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Liquid Ammonia for Hydrogen Storage
Presentation

Hydrogen storage and transportation technology is essentially necessary to realize hydrogen economy. Hydrogen can be stored in many different forms, as compressed or liquefied hydrogen in tanks, or as hydrogen carriers: a hydrogen-absorbing alloy, metal hydrides with light elements, organic hydrides and carbon-based hydrogen storage materials. Among them, solid-state hydrides with light elements such as MgH2, Mg(BH4)2 and NH3BH3 possess high hydrogen capacity, 7-20 mass%, However, the practical volumetric H2 density is below 8 kgH2/100L because the packing ratio is down to 50%. Ammonia is easily liquefied by compression at 1 MPa and 25°C, and has a high volumetric hydrogen…

Ammonia as an Energy Carrier for Renewable Energy
Presentation

At present, ammonia is mostly formed through reforming of natural gas (CH4). A 1,000 ton per day plant is said to consume about 35 GJ of natural gas to produce 1 ton of ammonia (22.5 GJ of enthalpy). About 50% of extra energy is wasted. If 1 ton ammonia is produced through water electrolysis, 22.5 GJ of electricity is necessary theoretically. Here again, extra electric energy must be wasted. The author discusses roughly how the efficiency depends upon the process size and the renewable energy cost.