Homogeneous Catalysis
Mostrando 13-24 de 46 artigos, teses e dissertações.
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13. Produção de monoéster via etanólise por hidrotalcitas termoativadas : síntese e caracterização
Among biofuels of the 1st generation, biodiesel stands out for its equivalent features to those of mineral diesel, however less polluting. It can be obtained by transesterification of triglyceride fats or vegetable oils by (m)ethanolysis. Aiming at improving the chemical process, different types of catalysis have been studied: i) homogeneous (acid e.g. H2SO4
Publicado em: 2011
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14. Estudo da produção de biodiesel a partir de óleo de babaçu e etanol utilizando a transesterificação alcalina tradicional com agitação mecânica e assistida por ultrassons / Evaluation of biodiesel production from babassu and ethanol applying traditional alkaline transesterification with mechanical stirring and under ultrasonic technology
Neste trabalho foram sintetizados ésteres etílicos do óleo de babaçu através da catálise alcalina em meio homogêneo. O planejamento de experimentos foi utilizado como ferramenta de otimização e também na identificação dos principais fatores que influenciam nas conversões em ésteres etílicos. As reações de transesterificação foram realizada
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/08/2010
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15. Produção de biodiesel através de transesterificação in situ de sementes de girassol via catálise homogênea e heterogênea
The objective of this work is to show the results of the in situ transesterification of sunflower seed oil with methanol on basic homogeneous and heterogeneous catalysis for the production of biodiesel. In homogeneous catalysis, the activity of KOH and K2CO3 were evaluated using the same oil:methanol ratio of 1:90. KOH showed to be more active than K2CO3, le
Química Nova. Publicado em: 2010
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16. Synthesis of biodiesel from transesterification os soybean oil by homogeneous and heterogeneous catalysis / Síntese de biodiesel a partir da transesterificação do óleo de soja por catálises homogênea e heterogênea
Biodiesel is defined as a mono alkyl ester of fatty acids of long chain derived from renewable sources such as vegetable oils and animal fats. Its importance is related to the use as an alternative fuel for diesel cycle engines. The biodiesel could be obtained by the transesterification reaction in which triacylglycerides (oil or grease) react with alcohol i
Publicado em: 2010
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17. Uso de equações lineares na determinação dos parâmetros de Michaelis-Menten
The Michaelis-Menten equation is used in many biochemical and bioinorganic kinetic studies involving homogeneous catalysis. Otherwise, it is known that determination of Michaelis-Menten parameters K M, Vmax, and k cat by the well-known Lineweaver-Burk double reciprocal linear equation does not produce the best values for these parameters. In this paper we pr
Química Nova. Publicado em: 2010
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18. Síntese e avaliação de sílica tipo M41S contendo cátions CTA em transesterificação catalítica
The investments in the biofuel production have increased a lot in the last years mainly because of smaller damages they cause to the environment in comparison with the derived conventional petroleum fuels. The reaction of biodiesel formation is denominated transesterification and, nowadays that reaction happens in the presence of homogeneous catalyst as the
Publicado em: 2010
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19. Esterificação de ácido oléico sobre catalisadores mesoporosos tipo SO4-2/MCM-41 visando a produção de biodiesel
Climatic changes, largely induced by the use of fossil fuels and the concern with the sustainable development, has become renewable sources of energy extremely important. Nowadays, renewable sources of energy can be obtained, among several available processes, starting from transesterification, esterification and pyrolysis reaction. The esterification reacti
Publicado em: 2009
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20. BIODIESEL A PARTIR DE ÓLEOS DE ALTA ACIDEZ: Desenvolvimento de um processo catalítico homogêneo
The present work aims at developing a process for the production of biodiesel from oils of high acidity, using a process in two steps in homogeneous catalysis. The first is the reaction of ethyl esterification of free fatty acid, catalyzed by H2SO4, occurring on triglycerides and the second is the transesterification of residual triglycerides, from the first
Publicado em: 2009
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21. Ozonização catalítica do chorume proveniente do antigo aterro controlado da cidade de Guaratinguetá-SP utilizando os íons Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ e Cr3+ / Homogeneous catalytic ozonation of leachate from Guaratinguetá - SP landfill, using the ions Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ e Cr3+
Durante anos, o lixo da cidade de Guaratinguetá foi aterrado e o seu produto recalcitrante não passou por nenhum tratamento físico ou mesmo químico, percolando diretamente sob o aterro. Mesmo tendo sido desativado e transformado em Parque Ecológico, o material depositado no local ao longo dos anos, continuará a ser decomposto por microrganismos e conti
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/05/2008
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22. Catalisadores contendo carbenos n-heterocíclicos como ligantes: propriedades, sínteses, aplicações e comparação com outros ligantes
N-heterocyclic carbenes (NHCs) have become of considerable importance in modern organometallic chemistry and homogeneous catalysis. There are several advantages in the use NHCs over their phosphorus analogues, which explains the enormous development of NHC ligands in the field of organometallic catalysis in the past few years. In this article, we present an
Química Nova. Publicado em: 2008
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23. Obtenção de ésteres etílicos e metílicos, por reações de transesterificação, a partir do óleo da palmeira Latino Americana macaúba - Acrocomia aculeata / Isolation of methilic and ethilic esters, by transferification reactions, from macauba trees oils- , Acrocomia aculeata
Ethyl esters and methyl esters (biodiesel) from oils of the fruits of the palm tree macauba (Acrocomia aculeata) were obtained by transesterification reactions performing the alcoholysis (methanolysis and ethanolysis) under homogeneous basic catalysis (using KOH, NaOH, CH3CH2OK, CH3CH2ONa CH3OK and CH3ONa), under homogeneous acid catalysis (using HCl and H2S
Publicado em: 2007
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24. Sintese e heterogeneização de complexos de paladio : aplicação em reações de acoplamento C-C / Synthesis and heterogeneization of palladium complexes : application in C-C cross-coupling reactions
In this work, palladium complexes, in which phosphored ligands are anchored to cyclophosphazenes were synthesized. These complexes, in solution or immobilized in inorganic matrices, were tested in the Suzuki cross-coupling reaction (between phenylboronic acid and bromobenzene, for example), the Stille cross-coupling reaction (between tributylvinyltin and
Publicado em: 2007