Utilization of coconut husk waste in the preparation of activated carbon by using chemical activators of KOH and NaOH

Abstract

Activated carbon can be produced from biomass that contains high number of lignin and cellulose such as coconut husk waste. Coconut husk waste contains about 32.5% cellulose and 37% lignin. The coconut husk activated carbon was prepared through the carbonization and physicochemical activation method which consisted of chemical activation and physical activation (gasification). Carbonization was done in muffle furnace at 500°C for 1.5 hours. Chemical activation of chars was done by using two variations of activating agents (KOH and NaOH), with impregnation ratio (activating agent:char) of 3:1. Physical activation was done in tubular reactor with CO2 gasification by various temperature (600-750°C, interval 50°C). Characterization of the activated carbon produced was done by iodine number test and SEM-EDX. The result shows that activated carbon from chemical activation by NaOH has insignificantly higher yield than activated carbon from chemical activation by KOH but has lower iodine number. Activated carbon with the highest iodine number was obtained from chemical activation by KOH and physical activation at 750°C, obtaining 706 mg/g of iodine number and overall yield of 17.3%. It can be concluded that development of activated carbon production by coconut husk waste as main precursor is succeeded since the properties of produced activated could reach high value of Iodine.