Technology
What is it?
Hydrogen is liquefied and stored at -253 °C, at ambient-moderate pressures, in cryogenic tanks through a multi-stage process of compression and cooling.
Why is it important?
More financially viable where high density hydrogen storage is required under limited space, or where a larger roundtrip distance is involved.
Characteristics
- Volumetric hydrogen density: 70.85 kg/m3at 1 bar
- Storage conditions: 2- 10 bar, 20K
- Well-to-tank efficiency range: 20-25%. The energy required to liquify the hydrogen is 6- 8 kW/kg LH2. Well-to-tank efficiency includes from the feedstock natural gas consumed to the low heating value of H2 delivered to tank
Benefits
- Higher volumetric storage capacity than compressed gas
- Fewer evaporation losses than typical compression mechanisms
Limitations
- Requires advanced and more expensive storage material
- Liquefaction requires complex technical plant
- Liquefied hydrogen incurs boil-off losses.
- To be liquefied, up to 40% of energy content of hydrogen is required
RD&D priorities
- Reduce boil-off (i.e. vaporisation) rates
- Improve engineering, insulation, heat exchangers and coolants
- Improve insulation material construction techniques to achieve larger scale and better insulated tanks
- Improve hydrogen compression technology
- Study and analyse the effects of vessel shape designs, stratification, and thermal overfill
- Conduct thermal-fluid dynamical analysis on the effects of flashing during the transport of liquid hydrogen from bulk storage to atmospheric on-site storage
- Develop low cost catalysts for improved ortho‐para conversion, and ortho‐para ratio measurement capability, to reduce boil off rate
- Conduct studies of impurity freeze‐out in H2 production
Known active organisations
- CSIRO
- Monash University
- Queensland University of Technology
- The University of New South Wales
- The University of Sydney
- The University of Western Australia