United Kingdom
A Simple Model for Calculating Peak Pressure in Vented Explosions of Hydrogen and Hydrocarbons
Apr 2019
Publication
The authors presented a basic mathematical model for estimating peak overpressure attained in vented explosions of hydrogen in a previous study (Sinha et al. [1]). The model focussed on idealized cases of hydrogen and was not applicable for realistic accidental scenarios like presence of obstacles initial turbulent mixture etc. In the present study the underlying framework of the model is reformulated to overcome these limitations. The flame shape computations are simplified. A more accurate and simpler formulation for venting is also introduced. Further by using simplifying assumptions and algebraic manipulations the detailed model consisting of several equations is reduced to a single equation with only four parameters. Two of these parameters depend only on fuel properties and a standard table provided in the Appendix can be used. Therefore to compute the overpressure only the two parameters based on enclosure geometry need to be evaluated. This greatly simplifies the model and calculation effort. Also since the focus of previous investigation was hydrogen properties of hydrocarbon fuels which are much more widely used were not accounted for. The present model also accounts for thermo-physical properties of hydrocarbons and provides table for fuel parameters to be used in the final equation for propane and methane. The model is also improved by addition of different sub-models to account for various realistic accidental scenarios. Moreover no adjustable parameters are used; the same equation is used for all conditions and all gases. Predictions from this simplified model are compared with experimentally measured values of overpressure for hydrogen and hydrocarbons and found to be in good agreement. First the results from experiments focussing on idealized conditions of uniformly mixed fuel in an empty enclosure under quiescent conditions are considered. Further the model applicability is also tested for realistic conditions of accidental explosion consisting of obstacles inside the enclosure non-uniform fuel distribution initial turbulent mixture etc. For all the cases tested the new simple model is found to produce reasonably good predictions.
Carbon Capture and Storage (CCS): The Way Forward
Mar 2018
Publication
Mai Bui,
Claire S. Adjiman,
André Bardow,
Edward J. Anthony,
Andy Boston,
Solomon Brown,
Paul Fennell,
Sabine Fuss,
Amparo Galindo,
Leigh A. Hackett,
Jason P. Hallett,
Howard J. Herzog,
George Jackson,
Jasmin Kemper,
Samuel Krevor,
Geoffrey C. Maitland,
Michael Matuszewski,
Ian Metcalfe,
Camille Petit,
Graeme Puxty,
Jeffrey Reimer,
David M. Reiner,
Edward S. Rubin,
Stuart A. Scott,
Nilay Shah,
Berend Smit,
J. P. Martin Trusler,
Paul Webley,
Jennifer Wilcox and
Niall Mac Dowell
Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets delivering low carbon heat and power decarbonising industry and more recently its ability to facilitate the net removal of CO2 from the atmosphere. However despite this broad consensus and its technical maturity CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus in this paper we review the current state-of-the-art of CO2 capture transport utilisation and storage from a multi-scale perspective moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS) and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.
Power Generation Analysis of Terrestrial Ultraviolet-Assisted Solid Oxide Electrolyzer Cell
Jan 2022
Publication
This paper presents a novel system design that considerably improves the entrapment of terrestrial ultraviolet (UV) irradiance in a customized honeycomb structure to produce hydrogen at a standard rate of 7.57 slpm for places with a UV index > 11. Thermolysis of high salinity water is done by employing a solid oxide electrolyzer cell (SOEC) which comprises three customized novel active optical subsystems to filter track and concentrate terrestrial UV solar irradiance by Fresnel lenses. The output of systems is fed to a desalinator a photovoltaic system to produce electrical energy and a steam generator with modified surface morphology to generate the required superheated steam for the SOEC. A simulation in COMSOL Multiphysics ver. 5.6 has shown that a customized honeycomb structure when incorporated on the copper–nickel surface of a steam generator improves its absorptance coefficient up to 93.43% (48.98%—flat case). This results in generating the required superheated steam of 650 ◦C with a designed active optical system comprising nine Fresnel lenses (7 m2 ) that offer the concentration of 36 suns on the honeycomb structure of the steam generator as input. The required 1.27 kW of electrical power is obtained by concentrating the photovoltaic system using In0.33Ga0.67N/Si/InN solar cells. This production of hydrogen is sustainable and cost effective as the estimated cost over 5 years by the proposed system is 0.51 USD/kg compared to the commercially available system which costs 3.18 USD/kg.
Hydrogen for Heating? Decarbonization Options for Households in the United Kingdom in 2050
Dec 2020
Publication
The heating sector makes up 10% of the United Kingdom’s carbon footprint and residential homes account for a majority of demand. At present central heating from a natural gas-fired boiler is the most common system in the UK but low or zero-carbon hydrogen and renewable electricity are the two primary energy replacement options to reduce the carbon footprint. An important consideration is how using either energy source would affect heating costs. This assessment projects the costs for a typical single-family UK household and climate performance in 2050 using low-GHG or GHG-neutral hydrogen renewable electricity or a combination of both. The cost of using boilers or fuel cells in 2050 with two types of hydrogen are assessed: produced via steam-methane reforming (SMR) combined with carbon capture and storage (CCS) and electrolysis using zero-carbon renewable electricity. The costs of heat pumps the most promising heating technology for the direct use of renewable electricity are also assessed in two scenarios: a heat pump only and a hybrid heat pump with an auxiliary hydrogen boiler.
You can download this document from the International Council On Clean Transportation website linked here
You can download this document from the International Council On Clean Transportation website linked here
Consequences of Catastrophic Releases of Ignited and Unignited Hydrogen Jet Releases
Sep 2009
Publication
The possibility of using a risk based approach for the safe installation and siting of stationary fuel cell systems depends upon the availability of normative data and guidance on potential hazards and the probabilities of their occurrence. Such guidance data is readily available for most common hydrocarbon fuels. For hydrogen however data is still required on the hazards associated with different release scenarios. This data can then be related to the probability of different types of scenarios from historical fault data to allow safety distances to be defined and controlled using different techniques. Some data on releases has started to appear but this data generally relates to hydrogen vehicle refuelling systems that are designed for larger throughput higher pressures and the general use of larger pipe diameters than are likely to be used for small fuel cell systems.
Prediction of Third Party Damage Failure Frequency for Pipelines Transporting Mixtures of Natural Gas and Hydrogen
Sep 2009
Publication
As Europe is gradually moving towards a hydrogen based society it has been acknowledged that adding certain amount of hydrogen as a clean energy carrier to the existing natural gas pipeline will help reduce the CO2 emissions which contribute to the greenhouse effect. On the other hand hydrogen has been demonstrated to be able to change the behaviour of the pipeline steel such as lower toughness and faster crack growth due to hydrogen embrittlement. Therefore it is necessary that the risks associated with the failure of the pipeline carrying mixtures of natural gas and hydrogen be assessed.<br/>The study reported in this paper is part of European NATURALHY project whose aim is to investigate the possibility of using the existing natural gas transmission pipelines to convey natural gas/hydrogen mixtures. According to the EGIG database the most common cause of failure for the existing natural gas pipelines is third party damage which mainly refers to a gouge a dent/gouge combination of known geometry. Among third party damage failures 90% are the result of immediate failure i.e. leakage or rupture of the pipeline and only 10% of them are the result of delayed failure. While its not expected that hydrogen will impact the immediate failure it could increase the vulnerability of the pipe to delayed failure through the initiation or activation of crack like defects.<br/>This paper will present a methodology to predict the probability of increased failures and describe a software tool that has been developed to perform the calculations.
Annual Science Review 2019
Mar 2019
Publication
Having a robust evidence base enables us to tackle real issues causing pain and suffering in the workplace. Critically it enables us to better understand developing issues and ways of working to ensure that we support innovation rather than stifle it through lack of knowledge. For example the work on the use of 3D printers in schools demonstrates HSE’s bility to engage and understand the risks to encourage safe innovation in a developing area (see p47).<br/>Other examples in this report show just a selection of the excellent work carried out by our staff often collaborating with others which contributes to improving how we regulate health and safety risks proportionately and effectively.<br/>One of HSEs key priorities is to prevent future cases of occupational lung disease by improving the management and control of hazardous substances. The case study on measuring Respirable Crystalline Silica exposure contributes to this and to recognise developing and future issues such as the work on diacetyl in the coffee industry (see p24 and p39). This type of scientific investigation gives our regulators good trusted information enabling critical decisions on the actions needed to protect workers.<br/>The case study on publishing new guidance on the use of Metalworking Fluids (MWF) demonstrates the important contribution of collaborative science to improving regulation. If used inappropriately exposure to MWF mist can cause serious long-term lung disease and it was recognised that users needed help to control this risk. HSE scientists and regulators worked with industry stakeholders to produce new free guidance which reflects changes in scientific understanding in a practical easy to use guide. As well as enabling users to better manage the risks and as a bonus likely save money it has assisted regulation by providing clear benchmarks for all to judge control against. An excellent example of science contributing to controlling serious health risks (see p22).<br/>These case studies are excellent examples of how science contributes to reducing risk. Hopefully they will inspire you to think about how risk in your workplace could be improved and where further work might be needed.
Irreproducibility in Hydrogen Storage Material Research
Sep 2016
Publication
The storage of hydrogen in materials has received a significant amount of attention in recent years because this approach is widely thought to be one of the most promising solutions to the problem of storing hydrogen for use as an alternative energy carrier in a safe compact and affordable form. However there have been a number of high profile cases in which erroneous or irreproducible data have been published. Meanwhile the irreproducibility of research results in a wide range of disciplines has been the subject of an increasing amount of attention due to problems with some of the data in the literature. In this Perspective we provide a summary of the problems that have affected hydrogen storage material research. We also discuss the reasons behind them and possible ways of reducing the likelihood of further problems occurring in the future.
Decarbonising Ships, Planes and Trucks: An Analysis of Suitable Low-carbon Fuels for the Maritime, Aviation and Haulage Sectors
Jan 2021
Publication
The high environmental impacts of transport mean that there is an increasing interest in utilising low-carbon alternative energy carriers and powertrains within the sector. While electricity has been mooted as the energy carrier of choice for passenger vehicles as the mass and range of the vehicle increases electrification becomes more difficult. This paper reviews the shipping aviation and haulage sectors and a range of low-carbon energy carriers (electricity biofuels hydrogen and electro fuels) that can be used to decarbonise them. Energy carriers were assessed based on their energy density specific energy cost lifecycle greenhouse gas emissions and land-use. In terms of haulage current battery electric vehicles may be technically feasible however the specific energy of current battery technology reduces the payload capacity and range when compared to diesel. To alleviate these issues biomethane represents a mature technology with potential co-benefits while hydrogen is close to competitiveness but requires significant infrastructure. Energy density issues preclude the use of batteries in shipping which requires energy dense liquids or compressed gaseous fuels that allow for retrofits/current hull designs with methanol being particularly appropriate here. Future shipping may be achieved with ammonia or hydrogen but hull design will need to be changed significantly. Regulations and aircraft design mean that commercial aviation is dependant on drop-in jet fuels for the foreseeable future with power-to-liquid fuels being deemed the most suitable option due to the scales required. Fuel costs and a lack of refuelling infrastructure were identified as key barriers facing the uptake of alternatives with policy and financial incentives required to encourage the uptake of low-carbon fuels.
Health and safety in the new energy economy
Dec 2010
Publication
Over the next decade and beyond the UK is set to take significant steps towards a new energy economy. This will be an economy where the technologies meeting<br/>our electricity heat and fuel needs have to deliver against three key criteria: sustainability security and affordability.<br/><br/>In this context a wide range of emerging energy technologies are expected to play an important role in reshaping the way we satisfy our energy requirements. The extent to which they do so however will depend fundamentally on their ability to be harnessed safely.<br/><br/>Compiled by HSE’s Emerging Energy Technologies Programme this report provides a current assessment of the health and safety hazards that key emerging energy technologies could pose both to workers and to the public at large. (Nuclear energy technologies fall outside the scope of this report.) But it also highlights how an appropriate framework can be and is being put in place to help ensure that these hazards are managed and controlled effectively – an essential<br/>element in enabling the technologies to make a major contribution to the UK’s energy future.
Indoor Use of Hydrogen, Knowledge Gaps and Priorities for the Improvement of Current Standards on Hydrogen, a Presentation of HyIndoor European Project
Sep 2013
Publication
To develop safety strategies for the use of hydrogen indoors the HyIndoor project is studying the behaviour of a hydrogen release deflagration or non-premixed flame in an enclosed space such as a fuel cell or its cabinet a room or a warehouse. The paper proposes a safety approach based on safety objectives that can be used to take various scenarios of hydrogen leaks into account for the safe design of Hydrogen and Fuel Cell (HFC) early market applications. Knowledge gaps on current engineering models and unknown influence of specific parameters were identified and prioritized thereby re-focusing the objectives of the project test campaign and numerical simulations. This approach will enable the improvement of the specification of openings and use of hydrogen sensors for enclosed spaces. The results will be disseminated to all stakeholders including hydrogen industry and RCS bodies.
Effect of Rotation on Ignition Thresholds of Stoichiometric Hydrogen Mixtures
Sep 2017
Publication
Successful transition to a hydrogen economy calls for a deep understanding of the risks associated with its widespread use. Accidental ignition of hydrogen by hot surfaces is one of such risks. In the present study we investigated the effect that rotation has on the reported ignition thresholds by numerically determining the minimum surface temperature required to ignite stoichiometric hydrogen-air using a hot horizontal cylinder rotating at various angular velocities ω. Numerical experiments showed a weak but interesting dependence of the ignition thresholds on rotation: the ignition thresholds increased by 8 K from 931 K to 939 K with increasing angular velocity (0 ≤ ω ≤ 240 rad/s). A further increase to ω = 480 rad/s resulted in a decrease in ignition surface temperature to 935 K. Detailed analysis of the flow patterns inside the vessel and in close proximity to the hot surface brought about by the combined effect of buoyancy and rotation as well as of the distribution of the wall heat flux along the circumference of the cylinder support our previous findings in which regions where temperature gradients are small were found to be prone to ignition.
Reversible Ammonia-based and Liquid Organic Hydrogen Carriers for High-density Hydrogen Storage: Recent Progress
Feb 2019
Publication
Liquid hydrogen carriers are considered to be attractive hydrogen storage options because of their ease of integration into existing chemical transportation infrastructures when compared with liquid or compressed hydrogen. The development of such carriers forms part of the work of the International Energy Agency Task 32: Hydrogen-Based Energy Storage. Here we report the state-of-the-art for ammonia-based and liquid organic hydrogen carriers with a particular focus on the challenge of ensuring easily regenerable high-density hydrogen storage.
East Coast Hydrogen Feasibility Report
Nov 2021
Publication
The highlights of the report include:
- East Coast Hydrogen has the potential to connect up to 7GW of hydrogen production by 2030 alone exceeding the UK Government’s 5GW by 2030 target in a single project. It represents an unmissable opportunity for government and the private sector to work together in delivering on our ambitious decarbonisation targets.
- East Coast Hydrogen can use the natural assets of the North of England including existing and potential hydrogen storage facilities and build on the hydrogen production in two of the UK’s largest industrial clusters in the North East and North West in turn ensuring significant private sector investment in the UK’s industrial heartlands.
- This would be the first step in the conversion of our national gas grid to hydrogen and will act as a blueprint for subsequent conversions across the UK.
- The project will also demonstrate the innovation engineering capabilities and economic opportunity in the North and create tens of thousands of highly skilled Green jobs in the future hydrogen economy."
Hydrogen Production, Distribution, Storage and Power Conversion in a Hydrogen Economy - A Technology Review
Aug 2021
Publication
To meet ambitious targets for greenhouse gas emissions reduction in the 2035-2050 timeframe hydrogen has been identified as a clean “green” fuel of interest. In comparison to fossil fuel use the burning of hydrogen results in zero CO2 emissions and it can be obtained from renewable energy sources. In addition to zero CO2 emissions hydrogen has several other attractive properties such as higher gravimetric energy content and wider flammability limits than most fossil fuels. However there are practical limitations to its widespread use at present which include low volumetric energy density in the gaseous state and high well-to-wheel costs when compared to fossil fuel production and distribution. In this paper a review is undertaken to identify the current state of development of key areas of the hydrogen network such as production distribution storage and power conversion technology. At present high technology costs still are a barrier to widespread hydrogen adoption but it is envisioned that as scale of production increases then costs are likely to fall. Technical barriers to a hydrogen economy adoption are not as significant as one might think as key technologies in the hydrogen network are already mature with working prototypes already developed for technologies such as liquid hydrogen composite cryotanks and proton exchange membrane fuel cells. It is envisioned that with continuous investment to achieve requisite scale that a hydrogen economy could be realised sooner rather than later with novel concepts such as turboelectric distributed propulsion enabled by a shift to hydrogen-powered network.
HyDeploy2 Report: Exemption
Jun 2021
Publication
Exemption is requested by Northern Gas Networks Ltd (NGN) from the obligation set out in Regulation 8(1) of the Gas Safety (Management) Regulations 1996 (GSMR) to convey only natural gas that is compliant with the Interchangeability requirements of Part I of Schedule 3 of the GSMR within a section of the NGN gas distribution network near Winlaton (the “field trial area”). The field trial area is owned and operated by Northern Gas Networks Ltd. The proposed conveyance of non-compliant gas (hereafter called the “Winlaton Field Trial”) will last for one year and is part of the Network Innovation Competition Project “HyDeploy2”.<br/>The project the first two phases of which are funded under the UK Network Innovation Competition scheme aims to demonstrate that natural gas containing levels of hydrogen beyond the upper limit set out in Schedule 3 of in the Gas Safety (Management) Regulations (GSMR) can be distributed and utilised safely and efficiently in the UK gas distribution networks. The first phase of the HyDeploy project is currently underway and includes a 10-month field trial that of hydrogen injection into part of a private gas distribution system owned and operated by Keele University. The second phase of the HyDeploy project (HyDeploy2) continues on from the work of the first phase and is scheduled to conclude with two 12-month field trials in which hydrogen will be injected into public gas networks owned and operated by NGN and Cadent Gas.<br/>Click on the supplements tab to view the other documents from this report
IGEM/SR/23 Review of Thermal Radiation and Noise for Hydrogen Venting
Nov 2021
Publication
IGEM/SR/23 (“Venting of natural gas”) provides recommendations for the conceptual design operation and safety aspects of permanent temporary and emergency venting of natural gas. The document was originally developed many years ago and the current edition dates to 1995. The document is due to be reviewed and updated for application to natural gas but the aim of this study is not to review the applicability of the document for natural gas but to assess the possible impact of 100% hydrogen on specific aspects of the existing guidance.<br/>A key element of the guidance concerns the safe dispersion distances for natural gas as vents are intended to provide a means of safely dispersing gas in the atmosphere without ignition. Guidance on safe dispersion distances for venting are provided in Section 6.6 accompanied by graphs showing the relationship between the mass flow rate through the vent and the safe (horizontal) dispersion distance. Details of the model used to predict the dispersion distances are given in Appendix 1. However for dispersion the guidance in IGEM/SR/23 has been superseded by similar guidance on hazard distances for unignited releases in IGEM/SR/25 (“Hazardous area classification of natural gas installations”) [2]. A comprehensive review of the applicability of IGEM/SR/25 to hydrogen is already underway for the LTS Futures project and is not duplicated here.<br/>However IGEM/SR/23 contains guidance on other important aspects relevant to the safe design and operation of vents which are not addressed elsewhere in the IGEM suite of standards; in particular guidance on hazard ranges for thermal radiation (in the event of an unplanned ignition of the venting gas) and noise.<br/>The main aim of this report is to assess the potential impact of replacing natural gas with 100% hydrogen on the guidance in IGEM/SR/23 concerned with thermal hazards with a secondary objective of assessing the available information to comment on the possible influence of hydrogen on noise.
A Combined Heat and Green Hydrogen (CHH) Generator Integrated with a Heat Network
Sep 2021
Publication
Combined heat and power (CHP) systems offer high energy efficiencies as they utilise both the electricity generated and any excess heat by co-suppling to local consumers. This work presents the potential of a combined heat and hydrogen (CHH) system a solution where Proton exchange membrane (PEM) electrolysis systems producing hydrogen at 60–70% efficiency also co-supply the excess heat to local heat networks. This work investigates the method of capture and utilisation of the excess heat from electrolysis. The analysed system was able to capture 312 kW of thermal energy per MW of electricity and can deliver it as heated water at either 75 ◦C or 45 ◦C this appropriate for existing district heat networks and lower temperature heat networks respectively. This yields an overall CHH system efficiency of 94.6%. An economic analysis was conducted based on income generated through revenue sales of both hydrogen and heat which resulted in a significant reduction in the Levelized Cost of Hydrogen.
Energy and Utility Skills - Hydrogen Competency Framework Report
Jul 2021
Publication
In 2020 the Department for Business Enterprise and Industrial Strategy (BEIS) commissioned Energy & Utility Skills to develop and deliver a Hydrogen Competency Framework as part of the Hy4Heat programme. The successful completion of this work is detailed in a new report published today.
The work done by Energy & Utility Skills was underpinned by three key pillars:
Collaboration
The resulting outputs of the design development stages are:
More details about this report can be found on the Energy & Utility Skills website.
The work done by Energy & Utility Skills was underpinned by three key pillars:
Collaboration
- Driving growth in engagement levels across the industry
- Designing the framework for both initial trials and any future rollout
- The framework ensures engineers will have all the skills knowledge and understanding they need
The resulting outputs of the design development stages are:
- A Comparative Analysis of Hydrogen and existing hydrocarbon gases
- A Skills Matrix that translates the analysis into skills knowledge and understanding
- An Interim Hydrogen Technical Standard that defines acceptable parameters and requirements for hydrogen installation work
- A Hydrogen Training Specification that will enable training course consistency and facilitate industry recognition
- An independent Hydrogen Assessment Module that will facilitate the addition of a hydrogen competence category on the Gas Safe Register
More details about this report can be found on the Energy & Utility Skills website.
Hybrid Hydrogen PEM Fuel Cell and Batteries Without DC–DC Converter
Sep 2013
Publication
Concerns about greenhouse gases as well as the price and security of oil supply have acted as a spur to sustainable automobile development. The hydrogen fuel cells electric vehicle (HFCEV) is generally recognised by leading automobile manufacturers and scientists as one of the optimum technologies for long-term future low carbon vehicle. In a typical HFCEV power train a DC–DC converter is required to balance the voltage difference between the fuel cells (FCs) stack and batteries. However research shows that a considerable amount of energy generated by the hydrogen FCs stack is deplete during this conversion process as heat. This experiment aims to improve the power train efficiency by eliminating the DC–DC converter by finding the best combination of FC stack and batteries matching the size and capacity of the electrical components.
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