In the last few years, hydrogen has gained more and more importance as a clean source of energy. In this context, the quality of hydrogen plays a decisive role as it significantly influences the efficiency and lifetime of fuel cells. In order to meet the high demands on hydrogen quality, specialized laboratories are required. One such laboratory is the HyLaB at the Zentrum für Sonnenenergie und Wasserstoff-Forschung Baden-Württemberg (ZSW) in Ulm, Germany.
HyLaB is a hydrogen quality laboratory that focuses on the analysis and evaluation of hydrogen samples. The ZSW Ulm is one of the leading research institutions in the field of hydrogen and fuel cell technology in Germany and thus contributes significantly to the further development of these technologies.
With HyLaB, the ZSW Ulm has a state-of-the-art hydrogen quality laboratory, which is of great importance for research purposes as well as for industry. The HyLaB hydrogen quality laboratory is one of only three independent laboratories in the world that can detect impurities in hydrogen down to the ppb range.
The ZSW in Ulm is one of the pioneers in fuel cell lifetime research. A particular focus is on the quality of the hydrogen, as this has a direct influence on the performance and lifetime of fuel cells.
Impurities in the hydrogen can reduce the functionality and performance of a fuel cell and significantly shorten the fuel cells lifetime. It is therefore essential that the hydrogen used in fuel cells is of high purity and meets specified quality standards.
In practice, this means that hydrogen quality must be monitored and controlled precisely to ensure that fuel cells operate smoothly in a variety of applications, from vehicles to stationary energy storage systems.
In order to protect fuel cells in vehicles from impurities in the hydrogen, the hydrogen delivered to filling stations must meet the international quality standards ISO 14687, SAE J2719 or, in Germany, the legally binding DIN EN 17124. The verification of these standards is complex and requires a corresponding range of equipment.
The HyLaB at ZSW Ulm has state-of-the-art methods and techniques for the analysis and evaluation of hydrogen samples. The HyLaB has the necessary equipment and has already demonstrated compliance with these standards in many projects.
In 2019, in the "Interlaboratory comparison for hydrogen purity analysis" of the MetrohyVe project, HyLaB was one of only three laboratories worldwide to be within the maximum allowed measurement deviations in all measurements in a comparison of 13 laboratories.
Hydrogen sampling with self-developed equipment
ZSW provides also hydrogen sampling at the dispenser of 700 bar passenger car HRS with our specially developed and approved device "HySaM". This device has inert lines and components to prevent adsorption and reaction of compounds such as sulfur, ammonia, formaldehyde and formic acid from the sample. Proper sampling at H2 fueling stations is a complex process. The HySaM device, developed with partner ZBT, is one of the few solutions for such sampling. On behalf of customers, hydrogen samples are regularly taken at hydrogen filling stations or other locations and analyzed in HyLaB according to the standards EN17124, ISO14687 and SAE J2719.
Currently, the focus of the RingWaBe project is the extension of the HySaM instrument to enable sampling at high flow hydrogen refueling stations for utility vehicles. The extension of the instrument will contribute to the improvement of the quality of the hydrogen also in the fuel cell commercial vehicle sector.
Integrating these projects and initiatives into the existing hydrogen infrastructure and energy systems can help improve hydrogen quality and, in turn, fuel cell efficiency and durability.
Ultimately, these projects promote the further acceptance and use of hydrogen as a sustainable and environmentally friendly energy source.
Fuel cell vehicles powered by hydrogen (H2) enable emission-free electric mobility with long ranges and short refueling times. However, depending on the production process and transport to the filling station, hydrogen can contain impurities that can damage the fuel cells. In order to guarantee the required long service life of fuel cells in vehicles, the hydrogen fuel quality must be regularly checked and ensured. The ZSW has developed processes for the cost-effective monitoring of hydrogen quality at filling stations.
Guidelines for the refueling of hydrogen vehicles
Fuel cell vehicles (FCEVs) are refueled at hydrogen refueling stations (HRS). And this goes for hydrogen passenger cars, which refuel at 700 bar, as well as commercial vehicles, which refuel at 350 bar. The refueling process is comparable to refueling gasoline or diesel vehicles. In 2009, the first HRS was released to the public in Germany. As of May 2023, there are around 163 operational hydrogen refueling stations in Germany, with a further 45 under construction.
In Germany, the development of a refueling station network for fuel cell commercial vehicles (350 bar tanks) began in 2020, and six stations were already in operation by September 2021. Real-time information on the HRS network in Germany and neighboring countries is available athttps://h2.live
In Germany, DIN EN 17127 (Guideline for H2 Refueling Technology and Quality Assurance) is legally binding after the implementation of the European Alternative Fuel Infrastructure Directive (AFID). As a result, hydrogen refuelling stations in Germany must pass a series of acceptance tests defined in SAE J2601 and ISO 19880-1 prior to approval. The tests check for safe shutdown if limits are exceeded or not met, correct compliance with refueling ramps or refueling protocols, and response to signals from the vehicle. For the test reports, a report template is used in Germany and in the future worldwide, which was largely developed by the ZSW.
Mobile acceptance system for hydrogen refueling stations (FSTM).
ZSW conducts acceptance tests on hydrogen refueling stations to ensure that they meet legal requirements before they are put into operation for the first time.
With the "Fueling Station Test Module" (FSTM), ZSW developed a mobile measuring system in 2018, with which these tests can be carried out for passenger car HRS. By September 2021, 26 fueling station acceptance tests have already been performed. If required, the FSTM can also be used to take hydrogen samples on the high and low pressure side of the installed vehicle tanks.
ZSW works closely with its partners H2-Mobility and CEP (Clean Energy Partnership).
The tests are carried out by qualified ZSW employees who have been appointed as competent persons in the areas of explosion protection and pressure equipment in accordance with the German law (BetrSichV). In addition, the employees are comprehensively qualified and certified as "Permit Holders" and "Permit Issuers" within the framework of the "Permit-to-Work" safety system. This system was significantly developed by Shell and is also recognized by other service station operators.
2023, in Europe, there are currently no suitable test facilities for the approval of hydrogen refueling stations for commercial vehicles (HeavyDuty HRS). The tests must therefore be carried out with commercial vehicles, which is time-consuming. In order to reduce the time required and to simplify the logistics of the tests, the ZSW has applied for funding to expand the existing FSTM for the acceptance of heavy-duty HRS.
An open challenge in refueling is the accurate determination of the amount of hydrogen delivered. For liquid fuels, this process is well established and relatively simple. For gaseous hydrogen, however, completely new methods and measuring devices are required. The devices currently approved by the PTB (Physikalisch-Technische Bundesanstalt) are based on gravimetric measurements and require unacceptably long on-site measurement times. The ZSW has therefore applied for funding to qualify a transfer meter available on the market as a standard for hydrogen quantity measurement with short measurement times. Positive preliminary tests have already been carried out together with the PTB.
Verification of hydrogen quality according to the standard is time-consuming and therefore costly. It cannot be performed continuously by offline analysis in the laboratory. In addition, pollutants that are not included in the standard can cause permanent damage to fuel cells (e.g., pollutants from modified manufacturing processes, other means of transportation, or new fueling station technology). It is almost impossible to detect these unknown substances with the highly specialized analysis technology in the laboratory. The ZSW is therefore working on the development of a simple, safe and relatively inexpensive method based on the "fuel cell as a quality sensor" for permanent quality monitoring of hydrogen.
In order to further improve hydrogen quality and advance hydrogen technology, various research projects and initiatives are underway at ZSW in Ulm. Some current projects are listed below:
H2-WANDEL model region Central Alb-Danube-East Württemberg: The aim of Hy-FIVE is to test a hydrogen economy in rural and urban areas. By creating a better infrastructure, the use of hydrogen is to be promoted. Activities are concentrated on four lighthouse projects that cover the entire value chain from production to use in industry, transport and neighbourhood solutions. This also includes monitoring and improving the quality of hydrogen to enable more efficient use of fuel cells in vehicles.
HyDRAITE (Hydrogen Dispersion and Risk Assessment Integration Toolbox for Europe): The EU collaborative project HyDRAITE deals with the quality assurance of hydrogen on an international level. The project has two main objectives: First, the influence of the exemplary pollutant component carbon monoxide on modern fuel cells is investigated. The second goal of the project is to qualify the sampling at hydrogen refueling stations and the subsequent analysis of the samples according to ISO 14687:2019. Also, lessons learned from the HyDRAITE project are to be fed back into the standardization bodies for ISO 14687 to provide scientifically sound guidance for the next revision of the document.
The hydrogen quality standard ISO 14687, SAE J2719 and DIN EN 17124 are crucial for the industry to ensure the safety, efficiency and performance of hydrogen technologies. ZSW-HyLaB offers the analysis of hydrogen according to the international standards. ZSW-HyLaB is one of the few independent laboratories able to perform these analysis.
ISO 14687: Focus on hydrogen purity
The ISO 14687 standard specifies the requirements for hydrogen purity and is essential for quality assurance in the hydrogen industry in Germany. ISO 14687 focuses specifically on hydrogen purity for fuel cell vehicles.
SAE J2719 Hydrogen Purity: Hydrogen Quality Requirements
SAE J2719 defines hydrogen quality requirements for use in fuel cell vehicles in the U.S. market. This standard is important to ensure the high hydrogen quality necessary for optimal performance of fuel cell applications.
DIN EN 17124: Hydrogen Production and Distribution
DIN EN 17124 specifies the requirements for the production and distribution of hydrogen in Germany. Compliance with these standards is necessary to ensure a safe and efficient hydrogen infrastructure.
In Germany, DIN EN 17127 (Guideline for H2 Refuelling Technology and Quality Assurance) is still legally binding after the implementation of the European Alternative Fuel Infrastructure Directive (AFID).
As a result, a series of acceptance tests defined in SAE J2601 and ISO 19880-1 must be passed before hydrogen refueling stations (HRS) are approved in Germany. DIN EN 17127 requires functional testing of the globally standardized refueling protocols according to SAE J2601, based on the test procedures of the international standard ISO 19880-1.
Measuring the quality of hydrogen is a critical factor in ensuring that hydrogen meets the requirements of various applications. To measure the quality of hydrogen, various analytical methods and technologies are used to identify and quantify impurities in the hydrogen. Hydrogen samples are analyzed according to international standards such as ISO 14687, SAE J2719 and DIN EN 17124.
Only a few laboratories, such as HyLaB at ZSW in Ulm, specialize in analyzing hydrogen quality according to these international standards and monitoring the purity of the hydrogen.
For full performance and long life of a fuel cell, scientific and technical limits of hydrogen quality must be met.
However, current hydrogen quality standards are based on work that is more than 17 years old and are therefore not fully suited to the requirements of current and future fuel cell systems and operating conditions. Therefore, the H2Fuel project will perform about 300 long-term measurements with different pollutants, pollutant concentrations, fuel cell components and load cycles to provide the data base for an urgently needed update of the standards.
The goal is to update the standards based on state-of-the-art fuel cell measurement data. The role of the H2Fuel project in hydrogen technology is to provide sound data and knowledge that will help to adapt and update existing standards and thus further improve hydrogen quality and fuel cell lifetime.
Within the H2Fuel project, about 300 long-term measurements will be performed at the ZSW in Ulm to investigate the hydrogen quality and lifetime of fuel cells.
HyLaB and ZSW work closely together with renowned partners in the field of hydrogen quality, such as the Center for Fuel Cell Technology (ZBT), Fraunhofer ISE, Ludwig-Bölkow-Systemtechnik GmbH (LBST) and the Heinrich-Heine-University Düsseldorf (HHUD). Associated industrial partners include companies such as Daimler, BMW, Ford and ElringKlinger. The project is funded by the German Federal Ministry of Transport and Digital Infrastructure (BMVI).