IDEALHY investigated the different steps in the hydrogen liquefaction process in detail, using innovations and greater integration in an effort to reduce specific energy consumption by 50% compared to state of the art, and simultaneously to reduce investment cost.
IDEALHY was assembled as companies, vendors and R&D actors, all with strategic interest in hydrogen liquefaction, formed a consortium and submitted an FCH-JU application during the fall of 2010.
The primary objective of IDEALHY was to develop a viable process scheme for large-scale hydrogen liquefaction with close to 50% reduced energy requirement relative to state-of-the-art technology. This was achieved by improving most sub-processes where progress could be achieved. Innovations contributing to reaching the goal were chiefly:
- Increasing the feed pressure of hydrogen by pre-compression
- Using a mixed refrigerant with energy-optimised composition for pre-cooling the hydrogen feed
- Replacing hydrogen-Claude cryogenic refrigeration with a Brayton cycle with mixed refrigerant consisting of helium and neon, inter- and aftercooled by chillers to reduce volume flowrates
- Using liquid expanders instead of throttling to increase the liquid yield in the final liquefaction stage
- Realising large-scale advantages with respect to improved component efficiencies
SINTEF conducted several research tasks contributing to the achievement of the project objectives:
- Providing an overview of existing and prospective liquefaction technologies
- Simulations and analyses of relevant options for different sub-processes
- Modelling and implementing thermodynamic model for continuous ortho-para conversion in simulation tools
- Design of the mixed-refrigerant pre-cooling process and global energy-optimisation of the composition by mathematical programming
- Simulating and analysing the new process developend in IDEALHY
- Interaction with external suppliers of rotating equipment