Porous carbon-silica composites and carbon materials from rice husk: Production technology, texture, and dispersity

A method based on carbonization in a fluidized-bed catalytic reactor is suggested for utilization of rice husks, which are hard-to-recycle waste from paddy production. The bottom ash resulting from carbonization at 465–600°C is a carbon-silica nanocomposite (C/SiO 2 ) with a SiO 2 content of 58.7–81.8 wt % and a specific surface area of S BET = 152–232 m 2 /g. Leaching of SiO 2 with hydrofluoric acid yields porous carbon materials with a specific surface area of 165–494 m 2 /g and a SiO 2 content of