Materiais híbridos à base de sílica obtidos pelo método sol-gel

Benvenutti, Edilson Valmir; Moro, Celso Camilo; Costa, Tânia Maria Haas; Gallas, Márcia Russman

doi:10.1590/s0100-40422009000700039

Cited by 59 publications

(35 citation statements)

References 127 publications

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“…The Magnesol ® adsorption curve is a typical "type I" isotherm, characteristic of microporous materials, where the main adsorption occurs at low relative P/P 0 pressures. 25,26 The silica isotherms present a different behavior, with a major adsorption for P/P 0 higher than 0.5. This curve is a typical "type IV" isotherm, characteristic of mesoporous materials.…”

Section: Characterization Of Inorganic Matricesmentioning

confidence: 99%

“…This curve is a typical "type IV" isotherm, characteristic of mesoporous materials. 25,26 The pore size distribution curves are showed in Figure 2, where it is possible to observe that the silica matrix presents a large amount of mesopores compared with Magnesol The SEM images are included in Figure 3. The Magnesol ® material presents spherical particles with diameters between 10 and 50 mm, while silica particles are larger than 100 mm.…”

Section: Characterization Of Inorganic Matricesmentioning

confidence: 99%

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Dry washing in biodiesel purification: a comparative study of adsorbents

Faccini¹,

Cunha²,

Moraes³

et al. 2011

J. Braz. Chem. Soc.

132

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O objetivo deste trabalho é comparar a eficiência de diferentes adsorventes na purificação de biodiesel produzido por transesterificação alcalina do óleo de soja (metanol/KOH). As metodologias propostas foram baseadas na utilização de Magnesol ® , sílica, Amberlite BD10 DRY ® e Purolite PD 206 ® como adsorventes e foram desenvolvidas por adsorção a 65 ºC. A eficiência de cada adsorvente foi medida através do teor residual de potássio, álcool, água e sabão, dissolvidos no biodiesel purificado. Como resultado, observamos que Magnesol ® e sílica apresentaram melhores propriedades de adsorção que Amberlite BD10 DRY® e Purolite PD 206 ® , especialmente para remover sabão, glicerina livre e ligada e potássio. Em comparação com a lavagem ácida convencional, estas matrizes foram consideradas adequadas para a remoção de espécies contaminantes inorgânicas e orgânicas do biodiesel. Os principais resultados encontrados para estes dois adsorventes (Magnesol ® 1% e sílica 2%) foram valores abaixo de 0,17 mg KOH g -1 de acidez, 1 mg kg -1 de potássio, 61 ppm de sabão, 500 mg kg -1 de água, 0,22% de metanol, 0,30% de glicerina livre e 0,03% de glicerina ligada.The purpose of this work is to compare the efficiency of different adsorbents in the purification of biodiesel produced by alkaline transesterification of soybean oil (Methanol/KOH). The proposed methodologies were based on the use of Magnesol ® , silica, Amberlite BD10 DRY ® and Purolite PD 206 ® as adsorbents and were developed by adsorption at 65 ºC. The response of each adsorbent was measured through the residual potassium, alcohol, water and soaps dissolved in the purified biodiesel. As a result, we observe that Magnesol ® and silica showed better adsorption properties than Amberlite BD10 DRY ® and Purolite PD 206 ® , especially for removing soap, free and bonded glycerol and potassium. In comparison to the conventional acid water washing, these matrices were found to be equally appropriate for the removal of inorganic and organic contaminant species from biodiesel. The main results found for these two adsorbents (Magnesol ® 1% and silica 2%) were values below 0.17 mg KOH g -1 for acid number, 1 mg kg -1 of K, 61 ppm of soap, 500 mg kg -1 of water, 0.22% of methanol and 0.03% of free glycerol. IntroductionBiodiesel is a diesel fuel substitute obtained mainly by basic catalytic transesterification of oils and fats, and it is composed by fatty acid mono-alkyl esters that are produced from the reaction of low-acid-number vegetable oils with an alcohol in the presence of a basic catalyst. [1][2][3] Biodiesel is currently produced by the base-catalyzed transmethylation of triglycerides, producing fatty acids methyl esters (FAME). 4,5 At the end of the reaction, the Faccini et al. 559 Vol. 22, No. 3, 2011 glycerol rich-phase is separated from the methyl ester layer by decantation.Methyl esters usually contain contaminant materials that are detrimental to the quality of the fuel, and must be eliminated from the product. Removal of glycerol and glycerides from biodies...

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Section: Characterization Of Inorganic Matricesmentioning

confidence: 99%

Section: Characterization Of Inorganic Matricesmentioning

confidence: 99%

Dry washing in biodiesel purification: a comparative study of adsorbents

Faccini¹,

Cunha²,

Moraes³

et al. 2011

J. Braz. Chem. Soc.

132

View full text Add to dashboard Cite

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“…A similar BET surface area and BJH cumulative pore volume 208 ± 5 m 2 g −1 and 0.47 ± 0.05 cm 3 g −1 were found for both. Figure presents the isotherms, and it is observed that the curves for Al 2 O 3 and Dab‐Al 2 O 3 were identical, typical of type IV mesoporous materials []. Figure also presents the pore size distribution curves for Al 2 O 3 and Dab‐Al 2 O 3 , obtained by BJH method.…”

Section: Resultsmentioning

confidence: 94%

Solid phase extraction of petroleum carboxylic acids using a functionalized alumina as stationary phase

Conto

Nascimento

Souza

et al. 2012

J of Separation Science

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Petroleum essentially consists of a mixture of organic compounds, mainly containing carbon and hydrogen, and, in minor quantities, compounds with nitrogen, sulphur, and oxygen. Some of these compounds, such as naphthenic acids, can cause corrosion in pipes and equipment used in processing plants. Considering that the methods of separation or clean up the target compounds in low concentrations and in complex matrix use large amounts of solvents or stationary phases, is necessary to study new methodologies that consume smaller amounts of solvent and stationary phases to identify the acid components present in complex matrix, such as crude oil samples. The proposed study aimed to recover acid compounds using the solid phase extraction method, employing different types of commercial stationary ion exchange phases (SAX and NH(2)) and new phase alumina functionalized with 1,4-bis(n-propyl)diazoniabicyclo[2.2.2]octane chloride silsesquioxane (Dab-Al(2)O(3)), synthesized in this work. Carboxylic acids were used as standard mixture in the solid phase extraction for further calculation of recovery yield. Then, the real sample (petroleum) was fractionated into saturates, aromatics, resins, and asphaltenes, and the resin fraction of petroleum (B1) was eluted through stationary ion exchange phases. The stationary phase synthesized in this work showed an efficiency of ion exchange comparable to that of the commercial stationary phases.

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“…It is possible the preparation of homogeneous bioinorganic hybrid materials with the organic and inorganic moieties dispersed at molecular or nanometric level. Another advantage is the planning of physicochemical characteristics, mainly the surface area and pore diameter of the materials, through the control of experimental M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 synthesis parameters [19,20]. Some precursors applied in the synthesis of chitosan/silica hybrid materials have been 3-glycidoxypropyltrimethoxysilane [21,22], 3-aminopropyltriethoxysilane, tetramethylorthosilicate [23,24] sodium silicate [25] and tetraethylorthosilicate (TEOS) [26][27].…”

mentioning

confidence: 99%