rice h usks b efore a nd a fter s team e xplosion (se)
DESCRIPTION
Rice H usks B efore A nd A fter S team E xplosion (SE). 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%). - PowerPoint PPT PresentationTRANSCRIPT
2nd International Conference on “INTEGRATIVE APPROACHES TOWARDS SUSTAINABILITY”
O. Bikovens, A. Vēveris, J. Grabis and J. Grāvītis
LSIWC, Rīga, Latvia, e-mail: [email protected]
EUROPEAN RICE HUSKS STUDIES WITH FOCUS ON UTILIZATION OPPORTUNITIES
11-14 May, 2005, Jūrmala, Latvia
Rice Husks Before And After Steam Explosion (SE) SE, extracted husks*
Rice husks SE husks water water/dioxan
Extractives
Ether soluble 0.4%
Ethanol soluble 5.0%
Extractives Total 5.4%
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%)
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
The Basic Components Of Rice Husks Ash
Concentration Of Minor Metallic Components In Rice Husks Ash (mg/kg)
Element Content (mg/kg) Sdev · t (95%)
Cd 0.347
Cr <0.7
Cu 2.08
Zn 15.1 ± 1.0
Pb <2.3
Ni <1.3
Co <1.3
High Tech Materials From Rice Husk
− Si (?)− nano-ceramics− alaoxy silicons− exceptionally selective and
voracious nano-sorbents− carbon ceramics
RICE HUSKS(SiO2)
Si
CO → CO2
O2
T
SiO2 + 2C → Si + 2CO
OXIDES
LOW TEMPERATURE
PLASMA
RICE HUSKS
PRODUCTS:
nano-powders (20-100 nm)β – SiCα -, β – Si3N4, X-ray amorphous
nano-ceramics
PLASMATRON
FT IR Spectra of Rice Husks
Characteristics of produced products
Precursors SSA, m2/g N, wt.% C/Si XRD
Rice husk 42 3.9 0.56 -SiC
Rice husk+SiO2 21.8 3.1 0.37 -SiC
Rice husk+Si 20.7 4.5 0.38 -SiC
reactor
P
powder
filter
heat
exc
hang
er
H2O
Quenchinggas
RFcoil
Plasmagas
P
P
ExperimentalThe 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
Acknowledgements
Many thanks to my colleagues: Oskars Bikovens, Andris Vēveris and the one of leading experts of low
temperature plasma physics and tehnology Academician of the ALS Jānis Grabis. The research was
done withouth any financial support