Safety

This work formed part of the H21 programme whose objective is to reach the point whereby it is feasible to convert the existing natural gas (NG) distribution network to 100% hydrogen (H2) and provide a contribution to decarbonising the UK’s heat and power sectors with the focus on decarbonised fuel at point of use. Hydrogen has an ATEX Gas Group of IIC compared to IIA for natural gas which means further precautions are necessary to prevent the ignitio Read More

This paper presents work undertaken by the HSE as part of the Hytunnel-CS project a consortium investigating safety considerations for fuel cell hydrogen (FCH) vehicles in tunnels and similar confined spaces. The sudden failure of a pressurised hydrogen vessel was identified as a scenario of concern due to the severity of the consequences associated with such an event. In order to investigate this scenario experimentally HSE designed a bespoke and reus Read More

The measurement of hydrogen concentration in fuel cell systems is an important prerequisite for the development of a control strategy to enhance system performance reduce purge losses and minimize fuel cell aging effects. In this perspective paper the working principles of hydrogen sensors are analyzed and their requirements for hydrogen control in fuel cell systems are critically discussed. The wide measurement range absence of oxygen high humidit Read More

A growing share of renewable energy production in the energy supply systems is key to reaching the European political goal of zero CO2 emission in 2050 highlighted in the green deal. Linked to the irregular production of solar and wind energies which have the highest potential for development in Europe massive energy storage solutions are needed as energy buffers. The European project HyPSTER [1] (Hydrogen Pilot STorage for large Ecosystem Read More

Hydrogen is the most abundant element on earth being a low polluting and high efficiency fuel that can be used for various applications such as power generation heating or transportation. As a reaction to climate change authorities are working for determining the most promising applications for hydrogen one of the best examples of crossborder initiative being the IPCEI (Important Project of Common European Interest) on Hydrogen under developm Read More

Due to the small characteristic molecular size of hydrogen small leaks are more common in hydrogen systems compared to similar systems with hydrocarbons. This together with the high reactivity makes an efficient ventilation system very important in hydrogen applications. There are several models available for ventilation sizing that are based on either a well-mixed assumption or a fully stratified situation. However experiments show that man Read More

The number of species and elementary reactions needed for describing the oxidation of fuels increases with the size of the molecule and in turn the complexity of detailed mechanisms. Although the kinetics for conventional fuels (H2 CH4 C3H8...) are somewhat well-established chemical integration in detonation applications remains a major challenge. Significant efforts have been made to develop reduction techniques that aim to keep the predi Read More

Natural ventilation is a well-known passive mitigation method to limit hydrogen build-up in confined spaces in case of accidental release [1-3]. In most cases a basic design of H2 infrastructure is adopted and vents installed for natural ventilation are adjusted according to safety targets and constraints of the considered structure. With the growing H2 mobility market the demand for H2 refueling infrastructure in our urban environment is on the rise. In Read More

Hydrogen (H2 ) is considered a suitable substitute for conventional energy sources because it is abundant and environmentally friendly. However the widespread adoption of H2 as an energy source poses several challenges in H2 production storage safety and transportation. Recent efforts to address these challenges have focused on improving the efficiency and cost-effectiveness of H2 production methods developing advanced storage technologies Read More

Hydrogen has the potential to be an important source of clean energy but the development of efficient and cost-effective methods for storing hydrogen is a key challenge that needs to be addressed in order to make widespread use of hydrogen as a possible energy sourc. There are different methods for storing hydrogen (i.e. compressed it at high pressures liquefied by cooling the hydrogen to a temperature of -253°C and stored with a chemical compoun Read More

The NREL Hydrogen Sensor Laboratory is comprised of researchers dedicated to furthering hydrogen sensor technology and detection methodology. NREL has teamed up with researchers at Environment and Climate Change Canada (ECCC) and Transport Canada (TC) to conduct research to quantify hydrogen emissions from Fuel Cell Electric Vehicles (FCEV). Test protocols will have a large effect on monitoring and regulating the hydrogen emissions from Read More

The interaction of a shock wave with a specific angle or concave wall due to its reflection and focusing is a way to onset the detonation provided sufficiently strong shock wave. In this work we present numerical simulation results of the detonation initiation due to the shock reflection and focusing in a 90-degree wedge for mixtures of H2 and air. The code used was ddtFoam [1–3] that is a component of the larger OpenFOAM open-source CFD package of de Read More

: This article investigates how safety culture impacts the safety performance of blue hydrogen projects. Blue hydrogen refers to decarbonized hydrogen produced through natural gas reforming with carbon capture and storage (CCS) technology. It is crucial to decide on a suitable safety policy to avoid potential injuries financial losses and loss of public goodwill. The system dynamics approach is a suitable tool for studying the impact of factors controlling s Read More

Hydrogen as a clean fuel offers a practical pathway to achieve net-zero targets. However due to its physical and chemical characteristics there are some safety concerns for large-scale hydrogen utilisation particularly in process safety management. Leakage of gaseous hydrogen especially in semi-confined spaces such as tunnels can lead to catastrophic outcomes including uncontrolled fire and explosion. The current paper describes the outcome of a Read More

Hydrogen is a promising environmentally friendly fuel with the potential for zero-carbon emissions particularly in maritime applications. However owing to its wide flammability range (4–75%) significant safety concerns persist. In confined spaces hydrogen leaks can lead to explosions posing a risk to both lives and assets. This study conducts a numerical analysis to investigate hydrogen flow within hydrogen storage rooms aboard ships with the goal of develo Read More

The adoption of liquid hydrogen (LH2) as an energy carrier presents significant opportunities for distributing large quantities of hydrogen efficiently. However ensuring safety of LH2 transfer operations requires the evo lution of suitable technologies and regulatory framework. This study offers an extensive overview of technical considerations and safety aspects pertaining to liquid hydrogen installations and mobile applications. A signif icant lack of regulations Read More

Hydrogen has the potential to make countries energetically self-sufficient and independent in the long term. Nevertheless its extreme combustion properties and its capability of permeating and embrittling most metallic materials produce significant safety concerns. The Hydrogen Incidents and Accidents Database 2.0 (HIAD 2.0) is a public repository that collects data on hydrogen-related undesired events mainly occurred in chemical and process industry. Thi Read More

Hydrogen energy is considered the most promising clean energy in the 21st century so hydrogen refuelling stations (HRSs) are crucial facilities for storage and supply. HRSs might experience hydrogen leakage (HL) incidents during their operation. Hydrogen-producing and refuelling integrated stations (HPRISs) could make thermal risks even more prominent than those of HRSs. Considering HL as the target in the HPRIS through the method of fault tree an Read More

Hydrogen has become a key enabler for decarbonization as countries pledge to reach net zero carbon emissions by 2050. With hydrogen infrastructure expanding rapidly beyond its established applications there is a requirement for robust safety practices solutions and regulations. Since the 1980s considerable efforts have been undertaken by the nuclear community to address hydrogen safety issues because in severe accidents of water-coo Read More

The Research Priorities Workshop (RPW) brought together experts from academia industry and government to identify and prioritise future research directions with regard to hydrogen safety. Over two days participants engaged in presentations and discussions covering key areas such as transportation and storage ignition phenomena cryogenic hydrogen risk assessment methodologies and others. A critical component of the workshop was the pri Read More

Quantitative Risk Assessments (QRA) is an important tool for enabling safe deployment of hydrogen technologies and is increasingly embedded in the permitting process. Following the framework developed in our companion paper we conducted a detailed QRA on the uncontrolled releases from a high-capacity hydrogen fueling station with liquid hydrogen (LH2) storage. We characterized gaseous and liquid hydrogen releases determined the caus Read More

Hydrogen tanks used in transportation are equipped with thermal pressure relief devices to prevent a tank rapture in case of fire exposure. The opening of the pressure relief valve in such a scenario would likely result in an impinging and (semi-) confined hydrogen jet fire. Therefore twelve largescale experiments of hydrogen jet fires and one large-scale propane reference experiment have been conducted with various degrees of confinement orientations o Read More

The safety of hydrogen-blended natural gas (HBNG) in a confined space is an issue especially for ventilation processes. In this study leakage and ventilation processes of low-pressure HBNG with different hydrogen-blended ratio (HBR) in a confined space are simulated and validated by experiment based on similarity criteria. For the leakage process the leak direction and HBR do not significantly affect gas accumulation behaviour. The required time for Read More

Green hydrogen is a promising energy vector for industrial applications. However hydrogen leaks can occur causing greenhouse effects and posing safety risks for operators and local communities potentially leading to legal liabilities. Industry 4.0 focuses on digital industrial modernization while Industry 5.0 emphasizes collaborative humancentered and sustainable processes. This study developed and analyzed an Industry 5.0 proof of concept as an a Read More

To mitigate the risk of hydrogen leakage in ship fuel systems powered by internal combustion engines a Bayesian network model was developed to evaluate the risk of hydrogen fuel leakage. In conjunction with the Bow-tie model fuzzy set theory and the Noisy-OR Gate model an in-depth analysis was also conducted to examine both the causal factors and potential consequences of such incidents. The Bayesian network model estimates the likelihood Read More

With increasing global interest in molecular hydrogen to replace fossil fuels more attention is being paid to potential leakages of hydrogen into the atmosphere and its environmental consequences. Hydrogen is not directly a greenhouse gas but its chemical reactions change the abundances of the greenhouse gases methane ozone and stratospheric water vapor as well as aerosols. Here we use a model ensemble of five global atmospheric c Read More