. Resoluções espaciais da ordem de 20um foram obtidas para o campo de velocidade calculado pela média amostral de vários campos instantâneos de velocidade. Os resultados experimentais da relação vazão-queda de pressão e os campos de velocidade obtidos mediante o u-PIV representam informação de grande valor para o desenvolvimento de modelos de redes de capilares no estudo do escoamento de emulsões em meios porosos.
During water injection, oil is swept through the reservoir to production wells by non-uniform displacement fronts originating large areas of entrapped oil in the reservoir. Uniform displacement fronts and better reservoir sweep can be achieved by improving the mobility ratio between water and oil. Usually, mobility ratio is reduced by changing the viscosity ratio between both phases. When injecting emulsions, mobility control is achieved by blocking water paths with dispersed phase drops with diameter of the same order of magnitude of the pore throats size. The application of emulsions as mobility control agents and the pore blocking effect may be developed by analyzing different flow regimes of emulsions through porous media. In the analysis presented here, two experimental setups were used using a constricted quartz capillary to represent a pore throat that connects two adjacent pore bodies to study the flow of emulsions in the pore scale. In the first experiment, pressure drop was measured at different imposed volumetric flow rates for three oil drop size emulsions at two oil concentrations and two different quartz capillaries. The results show that the ratio between the capillary constriction diameter and the oil drop size has a strong influence on the flow rate-pressure drop relation. Experimental results also indicate that the emulsion flow dominated by capillary effects (low capillary number) leads to a decrease of local mobility. In the second experiment, a microscopic particle image velocimetry (u-PIV) system was used to measure velocity fields of the flow of emulsion through a constricted micro-capillary. Ensemble-average was used in order to obtain resolution in the order of 20 um. The flow rate-pressure drop relation results and the u-PIV velocity fields of the emulsion flow through a constricted micro-capillary represent invaluable information that can be used in the development of a capillary network model to study the flow of emulsions through porous media.

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20

Asmaoglu, Serdar. "Synthesis And Charaterization Of Multi-hollow Opaque Polymer Pigmets." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614539/index.pdf.

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In the present work, a new generation opaque polymer pigment with multihollow structure was synthesized by suspension polymerization of &ldquo
Water-in-Oil-in-Water&rdquo
(W/O/W) emulsion system. Oil phase was methyl methacrylate and ethylene glycol dimethacrylate monomer mixture at 1:1 weight ratio. The dimension and distribution of hollows inside polymer particles are dependent on the size of water droplets which are encapsulated in micelles. For Water-in-Oil (W/O) assembly, a hydrophobic surfactant and hydrophilic co-surfactant (Span 80-Tween 80) combination with a hydrophilic/lipophilic balance (HLB) value between 5-8 was used. The effects of surfactant and co-surfactant composition on the stability of the W/O emulsion and also on the size of water droplets were studied. In addition, the effect of the ultrasonication on the average size of water droplets was investigated. The hollow size distribution which may possibly give the maximum scattering efficiency was predicted by a mathematical model based on the Mie scattering. The optimum size distribution for W/O emulsion was obtained at the monomer/surfactant/water ratio of 75.5/9.4/15.1 after ultrasonication for 30 seconds at 80 W power. The W/O/W emulsion was prepared by dispersing the W/O emulsion in aqueous solution of hydrophilic Triton X-405. The influence of surfactant concentration and mechanical mixing on monomer droplets was investigated by size measurement and optical microscopy. After stabilizing with 1 %w/w polyvinylpyrrolidone (PVP) solution, the W/O/W emulsion was polymerized at 55 °
C for 20 h. The surface morphology of synthesized polymer pigments was analyzed by scanning electron microscopy (SEM) and the inner hollow structure was confirmed by transmission electron microscopy (TEM). The analysis indicated that multihollow opaque polymer pigments were successfully synthesized. The opacity, the L*a*b* color, and the gloss properties of polymer pigments were examined by spectrophotometer and glossmeter. The opacity values were assessed by contrast ratio measurements, and the synthesized polymer pigments provided up to 97.3 % opacity (50 %v/v solid content). In addition, the pigments exhibited low gloss values, and yielded matt films.

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21

Inchingolo, Raffaella <1984&gt. "Study of the effect of minor compounds on the oxidative stability and physical properties of bulk oil, oil-in-water emulsion, and food emulsions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7002/1/Inchingolo_Raffaella_Tesi.pdf.

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Minor components are of particular interest due to their antioxidant and biological properties. Various classes of lipophilic minor components (plant sterols (PS) and α-tocopherol) were selected as they are widely used in the food industry. A Fast GC-MS method for PS analysis in functional dairy products was set up. The analytical performance and significant reduction of the analysis time and consumables, demonstrated that Fast GC-MS could be suitable for the PS analysis in functional dairy products. Due to their chemical structure, PS can undergo oxidation, which could be greatly impacted by matrix nature/composition and thermal treatments. The oxidative stability of PS during microwave heating was evaluated. Two different model systems (PS alone and in combination) were heated up to 30 min at 1000 W. PS degraded faster when they were alone than in presence of TAG. The extent of PS degradation depends on both heating time and the surrounding medium, which can impact the quality and safety of the food product destined to microwave heating/cooking. Many minor lipid components are included in emulsion systems and can affect the rate of lipid oxidation. The oxidative stability of oil-in-water (O/W) emulsions containing PS esters, ω-3 FA and phenolic compounds, were evaluated after a 14-day storage at room temperature. Due to their surface active character, PS could be particularly prone to oxidation when they are incorporated in emulsions, as they are more exposed to water-soluble prooxidants. Finally, some minor lipophilic components may increase oxidative stability of food systems due to their antioxidant activity. á-tocopherol partitioning and antioxidant activity was determined in the presence of excess SDS in stripped soybean O/W emulsions. Results showed that surfactant micelles could play a key role as an antioxidant carrier, by potentially increasing the accessibility of hydrophobic antioxidant to the interface.

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22

Inchingolo, Raffaella <1984&gt. "Study of the effect of minor compounds on the oxidative stability and physical properties of bulk oil, oil-in-water emulsion, and food emulsions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7002/.

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Minor components are of particular interest due to their antioxidant and biological properties. Various classes of lipophilic minor components (plant sterols (PS) and α-tocopherol) were selected as they are widely used in the food industry. A Fast GC-MS method for PS analysis in functional dairy products was set up. The analytical performance and significant reduction of the analysis time and consumables, demonstrated that Fast GC-MS could be suitable for the PS analysis in functional dairy products. Due to their chemical structure, PS can undergo oxidation, which could be greatly impacted by matrix nature/composition and thermal treatments. The oxidative stability of PS during microwave heating was evaluated. Two different model systems (PS alone and in combination) were heated up to 30 min at 1000 W. PS degraded faster when they were alone than in presence of TAG. The extent of PS degradation depends on both heating time and the surrounding medium, which can impact the quality and safety of the food product destined to microwave heating/cooking. Many minor lipid components are included in emulsion systems and can affect the rate of lipid oxidation. The oxidative stability of oil-in-water (O/W) emulsions containing PS esters, ω-3 FA and phenolic compounds, were evaluated after a 14-day storage at room temperature. Due to their surface active character, PS could be particularly prone to oxidation when they are incorporated in emulsions, as they are more exposed to water-soluble prooxidants. Finally, some minor lipophilic components may increase oxidative stability of food systems due to their antioxidant activity. á-tocopherol partitioning and antioxidant activity was determined in the presence of excess SDS in stripped soybean O/W emulsions. Results showed that surfactant micelles could play a key role as an antioxidant carrier, by potentially increasing the accessibility of hydrophobic antioxidant to the interface.

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23

Havre, Trond Erik. "Formation of calcium naphthenate in water/oil systems, naphthenic acid chemistry and emulsion stability." Doctoral thesis, Norwegian University of Science and Technology, Department of Chemical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-957.

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In recent years the production of crude oils with high amounts of naphthenic acids has increased. Certain problems are related to this type of crudes and a better understanding of the chemistry of the naphthenic acids is therefore of interest.

Synthetic model naphthenic acids, as well as commercial mixtures and crude oil naphthenic acids have been utilized to study the chemistry of naphthenic acids. Partitioning of naphthenic acids between oil and water and the dissociation equilibria in water have been studied in addition to their interfacial tension and micellisation behaviour.

A method for studying the precipitation of calcium naphthenate particles by means of near infrared spectroscopy was presented. It was shown that the method gives information about the induction period and about the rate of reaction for particle growth. Solubility products can also be estimated.

Near infrared spectroscopy were also utilized to study the ability of naphthenic acids and other amphiphiles to disintegrate asphaltene particles. It was shown that the structure of the naphthenic acids is important and that a commercial mixture of different surfactants had the best disintegration effect. The technique is applicable for screening the efficiency of various additives as disaggregation chemicals.

Emulsion stability was studied by means of Langmuir technique, critical electric field and bottle tests. The Langmuir study showed that the presence of Ca2⁺-ions at elevated pH gave rise to stable naphthenate monolayers. Oil/water emulsions stabilized with different carboxylic acids were investigated at different pH-levels and water-contents. It was demonstrated that water/oil emulsions could be stabilized by a combination of multilayer (D-phase) and asphaltene particles. Critical electric field was used to determine the emulsion stability of these systems and it was shown that a combination of 60% asphaltene particles and 40% D-phase gave the stablest w/o-emulsions. This investigation verifies the importance of D-phase stabilization in combination with asphaltene particles in systems with acidic heavy crude oil (including bitumen) and water.

Paper III and VI reprinted with kind permission of Elsevier, sciencedirect.com

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24

Hart, Helen Mary. "A study of the interaction between oil-in-water emulsion droplets and polymer particles." Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296451.

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25

Garg, Nidhi. "Synthesis and Characterization of Lactose-Amines with Respect to Oil-in-Water Emulsion Stability." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/225.

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Fatty amines (hexadecyl-amine) can be esterified to lactose via Schiff-base formation at temperatures of 60° C. Extending the time of the reaction results in a darker colored product due to the Maillard reaction. Due to the amphiphilic properties of the lactose-amines, the emulsion stabilization characteristics were investigated. In this study, synthesis of lactose-amines was done at four different heating and cooling cycles from 4 to 24 hours. Lactose-amines processed for 24 hours and 12 hours of constant heating and cooling cycles are named as 24H and 12H, respectively. Lactose-amines 4H and 8H were processed for 4 and 8 hours of constant heating at 60°C. The 24H and 12H samples were white in color as they were exposed to heat for short time (due to the cooling cycle) i.e. 2-2.5 and 1.5 hours, respectively, as compare to 4H and 8H (i.e. 4 hours and 8 hours, respectively). It was assumed that white colored compounds are early intermediates of Maillard browning reactions known as Amadori. The light brown color of the 4 hours heat-treated product might contain intermediate products of the Maillard browning reaction. The dark brown colored after 8 hours of constant heating might have advanced Maillard products and polymers. Each lactose-amine sample was used as emulsifiers in oil-in-water (20:80 ratio of oil: water) emulsion at four different concentrations (0.01%, 0.05%, 0.1%, and 1%). Negative controls consisted of hexadecyl-amine and lactose at the same concentrations as stated above, as well as an oil-in-water control. The positive control was an emulsion containing 2% whey protein (WP). Emulsions were formed with a microfluidizer 110S at a pressure of 6,900 psi. Emulsion stability was monitored by measuring the oil droplet sizes of each emulsion on day 0 and destabilization kinetics on day 1 and 5. The oil droplet size distribution and destabilization kinetics of the emulsions prepared with lactose-amines (4H, 8H, 12H, and 24H) at 0.01% of concentration were closer towards the negative controls (lactose, fatty-amine, and o/w). At 1% concentration, emulsions prepared with all types of lactose-amines had smaller droplet size similar to WPC 80. Destabilization kinetic profiles of the emulsions show that 1% lactose-amines produced more stabilized emulsions as compared to WPC 80 with respect to time. Emulsions of 4H and 24H were following the similar trend of droplet size distribution and destabilization rate as of WPC 80. Lactose-amines 8H and 12H emulsions were showing more destabilization and bigger oil droplet size as compared to 4H, 24H, and WPC 80. Droplet size distribution at day 0 and destabilization kinetics from day 0 to day 5 showed that the types of lactose-amines and their increasing concentrations have great influence on the stability of emulsions. This research has shown that lactose-amines produced at treatments of 24 and 4 hours are effective at stabilizing emulsions at 1% concentration.

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Ma, Tiezheng. "Oxidation Kinetics of Methyl Linoleate and α-Linolenate in Bulk and Oil-in-water Emulsion Systems." Kyoto University, 2014. http://hdl.handle.net/2433/188751.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第18313号
農博第2038号
新制||農||1020(附属図書館)
学位論文||H26||N4820(農学部図書室)
31171
京都大学大学院農学研究科食品生物科学専攻
(主査)教授安達修二, 教授河田照雄, 教授保川清
学位規則第4条第1項該当

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Ghoniem, Ahmad [Verfasser], and Rolf [Akademischer Betreuer] Daniels. "A Novel Moisture Protective Film Forming Oil-in-Water Pickering Emulsion / Ahmad Ghoniem ; Betreuer: Rolf Daniels." Tübingen : Universitätsbibliothek Tübingen, 2017. http://d-nb.info/1167408284/34.

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NEDDEN, ANA GABRIELA PILLA ZUR. "AN ANALYSIS OF THE DROP BREAKUP PROCESS IN AN OIL IN WATER EMULSION FLOWING TETWEEN PARALLEL DISKS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=17051@1.

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A produção de petróleo é geralmente acompanhada pela produção de água, que pode estar presente sob forma livre e emulsionada. As emulsões podem ser encontradas em quase todas as fases de produção: nos reservatórios, nos poços produtores, nas facilidades de produção, nos dutos de transporte, no processamento e no armazenamento O sistema de Bombeio Centrifugo Submerso (BCS) é um dos métodos utilizados na indústria para a elevação de petróleo para campos localizados tanto em terra como em mar. Ainda que seja o método de elevação artificial mais apropriado para a produção de petróleo quando há elevada produção de água, a eficiência da bomba é bastante reduzida quando há manuseio de misturas de água e óleo e a formação de emulsões. Este trabalho teve como objetivo o estudo do cisalhamento aos quais os fluidos estão expostos durante a passagem por um estágio de uma Bomba Centrífuga Submersa e seus efeitos no grau de emulsificação da mistura de água e óleo. Foi construído um aparato experimental composto por dois discos, um giratório e um fixo. Ao escoar através destes a mistura de fluidos sofre deformação cisalhante e extensional e seu grau de emulsificação, isto é, tamanho médio e distribuição dos diâmetros de bolhas, é medido a montante e a jusante do dispositivo.
Oil production is usually associated with the production of water, which may be found as a continuous phase or as a dispersed phase, in emulsions. Emulsions may be found in almost all the production stages: in reservoirs, production wells, production facilities, pipelines, in processing and in storage. The Electric Submersible Pump (ESP) is one of the methods employed in the industry to lift oil from fields located on land as well as at sea. Though this is the most appropriate artificial lift method for oil production when a considerable amount of water is produced, a pump’s efficiency is a greatly reduced when mixtures of water and oil are handled and emulsions begin to form. This paper intends to study the shearing imposed to fluids when flowing through a stage in a Electric Submersible Pump, and its effects in the degree of emulsification of the water and oil mixture. An experimental device was assembled consisting in two disks, one that spins and the other fixed. When flowing through them, a mixture of fluids is subjected to shearing and extensional deformation, and its degree of emulsification, i.e.: the average size and the bubble diameter distribution, may be measured upstream and downstream from the device.

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29

Xia, You. "Experiments on EHD injection, interaction and electrocoalescence of water droplet pairs in oil." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI039/document.

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Lorsque des champs électriques sont appliqués à des mélanges eau-huile, les petites gouttelettes d'eau sont attirées entre elles et se regroupent en gouttes plus grosses. Ce processus d’électrocoalescence rend plus efficace la séparation huile-eau par sédimentation.Des données expérimentales sur l’électrocoalescence de très petites gouttelettes sont nécessaires pour améliorer la compréhension de la dynamique de l'interface eau-huile et pour valider les modèles numériques. La configuration simple étudiée dans ce travail de thèse concerne une petite paire de gouttelettes tombant dans une cuve d'huile modèle et soumise à un champ électrique aligné avec l’axe de symétrie des gouttes et la gravité.La première partie du travail a consisté à générer de façon contrôlée d’une paire de très petites gouttelettes (dans la gamme de diamètres 20-200 microns) alignée avec le champ électrique. La génération de goutte à la demande, par méthode éléctrohydrodynamique (EHD) a été améliorée pour un meilleur contrôle du diamètre et de la charge électrique des gouttelettes injectées à partir d'une aiguille métallique unique. Ceci a été obtenu en appliquant à un ménisque d'eau pendant à l’extrémité de l’aiguille des impulsions électriques de forme optimisée.La caractérisation électrique et hydrodynamique des paires de gouttelettes et leur coalescence sont alors principalement déduites de l'analyse des vitesses de chute, avec et sans application d’un champ électrique à courant continu. Des données complètes de positions des gouttelettes et de leur vitesse en fonction du temps sont déduites de prises de vues vidéo. Une attention particulière a été accordée aux visualisations de très petites gouttelettes tombant à petites vitesses, associant des angles multiples de prise de vue, de forts zooms et des vidéos à grande vitesse.La modélisation des différents termes d'interactions hydrodynamiques et électrostatiques entre les gouttelettes permet de déduire des vitesses enregistrées leur masse charge électrique respectives. Quand se produit une coalescence des deux gouttelettes, un enregistrement de la vitesse de la gouttelette résultante, avec et sans tension électrique appliquée, permet de contrôler la conservation de la masse et de la charge électrique, et la validation du procédé.Un premier ensemble de données est constitué d'environ 70 cas différents, avec différentes paire des gouttelettes (dans une plage de diamètre limitée de façon à ce que les vitesses de chute soient comprises entre 0,1 et 0,3 mm/s) et en faisant varier la tension appliquée à courant continu ou alternatif. L'analyse des résultats et des incertitudes expérimentales et un exemple de comparaison possible avec des simulations numériques utilisant le logiciel Comsol Multiphysics ™, permettent d'effectuer des recommandations pour les travaux futurs.Ce travail a été financé par le projet “Fundamental understanding of electrocoalescence in heavy crude oils”; coordonné par SINTEF Energy Research. Le projet a été soutenu par The Research Council of Norway, dans le cadre du contrat n °: 206976 / E30, et par les partenaires industriels suivants: Wärtsilä Oil & Gas Systems AS, Petrobras et Statoil ASA
When electric fields are applied in oil-water mixtures small water droplets are attracted to others and merge in larger drops. This electrocoalescence process makes more efficient the oil-water separation by sedimentation.Experimental data on the electrocoalescence of very small droplets will be useful to improve the understanding of the dynamics of water-oil interface and to validate numerical models. The simple configuration studied consists in a small droplet pair falling in stagnant model oil, under electric field aligned with the symmetry axis of the droplet pair and the direction of gravity.First part of the work consisted in the well-controlled generation of very small droplet pair (range 20-200 microns) aligned with electric field. Droplet-on-Demand generation by EHD method was improved for a better control of the diameter and electric charge of droplets injected from a single metallic needle. This was obtained by applying to a pendant water meniscus optimized multistage high voltage electric pulses.Electrical and hydrodynamic characterization of the droplet pairs and their coalescence are then mainly deduced from the analysis of falling velocities, with and without applied DC electric field. A complete data set of droplet position and velocity is deduced from video. A special attention was paid to the visualizations of very small droplet and small falling velocities, involving multiple angle of view, strong zooming and high speed video.Modelling the different terms of hydrodynamic and electrostatic interactions between droplets allows deducing from the recorded velocities their respective mass and electric charge. When coalescence occurs, a record of the resulting single droplet velocity, with and without applied voltage, allows controlling the mass and charge conservations and validating the method.A first data set was constituted of about 70 different cases, with varying droplets pair (with a limited diameter range to remain with falling velocities between 0.1 and 0.3 mm/s) and varying applied DC or AC voltage. Analyses of the results and experimental uncertainties, and example of possible comparison with numerical simulations using Comsol Multiphysics™ software, allow performing some recommendations for future work.This work was funded by the project “Fundamental understanding of electrocoalescence in heavy crude oils”; co-ordinated by SINTEF Energy Research. The project was supported by The Research Council of Norway, under the contract no: 206976/E30, and by the following industrial partners: Wärtsilä Oil & Gas Systems AS, Petrobras and Statoil ASA

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Tansirikongkol, Anyarporn. "Development of a Synthetic Vernix Equivalent, and Its Water Handling and Barrier Protective Properties in Comparison with Vernix Caseosa." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1154393478.

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31

Covis, Rudy. "Synthèse de polysaccharides amphiphiles à partir de dextrane et application à la stabilisation d'émulsions directes et inverses." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL006N/document.

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Une nouvelle famille de dérivés amphiphiles du dextrane a été obtenue par réaction du dextrane avec le 1,2-époxydodécane en milieu basique. Deux voies de synthèse ont été étudiées. La première en milieu aqueux dispersé n’a permis d’obtenir que des taux de modification faibles (< 10 %) car l’homopolymérisation de l’époxyde est prépondérante. Au contraire, la réaction en milieu organique homogène a permis la synthèse de dérivés dont le taux de modification atteint 164 %. Des émulsions huile dans eau ont été préparées par sonication en présence de plusieurs dérivés hydrosolubles (τ ≤ 25 %). La fraction volumique d’huile (hexadécane ou nujol) est comprise entre 10 % et 50 %. La taille des gouttelettes augmente avec la fraction volumique d’huile mais ne dépend pas du taux de modification du dextrane entre 10 et 25 %. Ces émulsions ont un comportement de gel d’autant plus marqué que la fraction volumique d’huile dispersée augmente. Des émulsions inverses eau : chloroforme, stables pendant au moins 2 mois, ont été obtenues par sonication en présence de dérivés organosolubles (τ = 164 %). Le processus dynamique d’émulsification sous cisaillement a été étudié pour des émulsions directes (hexadécane / eau) dont la fraction volumique d’huile était comprise entre 10 et 60 % et pour différents gradients de vitesse. Un suivi continu in situ de la viscosité des émulsions et du rayon des gouttes formées montre que le temps caractéristique d’émulsification dépend du gradient de vitesse et du rapport des viscosités mais pas de la fraction volumique d’huile dispersée. Dans le cas d’un système newtonien, la viscosité finale et la taille finale des gouttes dépendent du gradient de vitesse appliqué alors qu’elles sont invariantes dans le cas du système non newtonien sur tout l’intervalle exploré
A new family of amphiphilic dextran derivatives was obtained by reaction of 1,2-epoxydodecane on dextran in basic medium. Two reaction procedures were examined. The first one was carried out in biphasic medium but produced only low degrees of hydrophobic substitution. Epoxide homopolymerization was indeed predominant. On the contrary, the reaction in a homogeneous organic medium allowed the synthesis of dextran derivatives with substitution degrees as high as 164 %. Oil-in-water emulsions were prepared by sonication in the presence of different hydrosoluble derivatives (τ ≤ 25 %). Oil volume fraction (hexadecane or nujol) ranged from 10 % to 50 %. The size of the emulsion droplets increased with the oil volume fraction but did not depend on the substitution degree of modified dextran between 10 and 25 %. These emulsions behave like a gel which strengthened with the oil volume fraction. Water-in-oil emulsions (water in chloroform) were obtained by sonication in the presence of organosoluble derivatives (τ = 164 %). They were stable over at least two months.Furthermore, dynamic emulsification process under shear flow was investigated for oil-in-water emulsions (hexadecane in water). The volume fraction of oil ranged from 10 % to 60 % and various shear rates were applied. Simultaneous in situ measurements of viscosity of emulsions and droplet size were performed. The characteristic time of emulsification depended on shear rate and viscosity ratio but was independent of the oil volume. For the newtonian system, final shear stress and final droplet size depended on the applied shear rate while they were invariant in the non newtonian system

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32

Bigikocin, Erman. "Effect Of High Hydrostatic Pressure (hhp) And High Dynamic Pressure (hdp) On Stability And Rheological Properties Of Model Oil-in-water Emulsions." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612416/index.pdf.

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High pressure applications are alternatives to conventional methods in food processing. They provide interesting modifications in food structures which leads to new product formulations. The aim of this study is to identify the effects of two different treatments, high hydrostatic pressure (HHP) and high dynamic pressure (HDP) on stability and rheological properties of model oil-in-water emulsions. Microfluidization was selected among the HDP homogenization techniques. The performance of each process was analyzed in terms of rheological modifications and emulsion stability improvements compared to the coarse emulsions which were prepared with colloid mill homogenization. Stability of emulsions was determined comparatively by using an analytical photo-centrifuge device employing a novel analysis technology. Whey protein isolate (WPI) was used as an emulsifier in combination with a food polysaccharide as a stabilizer. The polysaccharides used were xanthan gum, guar gum and locust bean gum which are widely used stabilizing ingredients in food industry. The effective disruption of oil droplets and the degradation of polysaccharides by the shear forces under high pressure in HDP microfluidization yielded finer emulsions with lower viscosities. The finer emulsions obtained with this homogenization technique led to distinctive improvements in emulsion stability. On the other hand, the improvements in stability by HHP treatment were due to the thickening of the emulsions mainly induced by protein unfolding. The corresponding increases in viscosity were intensified in emulsion formulations with higher oil content. Apart from these, HHP treatment was found to be relatively more contributing to the enhancements in viscoelastic properties.

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33

Fürtjes, Theresa Verfasser], and Stephan [Akademischer Betreuer] [Schreml. "Impact of a pH 5 Oil-in-Water (O/W) Emulsion on Skin Surface pH / Theresa Fürtjes ; Betreuer: Stephan Schreml." Regensburg : Universitätsbibliothek Regensburg, 2018. http://nbn-resolving.de/urn:nbn:de:bvb:355-epub-367214.

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Fürtjes, Theresa [Verfasser], and Stephan [Akademischer Betreuer] Schreml. "Impact of a pH 5 Oil-in-Water (O/W) Emulsion on Skin Surface pH / Theresa Fürtjes ; Betreuer: Stephan Schreml." Regensburg : Universitätsbibliothek Regensburg, 2018. http://d-nb.info/1152437542/34.

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Casari, Matheus Puttinati 1989. "Uso da espectroscopia por impedância para a medição da fração volumétrica de água em emulsões de água e óleo : The use of impedance spectroscopy for the water concentration measurement in water and oil emulsions." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265959.

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Orientador: Niederauer Mastelari
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-24T20:16:15Z (GMT). No. of bitstreams: 1 Casari_MatheusPuttinati_M.pdf: 7346334 bytes, checksum: 21f16ea44e6fdefa2b0445fe1a0b6b3a (MD5) Previous issue date: 2014
Resumo: A concentração volumétrica de água na produção de óleo cru é um parâmetro constantemente monitorado para acompanhar as sempre inconstantes propriedades do reservatório assim com para razões de otimização; resumindo, o que é importante é o volume de óleo na produção. A medição da concentração volumétrica de água é geralmente feita em bancada (colhendo uma amostra da produção e analisando-a em um laboratório) ou por sensores que monitoram a concentração em tempo real. Uma das técnicas utilizadas para a medição online da concentração de água é a espectroscopia por impedância. De fato, propriedades dielétricas e condutivas formam a impedância elétrica da solução. Na presente análise foram considerados os dois tipos básicos de emulsão: água em óleo (A/O) e óleo em água (O/A). O objetivo deste trabalho foi comparar a concentração de água medida com a predição do modelo matemático baseado nas medições das propriedades dielétricas e condutivas da solução. As emulsões de água e óleo foram sintetizadas em condições de laboratório. A concentração de água variou entre 13,1% à 41,1% em volume para as emulsões A/O e de 50% à 60% em volume para as emulsões O/A à temperaturas de 25°C à 62°C e salinidade da água de 0 (água deionizada), 1Kg/m³ e 10Kg/m³ de NaCl. A constante dielétrica e condutividade das emulsões foram medidas em um sensor composto por dois cilindros concêntricos cuja área dos eletrodos é bem maior que a distância entre eles. Essa geometria favorece os efeitos polarização e é apropriada para materiais dielétricos como as emulsões A/O, além de aumentar o erro de medição em soluções condutivas. Para melhores resultados com as emulsões O/A foi utilizado em sensor de placas paralelas com uma distância entre eletrodos bem maior que a sua área o que favorece os efeitos de transporte de carga. Os dados foram medidos por uma Ponte RLC de precisão Agilent E4980A em uma faixa de frequência de 20Hz à 1MHz. Os dados obtidos nos testes foram proporcionais à concentração de água na solução e seguiram o modelo matemático de Maxwell com um erro máximo de 4%. Os resultados também mostraram que a constante dielétrica não sofre influência significativa da temperatura e salinidade da água, assim como a medida do volume de água. Já para as emulsões O/A os testes mostraram grande influência da temperatura e salinidade da água nas medições, onde o conhecimento prévio destas condições é imprescindível ao método
Abstract: The volumetric concentration of water in crude oil production is a parameter constantly monitored to access the ever changing reservoir properties as well as for economical purposes; after all what is needed is the net oil production. The measurement of water concentration is usually done in over-the-bench (sampling the crude stream and screening in a chemistry lab) or by online instruments which continuously monitor the concentration. One of the techniques for online assessment of water concentration is the impedance spectroscopy. In fact, the dielectric and conductive property of the liquid phase is proportional to the electrical impedance. In the present analysis it was considered the two basic types of emulsions: the water in oil (W/O) and the oil in water (O/W). The objective of this work was to compare the measured water concentration against model's prediction based on the measured dielectric and conductive properties of the emulsions. The water and oil emulsions were synthesized in laboratory conditions. The water concentration range was 13.1% to 41.1% (v/v) for W/O emulsions and 50% to 60% (v/v) for O/W emulsions at temperatures of 25oC to 62oC and water salinity of 0 (de-ionized water), 1Kg/m³ and 10Kg/m³ of NaCl. The emulsion dielectric constant and conductivity were measured in a sensor made by two concentric cylinders whose electrodes area is much bigger than the distance between them. This geometry favors the polarization effects and is appropriate for dielectric solution as A/O emulsions. For better results for the O/A emulsion it was used a parallel electrode sensor where the distance between the electrodes is much bigger than the electrodes area which favors the charge transport effects. The data were measured by the Precision LCR Meter Agilent E4980A in a frequency range of 20Hz to 1MHz. The experimental data was found proportional to the volumetric concentration and follows Maxwell correlation within 4%. The experimental tests also disclosed that the dielectric constant, or the volumetric concentration, were almost insensitive to the changes in temperature and in salinity and so the water concentration of W/O emulsions. For O/W emulsions the tests showed a great influence of the temperature and salinity on the conductivity measurements. So, for O/W emulsions the temperature and water salinity must be considered
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica

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36

Tenghe, Lovette Asobo. "Formulation and evaluation of polymeric micelles for improved oral delivery of tenofovir disoproxil fumarate and zidovudine using poly-lactic-co-glycolic acid nanoparticles." University of the Western Cape, 2018. http://hdl.handle.net/11394/6770.

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Magister Pharmaceuticae - MPharm
Background: Tenofovir disoproxil fumarate (TDF) and Zidovudine (AZT) are both nucleotide and nucleoside analogue reverse transcriptase inhibitors (NtRTIs and NRTIs), respectively. They are used for the management and prevention of the Human Immunodeficiency Virus (HIV) infection. These drugs are faced with oral delivery challenges such as low intestinal permeability and extensive first pass liver metabolism for TDF and AZT, respectively. Their use may also be limited by dose-dependent adverse effects, which may result in treatment failure when patients become non-compliant and non-adherent to their prescribed antiretroviral (ARV) regimen. Non-compliance and non-adherence to ARV regimen may lead to drug resistance and a need for change in regimen, which can be very expensive, not only financially but in terms of morbidity and mortality. To solve such issues, a new drug can be formulated, or an existing drug can be modified. The development and formulation of a new drug is time consuming and expensive, especially with no available data and a high probability of failure. Modifying existing drugs is a cheaper, less time-consuming option with lower probability of failure. Such modification can be achieved via non-covalent interactions using various methods such as preparation of nano-particulates with polymeric micelles (a non-covalent interaction). Polymeric micelles offer a variety of polymers to choose from for drug modification purposes. Purpose: The aim of this study was to formulate polymeric nanoparticles of TDF and AZT using different ratios of poly-lactic-co-glycolic acid (PLGA), characterize the formulated nanoparticles (using the following analyses: particle size, zeta potential, encapsulation efficiency, hot stage microscopy, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy), analyze for stability during storage (2-8˚C) and determine the release rate of the active pharmaceutical ingredients in the formulated nanoparticles. Methods: Nanoparticles were prepared using a modified version of the double emulsion (water-in-oil-in-water) solvent evaporation and diffusion method. Two ratios of PLGA (50:50 and 85:15) were used to prepare four formulations (two each of TDF and AZT). Thereafter, the physicochemical and pharmaceutical properties of the formulations were assessed by characterizing the nanoparticles for particle size, zeta potential, polydispersity index, percentage yield, release profile and particle morphology, using the suggested analytical techniques. Results: For TDF-PLGA 85:15, TDF-PLGA 50:50, AZT-PLGA 85:15 and AZT-PLGA 50:50, nanoparticles of 160.4±1.7 nm,154.3±3.1 nm,127.0±2.32 nm and 153.2±4.3 nm, respectively, were recovered after washing. The polydispersity index (PDI) values were ≤0.418±0.004 after washing, indicating that the formulations were monodispersed. The zeta potential of the particles was -5.72±1 mV, -19.1 mV, -12.2±0.6 mV and -15.3±0.5 mV for TDF-PLGA 85:15, TDF-PLGA 50:50, AZT-PLGA 85:15 and AZT-PLGA 50:50 respectively after washing. The highest percentage yield was calculated to be 79.14% and the highest encapsulation efficiency obtained was 73.82% for AZT-PLGA 50:50, while the particle morphology showed spherical nanoparticles with signs of coalescence and aggregation for all formulated nanoparticles. The release profiles were biphasic; that is, an initial burst which indicated the presence of surface API followed by sustained release. Comparing the release profiles of AZT and TDF at pH 1.2 and 7.4, it was indicative that more AZT was released at pH 1.2 while more TDF was released at pH 7.4. On computing the release data further into various mathematical models, the Weibull model was found to be the best fit. The loaded nanoparticles showed an increase in stability after washing; however, they showed signs of gradual decrease in stability after 10 days of storage at 2-8°C. Conclusions: Relatively small, spherical and smooth nanoparticles were formulated. The nanoparticle release profile was indicative of sustained release; however, there was no conclusive indication that 48 hours duration was sufficient to release all encapsulated drug. Further studies with an increased API or polymer ratio in the formulation needs to be performed to determine if the encapsulation efficiency can be improved and in-vivo studies are required for a better understanding of the API release from formulations as well as its absorption in the body.

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Grosche, Lucas Caetano. "Study of the interactions between emulsion flow and a spectrometer probe based on numerical simulations." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-17102014-114519/.

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In the present work, the flow behavior of an oil-in-water emulsion around and inside the measurement chamber of an in-line optical sensor probe is studied. The emulsion consists of a metalworking fluid, with oil droplets diameter ranging from 100 nanometers to 100 micrometers. The design of the UV-Vis light spectrometer probe is in accordance with the concept proposed in the research project named EPM (Emulsion Process Monitor in Metalworking Processes), carried out within the scope of the BRAGECRIM program between the University of São Paulo and the University of Bremen. This study is based on the numerical simulation of the interactions between the emulsion and the measurement system using computational fluid dynamic techniques, and is aimed at evaluating the effects of the probe geometry, its position relative to the flow field, and fluid properties on the expected spectrometer readings. Such effects are correlated with changes in droplet concentration and or droplet size segregation inside the measurement chamber of the optical probe, which can cause changes in the scattered light intensity readings. Segregation effects due to flow disturbances around the probe can be neglected under normal measurement conditions, with the probe facing the slit area inlet against the flow stream. Based on the simulation results, even if the probe is misplaced, the effect on the measurements is still insignificant. In-situ measurements carried out in a laboratory set up installed in the injection tube of a drilling machine support the simulation results, since no segregation effect related to the measurement system was observed. In addition to the study, the possibility of bacteria attachment on the internal glass walls of the probe was evaluated and it was found that when the flow velocity is large enough to produce a wall shear stress of about 3-5 Pa the bacterial contamination may be avoided. Changes in the probe geometry are proposed in order to attain an isokinetic condition for the flow around and inside the probe, resulting in a higher wall shear stress for lower inlet flow velocities. An additional study was performed using a tracking particle model to understand the relevance of the individual particles behavior under different flow conditions. The results do not indicate any significant effect on the measurements inside the probe, although additional studies should be carried out in this topic by considering a population balance model for the oil droplets.
O presente trabalho tem como objetivo o estudo do comportamento do escoamento de uma emulsão do tipo óleo - em água que flui no interior de câmara/duto de medição e que tem como obstáculo em seu caminho uma sonda de um sensor óptico, sensor óptico este que deve avaliar em tempo real a estabilidade da emulsão onde está inserido. A emulsão é constituída por um fluido de corte para usinagem, com gotículas de óleo de diâmetro variando de 100 nanômetros para 100 micrometros. A sonda utilizada junto ao espectrômetro de luz UV- Vis está de acordo com o conceito proposto no projeto de pesquisa chamado EPM (Emulsion Process Monitor in Metalworking Fluid), realizado no âmbito do programa BRAGECRIM entre a Universidade de São Paulo e a Universidade de Bremen. Este estudo baseia-se na simulação numérica das interações entre a emulsão e o sistema de medição proposto, utilizando técnicas de Fluido Dinâmica Computacional (CFD), e tem por objetivo avaliar os efeitos da geometria da sonda, a sua posição em relação ao campo do escoamento, e propriedades do fluido, em especial as propriedades a serem medidas pelo espectrômetro. Tais efeitos estão correlacionadas com alterações na concentração de gotas e a segregação ou o tamanho das gotas dentro da câmara de medição da sonda óptica, o que pode causar mudanças nas leituras de intensidade de luz difusa. Efeitos de segregação devido a perturbações do escoamento em torno da sonda podem ser negligenciados, em condições normais de medição, com a sonda voltada para frente e sua área de entrada contra a corrente do escoamento. Com base nos resultados de simulação, mesmo que a sonda seja deslocada, o efeito sobre as medições ainda é insignificante. Medições foram efetuadas em laboratório e também foram realizadas medições in-situ utilizando um adaptador de medição acoplado diretamente no tubo de injeção de fluido de corte da máquina de perfuração, estes testes foram feitos para de validar os resultados obtidos por simulação, uma vez que não se observou qualquer efeito de segregação relacionada com o sistema de medição. Além disso, foi acrescentada ao estudo, a possibilidade de fixação de bactérias nas paredes de vidro internas da sonda e verificou-se que quando a velocidade de escoamento é suficientemente grande para produzir uma tensão de cisalhamento de cerca de 3-5 Pa a fixação de bacteriana pode ser evitado. Aproveitando os resultados do estudo para prevenção de contaminação por bactéria, mudanças na geometria da sonda foram propostas a fim de atingir uma condição isocinética para o escoamento ao redor e dentro da sonda, resultando em uma maior tensão de cisalhamento para baixas velocidades de fluxo de entrada. Por fim um estudo adicional foi realizado utilizando um modelo de rastreamento de partículas para compreender a relevância do comportamento individual de cada partícula no escoamento da emulsão. Os resultados não indicam qualquer efeito significativo sobre as medições no interior da sonda, embora estudos adicionais devem ser realizados neste tópico, considerando um modelo de balanço populacional para as gotículas de óleo.

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Bonilla, Riaño Adriana 1980. "Film thickness measurement with high spatial and temporal resolution planar capacitive sensing in oil-water pipe flow = Medida da espessura de filme usando sensor capacitivo de alta resolução espacial e temporal para escoamentos óleo-água em tubos." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265764.

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Orientadores: Antonio Carlos Bannwart, Oscar Mauricio Hernandez Rodriguez
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências
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Resumo: Neste trabalho, é apresentado o desenvolvimento de uma nova técnica para a medição da espessura do filme de água com alta resolução espacial e temporal em escoamento óleo-água. É proposto o uso de um sistema de medição de capacitância elétrica para medir filmes finos de água na proximidade da parede do tubo. O sistema conta com um sensor planar e foi necessário determinar a melhor geometria via simulações baseadas no Método de Elementos Finitos (FEM) para o caso de escoamento óleo-água. As características comparadas foram a profundidade de penetração do campo elétrico no filme de água, a sensibilidade, a resolução espacial mínima e a resposta quase-linear. Padrões de escoamento óleo-água disperso e anular instável foram estudados numa tubulação vertical de 12 m de comprimento, feita de vidro, com 50,8 milímetros de diâmetro interno. Os fluidos usados foram óleo mineral (com densidade 828 kg/m3 e viscosidade 220 mPas) e água da torneira. O trabalho experimental foi realizado nas instalações de escoamento multifásico do Laboratório de Engenharia Térmica e Fluidos (NETeF) da EESC-USP. Foi medida a espessura média do filme de água usando o sistema capacitivo e uma câmera de vídeo de alta velocidade. Para obter a espessura do filme de água a partir das imagens, foi proposto um algoritmo de pré-processamento e um algoritmo de segmentação que combina vários métodos disponíveis na literatura. Os resultados experimentais do sensor capacitivo mostraram que o sistema pode medir espessuras entre 400 µm e 2200 µm. O escoamento anular instável é caracterizado por grandes flutuações na no sentido do escoamento e na direção do perímetro, e estruturas interfaciais grandes (gotas). Por sua vez, o escoamento disperso tem flutuações menores no sentido do escoamento e na direção do perímetro, e estruturas interfaciais menores (gotículas). Uma estrutura interfacial média no espaço e no tempo é proposta para modelar a interface entre a região próxima à parede do tubo e a região do núcleo, e sua análise foi feita no domínio do tempo e da frequência. Foram estudadas a amplitude, velocidade e o comprimento da estrutura interfacial em cada par transmissor-receptor do sensor. Foi possível estabelecer correlações para a velocidade das estruturas em escoamento de óleo em água
Abstract: The development of a new technique for high spatial and temporal resolution film thickness measurement in oil-water flow is presented. A capacitance measurement system is proposed to measure thin water films near to the wall pipe. A planar sensor was chosen for sensing and some geometries were compared using finite elements method (FEM). The penetration depth, the sensitivity, the minimum spatial resolution (high spatial resolution) and the quasi-linear curve were the analyzed characteristics. Dispersed and unstable-annular oil-water flows patterns were studied in a 12-m long vertical glass pipe, with 50.8 mm of internal diameter, using mineral oil (828 kg/m3 of density and 220 mPa s of viscosity) and tap water. The experimental work was carried out in the multiphase-flow facilities of The Thermal-Fluids Engineering Laboratory (NETeF) of EESC-USP. Experiments with a high-speed video camera and the proposed capacitance system were performed to obtain images of the oil-water flow near the pipe wall. A pre-processing enhancement algorithm and a combined segmentation algorithm are proposed and allowed the measurement of characteristic space and time averaged water film thickness. Experimental results of the capacitive technique showed that the system could measure thickness between 400 µm and 2200 µm. It was possible to recognize and characterize typical behaviors of the two different flow patterns studied. Unstable-annular flow can be described by huge fluctuations on the flow direction and perimeter direction, and big interfacial structures (drops). On the other hand, dispersed flow has tiny fluctuations on the flow direction and perimeter direction, and smaller interfacial structures (droplets). An interfacial structure is suggested in order to model the interface between wall and core regions and it was analyzed in time and frequency domains; amplitude, velocity and wavelength at each pair transmitter-receiver of the sensor were studied. Correlations for the interfacial structure velocity were found for dispersed oil-in-water flow and unstable-annular flow
Doutorado
Explotação
Doutora em Ciências e Engenharia de Petróleo
CAPES

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Lignel, Sarah. "Emulsions eau-dans-huile générées par un procédé microfluidique : contribution à l'étude de la congélation de l'eau dispersée en émulsion." Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP2143/document.

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Ces travaux entrent dans la cadre du projet européen Fundamental and Applied Studies on Emulsion Stability (FASES). L'objectif de ce projet est de comprendre les phénomènes responsables de la déstabilisation des émulsions dans le temps, en relation avec les propriétés interfaciales de ces systèmes. Les travaux de thèse décrits dans ce mémoire se divisent en deux parties : ils portent tout d'abord sur la fabrication de gouttes d'émulsions eau-dans-huile par un procédé microfluidique, puis sur l'étude de la taille et de l'état de dispersion des gouttes sur la cristallisation de l'eau dispersée. Dans un premier temps, nous avons étudié les conditions opératoires permettant de fabriquer des gouttes de taille contrôlée par microfluidique avec le système de fluides mis en œuvre dans le projet FASES. Suivant le mode d'introduction des phases liquides, soit les débits, soit les pressions appliquées, ont été modifiés pour délimiter les zones de fabrication des gouttes. Afin de mieux comprendre les différences observées entre les deux modes d'introduction des fluides, un modèle reposant sur l'analogie entre circuits électriques et circuits microfluidiques a été proposé. Dans un second temps, les émulsions obtenues avec le dispositif microfluidique ont été analysées par calorimétrie et par thermo-microscopie. Les expériences ont permis de mettre en évidence, suivant les conditions étudiées (viscosité, taille des gouttes), différents processus de cristallisation des gouttes. Ces résultats mettent en avant directement le rôle du phénomène de sédimentation, les signaux de congélation observés dépendant fortement de l'état de dispersion des gouttes d'émulsion
This thesis takes place in the framework of the European project FASES (Fundamentaland Applied Studies on Emulsion Stability). The aim of this project is to understand the phenomena responsible for emulsions destabilization, in relation with the interfacial properties of these systems. The research work described in this thesis is divided into twoparts : the first part deals with the creation of water-in-oil emulsion droplets in a microfluidic device, and in the second part, the influence of the size and the state of dispersion of the droplets on the crystallization of dispersed water is analyzed.To begin with, the operating conditions required to create emulsion droplets by microfluidic were studied. Two modes of introduction of the liquid phases, based on flow and pressure-driven techniques, were used to create the droplets. Maps of the droplet formation regions were drawn as a function of the applied flow rates and pressures. In order to compare the two processes, a model based on the analogy between electrical and microfluidic circuits was proposed.Then, emulsions obtained with the microfluidic device were analyzed by calorimetry and thermo-microscopy. The experimental results evidenced different droplet crystallization processes, depending on the system parameters (oil phase viscosity, droplet size …). The water freezing signals strongly depend on the state of dispersion of the droplets, showing themajor role of droplet sedimentation in the emulsion destabilization process

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Vernay, Clara. "Déstabilisation de nappes liquides d'émulsions diluées." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS199/document.

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Le phénomène de dérive constitue un enjeu environnemental et sanitaire majeur lors de la pulvérisation de solutions phytosanitaires sur les surfaces agricoles. Sous l'action du vent, des gouttelettes peuvent dériver loin des champs ciblés et être source de pollution. Une stratégie pour limiter la dérive est de contrôler la distribution de taille des gouttes de spray, en réduisant la proportion de petites gouttes. Dans ce but, des additifs anti-dérives, tels que des émulsions diluées d'huile dans l'eau, ont été développés. Bien que largement étudiés, les effets de ces émulsions ne sont pas encore bien compris. L'objectif de cette thèse est d'élucider les mécanismes à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsions.La pulvérisation implique la fragmentation d'un flux de liquide par une buse hydraulique. A la sortie de la buse, une nappe libre de liquide est formée, puis déstabilisée en gouttes. Afin d'élucider les mécanismes à l'origine des effets anti-dérives des émulsions, nous étudions l'influence de ces émulsions sur les mécanismes de déstabilisation des nappes liquides. Une expérience modèle basée sur la collision d'une goutte de solution sur une cible solide est utilisée pour produire et visualiser des nappes liquides. Lors de l'impact, la goutte s'aplatit en une nappe qui s'étend radialement dans l'air, bordée par un bourrelet plus épais. Différents mécanismes de déstabilisation sont observés en fonction des propriétés des fluides. Une nappe d'eau pure s'étale radialement puis se rétracte par effet de la tension de surface ; simultanément, le bourrelet est déstabilisé en gouttes. Pour une émulsion diluée d'huile dans l'eau, le mécanisme de déstabilisation dominant est considérablement modifié: les nappes sont déstabilisées par la nucléation de trous qui perforent le film liquide lors de son expansion; les trous grandissent jusqu'à la formation d'un réseau de ligaments, qui est ensuite déstabilisé en gouttes.Une étude systématique de l'influence des paramètres physico-chimiques de l'émulsion, tels que la concentration en huile et la distribution de taille de gouttelettes d'huile, sur le mécanisme de perforation est conduite. Nous établissons une corrélation entre le nombre d'évènements de perforations observés dans les nappes modèles et la distribution de taille de gouttes de sprays formés avec des buses de pulvérisation agricoles. Ce résultat démontre la pertinence expérimentale de notre expérience modèle pour comprendre les mécanismes d'actions des formulations anti-dérives. Nous montrons ainsi que le mécanisme à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsion est un mécanisme de perforation.Pour comprendre les mécanismes à l'origine de la perforation, nous développons une technique optique permettant de mesurer le champ d'épaisseur de nappes liquides. Nous constatons que la formation d'un trou dans la nappe est systématiquement précédée par un amincissement local du film liquide. Nous montrons que cet amincissement est le résultat de l'entrée puis de l'étalement par effet Marangoni de gouttelettes d'huile à l'interface air/eau. L'amincissement du film liquide conduit in fine à sa rupture.Nous proposons un mécanisme de perforation en deux étapes: les gouttelettes d'huile (i) entrent à l'interface air/eau, et (ii) s'étalent à l'interface. La formulation de l'émulsion est un paramètre critique pour contrôler le processus de perforation. L'addition de sels ou de copolymères amphiphiles à des émulsions stabilisées par des tensio-actifs ioniques peut soit déclencher, soit inhiber le mécanisme de perforation. Nous montrons que l'entrée de gouttes d'huile à l'interface air/eau est l'étape limitante de ce mécanisme. Les interactions répulsives de nature stérique et/ou électrostatique entre les gouttelettes d'huile et l'interface stabilisent le film liquide, empêchant les gouttelettes d'entrer à l'interface, et ainsi inhibent le processus de perforation
One of the major environmental issues related to spraying of pesticides on cultivated crops is the drift phenomenon. Because of the wind, small droplets may drift away from the targeted crop and cause contamination. One way to reduce the drift is to control the spray drop size distribution and reduce the proportion of small drops. In this context, anti-drift additives have been developed, including dilute oil-in-water emulsions. Although being documented, the effects of oil-in-water emulsions on spray drop size distribution are not yet understood. The objective of this thesis is to determine the mechanisms at the origin of the changes of the spray drop size distribution for emulsion-based sprays.Agricultural spraying involves atomizing a liquid stream through a hydraulic nozzle. At the exit of the nozzle, a free liquid sheet is formed, which is subsequently destabilized into droplets. In order to elucidate the mechanisms causing the changes of the spray drop size distribution, we investigate the influence of emulsions on the destabilization mechanisms of liquid sheets. Model single-tear experiments based on the collision of one tear of liquid on a small solid target are used to produce and visualize liquid sheets with a fast camera. Upon impact, the tear flattens into a sheet radially expanding in the air bounded by a thicker rim. Different destabilization mechanisms of the sheet are observed depending on the fluid properties. A pure water sheet spreads out radially and then retracts due to the effect of surface tension. Simultaneously, the rim corrugates forming radial ligaments, which are subsequently destabilized into droplets. The destabilization mechanism is drastically modified when a dilute oil-in-water emulsion is used. Emulsion-based liquid sheets are destabilized through the nucleation of holes within the sheet that perforate the sheet during its expansion. The holes grow until they merge together and form a web of ligaments, which are then destabilized into drops.The physical-chemical parameters of the emulsion, such as emulsion concentration and emulsion droplet size distribution, are modified to rationalize their influence on the perforation mechanism. We correlate the size distribution of drops issued from conventional agricultural spray with the amount of perforation events in single-tear experiments, demonstrating that the single-tear experiment is an appropriate model experiment to investigate the physical mechanisms governing the spray drop size distribution of anti-drift formulations. We show that the relevant mechanism causing the increase of drops size in the emulsion-based spray is a perforation mechanism.To gain an understanding of the physical mechanisms at the origin of the perforation events, we develop an optical technique that allows the determination of the time and space-resolved thickness of the sheet. We find that the formation of a hole in the sheet is systematically preceded by a localized thinning of the liquid film. We show that the thinning results from the entering and Marangoni-driven spreading of emulsion oil droplet at the air/water interface. The localized thinning of the liquid film ultimately leads to the rupture of the film. We propose the perforation mechanism as a sequence of two necessary steps: the emulsion oil droplets (i) enter the air/water interface, and (ii) spread at the interface. We show that the formulation of the emulsion is a critical parameter to control the perforation. The addition of salt or amphiphilic copolymers can trigger or completely inhibit the perforation mechanism. We show that the entering of oil droplets at the air/water interface is the limiting step of the mechanism. Thin-film forces such as electrostatic or steric repulsion forces stabilize the thin film formed between the interface and the approaching oil droplets preventing the entering of oil droplets at the interface and so inhibit the perforation process

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BARRETO, GUILHERME LOPES. "CLATHRATE HYDRATE FORMING IN WATER-IN-OIL EMULSIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34572@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Uma combinação de fatores geológicos e econômicos exige que as empresas produzam petróleo e gás em campos com profundidades de água cada vez maiores. Muitas das vezes não é econômico, ou no pior dos casos impraticável, instalar uma plataforma sobre os cabeçotes dos poços, por isso acaba se tornando comum transportar petróleo e gás através de amarras submarinas que podem ser de até 145km ou mais. Geralmente isso significa que as temperaturas são baixas o bastante e as pressões altas o suficiente para tornar aquele ambiente dentro do que chamamos de envelope de formação de hidrato e ações deverão ser tomadas afim de evitar os plugs de hidrato. Como resultado, a indústria foi forçada a intensificar sua pesquisa em químicos e sistemas que evitasse a formação da estrutura cristalina. Uma dessas pesquisas em estudo é a avaliação de um fluido modelo, emulsão A/O, analisando suas principais características e verificando as propriedades reológicas da estrutura cristalina em formação. Para tornar a pesquisa viável, este hidrato é formado a pressão atmosférica utilizando moléculas hóspedes que proporcionam essa formação em tal pressão e baixa temperatura. Logo, é utilizada uma substância líquida chamada ciclopentano, que substituirá o gás natural e irá proporcionar a formação do hidrato nestas novas condições. Dessa forma, este trabalho apresentou diferentes emulsões A/O, de acordo com a porcentagem de água, e reologia do hidrato formado para cada uma delas.
A combination of geological and economic factors requires companies to produce oil and gas in fields with increasing water depths. It is often impractical to install a platform over the heads of the wells, so it is becoming common to transport oil and gas through underwater moorings that can be up to 145 km or more. Usually this means that the temperatures are low enough and the pressures high enough to make that environment into what we call a hydrate formation envelope and actions should be taken to avoid the hydrate plugs. As a result, the industry was forced to intensify its research into chemicals and systems that prevented the formation of the crystalline structure. One of these researches is the evaluation of a model fluid, A / O emulsion, analyzing its main characteristics and checking the rheological properties of the crystalline structure in formation. To make the search feasible, this hydrate is formed at atmospheric pressure using guest molecules that provide such formation at such pressure and low temperature. Therefore, a liquid substance called cyclopentane is used, which will replace the natural gas and will provide the formation of the hydrate under these new conditions. In this way, this work presented different A / O emulsions, according to the percentage of water, and rheology of the hydrate formed for each of them.

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Lin, Lu. "Characterizations of oil-in-water (O/W) emulsions containing different types of milk fats prepared using rhamnolipids as emulsifiers : [a thesis presented in partial fulfillment of the requirements for the degree of Master of Technology in Food Technology at Massey University, Auckland, New Zealand] EMBARGOED UNTIL 1 MARCH 2011." Massey University, 2009. http://hdl.handle.net/10179/1323.

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Emulsions containing three different types of milk fat fractions (MF13, MF27 and MF42) and anhydrous milk fat (AMF) were prepared at oil to water (O/W) ratios of 1:9, 3:7, 5:5 and 7:3 using rhamnolipids as emulsifiers. The prepared emulsions were analyzed for their storage stability and properties (colour, particle size, zeta potential and rheology). The effects of various factors (freezing/thawing, heating, pH, salts and ionic strength) on the stability of emulsions were also investigated. All emulsions prepared with an O/W ratio of 7:3, regardless of the type of milk fat, rendered a highly condensed, semi solid and cream-like substance whereas other emulsions containing less oil were in a liquid form. Among the four different O/W ratios tested, the highest emulsion stability during the storage of 12 weeks was observed from the emulsions containing 1:9 O/W ratios, due to a combine effect of smaller emulsion particle size and lower collision frequency between droplets. Interestingly, the emulsions with 7:3 O/W ratios were found to be more stable than the ones with 5:5 O/W ratios. This might be due to the limited movements of closely-packed emulsion droplets induced by the high oil concentration of 7:3 O/W ratios. The emulsion stability was significantly affected by low pH, especially at lower than pH 4, due to the loss of electrostatic repulsions between droplets leading to droplet coalescence and also possibly due to hydrolysis of rhamnolipid molecules. The presence of salts (NaCl, KCl and CaCl2) also rendered the emulsion unstable. The degree of instability was gradually increased with increasing salt concentrations. CaCl2 had the most significant effect even at a very low concentration. The viscosity of emulsions increased with increasing oil concentration but was not affected by the types of milk fats. Emulsions with 3:7, 5:5 and 7:3 O/W ratios exhibited non-Newtonian and shear thinning flow behaviour. At 7:3 O/W ratios, MF13 exhibited gel-like properties whereas both MF42 and AMF emulsions became more solid-like at higher frequency.

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Ratoi, Monica. "The design of lubricating oil in water emulsions." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243558.

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Barker, David Colin. "The lubricating properties of oil-in-water emulsions." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294971.

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West, P. E. "Oil-in-water emulsions for intravenous drug delivery." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233707.

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Vernay, Clara. "Déstabilisation de nappes liquides d'émulsions diluées." Electronic Thesis or Diss., Montpellier, 2015. http://www.theses.fr/2015MONTS199.

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Le phénomène de dérive constitue un enjeu environnemental et sanitaire majeur lors de la pulvérisation de solutions phytosanitaires sur les surfaces agricoles. Sous l'action du vent, des gouttelettes peuvent dériver loin des champs ciblés et être source de pollution. Une stratégie pour limiter la dérive est de contrôler la distribution de taille des gouttes de spray, en réduisant la proportion de petites gouttes. Dans ce but, des additifs anti-dérives, tels que des émulsions diluées d'huile dans l'eau, ont été développés. Bien que largement étudiés, les effets de ces émulsions ne sont pas encore bien compris. L'objectif de cette thèse est d'élucider les mécanismes à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsions.La pulvérisation implique la fragmentation d'un flux de liquide par une buse hydraulique. A la sortie de la buse, une nappe libre de liquide est formée, puis déstabilisée en gouttes. Afin d'élucider les mécanismes à l'origine des effets anti-dérives des émulsions, nous étudions l'influence de ces émulsions sur les mécanismes de déstabilisation des nappes liquides. Une expérience modèle basée sur la collision d'une goutte de solution sur une cible solide est utilisée pour produire et visualiser des nappes liquides. Lors de l'impact, la goutte s'aplatit en une nappe qui s'étend radialement dans l'air, bordée par un bourrelet plus épais. Différents mécanismes de déstabilisation sont observés en fonction des propriétés des fluides. Une nappe d'eau pure s'étale radialement puis se rétracte par effet de la tension de surface ; simultanément, le bourrelet est déstabilisé en gouttes. Pour une émulsion diluée d'huile dans l'eau, le mécanisme de déstabilisation dominant est considérablement modifié: les nappes sont déstabilisées par la nucléation de trous qui perforent le film liquide lors de son expansion; les trous grandissent jusqu'à la formation d'un réseau de ligaments, qui est ensuite déstabilisé en gouttes.Une étude systématique de l'influence des paramètres physico-chimiques de l'émulsion, tels que la concentration en huile et la distribution de taille de gouttelettes d'huile, sur le mécanisme de perforation est conduite. Nous établissons une corrélation entre le nombre d'évènements de perforations observés dans les nappes modèles et la distribution de taille de gouttes de sprays formés avec des buses de pulvérisation agricoles. Ce résultat démontre la pertinence expérimentale de notre expérience modèle pour comprendre les mécanismes d'actions des formulations anti-dérives. Nous montrons ainsi que le mécanisme à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsion est un mécanisme de perforation.Pour comprendre les mécanismes à l'origine de la perforation, nous développons une technique optique permettant de mesurer le champ d'épaisseur de nappes liquides. Nous constatons que la formation d'un trou dans la nappe est systématiquement précédée par un amincissement local du film liquide. Nous montrons que cet amincissement est le résultat de l'entrée puis de l'étalement par effet Marangoni de gouttelettes d'huile à l'interface air/eau. L'amincissement du film liquide conduit in fine à sa rupture.Nous proposons un mécanisme de perforation en deux étapes: les gouttelettes d'huile (i) entrent à l'interface air/eau, et (ii) s'étalent à l'interface. La formulation de l'émulsion est un paramètre critique pour contrôler le processus de perforation. L'addition de sels ou de copolymères amphiphiles à des émulsions stabilisées par des tensio-actifs ioniques peut soit déclencher, soit inhiber le mécanisme de perforation. Nous montrons que l'entrée de gouttes d'huile à l'interface air/eau est l'étape limitante de ce mécanisme. Les interactions répulsives de nature stérique et/ou électrostatique entre les gouttelettes d'huile et l'interface stabilisent le film liquide, empêchant les gouttelettes d'entrer à l'interface, et ainsi inhibent le processus de perforation
One of the major environmental issues related to spraying of pesticides on cultivated crops is the drift phenomenon. Because of the wind, small droplets may drift away from the targeted crop and cause contamination. One way to reduce the drift is to control the spray drop size distribution and reduce the proportion of small drops. In this context, anti-drift additives have been developed, including dilute oil-in-water emulsions. Although being documented, the effects of oil-in-water emulsions on spray drop size distribution are not yet understood. The objective of this thesis is to determine the mechanisms at the origin of the changes of the spray drop size distribution for emulsion-based sprays.Agricultural spraying involves atomizing a liquid stream through a hydraulic nozzle. At the exit of the nozzle, a free liquid sheet is formed, which is subsequently destabilized into droplets. In order to elucidate the mechanisms causing the changes of the spray drop size distribution, we investigate the influence of emulsions on the destabilization mechanisms of liquid sheets. Model single-tear experiments based on the collision of one tear of liquid on a small solid target are used to produce and visualize liquid sheets with a fast camera. Upon impact, the tear flattens into a sheet radially expanding in the air bounded by a thicker rim. Different destabilization mechanisms of the sheet are observed depending on the fluid properties. A pure water sheet spreads out radially and then retracts due to the effect of surface tension. Simultaneously, the rim corrugates forming radial ligaments, which are subsequently destabilized into droplets. The destabilization mechanism is drastically modified when a dilute oil-in-water emulsion is used. Emulsion-based liquid sheets are destabilized through the nucleation of holes within the sheet that perforate the sheet during its expansion. The holes grow until they merge together and form a web of ligaments, which are then destabilized into drops.The physical-chemical parameters of the emulsion, such as emulsion concentration and emulsion droplet size distribution, are modified to rationalize their influence on the perforation mechanism. We correlate the size distribution of drops issued from conventional agricultural spray with the amount of perforation events in single-tear experiments, demonstrating that the single-tear experiment is an appropriate model experiment to investigate the physical mechanisms governing the spray drop size distribution of anti-drift formulations. We show that the relevant mechanism causing the increase of drops size in the emulsion-based spray is a perforation mechanism.To gain an understanding of the physical mechanisms at the origin of the perforation events, we develop an optical technique that allows the determination of the time and space-resolved thickness of the sheet. We find that the formation of a hole in the sheet is systematically preceded by a localized thinning of the liquid film. We show that the thinning results from the entering and Marangoni-driven spreading of emulsion oil droplet at the air/water interface. The localized thinning of the liquid film ultimately leads to the rupture of the film. We propose the perforation mechanism as a sequence of two necessary steps: the emulsion oil droplets (i) enter the air/water interface, and (ii) spread at the interface. We show that the formulation of the emulsion is a critical parameter to control the perforation. The addition of salt or amphiphilic copolymers can trigger or completely inhibit the perforation mechanism. We show that the entering of oil droplets at the air/water interface is the limiting step of the mechanism. Thin-film forces such as electrostatic or steric repulsion forces stabilize the thin film formed between the interface and the approaching oil droplets preventing the entering of oil droplets at the interface and so inhibit the perforation process

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FARIAS, MANOEL LEOPOLDINO ROCHA DE. "IMPROVED HEAVY OIL RECOVERY BY INJECTION OF DILUTED OIL-IN-WATER EMULSIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23855@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
A injeção de água é o método de recuperação secundário mais utilizado no mundo. Mesmo em situações em que esse método não é o mais adequado, a facilidade de implantação e os menores custos comparativos impõem esse método como a opção selecionada. Em campos de óleo pesado, a razão de mobilidade desfavorável e as heterogeneidades de reservatório precipitam a formação de digitações viscosas e altos valores de saturação residual de óleo, levando a baixos fatores finais de recuperação. Os poços produtores desses campos produzem com altas frações de água muito rapidamente. O tratamento da água produzida é o principal custo operacional desses campos. O uso de emulsões diluídas de óleo em água foi avaliado como método de controle de mobilidade. Foi desenvolvido um extenso programa experimental em sandpacks de areia de sílica e plugs de arenito (Berea e Bentheimer) de forma a comparar as recuperações finais de óleo, perfis de pressão de injeção e razões água-óleo acumuladas nos casos de injeção de água, injeção de surfactantes e macroemulsões. Todos os meios porosos ensaiados foram saturados com petróleo cru originário da Bacia de Campos (20 graus API). Um estudo paramétrico foi feito de forma a identificar a influência da vazão de injeção, distribuição de tamanhos de gotas de óleo emulsionadas, concentração de óleo e permeabilidade no desempenho das emulsões injetadas. O programa foi complementado com um ensaio 3D (arenito Castlegate na configuração um quarto de five-spot) onde o fluido injetado foi dopado com Iodeto de Potássio para permitir melhor visualização da modificação de saturações de óleo e água com um tomógrafo de raios X. Os resultados obtidos indicaram ganhos na produção de óleo e redução da razão água-óleo acumulada. A possibilidade de preparar as emulsões óleo-água a serem injetadas a partir da água produzida pelo próprio campo traz um grande ganho ambiental ao se reduzir o descarte superficial de água oleosa. O efluente se transforma em um recurso.
Water injection is the most used secondary recovery method in the world. This option is generally chosen even in situations where it is not the most efficient alternative to recover the oil due to its comparative simple implementation and lower operational costs. In heavy oilfields, the unfavorable mobility ratio between injection and displaced fluids in addition to reservoir heterogeneities cause water fingering phenomenon, high residual oil saturation and consequently poor final oil recoveries. Producer wells start to produce high water cuts very soon. Produced water treatment for surface disposal is the main operational cost in these oilfields. The use of diluted oil-in-water macroemulsions was evaluated as a mobility control method for these cases. An extensive experimental program was performed using silica sandpacks and sandstone plugs (Berea and Bentheimer) in order to evaluate final oil recovery factors, cumulative water-oil ratio and pressure behavior, comparing water injection, surfactant solution injection and oil-in-water injection. All porous media were saturated with crude oil from Campos Basin (20 degrees API). A parametric study was performed to identify the effect of injection rate, oil droplets size distributions, emulsion oil concentration and permeability level in emulsion injection performance. The experimental program was completed by an X-Ray computerized tomography monitored experiment in a Castlegate sandstone block (1/4 five-spot configuration). This block was submitted to an alternate water/emulsion/water injection. All injection fluids were doped with Potassium Iodide in order to better visualize oil and water saturations changes during this experiment. The results obtained have indicated final oil recovery improvement and cumulative water/oil reduction. The possibility, after some treatment, to prepare diluted oil-in-water emulsions using produced water from the oilfield brings the additional environmental benefit to emulsion injection. It would be a way to convert an effluent in a resource with clear environmental advantages.

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Mehta, Shweta D. "Making and breaking of water in crude oil emulsions." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/3286.

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An understanding of the processes involved in oil spills, and how they interact to alter the composition and behavior of the oil with respect to time is essential to determine an effective oil spill response. The review of past research has shown more focus on the laboratory methods and computerized modeling schemes to estimate the formation and breaking of emulsions after an oil spill. However, relatively less effort has gone into the study of emulsions corresponding to actual field conditions. This research aims to simulate an oil spill at sea by developing a new technique to make water in oil emulsions, without disturbing the marine wildlife. Further, this research also attempts to analyze the viscosities of water in oil emulsions and determine appropriate emulsion breakers for different crude oil emulsions. The overall test design for the study includes a test apparatus for spreading and evaporation, three different crude oils, a mixing chamber to form the emulsion, and emulsion breakers. Experiments in this research attempt to gain a better understanding of the processes that occur after oil spills at sea. In particular, the rate of evaporation of different crude oils and the formation of crude oil emulsions on the sea surface have been investigated. It was observed that different crude oils behave differently when subjected to the same weathering procedure. Results indicate that the behavior of the crude oil on the sea surface, subjected to spreading, evaporation, and emulsification, can be predicted by using the new technique developed in this research. This technique can also assist the development of effective recovery equipments and materials.

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Yarranton, Harvey William. "Asphaltene solubility and asphaltene-stabilized water-in-oil emulsions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23096.pdf.

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URDANETA, SYGIFREDO COBOS. "FLOW OF OIL-IN-WATER EMULSIONS THROUGH CONSTRICTED CAPILLARIES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11323@1.

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AGÊNCIA NACIONAL DE PETRÓLEO
O escoamento de emulsões é encontrado em diversos processos de recuperação e produção de petróleo. O escoamento de emulsões em meios porosos depende de diversos parâmetros como a relação do tamanho das gotas ao tamanho dos poros, a razão de viscosidades, a vazão volumétrica e o efeito destes parâmetros ainda não é bem compreendido. Uma análise detalhada na escala microscópica dos fenômenos envolvidos se faz essencial para a melhora do entendimento completo do escoamento de emulsões em um reservatório. Isto permitiria o desenvolvimento de melhores modelos de simulação para o escoamento multifísico em meios porosos. Neste trabalho, o escoamento de emulsões óleo-água através de um capilar com garganta foi estudado através de experimentos e teoria. A análise experimental consistiu da visualização sob um microscópio do escoamento e da medição da queda de pressão em função da vazão para diferentes emulsões. A análise teórica englobou o estudo do escoamento em regime permanente de uma gota de óleo imersa em água através de um capilar e o estudo do escoamento transiente da mesma gota através de um capilar com uma garganta. Os resultados mostram que os modelos de escoamento de emulsões em meios porosos não devem ser baseados em propriedades macroscópicas da emulsão quando o tamanho das gotas da fase dispersa for da mesma ordem de grandeza do tamanho dos poros. Neste caso, a queda de pressão é função da tensão interfacial, a razão de viscosidades, a vazão e a razão entre o tamanho das gotas e o diâmetro do poro. Os resultados apresentados neste trabalho podem ser usados no projeto de emulsões apropriadas para controle de mobilidade em operações de recuperação avançada através de injeção de emulsões.
Flow of emulsions is found in many petroleum recovery and production processes and it is often referred to in the context of tertiary oil recovery. The characteristics of emulsion flow in porous media depend on several parameters such as medium drop size to pore size ratio, viscosity ratio, flow rate and the effect of these parameters is far from being entirely understood. A detailed analysis at a microscopic scale of the flow is essential to improve the understanding of flow of an emulsion in a reservoir. This would lead to the development of better simulation models, henceforth increasing the predictability capability of reservoir simulators for enhanced oil recovery applications. In this work, flow of oil-water emulsions through constricted capillaries, used as model for the geometry inside a porous media, is studied experimentally and theoretically. The experimental approach consisted of measuring pressure drop response as a function of flow rate for different emulsions and visualizing the flow under an optical microscope to understand the phenomena involved. The theoretical approach is divided in two parts. First, the immiscible steady flow of a infinite single drop suspended in an less viscous fluid through a capillary was analyzed by solving the Navier- Stokes equations with the appropriate boundary conditions for free-surface flow. The second part of the theoretical analysis consisted of solving the transient flow of a drop suspended in a less viscous fluid through a capillary with a constriction. It is shown the effect of capillary number and viscosity ratio over the main responses of the flow. The results show that models of emulsion flow in a porous media cannot be based on the macroscopic properties of the emulsion when the drop diameter is of the same order of magnitude as the pore throat diameter. In this case flow rate-pressure drop is a strong function of the interfacial tension, viscosity ratio, flow rate and drop to pore size ratio. The results can be used to design appropriate emulsions to control the water mobility during EOR operations by emulsion injection.

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