Preparation of PitchBased Spherical Activated Carbons by ZnCl2

A series of pitchbased spherical activated carbons (PSACs) were prepared by chemical activation with zinc chloride and physical activation with steam. The influence of activation process variables such as chemical ratio, activation temperature and holding time on the pore structure of PSACs was studied. The two series of PSACs with similar BET specific surface areas and total pore volume were also compared. The results show that PSAC with optimum BET specific surface areas (961 m2/g) was obtained under the activation temperature of 500 ℃, ZnCl2/carbon mass ratio of 2∶1 and the holding time of 3 h. Compared with the conventional steam activation, ZnCl2 chemical activation is more propitious to create mesopore structure.