[pt] Os catalisadores de platina, níquel e platina suportados em sílica-alumina e sílica mesoporosa (SBA-15) foram investigados para o hidrotratamento do óleo de coco para produção de bio-óleo. Os suportes foram carregados com 1 por cento de Pt e 5 por cento de Ni e os catalisadores resultantes foram caracterizados para determinar suas propriedades estruturais e de textura. Os catalisadores foram reduzidos e testados em um reator semi-descontínuo a 360 C sob 10 MPa de hidrogênio durante 4 horas. Foram obtidos 30-40 por cento de remoção de oxigênio. As curvas de destilação dos produtos e seu ponto de inflamação e gravidade específica (a 20 C) foram determinados pelos métodos oficiais ASTM e ABNT/NBR a serem comparados com o diesel derivado do petróleo. As curvas de destilação e as propriedades físico-químicas foram muito próximas das especificações estabelecidas pela legislação brasileira para o diesel comercial. Destilou-se 90 por cento do volume de cada produto na faixa de temperatura de 180-370 C, o ponto de inflamação ficou entre 76-81 e o número do índice de cetano foi calculado como 47-48, de acordo com as especificações do diesel comercial. Os produtos obtidos com os catalisadores Pt/SiO2Al2O3 e PtNi/SBA-15 também apresentaram gravidade específica dentro da faixa de especificação (865 e 860,0 kg/m3, respectivamente). Os catalisadores utilizados mostraram sua potencial aplicação para a produção de biocombustíveis na faixa de diesel de petróleo pelo processo de hidrotratamento de óleo de coco. / [en] Platinum, platinum nickel and nickel catalysts supported on silicaalumina and mesoporous silica (SBA-15) were investigated for hydrotreating of coconut oil to produce bio oil. The supports were loaded with 1 percent Pt and 5 percent Ni content and the resulted catalysts were caracterized to determine their strutural and textural properties. The catalysts were reduced and tested in a semi-batch reactor at 360 C under 10 MPa of hydrogen during 4 hours. It was obtainned 30-40 percent of oxygen removal. The distillation curves of products and their flash point and specific gravity (at 20 C) were determined by oficials ASTM, and ABNT/NBR methods to be compared with the petroleum-derived diesel. The distillation curves and physicochemical properties were very close to specifications stabilished by Brazilian legislation for comercial diesel. 90 percent of the volume of each product was distilled in the temperature range of 180-370 C, the flash point was between 76-81 and the cetane index number was calculated as 47-48 in agreement with the specifications for comercial diesel. The products obtainned using the Pt/SiO2Al2O3 and PtNi/SBA-15 catalysts also presented specific gravity within the specification range (865 e 860.0 kg/m3 respectively). The catalysts used showed their potential application for the production of biofuels in the petroleum diesel range by coconut oil hydrotreatment process.

Ce travail de thèse étudie l’influence de la morphologie des feuillets de sulfure de molybdène sur la sélectivité des catalyseurs d’hydrotraitement. Les feuillets de phase active présentent en effet deux types de bords appelés « M-edge » et « S-edge » susceptibles de conduire à des réactivités différentes. Le changement de la morphologie 2D des feuillets pourrait modifier les proportions de bords M et S exposés et ainsi les propriétés catalytiques des catalyseurs sulfures. Pour cela, des catalyseurs non promus (Mo) et promus (CoMo), supportés sur alumine ont été préparés par imprégnation à sec puis sulfurés dans des conditions variées (gaz et température). Des tests catalytiques en hydrodésulfuration (HDS) sélective des essences de FCC (sélectivité HDS/HYD) ont ensuite permis d’évaluer l’impact de la morphologie en s’appuyant sur des modèles géométriques construits à partir de calculs DFT et de caractérisations expérimentales (TEM, IR (CO), TPR, XPS). Les résultats obtenus pour les catalyseurs de type Mo semblent ainsi confirmer l’influence de la morphologie 2D sur la sélectivité HDS/HYD, le bord M paraissant être le plus sélectif pour les catalyseurs non promus. Ils mettent également en évidence l’importance de la réductibilité plus ou moins marquée des bords sur les propriétés catalytiques, notamment sur le bord M. Le changement des conditions de sulfuration semble donc affecter la morphologie des particules mais également les propriétés chimiques propres à chaque bord. En ce qui concerne les catalyseurs promus, la variation des conditions de sulfuration semble agir essentiellement au niveau de la répartition du promoteur entre les bords M et S. Cependant, les interactions avec le support paraissent constituer un frein aux effets de promotion. Dans ce contexte, les sulfurations à haute température sous H2S pur permettent d’obtenir des gains significatifs en activité et sélectivité. Ces résultats semblent dus à de faibles interactions avec le support et une décoration privilégiée du bord S qui pourrait favoriser la réaction d’HDS et limiter la réaction d’HYD. Au final, les interprétations effectuées en terme de morphologie 2D tendent à confirmer que ce paramètre peut constituer un axe de développement intéressant pour les catalyseurs d’hydrotraitement. L'optimisation des conditions de sulfuration permettraient bien de faire varier la morphologie et le taux de décoration du promoteur des catalyseurs, améliorant ainsi significativement l'activité et la sélectivité / This thesis examines the influence of the morphology of particles of molybdenum sulfide on selectivity of hydrotreating catalysts. Nanoparticles of active phase present two types of edges called “M-edge” and “S-edge” which may lead to different reactivities. The change in morphology of the 2D sheets could change the proportions of M and S edges exposed and thus the catalytic properties of sulfide catalysts. For this, non-promoted (Mo) and promoted (CoMo) catalysts, supported on alumina were prepared by dry impregnation and sulfide in various conditions (gas and temperature). Catalytic tests in selective hydrodesulfurization (HDS) of FCC gasoline (selectivity HDS /HYD) were then used to assess the impact of the morphology based on geometrical models which were constructed with DFT calculations and experimental characterizations (TEM, IR (CO), TPR, XPS). The results for Mo catalysts seem to confirm the influence of the 2D morphology selectivity HDS / HYD, M-edge appearing to be the most selective for non-promoted catalysts. They also highlight the importance of the reducibility more or less pronounced of the edges on the catalytic properties, especially on the M-edge. The different conditions of sulfidation seem to affect the morphology of the particles but also the specific chemical properties at each edge. Regarding to the promoted catalysts, the different conditions of sulfidation appear to act primarily at the distribution of the promoter between the M and S edges. However, interactions with the carrier appear to constitute an obstacle to promoting effects. In this context, sulfidations at high temperature in pure H2S lead to obtain significant gains in activity and selectivity. These results appear to be due to weak interactions with the carrier and to the presence of the promoter on the S-edge which could promote the HDS reaction and limit the HYD reaction. Finally, the interpretations made in terms of 2D morphology tend to confirm that this parameter can be an interesting line of development for hydrotreating catalysts. Optimization of the sulfidation conditions could effectively allow to vary the morphology and the rate of decoration of promoted catalysts which significantly improve the activity and selectivity

L'hydrotraitement est un procédé catalytique important dans le raffinage du pétrole qui utilise des catalyseurs bimétalliques sulfurés NiWS ou NiMoS (ou CoMoS) supportés sur alumine. Leur mode conventionnel de préparation implique l’imprégnation d'une solution aqueuse de sels de Mo/W et de Ni/Co, puis l’activation par un agent sulfo-réducteur (H2S/H2). Pour répondre aux exigences environnementales et améliorer l'efficacité de l'hydrotraitement, des améliorations permanentes de la performance de ces systèmes catalytiques sont attendues. Ce travail se concentre sur la préparation de catalyseurs d'hydrotraitement hautement actifs par une approche de chimie de surface contrôlée (CSC) qui implique l'imprégnation successive de précurseurs moléculaires de MoV et NiII en solvant organique sur un support silice-alumine traité thermiquement. Dans la première partie de cette thèse, la genèse de la phase active du catalyseur CSC et conventionnel Mo et NiMo est étudiée par quick-XAS combinée à d’autres techniques (chimiométrie, XPS, RPE, STEM-HAADF, modélisation moléculaire). Nous proposons ainsi des structures moléculaires depuis les précurseurs oxydes de Mo et Ni supportés jusqu’aux nombreuses espèces intermédiaires (oxysulfure et sulfures) en fonction de la température. Cette analyse multi-technique permet d'abord de révéler les spécificités de la genèse des catalyseurs CSC et conventionnels qui peuvent expliquer leurs différentes activités catalytiques. Ensuite, elle révèle également de nouvelles connaissances sur les mécanismes d’insertion du Ni dans la phase NiMoS en fonction de la préparation. Dans la seconde partie, la possibilité de remplacer Co et Ni comme promoteurs est explorée. Ceci est entrepris en synthétisant des catalyseurs alternatifs de type XYMoS, où X et Y sont des métaux de transition 3d. Comme suggéré par des études de modélisation quantiques antérieures, certaines formulations XYMoS peuvent présenter un effet de synergie analogue à ceux des phases actives CoMoS et NiMoS. L’étude des formulations les plus prometteuses méritent d'être approfondies afin de mieux comprendre leur fonctionnement. / Hydrotreating is an important catalytic process in petroleum refining which uses sulfided bimetallic catalysts NiWS or NiMoS (or CoMoS) supported on alumina. Their conventional preparation involves an incipient wetness impregnation of an aqueous solution of Mo/W and Ni/Co salts, and then activation by a sulfo-reductive agent (such as H2S/H2). To meet environmental regulations and improve the energy efficiency of hydrotreatment, permanent improvements on the performance of these catalytic systems are expected. This work is thus focused on the preparation of highly active hydrotreating catalysts through a controlled surface chemistry (CSC) approach; which involves the successive impregnation of Mo5+ and Ni2+ molecular precursors in an organic solvent on a thermally treated silica-alumina support. In the first part of this thesis, the active phase genesis of CSC and conventional Mo and NiMo catalysts is studied by in situ quick-XAS combined with various other techniques (chemometrics, XPS, EPR, STEM-HAADF, molecular modeling). We thus propose molecular structures from the oxide of supported Mo and Ni precursors up to the numerous intermediate sulfided species as a function of temperature. This multi-technique analysis enables first to reveal the specific features of the genesis of CSC and conventional catalysts which may explain their different catalytic activities. Then, it also reveals new insights into the mechanisms of Ni promoter incorporation into the NiMoS phase as a function of the preparation. In the second part, the feasibility of replacing Co and Ni as promoters is explored. Using the CSC method, we attempted to synthesize alternative catalysts of the form XYMoS ternary sulfides, where X and Y are 3d transition metals. As suggested by previous quantum simulations, certain XY formulations possibly reveal a synergy effect as observed in CoMoS and NiMoS active phases. The most promising formulations merit further investigations.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-10-13T19:12:36Z No. of bitstreams: 1 Dissertação de Mestrado PPEQ - Alexsandro Fausto de Araújo.pdf: 3235090 bytes, checksum: e4c74119c72ea3471a47fb36a515e632 (MD5) / Made available in DSpace on 2016-10-13T19:12:36Z (GMT). No. of bitstreams: 1 Dissertação de Mestrado PPEQ - Alexsandro Fausto de Araújo.pdf: 3235090 bytes, checksum: e4c74119c72ea3471a47fb36a515e632 (MD5) Previous issue date: 1998-11-13 / Com a crescente exigência dos mercados e da sociedade por produtos derivados do petróleo cada vez mais livres de contaminantes que prejudicam o meio ambiente e a qualidade dos mesmos, os parques de refino de petróleo vêm investindo cada vez mais em tecnologias que permitam uma produção mais limpa, rentável e econômica. Desse modo, O hidrotratamento tem assumido um papel cada vez mais importante dentro das refinarias, sendo aplicado em diversos cortes do petróleo, desde os mais leves até os mais pesados. O hidrotratamento consiste na adição de hidrogênio na carga a ser hidrotratada com o propósito de, através de reações de hidrogenação, reduzir ou eliminar os componentes contaminantes presentes na carga, como o enxofre, nitrogênio, oxigênio, olefinas, diolefinas e metais. A adição de hidrogênio é feita em cocorrente descendente, onde a carga e o hidrogênio entram misturados e pré aquecidos no topo do reator a uma razão pré-definida (Razão H2/Carga), sendo esta forma a mais utilizada em escala industrial devido aos seus inúmeros benefícios. O foco da unidade de HDT é o reator, pois é nele que os contaminantes são removidos da carga. O tipo de reator mais utilizado é o de leito fixo (Trickle Bed Reactor - TBR). A nafta é a principal matéria prima do setor petroquímico nacional, de modo que todas as unidades instaladas são baseadas nela. A partir dela são produzidos os componentes da primeira geração do setor petroquímico. O HDT de nafta ainda é um tema pouco explorado mas que vem recebendo maior importância nos últimos anos. Por isso, este trabalho foi desenvolvido sobre esse tema, construindo e simulando modelos dinâmicos de reatores de leito fixo, com alimentação em cocorrente de uma unidade reacional de HDT de nafta, composta por um reator trifásico de conversão de diolefinas, utilizado para o pré-tratamento da nafta de coqueamento retardado e dois reatores bifásicos (G-S) de HDT de nafta, dispostos em série com resfriamento por quenchs independentes entre os leitos dos reatores e entre os reatores, para a redução de teores de enxofre, nitrogênio e olefinas presentes na nafta através das reações de hidrodessulfurização, hidrodesnitrogenação e saturação de olefinas. Foram construídos dois programas em ambiente MATLAB®, um para simular o reator trifásico de conversão diolefinas e outro para os reatores bifásicos de HDT de nafta, ambos simularam correntes de alimentação de nafta com diferentes níveis de contaminação, para que fossem avaliados os efeitos. Os programas simularam os perfis dinâmicos das temperaturas das fases envolvidas e das concentrações dos contaminantes e hidrogênio. Os resultados obtidos para o reator de conversão de diolefinas e os reatores de HDT de nafta se mostraram bem coerentes com relação aos fenômenos envolvidos. O reator de conversão de diolefinas atingiu o estado estacionário aos 80 minutos e os reatores de HDT de nafta aos 2 minutos, com os teores de contaminantes próximos de zero na saída do reator. Os resultados das simulações realizadas para os dois tipos de nafta apresentaram perfis dinâmicos semelhantes diferindo apenas quanto à temperatura mais elevada atingida no início do primeiro reator de HDT de nafta no caso da nafta com maior teor de contaminação. / With the growing demand of markets and society by oil products increasingly free of contaminants that harm the environment and their quality, oil refining plants have been increasingly investing in technologies to cleaner production, profitable and economical. Thus, the hydrotreating has assumed an increasingly important role in the refinery and is used in many petroleum cuts, from the lightest to the heaviest. The hydrotreating is the addition of hydrogen in the load to be hydrotreated in order to, via hydrogenation reactions, reduce or eliminate the contaminating components present in the load, such as sulfur, nitrogen, oxygen, olefins, diolefins and metals. The addition of hydrogen is done in descending current, where load and hydrogen enter mixed and pre heated at the top of the reactor to a pre-defined (ratio H2/Oil), and this way the most used at industrial scale due to its numerous benefits. The focus of the HDT unit is the reactor, because that is where the contaminants are removed from the load. The most used type of reactor is the fixed bed (Trickle Bed Reactor - TBR). Naphtha is the main raw material of the national petrochemical industry, so that all installed units are based on it. From there, the components of the first generation of the petrochemical industry are produced. The naphtha HDT is still a subject little explored but it's getting more important in recent years. Therefore, this study was conducted on this issue, building and simulating dynamic models of fixed bed reactors with feed in cocurrente of a reactional unit of HDT naphtha, consisting of a three-phase reactor diolefins conversion, used for pretreatment naphtha delayed coking and two dual-phase reactors (G-S) naphtha HDT arranged in series with cooling by independent quenchs between beds of the reactor and between the reactors to reduce contents of sulfur, nitrogen and olefins present in the naphtha through reactions of hydrodesulfurization, hidrodesnitrogenação and saturation of olefins. Were built two programs in MATLAB®, one to simulate the three-phase reactor diolefins conversion and one for the dual-phase reactors naphtha HDT, both simulated currents naphtha feed with different levels of contamination, so that the effects are assessed. The simulated programs dynamic profiles of the temperatures of the phases involved and the concentrations of contaminants and hydrogen. The results obtained for diolefins conversion reactor and the reactors of naphtha HDT were well consistent with relation to the phenomena involved. The diolefins conversion reactor reached steady state at 80 minutes and the HDT reactors naphtha after 2 minutes, with near zero contaminant levels in the reactor output. The results of simulation performed for the two types of naphtha showed similar dynamic profiles differing only as to the highest temperature reached at the beginning of the first naphtha HDT reactor in the case of naphtha higher contamination level.

Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.

Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.

Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.