Orientador: Antonio Jose Gomez Cobo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T16:04:26Z (GMT). No. of bitstreams: 1 Suppino_RaphaelSoeiro_M.pdf: 3682407 bytes, checksum: 9e1b8ac86459e6d0a450f3e0aaea6013 (MD5) Previous issue date: 2010 / Resumo: A reação de hidrogenação parcial do benzeno em fase líquida tem sido estudada com vistas à obtenção do cicloexeno. Este produto de alto valor agregado pode ser utilizado para a obtenção de poliamidas, como o nylon, através de uma rota industrialmente simples e ecologicamente correta. Esta reação possui ainda uma importante aplicação na proteção ambiental, face às severas restrições à presença de compostos aromáticos nos combustíveis. O presente trabalho tem por objetivo estudar o desempenho de catalisadores de Ru/Al2O3 e Ru/CeO2 preparados através dos métodos de impregnação incipiente e impregnação úmida. Objetiva-se ainda estudar os efeitos da adição de solventes orgânicos ao meio reacional, e a utilização dos solventes na separação dos produtos da reação. Os catalisadores estudados foram preparados a partir de soluções aquosas de RuCl3.xH2O. No caso da impregnação incipiente, os sólidos foram secos a 358 K por 24 h e reduzidos sob fluxo de H2 a 573 K por 3 h. No caso da impregnação úmida, os catalisadores foram reduzidos com formaldeído a 353 K, durante a impregnação. Os suportes Al2O3 e CeO2 foram caracterizados através de titulação potenciométrica e a adsorção de N2 (método de B.E.T.) foi empregada para determinar a área específica dos sólidos. As técnicas de MEV+EDX e XPS permitiram avaliar a composição dos sólidos, enquanto que a formação da fase ativa dos catalisadores foi estudada através de TPR. O desempenho dos catalisadores foi avaliado na reação de hidrogenação parcial do benzeno em fase líquida, conduzida à pressão constante de 5 MPa de H2 e a 373 K num reator Parr do tipo slurry. A destilação extrativa dos produtos de reação foi estudada com o software Aspen Plus®. Os resultados obtidos indicam que os catalisadores de Ru/Al2O3, preparados por impregnação úmida, apresentam os melhores desempenhos catalíticos nesta reação. O rendimento de cicloexeno aumenta com a adição de solvente ao meio reacional, segundo a ordem: monoetanolamina > monoetilenoglicol > n-metil-2-pirrolidona > acetato de etila. Nas condições deste estudo o monoetilenoglicol foi o único solvente capaz de separar todos os produtos de reação com eficiência suficiente para um processo industrial / Abstract: The reaction of partial hydrogenation of benzene in liquid phase has been studied with the purpose of obtaining cyclohexene. This product of high aggregated value can be used to obtain polyamides such as nylon, through a route industrially simple and environmentally friendly. This reaction also has an important application in environmental protection, given the severe restrictions on the presence of aromatics in fuels. In this context, this work aims to study the performance of Ru/Al2O3 and Ru/CeO2 catalysts prepared by the methods of incipient impregnation and wet impregnation. Another object of the present work is to study the effects of adding organic solvents to the reaction medium, and the use of these solvents for the separation of reaction products. The catalysts were prepared from aqueous solutions of RuCl3. xH2O. In the case of incipient impregnation, the solids were dried at 358 K for 24 h and reduced under H2 flow at 573 K for 3 h. In the case of wet impregnation, the catalysts were reduced with formaldehyde at 353 K during the impregnation step. The supports Al2O3 and CeO2 were characterized by potentiometric titration and N2 adsorption (B.E.T. method) was used to determine the specific area of the solids. The techniques of SEM + EDX and XPS allowed the evaluation of the composition of solids, whereas the formation of the active phase of catalysts was studied by TPR. The performance of the catalysts was evaluated in the liquidphase partial hydrogenation of benzene carried out at H2 constant pressure of 5 MPa and 373 K in a slurry Parr reactor. The extractive distillation of the reaction products was studied with the software Aspen Plus ®. The results indicate that the catalysts Ru/Al2O3, prepared by wet impregnation, led to the best performances observed for this reaction. The yield of cyclohexene increases with the addition of solvent to the reaction medium, following the order: monoethanolamine > monoethylene glycol > n-methyl-2-pyrrolidone > ethyl acetate. In this study, monoethylene glycol was the only solvent able to efficiently separate all reaction products to obtain cyclohexene in an industrial process / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Um suporte catalítico superparamagnético nanoestruturado do tipo \"core-shell\" constituído de núcleos de magnetita revestidos por sílica, obtido por uma microemulsão reversa, foi utilizado como plataforma para o ancoramento de cátions de metais de transição que serviram como precursores na obtenção de nanopartículas de Rh(0), Pt(0) e Ru(0). A superfície do suporte de sílica foi funcionalizada com um aminosilano que permitiu um aumento significativo na quantidade dos íons metálicos sequestrada das soluções aquosas dos sais dos metais estudados. Os nanocatalisadores foram empregados em reações de hidrogenação de alquenos e cetonas em fase líquida e puderam ser facilmente separados pela aplicação de um campo magnético, que foi realizada pelo contato de um imã de neodímio com a parede do reator contendo o catalisador e o produto. A técnica de separação magnética utilizada foi capaz de isolar completamente o sólido da fase líquida, fazendo com que a utilização de outros métodos de separação como filtração e centrifugação, comumente utilizados em sistemas heterogêneos líquidos, fossem completamente dispensados. As reações de hidrogenação foram realizadas utilizando-se hidrogênio molecular como agente redutor e dispensou a utilização de agentes redutores mais drásticos como hidretos metálicos que não atendem aos princípios verdes em demanda na nossa sociedade.Todos os sólidos catalíticos desenvolvidos mostraram uma excelente possibilidade de reutilização que comprovou a estabilidade da fase ativa do catalisador, destaca-se a hidrogenação do benzeno pelo catalisador magnético de Rh(0) que pôde ser utilizado por até 20 vezes (número total de rotação igual a 10.240), sem queda significativa de atividade, com freqüência de rotação chegando a 1.167 h-1. A ocorrência de lixiviação de espécies cataliticamente ativas, que é comum em catálise heterogênea em fase líquida, não foi observada nas reações de hidrogenação estudadas. Este fato pode ser atribuído às condições reacionais brandas utilizadas, à forte aderência das nanopartículas metálicas ao suporte funcionalizado com grupos NH2 e ao eficiente método de separação magnética empregado. O procedimento de separação catalisador-produto, além de não fazer uso de métodos físicos de separação mais agressivos como uma centrifugação, permitiu o isolamento dos componentes dentro do próprio reator, descartando a exposição do catalisador à condições atmosféricas e o uso de solventes extras durante o procedimento de separação. / A core-shell superparamagnetic catalytic support comprised of magnetite nanoparticles recovered by silica was obtained using a reverse microemulsion. The material was used as a framework for anchoring transition metal cations that were used for the fabrication of Rh(0), Pt(0) and Ru(0) nanoparticles. The catalysts were employed in the hydrogenation of alkenes and ketones in liquid phase and they showed to be easily recoverable from liquid systems by placing a small neodymium magnet on the reactor wall. The magnetic separation technique provided a complete isolation of the catalyst from the liquid phase containing the products. It also made the use of other separation techniques, commonly used in achieving product separation in liquid-solid heterogeneous systems, such as filtration and centrifugation completely unnecessary. The surface of the silica support was modified with an aminosilane leading to a substantial increasing in the metal uptake from aqueous solutions of Rh, Pt and Ru salts. The hydrogenation reactions were carried out using molecular hydrogen as the reducing agent and they did not require any drastic reducers such as metal hydrides that would go against the principles of green chemistry. The stability of the catalysts were evidenced by the outstanding recycling properties. A single portion of the Rh0 catalyst for instance could be used for up to 20 times in the hydrogenation of benzene (TON: 10,240), and no significant loss in the catalytic activity was observed giving TOF values of up to 1167 h-1. Leaching of active catalytic species which is commonly encountered in heterogeneous solid-liquid systems was also absent in the hydrogenation reactions studied and this finding can be attributed to the mild reaction conditions used, the adherence of Rh, Pt and Ru nanoparticles to the magnetic support functionalized with NH2- groups and the efficient magnetic separation method used in isolating the product that dismiss the use of extra solvents and more aggressive separation methods such as a centrifugation.

Orientador: Antonio Jose Gomez Cobo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-03T03:39:51Z (GMT). No. of bitstreams: 1 Zonetti_PrisciladaCosta_M.pdf: 2908530 bytes, checksum: 3f02518e296dab156d7d4910c2097277 (MD5) Previous issue date: 2003 / Resumo: O presente trabalho tem como principal objetivo estudar a influência das condições de ativação (calcinação e redução) sobre o desempenho de catalisadores Ru/Ce02, destinados à reação de hidrogenação parcial do benzeno para a obtenção de cicloexeno. Para tanto, catalisadores de RulCe02 foram preparados pelo método da impregnação a seco, partindo-se de uma solução aquosa do precursor metálico RuCl3/xH20. Após a impregnação, os sólidos foram secos a 358K, por um período aproximadamente de 24 h. A seguir, os catalisadores foram submetidos aos tratamentos de calcinação em atmosfera de ar nas temperaturas de 473K e 673K, e/ou reduzidos em atmosfera de H2 nas temperaturas de 523K, 773K e 1023K. Os sólidos obtidos foram caracterizados por meio das técnicas de análise termogravimétrica, medida de área superficial específica (método B.E.T.), difração de raios X, quimissorção de O2, RTP e XPS. O desempenho dos catalisadores foi avaliado na reação de hidrogenação do benzeno, empregando-se um reator trifásico do tipo leito de lama ("slurry"). A reação foi conduzida sob pressão constante de 5,0 MPa de H2 e à temperatura de 373K, em meio reacional trifásico, contendo água e o aditivo TiC3. Os perfis de TPR dos catalisadores preparados sugerem que uma oxidação profunda do Ru é induzida pelo tratamento de calcinação. Os resultados das análises de XPS confirmam tal suposição, mostrando que o rutênio se encontra na forma de RU02 na amostra calcinada a 673K, enquanto que no sólido reduzido a 773K tem-se Ru no estado metálico. No entanto, a etapa de calcinação, seguida ou não de redução, é fortemente prejudicial ao desempenho catalítico, provavelmente devido à forte oxidação do rutênio, a qual pode ser promovida pelo suporte Ce02. Por sua vez, a redução direta conduz a catalisadores RulCe02 mais ativos, bem como a maiores rendimentos em cicloexeno, ao longo de toda a reação / Abstract: The aim of the present work is to study the influence of the activation conditions (calcination and reduction) on the performance of Ru/CeO2 catalysts, to the benzene partial hydrogenation reaction for cyc1ohexene production. Therefore, Ru/CeO2 catalysts were prepared by incipient wetness impregnation method, through an aquous solution of the RuChxH20 metallic precursor. After the impregnation, the solids were dried at 358K, for a period of 24h. To follow, the catalysts were submitted to the treatments of calcination in air atmosphere at the temperatures of 473K and 673K and/or reduction in H2 atmosphere at the temperatures of 523K, 773K and 1023K. The solids obtained were characterized by means of termogravimetric analysis, measure ofn specific superficial area (BET method), x-ray diffraction, oxygen chemisorption, RTP and XPS techniques. The performance of the catalysts was evaluated in the benzene hydrogenation reaction, with a slurry three-phase reactor. The reaction was lead under constant H2 pressure of 5,OMPa at the temperature of 373K, in a three-phase reactional medium with water and TiCl3 additive. RTP profiles of the prepared catalysts suggest that a deep oxidation of the Ru is induced for the ca1cination treatment. The results of the XPS analyses confirm such assuption, showing that in the ca1cinated sample at 673K the ruthenium form is RUO2, while in the solid reduced at 773K there is Ru in its metallic state. Howerer, the ca1cination step, followed or not of reduction, is strongly harmful to the catalytic perfomance. That is probably due to strong oxidation of the ruthenium, which can be promoted by the CeO2 support. In turn, the direct reduction leads to Ru/CeO2 catalysts more actives, as well as to higher yields of cyc1ohexene, throughout all the reaction / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Doctor of Philosophy / Department of Chemical Engineering / Mary E. Rezac / Characterizing a catalytic metal surface during heterogeneous hydrogenation is an enabling area of catalysis research. Available technology, however, often requires ultra-high vacuum or other limiting conditions which prohibit in operando research. Atomic force microscopy (AFM) can provide direct observations of fluid/solid interfaces at atmospheric conditions and in real time. Tapping-mode AFM can examine chemical and physical phenomena on surfaces in addition to topography. The work here describes using phase-angle information from tapping-mode AFM to observe liquid/solid interfaces in real time during the hydrogenation of styrene. Through optimized tuning and scanning procedures, it was possible to observe the onset of hydrogenation on the surface of palladium immersed in liquid in real time and with the topographic resolution inherent to AFM. This opens new avenues for in operando research on heterogeneous catalysis, a field that is of great fundamental and industrial importance. For reference, a catalytic membrane reactor (CMR) was used to observe the hydrogenation of phenylacetylene over a palladium layer as a batch process. It was determined that with a H2 diffusion rate of 3.7·10-9 mol/s and a theoretical, calculated H2 demand of at least 2.3·10-7 mol/s, the reaction would be hydrogen starved and would not progress at a realistic timescale for observation by AFM. By instead using either ethylbenzene (EB) or styrene (St) as the liquid in a solvent-free approach and injecting a small volume of the other liquid into the system mid-scan, the effects of changes in chemistry on tip-surface interactions were observable. EB injections in both EB and St-immersed scans showed no significant change in phase angle. Injecting St into an EB-immersed scan environment, however, caused an increase in phase which remained relatively constant for the remaining duration of the scan, demonstrating for the first time that a liquid-phase hydrogenation reaction can be observed in operando through the phase shift of tapping mode AFM.

Depuis plusieurs années, notre équipe de recherche s'intéresse au développement de nouvelles familles de dendrimères utilisant des dérivés bio sourcés (pentoses, glycérol ou dérivés correspondants) dont la valorisation est un sujet de recherche d'intérêt de notre région. Ainsi, certains glyco- ou glycérodendrimères dérivés de PPIs (polypropylène imines) ont déjà été obtenus et valorisés dans plusieurs domaines. Cette thèse présente la synthèse et la caractérisation de nouveaux dendrimères dérivés du glycérol. Leur efficacité dans des processus catalytiques et d'encapsulation de molécules d'intérêt a également été démontrée.Dans un premier temps, deux nouvelles familles de dendrimères directement constitués de glycérol en tant que brique élémentaire ont été synthétisées : l'une via des réactions de « click chemistry » pour obtenir des glycéroclickdendrimères, et l'autre via des réactions successives d'allylation et d'oxydation pour obtenir des glycéroladendrimères.Dans un second temps, la fonctionnalisation de dendrimères PAMAMs par du carbonate de glycérol a été effectuée par synthèse « classique » ou assistée par micro-ondes. L'efficacité de ces glycérodendrimères ainsi obtenus (en comparaison avec des glycérodendrimères dérivés de PPIs) a été évaluée : tout d'abord, pour la stabilisation de nanoparticules de platine utilisées en catalyse d'hydrogénation de cétones α,β-insaturées en milieu aqueux, puis, pour l'encapsulation de molécules organiques d'intérêt. Pour finir, une première approche de dynamique moléculaire a été réalisée afin de déterminer les propriétés structurales de deux glycérodendrimères issus de la réaction de couplage entre le carbonate de glycérol et un PAMAM ou un PPI. / Since a few years, our team is interested in developing dendrimers using different biosourced derivatives (pentoses, glycerol or derivatives) whose valuation is a prime research topic within our region. Some glyco- or glycerodendrimers derivate from PPIs (polypropylenimines) were already obtained and valued in several domains. This thesis presents the synthesis and the characterization of new glycerol-based dendrimers. Their efficiency in catalytic processes or for the encapsulation of molecules of interest was also demonstrated. First, two new families of dendrimers directly constituted of glycerol as building block, were synthesized: one via click chemistry reactions to obtain glyceroclickdendrimers, and the other, via successive reactions of allylation and oxidation to obtain glyceroladendrimers. Secondly, the functionalization of PAMAM's dendrimers with glycerol carbonate was carried out either by “classical” or microwave assisted synthesis. The efficiency of these glycerodendrimers (in comparison with PPI-based glycerodendrimers) was evaluated: firstly, for the stabilization of platinum nanoparticles used for the catalysis of hydrogenation of α,β-unsaturated ketones in aqueous media, and then, for the encapsulation of organic molecules of interest. Finally, a first molecular dynamics approach was realized to determine the structural properties of two glycerodendrimers from the coupling reaction between the glycerol carbonate and PAMAM or PPI.

The removal of trace amounts of acetylene in ethylene streams is a high-volume industrial process that must possess high selectivity of alkyne hydrogenation over hydrogenation of alkenes. Current technology uses metallic nanoparticles, typically palladium or platinum, for acetylene removal. However, problems arise due to the deactivation of the catalysts at high temperatures as well as low selectivities at high conversions. Pore expanded MCM-41 is synthesized via a two-step strategy in which MCM-41 was prepared via cetyltrimethylammonium bromide (CTMABr) followed by the hydrothermal treatment with N,N-dimethyldecylamine (DMDA). This material was washed with ethanol to remove DMDA, or calcined to remove both surfactants. PE-MCM-41 based materials were impregnated with palladium, gold, and palladium-gold nanoparticles. The removal of DMDA had an effect on both the conversion and selectivity, in which they were found to drop significantly. However, by using the bimetallic PdAu catalysts, higher selectivity could be achieved due to increased electron density.

Carbon dioxide levels in atmosphere are linked with a number of adverse environmental impacts including climate change. CO2 utilization is one of the available technologies to reduce CO2 emissions released into atmosphere by its conversion into value added products. Hydrogenation of CO2 into hydrocarbons (with methanol being an intermediate) can be achieved in a single-pot using bi-functional catalysis system composed of metal/metal-oxide and zeolite. In this study, activated novel indium cobalt (InCo) and zeolite beta samples (BEA) were used for the conversion of CO2 into a hydrocarbon mixture rich of iso-paraffins via methanol in a single pot. The objective was to investigate the effect of zeolite beta acidity (represented by SiO2/Al2O3 ratio) and the configuration of the reactor on the overall performance of the above mentioned bi-functional system. Three samples of zeolite beta with different SiO2/Al2O3 ratios were synthesized in-house (Beta-20, Beta-100 and Beta-300) and used along with commercial beta as methanol to hydrocarbons catalysts. XRD patterns of the synthesized samples showed that all of the obtained samples are zeolite beta with high crystallinity. Adsorption-desorption isotherms of the studied zeolites revealed micro-mesoporosity of the samples. Analysis of SEM images suggests that the particles of the studied samples are of a similar range of size (100-200 nm). Each zeolite sample was used to fill two reactor configurations: dual bed and mixed bed. Samples were tested at a temperature of 300 oC, a pressure of 50 bar and CO2:H2 ratio of 1:4 except for Beta-100 sample which was tested at a CO2:H2 ratio of 1:3. CO2 conversion is a characteristic of the methanol synthesis catalyst (InCo) and it ranged between 15% to 20% for all cases. Dimethyl ether (DME) generation in dual bed configuration was much faster and at much higher rates than in mixed bed configuration for all tested samples, indicating that mixed bed configuration is more stable for this particular system. Heavier hydrocarbons (C6 and C7) are generated in higher amounts over low acidic zeolite beta than over beta of high acidity. More acidic zeolite beta, however, was found to be more stable than beta of less acidity.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22684号 / 理博第4625号 / 新制||理||1665(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 北川 宏, 教授 吉村 一良, 教授 有賀 哲也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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Mgr. Jan Fránek 2011: The optimization the production of selected medicinal substances The diploma thesis dealt with optimization of production of fingolimod by hydrogenation. During the optimization of production, there was reduction of benzylic hydroxygroup and nitrogroup of nitrofingotriol. Reduction of two different groups caused dividing process of hydrogenation into two phases. The original intention was to optimize production only in the autoclave, but the need of using acidic catalytical medium in first phase led to dividing the production into reduction in the reactor and following catalyzed hydrogenation, already in neutral conditions, in the autoclave. The way of preparation of active substance by using an autoclave had not been explored in detail before. Evaluation of optimization is a part of results. There are also production charges on pilot plant included in results. Because the results of procedure of the pilot unit were not uniform, it was necessary to continue in optimization even after finishing the production in pilot plant. Following procedure modified according to the latest experiments was passed to the operating process.