Preparation, Characterization And Performance Of Activated Carbon Derived From Petroleum Coke

Because of its unique advantages activated carbon has been applied in solvent recovery, flue gas desulfurization, air purification, catalysts, catalyst supports, electric double layer capacitor as well as adsorption storage of fuel gas. The precursor species of activated carbon and preparation conditions largely affect the formation of pore structure and adsorption properties of activated carbon. While as a new source of energy microwave heating has good prospects in preparation of activated carbon derived from petroleum coke which can be considered as an alternative to the traditional heating method.In this study, Jingbo shot coke was used as precursors to produce activated carbon. Chemical activation with microwave heating was performed. The effects of activating agents, mixture method, microwave power, microwave radiation time and agent/coke ratio on the performance of activated carbon was discussed. Characterization of the activated carbon was performed by the iodine adsorption and benzene adsorption test, N₂ adsorption test, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction. The results showed that the effect of KOH activation of petroleum coke performed the best; microwave operating conditions had a decisive role in the physical and chemical properties, for instance pore structure, adsorption properties, surface functional groups and yields of AC. Especially the optimum KOH/coke ratio, microwave heating time, and microwave power existed. The experimental results of microwave treatment of petroleum coke showed the optimum condition were as follows: KOH/coke ratio of 3:1, microwave power of 900 W, microwave radiation time of 40 min. Under the optimal conditions the active carbon was obtained with BET surface area 2668.3 m2?g-1, total pore volume 1.39 cm3?g-1, average pore diameter distribution of 2.24 nm, micropore proportion 92.95%, iodine value 2281 mg?g-1 and benzene adsorption 1368 mg?g-1.This paper also studied the effect of KOH/coke ratio by electric heating furnace on the preparation of AC. Results showed that with the same KOH/coke, the AC made by electric heating method had lower surface area, total pore volume, average pore diameter and long activation time, microporous proportion compared with microwave heating method. It indicated that the microwave activation method had higher utilization of KOH, shorter activation time and less energy consumption. In addition, this paper also investigated the effects of activation temperature for both electric and microwave heating method on KOH-PC activation reaction and product performance. It was found that microwaves can efficiently and rapidly activate petroleum coke in lower KOH/coke ratio at 650 ℃, and obtain excellent performance of AC, which illustrated the microwave energy could lower the activation temperature of the reaction, improve reaction activity so as to saving production costs. Then the HSC Chemistry software was used to simulate the C-KOH reaction system, discussing the thermodynamically equilibrium composition changes with temperature under different KOH/C ratio.Finally, activated carbon loaded ZrO₂ solid acid catalyst for the desulfurization was investigated. The optimal preparation conditions of oxidative desulfurization catalyst were as follows: the mass ratio of the ZrO₂ and activated carbon 3:100, 0.5 mol?L-1 sulfuric acid soaked for 6h, calcined at 500 ℃ for 2.5h. The desulfurization rate of activated carbon loaded with solid super acid catalyst can reach over 93%.In summary, the microwave heating method has potential applications in the preparation of petroleum coke-based activated carbon preparation areas and it is worth further studying.