Optimization of Activated Carbons Prepared by H3PO4 and Steam Activation of Oil Palm Shells

Abstract

In this study, activated carbons were prepared from oil palm shells by physicochemical activation. The methodology of experimental design was used to optimize the preparation conditions. The influences of the impregnation ratio (0.6–3.4) and the activation temperature between 601°C and 799°C on the following three responses: activated carbon yield (R/AC-H3PO4), the iodine adsorption (I2/AC-H3PO4), and the methylene blue adsorption (MB/AC-H3PO4) results were investigated using analysis of variance (ANOVA) to identify the significant parameters. Under the experimental conditions investigated, the activation temperature of 770°C and impregnation ratio of 2/1 leading to the R/AC-H3PO4 of 52.10%, the I2/AC-H3PO4 of 697.86 mg/g, and the MB/AC-H3PO4 of 346.25 mg/g were found to be optimum conditions for producing activated carbon with well compromise of desirability. The two factors had both synergetic and antagonistic effects on the three responses studied. The micrographs of activated carbons examined with scanning electron microscopy revealed that the activated carbons were found to be mainly microporous and mesoporous.