United Kingdom

Global maritime transportation is responsible for around 3% of total anthropogenic green‐ house gas emissions and significant proportions of SOx NOx and PM emissions. Considering the predicted growth in shipping volumes to 2050 greenhouse gas emissions from ships must be cut by 75–85% per ton‐mile to meet Paris Agreement goals. This study reviews the potential of a range of alternative fuels for decarbonisation in maritime. A systematic literature review and information synthesis method was applied to evaluate fuel characteristics production pathways utilization technologies energy efficiency lifecycle environmental performance economic viability and cur‐ rent applicable policies. Alternative fuels are essential to decarbonisation in international shipping. However findings suggest there is no single route to deliver the required greenhouse gas emissions reductions. Emissions reductions vary widely depending on the production pathways of the fuel. Alternative fuels utilising a carbon‐intensive production pathway will not provide decarbonisation instead shifting emissions elsewhere in the supply chain. Ultimately a system‐wide perspective to creating an effective policy framework is required in order to promote the adoption of alternative propulsion technologies.

The current hydrogen generation technologies especially biomass gasification using fluidized bed reactors (FBRs) were rigorously reviewed. There are involute operational parameters in a fluidized bed gasifier that determine the anticipated outcomes for hydrogen production purposes. However limited reviews are present that link these parametric conditions with the corresponding performances based on experimental data collection. Using the constructed artificial neural networks (ANNs) as the supervised machine learning algorithm for data training the operational parameters from 52 literature reports were utilized to perform both the qualitative and quantitative assessments of the performance such as the hydrogen yield (HY) hydrogen content (HC) and carbon conversion efficiency (CCE). Seven types of operational parameters including the steam-to-biomass ratio (SBR) equivalent ratio (ER) temperature particle size of the feedstock residence time lower heating value (LHV) and carbon content (CC) were closely investigated. Six binary parameters have been identified to be statistically significant to the performance parameters (hydrogen yield (HY)) hydrogen content (HC) and carbon conversion efficiency (CCE) by analysis of variance (ANOVA). The optimal operational conditions derived from the machine leaning were recommended according to the needs of the outcomes. This review may provide helpful insights for researchers to comprehensively consider the operational conditions in order to achieve high hydrogen production using fluidized bed reactors during biomass gasification.

The assessment of appropriate operational procedures to govern the injection of a hydrogen/natural gas blend into Northern Gas Networks’ (NGN) Winlaton gas distribution network was a key requirement of the HyDeploy2 project. To perform this assessment the review was broken down into two areas procedures upstream of the emergency control valve (owned by NGN) and procedures downstream of the Emergency Control Valve (procedures which would be performed by Gas Safe registered individuals). Assessment of the upstream procedures was led by NGN (own and carry out all upstream procedures on NGN’s gas network) and assessment of the downstream procedures was led by Blue Flame Associates (an industry expert on downstream gas procedures).<br/>Methodologies were adopted to be able to highlight procedures that could potentially be used on the Winlaton trial network during the hydrogen blended gas injection period and if they were impacted by the changing of the gas within the network from natural gas to hydrogen blended gas. This method determined that for downstream gas procedures a total of 56 gas procedures required expert review resulting in 80 technical questions to be assessed and for the upstream gas procedures a total of 80 gas procedures required expert review resulting in 266 technical questions to be assessed.<br/>The operational procedures assessment has led to a determination as to whether a change is or is not required for relevant operational procedures where a basis of concern existed with respect to the injection of hydrogen blended gas. Any requirements to modify an existing procedure has been given in this report referencing the source as to where the detailed analysis for the change/no change recommendation has been given.<br/>The assessment took into account the associated experimental and research carried out as part of the HyDeploy and HyDeploy2 projects such as the assessment of gas characteristics materials impact appliance survey of assets on the Winlaton network and impact of hydrogen blended gas on gas detection equipment references to these studies have been given accordingly to associated impacted operational procedures.<br/>The conclusion of the assessment is that for upstream gas procedures there are some operational procedures that are unchanged some that require an increase in the frequency as to how often they are performed and some procedures which require a technical modification. For downstream domestic gas procedures all procedures applicable to a domestic gas installation were deemed to not be detrimentally affected by the introduction of a 20 mol% hydrogen blend.<br/>For upstream gas procedures an appropriate training package will be built off the back of the results presented in this report and disseminated accordingly to all relevant Operatives that will be responsible for the safety operation and maintenance of the Winlaton network during the hydrogen blend injection period. For downstream gas procedures the Gas Safe community have been fully engaged and informed about the trial.<br/>Click on the supplements tab to view the other documents from this report

The trial management philosophy of the Winlaton trial within HyDeploy2 has been developed to enable the overall objectives of the project to be achieved; the safe demonstration of operating a Gas Distribution Network (GDN) on a blend of natural gas and hydrogen. The approach taken to develop the management philosophy of the Winlaton trial has been to continue the trial management strategies deployed for the Keele trial under HyDeploy albeit with site specific modifications where necessary. This document provides an overview of the management and governance processes associated with the trial itself.<br/>Click on the supplement tab to view the other documents from this report

Winlaton site was chosen as the site for the HyDeploy 2 North East trial as it was seen as the site that offered a high degree of variability with regards materials on the network size of network and statistical representation of housing. The Winlaton trial network is an estate of the wider Winlaton gas network situated in Blaydon near Gateshead. The Winlaton trial network has been isolated from the wider Winlaton gas network where it was previously supplied from and will be supplied with the blended gas from NGN’s Low Thornley gas depot with the installation of a brand-new pressure regulating district governor.<br/>The data contained within this report outlines the expected seasonal gas demand on the Winlaton trial network and the associated leakage and repair history for the network. No unusual repairs or leakage behaviour has been observed on this network. A DSEAR assessment has been conducted on the governor station ensuring ATEX compliance. The network isolation and reinforcement requirements are also given in this report highlighting the necessary actions to isolate the trial network from the wider Winlaton gas network. The NGN Safety Case outlines the risks associated with the operation of a gas grid and the ALARP mitigations developed to minimise them and what response is necessary in case such risks are realised. The existing safety case will be amended to account for the infrastructural operational and commercial changes associated with the HyDeploy 2 project. The report also contains a detailed register of all the assets on the Winlaton trial network this data set was used to inform the scientific research programme and specifically to allow an assessment to be carried out with regards to the operability of the existing and newly installed assets on the Winlaton trial network with respect to the blended gas.<br/>Click on supplement tab to view the other documents from this report

Decarbonization in several countries is now linked to the prospect of implementing a national hydrogen economy. In countries with extensive natural gas infrastructure hydrogen may provide a real opportunity to decarbonize space heating. While this approach may prove technically and economically feasible in the longterm it is unclear whether consumers will be willing to adopt hydrogen-fueled appliances for heating and cooking should techno-economic feasibility be achieved. In response this paper develops an analytical framework for examining hydrogen acceptance which links together socio-technical barriers and social acceptance factors. Applying this framework the study synthesizes the existing knowledge on public perceptions of hydrogen and identifies critical knowledge gaps which should be addressed to support domestic hydrogen acceptance. The paper demonstrates that a future research agenda should account for the interactions between acceptance factors at the attitudinal socio-political market community and behavioral level. The analysis concludes that hydrogen is yet to permeate the public consciousness due to a lack of knowledge and awareness owing to an absence of information dissemination. In response consumer engagement in energy markets and stronger public trust in key stakeholders will help support social acceptance as the hydrogen transition unfolds. Affordability may prove the most critical barrier to the large-scale adoption of hydrogen homes while the disruptive impacts of the switchover and distributional injustice represent key concerns. As a starting point the promise of economic environmental and community benefits must be communicated and fulfilled to endorse the value of hydrogen homes.

Kinetic rate data for steam methane reforming (SMR) coupled with water gas shift (WGS) over an 18 wt. % NiO/α-Al₂O₃ catalyst are presented in the temperature range of 300–700 °C at 1 bar. The experiments were performed in a plug flow reactor under the conditions of diffusion limitations and away from the equilibrium conditions. The kinetic model was implemented in a one-dimensional heterogeneous mathematical model of catalytic packed bed reactor developed on gPROMS model builder 4.1.0®. The mathematical model of SMR process was simulated and the model was validated by comparing the results with the experimental values. The simulation results were in excellent agreement with the experimental results. The effect of various operating parameters such as temperature pressure and steam to carbon ratio on fuel and water conversion (%) H2 yield (wt. % of CH4) and H2 purity was modelled and compared with the equilibrium values.

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.

Cleavage of aromatic ether bonds through hydrogenolysis is one of the most promising routes for depolymerisation and transformation of lignin into value-added chemicals. Instead of using pressurized hydrogen gas as hydrogen source some reductive organic molecules such as methanol ethanol isopropanol as well as formates and formic acid can serve as hydrogen donor is the process called catalytic transfer hydrogenolysis. This is an emerging and promising research field but there are very few reports. In this paper a comprehensive review of the works is presented on catalytic transfer hydrogenolysis of lignin and lignin model compounds aiming to breakdown the aromatic ethers including α-O-4 β-O-4 and 4-O-5 linkages with focus on reaction mechanisms. The works are organised regarding to different hydrogen donors used to gain an in-depth understanding of the special role of various hydrogen donors in this process. Perspectives on current challenges and opportunities of future research to develop catalytic transfer hydrogenolysis as a competitive and unique strategy for lignin valorisation are also provided.

We investigate the influence of microstructural traps in hydrogen-assisted fatigue crack growth. To this end a new formulation combining multi-trap stress-assisted diffusion mechanism-based strain gradient plasticity and a hydrogen- and fatigue-dependent cohesive zone model is presented and numerically implemented. The results show that the ratio of loading frequency to effective diffusivity governs fatigue crack growth behaviour. Increasing the density of beneficial traps not involved in the fracture process results in lower fatigue crack growth rates. The combinations of loading frequency and carbide trap densities that minimise embrittlement susceptibility are identified providing the foundation for a rational design of hydrogen-resistant alloys.

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 Energy Innovation Needs Assessment (EINA) aims to identify the key innovation needs across the UK’s energy system to inform the prioritisation of public sector investment in low-carbon innovation. Using an analytical methodology developed by the Department for Business Energy & Industrial Strategy (BEIS) the EINA takes a system level approach and values innovations in a technology in terms of the system-level benefits a technology innovation provides. This whole system modelling in line with BEIS’s EINA methodology was delivered by the Energy Systems Catapult (ESC) using the Energy System Modelling Environment (ESMETM) as the primary modelling tool.

To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.

This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.

This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.

A viable hydrogen economy has thus far been hampered by the lack of an inexpensive and convenient hydrogen storage solution meeting all requirements especially in the areas of long hauls and delivery infrastructure. Current approaches require high pressure and/or complex heat management systems to achieve acceptable storage densities. Herein we present a manganese hydride molecular sieve that can be readily synthesized from inexpensive precursors and demonstrates a reversible excess adsorption performance of 10.5 wt% and 197 kgH₂ m^-3 at 120 bar at ambient temperature with no loss of activity after 54 cycles. Inelastic neutron scattering and computational studies confirm Kubas binding as the principal mechanism. The thermodynamically neutral adsorption process allows for a simple system without the need for heat management using moderate pressure as a toggle. A storage material with these properties will allow the DOE system targets for storage and delivery to be achieved providing a practical alternative to incumbents such as 700 bar systems which generally provide volumetric storage values of 40 kgH₂ m^-3 or less while retaining advantages over batteries such as fill time and energy density. Reasonable estimates for production costs and loss of performance due to system implementation project total energy storage costs roughly 5 times cheaper than those for 700 bar tanks potentially opening doors for increased adoption of hydrogen as an energy vector.

As the world prepares to exit from the COVID-19 crisis the pace of the global power revolution is expected to accelerate. A new publication from the World Energy Council in collaboration with PwC underscores the imperative for electricity grid owners and operators to fundamentally transform themselves to secure a role in a more integrated flexible and smarter electricity system in the energy transition to a low carbon future.

“Performing While Transforming: The Role of Transmission Companies in the Energy Transition” is based on in-depth interviews with CEOs and senior leaders from 37 transmission companies representing 35 countries and over 4 million kilometres – near global coverage - of the transmission network. While their roles will evolve transmission companies will remain at the heart of the electricity grid and need to balance the challenges of keeping the lights on while transforming themselves for the future.

The publication explores the various challenges affecting how transmission companies prepare and re-think their operations and business models and leverages the insights from interviewees to highlight four recommendations for transmission companies to consider in their journey:

• Focus on the future through enhanced forecasting and scenario planning  
• Shape the ecosystem by collaborating with new actors and enhancing interconnectivity
• Embrace automation and technology to optimise processes and ensure digital delivery
• Transform organisation to attract new talent and maintain social licence with consumers

The increasing demand for energy and commodities has led to escalating greenhouse gas emissions the chief of which is represented by carbon dioxide (CO2). Blue hydrogen (H2) a lowcarbon hydrogen produced from natural gas with carbon capture technologies applied has been suggested as a possible alternative to fossil fuels in processes with hard-to-abate emission sources including refining chemical petrochemical and transport sectors. Due to the recent international directives aimed to combat climate change even existing hydrogen plants should be retrofitted with carbon capture units. To optimize the process economics of such retrofit it has been proposed to remove CO2 from the pressure swing adsorption (PSA) tail gas to exploit the relatively high CO2 concentration. This study aimed to design and numerically investigate a vacuum pressure swing adsorption (VPSA) process capable of capturing CO2 from the PSA tail gas of an industrial steam methane reforming (SMR)-based hydrogen plant using NaX zeolite adsorbent. The effect of operating conditions such as purge-to-feed ratio and desorption pressure were evaluated in relation to CO2 purity CO2 recovery bed productivity and specific energy consumption. We found that conventional cycle configurations namely a 2-bed 4-step Skarstrom cycle and a 2-bed 6-step modified Skarstrom cycle with pressure equalization were able to concentrate CO2 to a purity greater than 95% with a CO2 recovery of around 77% and 90% respectively. Therefore the latter configuration could serve as an efficient process to decarbonize existing hydrogen plants and produce blue H2.

In comparison with the power sector large scale decarbonisation of heat has received relatively little attention at the infrastructural scale despite its importance in the global CO2 emissions landscape. In this study we focus on the regional transition of a heating sector from natural gas-based infrastructure to H2 using mathematical optimisation. A discrete spatio-temporal description of the geographical region of Great Britain was used in addition to a detailed description of all network elements for illustrating the key factors in the design of nation-wide H2 and CO2 infrastructure. We have found that the synergistic deployment of H2 production technologies such as autothermal reforming of methane and biomass gasification with CO2 abatement technologies such as carbon capture and storage (CCS) are critical in achieving cost-effective decarbonisation. We show that both large scale underground H2 storage and water electrolysis provide resilience and flexibility to the heating system competing on cost and deployment rates. The optimal regions for siting H2 production infrastructure are characterised by proximity to: (1) underground H2 storage (2) high demands for H2 (3) geological storage for CO2. Furthermore cost-effective transitions based on a methane reforming pathway may necessitate regional expansions in the supply of natural gas with profound implications for security of supply in nations that are already highly reliant potentially creating an infrastructure lock-in during the near term. We found that the total system cost comprising both investment and operational elements is mostly influenced by the natural gas price followed by biomass price and CapEx of underground caverns. Under a hybrid Regulated Asset Base (RAB) commercial framework with private enterprises delivering production infrastructure the total cost of heat supply over the infrastructure lifetime is estimated as 5.2–8.6 pence per kW h. Due to the higher cost relative to natural gas a Contract for Difference payment between d20 per MW h and d53 per MW h will be necessary for H2-derived heat to be competitive in the market.

The Fuel Cell Industry Review 2020 offers data analysis and commentary on key events in the industry in 2020. Now in its seventh year the Review has been compiled by a team led by E4tech - a specialist energy strategy consultancy with deep expertise in the hydrogen and fuel cell sector (see www.e4tech.com).



Despite the title of this publication we’ve said before that the fuel cell ‘industry’ is not a single industry at all. As those inside it know it is divided by different materials stages of maturity applications and regions – all contributors to the fact it has taken time to get going. But it does seem to be getting traction. Part of that is down to decades of hard work and investment in R&D technology improvement and demonstrations. Thankfully part of it is also down to changes in external conditions. Improving air quality is increasingly non-negotiable. Reducing greenhouse gas emissions likewise. And all while maintaining economic development and opportunity.



The growth spurt of the battery industry allied with some of the drivers above has catalysed thinking in where and how fuel cells can fit. Countries and regions which did not support batteries early on are scrambling to catch up and wish not to risk a repeat of their errors with fuel cells. So support is being targeted at industrial development and competitiveness as well as solving societal problems. Which in turn is helping industry to decide on and take investment steps: Weichai’s 20000 unit per annum PEM factory in China; Daimler and Volvo setting up their fuel cell truck JV; CHEM Energy building a factory for remote systems in S Africa."

Climate change and air quality concerns have pushed clean energy up the global agenda. As we switch over to new cleaner technologies and fuels our experience of using power heat and transport are going to change transforming the way we live work and get from A to B. Explore this guide to find out what hydrogen is how it is made transported and used what the experience would be like in the home for transport and for businesses and discover what the future of hydrogen might be.  

Visit the Energy Institute website for more information

Safety is an essential element for realizing the “hydrogen economy” – safe operation in all of its aspects from hydrogen production through storage distribution and use; from research development and demonstration to commercialization. As such safety is given paramount importance in all facets of the research development and demonstration of the U.S Department of Energy’s (DOE) Hydrogen Fuel Cells and Infrastructure Technologies (HFCIT) Program Office. The diversity of the DOE project portfolio is self-evident. Projects are performed by large companies small businesses DOE National Laboratories academic institutions and numerous partnerships involving the same. Projects range from research exploring advances in novel hydrogen storage materials to demonstrations of hydrogen refuelling stations and vehicles. Recognizing the nature of its program and the importance of safety planning DOE has undertaken a number of initiatives to encourage and shape safety awareness. The DOE Hydrogen Safety Review Panel was formed to bring a broad cross-section of expertise from the industrial government and academic sectors to help ensure the success of the program as a whole. The Panel provides guidance on safety-related issues and needs reviews individual DOE-supported projects and their safety plans and explores ways to bring learnings to broadly benefit the DOE program. This paper explores the approaches used for providing safety planning guidance to contractors in the context of their own (and varied) policies procedures and practices. The essential elements that should be included in safety plans are described as well as the process for reviewing project safety plans. Discussion of safety planning during the conduct of safety review site visits is also shared. Safety planning-related learnings gathered from project safety reviews and the Panel’s experience in reviewing safety plans are discussed.

Increasingly car manufacturers are turning to high pressure hydrogen storage for on-board power applications. Many prototypes use costly materials and fabrication methods such as Type 316L austenitic stainless steel and processes such as TIG (GTA) welding. There is a need to move to less expensive options without compromising safety to assist in developing economic vehicles. It is important that the behaviour of new/modified materials and joints (including those fabricated by new technologies) is understood at anticipated service temperatures and hydrogen pressure as the consequences of poor material choice could be severe. The greatest detrimental effect of gaseous hydrogen on the mechanical properties of metallic materials is commonly observed under conditions of dynamic plastic strain. Under such conditions an atomically clean surface is produced where hydrogen molecules will dissociate and penetrate the material. Thus static load test methods with hydrogen charging are not reliable for engineering data generation. To meet the need for dynamically straining material in a pressurised hydrogen environment TWI has developed a facility to load specimens in a high pressure environment for tensile toughness and fatigue testing. The design of this has involved a number of innovative steps. This paper outlines the requirements and the design and construction issues that were encountered when installing a facility which can not only perform tests at up to 1000bar (100MPa) but also for temperatures between –150°C to +85°C.

The paper presents the results of the CFD inter-comparison exercise SBEP-V3 performed within the activity InsHyde internal project of the HYSAFE network of excellence in the framework of evaluating the capability of various CFD tools and modelling approaches in predicting the physical phenomena associated to the short and long term mixing and distribution of hydrogen releases in confined spaces. The experiment simulated was INERIS-TEST-6C performed within the InsHyde project by INERIS consisting of a 1 g/s vertical hydrogen release for 240 s from an orifice of 20 mm diameter into a rectangular room (garage) of dimensions 3.78x7.2x2.88 m in width length and height respectively. Two small openings at the front and bottom side of the room assured constant pressure conditions. During the test hydrogen concentration time histories were measured at 12 positions in the room for a period up to 5160 s after the end of release covering both the release and the subsequent diffusion phases. The benchmark was organized in two phases. The first phase consisted of blind simulations performed prior to the execution of the tests. The second phase consisted of post calculations performed after the tests were concluded and the experimental results made available. The participation in the benchmark was high: 12 different organizations (2 non-HYSAFE partners) 10 different CFD codes and 8 different turbulence models. Large variation in predicted results was found in the first phase of the benchmark between the various modelling approaches. This was attributed mainly to differences in turbulence models and numerical accuracy options (time/space resolution and discretization schemes). During the second phase of the benchmark the variation between predicted results was reduced.

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.

Uptake of hydrogen vehicles is an ideal solution for countries that face challenging targets for carbon dioxide reduction. The advantage of hydrogen fuel cell electric vehicles is that they behave in a very similar way to petrol engines yet they do not emit any carbon containing products during operation. The hydrogen industry currently faces the dilemma that they must meet certain measurement requirements (set by European legislation) but cannot do so due to a lack of available methods and standards. This paper outlines the four biggest measurement challenges that are faced by the hydrogen industry including flow metering quality assurance quality control and sampling.

DNV GL believes that the National Transmission System (NTS) will be central to the future of decarbonised energy in the UK. The future NTS could transmit natural gas hydrogen blends of the two and carbon dioxide. New pipelines will be built however a large cost-saving is available if the existing NTS assets can also be re-purposed. To move towards this future National Grid Gas Transmission wants to develop a project to trial injection hydrogen into the NTS. This is an opportunity to show that National Grid is part of the solution to achieving Net Zero. The trial will demonstrate to the Government and public that re-purposing the NTS is cost-effective safe and involves minimal disruption.

This report sets out a roadmap of projects to provide the knowledge needed for the trial. The roadmap was developed by assessing the knowledge required and how much of it already existed. The knowledge already available is summarised in this report with references to where further details can be found. Gaps in the knowledge are then described. The roadmap consists of projects to conduct work to close the knowledge gaps. The results are summarised in the figures below and in the box to the right.  

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.

The largest known experiment on hydrogen-air deflagration in the open atmosphere has been analysed by means of the large eddy simulation (LES). The combustion model is based on the progress variable equation to simulate a premixed flame front propagation and the gradient method to decouple the physical combustion rate from numerical peculiarities. The hydrodynamic instability has been partially resolved by LES and unresolved effects have been modelled by Yakhot's turbulent premixed combustion model. The main contributor to high flame propagation velocity is the additional turbulence generated by the flame front itself. It has been modelled based on the maximum flame wrinkling factor predicted by Karlovitz et al. theory and the transitional distance reported by Gostintsev with colleagues. Simulations are in a good agreement with experimental data on flame propagation dynamics flame shape and outgoing pressure wave peaks and structure. The model is built from the first principles and no adjustable parameters were applied to get agreement with the experiment.