Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/17380 https://doi.org/10.14393/ufu.di.2012.138 |
Resumo: | Currently, the Fischer-Tropsch Synthesis comes up with a new rule, to contribute to the socio/economic/environmental, meeting the expectations of today\'s global world. Aiming at the production of alternative fuels and clean, arising mainly from biomass, in response to the current global requirements. In this work, we chose to study the catalyst Fe/Nb2O5 due to little research related to this system reactions/processes, and be more commercially interesting for large scale production. The parameters evaluated were the influence of temperature reduction, the Fe content present in the catalyst, GHSV and temperature reaction, under reaction conditions 225-275 °C and 20 bar in a fixed bed reactor. Catalysts were prepared with concentrations of 5, 10 and 20% Fe supported on niobia. The characterization by Temperature Programmed Reduction, showed that the reduction to Fe° catalysts obey these 2 steps. The interaction of species oxides (iron oxide and niobia) present in the catalysts was checked by infrared spectroscopy, confirming that the change in displacement or intensity of the bands is closely linked to their interaction, which grows with increasing content Fe in the catalyst. The evolution of species in the process of reduction of the catalysts was initially accompanied by diffuse reflectance spectroscopy Uv-Vis, noting that the interactions between species FexOy with Nb2O5, undergo a continuous decrease with temperature reduction, being more intense in iron content and higher temperatures decrease, and this result confirmed after analysis of x-ray diffraction. Subsequently, we used a qualitative analysis by Temperature Programmed Surface Reaction for proving the existence of the SMSI effect (interaction with the metal support) in these catalysts, noting that the increase in temperature caused a reduction in peak broadening consumption of the load reactive H2/CO = 2, or product formation, decreasing its intensity to the shift to higher temperatures, this drop in activity was most evident in catalyst content of 20% Fe. Through the catalytic tests, it was found that the growth of catalytic activity with increasing temperature reduction is probably due to higher amount of active sites which do not suffer significant SMSI effect. Assigning to the catalysts 5 and 10% Fe/Nb2O5, the best results in producing gasoline, diesel and C20+, due to the higher scattering sites present in the surface layer thereof, where maximizing selectivity of these becomes smaller at higher temperatures and GHSV. Comparing the results obtained in this work to others described in the literature with the iron-based catalysts supported on reducible oxides, there was a significant increase in the production of selectivities in the range of gasoline and diesel. |
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Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-TropschSíntese de Fischer-TropschCatalisador Fe/Nb2O5Atividade catalíticaSeletividadeFischer-Tropsch, Processo deCatalisadores de ferroFischer-Tropsch SynthesisFe/Nb2O5 catalystCatalytic activitySelectivityCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICACurrently, the Fischer-Tropsch Synthesis comes up with a new rule, to contribute to the socio/economic/environmental, meeting the expectations of today\'s global world. Aiming at the production of alternative fuels and clean, arising mainly from biomass, in response to the current global requirements. In this work, we chose to study the catalyst Fe/Nb2O5 due to little research related to this system reactions/processes, and be more commercially interesting for large scale production. The parameters evaluated were the influence of temperature reduction, the Fe content present in the catalyst, GHSV and temperature reaction, under reaction conditions 225-275 °C and 20 bar in a fixed bed reactor. Catalysts were prepared with concentrations of 5, 10 and 20% Fe supported on niobia. The characterization by Temperature Programmed Reduction, showed that the reduction to Fe° catalysts obey these 2 steps. The interaction of species oxides (iron oxide and niobia) present in the catalysts was checked by infrared spectroscopy, confirming that the change in displacement or intensity of the bands is closely linked to their interaction, which grows with increasing content Fe in the catalyst. The evolution of species in the process of reduction of the catalysts was initially accompanied by diffuse reflectance spectroscopy Uv-Vis, noting that the interactions between species FexOy with Nb2O5, undergo a continuous decrease with temperature reduction, being more intense in iron content and higher temperatures decrease, and this result confirmed after analysis of x-ray diffraction. Subsequently, we used a qualitative analysis by Temperature Programmed Surface Reaction for proving the existence of the SMSI effect (interaction with the metal support) in these catalysts, noting that the increase in temperature caused a reduction in peak broadening consumption of the load reactive H2/CO = 2, or product formation, decreasing its intensity to the shift to higher temperatures, this drop in activity was most evident in catalyst content of 20% Fe. Through the catalytic tests, it was found that the growth of catalytic activity with increasing temperature reduction is probably due to higher amount of active sites which do not suffer significant SMSI effect. Assigning to the catalysts 5 and 10% Fe/Nb2O5, the best results in producing gasoline, diesel and C20+, due to the higher scattering sites present in the surface layer thereof, where maximizing selectivity of these becomes smaller at higher temperatures and GHSV. Comparing the results obtained in this work to others described in the literature with the iron-based catalysts supported on reducible oxides, there was a significant increase in the production of selectivities in the range of gasoline and diesel.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em QuímicaAtualmente, a Síntese de Fischer-Tropsch surge com um novo preceito, de contribuir com as necessidades sócio/econômico/ambiental, atendendo aos anseios atuais do mundo global. Visando a produção de combustíveis alternativos e limpos, principalmente advindos da biomassa, em resposta as atuais exigências mundiais. Neste trabalho, optou-se pelo estudo do catalisador Fe/Nb2O5, devido a pouca pesquisa relacionada com este sistema em reações/processos, e por ser comercialmente mais interessante para produção em larga escala. Os parâmetros avaliados foram, a influência da temperatura de redução, teor de Fe presente no catalisador, GHSV e temperatura reacional, sob condições reacionais de 225 a 275 °C e 20 bar, em reator de leito fixo. Foram preparados catalisadores com teores de 5, 10 e 20% de Fe suportados em nióbia. A caracterização por Redução a Temperatura Programada, mostrou que, a redução para Fe° nestes catalisadores obedeceria 2 passos. A interação das espécies óxidas (óxido de ferro e nióbia) presentes nos catalisadores foi verificada por espectroscopia no infravermelho, constatando-se que a mudança no deslocamento ou a intensidade das bandas está intimamente ligada à interação destes, a qual cresce com a elevação do teor de Fe no catalisador. A evolução das espécies no processo de redução dos catalisadores, foi acompanhada inicialmente através de espectroscopia de reflectância difusa Uv-Vis, observando-se que as interações entre espécies FexOy com o Nb2O5, sofrem uma diminuição contínua com a temperatura de redução, sendo mais intensa em teor de ferro e temperaturas de redução maiores, sendo este resultado corroborado após análise de difração de raios-x. Posteriormente, utilizou-se de uma análise qualitativa por Reação Superficial a Temperatura Programada, para a comprovação da existência do efeito SMSI (interação do metal com o suporte) nestes catalisadores, notando-se que o aumento da temperatura de redução causou um alargamento no pico de consumo da carga reacional H2/CO = 2, ou formação de produtos, diminuindo sua intensidade com o deslocamento para temperaturas maiores, esta queda na atividade foi mais evidente no catalisador com teor de 20%Fe. Através dos testes catalíticos, constatou-se que, o crescimento da atividade catalítica com a elevação da temperatura de redução se deve provavelmente à maior quantidade de sítios ativos que não sofrem efeito SMSI significativo. Atribuí-se aos catalisadores 5 e 10% Fe/Nb2O5, os melhores resultados na produção de gasolina, diesel e C20+, devido à maior dispersão dos sítios presentes na camada superficial destes, onde a maximização destas seletividades se faz em maiores temperaturas e menores GHSV. Confrontando os resultados obtidos neste trabalho a outros descritos na literatura com catalisadores a base de ferro suportados em óxidos redutíveis, observou-se um significativo crescimento na produção de seletividades na faixa da gasolina e diesel.Universidade Federal de UberlândiaBRPrograma de Pós-graduação em QuímicaCiências Exatas e da TerraUFUSoares, Ricardo Reishttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782725J6Canobre, Sheila Cristinahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4775037T8Araujo, Antonio Souza dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4723120Y8Santos, Wayler Silva dos2016-06-22T18:48:33Z2013-05-202016-06-22T18:48:33Z2012-02-29info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfapplication/pdfSANTOS, Wayler Silva dos. Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch. 2012. 120 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2012. DOI https://doi.org/10.14393/ufu.di.2012.138https://repositorio.ufu.br/handle/123456789/17380https://doi.org/10.14393/ufu.di.2012.138porinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFU2022-10-24T17:00:01Zoai:repositorio.ufu.br:123456789/17380Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2022-10-24T17:00:01Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.none.fl_str_mv |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
title |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
spellingShingle |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch Santos, Wayler Silva dos Síntese de Fischer-Tropsch Catalisador Fe/Nb2O5 Atividade catalítica Seletividade Fischer-Tropsch, Processo de Catalisadores de ferro Fischer-Tropsch Synthesis Fe/Nb2O5 catalyst Catalytic activity Selectivity CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
title_full |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
title_fullStr |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
title_full_unstemmed |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
title_sort |
Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch |
author |
Santos, Wayler Silva dos |
author_facet |
Santos, Wayler Silva dos |
author_role |
author |
dc.contributor.none.fl_str_mv |
Soares, Ricardo Reis http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782725J6 Canobre, Sheila Cristina http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4775037T8 Araujo, Antonio Souza de http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4723120Y8 |
dc.contributor.author.fl_str_mv |
Santos, Wayler Silva dos |
dc.subject.por.fl_str_mv |
Síntese de Fischer-Tropsch Catalisador Fe/Nb2O5 Atividade catalítica Seletividade Fischer-Tropsch, Processo de Catalisadores de ferro Fischer-Tropsch Synthesis Fe/Nb2O5 catalyst Catalytic activity Selectivity CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
topic |
Síntese de Fischer-Tropsch Catalisador Fe/Nb2O5 Atividade catalítica Seletividade Fischer-Tropsch, Processo de Catalisadores de ferro Fischer-Tropsch Synthesis Fe/Nb2O5 catalyst Catalytic activity Selectivity CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Currently, the Fischer-Tropsch Synthesis comes up with a new rule, to contribute to the socio/economic/environmental, meeting the expectations of today\'s global world. Aiming at the production of alternative fuels and clean, arising mainly from biomass, in response to the current global requirements. In this work, we chose to study the catalyst Fe/Nb2O5 due to little research related to this system reactions/processes, and be more commercially interesting for large scale production. The parameters evaluated were the influence of temperature reduction, the Fe content present in the catalyst, GHSV and temperature reaction, under reaction conditions 225-275 °C and 20 bar in a fixed bed reactor. Catalysts were prepared with concentrations of 5, 10 and 20% Fe supported on niobia. The characterization by Temperature Programmed Reduction, showed that the reduction to Fe° catalysts obey these 2 steps. The interaction of species oxides (iron oxide and niobia) present in the catalysts was checked by infrared spectroscopy, confirming that the change in displacement or intensity of the bands is closely linked to their interaction, which grows with increasing content Fe in the catalyst. The evolution of species in the process of reduction of the catalysts was initially accompanied by diffuse reflectance spectroscopy Uv-Vis, noting that the interactions between species FexOy with Nb2O5, undergo a continuous decrease with temperature reduction, being more intense in iron content and higher temperatures decrease, and this result confirmed after analysis of x-ray diffraction. Subsequently, we used a qualitative analysis by Temperature Programmed Surface Reaction for proving the existence of the SMSI effect (interaction with the metal support) in these catalysts, noting that the increase in temperature caused a reduction in peak broadening consumption of the load reactive H2/CO = 2, or product formation, decreasing its intensity to the shift to higher temperatures, this drop in activity was most evident in catalyst content of 20% Fe. Through the catalytic tests, it was found that the growth of catalytic activity with increasing temperature reduction is probably due to higher amount of active sites which do not suffer significant SMSI effect. Assigning to the catalysts 5 and 10% Fe/Nb2O5, the best results in producing gasoline, diesel and C20+, due to the higher scattering sites present in the surface layer thereof, where maximizing selectivity of these becomes smaller at higher temperatures and GHSV. Comparing the results obtained in this work to others described in the literature with the iron-based catalysts supported on reducible oxides, there was a significant increase in the production of selectivities in the range of gasoline and diesel. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-02-29 2013-05-20 2016-06-22T18:48:33Z 2016-06-22T18:48:33Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
SANTOS, Wayler Silva dos. Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch. 2012. 120 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2012. DOI https://doi.org/10.14393/ufu.di.2012.138 https://repositorio.ufu.br/handle/123456789/17380 https://doi.org/10.14393/ufu.di.2012.138 |
identifier_str_mv |
SANTOS, Wayler Silva dos. Avaliação de catalisadores a base de ferro suportados em nióbia na Síntese de Fischer-Tropsch. 2012. 120 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Uberlândia, Uberlândia, 2012. DOI https://doi.org/10.14393/ufu.di.2012.138 |
url |
https://repositorio.ufu.br/handle/123456789/17380 https://doi.org/10.14393/ufu.di.2012.138 |
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language |
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Universidade Federal de Uberlândia BR Programa de Pós-graduação em Química Ciências Exatas e da Terra UFU |
publisher.none.fl_str_mv |
Universidade Federal de Uberlândia BR Programa de Pós-graduação em Química Ciências Exatas e da Terra UFU |
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reponame:Repositório Institucional da UFU instname:Universidade Federal de Uberlândia (UFU) instacron:UFU |
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Universidade Federal de Uberlândia (UFU) |
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Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU) |
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diinf@dirbi.ufu.br |
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