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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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Conversion of MixAlco Process Sludge to Liquid Transportation FuelsTeiseh, Eliasu 1973- 02 October 2013 (has links)
About 8 tons of dry undigested solid waste is generated by the MixAlco process for every 40 tons of food residue waste fed into the process. This MixAlco process produces liquid fuels and the sludge generated can be further converted into synthesis gas using the process of pyrolysis. The hydrogen component of the product synthesis gas may be separated by pressure swing adsorption and used in the hydrogenation of ketones into fuels and chemicals. The synthesis gas may also be catalytically converted into liquid fuels via the Fischer-Tropsch synthesis process.
The auger-type pyrolyzer was operated at a temperature between 630-770 degrees C and at feed rates in the range of 280-374 g/minute. The response surface statistical method was used to obtain the highest syngas composition of 43.9 +/- 3.36 v % H2/33.3 +/- 3.29 v % CO at 740 degrees C. The CH4 concentration was 20.3 +/- 2.99 v %. For every ton of sludge pyrolyzed, 5,990 g H2 (719.3 MJ), 65,000 g CO (660 MJ) and 21,170 g CH4 (1055.4 MJ) were projected to be produced at optimum condition. At all temperatures, the sum of the energies of the products was greater than the electrical energy needed to sustain the process, making it energy neutral.
To generate internal H2 for the MixAlco process, a method was developed to efficiently separate H2 using pressure swing adsorption (PSA) from the synthesis gas, with activated carbon and molecular sieve 5A as adsorbents. The H2 can be used to hydrogenate ketones generated from the MixAlco process to more liquid fuels. Breakthrough curves, cycle mass balances and cycle bed productivities (CBP) were used to determine the maximum hydrogen CBP using different adsorbent amounts at a synthesis gas feed rate of 10 standard lpm and pressure of 118 atm. A 99.9 % H2 purity was obtained. After a maximum CBP of 66 % was obtained further increases in % recovery led to a decrease in CBP.
The synthesis gas can also be catalytically converted into liquid fuels by the Fischer-Tropsch synthesis (FTS) process. A Co-SiO2/Mo-Pd-Pt-ZSM-5 catalyst with a metal-metal-acid functionality was synthesized with the aim of increasing the selectivity of JP-8 (C10-C17) fuel range. The specific surface areas of the two catalysts were characterized using the BET technique. The electron probe microanalyzer (with WDS and EDS capabilities) was then used to confirm the presence of the applied metals Co, Mo, Pd and Pt on the respective supports. In addition to the gasoline (C4-C12) also produced, the synthesis gas H2:CO ratio was also adjusted to 1.90 for optimum cobalt performance in an enhanced FTS process. At 10 atm (150 psig) and 250 degrees C, the conventional FTS catalyst Co-SiO2 produced fuels rich in hydrocarbons within the gasoline carbon number range. At the same conditions the Co-SiO2-Mo-Pd-Pt/HZSM-5 catalyst increased the selectivity of JP-8. When Co-SiO2/Mo-Pd-Pt-HZSM-5 was used at 13.6 atm (200 psig) and 250 degrees C, a further increase in the selectivity of JP-8 and to some extent diesel was observed. The relative amounts of olefins and n-paraffins decreased with the products distribution shifting more towards the production of isomers.
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Estudio de catalizadores microporosos Mo/zeolita en la reacción de deshidroaromatización de metanoPeris Chanzá, Ernesto José 07 January 2016 (has links)
[EN] This doctoral thesis shows the study carried out on Mo/zeolite
catalysts in the dehydroaromatization reaction of methane (MDA) with
the intention to contribute to this technical approximation regarding the
valorisation of said reactant. As it is observed from the information
contributed in the introductory chapter, methane (main component in
natural gas deposits, but also present in those of oil and coal) may be
considered, in a near future, as an alternative source to oil in obtaining
primary hydrocarbons for the petrochemical industry. Taking into
account the state-of-art previous to the start this thesis, it was
proposed to develop a series of studies adressed to surpass and
improve some of the difficulties referenced in the consulted literature.
In this sense, the work was oriented to mitigate the processes
involved in the accumulation of coke on the zeolitic acid sites and, this
way, reduce the high deactivation rates registered on the catalysts
usually employed in this reaction. In brief, the control of the density of
zeolitic acid sites (mainly, the excess of Brønsted ones) was designed
from distinct approaches: the reduction/elimination of this possible
excess by dealumination methods (chapter 5), their reduction by
means of selective exchange of the zeolite with mono- and divalent
cations (chapter 6) and their reduction by means of the use of a ZSM-
5 mesoporous sample (chapter 7). In view of the results obtained in
chapter 7, it was considered relevant to analyse the effect that zeolites
with large cavities or intersections could have in the tendency to
accumulate coke, the obtained data being supported by molecular
dynamic modelling (chapter 8). Finally, this thesis incorporates some
general conclusions regarding the shown work and, also, the future of
the MDA process. / [ES] En esta tesis doctoral se presenta el estudio llevado a cabo sobre
catalizadores Mo/zeolita en la reacción de deshidroaromatización de
metano (MDA) con la intención de contribuir a esta aproximación
técnica hacia la valorización de dicho reactante. Como se observa de
la información aportada en el capítulo de introducción, el metano
(componente principal de los yacimientos de gas natural, pero
también presente en aquellos de petróleo y carbón) se postula, en un
futuro próximo, como fuente alternativa al petróleo en la obtención de
hidrocarburos primarios para la industria petroquímica. Teniendo en
cuenta el estado del arte previo al inicio de esta tesis, se planteó el
desarrollo de un conjunto de estudios dirigidos a superar y mejorar
algunas de las dificultades a las que la literatura hacía referencia. En
este sentido, se orientó el trabajo a paliar los procesos causantes de
la acumulación de coque sobre los centros ácidos zeolíticos y, así,
poder reducir las elevadas tasas de desactivación registradas sobre
los catalizadores habitualmente empleados en esta reacción.
Brevemente, se diseñó el control de la densidad de centros ácidos
zeolíticos (concretamente, el exceso de aquellos de tipo Brønsted)
desde distintos enfoques: la reducción/eliminación de un posible
exceso por métodos de desaluminización (capítulo 5), su reducción
mediante intercambio selectivo de la zeolita con cationes mono y
divalentes (capítulo 6) y su reducción mediante el uso de una zeolita
ZSM-5 con mesoporos (capítulo 7). Por último, en vista de los
resultados obtenidos en el capítulo 7, se consideró relevante analizar
el efecto que zeolitas con cavidades o intersecciones de grandes
dimensiones podrían tener en la tendencia a acumular coque,
apoyando los datos obtenidos a este respecto con estudios de
modelización molecular (capítulo 8). Finalmente, esta tesis incorpora
unas conclusiones generales referidas al propio trabajo presentado y,
también, orientadas al futuro del proceso de MDA. / [CAT] En aquesta tesi doctoral es presenta l'estudi dut a terme sobre
catalitzadors Mo/zeolita en la reacció de deshidroaromatització de
metà (MDA) amb la intenció de contribuir a aquesta aproximació
tècnica cap a la valorització d'aquest reactant. Com s'observa de la
informació aportada en el capítol d'introducció, el metà (component
principal dels jaciments de gas natural, però també present en aquells
de petroli i carbó) es postula, en un futur pròxim, com font alternativa
al petroli en l'obtenció d'hidrocarburs primaris per a la indústria
petroquímica. Tenint en compte l'estat de l'art previ a l'inici d'aquesta
tesi, es va plantejar el desenvolupament d'un conjunt d'estudis dirigits
a superar i millorar algunes de les dificultats a les quals la literatura
feia referència. En aquest sentit, es va orientar el treball a pal·liar els
processos causants de l'acumulació de coc sobre el centres ácids
zeolítics i, així, poder reduir les elevades taxes de desactivació
registrades sobre els catalitzadors habitualmente emprats en aquesta
reacció. Breument, es va dissenyar el control de la densitat de centres
àcids zeolítics (concretament, l'excés d'aquells de tipus Brønsted) des
de distints enfocaments: la reducció/eliminació d'aquest possible
excés per métodes de desaluminització (capítol 5), la seua reducció
mitjançant intercanvi selectiu de la zeolita amb cations mono- i
divalents (capítol 6) i la seua reducció mitjançant l'ús d'una zeolita
ZSM-5 amb mesoporus (capítol 7). A partir dels resultats obtinguts en
el capítol 7, es va considerar rellevant analitzar l'efecte que zeolites
amb cavitats o interseccions de grans dimensions podrien tenir en la
tendència a acumular coc, recolzant les dades obtingudes a este
respecte amb estudis de modelització molecular (capítol 8).
Finalment, aquesta tesi incorpora unes conclusions generals referides
al propi treball presentat i, també, orientades al futur del procés de
MDA. / Peris Chanzá, EJ. (2015). Estudio de catalizadores microporosos Mo/zeolita en la reacción de deshidroaromatización de metano [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59441 / TESIS
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