The European Green Deal provides a roadmap to boost the efficient use of resources, restore biodiversity and cut pollution. Reaching this target will require certain actions including investments in environmentally friendly technologies, such as hydrogen. This project is the first large scale industry project that will provide the required metrological infrastructure (and traceability) that is needed to tackle the measurement challenges that are currently faced by the hydrogen industry. This will promote growth in several sectors (mobility, fuel cells, liquified hydrogen). The aim of this project is to ensure measurement traceability in the hydrogen distribution chain. Therefore, critical flow Venturi nozzles will be established as standards for use with high pressure gas and a traceability route will be established for liquified hydrogen. Without this, verifiable measurements will not be possible and hydrogen will not be accepted for use as an environmentally friendly fuel.
The European Green Deal includes a hydrogen strategy with the aim of 40 GW of renewable hydrogen electrolysers in Europe by 2030 . A production capacity of up to 8 Mt of hydrogen is expected by 2035. To meet the need for hydrogen it will be necessary to import hydrogen from another 40 GW of electrolysers installed by Europe’s neighbours . For example, Germany has partnered with Morocco to develop an industrial plant for green hydrogen exports to Germany . Based on these plans from the Green Deal, the industry, and the associated metrology need to be hydrogen-ready. The industrial needs have already been established through discussions with key stakeholders from the hydrogen industry (hydrogen producers, station operators, automotive manufacturers and standardisation bodies). Regarding the need for high energy storage capacities, hydrogen needs to be stored at high pressure or in the liquid phase. This leads to at least 3 key technical measurement challenges that need to be addressed to help the hydrogen market to grow.
At the moment it is not possible to offer calibration services to the hydrogen industry at high pressure (> 1 MPa) except for dispensers at refuelling stations, although meters are available for use with hydrogen at 100 MPa. The convener of ISO/TC 30/SC 2/WG 19 indicated a need for “flow metering technologies of high-pressure gas”. The first published results for high-pressure nozzle calibrations show that ISO 9300 is not applicable for hydrogen with sufficient accuracy as no uncertainty value is given. An adequate database of nozzle calibrations with hydrogen is needed. This emphasises the need to develop calibration methods and a traceability chain. The experimental work will be limited to 90 MPa, rather than 100 MPa, for safety reasons, but the results will be extrapolated up to 100 MPa. This need will be addressed using critical flow Venturi nozzles (objective 1).
Critical flow Venturi nozzles are very stable secondary standards, which are used in many laboratories as reference flow meters. Unfortunately, their response to hydrogen, especially above 1 MPa, has not been widely investigated and crucial reference data to connect low to high-pressure calibrations are missing. This needs to be investigated (objective 2).
For a complete view of the flow physics inside the nozzle a Computational Fluid Dynamics (CFD)model is needed, which takes into account the most relevant real gas effects (objective 3).
The number of hydrogen cars is increasing in Europe and fuel cell consumption needs to be accurately measured. However, the infrastructure is not currently available for such metrological measurements (up to 2.5 MPa and 4 kg/h). This will be addressed by creating a primary standard for the requested conditions (objective 4).
The use of liquified hydrogen is growing rapidly and new sectors are aiming to use this liquid fuel (e.g. aircraft, liquified hydrogen carriers, trains). As hydrogen is becoming a large volume transport fuel, the liquefaction process is also becoming a good candidate for cost reduction and increased efficiency. Indeed, it is expected that liquified hydrogen will become important as a fuel for large and frequently used vehicles, with alternatives to (gaseous) hydrogen vehicle storage solutions being required. Traceability is not available yet, which is a problem for international hydrogen producers and distributors because without traceability, there can be no consistency or trust in the measurement of liquid hydrogen. Solutions are needed for testing flow meters with liquified hydrogen and for a traceability route (objective 4).
|||COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS, A hydrogen strategy for a climate-neutral Europe, Brussels, 2020.|
|||COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS, Stepping up Europe’s 2030 climate ambition, Brussels, 2020.|
|||Federal Ministry for Economic Cooperation and Development, April 2021. [Online]. Available: www.bmz.de/en/development-policy/green-hydrogen|
16 September 2021 online