Norway

In the summer of 1985 a severe hydrogen-air explosion occurred in an ammonia plant in Norway. The accident resulted in two fatalities and the destruction of the building where the explosion took place. This paper presents the main findings from an investigation in 1985 and 1986 of the gas explosion and its consequences. The event started when a gasket in a water pump was blown out. The water pump was situated inside a 100 m long 10 m wide and 7 m high building. The pump was feeding water to a vessel containing hydrogen gas at pressure of 30 bars. This pressure caused a back flow of water flow through the pump and out through the failed gasket. The hydrogen reached the leakage point after about 3 minutes. The discharge of gas lasted some 20 to 30 seconds before the explosion occurred. The total mass of the hydrogen discharge was estimated at 10 to 20 kg hydrogen. The main explosion was very violent and it is likely that the gas cloud detonated. The ignition source was almost certainly a hot bearing. Several damage indicators were used to estimate the amount of hydrogen that exploded. The indicators include deflection of pipes and panels distances traveled by fragments and the distribution of glass breakage. We found that 3.5 to 7 kg of hydrogen must have been burning violently in the explosion. Window glass was broken up to 700 m from the centre of the explosion. Concrete blocks originally part of the north wall of the building and weighing 1.2 metric tons were thrown up to 16 meters. The roof of the building was lifted by an estimated 1.5 meters before resettling. The displacement of the roof caused a guillotine break of a 350 mm diameter pipe connected to the vessel that was the source of the original gas discharge. The gas composition in the vessel was 65 - 95 % hydrogen. This resulted in a large horizontal jet fire lasting about 30 seconds. Minor explosions occurred in the plant culvert system.<br/><br/>To our knowledge this gas explosion is one of the largest industrial hydrogen explosions reported. We believe this case history is a valuable reference for those who are investigating the nature of accidental<br/>hydrogen explosions.

Vented deflagration tests were conducted by UNIPI at B. Guerrini Laboratory during the experimental campaign for HySEA project. Experiments included homogeneous hydrogen-air mixture in a 10-18% vol. range of concentrations contained in an about 1 m3 enclosure called SSE (Small Scale Enclosure). Displacement measurements of a test plate were taken in order to acquire useful data for the validation of FE model developed by IMPETUS Afea. In this paper experimental facility displacement measurement system and FE model are briefly described then comparison between experimental data and simulation results is discussed.

The paper applies the multi-level perspective (MLP) in a descriptive study of three Norwegian ports to shed new light on the sociotechnical processes that structure their efforts to develop into zero emission energy hubs. While exogenous pressures cause tensions over port governance the studied ports utilize their full spectre of functions; as landlords operators authorities and community managers to enable transition. The respective approaches vary related to their local context market situation and social networks including port's relations with their owners. Individual orientations and organizational capacity further influence their engagement with radical innovation niches (e.g. OPS hydrogen LNG). The study highlights the active role of ports in sustainability transition. It shows how the interaction between geographical factors and institutional work influences the scope for new solutions around the individual port and how this makes for different feedback loops and contributions to sustainability transition in wider transport and energy systems.

One of the main benefits sought by including hydrogen in the alternative fuels mix is emissions reduction – eventually by 100%. However in the near term there is a very significant cost differential between fossil fuels and hydrogen. Hythane (a blend of hydrogen and natural gas) can act as a viable next step on the path to an ultimate hydrogen economy as a fuel blend consisting of 8−30 % hydrogen in methane can reduce emissions while not requiring significant changes in existing infrastructure. This work seeks to evaluate whether hythane may be safer than both hydrogen and methane under certain conditions. This is due to the fact hythane combines the positive safety properties of hydrogen (strong buoyancy high diffusivity) and methane (much lower flame speeds and narrower flammability limits as compared to hydrogen). For this purpose several different mixture compositions (e.g. 8 % 20 % and 30 % hydrogen) are considered. The evaluation of (a) dispersion characteristics (which are more positive than for methane) (b) combustion characteristics (which are closer to methane than hydrogen) and (c) Combined dispersion + explosion risk is performed. This risk is expected to be comparable to that of pure methane possibly lower in some situations and definitely lower than for pure hydrogen. The work is performed using the CFD software FLACS that has been well-validated for safety studies of both natural gas/methane and hydrogen systems. The first part of the work will involve validating the flame speeds and flammability limits predicted by FLACS against values available in literature. The next part of the work involves validating the overpressures predicted by the CFD tool for combustion of premixed mixtures of methane and hydrogen with air against available experimental data. In the end practical systems such as vehicular tunnels garages etc. is used to demonstrate positive safety benefits of hythane with comparisons to similar simulations for both hydrogen and methane.

Iron aluminides have been among the most studied intermetallics since the 1930s when their excellent oxidation resistance was first noticed. Their low cost of production low density high strength-to-weight ratios good wear resistance ease of fabrication and resistance to high temperature oxidation and sulfurization make them very attractive as a substitute for routine stainless steel in industrial applications. Furthermore iron aluminides allow for the conservation of less accessible and expensive elements such as nickel and molybdenum. These advantages have led to the consideration of many applications such as brake disks for windmills and trucks filtration systems in refineries and fossil power plants transfer rolls for hot-rolled steel strips and ethylene crackers and air deflectors for burning high-sulfur coal. A wide application for iron aluminides in industry strictly depends on the fundamental understanding of the influence of (i) alloy composition; (ii) microstructure; and (iii) number (type) of defects on the thermo-mechanical properties. Additionally environmental degradation of the alloys consisting of hydrogen embrittlement anodic or cathodic dissolution localized corrosion and oxidation resistance in different environments should be well known. Recently some progress in the development of new micro- and nano-mechanical testing methods in addition to the fabrication techniques of micro- and nano-scaled samples has enabled scientists to resolve more clearly the effects of alloying elements environmental items and crystal structure on the deformation behavior of alloys. In this paper we will review the extensive work which has been done during the last decades to address each of the points mentioned above.

A radical decarbonization pathway for the Norwegian society towards 2050 is presented. The paper focuses on the role of hydrogen in the transition when present Norwegian petroleum export is gradually phased out. The study is in line with EU initiatives to secure cooperation opportunities with neighbouring countries to establish an international hydrogen market. Three analytical perspectives are combined. The first uses energy models to investigate the role of hydrogen in an energy and power market perspective without considering hydrogen export. The second uses an economic equilibrium model to examine the potential role of hydrogen export in value creation. The third analysis is a socio-technical case study on the drivers and barriers for hydrogen production in Norway. Main conclusions are that access to renewable power and hydrogen are prerequisites for decarbonization of transport and industrial sectors in Norway and that hydrogen is a key to maintain a high level of economic activity. Structural changes in the economy impacts of new technologies and key enablers and barriers in this transition are discussed.

This paper compares two approaches for predicting the consequences of vented hydrogen deflagrations: empirical engineering models (EMs) and computational fluid dynamics (CFD) simulations. The study is part of the project ‘Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations’ (HySEA) funded by the Fuel Cells and Hydrogen 2 Joint Undertaking (FCH JU) under grant agreement No 671461. The HySEA project focuses on vented hydrogen deflagrations in containers and smaller enclosures with internal congestion representative of industrial applications. Data from experiments conducted as part of the HySEA project are used to evaluate predictions from a selection of EMs and the CFD tool FLACS. The experiments involve various obstacle and venting configurations and initially quiescent homogeneous hydrogen-air mixtures with hydrogen concentrations in the range 15–24 vol%. There is a significant scatter in the maximum reduced overpressures predicted by the different EMs in the present study. For certain configurations there is an order of magnitude difference between the different EM predictions. Two versions of the CFD tool FLACS are used in the present study: i) the standard commercial release FLACS v10.7r2 and ii) an in-house development version termed FLACS-beta. The commercial release generally over-predicts the maximum overpressures measured in the experiments while the development version of FLACS gives improved results for several configurations.

Hydrogen vehicles may emerge as a leading contender to replace today’s internal combustion engine powered vehicles. A Phenomena Identification and Ranking Table exercise conducted as part of the European Network of Excellence on Hydrogen Safety (HySafe) identified the use of hydrogen vehicles in road tunnels as a topic of important concern. An internal project called HyTunnel was duly established within HySafe to review identify and analyse the issues involved and to contribute to the wider activity to establish the true nature of the hazards posed by hydrogen vehicles in the confined space of a tunnel and their relative severity compared to those posed by vehicles powered by conventional fuels including compressed natural gas (CNG). In addition to reviewing current hydrogen vehicle designs tunnel design practice and previous research a programme of experiments and CFD modelling activities was performed for selected scenarios to examine the dispersion and explosion hazards potentially posed by hydrogen vehicles. Releases from compressed gaseous hydrogen (CGH2) and liquid hydrogen (LH2) powered vehicles have been studied under various tunnel geometries and ventilation regimes. The findings drawn from the limited work done so far indicate that under normal circumstances hydrogen powered vehicles do not pose a significantly higher risk than those powered by petrol diesel or CNG but this needs to be confirmed by further research. In particular obstructions at tunnel ceiling level have been identified as a potential hazard in respect to fast deflagration or even detonation in some circumstances which warrants further investigation. The shape of the tunnel tunnel ventilation and vehicle pressure relief device (PRD) operation are potentially important parameters in determining explosion risks and the appropriate mitigation measures.

Simulation of hydrogen embrittlement (HE) requires a coupled approach; on one side the models describing hydrogen transport must account for local mechanical fields while on the other side the effect of hydrogen on the accelerated material damage must be implemented into the model describing crack initiation and growth. This study presents a review of coupled diffusion and cohesive zone modelling as a method for numerically assessing HE of a steel structure. While the model is able to reproduce single experimental results by appropriate fitting of the cohesive parameters there appears to be limitations in transferring these results to other hydrogen systems. Agreement may be improved by appropriately identifying the required input parameters for the particular system under study.

Link to document download on Royal Society Website 

Gas switching reforming (GSR) is a promising technology for natural gas reforming with inherent CO₂ capture. Like conventional steam methane reforming (SMR) GSR can be integrated with CO₂ -gas shift and pressure swing adsorption units for pure hydrogen production. The resulting GSR-H2 process concept was techno-economically assessed in this study. Results showed that GSR-H2 can achieve 96% CO₂ capture at a CO₂ avoidance cost of 15 $/ton (including CO₂ transport and storage). Most components of the GSR-H2 process are proven technologies but long-term oxygen carrier stability presents an important technical uncertainty that can adversely affect competitiveness when the material lifetime drops below one year. Relative to the SMR benchmark GSR-H2 replaces some fuel consumption with electricity consumption making it more suitable to regions with higher natural gas prices and lower electricity prices. Some minor alterations to the process configuration can adjust the balance between fuel and electricity consumption to match local market conditions. The most attractive commercialization pathway for the GSR-H2 technology is initial construction without CO2 capture followed by simple retrofitting for CO₂ capture when CO₂ taxes rise and CO₂ transport and storage infrastructure becomes available. These features make the GSR-H2 technology robust to almost any future energy market scenario.

This paper describes validation of the computational fluid dynamics tool FLACS-Hydrogen. The validation study focuses on concentration and pressure data from vented deflagration experiments performed in 20-foot shipping containers as part of the project Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations (HySEA) funded by the Fuel Cells and Hydrogen 2 Joint Undertaking (FCH 2 JU). The paper presents results for tests involving inhomogeneous hydrogen-air clouds generated from realistic releases performed during the HySEA project. For both experiments and simulations the peak overpressures obtained for the stratified mixtures are higher than those measured for lean homogeneous mixtures with the same amount of hydrogen. Using an in-house version of FLACS-Hydrogen with the numerical solver Flacs3 and improved physics models results in significantly improved predictions of the peak overpressures compared to the predictions by the standard Flacs2 solver. The paper includes suggestions for further improvements to the model system.

The goal of the EU Horizon 2020 RISE project 778307 “Hydrogen fuelled utility vehicles and their support systems utilising metal hydrides” (HYDRIDE4MOBILITY) is in addressing critical issues towards a commercial implementation of hydrogen powered forklifts using metal hydride (MH) based hydrogen storage and PEM fuel cells together with the systems for their refuelling at industrial customers facilities. For these applications high specific weight of the metallic hydrides has an added value as it allows counterbalancing of a vehicle with no extra cost. Improving the rates of H2 charge/discharge in MH on the materials and system level simplification of the design and reducing the system cost together with improvement of the efficiency of system “MH store-FC” is in the focus of this work as a joint effort of consortium uniting academic teams and industrial partners from two EU and associated countries Member States (Norway Germany Croatia) and two partner countries (South Africa and Indonesia).<br/>The work within the project is focused on the validation of various efficient and cost-competitive solutions including (i) advanced MH materials for hydrogen storage and compression (ii) advanced MH containers characterised by improved charge-discharge dynamic performance and ability to be mass produced (iii) integrated hydrogen storage and compression/refuelling systems which are developed and tested together with PEM fuel cells during the collaborative efforts of the consortium.<br/>This article gives an overview of HYDRIDE4MOBILITY project focused on the results generated during its first phase (2017–2019).

The Pressure Peaking Phenomena (PPP) is the effect of introducing a light gas into a vented volume of denser gas. This will result in a nonequilibrium pressure as the light gas pushes the dense gas out at the vent. Large scale experiments have been performed to produce relevant evidence. The results were used to validate an analytical model. Pressure and temperature were measured inside a constant volume while the mass flow and vent area were varied. The analytical model was based on the conservation of mass and energy. The results showed that increasing the mass flow rate the peak pressure increases and with increasing the ventilation area the peak pressure decreases. Peak pressure was measured above 45 kPa. Longer combustion time resulted in higher temperatures increasing an underpressure effect. The experimental results showed agreement with the analytical model results. The model predicts the pressures within reasonable limits of+/-2 kPa. The pressure peaking phenomena could be very relevant for hydrogen applications in enclosures with limited ventilation. This could include car garages ship hull compartments as well as compressor shielding. This work shows that the effect can be modeled and results can be used in design to reduce the consequences.

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.

The expansion of wind and solar power is creating a growing need for power system flexibility. Dispatchable power plants with CO₂ capture and storage (CCS) offer flexibility with low CO₂ emissions but these plants become uneconomical at the low running hours implied by renewables-based power systems. To address this challenge the novel gas switching reforming (GSR) plant was recently proposed. GSR can alternate between electricity and hydrogen production from natural gas offering flexibility to the power system without reducing the utilization rate of the capital stock embodied in CCS infrastructure. This study assesses the interplay between GSR and variable renewables using a power system model which optimizes investment and hourly dispatch of 13 different technologies. Results show that GSR brings substantial benefits relative to conventional CCS. At a CO₂ price of V100/ton inclusion of GSR increases the optimal wind and solar share by 50% lowers total system costs by 8% and reduces system emissions from 45 to 4 kgCO₂/MWh. In addition GSR produces clean hydrogen equivalent to about 90% of total electricity demand which can be used to decarbonize transport and industry. GSR could therefore become a key enabling technology for a decarbonization effort led by wind and solar power.

Hydrogen induced failure under uniaxial tension is simulated in a duplex stainless steel considering microstructural feature of the material. There are three key ingredients in the modelling approach: image processing and finite element representation of the experimentally observed microstructure stress driven hydrogen diffusion and diffusion coupled cohesive zone modelling of fracture considering mixed failure mode. The microstructure used as basis for the modelling work is obtained from specimens cut in the transverse and longitudinal directions. It is found that the microstructure significantly influences hydrogen diffusion and fracture. The austenite phase is polygonal and randomly distributed in the transverse direction where a larger effective hydrogen diffusion coefficient and a lower hydrogen fracture resistance is found compared to the specimen in the longitudinal direction where the austenite phase is slender and laminated. This indicates that the proper design and control of the austenite phase help improve hydrogen resistance of duplex stainless steel. The strength of the interface in the shear direction is found to dominate the fracture mode and initiation site which reveals the importance of considering mixed failure mode and calibrating the hydrogen induced strength reduction in shear.

For decades risk assessment has been an important tool in risk management of activities in several industries world wide. It provides among others authorities and stakeholders with a sound basis for creating awareness about existing and potential hazards and risks and making decisions related to how they can prioritise and plan expenditures on risk reduction. The overall goal of the ongoing HySafe project is to contribute to the safe transition to a more sustainable development in Europe by facilitating the safe introduction of hydrogen technologies and applications. An essential element in this is the demonstration of safety: that all safety aspects related to production transportation and public use are controlled to avoid that introducing hydrogen as energy carrier should pose unacceptable risk to the society.<br/>History has proven that introducing risk analysis to new industries is beneficial e.g. in transportation and power production and distribution. However this will require existing methods and standards to be adapted to the specific applications. Furthermore when trying to quantify risk it is of utmost importance to have access to relevant accident and incident information. Such data may in many cases not be readily available and the utilisation of them will then require specific and long lasting data collection initiatives.<br/>In this paper we will present the work that has been undertaken in the HySafe project in developing methodologies and collecting data for risk management of hydrogen infrastructure. Focus is laid on the development of risk acceptance criteria and on the demonstration of safety and benefits to the public. A trustworthy demonstration of safety will have to be based on facts especially on facts widely known and emphasis will thus be put on the efforts taken to establish and operate a database containing hydrogen accident and incident information which can be utilised in risk assessment of hydrogen applications. A demonstration of safety will also have to include a demonstration of risk control measures and the paper will also present work carried out on safety distances and ignition source control.

Some 3% of global energy consumption today is used to produce hydrogen. Only 0.002% of this hydrogen about 1000 tonnes per annum(i) is used as an energy carrier. Yet as this timely position paper from DNV GL indicates hydrogen can become a major clean energy carrier in a world struggling to limit global warming.<br/>The company’s recently published 2018 Energy Transition Outlook(1) projects moderate uptake of hydrogen in this role towards 2050 then significant growth towards 2100. Building on that this position paper provides a more granular analysis of hydrogen as an energy carrier.

Potential risk exposure of 3rd parties i.e. people not involved in the actual operation of a plant is often a critical factor to gain authority approval and public acceptance for a development project. This is also highly relevant for development of demonstration facilities for hydrogen production and refuelling infrastructure. This paper presents and discusses results for risk exposure of 3rd parties based on risk assessment studies performed for the planned Hydrogen Technology Research Centre Hytrec in Trondheim. The methodology applied is outlined. Key assumptions and study uncertainties are identified and how these might affect the results are discussed.<br/>The purpose of Hytrec is to build a centre for research development and demonstration of hydrogen as an energy carrier. Hydrogen will be produced both by reforming of natural gas with CO2 capture and by electrolysis of water. The plant also includes a SOFC that will run on natural gas or hydrogen and produce heat and electricity for the Hytrec visitor centre. Hytrec will be located in a populated area without access control. Most of the units will be located within cabinets and modules.<br/>The authors acknowledge the Hytrec project and the Hytrec project partners Statoil Statkraft and DNV for their support and for allowing utilisation of results from the Hytrec QRA in this paper.

Fault trees and event trees have for decades been the most commonly applied modelling tools in both risk analysis in general and the risk analysis of hydrogen applications including infrastructure in particular. It is sometimes found challenging to make traditional Quantitative Risk Analyses sufficiently transparent and it is frequently challenging for outsiders to verify the probabilistic modelling. Bayesian Networks (BN) are a graphical representation of uncertain quantities and decisions that explicitly reveal the probabilistic dependence between the variables and the related information flow. It has been suggested that BN represent a modelling tool that is superior to both fault trees and event trees with respect to the structuring and modelling of large complex systems. This paper gives an introduction to BN and utilises a case study as a basis for discussing and demonstrating the suitability of BN for modelling the risks associated with the introduction of hydrogen as an energy carrier. In this study we explore the benefits of modelling a hydrogen refuelling station using BN. The study takes its point of departure in input from a traditional detailed Quantitative Risk Analysis conducted by DNV during the HyApproval project. We compare and discuss the two analyses with respect to their advantages and disadvantages. We especially focus on a comparison of transparency and the results that may be extracted from the two alternative procedures.

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.

This paper introduces the 3D risk management (3DRM) concept with particular emphasis on hydrogen installations (Hy3DRM). The 3DRM framework entails an integrated solution for risk management that combines a detailed site-specific 3D geometry model a computational fluid dynamics (CFD) tool for simulating flow-related accident scenarios methodology for frequency analysis and quantitative risk assessment (QRA) and state-of-the-art visualization techniques for risk communication and decision support. In order to reduce calculation time and to cover escalating accident scenarios involving structural collapse and projectiles the CFD-based consequence analysis can be complemented with empirical engineering models reduced order models or finite element analysis (FEA). The paper outlines the background for 3DRM and presents a proof-of-concept risk assessment for a hypothetical hydrogen filling station. The prototype focuses on dispersion fire and explosion scenarios resulting from loss of containment of gaseous hydrogen. The approach adopted here combines consequence assessments obtained with the CFD tool FLACS-Hydrogen from Gexcon and event frequencies estimated with the Hydrogen Risk Assessment Models (HyRAM) tool from Sandia to generate 3D risk contours for explosion pressure and radiation loads. For a given population density and set of harm criteria it is straightforward to extend the analysis to include personnel risk as well as risk-based design such as detector optimization. The discussion outlines main challenges and inherent limitations of the 3DRM concept as well as prospects for further development towards a fully integrated framework for risk management in organizations.

This paper describes a series of explosion experiments in inhomogeneous hydrogen air clouds in a standard 20′ ISO container. Test parameter variations included nozzle configuration jet direction reservoir back pressure time of ignition after release and degree of obstacles. The paper presents the experimental setup resulting pressure records and high speed videos. The explosion pressures from the experiments without obstacles were in the range of 0.4–7 kPa. In the experiments with obstacles the gas exploded more violently producing pressures in order of 100 kPa.

While most hydrogen research focuses on the technical and cost hurdles to a full-scale hydrogen economy little consideration has been given to the geopolitical drivers and consequences of hydrogen developments. The technologies and infrastructures underpinning a hydrogen economy can take markedly different forms and the choice over which pathway to take is the object of competition between different stakeholders and countries. Over time cross-border maritime trade in hydrogen has the potential to fundamentally redraw the geography of global energy trade create a new class of energy exporters and reshape geopolitical relations and alliances between countries. International governance and investments to scale up hydrogen value chains could reduce the risk of market fragmentation carbon lock-in and intensified geo-economic rivalry.

Nomograms for assessment of hazard distances from a blast wave generated by a catastrophic rupture of stand-alone (stationary) and onboard compressed hydrogen cylinder in a fire are presented. The nomograms are easy to use hydrogen safety engineering tools. They were built using the validated and recently published analytical model. Two types of nomograms were developed – one for use by first responders and another for hydrogen safety engineers. The paper underlines the importance of an international effort to unify harm and damage criteria across different countries as the discrepancies identified by the authors gave the expected results of different hazard distances for different criteria.