Catalysts Deactivation
Mostrando 13-24 de 38 artigos, teses e dissertações.
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13. Sobre a estabilidade de catalisadores de cobalto suportados durante a reforma do etanol
Catalisadores de cobalto suportados em γ-alumina e aluminato de magnésio modificados com lantânio e cério foram aplicados a diferentes condições de reforma do etanol. O desafio inicial foi tentar controlar a taxa de acúmulo de carbono, um dos principais fatores de desativação de catalisadores em condições de reforma a vapor do etanol. Análise
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/06/2012
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14. DESENVOLVIMENTO DE CATALISADORES A BASE DE NÍQUEL COM ESTRUTURA PEROVSQUITA PARA A UTILIZAÇÃO NA PRODUÇÃO DE GÁS DE SÍNTESE.
Nickel-based catalysts with perovskite like structure have shown promising application in several catalytic reactions such as in the partial oxidation of methane to obtain syngas (H2 + CO). However, these properties are potentially influenced by synthesis methods, calcinations conditions (temperature, time and atmosphere) and substitutions of sites A and/or
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/03/2011
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15. Síntese de catalisadores do tipo LaNixFe1-xO3 como precursores catalíticos para reação oxidação parcial do metano
Nickel-bases catalysts have been used in several reform reactions, such as in the partial oxidation of methane to obtain H2 or syngas (H2 + CO). High levels of conversion are usually obtained using this family of catalysts, however, their deactivation resulting from carbon deposition still remains a challenge. Different approaches have been tested aiming at
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/02/2011
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16. Poisoning and regeneration of Pt-Pd/WO3-ZrO2 short paraffin isomerization catalysts
WO3-ZrO2 catalysts promoted with Pt and Pd were tested as paraffin isomerization catalysts using n-hexane as model compound. Sulfur and amine poisoning and regeneration tests were used to assess the impact of the addition of Pt and Pd on the deactivation resistance and regenerability. Pt and PtPd catalysts were the most active for n-hexane isomerization. The
Química Nova. Publicado em: 2010
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17. Salinidade em petróleo bruto: otimização de metodologia e proposta de um novo método para extração de sais em petróleo
The quantity of salts in the crude oils depends on the origin and of the wells production and these salts cause several problems during the transport and the process of refine as corrosions, incrustations and deactivation of the employed catalysts in the refineries. In this study were implemented changes for improvements in the execution of ASTM D 6470 metho
Química Nova. Publicado em: 2010
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18. Estudo da desativação térmica de catalisadores à base de óxidos mistos de cério e zircônio / Study of thermal deactivation of catalysts based on mixed oxides of cerium and zirconium
Em termos ambientais, os catalisadores automotivos se destacam pelos resultados altamente significativos alcançados após seu uso obrigatório em veículos leves. No entanto, as condições térmicas em que eles operam podem levar a um processo de perda de atividade significativa, após certo tempo de operação. Dentro desse contexto, este trabalho estudou
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/08/2009
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19. Geração de H2 a partir do etanol : efeito da adição de terras raras (La2O3, CeO2) e Pt nas propriedades atalíticas de Co/Al2O3 para reforma do etanol
Ni or Co catalysts supported on Al2O3, La2O3-Al2O3 and CeO2-Al2O3 were prepared by impregnation of Al2O3 with an aqueous solution of lanthanum nitrate or ceria, followed by a calcination and incipient wetness impregnation with an aqueous solution of nickel or cobalt nitrate and promoted with Ag or Pt. The catalysts were characterized by temperature-programme
Publicado em: 2009
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20. Catalisadores de Pt suportados, obtidos pelo método solgel : efeito do cério na atividade e estabilidade nas reações de reforma do metano
The effect of Ce as a structural and electronic promoter on the activity and stability of Pt catalysts supported on Al2O3 for methane reforming reactions were investigated to elucidate the metal-support interaction. Pt/Al2O3 and Pt/CeO2-Al2O3 catalysts were prepared by conventional method of wet impregnation on commercial supports and on CeO2- Al2O3 mixed ox
Publicado em: 2009
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21. Transformação de cicloexano e metilcicloexano sobre as zeólitas HMCM-22, HZSM-5 e HUSY rendimento e seletividade a hidrocarbonetos leves
In Brazil, the oil production with high naphthenic hydrocarbon (HC) content and the hard growing for the petrochemical market have led to the necessity to maximize the production of light HC (in special light olefins). The new technologies must involve the use of acid catalysts that have high activity and selectivity. In despite of the naphthenic HC make par
Publicado em: 2009
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22. Filtro a base de nanofibras de carbono para sequestro de enxofre em efluentes gasosos ricos em H2S / Carbon nanofibers based filter to sulfur removal from efluents rich in H2S.
Over the last few decades, sulfur recovery from the H2S-containing acid gases have become more and more important due to the ever increasing standards of efficiency required by environmental protection measures. The general trend is to selectively transform H_2S into elemental sulfur which is a valuable product, by the modified Claus process. However, due to
Publicado em: 2009
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23. Catalisadores à base de Cu, Co ou Fe trocados ou suportados em zeólita USY avaliação na redução de NO com CO
The emissions of the nitrogen oxides (NOx) must be hardly reduced in the next years. The catalytic reduction of NO with CO is one of the possible processes with potential to be able to transform those oxides in N2. In that process, supported noble metals have been the most used, however, their low stability in the presence of water steam or SO2, have led to
Publicado em: 2008
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24. Preparação e caracterização de materiais com base zeolítica para aplicação em catálise
Today, heterogeneous catalysts are commonly used in chemical industries and became very important to several commercial processes. A key problem in catalysis is the evaluation of acid parameters in solid acids and their correlation with catalytic activity. This work involves the study of acidity for zeolites and heteropolyacids and their activity in model re
Publicado em: 2007