Submitted by João Vitor Munari Benetti (jvitormb@live.com) on 2018-09-26T20:06:18Z No. of bitstreams: 1 Dissertação Final João.pdf: 2286091 bytes, checksum: d5fc1e4e62e2b830f24943279cdec9af (MD5) / Approved for entry into archive by Elza Mitiko Sato null (elzasato@ibilce.unesp.br) on 2018-09-27T17:56:01Z (GMT) No. of bitstreams: 1 benetti_jvm_me_sjrp.pdf: 2729834 bytes, checksum: 78d52262fcb4441f86f4022910bcb982 (MD5) / Made available in DSpace on 2018-09-27T17:56:01Z (GMT). No. of bitstreams: 1 benetti_jvm_me_sjrp.pdf: 2729834 bytes, checksum: 78d52262fcb4441f86f4022910bcb982 (MD5) Previous issue date: 2018-09-03 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Emulsões óleo em água (O/W) são sistemas formados por dois líquidos imiscíveis, envolvendo a presença de uma fase contínua (água), uma fase dispersa (óleo), um emulsificante e energia introduzida por meio de agitação ou cavitação. A energia transmitida é capaz de aumentar a área interfacial entre as fases dispersa e contínua, enquanto o emulsificante adsorve na interface, estabilizando o sistema. A emulsificação é uma etapa anterior e fundamental à microencapsulação de compostos lipofílicos por spray drying, em que gotas de emulsão são rapidamente desidratadas em uma câmara de secagem, possibilitando a microencapsulação da fase dispersa. Neste trabalho, objetivou-se produzir emulsões O/W utilizando microgéis de isolado proteico de soja (SPI) como estabilizantes, avaliar a estabilidade e o comportamento reológico das emulsões em diferentes concentrações de cloreto de sódio (NaCl) e, posteriormente, produzir microcápsulas por spray drying, avaliando o potencial dos microgéis de SPI como material de parede. Suspensões com 10% m/m de SPI foram preparadas em água deionizada e submetidas à desnaturação por aquecimento a 80 ºC por 30 minutos, seguido de resfriamento a 4 ºC por 12 h. Após a formação do gel, as suspensões foram diluídas para 6% m/m de SPI com água ou soluções de NaCl e homogeneizadas sob alta pressão ou sonicadas para produção dos microgéis, usados para estabilizar emulsões O/W com diferentes teores de óleo produzidas por homogeneização a alta pressão ou sonicação. As emulsões sonicadas foram submetidas à secagem em spray dryer para produção de micropartículas contendo óleo encapsulado. Os microgéis de SPI foram caracterizados quanto à distribuição de tamanhos de partícula e ao potencial zeta. As emulsões O/W foram avaliadas quanto ao comportamento reológico, estabilidade e morfologia. A adição de NaCl influenciou diretamente no tamanho das partículas de SPI e em seu potencial zeta, visto que a presença do sal diminuiu a repulsão eletrostática entre os microgéis e resultou na formação de aglomerados. A reologia das emulsões foi avaliada por cisalhamento em regime permanente, observando-se o aumento do índice de consistência dos fluidos pseudoplásticos com o aumento da concentração de NaCl ou da fase dispersa (óleo) nas emulsões. Todas as emulsões se apresentaram estáveis por, pelo menos, 21 dias a temperatura de 25 ºC. O processo foi caracterizado quanto ao rendimento, e as microcápsulas de óleo foram caracterizadas quanto a retenção de óleo, umidade e morfologia. A secagem se mostrou mais eficiente para emulsões com teor de óleo mais baixo (5 a 7,5 %) e submetidas a secagem em temperaturas mais altas (160 a 170 °C). As microcápsulas apresentaram retenção de óleo acima de 80% e umidade adequada para produtos em pó (< 4%). As imagens das microcápsulas produzidas mostraram a formação de microesferas contendo óleo aprisionado na matriz proteica. Os microgéis de SPI se mostraram capazes de estabilizar emulsões com diferentes teores de óleo, além da possibilidade de serem utilizados como material de parede para microencapsular compostos lipofílicos por spray drying. / Oil-in-water (O/W) emulsions are systems formed by two immiscible liquids, involving a continuous phase (water), a dispersed phase (oil), an emulsifier and energy input by homogenization or cavitation. The transmitted energy is able to increase the interfacial area between the dispersed and continuous phases, while the emulsifier adsorbs at the interface, stabilizing the system. The emulsification is an earlier and fundamental step to microencapsulation of lipophilic compounds by spray drying, wherein emulsion droplets are rapidly dehydrated in a drying chamber, enabling the microencapsulation of the dispersed phase. The objective of this work was to produce emulsions using soybean protein isolate (SPI) microgels as O/W emulsion stabilizers, to evaluate the stability and rheological behavior of the emulsions at different concentrations of sodium chloride (NaCl), and to produce microcapsules by spray drying of the emulsions, evaluating the potential of SPI microgels as wall material. Suspensions with 10 wt% SPI were prepared in deionized water and subjected to gelation by heating at 80 °C for 30 minutes, followed by cooling at 4 °C for 12 h. After gel formation, the suspensions were diluted to 6 wt% SPI with water or NaCl solutions and homogenized under high pressure or sonication to produce the microgels, which were used to stabilize O/W emulsions with different oil contents produced by high-pressure or ultrasound homogenization. The emulsions were then submitted to drying in spray dryer for production of oil microcapsules. SPI microgels were characterized regarding their particle size distribution and zeta potential. O/W emulsions were evaluated regarding their rheological behavior, stability and morphology. The addition of NaCl directly influenced the size of the SPI particles and their zeta potential, since the presence of the salt decreased the electrostatic repulsion between the microgels and, consequently, the gel particles were approached, forming agglomerates. The rheological behavior of the emulsions was evaluated by means of steady shear tests, and an increase in the consistency index of the pseudoplastic fluids was observed with increasing NaCl or dispersed phase concentration in the emulsions. All the emulsions were stable for at least 21 days at 25 °C. The process was characterized regarding yield. and the oil microcapsules were characterized regarding oil retention, water content and morphology. The drying process showed to be more efficient to emulsions with lower oil content (5 a 7.5 wt%) and subjected to higher drying temperatures (160 a 170 °C). The microcapsules presented oil retention higher than 80% and water content suitable for powdered products (< 4%). The images of microcapsules showed the formation of microspheres containing oil droplets trapped in the protein matrix. The SPI microgels were able to stabilize emulsions with different oil contents, in addition to the possibility of being used as wall materials to microencapsulate lipophilic compounds by spray drying. / CNPq: 132640/2017-1

Ce manuscrit se concentre sur l’étude de la dynamique de drainage de gouttes d’eau dans une phase continue d’huile de paraffine. Les gouttes sont de taille millimétrique, déformables et évoluent dans un domaine de simulation carré de 1 cm de coté. La simulation du comportement de tels systèmes pose le problème général de la description numérique des écoulements multiphasiques non stationnaires. Un modèle simplifié dans une géométrie à deux dimensions est proposé et simulé en volumes finis. Il inclut les propriétés physico-chimiques des interfaces et notamment les phénomènes de coalescence et l’évolution d’un tensioactif soluble dans les gouttes. L’effet des conditions aux limites sur le drainage d’une unique goutte est étudié. Le rôle de la coalescence sur ce drainage est également décrit pour un modèle de deux gouttes. Quelques simulations sont enfin proposées avec des systèmes dispersés plus complexes. / This manuscript focuses on the description of the settling dynamics of water droplets in a continuous phase of paraffin oil. Droplets are of millimetre size, deformable and evolve in a square simulation domain of 1 cm side. The simulations of the behaviour of such systems raise the general problem of the numerical description of the flows occurring in multiphase unsteady systems. A simplified model in a two dimensional geometry is used and integrated with a finite volume numerical technique. It includes the interfacial mechanical and chemical properties and in particular the coalescence phenomena and the evolution of a water soluble surfactant. The effect of the boundary conditions on the drainage of a unique droplet is studied. The role of drop-drop coalescence on this drainage is also described for a model with two droplets. Some simulations are finally proposed with more complex dispersed systems.

The present-day challenge of oil industry is gradual decrease of conventional light crude reserves and increased consumption of hard-to-recover heavy crude. The goal of thesis is to establish change regularities of structural-mechanical properties and thermody-namic activation parameters for viscous flow in oil dispersed systems (ODS) of various composition (paraffin and naph-thene and aromatic bases) from Timan-Pechora petroleum region (Russia) in a broad range of temperatures and shear rates and under the exposure of external fields, and also to experimentally determine phase diagrams of binary hydrocarbon systems (nonadecane – decaline and nonadecane – naphthalene) modeling ODS mixture of completely opposite nature. Study results can be used for predicting and preventing structure formation during production, transport and storage of ODS's with various content of solid paraffins, resins and asphaltenes.:INTRODUCTION CHAPTER 1. ANALYSIS OF THE MODERN CONDITION AND METHODS OF RESEARCH OF HEAVY OILS 1.1 The current state of hydrocarbon reserves 1.2 Oil classification 1.3 Oil chemical composition 1.4 Influence of components of oil dispersed systems on their low-temperature properties 1.5 Structuring in oil dispersed systems 1.6 Rheological models of oil dispersed systems 1.7 Evaluation of the thermodynamic characteristics of the activation of the viscous flow of oil dispersed systems 1.8 Chemical composition and structural-mechanical properties of the oils from Timan-Pechora province 1.9 Modern methods of influencing the structure and properties of oil dispersed systems CONCLUSIONS TO CHAPTER 1 CHAPTER 2. OBJECTS AND METHODS OF RESEARCH 2.1 Objects of research 2.1.1 Physical and chemical properties of oils from Timan-Pechora province 2.1.2 Physical and chemical properties of high-boiling fractions from Timan-Pechora province 2.1.3 Physical and chemical properties of light distillate from heavy oil and individual hydrocarbons (nonadecane, decaline and naphthalene) 2.2 Research methods 2.2.1 Methods of conducting research on the physicochemical properties of oils 2.2.2 Methods of determining the group hydrocarbon composition of oil dispersed systems 2.2.3 Method for determination of low-temperature properties of binary systems 2.2.4 Methods for determining the structural and mechanical properties of oil dispersed systems from Timan-Pechora province 2.2.5 Characteristics of sources of external impact on oil 2.2.6. Methods of processing samples by external influence CONCLUSIONS TO CHAPTER 2 CHAPTER 3. INVESTIGATION OF LOW-TEMPERATURE PROPERTIES OF BINARY AND OIL DISPERSED SYSTEMS 3.1 Justification of the computational models used to describe the phase diagrams of binary systems 3.2 Investigation of low-temperature properties on model binary systems of nonadecane-decaline and nonadecane-naphthalene 3.3 Investigation of the low-temperature properties of a light distillate mixture (NK-330 °C) of heavy naphthenic-aromatic Yarega oil and light paraffin haryaga oil CONCLUSIONS TO CHAPTER 3 CHAPTER 4. INVESTIGATION OF CHANGES IN STRUCTURAL AND MECHANICAL PROPERTIES OF OILS AND THEIR HIGH-BOILING FRACTIONS UNDER EXTERNAL EXPOSURE 4.1 Determination of the type of liquid in oil dispersed systems at different temperatures 4.2 Determination of the dependence of the ultimate shear stress of oil dispersed systems on temperature 4.3 Investigation of the thixotropic properties of the oils from Timan-Pechora province 4.4 Impact of external fields on the rheological properties of heavy oil 4.5 Effects of external fields and diluents on the rheological properties of heavy oil CONCLUSIONS TO CHAPTER 4 CHAPTER 5. RESEARCH OF THERMODYNAMIC CHARACTERISTICS OF THE ACTIVATION OF A VISCOUS FLOW OF OILS AND HIGH-BOILING FRACTIONS UNDER DIFFERENT CONDITIONS (TEMPERATURES AND SHEAR RATE) 5.1 Liquidus temperature and activation energy of viscous flow of oil dispersed systems 5.2 Thermodynamic characteristics of the activation of a viscous flow of oil dispersed systems 5.3 Investigations of the strength of intermolecular interaction in oil dispersed systems as a function of the frequency of molecule jumps 5.4 Change in the activation energy of viscous flow of oil dispersed systems with increasing shear rate 5.5 Changes in thermodynamic characteristics of the activation of a viscous flow of oil dispersed systems with increasing shear rate 5.6 Changes in the strength of intermolecular interaction in oil dispersed systems with increasing shear rate CONCLUSIONS TO CHAPTER 5 CONCLUSION LIST OF ACCEPTED REDUCTIONS BIBLIOGRAPHY ANNEX 1. Act of introduction of development in LLC LUKOIL-Ukhtaneftepererabotka APPENDIX 2. Patent of the Russian Federation 'Method of preparation of heavy oil for refining

Depuis plusieurs décennies, une importante activité scientifique se concentre sur la description numérique, théorique ou expérimentale de l'hydrodynamique des écoulements multiphasiques. Ces écoulements sont caractérisés par l'existence d'interfaces, et d'une force à l'interface, la tension superficielle, séparant généralement deux fluides non miscibles. Un cas d'étude dans ce contexte est le problème du drainage d'une unique goutte dans une phase continue, l'ensemble étant soumis à la gravité. Ce système fait apparaître des écoulements récemment décrits pour une goutte d'eau dans l'huile de paraffine. Ce système constitue également un modèle simple pour l'étude des propriétés aux interfaces, Mais d'un point de vue numérique, se pose alors le problème de la stabilité des algorithmes pouvant être utilisés. Les effets aux interfaces impliquent en effet des domaines spatiaux très limités dans lesquels les grandeurs physiques entre les deux fluides sont discontinues. D'importants artéfacts numériques peuvent alors être générés dans les simulations et faire perdre la richesse de la physico-chimie du système considéré. Le problème de la simulation d'écoulements multiphasiques intéresse aussi bien le monde académique que le monde industriel. L'objectif de ce travail de thèse est donc d'implémenter les techniques numériques les plus récentes et de développer un code pour permettre la simulation de l'hydrodynamique de systèmes dispersés. Pour parvenir à ce but, il reste encore des problèmes algorithmiques importants à résoudre comme la prise en compte des effets thermocapillaires et thermosolutaux. Ces deux derniers points sont l'objet de cette thèse. / For several decades, an important scientific activity has focused on the numerical, theoretical and experimental hydrodynamics of drops. This work presents numerical results of a single droplet in the gravity field and in non-isothermal conditions. The simulation such a multiphase system is important in both academic and industrial world. This is particularly the case in the field of emulsions, wetting problems and evaporation. To achieve this goal, there are still important algorithmic problems due to the free moving interfaces and the description of capillary effects. Here, a Volume of Fluid technique has been implemented with high order temporal and spatial schemes to preserve the sharpness of the drop interface. The system under consideration is a simplified model consisting in a single water droplet in a continuous paraffin oil phase. These liquids are immiscible and non-compressible and the overall evolution is unsteady. Capillary contributions such as temperature and surfactant dependent surface tension are fully accounted for. This presentation is aimed to show the capabilities of VOF techniques for the simulations of unsteady multiphase systems in non-isothermal configurations. The role of the droplet initial position and temperature field is described with good numerical stability. There are still important problems remaining in the simulation of free interface systems with such a technique. Spurious currents induced by the description of capillarity can in particular come into play. But these latter can be controlled once the droplet average velocity due to drainage becomes large enough.