United Kingdom
Thermal Radiation Properties of Large Hydrogen Leaks from Gas Distribution Networks
Sep 2019
Publication
Determination of the behaviour of hydrogen when leaking from pipework on gas distribution assets is essential in assessing the comparative risk associated with using pure hydrogen in place of natural gas in existing assets. Experimental work considering the behaviour of gaseous hydrogen when released in large volumes from gas distribution pipework at pressures of up to 7 barg through holes of up to 200mm in diameter in both buried and unburied scenarios is currently underway. The present paper presents and briefly discusses the results from a set of ignited 20mm diameter releases of hydrogen at pressures up to 7 barg vertically upwards from a pipe in an open excavation. Gaseous releases which find a direct route to atmosphere have the potential to create significant volumes of flammable gas and subsequently significant fires in the case of ignition. It is important to understand both the dispersion distances and thermal hazard field to be able to understand the comparative risk posed when compared to natural gas releases in similar situations. Results of current work completed to date are presented alongside comparisons with known properties of natural gas releases and the potential implications to the comparative risk of hydrogen network operation. The work has been conducted at the DNV GL Spadeadam Testing and Research Centre UK as part of the UK Gas Distribution Networks and Ofgem National Innovation Competition funded H21 project.
Optimal Design and Operation of Integrated Wind-hydrogen-electricity Networks for Decarbonising the Domestic Transport Sector in Great Britain
Nov 2015
Publication
This paper presents the optimal design and operation of integrated wind-hydrogen-electricity networks using the general mixed integer linear programming energy network model STeMES (Samsatli and Samsatli 2015). The network comprises: wind turbines; electrolysers fuel cells compressors and expanders; pressurised vessels and underground storage for hydrogen storage; hydrogen pipelines and electricity overhead/underground transmission lines; and fuelling stations and distribution pipelines.<br/>The spatial distribution and temporal variability of energy demands and wind availability were considered in detail in the model. The suitable sites for wind turbines were identified using GIS by applying a total of 10 technical and environmental constraints (buffer distances from urban areas rivers roads airports woodland and so on) and used to determine the maximum number of new wind turbines that can be installed in each zone.<br/>The objective is the minimisation of the total cost of the network subject to satisfying all of the demands of the domestic transport sector in Great Britain. The model simultaneously determines the optimal number size and location of each technology whether to transmit the energy as electricity or hydrogen the structure of the transmission network the hourly operation of each technology and so on. The cost of distribution was estimated from the number of fuelling stations and length of the distribution pipelines which were determined from the demand density at the 1 km level.<br/>Results indicate that all of Britain's domestic transport demand can be met by on-shore wind through appropriately designed and operated hydrogen-electricity networks. Within the set of technologies considered the optimal solution is: to build a hydrogen pipeline network in the south of England and Wales; to supply the Midlands and Greater London with hydrogen from the pipeline network alone; to use Humbly Grove underground storage for seasonal storage and pressurised vessels at different locations for hourly balancing as well as seasonal storage; for Northern Wales Northern England and Scotland to be self-sufficient generating and storing all of the hydrogen locally. These results may change with the inclusion of more technologies such as electricity storage and electric vehicles.
Ammonia for Power
Sep 2018
Publication
A potential enabler of a low carbon economy is the energy vector hydrogen. However issues associated with hydrogen storage and distribution are currently a barrier for its implementation. Hence other indirect storage media such as ammonia and methanol are currently being considered. Of these ammonia is a carbon free carrier which offers high energy density; higher than compressed air. Hence it is proposed that ammonia with its established transportation network and high flexibility could provide a practical next generation system for energy transportation storage and use for power generation. Therefore this review highlights previous influential studies and ongoing research to use this chemical as a viable energy vector for power applications emphasizing the challenges that each of the reviewed technologies faces before implementation and commercial deployment is achieved at a larger scale. The review covers technologies such as ammonia in cycles either for power or CO2 removal fuel cells reciprocating engines gas turbines and propulsion technologies with emphasis on the challenges of using the molecule and current understanding of the fundamental combustion patterns of ammonia blends.
Uncovering the True Cost of Hydrogen Production Routes Using Life Cycle Monetisation
Oct 2020
Publication
Hydrogen has been identified as a potential energy vector to decarbonise the transport and chemical sectors and achieve global greenhouse gas reduction targets. Despite ongoing efforts hydrogen technologies are often assessed focusing on their global warming potential while overlooking other impacts or at most including additional metrics that are not easily interpretable. Herein a wide range of alternative technologies have been assessed to determine the total cost of hydrogen production by coupling life-cycle assessments with an economic evaluation of the environmental externalities of production. By including monetised values of environmental impacts on human health ecosystem quality and resources on top of the levelised cost of hydrogen production an estimation of the “real” total cost of hydrogen was obtained to transparently rank the alternative technologies. The study herein covers steam methane reforming (SMR) coal and biomass gasification methane pyrolysis and electrolysis from renewable and nuclear technologies. Monetised externalities are found to represent a significant percentage of the total cost ultimately altering the standard ranking of technologies. SMR coupled with carbon capture and storage emerges as the cheapest option followed by methane pyrolysis and water electrolysis from wind and nuclear. The obtained results identify the “real” ranges for the cost of hydrogen compared to SMR (business as usual) by including environmental externalities thereby helping to pinpoint critical barriers for emerging and competing technologies to SMR.
Effect of the Time Dependent Loading of Type IV Cylinders Using a Multi-scalemodel
Sep 2019
Publication
The current requirements for composite cylinders are still based on an arbitrary approach derived from the behaviour of metal structures that the designed burst pressure should be at least 2.5 times the maximum in-service pressure. This could lead to an over-designed composite cylinder for which the weight saving would be less than optimum. Moreover predicting the lifetime of composite cylinders is a challenging task due to their anisotropic characteristics. A federal research institute in Germany (BAM) has proposed a minimum load-cycle requirement that mitigates this issue by using a MonteCarlo analysis of the burst test results. To enrich this study more experiments are required however they are normally limited by the necessity of long duration testing times (loading rate and number of cylinders) and the design (stacking sequence of the composite layer). A multi-scale model incorporating the micromechanical behaviour of composite structures has been developed at Mines ParisTech. The model has shown similar behaviour to that of composite cylinders under different loading rates. This indicates that the model could assist the Monte-Carlo analysis study. An evaluation of the multi-scale model therefore has been carried out to determine its limitations in predicting lifetimes of composite cylinders. The evaluation starts with the comparison of burst pressures with type IV composite cylinders under different loading rates. A μCT-Scan of a type IV cylinder has been carried out at the University of Southampton. The produced images were analysed using the Fast-Fourier Transform (FFT) technique to determine the configuration of the composite layers which is required by the model. Finally the time dependent effect studied by using the multi scale model has been described. In the long-term this study can be used to conduct a parametric study for creating more efficient design of type IV cylinders.
A Probabilistic Framework for the Techno-economic Assessment of Smart Energy Hubs for Electric Vehicle Charging
Apr 2022
Publication
Smart energy hubs (Smart Hubs) equipped with Vehicle-to-Grid (V2G) charging photovoltaic (PV) energy generation and hydrogen storage capabilities are an emerging technology with potential to alleviate the impact of electric vehicles (EV) on the electricity grid. Their operation however is characterised by intermittent PV energy generation as well as uncertainties in EV traffic and driver preference. These uncertainties when combined with the need to maximise their financial return while guaranteeing driver satisfaction yields a challenging decision-making problem. This paper presents a novel Monte-Carlo-based modelling and computational framework for simulating the operation of Smart Hubs — providing a means for a holistic assessment of their technical and financial viability. The framework utilises a compact and representative mathematical model accounting for power losses PV module degradation variability in EV uptake price inflation driver preference and diversity in charge points and EVs. It provides a comprehensive approach for dealing with uncertainties and dependencies in EV data while being built on an energy management algorithm that maximises revenue generation ensures driver satisfaction and preserves battery life. The energy management problem is formulated as a mixed-integer linear programming problem constituting a business case that includes an adequate V2G reward model for drivers. To demonstrate its applicability the framework was used to assess the financial viability of a fleet management site for various caps on vehicle stay at the site. From the assessment controlled charging was found to be more financially rewarding in all cases yielding between 1.7% and 3.1% more revenue than uncontrolled charging. The self-consumption of the site was found to be nearly 100% due mainly to local load shifting and dispatchable hydrogen generation. V2G injection was however negligible — suggesting its unattractiveness for sites that do not participate in the demand side response market. Overall the numerical results obtained validate the applicability of the proposed framework as a decision-support tool in the sustainable design and operation of Smart Hubs for EV charging.
Technical Feasibility of Low Carbon Heating in Domestic Buildings
Dec 2020
Publication
Scotland’s Climate Change Plan set an ambition for emissions from buildings to be near zero by 2050 and targets 35% of domestic and 70% of non-domestic buildings’ heat to be supplied using low carbon technologies by 2032. The Climate Change (Emissions Reduction Targets) (Scotland) Act 2019 set a new target for emissions to be net zero by 2045 with interim targets of 75% by 2030 and 90% by 2040. The update to the Climate Change Plan will be published at the end of 2020 to reflect these new targets. The Energy Efficient Scotland programme launched in May 2018 sets out a wide range of measures to promote low carbon heating alongside energy efficiency improvements in Scotland’s buildings. Meeting these targets will require almost all households in Scotland to change the way they heat their homes. It is therefore imperative to advance our understanding of the suitability of the available low carbon heating options across Scotland’s building stock.<br/><br/>The aim of this work is to assess the suitability of low carbon heating technologies in residential buildings in Scotland. The outputs generated through this work will form a key part of the evidence base on low carbon heat which the Scottish Government will use to further develop and strengthen Scotland’s low carbon heat policy in line with the increased level of ambition of achieving Net Zero by 2045.
Vented Hydrogen-air Deflagrations in Low Strength Equipment and Buildings
Sep 2013
Publication
This paper aims to improve prediction capability of the vent sizing correlation presented in the form of functional dependence of the dimensionless deflagration overpressure on the turbulent Bradley number similar to our previous studies. The correlation is essentially upgraded based on recent advancements in understanding and modelling of combustion phenomena relevant to hydrogen-air vented deflagrations and unique large-scale tests carried out by different research groups. The focus is on hydrogen-air deflagrations in low-strength equipment and buildings when the reduced pressure is accepted to be below 0.1 MPa. The combustion phenomena accounted for by the correlation include: turbulence generated by the flame front itself; leading point mechanism stemming from the preferential diffusion of hydrogen in air in stretched flames; growth of the fractal area of the turbulent flame surface; initial turbulence in the flammable mixture; as well as effects of enclosure aspect ratio and presence of obstacles. The correlation is validated against the widest range of experimental conditions available to date (76 experimental points). The validation covers a wide range of test conditions: different shape enclosures of volume up to 120 m3; initially quiescent and turbulent hydrogen-air mixtures; hydrogen concentration in air from 6% to 30% by volume; ignition source location at enclosure centre near and far from a vent; empty enclosures and enclosures with obstacles.
Business Models for Low Carbon Hydrogen Production: A Report for BEIS
Aug 2020
Publication
Low carbon hydrogen could have a significant role to play in meeting the UK’s Net Zero target: the Committee on Climate Change (CCC) estimates that up to 270TWh of low carbon hydrogen could be needed in its ‘Further Ambition’ scenario. However at present there is no large-scale production of low carbon hydrogen in the UK not least as it is more costly than most high carbon alternatives. For hydrogen to be the viable option envisaged by the CCC projects may need to be deployed from the 2020s.<br/>BEIS has commissioned Frontier Economics to develop business models to support low carbon hydrogen production. This report builds on the earlier Carbon Capture Usage and Storage (CCUS) business models consultation2 and develops business models for BEIS to consider further. This report is a milestone in BEIS’ longer term process of developing hydrogen business models. It forms a part of BEIS’ wider research into a range of decarbonisation options across the economy.<br/>Further analysis will be required before a final decision is made.
Hydrogen Venting Under Variable Flow Conditions
Sep 2011
Publication
Safety distances for hydrogen plumes are currently derived using models developed for hydrocarbon releases. It is well known that hydrogen behaves in a significantly different manner to that of hydrocarbons when released to atmosphere. There are two main aspects involved with the development of safety distances for credible hydrogen releases; the intensity of the thermal radiation from such a plume should it be ignited and the distance downwind from the release point to the point where a flammable mixture with air no longer exists. A number of distinct areas of venting behaviour were investigated; Thermal radiation from ignited plumes from vertical open ended vent pipes Far field radiation measurements for direct comparison with models Thermal radiation from ignited plumes from vertical vent pipes terminating in a T-piece Thermal radiation measurements from ignited hydrogen with a 45 vent termination Hydrogen concentration measurements with a T-piece.
Hydrogen Energy
Feb 2007
Publication
The problem of anthropogenically driven climate change and its inextricable link to our global society’s present and future energy needs are arguably the greatest challenge facing our planet. Hydrogen is now widely regarded as one key element of a potential energy solution for the twenty-first century capable of assisting in issues of environmental emissions sustainability and energy security. Hydrogen has the potential to provide for energy in transportation distributed heat and power generation and energy storage systems with little or no impact on the environment both locally and globally. However any transition from a carbon-based (fossil fuel) energy system to a hydrogen-based economy involves significant scientific technological and socio-economic barriers. This brief report aims to outline the basis of the growing worldwide interest in hydrogen energy and examines some of the important issues relating to the future development of hydrogen as an energy vector.
Link to document download on Royal Society Website
Link to document download on Royal Society Website
Sensitive Intervention Points to Achieve Net-zero Emissions (Sixth Carbon Budget Policy Advisory Group)
Dec 2020
Publication
The group concluded that the transition to Net Zero can and will occur and will leave a positive legacy for future generations. They examined the UK as a complex adaptive system and identified recommendations for accelerating progress and reducing the risks of failure. The Group recognised an opportunity for Sensitive Intervention Points (SIPs) coinciding with these recommendations pointing to opportunities to accelerate a transition towards Net Zero by exploiting socio-economic tipping points.
These included:
These included:
- Deepening public engagement through investments to support measures to lower ‘thresholds’ to behavioural change such as energy efficiency or dietary alternatives. This can form part of a public engagement strategy for Net Zero that educates the public involves people in decision-making and provides trusted information at key decision points
- Delivering social justice via a clear long-term vision for specific regions coupled with mechanisms that reward the private sector for building industries in otherwise deprived areas starting now
- Government leading on Net Zero by requiring any company meeting with ministers and secretaries of state to have a plan to reach net zero emissions
- Leveraging global dynamics by introducing a border carbon adjustment and consider forming bilateral and multilateral preferential trading arrangements for environmental goods and services
- Penalising emissions by committing in the UK’s NDC to sequester 10% of CO2 emissions generated by fossil fuels and industry by 2030
- Increasing business ambition by identifying businesses that shape industries – celebrate and elevate them
- Accelerating technology via Pathfinder cities that can deliver comprehensive steps towards Net Zero and demonstrate the interactions required across complex systems of low-carbon electricity heat and transport
- Redirecting capital flows by introducing Net zero aligned and transparent accounting and auditing
- Harnessing legal avenues by legislating all regulators to regard the Paris Agreement Sixth Carbon Budget and 2050 Net Zero target in their duties.
Net Zero Public Dialogue
Mar 2021
Publication
This research project brought together members of the public from across the UK to participate in online workshops to explore:
- public understanding and perceptions of what reaching climate targets in the UK will mean for them individually and for society as a whole
- public attitudes and preferences towards the role that individual behaviour change should have in reaching net zero
- public perceptions of the easiest and toughest areas of change to help reach net zero
- public views on how they would prefer to engage with net zero policies and relevant initiatives that they feel could support the delivery of net zero
UKERC Research Atlas Landscape – Fuel Cells
Dec 2013
Publication
This UKERC Research Atlas Landscape provides an overview of the competencies and publicly funded activities in fuel cell research development and demonstration (RD&D) in the UK. It covers the main funding streams research providers infrastructure networks and UK participation in international activities.
Energy Innovation Needs Assessment: Carbon Capture Usage & Storage
Nov 2019
Publication
The Energy Innovation Needs Assessment (EINA) aims to identify the key innovation needs across the UK’s energy system to inform the prioritisation of public sector investment in low-carbon innovation. Using an analytical methodology developed by the Department for Business Energy & Industrial Strategy (BEIS) the EINA takes a system level approach and values innovations in a technology in terms of the system-level benefits a technology innovation provides. This whole system modelling in line with BEIS’s EINA methodology was delivered by the Energy Systems Catapult (ESC) using the Energy System Modelling Environment (ESMETM) as the primary modelling tool.
To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.
This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.
This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.
To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.
This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.
This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.
The Impact of Disruptive Powertrain Technologies on Energy Consumption and Carbon Dioxide Emissions from Heavy-duty Vehicles
Jan 2020
Publication
Minimising tailpipe emissions and the decarbonisation of transport in a cost effective way remains a major objective for policymakers and vehicle manufacturers. Current trends are rapidly evolving but appear to be moving towards solutions in which vehicles which are increasingly electrified. As a result we will see a greater linkage between the wider energy system and the transportation sector resulting in a more complex and mutual dependency. At the same time major investments into technological innovation across both sectors are yielding rapid advancements into on-board energy storage and more compact/lightweight on-board electricity generators. In the absence of sufficient technical data on such technology holistic evaluations of the future transportation sector and its energy sources have not considered the impact of a new generation of innovation in propulsion technologies. In this paper the potential impact of a number of novel powertrain technologies are evaluated and presented. The analysis considers heavy duty vehicles with conventional reciprocating engines powered by diesel and hydrogen hybrid and battery electric vehicles and vehicles powered by hydrogen fuel cells and freepiston engine generators (FPEGs). The benefits are compared for each technology to meet the expectations of representative medium and heavy-duty vehicle drivers. Analysis is presented in terms of vehicle type vehicle duty cycle fuel economy greenhouse gas (GHG) emissions impact on the vehicle etc.. The work shows that the underpinning energy vector and its primary energy source are the most significant factor for reducing primary energy consumption and net CO2 emissions. Indeed while an HGV with a BEV powertrain offers no direct tailpipe emissions it produces significantly worse lifecycle CO2 emissions than a conventional diesel powertrain. Even with a de-carbonised electricity system (100 g CO2/kWh) CO2 emissions are similar to a conventional Diesel fuelled HGV. For the HGV sector range is key to operator acceptability of new powertrain technologies. This analysis has shown that cumulative benefits of improved electrical powertrains on-board storage efficiency improvements and vehicle design in 2025 and 2035 mean that hydrogen and electric fuelled vehicles can be competitive on gravimetric and volumetric density. Overall the work demonstrates that presently there is no common powertrain solution appropriate for all vehicle types but how subtle improvements at a vehicle component level can have significant impact on the design choices for the wider energy system.
Scottish Offshore Wind to Green Hydrogen Opportunity Assessment
Dec 2020
Publication
Initial assessment of Scotland’s opportunity to produce green hydrogen from offshore wind
Summary of Key Findings
Summary of Key Findings
- Scotland has an abundant offshore wind resource that has the potential to be a vital component in our net zero transition. If used to produce green hydrogen offshore wind can help abate the emissions of historically challenging sectors such as heating transport and industry.
- The production of green hydrogen from offshore wind can help overcome Scotland’s grid constraints and unlock a massive clean power generation resource creating a clean fuel for Scottish industry and households and a highly valuable commodity to supply rapidly growing UK and European markets.
- The primary export markets for Scottish green hydrogen are expected to be in Northern Europe (Germany Netherlands & Belgium). Strong competition to supply these markets is expected to come from green hydrogen produced from solar energy in Southern Europe and North Africa.
- Falling wind and electrolyser costs will enable green hydrogen production to be cost-competitive in the key transport and heat sectors by 2032. Strategic investment in hydrogen transportation and storage is essential to unlocking the economic opportunity for Scotland.
- Xodus’ analysis supports a long-term outlook of LCoH falling towards £2/kg with an estimated reference cost of £2.3 /kg in 2032 for hydrogen delivered to shore.
- Scotland has extensive port and pipeline infrastructure that can be repurposed for hydrogen export to the rest of UK and to Europe. Pipelines from the ‘90s are optimal for this purpose as they are likely to retain acceptable mechanical integrity and have a metallurgy better suited to hydrogen service. A more detailed assessment of export options should be performed to provide a firm foundation for early commercial green hydrogen projects.
- There is considerable hydrogen supply chain overlap with elements of parallel sectors most notably the oil and gas offshore wind and subsea engineering sectors. Scotland already has a mature hydrocarbon supply chain which is engaged in supporting green hydrogen. However a steady pipeline of early projects supported by a clear financeable route to market will be needed to secure this supply chain capability through to widescale commercial deployment.
- There are gaps in the Scottish supply chain in the areas of design manufacture and maintenance of hydrogen production storage and transportation systems. Support including apprenticeships will be needed to develop indigenous skills and capabilities in these areas.
- The development of green hydrogen from offshore wind has the potential to create high value jobs a significant proportion which are likely to be in remote rural/coastal communities located close to offshore wind resources. These can serve as an avenue for workers to redeploy and develop skills learned from oil and gas in line with Just Transition principles.
Plasmonic Nickel Nanoparticles Decorated on to LaFeO3 Photocathode for Enhanced Solar Hydrogen Generation
Nov 2018
Publication
Plasmonic Ni nanoparticles were incorporated into LaFeO3 photocathode (LFO-Ni) to excite the surface plasmon resonances (SPR) for enhanced light harvesting for enhancing the photoelectrochemical (PEC) hydrogen evolution reaction. The nanostructured LFO photocathode was prepared by spray pyrolysis method and Ni nanoparticles were incorporated on to the photocathode by spin coating technique. The LFO-Ni photocathode demonstrated strong optical absorption and higher current density where the untreated LFO film exhibited a maximum photocurrent of 0.036 mA/cm2 at 0.6 V vs RHE and when incorporating 2.84 mmol Ni nanoparticles the photocurrent density reached a maximum of 0.066 mA/cm2 at 0.6 V vs RHE due to the SPR effect. This subsequently led to enhanced hydrogen production where more than double (2.64 times) the amount of hydrogen was generated compared to the untreated LFO photocathode. Ni nanoparticles were modelled using Finite Difference Time Domain (FDTD) analysis and the results showed optimal particle size in the range of 70–100 nm for Surface Plasmon Resonance (SPR) enhancement.
Combustion and Exhaust Emission Characteristics, and In-cylinder Gas Composition, of Hydrogen Enriched Biogas Mixtures in a Diesel Engine
Feb 2017
Publication
This paper presents a study undertaken on a naturally aspirated direct injection diesel engine investigating the combustion and emission characteristics of CH4-CO2 and CH4-CO2 -H2 mixtures. These aspirated gas mixtures were pilot-ignited by diesel fuel while the engine load was varied between 0 and 7 bar IMEP by only adjusting the flow rate of the aspirated mixtures. The in-cylinder gas composition was also investigated when combusting CH4-CO2 and CH4-CO2-H2 mixtures at different engine loads with in cylinder samples collected using two different sampling arrangements. The results showed a longer ignition delay period and lower peak heat release rates when the proportion of CO2 was increased in the aspirated mixture. Exhaust CO2 emissions were observed to be higher for 60 CH4:40CO2 mixture but lower for the 80CH4:20CO2 mixture as compared to diesel fuel only combustion at all engine loads. Both exhaust and in-cylinder NOx levels were observed to decrease when the proportion of CO2 was increased; NOx levels increased when the proportion of H2 was increased in the aspirated mixture. In-cylinder NOx levels were observed to be higher in the region between the sprays as compared to within the spray core attributable to higher gas temperatures reached post ignition in that region.
Hydrogen Effects in Non-ferrous Alloys: Discussion
Jun 2017
Publication
This is a transcript of the discussion session on the effects of hydrogen in the non-ferrous alloys of zirconium and titanium which are anisotropic hydride-forming metals. The four talks focus on the hydrogen embrittlement mechanisms that affect zirconium and titanium components which are respectively used in the nuclear and aerospace industries. Two specific mechanisms are delayed hydride cracking and stress corrosion cracking.
This article is a transcription of the recorded discussion of the session ‘Hydrogen in non-ferrous alloys’ at the Royal Society Discussion Meeting Challenges of Hydrogen in Metals 16–18 January 2017. The text is approved by the contributors. M.P. transcribed the session. M.A.S. assisted in the preparation of the manuscript.
Link to document download on Royal Society Website
This article is a transcription of the recorded discussion of the session ‘Hydrogen in non-ferrous alloys’ at the Royal Society Discussion Meeting Challenges of Hydrogen in Metals 16–18 January 2017. The text is approved by the contributors. M.P. transcribed the session. M.A.S. assisted in the preparation of the manuscript.
Link to document download on Royal Society Website
Zero-In on NI-Heat Exploring Pathways Towards Heat Decarbonisation in Northern Ireland
Jul 2020
Publication
Northern Ireland has achieved its 2020 targets in the electricity sector ahead of time with 46.8% of its electricity demand supplied by renewable generators. When it comes to heat the progress is less impressive – 68% of domestic heating is provided by oil and only around 2500 customers use low carbon heat generators in their homes. In addition 22% of consumers live in fuel poverty. Fuel poverty support programmes still propose the replacement of old oil boilers with new models or with gas boilers where a connection to the grid is possible.<br/>Failure of the commercial RHI scheme and the knock-on effect of the closure of the domestic RHI scheme caused significant damage to the industry and to the reputation of low carbon heat technologies leaving NI consumers without any explicit supporting mechanisms for low carbon heat supply. Decreases in carbon emissions from the heat sector are mainly achieved through switching from oil to gas heating. Gas infrastructure is under development in NI and promises to reach 60% of customers by 2022.
Annual Science Review 2018
Mar 2018
Publication
THIS ANNUAL SCIENCE Review showcases the high quality of science evidence and analysis that underpins HSE’s risk-based regulatory regime. To be an effective regulator HSE has to balance its approaches to informing directing advising and enforcing through a variety of activities. For this we need capacity to advance knowledge; to develop and use robust evidence and analysis; to challenge thinking; and to review effectiveness.<br/>In simple terms policy provides the route map to tackling issues. HSE is particularly well placed in terms of the three components of effective policy - “politics” “evidence” and “delivery”. Unlike most regulators and arms-length bodies HSE leads on policy development which draws directly on front line delivery expertise and intelligence; and we are also unusual in having our own world class science and insight capabilities.<br/>The challenge is to ensure we bring these components together to best effect to respond to new risk management and regulatory issues with effective innovative and proportionate approaches.<br/>Many of the articles in this Review relate to new and emerging technologies and the changing world of work and it is important to understand the risks these may pose and how they can be effectively controlled or how they themselves can contribute to improved health and safety in the workplace. Good policy development can support approaches to change that are proportionate relevant persuasive and effective. For example work described in these pages is: to help understand changing workplace exposures; to provide robust evidence to those negotiating alternatives to unduly prescriptive standards; to understand how best to influence duty<br/>holder behaviors in the changing world of work; to inform possible legislative changes to allow different modes of safe gas transmission; to change administrative processes for Appointed Doctors; and to support our position as a model modern regulator by further focusing our inspection activity where it matters most.<br/>The vital interface between HSE science and policy understand how best to influence duty holder behaviors in the changing world of work; to inform possible legislative changes to allow different modes of safe gas transmission; to change administrative processes for Appointed Doctors; and to support our position as a model modern regulator by further focusing our inspection activity where it matters most.<br/>We work well together and it is important we maintain this engagement as a conscious collaboration.
Oxford Energy Podcast – How a Traded Hydrogen Market Might Develop – Lessons from the Natural Gas Industry
Jun 2021
Publication
The appetite for a ‘hydrogen market’ has been growing in the past year or two and is often called a ‘market’ by governments regulators and other energy industry players. The question is what ‘hydrogen market’ are they referring to as there is currently no such market established? In this podcast David Ledesma talks to Patrick Heather Senior Research Fellow at the OIES and discusses how a future traded hydrogen market might develop what the prerequisites would be for the development of a wholesale market and whether there are lessons to be learned from the development of the European natural gas market. The podcast ends up by asking the fundamental question – If the European gas market took 25-30 years to liberalise and develop a liquid traded pricing hub where are we headed with hydrogen? Will we ever see a traded market in hydrogen and what must happen to get there? Patrick is cautiously optimistic in his response!
The podcast can be found on their website
The podcast can be found on their website
Establishing a Hydrogen Economy: The Future of Energy 2035
May 2019
Publication
The next few decades are expected to be among the most transformative the energy sector has ever seen. Arup envisages a world with a much more diverse range of heating sources and with significantly lower emissions and renewable energy powering transport.<br/>As part of this the establishment of a strong hydrogen economy is a very real opportunity and is within reaching distance. Our report uses the UK as a case study example and explores the challenges and opportunities for hydrogen in the context of the whole energy system.<br/>Read about the progress already being made in using hydrogen for transport and heat. And the need to progress policy and collaboration between government the private sector and other stakeholders to shape future demand change consumer perception and create the strong supply chains needed to allow the hydrogen economy to thrive.
Opportunity and Cost of Green Hydrogen in Kuwait: A Preliminary Assessment
Apr 2021
Publication
On April 7 2021 OIES with and the Kuwait Foundation for the Advancement of Sciences (KFAS) held the annual OIES-KFAS Workshop on Energy Transition Post-Pandemic in the Gulf. During the hydrogen session a paper titled “Opportunity and Cost of Green Hydrogen in Kuwait: A Preliminary Assessment” co-authored by Dr. Manal Shehabi was presented.
Like others states in the GCC Kuwait is seeking to explore hydrogen as part of its energy transition projects. The presentation highlights key technological opportunities for green hydrogen in Kuwait followed by a techno-economic assessments of producing it. Results of utilized hydrogen production model show that for production in 2032 average levelized cost of hydrogen (LCOH) is $3.23/kg using PEM technology & $4.41/kg using SOEC technology. Results indicate that green hydrogen in Kuwait is more competitive than in other regions but currently not competitive (>$1.5/kg) with oil coal and gas in absence of carbon taxes.
The research paper can be found on their website
Like others states in the GCC Kuwait is seeking to explore hydrogen as part of its energy transition projects. The presentation highlights key technological opportunities for green hydrogen in Kuwait followed by a techno-economic assessments of producing it. Results of utilized hydrogen production model show that for production in 2032 average levelized cost of hydrogen (LCOH) is $3.23/kg using PEM technology & $4.41/kg using SOEC technology. Results indicate that green hydrogen in Kuwait is more competitive than in other regions but currently not competitive (>$1.5/kg) with oil coal and gas in absence of carbon taxes.
The research paper can be found on their website
Ammonia-hydrogen Combustion in a Swirl Burner with Reduction of NOx Emissions
Sep 2019
Publication
Recently ammonia is being considered for fuelling gas turbines as a new sustainable source. It can undergo thermal cracking producing nitrogen hydrogen and unburned ammonia thus enabling the use of these chemicals most efficiently for combustion purposes. Ammonia being carbon-free may allow the transition towards a hydrogen economy. However one of the main constraints of this fuelling technique is that although the combustion of ammonia produces no CO2 there is a large NOx proportion of emissions using this fuel. In this work cracked ammonia obtained from a modified combustion rig designed at Cardiff University was used to simulate a swirl burner under preheating conditions via heat exchangers. The primary objective of this system is to find new ways for the reduction of NOx emissions by injecting various amounts of ammonia/hydrogen at different mixtures downstream of the primary flame zone. The amount of injected ammonia/hydrogen mixture (X) taken from the thermal cracking system was ranged from 0%-4% (vol %) of the total available fuel in the system while the remaining gas (1.00-X) was then employed as primary fuel into the burner. CHEMKIN- PRO calculations were conducted by employing a novel chemical reaction code developed at Cardiff University to achieve the goal of this paper. The predictions were performed under low pressure and rich conditions with an equivalence ratio ϕ =1.2 in a swirl burner previously characterised at output powers of ~10 kW. Ammonia and hydrogen blends were evaluated from 50% NH3 (vol %) with the remaining gas as hydrogen continuing in steps of 10% (vol %) NH3 increments. Results showed that the minimum unburned ammonia and higher flame temperature were achieved at 60%-40% NH3-H2 when compared to other blends but with high NO emissions. These NO levels were reduced by injecting a small amount of NH3/H2 mixture (X=4 %) downstream the primary zone in a generated circulations promoted by the new design of the burner which affecting the residence time hence reducing the NO emission in the exhaust gas.
The Curious Case of the Conflicting Roles of Hydrogen in Global Energy Scenarios
Oct 2019
Publication
As energy systems transition from fossil-based to low-carbon they face many challenges particularly concerning energy security and flexibility. Hydrogen may help to overcome these challenges with potential as a transport fuel for heating energy storage conversion to electricity and in industry. Despite these opportunities hydrogen has historically had a limited role in influential global energy scenarios. Whilst more recent studies are beginning to include hydrogen the role it plays in different scenarios is extremely inconsistent. In this perspective paper reasons for this inconsistency are explored considering the modelling approach behind the scenario scenario design and data assumptions. We argue that energy systems are becoming increasingly complex and it is within these complexities that new technologies such as hydrogen emerge. Developing a global energy scenario that represents these complexities is challenging and in this paper we provide recommendations to help ensure that emerging technologies such as hydrogen are appropriately represented. These recommendations include: using the right modelling tools whilst knowing the limits of the model; including the right sectors and technologies; having an appropriate level of ambition; and making realistic data assumptions. Above all transparency is essential and global scenarios must do more to make available the modelling methods and data assumptions used.
HyDeploy Report: Keele Information
Jun 2018
Publication
Keele University was chosen as the site for the HyDeploy project as it was seen as the site offered a high degree of control regarding safety functions high availability of operational data and minimal supply chain interfaces given that Keele University is the supplier transporter and distributer of natural gas at the site. The site was offered to the project as a living laboratory in line with the university's ambition to be at the forefront of energy innovation through the Smart Energy Network Demonstrator (SEND). Evidenced within this report is the supporting data that confirms the rationale for selecting Keele University and the necessary data to profile the section of the gas network which hydrogen will be injected into. The gas network at Keele University is segregated via the governor stations which regulate pressure within the network. The section of network which has been chosen for the HyDeploy project is the G3 network which is regulated by the G3 governor.
Investment Frameworks for Development of CCUS in the UK
Jul 2019
Publication
The CCUS Advisory Group (CAG) established in March 2019 is an industry-led group considering the critical challenges facing the development of CCUS market frameworks and providing insight into potential solutions. The CAG brings together experts from across the CCUS industry finance and legal sectors.<br/>The CAG has examined a range of business models focusing on industrial CCUS power production CO? transport and storage and hydrogen production. It has considered how the proposed business models interact in order to minimise issues such as cross-chain risk and has considered issues such as delivery capability. The conclusions of the CAG can be found in this report.
HyDeploy Project - First Project Progress Report
Dec 2017
Publication
The HyDeploy Project seeks to address a key issue for UK customers: how to reduce the carbon they emit in heating their homes. The UK has a world class gas grid delivering heat conveniently and safely to over 83% of homes. Emissions could be reduced by lowering the carbon content of gas through blending with hydrogen. Compared with solutions such as heat pumps this means that customers would not need disruptive and expensive changes in their homes. This Network Innovation Competition (NIC) funded project seeks to establish the level of hydrogen that can be safely blended with natural gas for transport and use in a UK network.
Under its Smart Energy Network Demonstration innovation programme Keele University is establishing its electricity and gas networks as facilities to drive forward innovation in the energy sector. The objective of HyDeploy is to trial natural gas blended with potentially up to 20% volume of hydrogen in a part of the Keele gas network. Before any hydrogen can be blended with natural gas in the network the percentage of hydrogen to be delivered must be approved by the Health and Safety Executive (HSE). It must be satisfied that the approved blended gas will be as safe to use as normal gas. Any approval will be given as an exemption to the Gas Safety (Management) Regulations. These regulations ensure the safe use and management of gas through the gas network in the UK. The evidence presented to the HSE comprises critically appraised literature combined with the results from a specifically commissioned experimental and testing programme. Based on engagement with all local customers this includes detailed safety checks on the network appliances and installations at Keele. Subject to approval by the HSE the hydrogen production and grid injection units will be installed and an extensive trial programme of blending will be undertaken. If hydrogen were blended at 20% volume with natural gas across the UK it would save around 6 million tonnes of carbon dioxide emissions every year the equivalent of taking 2.5 million cars off the road.
This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.
Under its Smart Energy Network Demonstration innovation programme Keele University is establishing its electricity and gas networks as facilities to drive forward innovation in the energy sector. The objective of HyDeploy is to trial natural gas blended with potentially up to 20% volume of hydrogen in a part of the Keele gas network. Before any hydrogen can be blended with natural gas in the network the percentage of hydrogen to be delivered must be approved by the Health and Safety Executive (HSE). It must be satisfied that the approved blended gas will be as safe to use as normal gas. Any approval will be given as an exemption to the Gas Safety (Management) Regulations. These regulations ensure the safe use and management of gas through the gas network in the UK. The evidence presented to the HSE comprises critically appraised literature combined with the results from a specifically commissioned experimental and testing programme. Based on engagement with all local customers this includes detailed safety checks on the network appliances and installations at Keele. Subject to approval by the HSE the hydrogen production and grid injection units will be installed and an extensive trial programme of blending will be undertaken. If hydrogen were blended at 20% volume with natural gas across the UK it would save around 6 million tonnes of carbon dioxide emissions every year the equivalent of taking 2.5 million cars off the road.
This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.
Measurement Challenges for Hydrogen Vehicles
Apr 2019
Publication
Uptake of hydrogen vehicles is an ideal solution for countries that face challenging targets for carbon dioxide reduction. The advantage of hydrogen fuel cell electric vehicles is that they behave in a very similar way to petrol engines yet they do not emit any carbon containing products during operation. The hydrogen industry currently faces the dilemma that they must meet certain measurement requirements (set by European legislation) but cannot do so due to a lack of available methods and standards. This paper outlines the four biggest measurement challenges that are faced by the hydrogen industry including flow metering quality assurance quality control and sampling.
A Temperature Controlled Mechanical Test Facility to Ensure Safe Materials Performance in Hydrogen at 1000 Bar
Sep 2007
Publication
Increasingly car manufacturers are turning to high pressure hydrogen storage for on-board power applications. Many prototypes use costly materials and fabrication methods such as Type 316L austenitic stainless steel and processes such as TIG (GTA) welding. There is a need to move to less expensive options without compromising safety to assist in developing economic vehicles. It is important that the behaviour of new/modified materials and joints (including those fabricated by new technologies) is understood at anticipated service temperatures and hydrogen pressure as the consequences of poor material choice could be severe. The greatest detrimental effect of gaseous hydrogen on the mechanical properties of metallic materials is commonly observed under conditions of dynamic plastic strain. Under such conditions an atomically clean surface is produced where hydrogen molecules will dissociate and penetrate the material. Thus static load test methods with hydrogen charging are not reliable for engineering data generation. To meet the need for dynamically straining material in a pressurised hydrogen environment TWI has developed a facility to load specimens in a high pressure environment for tensile toughness and fatigue testing. The design of this has involved a number of innovative steps. This paper outlines the requirements and the design and construction issues that were encountered when installing a facility which can not only perform tests at up to 1000bar (100MPa) but also for temperatures between –150°C to +85°C.
Guidelines and Recommendations for Indoor Use of Fuel Cells and Hydrogen Systems
Oct 2015
Publication
Deborah Houssin-Agbomson,
Simon Jallais,
Elena Vyazmina,
Guy Dang-Nhu,
Gilles Bernard-Michel,
Mike Kuznetsov,
Vladimir V. Molkov,
Boris Chernyavsky,
Volodymyr V. Shentsov,
Dmitry Makarov,
Randy Dey,
Philip Hooker,
Daniele Baraldi,
Evelyn Weidner,
Daniele Melideo,
Valerio Palmisano,
Alexandros G. Venetsanos,
Jan Der Kinderen and
Béatrice L’Hostis
Hydrogen energy applications often require that systems are used indoors (e.g. industrial trucks for materials handling in a warehouse facility fuel cells located in a room or hydrogen stored and distributed from a gas cabinet). It may also be necessary or desirable to locate some hydrogen system components/equipment inside indoor or outdoor enclosures for security or safety reasons to isolate them from the end-user and the public or from weather conditions.<br/>Using of hydrogen in confined environments requires detailed assessments of hazards and associated risks including potential risk prevention and mitigation features. The release of hydrogen can potentially lead to the accumulation of hydrogen and the formation of a flammable hydrogen-air mixture or can result in jet-fires. Within Hyindoor European Project carried out for the EU Fuel Cells and Hydrogen Joint Undertaking safety design guidelines and engineering tools have been developed to prevent and mitigate hazardous consequences of hydrogen release in confined environments. Three main areas are considered: Hydrogen release conditions and accumulation vented deflagrations jet fires and including under-ventilated flame regimes (e.g. extinguishment or oscillating flames and steady burns). Potential RCS recommendations are also identified.
A Comparison of Alternative Fuels for Shipping in Terms of Lifecycle Energy and Cost
Dec 2021
Publication
Decarbonization of the shipping sector is inevitable and can be made by transitioning into low‐ or zero‐carbon marine fuels. This paper reviews 22 potential pathways including conventional Heavy Fuel Oil (HFO) marine fuel as a reference case “blue” alternative fuel produced from natural gas and “green” fuels produced from biomass and solar energy. Carbon capture technology (CCS) is installed for fossil fuels (HFO and liquefied natural gas (LNG)). The pathways are compared in terms of quantifiable parameters including (i) fuel mass (ii) fuel volume (iii) life cycle (Well‐To‐ Wake—WTW) energy intensity (iv) WTW cost (v) WTW greenhouse gas (GHG) emission and (vi) non‐GHG emissions estimated from the literature and ASPEN HYSYS modelling. From an energy perspective renewable electricity with battery technology is the most efficient route albeit still impractical for long‐distance shipping due to the low energy density of today’s batteries. The next best is fossil fuels with CCS (assuming 90% removal efficiency) which also happens to be the lowest cost solution although the long‐term storage and utilization of CO2 are still unresolved. Biofuels offer a good compromise in terms of cost availability and technology readiness level (TRL); however the non‐GHG emissions are not eliminated. Hydrogen and ammonia are among the worst in terms of overall energy and cost needed and may also need NOx clean‐up measures. Methanol from LNG needs CCS for decarbonization while methanol from biomass does not and also seems to be a good candidate in terms of energy financial cost and TRL. The present analysis consistently compares the various options and is useful for stakeholders involved in shipping decarbonization.
Effect of Microstructural and Environmental Variables on Ductility of Austenitic Stainless Steels
Sep 2019
Publication
Austenitic stainless steels are used extensively in harsh environments including for high-pressure gaseous hydrogen service. However the tensile ductility of this class of materials is very sensitive to materials and environmental variables. While tensile ductility is generally insufficient to qualify a material for hydrogen service ductility is an effective tool to explore microstructural and environmental variables and their effects on hydrogen susceptibility to inform understanding of the mechanisms of hydrogen effects in metals and to provide insight to microstructural variables that may improve relative performance. In this study hydrogen precharging was used to simulate high-pressure hydrogen environments to evaluate hydrogen effects on tensile properties. Several austenitic stainless steels were considered including both metastable and stable alloys. Room temperature and subambient temperature tensile properties were evaluated with three different internal hydrogen contents for type 304L and 316L austenitic stainless steels and one hydrogen content for XM-11. Significant ductility loss was observed for both metastable and stable alloys suggesting the stability of the austenitic phase is not sufficient to characterize the effects of hydrogen. Internal hydrogen does influence the character of deformation which drives local damage accumulation and ultimately fracture for both metastable and stable alloys. While a quantitative description of hydrogen-assisted fracture in austenitic stainless steels remains elusive these observations underscore the importance of the hydrogen-defect interactions and the accumulation of damage at deformation length scales.
Material Testing and Design Recommendations for Components Exposed to Hydrogen Enhanced Fatigue – the Mathryce Project
Sep 2013
Publication
The three years European MATHRYCE project dedicated to material testing and design recommendations for components exposed to hydrogen enhanced fatigue started in October 2012. Its main goal is to provide an “easy” to implement methodology based on lab-scale experimental tests under hydrogen gas to assess the service life of a real scale component taking into account fatigue loading under hydrogen gas. Dedicated experimental tests will be developed for this purpose. In the present paper the proposed approach is presented and compared to the methodologies currently developed elsewhere in the world.
European Hydrogen Safety Training Platform for First Responders- Hyresponse Project
Sep 2013
Publication
The paper presents HyResponse project i.e. a European Hydrogen Safety Training Platform that targets to train First responders to acquire professional knowledge and skills to contribute to FCH permitting process as approving authority. The threefold training program is described: educational training operational-level training on mock-up real scale transport and hydrogen stationary installations and innovative virtual training exercises reproducing entire accident scenarios. The paper highlights how the three pilot sessions for European First Responders in a face to face mode will be organized to get a feedback on the training program. The expected outputs are also presented i.e. the Emergency Response Guide and a public website including teaching material and online interactive virtual training.
Probability of Occurrence of ISO 14687-2 Contaminants in Hydrogen: Principles and Examples from Steam Methane Reforming and Electrolysis (Water and Chlor-alkali) Production Processes Model
Apr 2018
Publication
According to European Directive 2014/94/EU hydrogen providers have the responsibility to prove that their hydrogen is of suitable quality for fuel cell vehicles. Contaminants may originate from hydrogen production transportation refuelling station or maintenance operation. This study investigated the probability of presence of the 13 gaseous contaminants (ISO 14687-2) in hydrogen on 3 production processes: steam methane reforming (SMR) process with pressure swing adsorption (PSA) chlor-alkali membrane electrolysis process and water proton exchange membrane electrolysis process with temperature swing adsorption. The rationale behind the probability of contaminant presence according to process knowledge and existing barriers is highlighted. No contaminant was identified as possible or frequent for the three production processes except oxygen (frequent for chlor-alkali membrane process) carbon monoxide (frequent) and nitrogen (possible) for SMR with PSA. Based on it a hydrogen quality assurance plan following ISO 19880-8 can be devised to support hydrogen providers in monitoring the relevant contaminants.
Predicting Radiative Characteristics of Hydrogen and Hythane Jet Fires Using Firefoam
Sep 2013
Publication
A possible consequence of pressurized hydrogen release is an under-expanded jet fire. Knowledge of the flame length radiative heat flux and fraction as well as the effects of variations in ground reflectance is important for safety assessment. The present study applies an open source CFD code FireFOAM to study the radiation characteristics of hydrogen and hydrogen/methane jet fires. For combustion the eddy dissipation concept for multi-component fuels recently developed by the authors in the large eddy simulation (LES) framework is used. The radiative heat is computed with the finite volume discrete ordinates model in conjunction with the weighted-sum-of-gray-gases model for the absorption/emission coefficient. The pseudo-diameter approach is used in which the corresponding parameters are calculated using the correlations of Birch et al. [22]. The predicted flame length and radiant fraction are in good agreement with the measurements of Schefer et al. [2] Studer et al. [3] and Ekoto et al. [6]. In order to account for the effects of variation in ground surface reflectance the emissivity of hydrogen flames was modified following Ekoto et al. [6]. Four cases with different ground reflectance are computed. The predictions show that the ground surface reflectance only has minor effect on the surface emissive power of the hydrogen jet fire. The radiant fractions fluctuate from 0.168 to 0.176 close to the suggested value of 0.16 by Ekoto et al.[6] based on the analysis of their measurements.
Numerical Study on Spontaneous Ignition of Pressurized Hydrogen Release Through a Length of Tube
Sep 2009
Publication
The issue of spontaneous ignition of highly pressurized hydrogen release is of important safety concern e.g. in the assessment of risk and design of safety measures. This paper reports on recent numerical investigation of this phenomenon through releases via a length of tube. This mimics a potential accidental scenario involving release through instrument line. The implicit large eddy simulation (ILES) approach was used with the 5th-order weighted essentially non-oscillatory (WENO) scheme. A mixture-averaged multi-component approach was used for accurate calculation of molecular transport. The thin flame was resolved with fine grid resolution and the autoignition and combustion chemistry were accounted for using a 21-step kinetic scheme.<br/>The numerical study revealed that the finite rupture process of the initial pressure boundary plays an important role in the spontaneous ignition. The rupture process induces significant turbulent mixing at the contact region via shock reflections and interactions. The predicted leading shock velocity inside the tube increases during the early stages of the release and then stabilizes at a nearly constant value which is higher than that predicted by one-dimensional analysis. The air behind the leading shock is shock-heated and mixes with the released hydrogen in the contact region. Ignition is firstly initiated inside the tube and then a partially premixed flame is developed. Significant amount of shock-heated air and well developed partially premixed flames are two major factors providing potential energy to overcome the strong under-expansion and flow divergence following spouting from the tube.<br/>Parametric studies were also conducted to investigate the effect of rupture time release pressure tube length and diameter on the likelihood of spontaneous ignition. It was found that a slower rupture time and a lower release pressure will lead to increases in ignition delay time and hence reduces the likelihood of spontaneous ignition. If the tube length is smaller than a certain value even though ignition could take place inside the tube the flame is unlikely to be sufficiently strong to overcome under-expansion and flow divergence after spouting from the tube and hence is likely to be quenched.
Injecting Hydrogen into the Gas Network- A Literature Search
Jan 2015
Publication
Hydrogen injection into the GB gas network is a likely consequence of using excess offshore wind generated electricity to power large-scale onshore electrolysis plants. Government and DECC in particular now have a keen interest in supporting technologies that can take advantage of the continued use of the gas networks. HSE can contribute to the government’s Growth and Green agendas by effectively regulating and safely enabling this technology.
This report will allow HSE to regulate effectively by pulling together scientific and engineering knowledge regarding the hazards of conveying hydrogen/methane mixtures in network pipes and its use in consumer appliances into a single ‘state-of-play’ report. It enables Energy Division to consider and assess submissions for ‘gas quality’ exemptions to the Gas Safety (Management) Regulations 1996 (GSMR).
In particular the report has examined the following hazards:
This report will allow HSE to regulate effectively by pulling together scientific and engineering knowledge regarding the hazards of conveying hydrogen/methane mixtures in network pipes and its use in consumer appliances into a single ‘state-of-play’ report. It enables Energy Division to consider and assess submissions for ‘gas quality’ exemptions to the Gas Safety (Management) Regulations 1996 (GSMR).
In particular the report has examined the following hazards:
- conveyance of H2/CH4 mixtures in network pipes
- use of H2/CH4 mixtures in consumer appliances (domestic/commercial/industrial)
- explosion and damage characteristics (and ignition likelihood) of H2/CH4 mixtures
- effects on odourisation
Numerical Modelling of Hazards of Hydrogen Storage
Sep 2017
Publication
For the general public to use hydrogen as a vehicle fuel they must be able to handle hydrogen with the same degree of confidence as conventional liquid and gaseous fuels. The hazards associated with jet releases from accidental leaks in a vehicle-refuelling environment must be considered if hydrogen is stored and used as a high-pressure gas since a jet release can result in a fire or explosion. This paper describes the work done by us in modelling some of the consequences of accidental releases of hydrogen implemented in our Fire Explosion Release Dispersion (FRED) software. The new dispersion model is validated against experimental data available in the open literature. The model predictions of hydrogen gas concentration as a function of distance are in good agreement with experiments. In addition FRED has been used to model the consequence of the bursting of a vessel containing compressed hydrogen. The results obtained from FRED i.e. overpressure as a function of distance match well in comparison to experiments. Overall it is concluded that FRED can model the consequences of an accidental release of hydrogen and the blast waves generated from bursting of vessel containing compressed hydrogen
Development of a Hydrogen and Fuel Cell Vehicle Emergency Response National Template
Sep 2013
Publication
The California Fuel Cell Partnership (CaFCP) is currently working with key stakeholders like the US Department of Energy (DOE) and National Fire Protection Association (NFPA) to develop a national template for educating and training first responders about hydrogen fuel cell-powered vehicles (FCV) and hydrogen fuelling infrastructure. Currently there are several existing programs that either have some related FCV/hydrogen material or have plans to incorporate this in the future. To create a robust national emergency responder (ER) program the strongest elements from these existing programs are considered for incorporation into the template. Working with the key stakeholders the national template will be evaluated on a regular basis to ensure accurate and up to date information and resources and effective teaching techniques for the emergency response community. This paper describes the evaluation process discusses elements of the template and reports on the steps and progress to implementation; all in the effort to effectively support the emergency response community as hydrogen infrastructure develops and FCVs are leased or sold.
Hydrogen Storage Performance of the Multi-principal-component CoFeMnTiVZr Alloy in Electrochemical and Gas–solid Reactions
Jun 2020
Publication
The single-phase multi-principal-component CoFeMnTiVZr alloy was obtained by rapid solidification and examined by a combination of electrochemical methods and gas–solid reactions. X-ray diffraction and high-resolution transmission electron microscopy analyses reveal a hexagonal Laves-phase structure (type C14). Cyclic voltammetry and electrochemical impedance spectroscopy investigations in the hydrogen absorption/desorption region give insight into the absorption/desorption kinetics and the change in the desorption charge in terms of the applied potential. The thickness of the hydrogen absorption layer obtained by the electrochemical reaction is estimated by high-resolution transmission electron microscopy. The electrochemical hydrogen storage capacity for a given applied voltage is calculated from a series of chronoamperometry and cyclic voltammetry measurements. The selected alloy exhibits good stability for reversible hydrogen absorption and demonstrates a maximum hydrogen capacity of ∼1.9 wt% at room temperature. The amount of hydrogen absorbed in the gas–solid reaction reaches 1.7 wt% at 298 K and 5 MPa evidencing a good correlation with the electrochemical results.
Ignited Releases of Liquid Hydrogen: Safety Considerations of Thermal and Overpressure Effects
Sep 2013
Publication
If the ‘Hydrogen Economy’ is to progress more hydrogen fuelling stations are required. In the short term and in the absence of a hydrogen distribution network these fuelling stations will have to be supplied by liquid hydrogen (LH2) road tankers. Such a development will increase the number of tanker offloading operations significantly and these may need to be performed in close proximity to the general public. LH2 was first investigated experimentally as large-scale spills of LH2 at a rate of 60 litres per minute. Measurements were made on un-ignited releases which included the concentration of hydrogen in air thermal gradients in the concrete substrate liquid pool formation and temperatures within the pool. Computational modelling on the un-ignited spills was also performed. The experimental work on ignited releases of LH2 detailed in this paper is a continuation of the work performed by Royle and Willoughby. The experimental findings presented are split into three phenomena; jet-fires in high and low wind conditions ‘burn-back’ of ignited clouds and secondary explosions post ‘burn-back’. The aim of this work was to determine the hazards and severity of a realistic ignited spill of LH2 focussing on; flammability limits of an LH2 vapour cloud flame speeds through an LH2 vapour cloud and subsequent radiative heat levels after ignition. An attempt was made to estimate the magnitude of an explosion that occurred during one of the releases. The results of these experiments will inform the wider hydrogen community and contribute to the development of more robust modelling tools. The resulting data were used to propose safety distances for LH2 offloading facilities which will help to update and develop guidance for codes and standards.
Innovation Insights Brief 2019: New Hydrogen Economy - Hope or Hype?
Jun 2019
Publication
Hydrogen and fuel cell technologies have experienced cycles of high expectations followed by impractical realities. This time around however falling renewable energy and fuel cell prices stringent climate change requirements and the discrete involvement of China are step changes. The combination of these factors is leading to realistic potential for hydrogen’s role in the Grand Transition.<br/>Having conducted exploratory interviews with leaders from all around the globe the World Energy Council is featuring eight use cases which illustrate hydrogen’s potential. These range from decarbonising hard-to-abate sectors such as heat industry and transport to supporting the integration of renewables and providing an energy storage solution.<br/>Dr Angela Wilkinson Secretary General and former Senior Director Scenarios and Business Insights: “Green and blue hydrogen can refresh those parts of the energy system transition that electrification cannot reach.”<br/>This Innovation Insights Brief is part of a series of publications by the World Energy Council focused on Innovation. In a fast-paced era of disruptive changes this brief aims at facilitating strategic sharing of knowledge between the Council’s members and the other energy stakeholders and policy shapers.
Modelling and Simulation of Lean Hydrogen-air Deflagrations
Sep 2013
Publication
The paper describes CFD modelling of lean hydrogen mixture deflagrations. Large eddy simulation (LES) premixed combustion model developed at the University of Ulster to account phenomena related to large-scale deflagrations was adjusted specifically for lean hydrogen-air flames. Experiments by Kumar (2006) on lean hydrogen-air mixture deflagrations in a 120 m3 vessel at initially quiescent conditions were simulated. 10% by volume hydrogen-air mixture was chosen for simulation to provide stable downward flame propagation; experiments with the smallest vent area 0.55 m2 were used as having the least apparent flame instabilities affecting the pressure dynamics. Deflagrations with igniter located centrally near vent and at far from the vent wall were simulated. Analysis of simulation results and experimental pressure dynamics demonstrated that flame instabilities developing after vent opening made the significant contribution to maximum overpressure in the considered experiments. Potential causes of flame instabilities are discussed and their comparative role for different igniter locations is demonstrated.
Clean Energy and the Hydrogen Economy
Jan 2017
Publication
In recent years new-found interest in the hydrogen economy from both industry and academia has helped to shed light on its potential. Hydrogen can enable an energy revolution by providing much needed flexibility in renewable energy systems. As a clean energy carrier hydrogen offers a range of benefits for simultaneously decarbonizing the transport residential commercial and industrial sectors. Hydrogen is shown here to have synergies with other low-carbon alternatives and can enable a more cost-effective transition to de-carbonized and cleaner energy systems. This paper presents the opportunities for the use of hydrogen in key sectors of the economy and identifies the benefits and challenges within the hydrogen supply chain for power-to-gas power-to-power and gas-to-gas supply pathways. While industry players have already started the market introduction of hydrogen fuel cell systems including fuel cell electric vehicles and micro-combined heat and power devices the use of hydrogen at grid scale requires the challenges of clean hydrogen production bulk storage and distribution to be resolved. Ultimately greater government support in partnership with industry and academia is still needed to realize hydrogen's potential across all economic sectors.
Link to document download on Royal Society Website
Link to document download on Royal Society Website
Innovation Insights Brief: Energy Scenarios Comparison Review
Apr 2019
Publication
Energy transition is a part of a much wider Grand Transition which is not all about energy. Energy transition cannot be achieved all at once or by any one actor. Relying only on better energy modelling and forecasting to guide successful transition will be fatal even in a data-rich era.<br/>It is timely for energy leaders to ask:<br/>Are global energy scenarios achieving their potential in opening up action on new energy futures?<br/>How do the Council’s World Energy Scenarios compare with global energy outlooks scenarios and normative visions used by others and what can we learn by contrasting the increasing richness of energy futures thinking?<br/>In anticipation of the 24th World Energy Congress the Council is refreshing its global energy foresight and updating its global scenarios narratives. The focus is on an ‘innovation twist to 2040’ and the use of scenarios to explore and navigate new exponential growth opportunities for accelerating successful energy transition in an era of epic and disruptive innovation.<br/>As a part of the refresh the Council has conducted a comparison study of global energy scenarios in order to test the continued plausibility relevance and challenge of its own existing scenario set the World Energy Scenarios 2016 launched at the 23rd World Energy Congress in Istanbul in 2016.<br/>By comparing the methods narratives and assumptions associated with a benchmarkable set of global energy futures initiatives and studies the Council seeks to provide our members with clearer understanding and new insights on energy transition while preparing them to better engage with leadership dialogues which pivot on visions of a new energy future.<br/>The review also provides an opportunity to reflect on the challenges and obstacles for utilising global energy scenarios to drive impact and the challenges in bridging agile and flexible qualitative storytelling with long term quantitative energy modelling."
Environmental Sustainability of Alternative Marine Propulsion Technologies Powered by Hydrogen - A Life Cycle Assessment Approach
Jan 2022
Publication
Shipping is a very important source of pollution worldwide. In recent years numerous actions and measures have been developed trying to reduce the levels of greenhouse gases (GHG) from the marine exhaust emissions in the fight against climate change boosting the Sustainable Development Goal 13. Following this target the action of hydrogen as energy vector makes it a suitable alternative to be used as fuel constituting a very promising energy carrier for energy transition and decarbonization in maritime transport. The objective of this study is to develop an ex-ante environmental evaluation of two promising technologies for vessels propulsion a H2 Polymeric Electrolytic Membrane Fuel Cell (PEMFC) and a H2 Internal Combustion Engine (ICE) in order to determine their viability and eligibility compared to the traditional one a diesel ICE. The applied methodology follows the Life Cycle Assessment (LCA) guidelines considering a functional unit of 1 kWh of energy produced. LCA results reveal that both alternatives have great potential to promote the energy transition particularly the H2 ICE. However as technologies readiness level is quite low it was concluded that the assessment has been conducted at a very early stage so their sustainability and environmental performance may change as they become more widely developed and deployed which can be only achieved with political and stakeholder’s involvement and collaboration.
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