Feasibility assessment of manufacturing carbonized blocks from rice husk charcoal

Artificial graphite has recently attracted significant interest as a promising carbon material for industrial applications because of its high heat and chemical resistance, excellent electrical conductivity, and low thermal expansion. However, its practical use is severely limited by its high preparation costs and poor cycling stability. In this study, rice husk charcoal (RHC) was prepared from agricultural biowaste using a pyrolysis (heat treatments) method in this study. We investigated the effect of the heat-treatment temperature on rice husk via elemental and thermogravimetric analyses. The results indicated that the rice husk heat treated at 400 °C (RHC 400) was thermally stable with a high carbon content. Its preparation process was also relatively inexpensive. Further, carbonized blocks were prepared using the fabricated RHC and compared their properties with those of artificial graphite scrap (AGS) carbonized blocks. The bulk density, porosity, flexural strength, and electrical resistivity of the RHC carbonized block were 1.14 g/cm, 24.65%, 52.55 MPa, and 142.93 μΩm, respectively. These results demonstrate that the flexural strength and electrical resistivity of the RHC-prepared block were higher than those of the AGS carbonized block. In contrast, its density was lower than that of the AGS carbonized block.