Preparation of Highly Activated Wood Charcoal by Two-step Carbonization

Chinese fir(Cunninghamia lanceolata) wood powder was carbonized at 500 ℃ followed by another step of carbonization at 1 000 ℃ to obtain highly activated wood charcoal. The optimal condition for preparing highly activated wood charcoal and the adsorptive properties of charcoal were evaluated. The main parameters such as temperature, holding time and heating rate were studied. It was found that adsorption capacities of methylene blue, iodine and benzene increased with increased carbonization temperature and holding time. Under the optimized conditions, the adsorption values of methylene blue, iodine and benzene of the wood charcoal were 330 mg/g,1 068.3 mg/g and 105.28 %, respectively. The yield was 14.29 %. The results indicate that this two-step carbonization process can improve the specific surface area and adsorption capacity of wood charcoal.