Enhanced pore formation in petroleum pitch using stabilization and synergistic steam/CO2 hybrid activation

Abstract

Effective pore formation in petroleum pitch (PP) is challenging because of its transformation into a stable graphitic structure at high temperatures, which is typical of soft carbon materials. This study introduces a hybrid physical activation (HPAC) process that uses steam and CO2 as simpler alternatives. The effect of HPAC on the pore structure formation of PP was investigated, and the effects of the activator ratio and temperature on pore formation were analyzed, focusing on the specific surface area, degree of graphitization, and pore structure changes. The activated carbon achieved a maximum specific surface area of 2506 m2 g-1 through the synergistic effect of HPAC. Moreover, the milling process was crucial for the effective stabilization of PP, and controlling the ratio of steam to CO2 optimized the pore formation. This study demonstrates that the HPAC method provides a valuable strategy for producing activated carbon from PP, and its application to various pitch materials, such as coal and wood tars, is expected to overcome the environmental pollution problems of chemical activation and the pore formation limitations of physical activation.