United Kingdom

The differences in behaviour of hydrogen when compared to natural gas under deflagration and detonation scenarios are well known. The authors currently work in the area of fire and explosion analysis and have identified what they feel are potential gaps in the current Body of Knowledge (BOK) available to the sector. This is especially related to the behaviour around secondary shock formation and interactions with surrounding structures especially with ‘open’ structures such as steel frameworks typically seen in an offshore environment and practicable methods for determining debris formation and propagation. Whilst the defence sector has extensive knowledge in these areas this is primarily in the area of high explosives where the level of shocks observed is stronger than those resulting from a hydrogen detonation. This information would need to be reviewed and assessed to ensure it is appropriate for application in the hydrogen sector. Therefore with a focus on practicality the authors have undertaken a two-phase approach. The first phase involves carrying out a through literature search and discussions within our professional networks in order to ascertain whether there is a gap in the BOK. If good research guidance and tools to support this area of assessment already exist the authors have attempted to collate and consolidate this into a form that can be made more easily available to the community. Secondly if there is indeed a gap in the BOK the authors have attempted to ensure that all relevant information is collated to act as a reference and provide a consistent baseline for future research and development activities.

This report is a detailed discussion related to safety shoes heat and flame personal protective equipment (PPE) and breathing apparatus (respiratory protective equipment RPE) required for working with natural gas (NG) and hydrogen (H2). This work was undertaken by HSE Science Division (SD) as part of Phase 2a of the H21 project. This report should be read alongside all the other relevant reports generated as part of this project. Recommendations made in this report are focused solely on the provision and use of PPE and should not be considered independently of recommendations made in the other relevant reports.<br/>Understanding the similarities and difference of PPE required for NG and H2 enables a deeper understanding of how the transition from NG to 100% H2 might change the way the gas distribution network is operated and managed.

Common root causes are often to be found in many if not most process safety incidents. Whilst largescale events are relatively rare such events can have devastating consequences. The subsequent investigations often uncover that the risks are rarely visible the direct causes are often hidden and that a ‘normalization of deviation’ is a common human characteristic. Process Safety Management (PSM) builds on the valuable lessons learned from past incidents to help prevent future recurrences. An understanding of how PSM originated and has evolved as a discipline over the past 200 years can be instructive when considering the safety implications of emerging technologies. An example is hydrogen production where risks must be effectively identified mitigated and addressed to provide safe production transportation storage and use .

Dilution ventilation is the current basis of safety following a flammable gas leak within a gas turbine enclosure and compliance requirements are defined for methane fuels in ISO 21789. These requirements currently define a safety criteria of a maximum flammable gas cloud size within an enclosure. The requirements are based on methane explosion tests conducted during a HSE Joint Industry Project which identified typical pressures associated with a range of gas cloud sizes. The industry standard approach is to assess the ventilation performance of specific enclosure designs against these requirements using CFD modelling. Gas turbine manufacturers are increasingly considering introducing hydrogen/methane fuel mixtures and looking towards operating with hydrogen alone. It is therefore important to review the applicability of current safety standards for these new fuels as the pressure resulting from a hydrogen explosion is expected to be significantly higher than that from a methane explosion. In this paper we replicate the previous methane explosion tests for hydrogen and hydrogen/methane fuel mixtures using the explosion modelling tool FLACS CFD. The results are used to propose updated limiting safety criteria for hydrogen fuels to support ventilation CFD analysis for specific enclosure designs. It is found that significantly smaller gas cloud sizes are likely to be acceptable for gas turbines fueled by hydrogen however significantly more hydrogen than methane is required per unit volume to generate a stoichiometric cloud (as hydrogen has a lower stoichiometric air fuel ratio than methane). This effect results in the total quantity of gas in the enclosure (and as such detectability of the gas) being broadly similar when operating gas turbines on hydrogen when compared to methane.

The Low Carbon Hydrogen Standard sets a maximum threshold for the amount of greenhouse gas emissions allowed in the production process for hydrogen to be considered ‘low carbon hydrogen’. Compliance with the standard will help ensure new low carbon hydrogen production makes a direct contribution to our carbon reduction targets.

This guidance sets out the methodology for calculating the emissions associated with hydrogen production and the steps producers should take to prove that the hydrogen they produce is compliant with the standard.

It is for use by hydrogen producers seeking support from government schemes and policies that have adopted the standard.

The standard requires hydrogen producers to:

• meet a GHG emissions intensity of 20g CO2e/MJLHV of produced hydrogen or less for the hydrogen to be considered low carbon
• calculate their greenhouse gas (GHG) emissions up to the ‘point of production’
• set out a risk mitigation plan for fugitive hydrogen emissions
• meet additional requirements for the use of biogenic inputs where relevant and as appropriate for the feedstock source and classification

This Supplement gives additional requirements and qualifications for the transmission of Hydrogen including Natural Gas/Hydrogen blended mixtures (subsequently referred to as NG/H blends) and for the repurposing of Natural Gas (NG) pipelines to Hydrogen service. For the purposes of this document any NG/H blend above 10% MOL is considered to be an equivalence to 100% hydrogen. For blends below 10% MOL there is no evidence to confirm that blends containing up to 10 mol.% hydrogen do not cause material degradation but it is considered that the risk is low.

This Supplement covers the design construction inspection testing operation and maintenance of steel pipelines and certain associated installations in Hydrogen service and the repurposing of NG pipelines to Hydrogen service at maximum operating pressure (MOP) exceeding 7 bar and not exceeding 137.9 bar.

This standard can be purchased here

Alongside our Sixth Carbon Budget Advice the Climate Change Committee (CCC) are publishing a paper from Professor Nick Chater the Committee’s behavioural science specialist. This paper considers three behavioural principles that explain how people have adapted so rapidly and how we might “build back better” as we emerge from the pandemic with a particular focus on meeting the challenge of dramatically reducing greenhouse gas (GHG) emissions over the coming decades. The principles are:

• The power law of practice: People organizations and whole industries learn to adapt to new ways of working following a surprisingly predictable pattern. This can help predict where adaptation to new ways of living and working is likely to succeed or fail.
• The status quo effect: People and organizations tend to prefer the current status quo but can often adjust rapidly to prefer a new status quo. However we tend to systematically underestimate such effects and therefore can sometimes resist changes that in retrospect we may ultimately prefer.
• Unwritten rules: Our social behaviour is guided by implicit guidelines about what is “appropriate” which can be somewhat independent of our personal values. Changing these implicit rules alongside changes in regulation and the law is crucial to adapting to new circumstances—and the pandemic has shown that rapid change is possible though sometimes resisted (e.g. new norms about mask wearing and social distancing).

There is a large literature exploring possible hydrogen futures using various modelling and scenario approaches. This paper compares the rates of transition depicted in that literature with a set of historical analogies. These analogies are cases in which alternative-fuelled vehicles have penetrated vehicle markets. The paper suggests that the literature has tended to be optimistic about the possible rate at which hydrogen vehicles might replace oil-based transportation. The paper compares 11 historical adoptions of alternative fuel vehicles with 24 scenarios from 20 studies that depict possible hydrogen futures. All but one of the hydrogen scenarios show vehicle adoption faster than has occurred for hybrid electric vehicles in Japan the most successful market for hybrids. Several scenarios depict hydrogen transitions occurring at a rate faster than has occurred in any of the historic examples. The paper concludes that scenarios of alternative vehicle adoption should include more pessimistic scenarios alongside optimistic ones.

The UK is investigating supplying hydrogen to homes and businesses instead of natural gas by “repurposing” the gas network. It presents a major engineering challenge which has never been done anywhere else in the world.

In a new report titled ‘Transitioning to hydrogen’ experts from a cross-professional engineering institution (PEI) working group including the IET have assessed the engineering risks and uncertainties and concluded there is no reason why repurposing the gas network to hydrogen cannot be achieved. But there are several engineering risks and uncertainties which need to be addressed.

<br/>Our industry is beginning its journey on the transition to providing the world with sufficient sustainable affordable and low emission energy.<br/><br/>Decarbonisation is now a key priority. Steps range from reducing emissions from traditional oil and gas operations to investing in renewable energy and supplementing natural gas supplies with greener gasses such as hydrogen.<br/><br/>This paper looks at the role hydrogen could play in decarbonisation.

Although the UK has done a great job of decarbonising electricity generation to get to net zero we need to tackle harder-to-decarbonise sectors like heat transport and industry. Decarbonised gas – biogases hydrogen and the deployment of carbon capture usage and storage (CCUS) – can make our manufacturing more sustainable minimise disruption to families and deliver negative emissions.

Developing the capability to produce hydrogen at scale is one of the key challenges in the race to meet the UK’s ambitious net zero targets. Using the East Neuk of Fife - with its abundant on- and offshore renewables resource and well-developed electricity and gas networks – as a test bed we investigated the use of surplus electricity generated by renewables to produce green hydrogen which could then be used to heat homes and businesses carbon-free.

Aims

The study focused on answering a number of important questions around bringing power-to-hydrogen to Fife including:

How much low-cost low-carbon electricity would be available to a power-to-hydrogen operator in Fife and how much hydrogen could be produced today and in 2040? How much hydrogen storage would be required to meet demand under three end-use cases: injection into the natural gas grid; use in a dedicated hydrogen grid for heating; and use as transport fuel for a small fleet of vehicles? What if any network upgrades could be avoided by implementing power-to-hydrogen? Which hydrogen end-use markets would be most attractive for a power-to-hydrogen operator? What are the regulatory legislative or market barriers to be overcome to realise large-scale deployment of power-to-hydrogen?

The study

Our expert researchers used a high-level model of the European electricity system and established wholesale prices generation volumes by generation type and constrained generation in Fife. Considering both the present day and a 2040 picture based on National Grid’s Two Degrees Future Energy Scenarios our team explored a number of configurations of power generation and hydrogen end-use to assess the value associated with producing hydrogen.

Alongside this modelling our team conducted a comprehensive review of power-to-hydrogen legislation and regulation and reports and academic papers to identify the current characteristics and direction of the sector observe where most progress had been made and identify lessons learned.

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.

Composite materials consisting of metal and metal oxide phases are being researched intensively for application in various energy conversion and storage technologies. In these applications composites are often expected to operate under redox conditions at elevated temperature. The understanding of the dynamics of composite phase and morphology evolution during redox cycling is still very limited yet critical to maximising performance and increasing durability. Here we track the microstructural evolution of a single composite particle over 200 redox cycles for hydrogen production by chemical looping using multi-length scale X-ray computed tomography. We show that redox cycling triggers a centrifugal redispersion of the metal phase and a centripetal clustering of porosity both seemingly driven by the asymmetric nature of oxygen exchange in composites. We show that initially the particle develops a large amount of internal porosity which boosts activity but on the long term this facilitates structural and compositional reorganisation and eventually degradation. We also correlate the microstructural data with phase and activity analysis to identify structure-property correlations which not only provide valuable insight into the evolution of composite materials under redox conditions but also for the design of new composite materials with enhanced durability.

It is well-known that deflagration to detonation transition (DDT) may be a significant threat for hydrogen explosions. This paper presents a summary of the work carried out for the development of models in order to enable the industrial computational fluid dynamic (CFD) tool FLACS to provide indications about the possibility of a deflagration-to-detonation transition (DDT). The likelihood of DDT has been expressed in terms of spatial pressure gradients across the flame front. This parameter is able to visualize when the flame front captures the pressure front which is the case in situations when fast deflagrations transition to detonation. Reasonable agreement was obtained with experimental observations in terms of explosion pressures transition times and flame speeds for several practical geometries. The DDT model has also been extended to develop a more meaningful criterion for estimating the likelihood of DDT by comparison of the geometric dimensions with the detonation cell size. The conclusion from simulating these experiments is that the FLACS DPDX criterion seems robust and will generally predict the onset DDTs with reasonable precision including the exact location where DDT may happen. The standard version of FLACS can however not predict the consequences if there is DDT as only deflagration flames are modelled. Based on the methodology described above an approach for predicting detonation flames and explosion loads has been developed. The second part of the paper covers new paradigms associated with risk assessment of a hydrogen infrastructure such as a refueling station. In particular approaches involving one-to-one coupling between CFD and FEA modelling are summarized. The advantages of using such approaches are illustrated. This can have wide-ranging implications on the design of things like protection walls against hydrogen explosions.

Hydrogen fuelling in the US is unattended activity although this precedent is not without several challenges that have been addressed in the past decade. This paper provides the recent history and the generic safety case which has established this precedent for hydrogen. The paper also explores the longer history of unattended gasoline fuelling and attempts to help place hydrogen fuelling into the longer history of fuelling personal vehicles.

CO₂ capture utilization and storage (CCUS) is recognized as a uniquely important option in global efforts to control anthropogenic greenhouse-gas (GHG) emissions. Despite significant progress globally in advancing the maturity of the various component technologies and their assembly into full-chain demonstrations a gap remains on the path to widespread deployment in many countries. In this paper we focus on the importance of business models adapted to the unique technical features and sociopolitical drivers in different regions as a necessary component of commercial scale-up and how lessons might be shared across borders. We identify three archetypes for CCUS development—resource recovery green growth and low-carbon grids—each with different near-term issues that if addressed will enhance the prospect of successful commercial deployment. These archetypes provide a framing mechanism that can help to translate experience in one region or context to other locations by clarifying the most important technical issues and policy requirements. Going forward the archetype framework also provides guidance on how different regions can converge on the most effective use of CCUS as part of global deep-decarbonization efforts over the long term.

The paper presents a numerical investigation of the critical roles played by the chemical compositions of syngas on laminar diffusion flame instabilities. Three different flame phenomena – stable flickering and tip-cutting – are formulated by varying the syngas fuel rate from 0.2 to 1.4 SLPM. Following the satisfactory validation of numerical results with Darabkhani et al. [1] the study explored the consequence of each species (H₂ CO CH₄ CO₂ N₂) in the syngas composition. It is found that low H₂:CO has a higher level of instability which however does not rise any further when the ratio is less than 1. Interestingly CO encourages the heat generation with less fluctuation while H₂ plays another significant role in the increase of flame temperature and its fluctuation. Diluting CH₄ into syngas further increases the instability level as well as the fluctuation of heat generation significantly. However an opposite effect is found from the same action with either CO₂ or N₂. Finally considering the heat generation and flame stability the highest performance is obtained from 25%H²+75%CO (81 W) followed by EQ+20%CO₂ and EQ+20%N₂ (78 W).

The Climate Change Committee (CCC) commissioned Element Energy to improve our evidence base on the potential of industrial deep-decarbonisation measures (fuel switching CCS/BECCS measures to reduce methane emissions) and develop pathways for their application. This report summarises the evidence and results of the work including:

• Evidence on the key constraints and costs for technology and infrastructure deployment
• The methodology and new Net Zero Industry Pathway (N-ZIP) model used to determine deep-decarbonisation pathways for UK industry (drawing on the evidence above)
• A set of pathways and wider sensitivities produced using the N-ZIP model which fed into the CCC’s Sixth Carbon Budget pathways
• Recommended actions and policy measures as informed by the study.

Electric trains (ET) and hydrogen trains (HT) are considered zero emission at the point of use. True emissions are dependent upon non-tailpipe sources primarily in energy production. We present UK carbon dioxide (CO₂) operating emission model outputs for conventionally fuelled trains (CFT) ETs and HTs between 2017 and 2050 under four National Grid electricity generation scenarios.



Comparing four service categories (urban regional intercity and high speed) to private conventionally fuelled vehicles (CFV) and electric vehicles considering average distance travelled per trip under different passenger capacity levels (125% 100% 75% 50% and 25%).



Results indicate by 2050 at 100% capacity CFTs produce a fifth of the emissions of CFVs per kilometre per person. Under two degree generation scenario by 2050 ETs produced 14 times and HTs produced five times less emissions than CFTs. Policymakers should encourage shifts away from private vehicles to public transport powered by low carbon electricity.

An overview of the HyDeploy project at Keele University where hydrogen is being blended with natural gas to demonstrate the feasibility of using hydrogen to heat our homes.

The need for energy storage to balance intermittent and inflexible electricity supply with demand is driving interest in conversion of renewable electricity via electrolysis into a storable gas. But high capital cost and uncertainty regarding future cost and performance improvements are barriers to investment in water electrolysis. Expert elicitations can support decision-making when data are sparse and their future development uncertain. Therefore this study presents expert views on future capital cost lifetime and efficiency for three electrolysis technologies: alkaline (AEC) proton exchange membrane (PEMEC) and solid oxide electrolysis cell (SOEC). Experts estimate that increased R&D funding can reduce capital costs by 0–24% while production scale-up alone has an impact of 17–30%. System lifetimes may converge at around 60000–90000 h and efficiency improvements will be negligible. In addition to innovations on the cell-level experts highlight improved production methods to automate manufacturing and produce higher quality components. Research into SOECs with lower electrode polarisation resistance or zero-gap AECs could undermine the projected dominance of PEMEC systems. This study thereby reduces barriers to investment in water electrolysis and shows how expert elicitations can help guide near-term investment policy and research efforts to support the development of electrolysis for low-carbon energy systems.

Industry is frequently framed as hard-to-decarbonize given its diversity of requirements technologies and supply chains many of which are unique to particular sectors. Net zero commitments since 2019 have begun to challenge the carbon intensity of these various industries but progress has been slow globally. Against this backdrop the United Kingdom has emerged as a leader in industrial decarbonization efforts. Their approach is based on industrial clusters which cut across engineering spatial and socio-political dimensions. Two of the largest of these clusters in England in terms of industrial emissions are the Humber and Merseyside. In this paper drawn from a rich mixed methods original dataset involving expert interviews (N = 46 respondents) site visits (N = 20) a review of project documents and the academic literature we explore ongoing efforts to decarbonize both the Humber and Merseyside through the lens of spatially expansive and technically complex megaprojects. Both have aggressive implementation plans in place for the deployment of net-zero infrastructure with Zero Carbon Humber seeking billions in investment to build the country’s first large-scale bioenergy with carbon capture and storage (BECCS) plant alongside a carbon transport network and hydrogen production infrastructure and HyNet seeking billions in investment to build green and blue hydrogen facilities along with a carbon storage network near Manchester and Liverpool. We draw from the social construction of technology (SCOT) literature to examine the relevant social groups interpretive flexibility and patterns of closure associated with Zero Carbon Humber and HyNet. We connect our findings to eight interpretive frames surrounding the collective projects and make connections to problems contestation and closure.

The effort to meet the ambitious targets of the Paris agreement is challenging many governments. The US and UK governments might have different approaches to achieving the targets but both will rely heavily on renewable energy sources such as wind and solar to power their economies. However these sources of power are unpredictable and ways will have to be developed to store renewable energy for hours days weeks seasons and maybe even years before it is used. As the disruptive and increasingly deadly impacts of climate change are being felt across the world the need to move to more sustainable sources of energy and to identify viable ways to store that energy has never been more important.<br/>This was the subject of the US–UK Science Forum on electrical storage in support of the grid which was held online from 17 – 18 March 2021. Co-organised by the Royal Society and the National Academy of Sciences it brought together a diverse group of 60 scientists policy makers industry leaders regulators and other key stakeholders for a wide-ranging discussion on all aspects of energy storage from the latest research in the field to the current status of deployment. It also considered the current national and international economic and policy contexts in which these developments are taking place. A number of key points emerged from the discussion. First it is clear that renewable energy will play an increasingly important role in the US and UK energy systems of the future and energy storage at a multi-terawatt hour scale has a vital role to play. Of course this will evolve differently to some extent in both countries and elsewhere according to the various geographical technological economic political social and regulatory environments. Second international collaboration is critical – no single nation will solve this problem alone. As two of the world’s leading scientific nations largest economies and per capita CO2 emitters with a long track record of collaboration the US and UK are well placed to play a vital role in addressing this critical challenge. As the discussion highlighted a wide range of energy storage technologies are now emerging and becoming increasingly available many of which have the potential to be critical components of a future net-zero energy system. A crucial next phase is in ensuring that these are technically developed as well as economically and political viable. This will require the support of a wide range of these potential solutions to ensure that their benefits remain widely available and to avoid costly ‘lock-in’. Scientists and science academies have a critical role to play in analysing technology options their combinations and their potential roles in future sustainable energy systems and in working with policymakers to incentivise investment and deployment.

Hydrogen blending into natural gas has attracted significant attention in domestic applications. The paper studied the effects of natural gas mixed with hydrogen at 0% (vol) 5% 10% 15% 20% and 25% on the performance of typical round-port gas stove (TRPGS) swirling strip-port gas stove (SSPGS) and radiant porous media gas stove (RPMGS). The experimental results show that flame length shortens with the increase of hydrogen proportion and the combustion remains stable when the hydrogen proportion is equal to or less than 25%. With increasing hydrogen proportion the measured heat inputs of the three types of domestic gas stoves decrease gradually and the average thermal efficiency of TRPGS and SSPGS increase by 0.82% and 1.18% respectively. In addition the average efficiency of the RPMGS first increases by 1.35% under a hydrogen proportion of 15% and then decreases by 1.36% under a hydrogen proportion of 25%. In terms of flue gas emission CO emission reduces significantly with increasing hydrogen proportion while NOX emissions remain almost unchanged.

This report sets out progress against our strategic framework for decarbonising aviation as well as the latest aviation emissions data and updated Jet Zero analysis.<br/>Among the significant milestones achieved since the Jet Zero strategy launch are the:<br/>- agreement at the International Civil Aviation Organization for a long-term aspirational goal for aviation of net zero 2050 carbon dioxide (CO2) emissions for international aviation<br/>- publication of the 2040 zero emissions airport target call for evidence<br/>significant progress on sustainable aviation fuels (SAF) including:<br/>- publishing the second SAF mandate consultation<br/>- launching a second round of the Advanced Fuels Fund<br/>- publishing the Philip New report and the government response on how to develop a UK SAF industry<br/>- publication of the government response to the UK ETS consultation setting out a range of commitments that will enhance the effectiveness of the UK Emissions Trading Scheme (ETS) for aviation<br/>- launch of the expressions of interest for 2 DfT- funded research projects into aviation’s non-CO2 impacts<br/>The report also acknowledges that big challenges remain and we need to continue to work across the aviation sector and with experts across the economy to ensure we continue to make progress on our path to decarbonise aviation.

Britain's gas networks are ready for hydrogen blending. Learn more about Britain's hydrogen blending capacity in the National Transmission System and Distribution Networks.