Dans ce travail nous étudions l’élaboration, la caractérisation et les applications de différents matériaux poreux. L’étude est organisée en trois parties majeures: la synthèse de zéolithes micro/mesoporeux et leur application potentielle dans l’industrie pétrochimique, l’étude théorique de mécanismes réactionnels sur des zeolites microporeux, et le design de métaux mesoporeux avec une chiralité intrinsèque de leur surface interne. Ces matériaux poreux montrent des propriétés excellentes, notamment pour des applications potentielles en catalyse et comme interfaces chirales. / In the present work, the elaboration, characterisation and applications of differentporous materials have been studied. Porous materials are divided into three categoriesdepending on the porous cavity size, namely microporous materials (pore diameter < 2nm), mesoporous materials (2 nm < pore diameter < 50 nm) and macroporous materials(pore diameter > 50 nm). The thesis work is organized in three major parts: the synthesisof hierarchical micro/mesoporous zeolites and their potential application for thepetrochemical industry, the theoretical study of reaction mechanisms on microporouszeolite and the design of mesoporous metals with intrinsic chirality at their inner surface.The hierarchical micro/mesoporous zeolite, composed of microporous andmesoporous features, has been prepared using carbon-silica (C/SiO2) composites derivedfrom a pyrolysis of hydrocarbon gas on silica gel. Our findings demonstrate that not onlythe presence of a high surface area and porosity, but also an improved efficiency of thesematerials for many petrochemical processes such as n-butene isomerization, nhexadecanecatalytic cracking and hydrocracking. The novel synthetic method is expectedto be generalized for other types of zeolites, and is considered to be a promising methodfor creating hierarchical micro/mesoporous zeolites for potential catalytic applications,especially in the petrochemical industry.In addition to the study of practical catalytic aspects, a theoretical approach hasbeen used to investigate potential reaction mechanisms such as the selective isomerizationof 1-butene into isobutene. More specifically, the monomolecular skeletal isomerizationof 1-butene into isobutene on H-FER zeolite was theoretically studied by using theONIOM approach. This process was found to involve the transformation of adsorbed 1-butene through 2-butoxide, isobutoxide, and tert-butyl cation intermediates. The ratedeterminingstep is the conversion of isobutoxide into isobutene, in which the reactionhas to proceed through the primary isobutyl cation transition state. The shape selectivitydue to the “nano-confinement” effect of the zeolite framework strongly affects theadsorption, the stability of alkoxide species and carbenium ion, as well as the skeletalisomerization mechanism of 1-butene.Moreover, the microporous and mesoporous zeolite, the generation of chiralmesoporous metal and its enantioselective recognition properties have been studied.Molecular imprinting (MI) is a major approach for generating materials withenantioselective properties. In this work, a chiral imprinted mesoporous platinum hasbeen obtained by the electrochemical reduction of platinum salts in the simultaneouspresence of a lyotropic liquid crystal phase and chiral template molecules. The resultingmaterials exhibit not only a dramatic increase in active surface area due to theirmesoporosity, but also a significant discrimination between two enantiomers of a chiralprobe, confirmed by both electrochemical and enantioselective adsorption experiments.Most importantly the porous platinum retains its chiral character even after removal of thechiral template molecule. Our findings could lead to the development of new materials,which are of potential interest for applications in areas such as chiral synthesis, sensors,separation, purification and drug development.

L'accès à l'eau potable est indispensable au développement de la vie. La pollution, liée aux activités anthropiques, constitue une menace pour la santé humaine et pour les espèces sauvages. Parmi les nombreux polluants retrouvés dans les eaux, la pollution par les métaux lourds constitue un problème environnemental d'intérêt mondial en raison de leur toxicité élevée, même à des concentrations très faibles, et de leur persistance dans la nature. De nombreuses méthodes peuvent être mises en oeuvre pour l'élimination des métaux lourds dans l'eau. Parmi elles, les procédés d'adsorption sont très attractifs car très efficaces et peu couteux. Les zéolithes sont des matériaux bien connus pour leurs propriétés d'échange. Les matériaux mésoporeux modifiés ou adsorbants carbonés sont également très attractifs du fait de leur importante surface spécifique. Dans ce manuscrit, les performances d'adsorption de cations métalliques en phase aqueuse sur des matériaux mésoporeux, silices SBA-15, SBA-16, KIT-6 modifiées par l'EDTA et carbone CMK-3 obtenu par réplication ont été étudiées et comparées avec celles de la zéolithe NaX. Les propriétés physico-chimiques de l'ensemble des matériaux ont été caractérisées par plusieurs techniques d'analyses. L'influence des paramètres expérimentaux (pH, temps de contact, température, concentration des ions métalliques et de la présence d'ions concurrents) sur l'adsorption a été étudiée en mode batch. L'efficacité de ces matériaux a également été étudiée dans un réacteur dynamique à lit fixe. Les résultats obtenus ont montré que tous les matériaux étudiés éliminent efficacement et rapidement les métaux divalents dans les eaux même à faible concentration. Néanmoins, le carbone CMK-3 s'avère être le meilleur adsorbant du fait de sa grande capacité d'adsorption même en présence d'espèces compétitrices. / Access to sustainable and clean drinking water is a main concern as the Earth's human population continues its steady growth. Unfortunately, many of the available water resources are becoming increasingly polluted as a result of the direct discharge of industrial effluents. Heavy metals pollution, in particular, is an environmental problem of global interest due to their high toxicity, even at very low concentrations, and persistence in nature. Many methods are available for metal ions removal including adsorption which is attracting a lot of attention recently. Zeolites are well known for having very high exchange capacities. On the other hand, many researchers are studying the removal of heavy metals by modified mesoporous materials or carbonaceous adsorbents. In this thesis, the adsorption efficiencies of several materials for heavy metal removal in aqueous phase were investigated and compared to those of the faujasite NaX zeolite. Mesoporous silica SBA-15, SBA-16, KIT-6 were synthesized and modified with EDTA. Moreover, CMK-3 carbon was nano-casted from SBA-15 then the physic-chemical properties of these materials were characterized by different techniques. The effects of several experimental conditions on adsorption such as pH, contact time, temperature, metal ions concentration and the presence of competitors were studied in batch experiments. Then the efficiency of all these materials was also studied in a dynamic fixed bed reactor. Based on the obtained results, it could be said that all these materials are good candidates for divalent heavy metals removal from waste water even at low concentration. However, CMK-3 material has a high sorption capacity even in presence of competitor species.

As cinzas de carvão são subprodutos da combustão de carvão mineral gerados em grandes quantidades a partir de usinas termelétricas no mundo todo. Nos últimos anos, pesquisas sobre a utilização das cinzas estão sendo desenvolvidas visando soluções sustentáveis, garantindo, assim, a preservação do meio ambiente e a saúde humana. As cinzas de carvão podem ser aproveitadas como matéria-prima para síntese de zeólita, material este que possui uma vasta gama de aplicações industriais. Em muitas dessas aplicações é requerido o uso de formas peletizadas de zeólitas. Nesse contexto, o objetivo do presente estudo foi desenvolver um método de obtenção de zeólita de cinzas leves de carvão na forma granular e avaliar seu uso como material adsorvente. A primeira etapa deste estudo consistiu na síntese e caracterização de zeólita convencional (ZCL) e de zeólita do tipo NaA com alto grau de pureza (ZA). As cinzas leves de carvão utilizadas na síntese das zeólitas foram coletadas na Usina Termelétrica Jorge Lacerda, localizada no Estado de Santa Catarina, Brasil, o maior complexo termelétrico a carvão da América Latina. O material de partida e as zeólitas sintetizadas em pó foram caracterizados em termos da composição química, composição mineralógica, morfologia, capacidade de troca catiônica, estabilidade térmica, área superficial específica, distribuição de poros e dos grupos funcionais. As fases zeolíticas formadas por tratamento hidrotérmico foram hidroxisodalita e traços de NaX. A zeólita do tipo NaA foi sintetizada por método de duas etapas apresentando grau de pureza de 84%. O valor de capacidade de troca catiônica da zeólita A com alto grau de pureza foi aproximadamente duas vezes maior do que o valor encontrado para a zeólita convencional (1,84 meq g-1 para ZCL e 3,81 meq g-1 para ZA). Na segunda etapa, os produtos zeolíticos sintetizados neste estudo foram peletizados com a aplicação de diferentes métodos. Os grânulos de zeólitas foram formados manualmente na forma de esferas na faixa de tamanho entre 3 mm e 7 mm a partir da mistura das zeólitas em pó com um ou mais agentes aglutinantes e adição de água deionizada. As diferentes metodologias experimentais de peletização das zeólitas sintetizadas foram comparadas e avaliadas por meio da determinação da capacidade de troca catiônica dos produtos obtidos, trabalhabilidade, resistência mecânica e estabilidade em água. O método de peletização no qual as argilas caulinita e bentonita foram usadas como agentes aglutinantes, na proporção de 5% em massa cada, foi considerado o melhor para a zeólita convencional. Para a zeólita A, foi selecionado o método com 10% de bentonita. Os valores de capacidade de troca catiônica dos produtos zeolíticos foram mantidos após o processo de peletização. Posteriormente foi realizado um estudo direcionado à aplicação da zeólita granular no tratamento de água. A amostra de zeólita A com alto grau de pureza peletizada, obtida pelo método otimizado, foi selecionada para ser usada como material adsorvente no processo de adsorção de íons cádmio em solução aquosa em coluna de leito fixo. Os resultados evidenciaram a potencialidade do uso da zeólita A peletizada no tratamento de efluentes. / Coal ashes are by-products of coal combustion generated in large quantities from thermoelectric plants worldwide. In recent years, research on the use of ash has been developed aiming at sustainable solutions, thus guaranteeing the preservation of the environment and human health. Coal ashes can be used as raw material for zeolite synthesis, which has a wide range of industrial applications. In many such applications the use of zeolite pelletized forms is required. In this context, the objective of the present study was to develop a method to obtain zeolite of light ash from coal in the granular form and to evaluate its use as an adsorbent material. The first step of this study was the synthesis and characterization of zeolite conventional (ZFA) and of the zeolite NaA type with a high degree of purity (ZA). The coal fly ashes used in the synthesis of the zeolites were collected in the Thermoelectric Complex Jorge Lacerda, located in the Santa Catarina State, Brazil, the largest coal burning thermoelectric complex of Latin America. The starting material and the zeolites synthesized in powder were characterized in terms of chemical composition, mineralogical composition, morphology, cation exchange capacity, thermal stability, specific surface area, pore distribution and functional groups. The zeolitic phases formed by conventional hydrothermal treatment were hydroxysodalite and traces of NaX. The zeolite of the NaA type was synthesized by a two-step method with a fusion step having a degree of purity of 84%. The value of cation exchange capacity of zeolite A with high purity was approximately two times higher than the value found for the zeolite conventional (1.84 meq g-1 for ZFA and 3.81 meq g-1 for ZA). In the second step, the zeolitic products synthesized in this study were pelletized with the application of different methods. The zeolite granules were formed manually in the form of spheres in the size range between 3 mm and 7 mm from the powder mixture of zeolite with one or more binders and addition of deionized water. The different experimental methodologies of pelletization the synthesized zeolites were compared and evaluated through of the determination of the cation exchange capacity, workability, mechanical strength and water stability. The pelletization method in which clays kaolinite and bentonite were used as binders in the proportion of 5% by weight each was considered the best for the conventional zeolite. For zeolite-A, was selected the method with 10% bentonite. The cation exchange capacity values of the zeolitic products were maintained after the pelletization process. Subsequently, a study was carried out on the application of granular zeolite in water treatment. The zeolite-A sample with high degree of pelletized purity, obtained by the optimized method, was selected to be used as adsorbent material in the adsorption process of cadmium ions in aqueous solution in a fixed bed column. The results evidenced the potential of the use of pelletized zeolite-A in the treatment of effluents.

Os processos anaeróbios têm sido recentemente adotados como unidades principais em sistemas de tratamento de efluentes, em virtude das inúmeras vantagens que apresentam. Este trabalho de pesquisa, no entanto, visa possibilitar a obtenção de fonte de carbono prontamente degradável a partir de uma das primeiras aplicações da biotecnologia anaeróbia: a digestão de lodo. A partir de um digestor hidrolítico e acidogênico de lodo primário foi possível a obtenção de efluentes com altas concentrações de DQO solúvel (da ordem de 4.000 mg/L) e ácidos graxos voláteis – AGV – (da ordem de 600 mg/L). Porém, foi necessária a aplicação de um processo de troca iônica para a remoção das altas concentrações de 'NH IND.4'POT.+' (da ordem de 480 mg/L) no efluente do DHL. A utilização de zeólitas – minerais de silício e alumínio – permitiu a remoção de íons amônio, através de experimentos em bateladas e colunas. As capacidades de adsorção de 'NH IND.4'POT.+' por massa de zeólitas atingidas foram de 8,0 mg 'NH IND.4'POT.+'/g. Adicionalmente, foi realizado o estudo da regeneração do mineral, através de processo biológico de nitrificação e posterior aplicação do mineral regenerado para remoção de 'NH IND.4'POT.+'. O processo resultou na obtenção de minerais com capacidades próximas às atingidas por amostras de zeólitas virgens. Além de restaurar grande parte da capacidade inicial de troca iônica do mineral (87% da capacidade inicial), o processo de regeneração biológica permite a obtenção de efluente com altas concentrações de nitrato (da ordem de 400 mg/L), podendo ser aproveitado para correção de solos com deficiência deste nutriente. O processo como um todo envolve conceitos de sustentabilidade aplicada aos sistemas de tratamento de efluentes, pois promove a utilização de subproduto de estações de tratamento, bem como a reutilização do mineral aplicado no processo de troca iônica. / Anaerobic processes have recently been widely adopted as core units in sewage treatment systems, due to several advantages inherent in these processes. However, this research aims at the acquisition of readily degradable carbon source by means of a primary application of anaerobic biotechnology: the sludge digestion. The use of a hidrolitic and acidogenic digester of primary sludge made it possible to achieve high concentrations for soluble COD (around 4.000 mg/L) and volatile fatty acids – VFA - (around 600 mg/L). Along with high concentrations of soluble COD and VFA, the effluent of the hidrolitic and acidogenic digester also presented undesirable significant amount of ammonium (480 mg 'NH IND.4'POT.+'/L), which was removed by the application of ion-exchange process. Natural zeolites were employed as the cation exchanger, achieving values of 8.0 mg 'NH IND.4'POT.+'/g for ammonium removal per unit mass of zeolite. The zeolite saturated with 'NH IND.4'POT.+' ions was biologically regenerated by nitrifying sludge. Regenerated zeolite samples were then reused for ammonium removal and presented removal capacities close to the ones achieved by fresh samples. The whole process (primary sludge digestion followed by ion-exchange process for ammonium removal and biological regeneration of saturated zeolite samples) comprises several sustainability concepts, as it promotes, concomitantly, primary sludge pre-digestion and the reutilization of the zeolite employed as cation exchanger for 'NH IND.4'POT.+' ions removal. In addition to partially recovering original exchange capacity (87% of original capacity), biological regeneration of saturated zeolite also produced, as effluent, highly nitrate concentrated solution (around 400 mg/L), which could be used as nitrogen source for soil enrichment.

Cinza leve de carvão, resíduo gerado em usina termelétrica, foi usada para sintetizar zeólita por meio de tratamento hidrotérmico com solução de NaOH. A cinza leve (CL-2) e a zeólita sintética (ZM-2) que foi predominantemente identificada como hidroxi-sodalita foram utilizadas como adsorventes dos corantes aniônicos índigo carmina (IC) e reativo laranja 16 (RL16) de soluções aquosas. Nos processos de adsorção, os efeitos de tempo de contato, concentração inicial de corantes, pH, massa de adsorventes e temperatura foram avaliados. O estudo cinético de adsorção demonstrou que os resultados apresentaram melhor ajuste ao modelo de pseudo-segunda ordem e que adsorção de superfície e difusão intrapartícula participaram no mecanismo de adsorção. Os parâmetros termodinâmicos demonstraram que a adsorção foi espontânea em todos os processos de adsorção. Os processos de adsorção foram de natureza endotérmica para todos os sistemas, com exceção do sistema IC/ZM-2, em que foi exotérmico. Os dados de entropia mostraram a ocorrência do aumento da desordem na interface sólido/solução durante a adsorção em todos os sistemas, exceto novamente no IC/ZM-2, no qual se verificou a diminuição da desordem na interface. As isotermas de adsorção ajustaram-se à equação linear de Langmuir. As capacidades máximas de adsorção foram 1,48 mg/g para o sistema IC/CL-2; 1,13 mg/g para IC/ZM-2; 0,96 mg/g para RL16/CL-2 e 1,14 mg/g para RL16/ZM-2 à temperatura ambiente. O estudo de dessorção realizado com água, com soluções aquosas ácidas e com solução aquosa básica demonstrou ser ineficiente tanto para a recuperação dos corantes quanto para a regeneração dos adsorventes. / Coal fly ash, a waste generated in coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. The fly ash (CL-2) and this synthesized zeolite (ZM-2) that was characterized as hydroxy-sodalite were used as adsorbents for anionic dyes indigo carmine (IC), and reactive orange 16 (RO16) from aqueous solutions. Effects of contact time, initial dye concentration, pH, adsorbent mass, and temperature were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism. The thermodynamics parameters demonstrated that the adsorption was spontaneous for all adsorption processes. The enthalpy data confirmed the endothermic nature for all adsorption processes except for IC/ZM-2 system which was exothermic. The entropy data showed an increased disorder at the solid/solution interface during the adsorption for all systems except for IC/ZM-2 whose negative entropy value indicated a decreased disorder at the interface. The adsorption isotherms were closely fitted to the Langmuir linear equation. The maximum adsorption capacities were 1.48 mg/g for the IC/CL-2 system; 1.13 mg/g for IC/ZM-2; 0.96 mg/g for RO16/CL-2, and 1.14 mg/g for RO16/ZM-2 at room temperature. The desorption study carried out with water, with acid aqueous solutions, and with an alkali aqueous solution showed to be inefficient both for recovering the dyes and regenerating the adsorbents.

In der vorliegenden Arbeit sollte untersucht werden, inwieweit man quantenchemische Methoden zur Berechnung von NMR-chemischen Verschiebungen auf Festkoerper anwenden kann. Es wurden die 29Si- und 17O-NMR-chemischen Verschiebungen von Zeolithen und dichten SiO2-Modifikationen berechnet. Dabei wurden zahlreiche Untersuchungen zur Abhaengigkeit der chemischen Verschiebung von der Festkoerperstruktur und von verschiedenen Parametern bei der Berechnung (Basissatz, Methode) durchgefuehrt. Die Qualitaet der Simulationen wurde an experimentellen Daten gemessen. Es konnte gezeigt werden, dass mit einer geeigneten Kombination von Rechenparametern eine Simulation von NMR-Spektren moeglich ist, die das Experimente sehr genau wiedergibt. / The following work studies, how far quantum chemical methods to compute NMR chemical shifts are applicable to solids. The 29Si and 17O NMR spectra of several zeolites and silicates were investigated. Numerous investigations were carried out to examine the dependence of the chemic al shift on the used zeolite structures and computing methods. The quality of the results was judged on experimental data. It could be shown, that a calculation of NMR spectra with a suitable combination of simulation parameters leads to results which reproduce very well the experimental results.

[pt] A síntese de Fischer-Tropsch converte o gás de síntese (H2 + CO), em uma variedade complexa de hidrocarbonetos na presença de um catalisador (principalmente Co/Al2O3). Neste trabalho foram estudados catalisadores de Co e o Fe (1 e 5% em massa), incorporados aos suportes: zeólitas KL, HL 0,1M e HL 1,0 M, além da peneira molecular mesoporosa MCM- 41, pelo método de impregnação úmida incipiente, para a reação de Fischer- Tropsch. As amostras preparadas foram analisadas pelas técnicas de: Espectometria de Emissão Atômica de Plasma Acoplado Induzido, Adsorção Física de N2 pelo método BET, Difração de Raios-X, Redução com Temperatura Programada, Microscopia Eletrônica de Transmissão (MET), Quimissorção de Hidrogênio e Espectroscopia no Infravermelho de piridina adsorvida. Além disso, as amostras foram avaliadas em um reator de leito fixo na reação de Fischer-Tropsch. Para as amostras de ferro, com mesmo teor e suportes diferentes, pode-se observar que a amostra suportada na MCM-41 apresentou um grau de redução menor. Entre as amostras de ferro suportadas na KL, a 5% Fe/KL apresentou maior grau de redução e foi observado por microscopia eletrônica de transmissão (MET) que as partículas de ferro apresentaram diâmetro em torno de 6 nm. Para as amostras de cobalto foi observado que a temperatura de redução da amostra suportada na MCM-41 foi mais alta. A amostra 5% Co/KL apresentou um maior grau de redução. Foi possível observar por MET que as partículas de cobalto apresentaram diâmetro variando entre 8 e 20 nm. Verificou-se que o catalisador com maior teor de ferro proporcionou uma maior conversão de CO, tendo sido a distribuição de produtos deslocada para as frações mais leves. Comparando os catalisadores de ferro suportados na zeólita KL e na MCM-41 pode-se concluir que as conversões são da mesma ordem de grandeza. Foi observado que o ferro foi mais ativo que o cobalto em termos de conversão do CO, sendo que o cobalto promoveu a formação de uma maior quantidade de produtos na faixa de diesel, assim como uma menor quantidade de leves. / [en] The Fischer- Tropsch synthesis converts the synthesis gas (H2 + CO), in a complex variety of hydrocarbons, using a catalyst (Co/Al2O3 normally) were introduced to the used supports by the wetness incipient impregnation. The samples were analyzed by several techniques such as: plasma- emission spectrometry (ICP- EAS), N2 physical adsorption by BET method, X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electronic microscopy (TEM), hydrogen chemisorption and Infrared Spectroscopy of adsorbed pyridine. The catalysts were evaluated using a fixed bed reactor in the Fischer-Tropsch synthesis. For the iron samples, with the same metal content and different supports, it was observed that the MCM-41 sample presented the lowest reduction level. Among the iron samples supported in KL zeolite, the 5% Fe/KL sample presented the largest reduction level. It was observed by transmission electronic microscopy that the iron particles diameter measured around 6 nm. For the cobalt samples, it was observed that the reduction temperature of the MCM-41 supported was the highest one. The 5% Co/KL sample presented the largest reduction level. It was observed by TEM that the cobalt particles presented diameters in the range from 8 to 20 nm. It was verified that the catalyst with the largest iron percentage promoved the highest CO conversion. The products distribuition was shifted to light fractions. It was observed similar conversions to iron catalysts supported in the KL zeolite and in the MCM- 41 mesoporous molecular sieve. The iron catalysts were more active than the cobalt ones in the CO conversion, but tha cobalt catalysts promoted a higher content of diesel fraction and lesser light fractions.

Made available in DSpace on 2014-12-17T15:42:09Z (GMT). No. of bitstreams: 1 AnaCRM_TESE.pdf: 3734770 bytes, checksum: 59720290841ee6807d60b116e21f2090 (MD5) Previous issue date: 2010-12-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Microporous materials zeolite type Beta and mesoporous type MCM-41 and AlMCM-41 were synthesized hydrothermally and characterized by methods of X-ray diffraction, Fourier transform infrared, scanning electron microscopy, surface acidity, nitrogen adsorption, thermal analysis TG / DTG. Also we performed a kinetic study of sunflower oil on micro and mesoporous catalysts. The microporous material zeolite beta showed a lower crystallinity due to the existence of smaller crystals and a larger number of structural defects. As for the mesoporous materials MCM-41 and AlMCM-41 samples showed formation of hexagonal one-dimensional structure. The study of kinetic behavior of sunflower oil with zeolite beta catalysts, AlMCM-41 and MCM-41 showed a lower activation energy in front of the energy of pure sunflower oil, mainly zeolite beta. In the thermal cracking and thermocatalytic of sunflower oil were obtained two liquid fractions containing an aqueous phase and another organic - organic liquid fraction (FLO). The FLO first collected in both the thermal cracking as the thermocatalytic, showed very high level of acidity, performed characterizations of physicochemical properties of the second fraction in accordance with the specifications of the ANP. The second FLO thermocatalytic collected in cracking of sunflower oil presented results in the range of diesel oil, introducing himself as a promising alternative for use as biofuel liquid similar to diesel, either instead or mixed with it / Os materiais microporosos tipo ze?lita beta e mesoporosos tipo MCM-41 e AlMCM-41 foram sintetizados hidrotermicamente e caracterizados pelos m?todos de difra??o de raios X, infravermelho por transformada de Fourier, microscopia eletr?nica de varredura, acidez superficial, adsor??o de nitrog?nio, an?lise t?rmica via TG/DTG. Ainda foi realizado um estudo do comportamento cin?tico termogravim?trico do ?leo de girassol sobre os catalisadores micro e mesoporosos citados. Usando curvas integrais da TG e o m?todo cin?tico de Vyazovkin, foram estimados a energia de ativa??o, as taxas de convers?o e o tempo degrada??o do ?leo em fun??o da temperatura. O material microporoso ze?lita beta apresentou menor cristalinidade, devido ? exist?ncia de cristais menores e um maior n?mero de defeitos estruturais. Quanto aos materiais mesoporosos MCM-41 e AlMCM-41 apresentaram amostras com forma??o da estrutura hexagonal unidimensional. O estudo do comportamento cin?tico do ?leo de girassol com os catalisadores ze?lita beta, AlMCM-41 e MCM-41, mostrou uma menor energia de ativa??o frente a energia do ?leo de girassol puro, principalmente a ze?lita beta. No craqueamento t?rmico e termocatal?tico do ?leo de girassol foram obtidas duas fra??es l?quidas contendo uma fase aquosa e outra org?nica fra??o l?quida org?nica (FLO). A primeira FLO coletada, tanto no craqueamento t?rmico quanto no termocatal?tico, apresentou ?ndice de acidez muito elevado, sendo assim foi realizada as caracteriza??es das propriedades f?sico-qu?micas da segunda fra??o de acordo com as especifica??es da ANP. As segundas FLOs coletadas no craqueamento termocatal?tico do ?leo de girassol apresentaram resultados na faixa adequada ao diesel de petr?leo, apresentando-se como uma alternativa promissora para utiliza??o como biocombust?vel l?quido similar ao diesel, seja em substitui??o, ou misturado a este

Made available in DSpace on 2014-12-17T15:42:28Z (GMT). No. of bitstreams: 1 ViniciusPSC_TESE.pdf: 2718372 bytes, checksum: e1cb932e65d078fa3eeb0af3e2b2ce2a (MD5) Previous issue date: 2013-11-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A catalyst of great interest to the scientific community tries to unite the structure of ordered pore diameter from mesoporous materials with the properties of stability and acid activity to microporous zeolites. Thus a large number of materials was developed in the past decades, which although being reported as zeolites intrinsically they fail to comply with some relevant characteristics to zeolites, and recently were named zeolitic materials of high accessibility. Among the various synthesis strategies employed, the present research approaches the synthesis methods of crystallization of silanized protozeolitic units and the method of protozeolitic units molded around surfactant micelles, in order for get materials defined as hierarchical zeolites and micro-mesoporous hybrid materials, respectively. As goal BEA/MCM-41 hybrid catalysts with bimodal pore structure formed by nuclei of zeolite Beta and cationic surfactant cetyltrimethylammonium were developed. As also was successfully synthesized the hierarchical Beta zeolite having a secondary porosity, in addition to the typical and uniform zeolite micropores. Both catalysts were applied in reactions of catalytic cracking of high density polyethylene (HDPE), to evaluate its properties in catalytic activity, aiming at the recycling of waste plastics to obtain high value-added raw materials and fuels. The BEA/MCM-41 hybrid materials with 0 days of pre-crystallization did not show enough properties for use in catalytic cracking reactions, but they showed superior catalytic properties compared to those ordered mesoporous materials of Al-MCM-41 type. The structure of Beta zeolite with hierarchical porosity leads the accessibility of HDPE bulky molecules to active centers, due to high external area. And provides higher conversion to hydrocarbons in the gasoline range, especially olefins which have great interest in the petrochemical industry / Um catalisador de grande interesse na comunidade cient?fica tenta unir a estrutura de di?metro de poros ordenados dos materiais mesoporosos e as propriedades de estabilidade e atividade ?cida similares ?s ze?litas microporosas. Assim um grande n?mero de materiais foi desenvolvido nas d?cadas passadas, onde embora sendo intrinsecamente relatadas como ze?litas deixam de cumprir com algumas caracter?sticas pertinentes ?s ze?litas, e recentemente foram nomeados de materiais zeol?ticos de elevada acessibilidade. Dentre as diversas estrat?gias de s?ntese empregadas, o presente trabalho de pesquisa abordou os m?todos de s?ntese da cristaliza??o de unidades protozeol?ticas silanizadas e o m?todo de unidades protozeol?ticas moldadas ao redor de micelas de surfactantes, para obter materiais definidos como ze?litas hierarquizadas e materiais h?bridos micro-mesoporoso, respectivamente. Como meta foram desenvolvidos catalisadores h?bridos BEA/MCM-41 com estrutura porosa bimodal formada por n?cleos da ze?lita Beta e surfactante cati?nico cetiltrimetilam?nio. Como tamb?m, sintetizados com sucesso a ze?lita Beta hierarquizada que possui uma porosidade secund?ria, em adi??o aos t?picos e uniformes microporos zeol?ticos. Ambos os catalisadores foram aplicados em rea??es de craqueamento catal?tico de polietileno de alta densidade, para avalia??o de suas propriedades na atividade catal?tica, visando a reciclagem de pl?sticos residuais para obten??o de mat?rias-primas de elevado valor agregado e combust?veis. Os materiais h?bridos BEA/MCM-41 com 0 dias de pr?-cristaliza??o n?o demonstraram propriedades suficientes para aplica??o em rea??es de craqueamento catal?tico, por?m evidenciaram propriedades catal?ticas superiores comparados aos materiais mesoporosos ordenados do tipo Al-MCM-41. A estrutura da ze?lita Beta de porosidade hierarquizada favorece a acessibilidade das mol?culas volumosas do PEAD aos centros ativos, devido ? elevada ?rea externa. E proporciona maior convers?o a hidrocarbonetos na faixa da gasolina, principalmente olefinas que possuem grande interesse na ind?stria petroqu?mica

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / O objetivo desta dissertaÃÃo foi de otimizar a reaÃÃo de esterificaÃÃo para a produÃÃo de biodiesel por meio da aplicaÃÃo de tÃcnicas de adsorÃÃo. A aplicaÃÃo da adsorÃÃo teve o intuito de remover a Ãgua formada no processo, uma vez que a mesma leva a desativaÃÃo do catalisador e desloca o equilÃbrio quÃmico para reaÃÃo de hidrolise. A presenÃa de Ãgua reduz o rendimento da reaÃÃo de esterificaÃÃo, o que torna necessÃrio a utilizaÃÃo de elevadas concentraÃÃes de Ãlcool no meio reacional. Para tanto, foi realizado dois planejamentos experimentais para as reaÃÃes de esterificaÃÃo sem e com adsorÃÃo da Ãgua formada no processo. Em ambos os planejamentos foram investigadas as variÃveis temperatura, concentraÃÃo de catalisador e razÃo molar entre o Ãlcool e o Ãcido graxo. No planejamento experimental realizado para a reaÃÃo de esterificaÃÃo sem adsorÃÃo da Ãgua formada, as variÃveis concentraÃÃo de catalisador e razÃo molar entre reagentes mostraram-se estatisticamente significativas para a resposta conversÃo a 95 % de confianÃa. O melhor resultado experimental foi obtido a temperatura de 110ÂC com uma razÃo molar de 9:1 e uma concentraÃÃo de 1% de catalisador. Jà no planejamento experimental para a reaÃÃo de esterificaÃÃo com a remoÃÃo da Ãgua formada no processo, as variÃveis temperatura e a concentraÃÃo de catalisador foram significativas estatisticamente para o intervalo de confianÃa estudado (95%). Observou-se que quanto maior a temperatura e maior a concentraÃÃo de catalisador, melhor foi o resultado experimental obtido. Os experimentos cinÃticos mostraram que ao realizar a reaÃÃo de esterificaÃÃo aplicando-se tÃcnicas de adsorÃÃo, o processo tornou-se mais sensÃvel a temperatura, uma vez que o valor de energia de ativaÃÃo aparente obtido para a reaÃÃo com adsorÃÃo de Ãgua foi de 26,66 kJ/mol e para a reaÃÃo sem adsorÃÃo da Ãgua formada foi de 18,43 kJ/mol. A anÃlise via CG/MS mostrou que o acompanhamento da reaÃÃo por meio do Ãndice de acidez à satisfatÃrio para acompanhar a dinÃmica da reaÃÃo, pois os valores de conversÃo obtidos pelos dois mÃtodos foram equivalentes. Na caracterizaÃÃo do biodiesel obtido com adsorÃÃo da Ãgua formada os parÃmetros de densidade, Ãndice de iodo e viscosidade cinemÃtica atenderam as especificaÃÃes exigidas pela ANP. Ao aplicar a metodologia desenvolvida no respectivo trabalho (aplicaÃÃo de tÃcnicas de adsorÃÃo na reaÃÃo de esterificaÃÃo), os teores de Ãsteres metÃlicos obtidos foram de 98,9 % e 99,4 % para os experimentos realizados a razÃo molar de 3:1, concentraÃÃo de 1% de catalisador e temperaturas de 90 e 100ÂC, respectivamente. / This dissertation aimed to optimize the esterification reaction for biodiesel production using an adsorption reaction system. Adsorption was applied to remove the water formed in the process, because water deactivates the catalyst and shifts the equilibrium towards the hydrolysis reaction. Water reduces the yield of the esterification reaction, which requires high concentrations of alcohol in the reaction medium. Two experimental designs were carried out for the esterification reactions. One with and one without adsorbing the water formed in the process. In both designs, the variables temperature, catalyst concentration, and molar ratio between alcohol and fatty acid were investigated. Catalyst concentration and the alcohol to FFA molar ratio were the most statistically significant responses on conversion (within a 95% level of confidence) when the reaction was carried out without the adsorption system. The best result was obtained in experimental temperature of 110ÂC with a molar ratio of 9:1 and with a concentration of 1% of catalyst. Temperature and catalyst concentration were the most statistically significant variables in the experiments carried out with the adsorption system (for the confidence level of 95%). Higher temperatures and higher catalyst concentration enhanced the yield into biodiesel. The kinetic experiments showed that with the adsorption system the process became more sensitive to temperature, since the value of the apparent activation energy of the reaction was 26.66 kJ/mol and without adsorption system the apparent activation energy was 18.43 kJ/mol. GC/MS analysis showed that acidity index was very satisfactory to evaluate the yield of biodiesel., because the conversions obtained in both methods were equivalent. Density, iodine value and kinematics viscosity were within the specifications required by ANP. The methodology developed in this study resulted in conversions of oleic acid into methyl esters of 98.9% and 99.4% for the experiments performed with a molar ratio of 3:1, concentration of 1% of catalyst and temperatures of 90 and 100  C, respectively.