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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Degrada??o termocatal?tica de petr?leo pesado utilizando SBA-15 contendo alum?nio e c?rio

Ara?jo, Larissa Cicianny Luz Ferreira de 26 August 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-13T19:56:34Z No. of bitstreams: 1 LarissaCiciannyLuzFerreiraDeAraujo_TESE.pdf: 3361603 bytes, checksum: 8da0327f1fa708d7b02bec63cf53a5f0 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-19T11:40:01Z (GMT) No. of bitstreams: 1 LarissaCiciannyLuzFerreiraDeAraujo_TESE.pdf: 3361603 bytes, checksum: 8da0327f1fa708d7b02bec63cf53a5f0 (MD5) / Made available in DSpace on 2017-06-19T11:40:01Z (GMT). No. of bitstreams: 1 LarissaCiciannyLuzFerreiraDeAraujo_TESE.pdf: 3361603 bytes, checksum: 8da0327f1fa708d7b02bec63cf53a5f0 (MD5) 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.
2

Degradacao termica e catalitica da borra oleosa de Petroleo com materiais nanoestruturados al-mcm-41 e AL-SBA-15

Paulino, Ana Adalgisa Dias 04 November 2012 (has links)
Made available in DSpace on 2014-12-17T14:09:14Z (GMT). No. of bitstreams: 1 AnaADP_TESE.pdf: 2810011 bytes, checksum: 6f11363dfc6e540fe688b7737b77893b (MD5) Previous issue date: 2012-11-04 / Aiming to reduce and reuse waste oil from oily sludge generated in large volumes by the oil industry, types of nanostructured materials Al-MCM-41 and Al-SBA-15, with ratios of Si / Al = 50, were synthesized , and calcined solids used as catalysts in the degradation of oily sludge thermocatalytic oil from oilfield Canto do Amaro, in the state of Rio Grande do Norte. Samples of nanostructured materials were characterized by thermogravimetric analysis (TG / DTG), X-ray diffraction (XRD), scanning electron microscopy (SEM), absorption spectroscopy in the infrared Fourier transform (FT-IR) and adsorption nitrogen (BET). The characterization showed that the synthesized materials resulted in a catalyst nanostructure, and ordered pore diameter and surface area according to existing literature. The oily sludge sample was characterized by determining the API gravity and sulfur content and SARA analysis (saturates, aromatics, resins and asphaltenes). The results showed a material equivalent to the average oil with API gravity of 26.1, a low sulfur content and considerable amount of resins and asphaltenes, presented above in the literature. The thermal and catalytic degradation of the oily sludge oil was performed from room temperature to 870 ? C in the ratios of heating of 5, 10 and 20 ? C min-1. The curves generated by TG / DTG showed a more accelerated degradation of oily sludge when it introduced the nanostructured materials. These results were confirmed by activation energy calculated by the method of Flynn-Wall, in the presence of catalysts reduced energy, in particular in the range of cracking, showing the process efficiency, mainly for extraction of lightweight materials of composition of oily sludge, such as diesel and gasoline / Com o objetivo de reduzir e reutilizar o res?duo de borra oleosa de petr?leo, gerado em grandes volumes pela ind?stria petrol?fera, materiais nanoestruturados dos tipos Al-MCM-41 e Al-SBA-15, com raz?es de Si/Al = 50, foram sintetizados, calcinados e utilizados como s?lidos catal?ticos na degrada??o termocatal?tica da borra oleosa de petr?leo, proveniente do campo petrol?fero Canto do Amaro, no estado do Rio Grande do Norte. 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 absor??o na regi?o do infravermelho com transformada de Fourier (FT-IR) 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. A amostra de borra oleosa foi caracterizada atrav?s da determina??o do grau API e do teor de enxofre e da an?lise do SARA (saturados, arom?ticos, resinas e asfaltenos). Os resultados mostraram um material equivalente ao petr?leo m?dio, com grau API de 26,1, baixo teor de enxofre e com quantidade consider?vel de resinas e asfaltenos, acima da apresentada na literatura. A degrada??o t?rmica e catal?tica da borra oleosa de petr?leo foi realizada da temperatura ambiente at? 870?C, nas raz?es de aquecimento de 5, 10 e 20oC min-1. As curvas geradas pela TG/DTG apresentaram uma degrada??o mais acelerada da borra oleosa quando se introduziram os materiais nanoestruturados. Esses resultados foram ratificados pela energia de ativa??o, calculada atrav?s do m?todo de Flynn-Wall, em que a presen?a dos catalisadores reduziu a energia, em especial na faixa de craqueamento, mostrando a efici?ncia do processo, principalmente para a extra??o de materiais leves da composi??o da borra oleosa, como diesel e gasolina

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