- Home
- A-Z Publications
- Publications
Publications
Polymer Electrolyte Membrane Fuel Cell and Hydrogen Station Networks for Automobiles: Status, Technology, and Perspectives
Feb 2021
Publication
The U.S. transportation sector accounts for 37% of total energy consumption. Automobiles are a primary application of polymer electrolyte membrane (PEM) fuel cells which operate under low temperature and high efficiency to reduce fossil fuel consumption and CO2 emissions. Using hydrogen fuel PEM fuel cells can reach a practical efficiency as high as 65% with water as the only byproduct. Almost all the major automakers are involved in fuel cell electric vehicle (FCEV) development. Toyota and Hyundai introduced FCEVs (the Mirai and NEXO respectively) to consumers in recent years with a driving range between 312 and 402 miles and cold-start capacity from -30 °C. About 50 fuel cell electric buses (FCEB) are operating in California and most of them have achieved the durability target i.e. 25000 h in real-world driving conditions. As of September 2020 over 8573 FCEVs have been sold or leased in the U.S. More than 3521 FCEVs and 22 FCEBs have been sold or leased in Japan as of September 2019. An extensive hydrogen station network is required for the successful deployment of FCEVs and FCEBs. The U.S. currently has over 44 hydrogen fuelling stations (HFSs) nearly all located in California. Europe has over 139 HFSs with ~1500 more stations planned by 2025. This review has three primary objectives: 1) to present the current status of FCEV/FCEB commercialization and HFS development; 2) to describe the PEM fuel cell research/development in automobile applications and the significance of HFS networks; and 3) to outline major challenges and opportunities.
Hydrogen Embrittlement of Steel Pipelines During Transients
May 2021
Publication
Blending hydrogen into natural gas pipelines is a recent alternative adopted for hydrogen transportation as a mixture with natural gas. In this paper hydrogen embrittlement of steel pipelines originally designed for natural gas transportation is investigated. Solubility permeation and diffusion phenomena of hydrogen molecules into the crystalline lattice structure of the pipeline material are followed up based on transient evolution of internal pressure applied on the pipeline wall. The transient regime is created through changes of gas demand depending on daily consumptions. As a result the pressure may reach excessive values that lead to the acceleration of hydrogen solubility and its diffusion through the pipeline wall. Furthermore permeation is an important parameter to determine the diffusion amount of hydrogen inside the pipeline wall resulting in the embrittlement of the material. The numerical obtained results have shown that using pipelines designed for natural gas conduction to transport hydrogen is a risky choice. Actually added to overpressure and great fluctuations during transients that may cause fatigue and damage the structure also the latter pressure evolution is likely to induce the diffusion phenomena of hydrogen molecules into the lattice of the structure leading to brittle the pipe material. The numerical simulation reposes on solving partial differential equations describing transient gas flow in pipelines coupled with the diffusion equation for mass transfer. The model is built using the finite elements based software COMSOL Multiphysics considering different cases of pipe material; API X52 (base metal and nutrided) and API X80 steels. Obtained results allowed tracking the evolution with time of hydrogen concentration through the pipeline internal wall based on the pressure variation due to transient gas flow. Such observation permits to estimate the amount of hydrogen diffused in the metal to avoid leakage of this flammable gas. Thus precautions may be taken to prevent explosive risks due to hydrogen embrittlement of steel pipelines among other effects that can lead to alter safe conditions of gas conduction.
Role of batteries and fuel cells in achieving Net Zero- Session 3
Mar 2021
Publication
The House of Lords Science and Technology Committee will hear from officials research funders and leading research consortia about the UK’s strategy for research and development of batteries and fuel cells to help meet the net-zero target.
The Committee will question officials from government departments and research councils about the UK’s increased support for battery development and how the initiatives and funding will evolve. The Committee will compare the support given to fuel cell research and ask how this technology will be developed for applications such as heavy transport. For both technologies it will ask how training will be delivered to provide a skilled workforce.
The Committee will also hear from leaders of research consortia asking them about support for their research sectors and how this compares with countries leading the development of the technologies. The Committee will explore coordination between research into batteries fuel cells and wider strategies such as for hydrogen and whether research for transport can be transferred to applications in other sectors such as power grids and heating.
At 10.00am: Oral evidence
Mr Tony Harper Industrial Strategy Challenge Director Faraday Battery Challenge at UK Research and Innovation (UKRI) at University of Central Lancashire
Dr Lucy Martin Deputy Director of Cross-Council Programmes and lead for Net Zero at University of Central Lancashire
Dr Bob Moran Deputy Director Head of Environment Strategy at University of Central Lancashire
Professor Paul Monks Chief Scientific Adviser at University of Central Lancashire
At 11.00am: Oral evidence
Professor Philip Taylor Director at EPSRC Supergen Energy Networks Hub and Pro-Vice Chancellor for Research and Enterprise at University of Bristol
Professor David Greenwood CEO High Value Manufacturing Catapult at University of Central Lancashire Director Industrial Engagement at University of Central Lancashire and Professor of Advanced Propulsion Systems at University of Warwick
Professor Paul Dodds Professor of Energy Systems at University of Central Lancashire
Possible questions
Parliament TV video of the meeting
This is part three of a three part enquiry.
Part one can be found here and part two can be found here.
The Committee will question officials from government departments and research councils about the UK’s increased support for battery development and how the initiatives and funding will evolve. The Committee will compare the support given to fuel cell research and ask how this technology will be developed for applications such as heavy transport. For both technologies it will ask how training will be delivered to provide a skilled workforce.
The Committee will also hear from leaders of research consortia asking them about support for their research sectors and how this compares with countries leading the development of the technologies. The Committee will explore coordination between research into batteries fuel cells and wider strategies such as for hydrogen and whether research for transport can be transferred to applications in other sectors such as power grids and heating.
At 10.00am: Oral evidence
Mr Tony Harper Industrial Strategy Challenge Director Faraday Battery Challenge at UK Research and Innovation (UKRI) at University of Central Lancashire
Dr Lucy Martin Deputy Director of Cross-Council Programmes and lead for Net Zero at University of Central Lancashire
Dr Bob Moran Deputy Director Head of Environment Strategy at University of Central Lancashire
Professor Paul Monks Chief Scientific Adviser at University of Central Lancashire
At 11.00am: Oral evidence
Professor Philip Taylor Director at EPSRC Supergen Energy Networks Hub and Pro-Vice Chancellor for Research and Enterprise at University of Bristol
Professor David Greenwood CEO High Value Manufacturing Catapult at University of Central Lancashire Director Industrial Engagement at University of Central Lancashire and Professor of Advanced Propulsion Systems at University of Warwick
Professor Paul Dodds Professor of Energy Systems at University of Central Lancashire
Possible questions
- On which aspects of battery and fuel cell research and development is the UK focusing and why?
- How successful have the UK’s new research initiatives been in advancing battery science and application?
- Does battery research receive greater public funding than fuel cell research? If so why?
- What technologies are seen as the most likely options for heavy transport i.e. HGVs buses and trains?
- What is the Government’s strategy for supporting the growth of skilled workers for battery and fuel cell research and development?
- To what extent is battery and fuel cell research and development coordinated in the UK? If so who is responsible for this coordination?
Parliament TV video of the meeting
This is part three of a three part enquiry.
Part one can be found here and part two can be found here.
Hydrogen Embrittlement and Notch Tensile Strength of Pearlitic Steel: A Numerical Approach
Dec 2020
Publication
This paper offers a numerical approach to the problem of hydrogen embrittlement and notch tensile strength of sharply notched specimens of high-strength pearlitic steel supplied in the form of hot rolled bars by using the finite element method in order to determine how the notch depth influences the concentration of hydrogen in the steady-state regime for different loading values. Numerical results show that the point of maximum hydrostatic stress (towards which hydrogen is transported by a mechanism of stress-assisted diffusion) shifts from the notch tip to the inner points of the specimen under increasing load with numerical evidence of an elevated inwards gradient of hydrostatic stress “pumping” hydrogen inside the sample.
Hydrogen Embrittlement in Advanced High Strength Steels and Ultra High Strength Steels: A New Investigation Approach
Dec 2018
Publication
In order to reduce CO2 emissions and fuel consumption and to respect current environmental norms the reduction of vehicles weight is a primary target of the automotive industry. Advanced High Strength Steels (AHSS) and Ultra High Strength Steel (UHSS) which present excellent mechanical properties are consequently increasingly used in vehicle manufacturing. The increased strength to mass ratio compensates the higher cost per kg and AHSS and UHSS are proving to be cost-effective solutions for the body-in-white of mass market products.
In particular aluminized boron steel can be formed in complex shapes with press hardening processes acquiring high strength without distortion and increasing protection from crashes. On the other hand its characteristic martensitic microstructure is sensitive to hydrogen delayed fracture phenomena and at the same time the dew point in the furnace can produce hydrogen consequently to the high temperature reaction between water and aluminum. The high temperature also promotes hydrogen diffusion through the metal lattice under the aluminum-silicon coating thus increasing the diffusible hydrogen content. However after cooling the coating acts as a strong barrier preventing the hydrogen from going out of the microstructure. This increases the probability of delayed fracture. As this failure brings to the rejection of the component during production or even worse to the failure in its operation diffusible hydrogen absorbed in the component needs to be monitored during the production process.
For fast and simple measurements of the response to diffusible hydrogen of aluminized boron steel one of the HELIOS innovative instruments was used HELIOS II. Unlike the Devanathan cell that is based on a double electrochemical cell HELIOS II is based on a single cell coupled with a solid-state sensor. The instrument is able to give an immediate measure of diffusible hydrogen content in sheet steels semi-products or products avoiding time-consuming specimen palladium coating with a guided procedure that requires virtually zero training.
Two examples of diffusible hydrogen analyses are given for Usibor®1500-AS one before hot stamping/ quenching and one after hot stamping suggesting that the increase in the number of dislocations during hot stamping could be the main responsible for the lower apparent diffusivity of hydrogen.
In particular aluminized boron steel can be formed in complex shapes with press hardening processes acquiring high strength without distortion and increasing protection from crashes. On the other hand its characteristic martensitic microstructure is sensitive to hydrogen delayed fracture phenomena and at the same time the dew point in the furnace can produce hydrogen consequently to the high temperature reaction between water and aluminum. The high temperature also promotes hydrogen diffusion through the metal lattice under the aluminum-silicon coating thus increasing the diffusible hydrogen content. However after cooling the coating acts as a strong barrier preventing the hydrogen from going out of the microstructure. This increases the probability of delayed fracture. As this failure brings to the rejection of the component during production or even worse to the failure in its operation diffusible hydrogen absorbed in the component needs to be monitored during the production process.
For fast and simple measurements of the response to diffusible hydrogen of aluminized boron steel one of the HELIOS innovative instruments was used HELIOS II. Unlike the Devanathan cell that is based on a double electrochemical cell HELIOS II is based on a single cell coupled with a solid-state sensor. The instrument is able to give an immediate measure of diffusible hydrogen content in sheet steels semi-products or products avoiding time-consuming specimen palladium coating with a guided procedure that requires virtually zero training.
Two examples of diffusible hydrogen analyses are given for Usibor®1500-AS one before hot stamping/ quenching and one after hot stamping suggesting that the increase in the number of dislocations during hot stamping could be the main responsible for the lower apparent diffusivity of hydrogen.
Renewable Hydrogen Production from the Organic Fraction of Municipal Solid Waste through a Novel Carbon-negative Process Concept
Apr 2022
Publication
Bioenergy with carbon capture and storage (BECCS) is one of the prevailing negative carbon emission technologies. Ensuring a hydrogen economy is essential to achieving the carbon-neutral goal. In this regard the present study contributed by proposing a carbon negative process for producing high purity hydrogen from the organic fraction of municipal solid waste (OFMSW). This integrated process comprises anaerobic digestion pyrolysis catalytic reforming water-gas shift and pressure swing adsorption technologies. By focusing on Sweden the proposed process was developed and evaluated through sensitivity analysis mass and energy balance calculations techno-economic assessment and practical feasibility analysis. By employing the optimum operating conditions from the sensitivity analysis 72.2 kg H2 and 701.47 kg negative CO2 equivalent emissions were obtained by treating 1 ton of dry OFMSW. To achieve these results 6621.4 MJ electricity and 325 kg of steam were utilized during this process. Based on this techno-economic assessment of implementing the proposed process in Stockholm when the negative CO2 equivalent emissions are recognized as income the internal rate of return and the discounted payback period can be obtained as 26% and 4.3 years respectively. Otherwise these values will be 13% and 7.2 years.
Study of the Effects of Changes in Gas Composition as Well as Ambient and Gas Temperature on Errors of Indications of Thermal Gas Meters
Oct 2020
Publication
Thermal gas meters represent a promising technology for billing customers for gaseous fuels however it is essential to ensure that measurement accuracy is maintained in the long term and in a broad range of operating conditions. The effect of hydrogen addition to natural gas will change the physicochemical properties of the mixture of natural gas and hydrogen. Such a mixture will be supplied through the gas system to consumers including households where the amounts of received gas will be metered. The physicochemical properties of hydrogen including the specific density or viscosity differ significantly from those of the natural gas components such as methane ethane propane nitrogen etc. Therefore it is of utmost importance to establish the impact of the changes in the gas composition caused by the addition of hydrogen to natural gas on the metrological properties of household gas meters including thermal gas meters. Furthermore since household gas meters can be installed outdoors and taking into account the fact that household gas meters are good heat exchangers the influence of ambient and gas temperature on the metrological properties of those meters should be investigated. This article reviews a test bench and a testing method concerning errors of thermal gas meter indicators using air and natural gas including the type containing hydrogen. The indication errors for thermal gas meters using air natural gas and natural gas with an addition of 2% 4% 5% 10% and 15% hydrogen were determined and then subjected to metrological analysis. Moreover the test method and test bench are discussed and the results of tests on the impact of ambient and gas temperatures (-25 ◦C and 55 ◦C respectively) on the errors of indications of thermal gas meters are presented. Conclusions for distribution system operators in terms of gas meter selection were drawn based on the test results.
New Integrated Process for the Efficient Production of Methanol, Electrical Power, and Heating
Jan 2022
Publication
In this paper a novel process is developed to cogenerate 4741 kg/h of methanol 297.7 kW of electricity and 35.73 ton/h of hot water including a hydrogen purification system an absorption– compression refrigeration cycle (ACRC) a regenerative Organic Rankine Cycle (ORC) and parabolic solar troughs. The heat produced in the methanol reactor is recovered in the ORC and ACRC. Parabolic solar troughs provide thermal power to the methanol distillation tower. Thermal efficiencies of the integrated structure and the liquid methanol production cycle are 78.14% and 60.91% respectively. The process’s total exergy efficiency and irreversibility are 89.45% and 16.89 MW. The solar thermal collectors take the largest share of exergy destruction (34%) followed by heat exchangers (30%) and mixers (19%). Based on the sensitivity analysis D17 (mixture of H2 and low-pressure fuel gas before separation) was the most influential stream affecting the performance of the process. With the temperature decline of stream D17 from −139 to −149 °C the methanol production rate and the total thermal efficiency rose to 4741.2 kg/h and 61.02% respectively. Moreover the growth in the hydrogen content from 55% to 80% molar of the feed gas the flow rate of liquid methanol and the total exergy efficiency declined to 4487 kg/h and 86.05%.
Hydrogen-assisted Cracking Paths in Oriented Pearlitic Microstructures: Resembling Donatello Wooden Sculpture Texture (DWST) & Mantegna’s Dead Christ Perspective (MDCP)
Jun 2020
Publication
Progressive cold drawing in eutectoid steel produces a preferential orientation of pearlitic colonies and ferrite/cementite lamellae thus inducing strength anisotropy in the steel and mixed mode propagation. While in the hot rolled steel (not cold drawn) the pearlitic microstructure is randomly oriented and the crack progresses in hydrogen by breaking the ferrite/cementite lamellae in heavily drawn steels the pearlitic microstructure is fully oriented and the predominant mechanism of hydrogen assisted cracking is the delamination (or decohesion) at the ferrite/cementite interface.
Hydrogen an Enabler of the Grand Transition Future Energy Leader Position Paper
Jan 2018
Publication
A major transformation and redesign of the global energy system is required towards decarbonisation and to achieve the Paris Agreement targets. This Grand Transition is a complex pressing issue where global joint efforts and system solutions are essential; with hydrogen being one of them.<br/>Hydrogen has the potential to be a powerful effective accelerator towards a low-carbon energy system capable of addressing multiple energy challenges: from facilitating the massive integration of renewables and decarbonisation of energy production to energy transportation in a zero-carbon energy economy to electrification of end uses.
The Merit and the Context of Hydrogen Production from Water and Its Effect on Global CO2 Emission
Feb 2022
Publication
For a green economy to be possible in the near future hydrogen production from water is a sought-after alternative to fossil fuels. It is however important to put things into context with respect to global CO2 emission and the role of hydrogen in curbing it. The present world annual production of hydrogen is about 70 million metric tons of which almost 50% is used to make ammonia NH3 (that is mostly used for fertilizers) and about 15% is used for other chemicals [1]. The hydrogen produced worldwide is largely made by steam CH4 reforming (SMR) which is one of the most energy-intensive processes in the chemical industry [2]. It releases based on reaction stoichiometry 5.5 kg of CO2 per 1 kg of H2 (CH4+ 2 H2O → CO2 + 4 H2). When the process itself is taken into account in addition the production [3] becomes about 9 kg of CO2 per kg of H2 and this ratio can be as high as 12 [4]. This results in the production of about one billion tons/year of CO2. The world annual CO2 emission from fossil fuels is however much larger: it is about 36 billion tons of which roughly 25% is emitted while generating electricity and heat 20% due to transport activity and 20% from other industrial processes. Because of the link between global warming and CO2 emissions there is an increasing move towards finding alternative approaches for energy vectors and their applications.
Ordered Clustering of Single Atomic Te Vacancies in Atomically Thin PtTe2 Promotes Hydrogen Evolution Catalysis
Apr 2021
Publication
Exposing and stabilizing undercoordinated platinum (Pt) sites and therefore optimizing their adsorption to reactive intermediates offers a desirable strategy to develop highly efficient Pt-based electrocatalysts. However preparation of atomically controllable Pt-based model catalysts to understand the correlation between electronic structure adsorption energy and catalytic properties of atomic Pt sites is still challenging. Herein we report the atomically thin two-dimensional PtTe2 nanosheets with well-dispersed single atomic Te vacancies (Te-SAVs) and atomically well-defined undercoordinated Pt sites as a model electrocatalyst. A controlled thermal treatment drives the migration of the Te-SAVs to form thermodynamically stabilized ordered Te-SAV clusters which decreases both the density of states of undercoordinated Pt sites around the Fermi level and the interacting orbital volume of Pt sites. As a result the binding strength of atomically defined Pt active sites to H intermediates is effectively reduced which renders PtTe2 nanosheets highly active and stable in hydrogen evolution reaction.
Requirements for Hydrogen Resistance of Materials in CI Engine Toxic Substances Powered by Biofuels
Aug 2019
Publication
It has been described the conception of using platinum catalytic layer in multi hole fuel injector atomizer. The catalytic layer has been placed on not working part of atomizer needle. The aim of modification was activation of dehydrogenation reaction paraffin to olefin hydrocarbons with escape hydrogen molecule in CI engine bio fuel. The modification of atomizer with catalytic layer and reaction process leads to the presence of hydrogen and its influence on structural materials properties after the catalysis which requires the high hydrogen and crack resistance of used materials. There is used high speed steel as material. Article describes how hydrogen and combustion gases influence on thermal friction processes on this material. First of all the investigations were conduct 359 engine with biodiesel. During test had been observed nitrogen oxides carbon monoxide and particles emission. The obtained results show that there is possibility to lower toxic substances emission in exhaust gases CI engine powered by biodiesel. On the second it has been described the influence of biodiesel (including hydrogen) on fuel injector components and their influence on structural materials characteristics. There has been presented how biodiesel with hydrogen influences on precision elements and injection and return discharges. The investigation has been made by using engine test bench and fuel injector and pumps test equipment.
Perspectives on Cathodes for Protonic Ceramic Fuel Cells
Jun 2021
Publication
Protonic ceramic fuel cells (PCFCs) are promising electrochemical devices for the efficient and clean conversion of hydrogen and low hydrocarbons into electrical energy. Their intermediate operation temperature (500–800 °C) proffers advantages in terms of greater component compatibility unnecessity of expensive noble metals for the electrocatalyst and no dilution of the fuel electrode due to water formation. Nevertheless the lower operating temperature in comparison to classic solid oxide fuel cells places significant demands on the cathode as the reaction kinetics are slower than those related to fuel oxidation in the anode or ion migration in the electrolyte. Cathode design and composition are therefore of crucial importance for the cell performance at low temperature. The different approaches that have been adopted for cathode materials research can be broadly classified into the categories of protonic–electronic conductors oxide-ionic–electronic conductors triple-conducting oxides and composite electrodes composed of oxides from two of the other categories. Here we review the relatively short history of PCFC cathode research discussing trends highlights and recent progress. Current understanding of reaction mechanisms is also discussed.
Hydrogen-induced Failure of TiNi Based Alloy with Coarse-grained and Ultrafine-grained Structure
Jul 2016
Publication
The objective of this work is to investigate the effect of hydrogen-induced fracture of TiNi-based alloy. In this report we performed the first studies comparing inelastic properties and fracture of the specimens of the binary alloy of TiNi wire under the action of hydrogen with coarse-grained (CG) and ultrafine-grained (UFG) microstructure. It is shown that hydrogen embrittlement (HE) occurs irrespective of the grain size in the studied specimens at approximately equal strain values. However compared to the specimens with CG structure those with UFG structure accumulate two to three times more hydrogen for the same hydrogenation time. It is found that hydrogen has a much smaller effect on the inelastic properties of specimens with UFG structure as compared to those with CG structure.
Patterned Membranes for Proton Exchange Membrane Fuel Cells Working at Low Humidity
Jun 2021
Publication
High performing proton exchange membrane fuel cells (PEMFCs) that can operate at low relative humidity is a continuing technical challenge for PEMFC developers. In this work micro-patterned membranes are demonstrated at the cathode side by solution casting techniques using stainless steel moulds with laser-imposed periodic surface structures (LIPSS). Three types of patterns lotus lines and sharklet are investigated for their influence on the PEMFC power performance at varying humidity conditions. The experimental results show that the cathode electrolyte pattern in all cases enhances the fuel cell power performance at 100% relative humidity (RH). However only the sharklet pattern exhibits a significant improvement at 25% RH where a peak power density of 450 mW cm−2 is recorded compared with 150 mW cm−2 of the conventional flat membrane. The improvements are explored based on high-frequency resistance electrochemically active surface area (ECSA) and hydrogen crossover by in situ membrane electrode assembly (MEA) testing.
Effect of α′ Martensite Content Induced by Tensile Plastic Prestrain on Hydrogen Transport and Hydrogen Embrittlement of 304L Austenitic Stainless Steel
Aug 2018
Publication
Effects of microstructural changes induced by prestraining on hydrogen transport and hydrogen embrittlement (HE) of austenitic stainless steels were studied by hydrogen precharging and tensile testing. Prestrains higher than 20% at 20 °C significantly enhance the HE of 304L steel as they induce severe α′ martensite transformation accelerating hydrogen transport and hydrogen entry during subsequent hydrogen exposure. In contrast 304L steel prestrained at 50 and 80 °C and 316L steel prestrained at 20 °C exhibit less HE due to less α′ after prestraining. The increase of dislocations after prestraining has a negligible influence on apparent hydrogen diffusivity compared with pre-existing α′. The deformation twins in heavily prestrained 304L steel can modify HE mechanism by assisting intergranular (IG) fracture. Regardless of temperature and prestrain level HE and apparent diffusivity ( Dapp ) increase monotonously with α′ volume fraction ( fα′ ). Dapp can be described as log Dapp=log(Dα′sα′/sγ)+log[fα′/(1−fα′)] for 10%<fα′<90% with Dα′ is diffusivity in α′ sα′ and sγ are solubility in α′ and austenite respectively. The two equations can also be applied to these more typical duplex materials containing both BCC and FCC phases.
Hydrogen Assisted Cracking in Pearlitic Steel Rods: The Role of Residual Stresses Generated by Fatigue Precracking
May 2017
Publication
Stress corrosion cracking (SCC) of metals is an issue of major concern in engineering since this phenomenon causes many catastrophic failures of structural components in aggressive environments. SCC is even more harmful under cathodic conditions promoting the phenomenon known as hydrogen assisted cracking (HAC) hydrogen assisted fracture (HAF) or hydrogen embrittlement (HE). A common way to assess the susceptibility of a given material to HAC HAF or HE is to subject a cracked rod to a constant extension rate tension (CERT) test until it fractures in this harsh environment. This paper analyzes the influence of a residual stress field generated by fatigue precracking on the sample’s posterior susceptibility to HAC. To achieve this goal numerical simulations were carried out of hydrogen diffusion assisted by the stress field. Firstly a mechanical simulation of the fatigue precracking was developed for revealing the residual stress field after diverse cyclic loading scenarios and posterior stress field evolution during CERT loading. Afterwards a simulation of hydrogen diffusion assisted by stress was carried out considering the residual stresses after fatigue and the superposed rising stresses caused by CERT loading. Results reveal the key role of the residual stress field after fatigue precracking in the HAC phenomena in cracked steel rods as well as the beneficial effect of compressive residual stress.
Environmentally-Assisted Cracking of Type 316L Austenitic Stainless Steel in Low Pressure Hydrogen Steam Environments
Aug 2019
Publication
A low pressure superheated hydrogen-steam system has been used to accelerate the oxidation kinetics while keeping the electrochemical conditions similar to those of the primary water in a pressurized water reactor. The initiation has been investigated using a Constant Extension Rate Tensile (CERT) test. Tests were performed on flat tapered specimens made from Type 316L austenitic stainless steel with strain rates of 2×10-6 and 2×10-8 ms-1 at room temperature and at an elevated temperature of 350 °C. R = 1/6 was chosen as a more oxidizing environment and R = 6 was selected as a more reducing environment where the parameter R represents the ratio between the oxygen partial pressure at the Ni/NiO transition and the oxygen partial pressure. Different exposures (1 day and 5 days) prior to loading were investigated post-test evaluation by scanning electron microscopy.
Accelerating to Net Zero with Hydrogen Blending Standards Development in the UK, Canada and the US - Part 2
Mar 2021
Publication
Hydrogen is expected to play a critical role in the move to a net-zero economy. However large-scale deployment is still in its infancy and there is still much to be done before we can blend hydrogen in large volumes into gas networks and ramp up the production that is required to meet demands of the energy transport and industry sectors. KTN Global Alliance will host two webinars to explore these challenges and opportunities in hydrogen blending on the 2nd and 3rd March 2021.
Exciting pilot projects are being conducted and explored in the UK Canada and US states such as California to determine the technical feasibility of blending hydrogen into existing natural gas systems. Whilst the deployment of hydrogen is in its early stages there is increasing interest around permitting significant percentage blends of hydrogen into gas networks which would enable the carbon intensity of gas supplies to be reduced creating a new demand for hydrogen and with the use of separation and purification technologies downstream support the transportation of pure hydrogen to markets.
Gaps in codes and standards need to be addressed to enable adoption and there may be opportunities for international collaboration and harmonisation to ensure that best practices are shared globally and to facilitate the growth of trade and export markets. There is an opportunity for the UK Canada and US three G7 countries to work together and show market making leadership in key enabling regulation for the new hydrogen economy.
Delivered by KTN Global Alliance on behalf of the British Consulate-General in Vancouver and the UK Science and Innovation Network in Canada and the US these two webinars will showcase hydrogen blending pilot projects in the UK Canada and California highlighting challenges and opportunities with regard to standards development for hydrogen blending and supporting further transatlantic collaboration in this area. The events also form part of the UK’s international engagement to build momentum towards a successful outcome at COP26 the UN climate summit that the UK will host in Glasgow in November 2021. The webinars will bring together experts from industry academia and policy from the UK Canada and California. Attendees will have an opportunity to ask questions and interact using Mentimeter.
Part 1 Highlights and Perspectives from the UK can be found here.
Exciting pilot projects are being conducted and explored in the UK Canada and US states such as California to determine the technical feasibility of blending hydrogen into existing natural gas systems. Whilst the deployment of hydrogen is in its early stages there is increasing interest around permitting significant percentage blends of hydrogen into gas networks which would enable the carbon intensity of gas supplies to be reduced creating a new demand for hydrogen and with the use of separation and purification technologies downstream support the transportation of pure hydrogen to markets.
Gaps in codes and standards need to be addressed to enable adoption and there may be opportunities for international collaboration and harmonisation to ensure that best practices are shared globally and to facilitate the growth of trade and export markets. There is an opportunity for the UK Canada and US three G7 countries to work together and show market making leadership in key enabling regulation for the new hydrogen economy.
Delivered by KTN Global Alliance on behalf of the British Consulate-General in Vancouver and the UK Science and Innovation Network in Canada and the US these two webinars will showcase hydrogen blending pilot projects in the UK Canada and California highlighting challenges and opportunities with regard to standards development for hydrogen blending and supporting further transatlantic collaboration in this area. The events also form part of the UK’s international engagement to build momentum towards a successful outcome at COP26 the UN climate summit that the UK will host in Glasgow in November 2021. The webinars will bring together experts from industry academia and policy from the UK Canada and California. Attendees will have an opportunity to ask questions and interact using Mentimeter.
Part 1 Highlights and Perspectives from the UK can be found here.
No more items...