Made available in DSpace on 2014-12-17T14:07:04Z (GMT). No. of bitstreams: 1 RosaneMPBO_TESE_partes_autorizadas.pdf: 623811 bytes, checksum: 3724885447cd319f325ecaa9845943f0 (MD5) Previous issue date: 2010-10-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, ceramic powders belonging to the system Nd2-xSrxNiO4 (x = 0, 0.4, 0.8, 1.2 and 1.6) were synthesized for their use as catalysts to syngas production partial. It was used a synthesis route, relatively new, which makes use of gelatin as organic precursor. The powders were analyzed at several temperatures in order to obtain the perovskite phase and characterized by several techniques such as thermal analysis, X-rays diffraction, Rietveld refinement method, specific surface area, scanning electron microscopy, energy dispersive spectroscopy of X-rays and temperature programmed reduction. The results obtained using these techniques confirmed the feasibility of the synthesis method employed to obtain nanosized particles. The powders were tested in differential catalytic conditions for dry reforming of methane (DRM) and partial oxidation of methane (POM), then, some systems were chosen for catalytic integrals test for (POM) indicating that the system Nd2-xSrxNiO4 for x = 0, 0.4 and 1.2 calcined at 900 ?C exhibit catalytic activity on the investigated experimental conditions in this work without showing signs of deactivation / Neste trabalho, p?s cer?micos pertencentes ao sistema Nd2-xSrxNiO4 (x = 0; 0,4; 0,8; 1,2 e 1,6) foram sintetizados visando sua utiliza??o como catalisadores para produ??o de g?s de s?ntese. Foi utilizada uma rota de s?ntese, relativamente nova, na qual faz uso de gelatina como precursor org?nico. Os p?s cer?micos sintetizados foram calcinados a v?rias temperaturas visando ? obten??o da fase perovsquita e ent?o caracterizados por v?rias t?cnicas, tais como: An?lise t?rmogravim?trica, difra??o de raios X, refinamento Rietveld, ?rea espec?fica (m?todo BET), microscopia eletr?nica de varredura, espectroscopia por dispers?o de energia de raios X e redu??o ? temperatura programada. Os resultados obtidos atrav?s destas t?cnicas confirmaram a viabilidade do m?todo de s?ntese empregado para obten??o de part?culas nanom?tricas. Os p?s foram submetidos a testes catal?ticos em condi??es diferenciais para rea??o de reforma a seco (RSM) e oxida??o parcial do metano (OPM), em seguida alguns sistemas foram escolhidos para testes catal?ticos integrais de OPM indicando que o sistema Nd2-xSrxNiO4 para x = 0, 0,4 e 1,2 calcinados a 900 ?C apresentam atividade catal?tica nas condi??es experimentais investigadas nesse trabalho sem mostrar sinais de desativa??o

Made available in DSpace on 2015-04-14T13:59:02Z (GMT). No. of bitstreams: 1 453098.pdf: 474247 bytes, checksum: 10fc86b156f20e478aff23c4bfac8b12 (MD5) Previous issue date: 2013-12-11 / The development of new materials for CO2 capture and transformation is of great importance to the use of fossil resources, preserving the environment. In this context, ionic liquids represent an environmentally friendly alternative, because they have negligible vapor pressure and can be reused. However, their CO2 absorption capacity not surpasses traditional solvents and their use as homogeneous catalysts in transformation processes of CO2 requires additional distillation process which increases the cost. Looking for enhance the application of ILs in these areas, in the present study were synthesized poly(ionic liquid)s (PILs) from polyurethane and the ionic liquid 1-butyl chloride-3-methylimidazolium (BMIM Cl), which were characterized structural (IR, NMR), thermal (DSC, TGA) and morphology (SEM); also nanoparticles of these were synthesized by multiple emulsification followed by solvent evaporation, and also characterized. These materials were evaluated in the process of CO2 capture and transformation of this gas in cyclic carbonate through cycloaddition reaction with propylene oxide. In capture assays, the PILs showed highest sorption capacity of CO2 than the IL precursor (BMIM Cl) and PU departure; the NP obtained for these, although they were obtained aggregated, showed faster rates of sorption. In the carbonation reactions PILs presented propylene oxide conversion values approximate to those obtained for BMIM Cl, moreover were easily separated by precipitation-filtration. Therefore, the PILs evaluated in this study showed positive results for its use in the process of capturing and processing CO2. / O desenvolvimento de novos materiais para captura e transforma??o de CO2 ? de grande import?ncia para o aproveitamento dos recursos f?sseis, preservando o meio ambiente. Neste contexto, os l?quidos i?nicos representam uma alternativa ambientalmente amig?vel, pois estes t?m press?o de vapor desprez?vel e podem ser reutilizados. Contudo, a sua capacidade de absor??o de CO2 ainda n?o supera os solventes tradicionais e sua aplica??o como catalisadores homog?neos na transforma??o de CO2 requer processos adicionais de destila??o o qual encarece o processo. Buscando potencializar a aplica??o dos LIs nestas ?reas, no presente trabalho foram sintetizados poli(l?quidos i?nicos) (PLIs), a partir de poliuretano e o liquido i?nico cloreto de 1-butil-3-metil imidazolio (BMIM Cl), os quais foram caracterizados estrutural (IV, RMN), t?rmica (DSC, TGA) e morfologicamente (MEV); al?m disso, foram sintetizadas nanopart?culas destes PLIs, mediante emulsifica??o m?ltipla seguida de evapora??o de solvente, e caracterizadas igualmente. Estes materiais foram avaliados nos processos de captura de CO2 e transforma??o deste g?s em carbonato c?clico, mediante rea??o de cicloadi??o com oxido de propileno. Nos ensaios de captura, os poli(l?quidos i?nicos) apresentaram maior capacidade de sor??o de CO2 do que o LI precursor (BMIM Cl) e o PU de partida; as NP obtidas destes, embora tenham sido obtidas agregadas, apresentaram taxas de sor??o mais r?pidas. Nas rea??es de carbonata??o os PLIs apresentaram valores de convers?o de oxido de propileno aproximados aos obtidos para o BMIM Cl, alem disso foram facilmente separados por precipita??o-filtra??o. Por tanto, os PLIs avaliados neste estudo apresentaram resultados favor?veis para seu uso nos processos de captura e transforma??o de CO2.

Made available in DSpace on 2015-04-14T13:59:14Z (GMT). No. of bitstreams: 1 466515.pdf: 2196084 bytes, checksum: 5f6d7c75b5387e4577daf1a339454354 (MD5) Previous issue date: 2014-03-31 / Gas hydrates are solids formed by crystal structures similar to ice, which may form when the water is in contact with low weight molecular gases (such as H2S, CO2, NH3 and/or light hydrocarbons), under certain conditions of temperature and pressure. Several studies show that gas hydrates may be a wide source of natural gas in the future, especially considering the fact that oil production tends to decline due to the high cost involved, which makes the interest in alternative sources, such as natural gas derived from unconventional sources, grow. However, in order to make gas hydrate exploitation possible, it's necessary to know how they are formed and what are the conditions that provide stability and dissociation. Different apparatus have been used to obtain gas hydrate. In this scenario, the present paper aims to use a unique system called Pilot Plant Synthesis of Gas Hydrates to synthesize different hydrates, with different compositions, in various reaction conditions. It is noticed that the present study was based on the synthesis of hydrates with its precipitation of at larger scales. The methane hydrates were characterized by X-ray diffractometer, Gas Chromatograph and Gas Chromatography Isotope Ratio Mass Spectrometer. / Os hidratos de g?s s?o s?lidos formados por estruturas cristalinas, semelhantes ao gelo, que podem se formar quando h? ?gua em contato com gases de baixo peso molecular (tais como: H2S, CO2, NH3 e/ou hidrocarbonetos leves), sob determinadas condi??es de press?o e temperatura. Diversos estudos mostram que os hidratos de g?s poder?o ser uma vasta fonte de g?s natural considerando, especialmente, o fato da produ??o de petr?leo estar propensa a diminuir, em raz?o do elevado custo desta atividade, o que faz crescer o interesse por outras fontes, como o g?s natural derivado de fontes n?o convencionais. Entretanto, para que a explora??o do g?s do hidrato seja poss?vel, faz-se necess?rio conhecer a maneira como estes s?o formados e quais s?o as condi??es que propiciam a sua estabilidade e dissocia??o. Diferentes aparatos j? foram utilizados para a obten??o dos hidratos de g?s at? os dias de hoje. Neste cen?rio, o presente trabalho se prop?e a utilizar um sistema in?dito (denominado Planta Piloto de S?ntese de Hidratos de G?s) para sintetizar diferentes hidratos de g?s, com diferentes composi??es dentro de variadas condi??es reacionais. Salienta-se que este estudo foi baseado na s?ntese de hidratos de metano, com a precipita??o dos mesmos em maiores escalas. Os hidratos de metano foram caracterizados atrav?s da difratometria de raios-X, na cromatografia gasosa e cromatografia gasosa acoplada ? Espectrometria de Massa de raz?o isot?pica.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:08:55Z No. of bitstreams: 1 DIS_DANIELI_BORN_GUERRA_COMPLETO.pdf: 6232841 bytes, checksum: 6cce70184509f5204d1a506262b6559b (MD5) / Made available in DSpace on 2017-06-30T18:08:55Z (GMT). No. of bitstreams: 1 DIS_DANIELI_BORN_GUERRA_COMPLETO.pdf: 6232841 bytes, checksum: 6cce70184509f5204d1a506262b6559b (MD5) Previous issue date: 2017-03-30 / In this work, we investigated the effects of ion implantation and irradiation on the structure and morphology of Bi e Bi2+xTe3-y nanowires exposed to Au and Cu beams with energies ranging from 30 keV to 1 MeV. The wires were grown by template-assisted electrodeposition with diameters of 30, 100 and 130 nm. Bi-rich compounds are obtained at -200 mV using an Ag/AgCl reference electrode. Almost stoichiometric nanowires are obtained at 0 mV vs Ag/AgCl. XRD measurements revealed a polycrystalline structure, with a strong peak in the planes (0 1 5) for Bi-rich wires and a preferential diffraction (1 1 0) for the Te-rich compounds. The dark field TEM analyzes indicates an influence of the nanochannel geometry on the grain size of nanowires. The irradiation parameters were selected based on simulations from SRIM and Iradina programs. The irradiations were performed with the wires deposited in transmission electron microscopy (TEM) grids. The irradiated nanowires presented different morphologies, depending on the irradiation conditions, sometimes presenting a ?wavy? morphology. Cu irradiations did not cause significant modifications in the crystalline structure of the samples. For samples irradiated with Au, TEM analysis revealed an amorphized structure, containing an embedded dispersion of small spherical crystallites. Besides, a distribution of nanoparticles dispersed in the vicinity of the irradiated wires was seen on the TEM grids, formed most probably from material redepositing due to sputtering. The 400 keV and 1 MeV Au ions have comparable stopping powers. However, for irradiations at 1 MeV the material underwent a greater erosion process, resulting in the formation of holes through the wires. / Neste trabalho, investigamos os efeitos de implanta??o e irradia??o i?nica na estrutura e morfologia de nanofios de Bi e Bi2+xTe3-y expostos a feixes de Au e Cu com energias que variam de 30 keV a 1 MeV. Os fios foram crescidos por eletrodeposi??o no modo template assisted com di?metros de 30, 100 e 130 nm. Compostos ricos em Bi s?o obtidos a -200 mV em rela??o a um el?trodo de refer?ncia de Ag/AgCl. Nanofios quase estequiom?tricos s?o obtidos a 0 mV vs. Ag/AgCl. As medidas DRX revelaram uma estrutura policristalina, com um forte pico dos planos (0 1 5) para fios ricos em Bi e uma difra??o preferencial (1 1 0) para os compostos ricos em Te. As an?lises de campo escuro de TEM indicam uma influ?ncia da geometria dos nanocanais no tamanho de gr?o do nanofio. Os par?metros de irradia??o foram selecionados com base em simula??es dos programas SRIM e Iradina. As irradia??es foram realizadas com os fios depositados em grades de microscopia eletr?nica de transmiss?o (TEM). Os nanofios irradiados apresentaram diferentes morfologias, dependendo das condi??es de irradia??o, podendo adquirir uma superf?cie "ondulada". As irradia??es realizadas com feixes de Cu n?o causaram modifica??es significativas na estrutura cristalina das amostras. Para as amostras irradiadas com Au. Observa??es de TEM revelam uma dispers?o de pequenos cristalitos esf?ricos embutidos em uma estrutura amorfizada. Al?m disso, uma distribui??o de nanopart?culas na vizinhan?a dos fios irradiados tamb?m foi observada nas grades TEM, provavelmente formada por redeposi??o de material devido ao sputtering. Ainda que os ?ons de Au de 400 keV e 1 MeV depositem valores de energia compar?veis, para irradia??es a 1 MeV o material sofreu um processo de eros?o maior, resultando na forma??o de furos atrav?s dos fios.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-07-26T14:25:23Z No. of bitstreams: 1 DIS_MARCOS_VINICIUS_FORTES_ALBA_COMPLETO.pdf: 1333852 bytes, checksum: c687fbcabc052faa5ed3567c986640e9 (MD5) / Made available in DSpace on 2016-07-26T14:25:23Z (GMT). No. of bitstreams: 1 DIS_MARCOS_VINICIUS_FORTES_ALBA_COMPLETO.pdf: 1333852 bytes, checksum: c687fbcabc052faa5ed3567c986640e9 (MD5) Previous issue date: 2016-02-15 / Nuclear Medicine enables, among other things, the visualization, characterization and quantification of biochemical processes, metabolism, biomarkers and receptors in vivo by molecular imaging. One of the methods of functional imaging available in this area is Positron Emission Tomography (PET), which depends on the administration of a radiopharmaceutical in the studied organism. One disease that can be studied by PET scan is multiple sclerosis (MS) through the access to the TSPO (Translocator protein) receptors density. The radiopharmaceutical [11C]-(R) -PK11195 has high affinity and selectivity for these receptors, which are increased in activated microglia cells in the case of MS. Therefore, the objective of this study was to develop and to validate the production process (synthesis, purification and quality control) of the radiotracer [11C]-(R)-PK11195 in the Radiopharmaceutical Production Center of the Brain Institute of Rio Grande do Sul (BraIns), allowing performing PET scans for the study of MS. The radioisotope was produced in the 16 MeV PETrace cyclotron (GE Healthcare) as [11C]CO2 via the nuclear reaction 14N (p, ?)11C after the bombardment of a gaseous target containing N2 and 0.5% of O2 with protons. The production was performed in the equipment TRACERlab FX-C Pro (GE Healthcare) to meet the requirements of Good Manufacturing Practices (GMP). The radiopharmaceutical quality control was carried out at the BraIns Quality Control Laboratory and the final product was tested for Identity and Radionuclidic Purity, Radiochemical Purity, Specific Activity, Residual Solvents, pH, Sterility, the Filtration Membrane Integrity and Bacterial Endotoxins. The synthesis was performed through the methylation of the precursor (R)-[N-desmethyl]PK11195 using [11C]CH3I (methyl iodide labeled with carbon-11) under the defined optimal conditions: 400 uL of dimethyl sulfoxide (DMSO), approximately 1 mg of precursor, approximately 10 mg of potassium hydroxide (KOH) at 40 ?C for 1 minute. The reaction mixture was then neutralized with 1 mol.L-1 hydrochloric acid and diluted with mobile phase (76% acetonitrile and 24% Milli-Q water). The diluted mixture was injected into a semi-preparative HPLC system for purification. Solid phase extraction (through Sep-Pak C18 cartridges - Waters) was used to remove the solvent. Product elution and formulation was conducted with 0.7 mL of ethanol and 6.3 ml of 0.9% saline (sterile and pyrogen free). Sterilization was performed by filtration on a 0.22 ?m pore membrane and, as well as the filling process, was carried out under laminar flow. The process steps could be optimized and fitted to the equipments and laboratories structure. Radiochemical yield of the process in relation to the [11C ]CH3I start activity was 15.5 ? 2.4 % ( 7471.5 ? 1283.8 MBq ; n = 39 ) . All batches were approved according to the specifications defined and tested in the quality control, reaching Radiochemical Purity levels greater than 99% and a Specific Activity of 39.7 ? 11.1 GBq / micromol , 10 minutes before the injection. All analytical methods were validated and met the requirements established by current regulations. Three consecutive batches were produced and approved by the quality control, so the process could be considered validated. The developed process was suitable for production of adequate doses of the radiopharmaceutical [11C]-(R)-PK11195 for clinical use at BraIns. The production of the radiopharmaceutical labeled with carbon-11 at the institute provides an additional tool for improving health services in the country and to improve the life quality of the patients. / A medicina nuclear possibilita, dentre outras coisas, a visualiza??o, caracteriza??o e quantifica??o de processos bioqu?micos, metab?licos, biomarcadores e receptores, in vivo, atrav?s da imagem molecular. Dentre as modalidades de imagem funcional dispon?veis nesta ?rea est? a Tomografia por Emiss?o de P?sitrons (PET), que depende da administra??o de um radiof?rmaco no organismo estudado. Uma das doen?as pass?veis de estudo atrav?s do exame PET ? a esclerose m?ltipla (EM), atrav?s do acesso ? densidade de receptores TSPO (Prote?na Translocadora). O radiof?rmaco [11C]-(R)-PK11195 possui alta afinidade e seletividade por estes receptores, aumentados nas c?lulas ativadas da micr?glia nos casos de EM. Portanto, o objetivo deste trabalho foi desenvolver e validar o processo produtivo (s?ntese, purifica??o e controle de qualidade) do radiof?rmaco [11C]-(R)-PK11195 no Centro de Produ??o de Radiof?rmacos do Instituto do C?rebro do RS (InsCer), possibilitando a realiza??o de exames PET para o estudo da EM. O radiois?topo foi produzido no C?clotron PETrace 16 MeV (GE Healthcare) na forma de [11C]CO2 atrav?s da rea??o nuclear 14N(p,?)11C, por meio do bombardeamento com pr?tons do alvo gasoso contento N2 e 0,5 % de O2. A produ??o foi realizada no equipamento TRACERlab FX-C pro (GE Healthcare) atendendo ?s exig?ncias de Boas Pr?ticas de Fabrica??o (BPF). O controle de qualidade do radiof?rmaco foi realizado no Laborat?rio de Controle de Qualidade do InsCer e o produto acabado foi submetido ?s an?lises de Identidade e Pureza Radionucl?dica, Pureza Radioqu?mica, Atividade Espec?fica, Solventes Residuais, pH, Esterilidade, Integridade da Membrana Filtrante e Teor de Endotoxinas. A s?ntese foi realizada atrav?s da metila??o do precursor (R)-[N-desmetil]PK11195 utilizando o [11C]CH3I (iodeto de metila marcado com carbono-11) sob as condi??es ?timas definidas: 400 ?L de dimetilsulf?xido (DMSO), aproximadamente 1 mg de precursor, aproximadamente 10 mg de hidr?xido de pot?ssio (KOH), a 40 ?C durante 1 minuto. A mistura de rea??o foi posteriormente neutralizada com ?cido clor?drico 1 mol.L-1 e dilu?da com fase m?vel (acetonitrila 76 % e ?gua Milli-Q 24 %). A mistura dilu?da foi injetada em sistema CLAE semi-preparativo para purifica??o. Extra??o de fase s?lida (atrav?s de cartuchos SepPak C18 ? Waters) foi utilizada para remo??o do solvente. A elui??o e formula??o do produto foi realizada com 0,7 mL de etanol e 6,3 mL de solu??o salina 0,9 % (est?ril e livre de pirog?nios). A esteriliza??o foi realizada atrav?s de filtra??o em membrana de poro de 0,22 ?m e, assim como o envase, ocorreu em fluxo laminar. As etapas do processo foram otimizadas e adequadas aos equipamentos e estrutura dos laborat?rios. O rendimento radioqu?mico do processo em rela??o ? atividade de [11C]CH3I de partida foi de 15,5?2,4 % (7471,5?1283,8 MBq; n=39). Todos os lotes produzidos foram aprovados quanto ?s especifica??es definidas e testadas no controle de qualidade, atingindo Pureza Radioqu?mica maior que 99 % e uma Atividade Espec?fica de 39,7?11,1 GBq/?mol, 10 minutos antes da inje??o. Todas as metodologias anal?ticas foram validadas e atenderam os crit?rios estabelecidos pela norma vigente. Tr?s lotes consecutivos foram produzidos e aprovados no controle de qualidade e o processo p?de ser considerado validado. O processo desenvolvido se mostrou adequado para produ??o do radiof?rmaco [11C]-(R)-PK11195 em doses suficientes para realiza??o de exames em pacientes no InsCer. A produ??o do radiof?rmaco marcado com carbono-11 no instituto disponibiliza mais uma ferramenta para melhoria dos servi?os de sa?de no pa?s e para melhoria da qualidade de vida dos pacientes.

Made available in DSpace on 2014-12-17T15:41:42Z (GMT). No. of bitstreams: 1 ArilsonJNS.pdf: 3626777 bytes, checksum: 66cf6233a47c3a2d53f0c71191f75125 (MD5) Previous issue date: 2007-11-12 / Heterogeneous catalysts such as aluminophosphate and silicoaluminophosphate, molecular sieves with AEL of ALPO-11 and SAPO-11, were synthesized by the hydrothermal method with the following molar composition: 2.9 Al +3.2 P + 3.5 DIPA +32.5 H20 (ALPO-11); 2.9 Al +3.2 P + 0.5 Si + 3.5 DIPA +32.5 H20 (SAPO-11) starting from silica (only in the SAPO-11), pseudoboehmite, orthophosphoric acid (85%) and water, in the presence of a di-isopropylamine organic template. The crystallization process occurred when the reactive hydrogel was charged into a vessel and autoclaved at 170?C for a period of 48 hours under autogeneous pressure. The obtained materials were washed, dried and calcined to remove the molecular sieves of DIPA. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), thermo gravimetric differential thermal analysis (TG/DTA) and nitrogen adsorption (BET). The acidic properties were determined using adsorption of n-butylamine followed by programmed thermodessorption. This method revealed that ALPO-11 has weaker acid sites due to structural defects, while SAPO-11 shows an acidity that ranges from weak to moderate. However, a small quantity of strong acid sites could be detected there. The deactivation of the catalysts was conducted by the cracking of the n-hexane in a fixed bed continuous flow microrreator coupled on line to a gas chromatograph. The main products obtained were: ethane, propane, isobutene, n-butane, n-pentane and isopentane. The Vyazovkin (model-free) kinetics method was used to determine the regeneration and removal of the organic template / Foram sintetizados catalisadores heterog?neos do tipo aluminofosfatos e silicoaluminofosfatos pelo m?todo hidrot?rmico a partir de alumina hidratada (pseudobohemita), ?cido fosf?rico 85%, s?lica gel, ?gua e diisopropilamina (DIPA) usada como direcionador estrutural org?nico. Estes reagentes foram misturados a fim de obter g?is com as seguintes composi??es: 2.9 Al +3.2 P + 3.5 DIPA +32.5 H20; para ALPO e 2.9 Al +3.2 P + 0.5 Si + 3.5 DIPA +32.5 H20 para SAPO. O processo de cristaliza??o ocorreu ? temperatura de 170 0C durante 48 h, quando foi poss?vel obter as fases puras para ALPO 11 e SAPO 11. Os materiais obtidos foram lavados com ?gua deionizada, secos e calcinados para remover as mol?culas do direcionador. Os materiais foram caracterizados por difra??o de raios-X (DRX), microscopia eletr?nica de varredura (MEV), espectroscopia de absor??o na regi?o do infravermelho (FTIR), an?lise t?rmica via TG/DTG e adsor??o de nitrog?nio (BET). As propriedades ?cidas foram determinadas usando adsor??o de n-butilamina seguida de termodessor??o programada. Este m?todo revelou que o ALPO 11 possuem s?tios ?cidos fracos devido a defeitos estruturais, j? a amostra SAPO 11 apresenta uma acidez tipicamente fraca a moderada. Entretanto, uma pequena quantidade de s?tios ?cidos fortes foi detectada. A desativa??o dos catalisadores foi conduzida pela rea??o de craqueamento do n-hexano em um microrreator catal?tico de leito fixo com fluxo cont?nuo acoplado em linha com um cromat?grafo a g?s. Como principais produtos foram obtidos: etano, propano, isobutano, n-butano,e n-pentano, isopentano. Para determinar a regenera??o e a remo??o do direcionador org?nico foi aplicado o m?todo cin?tico Vyazovkin (Model Free)

Made available in DSpace on 2014-12-17T14:06:51Z (GMT). No. of bitstreams: 1 ThiagoC.pdf: 1828528 bytes, checksum: f789d02379757a5c26566b00a092e4c1 (MD5) Previous issue date: 2009-02-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / heterogeneous catalyst such as a silicoaluminophosphate, molecular sieve with AEL (Aluminophosphate eleven) structure such as SAPO-11, was synthesized through the hydrothermal method starting from silica, pseudoboehmite, orthophosphoric acid (85%) and water, in the presence of a di-isopropylamine organic template. For the preparation of SAPO-11 in a dry basis it was used as reactants: DIPA; H3PO4; SiO4; Pseudoboehmite and distilled water. The crystallization process occurred when the reactive hydrogel was charged into a vessel and autoclaved at 200?C for a period of 72 hours under autogeneous pressure. The obtained material was washed, dried and calcined to remove the molecular sieves of DIPA. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), nitrogen adsorption (BET) and thermal analysis (TG/DTG). The acidic properties were determined using adsorption of nbutylamine followed by programmed thermodessorption. This method revealed that SAPO-11 shows an acidity that ranges from weak to moderate. However, a small quantity of strong acid sites could be detected there. The deactivation of the catalysts was conducted by artificial coking followed by the cracking of the n-hexane in a fixed bed with a continuous flow micro-reactor coupled on line to a gas chromatograph. The main products obtained were: ethane, propane, isobutene, n-butane, n-pentane and isopentane. The Vyazovkin (model-free) kinetics method was used to determine the regeneration and removal of the coke / Um catalisador heterog?neo do tipo silicoaluminofosfato, peneira molecular com estrutura AEL (Aluminophosphate eleven), como o SAPO-11, foi sintetizado pelo m?todo hidrot?rmico a partir de alumina hidratada (pseudobohemita), ?cido fosf?rico 85%, s?lica gel, ?gua e di-isopropilamina (DIPA) usada como direcionador estrutural org?nico. Para a prepara??o de SAPO-11 em base seca foram necess?rias como reagentes: DIPA; H3PO4:; SiO4; Pseudoboehmita e ?gua destilada. O processo de cristaliza??o ocorreu ? temperatura de 200 0C durante 72 h, quando foi poss?vel obter a fase pura para o SAPO-11. O material obtido foi lavado com ?gua deionizada, seco e calcinado para remover as mol?culas do direcionador. Posteriormente a amostra foi caracterizada por difra??o de raios-X (DRX), microscopia eletr?nica de varredura (MEV), espectroscopia de absor??o na regi?o do infravermelho (FT-IR), adsor??o de nitrog?nio (BET) e an?lise t?rmica via TG/DTG. As propriedades ?cidas foram determinadas usando adsor??o de n-butilamina seguida de termodessor??o programada. Este m?todo revelou que a amostra SAPO-11 apresenta uma acidez tipicamente fraca a moderada. Entretanto, uma pequena quantidade de s?tios ?cidos fortes foi detectada. A desativa??o dos catalisadores foi conduzida pelo coqueamento artificial da amostra, seguida da rea??o de craqueamento do n-hexano em um microrreator catal?tico de leito fixo com fluxo cont?nuo acoplado em linha com um cromat?grafo a g?s. Como principais produtos foram obtidos: etano, propano, isobutano, n-butano,e n-pentano, isopentano. Para determinar a regenera??o e a remo??o do coque foi aplicado o m?todo cin?tico Vyazovkin (Model Free Kinetics)

Made available in DSpace on 2014-12-17T14:07:19Z (GMT). No. of bitstreams: 1 DanieleMHM.pdf: 2362797 bytes, checksum: d58bd3fdee9f1e1945af3e9862aa11b8 (MD5) Previous issue date: 2007-04-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Ionic oxides with ABO3 structure, where A represents a rare earth element or an alkaline metal and B is a transition metal from group VIII of the periodic table are potential catalysts for oxidation and good candidates for steam reforming reaction. Different methods have been considered for the synthesis of the oxide materials with perovskite structure to produce a high homogeneous material with low amount of impurities and low calcination temperatures. In the current work, oxides with the LaNiO3 formula had been synthesized using the method of the polymeric precursors. The thermal treatment of the materials took place at 300 ?C for 2h. The material supported in alumina and/or zirconia was calcined at 800 ?C temperature for 4h. The samples had been characterized by the following techniques: thermogravimetry; infrared spectroscopy; X-ray diffraction; specific surface area; distribution of particle size; scanning electron microscopy and thermo-programmed reduction. The steam reforming reaction was carried out in a pilot plant using reducing atmosphere in the reactor with a mixture of 10% H2-Argon, a mass about 5g of catalyst, flowing at 50 mL.min-1. The temperature range used was 50 - 1000 oC with a heating rate of 10 oC.min-1. A thermal conductivity detector was used to analyze the gas after the water trapping, in order to permit to quantify the consumption of hydrogen for the lanthanum nickelates (LaNiO3). The results showed that lanthanum nickelate were more efficient when supported in alumina than when supported in zirconia. It was observed that the methane conversion was approximately 100% and the selectivity to hydrogen was about 70%. In all cases were verified low selectivity to CO and CO2 / ?xidos i?nicos com estrutura ABO3, onde A representa elemento terra rara ou metal alcalino e B ? um metal de transi??o especialmente do grupo VIII da tabela peri?dica s?o potenciais catalisadores para oxida??o e fortes candidatos para reforma a vapor. Diferentes m?todos t?m sido propostos para a s?ntese de ?xidos com estrutura perovisquita visando produzir um material com alta homogeneidade, baixa quantidade de impurezas e baixa temperatura de calcina??o. No presente trabalho, ?xidos do tipo LaNiO3 foram sintetizados utilizando o m?todo dos precursores polim?ricos. Os materiais foram tratados termicamente a 300 ?C por 2h, calcinados a 800 ?C por 4h e suportados em alumina e/ou zirconia. As amostras foram caracterizadas pelas seguintes t?cnicas: an?lise termogravim?trica; espectroscopia na regi?o do infravermelho; difra??o de raios-X; ?rea superficial; distribui??o do tamanho de part?cula; redu??o a temperatura programada e microscopia eletr?nica de varredura. Rea??es catal?ticas de reforma a vapor foram realizadas em uma planta piloto, usando-se atmosfera redutora com uma mistura de 10% H2-Arg?nio, uma massa de cerca de 5g de catalisador, com fluxo total de 50 mL.min-1. A temperatura variou de 50 a 1000 oC com raz?o de aquecimento de 10 oC.min-1. Um detector de condutividade t?rmica foi utilizado para analisar o g?s ap?s trapeamento da ?gua, permitindo assim quantificar o consumo de hidrog?nio para os niquelatos de lant?nio (LaNiO3). Os resultados mostraram que o niquelato de lant?nio, foi mais eficaz quando suportado em alumina que em zirconia, observou-se que a convers?o do metano foi pr?xima a 100% e seletividade ao hidrog?nio em torno de 70%. Em todos os casos verificou-se baixa seletividade ao CO e CO2

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-05T22:05:48Z No. of bitstreams: 1 LeonardoDeSaCosta_DISSERT.pdf: 2101335 bytes, checksum: ac42734e9bbfbba5815b32c66600ff2b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-15T23:04:07Z (GMT) No. of bitstreams: 1 LeonardoDeSaCosta_DISSERT.pdf: 2101335 bytes, checksum: ac42734e9bbfbba5815b32c66600ff2b (MD5) / Made available in DSpace on 2016-02-15T23:04:07Z (GMT). No. of bitstreams: 1 LeonardoDeSaCosta_DISSERT.pdf: 2101335 bytes, checksum: ac42734e9bbfbba5815b32c66600ff2b (MD5) Previous issue date: 2014-02-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Este trabalho teve a finalidade de promover a s?ntese, caracteriza??o e de propor uma estrutura molecular para os compostos de coordena??o envolvendo a furosemida (?cido 4- cloro-2-(2-furilmetilamino)-5-sulfamoil-benz?ico), com os ?ons met?licos Ni+2, Zn+2 e Co+2 . Os compostos foram obtidos em meio metan?ico por evapora??o do solvente ap?s o procedimento da s?ntese. Para caracteriza??o dos compostos de coordena??o, foram feitas as determina??es dos teores de metais por complexometria com EDTA, espectroscopia na regi?o do infravermelho (FTIR), solubilidade dos compostos em diversos solventes, an?lise termogravim?trica (TG), calorimetria explorat?ria diferencial (DSC), an?lise t?rmica diferencial (DTA) e a determina??o dos teores de carbono, nitrog?nio e hidrog?nio (CHN). Os resultados da espectroscopia na regi?o do infravermelho sugerem que o ligante se coordene de forma bidentada, com os ?ons met?licos. As intera??es com os centros met?licos ocorrem pela coordena??o do ?tomo de nitrog?nio do grupo amino e pelo ?tomo de oxig?nio do ?cido carbox?lico da estrutura da furosemida. Com os resultados dos teores de metais, an?lise elementar (CHN) e an?lise t?rmica, foram poss?veis propor as estruturas dos complexos. Os valores de condutividade molar em acetonitrila indicam que os complexos apresentam comportamento de n?o eletr?lito em solu??o. Os compostos apresentam alta solubilidade em metanol e acetonitrila, j? em ?gua s?o parcialmente insol?veis. Atrav?s dos resultados das an?lises t?rmicas (TG, DSC, DTA), obteve-se o comportamento t?rmico dos compostos como: etapas de desidrata??o, estabilidade t?rmica, decomposi??o e as energias envolvidas. / This work aimed to promote the synthesis, characterization and propose a plausible molecular structure for coordination compounds involving furosemide (4-Chloro-2-(2- furylmethylamino)-5-sulfamoyl-benzoic acid) with the metal ions Ni+2, Zn+2 and Co+2. The compounds were obtained in methanoic medium by evaporation of the solvent after the synthesis procedure. For characterization of coordination compounds determining the levels of metals by EDTA complexometry, infrared spectroscopy (FTIR), solubility of compounds in various solvents, thermogravimetry (TG), differential scanning calorimetry (DSC), differential thermal analysis were made (DTA), determination of the carbon , hydrogen and nitrogen (CHN). The results of infrared spectroscopy in the region suggest that the organic ligand is coordinated in a bidentate fashion to the metal ions, the metal center interactions to occur by the coordination of the nitrogen atom of the amino group and the oxygen atom of the carboxylic acid of the structure of furosemide. With the results of the levels of metal, elemental analysis (CHN) and thermal analysis has been possible to propose the structure of the ligand. The values of the molar conductivity of the complex in acetonitrile behavior suggest the non acetonitrile electrolyte solution. With the solubility tests it was found that the compounds have high solubility in methanol and acetonitrile, as are partially insoluble in water. From the results of thermal analysis (TG, DSC, DTA), it was possible to obtain the thermal behavior of the compounds as stages of dehydration, thermal stability, decomposition and the energies involved.

Made available in DSpace on 2014-12-17T15:01:23Z (GMT). No. of bitstreams: 1 JoseCN_DISSERT.pdf: 1767352 bytes, checksum: c57055b8c67d4fd6e0631c221643df35 (MD5) Previous issue date: 2010-06-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Supported catalysts of CuCl2 on s?lica were used in the methane oxychlorination reaction. The materials were synthesized by the ion exchange technique in a basic solution, using a copper-ammonia complex with 3 and 6 % of nominal copper loading. The materials where characterized by thermogravimetry (TG), X-ray Fluorescence Spectroscopy (XRF), Temperature Programmed Reduction (TPR), Scanning Electron Microscopy with X-ray microanalysis (SEM/EDS), BET specific area and pore distribution. The characterization confirms the presence of copper on the support surface, concluding that the ion exchange technique was adequate in the catalyst synthesis. For the reaction test, an oxychlorination bench scale unit was employed. The tests were carried at 673 and 773 K. The results showed the influence of temperature and catalyst copper content on the oxychlorination of methane reaction / Catalisadores do tipo CuCl2 suportados em s?lica, utilizados na convers?o do metano via oxiclora??o, foram sintetizados pelo m?todo de troca i?nica em meio b?sico, usando um complexo amoniacal de cobre, com cargas met?licas nominais de 3 e 6% de cobre. Os materiais foram caracterizados por: termogravimetria (TG), fluoresc?ncia de raios X (FRX), redu??o ? temperatura programada (RTP), microscopia eletr?nica de varredura com espectroscopia dispersiva de el?trons (MEV-EDS) e determina??o da ?rea especifica e volume de poro pelo M?todo BET. Os resultados das caracteriza??es indicavam a presen?a de cobre na superf?cie do suporte mostrando que o processo de impregna??o via troca i?nica foi adequado na s?ntese do catalisador. No teste catal?tico reacional foi utilizada uma planta de oxiclora??o, em escala de laborat?rio. Os experimentos catal?ticos foram avaliados nas temperaturas de 673 e 773 K. Os resultados obtidos mostraram influ?ncia da temperatura e teor de cobre dos catalisadores na rea??o de oxiclora??o do metano