Biomass-derived hydrogen storage: Technological trends, opportunities, and perspectives

Hydrogen is a promising alternative energy carrier. However, its practical deployment is hindered by challenges in developing a safe, efficient, and cost-effective storage system. Biomass-derived materials, particularly biochar and its composites with metal hydrides, have garnered increasing interest as sustainable and tunable candidates for enhancing solid-state hydrogen storage performance. This assesses recent advancements in the synthesis, structural characterization, and hydrogen storage capabilities of these materials. Special focus is given to the effects of activation conditions, surface area, porosity, and nanoparticle dispersion in hydrogen uptake. By comparing findings that utilize diverse amounts of biomass sources and preparation methods, this work outlines structure-performance relationships and identifies key parameters influencing storage efficiency. The review highlights both the potential, such as high gravimetric capacities and abundant renewable sources, and limitations, including the lack of cycling data and reliance on cryogenic conditions. It was found that some activated biochars, such as CS-900-4 (corn straw-derived) and MWTSC-50-3-700 (tamarind seeds-derived), have high storage capacities of 5.32 and 4.73 wt%, respectively, demonstrating the adaptability of biomass across a range of operating conditions for storing hydrogen. Furthermore, metal hydride composites, such as MgH₂ + 10 % Ni₃Fe/BC-3, exhibit improved absorption/desorption kinetics, as well as reduced operating temperatures. Additionally, recommendations are provided to guide future research toward more scalable, ambient-condition-compatible, and practically viable biomass-derived hydrogen storage systems. • Recent advancements in the synthesis, structure, and H 2 storage performance of biomass-based materials. • Main focus includes the effects of activation conditions, surface area, porosity, and nanoparticle dispersion on H 2 uptake. • Activated biochars from corn straw and tamarind seeds show high H2 storage capacities. • Metal hydride composites also exhibit improved absorption/desorption kinetics. • Recommendations are also provided to guide future research toward more scalable, feasible, and practical applications.