Bridging hydrogen production and storage: electrolysis-derived hydrogen for methanol and ammonia synthesis

Hydrogen is acknowledged as a fundamental element in the global clean energy revolution, functioning as both an energy transporter and an industrial feedstock. Nonetheless, the obstacles associated with direct hydrogen storage and delivery, arising from its low volumetric density, substantial energy requirements for compression or liquefaction, and safety considerations, restrict its extensive implementation. Chemical hydrogen storage in methanol and ammonia has emerged as a viable and scalable solution to overcome these obstacles. This work analyses the incorporation of renewable hydrogen generation through water electrolysis with subsequent methanol and ammonia synthesis, emphasizing their synergistic functions in carbon–neutral and carbon-free energy systems. Methanol synthesis facilitates the conversion of collected CO₂ into a liquid fuel that is compatible with current infrastructure, whilst ammonia serves as a carbon-free, high-density hydrogen carrier ideal for energy storage and international transit. The discourse includes reaction principles, catalytic systems, reactor designs, and novel low-pressure and plasma-assisted synthesis techniques. The evaluation evaluates system-level efficiency, techno-economic viability, and environmental performance, highlighting the significance of modular Power-to-Fuel concepts and digital process optimization. These ideas together delineate a cohesive framework for the integration of hydrogen generation, storage, and utilization, facilitating a sustainable, carbon–neutral energy future reliant on renewable molecular fuels.