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Investigation of Hydrogen Embrittlement Susceptibility and Fracture Toughness Drop after in situ Hydrogen Cathodic Charging for an X65 Pipeline Steel
Apr 2020
Publication
The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader category of High Strength Low Alloy Steels (HSLA) and its microstructure consists of equiaxed ferritic and bainitic grains with a low volume fraction of degenerated pearlite islands. The studied X65 steel specimens were extracted from pipes with 19.15 mm wall thickness. The fracture toughness parameters were determined after imposing the fatigue pre-cracked specimens on air on a specific electrolytic cell under a slow strain rate bending loading (according to ASTM G147-98 BS7448 and ISO12135 standards). Concerning the results of this study in the first phase the hydrogen cations’ penetration depth the diffusion coefficient of molecular and atomic hydrogen and the surficial density of blisters were determined. Next the characteristic parameters related to fracture toughness (such as J KQ CTODel CTODpl) were calculated by the aid of the Force-Crack Mouth Open Displacement curves and the relevant analytical equations.
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.
World Energy Issues Monitor 2021: Humanising Energy
Mar 2021
Publication
Based on data collection carried out between October and December 2020 and the testing of emerging findings with the Council’s regional communities during a series of digital workshops held during February 2021 the report has shown
- Energy leaders’ perceptions of areas of risk opportunity and priorities for action have radically changed over the last 12 months. While economic turbulence stemming from the ongoing reverberations of COVID-19 is the biggest area of uncertainty with uncertainty around economic trends increasing by a third over the previous year there is also a growing focus on the social agenda associated with a faster paced energy transition.
- There is an increased awareness of the societal and human impact of both recovery and the wider energy transition. The issue of energy affordability has rapidly risen up the industry’s priority list with its impact and uncertainty perceived 20% larger than a year ago. Energy affordability affects society across all geographies ranging from city dwellers in developed countries to the rural poor in developing ones.
- The emergence of a new generation of digital energy services and energy entrepreneurs. Increasingly agile disruptive technologies have taken advantage of the social upheaval to gain market share at the expense of supply-centric energy solutions. There is a growing focus on customer-centric demand-driven solutions and fast changing patterns of global and local demand.
Pd Catalysts Supported on Bamboo-Like Nitrogen-Doped Carbon Nanotubes for Hydrogen Production
Mar 2021
Publication
Bamboo-like nitrogen-doped carbon nanotubes (N-CNTs) were used to synthesize supported palladium catalysts (0.2–2 wt.%) for hydrogen production via gas phase formic acid decomposition. The beneficial role of nitrogen centers of N-CNTs in the formation of active isolated palladium ions and dispersed palladium nanoparticles was demonstrated. It was shown that although the surface layers of N-CNTs are enriched with graphitic nitrogen palladium first interacts with accessible pyridinic centers of N-CNTs to form stable isolated palladium ions. The activity of Pd/N-CNTs catalysts is determined by the ionic capacity of N-CNTs and dispersion of metallic nanoparticles stabilized on the nitrogen centers. The maximum activity was observed for the 0.2% Pd/N-CNTs catalyst consisting of isolated palladium ions. A ten-fold increase in the concentration of supported palladium increased the contribution of metallic nanoparticles with a mean size of 1.3 nm and decreased the reaction rate by only a factor of 1.4.
Design of Experiment to Predict the Time Between Hydrogen Purges for an Air-breathing PEM Fuel Cell in Dead-end Mode in a Closed Environment
Feb 2021
Publication
Fuel cells are promising technologies for zero-emission energy conversion. They are used in several applications such as power plants cars and even submarines. Hydrogen supply is crucial for such systems and using Proton Exchange Membrane Fuel Cell in dead-end mode is a solution to save hydrogen. Since water and impurities accumulate inside the stack purging is necessary. However the importance of operating parameters is not well known for fuel cells working in closed environments. A Design of Experiment approach studying time between two purges and cell performance was conducted on an air-breathing stack in a closed environment. The most influential parameters on the time between two purges are the relative humidity and the current load. Convection in the closed environment can decrease the stability of the fuel cell. A linear model with interactions between these last three parameters was found to accurately describe the studied responses.
Global Energy Transformation: A Roadmap to 2050
Apr 2019
Publication
Dolf Gielen,
Ricardo Gorini,
Nicholas Wagner,
Rodrigo Leme,
Laura Gutierrez,
Gayathri Prakash,
Elisa Asmelash,
Luis Janeiro,
Giacomo Gallina,
Guilia Vale,
Lorenzo Sani,
Xavier Garcia Casals,
Rabia Ferroukhi,
Bishal Parajuli,
Jinlei Feng,
Eva Alexandri,
Unnada Chewpreecha,
Mary Goldman,
Sophie Heald,
Jon Stenning,
Hector Pollitt,
Celia García-Baños and
Michael Renner
Increased use of renewable energy combined with intensified electrification could prove decisive for the world to meet key climate goals by 2050. This study from the International Renewable Energy Agency (IRENA) highlights immediately deployable cost-effective options for countries to fulfil climate commitments and limit the rise of global temperatures. The envisaged energy transformation would also reduce net costs and bring significant socio-economic benefits such as increased economic growth job creation and overall welfare gains.<br/>The report – the second under the Global Energy Transformation banner – expands IRENA’s comprehensive roadmap which examines technology pathways and policy implications to ensure a sustainable energy future. Ramping up electricity to over half of the global energy mix (up from one-fifth currently) in combination with renewables would reduce the use of fossil fuels responsible for most greenhouse-gas emissions.
The Influence of Refractory Metals on the Hydrogen Storage Characteristics of FeTi-based Alloys Prepared by Suspended Droplet Alloying
Jun 2020
Publication
The influence of the addition of refractory metals (molybdenum and tantalum) on the hydrogenation properties of FeTi intermetallic phase-based alloys was investigated. The suspended droplet alloying technique was applied to fabricate FeTiTa-based and FeTiMo-based alloys. The phase composition and hydrogen storage properties of the samples were investigated. The samples modified with the refractory metals exhibited lower plateau pressures and lower hydrogen storage capacities than those of the FeTi reference sample due to solid solution formation. It was observed that the equilibrium pressures decreased with the amount of molybdenum which is in good agreement with the increase in the cell parameters of the TiFe phase. Suspended droplet alloying was found to be a practical method to fabricate alloys with refractory metal additions; however it is appropriate for screening samples with desired chemical and phase compositions rather than for manufacturing purposes.
Study on Hydrogen from Renewable Resources in the EU
Feb 2016
Publication
Hydrogen can be produced from a broad range of renewable energy sources acting as a unique energy hub providing low or zero emission energy to all energy consuming sectors. Technically and efficiently producing hydrogen from renewable sources is a key enabler for these developments.<br/>Traditionally hydrogen has been produced from fossil sources by steam methane reforming of natural gas. At present the technology of choice to produce renewable ‘green’ hydrogen is water electrolysis using renewable electricity. The FCH JU has been supporting research and development of electrolyser technology and application projects aiming to increase the energy efficiency of electrolytic hydrogen production from renewable sources and to reduce costs.<br/>This study complements these activities by focusing on renewable hydrogen generation other than electrolysis. In this report these alternative hydrogen generation technologies are described characterized by their technical capabilities maturity and economic performance and assessed for their future potential.<br/>A methodology has been devised to first identify and structure a set of relevant green hydrogen pathways (eleven pathways depicted in the figure below) analyse them at a level of detail allowing a selection of those technologies which fit into and promise early commercialization in the framework of FCH 2 JU’s funding program.<br/>These originally proposed eleven pathways use solar thermal energy sunlight or biomass as major energy input.
Potential for Hydrogen Production from Sustainable Biomass with Carbon Capture and Storage
Jan 2022
Publication
Low-carbon hydrogen is an essential element in the transition to net-zero emissions by 2050. Hydrogen production from biomass is a promising bio-energy with carbon capture and storage (BECCS) scheme that could produce low-carbon hydrogen and generate the carbon dioxide removal (CDR) envisioned to be required to offset hard-to-abate emissions. Here we design a BECCS supply chain for hydrogen production from biomass with carbon capture and storage and quantify at high spatial resolution the technical potential for hydrogen production and CDR in Europe. We consider sustainable biomass feedstocks that have minimal impacts on food security and biodiversity namely agricultural residues and waste. We find that this BECCS supply chain can produce up to 12.5 Mtons of H2 per year (currently ~10 Mtons of H2 per year are used in Europe) and remove up to 133 Mtons CO2 per year from the atmosphere (or 3% of European total greenhouse gas emissions). We then perform a geospatial analysis to quantify transportation distances between where biomass feedstocks are located and potential hydrogen users and find that 20% of hydrogen potential is located within 25 km from hard-toelectrify industries. We conclude that BECCS supply chains for hydrogen production from biomass represent an overlooked near-term opportunity to generate carbon dioxide removal and low-carbon hydrogen.
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.
Durability of Anion Exchange Membrane Water Electrolyzers
Apr 2021
Publication
Interest in the low-cost production of clean hydrogen is growing. Anion exchange membrane water electrolyzers (AEMWEs) are considered one of the most promising sustainable hydrogen production technologies because of their ability to split water using platinum group metal-free catalysts less expensive anode flow fields and bipolar plates. Critical to the realization of AEMWEs is understanding the durability-limiting factors that restrict the long-term use of these devices. This article presents both durability-limiting factors and mitigation strategies for AEMWEs under three operation modes i.e. pure water-fed (no liquid electrolyte) concentrated KOH-fed and 1 wt% K2CO3-fed operating at a differential pressure of 100 psi. We examine extended-term behaviors of AEMWEs at the single-cell level and connect their behavior with the electrochemical chemical and mechanical instability of single-cell components. Finally we discuss the pros and cons of AEMWEs under these operation modes and provide direction for long-lasting AEMWEs with highly efficient hydrogen production capabilities.
Seasonal and Multi-Seasonal Energy Storage by Power-to-Methane Technology
Jun 2021
Publication
The time-range of applicability of various energy-storage technologies are limited by self-discharge and other inevitable losses. While batteries and hydrogen are useful for storage in a time-span ranging from hours to several days or even weeks for seasonal or multi-seasonal storage only some traditional and quite costly methods can be used (like pumped-storage plants Compressed Air Energy Storage or energy tower). In this paper we aim to show that while the efficiency of energy recovery of Power-to-Methane technology is lower than for several other methods due to the low self-discharge and negligible standby losses it can be a suitable and cost-effective solution for seasonal and multi-seasonal energy storage.
Hydrogen Explosion Hazards Limitation in Battery Rooms with Different Ventilation Systems
Sep 2019
Publication
When charging most types of industrial lead-acid batteries hydrogen gas is emitted. A large number of batteries especially in relatively small areas/enclosures and in the absence of an adequate ventilation system may create an explosion hazard. This paper describes full scale tests in confined space which demonstrate conditions that can occur in a battery room in the event of a ventilation system breakdown. Over the course of the tests full scale hydrogen emission experiments were performed to study emission time and flammable cloud formation according to the assumed emission velocity. On this basis the characteristics of dispersion of hydrogen in the battery room were obtained. The CFD model Fire Dynamic Simulator (NIST) was used for confirmation that the lack of ventilation in a battery room can be the cause of an explosive atmosphere developing and leading to a potential huge explosive hazard. It was demonstrated that different ventilation systems provide battery rooms with varying efficiencies of hydrogen removal. The most effective type appeared to be natural ventilation which proved more effective than mechanical means.
Future Cost and Performance of Water Electrolysis: An Expert Elicitation Study
Nov 2017
Publication
The need for energy storage to balance intermittent and inflexible electricity supply with demand is driving interest in conversion of renewable electricity via electrolysis into a storable gas. But high capital cost and uncertainty regarding future cost and performance improvements are barriers to investment in water electrolysis. Expert elicitations can support decision-making when data are sparse and their future development uncertain. Therefore this study presents expert views on future capital cost lifetime and efficiency for three electrolysis technologies: alkaline (AEC) proton exchange membrane (PEMEC) and solid oxide electrolysis cell (SOEC). Experts estimate that increased R&D funding can reduce capital costs by 0–24% while production scale-up alone has an impact of 17–30%. System lifetimes may converge at around 60000–90000 h and efficiency improvements will be negligible. In addition to innovations on the cell-level experts highlight improved production methods to automate manufacturing and produce higher quality components. Research into SOECs with lower electrode polarisation resistance or zero-gap AECs could undermine the projected dominance of PEMEC systems. This study thereby reduces barriers to investment in water electrolysis and shows how expert elicitations can help guide near-term investment policy and research efforts to support the development of electrolysis for low-carbon energy systems.
Role of Hydrogen in a Low-Carbon Electric Power System: A Case Study
Jan 2021
Publication
The European Union set a 2050 decarbonization target in the Paris Agreement to reduce carbon emissions by 90–95% relative to 1990 emission levels. The path toward achieving those deep decarbonization targets can take various shapes but will surely include a portfolio of economy-wide low-carbon energy technologies/options. The growth of the intermittent renewable power sources in the grid mix has helped reduce the carbon footprint of the electric power sector. Under the need for decarbonizing the electric power sector we simulated a low-carbon power system. We investigated the role of hydrogen for future electric power systems under current cost projections. The model optimizes the power generation mix economically for a given carbon constraint. The generation mix consists of intermittent renewable power sources (solar and wind) and dispatchable gas turbine and combined cycle units fuelled by natural gas with carbon capture and sequestration as well as hydrogen. We created several scenarios with battery storage options pumped hydro hydrogen storage and demand-side response (DSR). The results show that energy storage replaces power generation and pumped hydro entirely replaces battery storage under given conditions. The availability of pumped hydro storage and demand-side response reduced the total cost as well as the combination of solar photovoltaic and pumped hydro storage. Demand-side response reduces relatively costly dispatchable power generation reduces annual power generation halves the shadow carbon price and is a viable alternative to energy storage. The carbon constrain defines the generation mix and initializes the integration of hydrogen (H2). Although the model rates power to gas with hydrogen as not economically viable in this power system under the given conditions and assumptions hydrogen is important for hard-to-abate sectors and enables sector coupling in a real energy system. This study discusses the potential for hydrogen beyond this model approach and shows the differences between cost optimization models and real-world feasibility.
Transport Energy Air Pollution Model
May 2019
Publication
The transport sector remains at the centre of any debates around energy conservation exaggerated by the stubborn and overwhelming reliance on fossil fuels by its motorised forms whether passenger and freight road rail sea and air.<br/>The very slow transition to alternative fuel sources to date has resulted in this sector being increasingly and convincingly held responsible for the likely failure of individual countries including the UK to meet their obligations under consecutive international climate change agreements.<br/>Electrification of transport is largely expected to take us down the path to a ‘zero carbon future’ (CCC 2019; DfT 2018). But there are serious concerns about future technology performance availability costs and uptake by consumers and businesses. There are also concerns about the increasing gap between lab and ‘real world’ performance of energy use carbon and air pollution emissions. Recently the role of consumer ‘lifestyles’ has increased in prominence (e.g. IPCC 2018) but as yet has not been taken seriously by the DfT BEIS or even the CCC (2019).
The Effect of Graphite Size on Hydrogen Absorption and Tensile Properties of Ferritic Ductile Cast Iron
Jun 2019
Publication
Ductile cast iron (DCI) is one of prospective materials used for the hydrogen equipment because of low-cost good workability and formability. The wide range of mechanical properties of DCI is obtained by controlling microstructural factors such as graphite size volume fraction of graphite matrix structure and so on. Therefore it is important to find out an optimal microstructural condition that is less susceptible to hydrogen embrittlement. In this study the effects of graphite size on the hydrogen absorption capability and the hydrogen-induced ductility loss of ferritic DCI were investigated.<br/>Several kinds of ferritic DCIs with a different graphite diameter of about 10 µm - 30 µm were used for the tensile test and the hydrogen content measurement. Hydrogen charging was performed prior to the tensile test by exposing a specimen to high-pressure hydrogen gas. Then the tensile test was performed in air at room temperature. The hydrogen content of a specimen was measured by a thermal desorption analyzer.<br/>It was found that the amount of hydrogen stored in DCI was dependent on the graphite size. As the graphite diameter increased the hydrogen content sharply increased at a certain graphite diameter and then it became nearly constant irrespective of increase in graphite diameter. In other words there was the critical graphite diameter that significantly changed the hydrogen absorption capability. The ductility was decreased by hydrogen and the hydrogen-induced ductility loss was dependent on the hydrogen content. Therefore the hydrogen embrittlement of DCI became remarkable when the graphite size was larger than the critical value.
Fuel Cell Codes and Standards Resource
Jan 2021
Publication
Although hydrogen has been used in industry for decades its use as a fuel for vehicles or stationary power generation in consumer environments is relatively new. As such hydrogen and fuel cell codes and standards are in various stages of development. Industry manufacturers the government and other safety experts are working with codes and standards development organizations to prepare review and promulgate technically-sound codes and standards for hydrogen and fuel cell technologies and systems.
Codes and standards are being adopted revised or developed for vehicles; fuel delivery and storage; fueling service and parking facilities; and vehicle fueling interfaces. Codes and standards are also being adopted revised or developed for stationary and portable fuel cells and interfaces as well as hydrogen generators. A list of current of international codes and standards is available on the Fuel Cells Codes and Standards Resource.
Link to website
Codes and standards are being adopted revised or developed for vehicles; fuel delivery and storage; fueling service and parking facilities; and vehicle fueling interfaces. Codes and standards are also being adopted revised or developed for stationary and portable fuel cells and interfaces as well as hydrogen generators. A list of current of international codes and standards is available on the Fuel Cells Codes and Standards Resource.
Link to website
Potential Economic Impacts of the HyNet North West Project
Jan 2018
Publication
The objective of the analysis is to provide a robust assessment of the economic impact of HyNet NW over the period to 2050 across both the North West of England and the UK as a whole. Impact is assessed through modelling of direct indirect and induced effect frameworks:
Consideration is also given to the potential impacts of inward investment attracted to the North West/UK in the wake of the Project.
- Direct effects – activities that directly accrue due to the construction and operation of the facilities;
- Indirect effects – the purchase of goods and services to facilitate construction/operation; and
- Induced effects – spending of wages and salaries generated directly and indirectly through construction and operation.
Consideration is also given to the potential impacts of inward investment attracted to the North West/UK in the wake of the Project.
Synthesis and Characterisation of Platinum-cobalt-manganese Ternary Alloy Catalysts Supported on Carbon Nanofibers: An Alternative Catalyst for Hydrogen Evolution Reaction
Mar 2020
Publication
A systematic method for obtaining a novel electrode structure based on PtCoMn ternary alloy catalyst supported on graphitic carbon nanofibers (CNF) for hydrogen evolution reaction (HER) in acidic media is proposed. Ternary alloy nanoparticles (Co0.6Mn0.4 Pt) with a mean crystallite diameter under 10 nm were electrodeposited onto a graphitic support material using a two-step pulsed deposition technique. Initially a surface functionalisation of the carbon nanofibers is performed with the aid of oxygen plasma. Subsequently a short galvanostatic pulse electrodeposition technique is applied. It has been demonstrated that if pulsing current is employed compositionally controlled PtCoMn catalysts can be achieved. Variations of metal concentration ratios in the electrolyte and main deposition parameters such as current density and pulse shape led to electrodes with relevant catalytic activity towards HER. The samples were further characterised using several physico-chemical methods to reveal their morphology structure chemical and electrochemical properties. X-ray diffraction confirms the PtCoMn alloy formation on the graphitic support and energy dispersive X-ray spectroscopy highlights the presence of the three metallic components from the alloy structure. The preliminary tests regarding the electrocatalytic activity of the developed electrodes display promising results compared to commercial Pt/C catalysts. The PtCoMn/CNF electrode exhibits a decrease in hydrogen evolution overpotential of about 250 mV at 40 mA cm−2 in acidic solution (0.5 M H2SO4) when compared to similar platinum based electrodes (Pt/CNF) and a Tafel slope of around 120 mV dec−1 indicating that HER takes place under the Volmer-Heyrovsky mechanismm
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