Characterization of chars pyrolyzed from oil palm stones for the preparation of activated carbons

Chars pyrolyzed from oil palm stones, an abundant palm-oil mill solid waste, for the preparation of activated carbons were characterized in this paper. An ultra-pycnometer and a mercury intrusion porosimeter were used to measure the solid and apparent densities of the samples, respectively and a thermogravimetric analyzer was used for proximate analysis. The effects of pyrolysis temperature and retention time on the char yield and BET surface area of the chars were investigated. The optimum condition for pyrolysis was found to be at a pyrolysis temperature of 800 degrees C for a retention time of 3 h. The SEM micrographs of the char surfaces verified the presence of porosity. The experimental results showed that it was feasible to prepare chars with sufficient densities and relatively high porosities from oil palm stones for the further preparation of activated carbons. (C) 1998 Elsevier Science B.V. All rights reserved.