Effect of cooling rate of KOH activation process on activated carbons

Activated carbon was fabricated from rice husks by KOH activation. The effect of the initial cooling rate of activation on the pore structure in the activated carbon fabricated by KOH activation was investigated. The specific surface area of the activated carbon increased from 1813 to 2418 m2/g with increasing the cooling rate from 3 to 32 ºC/min. The micropore diameter in the activated carbons was distributed approximately 0.6 and 1.1 nm. The micropore volume increased from 0.86 to 1.29 cm3/g with increasing initial cooling rate. The proportion of the volume Vmicro to the total pore volume Vtotal was calculated to be in the range from 90 to 96 %. Thus, the micropore structure of the activated carbon was strongly affected on the initial cooling rate on alkali activation.