Publications

Hydrogen stations and supply systems for public transport have been demonstrated in a number of European cities during the last four years. The first refuelling facility was put into operation in Reykjavik in April 2003. Experience from the four years of operation shows that safety related incidents are more frequent in the user interface than in the other parts of the hydrogen refuelling station (HRS). This might be expected taking into account the fact that the refuelling is manually operated and that according to industrial statistics human failures normally stand for more than 80% of all safety related incidents. On the other hand the HRS experience needs special attention since the refuelling at the existing stations is carried out by well trained personnel and that procedures and systems are followed closely. So far the quality and safety approach to hydrogen refuelling stations has been based on industrial experience. This paper addresses the challenge related to the development of safe robust and easy to operate refuelling systems. Such systems require well adapted components and system solutions as well as user procedures. The challenge to adapt the industrial based quality and safety philosophy and methodologies to new hydrogen applications and customers in the public sector is addressed. Risk based safety management and risk acceptance criteria relevant to users and third party are discussed in this context. Human factors and the use of incident reporting as a tool for continuous improvement are also addressed. The paper is based on internal development programmes for hydrogen refuelling stations in Hydro and on participation in international EU and IPHE projects such as CUTE HyFLEET:CUTE HySafe and HyApproval.

On Wednesday 3rd of June 2020 Norwegian Minister for Petroleum and Energy Tina Bru and Minister for Climate and Environment Sveinung Rotevatn presented the Norwegian government's hydrogen strategy.<br/>The strategy sets the course for the government's efforts to stimulate development of hydrogen-related technologies. Hydrogen as an energy carrier can contribute to reduction of greenhouse gases and create value for the Norwegian business sector. The government wishes to prioritise efforts in areas where Norway Norwegian enterprises and technology clusters may influence the development of hydrogen related technologies and where there are opportunites for increased value creation and green growth. For hydrogen to be a low-carbon or emission-free energy carrier it must be produced with no or low emissions such as through water electrolysis with renewable electricity or from natural gas with carbon capture and storage.<br/>Today technology maturity and high costs represent barriers for increased use of hydrogen especially in the transport sector and as feedstock in parts of industry. If hydrogen and hydrogen-based solutions such as ammonia are to be used in new areas both the technology and the solutions must become more mature. In this respect further technology development will be vital.

Recently we have seen hydrogen (re)emerge as an important component of widespread decarbonisation of energy sectors. From an Australian perspective this brings with it an opportunity to store transport and export renewable energy—either as liquefied hydrogen or in a carrier such as ammonia. The growth of the hydrogen industry to now include the power and transport sectors as well as the notion of hydrogen export has broadened the range of safety considerations required and seen them extend into the realm of the consumer for the first time.<br/>Hydrogen as well as ammonia and other carriers such as methanol are existing industrial chemicals which have established protocols for their handling and use in the chemicals sector. As their use in energy and transport increases especially in the context of widespread domestic use their handling and use by inexperienced people in less-controlled environments expands shifting the risk profiles and management systems required. There is also the potential for novel hydrogen carriers such as methylcyclohexane/toluene to reach commercial viability at industrial scale.<br/>This paper will discuss some of these emerging applications of hydrogen and its carriers and discuss some of the technological innovations under development that may accompany a new energy industry— with some consideration given to their potential risks and the required safety considerations. In addition we will also provide an overview of global activity in this area and how new standards and regulations would need to be developed for the adaption of these technologies in an Australian context.

Determining the risk of accidental ignition of flammable mixtures is a topic of tremendous importance in industry and aviation safety. The concept of minimum ignition energy (MIE) has traditionally formed the basis for studying ignition hazards of fuels. In recent years however the viewpoint of ignition as a statistical phenomenon has formed the basis for studying ignition as this approach appears to be more consistent with the inherent variability in engineering test data. We have developed a very low energy capacitive spark ignition system to produce short sparks with fixed lengths of 1 to 2 mm. The ignition system is used to perform spark ignition tests in lean hydrogen oxygen-argon test mixtures over a range of spark energies. The test results are analyzed using statistical tools to obtain probability distributions for ignition versus spark energy demonstrating the statistical nature of ignition. The results also show that small changes in the hydrogen concentration lead to large changes in the ignition energy and dramatically different flame characteristics. A second low-energy spark ignition system is also developed to generate longer sparks with varying lengths up to 10 mm. A second set of ignition tests is performed in one of the test mixtures using a large range of park energies and lengths. The results are analyzed to obtain a probability distribution for ignition versus the spark energy per unit spark length. Preliminary results show that a single threshold MIE value does not exist and that the energy per unit length may be a more appropriate parameter for quantifying the risk of ignition.

Performing research in the interest of providing relevant safety requirements is a valuable and essential endeavor but translating research results into enforceable requirements adopted into codes and standards a process sometimes referred to as codification can be a separate and challenging task. This paper discusses the process utilized to successfully translate research results related to bulk gaseous hydrogen storage separation (or stand-off) distances into code requirements in NFPA 55:Storage Use and Handling of Compressed Gases and Cryogenic Fluids in Portable and StationaryContainers Cylinders and Tanks and NFPA 2: Hydrogen Technologies. The process utilized can besummarized as follows: First the technical committees for the documents to be revised were engaged to confirm that the codification process was endorsed by the committee. Then a sub-committee referred to as a task group was formed. A chair must be elected or appointed. The chair should be a generalist with code enforcement or application experience. The task group was populated with several voting members of each technical committee. By having voting members as part of the task group the group becomes empowered and uniquely different from any other code proposal generating body. The task group was also populated with technical experts as needed but primarily the experts needed are the researchers involved. Once properly populated and empowered the task group must actively engage its members. The researchers must educate the code makers on the methods and limitations of their work and the code makers must take the research results and fill the gaps as needed to build consensus and create enforceable code language and generate a code change proposal that will be accepted. While this process seems simple there are pitfalls along the way that can impede or nullify the desired end result – changes to codes and standards. A few of these pitfalls include: wrong task group membership task group not empowered task group not supported in-person meetings not possible consensus not achieved. This paper focuses on the process used and how pitfalls can be avoided for future efforts.

Wet dust removal systems used to control dust in the polishing or grinding process of Mg alloy products are frequently associated with potential hydrogen explosion caused by magnesium-water reaction. For purpose of avoiding hydrogen explosion risks we try to use a combination of chitosan (CS) and sodium phosphate (SP) to inhibit the hydrogen evolution reaction between magnesium alloy waste dust and water. The hydrogen evolution curves and chemical kinetics modeling for ten different mixing ratios demonstrate that 0.4% wt CS + 0.1% wt SP yields the best inhibition efficiency with hydrogen generation rate of almost zero. SEM and EDS analyses indicate that this composite inhibitor can create a uniform smooth tight protective film over the surface of the alloy dust particles. FTIR and XRD analysis of the chemical composition of the surface film show that this protective film contains CS and SP chemically adsorbed on the surface of ZK60 but no detectable Mg(OH)2 suggesting that magnesium-water reaction was totally blocked. Our new method offers a thorough solution to hydrogen explosion by inhibiting the hydrogen generation of magnesium alloy waste dust in a wet dust removal system.

Hydrogen will presumably become an important substitute for carbon as a reductant in the metallurgical industry for processes such as steel production. However the challenge to supply enough CO2 -free hydrogen for metallurgical processes has not been resolved yet. This paper reviews different production technologies for hydrogen and their advantages and drawbacks. Additionally it will highlight the development of plasma technology to produce hydrogen and carbon black which has been taking place at SINTEF during the last 30 years.

Proper management of hydrogen gas is very important for safety security of nuclear power plants. Hydrogen removal by water formation reaction on a catalyst is one of the candidates for creating hydrogen free system. We observed in situ and time-resolved structure change of palladium metal nanoparticle catalyst during the water formation reaction by using X-ray absorption spectroscopy technique. A poisoning effect by carbon monoxide on catalytic activity was also studied. We have found that the creation of oxidized surface layer on palladium metal nanoparticles plays an important role for the water formation reaction process.

Sandia National Laboratories is working with stakeholders to develop scientific data for use by standards development organizations to create hydrogen codes and standards for the safe use of liquid hydrogen. Knowledge of the concentration field and flammability envelope for high-pressure hydrogen leaks is an issue of importance for the safe use of liquid hydrogen. Sandia National Laboratories is engaged in an experimental and analytical program to characterize and predict the behaviour of liquid hydrogen releases. This paper presents a model for computing hydrogen dilution distances for cold hydrogen releases. Model validation is presented for leaks of room temperature and 80 K high-pressure hydrogen gas. The model accounts for a series of transitions that occurs from a stagnate location in the tank to a point in the leak jet where the concentration of hydrogen in air at the jet centerline has dropped to 4% by volume. The leaking hydrogen is assumed to be a simple compressible substance with thermodynamic equilibrium between hydrogen vapor hydrogen liquid and air. For the multi-phase portions of the jet near the leak location the REFPROP equation of state models developed by NIST are used to account for the thermodynamics. Further downstream the jet develops into an atmospheric gas jet where the thermodynamics are described as a mixture of ideal gases (hydrogen–air mixture). Simulations are presented for dilution distances in under-expanded high-pressure leaks from the saturated vapor and saturated liquid portions of a liquid hydrogen storage tank at 10.34 barg (150 PSIG).

Identifying sustainable energy vectors is perhaps one of the most critical issues that needs addressing to achieve a climate-neutral society by 2050. In this context the hydrogen economy has been proposed as a solution to mitigate our current fossil-based energy system while the concept of the circular economy aims to boost the efficient use of resources. Photoreforming offers a promising opportunity for recycling and transforming widely available biomass-derived wastes (e.g. crude glycerol from biodiesel) into clean hydrogen fuel. This processing technology may be a versatile method that can be performed not only under UV light but also under visible light. However this approach is currently at the lab-scale and some inherent challenges must be overcome not least the relatively modest hydrogen production rates for the lamps’ substantial energy consumption. This study aims to assess the main environmental impacts identifying the hotspots and possible trade-off in which this technology could operate feasibly. We introduce an assessment of the windows of opportunity using seven categories of environmental impact with either artificial light or sunlight as the source of photocatalytic conversion. We compared the environmental indicators from this study with those of the benchmark water electrolysis and steam–methane reforming (SMR) technologies which are currently operating at a commercial scale. The results obtained in this study situate biowaste photoreforming within the portfolio of sustainable H2 production technologies of interest for future development in terms of target H2 production rates and lifetimes of sustainable operation.

In order to gain a better understanding of hazards linked with Hydrogen/Natural gas mixtures transport by pipeline the National Institute of Industrial Environment and Risks (INERIS) alongside with the Atomic Energy Commission (CEA) the industrial companies Air Liquide and GDF SUEZ and the French Research Institutes ICARE and PPRIME (CNRS) have been involved in a project called HYDROMEL. This project was partially funded by the French National Research Agency (ANR) in the framework of its PAN-H program aimed at promoting the R&D activities related to the hydrogen deployment. Firstly the project partners investigated how a NG/H2 mixture may influence the modelling of a hazard scenario i.e. how the addition of a quantity of hydrogen in natural gas can increase the potential of danger. Therefore it was necessary to build an experimental database of physics properties for mixtures. Secondly effect distances in accidental scenarios that could happen on pipelines have been calculated with existing models adapted to the mixtures. This part was preceded by a benchmark exercise between all partners models and experimental results found in the literature. Finally the consortium wrote a good practice guideline for modelling the effects related to the release of natural gas /hydrogen mixture?. The selected models and their comparison with data collected in the literature as well as the experimental results of this project and the main conclusions of the guidelines are presented in this paper.

Safety distances for hydrogen plumes are currently derived using models developed for hydrocarbon releases. It is well known that hydrogen behaves in a significantly different manner to that of hydrocarbons when released to atmosphere. There are two main aspects involved with the development of safety distances for credible hydrogen releases; the intensity of the thermal radiation from such a plume should it be ignited and the distance downwind from the release point to the point where a flammable mixture with air no longer exists. A number of distinct areas of venting behaviour were investigated; Thermal radiation from ignited plumes from vertical open ended vent pipes Far field radiation measurements for direct comparison with models Thermal radiation from ignited plumes from vertical vent pipes terminating in a T-piece Thermal radiation measurements from ignited hydrogen with a 45 vent termination Hydrogen concentration measurements with a T-piece.

Diffusion coefficient is in significant dependence on vacancy concentration due to that migration of vacancy is the dominant mechanism of atom transport or diffusion in processes such as void formation dislocation movement and solid phase transformation. This study aims to investigate the effect of vacancy concentration on hydrogen diffusion in alpha-Fe by molecular dynamics simulations especially at low temperatures and with loading. Comparisons of the diffusion coefficients between alpha-Fe with a perfect structure and different-concentration vacancies as well as comparisons between experimental and theoretical results had been made to characterize and summarize the effect of vacancy on hydrogen diffusion coefficient.

A hydrogen fuel is expected to expand its demand in the future. However hydrogen has to be treated with enough caution because of wide combustible conditions and easiness to ignite. Detonation accidents are caused in hydrogen gas such as the explosion accident in Fukushima first nuclear plant (2011). Therefore it is necessary to comprehend initiation conditions of detonation to prevent its detonation explosion. In the present study cylindrical detonation induced by direct initiation is simulated to understand the dependency of equivalence ratios in hydrogen-oxygen mixture. The several detailed kinetic models are compared to select the most appropriate model for detonation in a wide range of equivalence ratios. The Petersen-Hanson model is used in the present study due to the best agreement among the other models. In the numerical results of cylindrical detonation induced by direct initiation a cellular structure which is similar to the experimental smoked foil record is observed. The local pressure is up to 12 MPa under the condition at the standard state. The ignition process of cylindrical detonation has two stages. At the first stage the normalized cell width /L1/2 at each equivalence ratio increases linearly. At the second stage cell bifurcations appear due to a generation of new transverse waves. It is observed that a transverse wave transforms to a transverse detonation at the end of the first stage and after that some disturbance is developed to be a new transverse wave at the beginning of the second stage.

Report presents the preliminary experimental results on hydrogen subsonic leakage in a closed vessel under the well-controlled boundary/initial conditions. Formation of hydrogen-air gas mixture cloud was studied for a transient (10 min) upward hydrogen leakage which was followed by subsequent evolution (15 min) of explosive cloud. Low-intensity ( 0.46⋅10−3 m3/sec) hydrogen release was performed via circular (diameter 0.014 m) orifice located in the bottom part of a horizontal cylindrical vessel ( ≈4 m3). A spatially distributed net of the 24 hydrogen sensors and 24 temperature sensors was used to permanently track the time dependence of the hydrogen concentration and temperature fields in vessel. Analysis of the simultaneous experimental records for the different spatial points permits to delineate the basic flow patterns and stages of hydrogen subsonic release in closed vessel in contrast to hydrogen jet release in open environment. The quantitative data were obtained for the averaged speeds of explosive cloud envelop (50% fraction of the Lower Flammability Limit (LFL)) propagation in the vertical and horizontal directions. The obtained data will be used as an experimental basis for development of the guidelines for an indoors allocation of the hydrogen sensors. Data can be also used as a new benchmark case for the reactive Computational Fluid Dynamics codes validation.

New codes and standards are being developed to facilitate the safe deployment of emerging hydrogen technologies. Hydrogen markets will benefit from standards that address the specific properties of hydrogen hydrogen effects on strength of materials and hydrogen compressed gas storage at pressures up to 70 MPa. The need for validation of new hydrogen requirements has been identified by codes and standards technical committees. The US Department of Energy (DOE) office of Energy Efficiency and Renewable Energy (EERE) has tasked the National Renewable Energy Laboratory (NREL) with the role of supporting hydrogen codes and standards research and development needs. NREL has provided validation test support to several new standards development efforts including pressure testing of 70 MPa on board vehicle storage systems flaw testing of stationary hydrogen tanks fill protocols for hydrogen fuel dispensing and hydrogen compatibility testing for hydrogen pressure relief devices (HPRD’s). Validation test results are presented for these four specific standards development needs.

The Department of Energy the Department of Defense's Defense Logistics Agency and the Department of Transportation's Federal Transit Administration have funded learning demonstrations and early market deployments to provide insight into applications of hydrogen technologies on the road in the warehouse and as stationary power. NREL's analyses validate the technology in real-world applications reveal the status of the technology and facilitate the development of hydrogen and fuel cell technologies manufacturing and operations. This paper presents the maintenance safety and operation data of fuel cells in multiple applications with the reported incidents near misses and frequencies. NREL has analyzed records of more than 225000 kilograms of hydrogen that have been dispensed through more than 108000 hydrogen fills with an excellent safety record.

The shipping industry is becoming increasingly visible on the global environmental agenda. Shipping's share of air pollution is becoming significant and public concern has led to ongoing political pressure to reduce shipping emissions. International legislation at the IMO governing the reduction of SOx and NOx emissions from shipping is being enforced and both the European Union and the USA are planning to introduce further regional laws to reduce emissions. Therefore new approaches for more environmental friendly and energy efficient energy converter are under discussion. One possible solution will be the use of fuel cell systems for auxiliary power or even main propulsion. The paper summarizes the legal background in international shipping related to the use of fuel cells and gas as fuel in ships. The focus of the paper will be on the first experiences on the use of fuel cell systems on board of ships. In this respect an incident on a fuel cell ship in Hamburg will be discussed. Moreover the paper will point out the potential for the use of fuel cell systems on board. Finally an outlook is given on ongoing and planed projects for the use of fuel cells on board of ships.

Zero Emission Vehicles (ZEVs) are necessary to help reduce the emissions in the transportation sector which is responsible for 40% of overall greenhouse gas emissions. There are two types of ZEVs Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs) Commercial Success of BEVs has been challenging thus far also due to limited range and very long charging duration. FCEVs using H2 infrastructure with SAE J2601 and J2799 standards can be consistently fuelled in a safe manner fast and resulting in a range similar to conventional vehicles. Specifically fuelling with SAE J2601 with the SAE J2799 enables FCEVs to fill with hydrogen in 3-5 minutes and to achieve a high State of Charge (SOC) resulting in 300+ mile range without exceeding the safety storage limits. Standardized H2 therefore gives an advantage to the customer over electric charging. SAE created this H2 fuelling protocol based on modelling laboratory and field tests. These SAE standards enable the first generation of commercial FCEVs and H2 stations to achieve a customer acceptable fueling similar to today's experience. This report details the advantages of hydrogen and the validation of H2 fuelling for the SAE standards.

The physical processes of the explosion of the hydrogen cloud which is formed as a result of the instantaneous destruction of high-pressure cylinder in the fuelling station are investigated. To simulate the formation of hydrogen-air mixture and its combustion a three-dimensional model of an instantaneous explosion of the gas mixture based on the Euler equations supplemented by the conservation laws of mixture components solved by Godunov method is used. To reduce the influence of the overpressure effects in the shock wave on the surrounding environment it is proposed to use a number of protective measures. An estimation of the efficiency of safety devices is carried out by monitoring the overpressure changes in several critical points. To reduce the pressure load on the construction of protective devices a range of constructive measures is also offered.

As the offshore energy landscape transitions to renewable energy useful decommissioned or abandoned oil and gas infrastructure can be repurposed in the context of the circular economy. Oil and gas platforms for example offer opportunity for hydrogen (H2) production by desalination and electrolysis of sea water using offshore wind power. However as H2 storage and transport may prove challenging this study proposes to react this H2 with the carbon dioxide (CO2) stored in depleted reservoirs. Thus producing a more transportable energy carriers like methane or methanol in the reservoir. This paper presents a novel thermodynamic analysis of the Goldeneye reservoir in the North Sea in Aspen Plus. For Goldeneye which can store 30 Mt of CO2 at full capacity if connected to a 4.45 GW wind farm it has the potential to produce 2.10 Mt of methane annually and abate 4.51 Mt of CO2 from wind energy in the grid.

In the present work the CFD modeling of cryogenic hydrogen releases in quiescent environment is presented. Two tests from the series of experiments performed in the ICESAFE facility at KIT (Karlsruhe Institute for Technology) have been simulated within the SUSANA project. During these tests hydrogen at temperature of 37K and 36K and at pressure of 19 and 29 bars respectively is released horizontally. The release at the nozzle is sonic and the modeling of the under-expanded jet was performed using two different approaches: the Ewan and Moodie approach and a modification of the Ewan and Moodie approach (modified Ewan and Moodie) that is introduced here and employs the momentum balance to calculate the velocity in the under-expanded jet. Using these approaches a pseudo-diameter is calculated and this diameter is set as source boundary in the simulation. Predictions are consistent with measurements for both experiments with both approaches. However the Ewan and Moodie approach seems to perform better.

There are times in engineering when it seems that safety and equipment cost reduction are conflicting priorities. This could be the case for pressure relief valves and vent stack sizing. This paper explores the role that component availability (particularly variety in flow and orifice diameters) plays in the engineer’s decision of a relief valve. This paper outlines the guidelines and assumptions in sizing and selecting pressure relief devices (PRDs) found in a typical high pressure hydrogen fueling station. It also provides steps in sizing the station common vent stack where the discharge gas is to be routed to prior being released into the atmosphere. This paper also explores the component availability landscape for hydrogen station designers and identifies opportunities for improvement in the supply chain of components as hydrogen fueling stations increase in number and size. American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section VIII (ASME BPVC Section VIII) Compressed Gas Association S-1.3 (CGA S-1.3) and American Petroleum Institute 520 (API 520) standards provide specific design criteria for hydrogen pressure relief valves. Results of these calculations do not match the available components. The available safety relief valves are 50 to 87 times larger than the required calculated flow capacities. Selecting a significantly oversized safety relief valve affects the vent stack design as the stack design requires sizing relative to the actual flowrate of the safety relief valve. The effect on the vent stack size in turn negatively affects site safety radiation threshold set back distances.

Safety-barrier diagrams have proven to be a useful tool in documenting the safety measures taken to prevent incidents and accidents in process industry. In Denmark they are used to inform the authorities and the nonexperts on safety relevant issues as safety-barrier diagrams are less complex compared to fault trees and are easy to understand. Internationally there is a growing interest in this concept with the use of so-called “bowtie” diagrams which are a special case of safety-barrier diagrams. Especially during the on-going introduction of new hydrogen technologies or applications as e.g. hydrogen refueling stations this technique is considered a valuable tool to support the communication with authorities and other stakeholders during the permitting process. Another advantage of safety-barrier diagrams is that there is a direct focus on those system elements that need to be subject to safety management in terms of design and installation operational use inspection and monitoring and maintenance. Safety-barrier diagrams support both quantitative and qualitative or deterministic approaches. The paper will describe the background and syntax of the methodology and thereafter the use of such diagrams for hydrogen technologies are demonstrated.

We at Kawasaki Heavy Industries have proposed a "CO2-Free H2 supply chain" using abundant brown coal of Australian origin as the energy source. This chain will store CO2 generated during the process for producing hydrogen from brown coal in a project (Carbon Net) that the Australia Government is promoting. Thus Japan can import CO2-free hydrogen. The supply chain consists of the hydrogen production system the hydrogen transport/storage system and the hydrogen use system. Related to their designs we have to consider their hazards polluted scenarios and safety measures via a safety assessment process that is compliant with international risk assessment standards. To verify safety designs related experiments and analyses will be conducted. This paper describes the approach to safety design for especially the related liquid hydrogen facilities.