Preparation of Spherical Activated Carbon Based on Coal Pitch

摘要

Sphere formation of pyridine soluble fraction of a coal tar pitch in fluid suspension is investigated in this study. Factors influencing pitch dispersion and sphere formation are examined, which include water/pyridine solvent ratio, sphere formation temperature, stirring speed and time and other conditions. The effect of carbonization conditions of the oxidation-stabilized pitch spheres on adsorption properties is evaluated. The results show that processing conditions have significant influence on pitch sphere formation process: suitable spheres with spherical degree of 0.976 and nominal diameter around 20-30 urn are formed under the conditions of water/pyridine solvent ratio = 1, sphere formation temperature = 90℃ , stirring speed = 200 rpm and stirring time = 20 minutes. These pitch spheres were carbonized at a temperature of 700℃ , a heating rate of 5℃ /min and dwell time of 40 minutes, resulting in the SAC with iodine adsorption of 973 mg/g, benzene adsorption of 489 mg/g, methyl blue adsorption of 193mg/g and specific surface area of 1002 m /g, respectively. The sphere shape and topography of the PS and PSAC are studied by SEM.