Cost-efficient small scale hydrogen liquefaction

Expected Outcome

As the hydrogen economy grows and diversifies itself, the need for smaller-scale, point-of-use hydrogen liquefaction will become increasingly important. For applications such as remote transportation hubs, off-grid or remote communities as well as hydrogen-powered industrial facilities with lower LH2 demand (less than 5 metric tons per day (tpd)), having efficient and decentralised liquefaction capabilities is crucial.

While centralised, large-scale liquefaction plants can achieve economies of scale, small-scale facilities need to be cost-competitive and efficient to ensure their viability. This includes optimising energy use, ensuring safety, and designing equipment that can handle fluctuating demand. New technologies and innovations are required to bring down the capital and operational costs associated with small-scale liquefaction of LH2.

Project results are expected to contribute to all the following outcomes:

• Contribute to the roll-out of next generation decentralised hydrogen liquefaction technologies;
• Initiate the deployment of liquid hydrogen for off-takers with lower LH2 demand.

Project results are expected to contribute to the following objectives and KPIs of the Clean Hydrogen JU SRIA:

• Increase efficiency and reduce costs of hydrogen liquefaction technologies for small scale liquefaction (<5 tpd);
• Reducing the energy intensity for small-scale hydrogen liquefaction to 12 kWh/kgH2 at 500kg/day and 10 kWh/kgH2 at 5 tpd.
• Reducing H2 liquefaction cost to about 3.5 €//kg

Scope

The hydrogen liquefaction process is generally composed of the following main technological sub-systems: pre-cooling (incl. heat exchangers with cooling fluid & compressors), cooling (incl. compression), coldbox (including heat exchangers and ortho-para conversion), expansion and boil-off gas management.

To overcome the technological barriers of small-scale hydrogen liquefaction and to prepare a future deployment of smaller LH2 volumes at a higher TRL, the innovative hydrogen liquefaction system developed in proposals should address the following elements:

• Assessment of currently offered technologies for small scale liquefaction plants (<5 tpd)
• Description of proposed technology elements, including e.g.:
• O-P conversion
• Precooling to an intermediate temperature in the range of 80-110 K
• Cryogenic cooling further to 20-30 K
• Handling/re-liquefaction of gas return from adjacent storage
• Conceptual design optimisation at system scale (incl. all necessary BoPs)
• Development of an innovative small-scale hydrogen liquefaction system (sub-modules, cycle or even equipment) that should:
• Demonstrate technical and economic improvements at scale (at least >500 kg/day) with a potential for scaling up.
• Be capable of reducing the energy consumption and specific cost of hydrogen liquefaction at indicated scale.
• Demonstrate the capability of the concept for operating at lower and/or fluctuating load (50-100 %) to be in line with hydrogen production via e.g. water electrolysis from renewable sources;
• Demonstrate through to the prototype’s operation, a specific power consumption of 12 kWh/kg for 500 kg/day liquefaction capacity considering feed hydrogen at 20 bar and 20 oC.

The focus should be on the following:

• Reduce the specific energy requirements, e.g. by optimising pre-cooling to an intermediate temperature in the range 80-110 K, and/or by applying innovative thermodynamic optimisation, and/or by improving boil-off recovery strategies etc;
• Evaluate the cost-benefit for handling/re-liquefaction of gas return from adjacent storage;
• Conduct advanced thermal studies on those components or processes generating the highest irreversibility, providing key design features to optimise the small-scale units;
• Create a system’s oriented Digital Twin of the new thermal/thermodynamic concept to support the design phase, to extend the description of its behaviour beyond the experimental set-up limits, and by scalability studies generate data to assess the feasibility up to 5 tpd;
• The validated industrial prototype should prove and support the scalability of the innovative concept to suit flowrates up to 5 tpd.

The proposed technology to be developed should be benchmarked against the technologies commercially available today based either on the Helium Brayton and the Claude cycle at 1 tpd and 5 tpd and should demonstrate reduced liquefaction cost.

Proposals should also address the following economic and regulatory issues:

• The innovative concept should demonstrate a specific liquefaction cost of around 3.5 €/kg for a small-scale unit (1 tpd);
• The project should define a suitable roadmap to prepare the deployment of small volumes of liquid hydrogen solutions;
• Perform techno-economic analysis to identify CAPEX and OPEX drivers, potential paths to improvements, and assess the scalability of the technology. The analysis should focus on especially relevant business cases for the technology such as distributed small-scale liquefaction and re-liquefaction of gas return from adjacent storage.
• Perform conceptual design optimisation to enhance performance, reduce costs, ease of installation and meet stakeholder requirements more effectively;
• Propose accurate business models for commercialisation purposes;
• Contribute to the development of regulations, codes and standards needed for the LH2 safety issues;

Proposals are expected to address sustainability and circularity aspects.

For additional elements applicable to all topics please refer to section 2.2.3.2

Activities are expected to start at TRL 4 and achieve TRL 6 by the end of the project - see General Annex B.

The JU estimates that an EU contribution of maximum EUR 6.00 million would allow these outcomes to be addressed appropriately.

Technology Readiness Level - Technology readiness level expected from completed projects

Activities are expected to start at TRL 4 and achieve TRL 6 by the end of the project - see General Annex B.