Depuis quelques années la demande en gazole dépasse la production des raffineries européennes et inversement pour les essences. L'objectif de cette thèse est de valoriser l'excédent d'essences et de satisfaire la demande en diesel en utilisant le procédé d'oligomérisation des oléfines. Nous nous sommes intéressés à l'oligomérisation du pentène qui, au contact d'un catalyseur solide acide, s'oligomérise en molécules plus lourdes de 10 à 25/30 atomes de carbone. Nous avons choisi les zéolithes et la mordénite en particulier comme catalyseur de la réaction. Afin d'améliorer le transport des molécules aux sites actifs nous avons modifié la texture des mordénites par la création d'un réseau secondaire de mésopores au sein de leurs cristaux, en utilisant deux traitements post-synthèse différents : la dessilication et la recristallisation. La dessilication génère des mésopores intra et inter-cristallins (de 10 nm à 100 nm de diamètre) par dissolution partielle de la zéolithe en présence d'une solution basique. La recristallisation conduit à une mésoporosité organisée et monodispersée en taille (petits mésopores de 4 nm) grâce à l'utilisation d'un agent structurant sous conditions hydrothermiques. Nous avons ainsi obtenu des mordénites micro-mésoporeuses de texture, porosité et acidité différentes en fonction du traitement appliqué. Finalement, après l'élaboration du micro-pilote expérimental, nous avons comparé les performances de nos catalyseurs optimisés de mordénites micro-mésoporeuses à celles des catalyseurs de référence (conversion, stabilité, sélectivité, rendement en oligomères C15-C20+, degré de branchement des produits) afin d'établir les relations structure-acidité-performances catalytiques. Nous avons mis en évidence l'impact positif de l'insertion de mésopores dans le catalyseur sur la conversion, la stabilité et le rendement en oligomères C15-C20+. Une méthodologie de caractérisation du degré de branchement des produits de réaction a également été mise au point pour compléter l'analyse des performances catalytiques. / Recently the demand in diesel has been exceeding the production of European refineries and, inversely for gasoline. The objective of this thesis is to increase the value of the gasoline excess and meet the demand in diesel using the olefin oligomerization process. We focused on the oligomerization of pentene, which can transform into heavier molecules from 10 to 25/30 carbon atoms in contact with a solid acid catalyst . We chose zeolites as catalysts and more specifically mordenite. To improve the molecular transport to the active sites we have modified the mordenite texture by creating a secondary mesoporous framework inside the crystals, using two different post-synthesis treatments: desilication and recrystallization. Desilication treatment generates intra and inter-crystalline mesopores (from 10 nm to 100 nm diameter) by partial dissolution of the zeolite in the presence of a basic solution. Recrystallization creates a well-organized mesoporosity with a uniform diameter (small mesopores of 4 nm) due to the use of an organic template of mesopores under hydrothermal conditions. Starting from the same parent mordenite we obtained micro-mesoporous mordenites with different textures, porosity and acidity properties depending on the treatment. Finally, after the development of the experimental pilot, we compared the performance (conversion, stability, selectivity, yield in oligomers C15-C20+, branching degree of the products) of our optimized catalysts of micro-mesoporous mordenite with some reference catalysts in order to establish relations between structure-acidity and catalytic performance. We highlighted the positive impact of the introduction of mesopores in the catalyst on the conversion, stability and yield in oligomers C15-C20+. A methodology to characterize the branching degree of the products has also been developed for completing the analysis of catalytic performances.

Le présent projet de maîtrise s’intitule Conversion du méthanol en éther di-méthylique (DME) et de ce dernier en acétate de méthyle. Échelonné sur 24 mois, le travail a été scindé en deux parties importantes : la synthèse du DME par déshydratation du méthanol; la carbonylation du DME en acétate de méthyle. La caractérisation de ces deux systèmes catalytiques a pour but d’être une alternative à la synthèse industrielle des acétyles passant par la carbonylation du méthanol sous l’action de l’iodure de méthyle comme co-catalyseur avec le rhodium. L’impact de l’iodure de méthyle sur le plan économique fait l’objet du plusieurs efforts de développement dont une des avenues est celle passant par le DME. L’optimisation de la première réaction s’est conduite autour du choix de catalyseur, de la température, de la pression et des conditions hydrodynamiques. Ceci a permis de caractériser les performances de la réaction dont les trois principaux indicateurs choisis sont la conversion, la sélectivité et le taux de production. L’alumine-[gamma] comme catalyseur dans un réacteur à lit fixe permet d’atteindre une conversion du méthanol totalement sélective au DME de 80% à une LHSV (liquid hour space velocity) de 11h[indice supérieur -1] et ce à 330 °C et 2514 kPa. Le taux de production maximal calculé a été de 7.35 {gDME / gcat. [indice supérieur Xh]}. La carbonylation du DME s’est faite sous l’action de la zéolithe Mordénite et également dans un réacteur à lit fixe. Le ratio molaire des réactifs CO:DME, la température et la pression et ont été l’objet de l’étude paramétrique. À une GHSV[indice inférieur CO] de 1062 h[indice supérier -1], un ratio CO:DME de 10:1, une température de 230 °C et une pression de 3204 kPa (450 psig), il a été possible d’atteindre une conversion du DME en acétate de méthyle de 9%. Les résultats expérimentaux de chacune de ces deux réactions ont été analysés par rapport aux modèles théoriques d’équilibre thermodynamique ainsi qu’aux valeurs expérimentales répertoriées dans la littérature scientifique.

Le présent projet de maîtrise s’intitule Conversion du méthanol en éther di-méthylique (DME) et de ce dernier en acétate de méthyle. Échelonné sur 24 mois, le travail a été scindé en deux parties importantes : la synthèse du DME par déshydratation du méthanol; la carbonylation du DME en acétate de méthyle. La caractérisation de ces deux systèmes catalytiques a pour but d’être une alternative à la synthèse industrielle des acétyles passant par la carbonylation du méthanol sous l’action de l’iodure de méthyle comme co-catalyseur avec le rhodium. L’impact de l’iodure de méthyle sur le plan économique fait l’objet du plusieurs efforts de développement dont une des avenues est celle passant par le DME. L’optimisation de la première réaction s’est conduite autour du choix de catalyseur, de la température, de la pression et des conditions hydrodynamiques. Ceci a permis de caractériser les performances de la réaction dont les trois principaux indicateurs choisis sont la conversion, la sélectivité et le taux de production. L’alumine-[gamma] comme catalyseur dans un réacteur à lit fixe permet d’atteindre une conversion du méthanol totalement sélective au DME de 80% à une LHSV (liquid hour space velocity) de 11h[indice supérieur -1] et ce à 330 °C et 2514 kPa. Le taux de production maximal calculé a été de 7.35 [symboles non conformes]. La carbonylation du DME s’est faite sous l’action de la zéolithe Mordénite et également dans un réacteur à lit fixe. Le ratio molaire des réactifs CO:DME, la température et la pression et ont été l’objet de l’étude paramétrique. À une GHSV[indice inférieur CO] de 1062 h[indice supérier -1], un ratio CO:DME de 10:1, une température de 230 °C et une pression de 3204 kPa (450 psig), il a été possible d’atteindre une conversion du DME en acétate de méthyle de 9%. Les résultats expérimentaux de chacune de ces deux réactions ont été analysés par rapport aux modèles théoriques d’équilibre thermodynamique ainsi qu’aux valeurs expérimentales répertoriées dans la littérature scientifique.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-03-27T21:15:45Z No. of bitstreams: 1 ERIVALDO GENUÍNO LIMA - TESE (PPGEQ) 2017.pdf: 3180376 bytes, checksum: d01c9d5a44e6812cfd719a5ce7cab9e6 (MD5) / Made available in DSpace on 2018-03-27T21:15:45Z (GMT). No. of bitstreams: 1 ERIVALDO GENUÍNO LIMA - TESE (PPGEQ) 2017.pdf: 3180376 bytes, checksum: d01c9d5a44e6812cfd719a5ce7cab9e6 (MD5) Previous issue date: 2017-03-06 / Capes / O trabalho teve como objetivo preparar um grupo de catalisadores heterogêneos e avaliá-los na reação de transesterificação do óleo de soja com metanol para produzir biodiesel. O método hidrotérmico em condições estáticas foi utilizado para sintetizar a zeólita mordenita sódica com composição molar 6Na2O: Al2O3: 30SiO2: 780H2O. A deposição do óxido de molibdênio foi realizada pelo método de impregnação por via úmida. Os catalisadores (VD, 8%MoO3/VD, NaMOR, 8%MoO3/NaMOR, HMOR e 8%MoO3/HMOR) foram caracterizados por DRX, FRX-ED, MEV, Adsorção física de N2, FTIR e TPD-NH3. A reação de transesterificação do óleo de soja foi conduzida em reator batelada sem agitação, durante tempos diferentes de reação (1, 2, 3, 4, 6, 12 e 24 horas) a 200°C, utilizando uma relação soja/metanol de 1:12 e 5% de catalisador. O biodiesel foi caracterizado a partir da viscosidade cinemática, análise termogravimétrica, massa específica e índice de acidez. Os êxitos das sínteses das zeólitas mordenitas (NaMOR e HMOR) foram evidenciados pelas técnicas de DRX, FRX-ED e adsorção física de N2. Os padrões de difração de raios X da argila verde dura (VD) apresentaram picos característicos da estrutura que pertence ao grupo das esmectitas. Observou-se que a adição do molibidênio às amostras (NaMOR e HMOR) promove a redução na área superficial específica. Pela análise de Dessorção termoprogramada de NH3 os catalisadores apresentaram caracteristicas ácidas distintas, no caso dos catalisadores VD e 8%MoO3/VD apresentaram maior concentração de sítios ácidos fortes e uma pequena quantidade de sítios ácidos fracos, os catalisadores NaMOR e MoO3/NaMOR exibiram sítios de natureza fracos e médios e nos catalisados HMOR e MoO3/HMOR apresentaram picos em duas faixas de temperaturas com sítios ácidos fracos e fortes, podendo ser característicos de Brönsted e/ou Lewis. Os valores de viscosidade cinemática que mais se aproximaram da faixa exigida pela norma 45/2014 da Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP), foram com os tempos reacionais de 12 e 24 horas e catalisadores (8%MoO3/VD, 8%MoO3/NaMOR e 8%MoO3/HMOR). Na análise termogravimétrica dos biodieseis produzidos com 12 e 24 horas de reação, constatou-se a presença de duas regiões de perdas de massa, referente à volatilização dos ésteres metílicos e triglicerídeos não convertidos. Nos testes de massa específica e índice de acidez somente os catalisadores (8%MoO3/VD, 8%MoO3/NaMOR e 8%MoO3/HMOR) atenderam as especificações exigidas pela Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP). / The objective of the work was to prepare a group of heterogeneous catalysts and to evaluate them in the reaction of transesterification of soybean oil with methanol to produce biodiesel. The hydrothermal method under static conditions was used to synthesize the sodium mordenite zeolite with molar composition 6Na2O: Al2O3: 30SiO2: 780H2O. The deposition of molybdenum oxide was carried out by the wet impregnation method. The catalysts (VD, 8% MoO3/VD, NaMOR, 8% MoO3/NaMOR, HMOR and 8% MoO3/HMOR) were characterized by DRX, FRX-ED, SEM, physical adsorption of N2, FTIR and TPD-NH3. The transesterification reaction of the soybean oil was conducted in a batch reactor without stirring during different reaction times (1, 2, 3, 4, 6, 12 and 24 hours) at 200 °C using a soy/methanol ratio of 1:12 and 5% catalyst. Biodiesel was characterized by kinematic viscosity, thermogravimetric analysis, specific mass and acidity index. The successes of the mordenite zeolite syntheses (NaMOR and HMOR) were evidenced by the XRD, FRX-ED and N2 physical adsorption techniques. The X-ray diffraction patterns of the hard green clay (VD) showed characteristic peaks of the structure that belong to the group of smectites. It was observed that the addition of molybdenum to the samples (NaMor and HMOR) promotes the reduction in the specific surface area. In the case of the catalysts VD and 8% MoO3/VD presented higher concentration of strong acid sites and a small amount of weak acidic sites, the NaMOR and MoO3/NaMOR catalysts exhibited nature And weak and medium sites and HMOR and MoO3/HMOR catalysts showed peaks at two temperature ranges with weak and strong acid sites, which may be characteristic of Brönsted and / or Lewis. The kinematic viscosity values that most approached the range required by the 45/2014 standard of the National Agency of Petroleum, Natural Gas and Biofuels (ANP) were with reaction times of 12 and 24 hours and catalysts (8% MoO3/VD, 8% MoO3/NaMOR and 8% MoO3/HMOR). In the thermogravimetric analysis of the biodiesel produced with 12 and 24 hours of reaction, it was verified the presence of two regions of mass loss, related to the volatilization of the methyl esters and unconverted triglycerides. In the tests of specific mass and acidity index only the catalysts (8% MoO3/VD, 8% MoO3/ NaMOR and 8% MoO3/HMOR) met the specifications required by the National Agency of Petroleum, Natural Gas and Biofuels (ANP).

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-09T13:11:00Z No. of bitstreams: 1 2016 - Glenda Cristina da Silva Lopes.pdf: 3117864 bytes, checksum: 398fb3e84e1b16247f7cc7afb1069541 (MD5) / Made available in DSpace on 2017-06-09T13:11:00Z (GMT). No. of bitstreams: 1 2016 - Glenda Cristina da Silva Lopes.pdf: 3117864 bytes, checksum: 398fb3e84e1b16247f7cc7afb1069541 (MD5) Previous issue date: 2016-08-26 / Funda??o de Apoio a Pesquisa Cient?fica e Tecnol?gica da UFRRJ-FAPUR / In the present dissertation it was conduced the study of the mesoporous mordenite production by the direct synthesis using hydrothermal media or dry gel convertion. Activated charcoal, starch, carboxymethylcellulose and carbon black were used as mesoporosity templating. To evaluate the effect of these templates, samples were prepared with molar composition of 20 SiO2: 1 Al2O3: 6 Na2O: 600 H2O, by hydrothermal synthesis and 20 SiO2: 1 Al2O3: 4 Na2O, by dry synthesis, following procedures described in the literature and adding different amounts of templates to the synthesis gel. As reagents for the synthesis gel assay, were utilized sodium hydroxide, sodium aluminate, silica (Aerosil 200) and deionized water. The synthesis temperature was 175 ? C, while the synthesis time was 5 days and 3 days for the hydrothermal and dry method, respectively. For characterization of the samples was used X-ray diffraction (XRD), analysis by nitrogen adsorption/desorption measurements and determination of the acidity by temperature programmed desorption of ammonia (NH3-TPD). An evaluation of the samples was carried out using the n-heptane cracking reaction at 380 ? C. By X-ray diffraction, it was observed that the majority of the experiments formated of mordenite phase. The textural properties, particularly the volume of mesopores, improved in most samples synthesized in the presence of the template, however, the values obtained were lower than those defined in the literature for mesoporous materials. The samples showed only a peak of ammonia adsorption in NH3-TPD profiles, related to weak acid sites. Most samples synthesized in the presence of drivers showed an increase in the conversion of n-heptane, while the samples obtained by dry gel convertion showed higher conversion than the hydrothermally synthesized. / No presente trabalho foi realizado o estudo da produ??o de mordenita mesoporosa a partir da s?ntese direta, em meio hidrot?rmico e seco, na presen?a do carv?o ativado, amido, carboximetilcelulose e negro de fumo como direcionadores de mesoporosidade. Para avaliar o efeito desses direcionadores, foram preparadas amostras com composi??o molar de 20 SiO2: 1 Al2O3: 6 Na2O: 600 H2O, pela s?ntese hidrot?rmica e 20 SiO2: 1 Al2O3: 4 Na2O, pela s?ntese seca, seguindo os procedimentos descritos na literatura e adicionando quantidades diferentes dos direcionadores ao gel de s?ntese. Como reagentes para o gel de s?ntese, foram utilizados hidr?xido de s?dio, aluminato de s?dio, s?lica (aerosil 200) e ?gua deionizada. A temperatura de s?ntese foi de 175 ?C, enquanto o tempo de s?ntese foi de 5 dias e 3 dias, para o m?todo hidrot?rmico e seco, respectivamente. Para caracteriza??o das amostras usou-se difra??o de raios X (DRX), an?lise textural por medidas de adsor??o/dessor??o de nitrog?nio e determina??o da acidez por dessor??o de am?nia ? temperatura programada (TPD-NH3). Realizou-se a avalia??o catal?tica das amostras atrav?s da rea??o de craqueamento de n-heptano a 380 ?C. Pelos difratogramas de raios X, foi observado que na maioria dos experimentos ocorreu a forma??o da mordenita. As propriedades texturais, especialmente o volume de mesoporos, melhoraram na maioria das amostras sintetizadas na presen?a do direcionador, por?m, os valores obtidos foram inferiores aos definidos pela literatura para materiais mesoporosos. As amostras apresentaram apenas um pico de adsor??o de am?nia nos perfis de TPD-NH3, referentes aos s?tios ?cidos fracos. A maioria das amostras sintetizadas na presen?a dos direcionadores apresentou aumento na convers?o do n-heptano, sendo que as amostras obtidas por s?ntese em meio seco apresentaram maior convers?o do que as sintetizadas em meio hidrot?rmico.

This thesis focuses on developing an alternative system for membrane electrode assembly (MEA) formation to use with a direct methanol fuel cell (DMFC). The approach involves incorporating inorganic fillers with an industry standard Nafion polymer as part of a methanol resistant composite barrier layer at the anode/membrane interface of MEA featuring Nafion 117 membranes. This procedure is used to reduce the fuel cell losses related to the crossover of un-oxidised methanol through the membrane and prevent its subsequent reaction at the cathode. The inorganic filler used within this study was mordenite that has Si/Al ratio of 5 and by incorporating this into the barrier layer a superior DMFC performance has been achieved in comparison to a standard MEA featuring a Nafion 117 membrane. The voltage, current density and power density used as a measure of DMFC performance under a range of methanol molarities (1M-4M) and cell temperatures (40°C-70°C) have been taken for both the novel and standard MEA. Linear sweep voltammetry (LSV) and AC impedance spectroscopy (ACIS) were used to give some insight into what was occurring within the MEA with regards to methanol crossover current and the proton conductivity within the DMFC. To obtain the best possible DMFC performance a range of mordenite loadings from 0wt%1.0wt% were utilised and an optimum loading of 0.5wt% was reached. MEA which featured mordenite that had undergone ion exchange into a protonated form (from the sodium form) and had a silane functional group (glycidoxypropyltrimethoxysilane) grafted onto the surface, gave DMFC performances that were as much as 50% better than the standard. The highest power density obtained with this MEA was 43.6mW/cm-2 compared to the 35mW/cm-2 obtained using the standard. Values obtained for the methanol crossover current and proton conductivity under working DMFC operating conditions showed that this novel MEA had as much as 16% lower methanol permeability compared to the standard combined with comparable proton conductivity when using a 1M methanol feed. The durability of a novel MEA featuring the 0.5wt% functionalised H-mordenite composite barrier layer was tested in the DMFC and compared to a standard MEA at a constant current of 50mA/cm-2 over 100 hours. The cell potential fell by 0.1mV/h in comparison to a 0.23mV/h loss observed with the standard. The work reported within this study aims to show that by incorporating a thin Nafion/mordenite composite layer at the anode/membrane interface within an MEA will result in improvements in DMFC performance. The development of this technology has led to the application for a patent due to the potential for the commercial development of DMFC using this novel approach.

The nutrients available in urine make it a good resource as fertilizer. Limited availability of natural phosphorus (P) is compelling people to think about recovering and returning it back to the land from waste stream. Urine comprising the majority of nitrogen (N) and P among other household wastewater, if managed separately, will benefit human against expensive commercial fertilizers, and eventually will reduce environmental problems. Various reactive filter systems have been studied since late 90’s as a potential system to recover N & P from urine and wastewater as a whole. Most studies are however limited to the laboratory scale only. Optimization of such technologies is one of the prime focuses in this area of research. This thesis project used the combination of two sorptive reactive materials, namely mordenite and polonite, to remove NH4-N and PO4-P from the source separated human urine. This two months laboratory scale study recommends dilution and storage to be a minimum pretreatment for urine. However as the influent’s NH4-N concentration was extremely high, further dilution or other relevant pretreatment is recommended. In overall, mordenite materials performed better for NH4-N removal reaching as high as 79% whereas polonite materials showed better results for PO4-P removal and the efficiency was as high as 97%. The reduction in NH4-N might also be due to the conversion of nitrogen into other forms. Mordenite materials showed a good potential for PO4-P removal and was up to 88% efficient initially. Both materials did not show the tendency of breakthrough for PO4-P until the end. The salinity measured as electric conductivity was reduced by both materials until about initial half-time period of the experiment. Since mordenite was the first unit to face the highly concentrated urine, it got saturated earlier and started showing the fluctuations in reduction and release for nutrients. The results obtained in this study provide the positive scenario for it to be implemented in the full scale system. However more elaborated studies in full scale addressing the major limitation of this project needs to be done before introducing the system for public uses.

L'adsorption de l'anthracène et de molécules de type Diphényl-polyènes (trans-Stilbene, 1,4-Diphenyl-1,3 butadiene, 1,6-Diphenyl-1,3,5-hexatriene) a été étudiée par simulations Monte Carlo, absorption UV-visible par réflexion diffuse, diffusion Raman multiexcitation et Résonance Paramagnétique Electronique (RPE) dans des zéolithes (aluminosilicates) à canaux de type Ferrierite (M-FER), ZSM-5 (MnZSM-5) et Mordenite (M-MOR).<br />Les résultats mettent en évidence l'insertion des molécules dans les canaux. Dans le cas de cations polarisants (M = H+ et Li+) une ionisation spontanée produit la formation de paires radical cation – électron de longue durée. Au cours de la recombinaison de charges, des paires électron-trou sont mises en évidence par des techniques impulsionnelles de RPE. Dans le cas des molécules insérées sans modification chimique (M = Na+, K+, Rb+, Cs+), la photolyse UV induit des paires de radicaux dont la lente recombinaison implique des phénomènes de transferts d'électrons régis par la théorie de Marcus. L'exceptionnelle stabilité des paires de radicaux est attribuée au confinement des molécules dans les canaux, à la teneur en aluminium et à la nature des cations de la zéolithe. Ces paires de radicaux sont des intermédiaires réactionnels mis en jeu dans les processus catalytiques et de photodégradation d'hydrocarbures. Ils sont aussi impliqués dans le processus primordial de l'effet photovoltaïque.

Na última década sistemas supramoleculares vêm atraindo a atenção de muitos pesquisadores na área da química. Este interesse é devido a capacidade dos sistemas supramoleculares mimetizarem sistemas biológicos e pelo seu importante papel na construção de novos materiais com interesse tecnológico. No contexto de interações supramoleculares as espécies oxocarbônicas têm se mostrado como excelentes sondas para o estudo dessas interações devido às características sui generis dos seus espectros eletrônicos e vibracionais, o que por sua vez decorre da presença do efeito Jahn-Teller. Neste trabalho foram investigados os sistemas supramoleculares: mordenita/ácido esquárico, tiouréia/ácido esquárico e agregação de esquaraínas em solução. Nessa investigação foram utilizadas técnicas de espectroscopia eletrônica e vibracional. As espectroscopias Raman e Raman ressonante se mostraram eficientes para o estudo dos sistemas supramoleculares acima. Através do uso das espectroscopias eletrônica e vibracional foi possível caracterizar interações do tipo \"transferência de carga\" em mordenitas incluídas, caracterizar clatratos formados por tiouréia e espécies oxocarbônicas, e determinar os modos vibracionais envolvidos no processo de agregação em solução de esquaraínas e, conseqüentemente, sua geometria de agregação. / Over the last decade supramolecular systems have received the attention of many researchers. Such interest can be explained by the ability of supramolecular systems to mimic biological systems, as well as by their important role in the design of new materials with technological relevance. In the context of supramolecular interactions oxocarbon species have proved to be excellent probes for the study of such interactions thanks to the unique features of their vibrational and electronic spectra, a consequence of the Jahn-Teller effect. In the present work the following systems were investigated: Mordenite/squaric acid, thioureia/squaric acid and aggregated squaraines in solution. Electronic and vibrational spectroscopies were the techniques of choice. Raman and resonance Raman spectroscopies showed to be convenient techniques for the study of the forementioned systems. It was possible to characterize the charge-transfer interaction induced by the restrict geometry in mordenite, the clathrate-like host formed by thioureia squaric acid, as well as to determine the nature of the squaraines aggregates formed in solutions.

Made available in DSpace on 2016-06-02T19:56:59Z (GMT). No. of bitstreams: 1 6783.pdf: 3853594 bytes, checksum: 5c76462cb2ede47f0f6638372f3f2364 (MD5) Previous issue date: 2015-02-18 / Financiadora de Estudos e Projetos / The fluid catalytic cracking (FCC) is one of the most important process in the petroleum refining industry, being responsible for the increase of the yield of the most valuable light hydrocarbons. On the other hand, the FCC process generates big amounts of CO, NOx and SOx emissions. The CO emissions from the most of pollution sources are abatement using noble metal based catalysts. However, the growing demand and scarcity of those metals have caused an increase in the process cost and consequently promoting studies to find alternative catalysts with comparable efficiency and lower in cost. In this respect, the literature had presented interesting results with transitions metal catalysts. Thus, the objective of this work was to prepare exchanged or impregnated Fe or Mn on H-mordenite or Ce-mordenite, which were evaluated between 150 and 550 oC in the CO oxidation with O2, in the presence or absence of interfering compounds (water steam or SO2). The catalysts were characterized by ICP-OES, DRX, DRS-UV-VIS and Mössbauer spectroscopy. The results showed that the preparation procedures of the interchanged or impregnated Fe or Mn catalysts were adequate, and no mordenite crystallinity loss was observed. Contrary to the exchanged Fe or Mn based catalysts, those based on impregnated Fe or Mn oxides showed a important potential as catalysts in the CO oxidation with O2. Then, in the applied operational conditions the Ce-MOR/Fe10, Ce-MOR/Mn5, Ce-MOR/Mn10 e H-MOR/Mn5 catalysts were able to produce an effluent with CO content lower than 500 ppm, which is the allowed limit by the environmental regulations related with FCC units. In the presence of water steam the evaluated Fe or Mn catalysts presented activity loss that was recovered after the elimination of that interfering from the feed. Nevertheless, in the presence of SO2, the tested catalysts showed an irreversible and significantly activity loss. / O craqueamento catalítico fluido (FCC) é uma das etapas mais importantes no refino de petróleo, sendo responsável pelo aumento do rendimento em frações leves, de maior valor agregado. Por outro lado, o FCC é responsável na refinaria por uma grande parcela das emissões de monóxido de carbono (CO), óxidos de nitrogênio (NOx) e óxidos de enxofre (SOx). O CO, em particular, na maioria das fontes poluidoras é eliminado via oxidação sobre catalisadores à base de metais nobres. Porém, o aumento na demanda desses metais e sua baixa disponibilidade criam um forte impacto no custo do processo, surgindo a necessidade de buscar catalisadores alternativos, com eficiência comparável e de menor custo. Assim, o objetivo deste trabalho foi preparar catalisadores à base de ferro ou manganês impregnados ou trocados em H-mordenita ou Ce-mordenita e avaliá-los entre 150 e 550 oC na oxidação de CO com oxigênio (O2), na ausência ou presença de compostos interferentes à reação como vapor de água e dióxido de enxofre (SO2). Os catalisadores foram caracterizados por espectroscopia de emissão atômica (ICP-OES), difração de raios X (DRX), espectroscopia de reflectância difusa (DRS-UV-VIS), redução com H2 à temperatura programada (RTP-H2) e espectroscopia Mössbauer (MOSS). Os resultados mostraram que os procedimentos de preparação dos catalisadores, trocados ou suportados, foram eficientes, não se observando perda de cristalinidade da mordenita. Os catalisadores com óxidos de Fe ou Mn suportados na mordenita apresentaram um importante potencial para serem utilizados como catalisadores na oxidação de CO com O2, contrário ao que ocorreu com cátions de Fe ou Mn em sítios de troca. Assim, nas condições operacionais utilizadas, os catalisadores Ce-MOR/Fe10, Ce-MOR/Mn5, Ce-MOR/Mn10 e H-MOR/Mn5 foram capazes de converter CO suficiente para produzir um efluente gasoso com teor menor que 500 ppm de CO, sendo essa a concentração limite permitida pela legislação que rege as emissões de unidades FCC. Os catalisadores impregnados com Fe e Mn, quando avaliados na presença de vapor de água e de SO2, ocorreu perda da atividade, a que foi recuperada somente no caso do vapor de água.