Netherlands

This paper presents a compilation of the results supplied by HySafe partners participating in the Standard Benchmark Exercise Problem (SBEP) V2 which is based on an experiment on hydrogen combustion that is first described. A list of the results requested from participants is also included. The main characteristics of the models used for the calculations are compared in a very succinct way by using tables. The comparison between results together with the experimental data when available is made through a series of graphs. The results show quite good agreement with the experimental data. The calculations have demonstrated to be sensitive to computational domain size and far field boundary condition.

Uptake of hydrogen vehicles is an ideal solution for countries that face challenging targets for carbon dioxide reduction. The advantage of hydrogen fuel cell electric vehicles is that they behave in a very similar way to petrol engines yet they do not emit any carbon containing products during operation. The hydrogen industry currently faces the dilemma that they must meet certain measurement requirements (set by European legislation) but cannot do so due to a lack of available methods and standards. This paper outlines the four biggest measurement challenges that are faced by the hydrogen industry including flow metering quality assurance quality control and sampling.

The Joint Research Centre (JRC) of the European Commission together with the European Association of Research and Technology Organisations (EARTO) the European Standards Organisations (ESO) CEN and CENELEC and the European Commission Directorate-General Enterprise and Industry (ENTR) have launched an initiative within the context of the European Forum on Science and Industry to bring the scientific and standardization communities closer together. The second and very successful workshop in a series entitled “Putting Science into Standards" was held in at the Institute for Energy and Transport of the JRC in Petten on 21-22 October 2014.<br/>The workshop focused on Power to Hydrogen (P2H) and Hydrogen Compressed Natural Gas (HCNG) which represent a promising and major contribution to the challenging management of increased integration of renewable energy sources in the overall energy system. The workshop offered a platform to exchange ideas on technologies policy and standardization issues. The participation of major stakeholders from both industry and research to this event proved fruitful in moving towards consensus on the relevant technical issues involved and at identifying a common way forward to increase the maturity and market visibility of P2H components and systems. Other outcomes include a clarification of expectations of industry of where and how policy and standardization can contribute to a competitive development of P2H and related issues. The workshop results will be used to devise a roadmap on "Opportunities for Power to Hydrogen and HCNG" by CEN/CENELEC outlining the next steps of standardization activities.

Membrane reactors for hydrogen production can increase both the hydrogen production efficiency at small scale and the electric efficiency in micro-cogeneration systems when coupled with Polymeric Electrolyte Membrane fuel cells. This paper discusses the achievements of three European projects (FERRET FluidCELL BIONICO) which investigate the application of the membrane reactor concept to hydrogen production and micro-cogeneration systems using both natural gas and biofuels (biogas and bio-ethanol) as feedstock. The membranes used to selectively separate hydrogen from the other reaction products (CH4 CO2 H2O etc.) are of asymmetric type with a thin layer of Pd alloy (<5 μm) and supported on a ceramic porous material to increase their mechanical stability. In FERRET the flexibility of the membrane reactor under diverse natural gas quality is validated. The reactor is integrated in a micro-CHP system and achieves a net electric efficiency of about 42% (8% points higher than the reference case). In FluidCELL the use of bio-ethanol as feedstock for micro-cogeneration Polymeric Electrolyte Membrane based system is investigated in off-grid applications and a net electric efficiency around 40% is obtained (6% higher than the reference case). Finally BIONICO investigates the hydrogen production from biogas. While BIONICO has just started FERRET and FluidCELL are in their third year and the two prototypes are close to be tested confirming the potentiality of membrane reactor technology at small scale.

A rapid transition towards a CO2-neutral steel industry is required to limit climate change. Such a transition raises questions of justice as it entails positive and negative impacts unevenly distributed across societal stakeholders. To enable stakeholders to address such concerns this paper assesses the justice implications of three options that reduce emissions: CO2 capture and storage (CCS) on steel (up to 70%) bio-based steelmaking (up to 50%) and green hydrogen-based steel production (up to 100%). We select justice indicators from the energy climate labour and environmental justice literature and assess these indicators qualitatively for each of the technological routes based on literature and desk research. We find context-dependent differences in justness between the different technological routes. The impact on stakeholders varies across regions. There are justice concerns for local communities because of economic dependence on and environmental impact of the industry. Communities elsewhere are impacted through the siting of infrastructure and feedstock production. CCS and bio-based steelmaking routes can help retain industry and associated economic benefits on location while hydrogen-based steelmaking may deal better with environmental concerns. We conclude that besides techno-economic and environmental information transparency on sector-specific justice implications of transforming steel industries is essential for decision-making on technological routes

In this article we show a refuelling strategy analysis using different injector configurations to refuel a 70 MPa composite reinforced type 4 tank. The gas has been injected through single openings of different diameters (3 mm 6 mm and 10 mm) and alternatively through multiple small holes (4 × 3 mm). For each injector configuration slow (12 min) and faster (3 min) fillings have been performed. The gas temperature has been measured at different positions inside the tank as well as the temperatures of the wall materials at various locations: on the external surface and at the interface between the liner and the fiber reinforced composite. In general the larger the injector diameter and the slower the filling the higher the chance that the gas develops vertical temperature gradients (a so-called gas temperature stratification) resulting in higher than average temperatures near the top of the tank and lower than average at its bottom. While the single 3 mm opening injector causes homogeneous gas temperatures for both filling speeds both the 6 mm and 10 mm opening injectors induce gas temperature stratification during the 12 min fillings. The injector with multiple holes has an area comparable to the 6 mm single opening injector: in general this more complex geometry tends to limit the inhomogeneity of gas temperatures during slow fillings. When gas temperature stratification develops the wall materials temperature is also locally affected. This results in a higher than average temperature at the top of the tank and higher the slower the filling.

In this paper a case of hydrogen release in a typical research laboratory for the characterisation of hydrogen solid-state storage materials has been considered. The laboratory is equipped with various testing equipments for the assessment of hydrogen capacity in materials typically in the 1 to 200 bar pressure range and temperatures up to 500°C. Hydrogen is delivered at 200 bar by a 50 l gas bottle and a compressor located outside the laboratory. The safety measures directly related to hydrogen hazard consist in a distributed ventilation of the laboratory and air extraction fume hoods located on top of each instrument. Goal of this work is the modelling of hydrogen accidental release in a real laboratory case in order to provide a more fundamental basis for the laboratory safety design and assist the decision on the number and position of the safety sensors. The computational fluid dynamics code (CFD) ANSYS-CFX has been selected in order to perform the numerical investigations. Two basic accidental release scenarios have been assumed both at 200 bar:  a major leak corresponding to a guillotine breaking of the hydrogen distribution line and a smaller leak typical for a not properly tight junction.

Hydrogen technologies are expected to play a key role in implementing the transition from a fossil fuel- based to a more sustainable lower-carbon energy system. To facilitate their widespread deployment the safe operation and hydrogen systems needs to be ensured together with the evaluation of the associated risk.<br/>HIAD has been designed to be a collaborative and communicative web-based information platform holding high quality information of accidents and incidents related to hydrogen technologies. The main goal of HIAD was to become not only a standard industrial accident database but also an open communication platform suitable for safety lessons learned and risk communication as well as a potential data source for risk assessment; it has been set up to improve the understanding of hydrogen unintended events to identify measures and strategies to avoid incidents/accidents and to reduce the consequence if an accident occurs.<br/>In order to achieve that goal the data collection is characterized by a significant degree of detail and information about recorded events (e.g. causes physical consequences lesson learned). Data are related not only to real incident and accidents but also to hazardous situations.<br/>The concept of a hydrogen accident database was generated in the frame of the project HySafe an EC co-funded NoE of the 6th Frame Work Programme. HIAD was built by EC-JRC and populated by many HySafe partners. After the end of the project the database has been maintained and populated by JRC with publicly available events. The original idea was to provide a tool also for quantitative risk assessment able to conduct simple analyses of the events; unfortunately that goal could not be reached because of a lack of required statistics: it was not possible to establish a link with potential event providers coming from private sector not willing to share information considered confidential. Starting from June 2016 JRC has been developing a new version of the database (i.e. HIAD 2.0); the structure of the database and the web-interface have been redefined and simplified resulting in a streamlined user interface compared to the previous version of HIAD. The new version is mainly focused to facilitate the sharing of lessons learned and other relevant information related to hydrogen technology; the database will be public and the events will be anonymized. The database will contribute to improve the safety awareness fostering the users to benefit from the experiences of others as well as to share information from their own experiences.

Nowadays nearly 50% of the hydrogen produced worldwide comes from Steam Methane Reforming (SMR) at an environmental burden of 10.5 t_CO2 eq/t_H2 accelerating the consequences of global warming. One way to produce clean hydrogen is via methane pyrolysis using melts of metals and salts. Compared to SMR significant less CO₂ is produced due to conversion of methane into hydrogen and carbon making this route more sustainable to generate hydrogen. Hydrogen is produced with high purity and solid carbon is segregated and deposited on the molten bath. Carbon may be sold as valuable co-product making industrial scale promising. In this work methane pyrolysis was performed in a quartz bubble column using molten gallium as heat transfer agent and catalyst. A maximum conversion of 91% was achieved at 1119 °C and ambient pressure with a residence time of the bubbles in the liquid of 0.5 s. Based on in-depth analysis of the carbon it can be characterized as carbon black. Techno-economic and sensitivity analyses of the industrial concept were done for different scenarios. The results showed that if co-product carbon is saleable and a CO₂ tax of 50 euro per tonne is imposed to the processes the molten metal technology can be competitive with SMR.

To develop safety strategies for the use of hydrogen indoors the HyIndoor project is studying the behaviour of a hydrogen release deflagration or non-premixed flame in an enclosed space such as a fuel cell or its cabinet a room or a warehouse. The paper proposes a safety approach based on safety objectives that can be used to take various scenarios of hydrogen leaks into account for the safe design of Hydrogen and Fuel Cell (HFC) early market applications. Knowledge gaps on current engineering models and unknown influence of specific parameters were identified and prioritized thereby re-focusing the objectives of the project test campaign and numerical simulations. This approach will enable the improvement of the specification of openings and use of hydrogen sensors for enclosed spaces. The results will be disseminated to all stakeholders including hydrogen industry and RCS bodies.

Magnesium hydride owns the largest share of publications on solid materials for hydrogen storage. The “Magnesium group” of international experts contributing to IEA Task 32 “Hydrogen Based Energy Storage” recently published two review papers presenting the activities of the group focused on magnesium hydride based materials and on Mg based compounds for hydrogen and energy storage. This review article not only overviews the latest activities on both fundamental aspects of Mg-based hydrides and their applications but also presents a historic overview on the topic and outlines projected future developments. Particular attention is paid to the theoretical and experimental studies of Mg-H system at extreme pressures kinetics and thermodynamics of the systems based on MgH₂ nanostructuring new Mg-based compounds and novel composites and catalysis in the Mg based H storage systems. Finally thermal energy storage and upscaled H storage systems accommodating MgH₂ are presented.

Interest in the future is not new. Economic constraints and acceptability considerations of today compel decision-makers from industry and authorities to speculate on possible safety risks originating from a hydrogen economy developed in the future. Tools that support thinking about the long-term consequences of today's actions and resulting technical systems are usually prognostic based on data from past performance of past or current systems. It has become convention to assume that the performance of future systems in future environments can be accommodated in the uncertainties of such prognostic models resulting from sensitivity studies. This paper presents an alternative approach to modelling future systems based on narratives about the future. Such narratives based on the actions and interactions of individual "agents" are powerful means for addressing anxiety about engaging the imagination in order to prepare for events that are likely to occur detect critical conditions and to thus achieve desirable outcomes. This is the methodological base of Agent-Based Models (ABM) and this paper will present the approach discuss its strengths and weaknesses and present a preliminary application to modelling safety risks related to energy scenarios in a possible future hydrogen economy.

The project “Towards a Hydrogen Refuelling Infrastructure for Vehicles” (THRIVE) aimed at the determination of conditions to stimulate the building of a sustainable infrastructure for hydrogen as a car fuel in The Netherlands. Economic scenarios were constructed for the development of such an infrastructure for the next one to four decades. The eventual horizon will require the erection of a few hundred to more than a thousand hydrogen refuelling stations (HRS) in The Netherlands. The risk acceptability policy in The Netherlands implemented in the External Safety Establishments decree requires the assessment and management of safety risks imposed on the public by car fuelling stations. In the past a risk-informed policy has been developed for the large scale introduction of liquefied petroleum gas (LPG) as a car fuel and a similar policy will also be required if hydrogen is introduced in the public domain. A risk assessment methodology dedicated to cope with accident scenarios relevant for hydrogen applications is to be developed. Within the THRIVE project a demo risk assessment was conducted for the possible implementation of an HRS within an existing station for conventional fuels. The studied station is located in an urban area occupied with housing and commercial activities. The HRS is based on delivery and on-site storage of liquid hydrogen and dispensing of high pressure gaseous hydrogen into vehicles. The main challenges in the risk assessment were in the modelling of release and dispersion of liquid hydrogen. Definition of initial conditions for computational fluid dynamics (CFD) modelling to evaluate dispersion of a cold hydrogen air mixture appears rather complex and is not always fully understood. The modelling assumptions in the initial conditions determine to a large extent the likelihood and severity of potential explosion effects. The paper shows the results of the investigation and the sensitivity to the basic assumptions in the model input.

With regard to the goals of the European HySafe Network research facilities are essential for the experimental investigation of relevant phenomena for testing devices and safety concepts as well as for the generation of validation data for the various numerical codes and models. The integrating activity ‘Integration of Experimental Facilities (IEF)’ has provided basic support for jointly performed experimental work within HySafe. Even beyond the funding period of the NoE HySafe in the 6th Framework Programme IEF represents a long lasting effort for reaching sustainable integration of the experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners emphasis was put on the know-how transfer between the partners. The strategy for reaching the objectives consisted of two parts. On the one hand a documentation of the experimental capacities has been prepared and analysed. On the other hand a communication base has been established by means of biannual workshops on experimental issues. A total of 8 well received workshops has been organised covering topics from measurement technologies to safety issues. Based on the information presented by the partners a working document on best practice including the joint experimental knowledge of all partners with regard to experiments and instrumentation was created. Preserving the character of a working document it was implemented in the IEF wiki website which was set up in order to provide a central communication platform. The paper gives an overview of the IEF network activities over the last 5 years.

Contrary to several reports in the recent literature the use of oxygen sensors for indirectly monitoring ambient hydrogen concentration has serious drawbacks. This method is based on the assumption that a hydrogen release will displace oxygen which is quantified using oxygen sensors. Despite its shortcomings the draft Hydrogen Vehicle Global Technical Regulation lists this method as a means to monitor hydrogen leaks to verify vehicle fuel system integrity. Experimental evaluations that were designed to impartially compare the ability of commercial oxygen and hydrogen sensors to reliably measure and report hydrogen concentration changes are presented. Numerous drawbacks are identified and discussed.

Evaluations of the uncertainties resulting from risk assessment tools to predict releases from the various hydrogen storage types are important to support risk informed safety management. The tools have to predict releases from a wide range of storage pressures (up to 80 MPa) and temperatures (at 20K) e.g. the cryogenic compressed gas storage covers pressures up to 35 MPa and temperatures between 33K and 338 K. Accurate calculations of high pressure releases require real gas EOS. This paper compares a number of EOS to predict hydrogen properties typical in different storage types. The vessel dynamics are modelled to evaluate the performance of various EOS to predict exit pressures and temperatures. The results are compared to experimental data and results from CFD calculations.

The three years European MATHRYCE project dedicated to material testing and design recommendations for components exposed to hydrogen enhanced fatigue started in October 2012. Its main goal is to provide an “easy” to implement methodology based on lab-scale experimental tests under hydrogen gas to assess the service life of a real scale component taking into account fatigue loading under hydrogen gas. Dedicated experimental tests will be developed for this purpose. In the present paper the proposed approach is presented and compared to the methodologies currently developed elsewhere in the world.

The United Nations Economic Commission for Europe Global Technical Regulation (GTR) Number 13 (Global Technical Regulation on Hydrogen and Fuel Cell Vehicles) is the defining document regulating safety requirements in hydrogen vehicles and in particular fuel cell electric vehicles (FCEVs). GTR Number 13 has been formally adopted and will serve as the basis for the national regulatory standards for FCEV safety in North America (led by the United States) Japan Korea and the European Union. The GTR defines safety requirements for these vehicles including specifications on the allowable hydrogen levels in vehicle enclosures during in-use and post-crash conditions and on the allowable hydrogen emissions levels in vehicle exhaust during certain modes of normal operation. However in order to be incorporated into national regulations that is to be legally binding methods to verify compliance with the specific requirements must exist. In a collaborative program the Sensor Laboratories at the National Renewable Energy Laboratory in the United States and the Joint Research Centre Institute for Energy and Transport in the Netherlands have been evaluating and developing analytical methods that can be used to verify compliance with the hydrogen release requirements as specified in the GTR.

During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from −40 °C to 85 °C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the simulation results have been compared with new experimental data for different filling and emptying strategies. The comparison between experiments and simulations is shown for the temperatures of the gas inside the tank for the temperatures at the interface between the liner and the composite material and for the temperatures on the external surface of the vessel.

A benchmarking exercise on quantitative risk assessment (QRA) methodologies has been conducted within the project HyQRA under the framework of the European Network of Excellence (NoE) HySafe. The aim of the exercise was basically twofold: (i) to identify the differences and similarities in approaches in a QRA and their results for a hydrogen installation between nine participating partners representing a broad spectrum of background in QRA culture and history and (ii) to identify knowledge gaps in the various steps and parameters underlying the risk quantification. In the first step a reference case was defined: a virtual hydrogen refuelling station (HRS) in virtual surroundings comprising housing school shops and other vulnerable objects. All partners were requested to conduct a QRA according to their usual approach and experience. Basically participants were free to define representative release cases to apply models and frequency assessments according their own methodology and to present risk according to their usual format. To enable inter-comparison a required set of results data was prescribed like distances to specific thermal radiation levels from fires and distances to specific overpressure levels. Moreover complete documentation of assumptions base data and references was to be reported. It was not surprising that a wide range of results was obtained both in the applied approaches as well as in the quantitative outcomes and conclusions. This made it difficult to identify exactly which assumptions and parameters were responsible for the differences in results as the paper will show. A second phase was defined in which the QRA was determined by a more limited number of release cases (scenarios). The partners in the project agreed to assess specific scenarios in order to identify the differences in consequence assessment approaches. The results of this phase provide a better understanding of the influence of modelling assumptions and limitations on the eventual conclusions with regard to risk to on-site people and to the off-site public. This paper presents the results and conclusions of both stages of the exercise.

The aim of the study is to identify and quantify the additional risks related to hydrogen explosions during the operation of a hydrogen-driven car. In a first attempt the accidents or failures of a simple one-tank hydrogen storage system have been studied as a main source of risk. Three types of initiators are taken into account: crash accidents fire accidents without crash (no other cars are involved) and hydrogen leakages in normal situation with following ignition. The consequences of hydrogen ignition and/or explosion depend strongly on environmental conditions (geometry wind etc.) therefore the different configurations of operational and environmental conditions are specified.<br/>Then Event Tree/Fault Tree methods are applied for the risk assessment.<br/>The results of quantification permit to draw conclusions about the overall added risk of hydrogen technology as well as about the main contributors to the risk. Results of this work will eventually contribute to the on-going pre-normative research in the field of hydrogen safety.

Hydrogen has the potential to be used by many countries as part of decarbonising the future energy system. Hydrogen can be used as a fuel ‘vector’ to store and transport energy produced in low-carbon ways. This could be particularly important in applications such as heating and transport where other solutions for low and zero carbon emission are difficult. To enable the safe uptake of hydrogen technologies it is important to develop the international scientific evidence base on the potential risks to safety and how to control them effectively. The International Association for Hydrogen Safety (known as IA HySAFE) is leading global efforts to ensure this. HSE hosted the 2018 IA HySAFE Biennial Research Priorities Workshop. A panel of international experts presented during nine key topic sessions: (1) Industrial and National Programmes; (2) Applications; (3) Storage; (4) Accident Physics – Gas Phase; (5) Accident Physics – Liquid/ Cryogenic Behaviour; (6) Materials; (7) Mitigation Sensors Hazard Prevention and Risk Reduction; (8) Integrated Tools for Hazard and Risk Assessment; (9) General Aspects of Safety.<br/>This report gives an overview of each topic made by the session chairperson. It also gives further analysis of the totality of the evidence presented. The workshop outputs are shaping international activities on hydrogen safety. They are helping key stakeholders to identify gaps in knowledge and expertise and to understand and plan for potential safety challenges associated with the global expansion of hydrogen in the energy system.

For refuelling on-board hydrogen tanks table-based or formula based protocols are commonly used. These protocols are designed to achieve a tank filling close to 100% SOC (State of Charge) in s safe way: without surpassing temperature (-40°C to 85°C) and pressure limits (125% Nominal Working Pressure NWP). The ambient temperature the initial pressure and the volume category of the (compressed hydrogen storage system CHSS are used as inputs to determine the final target pressure and the pressure ramp rate (which controls the filling duration). However abnormal out-of-spec events (e.g. misinformation of storage system status and characteristics of the storage tanks) may occur and result in a refuelling in which the safety boundaries are surpassed. In the present article the possible out of specification (out-of-spec) events in a refuelling station have been analyzed. The associated hazards when refuelling on-board hydrogen tanks have been studied. Experimental results of out-of-spec event tests performed on a type 3 tank are presented. The results show that on the type 3 tank the safety temperature limit of 85°C was only surpassed under a combination of events; e.g. an unnoticed stop of the cooling of the gas combined with a wrong input of ambient temperature at a very warm environment. On the other hand under certain events (e.g. cooling the gas below the target temperature) and in particular under cold environmental conditions the 100% SOC limit established in the fuelling protocols has been surpassed. Hydrogen safety on-board tanks refuelling protocols out-of-spec events.

The study analyses the role of hydrogen in the National Energy and Climate Plans (NECPs) and identifies and highlights opportunities for hydrogen technologies to contribute to effective and efficient achievement of the 2030 climate and energy targets of the EU and its Member States.<br/>The study focuses on the potential and opportunities of renewable hydrogen produced by electrolysers using renewable electricity and of low-carbon hydrogen produced by steam methane reforming combined with CCS. The opportunities for and impacts of hydrogen deployment are assessed and summarised in individual fiches per Member State.<br/>The study analyses to what extent policy measures and industrial initiatives are already being taken to facilitate large-scale implementation of hydrogen in the current and the next decades. The study concludes by determining the CO2 reduction potential beyond what is foreseen in the NECPs through hydrogen energy technologies estimating the reduction of fossil fuel imports and reliance the prospective cost and the value added and jobs created. National teams working on decarbonisation roadmaps and updates of the NECPs are welcome to consider the opportunities and benefits of hydrogen deployment identified in this study.

Although today hydrogen is distributed mainly by trailers in the long terms pipeline distribution will be more suitable if large amounts of hydrogen are produced on industrial scale. Therefore from the safety point of view it is essential to compare hydrogen pipelines to natural gas pipelines which are well established today. Within the paper we compare safety implications in accidental situations. We do not look into technological aspects such as compressors or seals.<br/>Using a CFD (Computational Fluid Dynamics) tool it is possible to investigate the effects of different properties (density diffusivity viscosity and flammability limits) of hydrogen and methane on the dispersion process. In addition CFD tools allow studying the influence of different release scenarios geometrical configurations and atmospheric conditions. An accidental release from a pipeline is modelled. The release is simulated as a flow though a small hole between the high-pressure pipeline and the environment. A part of the pipeline is included in the simulations as high-pressure reservoir. Due to the large pressure difference between the pipeline and the environment the flow conditions at the release become critical.<br/>For the assumed scenarios larger amount of flammable mixture could be observed in case of hydrogen release. On the other hand because of buoyancy and a higher sonic speed at the release the hydrogen clouds are farther from the ground level or buildings than in case of the methane clouds decreasing the probability of ignition and reducing the flame acceleration due to obstacles in case of ignition. Results on the effect of wind in the release scenarios are also described.