Extraction of SiO2 from gasified rice husk carbon simultaneously rice husk activated carbon production: Restudy on product properties, activation mechanism, and evolution law of pore structure

Abstract

The goal of this work was to provide a theoretical basis for efficient and harmless utilization of gasified rice husk carbon (RHC), and further understand its activation mechanism and evolution law of pore structure. K2CO3 was used to extract SiO2 from RHC, and then the rice husk activated carbon (RAC) was prepared by activating the separated rice husk activated carbon precursor (ACP). Results showed that the specific surface area of the RAC prepared via the ACP was 1006.208 m2/g upon the yield of SiO2 was 20.64%. Compared with the particle size of RHC, the K2CO3 mass fraction have a significant effect on the yield of SiO2 and the K2CO3 content of ACP surface The activation process of ACP mainly depended on the content of K2CO3 adsorbed on its inner surface and internal structure. With an increase in K2CO3mass fraction, the pore structure of RAC roughly went through two primary stages (full development period to transitional development period). Besides, SiO2 has a great amount of ∼5 nm of mesopores and tended to crystallize upon sintered at 950°C for 4 h

Keywords

• Gasified rice husk carbon
• K2CO3
• Extract
• SiO2
• Rice husk activated carbon