Rice Husks Before And After Steam Explosion (SE) SE, extracted husks* Rice husksSE husks waterwater/dioxan Extractives Ether soluble0.4% Ethanol soluble5.0% Extractives Total5.4% Polysaccharides Rha0.1% Ara1.7%0.2% Xyl14.4%2.8% 2.3% Man0.3%0.2% 0.1% Glc33.4%32.9% 49.2% Gal1.6%0.8% 1.2% Polysaccarides Total51.5%37.0% 52.8% Lignin (AcBr)25.5%45.8% 20.0% Klason Residual23.5%30.4%33.8% Ash15.5%17.7%18.6%24.9% Total98.0%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%)

Componentswt (%)mg/kgError ± (%) SiO Al 2 O Fe 2 O CaO MgO Na 2 O K2OK2O Loss of mass 1000ºC1.70 Total98.67 The Basic Components Of Rice Husks Ash

Concentration Of Minor Metallic Components In Rice Husks Ash (mg/kg) ElementContent (mg/kg)S dev · t (95%) Cd0.347 Cr<0.7 Cu2.08 Zn15.1± 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 (SiO 2 ) Si CO → CO 2 O2O2 T SiO 2 + 2C → Si + 2CO OXIDES

LOW TEMPERATURE PLASMA RICE HUSKS PRODUCTS: nano-powders ( nm) β – SiC α -, β – Si 3 N 4, X-ray amorphous nano-ceramics PLASMATRON

FT IR Spectra of Rice Husks

Characteristics of produced products PrecursorsSSA, m 2 /gN, wt.%C/SiXRD Rice husk  -SiC Rice husk+SiO  -SiC Rice husk+Si  -SiC

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

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