Activated Carbon

The process of activation is carried out in two stages. Firstly the coconut shell is converted into shell charcoal by carbonization process which is usually carried out in mud-pits, brick kilns and metallic portable kilns. The coconut shell charcoal is activated by reaction with steam at a temperature of 900oC -1100oC under controlled atmosphere in a rotary kiln. The reaction between steam and charcoal takes place at the internal surface area, creating more sites for adsorption. The temperature factor, in the process of activation is very important. Below 900oC the reaction becomes too slow and is very uneconomical. Above 1100°C the reaction becomes diffusion controlled and therefore takes place on the outer surface of the charcoal resulting in loss of charcoal.

Granular activated carbon is used in continuous process in areas like water treatment(drinking & effluent water), removal of mercury from effluents or alkali cells, solvent recovery, gold recovery, removal of odour, gas masks, as catalyst carrier, for decholorination of water, purification & separation of gases, kitchen hoods, dry cleaning etc.