Chemical and electrical properties of activated carbon from Samui Island young coconut waste

Abstract

Solid coconut waste has been a chronic issue that can lead to an environmental problem in Samui Island. Therefore, we are interested in processing this waste into a more valuable product. Many previous studies have evaluated the characteristics of activated carbon (AC) using chemical properties, but not electrical properties. In this work, we analyze the electrical properties of AC to identify a wide range of potential applications. The whole coconut with husk was turned into AC under different activation parameters (temperature, impregnation ratio of KOH and time) using one-factor-at-a-time method. The results showed that with higher activation temperature (750-850°C), the iodine adsorption number increased but the yield decreased. Excessive impregnation ratio and longer activation time could lower the iodine adsorption number due to the collapse of micropores into larger pores. The SEM images revealed that after activation process, a well-developed pore structure is achieved. The highest iodine adsorption number was obtained at 1356.80 mg/g at activation condition of 800°C, impregnation ratio of 1:2 and activation time of 2 hrs. The electrical property of activated carbon was remarkably improved from the initial char, in accordance with the iodine number result. The lowest resistivity was also achieved at the same condition as above.