Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10393823 | Biomass and Bioenergy | 2011 | 8 Pages |
Abstract
Rice husk ash (RHA) is an abundant agricultural by-product. The present research work deals with the production of silica powders and active carbon from RHA with a consecutive method. The RHA is firstly treated with acid leaching to remove mineral composition, and then is boiled with base to leach silica. The filtrate is used to synthesize silica powders with CO2 precipitator and solid residue is used to prepare active carbon. The optimum conditions of preparing silica powders are as follows: the concentration of Na2CO3 is 25Â wt.%, the base-leached time is 4Â h, and the impregnation ratio of Na2CO3 solution to RHA is 6:1. The yield of silica leached from RHA is 84.57Â wt.%. The synthesized silica powders are hydrated with amorphous structure, moreover, with a relative smooth surface and high purity. The residue is activated with potassium hydroxide (KOH) after base-leached. The activated carbons are found to be a mixture of micropore and mesopore pore structures. The maximum pore volume, BET surface area and iodine adsorption capacity of as-prepared active carbon can reach 1.22Â cm3/g, 1936.62Â m2/g and 1259.06Â mg/g, respectively. Field emission scanning electron microscopy (SEM) is used to characterize the morphological features of the ash after step by step treatment.
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Authors
Dongmin An, Yupeng Guo, Bo Zou, Yanchao Zhu, Zichen Wang,