Textural Characteristics of Coconut Shell-Based Activated Carbons with Steam Activation

Abstract

Activated carbons were prepared from coconut shells by using carbonization at 600 °C for 2 h followed by water steam activation. Effects of activation temperature, hold time and water steam amount on the yield, BET surface area and micropore volume of activated carbons were evaluated. The pore structure of the activated carbon was characterized by N2 adsorption at 77K. Surface area, micropore volume and pore size distribution (PSD) of the carbons were determined by the Brunauer–Emmett–Teller (BET) equation, Dubinin–Astakhov (DA) and the Non-Local Density Functional Theory (NLDFT) methods, respectively. The results show that activated carbons with specific surface area of 1500 m2/g and pore size lower than 2 nm can be produced at 900 °C for 1~2 h. Hold time could be reduced by increasing steam amount and activation temperature, but micropore was enlarged and yield was decreased. Increasing hold time could produce more micropores when steam amount and activation temperature were more appropriate. Pore size distribution shows that activated carbons are microporous dominant.