The quality of the hydrogen delivered by refuelling stations is critical for end-users and society. The purity of the hydrogen dispensed at hydrogen refuelling points should comply with the technical specifications included in the ISO 14687:2019 and EN 17124:2022 standards. Once laboratories have set up methods, they need to verify their performances, for example through participation in interlaboratory comparisons. Due to the challenge associated with the production of stable reference materials and transport of these which are produced in hydrogen at high pressure (>10 bar), interlaboratory comparisons have been organized in different steps, with increasing extent. This study describes an inter-laboratory comparison exercise for hydrogen fuel involving a large number of participants (13 laboratories), completed in less than a year and included eight key contaminants of hydrogen fuel at level close to the ISO14687 threshold. These compounds were selected based on their high probability of occurrence or because they have been found in hydrogen fuel samples. For the results of the intercomparison, it appeared that fully complying with ISO 21087:2019 is still challenging for many participants and highlighted the importance of organising these types of exercises. Many laboratories performed corrective actions based on their results, which in turn significantly improved their performances. © 2024 The Author(s)

To meet the new regulation for the deployment of alternative fuels infrastructure which sets targets for electric recharging and hydrogen refuelling infrastructure by 2025 or 2030, a large infrastructure comprising truck-suitable hydrogen refuelling stations will soon be required. However, further standardisation is required to support the uptake of hydrogen for heavy-duty transport for Europe’s green energy future. Hydrogen-powered vehicles require pure hydrogen as some contaminants can reduce the performance of the fuel cell even at very low levels. Even if previous projects have paved the way for the development of the European quality infrastructure for hydrogen conformity assessment, sampling systems and methods have yet to be developed for heavy-duty hydrogen refuelling stations (HD-HRS). This study reviews different aspects of the sampling of hydrogen at heavy-duty hydrogen refuelling stations for purity assessment, with a focus on the current and future specifications and operations at HD-HRS. This study describes the state-of-the art of sampling systems currently under development for use at HD-HRS and highlights a number of aspects which must be taken into consideration to ensure safe and accurate sampling: risk assessment for the whole sampling exercise, selection of cylinders, methods to prepare cylinders before the sampling, filling pressure, and venting of the sampling systems. 

Biomethane may contain trace components that can have adverse effects on gas vehicles performances and on the pipelines when injected in the gas grid. Biomethane quality assurance against specifications is therefore crucial for the integrity of the end-users’ appliances. Analytical methods used to assess biomethane conformity assessment must be validated properly and possibly, new methods specifically for biomethane should be developed. This paper provides an overview of the biomethane quality assurance infrastructure and the challenges faced with focus on sampling, analysis methods, reference gas mixtures, and performance evaluation. Currently, requirements for analytical method validation and fit-for-purpose assessments do not exist for biomethane. The industry is in urgent need of a protocol to evaluate the fit-for-purpose of methods in a harmonized manner. Reference gas mixtures to check the accuracy of the instrument and to determine the traceability of the measurement are also urgently required. 

It is foreseen that hydrogen heavy-duty (HD) vehicles will be used to a large extent to support the transition to zero emission transport in Europe by 2050. Ensuring the quality of hydrogen is crucial to guarantee a smooth transition. To demonstrate the quality of hydrogen, sampling systems adapted to HD conditions are being developed and tested as part of the EU-funded project MetHyTrucks (Metrology to support standardisation of hydrogen fuel sampling for heavy duty hydrogen transport). Poor sampling can lead to damage to fleets of HD vehicles, making standardization crucial for the shared HD Hydrogen Refuelling Station (HRS) network. Reliable, specific sampling systems for HD-HRS, designed for both gaseous and particulate phases, are currently being developed in the European Partnership on Metrology project MetHyTrucks. The dynamic nature of a HD-HRS, with changes in pressure, flow and temperature during refuelling, can affect the reliability of sampling. Moreover, the hydrogen fuel sampling at the HD-HRS is an operation performed in a potentially explosive atmosphere area involving safety risks. This paper discusses the parameters that can affect sampling when assessing hydrogen purity at a HD-HRS. 

The European Partnership on Metrology project BiometCAP (Protocol for SI-traceable validation of methods for biomethane conformity assessment) has developed a comprehensive performance assessment protocol tailored to benchmark and characterise analytical systems such as gas analysers. The outcomes, including practical tests, will contribute to the development of standards. This article highlights some of the findings obtained so far in the BiometCAP project, showing the applicability of this protocol to assess the performance of analysis techniques used for quantifying terpenes, siloxanes and halogenated volatile organic compounds in biomethane. 

The global impact of anthropogenic greenhouse gas emissions on climate change is undeniable, with carbon dioxide (CO2) identified as the primary contributor to global warming. Urgent action is required to mitigate global warming by reducing anthropogenic CO2 emissions to achieve net-zero levels. Carbon capture and storage (CCS) stands as a proven technology to curtail CO2 emissions from various sources by capturing and sequestering CO2 in geological formations. To address the challenge of deploying CCS on a global scale, it is crucial to accurately quantify the captured, transported, and stored CO2 since quantification underpins regulations and commercial contracts. However, the lack of standardization in CCS projects and measurement methodologies poses a significant challenge, necessitating a common measurement framework to ensure the transparency and reliability of these efforts. This article provides a comprehensive review, with 211 references, of the latest results and operating conditions for current measurement technologies covering the entire measuring system and not just a single instrument. As such, it is a first-of-its-kind effort at establishing a comprehensive framework for CCS measurement. This article serves as a source of references and as a step toward developing an international documentary standard for the transferred CO2 measurement. By addressing measurement challenges and providing comprehensive recommendations for future research, it contributes to the ongoing efforts to mitigate global warming through the widespread deployment of CCS technology.

In this study, we evaluated the performances of a custom-built optical feedback cavity enhanced absorption spectroscopy (OFCEAS) instrument for the determination of the composition of energy gases, focusing on methane and carbon dioxide as main components, and carbon monoxide as impurities, in comparison with the well-established, validated, and traceable gas chromatographic method. A total of 115 real sample gases collected in biogas plants or landfills were analyzed using with both techniques over a period of 12 months. The comparison of the techniques showed that the virtual model which allows the measurement, needs to be optimized using real samples of varied compositions. The OFCEAS measurement technique was found to be capable of measuring both the main components and a trace component in different matrices; to within a 2% measurement uncertainty (higher than the gas chromatograph/thermal conductivity detector (GC/TCD) method). The OFCEAS method exhibits a very fast response, does not require daily calibration, and can be implemented online. The agreements between the OFCEAS technique and the GC/TCD method show that the drift of the OFCEAS instruments remains acceptable in the long term as long as no change is made to the virtual model. Matrix effects were observed, and those need to be taken into consideration when analyzing different types of samples. © 2023 The Author(s). Published by IOP Publishing Ltd.

Novel traceable analytical methods and reference gas standards were developed for the detection of trace-level ammonia in biogas and biomethane. This work focused on an ammonia amount fraction at an upper limit level of 10 mg m-3(corresponding to approximately 14 μmol mol-1) specified in EN 16723-1:2016. The application of spectroscopic analytical methods, such as Fourier transform infrared spectroscopy, cavity ring-down spectroscopy, and optical feedback cavity-enhanced absorption spectroscopy, was investigated. These techniques all exhibited the necessary ammonia sensitivity at the required 14 μmol mol-1amount fraction. A 29-month stability study of reference gas mixtures of 10 μmol mol-1ammonia in methane and synthetic biogas is also reported. 

Europe’s low-carbon energy policy favors a greater use of fuel cells and technologies based on hydrogen used as a fuel. Hydrogen delivered at the hydrogen refueling station must be compliant with requirements stated in different standards. Currently, the quality control process is performed by offline analysis of the hydrogen fuel. It is, however, beneficial to continuously monitor at least some of the contaminants onsite using chemical sensors. For hydrogen quality control with regard to contaminants, high sensitivity, integration parameters, and low cost are the most important requirements. In this study, we have reviewed the existing sensor technologies to detect contaminants in hydrogen, then discussed the implementation of sensors at a hydrogen refueling stations, described the state-of-art in protocols to perform assessment of these sensor technologies, and, finally, identified the gaps and needs in these areas. It was clear that sensors are not yet commercially available for all gaseous contaminants mentioned in ISO14687:2019. The development of standardized testing protocols is required to go hand in hand with the development of chemical sensors for this application following a similar approach to the one undertaken for air sensors. © 2021 by the authors. 

Hydrogen fuel cells are an alternative power supply for electric drive trains and could represent 32 % of fuel demand by 2050. To deploy fuel cell electrical vehicles, there is current regulatory barriers (ISO 14687, OIML recommendations) that requires accurate measurements. The European funded project MetroHyVe has provided solutions and improvements in the four measurements challenges (flow metering, quality control, quality assurance and sampling). New challenges arised due to increase of hydrogen economy, therefore a new European project MetroHyVe 2 started in 2020 and its objectives will provide perspectives for the hydrogen economy to solve all regulatory barriers (ISO 14687, ISO 19880-8, ISO 19880-1, ISO 21087, OIML R139-1) and new measurement challenges (flow metering, quality control, sampling and fuel cell stack testing). The presentation will provide a comprehensive overview of the project achievements. The achievements around primary standard for flow metering (light and heavy duty), worldwide inter-laboratory comparison for hydrogen fuel quality, hydrogen sampling intercomparison and fuel cell stack testing recommendations will be highlighted.