Research On The Preparation Technology Of High Surface Area Activated Carbons From Petroleum Coke

Activated carbons (AC) were prepared from a green petroleum coke (PC) from SINOPEC Liaoyang Petrochemical Company with KOH as activating agent. The effects of different preparation conditions including the ratio of KOH to coke, the activation temperature, the activation time, the particle size of the PC, the content of H2 in the nitrogen, the flow rate of N2, the introduction of H2 at different temperature and the content of H2O in mixed materials on the porosity development of the resulting AC were investigated as the H2 were introduced into the carrier gas in the activation system. It has been found that as the ratio of KOH to coke 2:1, the activation temperature 780℃, the activation time 60 min, the particle size of the PC smaller than 100 mesh and the total flow rate 140 ml/min which the content of H2 30%, AC with high surface area of 2703 m2/g, pore volume of 1.13 ml/g, iodine value of 374 mg/g and methylene blue value of 296 mg/g could be prepared. As compared with the AC prepared in the same conditions except that the carrier gas is pure nitrogen, the BET surface area, the pore volume, the iodine value and the methylene blue value of the AC prepared in the presence of 30%H2 increased about 500 m2/g,0.26 ml/g,374 mg/g and 296 mg/g, respectively. Therefore, the presence of H2 in the activation system is favorable to the KOH activation of PC. Additionally, the petroleum coke of Daqing, anthracite of Taixi and char were also used as precursor for the KOH activation system to verify the promotion of activation in the presence of H2.On the basis of the horizontal tube reactor in the laboratory, the continuous vertical activation mechanism was designed and constructed. The debugging test of the mechanism including the feeding rate, the material balance, the pressure inside furnace, the temperature distribution and the temperature distribution during the activation were conducted. The discharging rate is 92% as the activation mechanism is normally operated in the cold state experiment. The pressure inside furnace could be exactly controlled by adjusting the valve of gas outlet. The temperature distribution of mechanism could be controlled and kept relatively invariant during the activation process. The debugging test lays a good foundation for the security and stability of continuous production of high surface area activated carbons and its industrialization.