Liquid Hydrogen on-board storage tanks

Topic description

Specific Challenge:

Commercial trucks, that are responsible for a quarter of road transport CO2 emissions, are particularly sensitive to H2 storage system density. The length and height of road vehicles in EU are limited to 16.5m and 4m, respectively. As a consequence, truck manufacturers have to choose between less payload (since a bulky H2 takes valuable space away from the cargo) and less range when designing H2 vehicles. The range limitation is less critical for fleet trucks with short routes: 350 bar H2 storage seems to be sufficient for municipal vehicles, buses and even parcel delivery trucks. For trucking applications with larger payload and less dense HRS network, for instance regional and long haul, other solutions need to be investigated. Pressures of 500 to 700 bar indeed offer more volumetric capacity (more than 20 to 45% over 350 bar) but these solutions are costly and bring in hurdles on the infrastructure where large capacities need to be dispensed rapidly, while controlling the inlet temperature and allowing high station demand (“back-to-back”).

350/700 bar storage requires compression and high-pressure storage at the hydrogen station, which takes footprint and important CAPEX/OPEX. Those will not be needed for LH2 on-board, which require solely a LH2 tank and a transfer pump in addition to dispenser(s), allowing to save costs on the whole H2 chain. No industrial actors or consortia have started to develop consistently such technology in the world. Actors of the EU industry are currently well positioned and by pursuing this activity, have the potential to become world leaders.

Storing LH2 (Liquid Hydrogen) on-board offers unprecedented storage density (two times more compared to 700 bar) while greatly improving the cost and complexity of high-throughput gaseous H2 refuelling stations. Even though on-board LH2 storage has been disregarded for light-duty vehicles (see the example of BMW 7 Hydrogen mini-series in 2005-2007 [25]), its relevance for applications that require larger capacities (40 to more than 100kg H2) and that experience much more utilization (more than 100,000 km/year) deserve to be carefully evaluated.

LH2 tanks have been used as stationary storage in industrial facilities, and of course in various space programs, for half a century. However, no on-board LH2 storage for transportation vehicles exists today. The on-board environment has very unique challenges for LH2: insulation optimization vs. gravimetric, functional, mechanical and safety requirements, fluid regulations for various modes (acceleration, parking refuelling etc.), compliance with stringent regulations and end-user interface.

[25]: For reference, estimated performances for the BMW 7 LH2 storage system are 9% wtH2 and 40 gH2/L for a capacity of 8 kg H2

The objective is to evaluate the feasibility of using LH2 for heavy-duty vehicles through a design study followed by a demonstration test bench. The first phase of this effort will consist of mechanical and fluid design. This will include an investigation from the end-user perspective, by simulating real-life utilization (H2 extraction, driving, parking and refuelling) and making sure that the state-of-charge, the actual boil-off and the refuelling are compatible with the expectations. A few configurations will be used as benchmark: rail mounting, behind cab, and within frame. The overall shape of the storage system is important, and advanced storage solutions to optimize the energy density (through e.g. a single vacuum jacket with multiple cylinders) should be investigated. The mechanical design should meet all requirements typical of the trucking industry in terms of durability, exposure to harsh environments, vibrations, accelerations, safeties. Pressure in the LH2 storage tank should be compatible with the pressure at which the fuel cell typically operates. Alternatively, mitigation strategies should be proposed.

The nominal target capacity considered in the scope of this topic is 40-100 kg LH2, with gravimetric and volumetric (usable) system densities of 10% wt H2 and 45 g H2/L for a 24 to 72 hour-dormancy, boil-off rates < 5%/day and compatibility with fuelling rates of up to 10 kg/min.

All the activities should consider the current EC79/200926 (liquid hydrogen storage systems) and other relevant standards. Refuelling technologies are not within the scope of this topic, although the prototype should be compatible with an efficient refuelling process. The consortium should establish links with ongoing projects dedicated to relevant applications such as H2HAUL27 and future project under ongoing FCH 2 JU call 2019 “Topic FCH-04-2-2019: Refuelling Protocols for Medium and Heavy-Duty Vehicles”.

TRL at start of the project: 4 and TRL at the end of the project: 5.

Any safety-related event that may occur during execution of the project shall be reported to the European Commission's Joint Research Centre (JRC) dedicated mailbox JRC-PTT-H2SAFETY@ec.europa.eu , which manages the European hydrogen safety reference database, HIAD and the Hydrogen Event and Lessons LEarNed database, HELLEN.

The FCH 2 JU considers that proposals requesting a contribution from the EU of EUR 2 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.

Expected duration: 3 years

The much greater intrinsic energy density of LH2 (70 g/L) compared to 350 bar (24 g/L) and 700 bar (40 g/L) enables to increase dramatically the autonomy of the vehicle, and come closer to LNG truck autonomy; also reducing the overall number of hydrogen stations needed, and hence the average hydrogen cost at the pump.

The following KPIs should be reached by the end of the project:

• CAPEX storage tank: €320/kg H2;
• Volumetric capacity at tank system level: 0.045kg/L28;
• Gravimetric capacity at tank system level: 10% (H2/(H2+tank system)).

In addition, although not addressed in this topic, it should contribute to pave the way towards the following KPIs on the infrastructure side as LH2 on-board storage solutions mature: station energy consumption of 0.05kWh/kg and CAPEX HRS: 2M€ @2t/day.

This project should represent the first step towards large adoption of the on-board LH2 technology and the creation of related standardized refuelling protocols. By enabling longer haul applications and cheaper cost of hydrogen at the pump, the LH2 on-board technology should enable larger scale deployments of hydrogen trucks than with state of the art storage methods, thus proving as unavoidable for zero emission heavy-duty transportation.

The conditions related to this topic are provided in the chapter 3.3 of the FCH2 JU 2020 Annual Work Plan and in the General Annexes to the Horizon 2020 Work Programme 2018– 2020 which apply mutatis mutandis.