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Loss of Integrity of Hydrogen Technologies: A Critical Review
Jul 2020
Publication
Hydrogen is one of the main candidates in replacing fossil fuels in the forthcoming years. However hydrogen technologies must deal with safety aspects due to the specific substance properties. This study aims to provide an overview on the loss of integrity (LOI) of hydrogen equipment which may lead to serious consequences such as fires and explosions. Substantial information regarding the hydrogen lifecycle its properties and safety related aspects has gathered. Furthermore focus has placed on the phenomena responsible for the LOI (e.g. hydrogen embrittlement) and material selection for hydrogen services. Moreover a systematic review on the hydrogen LOI topic has conducted to identify and connect the most relevant and active research group within the topic. In conclusion a significant dearth of knowledge in material behaviour of hydrogen technologies has highlighted. It is thought that is possible to bridge this gap by strengthening the collaborations between scientists from different research fields.
Crack Size Dependency of Shear-mode Fatigue Threshold in Bearing Steel Subjected to Continuous Hydrogen Charging
Jun 2019
Publication
Premature delamination failure characterized by the white structure flaking (WSF) or the white etching crack (WEC) often occurs in rolling element bearings and it deteriorates the durability of bearing substantially. It is known that this failure is caused by shear-mode (Mode II and Mode III) crack growth in conjunction with evolution and invasion of hydrogen into material during operation. To ensure the structural integrity associated with rolling element bearing it is important to clarify the effect of hydrogen on the shear-mode fatigue crack growth behavior near the threshold level.<br/>In our previous study the effect of hydrogen on the shear-mode fatigue crack growth behavior in a bearing steel of JIS SUJ2 was examined near the threshold level. Consequently it was shown that the threshold stress intensity factor (SIF) range for shear-mode fatigue crack growth decreased significantly by action of hydrogen. However the investigation was made only for a crack with a surface length of about 900 mm. To thoroughly understand the critical condition for delamination failure it is important to investigate the crack size dependency of the threshold level for a shear-mode small fatigue crack in the presence of hydrogen. In the present study correspondingly the threshold SIF ranges for a shear-mode crack with different length were additionally measured in the same material by using a novel technique that enables continuous charging of hydrogen in a specimen during long-term fatigue test. Then a clear reduction in crack growth rate and a crack size dependency of the threshold SIF range were observed under the environmental condition of continuous hydrogen charging.
Alternative Marine Fuels: Prospects Based on Multi-criteria Decision Analysis Involving Swedish Stakeholders
May 2019
Publication
There is a need for alternative marine fuels in order to reduce the environmental and climate impacts of shipping in the short and long term. This study assesses the prospects for seven alternative fuels for the shipping sector in 2030 including biofuels by applying a multi-criteria decision analysis approach that is based on the estimated fuel performance and on input from a panel of maritime stakeholders and by considering explicitly the influence of stakeholder preferences. Seven alternative marine fuels—liquefied natural gas (LNG) liquefied biogas (LBG) methanol from natural gas renewable methanol hydrogen for fuel cells produced from (i) natural gas or (ii) electrolysis based on renewable electricity and hydrotreated vegetable oil (HVO)—and heavy fuel oil (HFO) as benchmark are included and ranked by ten performance criteria and their relative importance. The criteria cover economic environmental technical and social aspects. Stakeholder group preferences (i.e. the relative importance groups assign to the criteria) influence the ranking of these options. For ship-owners fuel producers and engine manufacturers economic criteria in particular the fuel price are the most important. These groups rank LNG and HFO the highest followed by fossil methanol and then various biofuels (LBG renewable methanol and HVO). Meanwhile representatives from Swedish government authorities prioritize environmental criteria specifically GHG emissions and social criteria specifically the potential to meet regulations ranking renewable hydrogen the highest followed by renewable methanol and then HVO. Policy initiatives are needed to promote the introduction of renewable marine fuels.
Transitioning to Hydrogen
Jan 2020
Publication
The UK is investigating supplying hydrogen to homes and businesses instead of natural gas by “repurposing” the gas network. It presents a major engineering challenge which has never been done anywhere else in the world.
In a new report titled ‘Transitioning to hydrogen’ experts from a cross-professional engineering institution (PEI) working group including the IET have assessed the engineering risks and uncertainties and concluded there is no reason why repurposing the gas network to hydrogen cannot be achieved. But there are several engineering risks and uncertainties which need to be addressed.
In a new report titled ‘Transitioning to hydrogen’ experts from a cross-professional engineering institution (PEI) working group including the IET have assessed the engineering risks and uncertainties and concluded there is no reason why repurposing the gas network to hydrogen cannot be achieved. But there are several engineering risks and uncertainties which need to be addressed.
A Review of the CFD Modeling of Hydrogen Production in Catalytic Steam Reforming Reactors
Dec 2022
Publication
Global demand for alternative renewable energy sources is increasing due to the consumption of fossil fuels and the increase in greenhouse gas emissions. Hydrogen (H2 ) from biomass gasification is a green energy segment among the alternative options as it is environmentally friendly renewable and sustainable. Accordingly researchers focus on conducting experiments and modeling the reforming reactions in conventional and membrane reactors. The construction of computational fluid dynamics (CFD) models is an essential tool used by researchers to study the performance of reforming and membrane reactors for hydrogen production and the effect of operating parameters on the methane stream improving processes for reforming untreated biogas in a catalyst-fixed bed and membrane reactors. This review article aims to provide a good CFD model overview of recent progress in catalyzing hydrogen production through various reactors sustainable steam reforming systems and carbon dioxide utilization. This article discusses some of the issues challenges and conceivable arrangements to aid the efficient generation of hydrogen from steam reforming catalytic reactions and membrane reactors of bioproducts and fossil fuels.
Analysis of Samples Cleaning Methods Prior to Hydrogen Content Determination in Steel
May 2020
Publication
There are multiple references to sample cleaning methods prior to hydrogen content determination or hydrogen spectroscopy analysis but there is still no unified criteria; different authors use their own “know-how” to perform this task. The aim of this paper is to solve or at least clarify this issue. In this work the most commonly used sample cleaning methods are compared. Then five different methodologies are applied on certified hydrogen content calibration pins and on high strength steel concrete-prestressing strands and the three main situations regarding hydrogen content in the microstructural net (non-charged charged and charged and uncharged) are studied. It was concluded that the HCl solution C-3.5 cleaning method recommended by ASTM G1 introduces large amounts of hydrogen in the samples; but can be useful for eliminating superficial oxides if necessary. The rest of the methods had similar results; but the more complete ones that involve ultrasounds and last longer than 8 min are not appropriated when important diffusion may occur on the samples during their application. Simple methods that involve acetone or trichloroethylene and last around 1 min are preferable for almost all situations as these are faster easier and cheaper. As a final recommendation as trichloroethylene is toxic the simple acetone method is in general the most convenient one for regular hydrogen content analysis.
Power to Gas Linking Electricity and Gas in a Decarbonising World
Oct 2018
Publication
Since the COP 21 meeting in Paris in December 2015 there has been a growing realisation that with the long-term objective that the energy system should be approaching carbon-neutrality by 2050 continuing to burn significant quantities of fossil-derived natural gas will not be sustainable. If existing natural gas infrastructure is to avoid becoming stranded assets plans to decarbonise the gas system need to be developed as a matter of urgency in the next three to five years given the typical life expectancy of such assets of 20 years or more. One of the options to decarbonise gas is “power-to-gas”: production of hydrogen or renewable methane via electrolysis using surplus renewable electricity. This Energy Insight reviews the status of power-to-gas and makes an assessment of potential future development pathways and the role which it could play in decarbonising the energy system.
Link to document on the OIES website
Link to document on the OIES website
Homogeneous Hydrogen Deflagrations in Small Scale Enclosure. Experimental Results
Sep 2017
Publication
University of Pisa performed experimental tests in a 1m3 facility which shape and dimensions resemble a gas cabinet for the HySEA project founded by the Fuel Cells and Hydrogen 2 Joint Undertaking with the aim to conduct pre-normative research on vented deflagrations in real-life enclosures and containers used for hydrogen energy applications in order to generate experimental data of high quality. The test facility named Small Scale Enclosure (SSE) had a vent area of 042m2 which location could be varied namely on the top or in front of the facility while different types of vent were investigated. Three different ignition location were investigated as well and the range of Hydrogen concentration ranged between 10 and 18% vol. This paper is aimed to summarize the main characteristics of the experimental campaign as well as to present its results.
A Fully Renewable and Efficient Backup Power System with a Hydrogen-biodiesel-fueled IC Engine
Jan 2019
Publication
Renewable energy is free abundant clean and could contribute towards a significant reduction of the global warming emissions. It is massively introduced as a source of electricity production across the globe and is expected to become the primary source of energy within the following decades. However despite the naturally replenished energy the supply is not always available. For this reason it is necessary at times of excess energy any surplus quantity to be sufficiently captured stored and later used when a deficit occurs. In this paper an overview of a backup power system operating with a hydrogen-biodiesel dual-fuel internal combustion engine is provided. The system is utilizing the organic chemical hydride method for safe hydrogen storage and transportation. The high energy content of hydrogen stored in the form of an organic hydride under ambient conditions makes it an ideal energy backup medium for large-scale and long-term applications. The research work focusses on the operation and emissions output of the dual-fuel internal combustion engine running on fully renewable fuels and the results are compared with the conventional petroleum-derived diesel engine. Biodiesel-hydrogen operation shows significant benefits in the reduction of carbon and soot emissions but deteriorates the NOx formation compared to the conventional diesel-powered engines. The operation of the engine at high loads can provide high exhaust thermal energy while alternative combustion strategies are necessary to be implemented at low load conditions for the optimum operation of the backup power system.
Fuel Cells and Hydrogen: Joint Undertaking Programme Review 2012 Final Report
Mar 2013
Publication
Initiated in 2011 the 2012 programme review edition covered 71‘live’ projects from the 2008 2009 and 2010 calls for proposals together with some projects from the 2011 call. Total funding for these projects stands at close to € 450 million 50% of which comes from FCH JU financial contributions and 50% of which comes from industry and research in-kind contributions.
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.
Evaluation of Blistered and Cold Deformed ULC Steel with Melt Extraction and Thermal Desorption Spectroscopy
Dec 2019
Publication
Hydrogen characterization techniques like melt extraction and thermal desorption spectroscopy (TDS) are useful tools in order to evaluate and understand the interaction between hydrogen and metals. These two techniques are used here on cold deformed ultra-low carbon (ULC) steel with and without hydrogen induced damage. The material is charged electrochemically in order to induce varying amounts of hydrogen and variable degrees of hydrogen induced damage. The aim of this work is to evaluate to which extent the hydrogen induced damage would manifest itself in melt extraction and TDS measurements.
Hydrogen Europe Podcast: Hydrogen, The First Element: Why Renewable Hydrogen? Why Now?
Mar 2022
Publication
In the first episode of Hydrogen Europe's podcast "Hydrogen the first element" our CEO Jorgo Chatzimarkakis discusses with NEL's CEO and President of Hydrogen Europe Jon Andre Løkke. Starting off on how Jon joined the hydrogen sector the two CEOs investigate the historical moment renewable hydrogen is currently living.
Validation of a 3d Multiphase-multicomponent CFD Model for Accidental Liquid and Gaseous Hydrogen Releases
Sep 2017
Publication
As hydrogen-air mixtures are flammable in a wide range of concentrations and the minimum ignition energy is low compared to hydrocarbon fuels the safe handling of hydrogen is of utmost importance. Additional hazards may arise with the accidental spill of liquid hydrogen. Such a release of LH2 leads to a formation of a cryogenic pool a dynamic vaporization process and consequently a dispersion of gaseous hydrogen into the environment. Several LH2 release experiments as well as modelling approaches address this phenomenology. In contrast to existing approaches a new CFD model capable of simulating liquid and gaseous distribution was developed at Forschungszentrum Jülich. It is validated against existing experiments and yields no substantial lacks in the physical model and reveals a qualitatively consistent prediction. Nevertheless the deviation between experiment and simulation raises questions on the completeness of the database in particular with regard to the boundary conditions and available measurements.
South Korea’s Big Move to Hydrogen Society
Nov 2020
Publication
Extensive energy consumption has become a major concern due to increase of greenhouse gas emissions and global warming. Hence hydrogen has attracted attention as a green fuel with zero carbon emission for green transportation through production of electric vehicles with hydrogen fuel cells. South Korea has launched a hydrogen society policy with the objective of expanding production of hydrogen from renewable energy sources. The hydrogen economy will play a critical role in reducing atmospheric pollution and global arming. However new development of infrastructure for hydrogen refuelling and increasing awareness of the hydrogen economy is required together with reduced prices of hydrogen-driven vehicles that are promising options for a sustainable green hydrogen economy.
The Residual Strength of Automotive Hydrogen Cylinders After Exposure to Flames
Sep 2017
Publication
Fuel cell vehicles and some compressed natural gas vehicles are equipped with carbon fiber reinforced plastic (CFRP) composite cylinders. Each of the cylinders has a pressure relief device designed to detect heat and release the internal gas to prevent the cylinder from bursting in a vehicle fire accident. Yet in some accident situations the fire may be extinguished before the pressure relief device is activated leaving the high-pressure fuel gas inside the fire-damaged cylinder. To handle such a cylinder safely after an accident it is necessary that the cylinder keeps a sufficient post-fire strength against its internal gas pressure but in most cases it is difficult to accurately determine cylinder strength at the accident site. One way of solving this problem is to predetermine the post-fire burst strengths of cylinders by experiments. In this study automotive CFRP cylinders having no pressure relief device were exposed to a fire to the verge of bursting; then after the fire was extinguished the residual burst strengths and the overall physical state of the test cylinders were examined. The results indicated that the test cylinders all recorded a residual burst strength at least twice greater than their internal gas pressure for tested cylinders with new cylinder burst to nominal working pressure in the range 2.67–4.92 above the regulated ratio of 2.25.
Deflagration-to-detonation Transition of H2-CO-Air Mixtures in a Partially Obstructed Channel
Sep 2019
Publication
In this study an explosion channel is used to investigate flame dynamics in homogeneous hydrogencarbon monoxide-air (H2-CO-air) mixtures. The test rig is a small scale 6 m channel at a rectangular cross section of 300x60 mm. Obstacles of a blockage ratio of BR=60% and a spacing of s=300mm are placed in first part of the channel. A 2.05 m long unobstructed part in the rear of the channel allows for investigation of freely propagating flames and detonations. The fuel composition is varied from 100/0 to 50/50 Vol.-% H2/CO mixtures. The overall fuel content ranges from 15 to 40 Vol.-% in air aiming to obtain fast flames and deflagration-to-detonation transition (DDT). Flame speed and dynamic pressure data are evaluated. Results extend data obtained by [1] and can be used for validation of numerical frameworks. Limits for fast flames and DDT in homogeneous H2-CO-air mixtures at the given geometry are presented.
Oxford Energy Podcast – Energy Transition Post-Pandemic in the Gulf: Clean Energy, Sustainability and Hydrogen
Jun 2021
Publication
The COVID-19 pandemic has exacerbated challenges faced by hydrocarbon exporters in the Gulf owing to the global push to transition to cleaner energy sources. In this podcast Manal Shehabi (OIES) discusses with David Ledesma a recent OIES-KFAS workshop held in April 2021 titled “Energy Transition Post-Pandemic in the Gulf States” held with support from the Kuwait Foundation for the Advancement of Sciences (KFAS). They discuss separate but interrelated issues on clean energy economic and climate sustainability and hydrogen. Specially they examine how the global energy transition outlook has changed post-pandemic along with its impacts on Gulf States’ economies and energy transition projects. They explain implications to Gulf states’ sustainability evaluating whether these countries are fiscally sustainable post-pandemic and their urgent need for energy and economic diversification. They focus in on the possibility of the Gulf States’ using hydrogen to diversify both in domestic and export markets evaluating opportunities and challenges for both blue and green hydrogen. A preliminary case study on the economics of hydrogen in Kuwait is highlighted as indication of whether Gulf states can produce green hydrogen competitively. They conclude with policy recommendations to increase economic sustainability and resilience post-pandemic both through the energy transition and responses to it.
The podcast can be found on their website
The podcast can be found on their website
Review of the Durability of Polymer Electrolyte Membrane Fuel Cell in Long-Term Operation: Main Influencing Parameters and Testing Protocols
Jul 2021
Publication
Durability is the most pressing issue preventing the efficient commercialization of polymer electrolyte membrane fuel cell (PEMFC) stationary and transportation applications. A big barrier to overcoming the durability limitations is gaining a better understanding of failure modes for user profiles. In addition durability test protocols for determining the lifetime of PEMFCs are important factors in the development of the technology. These methods are designed to gather enough data about the cell/stack to understand its efficiency and durability without causing it to fail. They also provide some indication of the cell/stack’s age in terms of changes in performance over time. Based on a study of the literature the fundamental factors influencing PEMFC long-term durability and the durability test protocols for both PEMFC stationary and transportation applications were discussed and outlined in depth in this review. This brief analysis should provide engineers and researchers with a fast overview as well as a useful toolbox for investigating PEMFC durability issues.
Ignition of H2-NO2/N2O4 Mixtures Under Volumetric Expansion Conditions
Sep 2019
Publication
The competition between chemical energy release rate and volumetric expansion related to shock wave’s dynamics is of primary importance for a number of situations relevant to explosion safety. While studies have been performed on this topic over the years they have been limited to mixtures with monotonous energy release profile. In the present study the ignition of H2-NO2/N2O4 mixtures which exhibit a single-step or a two-step energy release rate profile depending on the equivalence ratio has been investigated under volumetric expansion conditions. The rate of expansion has been calculated using the Taylor-Sedov solution and accounted for using 0-D numerical simulations with time-dependent specific volume. The results were analyzed in terms of a Damkohler number defined as the ratio of the expansion to ignition times. For mixtures with non-monotonous energy release rate profiles two critical Damkohler numbers can be identified one for each of the steps of energy release. It was also shown that the fluid element which is the most likely to ignite corresponds to the one behind a shock propagating at the Chapman-Jouguet velocity. The thermo-chemical dynamics have been analyzed about the critical conditions using energy release rate per reaction rate of production and sensitivity analyses.
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