Rice Husks Before And After Steam Explosion (SE)

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Rice Husks Before And After Steam Explosion (SE)
      SE, extracted husks SE, extracted husks
  Rice husks SE husks water water/dioxan
  Extractives Extractives  
Ether soluble 0.4      
Ethanol soluble 5.0      
Extractives Total 5.4      
  Polysaccharides Polysaccharides  
Rha 0.1 0.1    
Ara 1.7 0.2    
Xyl 14.4 2.8   2.3
Man 0.3 0.2   0.1
Glc 33.4 32.9   49.2
Gal 1.6 0.8   1.2
Polysaccarides Total 51.5 37.0   52.8
Lignin (AcBr) 25.5 45.8   20.0
Klason Residual 23.5 30.4 33.8  
Ash 15.5 17.7 18.6 24.9
Total 98.0 100.5   97.7
Rha rhamnose Ara arabinose Xyl xylose Man
mannose Glc glucose Gal galactose (as anhydro
sugars)
Lignin (AcBr lignin determined by acetyl bromide
method
- Extracted with water and dioxan (90)
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The Basic Components Of Rice Husks Ash
Components wt () mg/kg Error ()
SiO2 90.50 905000 0.5
Al2O3 0.59 5900 0.1-0.2
Fe2O3 0.51 5100 0.1
CaO 0.65 6500 0.1-0.2
MgO 0.48 4800 0.1-0.2
Na2O 0.41 4100 0.1
K2O 3.83 38300 0.15
Loss of mass      
1000ºC 1.70    
Total 98.67    
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Concentration Of Minor Metallic Components In
Rice Husks Ash (mg/kg)
Element Content (mg/kg) Sdev t (95)
Cd 0.347  
Cr lt0.7  
Cu 2.08  
Zn 15.1 1.0
Pb lt2.3  
Ni lt1.3  
Co lt1.3  
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High Tech Materials From Rice Husk

• Si (?)
• nano-ceramics
• alaoxy silicons
• exceptionally selective and voracious
  nano-sorbents
• carbon ceramics

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CO ? CO2
OXIDES
RICE HUSKS (SiO2)
T
Si
O2
SiO2 2C ? Si 2CO
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LOW TEMPERATURE PLASMA
RICE HUSKS
PRODUCTS
nano-powders (20-100 nm) ß SiC a -, ß Si3N4,
X-ray amorphous nano-ceramics
PLASMATRON
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FT IR Spectra of Rice Husks
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Characteristics of produced products
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Experimental The nanosize nitride or oxide based
composites are prepared by evaporation of coarse
commercially available powders of chemical
elements and their compounds and subsequent
condensation of products into a radio frequency
inductively coupled nitrogen or oxygen plasma
(ICP). The elaborated experimental apparatus
(Fig. 1) consists of radio-frequency (5.28 MHz)
oscillator with maximum power of 100 kW, quartz
discharge tube with induction coil, raw powder
and gas supply systems, water cooled stainless
steel reactor and heat exchanger, and cloth
filter for collecting powders. Optimal parameters
of the radio-frequency oscillator and parameters
of the plasma are determined by calorimetric
methods. The growth of product particles and
their phase and chemical composition are
regulated by changing the velocity of the plasma
flow and introducing cold gas (ammonia,
hydrocarbon, hydrogen, air) into vapours. The
process is optimised by studying the dependence
of the particle size, their phase and chemical
composition, and the production rate on the flow
rate of plasma and cooling gases, the feeding
rate of precursor powders, parameters of the
plasma flow. The chemical and phase composition
of prepared powders is determined by conventional
chemical and X-ray powder diffraction analysis.
The specific surface area of powders is
determined by the BET argon adsorption-desorption
method but the shape of particles by transmission
electronic microscopy
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Acknowledgements Many thanks to my colleagues
Oskars Bikovens, Andris Veveris and the one of
leading experts of low temperature plasma
physics and tehnology Academician of the ALS
Janis Grabis. The research was done withouth
any financial support