Co-valorization of delayed petroleum coke - palm kernel shell for activated carbon production

In this study, a binary mixture of petroleum coke and palm kernel shell had been investigated as potential starting materials for activated carbon production. Single-stage potassium carbonate (K₂CO₃) activation under nitrogen (N₂) atmosphere was adopted in this research study. Effect of several operating parameters that included the impregnation ratio (1-3 wt./wt.), activation temperature (600-800 °C), and dwell time (1-2 hrs) were analyzed by using the Box-Behnken experimental design. Influence of these parameters towards activated carbon yield (Y₁) and carbon dioxide (CO₂) adsorption capacity at an atmospheric condition (Y₂) were investigated. The optimum conditions for the activated carbon production were attained at impregnation ratio of 1.75:1, activation temperature of 680 °C, and dwell time of 1 h, with its corresponding Y₁ and Y₂ is 56.2 wt.% and 2.3991 mmol/g, respectively. Physicochemical properties of the pristine materials and synthesized activated carbon at the optimum conditions were analyzed in terms of their decomposition behavior, surface morphology, elemental composition, and textural characteristics. The study revealed that the blend of petroleum coke and palm kernel shell can be effectively used as the activated carbon precursors, and the experimental findings demonstrated comparable CO₂ adsorption performance with commercial activated carbon as well as that in literatures.