Germany
Study of the Microstructural and First Hydrogenation Properties of TiFe Alloy with Zr, Mn and V as Additives
Jul 2021
Publication
In this paper we report the effect of adding Zr + V or Zr + V + Mn to TiFe alloy on microstructure and hydrogen storage properties. The addition of only V was not enough to produce a minimum amount of secondary phase and therefore the first hydrogenation at room temperature under a hydrogen pressure of 20 bars was impossible. When 2 wt.% Zr + 2 wt.% V or 2 wt.% Zr + 2 wt.% V + 2 wt.% Mn is added to TiFe the alloy shows a finely distributed Ti2Fe-like secondary phase. These alloys presented a fast first hydrogenation and a high capacity. The rate-limiting step was found to be 3D growth diffusion controlled with decreasing interface velocity. This is consistent with the hypothesis that the fast reaction is likely to be the presence of Ti2Fe-like secondary phases that act as a gateway for hydrogen.
SimSES: A Holistic Simulation Framework for Modeling and Analyzing Stationary Energy Storage Systems
Feb 2022
Publication
The increasing feed-in of intermittent renewable energy sources into the electricity grids worldwide is currently leading to technical challenges. Stationary energy storage systems provide a cost-effective and efficient solution in order to facilitate the growing penetration of renewable energy sources. Major technical and economical challenges for energy storage systems are related to lifetime efficiency and monetary returns. Holistic simulation tools are needed in order to address these challenges before investing in energy storage systems. One of these tools is SimSES a holistic simulation framework specialized in evaluating energy storage technologies technically and economically. With a modular approach SimSES covers various topologies system components and storage technologies embedded in an energy storage application. This contribution shows the capabilities and benefits of SimSES by providing in-depth knowledge of the implementations and models. Selected functionalities are demonstrated with two use cases showing the easy-to-use simulation framework while providing detailed technical analysis for expert users. Hybrid energy storage systems consisting of lithium-ion and redox-flow batteries are investigated in a peak shaving application while various system topologies are analyzed in a frequency containment reserve application. The results for the peak shaving case study show a benefit in favor of the hybrid system in terms of overall cost and degradation behavior in applications that have a comparatively low energy throughput during lifetime. In terms of system topology a cascaded converter approach shows significant improvements in efficiency for the frequency containment reserve application.
Heat Radiation of Burning Hydrogen Air Mixtures Impurified by Organic Vapour and Particles
Sep 2007
Publication
Experiments were performed to investigate the radiative heat emission of small scale hydrogen/air explosions also impurified by minor amounts of inert particles and organic fuels. A volume of 1.5 dm3 hydrogen was injected into ambient air as free-jet and ignited. In further experiments simultaneously inert Aerosil and combustible fuels were injected into the blasting hydrogen/air gas cloud. Fuels were a spray of a solvent (Dipropyleneglycol-methylether) and dispersed particles (milk powder). The combustion was observed with a DV camcorder an IR camera and two different fast scanning spectrometers in NIR and IR range using a sampling rate of 100 spectra/s. The intensity calibrated spectra were analyzed using ICT-BaM code to evaluate emission temperature and intensity of H2O CO2 CO NO and soot emission. Using the same code combined with the experimental results total heat emission of such explosions was estimated.
Hydrogen Storage in Glass Capillary Arrays for Portable and Mobile Systems
Sep 2009
Publication
A crucial problem of new hydrogen technologies is the lightweight and also safe storage of acceptable amounts of hydrogen for portable or mobile applications. A new and innovative technology based on capillary arrays has been developed. These systems ensure safe infusion storage and controlled release of hydrogen gas although storage pressures up to 1200 bar are applied. This technology enables the storage of a significantly greater amount of hydrogen than other approaches. In storage tests with first capillary arrays a gravimetric storage capacity of about 33% and a volumetric capacity of 28% was determined at a comparative low pressure of only 400 bar. This is much more than the actual published storage capacities which are to find for other storage systems. This result already surpassed the US Department of Energy's 2010 target and it is expected to meet the DOE's 2015 target in the near future.<br/>Different safety aspects have been evaluated. On the one hand experiments with single capillaries or arrays of them have been carried out. The capillaries are made of quartz and other glasses. Especially quartz has a three times higher strength than steel. At the same time the density is about three times lower which means that much less material is necessary to reach the same pressure resistance. The pressure resistance of single capillaries has been determined in dependence of capillary materials and dimensions wall thickness etc. in order to find out optimal parameters for the “final” capillaries. In these tests also the sudden release of hydrogen was tested in order to observe possible spontaneous ignitions. On the other hand a theoretical evaluation of explosion hazards was done. Different situations were analyzed e.g. release of hydrogen by diffusion or sudden rupture.
Large Scale Experiments- Deflagration and Deflagration to Detonation within a Partial Confinement Similar to a Lane
Sep 2005
Publication
About 20 years ago Fraunhofer ICT has performed large scale experiments with premixed hydrogen air mixtures [1]. A special feature has been the investigation of the combustion of the mixture within a partial confinement simulating some sort of a “lane” which may exist in reality within a hydrogen production or storage plant for example. Essentially three different types of tests have been performed: combustion of quiescent mixtures combustion of mixtures with artificially generated turbulence by means of a fan and combustion of mixtures with high speed flame jet ignition. The observed phenomena will be discussed on the basis of measured turbulence levels flame speeds and overpressures. Conditions for DDT concerning critical turbulence levels and flame speeds as well as a scaling rule for DDT related to the detonation cell size of the mixture can be derived from the experiments for this special test setup. The relevance of the results with respect to safety aspects of future hydrogen technology is assessed. Combustion phenomena will be highlighted by the presentation of impressive high speed film videos.
Results of the HySafe CFD Validation Benchmark SBEPV5
Sep 2007
Publication
The different CFD tools used by the NoE HySafe partners are applied to a series of integral complex Standard Benchmark Exercise Problems (SBEPs). All benchmarks cover complementarily physical phenomena addressing application relevant scenarios and refer to associated experiments with an explicit usage of hydrogen. After the blind benchmark SBEPV1 and SBEPV3 with subsonic vertical release in a large vessel and in a garage like facility SBEPV4 with a horizontal under-expanded jet release through a small nozzle SBEPV5 covers the scenario of a subsonic horizontal jet release in a multi-compartment room.<br/>As the associated dispersion experiments conducted by GEXCON Norsk Hydro and STATOIL were disclosed to the participants the whole benchmark was conducted openly. For the purpose of validation only the low momentum test D27 had to be simulated.<br/>The experimental rig consists of a 1.20 m x 0.20 m x 0.90 m (Z vertical) vessel divided into 12 compartments partially even physically by four baffle plates. In each compartment a hydrogen concentration sensor is mounted. There is one vent opening at the wall opposite the release location centrally located about 1 cm above floor with dimensions 0.10 m (Y) times 0.20 m (Z). The first upper baffle plate close to the release point is on a sensitive location as it lies nearly perfectly in the centre of the buoyant jet and thus separates the flow into the two compartments. The actual release was a nominally constant flow of 1.15 norm liters for 60 seconds. With a 12mm nozzle diameter this corresponds to an average exit velocity of 10.17 m/s.<br/>6 CFD packages have been applied by 7 HySafe partners to simulate this experiment: ADREAHF by NCSRD FLACS by GexCon and DNV KFX by DNV FLUENT by UPM and UU CFX by HSE/HSL and GASFLOW by FZK. The results of the different participants are compared against the experimental data. Sensitivity studies were conducted by FZK using GASFLOW and by DNV applying KFX.<br/>Conclusions based on the comparisons and the sensitivity studies related to the performance of the applied turbulence models and discretisation schemes in the release and diffusion phase are proposed. These are compared to the findings of the previous benchmark exercises.
Achievements of The EC Network of Excellence Hysafe
Sep 2009
Publication
In many areas European research has been largely fragmented. To support the required integration and to focus and coordinate related research efforts the European Commission created a new instrument the Networks of Excellences (NoEs). The goal of the NoE HySafe has been to provide the basis to facilitate the safe introduction of hydrogen as an energy carrier by removing the safety related obstacles. The prioritisation of the HySafe internal project activities was based on a phenomena identification and ranking exercise (PIRT) and expert interviews. The identified research headlines were “Releases in (partially) confined areas” “Mitigation” and “Quantitative Risk Assessment”. Along these headlines existing or planned research work was re-orientated and slightly modified to build up three large internal research projects “InsHyde” “HyTunnel” and “HyQRA”. In InsHyde realistic indoor hydrogen leaks and associated hazards have been investigated to provide recommendations for the safe use of indoor hydrogen systems including mitigation and detection means. The appropriateness of available regulations codes and standards (RCS) has been assessed. Experimental and numerical work was conducted to benchmark simulation tools and to evaluate the related recommendations. HyTunnel contributed to the understanding of the nature of the hazards posed by hydrogen vehicles inside tunnels and its relative severity compared to other fuels. In HyQRA quantitative risk assessment strategies were applied to relevant scenarios in a hydrogen refuelling station and the performance was compared to derive also recommendations. The integration provided by the network is manifested by a series of workshops and benchmarks related to experimental and numerical work. Besides the network generated the following products: the International Conference on Hydrogen Safety the first academic education related to hydrogen safety and the Safety Handbook. Finally the network initiated the founding of the International Association for Hydrogen Safety which will open up the future networking to all interested parties on an international level. The indicated results of this five years integration activity will be described in short.
Impact of Hydrogen Admixture on Combustion Processes – Part I: Theory
Jun 2020
Publication
Climate change is one of today’s most pressing global challenges. Since the emission of greenhouse gases is often closely related to the use and supply of energy the goal to avoid emissions requires a fundamental restructuring of the energy system including all parts of the technology chains from production to end-use. Natural gas is today one of the most important primary energy sources in Europe with utilization ranging from power generation and industry to appliances in the residential and commercial sector as well as mobility. As natural gas is a fossil fuel gas utilization is thus responsible for significant emissions of carbon dioxide (CO2 ) a greenhouse gas. However the transformation of the gas sector with its broad variety of technologies and end-use applications is a challenge as a fuel switch is related to changing physical properties. Today the residential and commercial sector is the biggest end user sector for natural gas in the EU both in terms of consumption and in the number of installed appliances. Natural gas is used to provide space heating as well as hot water and is used in cooking and catering appliances with in total about 200 million gas-fired residential and commercial end user appliances installed. More than 40 % of the EU gas consumption is accounted for by the residential and commercial sector. The most promising substitutes for natural gas are biogases and hydrogen. The carbon-free fuel gas hydrogen may be produced e.g. from water and renewable electricity; therefore it can be produced with a greatly lowered carbon footprint and on a very large scale. As a gaseous fuel it can be transported stored and utilised in all end-use sectors that are served by natural gas today: Power plants industry commercial appliances households and mobility. Technologies and materials however need to be suitable for the new fuel. The injection of hydrogen into existing gas distribution for example will impact all gas-using equipment in the grids since these devices are designed and optimized to operate safely efficiently and with low pollutant emissions with natural gas as fuel. The THyGA project1 focusses on all technical aspects and the regulatory framework concerning the potential operation of domestic and commercial end user appliances with hydrogen / natural gas blends. The THyGA deliverables start with theoretical background from material science (D2.4) and combustion theory (this report) and extend to the project’s experimental campaign on hydrogen tolerance tests as well as reports on the status quo and potential future developments on rules and standards as well as mitigation strategies for coping with high levels of hydrogen admixture. By this approach the project aims at investigating which levels of hydrogen blending impact the various appliance technologies to which extent and to identify the regime in which a safe efficient and low-polluting operation is possible. As this is in many ways a question of combustion this report focuses on theoretical considerations about the impact of hydrogen admixture on combustion processes. The effects of hydrogen admixture on main gas quality properties as well as combustion temperatures laminar combustion velocities pollutant formation (CO NOx) safety-related aspects and the impact of combustion control are discussed. This overview provides a basis for subsequent steps of the project e.g. for establishing the testing program. A profound understanding of the impact on hydrogen on natural gas combustion is also essential for the development of mitigation strategies to reduce potential negative consequences of hydrogen admixture on appliances.
This is part one. Part two of this project can be found at this link
This is part one. Part two of this project can be found at this link
Experimental Study of Hydrogen-Air Deflagrations in Flat Layer
Sep 2007
Publication
In the present paper the results of experiments on study of high-speed deflagrations in flat layer of hydrogen-air mixtures unconfined from below are presented. The experiments were performed in two different rectangular channels: small-scale with mixture volume up to 0.4 m3 and large-scale with volume up to 5.5 m3. The main goal of the experiments was to examine the possibility of the layer geometries to maintain high-speed deflagration and detonation. With the aim to study a range of combustion regimes the experiments were performed varying degree of channel obstruction hydrogen concentration and thickness of the layer. Depending on the experimental conditions all major combustion regimes were observed: slow flame fast – ‘choked’ flame and steady-state detonation. It was found that minimum layer layer thickness in the range of 8 to 15 detonation cell widths is required for sustainable detonations.
Hydrogen-air Deflagrations in Open Atmosphere- Large Eddy Simulation Analysis of Experimental Data
Sep 2005
Publication
The largest known experiment on hydrogen-air deflagration in the open atmosphere has been analysed by means of the large eddy simulation (LES). The combustion model is based on the progress variable equation to simulate a premixed flame front propagation and the gradient method to decouple the physical combustion rate from numerical peculiarities. The hydrodynamic instability has been partially resolved by LES and unresolved effects have been modelled by Yakhot's turbulent premixed combustion model. The main contributor to high flame propagation velocity is the additional turbulence generated by the flame front itself. It has been modelled based on the maximum flame wrinkling factor predicted by Karlovitz et al. theory and the transitional distance reported by Gostintsev with colleagues. Simulations are in a good agreement with experimental data on flame propagation dynamics flame shape and outgoing pressure wave peaks and structure. The model is built from the first principles and no adjustable parameters were applied to get agreement with the experiment.
An Intercomparison Exercise on the Capabilities of CFD Models to Predict Distribution and Mixing of H2 in a Closed Vessel.
Sep 2005
Publication
This paper presents a compilation and discussion of the results supplied by HySafe partners participating in the Standard Benchmark Exercise Problem (SBEP) V1 which is based on an experiment on hydrogen release mixing and distribution inside a vessel. Each partner has his own point of view of the problem and uses a different approach to the solution. The main characteristics of the models employed for the calculations are compared. The comparison between results together with the experimental data when available is made. Relative deviations of each model from the experimental values are also included. Explanations and interpretations of the results are presented together with some useful conclusions for future work.
Complex Hydrides as Solid Storage Materials- First Safety Tests
Sep 2007
Publication
Hydrogen technology requires efficient and safe hydrogen storage systems. For this purpose storage in solid materials such as high capacity complex hydrides is studied intensely. Independent from the actual material to be used eventually any tank design will combine nanoscale powders of highly reactive material with pressurized hydrogen gas and so far little is known about the behaviour of these mixtures in case of incidents. For a first evaluation of a complex hydride in case of a tank failure NaAlH4 (doped with Ti) was investigated in a small scale tank failure tests. 80-100 ml of the material were filled into a heat exchanger tube and sealed under argon atmosphere with a burst disk. Subsequently the NaAlH4 was partially desorbed by heating. When the powder temperature reached 130 °C and the burst disk ruptured at 9 bar hydrogen overpressure the behaviour of the expelled powder was monitored using a high speed camera an IR camera as well as sound level meters. Expulsion of the hydrogen storage material into (dry) ambient atmosphere yields a dust cloud of finely dispersed powder which does not ignite spontaneously. Similar experiments including an external source of ignition (spark / water reacting with NaAlH4) yield a flame of reacting powder. The intensity will be compared to the reaction of an equivalent amount of pure hydrogen.
Measuring and Modelling Unsteady Radiation of Hydrogen Combustion
Sep 2005
Publication
Burning hydrogen emits thermal radiation in UV NIR and IR spectral range. Especially in the case of large cloud explosion the risk of heat radiation is commonly underestimated due to the non-visible flame of hydrogen-air combustion. In the case of a real explosion accident organic substances or inert dust might be entrained from outer sources to produce soot or heated solids to substantially increase the heat release by continuum radiation. To investigate the corresponding combustion phenomena different hydrogen-air mixtures were ignited in a closed vessel and the combustion was observed with fast scanning spectrometers using a sampling rate up to 1000 spectra/s. In some experiments to take into account the influence of organic co-combustion a spray of a liquid glycol-ester and milk powder was added to the mixture. The spectra evaluation uses the BAM code of ICT to model bands of reaction products and thus to get the temperatures. The code calculates NIR/IR-spectra (1 - 10 μm) of non-homogenous gas mixtures of H2O CO2 CO NO and HCl taking into consideration also emission of soot particles. It is based on a single line group model and makes also use of tabulated data of H2O and CO2 and a Least Squares Fit of calculated spectra to experimental ones enables the estimation of flame temperatures. During hydrogen combustion OH emits an intense spectrum at 306 nm. This intermediary radical allows monitoring the reaction progress. Intense water band systems between 1.2 and 3 μm emit remarkable amounts of heat radiation according to a measured flame temperature of 2000 K. At this temperature broad optically-thick water bands between 4.5 μm and 10 μm contribute only scarcely to the total heat output. In case of co-combustion of organic materials additional emission bands of CO and CO2 as well as a continuum radiation of soot and other particles occur and particularly increase the total thermal output drastically.
An Intercomparison Exercise on the Capabilities of CFD Models to Predict Deflagration of a Large-Scale H2-Air Mixture in Open Atmosphere
Sep 2005
Publication
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.
Explosion Characteristics of Hydrogen-air and Hydrogen-Oxygen Mixtures at Elevated Pressures
Sep 2005
Publication
An essential problem for the operation of high pressure water electrolyzers and fuel cells is the permissible contamination of hydrogen and oxygen. This contamination can create malfunction and in the worst case explosions in the apparatus and gas cylinders. In order to avoid dangerous conditions the exact knowledge of the explosion characteristics of hydrogen/air and hydrogen/oxygen mixtures is necessary. The common databases e.g. the CHEMSAFE® database published by DECHEMA BAM and PTB contains even a large number of evaluated safety related properties among other things explosion limits which however are mainly measured according to standard procedures under atmospheric conditions.<br/>Within the framework of the European research project “SAFEKINEX” and other research projects the explosion limits explosion pressures and rates of pressure rise (KG values) of H2/air and H2/O2 mixtures were measured at elevated conditions of initial pressures and temperatures by the Federal Institute of Materials Research and Testing (BAM). Empirical equations of the temperature influence could be deduced from the experimental values. An anomaly was found at the pressure influence on the upper explosion limits of H2/O2 and H2/air mixtures in the range of 20 bars. In addition explosion pressures and also rates of pressure rises have been measured for different hydrogen concentrations inside the explosion range. Such data are important for constructive explosion protection measures. Furthermore the mainly used standards for the determination of explosion limits have been compared. Therefore it was interesting to have a look at the systematic differences between the new EN 1839 tube and bomb method ASTM E 681-01 and German DIN 51649-1.
Analysis Methodology for Hydrogen Behaviour in Accident Scenarios
Sep 2005
Publication
Hydrogen is not more dangerous than current fossil energy carriers but it behaves differently. Therefore hydrogen specific analyses and countermeasures will be needed to support the development of safe hydrogen technologies. A systematic step-by-step procedure for the mechanistic analysis of hydrogen behaviour and mitigation in accidents is presented. The procedure can be subdivided into four main parts:<br/>1) 3D modelling of the H2-air mixture generation<br/>2) hazard evaluation for this mixture based on specifically developed criteria for flammability flame acceleration and detonation on-set<br/>3) numerical simulation of the appropriate combustion regime using verified 3D-CFD codes and<br/>4) consequence analysis based on the calculated pressure and temperature loads.
An Inter-Comparison Exercise on the Capabilities of CFD Models to Predict the Short and Long Term Distribution and Mixing of Hydrogen in a Garage
Sep 2007
Publication
Alexandros G. Venetsanos,
E. Papanikolaou,
J. García,
Olav Roald Hansen,
Matthias Heitsch,
Asmund Huser,
Wilfried Jahn,
Jean-Marc Lacome,
Thomas Jordan,
H. S. Ledin,
Dmitry Makarov,
Prankul Middha,
Etienne Studer,
Andrei V. Tchouvelev,
Franck Verbecke,
M. M. Voort,
Andrzej Teodorczyk and
M. A. Delichatsios
The paper presents the results of the CFD inter-comparison exercise SBEP-V3 performed within the activity InsHyde internal project of the HYSAFE network of excellence in the framework of evaluating the capability of various CFD tools and modelling approaches in predicting the physical phenomena associated to the short and long term mixing and distribution of hydrogen releases in confined spaces. The experiment simulated was INERIS-TEST-6C performed within the InsHyde project by INERIS consisting of a 1 g/s vertical hydrogen release for 240 s from an orifice of 20 mm diameter into a rectangular room (garage) of dimensions 3.78x7.2x2.88 m in width length and height respectively. Two small openings at the front and bottom side of the room assured constant pressure conditions. During the test hydrogen concentration time histories were measured at 12 positions in the room for a period up to 5160 s after the end of release covering both the release and the subsequent diffusion phases. The benchmark was organized in two phases. The first phase consisted of blind simulations performed prior to the execution of the tests. The second phase consisted of post calculations performed after the tests were concluded and the experimental results made available. The participation in the benchmark was high: 12 different organizations (2 non-HYSAFE partners) 10 different CFD codes and 8 different turbulence models. Large variation in predicted results was found in the first phase of the benchmark between the various modelling approaches. This was attributed mainly to differences in turbulence models and numerical accuracy options (time/space resolution and discretization schemes). During the second phase of the benchmark the variation between predicted results was reduced.
Hydrogen Embrittlement at Cleavage Planes and Grain Boundaries in Bcc Iron—Revisiting the First-Principles Cohesive Zone Model
Dec 2020
Publication
Hydrogen embrittlement which severely affects structural materials such as steel comprises several mechanisms at the atomic level. One of them is hydrogen enhanced decohesion (HEDE) the phenomenon of H accumulation between cleavage planes where it reduces the interplanar cohesion. Grain boundaries are expected to play a significant role for HEDE since they act as trapping sites for hydrogen. To elucidate this mechanism we present the results of first-principles studies of the H effect on the cohesive strength of α-Fe single crystal (001) and (111) cleavage planes as well as on the Σ5(310)[001] and Σ3(112)[11¯0] symmetrical tilt grain boundaries. The calculated results show that within the studied range of concentrations the single crystal cleavage planes are much more sensitive to a change in H concentration than the grain boundaries. Since there are two main types of procedures to perform ab initio tensile tests different in whether or not to allow the relaxation of atomic positions which can affect the quantitative and qualitative results these methods are revisited to determine their effect on the predicted cohesive strength of segregated interfaces
Modeling of Hydrogen Flame Dynamics in Narrow Gap with Bendable Walls
Sep 2017
Publication
A concept of volume porosity together with model of moving walls were elaborated and implemented into the COM3D code. Additionally to that a support of real-time data exchange with finite-element code ABAQUS - © Dassault Systèmes provided possibility to perform simulations of the gas-dynamic simultaneously with geometrical adaptation of environmental conditions. Based on the data obtained in the KIT combustion experiments in narrow gaps the authors performed a series of the simulation on the combustion in the corresponding conditions. Obtained numerical results demonstrated good agreement with the observed experimental data. These data were also compared with those obtained in the simulation without wall bending where simulation showed considerably different combustion regime. Application of the developed technique allows to obtain results unreachable without accounting on wall displacements which demonstrates massive over-estimation of the pressures observed during flame propagation.
H2FC European Infrastructure; Research Opportunities to Focus on Scientific and Technical Bottlenecks
Sep 2013
Publication
The European Strategy Forum on Research Infrastructures (ESFRI) recognizes in its roadmap for Research Infrastructures that ?in the near future hydrogen as an energy carrier derived from various other fuels and fuel cells as energy transformers are expected to come into a major role for mobility but also for different other mobile and stationary applications? |1|. This modern hydrogen driven society lags far behind the reality. Because of that it is conform to question the current situation concerning the belief that already most is comprehensively investigated and developed concerning hydrogen technology is correct and already done. From that it appears the hydrogen technology is market ready only partial and not prepared in a sufficient way to get finally included and adopted in modern hydrogen driven society and especially the acceptance of the society is a critical. Beside this critical view through society several scientific and technical bottlenecks still discoverable. Nevertheless it is possible to foster furthermore science and development on hydrogen technology. The ?Integrating European Infrastructure? was created to support science and development of hydrogen and fuel cell technologies towards European strategy for sustainable competitive and secure energy also while identifying scientific and technical bottlenecks to support solutions based on. Its acronym is H2FC European Infrastructure and was formed to integrate the European R&D community around rare and/or unique infrastructural elements that will facilitate and significantly enhance the research and development of hydrogen and fuel cell technology.
State-of-the-Art and Research Priorities in Hydrogen Safety
Sep 2013
Publication
On October 16-17 2012 the International Association for Hydrogen Safety (HySafe) in cooperation with the Institute for Energy and Transport of the Joint Research Centre of the European Commission (JRC IET Petten) held a two-day workshop dedicated to Hydrogen Safety Research Priorities. The workshop was hosted by Federal Institute for Materials Research and Testing (BAM) in Berlin Germany. The main idea of the Workshop was to bring together stakeholders who can address the existing knowledge gaps in the area of the hydrogen safety including identification and prioritization of such gaps from the standpoint of scientific knowledge both experimental and theoretical including numerical. The experience highlighting these gaps which was obtained during both practical applications (industry) and risk assessment should serve as reference point for further analysis. The program included two sections: knowledge gaps as they are addressed by industry and knowledge gaps and state-of-the-art by research. In the current work the main results of the workshop are summarized and analysed.
Determination of Distribution Function Used in Monte Carlo Simulation on Safety Analysis of Hydrogen Vessels
Sep 2019
Publication
The test data of static burst strength and load cycle strength of composite pressure vessels are often described by GAUSSian normal or WEIBULL distribution function to perform safety analyses. The goodness of assumed distribution function plays a significant role in the inferential statistics to predict the population properties by using limited test data. Often GAUSSian and WEIBULL probability nets are empirical methods used to validate the distribution function; Anderson-Darling and Kolmogorov-Smirnov tests are the mostly favorable approaches for Goodness of Fit. However the different approaches used to determine the parameters of distribution function lead mostly to different conclusions for safety assessments.<br/>In this study six different methods are investigated to show the variations on the rates for accepting the composite pressure vessels according to GTR No. 13 life test procedure. The six methods are: a) Norm- Log based method b) Least squares regression c) Weighted least squares regression d) A linear approach based on good linear unbiased estimators e) Maximum likelihood estimation and f) The method of moments estimation. In addition various approaches of ranking function are considered. In the study Monte Carlo simulations are conducted to generate basic populations based on the distribution functions which are determined using different methods. Then the samples are extracted randomly from a population and evaluated to obtain acceptance rate. Here the “populations” and “samples” are corresponding to the burst strength or load cycle strength of the pressure vessels made from composite material and a plastic liner (type 4) for the storage of hydrogen. To the end the results are discussed and the best reliable methods are proposed.
Development of a Generalized Integral Jet Model
Sep 2017
Publication
Integral type models to describe stationary plumes and jets in cross-flows (wind) have been developed since about 1970. These models are widely used for risk analysis to describe the consequences of many different scenarios. Alternatively CFD codes are being applied but computational requirements still limit the number of scenarios that can be dealt with using CFD only. The integral models however are not suited to handle transient releases such as releases from pressurized equipment where the initially high release rate decreases rapidly with time. Further on gas ignition a second model is needed to describe the rapid combustion of the flammable part of the plume (flash fire) and a third model has to be applied for the remaining jet fire. The objective of this paper is to describe the first steps of the development of an integral-type model describing the transient development and decay of a jet of flammable gas after a release from a pressure container. The intention is to transfer the stationary models to a fully transient model capable to predict the maximum extension of short-duration high pressure jets. The model development is supported by conducting a set of transient ignited and unignited spontaneous releases at initial pressures between 25bar and 400bar. These data forms the basis for the presented model development approach.
Path to Hydrogen Competitiveness: A Cost Perspective
Jan 2020
Publication
This latest Hydrogen Council report shows that the cost of hydrogen solutions will fall sharply within the next decade – and sooner than previously expected. As scale up of hydrogen production distribution equipment and component manufacturing continues cost is projected to decrease by up to 50% by 2030 for a wide range of applications making hydrogen competitive with other low-carbon alternatives and in some cases even conventional options.
Significant cost reductions are expected across different hydrogen applications. For more than 20 of them such as long-distance and heavy-duty transportation industrial heating and heavy industry feedstock which together comprise roughly 15% of global energy consumption the hydrogen route appears the decarbonisation option of choice – a material opportunity.
The report attributes this trajectory to scale-up that positively impacts the three main cost drivers:
To deliver on this opportunity supporting policies will be required in key geographies together with investment support of around $70 billion in the lead up to 2030 in order to scale up and achieve hydrogen competitiveness. While this figure is sizable it accounts for less than 5% of annual global spending on energy. For comparison support provided to renewables in Germany totalled roughly $30 billion in 2019.
The study is based on real industry data with 25000 data points gathered and analysed from 30 companies using a rigorous methodology. The data was collected and analytical support provided by McKinsey & Company and it represents the entire hydrogen value chain across four key geographies (US Europe Japan/Korea and China). Data was also reviewed by an independent advisory group comprised of recognised hydrogen and energy transition experts.
You can download the full report from the Hydrogen Council website here
The executive summary can be found here
Significant cost reductions are expected across different hydrogen applications. For more than 20 of them such as long-distance and heavy-duty transportation industrial heating and heavy industry feedstock which together comprise roughly 15% of global energy consumption the hydrogen route appears the decarbonisation option of choice – a material opportunity.
The report attributes this trajectory to scale-up that positively impacts the three main cost drivers:
- Strong fall in the cost of producing low carbon and renewable hydrogen;
- Lower distribution and refuelling costs thanks to higher load utilisation and scale effect on infrastructure utilisation; and
- Dramatic drop in the cost of components for end-use equipment under scaling up of manufacturing.
To deliver on this opportunity supporting policies will be required in key geographies together with investment support of around $70 billion in the lead up to 2030 in order to scale up and achieve hydrogen competitiveness. While this figure is sizable it accounts for less than 5% of annual global spending on energy. For comparison support provided to renewables in Germany totalled roughly $30 billion in 2019.
The study is based on real industry data with 25000 data points gathered and analysed from 30 companies using a rigorous methodology. The data was collected and analytical support provided by McKinsey & Company and it represents the entire hydrogen value chain across four key geographies (US Europe Japan/Korea and China). Data was also reviewed by an independent advisory group comprised of recognised hydrogen and energy transition experts.
You can download the full report from the Hydrogen Council website here
The executive summary can be found here
Ia-HySafe Standard Benchmark Exercise Sbep-V21- Hydrogen Release and Accumulation within a Non-Ventilated Ambient Pressure Garage at Low Release Rates
Sep 2011
Publication
The successful Computational Fluid Dynamics (CFD) benchmarking activity originally started within the EC-funded Network of Excellence HySafe (2004-2009) continues within the research topics of the recently established “International Association of Hydrogen Safety” (IA-HySafe). The present contribution reports the results of the standard benchmark problem SBEP-V21. Focus is given to hydrogen dispersion and accumulation within a non-ventilated ambient pressure garage both during the release and post-release periods but for very low release rates as compared to earlier work (SBEP-V3). The current experiments were performed by CEA at the GARAGE facility under highly controlled conditions. Helium was vertically released from the centre of the 5.76 m (length) x 2.96 m (width) x 2.42 m (height) facility 22 cm from the floor from a 29.7 mm diameter opening at a volumetric rate of 18 L/min (0.027 g/s equivalent hydrogen release rate compared to 1 g/s for SBEP-V3) and for a period of 3740 seconds. Helium concentrations were measured with 57 catharometric sensors at various locations for a period up to 1.1 days. The simulations were performed using a variety of CFD codes and turbulence models. The paper compares the results predicted by the participating partners and attempts to identify the reasons for any observed disagreements.
HIAD – Hydrogen Incident and Accident Database
Sep 2011
Publication
The Hydrogen Incident and Accident Database (HIAD) is being developed as a repository of systematic data describing in detail hydrogen-related undesired events (incidents or accidents). It is an open web-based information system serving various purposes such as a data source for lessons learnt risk communication and partly risk assessment. The paper describes the features of the three HIAD modules – the Data Entry Module (DEM) the Data Retrieval Module (DRM) and the Data Analysis Module (DAM) – and the potential impact the database may have on hydrogen safety. The importance of data quality assurance process is also addressed.
Radiation from Hydrogen Jet Fires Investigated by Time-resolved Spectroscopy
Sep 2013
Publication
Jet fires develop on release of hydrogen from pressurized storage depending on orifice pressures and volumes. Risks arise from flame contact dispersion of hot gases and heat radiation. The latter varies strongly in time at short scales down to milliseconds caused by turbulent air entrainment and fluctuations. These jets emit bands of OH in the UV and water in the NIR and IR spectral range. These spectra enable the temperature measurement and the estimation of the air number of the measuring spot which can be used to estimate the total radiation at least from the bright combustion zones. Compared to video and IR camera frames the radiation enables to estimate species and temperatures distributions and total emissions. Impurities generate continuum radiation and the emission of CO2 in the IR indicates air entrainment which can be compared to CHEMKIN II calculation of the reaction with air.
Experimental Investigation of Flame and Pressure Dynamics after Spontaneous Ignition in Tube Geometry
Sep 2013
Publication
Spontaneous ignition processes due to high pressure hydrogen releases into air are known phenomena. The sudden expansion of pressurized hydrogen into a pipe filled with ambient air can lead to a spontaneous ignition with a jet fire. This paper presents results of an experimental investigation of the visible flame propagation and pressure measurements in 4 mm extension tubes of up to 1 m length attached to a bulk vessel by a rupture disc. Transparent glass tubes for visual observation and shock wave pressure sensors are used in this study. The effect of the extension tube length on the development of a stable jet fire after a spontaneous ignition is discussed.
Experimental Investigation of Nonideality and Nonadiabatic Effects Under High Pressure Releases
Sep 2013
Publication
Due to the nonideality of a high pressure hydrogen release the possibility of a two-phase flow and its effect on the dynamics of the discharge process was experimentally investigated. A small-scale facility was designed and constructed to simulate the transient blow-down of a cryogenic fluid through a small break. Gaseous and liquid nitrogen were planned to were used as a surrogate for GH2 and LH2. The results will complement the quasi-stationary safety regulation tests and will provide time-dependent data for verification of the theoretical models. Different orifice sizes (0.5 1 2 4 mm) and initial N2 pressures (30 – 200 bar) were used in the tests. The measured time-dependent data for vessel discharge pressure thrust discharge mass flow rate and gas temperatures were compared against a theoretical model for high pressure nitrogen release. This verification for nitrogen also assures the equation of state for hydrogen which is based on the same methodology.
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Sep 2007
Publication
Composite cylinders with metal liner are used for the storage of compressed hydrogen in automotive application. These hybrid pressure cylinders are designed for a nominal working pressure of up to 70 MPa. They also have to withstand a temperature range between -40°C and +85°C according GRPE draft [1] and for short periods up to a maximum temperature of 140°C during filling (fast filling) [2]. In order to exploit the material properties efficiently with a high degree of lightweight optimization and a high level of safety on the same time a better understanding of the structural behavior of hybrid designs is necessary. Work on this topic has been carried out in the frame of a work package on safety aspects and regulation (Subproject SAR) of the European IP StorHy (www.storhy.net). The temperature influence on the composite layers is distinctive due to there typical polymer material behavior. The stiffness of the composite layer is a function of temperature which influences global strains and stress levels (residual stresses) in operation. In order to do an accurate fatigue assessment of composite hybrid cylinders a realistic modeling of a representative temperature load is needed. For this climate data has been evaluated which were collected in Europe over a period of 30 years [3]. Assuming that the temperature follows a Gaussian (normal) distribution within the assessed period of 30 years it is possible to generate a frequency distribution for different temperature classes for the cold extreme and the hot extreme. Combining these distributions leads to the overall temperature range distribution (frequency over temperature classes). The climatic temperature influence the filling temperature and the pressure load have to be considered in combination with the operation profile of the storage cylinder to derive a complete load vector for an accurate assessment of the lifetime and safety level.
The Correlation Method to Analyze the Gas Mixing Process On The Basis Of BOS Method
Sep 2011
Publication
Structures formed during gas mixing following an injection of a gas into atmosphere are analyzed using optic methods based on the detection of density non-uniformities. Methods for determination of fractal parameters for a random distribution of these non-uniformities are described and information revealed on the gas mixing structure is analyzed. The BOS (background oriented schlieren) technique is utilized to obtain the optical image of the forming structures which afterward is processed using the correlation procedure allowing to extract the quantitative information on the mixing. Additionally a possibility to link the characteristics of the injected gas source and the system fractal parameters was demonstrated. The method can be used in the development of the non-contact methods for the evaluation of the gaseous system parameters based on the optical diagnostics and potentially for the obtaining more detailed information of the gaseous turbulence.
Let’s Go Green With Hydrogen! The General Public’s Perspective
Sep 2011
Publication
It is well known in socio-economics that the success of an innovation process depends to a great extent on public acceptance. The German HyTrust project analyzes the current state of public acceptance in hydrogen technology in the mobility sector. This paper focuses on cutting-edge results of interviews focus groups and a representative survey. Based on these results almost 80% of the Germans are in favor of introducing hydrogen vehicles. But from the perspective of the general public it is important that hydrogen is produced in an environmentally friendly way. HyTrust is the socio-scientific research project that accompanies the German Federal Government's National Innovation Programme.
Hydrogen and Fuel Cell Stationary Applications: Key Findings of Modelling and Experimental Work in the Hyper Project
Sep 2009
Publication
Síle Brennan,
A. Bengaouer,
Marco Carcassi,
Gennaro M. Cerchiara,
Andreas Friedrich,
O. Gentilhomme,
William G. Houf,
N. Kotchourko,
Alexei Kotchourko,
Sergey Kudriakov,
Dmitry Makarov,
Vladimir V. Molkov,
Efthymia A. Papanikolaou,
C. Pitre,
Mark Royle,
R. W. Schefer,
G. Stern,
Alexandros G. Venetsanos,
Anke Veser,
Deborah Willoughby,
Jorge Yanez and
Greg H. Evans
"This paper summarises the modelling and experimental programme in the EC FP6 project HYPER. A number of key results are presented and the relevance of these findings to installation permitting guidelines (IPG) for small stationary hydrogen and fuel cell systems is discussed. A key aim of the activities was to generate new scientific data and knowledge in the field of hydrogen safety and where possible use this data as a basis to support the recommendations in the IPG. The structure of the paper mirrors that of the work programme within HYPER in that the work is described in terms of a number of relevant scenarios as follows: 1. high pressure releases 2. small foreseeable releases 3. catastrophic releases and 4. the effects of walls and barriers. Within each scenario the key objectives activities and results are discussed.<br/>The work on high pressure releases sought to provide information for informing safety distances for high-pressure components and associated fuel storage activities on both ignited and unignited jets are reported. A study on small foreseeable releases which could potentially be controlled through forced or natural ventilation is described. The aim of the study was to determine the ventilation requirements in enclosures containing fuel cells such that in the event of a foreseeable leak the concentration of hydrogen in air for zone 2 ATEX is not exceeded. The hazard potential of a possibly catastrophic hydrogen leakage inside a fuel cell cabinet was investigated using a generic fuel cell enclosure model. The rupture of the hydrogen feed line inside the enclosure was considered and both dispersion and combustion of the resulting hydrogen air mixture were examined for a range of leak rates and blockage ratios. Key findings of this study are presented. Finally the scenario on walls and barriers is discussed; a mitigation strategy to potentially reduce the exposure to jet flames is to incorporate barriers around hydrogen storage equipment. Conclusions of experimental and modelling work which aim to provide guidance on configuration and placement of these walls to minimise overall hazards is presented. "
Simulation and Techno-Economic Analysis of a Power-to-Hydrogen Process for Oxyfuel Glass Melting
Dec 2021
Publication
As an energy-intensive industry sector the glass industry is strongly affected by the increasingly stringent climate protection targets. As established combustion-based production systems ensure high process stability and glass quality an immediate switch to low greenhouse gas emission processes is difficult. To approach these challenges this work investigates a step-by-step integration of a Power-to-Hydrogen concept into established oxyfuel glass melting processes using a simulation approach. This is complemented by a case study for economic analysis on a selected German glass industry site by simulating the power production of a nearby renewable energy park and subsequent optimization of the power-to-hydrogen plant performance and capacities. The results of this study indicate that the proposed system can reduce specific carbon dioxide emissions by up to 60 % while increasing specific energy demand by a maximum of 25 %. Investigations of the impact of altered combustion and furnace properties like adiabatic flame temperature (+25 °C) temperature efficiency (∆ξ = −0.003) and heat capacity flow ratio (∆zHL = −0.009) indicate that pure hydrogen-oxygen combustion has less impact on melting properties than assumed so far. Within the case study high CO2 abatement costs of 295 €/t CO2-eq. were determined.. This is mainly due to the insufficient performance of renewable energy sources. The correlations between process scaling and economic parameters presented in this study show promising potential for further economic optimization of the proposed energy system in the future.
The Structure and Flame Propagation Regimes in Turbulent Hydrogen Jets
Sep 2009
Publication
Experiments on flame propagation regimes in a turbulent hydrogen jet with velocity and hydrogen concentration gradients have been performed at the FZK hydrogen test site HYKA. Horizontal stationary hydrogen jets released at normal and cryogenic temperatures of 290K and 80 and 35K with different nozzle diameters and mass flow rates in the range from 0.3 to 6.5 g/s have been investigated. Sampling probe method and laser PIV technique have been used to evaluate distribution of hydrogen concentration and flow velocity along and across the jet axis. High-speed photography (1000 fps) combined with a Background Oriented Schlieren (BOS) system was used for the visual observation of the turbulent flame propagation. In order to investigate different flame propagation regimes the ignition position was changed along the jet axis. It was found that the maximum flame velocity and pressure loads can only occur if the hydrogen concentration at the ignition point exceeds 11% of hydrogen in air. In this case the flame propagates in both directions up- and downstream the jet flow whereas in the opposite case the flame propagates only downstream. Such a behavior is consistent with previous experiments according to that the flame is able to accelerate effectively only if the expansion rate σ of the H2-air mixture is higher than a critical value σ* = 3.75 (like for the 11% hydrogen-air mixture). The measured data allow conservative estimates of the safety distance and risk assessment for realistic hydrogen leaks.
Partitioning of Interstitial Segregants during Decohesion: A DFT Case Study of the Σ3 Symmetric Tilt Grain Boundary in Ferritic Steel
Sep 2019
Publication
The effect of hydrogen atoms at grain boundaries in metals is usually detrimental to the cohesion of the interface. This effect can be quantified in terms of the strengthening energy which is obtained following the thermodynamic model of Rice and Wang. A critical component of this model is the bonding or solution energy of the atoms to the free surfaces that are created during decohesion. At a grain boundary in a multicomponent system it is not immediately clear how the different species would partition and distribute on the cleaved free surfaces. In this work it is demonstrated that the choice of partitioning pattern has a significant effect on the predicted influence of H and C on grain boundary cohesion. To this end the Σ3(112)[11¯0] symmetric tilt grain boundary in bcc Fe with different contents of interstitial C and H was studied taking into account all possible distributions of the elements as well as surface diffusion effects. H as a single element has a negative influence on grain boundary cohesion independent of the details of the H distribution. C on the other hand can act both ways enhancing or reducing the cohesion of the interface. The effect of mixed H and C compositions depends on the partition pattern. However the general trend is that the number of detrimental cases increases with increasing H content. A decomposition of the strengthening energy into chemical and mechanical contributions shows that the elastic contribution dominates at high C contents while the chemical contribution sets the trend for high H contents.
Scale-up of Milling in a 100 L Device for Processing of TiFeMn Alloy for Hydrogen Storage Applications: Procedure and characterization
Feb 2019
Publication
In this work the mechanical milling of a FeTiMn alloy for hydrogen storage purposes was performed in an industrial milling device. The TiFe hydride is interesting from the technological standpoint because of the abundance and the low cost of its constituent elements Ti and Fe as well as its high volumetric hydrogen capacity. However TiFe is difficult to activate usually requiring a thermal treatment above 400 °C. A TiFeMn alloy milled for just 10 min in a 100 L industrial milling device showed excellent hydrogen storage properties without any thermal treatment. The as-milled TiFeMn alloy did not need any activation procedure and showed fast kinetic behavior and good cycling stability. Microstructural and morphological characterization of the as-received and as-milled TiFeMn alloys revealed that the material presents reduced particle and crystallite sizes even after such short time of milling. The refined microstructure of the as-milled TiFeMn is deemed to account for the improved hydrogen absorption-desorption properties.
How Hydrogen Empowers the Energy Transition
Jan 2017
Publication
This report commissioned by the Hydrogen Council and announced in conjunction with the launch of the initiative at the World Economic Forum in January 2017 details the future potential that hydrogen is ready to provide and sets out the vision of the Council and the key actions it considers fundamental for policy makers to implement to fully unlock and empower the contribution of hydrogen to the energy transition.
In this paper we explore the role of hydrogen in the energy transition including its potential recent achievements and challenges to its deployment. We also offer recommendations to ensure that the proper conditions are developed to accelerate the deployment of hydrogen technologies with the support of policymakers the private sector and society.
You can download the full report from the Hydrogen Council website here
In this paper we explore the role of hydrogen in the energy transition including its potential recent achievements and challenges to its deployment. We also offer recommendations to ensure that the proper conditions are developed to accelerate the deployment of hydrogen technologies with the support of policymakers the private sector and society.
You can download the full report from the Hydrogen Council website here
Concepts for Improving Hydrogen Storage in Nanoporous Materials
Feb 2019
Publication
Hydrogen storage in nanoporous materials has been attracting a great deal of attention in recent years as high gravimetric H2 capacities exceeding 10 wt% in some cases can be achieved at 77 K using materials with particularly high surface areas. However volumetric capacities at low temperatures and both gravimetric and volumetric capacities at ambient temperature need to be improved before such adsorbents become practically viable. This article therefore discusses approaches to increasing the gravimetric and volumetric hydrogen storage capacities of nanoporous materials and maximizing the usable capacity of a material between the upper storage and delivery pressures. In addition recent advances in machine learning and data science provide an opportunity to apply this technology to the search for new materials for hydrogen storage. The large number of possible component combinations and substitutions in various porous materials including Metal-Organic Frameworks (MOFs) is ideally suited to a machine learning approach; so this is also discussed together with some new material types that could prove useful in the future for hydrogen storage applications.
Safety Considerations and Approval Procedures for the Integration of Fuel Cells on Board of Ships
Sep 2009
Publication
The shipping industry is becoming increasingly visible on the global environmental agenda. Shipping's hare of emissions to air is regarded to be significant and public concern lead 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 additional 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 main propulsion. The presentation summarizes the legal background in international shipping related to the use for gas as ship fuel and fuel cells. The focus of the presentation will be on the safety principles for the use of gas as fuel and fuel cells on board of ships and boats. The examples given show the successful integration of such systems on board of ships. Furthermore a short outlook will be given to the ongoing and planed projects for the use of fuel cells on board of ships.
Effect of Temperature on Laminar Flame Velocity for Hydrogen-air Mixtures at Reduced Pressures
Sep 2013
Publication
The work was done with respect to hydrogen safety of ITER vacuum vessel in cases of loss of cooling and loss of vacuum accidents. Experiments were conducted at sub-atmospheric pressures from 1 bar to 200 mbar and elevated temperatures up to 300 oC. Hydrogen concentration was changed from lower to upper flammability limits in all the range of pressures and temperatures. The experiments were performed in a spherical explosion bomb equipped with two quartz windows. The flame propagation velocity was measured using pressure method and high speed shadow cinematography. The theoretical flame velocities were calculated by Cantera code using Lutz and Mueller mechanisms. The influence of the initial temperature and pressure conditions on the laminar flame speed SL overall reaction order n and Markstein length LM are presented in this work and compared with the results of a theoretical model.
Application of Hydrides in Hydrogen Storage and Compression: Achievements, Outlook and Perspectives
Feb 2019
Publication
José Bellosta von Colbe,
Jose-Ramón Ares,
Jussara Barale,
Marcello Baricco,
Craig Buckley,
Giovanni Capurso,
Noris Gallandat,
David M. Grant,
Matylda N. Guzik,
Isaac Jacob,
Emil H. Jensen,
Julian Jepsen,
Thomas Klassen,
Mykhaylo V. Lototskyy,
Kandavel Manickam,
Amelia Montone,
Julian Puszkiel,
Martin Dornheim,
Sabrina Sartori,
Drew Sheppard,
Alastair D. Stuart,
Gavin Walker,
Colin Webb,
Heena Yang,
Volodymyr A. Yartys,
Andreas Züttel and
Torben R. Jensen
Metal hydrides are known as a potential efficient low-risk option for high-density hydrogen storage since the late 1970s. In this paper the present status and the future perspectives of the use of metal hydrides for hydrogen storage are discussed. Since the early 1990s interstitial metal hydrides are known as base materials for Ni – metal hydride rechargeable batteries. For hydrogen storage metal hydride systems have been developed in the 2010s [1] for use in emergency or backup power units i. e. for stationary applications.<br/>With the development and completion of the first submarines of the U212 A series by HDW (now Thyssen Krupp Marine Systems) in 2003 and its export class U214 in 2004 the use of metal hydrides for hydrogen storage in mobile applications has been established with new application fields coming into focus.<br/>In the last decades a huge number of new intermetallic and partially covalent hydrogen absorbing compounds has been identified and partly more partly less extensively characterized.<br/>In addition based on the thermodynamic properties of metal hydrides this class of materials gives the opportunity to develop a new hydrogen compression technology. They allow the direct conversion from thermal energy into the compression of hydrogen gas without the need of any moving parts. Such compressors have been developed and are nowadays commercially available for pressures up to 200 bar. Metal hydride based compressors for higher pressures are under development. Moreover storage systems consisting of the combination of metal hydrides and high-pressure vessels have been proposed as a realistic solution for on-board hydrogen storage on fuel cell vehicles.<br/>In the frame of the “Hydrogen Storage Systems for Mobile and Stationary Applications” Group in the International Energy Agency (IEA) Hydrogen Task 32 “Hydrogen-based energy storage” different compounds have been and will be scaled-up in the near future and tested in the range of 500 g to several hundred kg for use in hydrogen storage applications.
Enabling Large-scale Hydrogen Storage in Porous Media – The Scientific Challenges
Jan 2021
Publication
Niklas Heinemann,
Juan Alcalde,
Johannes M. Miocic,
Suzanne J. T. Hangx,
Jens Kallmeyer,
Christian Ostertag-Henning,
Aliakbar Hassanpouryouzband,
Eike M. Thaysen,
Gion J. Strobel,
Cornelia Schmidt-Hattenberger,
Katriona Edlmann,
Mark Wilkinson,
Michelle Bentham,
Stuart Haszeldine,
Ramon Carbonell and
Alexander Rudloff
Expectations for energy storage are high but large-scale underground hydrogen storage in porous media (UHSP) remains largely untested. This article identifies and discusses the scientific challenges of hydrogen storage in porous media for safe and efficient large-scale energy storage to enable a global hydrogen economy. To facilitate hydrogen supply on the scales required for a zero-carbon future it must be stored in porous geological formations such as saline aquifers and depleted hydrocarbon reservoirs. Large-scale UHSP offers the much-needed capacity to balance inter-seasonal discrepancies between demand and supply decouple energy generation from demand and decarbonise heating and transport supporting decarbonisation of the entire energy system. Despite the vast opportunity provided by UHSP the maturity is considered low and as such UHSP is associated with several uncertainties and challenges. Here the safety and economic impacts triggered by poorly understood key processes are identified such as the formation of corrosive hydrogen sulfide gas hydrogen loss due to the activity of microbes or permeability changes due to geochemical interactions impacting on the predictability of hydrogen flow through porous media. The wide range of scientific challenges facing UHSP are outlined to improve procedures and workflows for the hydrogen storage cycle from site selection to storage site operation. Multidisciplinary research including reservoir engineering chemistry geology and microbiology more complex than required for CH4 or CO2 storage is required in order to implement the safe efficient and much needed large-scale commercial deployment of UHSP.
Progress in Power-to-Gas Energy Systems
Dec 2022
Publication
Hydrogen is expected to become a key component in the decarbonized energy systems of the future. Its unique chemical characteristics make hydrogen a carbon-free fuel that is suitable to be used as broadly as fossil fuels are used today. Since hydrogen can be produced by splitting water molecules using electricity as the only energy input needed hydrogen offers the opportunity to produce a fully renewable fuel if the electricity input also only stems from renewable sources. Once renewable electricity is converted into hydrogen it can be stored over long periods of time and transported over long even intercontinental distances. Underground hydrogen storage pipelines compressors liquefaction-units and transportation ships are infrastructures and suitable technologies to establish a global hydrogen energy system. Several chemical synthesis routes exist to produce more complex products from green hydrogen to fulfil the demands of various end-users and industries. One exemplary power-to-gas product is methane which can be used as a natural gas substitute. Furthermore ammonia alcohols kerosene and all other important products from hydrocarbon chemistry can be synthesized using green hydrogen.
Carbon Capture and Storage (CCS): The Way Forward
Mar 2018
Publication
Mai Bui,
Claire S. Adjiman,
André Bardow,
Edward J. Anthony,
Andy Boston,
Solomon Brown,
Paul Fennell,
Sabine Fuss,
Amparo Galindo,
Leigh A. Hackett,
Jason P. Hallett,
Howard J. Herzog,
George Jackson,
Jasmin Kemper,
Samuel Krevor,
Geoffrey C. Maitland,
Michael Matuszewski,
Ian Metcalfe,
Camille Petit,
Graeme Puxty,
Jeffrey Reimer,
David M. Reiner,
Edward S. Rubin,
Stuart A. Scott,
Nilay Shah,
Berend Smit,
J. P. Martin Trusler,
Paul Webley,
Jennifer Wilcox and
Niall Mac Dowell
Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets delivering low carbon heat and power decarbonising industry and more recently its ability to facilitate the net removal of CO2 from the atmosphere. However despite this broad consensus and its technical maturity CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus in this paper we review the current state-of-the-art of CO2 capture transport utilisation and storage from a multi-scale perspective moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS) and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.
Radiation Damage of Reactor Pressure Vessel Steels Studied by Positron Annihilation Spectroscopy—A Review
Oct 2020
Publication
Safe and long term operation of nuclear reactors is one of the most discussed challenges in nuclear power engineering. The radiation degradation of nuclear design materials limits the operational lifetime of all nuclear installations or at least decreases its safety margin. This paper is a review of experimental PALS/PLEPS studies of different nuclear reactor pressure vessel (RPV) steels investigated over last twenty years in our laboratories. Positron annihilation lifetime spectroscopy (PALS) via its characteristics (lifetimes of positrons and their intensities) provides useful information about type and density of radiation induced defects. The new results obtained on neutron-irradiated and hydrogen ions implanted German steels were compared to those from the previous studies with the aim to evaluate different processes (neutron flux/fluence thermal treatment or content of selected alloying elements) to the microstructural changes of neutron irradiated RPV steel specimens. The possibility of substitution of neutron treatment (connected to new defects creation) via hydrogen ions implantation was analyzed as well. The same materials exposed to comparable displacement damage (dpa) introduced by neutrons and accelerated hydrogen ions shown that in the results interpretation the effect of hydrogen as a vacancy-stabilizing gas must be considered too. This approach could contribute to future studies of nuclear fission/fusion design steels treated by high levels of neutron irradiation.
Validation Strategy for CFD Models Describing Safety-relevant Scenarios Including LH2/GH2 Release and the Use of Passive Autocatalytic Recombiners
Sep 2013
Publication
An increase in use of hydrogen for energy storage and clean energy supply in a future energy and mobility market will strengthen the focus on safety and the safe handling of hydrogen facilities. The ability to simulate the whole chain of physical phenomena that may occur during an accident is mandatory for future safety studies on an industrial or urban scale. Together with the RWTH Aachen University Forschungszentrum Jülich (JÜLICH) develops numerical methods to predict safety incidents connected with the release of either LH2 or GH2 using the commercial CFD code ANSYS CFX. The full sequence from the release distribution or accumulation of accidentally released hydrogen till the mitigation of accident consequences by safety devices is considered. For specific phenomena like spreading and vaporization of LH2 pools or the operational behavior of passive auto-catalytic recombiners (PAR) in-house sub-models are developed and implemented. The paper describes the current development status gives examples of the validation and concludes with future work to provide the full range of hydrogen release and recombination simulation.
Irreproducibility in Hydrogen Storage Material Research
Sep 2016
Publication
The storage of hydrogen in materials has received a significant amount of attention in recent years because this approach is widely thought to be one of the most promising solutions to the problem of storing hydrogen for use as an alternative energy carrier in a safe compact and affordable form. However there have been a number of high profile cases in which erroneous or irreproducible data have been published. Meanwhile the irreproducibility of research results in a wide range of disciplines has been the subject of an increasing amount of attention due to problems with some of the data in the literature. In this Perspective we provide a summary of the problems that have affected hydrogen storage material research. We also discuss the reasons behind them and possible ways of reducing the likelihood of further problems occurring in the future.
Indoor Use of Hydrogen, Knowledge Gaps and Priorities for the Improvement of Current Standards on Hydrogen, a Presentation of HyIndoor European Project
Sep 2013
Publication
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.
Reversible Ammonia-based and Liquid Organic Hydrogen Carriers for High-density Hydrogen Storage: Recent Progress
Feb 2019
Publication
Liquid hydrogen carriers are considered to be attractive hydrogen storage options because of their ease of integration into existing chemical transportation infrastructures when compared with liquid or compressed hydrogen. The development of such carriers forms part of the work of the International Energy Agency Task 32: Hydrogen-Based Energy Storage. Here we report the state-of-the-art for ammonia-based and liquid organic hydrogen carriers with a particular focus on the challenge of ensuring easily regenerable high-density hydrogen storage.
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