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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Processing, Pre-Aging, and Aging of NiTi-Hf (15-20 at.%) High Temperature Shape Memory Alloy from Laboratory to Industrial Scale

Gantz, Faith 12 1900 (has links)
The overarching goal of this research was to generate a menu of shape memory alloys (SMAs) actuator materials capable of meeting the demands of aerospace applications. Material requirements were recognized to meet the demand for high temperature SMAs with actuating temperatures above 85 °C and provide material options capable of performing over 100K actuation cycles. The first study is a preliminary characterization for the down selection of Ni-rich NiTiHf15 compositions chosen for a more in-depth examination of the nano-precipitation and evolution of the H-phase. To make this selection, the effect of Ni content in Ni-rich NiTiHf high temperature shape memory alloys (HTSMAs) on processability, microstructure, and hardness was analyzed for three compositions (Ni50.1TiHf15, Ni50.3TiHf15, Ni50.5TiHf15). Each composition was characterized under three conditions: homogenized, 25%, and 50% thickness reduction through hot-rolling. The second study emphasized the processing and aging response of an industrially produced, hot-extruded Ni50.3Ti29.7Hf20 (at%) HTSMA. The samples were sectioned into two halves with half remaining as-extruded and the other half hot-rolled to a 25% reduction in thickness. A portion of both conditions underwent conventional aging for 3 hours at various temperatures ranging from 450-750 °C, and the other portion was pre-aged for 12 hours at 300 °C followed by conventional aging treatments. After processing, the samples were characterized by differential scanning calorimetry (DSC), Vickers hardness (HV) testing, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and synchrotron radiation X-ray diffraction (SR-XRD). The relationship between the introduction of texturing, pre-aging, and aging on Ni-rich and high Hf-content compositions was investigated.
2

Dynamic Modelling and Control of MEA

Nittaya, Thanita January 2014 (has links)
Greenhouse gas (GHG) emission control has been extensively studied over the past decade. One GHG mitigation alternative is post-combustion carbon dioxide (CO2) capture using chemical absorption, which is a promising alternative due to its proven technology and the relative ease to install on existing coal-fired power plants. Nevertheless, the implementation of commercial-scale CO2 capture plants faces several challenges, such as high energy consumption, commercial availability, and geological CO2 storage. Therefore, there is a great incentive to develop studies that provide insights needed to design and dynamically operate industrial-scale CO2 capture plants for coal-fired power plants. This work presents a mechanistic dynamic model of a pilot plant of a post-combustion CO2 capture plant using the monoethanolamine (MEA) absorption processes. This model was implemented in gPROMS. The process insights gained from the sensitivity analysis, on six manipulated variables and six potential controlled variables, was used to determine promising control schemes for this pilot plant. This study then proposed three decentralized control structures. The first control scheme was designed based on the traditional-RGA (Relative Gain Array) analysis, whereas the other two control schemes were designed using heuristics. The performance evaluation of those control structures were conducted under eight scenarios, e.g. changes in flue gas composition, set point tracking, valve stiction, reboiler heat duty constraint, and flue gas flow rate. Under the condition where the reboiler temperature is to be controlled, a control scheme obtained from the heuristic showed faster response to achieve the process control objectives (90% CO2 capture rate and 95 mol% CO2 purity in the CO2 product stream) than the RGA-based control scheme. Furthermore, this study describes a step-by-step method to scale-up an MEA absorption plant for CO2 capture from a 750 MW supercritical coal-fired power plants. This industrial-scale CO2 capture plant consists of three absorbers (11.8 m diameter, 34 m bed height) and two strippers (10.4 m diameter, 16 m bed height) to achieve 87% CO2 captured rate and 95% CO2 purity in the CO2 product stream. It was calculated that the reboiler heat duty of 4.1GJ is required to remove 1 tonne of CO2 at the base case condition (20 kmol/s of flue gas flow rate with 16.3 mol% of CO2). The mechanistic model of an industrial-scale CO2 capture plant including a proposed control structure was evaluated using different scenarios. The performance evaluation result revealed that this plant can accommodate a maximum flue gas flow rate of +22% from the nominal condition due to absorbers??? flooding constraints. Moreover, it is able to handle different disturbances and offers prompt responses (After a plant is disturbed by an external perturbation, control variables in that plant are able to return to their set points in timely fashion using the adjustment of manipulated variables.) without significant oscillating signal or offset. In addition, this study highlights that the poor wetting in the strippers can be avoided by the implementation of a process scheduling, which has not been presented in any publications. Based on the above, the mechanistic models of CO2 absorption plants and proposed control structures provide insights regarding dynamic behaviour and controllability of these plants. In addition, the industrial-scale CO2 capture plant model can be used for future studies, i.e. integration of power plant and CO2 capture plant, feasibility of plant operation, and controllability improvement.
3

Assessment of mixing quality in full-scale, biogas-mixed anaerobic digestion using CFD

Dapelo, Davide, Bridgeman, John 15 June 2018 (has links)
Yes / An Euler-Lagrange CFD model is applied to a full-scale, biogas-mixed anaerobic digester to improve mixing efficiency and improve overall performance. Two quantitative mixing criteria previously adopted in anaerobic digestion (viz., uniformity index and dead volume) are critically assessed for the first time. A novel qualitative method is introduced to clarify the output of the quantitative methods. The first-ever quantitative assessment of mixing quality in full-scale, biogas-mixed anaerobic digestion is then proposed, and a strategy to improve mixing, involving the combined use of concentric nozzle manifolds at the base of the digester, is evaluated. / University of Birmingham (UK) Postgraduate Teaching Assistantship award; University of Bradford (UK) Postdoctoral research assistant contract, who provided financial support
4

Panneaux composites bio-sourcés destinés à l'isolation des bâtiments : caractérisation des ressources et procédé de production / Bio-based composite panels for building insulation : Characterization of resources and production process

Colson, Valentin 02 May 2019 (has links)
L'objectif de cette thèse est de développer de nouveaux composites isolants biosourcés à partir de coproduits de l'agriculture exploitables dans le secteur du bâtiment. Les travaux s'organisent en trois principales étapes : La première, au travers d'un travail de formulation et de caractérisation, vise à évaluer les propriétés mécaniques, thermiques et hygriques de composites biosourcés obtenus par agglomération de granulats végétaux avec différents types de liants biosourcés et minéraux. Plusieurs agro-ressources sont envisagées (paille de blé, colza, anas, chènevotte et rafles de maïs). Une solution associant des granulats de chènevotte avec un liant biosourcé thermodurcissable est sélectionnée. La suite des travaux se focalise sur la recherche d'un procédé de mise en forme adapté à la fabrication de panneaux rigides isolants réalisés à partir de la formulation du composite de chènevotte. La fabrication de panneaux composites est testée sur différents outillages disponibles en laboratoire ainsi que sur des outils industriels permettant de tester les différentes technologies existantes. La possibilité de fabriquer le panneau rigide isolant de chènevotte sur une ligne de production industrielle entièrement automatisée est démontrée. Enfin, de nouvelles solutions permettant d'améliorer la réaction au feu des panneaux composites sont testées ce qui permet d'identifier des solutions adaptées au composite étudié. / The objective of this thesis is to develop new insulation composites from agricultural by-products for building applications. The research work is divided in three main steps : The first one focuses on the formulation of bio-based composites obtained by agglomeration of vegetal aggregates with different types of binders (bio-based or mineral binders), and on the characterization of their mechanical, thermal and hygric properties. Several bio-aggregates are envisaged (wheat straw, rape straw, flax shiv, hemp shiv and corn cob). A solution combining hemp shiv aggregates bonded with a bio-based thermosetting adhesive is selected. The next step aims to identify a suitable manufacturing process to produce rigid insulation panels using the previously determined composite formulation. Several manufacturing trials are conducted on different laboratory and industrial tools which allow to experiment existing manufacturing technologies. The possibility to produce the rigid insulation panel from hemp shiv at the industrial scale on a fully automatized production line is demonstrated. Finally, new solutions to improve the fire reaction of the insulation panels are tested which allows to identify suitable solutions for the developed composites.
5

BSF-colony management efficiency at a large scale fly larvae composting company in Kenya – A field study / Utvärdering av flugkolonieffektiviteten på ett storskaligt fluglarvskomposteringsföretag i Kenya – En fältstudie

Anderberg, Hilda January 2023 (has links)
The majority of organic waste globally is either dumped or placed on landfills, which can result in spreading of disease and pests, methane gas emissions, the deterioration of landscapes and odour pollution. One of the solutions to poor organic waste management is to create value from waste. A way to do this is with black soldier fly (Hermetia illucens) larvae (BSFL) composting. The interest for BSFL composting has increased the past 10 years mainly because it is a technology with relatively low investment costs. The part of the process where the seed larvae that are used in the treatment are produced is called BSF-colony. Producing seed larvae in an efficient way is an important part of the technology’s feasibility. However, there is limited research published on BSF-colony management, especially on a larger scale. The aim of the study was to investigate the factors that impact the efficiency of the BSF-colony on a large scale BSFL composting company in Kenya in a semi-open setting. The efficiency of the BSF-colony management was assessed in terms of emergence rate (percentage of pupa that emerge as flies), hatching rate (percentage of eggs that hatch and survive to 5 day old larva) and number of eggs laid per female BSF. The result of the study suggests that parasitic wasps (Dirhinus giffardii) can reduce the emergence rate significantly, and high temperatures and water shortage for the adult BSF can reduce the egg production. Observations made during the study indicate that personnel routines and how the BSF-colony is arranged also could affect the egg production significantly. The overall variation in the results suggests that other factors, beyond the ones investigated in the study, impact the efficiency of the BSF-colony, and further research regarding BSF-colony management is recommended / Merparten av det organiska avfallet i världen dumpas eller läggs på deponier, vilket kan leda till spridning av sjukdomar och skadedjur, utsläpp av metangas, förstörelse av landskap och luktföroreningar. En av lösningarna på bristfällig hantering av organiskt avfall är att skapa värde av avfallet. Ett sätt att göra det är med hjälp av fluglarvskompostering med amerikansk soldatfluga (Hermetia illucens). Intresset för fluglarvskompostering har ökat under de senaste tio åren, främst på grund av att det är en teknik som inte behöver innebära höga investeringskostnader. Flugkolonin är den del av processen där sättlarverna som användes i komposteringen produceras. Att sättlarver produceras på ett effektivt sätt är en viktig del av teknikens genomförbarhet. Det finns dock begränsad forskning publicerad om effektivisering av flugkolonier, speciellt sådan som berör storskaliga kolonier. Syftet med studien var att undersöka vilka faktorer som påverkar flugkolonins effektivitet på ett storskaligt fluglarvskomposteringsföretag i Kenya i en halvöppen miljö. Flugkolonins effektivitet bedömdes i termer av metamorfosfrekvens (den andel av pupporna som blir flugor), antalet lagda ägg per fluga och kläckningsfrekvens (den andel ägg som kläcks och överlever till 5-7 dagar gamla larver). Resultatet av studien tyder på att parasitsteklar kan minska metamorfosfrekvensen avsevärt, och att höga temperaturer samt vattenbrist kan minska äggproduktionen. De observationer som gjordes under studien tyder på att personalens rutiner och hur flugkolonin är anordnad också kan påverka äggproduktionen avsevärt. Den relativt stora variationen i alla resultat tyder på att andra faktorer än de som undersökts i studien påverkar flugkolonins effektivitet, fortsatta studier inom effektivisering av flugkolonier rekommenderas
6

Vinification continue avec levures immobilisées : analyse du système et conception du réacteur industriel / Continuous wine-making with immobilized yeast cells : system analysis and industrial reactor design

Kassim Houssenaly, Caroline 27 February 2012 (has links)
Un nouveau procédé intensifié de vinification continue avec un mélange de levures S.cerevisiae et Sch.pombe immobilisées dans des billes d’alginate est proposé. A l’échelle laboratoire, l’étude de la teneur en billes et de la configuration du réacteur conduit à l’obtention d’un réacteur de type lit fixe permettant une production de vin en 35 heures. Des validations du procédé aux échelles pilote (170 L) puis industrielle (120 hL) montrent que, en cave, du vin de qualité semblable au témoin est produit en 2 à 3 jours. Une analyse du comportement du réacteur a identifié des raisons de pertes de performances liées à l’hydrodynamique lors du changement d’échelle ainsi que des axes améliorations possibles. Ce procédé permet d’obtenir un vin de qualité maitrisée et un gain de temps de plusieurs semaines / From a batch to another, produced wines are usually different because of the different alcoholic and malolactic fermentation courses. To blend wines quality and continue wine production industrialization, a new continuous process, using Ca-alginate immobilized yeast cells, was developed for red wine-making. Working with a blending of S.cerevisiae and Sch.pombe allowed the regrouping of the alcoholic and malolactic fermentations in a unique step. After testing different reactor set-ups at lab scale, the selected process, a vertical bed reactor, was used in real wine-making conditions, firstly in a pilot reactor (170 L) and then in an industrial one (120 hL). The results showed that continuous wine-making was possible in 2 to 3 days. The wine presented nearly the same sensory profile compared to a classical one. Thanks to the analysis of the reactor behaviour, we were able to explain the efficiency losses linked to the hydrodynamic, observed during the scale-up. This new intensified process enables to obtain a wine with a controlled quality and to save several weeks of production time
7

Rhéologie d’un nouveau matériau granulaire carboné / Rheology of a new carbon-based granular material

Figura, Florent 27 January 2017 (has links)
Carbone Savoie est une société française spécialisée dans les solutions cathodiques en carbone et graphite pour l’électrolyse de l’aluminium primaire. La fabrication de ces produits requiert un savoir-faire important en raison de la complexité de procédé. Le malaxage, première étape du procédé, permet le mélange intime des particules carbonées et d’un liant. Les grains carbonés de tailles variées comme le coke calciné, anthracite calciné, et le graphite constituent un empilement multimodal d’une dizaine de microns à quelques centimètres. Le liant actuel est liquide à haute température, se caractérise par un haut rendement en carbone, est cokéfiable mais toxique. La législation européenne sur les produits chimiques (REACH) l’a identifié comme « substance extrêmement préoccupante », le risque associé étant une interdiction de son utilisation. Dans ce contexte, Carbone Savoie a lancé un projet de recherche visant à substituer cette matière première dangereuse. Le premier objectif a été de déterminer des compositions possibles pour ce nouveau liant ainsi que leur comportement rhéologique. Une première composition a montré un comportement newtonien à pH basique. Un additif à point de gélification, dont le comportement a fait l’objet d’une étude, a été utilisé pour une deuxième composition. La meilleure méthode de mélange fut ensuite sélectionnée puis son efficacité avec le nouveau liant validée. Une troisième composition, qui est une suspension, a montré un comportement rhéofluidifiant. Cette dernière s’est avérée être la meilleure candidate pour substituer le brai. Le deuxième objectif du travail a été la détermination des conditions de malaxage avec le nouveau liant. L’étude du mélange granulaire carboné est basée sur une méthode de suivi d’intensité de malaxage. Grâce à la courbe d’intensité enregistrée en fonction du ratio massique liquide/solide, les différents états de l’eau dans le mélange en fonction de la saturation en liant du système ont été définis : régime pendulaire, funiculaire, capillaire et goutte. Le régime capillaire est particulièrement intéressant car il s’agit du régime d’extrusion des cathodes. L’influence sur le procédé (cinétique de mouillage, étendue du régime capillaire) de la viscosité du liant a été étudiée : une viscosité élevée permet une plus grande tolérance du procédé vis-à-vis des variations de l’empilement granulaire des matières sèches d’une formulation à l’autre ou encore la difficulté de produire des poudres de granulométrie fixe. Enfin, une corrélation entre les résultats obtenus et l’échelle industrielle a été trouvée. Les propriétés finales d’une cathode peuvent être reliées à la qualité de la pâte en sortie de malaxeur grâce à la détermination de la cohésion via une cellule de cisaillement annulaire. / Carbone Savoie is a French company specialized in the production of carbon and graphite cathodic solutions for the primary aluminum industry. The production of cathodes requires an important know-how because of its complex manufacturing process. The first step of the process consists in mixing the carbonaceous raw materials with a binder. The raw materials (calcined coke and anthracite or graphite) have different size and represent a multimodal carbon aggregate (from tens of microns to a few centimeters). The current binder is liquid at high temperature, has a high carbon yield and is coking but poisonous. The European regulations on chemical products (REACH) identified the pitch binder as “substance of very high concern”. Therefore, that product could become prohibited. Within this context, Carbone Savoie initiated a research project in order to substitute that hazardous material. First of all, the project aims at determining possible compositions for the new binder and to describe their rheological behavior. A first formulation had a Newtonian behavior for high pH values. An additive with a gel point which behavior has been studied was used for a second formulation. The best mixing process was then chosen and its efficiency was tested with this new binder. A third formulation which was a suspension showed a shear-thinning behavior. It appeared to be the best candidate to substitute pitch as a binder for the production of cathode blocks. The second goal of the project was the determination of the mixing conditions with this new binder. The study of the mixing of the carbon aggregate with the binder is based on a tracking of the mixing intensity. Thanks to the plot of the intensity-liquid/solid ratio curve, different states were defined for the system according to the binder content (pendular state, funicular state, capillary state and solid/liquid dispersion state). The capillary state is of a major concern because the paste is extruded in that state. The impact on the process (wetting kinetics, width of the capillary state) of the rheological behavior of the binder has been studied: a high viscosity allows a better tolerance to the variability in the size of the carbon aggregate from a formulation to another and also to the trouble of producing powders with very small particles sizes. Finally, a correlation between these results and the industrial scale has been found. Final properties of cathodes blocks can be linked with the paste quality just after the mixing step thanks to the determination of the paste cohesion with a ring shear tester.
8

Uklanjanje visokog sadržaja organskih i neorganskih polutanata iz podzemnih voda Vojvodine primenom nanofiltracije / Organic and inorganic polutants high content removal from Vojvodina groundwater by application of nanofiltration

Kukučka Miroslav 23 September 2016 (has links)
<p>Cilj ovog rada je ispitivanje mogućnosti uklanjanja visokih koncentracija organskih i neorganskih materija iz vodenih rastvora &bdquo;Cross-Flow&ldquo; nanofiltracijom primenom spiralno uvijenih membrana. Mogućnosti separacije NOM-a, amonijum-jona i ukupnog arsena su ispitivane na koncentratima-otpadnim vodama dobijenim iz industrijskih nanofiltracionih uređaja i obuhvaćeni su eksperimentima serije NFCP. Izdvajanje visokih koncentracija jona kalcijuma, magnezijuma, gvožđa i mangana je ispitivano iz prirodnih podzemnih voda i izvedeno je u eksperimentima serije NFWP. Određeni su optimalni fluksevi i transmembranski pritisci, kao i koncentracije doziranja kompleksirajućih supstanci. Dobijeni poluindustrijski rezultati su praktično primenjivi u velikoj skali za pripremu pijaće vode kako iz dubokih, tako i iz plitkih akvifera. Primena prikazanih rezultata u pripremi vode za piće od vode dubokih izdani uz značajne u&scaron;tede resursa je namenjena prvenstveno lokacijama u Panonskom basenu. Tretman bunarske vode plitkih izdani je pogodan posebno zbog dodatka organskih kompleksirajućih agenasa koji supstitui&scaron;u uobičajene postupke deferizacije i demanganizacije i na taj način znatno smanjuju kako investicione, tako i eksploatacione tro&scaron;kove postrojenja. Dobijeni rezultati su poslužili kao osnova za izradu idejnog re&scaron;enja industrijskog postrojenja za kondicioniranje pijaće vode od bunarske vode duboke izdani iz regiona grada Zrenjanina, kao i izradu idejnog re&scaron;enja industrijskog postrojenja za kondicioniranje pijaće vode od bunarske vode plitke izdani regiona grada Bačke Palanke za naseljeno mesto Despotovo.</p> / <p>The goal of this thesis was to examine removal possibility of high concentrations of organic and inorganic matter from aquatic solution using &ldquo;Cross-flow&rdquo; spiral wound nanofiltration membranes. Natural organic matter, ammonia ions and total arsenic removal was examined using concentrates &ndash; waste water obtained from industrial nanofiltration plant and they present NFCP experiment series. Removal of high concentrations of calcium, magnesium, iron and manganese ions was a part of NFWP experiments and was conducted using natural groundwater. Optimal fluxes and transmembrane pressures, as well as complexing substances dosage concentrations were determined. Obtained results in semi industrial scale are practically applicable on the large scale plants for drinking water preparation from deep wells, as well as from shallow aquifers. Application of presented results, concerning drinking water preparation from deep wells with significant savings of water resources, is designed especially for locations in Pannonia basin. Shallow aquifer well water treatment is applicable in practice especially because of addition of organic complexation agents that substitutes conventional deferization and manganese removal methods ultimately reducing investment and exploitation costs. On the basis of obtained results, industrial plant that produces drinking water from Zrenjanin aquifer deep well was designed. Furthermore, potable water industrial plant was designed that used shallow aquifer well water located in Bačka Palanka region, settlement Despotovo.</p>
9

Desenvolvimento, síntese e caracterização de nanopartículas magnéticas hidrofílicas e lipofílicas para aplicação em nanotecnologia do petróleo / Development, synthesis and characterization of hydrophilic and lipophilic magnetic nanoparticles applied to oil nanotechnology

Silva, Delmarcio Gomes da 22 April 2014 (has links)
A tese de doutorado tem como foco o desenvolvimento de nanopartículas superparamagnéticas (Fe3O4 - magnetita) hidrofílicas e lipofílicas aplicadas à nanotecnologia do petróleo. Inicialmente, os objetivos foram voltados para a elaboração e transferência de tecnologia envolvendo uma rota de síntese de nanopartículas lipofílicas, em escala semi-industrial. Para isso, foram realizados ensaios piloto num reator com capacidade de uma tonelada, visando a produção de nanopartículas magnéticas recobertas com ácido esteárico. Mais tarde, esse trabalho foi otimizado, permitindo sua execução em laboratório, prosseguindo depois, com um escopo mais amplo, incluindo a síntese de nanopartículas recobertas com polímero hidrofílico. Nesse sentido, foram desenvolvidas duas rotas inéditas para produção desses nanomateriais. Em um segundo estágio, as investigações foram voltadas para a utilização das nanopartículas sintetizadas, em estudos de avaliação das condições dos reservatórios de petróleo. Para isso, a técnica de ressonância magnética nuclear (RMN) foi explorada, monitorando o efeito da concentração dessas nanopartículas superparamagnéticas sobre o tempo de relaxação dos prótons, e o consequente efeito de contraste nas imagens em função da magnetização. A aplicação desse tipo de ferramenta (RMN) já vem sendo feita (sem nanopartículas magnéticas) pelas empresas prestadoras de serviço ao setor de petróleo e gás, na avaliação e perfilagem de reservatórios. Isso motivou o estudo dos nanomateriais magnéticos como sondas para melhorar o mapeamento de fluidos em meio poroso. Eles seriam aplicados como aditivos em fluidos de injeção em reservatórios, tanto para imageamento, como para a obtenção de parâmetros petrofísicos. Por fim, devido à presença de grupos carboxílicos na superfície das nanopartículas hidrofílicas, foram investigadas suas interações com microcristais de carbonato de cálcio, pensando no modelo de reservatório petrolífero do tipo carbonáceo. Explorando técnicas de microscopia eletrônica de varredura (MEV) e de microscopia Raman confocal, a presença das nanopartículas magnéticas sobre a superfície da matriz mineral foi constatada, confirmando sua interação efetiva com o CaCO3. Abordando a síntese, caracterização e aplicações das nanopartículas superparamagnéticas, esta tese proporciona uma base para estudos de aplicação de nanomateriais, assunto cada vez mais relevante, diante dos inúmeros problemas e desafios enfrentados pelo setor de petróleo e gás. / The Ph.D thesis is focused on the preparation of hydrophilic and lipophilic superparamagnetic nanoparticles (Fe3O4 - magnetite) for application in oil nanotechnology. The initial efforts have been directed to the upscaling of a laboratory route of synthesis of lipophilic nanoparticles, aiming technology transfer to the industry. Accordingly, a pilot process, involving a one ton reactor, has been tested for the production of magnetic nanoparticles coated with stearic acid. After this, the research has evolved, allowing the production in the laboratory scale, and continued, pursuing the development of nanoparticles coated with a hydrophilic polymer. Two new routes for the production of these nanomaterials have been developed. In a second step, the investigations were directed to the application of these nanoparticles to the evaluation of oil reservoirs, by monitoring the proton relaxation times, using nuclear magnetic resonance (NMR), and the consequent contrasting effects observed on the images, as a function of the magnetization and the concentration of these particles. Currently, NMR tools are being employed in the oil and gas sector for the evaluation and profiling of reservoirs. This fact has stimulated the use of such nanomaterials for improving the mapping of the fluids in porous media. Introduced as additives for fluid injection into reservoirs, they can enhance the imaging and also perform the rating of petrophysical parameters. Finally, the presence of carboxylic groups on the surface of the hydrophilic nanoparticles has been explored in studies of interaction with calcium carbonate, simulating a carbonaceous type reservoir. Based on electron microscopy (SEM) and confocal Raman microscopy, the presence of magnetic nanoparticles on the surface of the mineral matrix has confirmed the interaction of these particles with the CaCO3 surface. By developing the synthesis, characterization and application of superparamagnetic nanoparticles, this work provides a useful starting point for further research on the use nanoparticles, for solving problems and challenges in the oil and gas sector.
10

Desenvolvimento, síntese e caracterização de nanopartículas magnéticas hidrofílicas e lipofílicas para aplicação em nanotecnologia do petróleo / Development, synthesis and characterization of hydrophilic and lipophilic magnetic nanoparticles applied to oil nanotechnology

Delmarcio Gomes da Silva 22 April 2014 (has links)
A tese de doutorado tem como foco o desenvolvimento de nanopartículas superparamagnéticas (Fe3O4 - magnetita) hidrofílicas e lipofílicas aplicadas à nanotecnologia do petróleo. Inicialmente, os objetivos foram voltados para a elaboração e transferência de tecnologia envolvendo uma rota de síntese de nanopartículas lipofílicas, em escala semi-industrial. Para isso, foram realizados ensaios piloto num reator com capacidade de uma tonelada, visando a produção de nanopartículas magnéticas recobertas com ácido esteárico. Mais tarde, esse trabalho foi otimizado, permitindo sua execução em laboratório, prosseguindo depois, com um escopo mais amplo, incluindo a síntese de nanopartículas recobertas com polímero hidrofílico. Nesse sentido, foram desenvolvidas duas rotas inéditas para produção desses nanomateriais. Em um segundo estágio, as investigações foram voltadas para a utilização das nanopartículas sintetizadas, em estudos de avaliação das condições dos reservatórios de petróleo. Para isso, a técnica de ressonância magnética nuclear (RMN) foi explorada, monitorando o efeito da concentração dessas nanopartículas superparamagnéticas sobre o tempo de relaxação dos prótons, e o consequente efeito de contraste nas imagens em função da magnetização. A aplicação desse tipo de ferramenta (RMN) já vem sendo feita (sem nanopartículas magnéticas) pelas empresas prestadoras de serviço ao setor de petróleo e gás, na avaliação e perfilagem de reservatórios. Isso motivou o estudo dos nanomateriais magnéticos como sondas para melhorar o mapeamento de fluidos em meio poroso. Eles seriam aplicados como aditivos em fluidos de injeção em reservatórios, tanto para imageamento, como para a obtenção de parâmetros petrofísicos. Por fim, devido à presença de grupos carboxílicos na superfície das nanopartículas hidrofílicas, foram investigadas suas interações com microcristais de carbonato de cálcio, pensando no modelo de reservatório petrolífero do tipo carbonáceo. Explorando técnicas de microscopia eletrônica de varredura (MEV) e de microscopia Raman confocal, a presença das nanopartículas magnéticas sobre a superfície da matriz mineral foi constatada, confirmando sua interação efetiva com o CaCO3. Abordando a síntese, caracterização e aplicações das nanopartículas superparamagnéticas, esta tese proporciona uma base para estudos de aplicação de nanomateriais, assunto cada vez mais relevante, diante dos inúmeros problemas e desafios enfrentados pelo setor de petróleo e gás. / The Ph.D thesis is focused on the preparation of hydrophilic and lipophilic superparamagnetic nanoparticles (Fe3O4 - magnetite) for application in oil nanotechnology. The initial efforts have been directed to the upscaling of a laboratory route of synthesis of lipophilic nanoparticles, aiming technology transfer to the industry. Accordingly, a pilot process, involving a one ton reactor, has been tested for the production of magnetic nanoparticles coated with stearic acid. After this, the research has evolved, allowing the production in the laboratory scale, and continued, pursuing the development of nanoparticles coated with a hydrophilic polymer. Two new routes for the production of these nanomaterials have been developed. In a second step, the investigations were directed to the application of these nanoparticles to the evaluation of oil reservoirs, by monitoring the proton relaxation times, using nuclear magnetic resonance (NMR), and the consequent contrasting effects observed on the images, as a function of the magnetization and the concentration of these particles. Currently, NMR tools are being employed in the oil and gas sector for the evaluation and profiling of reservoirs. This fact has stimulated the use of such nanomaterials for improving the mapping of the fluids in porous media. Introduced as additives for fluid injection into reservoirs, they can enhance the imaging and also perform the rating of petrophysical parameters. Finally, the presence of carboxylic groups on the surface of the hydrophilic nanoparticles has been explored in studies of interaction with calcium carbonate, simulating a carbonaceous type reservoir. Based on electron microscopy (SEM) and confocal Raman microscopy, the presence of magnetic nanoparticles on the surface of the mineral matrix has confirmed the interaction of these particles with the CaCO3 surface. By developing the synthesis, characterization and application of superparamagnetic nanoparticles, this work provides a useful starting point for further research on the use nanoparticles, for solving problems and challenges in the oil and gas sector.

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