France
Hydrogen Storage: Recent Improvements and Industrial Perspectives
Sep 2017
Publication
Efficient storage of hydrogen is crucial for the success of hydrogen energy markets (early markets as well as transportation market). Hydrogen can be stored either as a compressed gas a refrigerated liquefied gas a cryo-compressed gas or in hydrides. This paper gives an overview of hydrogen storage technologies and details the specific issues and constraints related to the materials behaviour in hydrogen and conditions representative of hydrogen energy uses. It is indeed essential for the development of applications requiring long-term performance to have good understanding of long-term behaviour of the materials of the storage device and its components under operational loads.
Hydrogen-air Vented Explosions- New Experimental Data
Sep 2013
Publication
The use of hydrogen as an energy carrier is a real perspective in Europe since a number of breakthroughs obtained in the last decades open the possibility to envision a deployment at the industrial scale if safety issues are duly accounted. However on this particular aspects experimental data are still lacking especially about the explosion dynamics in realistic dimensions. The purpose of this paper is to provide a set of totally new and well instrumented hydrogen - air vented explosions. Experiments were performed in a large explosion chamber within the scope of the DIMITRHY project (sponsored by the National French Agency for Research). The 4 m3 rectangular experimental chamber (2 m height 2 m width and 1 m depth) is equipped with transparent walls and is vented (0.25 and 0.5 m2 square vents).. Six pressure gauges were used to measure the overpressure evolution inside and outside the chamber. Six concentration gauges were used to control the hydrogen repartition in the vessel. The hydrogen-air cloud was seeded with micro particles of ammonium chloride to see the propagation of the flame the movement of the cloud inside and outside the chamber. The incidence of reactivity vent size ignition position and non homogenous repartition of hydrogen received a particular attention.
Application of Natural Ventilation Engineering Models to Hydrogen Build Up in Confined Zones
Sep 2013
Publication
Correlative engineering models (Linden 1994) are compared to recent published (Cariteau et al. (2009) Pitts et al. (2009) Barley and Gawlick (2009) Swain et al. (1999) Merilo et al. (2010)) and unpublished (CEA experiments in a 1 m3 with two openings) experimental hydrogen or helium distribution in enclosures (with one and two openings). The modelling-experiments comparison is carried out in transient and in steady state conditions. On this basis recommendations and limits of use of these models are proposed.
Residual Performance of Composite Pressure Vessels Submitted to Mechanical Impacts
Sep 2017
Publication
Type IV pressure vessels are commonly used for hydrogen on-board stationary or bulk storages. During their lifetime they can be submitted to mechanical impacts creating damage within the composite structure not necessarily correlated to what is visible from the outside. When an impact is suspected or when a cylinder is periodically inspected it is necessary to determine whether it can safely stay in service or not. The FCH JU project Hypactor aims at creating a large database of impacts characterized by various non destructive testing (NDT) methods in order to provide reliable pass-fail criteria for damaged cylinders. This paper presents some of the tests results investigating short term burst) and long term (cycling) performance of impacted cylinders and the recommendations that can be made for impact testing and NDT criteria calibration.
Energy Technology Perspectives 2020- Special Report on Carbon Capture Utilisation and Storage
Sep 2020
Publication
Energy Technology Perspectives 2020 is a major new IEA publication focused on the technology needs and opportunities for reaching international climate and sustainable energy goals. This flagship report offers vital analysis and advice on the clean energy technologies the world needs to meet net-zero emissions objectives.
The report’s comprehensive analysis maps out the technologies needed to tackle emissions in all parts of the energy sector including areas where technology progress is still lacking such as long-distance transport and heavy industries. It shows the amount of emissions reductions that are required from electrification hydrogen bioenergy and carbon capture utilisation and storage. It also provides an assessment of emissions from existing infrastructure and what can be done to address them.
Link to Document on IEA website
The report’s comprehensive analysis maps out the technologies needed to tackle emissions in all parts of the energy sector including areas where technology progress is still lacking such as long-distance transport and heavy industries. It shows the amount of emissions reductions that are required from electrification hydrogen bioenergy and carbon capture utilisation and storage. It also provides an assessment of emissions from existing infrastructure and what can be done to address them.
Link to Document on IEA website
Vented Explosion of Hydrogen/Air Mixtures: Influence of Vent Cover and Stratification
Sep 2017
Publication
Explosion venting is a prevention/mitigation solution widely used in the process industry to protect indoor equipment or buildings from excessive internal pressure caused by an accidental explosion. Vented explosions are widely investigated in the literature for various geometries hydrogen/air concentrations ignition positions initial turbulence etc. In real situations the vents are normally covered by a vent panel. In the case of an indoor leakage the hydrogen/air cloud will be stratified rather than homogeneous. Nowadays there is a lack in understanding about the vented explosion of stratified clouds and about the influence of vent cover inertia on the internal overpressure. This paper aims at shedding light on these aspects by means of experimental investigation of vented hydrogen/air deflagration using an experimental facility of 1m3 and via numerical simulations using the computational fluid dynamics (CFD) code FLACS
Adaptation of Hydrogen Transport Models at the Polycrystal Scale and Application to the U-bend Test
Dec 2018
Publication
Hydrogen transport and trapping equations are implemented in a FE software using User Subroutines and the obtained tool is applied to get the diffusion fields in a metallic sheet submitted to a U-Bend test. Based on a submodelling process mechanical and diffusion fields have been computed at the polycrystal scale from which statistical evaluation of the risk of failure of the sample has been estimated.
The Role of Critical Minerals in Clean Energy Transitions
May 2021
Publication
Minerals are essential components in many of today’s rapidly growing clean energy technologies – from wind turbines and electricity networks to electric vehicles. Demand for these minerals will grow quickly as clean energy transitions gather pace. This new World Energy Outlook Special Report provides the most comprehensive analysis to date of the complex links between these minerals and the prospects for a secure rapid transformation of the energy sector.
Alongside a wealth of detail on mineral demand prospects under different technology and policy assumptions it examines whether today’s mineral investments can meet the needs of a swiftly changing energy sector. It considers the task ahead to promote responsible and sustainable development of mineral resources and offers vital insights for policy makers including six key IEA recommendations for a new comprehensive approach to mineral security."
Link to International Energy Agency website
Alongside a wealth of detail on mineral demand prospects under different technology and policy assumptions it examines whether today’s mineral investments can meet the needs of a swiftly changing energy sector. It considers the task ahead to promote responsible and sustainable development of mineral resources and offers vital insights for policy makers including six key IEA recommendations for a new comprehensive approach to mineral security."
Link to International Energy Agency website
Static and Dynamic Studies of Hydrogen Adsorption on Nanoporous Carbon Gels
Jun 2019
Publication
Although hydrogen is considered to be one of the most promising green fuels its efficient and safe storage and use still raise several technological challenges. Physisorption in porous materials may offer an attractive means of storage but the state-of-the-art capacity of these kinds of systems is still limited. To overcome the present drawbacks a deeper understanding of the adsorption and surface diffusion mechanism is required along with new types of adsorbents developed and/or optimised for this purpose. In the present study we compare the hydrogen adsorption behaviour of three carbon gels exhibiting different porosity and/or surface chemistry. In addition to standard adsorption characterisation techniques neutron spin-echo spectroscopy (NSE) has been also applied to explore the surface mobility of the adsorbed hydrogen. Our results reveal that both the porosity and surface chemistry of the adsorbent play a significant role in the adsorption of in these systems.
Effects of Hydrogen Addition on Design, Maintenance and Surveillance of Gas Networks
Jul 2021
Publication
Hydrogen when is blended with natural gas over time degrades the materials used for pipe transport. Degradation is dependent on the proportion of hydrogen added to the natural gas. The assessment is made according to hydrogen permeation risk to the integrity of structures adaptation of surveillance and maintenance of equipment. The paper gives a survey of HE and its consequence on the design and maintenance. It is presented in a logical sequence: the design before use; the hydrogen embrittlement (HE) effects on Maximum Allowable Operating Pressure (MAOP); maintenance and surveillance during use of smooth and damaged pipes; and particularly for crack-like defects corrosion defects and dents.
Role of Chemical Kinetics on the Detonation Properties of Hydrogen, Natural Gas & Air Mixtures
Sep 2005
Publication
The first part of the present work is to validate a detailed kinetic mechanism for the oxidation of hydrogen – methane – air mixtures in a detonation waves. A series of experiments on auto-ignition delay times have been performed by shock tube technique coupled with emission spectrometry for H2 / CH4 / O2 mixtures highly diluted in argon. The CH4/H2 ratio was varied from 0 to 4 and the equivalence ratio from 0.4 up to 1. The temperature range was from 1250 K to 2000 K and the pressure behind reflected shock waves was between 0.15 and 1.6 MPa. A correlation was proposed between temperature (K) concentration of chemical species (mol m-3) and ignition delay times. The experimental auto-ignition delay times were compared to the modelled ones using four different mechanisms from the literature: GRI [22] Marinov et al. [23] Hughes et al. [24] Konnov [25]. A large discrepancy was generally found between the different models. The Konnov’s model that predicted auto-ignition delay times close to the measured ones has been selected to calculate the ignition delay time in the detonation waves. The second part of the study concerned the experimental determination of the detonation properties namely the detonation velocity and the cell size. The effect of the initial composition hydrogen to methane ratio and the amount of oxygen in the mixture as well as the initial pressure on the detonation velocity and on the cell size were investigated. The ratio of methane / (methane + hydrogen) varied between 0 and 0.6 for 2 different equivalence ratio (0.75 and 1) while the initial pressure was fixed to 10 kPa. A correlation was established between the characteristic cell size and the ignition delay time behind the leading shock of the detonation. It was clearly showed that methane has an important inhibitor effect on the detonation of these combustible mixtures.
HySafe European Network of Excellence on Hydrogen Safety
Sep 2005
Publication
Introduction and commercialisation of hydrogen as an energy carrier of the future make great demands on all aspects of safety. Safety is a critical issue for innovations as it influences the economic attractiveness and public acceptance of any new idea or product. However research and safety expertise related to hydrogen is quite fragmented in Europe. The vision of a significant increased use of hydrogen as an energy carrier in Europe could not go ahead without strengthening and merging this expertise. This was the reason for the European Commission to support the launch on the first of March 2004 of a so-called Network of Excellence (NoE) on hydrogen safety: HySafe.
On Numerical Simulation of Liquefied and Gaseous Hydrogen Releases at Large Scales
Sep 2005
Publication
The large eddy simulation (LES) model developed at the University of Ulster has been applied to simulate releases of 5.11 m3 liquefied hydrogen (LH2) in open atmosphere and gaseous hydrogen (GH2) in 20-m3 closed vessel. The simulations of a spill of liquefied hydrogen confirmed the advantage of LES application to reproduce experimentally observed eddy structure of hydrogen-air cloud. The inclination angle of simulated cloud is close to experimentally reported 300. The processes of two phase hydrogen release and heat transfer were simplified by inflow of gaseous hydrogen with temperature 20 K equal to boiling point. It is shown that difference in inflow conditions geometry and grid resolution affects simulation results. It is suggested that phenomenon of air condensationevaporation in the cloud in temperature range 20-90 K should be accounted for in future. The simulations reproduced well experimental data on GH2 release and transport in 20-m3 vessel during 250 min including a phenomenon of hydrogen concentration growth at the bottom of the vessel. Higher experimental hydrogen concentration at the bottom is assumed to be due to non-uniformity of temperature of vessel walls generating additional convection. The comparison of convective and diffusion terms in Navie-Stokes equations has revealed that a value of convective term is more than order of magnitude prevail over a value of turbulent diffusion term. It is assumed that the hydrogen transport to the bottom of the vessel is driven by the remaining chaotic flow velocities superimposed on stratified hydrogen concentration field. Further experiments and simulations with higher accuracy have to be performed to confirm this phenomenon. It has been demonstrated that hydrogen-air mixture became stratified in about 1 min after release was completed. However one-dimensional models are seen not capable to reproduce slow transport of hydrogen during long period of time characteristic for scenarios such as leakage in a garage.
Massive H2 Production With Nuclear Heating, Safety Approach For Coupling A VHTR With An Iodine Sulfur Process Cycle
Sep 2005
Publication
In the frame of a sustainable development investigations dealing with massive Hydrogen production by means of nuclear heating are carried out at CEA. For nuclear safety thermodynamic efficiency and waste minimization purposes the technological solution privileged is the coupling of a gas cooled Very High Temperature Reactor (VHTR) with a plant producing Hydrogen from an Iodine/Sulfur (I/S) thermochemical cycle. Each of the aforementioned facilities presents different risks resulting from the operation of a nuclear reactor (VHTR) and from a chemical plant including Hydrogen other flammable and/or explosible substances as well as toxic ones. Due to these various risks the safety approach is an important concern. Therefore this paper deals with the preliminary CEA investigations on the safety issues devoted to the whole plant focusing on the safety questions related to the coupling between the nuclear reactor and the Hydrogen production facility. Actually the H2 production process and the energy distribution network between the plants are currently at a preliminary design stage. A general safety approach is proposed based on a Defence In Depth (DID) principle permitting to analyze all the system configurations successively in normal incidental and accidental expected operating conditions. More precisely the dynamic answer of an installation to a perturbation affecting the other one during the previous conditions as well as the potential aggressions of the chemical plant towards the nuclear reactor have to be considered. The methodology presented in this paper is intended to help the designer to take into account the coupling safety constraints and to provide some recommendations on the global architecture of both plants especially on their coupling system. As a result the design of a VHTR combined to a H2 production process will require an iterative process between design and safety requirements.
Compatibility of Metallic Materials with Hydrogen Review of the Present Knowledge
Sep 2007
Publication
In this document after a review of the accidents/incidents are described the different interactions between hydrogen gas and the most commonly used materials including the influence of "internal" and "external" hydrogen the phenomena occurring in all ranges of temperatures and pressures and Hydrogen Embrittlement (HE) created by gaseous hydrogen. The principle of all the test methods used to investigate this phenomenon are presented and discussed. The advantages and disadvantages of each method will be explained. The document also covers the influence of all the parameters related to HE including the ones related to the material itself the ones related to the design and manufacture of the equipment and the ones related to the hydrogen itself (pressure temperature purity etc). Finally recommendations to avoid repetition of accidents/incidents mentioned before are proposed.
Assessing the Durability and Integrity of Natural Gas Infrastructures for Transporting and Distributing Mixtures of Hydrogen and Natural Gas
Sep 2005
Publication
Extensive infrastructure exists for the transport of natural gas and it is an obvious step to assess its use for the movement of hydrogen. The Naturalhy project’s objective is to prepare the European natural gas industry for the introduction of hydrogen by assessing the capability of the natural gas infrastructure to accept mixtures of hydrogen and natural gas. This paper presents the ongoing work within both Durability and Integrity Work Packages of the Naturalhy project. This work covers a gap in knowledge on risk assessment required for delivering H2+natural gas blends by means of the existing natural gas grids in safe operation.<br/>Experiments involving several parts of the existing infrastructure will be described that are being carried out to re-examine the major risks previously studied for natural gas including: effect of H2 on failure behaviour and corrosion of transmission pipes and their burst resistance (link to the Work Package Safety) on permeability and ageing of distribution pipes on reliability and ageing of domestic gas meters tightness to H2 of domestic appliances and their connexions. The information will be integrated into existing Durability assessment methodologies originally developed for natural gas.<br/>An Integrity Management Tool will be developed taking account of the effect of hydrogen on the materials properties. The tool should enable a cost effective selection of appropriate measures to control the structural integrity and maintaining equipment. The main measures considered are monitoring non destructive examination (pigging and non pigging) and repair strategies. The tool will cover a number of parameters e.g.: percentage of hydrogen in the gas mixture material of construction operating conditions and condition of cathodic protection. Thus the Integrity Management Tool will yield an inspection and maintenance plan based on the specific circumstances.
Interaction of Hydrogen with the Bulk, Surface and Subsurface of Crystalline RuO2 from First Principles
Feb 2021
Publication
Hydrogen and its interaction with metal oxide surfaces is of major importance for a wide range of research and applied fields spanning from catalysis energy storage microelectronics to metallurgy. This paper reviews state of the art of first principles calculations on the well-known ruthenium oxide (RuO2) surface in its (110) orientation and its interaction with hydrogen. In addition to it the paper also fills gaps in knowledge with new calculations and results on the (001) surface. Bulk and surface interactions are thoroughly reviewed. This includes systematic analysis of adsorption sites local agglomeration propensity of hydrogen and migration pathways in which literature data and their potential deviations are explained. We notably discuss novel results on propensity for agglomeration of hydrogen within bulk channels [001] oriented in which the proton-like behavior of adsorbed hydrogen hinders further agglomeration in adjacent channels. The paper brings new insights into the migration pathways on the surface and in bulk both exhibiting preferential diffusion paths along the [001] direction. The paper finally investigates the subsurface region. We show that while the subsurface has more stable sites for adsorption compared to bulk its accessibility from the surface shows prohibitive activation barriers inhibiting penetration into subsurface and bulk. We further calculate and discuss adsorption and penetration processes on the alternative RuO2 (001) surface.
Combined Cooling and Power Management Strategy for a Standalone House Using Hydrogen and Solar Energy
May 2021
Publication
Tropical climate is characterized by hot temperatures throughout the year. In areas subject to this climate air conditioning represents an important share of total energy consumption. In some tropical islands there is no electric grid; in these cases electricity is often provided by diesel generators. In this study in order to decarbonize electricity and cooling production and to improve autonomy in a standalone application a microgrid producing combined cooling and electrical power was proposed. The presented system was composed of photovoltaic panels a battery an electrolyzer a hydrogen tank a fuel cell power converters a heat pump electrical loads and an adsorption cooling system. Electricity production and storage were provided by photovoltaic panels and a hydrogen storage system respectively while cooling production and storage were achieved using a heat pump and an adsorption cooling system respectively. The standalone application presented was a single house located in Tahiti French Polynesia. In this paper the system as a whole is presented. Then the interaction between each element is described and a model of the system is presented. Thirdly the energy and power management required in order to meet electrical and thermal needs are presented. Then the results of the control strategy are presented. The results showed that the adsorption cooling system provided 53% of the cooling demand. The use of the adsorption cooling system reduced the needed photovoltaic panel area the use of the electrolyzer and the use of the fuel cell by more than 60% and reduced energy losses by 7% (compared to a classic heat pump) for air conditioning.
Hydrogen Fuel Cell Road Vehicles: State of the Art and Perspectives
Nov 2020
Publication
Driven by a small number of niche markets and several decades of application research fuel cell systems (FCS) are gradually reaching maturity to the point where many players are questioning the interest and intensity of its deployment in the transport sector in general. This article aims to shed light on this debate from the road transport perspective. It focuses on the description of the fuel cell vehicle (FCV) in order to understand its assets limitations and current paths of progress. These vehicles are basically hybrid systems combining a fuel cell and a lithium-ion battery and different architectures are emerging among manufacturers who adopt very different levels of hybridization. The main opportunity of Fuel Cell Vehicles is clearly their design versatility based on the decoupling of the choice of the number of Fuel Cell modules and hydrogen tanks. This enables manufacturers to meet various specifications using standard products. Upcoming developments will be in line with the crucial advantage of Fuel Cell Vehicles: intensive use in terms of driving range and load capacity. Over the next few decades long-distance heavy-duty vehicles and fleets of taxis or delivery vehicles will develop based on range extender or mild hybrid architectures and enable the hydrogen sector to mature the technology from niche markets to a large-scale market.
Hydrogen Recovery from Waste Gas Streams to Feed (High-Temperature PEM) Fuel Cells: Environmental Performance under a Life-Cycle Thinking Approach
Oct 2020
Publication
Fossil fuels are being progressively substituted by a cleaner and more environmentally friendly form of energy where hydrogen fuel cells stand out. However the implementation of a competitive hydrogen economy still presents several challenges related to economic costs required infrastructures and environmental performance. In this context the objective of this work is to determine the environmental performance of the recovery of hydrogen from industrial waste gas streams to feed high-temperature proton exchange membrane fuel cells for stationary applications. The life-cycle assessment (LCA) analyzed alternative scenarios with different process configurations considering as functional unit 1 kg of hydrogen produced 1 kWh of energy obtained and 1 kg of inlet flow. The results make the recovery of hydrogen from waste streams environmentally preferable over alternative processes like methane reforming or coal gasification. The production of the fuel cell device resulted in high contributions in the abiotic depletion potential and acidification potential mainly due to the presence of platinum metal in the anode and cathode. The design and operation conditions that defined a more favorable scenario are the availability of a pressurized waste gas stream the use of photovoltaic electricity and the implementation of an energy recovery system for the residual methane stream.
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