Vacuum-assisted synthesis of spherical activated carbon using coal tar pitch with low softening point by copolymerization

Coal tar pitch with a softening point (SP) of 78 degrees C is mixed with divinylbenzene (DVB) and then spheroidized by suspension method in dimethyl silicone oil for 1 h. During the spheroidization process, the mixtures of pitch and DVB are copolymerized due to vinyl in DVB. After vacuum-assisted heat treatment, the copolymer spheres can be stabilized completely and then carbonized directly at high temperature under Ar atmosphere without melting and deformation. After activation using steam at 850 degrees C for 1.5 h, spherical activated carbon (SAC) with smooth surface and specific surface area S-BET = 520 m(2 )g(-1) can be prepared. Further studies show that mesopore volume of the SAC is 0.29 cm(3) g(-1) , which accounts for 72.5% of the total pore volume. The good spherical morphology, smooth surface and rich pores (micropores and mesopores) can be attributed to appropriate copolymerization and vacuum-assisted treatment.