HYDROGEN STORAGE THROUGH WASTES: AN ECO-FRIENDLY SOLUTION FOR ENERGY TRANSPORTATION WASTE TO TREASURE (WTT) APPROACH

This study explores an innovative method for hydrogen storage by reactivating spent coconut-based activated carbon (SAC), originally used in water filtration, through chemical activation with KOH. The resulting activated carbons (ACs) exhibit high specific surface areas (ABET up to 2600 m²/g) and total pore volumes (VT up to 1.50 cm³/g). Additionally, the reactivation process enhances carbon purity and results in carbon enrichment, yielding a higher quality material than the pristine SAC. The research examines the influence of the carbon/KOH ratio on pore size distribution (PSD) and textural properties, alongside the impact of different carbon precursors on hydrogen absorption efficiency under both low and high pressures. A maximum 62% increase in hydrogen adsorption was observed at 1 bar, with a hydrogen uptake of approximately 5 wt% at 77 K and 40 bar, and a total storage capacity of around 40 kg/m³, aligning with existing literature. The study highlights the importance of pore volume and micropore size in determining the suitability of ACs for specific hydrogen storage applications. Additionally, a comparative evaluation with high-performance commercial carbons was performed to assess the efficiency of the reactivated ACs in hydrogen storage, positioning them as viable alternatives to existing materials. Overall, this research contributes to the development of cost-effective, environmentally friendly hydrogen storage materials by optimizing AC production from waste-derived precursors, promoting waste reduction and circular material use within the energy sector.