Novel Method for Preparing Activated Carbons with High Specific Surface Area from Rice Husk

Abstract

This study reports the novel dry activation for preparing activated carbon with a high specific surface area from rice husks using solid NaOH. Materials were characterized by N2 adsorption, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The effects of mass ratio (1–4) and the activation process (dry activation or impregnation) on the surface area were studied, explicating the mechanism of pore development. With a mass ratio of 3, carbons prepared by dry activation possessed a much higher surface area of 2841 m2/g than the 933 m2/g for impregnation. For the adsorption of phenol, their maximum adsorption capacities were 351.4 and 160.8 mg/g, fitting with the Langmuir model. In addition, the economic analysis estimated a significant gross profit margin of 40.2% for the product. Therefore, it is demonstrated that dry activation is an effective and convenient method for obtaining low cost activated carbon with outstanding surface area.