United Kingdom
Economic Impact Assessment: Hydrogen is Ready to Power the UK’s Green Recovery
Aug 2020
Publication
Hydrogen solutions have a critical role to play in the UK not only in helping the nation meet its net-zero target but in creating the economic growth and jobs that will kickstart the green recovery.
The Government must act now to ensure that the UK capitalises on the opportunity presented by hydrogen and builds a world-leading industry.
COVID-19 has caused significant economic upheaval across the country with unemployment expected to reach up to 14.8 per cent by the end of 20201. The UK must identify those areas of the economy which have significant economic growth potential and can deliver long-term and sustainable increases in GVA and jobs. It will be important to consider regional factors and ensure that investment is targeted in those areas that have been hardest hit by the crisis.
Many major economies have identified hydrogen as a key part of both decarbonisation and economic recovery. As part of its stimulus package Germany announced a €9billion investment in green hydrogen solutions aiming to deploy 5GW by 2030. The Hydrogen Council estimates a future hydrogen and equipment market worth $2.5 trillion globally by 2050 supporting 30 million new jobs.
Hydrogen offers the UK a pathway to deep cost-effective decarbonisation while delivering economic growth and job creation. It should therefore be at the heart of the Government’s green recovery programme ensuring that the UK builds back better and greener.
The Government must act now to ensure that the UK capitalises on the opportunity presented by hydrogen and builds a world-leading industry.
COVID-19 has caused significant economic upheaval across the country with unemployment expected to reach up to 14.8 per cent by the end of 20201. The UK must identify those areas of the economy which have significant economic growth potential and can deliver long-term and sustainable increases in GVA and jobs. It will be important to consider regional factors and ensure that investment is targeted in those areas that have been hardest hit by the crisis.
Many major economies have identified hydrogen as a key part of both decarbonisation and economic recovery. As part of its stimulus package Germany announced a €9billion investment in green hydrogen solutions aiming to deploy 5GW by 2030. The Hydrogen Council estimates a future hydrogen and equipment market worth $2.5 trillion globally by 2050 supporting 30 million new jobs.
Hydrogen offers the UK a pathway to deep cost-effective decarbonisation while delivering economic growth and job creation. It should therefore be at the heart of the Government’s green recovery programme ensuring that the UK builds back better and greener.
You can download the whole document from the Hydrogen Taskforce website at the following links
- Economic Impact Assessment Summary
- Economic impact Assessment Methodology
- Economic impact Assessment of the Hydrogen Value Chain of the UK infographic
- Imperial College Consultants Review of the EIA.
Modelling a Kinetic Deviation of the Magnesium Hydrogenation Reaction at Conditions Close to Equilibrium
May 2019
Publication
A model has been derived for the magnesium hydrogenation reaction at conditions close to equilibrium. The reaction mechanism involves an adsorption element where the model is an extension of the Langmuir adsorption model. The concept of site availability (σs) is introduced whereby it has the capability to reduce the reaction rate. To improve representation of σs an adaptable semi-empirical equation has been developed. Supplement to the surface reaction a rate equation has been derived considering resistance effects. It was found that close to equilibrium surface resistance dominated the reaction.
Hy4Heat Final Progress Report
Apr 2022
Publication
A final report covering covering activity in 2021 and early 2022 including: standards and certification safety assessment and appliance and meter development. It has a foreword from Mark Taylor BEIS Deputy Director for Energy Innovation and an introduction letter from Arup Hy4Heat Director Mark Neller.
Modelling Liquid Hydrogen Release and Spread on Water
Sep 2017
Publication
Consequence modelling of high potential risks of usage and transportation of cryogenic liquids yet requires substantial improvements. Among the cryogenics liquid hydrogen (LH2) needs especial treatments and a comprehensive understanding of spill and spread of liquid and dispersion of vapor. Even though many of recent works have shed lights on various incidents such as spread dispersion and explosion of the liquid over land less focus was given on spill and spread of LH2 onto water. The growing trend in ship transportation has enhanced risks such as ships’ accidental releases and terrorist attacks which may ultimately lead to the release of the cryogenic liquid onto water. The main goal of the current study is to present a computational fluid dynamic (CFD) approach using OpenFOAM to model release and spread of LH2 over water substrate and discuss previous approaches. It also includes empirical heat transfer equations due to boiling and computation of evaporation rate through an energy balance. The results of the proposed model will be potentially used within another coupled model that predicts gas dispersion]. This work presents a good practice approach to treat pool dynamics and appropriate correlations to identify heat flux from different sources. Furthermore some of the previous numerical approaches to redistribute or in some extend manipulate the LH2 pool dynamic are brought up for discussion and their pros and cons are explained. In the end the proposed model is validated by modelling LH2 spill experiment carried out in 1994 at the Research Centre Juelich in Germany.
Enabling Efficient Networks For Low Carbon Futures: Options for Governance and Regulation
Sep 2015
Publication
This report summarises key themes emerging from the Energy Technologies Institute’s (ETI) project ‘Enabling efficient networks for low carbon futures’. The project aimed to explore the options for reforming the governance and regulatory arrangements to enable major changes to and investment in the UK’s energy network infrastructures. ETI commissioned four expert perspectives on the challenges and options facing the UK.
Burning Velocity and Markstein Length Blending Laws for Methane/Air and Hydrogen/Air Blends
Sep 2016
Publication
"Because of the contrasting chemical kinetics of methane and hydrogen combustion the development of blending laws for laminar burning velocity ul and Markstein length for constituent mixtures of CH4/air and H2/air presents a formidable challenge. Guidance is sought through a study of analytical expressions for laminar burning velocity. For the prediction of burning velocities of blends six blending laws were scrutinised. The predictions were compared with the measured burning velocities made by Hu et al. under atmospheric conditions. These covered equivalence ratios ranging from 0.6 to 1.3 and the full fuel range for H2 addition to CH4. This enabled assessments to be made of the predictive accuracy of the six laws. The most successful law is one developed in the course of the present study involving the mass fraction weighting of the product of ul density heat of reaction and specific heat divided by the thermal conductivity of the mixture. There was less success from attempts to obtain a comparably successful blending law for the flame speed Markstein length Lb despite scrutiny of several possibilities. Details are given of two possible approaches one based on the fractional mole concentration of the deficient reactant. A satisfactory empirical law employs mass fraction weighting of the product ulLb.
HyDeploy Webinar - Public Perceptions
May 2020
Publication
HyDeploy is a pioneering hydrogen energy project designed to help reduce UK CO2 emissions and reach the Government’s net zero target for 2050.
As the first ever live demonstration of hydrogen in homes HyDeploy aims to prove that blending up to 20% volume of hydrogen with natural gas is a safe and greener alternative to the gas we use now. It is providing evidence on how customers don’t have to change their cooking or heating appliances to take the blend which means less disruption and cost for them. It is also confirming initial findings that customers don’t notice any difference when using the hydrogen blend.
As the first ever live demonstration of hydrogen in homes HyDeploy aims to prove that blending up to 20% volume of hydrogen with natural gas is a safe and greener alternative to the gas we use now. It is providing evidence on how customers don’t have to change their cooking or heating appliances to take the blend which means less disruption and cost for them. It is also confirming initial findings that customers don’t notice any difference when using the hydrogen blend.
OIES Podcast – Hydrogen: Current Challenges in Creating Viable Business Cases
Apr 2022
Publication
In this podcast David Ledesma talks to Martin Lambert Head of OIES Hydrogen Research about the key messages from the recent European Hydrogen Conference and how they fit with the ongoing research in OIES. In particular they cover the heightened energy security concerns following the Russian invasion of Ukraine and hydrogen ambitions in the REPowerEU document published by the European Commission in early March 2002. They then go on to talk about the growing realism about where hydrogen is more likely to play a role and some of the key challenges to be overcome. Addressing the challenges of creating business cases for use of hydrogen in specific sectors and for transporting it to customers the conversation also addresses the importance of hydrogen storage and the recognition that this area needs more focus both technically and commercially. Finally they talk about the geopolitics of hydrogen and how energy security concerns may influence future development pathways.
The podcast can be found on their website
The podcast can be found on their website
High Pressure Hydrogen Tank Rupture: Blast Wave and Fireball
Oct 2015
Publication
In the present study the phenomena of blast wave and fireball generated by high pressure (35 MPa) hydrogen tank (72 l) rupture have been investigated numerically. The realizable k-ε turbulence model was applied. The simulation of the combustion process is based on the eddy dissipation model coupled with the one step chemical reaction mechanism. Simulation results are compared with experimental data from a stand-alone hydrogen fuel tank rapture following a bonfire test. The model allows the study of the interaction between combustion process and blast wave propagation. Simulation results (blast wave overpressure fireball shape and size) follow the trends observed in the experiment.
The Mitigation of Hydrogen Explosions Using Water Fog, Nitrogen Dilution and Chemical Additives
Sep 2013
Publication
This paper describes research work that has been performed at LSBU using both a laminar burning velocity rig and a small scale cylindrical explosion vessel to explore the use of very fine water fog nitrogen dilution and sodium hydroxide additives in the mitigation of hydrogen deflagrations. The results of the work suggest that using a combination of the three measures together produces the optimal mitigation performance and can be extremely effective in: inhibiting the burning velocity reducing the rate of explosion overpressure rise and narrowing the flammability limits of hydrogen-oxygen-nitrogen mixtures.
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.
Vented Hydrogen Deflagrations in an ISO Container
Sep 2017
Publication
The commercial deployment of hydrogen will often involve housing portable hydrogen fuel cell power units in 20-foot or 40-foot shipping containers. Due to the unique properties of hydrogen hazards identification and consequence analysis is essential to safe guard the installations and design measures to mitigate potential hazards. In the present study the explosion of a premixed hydrogen-air cloud enclosed in a 20-foot container of 20’ x 8’ x 8’.6” is investigated in detail numerically. Numerical simulations have been performed using HyFOAM a dedicated solver for vented hydrogen explosions developed in-house within the frame of the open source computational fluid dynamics (CFD) code OpenFOAM toolbox. The flame wrinkling combustion model is used for modelling turbulent deflagrations. Additional sub-models have been added to account for lean combustion properties of hydrogen-air mixtures. The predictions are validated against the recent experiments carried out by Gexcon as part of the HySEA project supported by the Fuel Cells and Hydrogen 2 Joint Undertaking (FCH 2 JU) under the Horizon 2020 Framework Programme for Research and Innovation. The effects of congestion within the containers on the generated overpressures are also investigated.
Hydrogen for Cooking: A Review of Cooking Technologies, Renewable Hydrogen Systems and Techno-Economics
Dec 2022
Publication
About 3 billion people use conventional carbon-based fuels such as wood charcoal and animal dung for their daily cooking needs. Cooking with biomass causes deforestation and habitat loss emissions of greenhouse gases and smoke pollution that affects people’s health and well-being. Hydrogen can play a role in enabling clean and safe cooking by reducing household air pollution and reducing greenhouse gas emissions. This first-of-a-kind review study on cooking with hydrogen assessed existing cooking technologies and hydrogen systems in developing country contexts. Our critical assessment also included the modelling and experimental studies on hydrogen. Renewable hydrogen systems and their adoptability in developing countries were analysed. Finally we presented a scenario for hydrogen production pathways in developing countries. Our findings indicated that hydrogen is attractive and can be safely used as a cooking fuel. However radical and disruptive models are necessary to transform the traditional cooking landscape. There is a need to develop global south-based hydrogen models that emphasize adoptability and capture the challenges in developing countries. In addition the techno-economic assumptions of the models vary significantly leading to a wide-ranging levelized cost of electricity. This finding underscored the necessity to use comprehensive techno-economic assumptions that can accurately predict hydrogen costs.
Mapping of Hydrogen Fuel Quality in Europe
Nov 2020
Publication
As part of FCH-JU funded HyCoRA project running from 2014 to 2017 28 gaseous and 13 particulate samples were collected from hydrogen refuelling stations in Europe. Samples were collected with commercial sampling instruments and analysis performed in compliance with prevailing fuel quality standards. Sampling was conducted with focus on diversity in feedstock as well as commissioning date of the HRS. Results indicate that the strategy for sampling was good. No evidence of impurity cross-over was observed. Parallel samples collected indicate some variation in analytical results. It was however found that fuel quality was generally good. Fourteen analytical results were in violation with the fuel tolerance limits. Therefore eight or 29% of the samples were in violation with the fuel quality requirements. Nitrogen oxygen and organics were the predominant impurities quantified. Particulate impurities were found to be within fuel quality specifications. No correlation between fuel quality and hydrogen feedstock or HRS commissioning date was found. Nitrogen to oxygen ratios gave no indication of samples being contaminated by air. A comparison of analytical results between two different laboratories were conducted. Some difference in analytical results were observed.
Innovation Insights Brief - Five Steps to Energy Storage
Jan 2020
Publication
As the global electricity systems are shaped by decentralisation digitalisation and decarbonisation the World Energy Council’s Innovation Insights Briefs explore the new frontiers in energy transitions and the challenges of keeping pace with fast moving developments. We use leadership interviews to map the state of play and case studies across the whole energy landscape and build a broader and deeper picture of new developments within and beyond the new energy technology value chain and business ecosystem.<br/><br/>With major decarbonisation efforts and the scaling up of renewable power generation the widespread adoption of energy storage continues to be described as the key game changer for electricity systems. Affordable storage systems are a critical missing link between intermittent renewable power and a 24/7 reliability net-zero carbon scenario. Beyond solving this salient challenge energy storage is being increasingly considered to meet other needs such as relieving congestion or smoothing out the variations in power that occur independently of renewable-energy generation. However whilst there is plenty of visionary thinking recent progress has focused on short-duration and battery-based energy storage for efficiency gains and ancillary services; there is limited progress in developing daily weekly and even seasonal cost-effective solutions which are indispensable for a global reliance on intermittent renewable energy sources.
Analysis of Wind to Hydrogen Production and Carbon Capture Utilisation and Storage Systems for Novel Production of Chemical Energy Carriers
Apr 2022
Publication
As the offshore energy landscape transitions to renewable energy useful decommissioned or abandoned oil and gas infrastructure can be repurposed in the context of the circular economy. Oil and gas platforms for example offer opportunity for hydrogen (H2) production by desalination and electrolysis of sea water using offshore wind power. However as H2 storage and transport may prove challenging this study proposes to react this H2 with the carbon dioxide (CO2) stored in depleted reservoirs. Thus producing a more transportable energy carriers like methane or methanol in the reservoir. This paper presents a novel thermodynamic analysis of the Goldeneye reservoir in the North Sea in Aspen Plus. For Goldeneye which can store 30 Mt of CO2 at full capacity if connected to a 4.45 GW wind farm it has the potential to produce 2.10 Mt of methane annually and abate 4.51 Mt of CO2 from wind energy in the grid.
Recent Progress in Ammonia Fuel Cells and their Potential Applications
Nov 2020
Publication
Conventional technologies are largely powered by fossil fuel exploitation and have ultimately led to extensive environmental concerns. Hydrogen is an excellent carbon-free energy carrier but its storage and long-distance transportation remain big challenges. Ammonia however is a promising indirect hydrogen storage medium that has well-established storage and transportation links to make it an accessible fuel source. Moreover the notion of ‘green ammonia’ synthesised from renewable energy sources is an emerging topic that may open significant markets and provide a pathway to decarbonise a variety of applications reliant on fossil fuels. Herein a comparative study based on the chosen design working principles advantages and disadvantages of direct ammonia fuel cells is summarised. This work aims to review the most recent advances in ammonia fuel cells and demonstrates how close this technology type is to integration with future applications. At present several challenges such as material selection NOx formation CO2 tolerance limited power densities and long term stability must still be overcome and are also addressed within the contents of this review.
Deep Decarbonisation Pathways for Scottish Industries: Research Report
Dec 2020
Publication
The following report is a research piece outlining the potential pathways for decarbonisation of Scottish Industries. Two main pathways are considered hydrogen and electrification with both resulting in similar costs and levels of carbon reduction.
The Role of Hydrogen and Fuel Cells in the Global Energy System
Dec 2018
Publication
Hydrogen technologies have experienced cycles of excessive expectations followed by disillusion. Nonetheless a growing body of evidence suggests these technologies form an attractive option for the deep decarbonisation of global energy systems and that recent improvements in their cost and performance point towards economic viability as well. This paper is a comprehensive review of the potential role that hydrogen could play in the provision of electricity heat industry transport and energy storage in a low-carbon energy system and an assessment of the status of hydrogen in being able to fulfil that potential. The picture that emerges is one of qualified promise: hydrogen is well established in certain niches such as forklift trucks while mainstream applications are now forthcoming. Hydrogen vehicles are available commercially in several countries and 225 000 fuel cell home heating systems have been sold. This represents a step change from the situation of only five years ago. This review shows that challenges around cost and performance remain and considerable improvements are still required for hydrogen to become truly competitive. But such competitiveness in the medium-term future no longer seems an unrealistic prospect which fully justifies the growing interest and policy support for these technologies around the world.
Monte-Carlo-analysis of Minimum Load Cycle Requirements for Composite Cylinders for Hydrogen
Sep 2017
Publication
Existing regulations and standards for the approval of composite cylinders in hydrogen service are currently based on deterministic criteria (ISO 11119-3 UN GTR No. 13). This paper provides a systematic analysis of the load cycle properties resulting from these regulations and standards. Their characteristics are compared with the probabilistic approach of the BAM. Based on Monte-Carlo simulations the available design range of all concepts is compared. In addition the probability of acceptance for potentially unsafe design types is determined.
Electric and Hydrogen Buses: Shifting from Conventionally Fuelled Cars in the UK
May 2020
Publication
For the UK to meet their national target of net zero emissions as part of the central Paris Agreement target further emphasis needs to be placed on decarbonizing public transport and moving away from personal transport (conventionally fuelled vehicles (CFVs) and electric vehicles (EVs)). Electric buses (EBs) and hydrogen buses (HBs) have the potential to fulfil requirements if powered from low carbon renewable energy sources.
A comparison of carbon dioxide (CO2) emissions produced from conventionally fuelled buses (CFB) EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition emissions per person at different vehicle capacity levels (100% 75% 50% and 25%) were projected for CFBs HBs EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.
Results indicated that CFVs produced 30 g CO2km−1 per person compared to 16.3 g CO2 km−1 per person by CFBs by 2050. At 100% capacity under the two-degree scenario CFB emissions were 36 times higher than EBs 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.
Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.
A comparison of carbon dioxide (CO2) emissions produced from conventionally fuelled buses (CFB) EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition emissions per person at different vehicle capacity levels (100% 75% 50% and 25%) were projected for CFBs HBs EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.
Results indicated that CFVs produced 30 g CO2km−1 per person compared to 16.3 g CO2 km−1 per person by CFBs by 2050. At 100% capacity under the two-degree scenario CFB emissions were 36 times higher than EBs 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.
Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.
A Modelling Study for the Integration of a PEMFC Micro-CHP in Domestic Building Services Design
May 2018
Publication
Fuel cell based micro-combined heat and power (CHP) units used for domestic applications can provide significant cost and environmental benefits for end users and contribute to the UK’s 2050 emissions target by reducing primary energy consumption in dwellings. Lately there has been increased interest in the development of systematic methods for the design of such systems and their smoother integration with domestic building services. Several models in the literature whether they use a simulation or an optimisation approach ignore the dwelling side of the system and optimise the efficiency or delivered power of the unit. However the design of the building services is linked to the choice of heating plant and its characteristics. Adding the dwelling’s energy demand and temperature constraints in a model can produce more general results that can optimise the whole system not only the micro-CHP unit. The fuel cell has various heat streams that can be harvested to satisfy heat demand in a dwelling and the design can vary depending on the proportion of heat needed from each heat stream to serve the energy demand. A mixed integer non-linear programming model (MINLP) that can handle multiple heat sources and demands is presented in this paper. The methodology utilises a process systems engineering approach. The model can provide a design that integrates the temperature and water flow constraints of a dwelling’s heating system with the heat streams within the fuel cell processes while optimising total CO2 emissions. The model is demonstrated through different case studies that attempt to capture the variability of the housing stock. The predicted CO2 emissions reduction compared to a conventionally designed building vary from 27% to 30% and the optimum capacity of the fuel cell ranges between 1.9 kW and 3.6 kW. This research represents a significant step towards an integrated fuel cell micro-CHP and dwelling design.
High-stability, High-capacity Oxygen Carriers: Iron Oxide-perovskite Composite Materials for Hydrogen Production by Chemical Looping
Jun 2015
Publication
Iron oxide has been widely used as an oxygen carrier material (OCM) for hydrogen production by chemical looping due to its favourable thermodynamic properties. In spite of this iron oxide loses much of its activity after redox cycling mainly due to sintering and agglomeration. Perovskites such as La0.7Sr0.3FeO3-d (LSF731) have been suggested as potential candidate OCMs for hydrogen production due to their excellent oxygen transport properties and stability under cycling. However hydrogen production per cycle for a similar carrier weight is lower than with iron oxide. This work proposes the use of composite OCMs made of iron oxide clusters embedded in an LSF731 matrix. The perovskite matrix facilitates oxygen transport to the iron oxide clusters while preventing agglomeration. Two preparation methods mechanical mixing and a modified Pechini method were used to obtain composite materials with different iron oxide weight fractions 11 and 30 wt.%. The reactivity of these OCMs was studied in a thermogravimetric analyser. Hydrogen production and carrier stability were investigated in a microreactor over 25 redox cycles while periodically feeding carbon monoxide and water in order to produce carbon dioxide and hydrogen in separate streams. Hydrogen production was stable over 25 cycles for LSF731 and the composite OCM with 30 wt.% iron oxide produced by the modified Pechini method but iron oxide particles alone underwent a decrease in the hydrogen production with cycling. The hydrogen production during the 25th cycle was eight times higher for the composite material than for iron oxide alone and four times higher than for LSF731. The hydrogen production was therefore also higher than that expected from a simple combination of the iron oxide and LSF731 alone indicating a synergetic effect whereby the LSF731 may have a higher effective oxygen capacity when in the form of the composite material.
Combustion Features of CH4/NH3/H2 Ternary Blends
Mar 2022
Publication
The use of so-called “green” hydrogen for decarbonisation of the energy and propulsion sectors has attracted considerable attention over the last couple of decades. Although advancements are achieved hydrogen still presents some constraints when used directly in power systems such as gas turbines. Therefore another vector such as ammonia can serve as a chemical to transport and distribute green hydrogen whilst its use in gas turbines can limit combustion reactivity compared to hydrogen for better operability. However pure ammonia on its own shows slow complex reaction kinetics which requires its doping by more reactive molecules thus ensuring greater flame stability. It is expected that in forthcoming years ammonia will replace natural gas (with ~ 90% methane in volume) in power and heat production units thus making the co-firing of ammonia/methane a clear path towards replacement of CH4 as fossil fuel. Hydrogen can be obtained from the precracking of ammonia thus denoting a clear path towards decarbonisation by the use of ammonia/hydrogen blends. Therefore ammonia/methane/hydrogen might be co-fired at some stage in current combustion units hence requiring a more intrinsic analysis of the stability emissions and flame features that these ternary blends produce. In return this will ensure that transition from natural gas to renewable energy generated e-fuels such as so-called “green” hydrogen and ammonia is accomplished with minor detrimentals towards equipment and processes. For this reason this work presents the analysis of combustion properties of ammonia/methane/hydrogen blends at different concentrations. A generic tangential swirl burner was employed at constant power and various equivalence ratios. Emissions OH*/NH*/NH2*/CH* chemiluminescence operability maps and spectral signatures were obtained and are discussed. The extinction behaviour has also been investigated for strained laminar premixed flames. Overall the change from fossils to e-fuels is led by the shift in reactivity of radicals such as OH CH CN and NH2 with an increase of emissions under low and high ammonia content. Simultaneously hydrogen addition improves operability when injected up to 30% (vol) an amount at which the hydrogen starts governing the reactivity of the blends. Extinction strain rates confirm phenomena found in the experiments with high ammonia blends showing large discrepancies between values at different hydrogen contents. Finally a 20/55/25% (vol) methane/ammonia/hydrogen blend seems to be the most promising at high equivalence ratios (1.2) with no apparent flashback low emissions and moderate formation of NH2/OH radicals for good operability.
HyDeploy: The UK’s First Hydrogen Blending Deployment Project
Mar 2019
Publication
The HyDeploy project is the UK’s first practical project to demonstrate that hydrogen can be safely blended into the natural-gas distribution system without requiring changes to appliances and the associated disruption. The project is funded under Ofgem’s Network Innovation Competition and is a collaboration between Cadent Gas Northern Gas Networks Progressive Energy Ltd Keele University (Keele) Health & Safety Laboratory and ITM Power. Cadent and Northern Gas Networks are the Gas Distribution Network sponsors of the project. Keele University is the host site providing the gas-distribution network which will receive the hydrogen blend. Keele University is the largest campus university in the UK. Health & Safety Laboratory provides the scientific laboratories and experimental expertise. ITM Power provides the electrolyser that produces the hydrogen. Progressive Energy Ltd is the project developer and project manager. HyDeploy is structured into three distinct phases. The first is an extensive technical programme to establish the necessary detailed evidence base in support of an application to the Health & Safety Executive for Exemption to Schedule 3 of the Gas Safety (Management) Regulations (GS(M)R) to permit the injection of hydrogen at 20 mol%. This is required to allow hydrogen to be blended into a natural-gas supply above the current British limit of 0.1 mol%.
The second phase comprises the construction of the electrolyser and grid entry unit along with the necessary piping and valves to allow hydrogen to be mixed and injected into the Keele University gas-distribution network and to ensure all necessary training of operatives is conducted before injection. The third phase is the trial itself which is due to start in the summer of 2019 and last around 10 months. The trial phase also provides an opportunity to undertake further experimental activities related to the operational network to support the pathway to full deployment of blended gas. The outcome of HyDeploy is principally developing the initial evidence base that hydrogen can be blended into a UK operational natural-gas network without disruption to customers and without prejudicing the safety of end users. If deployed at scale hydrogen blending at 20 mol% would unlock 29 TWh pa of decarbonized heat and provide a route map for deeper savings. The equivalent carbon savings of a national roll-out of a 20-mol% hydrogen blend would be to remove 2.5 million cars from the road.
HyDeploy is a seminal UK project for the decarbonization of the gas grid via hydrogen deployment and will provide the first stepping stone for setting technical operational and regulatory precedents of the hydrogen vector.
The second phase comprises the construction of the electrolyser and grid entry unit along with the necessary piping and valves to allow hydrogen to be mixed and injected into the Keele University gas-distribution network and to ensure all necessary training of operatives is conducted before injection. The third phase is the trial itself which is due to start in the summer of 2019 and last around 10 months. The trial phase also provides an opportunity to undertake further experimental activities related to the operational network to support the pathway to full deployment of blended gas. The outcome of HyDeploy is principally developing the initial evidence base that hydrogen can be blended into a UK operational natural-gas network without disruption to customers and without prejudicing the safety of end users. If deployed at scale hydrogen blending at 20 mol% would unlock 29 TWh pa of decarbonized heat and provide a route map for deeper savings. The equivalent carbon savings of a national roll-out of a 20-mol% hydrogen blend would be to remove 2.5 million cars from the road.
HyDeploy is a seminal UK project for the decarbonization of the gas grid via hydrogen deployment and will provide the first stepping stone for setting technical operational and regulatory precedents of the hydrogen vector.
Paths to Low-cost Hydrogen Energy at a Scale for Transportation Applications in the USA and China via Liquid-hydrogen Distribution Networks
Dec 2019
Publication
The cost of delivered H2 using the liquid-distribution pathway will approach $4.3–8.0/kg in the USA and 26–52 RMB/kg in China by around 2030 assuming large-scale adoption. Historically hydrogen as an industrial gas and a chemical feedstock has enjoyed a long and successful history. However it has been slow to take off as an energy carrier for transportation despite its benefits in energy diversity security and environmental stewardship. A key reason for this lack of progress is that the cost is currently too high to displace petroleum-based fuels. This paper reviews the prospects for hydrogen as an energy carrier for transportation clarifies the current drivers for cost in the USA and China and shows the potential for a liquid-hydrogen supply chain to reduce the costs of delivered H2. Technical and economic trade-offs between individual steps in the supply chain (viz. production transportation refuelling) are examined and used to show that liquid-H2 (LH2) distribution approaches offer a path to reducing the delivery cost of H2 to the point at which it could be competitive with gasoline and diesel fuel.
PRD Hydrogen Release and Dispersion, a Comparison of CFD Results Obtained from Using Ideal and Real Gas Law Properties.
Sep 2005
Publication
In this paper CFD techniques were applied to the simulations of hydrogen release from a 400-bar tank to ambient through a Pressure Relieve Device (PRD) 6 mm (¼”) opening. The numerical simulations using the TOPAZ software developed by Sandia National Laboratory addressed the changes of pressure density and flow rate variations at the leak orifice during release while the PHOENICS software package predicted extents of various hydrogen concentration envelopes as well as the velocities of gas mixture for the dispersion in the domain. The Abel-Noble equation of state (AN-EOS) was incorporated into the CFD model implemented through the TOPAZ and PHOENICS software to accurately predict the real gas properties for hydrogen release and dispersion under high pressures. The numerical results were compared with those obtained from using the ideal gas law and it was found that the ideal gas law overestimates the hydrogen mass release rates by up to 35% during the first 25 seconds of release. Based on the findings the authors recommend that a real gas equation of state be used for CFD predictions of high-pressure PRD releases.
Theoretical Insights into the Hydrogen Evolution Reaction on the Ni3N Electrocatalyst
Jun 2021
Publication
Ni-based catalysts are attractive alternatives to noble metal electrocatalysts for the hydrogen evolution reaction (HER). Herein we present a dispersion-corrected density functional theory (DFT-D3) insight into HER activity on the (111) (110) (001) and (100) surfaces of metallic nickel nitride (Ni3N). A combination of water and hydrogen adsorption was used to model the electrode interactions within the water splitting cell. Surface energies were used to characterise the stabilities of the Ni3N surfaces along with adsorption energies to determine preferable sites for adsorbate interactions. The surface stability order was found to be (111) < (100) < (001) < (110) with calculated surface energies of 2.10 2.27 2.37 and 2.38 Jm−2 respectively. Water adsorption was found to be exothermic at all surfaces and most favourable on the (111) surface with Eads = −0.79 eV followed closely by the (100) (110) and (001) surfaces at −0.66 −0.65 and −0.56 eV respectively. The water splitting reaction was investigated at each surface to determine the rate determining Volmer step and the activation energies (Ea) for alkaline HER which has thus far not been studied in detail for Ni3N. The Ea values for water splitting on the Ni3N surfaces were predicted in the order (001) < (111) < (110) < (100) which were 0.17 0.73 1.11 and 1.60 eV respectively overall showing the (001) surface to be most active for the Volmer step of water dissociation. Active hydrogen adsorption sites are also presented for acidic HER evaluated through the ΔGH descriptor. The (110) surface was shown to have an extremely active Ni–N bridging site with ΔGH = −0.05 eV.
Rayleigh-Taylor Instability: Modelling and Effect on Coherent Deflagrations
Sep 2013
Publication
The modelling of Rayleigh–Taylor instability during premixed combustion scenarios is presented. Experimental data obtained from experiments undertaken by FM Global using their large-scale vented deflagration chamber was used to develop the modelling approach. Rayleigh–Taylor instability is introduced as an additional time-dependent combustion enhancing mechanism. It is demonstrated that prior to the addition of this mechanism the LES deflagration model under-predicted the experimental pressure transients. It is confirmed that the instability plays a significant role throughout the coherent deflagration process. The addition of the mechanism led to the model more closely replicating the pressure peak associated with the external deflagration.
Statistics, Lessons Learned and Recommendations from Analysis of HIAD 2.0 Database
Mar 2022
Publication
The manuscript firstly describes the data collection and validation process for the European Hydrogen Incidents and Accidents Database (HIAD 2.0) a public repository tool collecting systematic data on hydrogen-related incidents and near-misses. This is followed by an overview of HIAD 2.0 which currently contains 706 events. Subsequently the approaches and procedures followed by the authors to derive lessons learned and formulate recommendations from the events are described. The lessons learned have been divided into four categories including system design; system manufacturing installation and modification; human factors and emergency response. An overarching lesson learned is that minor events which occurred simultaneously could still result in serious consequences echoing James Reason's Swiss Cheese theory. Recommendations were formulated in relation to the established safety principles adapted for hydrogen by the European Hydrogen Safety Panel considering operational modes industrial sectors and human factors. This work provide an important contribution to the safety of systems involving hydrogen benefitting technical safety engineers emergency responders and emergency services. The lesson learned and the discussion derived from the statistics can also be used in training and risk assessment studies being of equal importance to promote and assist the development of sound safety culture in organisations.
Effect of Hydrogen-diesel Fuel Co-combustion on Exhaust Emissions with Verification Using an Inecylinder Gas Sampling Technique
Aug 2014
Publication
The paper presents an experimental investigation of hydrogen-diesel fuel co-combustion carried out on a naturally aspirated direct injection diesel engine. The engine was supplied with a range of hydrogen-diesel fuel mixture proportions to study the effect of hydrogen addition (aspirated with the intake air) on combustion and exhaust emissions. The tests were performed at fixed diesel injection periods with hydrogen added to vary the engine load between 0 and 6 bar IMEP. In addition a novel inecylinder gas sampling technique was employed to measure species concentrations in the engine cylinder at two inecylinder locations and at various instants during the combustion process. The results showed a decrease in the particulates CO and THC emissions and a slight increase in CO2 emissions with the addition of hydrogen with fixed diesel fuel injection periods. NOx emissions increased steeply with hydrogen addition but only when the combined diesel and hydrogen co-combustion temperatures exceeded the threshold temperature for NOx formation. The inecylinder gas sampling results showed higher NOx levels between adjacent spray cones in comparison to sampling within an individual spray cone.
An Independent Assessment of the UK’s Clean Growth Strategy: From Ambition to Action
Nov 2018
Publication
This report provides the Committee on Climate Change’s response to the UK Government’s Clean Growth Strategy.
The report finds that:
The report finds that:
- The Government has made a strong commitment to achieving the UK’s climate change targets.
- Policies and proposals set out in the Clean Growth Strategy will need to be firmed up.
- Gaps to meeting the fourth and fifth carbon budgets remain. These gaps must be closed.
- Risks of under-delivery must be addressed and carbon budgets met on time.
Progressing the Gas Goes Green Roadmap to Net Zero Webinar
Dec 2021
Publication
The Gas Goes Green Programme developed by the gas networks and the Energy Networks Association (ENA) describes a viable pathway to the injection of hydrogen and biomethane as a practical step towards the decarbonisation of the UK gas sector and will play a key role in the UK’s Net Zero energy strategy. It therefore follows that technical and management teams in the supply chain and related industries will need a sound understanding of the issues surrounding this deployment. This video shares the industry’s progress towards implementing the Gas Goes Green programme. Presenters including Oliver Lancaster CEO IGEM Dr Thomas Koller Programme Lead Gas Goes Green at the Energy Network Association (ENA) and Ian McCluskey CEng FIMechE FIGEM Head of Technical and Policy IGEM share their views on what has already been achieved and explain what they feel still needs to be done to develop the decarbonised gas network of tomorrow.
Reducing Emissions in Northern Ireland
Feb 2019
Publication
In this report the Committee sets out how Northern Ireland can reduce its greenhouse gas emissions between now and 2030 in order to meet UK-wide climate change targets.
The report’s key findings are:
The report’s key findings are:
- Existing policies are not enough to deliver this reduction
- There are excellent opportunities to close this gap and go beyond 35%
- Meeting the cost-effective path to decarbonisation in Northern Ireland will require action across all sectors of the economy and a more joined-up approach
Characterising the Performance of Hydrogen Sensitive Coatings for Nuclear Safety Applications
Sep 2017
Publication
The detection of hydrogen gas is essential in ensuring the safety of nuclear plants. However events at Fukushima Daiichi NPP highlighted the vulnerability of conventional detection systems to extreme events where power may be lost. Herein chemochromic hydrogen sensors have been fabricated using transition metal oxide thin films sensitised with a palladium catalyst to provide passive hydrogen detection systems that would be resilient to any plant power failures. To assess their viability for nuclear safety applications these sensors have been gamma-irradiated to four total doses (0 5 20 50 kGy) using a Co-60 gamma radioisotope. Optical properties of both un-irradiated and irradiated samples were investigated to compare the effect of increased radiation dose on the sensors resultant colour change. The results suggest that gamma irradiation at the levels examined (>5 kGy) has a significant effect on the initial colour of the thin films and has a negative effect on the hydrogen sensing abilities.
Integration of Experimental Facilities: A Joint Effort for Establishing a Common Knowledge Base in Experimental Work on Hydrogen Safety
Sep 2009
Publication
With regard to the goals of the European HySafe Network research facilities are essential for the experimental investigation of relevant phenomena for testing devices and safety concepts as well as for the generation of validation data for the various numerical codes and models. The integrating activity ‘Integration of Experimental Facilities (IEF)’ has provided basic support for jointly performed experimental work within HySafe. Even beyond the funding period of the NoE HySafe in the 6th Framework Programme IEF represents a long lasting effort for reaching sustainable integration of the experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners emphasis was put on the know-how transfer between the partners. The strategy for reaching the objectives consisted of two parts. On the one hand a documentation of the experimental capacities has been prepared and analysed. On the other hand a communication base has been established by means of biannual workshops on experimental issues. A total of 8 well received workshops has been organised covering topics from measurement technologies to safety issues. Based on the information presented by the partners a working document on best practice including the joint experimental knowledge of all partners with regard to experiments and instrumentation was created. Preserving the character of a working document it was implemented in the IEF wiki website which was set up in order to provide a central communication platform. The paper gives an overview of the IEF network activities over the last 5 years.
Mixed E-learning and Virtual Reality Pedagogical Approach for Innovative Hydrogen Safety Training for First Responders
Oct 2015
Publication
Within the scope of the HyResponse project the development of a specialised training programme is currently underway. Utilizing an andragogy approach to teaching distance learning is mixed with classroom instructors-led activities while hands-on training on a full-scale simulator is coupled with an innovative virtual reality based experience. Although the course is dedicated mainly to first responders provision has been made to incorporate not only simple table-top and drill exercises but also full-scale training involving all functional emergency response organisations at multi-agency cooperation level. The developed curriculum includes basics of hydrogen safety first responders' procedures and incident management expectations
Gas Goes Green: Delivering the Pathway to Net Zero
May 2020
Publication
Gas Goes Green brings together the engineering expertise from the UK’s five gas network operators building on the foundations of our existing grid infrastructure innovation projects and the wider scientific community. This is a blueprint to meet the challenges and opportunities of climate change delivering net zero in the most cost effective and least disruptive way possible.<br/>Delivering our vision is not just an engineering challenge but will involve active participation from policy makers regulators the energy industry and consumers. Gas Goes Green will undertake extensive engagement to deliver our programme and collaborate with existing projects already being delivered across the country.<br/>Britain’s extensive gas network infrastructure provides businesses and the public with the energy they need at the times when they need it the most. The gas we deliver plays a critical role in our everyday lives generating electricity fuelling vehicles heating our homes and providing the significant amounts of energy UK heavy industry needs. The Gas Goes Green programme aims to ensure that consumers continue to realise these benefits by transitioning our infrastructure into a net zero energy system.
Numerical Investigation of Hydrogen-air Deflagrations in a Repeated Pipe Congestion
Sep 2019
Publication
Emerging hydrogen energy technologies are creating new avenues for bring hydrogen fuel usage into larger public domain. Identification of possible accidental scenarios and measures to mitigate associated hazards should be well understood for establishing best practice guidelines. Accidentally released hydrogen forms flammable mixtures in a very short time. Ignition of such a mixture in congestion and confinements can lead to greater magnitudes of overpressure catastrophic for both structure and people around. Hence understanding of the permissible level of confinements and congestion around the hydrogen fuel handling and storage unit is essential for process safety. In the present study numerical simulations have been performed for the hydrogen-air turbulent deflagration in a well-defined congestion of repeated pipe rig experimentally studied by [1]. Large Eddy Simulations (LES) have been performed using the in-house modified version of the OpenFOAM code. The Flame Surface Wrinkling Model in the LES context is used for modelling deflagrations. Numerical predictions concerning the effects of hydrogen concentration and congestion on turbulent deflagration overpressure are compared with the measurements [1] to provide validation of the code. Further insight about the flame propagation and trends of the generated overpressures over the range of concentrations are discussed.
Sectoral Scenarios for the Fifth Carbon Budget
Nov 2015
Publication
This report forms part of the Committee’s advice on the level of the fifth carbon budget.<br/>The report describes the scenarios used by the Committee to inform its judgements over the cost-effective path to meeting the UK’s greenhouse reduction targets in the period 2028-2032.
Best Practice in Numerical Simulation and CFD Benchmarking. Results from the SUSANA Project
Sep 2017
Publication
Correct use of Computational Fluid Dynamics (CFD) tools is essential in order to have confidence in the results. A comprehensive set of Best Practice Guidelines (BPG) in numerical simulations for Fuel Cells and Hydrogen applications has been one of the main outputs of the SUSANA project. These BPG focus on the practical needs of engineers in consultancies and industry undertaking CFD simulations or evaluating CFD simulation results in support of hazard/risk assessments of hydrogen facilities as well as on the needs of regulatory authorities. This contribution presents a summary of the BPG document. All crucial aspects of numerical simulations are addressed such as selection of the physical models domain design meshing boundary conditions and selection of numerical parameters. BPG cover all hydrogen safety relative phenomena i.e. release and dispersion ignition jet fire deflagration and detonation. A series of CFD benchmarking exercises are also presented serving as examples of appropriate modelling strategies.
Fire Tests Carried Out in FCH JU FIRECOMP Project, Recommendations and Application to Safety of Gas Storage Systems
Sep 2017
Publication
In the event of a fire composite pressure vessels behave very differently from metallic ones: the material is degraded potentially leading to a burst without significant pressure increase. Hence such objects are when necessary protected from fire by using thermally-activated devices (TPRD) and standards require testing cylinder and TPRD together. The pre-normative research project FireComp aimed at understanding better the conditions which may lead to burst through testing and simulation and proposed an alternative way of assessing the fire performance of composite cylinders. This approach is currently used by Air Liquide for the safety of composite bundles carrying large amounts of hydrogen gas.
On the Use of Hydrogen in Confined Spaces: Results from the Internal Project InsHyde
Sep 2009
Publication
Alexandros G. Venetsanos,
Paul Adams,
Inaki Azkarate,
A. Bengaouer,
Marco Carcassi,
Angunn Engebø,
E. Gallego,
Olav Roald Hansen,
Stuart J. Hawksworth,
Thomas Jordan,
Armin Keßler,
Sanjay Kumar,
Vladimir V. Molkov,
Sandra Nilsen,
Ernst Arndt Reinecke,
M. Stöcklin,
Ulrich Schmidtchen,
Andrzej Teodorczyk,
D. Tigreat,
N. H. A. Versloot and
L. Boon-Brett
The paper presents an overview of the main achievements of the internal project InsHyde of the HySafe NoE. The scope of InsHyde was to investigate realistic small-medium indoor hydrogen leaks and provide recommendations for the safe use/storage of indoor hydrogen systems. Additionally InsHyde served to integrate proposals from HySafe work packages and existing external research projects towards a common effort. Following a state of the art review InsHyde activities expanded into experimental and simulation work. Dispersion experiments were performed using hydrogen and helium at the INERIS gallery facility to evaluate short and long term dispersion patterns in garage like settings. A new facility (GARAGE) was built at CEA and dispersion experiments were performed there using helium to evaluate hydrogen dispersion under highly controlled conditions. In parallel combustion experiments were performed by FZK to evaluate the maximum amount of hydrogen that could be safely ignited indoors. The combustion experiments were extended later on by KI at their test site by considering the ignition of larger amounts of hydrogen in obstructed environments outdoors. An evaluation of the performance of commercial hydrogen detectors as well as inter-lab calibration work was jointly performed by JRC INERIS and BAM. Simulation work was as intensive as the experimental work with participation from most of the partners. It included pre-test simulations validation of the available CFD codes against previously performed experiments with significant CFD code inter-comparisons as well as CFD application to investigate specific realistic scenarios. Additionally an evaluation of permeation issues was performed by VOLVO CEA NCSRD and UU by combining theoretical computational and experimental approaches with the results being presented to key automotive regulations and standards groups. Finally the InsHyde project concluded with a public document providing initial guidance on the use of hydrogen in confined spaces.
Hysafe SBEP-V20: Numerical Predictions of Release Experiments Inside a Residential Garage With Passive Ventilation
Sep 2009
Publication
This work presents the results of the Standard Benchmark Exercise Problem (SBEP) V20 of Work Package 6 (WP6) of HySafe Network of Excellence (NoE) co-funded by the European Commission in the frame of evaluating the quality and suitability of codes models and user practices by comparative assessments of code results. The benchmark problem SBEP-V20 covers release scenarios that were experimentally investigated in the past using helium as a substitute to hydrogen. The aim of the experimental investigations was to determine the ventilation requirements for parking hydrogen fuelled vehicles in residential garages. Helium was released under the vehicle for 2 h with 7.200 l/h flow rate. The leak rate corresponded to a 20% drop of the peak power of a 50 kW fuel cell vehicle. Three double vent garage door geometries are considered in this numerical investigation. In each case the vents are located at the top and bottom of the garage door. The vents vary only in height. In the first case the height of the vents is 0.063 m in the second 0.241 m and in the third 0.495 m. Four HySafe partners participated in this benchmark. The following CFD packages with the respective models were applied to simulate the experiments: ADREA-HF using k–ɛ model by partner NCSRD FLACS using k–ɛ model by partner DNV FLUENT using k–ɛ model by partner UPM and CFX using laminar and the low-Re number SST model by partner JRC. This study compares the results predicted by the partners to the experimental measurements at four sensor locations inside the garage with an attempt to assess and validate the performance of the different numerical approaches.
HIAD 2.0 – Hydrogen Incident and Accident Database
Sep 2019
Publication
Hydrogen technologies are expected to play a key role in implementing the transition from a fossil fuel- based to a more sustainable lower-carbon energy system. To facilitate their widespread deployment the safe operation and hydrogen systems needs to be ensured together with the evaluation of the associated risk.<br/>HIAD has been designed to be a collaborative and communicative web-based information platform holding high quality information of accidents and incidents related to hydrogen technologies. The main goal of HIAD was to become not only a standard industrial accident database but also an open communication platform suitable for safety lessons learned and risk communication as well as a potential data source for risk assessment; it has been set up to improve the understanding of hydrogen unintended events to identify measures and strategies to avoid incidents/accidents and to reduce the consequence if an accident occurs.<br/>In order to achieve that goal the data collection is characterized by a significant degree of detail and information about recorded events (e.g. causes physical consequences lesson learned). Data are related not only to real incident and accidents but also to hazardous situations.<br/>The concept of a hydrogen accident database was generated in the frame of the project HySafe an EC co-funded NoE of the 6th Frame Work Programme. HIAD was built by EC-JRC and populated by many HySafe partners. After the end of the project the database has been maintained and populated by JRC with publicly available events. The original idea was to provide a tool also for quantitative risk assessment able to conduct simple analyses of the events; unfortunately that goal could not be reached because of a lack of required statistics: it was not possible to establish a link with potential event providers coming from private sector not willing to share information considered confidential. Starting from June 2016 JRC has been developing a new version of the database (i.e. HIAD 2.0); the structure of the database and the web-interface have been redefined and simplified resulting in a streamlined user interface compared to the previous version of HIAD. The new version is mainly focused to facilitate the sharing of lessons learned and other relevant information related to hydrogen technology; the database will be public and the events will be anonymized. The database will contribute to improve the safety awareness fostering the users to benefit from the experiences of others as well as to share information from their own experiences.
Gas Build-up in a Domestic Property Following Releases of Methane/Hydrogen Mixtures
Sep 2007
Publication
The EC funded Naturalhy project is investigating the possibility of promoting the swift introduction of hydrogen as a fuel by mixing hydrogen with natural gas and transporting this mixture by means of the existing natural gas pipeline system to end-users. Hydrogen may then be extracted for use in hydrogen fuel cell applications or the mixture may be used directly in conventional gas-fired equipment. This means that domestic customers would receive a natural gas (methane)/hydrogen mixture delivered to the home. As the characteristics of hydrogen are different from natural gas there may be an increased risk to end-users in the event of an accidental release of gas from internal pipe work or appliances. Consequently part of the Naturalhy project is aimed at assessing the potential implications on the safety of the public which includes end-users in their homes. In order to understand the nature of any gas accumulation which may form and identify the controlling parameters a series of large scale experiments have been performed to study gas accumulations within a 3 m by 3 m by 2.3 m ventilated enclosure representing a domestic room. Gas was released vertically upwards at a pressure typical of that experienced in a domestic environment from hole sizes representative of leaks and breaks in pipe work. The released gas composition was varied and included methane and a range of methane/hydrogen mixtures containing up to 50% hydrogen. During the experiments gas concentrations throughout the enclosure and the external wind conditions were monitored with time. The experimental data is presented. Analysis of the data and predictions using a model developed to interpret the experimental data show that both buoyancy and wind driven ventilation are important.
Towards a Set of Design Recommendations for Pressure Relief Devices On-board Hydrogen Vehicles
Oct 2015
Publication
Commercial use of hydrogen on-board fuel cell vehicles necessitates the compression of hydrogen gas up to 700 bar raising unique safety challenges. Potential hazards to be addressed include jet fires from high-pressure hydrogen on-board storage. Previous studies investigated effects of jet fires that occur when pressure relief devices (PRDs) on hydrogen fuel cell vehicles activate. This investigation examines plane jets’ axis switching and flame length accounting for compressibility effects and turbulent combustion near the point of release. Comparison with experimental data and previous plane jet simulation results reveal that combustion process does not affect flow dynamics in compressible region of jet flow. Furthermore a theoretical design of a variable aperture pressure relief device is examined which would enable the blow-down time to be minimized while reducing deterministic separation distances is examined using Computational Fluid Dynamics (CFD) techniques. Design recommendations are suggested for a novel PRD design.
Vented Confined Explosions Involving Methane/Hydrogen Mixtures
Sep 2009
Publication
The EC funded Naturalhy project is assessing the potential for using the existing gas infrastructure for conveying hydrogen as a mixture with natural gas (methane). The hydrogen could then be removed at a point of use or the natural gas/hydrogen mixture could be burned in gas-fired appliances thereby providing reduced carbon emissions compared to natural gas. As part of the project the impact on the safety of the gas system resulting from the addition of hydrogen is being assessed. A release of a natural gas/hydrogen mixture within a vented enclosure (such as an industrial housing of plant and equipment) could result in a flammable mixture being formed and ignited. Due to the different properties of hydrogen the resulting explosion may be more severe for natural gas/hydrogen mixtures compared to natural gas. Therefore a series of large scale explosion experiments involving methane/hydrogen mixtures has been conducted in a 69.3 m3 enclosure in order to assess the effect of different hydrogen concentrations on the resulting explosion overpressures. The results showed that adding up to 20% by volume of hydrogen to the methane resulted in a small increase in explosion flame speeds and overpressures. However a significant increase was observed when 50% hydrogen was added. For the vented confined explosions studied it was also observed that the addition of obstacles within the enclosure representing congestion caused by equipment and pipework etc. increased flame speeds and overpressures above the levels measured in an empty enclosure. Predictions of the explosion overpressure and flame speed were also made using a modified version of the Shell Global Solutions model SCOPE. The modifications included changes to the burning velocity and other physical properties of methane/hydrogen mixtures. Comparisons with the experimental data showed generally good agreement.
Hydrogen in a Low-carbon Economy
Nov 2018
Publication
This report by the Committee on Climate Change (CCC) assesses the potential role of hydrogen in the UK’s low-carbon economy.
It finds that hydrogen:
It finds that hydrogen:
- is a credible option to help decarbonise the UK energy system but its role depends on early Government commitment and improved support to develop the UK’s industrial capability
- can make an important contribution to long-term decarbonisation if combined with greater energy efficiency cheap low-carbon power generation electrified transport and new ‘hybrid’ heat pump systems which have been successfully trialled in the UK
- could replace natural gas in parts of the energy system where electrification is not feasible or is prohibitively expensive for example in providing heat on colder winter days industrial heat processes and back-up power generation
- is not a ‘silver bullet’ solution; the report explores some commonly-held misconceptions highlighting the need for careful planning
- Government must commit to developing a low-carbon heat strategy within the next three years
- Significant volumes of low-carbon hydrogen should be produced in a carbon capture and storage (CCS) ‘cluster’ by 2030 to help the industry grow
- Government must support the early demonstration of the everyday uses of hydrogen in order to establish the practicality of switching from natural gas to hydrogen
- There is low awareness amongst the general public of reasons to move away from natural gas heating to low-carbon alternatives
- A strategy should be developed for low-carbon heavy goods vehicles (HGVs) which encourages a move away from fossil fuels and biofuels to zero-emission solutions by 2050
Net Zero The UK's Contribution to Stopping Global Warming
May 2019
Publication
This report responds to a request from the Governments of the UK Wales and Scotland asking the Committee to reassess the UK’s long-term emissions targets. Our new emissions scenarios draw on ten new research projects three expert advisory groups and reviews of the work of the IPCC and others.<br/>The conclusions are supported by detailed analysis published in the Net Zero Technical Report that has been carried out for each sector of the economy plus consideration of F-gas emissions and greenhouse gas removals.
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