Ammonia

Technology

What is it?

Ammonia is synthesised from hydrogen and nitrogen via one of a variety of methods. Ammonia can then be transported, and the hydrogen extracted again at the point of use via a thermal decomposition and separation process.

Why is it important?

Ammonia can be transported under mild conditions and be utilised directly or converted back into hydrogen for use.

Characteristics

• Volumetric hydrogen density: High (10.7kg H₂ / m³ at 10 bar and 25°C)
• Gravimetric hydrogen density: High (17.8% by mass)
• Storage conditions: Liquid at ambient temperature, 10-11 bar pressure
• Energy efficiency: Varies depending on synthesis approach. See Haber-Bosch synthesis method for conventional synthesis

Benefits

• Cracking leads to formation of nitrogen gas, which is innocuous and can be released back into the atmosphere
• Can be stored at mild temperature and pressure for transport
• Can leverage existing ammonia handling and transport infrastructure
• High Gravimetric hydrogen density: 17.8% by mass
• High Volumetric hydrogen density -10.7kg H₂ / 100L at 10 bar and 25°C

Limitations

• Requires cracking at point of use to extract hydrogen
• See limitations for each synthesis method
• High toxicity of ammonia vapours
• Note: Various ammonia technologies in development cover the whole TRL scale

RD&D priorities

• Develop higher efficiency and lower cost synthesis methods

Known active organisations

• The Australian National University
• CSIRO
• Monash University
• The University of Adelaide
• The University of Newcastle
• The University of Sydney
• The University of Technology Sydney
• The University of Western Australia