The impact of H2 partial pressure (H2 pp) during the hydrotreating of heavy gas oil, derived from Athabasca bitumen, over commercial NiMo/¥ã-Al2O3 catalyst was studied in a micro-trickle bed reactor. The experimental conditions were varied as follows: temperature: 360 to 400¨¬C, pressure: 7 to 11 MPa, gas/oil ratio: 400 to 1270 mL/mL, H2 purity range of 0 to 100 vol. % (with the rest either CH4 or He), and LHSV range of 0.65 to 2 h-1. The two main objectives of the project were to study the nature of the dependence of H2 pp on temperature, pressure, gas/oil ratio, LHSV (Liquid Hourly Space Velocity), and H2 purity. The project was divided into three phases: in phase one the effect of H2 purity on hydrotreating of heavy gas oil (HGO) was studied, in phase two the nature of H2 pp dependency and the effect of H2 pp on hydrotreating of HGO was investigated, and in phase three kinetic studies were carried out using different kinetic models.<p> The objective of phase one was to study the effect of hydrogen purity on hydrotreating of HGO was studied in a trickle bed reactor over a commercial Ni−Mo/¥ã-alumina catalyst. Methane was used as a diluent for the hydrogen stream, and its effect on the catalyst performance was compared to that of helium, which is inert toward the catalyst. Furthermore, a deactivation study was conducted over a period of 66 days, during which the catalyst was subjected to H2 purities ranging from 75 to 95% (with the rest methane); no significant deterioration in the hydroprocessing activities of the catalyst was observed. Therefore, it was concluded that methane was inert toward a commercial Ni−Mo/¥ã-alumina catalyst. However, its presence resulted in hydrogen partial pressure reduction, which in turn led to a decrease in hydrodesulphurization (HDS), hydrodenitrogenation (HDN), hydrodearomatization (HDA) conversions. This reduction can be offset by increasing the total pressure of the system. HDS, HDN, HDA, and mild hydrocracking (MHC) conversions were studied. Also determined were cetane index, density, aniline point, diesel index, and fractional distribution of the products.<p> The main objective of phase two was to study the effects of H2 pp on hydrotreating conversions, feed vaporization, H2 dissolution, and H2 consumption were studied. The results show that HDN and HDA are significantly more affected by H2 partial pressure than HDS; with the HDN being the most affected. For instance as the inlet H2 partial pressure was increased from 4.6 to 8.9 MPa HDS, HDN, and HDA conversions increased for 94.9%, 55.1%, and 46.0% to 96.7%, 83.9%, and 58.0% , respectively. Moreover, it was observed that H2 dissolution and H2 consumption increased with increasing H2 pp. No clear trend was observed for the effect of H2 pp on feed vaporization.<p> In phase three the kinetics of HDS, HDN, and HDA were studied. The power law, multi-parameter, and Langmuir - Hinshelwood type models were used to fit the data. The prediction capacities of the resulting models were tested. It was determined that, while multi-parameter model yielded better prediction, L-H had an advantage in that it took a lesser number of experimental data to determine its parameters. Kinetic fitting of the data to a pseudo-first-order power law model suggested that conclusions on the effect of H2 pp on hydrotreating activities could be equally drawn from either inlet or outlet hydrogen partial pressure. However, from the catalyst deactivation standpoint, it is recommended that such conclusions are drawn from the outlet H2 partial pressure, since it is the reactor point with the lowest hydrogen partial pressure.

The impact of H2 partial pressure (H2 pp) during the hydrotreating of heavy gas oil, derived from Athabasca bitumen, over commercial NiMo/¥ã-Al2O3 catalyst was studied in a micro-trickle bed reactor. The experimental conditions were varied as follows: temperature: 360 to 400¨¬C, pressure: 7 to 11 MPa, gas/oil ratio: 400 to 1270 mL/mL, H2 purity range of 0 to 100 vol. % (with the rest either CH4 or He), and LHSV range of 0.65 to 2 h-1. The two main objectives of the project were to study the nature of the dependence of H2 pp on temperature, pressure, gas/oil ratio, LHSV (Liquid Hourly Space Velocity), and H2 purity. The project was divided into three phases: in phase one the effect of H2 purity on hydrotreating of heavy gas oil (HGO) was studied, in phase two the nature of H2 pp dependency and the effect of H2 pp on hydrotreating of HGO was investigated, and in phase three kinetic studies were carried out using different kinetic models.<p> The objective of phase one was to study the effect of hydrogen purity on hydrotreating of HGO was studied in a trickle bed reactor over a commercial Ni−Mo/¥ã-alumina catalyst. Methane was used as a diluent for the hydrogen stream, and its effect on the catalyst performance was compared to that of helium, which is inert toward the catalyst. Furthermore, a deactivation study was conducted over a period of 66 days, during which the catalyst was subjected to H2 purities ranging from 75 to 95% (with the rest methane); no significant deterioration in the hydroprocessing activities of the catalyst was observed. Therefore, it was concluded that methane was inert toward a commercial Ni−Mo/¥ã-alumina catalyst. However, its presence resulted in hydrogen partial pressure reduction, which in turn led to a decrease in hydrodesulphurization (HDS), hydrodenitrogenation (HDN), hydrodearomatization (HDA) conversions. This reduction can be offset by increasing the total pressure of the system. HDS, HDN, HDA, and mild hydrocracking (MHC) conversions were studied. Also determined were cetane index, density, aniline point, diesel index, and fractional distribution of the products.<p> The main objective of phase two was to study the effects of H2 pp on hydrotreating conversions, feed vaporization, H2 dissolution, and H2 consumption were studied. The results show that HDN and HDA are significantly more affected by H2 partial pressure than HDS; with the HDN being the most affected. For instance as the inlet H2 partial pressure was increased from 4.6 to 8.9 MPa HDS, HDN, and HDA conversions increased for 94.9%, 55.1%, and 46.0% to 96.7%, 83.9%, and 58.0% , respectively. Moreover, it was observed that H2 dissolution and H2 consumption increased with increasing H2 pp. No clear trend was observed for the effect of H2 pp on feed vaporization.<p> In phase three the kinetics of HDS, HDN, and HDA were studied. The power law, multi-parameter, and Langmuir - Hinshelwood type models were used to fit the data. The prediction capacities of the resulting models were tested. It was determined that, while multi-parameter model yielded better prediction, L-H had an advantage in that it took a lesser number of experimental data to determine its parameters. Kinetic fitting of the data to a pseudo-first-order power law model suggested that conclusions on the effect of H2 pp on hydrotreating activities could be equally drawn from either inlet or outlet hydrogen partial pressure. However, from the catalyst deactivation standpoint, it is recommended that such conclusions are drawn from the outlet H2 partial pressure, since it is the reactor point with the lowest hydrogen partial pressure.

Bitumen-derived heavy gas oil contains large amounts of sulfur (~4.0 wt.%) and nitrogen (~0.4 wt.%), which need to be lowered before it becomes suitable as a feedstock for refineries. The most widely used upgrading process is hydrotreating, and the conventional catalyst used for hydrotreating is Ni or Co and Mo or W supported on γ-Al2O3. Additionally, environmentally driven regulations impose strict limits on sulfur and nitrogen levels in transportation fuels. Therefore, the main focus of this work was to enhance the activity of a NiMo supported catalyst through its modification and to improve its selectivity to removal of bulky sulfur- and nitrogen-containing compounds from heavy gas oil under industrial hydrotreating conditions. This work was divided into four phases, and this thesis summarizes the research outcomes of each phase. The first phase examined the effects of chelating ligands, specifically, ethylenediaminetetraacetic acid (EDTA), on hydrotreating activity and the sulfidation mechanism. EDTA was seen to have a beneficial effect on hydrotreating activity. Detailed mechanistic aspects of interactions between support and EDTA, EDTA and metallic species, support and metal, support and active phase, and metallic species and metallic species at different reaction conditions, were also studied. Characterization by XANES revealed that the presence of a chelating agent delayed nickel sulfidation, which was the main cause of improvement in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. It also showed that EDTA plays a role in redistribution of active phases during sulfidation and favors the formation of octahedral molybdenum oxides. The second phase studied the effects of support modification and combinations of different supports and EDTA. In this phase, several mesoporous materials, including M-SBA-15 (M= Al, Ti and Zr), mesoporous mixed metal oxides (TiO2-Al2O3, ZrO2-Al2O3 andSnO2-Al2O3) and mesoporous metal oxides (ZrO2, Al2O3), were synthesized and used as support materials for a NiMo catalyst. NiMo/M-SBA-15 catalysts showed higher HDS and HDN activities and, the increase in activity is attributed to incorporation of heteroatoms in an SBA-15 matrix, which resulted in increase in metal support interaction, acidic strength and dispersion of active metals. The addition of EDTA to these catalysts helps in the formation of octahedral molybdenum oxide, which are easily reducible during sulfidation. This is evident from the XANES Mo LIII-edge study of the oxide catalysts. The increase in hydrodenitrogenation (HDN), hydrodesulfurization (HDS) and hydrodearomatization (HDA) activities as compared to that shown by the NiMo/γ-Al2O3 catalyst were also observed on addition of EDTA in large-pore, high-surface-area mesoporous zirconia supported NiMo catalysts. The incorporation of different metal oxides in alumina, as in the case of mixed metal oxides, resulted in a change in acidic strength and metal support interactions. It was observed with acridine-FTIR analysis that the catalysts with higher acidic strength tightly held acridine at high temperatures. This implies that catalysts with higher acidity are prone to inhibition by nitrogen-containing compounds present in feed, which will affect catalytic activity. The HDS and HDN activities for hydrotreating of heavy gas oil suggest that mesoporous alumina and titania-alumina supported catalysts perform better as compared to the conventional NiMo/γ-Al2O3 catalyst. Therefore, the effects of EDTA to Ni molar ratio (EDTA/Ni = 0 to 2) on the activities of the NiMo/MesoAl2O3 and NiMo/MesoTiO2-Al2O3 catalysts were studied, and EDTA was observed to have a negative impact on catalytic activity for these catalysts. This is attributed to a decrease in the active metal dispersion in these catalysts caused by the addition of EDTA. The catalysts NiMo/MesoAl2O3 and NiMo/MesoTiO2-Al2O3 without EDTA showed high active metal dispersion due to their high surface area and ordered structure. The third phase studied the combined effects of phosphorus and EDTA on the hydrotreating activity of NiMo supported catalysts. The effects of method of phosphorus addition (sequential and co-impregnation method) were also studied. When phosphorus was added using a co-impregnation method, as in the catalyst NiMoP/MesoAl2O3(CI), an increase in HDN, HDA and HDS activities was observed. However, the catalysts containing both EDTA and phosphorus showed a decrease in HDS and HDN activities. The fourth phase included a kinetic study using the Power Law and L-H models. The catalyst, NiMoP/mesoAl2O3(CI), was found to have higher HDN and HDS activities as compared to a conventional γ-Al2O3 supported catalyst containing phosphorus.

Four nickel-molybdenum catalysts were synthesized on gamma alumina with higher surface area and on NiMo catalyst was prepared using gamma alumina with lower surface area. Catalysts with higher-surface-area support were prepared by co-impregnation, sequential impregnation and adding phosphorous. Theses catalysts were calcined at 500  ͦC. Effect of higher calcination temperature was investigated by preparation of one catalyst calcined at 700 ͦC. Catalysts were thoroughly characterized via four characterization techniques. The hydrotreating activity of three catalysts was carried out in a micro reactor at high pressure and three different temperatures with Nynas vacuum middle distillate. Prior to the test, sulfiding was carried out to activate the catalysts. Hydrotreated-oil samples as products were analyzed to evaluate the activity and conversion of the catalyst. Also, the spent catalysts were characterized to evaluate the surface area characteristics and deactivation of catalysts. Addition of phosphorous to NiMo/gamma-Al2O3 improved the interaction between the metals and the support as well as reduced the coke formation as observed in scanning electron microscopy micrographs.

Made available in DSpace on 2016-06-02T19:56:49Z (GMT). No. of bitstreams: 1 4974.pdf: 3642452 bytes, checksum: 9983d14f77babcbd0c76cb3ef274c7c6 (MD5) Previous issue date: 2013-02-18 / Universidade Federal de Sao Carlos / Mo, NiMo or NiMoP HDS catalysts were supported on Al2O3, Al2O3-TiO2 or TiO2. These supports were synthesized via sol-gel and in the case o TiO2 it was used a commercial sample. The active phases were introduced by impregnation. Supports and catalysts in the oxide form were characterized by X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DRSUV-Vis), thermogravimetric analyses (TG), temperature-programmed reduction with H2 (TPR-H2), N2 adsorption/desorption, energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence (XRF), temperature-programmed desorption of NH3 (TPD-NH3), high resolution transmission electron microscopy (HRTEM) and evaluated at 300°C in the HDS of thiophene, used as a model molecule. Alumina presented a high specific surface area and meso/macroprous characteristics, allowing a high dispersion of the active phases, as was evidenced by XRD and DRSUV-VIS data. A HRTEM image of a NiMo/Al2O3 catalyst showed the presence of crystalline MoS2 whose activity was substantially promoted by the presence of Ni. The NiMo catalysts were active in the HDS of thiophene, however, the activity was enhanced significantly by the incorporation of P. This result corroborates the positive influence of P in the preparation of HDS catalysts. It was suggested that P must participate as promoter in the formation of the NiMoS phase during the sulfidation process of the Ni and Mo oxides. The supported NiMoP catalysts prepared in this work were more active than a commercial NiMoP/ Al2O3 catalyst, with this result validating the preparation procedures used here. The titania addition in the alumina framework led to NiMo catalysts possessing lower activity. That behavior was attributed to the formation of Ni and Mo sulfides without interaction diminishing the generation NiMoS phase, which is highly active in the HDS of sulfured organic compounds. / Catalisadores para hidrodessulfurização (HDS) contendo Mo, NiMo ou NiMo e o aditivo fósforo (P), foram suportados sobre Al2O3, Al2O3-TiO2 ou TiO2. A alumina e a alumina-titânia foram sintetizadas via sol-gel e, no caso da titânia pura, utilizada uma amostra comercial. A introdução dos sais precursores da fase ativa foi realizada via impregnação. Suportes e catalisadores na forma de óxidos foram caracterizados através de difração de raios X (DRX), espectroscopia por refletância difusa no ultravioleta visível (DRSUV-VIS), termogravimetria (TG), redução com hidrogênio à temperatura programada (RTP-H2), adsorção/dessorção de N2, espectroscopia de energia dispersiva de raios X (EDX), fluorescência de raios X (FRX), dessorção de amônia a temperatura programada (TPD-NH3), microscopia eletrônica de transmissão de alta resolução (HRTEM) e avaliados a 300&#8304;C na HDS do tiofeno. A alumina apresentou uma alta área superficial específica e características meso/macroporosa, possibilitando alta dispersão das fases ativas, conforme evidenciado por DRX e dados de DRSUV-VIS. A imagem de HRTEM do catalisador NiMo/Al2O3 mostrou a presença de MoS2 cuja atividade foi promovida substancialmente pela presença de Ni. Os catalisadores NiMo sobre os suportes utilizados foram ativos no HDS do tiofeno, entretanto, essa atividade foi melhorada pela incorporação de P. Esse resultado ratifica a influência positiva da utilização desse aditivo na preparação de catalisadores de HDS. O fósforo deve atuar como um promotor na formação de espécies NiMoS durante o processo de sulfetação dos óxidos de Mo e Ni. Os catalisadores NiMoP preparados neste trabalho apresentaram atividade específica superior à de um catalisador NiMoP/Al2O3 comercial, o que valida os procedimentos de preparação utilizados no trabalho. A adição de titânia na alumina durante a síntese sol-gel conduziu a catalisadores com menor atividade. Esse resultado foi atribuído à formação de sulfetos de Ni e Mo não interativos, com a consequente diminuição da formação da fase NiMoS de alta atividade no HDS de compostos organo-sulfurados.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-27T00:23:28Z No. of bitstreams: 1 MariliaMedeirosDeAraujo_DISSERT.pdf: 6949653 bytes, checksum: 7d29f43511f0222c25f36a334b8da9e7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-09-02T19:09:47Z (GMT) No. of bitstreams: 1 MariliaMedeirosDeAraujo_DISSERT.pdf: 6949653 bytes, checksum: 7d29f43511f0222c25f36a334b8da9e7 (MD5) / Made available in DSpace on 2016-09-02T19:09:47Z (GMT). No. of bitstreams: 1 MariliaMedeirosDeAraujo_DISSERT.pdf: 6949653 bytes, checksum: 7d29f43511f0222c25f36a334b8da9e7 (MD5) Previous issue date: 2016-02-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Esta disserta??o consistiu em avaliar os efeitos da Pol?tica de Valoriza??o do Sal?rio M?nimo sobre o emprego e a distribui??o de renda no longo prazo. Com base nas teorias de Keynes e Kalecki foram discutidos os efeitos de um aumento do sal?rio sobre o n?vel de emprego e sobre a distribui??o de renda, e os prov?veis canais e fatores a partir dos quais esses efeitos podem incidir sobre as vari?veis em quest?o. A metodologia da disserta??o apoiou-se no uso de simula??es computacionais, no modelo macroecon?mico multissetorial MKS, de Cavalcanti Filho (2002). Para um conjunto de combina??es de par?metros de pol?ticas econ?micas, a an?lise das simula??es gerou resultados, que correspondem aos efeitos apontados pelos fundamentos te?ricos. Conclui-se que, para as diferentes combina??es de pol?ticas fiscal e monet?ria simuladas, a Pol?tica de Valoriza??o do Sal?rio M?nimo se mostrou eficaz para os objetivos a que se prop?e a regra de reajuste. / This research aimed at evaluating the effects of Minimum Wage Enhancement Policy of employment and long-term income distribution. Based on the theories of Keynes and Kalecki, the effects of salary raise on employment and on income distribution were discussed as well as the channels and factors from which these effects may relate to the variables involved. The methodology of this dissertation consisted of generation of computer simulations based on the multisectorial macroeconomic MKS model developed by Cavalcanti Filho (2002) to test the effects of Minimum Wage Enhancement Policy and check whether the keynesian and kaleckian channels and factors and were valid. For a set of economic policy parameter combinations (tax rates, rules for the expansion of public spending and the determination of interest rates by the Central Bank), the analysis of the simulations generated results that correspond to the ones mentioned by the theoretical basis. The conclusion is that for different combinations of fiscal and monetary simulated policies, the Minimum Wage Enhancement Policy is effective to expand employment and improve income distribution in workers favor.

Três catalisadores contendo o mesmo teor de fase ativa (20% de óxido de molibdênio e 4% de óxido de níquel), mas constituídos por diferentes suportes (alumina, sílica-alumina e alumina zeólita) foram preparados com o objetivo de se obter catalisadores bifuncionais com acidez distinta e boa dispersão da fase metálica visando analisar o papel da acidez do suporte na conversão da tetralina. Os catalisadores e seus respectivos suportes foram caracterizados na formas óxido e sulfeto e avaliados na reação de hidrogenação da tetralina, que representa bem os monoaromáticos presentes nas correntes de petróleo. A caracterização textural mostrou que tanto a área específica quanto o volume de poros foram pouco alterados após a incorporação dos óxidos metálicos aos suportes. Os catalisadores apresentaram uma dispersão relativamente boa da fase ativa, conforme indicado pelos resultados de MET, DRX e DRS. Os resultados obtidos por TPD de n-propilamina e por espectroscopia de IV de piridina mostraram que a incorporação de óxidos de molibdênio e níquel levou a um aumento da acidez de Brönsted, o que foi atribuído à criação de novos sítios ácidos associados ao óxido de molibdênio ou a sítios de interface deste com o suporte. Obteve-se uma boa correlação entre a atividade de conversão da tetralina e o rendimento em produtos aromáticos e abertura de ciclo naftênico com a acidez de Brönsted do suporte, com a seguinte ordem de atividade para a conversão da tetralina: NiMo/alumina < NiMo/sílica-alumina < NiMo/alumina zeólita. O aumento do rendimento de produtos de hidrogenação foi relacionado à existência de um efeito eletrônico entre os sítios de Brönsted do suporte e as partículas de sulfeto suportado. No entanto, para o catalisador suportado em alumina-zeólita, onde em princípio a fase hidrogenante estaria distante dos sítios ácidos, sugeriu-se a possibilidade de uma rota alternativa de hidrogenação a partir do metil-indano formado nos centros ácidos da zeólita. / Three sulfided catalysts with the same active phase content (20 wt% of molybdenum oxide and 4 wt% of nickel oxide) and deposited on different supports (alumina, silica-alumina and alumina-Y zeolite) were prepared aiming to obtain bifunctional catalysts with different acidities and good dispersion of the sulfide phase for analyzing the role of the support acidity on the hydroconversion of tetraline. The supports and respective catalysts were characterized in the oxide and sulfide forms and were evaluated for the hydroconversion of tetraline, which is representative of the monoaromatic compounds present in the diesel fraction. The textural characterization indicated that the specific surface areas as well as the pore volumes were very little affected by the impregnation of the metal oxides in the supports. The catalysts presented a relatively good dispersion of the active phase as indicated by TEM, XRD and DRS results. Pyridine IR spectroscopy and n-propylamine TPD results showed an increase of Brönsted acidity after impregnation of molybdenum and nickel oxides, which were attributed to the creation of new acidic sites associated to the supported molybdenum oxide or to sites at the interface of this oxide with the support. A good correlation of the support Brönsted acidity with the overall conversion of tetraline was observed, as well as with the aromatic and ring opening product yields. The following activity ranking for tetraline conversion was observed: NiMo/alumina < NiMo/silica-alumina < NiMo/alumina-zeolite. An increase of the hydrogenation product yields with the support acidity was also observed which was ascribed to an electronic effect between the support acidic Brönsted sites and the sulfide particles. However, for alumina-zeolite supported catalyst, where acidic and hydrogenating sites are not in close vicinity, an alternative reaction route was proposed considering the hydrogenation of the methyl-indane formed by tetraline isomerization on the Brönsted sites.

Made available in DSpace on 2016-06-02T19:55:30Z (GMT). No. of bitstreams: 1 3537.pdf: 5456766 bytes, checksum: 06fbf40d0a799d854a630fbd134a05e8 (MD5) Previous issue date: 2011-03-28 / Financiadora de Estudos e Projetos / The preparation of Mo, CoMo or NiMo catalysts supported on &#61543;-Al2O3, ZrO2 and &#61543;- Al2O3-ZrO2 was studied. The zirconia contend added into alumina was 20 or 40 % wt.. The supports were synthesized via sol-gel and impregnation or direct addition in the synthesis mixture were used to incorporate the metals. The solids were characterized by thermogravimetric analysis (TG/DTG), X-ray diffraction (XRD), X-ray fluorescence (XRD), Zeta potential, N2 adsorption/desorption, hydrogen temperature programmed reduction (H2- TPR), ultraviolet visible diffuse reflectance spectroscopy (DRS-UVvis), transmission electron microscopy (TEM) and evaluated in the HDS of thiophene used as model molecule. The results showed that the synthesis via sol-gel allowed the formation of the above supports with high specific surface area, with zirconia being highly distributed in the alumina framework. The metal incorporation through impregnation or in situ led to catalysts with Mo, Co or Ni species highly dispersed. The activity data of the thiophene HDS on these catalysts indicated a promoter effect of the incorporation of about 20% of zirconia in the alumina that was simultaneous to the well known Co or Ni promoter character, this evidencing that the Mo activity is affected by the nature of the promoter metal and the textural and physico-chemical properties of the supports, which are strongly involved in the HDS mechanism. The main products of the thiophene HDS were butene-1, n-butane, trans-butene-2 and cis-butene-2, result that corroborates the high selective nature of the Mo based catalysts. Due to the close values of the specific reaction rate of the thiophene HDS on the studied catalysts, it can be concluded that the in situ preparation led to catalysts with very similar properties to those prepared by traditional impregnation. This result is highly attractive from a commercial point of view because it eliminates several steps in the catalysts preparation process, therefore, decreasing the preparation time and costs of labor and energy. / Estudou-se a preparação de catalisadores de HDS à base de Mo, CoMo e NiMo suportados sobre &#61543;-Al2O3, ZrO2 e &#61543;-Al2O3-ZrO2. O teor de zircônia incorporada na alumina foi de 20 ou 40 % (m/m). Esses suportes foram sintetizados via sol-gel e a incorporação dos metais realizada por impregnação ou por adição direta dos sais precursores à mistura de síntese. Os sólidos foram caracterizados por análise termogravimétrica (TG/DTG), difração de raios X (DRX), fluorescência de raios X (FRX), potencial Zeta, adsorção/dessorção de N2, redução com hidrogênio a temperatura programada (RTP-H2), espectroscopia por reflectância difusa no ultavioleta visível (DRS-UVvis), microscopia eletrônica de transmissão (MET) e avaliados na hidrodessulfurização do tiofeno utilizado como molécula modelo. Os resultados mostraram que a síntese sol-gel possibilitou a obtenção dos suportes acima com alta área superficial específica, com a zircônia bem distribuída ao longo da rede da alumina. A incorporação dos metais por impregnação ou in situ resultou em catalisadores com alta dispersão das espécies de Mo, Co ou Ni. Dados de atividade de HDS do tiofeno sobre esses catalisadores mostraram que a incorporação da zircônia na alumina, em teores em torno de 20%, teve um efeito promotor nessa reação, o qual se somou ao conhecido caráter promotor do Co e do Ni, evidenciando que a atividade do Mo é afetada pela natureza do metal promotor e pelas propriedades texturais e físico-químicas do suporte, fatores esses envolvidos fortemente no mecanismo de HDS. Os principais produtos da hidrodessulfurização do tiofeno foram buteno-1, n-butano, trans-buteno-2 e cis-buteno-2, o que confirmou a natureza altamente seletiva para HDS dos catalisadores à base de Mo. Pelos valores próximos da taxa específica de reação de HDS do tiofeno sobre espécies de Mo, CoMo ou NiMo, incorporadas por impregnação ou in situ, conclui-se que esse último procedimento conduziu a catalisadores com propriedades similares aos preparados por impregnação tradicional. Esse resultado é altamente atraente do ponto de vista comercial, visto que elimina várias etapas no processo de preparação do catalisador e, consequentemente, diminuindo-se o tempo de preparação e os custos de mão de obra e energia.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-03T20:13:14Z No. of bitstreams: 1 NaideMariaPinheiro_DISSERT.pdf: 846679 bytes, checksum: efdab56810b0bea9a7735f96f3ca7b86 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-09T11:53:17Z (GMT) No. of bitstreams: 1 NaideMariaPinheiro_DISSERT.pdf: 846679 bytes, checksum: efdab56810b0bea9a7735f96f3ca7b86 (MD5) / Made available in DSpace on 2017-01-09T11:53:17Z (GMT). No. of bitstreams: 1 NaideMariaPinheiro_DISSERT.pdf: 846679 bytes, checksum: efdab56810b0bea9a7735f96f3ca7b86 (MD5) Previous issue date: 2016-06-29 / As quest?es jur?dicas peculiares ?s pessoas idosas ganham especial relevo num cen?rio nacional marcado por um vertiginoso processo de envelhecimento populacional. Dentre as in?meras viola??es de que s?o v?timas essas pessoas, ganha destaque o aviltamento das suas liberdades individuais, mediante a supress?o de suas vontades. A pesquisa desenvolvida ao longo deste trabalho tem por objetivo analisar a possibilidade de limita??o do direito ? liberdade individual de pessoa idosa l?cida, especialmente, quando a preserva??o dessa liberdade p?e em risco direitos da mais elevada estatura pertencentes ao mesmo titular. Adota como metodologia de pesquisa o estudo de caso e a pesquisa bibliogr?fica, incluindo, nessa ?ltima, a explora??o de doutrina, legisla??o e decis?es judiciais. O estudo apresenta um tra?ado hist?rico do reconhecimento do direito ? liberdade individual e destaca a sua positiva??o na Constitui??o Federal de 1988. Salienta o car?ter n?o absoluto do direito ? liberdade. Discute se o indiv?duo ? obrigado ao exerc?cio de direito fundamental. Situa a autonomia como uma face do direito ? liberdade. Enfatiza que a senectude n?o se desvela, por si s?, como causa de incapacidade civil. Analisa as altera??es legislativas ocorridas em 2015, quanto ao resguardo da autonomia do indiv?duo. Evidencia a prote??o ? autonomia da pessoa idosa no direito brasileiro e no direito internacional. Examina a viabilidade de garantia da prote??o ? pessoa idosa, resguardando, ao mesmo tempo, a sua autonomia. Explicita os limites ? atua??o do Minist?rio P?blico, quando diante de pessoa idosa l?cida em situa??o de risco. Empreende estudo de caso, no qual o Judici?rio reconhece que a liberdade do idoso l?cido deveria ser preservada, ainda que desse resguardo resultasse a morte do anci?o. A partir da an?lise do elenco de bens prim?rios de John Rawls e da investiga??o dos direitos integrantes do m?nimo existencial, delineia novo conceito - o de m?nimo essencial -, constitu?do pelas liberdades individuais. Distingue m?nimo essencial de n?cleo essencial dos direitos fundamentais e explicita o ambiente de aplicabilidade do novo conceito. Chega ? conclus?o da utilidade da ado??o do m?nimo essencial como par?metro para solu??o de casos que envolvam direitos de apenas um titular, destacando a relev?ncia de seu emprego no resguardo da autonomia da pessoa idosa. / The distinctive legal issues concerning the elderly take on special importance in a national scenario where a vertiginous aging process of the population is taking place. Among the numerous violations of rights the elderly are subject to is the debasement of their individual freedom through the suppression of their right to choice. The research developed throughout this work aims to examine the possibility of limiting the right to individual freedom of a mentally healthy elderly, especially when the preservation of that freedom endangers rights of a higher order belonging to that same individual. The research methodology adopted is that of case study and bibliography research including, in the latter, an investigation into the doctrine, the laws and judicial decisions. The study presents a historical tracing of the recognition of the right to individual freedom and underscores its assertiveness in the Federal Constitution of 1988. It stresses that the right to freedom is not a right of an absolute nature; argues whether the individual is required to exercise a fundamental right; places autonomy as the focus of the right to individual freedom; emphasizes that senescence alone does not suffice to cause civil disability; analyzes the legislative changes that took place in 2015 regarding the protection of individual autonomy; gives prominence to the protection of the autonomy of the elderly in Brazilian law and international law; examines the feasibility of ensuring protection for the elderly, while protecting their autonomy; expounds on the limits of the District Attorney?s authority, when dealing with a mentally healthy elderly who is at risk; and carries on a case study in which the judiciary system recognizes that the freedom of a mentally healthy elderly should be preserved, even if that protection resulted in the death of such elderly person. As a result of the analysis of John Rawls? index of primary goods and an investigation of those rights that make up the existential minimum, a new concept is outlined ? the essential minimum ?, made up of individual freedoms. It makes a distinction between the essential minimum and the essential core of the fundamental rights and describes the environment for the applicability of the new concept. In conclusion, it asserts the usefulness of adopting the essential minimum as a parameter for the resolution of cases involving the rights of only one individual, highlighting the relevance of its use in the protection of the autonomy of the elderly.

Três catalisadores contendo o mesmo teor de fase ativa (20% de óxido de molibdênio e 4% de óxido de níquel), mas constituídos por diferentes suportes (alumina, sílica-alumina e alumina zeólita) foram preparados com o objetivo de se obter catalisadores bifuncionais com acidez distinta e boa dispersão da fase metálica visando analisar o papel da acidez do suporte na conversão da tetralina. Os catalisadores e seus respectivos suportes foram caracterizados na formas óxido e sulfeto e avaliados na reação de hidrogenação da tetralina, que representa bem os monoaromáticos presentes nas correntes de petróleo. A caracterização textural mostrou que tanto a área específica quanto o volume de poros foram pouco alterados após a incorporação dos óxidos metálicos aos suportes. Os catalisadores apresentaram uma dispersão relativamente boa da fase ativa, conforme indicado pelos resultados de MET, DRX e DRS. Os resultados obtidos por TPD de n-propilamina e por espectroscopia de IV de piridina mostraram que a incorporação de óxidos de molibdênio e níquel levou a um aumento da acidez de Brönsted, o que foi atribuído à criação de novos sítios ácidos associados ao óxido de molibdênio ou a sítios de interface deste com o suporte. Obteve-se uma boa correlação entre a atividade de conversão da tetralina e o rendimento em produtos aromáticos e abertura de ciclo naftênico com a acidez de Brönsted do suporte, com a seguinte ordem de atividade para a conversão da tetralina: NiMo/alumina < NiMo/sílica-alumina < NiMo/alumina zeólita. O aumento do rendimento de produtos de hidrogenação foi relacionado à existência de um efeito eletrônico entre os sítios de Brönsted do suporte e as partículas de sulfeto suportado. No entanto, para o catalisador suportado em alumina-zeólita, onde em princípio a fase hidrogenante estaria distante dos sítios ácidos, sugeriu-se a possibilidade de uma rota alternativa de hidrogenação a partir do metil-indano formado nos centros ácidos da zeólita. / Three sulfided catalysts with the same active phase content (20 wt% of molybdenum oxide and 4 wt% of nickel oxide) and deposited on different supports (alumina, silica-alumina and alumina-Y zeolite) were prepared aiming to obtain bifunctional catalysts with different acidities and good dispersion of the sulfide phase for analyzing the role of the support acidity on the hydroconversion of tetraline. The supports and respective catalysts were characterized in the oxide and sulfide forms and were evaluated for the hydroconversion of tetraline, which is representative of the monoaromatic compounds present in the diesel fraction. The textural characterization indicated that the specific surface areas as well as the pore volumes were very little affected by the impregnation of the metal oxides in the supports. The catalysts presented a relatively good dispersion of the active phase as indicated by TEM, XRD and DRS results. Pyridine IR spectroscopy and n-propylamine TPD results showed an increase of Brönsted acidity after impregnation of molybdenum and nickel oxides, which were attributed to the creation of new acidic sites associated to the supported molybdenum oxide or to sites at the interface of this oxide with the support. A good correlation of the support Brönsted acidity with the overall conversion of tetraline was observed, as well as with the aromatic and ring opening product yields. The following activity ranking for tetraline conversion was observed: NiMo/alumina < NiMo/silica-alumina < NiMo/alumina-zeolite. An increase of the hydrogenation product yields with the support acidity was also observed which was ascribed to an electronic effect between the support acidic Brönsted sites and the sulfide particles. However, for alumina-zeolite supported catalyst, where acidic and hydrogenating sites are not in close vicinity, an alternative reaction route was proposed considering the hydrogenation of the methyl-indane formed by tetraline isomerization on the Brönsted sites.