Basically any carbon containing precursor can be used for the prepration of activated carbon. There are two main methods, which can be classified as the chemical and physical, both using high tempertures (>500 oC). The chemical method can use adsorption of phosphoric, acid, zinc chloide, KOH, etc. while the physical can use water vapor, CO2, etc. In order to Control the burn-off protective attmsophere is used. After the thermal treatmentas, the chrred residue should be washed by dilute acids in order to remove ash componenets. If you want to prepare activated carbons it is better to follow the steps, which are well-explained in the literature.