Development of activated carbon from vine shoots by physical and chemical activation methods. Some insight into activation mechanisms

Activated carbons (ACs) are prepared from vine shoots (VS) by the method of physical activation in air, CO2 and steam atmospheres and by the method of chemical activation with H3PO4, ZnCl2 and KOH aqueous solutions. The ACs were characterized texturally by N-2 adsorption at -196 A degrees C, mercury porosimetry, and density measurements. The method of chemical activation has been proved to be more effective than the method of physical activation to prepare ACs with a well-developed porosity. ACs with high micro- and mesopore volumes are prepared with ZnCl2 and H3PO4. Using ZnCl2, the volume of micropores is 0.62 cm(3) g(-1) and the volume of mesopores is 0.81 cm(3) g(-1). A greater development of macroporosity is obtained by KOH activation. The volume of macropores is as high as 1.13 cm(3) g(-1) for the resulting AC. Yield of the process of preparation of the ACs is low for the method of chemical activation. Some insights into the performance of the activating agents in the activation process are provided.