Skip to main content
European Commission logo print header

Pre-normative REsearch for Safe use of Liquide HYdrogen

Periodic Reporting for period 2 - PRESLHY (Pre-normative REsearch for Safe use of Liquide HYdrogen)

Reporting period: 2019-07-01 to 2021-05-31

Hydrogen is a highly versatile chemical energy storage, enabling sector coupling and deep decarbonisation of the energy system. Scaling up hydrogen based solutions and realising higher volumes requires more powerful and still economic hydrogen supply infrastructures. With its relatively high density cryogenic liquid hydrogen (LH2) is the most promising option for large scale, compact, lightweight storage and efficient long distance transport of hydrogen. Especially, for the transport sector with the planned large bus fleets, the emerging hydrogen fuelled train, boat, truck and aviation projects and even for the pre-cooled 70 MPa car refuelling liquid hydrogen offers sufficient densities and gains in efficiency over gaseous transport, storage and supply.

However, LH2 implies specific hazards and risks, which are very different from those associated with the relatively well-known compressed gaseous hydrogen. Although these specific issues are usually well reflected and managed in large-scale industry and aerospace applications of LH2, experience with LH2 in a distributed energy system is lacking. Transport and storage of LH2 in urban areas and the daily use by the untrained general public will require higher levels of safety provisions accounting for the very special properties.

Therefore the PRESLHY project does pre-normative research for improving the understanding of the most relevant and currently poorly understood phenomena related to high risk scenarios of potentially new LH2 applications and supply schemes. The research work consists of analytical work, numerical simulations and in particular a well-designed experimental program. The results of this research enhances the state-of-the-art in hydrogen safety engineering and promote the initiation or revision of risk informed, performance based, LH2 specific, international standards. Thereby it will help safely introducing and scaling up the use of the versatile and carbon free energy vector hydrogen.
In the reporting period the beneficiaries have initialised the project and installed necessary administrative and management schemes. The required meeting structures and communication channels have been set up. The website has been built to serve as a colaboration platform and repository for all project documents, as a meeting planning tool and provides further means for cooperation. The data management plan has been developed and further iterated to make sure that all generated data of the project will be findable, openly accessible, interoperable and reusable on the long term. This will help to maximise the sustainable impact of the research work executed.
The external network has been activated and further developed. PRESLHY entered in a partnership with the Norwegian project SH2IFT, which has similar objectives for LH2 but a complementary working program. Additionally, the project has been presented to essential members of the external network, the IEA, ISO, EHSP, etc. in the framework of the initial dissemination activities.
In the initial phase the beneficiaries also prepared the scientific and technical basis by working out the state-of-the-art at the beginning of the project. The technical status was captured in two reports, the state-of –the-art report and the installation description, the scientific basis was summarised in 3 separate reports dedicated to the phenomena “release and mixing”, “ignition” and “combustion”. The situation with regard to regulations, codes and standards has been analysed in a special RCS report. The scientific and risk weighted research priorities have been assessed via a PIRT study and a dedicated open work shop “LH2 Research Priorities Workshop, Buxton, UK – 18 September 2018“, involving numerous international external experts. On the basis of this extensive preparatory work the experimental program has been adjusted, further refined and finally started.

In the first 18 months 3 out of 12 experimental series, one for release and two for ignition, have been completed and documented. A subset of the more than 200 tests of the DISCHA release experiment have been published in KITopen and can be accessed freely, worldwide via For the other 3 scheduled experiments the major preparatory work, consisting of detailed design, purchase and construction, installation of system including set-up of measurement techniques, safety assessments and checks have been successfully done. However, the actual execution of the experiments experienced a certain delay, caused by the late kick-off meeting and by problems in the delivery and construction of special parts required for cryogenic conditions.
The first test results demonstrated by very good reproducibility a high quality in the experimental set-ups and revealed interesting effects regarding hot surface ignition and electrostatic field generation by cryogenic discharges. The scientific exploitation is on its way.

24 common scientific publications have been issued or are in preparation. The project has been presented at 5 conferences, flyers newsletters and posters have been produced and distributed. The project has been listed in H2FC JU Success Stories Report. Two open workshops were organised, the LH2 Research Priorities Workshop in Buxton UK on 18 September 2018, supported by JRC and US DoE, and the HySafe-PRESLHY-SH2IFT- joint workshop for LH2 Safety in Bergen, Norway 6 March 2019 attracting more than 80 participants.

Finally, the PRESLHY project has successfully started potential standardisation work via initiating the Preliminary Working Item PWI ISO/24077 for "Safe Use of Liquid Hydrogen in Non-Industrial Settings" at ISO TC 197 with PRESLHY coordinator as acting PWI manager.
PRESLHY has summarized the state-of-the-art at the beginning of the project as a reference point. Knowledge gaps have been prioritised with regard to scientific relevance and importance for the potential applications.
The project has shown that the RCS situation is ambiguous, potentially over-conservative and lacks a solid scientific basis. These findings gave a strong momentum to the relevant international standards developing organizations (SDO) and initiated the formation of the Preliminary Working Topic PWI 24077 at the ISO TC 197. After several discussions, it is anticipated that the project results could stimulate and provide a suitable basis for the revision and extension of the ISO/TR 15916:2015 “BASIC CONSIDERATIONS FOR THE SAFETY OF HYDROGEN SYSTEMS”. Other standardization frameworks, like for aviation or maritime applications, are quite special and therefore considered with lower priority.

PRESLHY has just started the experimental campaign, which is the basis for an improved understanding of the most important phenomena, corresponding modelling work and validation of current extrapolations. Partners developed first models for multi-phase releases and jet-fire radiation correlations suitable for more appropriate hazard or safety distance definitions. Those first models will be validated and further relevant knowledge gaps will be filled with the next experiments. The FAIR data management will make sure that the results of the project and the advanced state-of-the-art have sustainable and broadest impact.
DISCHA E3.1 test facility without LN2 cooling pool
DISCHA E3.1 part A cryo-release, original and BOS post-processed
Group photo at the LH2 Research Priorities Workshop 09/2018 in Buxton, UK
PRESLHY network
Ignition tests E4.3 prepared at HSE
Group photo at the PRESLHY kick-off meeting 04/2018 in Karlsruhe
PRESLHY website
Notification of the establishment of PWI ISO/24077
Experimental set-up for hot surface ignition tests E4.1 at INERIS
Experimental set-up for the FA and DDT tests at cryogenic temperatures E5.1 at KIT/PS