The role of K2CO3 during the chemical activation of petroleum coke with KOH

The fundamentals of the chemical activation process involved in the formation of K2CO3 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 K2CO3 have been studied. In comparison with the activation by KOH, the activation by K2CO3 results in a relatively low activation yield and a low surface area. The K2CO3 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 K2CO3. Possible reactions involving K2CO3 activation have been proposed and defined more clearly using thermodynamic calculations. (C) 2010 Elsevier B.V. All rights reserved.