Hydrogen adsorption behavior of mechanically milled and pelletized coconut shell activated carbon

Activated carbon can be the best selection for the solid media of hydrogen storage materials because of cheap, good availability, high quantity of pore on its surface and good adsorption capacity. To obtain optimal handling of coconut charcoal-based (CSAC) without reducing its property on hydrogen adsorption capacity, the effect of mechanochemical and pelletizing process to CSAC was examined. Mechanical milling by using planetary ball mill was conducted to reduce particle size distribution and to mechanochemically process CSAC with KOH. CSAC particles reduce its particle size distribution to nano- and submicron-size due to mechanical milling. After mechanochemical and pelletizing process, the surface area and pore volume of CSAC decrease to 68.5% and 61% compared with those of as received sample. However, hydrogen adsorption capacity of CSAC pellet only decrease 5 and 9% at measurement pressure and temperature of 4000 kPa, -5°C and 4000 kPa, 25°C, respectively.