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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.
141

Simulation study of surfactant transport mechanisms in naturally fractured reservoirs

Abbasi Asl, Yousef 03 January 2011 (has links)
Surfactants both change the wettability and lower the interfacial tension by various degrees depending on the type of surfactant and how it interacts with the specific oil. Ultra low IFT means almost zero capillary pressure, which in turn indicates little oil should be produced from capillary imbibition when the surfactant reduces the IFT in naturally fractured oil reservoirs that are mixed-wet or oil-wet. What is the transport mechanism for the surfactant to get far into the matrix and how does it scale? Molecular diffusion and capillary pressure are much too slow to explain the experimental data. Recent dynamic laboratory data suggest that the process is faster when a pressure gradient is applied compared to static tests. A mechanistic chemical compositional simulator was used to study the effect of pressure gradient on chemical oil recovery from naturally fractured oil reservoirs for several different chemical processes (polymer, surfactant, surfactant-polymer, alkali-surfactant-polymer flooding). The fractures were simulated explicitly by using small gridblocks with fracture properties. Both homogeneous and heterogeneous matrix blocks were simulated. Microemulsion phase behavior and related chemistry and physics were modeled in a manner similar to single porosity reservoirs. The simulations indicate that even very small pressure gradients (transverse to the flow in the fractures) are highly significant in terms of the chemical transport into the matrix and that increasing the injected fluid viscosity greatly improves the oil recovery. Field scale simulations show that the transverse pressure gradients promote transport of the surfactant into the matrix at a feasible rate even when there is a high contrast between the permeability of the fractures and the matrix. These simulations indicate that injecting a chemical solution that is viscous (because of polymer or foam or microemulsion) and lowers the IFT as well as alters the wettability from mixed-wet to water-wet, produces more oil and produces it faster than static chemical processes. These findings have significant implications for enhanced oil recovery from naturally fractured oil reservoirs and how these processes should be optimized and scaled up from the laboratory to the field. / text
142

Carbide and Carbide-Derived Carbon Materials with Hierarchical Pore Architecture

Borchardt, Lars 13 March 2013 (has links) (PDF)
This thesis addressed the development of new porous carbides and carbide-derived carbons; in particular materials based on silicon-, boron-, tungsten-, and titanium carbide. Therefore, different hard- and soft-templating approaches were applied and the materials were additionally functionalized with catalytic active components and shaped into nm- and mm-sized spherical particles.
143

Avalia??o de inibidores verdes microemulsionados na inibi??o ? corros?o do a?o carbono AISI 1020

Almeida, C?ssia Carvalho de 25 October 2012 (has links)
Made available in DSpace on 2014-12-17T14:07:04Z (GMT). No. of bitstreams: 1 CassiaCA_DISSERT.pdf: 2177170 bytes, checksum: cdd70e45de9bf16e746160bcfa2059cf (MD5) Previous issue date: 2012-10-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In general, among the corrosion inhibitors surfactants are the most commonly used compounds, because they are significantly effective by forming protective films on anodic and cathodic areas. In this study, microemulsions containing he biodegradable saponified coconut oil as surfactant (SME-OCS) was used as green corrosion inhibitors. With this purpose, methanolic extracts of Ixora coccinea Linn (IC) and a polar fraction rich in alkaloids (FA) obtained from Croton cajucara Benth solubilized in the SME-OCS system were examined in the presence of AISI 1020 carbon steel, in saline solution (NaCl 3,5 %). The efficiency of corrosion inhibition of IC and FA were evaluated in the following microemulsions: SME-OCS-IC and SME-OCS-FA. The microemulsion system SME-OCS in the presence and absence of IC and FA was assessed by measurements of weight loss and the electrochemical method of polarization resistance, with variation in the concentration of IC and FA (50 - 400 ppm), showing significant results of corrosion inhibition (83,6 % SME-OCS; 92,2 % SME-OCS-FA; and 95,3 % SME-OCS-IC) / Em linhas gerais, dentre os inibidores de corros?o mais utilizados se encontram os tensoativos, que s?o significantemente eficazes por formarem pel?culas protetoras sobre ?reas an?dicas e cat?dicas. No presente trabalho, utilizou-se o tensoativo biodegrad?vel ?leo de coco saponificado microemulsionado (SME-OCS) para aplicabilidade como inibidor verde de corros?o. Para tanto, o extrato metan?lico de Ixora coccinea Linn (IC) e uma fra??o polar rica em alcaloides (FA) obtida de Croton cajucara Benth, solubilizados no sistema SME-OCS, foram avaliados na presen?a do a?o carbono AISI 1020, em meio salino (NaCl 3,5 %). Desta forma, as efici?ncias de inibi??es ? corros?o de IC e FA foram avaliadas nas seguintes microemuls?es: SME-OCS-IC e SME-OCS-FA. O sistema microemulsionado SME-OCS na presen?a e na aus?ncia de IC e FA foi avaliado por medidas de perda de massa e pelo m?todo eletroqu?mico de resist?ncia ? polariza??o, com varia??o da concentra??o dos vegetais IC e FA (50 400 ppm), tendo sido obtidos resultados significativos de inibi??es ? corros?o (83,6 % SME-OCS, 92,2 % SME-OCS-FA e 95,3 % SME-OCS-IC)
144

Characterization of a metal-extracting water-poor microemulsion / Caractérisation d'une microémulsion pauvre en eau et adaptive à l'extraction de métaux

Lopian, Tobias 20 November 2017 (has links)
Le recyclage des terres rares à partir de déchets électroniques n'a toujours pas trouvé une réalisation industrielle significative. L'une des raisons est le manque de procédures de séparation optimisées en raison de connaissances fondamentales médiocres sur ces systèmes. En raison des similitudes chimiques et physiques de ces métaux, la conception d'une formulation efficace, adaptative et prédictive est toujours hors de portée des possibilités. L'interprétation supramoléculaire de la formation complexe dans la phase organique est de plus en plus importante au cours des dernières années. C'est l'approche la plus prometteuse permettant l'explication de divers phénomènes, tels que la formation de la troisième phase et les signaux forts dans de petites expériences de diffusion et de revenir à des méthodes bien connues de la science des tensioactifs. Notre contribution à une compréhension plus complète dans cette matière est l'analyse du comportement électrodynamique de ces phases et la corrélation de ces résultats avec les résultats des propriétés d'auto-assemblage et du transport de masse dans ces médias. Pour cette étude, nous avons spécifiquement conçu un modèle de référence, en passant un processus d'extraction à ses quatre composants fondamentaux: l'extracteur avant l'extraction (acide Di-(2-éthylhexyl) phosphorique, HDEHP), l'extrait après extraction (son sel de sodium, NaDEHP ), le toluène comme diluant apolaire et de l'eau. Un prisme de phase de Gibbs a été préparé (illustré sur la figure 1), où l'axe z donne le rapport de HDEHP à NaDEHP, ce qui représente le développement d'une extraction. Couvrant le domaine de basse fréquence, la spectroscopie d'impédance a été la méthode de choix afin de déterminer la conductivité dépendant de la fréquence. En utilisant la spectroscopie de relaxation diélectrique, nous révélons des processus dynamiques rapides à haute fréquence. Des mesures combinées SAXS et SANS ont été effectuées pour comparer les tendances électrodynamiques avec les propriétés d'agrégation et les interactions entre groupes. Deux phénomènes ont été identifiés comme responsables du profil de conductivité dans les systèmes micellaires inverse: la formation d'agrégats chargés par la dissimulation et la percolation. Tout au long du système de référence, ces deux processus ont été sondés en fonction de trois variables: la concentration totale d'agent d'extraction, le rapport eau-agent tensioactif et le rapport Na: H. En tant que résultat majeur, l'eau joue un rôle important dans les deux processus. En cas de percolation, les agrégats inverse ne peuvent pas fusionner en l'absence d'eau. Par conséquent, la conductivité électrique est interdite. Dans les systèmes dilués, l'eau facilite le processus de dismutation, entraînant une augmentation de la conductivité. / Recycling of rare earths from electronic waste has still not found a significant industrial realization. One reason is the lack of optimized separation procedures due to poor fundamental knowledge on these systems. Due to the chemical and physical similarities of these metals, designing an efficient, adaptive and predictive formulation is still out of scope of possibilities. The supramolecular interpretation of complex-formation in the organic phase has gained an increasing importance in the last years. It is the most promising approach allowing the explanation of diverse phenomena, such as third phase formation and strong signals in small scattering experiments and to revert to methods well known from surfactant science. Our contribution towards a more complete understanding in this matter is the analysis of the electrodynamic behaviour of such phases and the correlation of these findings with the results of self-assembly properties and mass transport in these media.For this study, we specifically designed a reference model, breaking an extraction process down to its four fundamental components: The extractant before extraction (Di-(2-ethylhexyl)phosphoric acid, HDEHP), the extractant after extraction (its sodium salt, NaDEHP), toluene as apolar diluent and water. A Gibbs phase prism has been prepared (illustrated in Figure 1), where the z-axis gives the ratio of HDEHP to NaDEHP, representing the development of an extraction. Covering the low frequency-domain, impedance spectroscopy has been the method of choice in order to determine the frequency-dependent conductivity. Using dielectric relaxation spectroscopy, we reveal fast dynamic processes at high frequencies. Combined SAXS and SANS measurements have been performed to compare the electrodynamic trends with aggregation properties and intercluster interactions.Two phenomena have been identified to be responsible for the conductivity profile in reverse micellar systems: the formation of charged aggregates through dismutation and percolation. Throughout the reference system, these two processes have been probed as function of three variables: total extractant concentration, the water-to-surfactant ratio and the Na:H-ratio. As a major result, water plays a significant role in both processes. In case of percolation, reverse aggregates are not able to merge in the absence of water. Therefore, electrical conductivity is prohibited. In dilute systems, water facilitates the dismutation–process leading to an increase in conductivity.
145

Aplica??o de sistemas microemulsionados ?cidos em acidifica??o de po?os

Aum, Pedro Tup? Pandava 04 July 2011 (has links)
Made available in DSpace on 2014-12-17T14:08:46Z (GMT). No. of bitstreams: 1 PedroTPA_DISSERT.pdf: 2026522 bytes, checksum: 77beea38c42704a86dbc6a2648061f42 (MD5) Previous issue date: 2011-07-04 / Stimulation operations have with main objective restore or improve the productivity or injectivity rate in wells. Acidizing is one of the most important operations of well stimulation, consist in inject acid solutions in the formation under fracture formation pressure. Acidizing have like main purpose remove near wellbore damage, caused by drilling or workover operations, can be use in sandstones and in carbonate formations. A critical step in acidizing operation is the control of acid-formation reaction. The high kinetic rate of this reaction, promotes the consumed of the acid in region near well, causing that the acid treatment not achive the desired distance. In this way, the damage zone can not be bypassed. The main objective of this work was obtain stable systems resistant to the different conditions found in field application, evaluate the kinetic of calcite dissolution in microemulsion systems and simulate the injection of this systems by performing experiments in plugs. The systems were obtained from two non ionic surfactants, Unitol L90 and Renex 110, with sec-butanol and n-butanol like cosurfactants. The oily component of the microemlsion was xilene and kerosene. The acqueous component was a solution of HCl 15-26,1%. The results shown that the microemulsion systems obtained were stable to temperature until 100?C, high calcium concentrations, salinity until 35000 ppm and HCl concentrations until 25%. The time for calcite dissolution in microemulsion media was 14 times slower than in aqueous HCl 15%. The simulation in plugs showed that microemulsion systems promote a distributed flux and promoted longer channels. The permeability enhancement was between 177 - 890%. The results showed that the microemulsion systems obtained have potential to be applied in matrix acidizing / As opera??es de estimula??o s?o opera??es realizadas com a finalidade de restaurar ou melhorar o ?ndice de produ??o ou inje??o dos po?os. Dentre as opera??es de estimula??o, destaca-se a opera??o de acidifica??o, que consiste na inje??o de solu??es ?cidas na forma??o, com press?o abaixo da press?o de fratura da forma??o. A acidifica??o tem como principal objetivo remover danos causados nas etapas de perfura??o e/ou workover, podendo ser realizada tanto em arenitos quanto em carbonatos. Um dos pontos mais cr?ticos da opera??o de acidifica??o ? o controle da rea??o ?cido-rocha, pois a elevada velocidade da rea??o faz com que o ?cido seja todo consumido na regi?o pr?xima ao po?o, fazendo com que o tratamento ?cido n?o atinja a dist?ncia desejada. Dessa maneira, as regi?es com dano podem n?o ser ultrapassadas. Este trabalho teve como objetivo obter sistemas microemulsionados est?veis ?s diferentes condi??es encontradas no campo de aplica??o, avaliar a cin?tica de dissolu??o da calcita nesses sistemas, bem como, simular a inje??o desses sistemas realizando ensaios em plugues. Utilizaram-se sistemas microemulsionados obtidos a partir dos tensoativos Renex 110, Unitol L90 e o OMS (?leo de mamona saponificado). Foram utilizandos o sec-butanol e o n-butanol como cotensoativos. Como componentes org?nicos foram utilizados o xileno e o querosene e como componente aquoso foram utilizadas solu??es de HCl variando-se a concentra??o de 15-26,1%. Os resultados mostraram que os sistemas microemulsionados foram est?veis ? temperaturas de at? 100?C, ? concentra??es elevadas de c?lcio, ? salinidade de at? 35000 ppm e a concentra??es de HCl de at? 25%. A cin?tica de dissolu??o da calcita, ao utilizar os sistemas microemulsionados ?cidos, foi at? 14 vezes mais lenta quando comparada com a solu??o de HCl 15%. Os resultados da inje??o dos sistemas ?cidos mostraram que as microemuls?es favorecem um fluxo mais distribu?do com rela??o ao HCl 15%, bem como, formam canais mais longos, promovendo incrementos na permeabilidade dos plugues de 177 - 890%. Os resultados mostraram que os sistemas microemulsionados possuem potencial para aplica??o em opera??es de acidifica??o de po?os
146

Extra??o de metais (K, Mg, Ba, Ca, Cr, Mn, Li, Fe) de ?gua produzida utilizando sistema microemulsionado

Nascimento, Yasmine ?sis Fernandes do 07 January 2014 (has links)
Made available in DSpace on 2014-12-17T14:08:54Z (GMT). No. of bitstreams: 1 YasmineIFN_DISSERT.pdf: 3060416 bytes, checksum: 9c16a86ed5e6a8b081b1d3520826bad4 (MD5) Previous issue date: 2014-01-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The produced water is a byproduct formed due to production of petroleum and carries with it a high amount of contaminants such as oil particles in suspension, organic compounds and metals. Thus, these latter pollutants are very difficult to treat because of its high solubility in water. The objective of this work is to use and evaluate a microemulsioned system to remove metals ( K , Mg , Ba , Ca , Cr , Mn , Li , Fe ) of synthetic produced water. For the extraction of metals, it was used a pseudoternary diagram containing the following phases: synthetic produced water as the aqueous phase (AP), hexane as organic phase (OP), and a cosurfactant/surfactant ratio equal to four (C/S = 4) as the third phase, where the OCS (saponified coconut oil) was used as surfactant and n-butanol as cosurfactant. The synthetic produced water was prepared in a bench scale and the region of interest in the diagram for the removal of metals was determined by experimental design called. Ten points located in the phase Winsor II were selected in an area with a large amount of water and small amounts of reagents. The samples were analyzed in atomic absorption spectrometer, and the results were evaluated through a statistical assesment, allowing the efficiency analysis of the effects and their interactions. The results showed percentages of extraction above 90% for the metals manganese, iron, chromium, calcium, barium and magnesium, and around 45% for metals lithium and potassium. The optimal point for the simultaneous removal of metals was calculated using statistical artifact multiple response function (MR). This calculation showed that the point of greatest extraction of metals occurs was the J point, with the composition [72% AP, 9% OP, 19% C/S], obtaining a global extraction percentage about 80%. Considering the aspects analyzed, the microemulsioned system has shown itself to be an effective alternative in the extraction of metals on synthetic produced water remediation / A ?gua produzida ? um subproduto gerado na produ??o do petr?leo e possui uma grande quantidade de contaminantes, tais como part?culas de ?leo em suspens?o, compostos org?nicos e metais, sendo estes ?ltimos poluentes de dif?cil tratamento devido a sua alta solubilidade em ?gua. O objetivo deste trabalho ? utilizar e avaliar um sistema microemulsionado na extra??o de metais (K, Mg, Ba, Ca, Cr, Mn, Li, Fe) contidos na ?gua produzida. Utilizou-se um diagrama pseudotern?rio de um sistema contendo em sua composi??o: ?gua produzida sint?tica como fase aquosa (FA), hexano como fase org?nica (FO), e uma raz?o cotensoativo/tensoativo igual a quatro (C/T=4), sendo utilizado o OCS (?leo de coco saponificado) como tensoativo e n-butanol como cotensoativo. A ?gua produzida sint?tica foi preparada em escala de bancada e a regi?o de interesse para a remo??o dos metais foi determinada atrav?s do planejamento experimental de mistura, sendo escolhidos dez pontos localizados na fase de Winsor II, em uma ?rea com uma grande quantidade de ?gua e pouca quantidade de mat?ria ativa ou solvente. As amostras foram analisadas no espectr?metro de absor??o at?mica, e os resultados obtidos foram avaliados atrav?s de um tratamento estat?stico permitindo a an?lise da efici?ncia dos efeitos das vari?veis estudadas e suas intera??es. Os resultados apresentaram percentuais de extra??o acima de 90% para os metais mangan?s, ferro, cromo, c?lcio, b?rio e magn?sio, e em torno de 45% para o l?tio e o pot?ssio. O ponto ?timo para a remo??o simult?nea dos metais foi calculado atrav?s do recurso estat?stico de m?ltipla fun??o de resposta (MR). O c?lculo permitiu observar que o ponto onde ocorre o maior percentual de extra??o dos metais foi o ponto J com a composi??o [72% FA, 9% FO, 19% C/T], obtendo percentual de extra??o global em torno de 80% de todos os metais. Tendo em vista os aspectos analisados, o sistema microemulsionado estudado mostrou-se como uma eficiente alternativa na extra??o de metais de ?gua produzida sint?tica
147

Sistemas microemulsionados como carreador lip?dico para f?rmacos insol?veis

Damasceno, Bolivar Ponciano Goulart de Lima 19 June 2010 (has links)
Made available in DSpace on 2014-12-17T14:13:35Z (GMT). No. of bitstreams: 1 BolivarPGLD_DISSERT.pdf: 1624811 bytes, checksum: 4e49d5598ae806bbd9ddd7c33b6e903c (MD5) Previous issue date: 2010-06-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Several pharmaceutical products have been developed in recent years aiming to enhance the treatment of diseases by increasing the effectiveness of drugs. Many of these new products are based on new drug delivery systems. Among these, microemulsions, which were first studied in 1943 by Hoar and Schulman, is of great interest. Microemulsion can be defined as a thermodynamically stable, isotropic, translucent and transparent system of two immiscible liquids stabilized by a surfactant film located in the oil / water interface. The aim os this work was the incorporation of Amphotericin B and Simvasatin to a microemulsion system and analyzes its physicochemical properties and their therapeutical activity when incorporated into this system. Some very promising results were achieved as the reduction of the toxicity and maintenance of the efficacy of the Amphotericin B incorpored into a microemulsion, which was demonstrated in the in vitro pharmacotoxicological study. As for the incorporation of Simvastatin in microemulsion, it was observed a significant improvement in the potential antiinflammatory and anti-infective properties when the system was use to treat infected wounds (simvastatin pleiotropic effects). Therefore, it can be concluded that the incorporation of these drugs into microemulsion system reveal the potential of microemulsions as a promising and novel dosage form, qualifying them for future trials in order to make them available in the pharmaceutical market / In?meros produtos farmac?uticos v?m sendo desenvolvidos nos ?ltimos anos com a finalidade de incrementar o tratamento de doen?as pelo aumento da efic?cia de f?rmacos. Grande parte destes novos produtos est? baseada nos novos sistemas transportadores de f?rmacos. Entre eles destacamse as microemuls?es, que foram primeiramente estudadas em 1943 por Hoar e Schulman. Microemuls?o pode ser definida como um sistema termodinamicamente est?vel, isotr?pico, transl?cido e transparente de dois l?quidos imisc?veis estabilizados por um filme de tensoativos localizados na interface ?leo/?gua. O objetivo deste trabalho foi incorporar anfotericina B e sinvastatina em um sistema microemulsionado e analisar suas propriedades f?sico-qu?micas e suas a??es terap?uticas ap?s a incorpora??o destes f?rmacos ao sistema. Alguns resultados muito promissores foram alcan?ados como a redu??o da toxicidade e a perman?ncia da efic?cia da anfotericina B incorporada em uma microemuls?o durante o estudo farmacotoxicol?gico in vitro. Quanto ? incorpora??o da sinvastatina na microemuls?o, foi constatada uma melhora significativa no potencial antiinflamat?rio e antiinfeccioso (efeitos pleiotr?picos da sinvastatina) em feridas tratadas com esse sistema. Portanto, podemos concluir que a incorpora??o desses f?rmacos em sistemas microemulsionados faz das microemuls?es uma nova e promissora apresenta??o farmac?utica, habilitando-a a futuros ensaios com a finalidade de torn?-los dispon?veis no mercado farmac?utico
148

Desenvolvimento de microemuls?es contendo fotoprotetores inorg?nicos nanoparticulador

Surmann, Luciana Loffredo 12 February 2008 (has links)
Made available in DSpace on 2014-12-17T14:16:22Z (GMT). No. of bitstreams: 1 LucianaRS_Pre_textuais.pdf: 37160 bytes, checksum: 5c10ca3517f836e974edc672ecd286cb (MD5) Previous issue date: 2008-02-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The inorganic actives, represented mainly by microfine zinc oxide and titanium dioxide, have shown great potential to protect against large UV spectrum. The aim of this study is the development, characterization and analysis of stability in the short term of microemulsions containing inorganic fotoprotection agents. The microemulsions identified by the phases diagram containing the metallic oxides were produced by two different methods and subjected to the centrifugation test and thermal stress cycles, and subsequently characterized by macroscopic evaluation, test dilution, electrical conductivity, pH, particle size, and zeta potential. This study highlights the influence of the metal oxides addition in the structure and distribution of micelles in the microemulsions / Os agentes fotoprotetores inorg?nicos, representados principalmente pelo ?xido de zinco e di?xido de tit?nio microfinos, t?m mostrado grande potencial de prote??o contra amplo espectro de radia??o UV. O objetivo deste trabalho consiste no desenvolvimento, caracteriza??o e estudo de estabilidade a curto termo de microemuls?es contendo agentes fotoprotetores inorg?nicos. As microemuls?es identificadas pelo diagrama de fases e adicionadas dos ativos fotoprotetores foram elaboradas a partir de dois m?todos diferentes e submetidas ao teste de centrifuga??o e ciclos gelo-degelo, sendo posteriormente caracterizadas pela avalia??o macrosc?pica, teste de dilui??o, condutividade el?trica, pH, granulometria e determina??o de potencial zeta. Este estudo evidencia a influ?ncia da adi??o dos ?xidos met?licos na estrutura??o micelar e distribui??o de tamanho de part?culas das microemuls?es
149

Aplica??o de microemuls?es na solubiliza??o de fra??es pesadas de petr?leo

Gomes, Diego ?ngelo de Ara?jo 06 March 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:18Z (GMT). No. of bitstreams: 1 DiegoAAG_partesautorizadas.pdf: 1805054 bytes, checksum: 0bbdfaaf4272f15a091664e96c012ed7 (MD5) Previous issue date: 2009-03-06 / This work presents studies related to the use of microemulsions in the solubilization of heavy crude oil fractions responsible by the formation of deposits. The first stage of the work was addressed to the construction of phases diagrams, with the intention of determining the area within which the microemulsion is formed. The following systems were studied: UNITOL L 90 n-Butanol - Water - Kerosene (system 1); UNITOL L 90 - n-Butanol - Water - Xylene (system 2); UNITOL L 90 n-Butanol - Water - Kerosene/Xylene 10% (system 3); UNITOL L 90 - Sec-Butanol - Water - Xylene (system 4). In parallel experiments of physical adsorption were carried out by the static method, with the intention of simulating natural conditions of reservoirs. Crude oil of the Fazenda Bel?m field (Rio Grande do Norte), was used as solute, xylene as solvent and the Assu sandstone (Rio Grande do Norte, Brazil) and Botucatu sandstone (Paran?, Brazil) as rock reservoirs. The curves of adsorption presented the S format type, in agreement with the classification proposed by Giles, Smith and Huitson (1974). The solubilization process was accomplished in the batch method, by varying the time of agitation, the microemulsions and the solid/solution ratio. The experiments showed that the microemulsions presented high efficiency in the solubilization of the crude oil adsorbed on the sandstones. System 2 presented an efficiency of 99% for the Assu sandstone and 97% for the Botucatu sandstone / No presente trabalho foi avaliado o desempenho das microemuls?es na solubiliza??o de fra??es pesadas do petr?leo, respons?veis pela forma??o de dep?sitos. A primeira fase do trabalho foi direcionada ? constru??o dos diagramas de fases, com o intuito de determinar a regi?o na qual a microemuls?o ? formada. Os seguintes sistemas foram estudados: UNITOL L 90 n-Butanol ?gua Querosene (sistema 1); Unitol L 90 n-Butanol ?gua Xileno (sistema 2); Unitol L 90 n-Butanol ?gua Querosene/Xileno 10% (sistema 3); Unitol L 90 Sec-Butanol ?gua Xileno (sistema 4). Em paralelo foram conduzidos experimentos de adsor??o f?sica pelo m?todo est?tico, com o intuito de simular condi??es naturais de reservat?rio. Utilizou-se ?leo bruto do campo de Fazenda Bel?m, (Petrobras - Rio Grande do Norte), xileno como solvente, arenito Assu (Rio Grande do Norte, Brasil) e arenito Botucatu (Paran?, Brasil) como rochas reservat?rio. As curvas de adsor??o foram enquadradas no formato S , de acordo com a classifica??o proposta por Giles, Smith & Huitson (1974). O processo de solubiliza??o foi realizado em regime de batelada, variando o tempo de agita??o, as microemuls?es e a raz?o arenito/microemuls?o. Ensaios mostraram que os sistemas apresentaram alta efici?ncia na solubiliza??o do ?leo bruto adsorvido sobre os arenitos. O sistema 2 apresentou uma efici?ncia de 99% para o arenito Assu e 97% para o arenito Botucatu
150

Reciclagem de material asf?ltico fresado utilizando solventes e microemuls?es

Gomes Filho, Fernando Francisco 30 December 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:21Z (GMT). No. of bitstreams: 1 FernandoFGF.pdf: 1543921 bytes, checksum: 28fee7b00926ff19375c7b0098bc6b3d (MD5) Previous issue date: 2009-12-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / With the increase of asphalt milling services was also a significant increase in recycling services pavements. The techniques used today are basically physical processes in which the milled material is incorporated into new asphalt mixtures or executed on site, with the addition of virgin asphalt and rejuvenating agent. In this paper seeks to analyze the efficiency of extraction of CAP (Petroleum Asphalt Cement) mixtures from asphalt milling, using commercial solvents and microemulsions. The solvents were evaluated for their ability to solubilize asphalt using an extractor reflux-type apparatus. Pseudoternary diagrams were developed for the preparation of microemulsion O/W surfactant using a low-cost coconut oil saponified (OCS). Microemulsions were used to extract the CAP of asphalt through physicochemical process cold. Analysis was performed concentration of CAP in solution by spectroscopy. The data provided in the analysis of concentration by the absorbance of the solution as the basis for calculating the percentage of extraction and the mass flow of the CAP in the solution. The results showed that microemulsions prepared with low concentration of kerosene and butanol/OCS binary has high extraction power of CAP and its efficiency was higher than pure kerosene, reaching 95% rate of extraction / Com o aumento dos servi?os de fresagem asf?ltica houve tamb?m um incremento significativo nos servi?os de reciclagem de pavimentos asf?lticos. As t?cnicas hoje empregadas s?o basicamente processos f?sicos nas quais o material fresado ? incorporado a novas misturas asf?lticas ou executado in loco , com a incorpora??o de asfalto virgem e agente rejuvenecedor. Nesse trabalho prop?e-se analisar a efici?ncia na extra??o do CAP (Cimento Asf?ltico de Petr?leo) de misturas proveniente de fresagem asf?ltica, utilizando solventes comerciais e microemuls?es. Os solventes foram avaliados quanto a sua capacidade de solubilizar asfalto utilizando um extrator por refluxo do tipo Soxhlet. Foram desenvolvidos diagramas pseudotern?rios para elabora??o de microemuls?o O/A utilizando tensoativo de baixo custo como o ?leo de coco saponificado (OCS). As microemuls?es foram utilizadas para extrair o CAP da mistura betuminosa atrav?s de processo f?sico-qu?mico a frio. Foi realizada an?lise de concentra??o de CAP na solu??o atrav?s de espectroscopia. Os dados fornecidos na an?lise da concentra??o atrav?s da absorb?ncia da solu??o serviram de base para o c?lculo do percentual de extra??o e do fluxo m?ssico do CAP na solu??o. Os resultados mostraram que microemuls?es elaboradas com baixa concentra??o de querosene e do bin?rio butanol/OCS tem grande poder de extra??o de CAP, sua efici?ncia foi maior do que o querosene puro, alcan?ando taxa de 95% de extra??o

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