Made available in DSpace on 2014-12-17T14:07:15Z (GMT). No. of bitstreams: 1
MariaSBF_TESE.pdf: 2706042 bytes, checksum: e909d3cb5ee177d47cc6917725b38335 (MD5)
Previous issue date: 2013-05-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In recent years, the area of advanced materials has been considerably, especially when it comes to materials for industrial use, such as is the case with structured porosity of catalysts suitable for catalytic processes.
The use of catalysts combined with the fast pyrolysis process is an alternative to the oxygenate production of high added value, because, in addition to increasing the yield and quality of products, allows you to manipulate the selectivity to a product of interest, and therefore allows greater control over the characteristics of the final product.
Based on these arguments, in this work were prepared titanium catalysts supported on MCM-41 for use in catalytic pyrolysis of biomass, called elephant grass.
The reactions of pyrolysis of biomass were performed in a micro pyrolyzer, Py-5200, coupled to GC / MS, the company CDS Corporation, headquartered in the United States. The catalysts Ti-MCM-41 in different molar ratios were characterized by XRD, TG / DTG, FT-IR, SEM, XRF, UV-visible adsorption of nitrogen and the distribution of particle diameter and specific surface area measurement by the BET method. From the catalytic tests it was observed that the catalysts synthesized showed good results for the pyrolysis reaction.The main products were obtained a higher yield of aldehydes, ketones and furan. It was observed that the best reactivity is a direct function of the ratio Si/Ti, nature and concentration of the active species on mesoporous supports. Among the catalysts Ti-MCM-41 (molar ratio Si / Ti = 25 and 50), the ratio Si / Ti = 25 (400 ? C and 600 ? C) favored the cracking of oxygenates such as acids , aldehydes, ketones, furans and esters. Already the sample ratio Si / Ti = 50 had the highest yield of aromatic oxygenates / Nos ?ltimos anos, a ?rea de materiais tem avan?ado consideravelmente, principalmente, quando se trata de materiais para uso industrial, como ? o caso de catalisadores estruturados com porosidade adequada para os processos catal?ticos.
O uso de catalisadores combinados ao processo de pir?lise r?pida ? uma alternativa para a produ??o de compostos oxigenados de alto valor agregado, pois, al?m de elevar o rendimento e qualidade dos produtos, permite manipular a seletividade para um produto de interesse e, portanto, permite um maior controle sobre as caracter?sticas do produto final.
Com base nesses argumentos, neste trabalho foram preparados catalisadores de tit?nio suportados em MCM-41 para uso em pir?lise catal?tica da biomassa, denominada de capim elefante.
As rea??es de pir?lise da biomassa foram realizadas em um micro pirolisador, Py-5200, acoplado ao GC/MS, da empresa CDS Corporation, sediada nos Estados Unidos. Os catalisadores Ti-MCM-41, em diferentes raz?es molares, foram caracterizados por DRX, TG/DTG, FT-IR, MEV, FRX, UV-Vis?vel, adsor??o de nitrog?nio, distribui??o de di?metro de part?culas e medidas de ?rea espec?fica pelo m?todo BET.
A partir dos testes catal?ticos foi poss?vel observar que os catalisadores sintetizados apresentaram bons resultados para a rea??o de pir?lise. Entre os catalisadores Ti-MCM-41 (raz?es molares Si/Ti = 25 e 50), o de raz?o Si/Ti=25 (temperatura de 400?C e 600?C) favoreceu o craqueamento de compostos oxigenados, tais como, ?cidos, alde?dos, cetonas, furanos e ?steres. J? a amostra de raz?o Si/Ti = 50 apresentou maior rendimento de arom?ticos oxigenados
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12824 |
| Date | 17 May 2013 |
| Creators | Fontes, Maria do Socorro Braga |
| Contributors | CPF:06117988320, http://lattes.cnpq.br/3318871716111536, Vitor Sobrinho, Eledir, CPF:64656969915, http://lattes.cnpq.br/8488499388852606, Barros, Joana Maria de Farias, CPF:85239658404, http://lattes.cnpq.br/1016070459137884, Ricardo, N?gila Maria Pontes Silva, CPF:11279281391, Braga, Renata Martins, CPF:05165674460, http://lattes.cnpq.br/4603529162393328, Pergher, Sibele Berenice Castella, CPF:50942611004, http://lattes.cnpq.br/5249001430287414, Melo, Dulce Maria de Ara?jo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia de Materiais, UFRN, BR, Processamento de Materiais a partir do P?; Pol?meros e Comp?sitos; Processamento de Materiais a part |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0018 seconds