High-Capacity Hydrogen Storage in Clathrate Hydrate Using Bio-Based Porous Materials

Hydrate-based hydrogen storage technology has garnered significant attention due to its high safety and environmental friendliness. However, challenges such as low hydrogen storage density and slow storage kinetics remain to be addressed. Porous carbon materials are emerging as promising candidates for enhancing hydrate-based hydrogen storage, owing to their abundant rough surfaces that provide heterogeneous nucleation sites for hydrates, high specific surface area, and excellent thermal conductivity that facilitates mass and heat transfer. Both porous carbon and porous plant-based materials are environmentally friendly, cost-effective, and readily available. A comparative study of their performance in hydrogen storage via hydrates revealed the superior potential of porous carbon. Specifically, pre-wetting the porous materials by immersion to disperse a tetrahydrofuran (THF) solution enhanced gas-liquid mass transfer, and a second-stage injection strategy increased the driving force in the later stage. Kinetic studies of hydrate formation showed a distinct induction period for porous plant materials, whereas porous carbon materials exhibited no induction period. Among the tested porous carbons, peach pit carbon demonstrated the best hydrogen storage capacity. Furthermore, to improve the hydrogen storage kinetics within the pores of peach pit carbon, the addition of 500 ppm sodium dodecyl sulfate (SDS) was investigated. Results indicated a significant synergistic effect between THF and SDS, achieving a hydrogen storage density of 0.828 wt% at 274.15 K and 18 MPa. This represents a 23% enhancement compared to the system without SDS. A possible mechanism for the promoted hydrogen hydrate formation in peach pit carbon with the synergistic combination of THF and SDS was proposed, attributing the enhancement to SDS-induced gas enrichment and the abundant pore channels of peach pit carbon that facilitate hydrogen mass transfer and solution transport. This work provides theoretical support for the rapid and efficient formation of high-density hydrogen hydrates, offering new insights for advancing hydrate-based hydrogen storage toward industrial application.