Textural Characteristics of Activated Carbons Prepared from Oil Palm Shells Activated with ZnCl2 and Pyrolysis Under Nitrogen and Carbon Dioxide

The textural characteristics of activated carbon prepared from oil palm shells activated with zinc chloride (ZnCl2) and pyrolysis under nitrogen and carbon dioxide were studied in this paper. The pyrolysis was carried out at different activation temperatures in the range of 400oC–800oC. The BET surface areas obtained were in the range of 1429.71–1134.74 m2 g–1. The difference of values between micropore surface area and external surface area showed that the activated carbons were predominantly microporous adsorbents. The Dubinin-Astakhov (D-A) approach was used to study the pore size diameter of activated carbon. The pore size diameters of activated carbons obtained were in the range of 1.76–1.84 nm and the exponent (n) parameter in the range of 1.2 to 1.6 indicated predominantly micropores. The Dubinin-Radushkevich (D-R) method was used to evaluate the micropore volume of activated carbon. The micropore volumes found were in the range of 0.74–0.619 cm3 g–1. The structural morphology and composition of activated carbons were evaluated by SEM-EDX. It was clearly seen that the activated carbons were full of cavities, and some of Zn metals were still trapped at the surface of activated carbons. In general, the heterogeneous and predominantly microporous activated carbon was produced.