Microwave heating with potassium hydroxide activation for converting water hyacinth into activated carbon

Abstract

Activated carbon was successfully synthesized form dried water hyacinth via KOH activation with microwave irradiation. Resultant activated carbon with large specific surface area can be produced using microwave irradiation for 1 minute which was consumed less time than conventional heating method that consumed 1 hour. Microwave irradiation can be a strategic way to improve uniform and quick heating to prepare porous carbons by inducing dipole rotation in atomic scale and creating a frictional force between atoms and molecules within heated material so that volumetric heating inside the heated material is realized. The BET analysis shown that the activated carbon, derived by KOH activated with microwave irradiation for 1 minute with mass radio of potassium hydroxide to carbonized water hyacinth at 3:1, possessed a large specific surface area of 1,073 m2 g-1-carbon. Furthermore, methods for adding water into activation system was also studied. Specific surface area of activated carbon prepared by using both wet nitrogen gas and wet impregnation possessed specific surface area of 208 m2 g-1-carbon.