Metrology to support standardisation of hydrogen fuel sampling for HD

Work packages   Objectives   Outcomes and impact   Downloads

Overview

Hydrogen can significantly contribute to reducing emissions from the transportation sector as it is particularly well suited as a fuel for long‑haul heavy‑duty (HD) vehicles. The uptake of hydrogen for heavy‑duty transport requires further standardisation to support Europe’s green energy future. Sampling systems and methods have already been developed for use at hydrogen refuelling stations (HRS) for light‑duty (LD) vehicles, however there is a lack of technical evidence for heavy‑duty transport. This project will deliver the evidence needed for the standardisation of hydrogen fuel sampling for heavy‑duty applications. This will include the development of dedicated sampling systems for contaminants (gaseous species and particulate matter), methodologies for the validation of sampling methods, guidelines for the evaluation of sampling representativeness, uncertainty budgets, safety considerations and venting protocols. The outputs will be directly fed into ongoing standardisation activities in CEN/TC 268 and ISO/TC 197.

Work packages

WP1: Parameters influencing the representativeness of the sample

The aim of this work package is to investigate the impact of critical parameters (e.g. refuelling protocols, flowrate, pressure) on the representativeness of the samples taken at a HD-HRS when using different sampling strategies (parallel sampling and direct sampling for the gaseous species, and direct sampling for the particulates). Erroneous results can arise from using an inappropriate sampling approach. This WP will also provide guidance on the typical heavy-duty HRS systems and operational conditions that are available in Europe. In addition, evidence and guidance will be provided to improve the representativeness of the samples taken using the different approaches. For each strategy, different sampling vessels will be used to collect the hydrogen sample. The influence of the parameters, which are specific to the sampling vessel, will also be investigated. As safety is critical at hydrogen refuelling stations, and as the sampling exercise is not part of the normal procedure at HRS, safety during the sampling is a key element to consider for the standardisation of the sampling process. This WP also aims to investigate critical safety and venting requirements in order to provide recommendations to standardisation committees on how to ensure safety during sampling at heavy duty HRS.

For more information please contact WP1 leader: Thomas Bacquart, email: thomas.bacquart@npl.co.uk

WP2: Development and validation of sampling methodologies for HD hydrogen refuelling stations

The aim of this work package is to develop sampling methods, for gaseous species and particulates, which are adapted to the relevant nozzle geometries that are used for heavy duty hydrogen applications and to the parameters prevailing at these hydrogen refuelling stations (flow rate, pressure, etc.). This work package will focus on hydrogen refuelling stations working at 350 bar with a flow of up to 120 g/s. The sampling systems/methods will focus on sampling, for offline analysis, in order to assess hydrogen purity according to ISO 14687 and EN 17124. This work package will study several aspects of the sampling chain including the sampling equipment and the installation of the equipment at hydrogen refuelling stations. The findings of this work package will provide inputs for the guidelines and protocols developed in WP3.

For more information please contact WP2 leader: Thor Aarhaug, email: thor.a.aarhaug@sintef.no

WP3: Development of guidelines and protocols

The aim of this work package is to develop protocols and guidelines for the use and validation of sampling systems at heavy duty HRS. The current ISO 19880-9 ‘Gaseous hydrogen - Fuelling stations - Part 9: Sampling for fuel quality analysis’ is based on sampling practices for hydrogen fuel sampling at passenger HRS. The methodologies, or sampling systems, described therein are however not applicable to heavy duty HRS due to major differences in flow rate, nozzle geometry etc. For many impurities (specified in grade D of ISO 14687:2019) sampling has been demonstrated to be a major factor that influences the analytical results. Previous projects such as EMPIR JRPs 16ENG01 MetroHyVe and 19ENG04 MetroHyVe 2 have highlighted the importance of material compatibility for the sampling vessels, the importance of the preparation of the vessels before the sampling and the purge of the sampling system. Every step from the vessel preparation to the transportation must be undertaken following procedures that must be validated.

For more information please contact WP3 leader: Stefan Persijn, email: spersijn@vsl.nl

WP4: Creating impact

Dissemination and communication of project activities and impact by creating a stakeholder committee, project website, conference presentations, peer-reviewed journal papers, articles in trade journals and magazines.

For more information please contact WP4 leader: Alexandra Kostereva, email: alexandra.kostereva@gerg.eu

Objectives

The specific objectives of the project are:

1. To develop three reference methods/systems based on new hardware for interfacing relevant nozzle geometries for hydrogen heavy duty applications. This includes addressing methods for both gaseous and particulate phases. In addition, method comparison with existing methods for sampling for light duty applications will be documented to demonstrate equivalence or identified bias.
2. To develop methodologies for the validation of sampling systems. This includes method validation, including evidence of the impact of physical parameters (e.g. pressure and flow) on sampling representativeness. Gas sampling validation includes accurate gas contamination and an assessment of the recovery yield. The system will be laboratory based for flexibility in fluid physical parameter control and gas composition.
3. To develop guidelines for the evaluation of the uncertainty of the sampling and for the sampling representativeness including the minimum sample size (target uncertainties of 10 %), and sample volume/gravimetric requirements by performing repeated samplings under varying conditions.
4. To support the standardisation of the safe heavy‑duty sampling of hydrogen: including the venting of hydrogen, risk assessment and the training of stakeholders.

5.  

   To contribute to the standards development work of the technical committees CEN/TC 268 and ISO/TC 197 to ensure that the outputs of the project are aligned with their needs, communicated quickly to those developing the standards and to those who should use them, and in a form that can be incorporated into the standards at the earliest opportunity.
    

Outcomes and impact

Outcomes for industrial and other user communities

This project’s outcomes will enable fit‑for‑purpose hydrogen sampling services to be used by industries, testing laboratories, research organisations and other end‑users. End‑users will be able to rely on hydrogen purity assessments, which will in turn contribute to preventing serious damage to hydrogen‑powered trucks and buses and it will secure and improve the overall European quality infrastructure for hydrogen conformity assessment. Considering the existing fleet of 500, and a future fleet of 60000, vehicles, it is critical to ensure that hydrogen fuel will not reduce vehicle lifetime, increase the cost of ownership significantly and the availability of the service for the early adopter communities. Maintaining a high level of service will be key for the successful energy transition towards green energy and lower CO₂ emissions.

The project’s dissemination activities will enable the uptake of the outcomes by industrial stakeholders including HRS operators, fuel cell electric heavy duty vehicles, fleet operators, hydrogen producers, testing laboratories, research institutes and other end‑users as well as standardisation committees.

The project’s outcomes will contribute to lowering the detrimental impact of transport-related air pollution on the climate and health via extended implementation of hydrogen mobility.

As outlined above, it is anticipated that a major outcome of this project will be the widespread uptake and use of the sampling systems developed in the project throughout Europe and globally. Another outcome will be the increase in new services for hydrogen quality monitoring using the new solutions developed in this project. Due to the close collaboration between the participants and industrial stakeholders, the industry will be able to use the services developed in this project (new capabilities to sample hydrogen at HD‑HRS) to demonstrate that the hydrogen they deliver has the required quality. Eventually, the industry will also be able to use the design of the sampling systems developed in this project to build their own sampling systems for internal use.

Outcomes for the metrology and scientific communities

This project will deliver protocols and guidelines to enable the metrological community to obtain an insight into the actual challenges associated with representative sampling. This will allow tailored sampling systems to be developed and validated.

The successful delivery of the project will significantly advance the scientific state‑of‑the‑art by providing newly developed sampling systems that will be capable of collecting representative and thus reliable samples of the hydrogen delivered at the station. This will be a key tool for the hydrogen quality assessment chain. These developments will be brought to the metrological communities through workshops, webinars and other dissemination activities.

Gas metrology and commercial gas analysis laboratories will be able to use suitable sampling strategies at heavy duty refuelling stations to ensure that representative samples of hydrogen can be taken and transported to their laboratory.

NMIs having developed traceable and reliable methods for hydrogen quality assessment will be able to expand their services to the sampling of hydrogen at HRS. Whilst these new capabilities will support industry, the science community such as universities or laboratories will also benefit from the outcomes regarding the representativeness of a sample. The NMIs and DIs will provide metrological traceability from the nozzle at the HRS to the laboratory for hydrogen quality assessment as required for safe and reliable distribution of hydrogen at the HRS. This will address the demand for renewable energy and it will enable society to prepare for the energy transition.

Outcomes for relevant standards

The project’s outcomes will provide direct input to several working groups within TC 197: WG 24, WG 29, WG 27, WG 28 and WG3 3. This project is of most relevance for ISO/TC 197/WG 33 “Sampling for fuel quality analysis” as it will provide direct input on the results of the project to be considered for use in the development of ISO 19880‑9. This project will also liaise with the standards developing organisations that are responsible for EN 17124, EN 17127, ISO 19880‑8, ISO 19880‑1 and ISO 14687.

This project will also provide input to the activities of other technical committees, such as BIPM WGFF, EURAMET/Metchem SC‑GAS, and national working groups and mirror committees. In addition, the project’s outputs will be disseminated to the European Metrology Network (EMN) for Energy Gases as several participants are active members of this EMN. Sampling representativeness and the evaluation of uncertainties, due to sampling, will also be important for gases other than hydrogen and some of the outcomes (for example the guidelines on sample representativeness) of this project will be used in other fields (e.g. biomethane).

Longer-term economic, social and environmental impacts

In addition to supporting long-term climate change targets, hydrogen buses and heavy‑duty vehicles will improve air quality and provide health benefits as only water is emitted from the tailpipes; this will prevent people from breathing in carbon dioxide and carbon monoxide emissions and it will reduce the frequency of pollution peaks. As more heavy‑duty HRS are built, the number of Fuel Cell Electrical Vehicles (FCEVs) will increase and they will become more visible to society. However, as for any new market, public safety needs to be guaranteed and acceptance needs to be obtained. These can only be achieved by minimising operational problems, which will in turn be achieved by confidence and assurance that the hydrogen fuel has the required quality. Performing representative sampling is of paramount importance for the quality assessment. As enhanced acceptance of FCEVs is achieved, these vehicles will be more and more regarded as normal road vehicles rather than as a prototype or a small fleet. Societal acceptance of hydrogen fuel is essential to achieve the energy transition towards a greener society. As mentioned in the strategic agenda from the EMN for Energy Gases, it is clear that the electricity grid alone cannot support user energy demands. Moreover, diversification by the development of hydrogen technology would allow society to absorb a shock in a major energy input.

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