5a Zeolite
Mostrando 1-12 de 82 artigos, teses e dissertações.
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1. Study of Catalytic Pyrolysis of Biomass Sorghum (Sorghum bicolor L. Moench) Using Design of Experiments and Surface Response Methodology
This study proposes a screen of variables that have an influence on the modification of the bio-oil chemical composition as a unique critical quality attribute (CQA) throughout the pyrolytic process (zeolite, ZSM-5) by using a 24 full factorial design, followed by optimization through a response surface methodology (RSM) based on central composite design (CC
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. The influence of separately and combined bentonite and kaolinite as binders for pelletization of NaA zeolite from coal fly ash
Abstract Pelletization of zeolitic materials is required to facilitate their practical industrial and commercial applications. Zeolite-NaA was synthesized from fly ash by the fusion method and shaped into spherical granules. Bentonite, kaolinite, and a combination of bentonite with kaolinite were tested as binders with different contents from 5 to 10 wt%. Th
Cerâmica. Publicado em: 2022
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3. Optimization and Study of the Response Surface of Properties for the Synthesis of ZSM-5 Zeolites with Hierarchical Pore Structure Obtained by Desilication
Hierarchical ZSM-5 zeolites were prepared by alkali treatment (desilication) at two temperatures, two reaction times, and two NaOH concentrations. A 23 factorial design was used to study the effect of these variables on the crystallinity, microporosity, and mesoporosity of the zeolite due to the desilication treatment. The factorial design analysis showed th
J. Braz. Chem. Soc.. Publicado em: 2021-06
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4. Reordering of Depolymerized Silicates as Adsorbents for Large Nitrogen Compounds
The adsorption capacities of two synthesized zeolites (crystalline ZSM-5 and semi-crystalline faujasite Y) for a mixture of indole, quinoline and carbazole were studied. The different samples obtained show different crystalline degree, mesoporosity and Si/Al ratios. The synthesis procedure is based on the simultaneous depolymerization of a mixture of high su
J. Braz. Chem. Soc.. Publicado em: 2021-01
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5. SYNTHESIS, CHARACTERIZATION, ADSORPTION AND THERMODYNAMIC STUDIES OF PURE AND BINARY CO2-N2 MIXTURES ON OXYGEN ENRICHED NANOSTRUCTURED CARBON ADSORBENTS
Abstract Oxygen enriched porous carbons have been synthesized by a nanocasting technique using mesoporous zeolite as template and epoxy resin as precursor. Characterization results show the effect of the nanocasting technique on the development of heterogeneous surface, high basicity, and high surface area of 686.37 m2g-1, beneficial for CO2 adsorption. Pure
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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6. Síntese de CoFe2O4 sobre os suportes MgAl2O4 e ZSM-5 para uso na degradação de poluente orgânico pelo processo foto-Fenton heterogêneo sob irradiação visível e solar
RESUMO Neste trabalho, ferrita de cobalto (CoFe2O4) foi sintetizada sobre aluminato de magnésio (MgAl2O4) e zeólita ZSM-5 e a atividade catalítica desses materiais na reação foto-Fenton visando a decomposição de um poluente orgânico em solução aquosa foi avaliada. Ferrita de cobalto foi sintetizada sobre os suportes pela rota solvotérmica. Os mate
Matéria (Rio J.). Publicado em: 25/11/2019
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7. Catalytic Transformation Conditions of Ethanol on Dealuminated BEA Zeolites
Catalysis is an important tool in obtaining a range of derivative products from renewable sources, such as ethanol. Solid-state dealumination using ammonium hexafluorosilicate on the BEA zeolite under the treatment at temperature of 190 °C, 70 mol% dealumination in the presence of humidity and washing with buffer solution at 25 °C generated larger pores. T
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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8. CHARACTERIZATION AND BEHAVIOUR OF PT CATALYSTS SUPPORTED ON BASIC MATERIALS IN DRY REFORMING OF METHANE
ABSTRACT Different basic materials, such as K-L zeolite, K-Al2O3, K-Mg/Al mixed oxide and MgO, were used as supports of Pt-catalysts for the dry reforming of methane (DR) reaction. The effects of the distribution of basic strength in the support on the metal-support properties and catalyst performance were evaluated. The density of strong and the total basic
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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9. Desilication of ZSM-5 and ZSM-12 Zeolites with Different Crystal Sizes: Effect on Acidity and Mesoporous Initiation
In the present work, the desilication of the H-ZSM-5 and H-ZSM-12 zeolites with Si/AL ratios of 28 and 56 and crystal sizes of around 200 and 600 nm, respectively, was performed. Through electron transmission microscopy analysis, it was possible to verify the influence of aluminium gradients on smaller crystals in addition to the exact moment at which the fo
Mat. Res.. Publicado em: 11/02/2019
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10. Catalytic hydrogen generation from NaBH 4 /H 2 O system: effects of catalyst and promoters
Abstract A hydrogen generation system based on NaBH4 hydrolysis is affected by the nature of the catalyst and catalyst promoter. Various catalyst promoters such as Al2O3 nanoparticles, Al2O3 particles, ZrO2 sand, SiO2, MMT clay, CNT and zeolite are compared with respect to hydrogen generation (HG) and hydrogen generation rate (HGR). The highest HG and HGR ar
Braz. J. Chem. Eng.. Publicado em: 2018-01
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11. Study on the NaOH/metakaolin Ratio and Crystallization Time for Zeolite a Synthesis from Kaolin Using Statistical Design
The NaOH/metakaolin ratio and crystallization time were studied for the synthesis of zeolite NaA from a sample of kaolin from a Capim mine. The tests were carried out by using statistical design with axial points and replication of the central point. The samples obtained were characterized by X-ray diffraction (DRX), scanning electron microscopy and chemical
Mat. Res.. Publicado em: 13/04/2017
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12. SYNTHESIS OF CUMENE BY TRANSALKYLATION OVER MODIFIED BETA ZEOLITE: A KINETIC STUDY
Abstract In the present study, transalkylation of 1,4-diispropylbenzene (DIPB) with benzene in the presence of modified beta zeolite was performed to produce cumene in a fixed bed reactor. Beta zeolite was exchanged with cerium in order to modify its catalytic activity. Activity of the modified catalyst was evaluated in the range of temperature 493K-593K, sp
Braz. J. Chem. Eng.. Publicado em: 2016-12