Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T13:04:19Z No. of bitstreams: 1 RafaelChavesLima_DISSERT.pdf: 15500276 bytes, checksum: 4f1a759afd6ed9c7eeb174d02f229d3e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-13T20:23:09Z (GMT) No. of bitstreams: 1 RafaelChavesLima_DISSERT.pdf: 15500276 bytes, checksum: 4f1a759afd6ed9c7eeb174d02f229d3e (MD5) / Made available in DSpace on 2018-03-13T20:23:09Z (GMT). No. of bitstreams: 1 RafaelChavesLima_DISSERT.pdf: 15500276 bytes, checksum: 4f1a759afd6ed9c7eeb174d02f229d3e (MD5) Previous issue date: 2018-01-30 / O Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A assimila??o do modo como uma ze?lita ? formada partindo de um sistema amorfo e o controle sobre tamanho e morfologia dos produtos de s?ntese s?o aspectos fundamentais para a ?engenharia zeol?tica?. Um sistema para a s?ntese da ze?lita mordenita foi estudado, o qual possibilitou a obten??o de fase MOR sem indica??o da presen?a de qualquer outra fase. Foram realizadas varia??es nos par?metros: condi??o de tratamento t?rmico, temperatura, tempo, dilui??o do gel, teor e grau de pureza da ?gua, teor de s?dio, envelhecimento e tipo de s?lica, visando o estabelecimento da rela??o entre o tamanho e a morfologia dos produtos de s?ntese com as modifica??es efetuadas. A temperatura de cristaliza??o mostrou ser um fator primordial com rela??o ao tamanho de part?culas e cristalitos. A dilui??o do gel de s?ntese (50% m/m) proporcionou uma redu??o na agrega??o dos cristalitos e a varia??o do teor de ?gua na s?ntese implicou em mudan?as nas taxas de zeolitiza??o. O teor de s?dio modificou o crescimento dos cristais e o aumento de intercrescimentos e agrega??es de part?culas. Mudan?as na fonte de s?lica incrementaram a taxa de crescimento dos cristais e contribuiram para altera??es no tamanho dos mesmos. Cristais maiores foram obtidos a partir de sistemas com maior concentra??o de c?tions s?dio enquanto agregados de nanocristalitos. Agregados de pequenos cristalitos de mordenita pura de at? cerca de 50 nm foram obtidos com s?nteses realizadas a 150 ?C e com a dilui??o do gel j? preparado. Menores teores de s?dio e ?gua e o uso de fontes de s?lica de maior ?rea espec?fica (relativa a este tipo de material) tamb?m tendem ? resultar em menores cristalitos. Condi??es opostas viabilizaram o maior crescimento, gerando cristais de at? 1 ?m em m?dia. Os resultados mostraram que ? poss?vel exercer algum controle sobre o tamanho de part?cula e de cristalitos da ze?lita mordenita atrav?s do ajuste de par?metros inerentes ao sistema convencional de s?ntese. / The assimilation of the way a zeolite is formed from an amorphous system and the control over size and morphology of the synthesis products are fundamental aspects for "zeolitic engineering". A system for the synthesis of the mordenite zeolite was studied, which made it possible to obtain MOR phase without indicating the presence of any other phase. Variations were made in the parameters: thermal treatment condition, temperature, time, gel dilution, water content and degree of purity, sodium content, aging and type of silica, aiming to establish the relationship between product size and morphology with the modifications made. The crystallization temperature showed to be a prime factor with respect to particle size and crystallites. Dilution of the synthesis gel (50% w / w) provided a reduction in the crystallite aggregation and the variation of the water content in the synthesis implied changes in zeolitization rates. The sodium content modified the growth of the crystals and the increase of intergrowths and aggregations of particles. Changes in the silica source increased the growth rate of the crystals and contributed to changes in their size. Larger crystals were obtained from systems with higher concentrations of sodium cations as nanocrystallite aggregates. Aggregates of small pure mordenite crystallites of up to about 50 nm were obtained with syntheses performed at 150 ? C and with the dilution of the already prepared gel. Lower sodium and water content and the use of silica sources with a greater specific area (relative to this type of material) also tend to result in smaller crystallites. Opposite conditions enabled the highest growth, generating crystals up to 1 ?m on average. The results showed that it is possible to exert some control over the particle size and crystallites of the mordenite zeolite by adjusting parameters inherent to the conventional synthesis system.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:35:59Z No. of bitstreams: 1 IzabelCristinaMedeirosCosta_DISSERT.pdf: 7508849 bytes, checksum: baba9399e7458c8670380f1bc49a950c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T00:21:16Z (GMT) No. of bitstreams: 1 IzabelCristinaMedeirosCosta_DISSERT.pdf: 7508849 bytes, checksum: baba9399e7458c8670380f1bc49a950c (MD5) / Made available in DSpace on 2016-06-07T00:21:16Z (GMT). No. of bitstreams: 1 IzabelCristinaMedeirosCosta_DISSERT.pdf: 7508849 bytes, checksum: baba9399e7458c8670380f1bc49a950c (MD5) Previous issue date: 2015-11-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Neste trabalho foi realizado um estudo dos par?metros de s?ntese da ze?lita MCM-22 (estrutura MWW) com o intuito de otimizar a obten??o deste material e aumentar sua acessibilidade, tanto pelo aumento de superf?cie externa, quanto pela gera??o de mesoporos. Foram realizadas s?nteses de rela??o Si/Al= 15 e Si/Al=50 sob condi??es est?ticas em diferentes temperaturas e com indu??o por sementes, as quais resultaram em MCM-22 pura e cristalina de rela??o Si/Al= 15 em 3 dias e Si/Al=50 em 11 dias. A redu??o do teor de hexametileneimina (HMI) foi estudada na s?ntese em agita??o. As condi??es de redu??o foram de 30 % de HMI na s?ntese padr?o de 7 dias e em s?ntese empregando sementes com tempos de 1, 2, 3 e 4 dias. Redu??o de 45 % de HMI com adi??o de ?gua-m?e e tempos de 2, 4, 5 e 7 dias. Quanto ao aumento de acessibilidade na MCM-22, buscou-se aumentar a velocidade de cristaliza??o e redu??o do tempo, com o objetivo de se obter cristais de menor tamanho. Alguns agentes foram empregados para acelerar a obten??o da MCM-22, foram estes as sementes, ?gua-m?e, incremento de temperatura e dissolu??o da s?lica. Com rela??o ainda ao aumento de acessibilidade na MCM-22, foram estudados tratamentos ?cidos para retirada de alum?nio e gera??o de mesoporos e a silaniza??o de proto-unidades zeol?ticas, que atua tamb?m na forma??o de mesoporos e na diminui??o dos cristais. O tratamento com ?cido ox?lico de concentra??o 0,5 mol/ L resultou na forma??o de mesoporos de 3 nm e a s?ntese empregando a silaniza??o de proto-unidades zeol?ticas de pr?-cristaliza??o de tr?s dias resultou na redu??o de 70 % no tamanho dos cristais e em poros mais abertos, com alguns destes com di?metros na faixa de mesoporos (2,6 nm). / In this paper a synthesis parameters study was conducted in order to optimize the obteinment of MCM-22 (MWW structure) and increase its accessibility, getting higher external surface and generating mesopores. Syntheses with Si / Al = 15 and Si / Al = 50 ratios were performed under static conditions at different temperatures and with seeds induction, which resulted in MCM-22 pure and crystalline (Si / Al ratio = 15) after 3 days and Si / Al = 50 after 11 days. The reduction of hexamethyleneimine content (HMI) was studied in the stirring synthesis and a HMI reduction of 47% was possible through the mother liquor reuse, in addition, a specific area of 481 m? / g has been obtained in the fourth synthesis day. Regarding the increase of accessibility of the MCM-22 zeolite skeins of MCM-22 plates with about 2 ?m were obtained, through the use of dissolved silica, addition of seeds, increased temperature and synthesis time of 2 days. A significant value of specific area was found for this material, around 500 m? / g. Also with respect to the increase of MCM-22 accessibility, treatment with oxalic acid concentration of 0.5 mol / L and silanization of proto-zeolitic units resulted in the mesopores formation . Furthermore, silanization still favored reduction of 70 % in crystal size and a specific area of 566 m? / g.

Made available in DSpace on 2014-12-17T15:01:17Z (GMT). No. of bitstreams: 1 ErikaaAS.pdf: 744693 bytes, checksum: 969bbaf028a15425563a34bdced20b1e (MD5) Previous issue date: 2005-07-21 / The formation of paraffin deposits is common in the petroleum industry during production, transport and treatment stages. It happens due to modifications in the thermodynamic variables that alter the solubility of alkanes fractions present in petroleum. The deposition of paraffin can provoke significant and growing petroleum losses, arriving to block the flow, hindering to the production. This process is associated with the phases equilibrium L-S and the stages and nucleation, growth and agglomeration the crystals. That process is function of petroleum intrinsic characteristics and temperature and pressure variations, during production. Several preventive and corrective methods are used to control the paraffin crystallization, such as: use of chemical inhibitors, hot solvents injection, use of termochemistry reactions, and mechanical removal. But for offshore exploration this expensive problem needs more investigation. Many studies have been carried through Wax Appearance Temperature (WAT) of paraffin; therefore the formed crystals are responsible for the modification of the reologics properties of the oil, causing a lot off operational problems. From the determination of the WAT of a system it is possible to affirm if oil presents or not trend to the formation of organic deposits, making possible to foresee and to prevent problems of wax crystallization. The solvent n-paraffin has been widely used as fluid of perforation, raising the production costs when it is used in the removal paraffin deposits, needing an operational substitute. This study aims to determine the WAT of paraffin and the interference off additives in its reduction, being developed system paraffin/solvent/surfactant that propitiates the wax solubilization. Crystallization temperatures in varied paraffin concentrations and different solvents were established in the first stage of the experiments. In the second stage, using the methodology of variation of the photoelectric signal had been determined the temperature of crystallization of the systems and evaluated the interferences of additives to reduction of the WAT. The experimental results are expressed in function of the variations of the photoelectric signals during controlled cooling, innovating and validating this new methodology to determine WAT, relatively simple with relation the other applied that involve specific equipments and of high cost. Through the curves you differentiate of the results had been also identified to the critical stages of growth and agglomeration of the crystals that represent to the saturation of the system, indicating difficulties of flow due to the increase of the density / A forma??o de dep?sito paraf?nico ? comum na ind?stria do petr?leo durante as etapas de produ??o, movimenta??o e tratamento e ocorre em decorr?ncia de modifica??es nas vari?veis termodin?micas que alteram a solubilidade das fra??es de alcanos presentes no petr?leo. A cristaliza??o de parafinas pode provocar significativas e crescentes perdas de petr?leo, chegando a bloquear o fluxo, impedindo ? produ??o. Esse processo est? associado ao equil?brio de fases L-S e as etapas de nuclea??o, crescimento e aglomera??o dos cristais. Existem v?rios m?todos preventivos e corretivos para controlar a cristaliza??o de parafinas, dentre os quais se destacam: o uso de inibidores qu?micos, a inje??o de solventes aquecidos, o emprego de rea??es termoqu?micas e a remo??o mec?nica, por?m quanto ? explora??o offshore pouco se conhece, tornando-se indispens?vel investigar este custoso problema. Muitos estudos t?m sido realizados quanto ? temperatura de in?cio do aparecimento dos cristais (TIAC) da parafina, pois os cristais formados s?o respons?veis pela modifica??o das propriedades reol?gicas do petr?leo, causando diversos problemas operacionais. A partir da determina??o da TIAC de um sistema ? poss?vel afirmar se um petr?leo apresenta ou n?o tend?ncia ? forma??o de dep?sitos org?nicos, possibilitando prever e evitar problemas de cristaliza??o paraf?nica. O solvente n-parafina tem sido amplamente utilizado como fluido de perfura??o, elevando os custos de produ??o quando ? empregado na remo??o de dep?sitos paraf?nicos, necessitando de um substituto operacional. Este estudo visa determinar a TIAC da parafina e ? interfer?ncia de aditivos na sua redu??o, desenvolvendo um sistema parafina/solvente/tensoativo que propicie a solubiliza??o paraf?nica. Na primeira etapa dos experimentos, foram determinadas as temperaturas de cristaliza??o em concentra??es de parafina variadas e diferentes solventes. Na segunda etapa, utilizando a metodologia de varia??o do sinal fotoel?trico foi determinada a temperatura de cristaliza??o dos sistemas e avaliadas as interfer?ncias dos aditivos quanto ? redu??o da TIAC. Os resultados s?o expressos em fun??o das varia??es do sinal fotoel?trico, durante resfriamento controlado, inovando e validando esta metodologia de determina??o da TIAC, relativamente simples com rela??o ?s outras aplicadas que envolvem equipamentos espec?ficos e de alto custo. Atrav?s das curvas diferencias dos resultados tamb?m foram identificadas ?s etapas cr?ticas de crescimento e aglomera??o dos cristais que representam ? satura??o do sistema, indicando dificuldades de fluxo devido ao aumento da densidade

Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 AndreACP_DISSERT.pdf: 6190808 bytes, checksum: 21a983a9627b562fbe33e41da8ebdfd8 (MD5) Previous issue date: 2013-08-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Polymer particles in the nanometer range are of fundamental interest today, especially when used as carrier systems in the controlled release of drugs, cosmetics and nutraceuticals, as well as in coating materials with magnetic properties. The main objective of the present study concerns the production of submicron particles of poly (methyl methacrylate) (PMMA) by crystallization of a polymer solution by thermally controlled cooling. In this work, PMMA solutions in ethanol and 1-propanol were prepared at different concentrations (1% to 5% by weight) and crystallized at different cooling rates (0.2 to 0.8 ? C / min) controlled linearly. Analysis of particle size distribution (DLS / CILAS) and scanning electron microscopy (SEM) were performed in order to evaluate the morphological characteristics of the produced particles. The results demonstrated that it is possible to obtain submicron polymer perfectly spherical particles using the technique discussed in this study. It was also observed that, depending on the cooling rate and the concentration of the polymer solution, it is possible to achieve high yield in the formation of submicron particles. In addition, preliminary tests were performed in order to verify the ability of this technique to form particulated carrier material with magnetic properties. The results showed that the developed technique can be an interesting alternative to obtain polymer particles with magnetic properties / Part?culas polim?ricas formadas em escala nanom?trica s?o de fundamental interesse atualmente, principalmente quando utilizadas como sistemas carreadores na libera??o controlada de f?rmacos, cosm?ticos e nutrac?uticos, al?m do interesse pr?tico no recobrimento de materiais com propriedades magn?ticas. O principal objetivo do presente estudo diz respeito ? produ??o de part?culas submicrom?tricas de poli(metacrilato de metila) (PMMA) atrav?s da t?cnica de cristaliza??o de uma solu??o polim?rica por resfriamento controlado termicamente, segundo um perfil de taxa linear de resfriamento. Neste trabalho, solu??es de PMMA em etanol e 1-propanol foram preparadas em diferentes concentra??es (1% a 5% em massa) e cristalizadas em diferentes taxas de resfriamento (0,2 a 0,8 ?C/min) controladas linearmente. An?lises de distribui??o de part?culas (DLS/CILAS) e microscopia eletr?nica de varredura (MEV) foram realizadas com o intuito de avaliar as caracter?sticas morfol?gicas das part?culas formadas. Os resultados demonstraram que ? poss?vel obter part?culas polim?ricas submicrom?tricas com morfologia perfeitamente esf?rica utilizando a t?cnica abordada no presente estudo. Observou-se tamb?m que, a depender da taxa de resfriamento e da concentra??o da solu??o polim?rica, ? poss?vel ter alto rendimento na forma??o de part?culas submicrom?tricas. Adicionalmente, foram realizados testes preliminares com o prop?sito de verificar a capacidade desta t?cnica em formar part?culas carreadoras de materiais com propriedades magn?ticas. Os resultados permitiram concluir que a t?cnica estudada pode ser uma alternativa interessante na obten??o de part?culas polim?ricas com propriedades magn?ticas

Made available in DSpace on 2014-12-17T15:01:37Z (GMT). No. of bitstreams: 1 HumbertoNMO_dissert.pdf: 1947865 bytes, checksum: 483437cde9982b75917556f1e4d183b7 (MD5) Previous issue date: 1999-06-11 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In the present work are established initially the fundamental relationships of thermodynamics that govern the equilibrium between phases, the models used for the description of the behavior non ideal of the liquid and vapor phases in conditions of low pressures. This work seeks the determination of vapor-liquid equilibrium (VLE) data for a series of multicomponents mixtures of saturated aliphatic hydrocarbons, prepared synthetically starting from substances with analytical degree and the development of a new dynamic cell with circulation of the vapor phase. The apparatus and experimental procedures developed are described and applied for the determination of VLE data. VLE isobarics data were obtained through a Fischer s ebulliometer of circulation of both phases, for the systems pentane + dodecane, heptane + dodecane and decane + dodecane. Using the two new dynamic cells especially projected, of easy operation and low cost, with circulation of the vapor phase, data for the systems heptane + decane + dodecane, acetone + water, tween 20 + dodecane, phenol + water and distillation curves of a gasoline without addictive were measured. Compositions of the equilibrium phases were found by densimetry, chromatography, and total organic carbon analyzer. Calibration curves of density versus composition were prepared from synthetic mixtures and the behavior excess volumes were evaluated. The VLE data obtained experimentally for the hydrocarbon and aqueous systems were submitted to the test of thermodynamic consistency, as well as the obtained from the literature data for another binary systems, mainly in the bank DDB (Dortmund Data Bank), where the Gibbs-Duhem equation is used obtaining a satisfactory data base. The results of the thermodynamic consistency tests for the binary and ternary systems were evaluated in terms of deviations for applications such as model development. Later, those groups of data (tested and approved) were used in the KijPoly program for the determination of the binary kij parameters of the cubic equations of state original Peng-Robinson and with the expanded alpha function. These obtained parameters can be applied for simulation of the reservoirs petroleum conditions and of the several distillation processes found in the petrochemistry industry, through simulators. The two designed dynamic cells used equipments of national technology for the determination of VLE data were well succeed, demonstrating efficiency and low cost. Multicomponents systems, mixtures of components of different molecular weights and also diluted solutions may be studied in these developed VLE cells / No presente trabalho s?o inicialmente estabelecidas as rela??es termodin?micas fundamentais que governam o equil?brio entre fases, sendo apresentados os modelos utilizados para a descri??o do comportamento n?o ideal das fases l?quidas e vapor em condi??es de baixas press?es. Este trabalho visou a determina??o de dados de equil?brio l?quido-vapor (ELV) para uma s?rie de misturas de hidrocarbonetos alif?ticos saturados multicomponentes preparadas sinteticamente a partir de subst?ncias com grau P.A., e o desenvolvimento de uma nova c?lula din?mica com circula??o da fase vapor. Os dispositivos e os procedimentos experimentais s?o descritos e aplicados para a determina??o destes dados de EL V. Dados de EL V isob?ricos foram determinados, atrav?s de um ebuli?metro Fischer de circula??o das fases l?quida e vapor, para os sistemas pentano + do decano, heptano + dodecano, decano + dodecano. Atrav?s das duas novas c?lulas din?micas especialmente projetadas, de f?cil opera??o e baixo custo, com circula??o da fase vapor, os sistemas heptano + decano + dodecano, acetona + ?gua, tween 20 + dodecano, fenol + ?gua e curva de destila??o de uma gasolina sem aditivo foram estudados experimentalmente. As composi??es das fases em equil?brio foram encontradas por densimetria, cromatografia e analisador de carbono org?nico total. Curvas de calibra??o de densidade versus composi??o foram preparadas a partir de misturas sint?ticas e avaliados os comportamentos de seus volumes de excesso. Os dados de ELV obtidos experimentalmente para os sistemas aquosos e hidrocarbonetos foram submetidos a testes de consist?ncia termodin?mica, bem como os dados obtidos da literatura para outros sistemas bin?rios, principalmente no banco de dados DDB (Dortmund Data Bank), utilizando a equa??o de Gibbs-Duhem, obtendo uma s?rie de dados com consist?ncia satisfat?ria. Os resultados dos testes de consist?ncia termodin?mica, obtidos para os sistemas bin?rios e tern?rio, foram avaliados em termos de desvios para aplica??es tais como desenvolvimento de modelos. Posteriormente, esses conjuntos de dados (testados e aprovados) foram usados no programa KijPoly para a determina??o dos par?metros bin?rios kij das equa??es de estado c?bicas de Peng-Robinson original e com a fun??o alfa expandida. Os par?metros obtidos podem ser aplicados para simula??o das condi??es de reservat?rios de petr?leo e dos v?rios processos de destila??o encontrados na ind?stria petroqu?mica, atrav?s de simuladores. Os dois novos projetos de c?lulas din?micas usaram equipamentos de tecnologia nacional para a determina??o de dados de ELV foram bem sucedidos, demonstrando efici?ncia e baixo custo. Sistemas multicomponentes e com componentes de diferentes pesos moleculares, e at? em concentra??es dilu?das foram e podem ser estudados nessas c?lulas de ELV desenvolvidas

Made available in DSpace on 2014-12-17T15:03:30Z (GMT). No. of bitstreams: 1 LilianeFGL_DISSERT.pdf: 931554 bytes, checksum: 0bbe7c36b3d8afca89214b8b2d97bd81 (MD5) Previous issue date: 2012-12-07 / This study investigated the influence of the molar ratio, the phosphorus initial concentration, the mixture gradient, mixing time, pH and the secondary nucleation on struvite s crystallization in synthetic water in batch reactors. The study was divided into two stages. The first investigated struvite s crystallization at different Mg:N:P molar ratios and at different initial concentrations of magnesium, nitrogen and phosphorus. It was also evaluated the importance of secondary nucleation on the struvite s crystallization. In the second, five parameters were tested to evaluate their influence on the struvite s crystallization, which were: Mg:N:P molar ratio, initial concentration of phosphate, mixing time, mixture gradient and pH. The best conditions for struvite s crystallization were: Mg:N:P = 1,3:1:1 molar ratio; mixture gradient = 60 rpm, pH = 10.0, mixing time = 5 minutes and high initial concentrations of the constituent ions of struvite. Furthermore, the use of struvite crystals as seed influenced positively on the struvite s crystallization / O presente estudo investigou a influ?ncia da raz?o molar, da concentra??o inicial de f?sforo, do gradiente de mistura, do tempo de mistura, do pH e da nuclea??o secund?ria na cristaliza??o de estruvita em ?gua sint?tica, em reatores em batelada. A pesquisa foi dividida em duas etapas. A primeira investigou a cristaliza??o da estruvita em ?gua sint?tica em diferentes raz?es molares Mg:N:P e concentra??es iniciais de magn?sio, nitrog?nio e f?sforo, sendo tamb?m avaliada a import?ncia da nuclea??o secund?ria na cristaliza??o da estruvita. Na segunda etapa, cinco par?metros foram testados para avaliar a influ?ncia destes na cristaliza??o da estruvita, quais sejam: raz?o molar Mg:N:P, concentra??o inicial de f?sforo, gradiente de mistura, tempo de mistura e pH. As melhores condi??es observadas para a cristaliza??o de estruvita foram: raz?o molar Mg:N:P = 1,3:1:1; gradiente de mistura = 60 rpm; pH = 10,0; tempo de mistura = 5 minutos e elevadas concentra??es iniciais dos ?ons constituintes da estruvita. Al?m disso, a utiliza??o de cristais de estruvita como semente influenciou positivamente na cristaliza??o da estruvita

Made available in DSpace on 2014-12-17T15:01:49Z (GMT). No. of bitstreams: 1 ErikaASG_TESE_partes_autorizadas.pdf: 3587859 bytes, checksum: 8731a4ebad1b8f6f11b36c879b4a1a76 (MD5) Previous issue date: 2009-12-30 / The WAT is the temperature at the beginning of the appearance of wax crystals. At this temperature the first wax crystals are formed by the cooling systems paraffin / solvents. Paraffins are composed of a mixture of saturated hydrocarbons of high molecular weight. The removal of petroleum from wells and the production lines means a surcharge on produced oil, thus solubilize these deposits formed due to modifications of thermodynamics has been a constant challenge for companies of oil exploration. This study combines the paraffin solubilization by microemulsion systems, the determination of WAT systems paraffin / solvent and performance of surfactant in reducing the crystallization. We used the methods: rheological and the photoelectric signal, validating the latter which was developed to optimize the data obtained due to sensitivity of the equipment used. Methods developed for description of wax precipitation are often in poor agreement with the experimental data, they tend to underestimate the amount of wax at temperatures below the turbidity point. The Won method and the Ideal solution method were applied to the WAT data obtained in solvent systems, best represented by the second interaction of Won method using the solvents naphtha, hexane and LCO. It was observed that the results obtained by WAT photoelectric signal when compared with the viscosity occur in advance, demonstrating the greatest sensitivity of the method developed. The ionic surfactant reduced the viscosity of the solvent systems as it acted modifying the crystalline structure and, consequently, the pour point. The curves show that the WAT experimental data is, in general, closer to the modeling performed by the method of Won than to the one performed by the ideal solution method, because this method underestimates the curve predicting the onset of paraffin hydrocarbons crystallization temperature. This occurs because the actual temperature measured was the crystallization temperature and the method proposes the fusion temperature measurement. / A TIAC ? a temperatura de in?cio do aparecimento dos cristais de parafina. Nesta temperatura os primeiros cristais de parafina s?o formados, pelo resfriamento de sistemas parafina/solventes. As parafinas s?o compostas de uma mistura de hidrocarbonetos saturados de alto peso molecular. A remo??o de parafinas dos po?os e das linhas de produ??o significa um custo adicional ao petr?leo produzido, portanto solubilizar estes dep?sitos formados decorrentes das modifica??es termodin?micas tem sido um desafio constante das empresas exploradoras de petr?leo. Este estudo alia a solubiliza??o paraf?nica por sistemas microemulsionados, ? determina??o da TIAC dos sistemas parafina/solvente e a atua??o do tensoativo na redu??o da cristaliza??o. Utilizaram-se os m?todos: reol?gico e o do sinal fotoel?trico, validando este ?ltimo o qual foi desenvolvido visando aperfei?oar os dados obtidos devido a sensibilidade do equipamento utilizado. M?todos desenvolvidos para descri??o da precipita??o da cera est?o freq?entemente em pobre concord?ncia com os dados experimentais; eles tendem a subestimar a quantidade de cera ?s temperaturas abaixo do ponto de turbidez. Foram aplicados os m?todos de Won e o da solu??o ideal aos dados de TIAC da parafina obtidos em sistemas com solventes, sendo melhor representado pela segunda intera??o do m?todo de Won com os solventes: nafta, hexano e LCO. Foi observado que os resultados de TIAC obtidos pelo sinal fotoel?trico quando comparados com a viscosidade, ocorrem antecipadamente, demonstrando a maior sensibilidade do m?todo desenvolvido. O tensoativo i?nico reduziu a viscosidade dos sistemas paraf?nicos, pois ele atuou modificando a estrutura cristalina, conseq?entemente o ponto de fluidez. As curvas que representam os dados experimentais da TIAC est?o, de maneira geral, mais pr?ximas da modelagem realizada pelo m?todo de Won do que da solu??o ideal, pois este m?todo subestima a curva de predi??o do in?cio da temperatura de cristaliza??o da parafina com os hidrocarbonetos. Isto ocorre porque a temperatura real medida foi a de cristaliza??o, e a proposta pelos m?todos ? a de fus?o