
The preparation of activated carbons derived from oil palm shells, chemically activated by potassium hydroxide and physically activated by steam was investigated in this paper. The Methodology of Experimental Design (MED) was used to optimize the preparation conditions. The effects of two preparation variables: the activation temperature ranging from 601 to 799°C and the impregnation ratio ranging from 0.6 to 3.4 were studied on the activated carbon yield (R/AC-KOH), the iodine adsorption capacities (I2/AC-KOH) and methylene blue adsorption capacities (MB/AC-KOH) results. The experimental results from the analysis of variance (ANOVA) permits to identified the significant factors on each experimental design response. The optimum conditions for activated carbons physicocshemically activated by KOH and steam (AC-KOH) were activation temperature of 630°C, and impregnation ratio of 1/1 which lead to the activated carbon yield of 38.71%, I2/AC-KOH of 803.72 mg/g and MB/AC-KOH of 457.36 mg/g. The morphologies of the raw material and activated carbon obtained under optimum conditions were visualized using Scanning Electron Microscopy.