Template free ZSM-5 from siliceous rice hull ash with varying C contents

Vempati, R. K.; Borade, Ramesh B.; Hegde, Ramesh S.; Komarneni, Sridhar

doi:10.1016/j.micromeso.2006.02.008

Cited by 69 publications

(36 citation statements)

References 9 publications

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“…1 The hulls generated by the rice processing are burnt and the ashes, some 20% by weight, have been used as cheap source of silica for the production of building materials. 2 -5 More sophisticated uses have been suggested, for example Vempati et al 6 prepared template-free ZSM-5 from rice hull ash with varying C contents.…”

Section: Introductionmentioning

confidence: 99%

Mesoporous silica from rice hull ash

Sánchez‐Flores¹,

Pacheco‐Malagón²,

Pérez-Romo³

et al. 2007

J of Chemical Tech & Biotech

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In the synthesis of mesoporous materials, the use of a template with an adequate porosity is normally favoured. As far as silica is concerned, many sophisticated procedures directed towards this goal have been published. It is already well documented that rice hull contains relatively pure silica after combustion of the residual organic matter. The authors of this contribution have recently demonstrated that large surface area silicates react with glycerol around 200• C to give depolymerized silica with a chemical composition similar to that of poly-alkoxides. The interest in this so-called depolymerization is to allow easy formation of reactive gels which retain the memory of the porous structure of the original starting material. Rice hull ash (RHA), obtained after combustion of the organic residues at 500• C, gives a silica characterized by mesopores with an average diameter about 3.5 nm. It is shown that RHA reacts with glycerol at 200• C to form gels which, after hydrolysis and calcination, retain the mesoporous character. The hydrolysis procedure and especially, the pH is important for the distribution of the mesoporosity. The very simple reaction of a by-product of the food industry with glycerol, a ''green reagent'', gives a mesoporous solid silica in the form of a reactive gel, with many potential uses. Its use in a new procedure for the synthesis of a supported ZSM-5 zeolite has been demonstrated.

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Section: Introductionmentioning

confidence: 99%

Mesoporous silica from rice hull ash

Sánchez‐Flores¹,

Pacheco‐Malagón²,

Pérez-Romo³

et al. 2007

J of Chemical Tech & Biotech

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“…Organic templates for example, tetramethylammonium hydroxide (TMAOH), make 50% of the production cost and require calcinations which result in the pollution problems (Vempati et al, 2006). In our environmentally friendly process, no expensive organic template was used and so, the cost of synthesis can be decreased.…”

Section: Economical Advantagesmentioning

confidence: 99%

Synthesis of nanozeolite sodalite from rice husk ash without organic additives

2010

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Rice husks are an excellent source of high-grade amorphous silica which can be extracted from rice husk ash by a suitable alkali solution. The aim of this study is to synthesise nanozeolite sodalite by a hydrothermal method with extracted silica from rice husk as an agricultural waste without organic additives. The effect of crystallisation time on the properties of final products was investigated and the synthesised zeolite was characterised by XRD, SEM, EDX, FT-IR, and BET techniques. Results revealed the significant effects of crystallisation time on the structural properties of nanozeolite. Synthesis of sodalite nanocrystal with crystallite size ranging from 30 to 60 nm was achieved at 60 • C and aging of 5 h, without any organic additive.Le son de riz est une excellente source de silice amorphe de haute qualité qui peutêtre extraite des cendres de son de rizà l'aide d'une solution alcaline adaptée. L'objectif de la présenteétude est de synthétiser les nanozéolites de sodalite au moyen d'une méthode hydrothermale, en extrayant, sans additifs organiques, de la siliceà partir du son de riz (déchet agricole). L'effet du temps de cristallisation sur les propriétés des produits finaux aétéétudié et la zéolite synthétisée aété analysée grâce aux techniques de DRX, MEB, EDX, FT-IR, et BET. Les résultats ont révélé les effets significatifs du temps de cristallisation sur les propriétés structurelles des nanozéolites. La synthèse des nanocristaux de sodalite, avec une taille de cristallite allant de 30à 60 nm, aété réaliséeà une température de 60 • C et après 5 heures, sans aucun additif organique.

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“…Some researchers reported preparation of hierarchical ZSM-5 by post synthesis as demetalisation and desilication without organic template done [7][8][9], while the other researchers published the synthesis of hierarchical ZSM-5 by direct template (supramolecular and solids template) [10][11][12][13]. The synthesis also requires silica and alumina source, in order to decrease the cost of ZSM-5, many researcher substituted the commercial chemical products by the natural ones.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Hierarchical ZSM-5 from Indonesian Kaolin by Adding Silica

Hartati¹,

Widati²,

Setyawati³

et al. 2016

ChChT

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Abstract. Hierarchical ZSM-5 was prepared using Bangka kaolin-Indonesia in the absence of structure directing agent. The effect of hydrothermal time and temperature was investigated. The prepared samples were characterized by XRD, XRF, FT-IR, and N 2 adsorption/desorption. The results show that hierarchical ZSM-5 can be obtained at hydrothermal temperature of 393-448 K. Moreover, this method also produces mordenite and quartz as by-products.

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Template free ZSM-5 from siliceous rice hull ash with varying C contents

Cited by 69 publications

References 9 publications

Mesoporous silica from rice hull ash

Mesoporous silica from rice hull ash

Synthesis of nanozeolite sodalite from rice husk ash without organic additives

Preparation of Hierarchical ZSM-5 from Indonesian Kaolin by Adding Silica

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