Conversion of raw rice husks to SiC by pyrolysis in nitrogen atmosphere

Krishnarao, R. V.; Mahajan, Y. R.; Kumar, T. Jagadish

doi:10.1016/s0955-2219(97)00093-9

Cited by 58 publications

(40 citation statements)

References 20 publications

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“…There are several reports, which explain all aspects of formation of SiC from rice husk [185][186][187][188][189][190][191][192][193][194].In most of the cases, the formation ofSiC is carried out in two steps. The rice husks are pyrolyzed in the absence of air at a temperature of 700-900°C and then fired at temperatures of 1500°Cin an inert or reducing atmosphere [195].…”

Section: Sic Formation From Rice Huskmentioning

confidence: 99%

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Review on the physicochemical treatments of rice husk for production of advanced materials

Soltani

Bahrami

Pech-Canul

et al. 2015

Chemical Engineering Journal

504

231

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Section: Sic Formation From Rice Huskmentioning

confidence: 99%

“…In another investigation, Krishnarao and co-workers [191]pyrolyzed rice husks without pre-coking in a graphite resistance heating furnace at 1100-1400°C in nitrogen atmosphere. They reported the formation of good quality (needle-type) SiC whiskers without the detection of Si 3 N 4 .…”

Section: (Figure 22)mentioning

confidence: 99%

Review on the physicochemical treatments of rice husk for production of advanced materials

Soltani

Bahrami

Pech-Canul

et al. 2015

Chemical Engineering Journal

504

231

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“…At present, RH and especially rice husks ashes (RHA) obtained after controlled burning of rice husks are the raw materials for the production of a series of silicon-based materials (Sun & Gong, 2001;Mishra et al, 1986;Della et al, 2002;Watari et al, 2003), including silica (James & Rao, 1986;Kalapathy et al, , 2002Zaky et al, 2008), activated carbon (Watari et al, 2006;Kalderis et al, 2008), sodium silicate Sekar & Virutha, 2005), silicon tetrachloride (Basu et al, 1973;Seo et al, 2003), sodium silicofluoride (Sun & Gong, 2001) and silanes (Acharya et al, 1980;Nandi et al, 1991). The high reactivity and purity of RHA makes it an ideal starting material/silica source for preparing advanced materials like sialon (Sun & Gong, 2001;Rahnman & Saleh, 1995), silicon carbide (Krishnarao et al, 1998;Rodriguez-Lugo et al, 2002;Sujirote & Leangsuwan, 2003), silicon nitride (Kumar & Godkhindi, 1996;Real et al, 2004), cordierite (Sun & Gong, 2001;S. Kurama & H. Kurama, 2008), forsterite (Sun & Gong, 2001), gehlenite (Sun & Gong, 2001;Han et al, 1999), pure elemental silicon (Sun & Gong, 2001;Hunt et al, 1984), magnesium silicide (Acharya et al, 1980;Ghosh et al, 1991), Si-O-C fibers (Sun & Gong, 2001;Shimokawa et al, 1992), zeolites (Gokhal et al, 1986;Chareonpanich et al, 2004) etc.…”

mentioning

confidence: 99%

Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Turmanova

Genieva²,

Vlaev³

2012

IJC

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Rice husks are an important by-product of rice milling process and are major waste product of the agricultural industry. Rice husk contain nearly 20 mass% silica, which is present in hydrated amorphous form. They have now become a great source as a raw biomass material for manufacturing of value-added silicon composite products, including silicon carbide, silicon nitride, silicon tetrachloride, magnesium silicide, pure silicon, zeolite, fillers of rubber and plastic composites, cement, adsorbent and support of heterogeneous catalysts. The rice husk was subjected to pyrolysis in fluidized-bed pilot plant in air or nitrogen atmosphere. The controlled thermal degradation of the rice husks in air or nitrogen leads to production of white rice husks ash (WRHA) and black rice husks ash (BRHA) respectively. WRHA contains almost pure (95mass %) silica in a hydrated amorphous form, similar to silica gel, with high porosity and reactive surface OH groups. BRHA contains different amounts of carbon and silica in amorphous form with high specific surface area and porosity. The raw rice husks and the obtained pyrolysis products were used as fillers of polypropylene (PP) and tetrafluoroethylene-ethylene copolymer (TFE-E) composites. The kinetics and thermodynamics of water adsorption onto filled polypropylene composites during soaking were studied at different temperatures, quantities and nature of fillers. It was established, that the adsorption kinetics was limited by intra-particle diffusion in plane sheet particles. The sorption process is exothermal in nature and accompanied with decrease of the entropy.The physicomechanical properties of composite materials were determined. The fillers introduced in polypropylene change the mechanical strength and make the composites brittle. This change is more pronounced for the composites with BRHA and RRH, followed by WRHA. The composites studied showed lower elongation at break. The biggest decrease was observed for the composites with BRHA where ε decrease from 500 (for the initial PP) to 7 % at filling degree of 20 mass %. The effects of the amount of adsorbed water, temperature and treatment time on the composites tensile properties were estimated. It was found after immersion in water that the composites improve their tensile strength compared to initial non-treated samples. The thermal stability and kinetics of non-isothermal degradation of PP and TFE-E composites filled with 10 or 20 mass % vigorously grounded and mixed RRH, BRHA, WRHA and Aerosil Degussa (AR) were studied. Using different calculation procedures the most probably kinetic mechanism was found to be described by kinetic equations of n -th order (F n mechanism). The kinetic parameters were obtained, and a linear dependence between ln A and E was observed, known also as kinetic compensation effect.The abundance of a waste from paddy milling industry, as well as its interesting complex of behaviors are prerequisite for success for obtaining of cheap and valuable products and gives a new alternatives for its ...

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“…This husk can be used as an additive for cement and co--ncrete fabrication [1,2]. Rice husk contains high silicon as a consequence it has become a source for preparation of elementary silicon [3,4], especially silica [5,6], silicon carbide [7], silicon nitride [8] and a number of silicon compounds. Utilization of rice husk as a resource of silica is based on removal of impurities with low effort and the high specific surface.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization of Silica Obtained from Rice Husk and Determination its Silica Content by Modified Volumetric Method

Kayal

Singh²

2016

Eur Chem Tech J

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The objective of the work was to develop pure silica with high surface area from rice husk by chemical and heat treatment. The silica samples were characterized in terms of chemical composition, particle size distribution, morphology and surface area. The amount of silica was determined by a modified volumetric method. The trace impurities in silica were quantitatively determined by inductive coupled plasma atomic emission spectroscopy (ICP-AES). A 99 % silica powder with surface area 282 m 2

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Conversion of raw rice husks to SiC by pyrolysis in nitrogen atmosphere

Cited by 58 publications

References 20 publications

Review on the physicochemical treatments of rice husk for production of advanced materials

Review on the physicochemical treatments of rice husk for production of advanced materials

Obtaining Some Polymer Composites Filled with Rice Husks Ash-A Review

Synthesis, characterization of Silica Obtained from Rice Husk and Determination its Silica Content by Modified Volumetric Method

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