Alumina Production
Mostrando 13-24 de 81 artigos, teses e dissertações.
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13. A Simple Way to Produce γ-Alumina From Aluminum Cans by Precipitation Reactions
Abstract In this paper, a new way for γ-alumina synthesis was proposed, the raw material being aluminum powders obtained by high-energy milling of aluminum cans. This seems a good option for this metal recycling and energy saving, as well as hydrogen production. The materials were prepared by precipitation techniques, in which aluminum powders reacted with
Mat. Res.. Publicado em: 21/07/2016
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14. NANOPARTICLES OF TUNGSTEN AS LOW-COST MONOMETALLIC CATALYST FOR SELECTIVE HYDROGENATION OF 3-HEXYNE
Low-cost tungsten monometallic catalysts containing variable amounts of metal (4.5, 7.1 and 8.5%W) were prepared by impregnating alumina with ammonium metatungstate as an inexpensive precursor. The catalysts were characterized using ICP, XPS, XRD, TPR and hydrogen chemisorption. These techniques revealed mainly WO3-Al2O3 (W6+) species on the surface. The eff
Quím. Nova. Publicado em: 2016-01
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15. Incorporation of in Natura and Calcined Red Muds into Clay Ceramic
Brazil is one of the world greatest aluminum producer and also comprises a large industrial sector dedicated to the production of alumina (Al2O3) by the traditional Bayer process. During this process an insoluble residue, known as red-mud, is generated and normally discarded. A possible use for the red mud is its incorporation into clay ceramics. Indeed, thi
Mat. Res.. Publicado em: 23/10/2015
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16. Production of porous ceramic materialusing different sources of alumina and calcia
ABSTRACTNumerous papers and publications report the use of microporous calcium hexaluminate (CaO.6Al2O3; CA6) as a key raw material for high temperature insulating materials. This material has unique properties with respect to chemical purity and mineral composition. Another important property of CA6 is its structure, which consists of platelet-shaped crysta
Matéria (Rio J.). Publicado em: 2015-09
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17. CARACTERIZAÇÃO E ATIVIDADE CATALÍTICA DE K2CO3/AL2O3 NA TRANSESTERIFICAÇÃO DO ÓLEO DE GIRASSOL COM AQUECIMENTO CONVENCIONAL E MICRO-ONDAS
Commercial and synthetic mesoporous aluminas impregnated with potassium carbonate were characterized by X-ray diffraction (XRD), nitrogen physisorption, infrared spectroscopy and 27Al MAS NMR. The activities in the transesterification reaction of sunflower oil with methanol for biodiesel production were evaluated. 27Al MAS NMR spectra evidenced the presence
Quím. Nova. Publicado em: 2015-02
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18. Flash Pyrolysis of Oleic Acid as a Model Compound Adsorbed on Supported Nickel Catalysts for Biofuel Production
A pirólise rápida do ácido oleico foi estudada sobre catalisadores com 10% Ni suportados em sílica e alumina. Os catalisadores foram impregnados com 10% m/m de ácido oleico. Os precursores secos e os catalisadores contendo ácido oleico foram caracterizados por análise termogravimétrica. Os catalisadores calcinados foram analisados por difração de r
J. Braz. Chem. Soc.. Publicado em: 2014-12
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19. Use of heterogeneous catalysts in methylic biodiesel production induced by microwave irradiation
The effect of different heterogeneous catalysts on the microwave-assisted transesterification of sunflower oil for the production of methylic biodiesel in a monomode microwave reactor is described. The experiments were carried out at 70 ºC with a 16:1 methanolsunflower oil molar ratio and different heterogeneous basic and acidic catalysts. The results showe
Quím. Nova. Publicado em: 2014-06
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20. 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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21. Imobilização da tanase de Paecilomyces variotii e ação em reações de hidrólise e síntese / Immobilization of tannase from Pecilomyces variotii and reactions of hydrolysis and synthesis
Tannin acyl hydrolase (TAH) known as tannase (EC 3.1.1.20) is an enzyme that hydrolyzes esters of hydrolysable tannins producing gallic acid and glucose as the reaction medium is polar. However, the literature indicates their ability to produce also gallic acid esters in organic media. Our research group has isolated a fungus, Paecilomyces variotii, tannase
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/06/2012
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22. ESTUDO EXPERIMENTAL DA COMBUSTÃO DO GLP E GLICEROL RESIDUAL DERIVADO DA PRODUÇÃO DE BIODIESEL EM MEIOS POROSOS RADIANTE / EXPERIMENTAL STUDY OF LPG COMBUSTION OF GLYCEROL AND RESIDUAL DERIVED FROM BIODIESEL PRODUCTION IN RADIANT POROUS MEDIA
The increasing production of biodiesel has caused increased production of residue glycerol. The large amount of glycerin (our glycerol) in the market causes a surplus unusable commercially and industrially, which should give a correct destination. At this point, the porous combustion is characterized by burning within an inert medium, to the pollutants reduc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/05/2012
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23. Estudo da influência da força de corte em usinagem a verde nas propriedades mecânicas de cerâmicas sinterizadas / Influence of the cutting force of green machining on the mechanical properties of sintered ceramics
The present study deals with the measurement forces of green machining ceramics and their correlation with the mechanical properties after sintering. The green machining is employed in crude compacts either to check raw formats without compromising the extreme dimensional accuracy or to obtain a preform prior to finish machining after sintering, extensively
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/01/2012
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24. Concretes with red mud coarse aggregates
Red mud (RM) is a mineral waste, residue of the Bayer process used to obtain alumina from bauxite. While the exploration of rolled pebble damages the environment and is much more controlled by the government, the huge RM disposal areas do not stop increasing and polluting soil, rivers and groundwater sources in Amazon. In this work, the material mixtures use
Materials Research. Publicado em: 27/03/2012