Generation of High Quality Biogenic Silica by Combustion of Rice Husk and Rice Straw Combined with Pre- and Post-Treatment Strategies—A Review (original) (raw)
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Biogenic Silica from Rice Husk Ash -Sustainable Sources for the Synthesis of Value Added Silica
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Production of Silica from Rice husk
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Rice husk (RH) is an agricultural waste, which is easily available in the market and Silica (SiO2) is the most abundant material in the earth's crust. This paper addresses the production of silica from the rice husk. The Rice husk ash (RHA) is obtained by burning of rice husk in a muffle furnace at a temperature of 500, 600 and 700 0 C, which is bio-organic Silica (SiO2) and has high pozzolanic activity. The temperature and the time duration for the combustion process are optimized. X-ray Fluorescence (XRF) analysis is carried out to determine the chemical composition of rice husk and that of the rice husk ash. The formed rice husk ash is treated with Sodium hydroxide (NaOH) and Hydrochloric acid (HCl) to produce silica. The obtained silica is used for the various applications like automotive industry, cosmetic industry, etc. The compound of silica like Sodium silicate (NaSiO3) is used for water treatment, concrete treatment, cement production, etc. The brief explanation for the...
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The objective of the present work is to develop a procedure for obtaining and characterization active silica with a high specific surface area from rice husk ash. The relative amount of silica was increased after burning out the carbonaceous material at different times and temperatures. A 95% silica powder could be produced after heat-treating at 700 jC for 6 h. The specific surface area of particles was increased after wet milling from 54 to 81 m 2 /g. D
Горение и Плазмохимия, 2019
Extraction of silica from rice husk is an emerging trend in the current research field. Large amount of rice husk (RH) are treated as waste and disposed of at the landfill site. These waste materials can also cause fire, which may lead to severe environmental pollutions. The airborne particles produced from dust may induce respiratory disease to human beings. The burning of rice husk results in the formation of rice husk ash (RHA) with major SiO2 content with 10 to 20% of carbon and organic components depending on the burning conditions, the furnace type, the rice variety, the climate and the geographical area. Moreover, the commonly used silica precursor like tetraethoxysilane is more expensive, and hence rice husk ash(RHA) and other waste sources having silica are used as an alternative. Acid leaching of the rice husk can carried out to remove soluble elemental impurities and hence it increases the purity of the silica content. The organic compounds in rice husk and other waste ma...
INVESTIGATION ON PRODUCING SILICA FROM RICE HUSK BIOMASS
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Intending to contribute with the valorization of rural squanders that present transfer issues and the utilization of sustainable power sources, was looked into the rice husk burning in climatic foaming fluidized bed reactor. The technique was to assess the air overabundance impact in the pipe gases and the powder attributes. It was resolved the gases organization (CO, CO2 and NOx) and portrayed theash produced (XRD, XRF). 40%excessair advances temperatures inside the reactor around 700°C with higher change efficienciesbut declining the nebulous silica capability of the fiery debris. Opposite conduct was confirm at 128% overabundance air. The pipe gases demonstrated relative inconstancy for each working condition. In the CO case, a normal grouping of 200 ppm was found (on a dry premise of 11% O2) for air overabundance somewhere in the range of 40.0% and 82.5%.
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Recent Progress on the Development of Engineered Silica Particles Derived from Rice Husk
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The development of engineered silica particles by using low-cost renewable or waste resources is a key example of sustainability. Rice husks have emerged as a renewable resource for the production of engineered silica particles as well as bioenergy. This review presents a state-of-the-art process for the development of engineered silica particles from rice husks via a bottom-up process. The first part of this review focuses on the extraction of Si from rice husks through combustion and chemical reactions. The second part details the technologies for synthesizing engineered silica particles using silicate obtained from rice husks. These include technologies for the precipitation of silica particles, the control of morphological properties, and the synthesis of ordered porous silica particles. Finally, several issues that need to be resolved before this process can be commercialized are addressed for future research.
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Journal of Materials Science, 2003
Rice husk is an abundantly available waste material in all rice producing countries. In certain regions, it is sometimes used as a fuel for parboiling paddy in the rice mills. The partially burnt rice husk in turn contributes to more environmental pollution. There have been efforts not only to overcome this but also to find value addition to these wastes using them as secondary source of materials. Rice husk contains nearly 20% silica, which is present in hydrated amorphous form. On thermal treatment, the silica converts to crystobalite, which is a crystalline form of silica. However, under controlled burning conditions, amorphous silica with high reactivity, ultra fine size and large surface area is produced. This micro silica can be a source for preparing advanced materials like SiC, Si3N4, elemental Si and Mg2Si. Due to the high pozzolanic activity, this rice husk silica also finds application in high strength concrete as a substitute for silica fume. Possibility of using this silica as filler in polymers is also studied. The present paper is an attempt to consolidate and critically analyse the research work carried out so far on the processing, properties and application of rice husk silica in various laboratories and also highlighting some results on the processing and characterization of RHA and reactive silica obtained from it in the authors' laboratory.
Rice Straw Ash-A Novel Source of SilicaNanoparticles
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In this study chemical method of dissolution-precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (RSA), the waste ma- terial of rice cultivation. The morphology, particle size, structure and area of spe- cific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and analysis technique for the measurement of the specific surface area of materials (BET). In addition, chemical composition of RSA, used and the synthesized silica nanoparticles was studied by X-ray fluorescence (XRF) spectroscopy. The effects of sodium hydroxide concentration, precipitation reaction temperature and precipi- tation reaction duration on the area of a specific surface were determined through Design of Experiments (DOE) Technique. Results depicted that silica nanoparticles with particle size of 10-15 nanometers were successfully synthesized. Average area of a specific surface and ...
Preparation of silica nanoparticles from semi-burned rice straw ash
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Semi-burned rice straw ash (SBRSA), as waste material provided from gas production unit of rice straw, was used to prepare silica nanoparticles. Box-Behnken statistical experimental design was used to optimize the factors affecting the dissolution efficiency of the silica such as stoichiometry (NaOH:SiO 2 ), reaction time and reaction temperature, and to determine the optimum conditions for the extraction process. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) have been used for the characterization of the SBRSA while UV/VIS/NIR Spectrophotometer was used to measure the concentration of the silica in the solution. The results show that the main constituent of SBRSA is silica (62%). Statistical design shows that the dissolution efficiency was in an agreement with the generated model and the experimental results. It is observed that the dissolution efficiency of silica was increased by increasing leaching temperature, time and stoichiometery. At stoichiometric value 1 and 2, the dissolution efficiency of silica was increased by increasing leaching temperature and time and did not reach 99% efficiency. By increasing the stoichiometric value up to 3, the dissolution efficiency reaches 99.88% at 100°C and 4 h.