Effect of variations in milling speed with high energy milling treatment on surface area of biochar material

Abstract

Biochar is a renewable and abundant carbon source and is useful for increasing food security and plant diversity in areas with poor soil conditions, lack of organic matter, lack of water availability and chemical fertilizers. Biochar micro porous structure can be produced from corncob material which inherits the architecture of raw materials. To increase the surface area of the biochar material, high energy milling treatment was carried out in this study by varying the speed of milling in the same milling time. Milling time is carried out at 3 hours with milling speeds varying of 300, 500 and 700 rpm. The samples were characterized by X-ray diffraction, scanning electron microscope (SEM), particle size analyser (PSA), and surface area analysis - Brunauer, Emmett and Teller (SAA-BET). The test results show that at speed of 300, 500 and 700 rpm it has produced biochar with a particle size of 947,9; 868,5 and 799,2 nm, respectively. While the SAA-BET test has produced a surface area of 10.115; 15.889 and 18.303 m2/g. This study describes an increase of surface area when compared without milling treatment which has a surface area of 7917 m2/g.