These chars were well mixed with water and KOH in a grass beaker with the weight ratios of KOH per char equal to 1 and 4. The mixed chars were dried in oven at 120o
C for 24 h to obtain the dried mixtures consisting of chars and KOH. The dried mixtures
were heated in oven from room temperature to 850oC (1027 K) with a rate of 15 oC.min-1, and temperatures for 20 to150 minutes. When the time was up, the nitrogen gas was switch off and CO2
immediately flowed into the oven. The activated carbons obtained were thoroughly washed with distilled water several times, dried at 110oC, cooled at room temperature and stored in desiccators for activated carbon characterization