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Craqueamento termocatal?tico de ?leo de girassol na presen?a da peneira molecular SAPO-5Oliveira, Ricardo Miguel de 06 December 2011 (has links)
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Previous issue date: 2011-12-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The catalytic cracking of triglycerides presents itself as a possible alternative to the
production of biofuels with low emission of pollutants. In this work were synthesized the
SAPO-5, the catalysts for the cracking reaction of soybean oil is presented. The solids were
powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG) and infrared
spectroscopy (FTIR). The analyses indicated that the synthesis method has employed to
obtain materials with high surface area and high acid. The soybean oil thermal and thermal
catalytic cracking, realized from the room temperature to 450 ?C in a simple distillation
system, has allowed obtaining two liquid fractions, each consisting of two phases, one
aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has
shown high acid index, even in the thermal catalytic process. The products obtained in the
cracking of soybean oil were analyzed by distillation, acid number, infra-red spectroscopy,
density, viscosity, carbon residue, cetane number determination and characterization. The
analysis of the products obtained in the presence and in the absence of the SAPO-5 permitted
to conclude that all the solids tested presented catalytic activity in the deoxygenation of final
products only at the second step of the cracking process / O craqueamento catal?tico de triacilglicer?deos se apresenta como uma alternativa vi?vel para
a produ??o de biocombust?veis com baixa emiss?o de poluentes. Neste trabalho foi sintetizado
o SAPO-5, o catalisador foi utilizado na rea??o de craqueamento do ?leo de Girassol. O
s?lido foi caracterizado por difra??o de raios -X, an?lise termogravim?trica, espectroscopia no
infravermelho. As an?lises indicaram que atrav?s do m?todo de s?ntese empregado foram
obtidos materiais com elevada ?rea espec?fica e alta acidez. A partir do craqueamento t?rmico
e termocatal?tico do ?leo de girassol, realizado desde a temperatura ambiente at? 450 oC em
um sistema de destila??o simples, foram obtidas duas fra??es l?quidas, cada uma contendo
duas fases, uma aquosa e outra org?nica. A primeira fra??o do l?quido org?nico obtido
apresentou alto ?ndice de acidez, no processo de craqueamento t?rmico. Os produtos obtidos
no craqueamento de ?leo de Girassol foram analisados por destila??o, ?ndice de acidez,
espectroscopia no infravermelho, densidade, viscosidade e determina??o do ?ndice de cetano.
A an?lise dos produtos obtidos na presen?a e na aus?ncia do SAPO-5, sintetizados permitiu
concluir que todos os s?lidos testados apresentaram atividade catal?tica para a desoxigena??o
dos produtos finais apenas na segunda etapa do processo de craqueamento
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S?ntese e caracteriza??o de ?xidos de zinco e de magn?sio suportados em A1SBA-15 para produ??o de biodieselGalv?o, Luzia Patr?cia Fernandes de Carvalho 23 August 2012 (has links)
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Previous issue date: 2012-08-23 / To overcome the challenge of meeting growing energy demand in a sustainable way,
biodiesel has shown very promising as alternative energy can replace fossil fuels, even
partially. Industrially, the biodiesel is produced by homogeneous transesterification reaction
of vegetable oils in the presence of basic species used as catalysts. However, this process is
the need for purification of the esters obtained and the removal of glycerin formed after the
reaction. This context, the alternative catalysts have that can improve the process of biodiesel
production, aiming to reduce costs and facilitate its production. In this study, the AlSBA-15
support with Si / Al ratio = 50 was synthesized, as like as the heterogeneous catalysts of zinc
oxide and magnesium supported on mesoporous AlSBA-15 silica, in the concentrations of 5,
10, 15 and 30 %, relative to the support. The textural properties and structural characterization
of catalysts and supports were determined by techniques: X-ray diffraction (XRD), scanning
electron microscopy (SEM), transmission electron microscopy (TEM) coupled to the
chemical analyzer, adsorption / desorption of N2, thermal analysis (TG / DTG), absorption
spectroscopy in the infrared (FTIR) and X-ray photoelectron spectroscopy (XPS).
Characterization results indicated that the support AlSBA-15 retained the hexagonal ordered
after the incorporation of zinc oxide and magnesium oxide in the holder. For heterogeneous
catalysts, ZnO-AlSBA-15, that was observed the presence of zinc oxide nanoparticles
dispersed in the surface and interior channels of the mesoporous and microporous support.
The catalytic activity was evaluated by the transesterification reaction of sunflower oil via
methylic route, and some reaction parameters were optimized with the most active catalyst in
biodiesel production by sunflower oil. For the series of heterogeneous catalysts, the sample
with 30 % ZnO supported on AlSBA-15 showed a better conversion of triglyceride to methyl
esters, about 95.41 % of reaction conditions: temperature 175 ?C, with molar ratio of 42:1,
stirring at 200 rpm and under a pressure of 14 bar for 6 h. The catalyst MgO-AlSBA-15
showed no catalytic activity in the studied reactions / Para superar o desafio de atender a crescente demanda por energia de forma sustent?vel, o
biodiesel tem se demonstrado bastante promissor como alternativa energ?tica, que possa
substituir os combust?veis fosseis, mesmo que parcialmente. Industrialmente, o biodiesel ?
produzido atrav?s de rea??o homog?nea de transesterifica??o de ?leos vegetais na presen?a de
esp?cies b?sicas utilizadas como catalisadores. Entretanto, este processo h? a necessidade de
purifica??o dos ?steres obtidos e a remo??o da glicerina formada ap?s a rea??o. Diante deste
contexto, tem-se buscado catalisadores alternativos, que possa aprimorar o processo de
produ??o de biodiesel, visando diminuir os custos e facilitar a sua produ??o. Neste trabalho,
foram sintetizados o suporte AlSBA-15 na raz?o Si/Al = 50, e os catalisadores heterog?neos
de ?xido de zinco e de magn?sio suportado sobre s?lica mesoporosa AlSBA-15, nas
concentra??o de 5, 10, 15 e 30 %, com rela??o ao suporte. As propriedades texturais e a
caracteriza??o estrutural dos catalisadores e do suporte foram determinadas pelas t?cnicas de:
difratometria de raios X (DRX), microscopia eletr?nica de varredura (MEV), microscopia
eletr?nica de transmiss?o (MET) acoplada ao analisador qu?mico, adsor??o/dessor??o de N2,
an?lise t?rmica (TG/DTG), espectroscopia de absor??o na regi?o do infravermelho (FTIR) e
espectroscopia fotoeletr?nica de raios X (XPS). Os resultados de caracteriza??o indicaram
que o suporte AlSBA-15 preservou a estrutura hexagonal ordenada, ap?s a incorpora??o do
?xido de zinco e do ?xido de magn?sio no suporte. Em rela??o aos catalisadores
heterog?neos, ZnO-AlSBA-15, observou-se a presen?a de nanopart?culas de ?xido de zinco
dispersas na superf?cie e no interior dos canais microporosos e mesoporosos do suporte. A
atividade catal?tica foi avaliada pela rea??o de transesterifica??o do ?leo de girassol via rota
met?lica, e alguns par?metros reacionais foram otimizados com o catalisador mais ativo na
produ??o de biodiesel pelo ?leo de girassol. Para as s?ries de catalisadores heterog?neos, a
amostra com 30 % ZnO suportado na AlSBA-15 apresentou melhor convers?o dos
triglicer?deos em ?steres met?licos, cerca de 95,41 %, nas condi??es reacional de: temperatura
de 175 ?C, com raz?o molar de 42:1, em agita??o de 200 rpm e sob press?o de 14 bar durante
6 h. O catalisador MgO-AlSBA-15 n?o apresentou atividade catal?tica nas rea??es estudadas
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Aspergillus terreus isolamento, identifica??o e avalia??o da capacidade catal?tica na redu??o de cetonas pr?-quiraisEspeleta, Alexandre de Freitas 30 September 2014 (has links)
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Previous issue date: 2014-09-30 / The object of this inquiry is the isolation, the selection and the potential evaluation of a microorganism with biocatalytic activity in carrying out selective-stereo biorreduction of pro-chial ketones. In the research procedure, Fungi was isolated from soil samples contaminated with lead. Only one of the isolates fungi, identified as Aspergillus terreus, presented good catalytic activity in the reduction of acetophenone. The biomass was grown submerged in broth culture, inoculated with 1,1 x 103 (spores/mL of malt extract) and maintained at 30?C under orbital agitation. Morphological differences and catalytic activity were evaluated in function of the orbit of agitation during the growth process. The catalytic activity in terms of conversion of acetophenone and enantiomeric excess (S), ee_S, in 1-feniletanol, was determinate in conjunction with the growth curve of the fungus. The results were used to construct a graphic showing the variation of quality of the catalyst, according to age of biomass. Apart from acetophenone were tested o-Xacetophenone, p-Xacetophenone and m-Xacetophenone (X = methyl, methoxy, nitro, fluorine, bromine). For reaction with 24 hours growing cells (30?C; 150rpm/r = 50mm), the conversions were between 27% and 97% with ee_S between 41% and 83%. For reactions with cells in suspension in buffered medium (pH = 4.5 ? 6,5) was decrease in activity/selectivity at pH above 5.5. The kinetics of conversion was evaluated for biomasses with different ages and for various concentrations of acetophenone. An amount between 100mg and 200mg of biomass (dry mass) with 168 hours of culture can convert 100mg of acetophenone to 1(S)-feniletanou ee_S (91%) with 98% yield in 72 hours of reaction (93% at 48 hours). The development of this process described above, constitutes the body of this thesis. / O objetivo desta pesquisa ? o isolamento, a sele??o e a avalia??o de um microorganismo com atividade biocatalisadora na biorredu??o estereoseletiva de cetonas pro-quirais. No procedimento de investiga??o, fungos foram isolados de amostras de solo contaminadas com chumbo. Apenas um dos fungos isolados, identificado geneticamente como Aspergillus terreus, apresentou boa atividade catal?tica na redu??o de acetofenona. A biomassa foi cultivada submersa no caldo de cultura, inoculado com 1,1x103 (esporos/mL de extrato de malte) e mantido a 30? sob agita??o orbital. Diferen?as morfol?gicas e de atividade catal?tica foram avaliadas em fun??o da ?rbita de agita??o durante o crescimento. A atividade catal?tica, em termos de convers?o da acetofenona e do excesso enantiom?rico (S), ee_S, no 1-feniletanol, foi determinada em conjunto com a curva de crescimento do fungo. Os resultados foram usados para construir um gr?fico mostrando a varia??o da qualidade do catalisador em fun??o da idade da biomassa. Al?m de acetofenona, foram testadas o-Xacetofenona, p-Xacetofenona e m-Xacetofenona (X=metil, metoxi, nitro, fl?or, bromo). Para 24 horas de rea??o com c?lulas em crescimento (30?C; 150rpm/r = 50mm), as convers?es ficaram entre 94 e 100%, com ee_S ? 98% para acetofenona e para acetofenonas orta ou meta substitu?das. Com substituintes na posi??o para, a convers?o ficou entre 27% e 97%, com ee_S entre 41% e 83%. Para rea??es com c?lulas em suspens?o em meio tamponado (pH = 4,5 ? 6,5), houve queda na atividade/seletividade em pH acima de 5,5. A cin?tica de convers?o foi avaliada para biomassas com idades distintas e para v?rias concentra??es de acetofenona. Uma quantidade entre 100mg e 200mg de biomassa (massa seca) com 168 horas de cultura, pode converter 100mg de acetofenona a 1(S)-feniletanol (ee_S 91%), com 98% de rendimento em 72 horas de rea??o (93% em 48 horas). O desenvolvimento desse processo, acima descrito, constitui o corpo desta Tese.
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Degrada??o termocatal?tica de petr?leo pesado utilizando SBA-15 contendo alum?nio e c?rioAra?jo, Larissa Cicianny Luz Ferreira de 26 August 2016 (has links)
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Previous issue date: 2016-08-26 / Os nanomateriais (catalisadores) mesoporosos e microporosos s?o considerados promissores para obten??o de derivados leves a partir de fra??es pesadas do petr?leo e como adsorventes para prote??o ambiental. Este trabalho reportou a sintetize pelo m?todo hidrot?rmico, e caracteriza??o de catalisadores heterog?neos mesoporosos, do tipo SBA-15, com adi??o dos metais c?rio e alum?nio, avaliando sua atividade e seletividade na degrada??o t?rmica de ?leo pesado. As amostras dos materiais nanoestruturados foram caracterizadas por an?lise termogravim?trica (TG/DTG), difra??o de raios X (DRX), microscopia eletr?nica de varredura (MEV), espectroscopia de fluoresc?ncia de raios X (FRX), espectroscopia de absor??o na regi?o do infravermelho com transformada de Fourier (FTIR) e adsor??o de nitrog?nio (BET). A caracteriza??o mostrou que os materiais sintetizados resultaram em um catalisador nanoestruturado, ordenado e com di?metro de poros e ?rea superficial de acordo com a literatura existente. Com o intuito de verificar a atividade catal?tica dos mesmos, utilizou-se uma amostra de petr?leo pesado (?API=14), fornecido pela Petrobras, realizando-se atrav?s da termogravimetria o processo de degrada??o t?rmica e catal?tica do ?leo. Mediante as curvas termogravim?tricas obtidas, observou-se uma redu??o na temperatura de in?cio do processo de decomposi??o catal?tica do petr?leo. Atrav?s do modelo cin?tico n?o isot?rmico de Ozawa Flynn Wall (OFW) obtiveram-se alguns par?metros para determina??o da energia de ativa??o aparente das decomposi??es. Os resultados obtidos das difra??es de raio X mostraram atrav?s de picos caracter?sticos que a estrutura hexagonal foi formada, verificando que a melhor raz?o foi Si/Ce = 5 devido a sua intensidade em alto ?ngulo. Os espectros de infravermelho apresentaram absor??es caracter?sticas de materiais da fam?lia SBA-15. Da adsor??o de nitrog?nio, obtendo-se par?metros compat?veis aos encontrados na literatura, que lhes conferem serem promissores na ?rea da degrada??o de petr?leo, devido aos seus mesoporos facilitarem o acesso de grandes mol?culas. O di?metro m?dio dos poros variou significativamente com a incorpora??o do alum?nio e do c?rio. A espessuras de parede (Wt) ficou na faixa de 2,96 a 4,07 nm, observando assim um aumento deste par?metro que deve-se a incorpora??o dos metais na parede, indicando que a incorpora??o do c?rio, n?o bloqueou os mesoporos. O acr?scimo de alum?nio reduziu a area superficial (SBET) de 893 para 763 m2g-1, no entanto com o acr?scimo do c?rio com o alum?nio esta ?rea aumentou para 826 m2g-1. Para o petr?leo a temperatura inicial e final de perda de massa; apresentando apenas dois eventos devido ao teor de enxofre mercapt?dico, o qual influencia no surgimento do terceiro evento, j? que esse teor ? medido pela quantidade de enxofre nos an?is arom?ticos (HC pesados). A mistura do Petr?leo + 12% de Ce5Al50SBA-15 evidenciando a atividade catal?tica deste material. / Nanomaterials (catalysts) are microporous and mesoporous considered promising for obtaining light oil products from heavy oil fractions and adsorbents for environmental protection. This paper reported the synthesizes by hydrothermal method, and characterization of mesoporous heterogeneous catalysts, the SBA-15 type with addition of metals cerium and aluminum, evaluating their activity and selectivity in the thermal degradation of heavy oil. Samples of nanostructured materials were characterized by thermal gravimetric analysis (TG / DTG), X-ray diffraction (XRD), scanning electron microscopy (SEM), ray fluorescence spectroscopy X (XRF) spectroscopy, absorption in the infrared region Fourier transform (FTIR) and nitrogen adsorption (BET). The characterization showed that the synthesized materials resulted in a nanostructured catalyst and ordered pore diameter and surface area according to the literature. In order to check the catalytic activity of the same, we used a heavy oil sample (?API = 14), supplied by Petrobras, is performing through thermogravimetry the process of thermal and catalytic degradation of the oil. Through the thermogravimetric curves, it was observed a reduction in the opening of oil decomposition catalytic process temperature. Through non isothermal kinetic model Ozawa Flynn Wall (OFW) gave some parameters to determine the apparent activation energy of decomposition. Obtaining as results of X-ray diffraction showed through characteristic peaks that the hexagonal structure was formed, noting that the best reason was Si / Ce = 5 because of its intensity at a high angle. The infrared spectra showed absorptions family material characteristics SBA-15. The nitrogen adsorption, obtaining parameters compatible with those found in the literature which confer them to be promising in the field of oil degradation due to their mesopores facilitate access of large molecules. The average pore diameter varied significantly with the incorporation of aluminum and cerium. The wall thickness (Wt) was in the range from 2.96 to 4.07 nm, thus observing an increase in this parameter which is due to incorporation of the metals into the wall, indicating that the incorporation of cerium, did not block the mesopores. The addition of aluminum reduced the surface area (SBET) of 893 to 763 m2 g-1, however with the addition of cerium with aluminum this area increased to 826 m2 g-1. For the oil temperature and the initial end of weight loss; presenting only two events due to mercapt?dico sulfur, which influences the appearance of the third event, since that content is measured by the amount of sulfur in aromatic rings (heavy HC). The mixture of oil + 12% of Ce5Al50SBA-15 showing the catalytic activity of this material.
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S?ntese e impregna??o de peneiras moleculares Fe MCM-41 derivada de s?lica da casca do arrozMiranda, Auristela Carla de 28 November 2011 (has links)
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Previous issue date: 2011-11-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The mesoporous molecular sieves of the MCM-41 and FeMCM-41 type are considered
promissory as support for metals used as catalysts in oil-based materials refine processes and
as adsorbents for environmental protection proposes. In this work MCM-41 and FeMCM41
were synthesized using rice husk ash - RHA as alternative to the conventional silica source.
Hydrothermal synthesis was the method chosen to prepare the materials. Pre-defined
synthesis parameters were 100?C for 168 hours, later the precursor was calcinated at 550?C
for 2 hours under nitrogen and air flow. The sieves containing different proportions of iron
were produced by two routes: introduction of iron salt direct synthesis; and a modification
post synthesis consisting in iron salt 1 % and 5% impregnation in the material followed by
thermal decomposition. The molecular sieves were characterized by X ray diffraction XRD,
Fourier transform infrared spectroscopy FT-IR, X ray fluorescence spectroscopy XFR,
scanning electronic microscopy SEM, specific surface area using the BET method,
Termogravimetry TG. The kinetic model of Flynn Wall was used with the aim of
determining the apparent activation energy of the surfactant remove (CTMABr) in the MCM-
41 porous. The analysis made possible the morphology characterization, identifying the
presence of hexagonal structure typical for mesoporous materials, as well as observation of
the MCM41 and iron of characteristic bands. / As peneiras moleculares mesoporosas do tipo MCM-41 e FeMCM-41, s?o
consideradas promissoras como suporte para metais, usadas como catalisadores em processos
de refino de materiais a base de petr?leo e como adsorventes com o prop?sito de prote??o
ambiental. Neste trabalho MCM-41 e FeMCM-41 foram sintetizadas utilizando a cinza da
casca de arroz CCA, como alternativa para a fonte de s?lica. O m?todo escolhido foi a
s?ntese hidrotermal para o preparo dos materiais, a temperatura de 100 ?C por 168 horas em
estufa, posteriormente foi calcinado a 550 ?C por 2 horas sob fluxo de nitrog?nio e ar. As
peneiras moleculares contendo diferentes propor??es de ferro foram produzidas por duas
rotas: introdu??o do sal de ferro no gel de s?ntese e impregna??o de 1% e 5% de ferro no
MCM-41 sintetizado. As peneiras moleculares foram caracterizadas por difra??o de raios X
DRX, espectroscopia no infravermelho por transformada de Fourier (Fourier transform
infrared spectroscopy FT-IR), espectroscopia de fluoresc?ncia de raios X FRX,
microscopia eletr?nica de varredura MEV, ?rea superficial espec?fica atrav?s do m?todo
BET e Termogravimetria TG. O modelo cin?tico de Flynn Wall foi utilizado com o objetivo
de determinar a energia de ativa??o aparente da remo??o do surfactante (CTMABr) nos poros
do MCM-41. As an?lises possibilitaram a caracteriza??o morfol?gica, identificando a
presen?a da estrutura hexagonal t?pica dos materiais mesoporosos, assim como das bandas
caracter?sticas do MCM41 e do ferro.
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S?ntese de catalisadores nanoporosos na aus?ncia total e parcial de direcionadores org?nicos para pir?lise catal?tica de ?leos pesados e intermedi?riosCosta, Maria Jos? Fonseca 03 June 2013 (has links)
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Previous issue date: 2013-06-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The processing of heavy oil produced in Brazil is an emergency action and a strategic
plan to obtain self-sufficiency and economic surpluses. Seen in these terms, it is indispensable
to invest in research to obtain new catalysts for obtaining light fraction of hydrocarbons from
heavy fractions of petroleum. This dissertation for the degree of Doctor of Philosophy reports
the materials preparation that combine the high catalytic activity of zeolites with the greater
accessibility of the mesoporosity, more particularly the HZSM-5/MCM-41 hybrid, done by
synthesis processes with less environmental impact than conventional ones. Innovative
methodologies were developed for the synthesis of micro-mesoporous hybrid material by dual
templating mechanism and from crystalline zeolitic aluminosilicate in the absence of organic
template. The synthesis of hybrid with pore bimodal distribution took place from one-single
organic directing agent aimed to eliminate the use of organic templates, acids of any kind or
organic solvents like templating agent of crystalline zeolitic aluminosilicate together with
temperature-programmed microwave-assisted, making the experimental procedures of
preparation most practical and easy, with good reproducibility and low cost. The study about
crystalline zeolitic aluminosilicate in the absence of organic template, especially MFI type, is
based on use of H2O and Na+ cation playing a structural directing role in place of an organic
template. Advanced characterization techniques such as X-Ray Diffraction (XRD), Fourier
Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Highresolution
Transmission Electron Microscopy (HRTEM), Adsorption of N2 and CO2, kinetic
studies by Thermogravimetric Analysis (TGA) and Pyrolysis coupled to Gas
Chromatography/Mass Spectrometry (Pyrolysis-GC/MS) were employed in order to evaluate
the synthesized materials. Achieve the proposed objectives, has made available a set of new
methodologies for the synthesis of zeolite and hybrid micro-mesoporous material, these
suitable for catalytic pyrolysis of heavy oils aimed at producing light fraction / O processamento do petr?leo pesado produzido no Pa?s ? uma a??o emergencial e
estrat?gica para obter a auto-sufici?ncia e super?vits econ?micos. Neste sentido, ?
indispens?vel o investimento em pesquisas de novos catalisadores para obten??o de derivados
leves a partir de fra??es pesadas do petr?leo. O trabalho de doutorado aqui reportado dedicouse
? prepara??o de materiais que combinem, numa ?nica estrutura, a elevada atividade
catal?tica de ze?litas, com melhor acessibilidade de materiais mesoporosos, como a estrutura
h?brida HZSM-5/MCM-41, utilizando processos de s?ntese com menor impacto ambiental que
os convencionais. Metodologias inovadoras foram desenvolvidas para a s?ntese do catalisador
h?brido micro-mesoporoso ou ze?lito-mesoporoso por mecanismo de direcionamento
estrutural via duplo agente diretor org?nico e tamb?m a partir de estrutura zeol?tica sintetizada
na aus?ncia total de direcionador org?nico. Esse ?ltimo, tamb?m chamado de s?ntese do
h?brido com distribui??o bimodal de poros a partir de um ?nico agente diretor org?nico, visou
eliminar o uso dos direcionadores org?nicos, ?cidos de qualquer natureza ou solventes
org?nicos como molde estrutural da estrutura zeol?tica em conjunto com o m?todo
hidrot?rmico assistido por irradia??o via micro-ondas, tornando o procedimento experimental
de prepara??o pr?tico e simples, com boa reprodutibilidade e menor custo. A metodologia de
prepara??o da ze?lita MFI do tipo ZSM-5 utiliza H2O e c?tions Na+ no papel de
direcionamento estrutural e compensa??o de cargas na estrutura. T?cnicas relevantes de
caracteriza??o, como Difra??o de Raios-X (XRD), Espectroscopia no Infravermelho com
Transformada de Fourier (FTIR), Microscopia Eletr?nica de Varredura (SEM), Microscopia
Eletr?nica de Transmiss?o de Alta Resolu??o (HRTEM), Adsor??o de N2 e CO2, estudos
cin?ticos via An?lises Termogravim?tricas (TGA) e Pir?lise acoplada ? Cromatografia
Gasosa/Espectrometria de Massas (Pyrolysis-GC/MS), foram empregadas no intuito de
avaliar os materiais sintetizados. Alcan?ados os objetivos propostos, disponibilizou-se um
conjunto de novas metodologias para s?ntese de catalisadores zeol?ticos e h?bridos micromesoporosos,
estes adequados para pir?lise catal?tica de ?leos pesados visando ? produ??o de
derivados leves
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S?ntese e caracteriza??o de materiais nanoporosos para pir?lise catal?tica de ?leos pesadosCosta, Maria Jos? Fonseca 22 December 2008 (has links)
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Previous issue date: 2008-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work reports the study of nanoporous structures, aiming at their use in research directed to the current demand of the petroleum industry to value heavy oil. Initially,
two ways were chosen for the synthesis of porous structures from the molecular sieves of type Si-MCM-41. In the first way, the structure MCM-41 is precursory for heteroatom substitutes of silicon, generating catalyst of the type Al-MCM-41 from two different methods of incorporation of the metal. This variation of the incorporation method of Aluminum in the
structure of Si-MCM-41 was carried out through the conventional procedure, where the aluminum source was incorporated to the gel of synthesis, and the procedure post-synthesis, where the Aluminum source was incorporated in catalyst after the synthesis of Si-MCM-41. In the second way, the MCM-41 acts as a support for growth of nanocrystals of zeolite embedded in their mesoporous, resulting in hybrid MCM-41/ZSM-5 catalyst. A comparative
analysis was carried through characterizations by XRD, FTIR, measures of acidity through n-butylamine adsorption for TGA, SEM-XRF and N2 adsorption. Also crystalline aluminosilicate with zeolitic structure MFI of type ZSM-5 was synthesized without using organic templates. Methodologies to the preparation of these materials are related by literature
using conventionally reactants that supply oxides of necessary silicon and aluminum, as well as a template agent, and in some cases co-template. The search for new routes of preparation for the ZSM-5 aimed at, above all, the optimization of the same as for the time and the temperature of synthesis, and mainly the elimination of the use of organic templates, that are material of high cost and generally very toxic. The current study is based on the use of the H2O and Na+ cations playing the role of structural template and charge compensation in the structure. Characterizations by XRD, FTIR, SEM-XRF and N2 adsorption were also conducted for this material in order to compare the samples of ZSM-5 synthesized in the absence of template and those used industrially and synthesized using structuring / O presente trabalho relata o estudo de estruturas nanoporosas, visando o uso em pesquisas que atendam a atual demanda da ind?stria do petr?leo, de valorizar ?leos pesados. Inicialmente, optou-se por duas vertentes para a s?ntese de estruturas porosas a partir da peneira molecular do tipo Si-MCM-41. Na primeira vertente, a estrutura MCM-41 ?
precursora para hetero?tomos substituintes do sil?cio, gerando catalisadores do tipo Al-MCM-41 a partir de dois diferentes m?todos de incorpora??o do metal. Essa varia??o do
m?todo de incorpora??o do Alum?nio na estrutura do Si-MCM-41 se deu atrav?s do procedimento convencional, no qual a fonte de alum?nio foi incorporada ao gel de s?ntese e do
procedimento p?s-s?ntese, no qual a fonte de Alum?nio foi incorporada ao catalisador ap?s a s?ntese do Si-MCM-41. Na segunda vertente, o MCM-41 age como suporte para o
crescimento de nanocristais de ze?lita embutidos nos seus mesoporos, resultando no catalisador h?brido MCM-41/ZSM-5. Uma an?lise comparativa foi realizada atrav?s de
caracteriza??es por XRD, FTIR, medidas de acidez atrav?s de dessor??o de n-butilamina por TGA, SEM-XRF e Adsor??o de N2. Tamb?m foi sintetizado um aluminossilicato cristalino
com estrutura zeol?tica MFI do tipo ZSM-5, na aus?ncia total de direcionador org?nico. Metodologias relacionadas ? prepara??o desses materiais s?o relatadas pela literatura
utilizando-se convencionalmente reagentes que forne?am os ?xidos de sil?cio e de alum?nio necess?rios, bem como um agente direcionador, e em alguns casos at? co-direcionadores. A busca por novas rotas de prepara??o para a ZSM-5 visou, sobretudo, a otimiza??o da mesma no que se refere ao tempo e ? temperatura de s?ntese, e principalmente a elimina??o do uso dos direcionadores org?nicos, que s?o materiais de alto custo e geralmente muito t?xicos. O
atual estudo se baseia na utiliza??o da H2O e dos c?tions Na+ desempenhando o papel de direcionamento estrutural e compensa??o de cargas na estrutura. Caracteriza??es por XRD, FTIR, SEM-XRF e Adsor??o de N2 tamb?m foram realizadas para esse material, a fim de comparar as amostras de ZSM-5 sintetizadas na aus?ncia do direcionador e aquelas utilizadas industrialmente e sintetizadas utilizando estruturantes
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