Zeolites
Mostrando 13-24 de 127 artigos, teses e dissertações.
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13. Evaluation of the Sustainability of Integrated Hydrothermal Synthesis of Zeolites Obtained from Waste
The high Si and Al contents in the amorphous phase of coal fly ash have been used for its conversion into zeolites. This process converts a toxic low-value by-product into a product used in a number of environmental applications, but has the disadvantage of introducing contaminants. Despite the large number of studies on the conversion of fly ash into zeolit
J. Braz. Chem. Soc.. Publicado em: 2018-07
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14. Synergistic Effect of 4A Zeolite from Rice Husk Ash without Aging Time and Silane on the Adhesion Properties of a Warm Mix Asphalt
4A Zeolite was synthesized using rice husk ash (RHA) as a raw material in a microwave-assisted hydrothermal synthesis. Two new procedures were proposed: procedure A, using RHA as the raw material, and procedure B, using the depolymerized RHA. Both procedures were performed using microwave-assisted hydrothermal synthesis, and neither synthesis required an agi
J. Braz. Chem. Soc.. Publicado em: 2018-01
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15. Ordered Silica Particles Made by Nonionic Surfactant for VOCs Sorption
Adsorption of light organic compounds such acetone, 1-propanol and carbon dioxide was tested by using mesoporous silica materials made from non ionic surfactant with long chain and silica sources as tetraethylorthosilicate TEOS and modified Na-X and Li-A Zeolites. X-ray powder diffraction (XRD), nitrogen adsorption-desorption analysis and scanning electron m
Mat. Res.. Publicado em: 26/06/2017
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16. ANAEROBIC DIGESTION OF WASTEWATER WITH HIGH SULFATE CONCENTRATION USING MICRO-AERATION AND NATURAL ZEOLITES
Abstract The behavior of anaerobic digestion in batch and UASB reactors using a microaerobic process and natural zeolites was studied. Laboratory assays were carried out across 4 sets of variables: different COD/SO42- ratios, different airflow levels, with and without natural zeolites and room and mesophilic controlled temperatures. The microaerobic process
Braz. J. Chem. Eng.. Publicado em: 2016-12
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17. Crystallization of Zeolite A Coatings from Natural Zeolite
An investigation was carried out to determine the possibility of preparing coatings of synthetic zeolites on stainless steel from mixtures containing natural zeolite. Hydrothermal synthesis was applied and the coatings obtained were characterized by various techniques. It was observed that crystalline zeolite A coatings could be prepared from natural clinopt
Mat. Res.. Publicado em: 10/11/2016
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18. Synthesis and Characterization of Al-TON Zeolite Using a Dialkylimizadolium as Structure-Directing Agent
In this work, the synthesis of zeolites using 1-butyl-3-methylimidazolium chloride [C4MI]Cl as a structure-directing agent was investigated. The organic cation shows effectiveness and selectivity for the syntheses of TON zeolites under different reaction conditions compared to the traditional structure-directing agent, 1,8-diaminooctane. The 1-butyl-3-methyl
Mat. Res.. Publicado em: 07/11/2016
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19. Integrated Synthesis of Zeolites Using Coal Fly Ash: Element Distribution in the Products, Washing Waters and Effluent
Coal fly ash has been proposed as an alternative raw material for zeolite synthesis, however, the mobilization of toxic elements of this material into zeolite products, washing water and effluent is rarely addressed. In this study, Brazilian coal fly ash was used in the integrated synthesis (two steps) of zeolites Na-P1 and 4A and the distribution of approxi
J. Braz. Chem. Soc.. Publicado em: 2016-11
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20. Preparation of Mesoporous Fe2O3-Supported ZSM-5 Zeolites by Carbon-Templating and their Evaluation as Photo-Fenton Catalysts to Degrade Organic Pollutant
Mesoporous Fe2O3-supported ZSM-5 zeolites were prepared by carbon-templating and subsequently evaluated as photo-Fenton catalysts to degrade a dye used as a model heavy organic pollutant. The synthesis procedure of the mesoporous ZSM-5 zeolites was performed employing a nucleating gel and carbon particles as mesopores template. Thereafter, the precursor salt
Mat. Res.. Publicado em: 20/10/2016
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21. PROPRIEDADES E AVALIAÇÃO CATALÍTICA DA ZEÓLITA X NANOMÉTRICA CONTENDO CÁTIONS METILAMÔNIO
The reduction of zeolite particle is one of the main features currently searched; it is due to the catalytic gains that these materials come in some reactions. In this work two faujasite zeolites of type X were evaluated, a micrometer and nanometric. Zeolites in sodium form were exchanged ionically with methylammonium cations. These materials were evaluated
Quím. Nova. Publicado em: 2016-07
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22. USE OF A LOW-COST TEMPLATE-FREE ZSM-5 FOR ATMOSPHERIC PETROLEUM RESIDUE PYROLYSIS
To understand the physicochemical properties and catalytic activity during the pyrolysis of atmospheric petroleum residue, a template-free ZSM-5 zeolite was synthesized using a direct method without additional seeds or an organic structure director and compared with conventionally synthesized ZSM-5. The crystallinities of the two zeolites were evaluated by X
Quím. Nova. Publicado em: 2016-04
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23. Thermal and catalytic pyrolysis of plastic waste
Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtai
Polímeros. Publicado em: 04/03/2016
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24. Ultem®/ZIF-8 Mixed Matrix Membranes for Gas Separation: Transport and Physical Properties
Mixed matrix membranes are promising options for improving gas separation processes. Zeolitic imidazolate frameworks (ZIFs) have a porous structure similar to conventional zeolites, being capable in principle of separating gases based on their differences in kinetic diameter while offering the advantage of having a partial organic character. This partial org
Mat. Res.. Publicado em: 19/02/2016