The role of K_2CO_3 during the chemical activation of petroleum coke with KOH

摘要

The fundamentals of the chemical activation process involved in the formation of K_2CO_3 during the chemical activation of petroleum coke with KOH have been analyzed. For this purpose, the influence of the activation temperature on the development of porosity in the activated carbon and changes to the potassium compounds were investigated by X-ray diffraction analysis, Fourier transform infrared and N_2 adsorption isotherms. The effects of the precursors, the previous mixing methods and temperatures of activation with K_2CO_3 have been studied. In comparison with the activation by KOH, the activation by K_2CO_3 results in a relatively low activation yield and a low surface area. The K_2CO_3 that formed in the initial pores as a result of the KOH activation plays an important role in the development of porosity. The structure and the chemical composition of the precursors affect the activation with K_2CO_3. Possible reactions involving K_2CO_3 activation have been proposed and defined more clearly using thermody-namic calculations.