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Previous issue date: 2015-07-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Esse estudo prop?s-se a obter biodiesel a partir da esterifica??o do ?cido oleico com os catalisadores Zr-SBA-15, Nb-SBA-15, SO42-/Zr-SBA-15 e SO42-/Nb-SBA-15 obtidos pela inser??o de Zr e Nb no suporte SBA-15 e sulfata??o do suporte impregnado. O suporte SBA-15 foi sintetizado pelo m?todo hidrot?rmico. O catalisador foi incialmente sintetizado pelo m?todo de impregna??o via ?mida, adicionando 4,2 mL de uma solu??o ? 30 % do percursor do metal (Zr e Nb) em cada grama da SBA-15. Ap?s a impregna??o foi realizado o processo de sulfata??o. As condi??es reacionais da s?ntese do biodiesel utilizadas nesse estudo foram: quantidade de catalisador (5% em massa), raz?o molar de metanol:?cido oleico (20:1), tempo reacional (8 h) e temperatura de refluxo (65?C). Os catalisadores foram analisados por: difra??o de raios-X (DRX), an?lise termogravim?trica (TG/DTG), espectroscopia de infravermelho por transformada de Fourier (FTIR), adsor??o/dessor??o de nitrog?nio, microscopia eletr?nica de varredura (MEV), espectroscopia de energia dispersiva (EDS) e teste de acidez para identifica??o da estrutura, composi??o e verifica??o da presen?a de s?tios ?cidos. Os resultados de caracteriza??o indicaram que o suporte SBA-15 preservou a estrutura hexagonal ordenada, ap?s a incorpora??o de Zr e Nb. Observou-se a presen?a de nanopart?culas desses metais dispersas na superf?cie e no interior dos canais microporosos e mesoporosos dos catalisadores Zr-SBA-15 e Nb-SBA-15. Ap?s a sulfata??o, aumentou a quantidade de s?tios ?cidos e a estrutura ordenada foi mantida. Para os catalisadores Zr-SBA-15 e SO42-/Zr-SBA-15 houve a forma??o das estruturas tetragonal e monocl?nica do ZrO2, j? para os demais catalisadores Nb-SBA-15 e SO42-/Nb-SBA-15 formaram-se estruturas amorfas. A atividade catal?tica foi avaliada pela rea??o de esterifica??o do ?cido oleico via rota et?lica, utilizando todos os catalisadores sintetizados. O biodiesel obtido com SO42-/Zr-SBA-15 apresentou propriedades f?sico-qu?micas dentro das normas especificadas pela resolu??o N?7/2008 da ANP e melhor rendimento com 80,7%. Foi verificado que os catalisadores sulfatados, produziram maior rendimento com rela??o aos n?o sulfatados. O suporte SBA-15 n?o apresentou atividade catal?tica. / Fatty acids such as oleic acid, have received particular attention as raw material, due to
its abundance, availability and relatively high purity, being considered as potential materials
for production of biodiesel. The esterification reaction of oleic acid using heterogeneous
catalysts can be a promising alternative for biodiesel production. This study proposes to find a
biodiesel through esterification of oleic acid with Zr-SBA-15, Nb-SBA-15, SO42?/Zr-SBA-15 and SO4
2?/Nb-SBA-15 catalysts, obtained by insertion of Zr and Nb in support SBA-15 and sulfation of the impregnated support. SBA-15 support was synthesized by hydrothermal method. Support SBA-15 was synthesized by hydrothermal method. The catalyst was initially synthesized by the wet impregnation method, followed by sulfation process. The catalysts were analyzed: X-ray diffraction (XRD), thermal analysis (TG/DTG), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and acidity test to identify the structure,
composition and verification the presence acid sites. The characterization results indicated
that the SBA-15 support preserved the ordered hexagonal structure after the incorporation of Zr and Nb. It was observed the presence of nanoparticles these metal dispersed on the surface and within the microporous and mesoporous channels of Zr-SBA-15 and Nb-SBA-15 catalysts. After sulfation, increased amount of acid sites and the ordered structure was maintained. For Zr-SBA-15 and SO4
2?/Zr-SBA-15 catalyst was the formation of tetragonal and monoclinic structures of ZrO2, as for the other, Nb-SBA-15 and SO42?/Nb-SBA-15 catalyst were formed amorphous structures. The catalytic activity was evaluated by the esterification reaction of oleic acid via ethyl route, using all the synthesized catalysts.
Biodiesel obtained with SO42?/Zr-SBA-15 presented physicochemical properties within the
standards specified by the Resolution N? 45/2014 ANP and obtained the best yield with 80.7%. It was found that sulfated catalysts, produced higher yields with respect to nonsulfated. The SBA-15 support showed no catalytic activity.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20558 |
| Date | 22 July 2015 |
| Creators | Evangelista, Jo?o Paulo da Costa |
| Contributors | 35530502415, http://lattes.cnpq.br/9770622597949866, Gondim, Amanda Duarte, 03014598437, http://lattes.cnpq.br/6738828245487480, Coriolano, Ana Catarina Fernandes, 83744479404, http://lattes.cnpq.br/5552621403067808, Delgado, Regina C?lia de Oliveira Brasil, 87774151400, http://lattes.cnpq.br/1862313412291911, Souza, Luiz Di, Ara?jo, Antonio Souza de |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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