Preparation of activated carbon from sawdust by phosphoric acid activation

Activated carbons were prepared from sawdust by phosphoric acid activation under different operation conditions.The effects of operation parameters such as impregnation ratio,activation temperature and time on the adsorption properties of activated carbons were measured and analyzed in order to optimize these operation conditions.The experimental results show that under the experimental conditions studied,both the yield and the methylene blue decolo-(ration) of activated carbon can reach a relatively high value in the chemical activation process with the impregnation (ratio) of H_3PO_4/sawdust 100%-150%,activation temperature of 500 ℃ carbonized for 60-90 min which are the (optimum) activation conditions in making wooden activated carbon.The most important operation parameter in chemical activation with phosphoric acid was found to be the impregnation ratio.The porosity of activated carbon can be well-developed and a relatively high specific surface area of 1 536 m~2/g can be obtained under the optimized conditions.