Netherlands
Best Practice in Numerical Simulation and CFD Benchmarking. Results from the SUSANA Project
Sep 2017
Publication
Correct use of Computational Fluid Dynamics (CFD) tools is essential in order to have confidence in the results. A comprehensive set of Best Practice Guidelines (BPG) in numerical simulations for Fuel Cells and Hydrogen applications has been one of the main outputs of the SUSANA project. These BPG focus on the practical needs of engineers in consultancies and industry undertaking CFD simulations or evaluating CFD simulation results in support of hazard/risk assessments of hydrogen facilities as well as on the needs of regulatory authorities. This contribution presents a summary of the BPG document. All crucial aspects of numerical simulations are addressed such as selection of the physical models domain design meshing boundary conditions and selection of numerical parameters. BPG cover all hydrogen safety relative phenomena i.e. release and dispersion ignition jet fire deflagration and detonation. A series of CFD benchmarking exercises are also presented serving as examples of appropriate modelling strategies.
Risk Assessment of Hydrogen Explosion for Private Car with Hydrogen-driven Engine
Sep 2009
Publication
The aim of the study is to identify and quantify the additional risks related to hydrogen explosions during the operation of a hydrogen-driven car. In a first attempt the accidents or failures of a simple one-tank hydrogen storage system have been studied as a main source of risk. Three types of initiators are taken into account: crash accidents fire accidents without crash (no other cars are involved) and hydrogen leakages in normal situation with following ignition. The consequences of hydrogen ignition and/or explosion depend strongly on environmental conditions (geometry wind etc.) therefore the different configurations of operational and environmental conditions are specified.<br/>Then Event Tree/Fault Tree methods are applied for the risk assessment.<br/>The results of quantification permit to draw conclusions about the overall added risk of hydrogen technology as well as about the main contributors to the risk. Results of this work will eventually contribute to the on-going pre-normative research in the field of hydrogen safety.
How Far Away is Hydrogen? Its Role in the Medium and Long-term Decarbonisation of the European Energy System
Nov 2015
Publication
Hydrogen is a promising avenue for decarbonising energy systems and providing flexibility. In this paper the JRC-EU-TIMES model – a bottom-up technology-rich model of the EU28 energy system – is used to assess the role of hydrogen in a future decarbonised Europe under two climate scenarios current policy initiative (CPI) and long-term decarbonisation (CAP). Our results indicate that hydrogen could become a viable option already in 2030 – however a long-term CO2 cap is needed to sustain the transition. In the CAP scenario the share of hydrogen in the final energy consumption of the transport and industry sectors reaches 5% and 6% by 2050. Low-carbon hydrogen production technologies dominate and electrolysers provide flexibility by absorbing electricity at times of high availability of intermittent sources. Hydrogen could also play a significant role in the industrial and transport sectors while the emergence of stationary hydrogen fuel cells for hydrogen-to-power would require significant cost improvements over and above those projected by the experts.
International Association for Hydrogen Safety ‘Research Priorities Workshop’, September 2018, Buxton, UK
Sep 2018
Publication
Hydrogen has the potential to be used by many countries as part of decarbonising the future energy system. Hydrogen can be used as a fuel ‘vector’ to store and transport energy produced in low-carbon ways. This could be particularly important in applications such as heating and transport where other solutions for low and zero carbon emission are difficult. To enable the safe uptake of hydrogen technologies it is important to develop the international scientific evidence base on the potential risks to safety and how to control them effectively. The International Association for Hydrogen Safety (known as IA HySAFE) is leading global efforts to ensure this. HSE hosted the 2018 IA HySAFE Biennial Research Priorities Workshop. A panel of international experts presented during nine key topic sessions: (1) Industrial and National Programmes; (2) Applications; (3) Storage; (4) Accident Physics – Gas Phase; (5) Accident Physics – Liquid/ Cryogenic Behaviour; (6) Materials; (7) Mitigation Sensors Hazard Prevention and Risk Reduction; (8) Integrated Tools for Hazard and Risk Assessment; (9) General Aspects of Safety.<br/>This report gives an overview of each topic made by the session chairperson. It also gives further analysis of the totality of the evidence presented. The workshop outputs are shaping international activities on hydrogen safety. They are helping key stakeholders to identify gaps in knowledge and expertise and to understand and plan for potential safety challenges associated with the global expansion of hydrogen in the energy system.
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.
Analysis of Out-of-spec Events During Refueling of On-board Hydrogen Tanks
Sep 2017
Publication
For refuelling on-board hydrogen tanks table-based or formula based protocols are commonly used. These protocols are designed to achieve a tank filling close to 100% SOC (State of Charge) in s safe way: without surpassing temperature (-40°C to 85°C) and pressure limits (125% Nominal Working Pressure NWP). The ambient temperature the initial pressure and the volume category of the (compressed hydrogen storage system CHSS are used as inputs to determine the final target pressure and the pressure ramp rate (which controls the filling duration). However abnormal out-of-spec events (e.g. misinformation of storage system status and characteristics of the storage tanks) may occur and result in a refuelling in which the safety boundaries are surpassed. In the present article the possible out of specification (out-of-spec) events in a refuelling station have been analyzed. The associated hazards when refuelling on-board hydrogen tanks have been studied. Experimental results of out-of-spec event tests performed on a type 3 tank are presented. The results show that on the type 3 tank the safety temperature limit of 85°C was only surpassed under a combination of events; e.g. an unnoticed stop of the cooling of the gas combined with a wrong input of ambient temperature at a very warm environment. On the other hand under certain events (e.g. cooling the gas below the target temperature) and in particular under cold environmental conditions the 100% SOC limit established in the fuelling protocols has been surpassed. Hydrogen safety on-board tanks refuelling protocols out-of-spec events.
A Personal Retrospect on Three Decades of High Temperature Fuel Cell Research; Ideas and Lessons Learned
Feb 2021
Publication
In 1986 the Dutch national fuel cell program started. Fuel cells were developed under the paradigm of replacing conventional technology. Coal-fired power plants were to be replaced by large-scale MCFC power plants fuelled by hydrogen in a full-scale future hydrogen economy. With today's knowledge we will reflect on these and other ideas with respect to high temperature fuel cell development including the choice for the type of high temperature fuel cell. It is explained that based on thermodynamics proton conducting fuel cells would have been a better choice and the direct carbon fuel cell even more so with electrochemical gasification of carbon as the ultimate step. The specific characteristics of fuel cells and multisource multiproduct systems were not considered whereas we understand now that these can provide huge driving forces for the implementation of fuel cells compared to just replacing conventional combined heat and power production technology.
Opportunities for Hydrogen Energy Technologies Considering the National Energy & Climate Plans
Aug 2020
Publication
The study analyses the role of hydrogen in the National Energy and Climate Plans (NECPs) and identifies and highlights opportunities for hydrogen technologies to contribute to effective and efficient achievement of the 2030 climate and energy targets of the EU and its Member States.<br/>The study focuses on the potential and opportunities of renewable hydrogen produced by electrolysers using renewable electricity and of low-carbon hydrogen produced by steam methane reforming combined with CCS. The opportunities for and impacts of hydrogen deployment are assessed and summarised in individual fiches per Member State.<br/>The study analyses to what extent policy measures and industrial initiatives are already being taken to facilitate large-scale implementation of hydrogen in the current and the next decades. The study concludes by determining the CO2 reduction potential beyond what is foreseen in the NECPs through hydrogen energy technologies estimating the reduction of fossil fuel imports and reliance the prospective cost and the value added and jobs created. National teams working on decarbonisation roadmaps and updates of the NECPs are welcome to consider the opportunities and benefits of hydrogen deployment identified in this study.
Soft-linking of a Behavioral Model for Transport with Energy System Cost optimization Applied to Hydrogen in EU
Sep 2019
Publication
Fuel cell electric vehicles (FCEV) currently have the challenge of high CAPEX mainly associated to the fuel cell. This study investigates strategies to promote FCEV deployment and overcome this initial high cost by combining a detailed simulation model of the passenger transport sector with an energy system model. The focus is on an energy system with 95% CO2 reduction by 2050. Soft-linking by taking the powertrain shares by country from the simulation model is preferred because it considers aspects such as car performance reliability and safety while keeping the cost optimization to evaluate the impact on the rest of the system. This caused a 14% increase in total cost of car ownership compared to the cost before soft-linking. Gas reforming combined with CO2 storage can provide a low-cost hydrogen source for FCEV in the first years of deployment. Once a lower CAPEX for FCEV is achieved a higher hydrogen cost from electrolysis can be afforded. The policy with the largest impact on FCEV was a purchase subsidy of 5 k€ per vehicle in the 2030–2034 period resulting in 24.3 million FCEV (on top of 67 million without policy) sold up to 2050 with total subsidies of 84 bln€. 5 bln€ of R&D incentives in the 2020–2024 period increased the cumulative sales up to 2050 by 10.5 million FCEV. Combining these two policies with infrastructure and fuel subsidies for 2030–2034 can result in 76 million FCEV on the road by 2050 representing more than 25% of the total car stock. Country specific incentives split of demand by distance or shift across modes of transport were not included in this study.
CFD Modelling of Accidental Hydrogen Release from Pipelines
Sep 2005
Publication
Although today hydrogen is distributed mainly by trailers in the long terms pipeline distribution will be more suitable if large amounts of hydrogen are produced on industrial scale. Therefore from the safety point of view it is essential to compare hydrogen pipelines to natural gas pipelines which are well established today. Within the paper we compare safety implications in accidental situations. We do not look into technological aspects such as compressors or seals.<br/>Using a CFD (Computational Fluid Dynamics) tool it is possible to investigate the effects of different properties (density diffusivity viscosity and flammability limits) of hydrogen and methane on the dispersion process. In addition CFD tools allow studying the influence of different release scenarios geometrical configurations and atmospheric conditions. An accidental release from a pipeline is modelled. The release is simulated as a flow though a small hole between the high-pressure pipeline and the environment. A part of the pipeline is included in the simulations as high-pressure reservoir. Due to the large pressure difference between the pipeline and the environment the flow conditions at the release become critical.<br/>For the assumed scenarios larger amount of flammable mixture could be observed in case of hydrogen release. On the other hand because of buoyancy and a higher sonic speed at the release the hydrogen clouds are farther from the ground level or buildings than in case of the methane clouds decreasing the probability of ignition and reducing the flame acceleration due to obstacles in case of ignition. Results on the effect of wind in the release scenarios are also described.
The Safe Use of the Existing Natural Gas System for Hydrogen (Overview of the NATURALHY-Project)
Sep 2005
Publication
The transition period towards the situation in which hydrogen will become an important energy carrier will be lengthy (decades) costly and needs a significant R&D effort. It’s clear therefore that the development of a hydrogen system requires a practical strategy within the context of the existing assets. Examining the potential of the existing extensive natural gas chain (transmission - distribution - end user infrastructures and appliances) is a logical first step towards the widespread delivery of hydrogen.
The project will define the conditions under which hydrogen can be mixed with natural gas for delivery by the existing natural gas system and later withdrawn selectively from the pipeline system by advanced separation technologies. Membranes will be developed to enable this separation. The socio-economic and life cycle consequences of this hydrogen delivery approach will be mapped out. By adding hydrogen to natural gas the physical and chemical properties of the mixture will differ from “pure” natural gas. As this may have a major effect on safety issues and durability issues (which also have a safety component) related to the gas delivery and the performance of end use appliances these issues are particularly addressed in the project.
The project is executed by a European consortium of 39 partners (including 15 from the gas industry). In this project set up under the auspices of GERG The European Gas Research Group there are leading roles for N.V. Nederlandse Gasunie (NL) Gaz de France (F) TNO (NL) ISQ (P) the Universities of Loughborough and Warwick (UK) and Exergia (GR). Guidance will be provided by a Strategic Advisory Committee consisting of representatives from relevant (inter)national organizations.
The project started on 1st May 2004 and will run for 5 years. The European Commission has selected the Integrated Project NATURALHY for financial support within the Sixth Framework Programme.
The project will define the conditions under which hydrogen can be mixed with natural gas for delivery by the existing natural gas system and later withdrawn selectively from the pipeline system by advanced separation technologies. Membranes will be developed to enable this separation. The socio-economic and life cycle consequences of this hydrogen delivery approach will be mapped out. By adding hydrogen to natural gas the physical and chemical properties of the mixture will differ from “pure” natural gas. As this may have a major effect on safety issues and durability issues (which also have a safety component) related to the gas delivery and the performance of end use appliances these issues are particularly addressed in the project.
The project is executed by a European consortium of 39 partners (including 15 from the gas industry). In this project set up under the auspices of GERG The European Gas Research Group there are leading roles for N.V. Nederlandse Gasunie (NL) Gaz de France (F) TNO (NL) ISQ (P) the Universities of Loughborough and Warwick (UK) and Exergia (GR). Guidance will be provided by a Strategic Advisory Committee consisting of representatives from relevant (inter)national organizations.
The project started on 1st May 2004 and will run for 5 years. The European Commission has selected the Integrated Project NATURALHY for financial support within the Sixth Framework Programme.
Modelling of Lean Uniform and Non-Uniform Hydrogen-Air Mixture Explosions in a Closed Vessel
Sep 2009
Publication
Simulation of hydrogen-air mixture explosions in a closed large-scale vessel with uniform and nonuniform mixture compositions was performed by the group of partners within the EC funded project “Hydrogen Safety as an Energy Carrier” (HySafe). Several experiments were conducted previously by Whitehouse et al. in a 10.7 m3 vertically oriented (5.7-m high) cylindrical facility with different hydrogen-air mixture compositions. Two particular experiments were selected for simulation and comparison as a Standard Benchmark Exercise (SBEP) problem: combustion of uniform 12.8% (vol.) hydrogen-air mixture and combustion of non-uniform hydrogen-air mixture with average 12.6% (vol.) hydrogen concentration across the vessel (vertical stratification 27% vol. hydrogen at the top of the vessel 2.5% vol. hydrogen at the bottom of the vessel); both mixtures were ignited at the top of the vessel. The paper presents modelling approaches used by the partners comparison of simulation results against the experiment data and conclusions regarding the non-uniform mixture combustion modelling in real-life applications.
Prospects and Challenges for Green Hydrogen Production and Utilization in the Philippines
Apr 2022
Publication
The Philippines is exploring different alternative sources of energy to make the country less dependent on imported fossil fuels and to reduce significantly the country's CO2 emissions. Given the abundance of renewable energy potential in the country green hydrogen from renewables is a promising fuel because it can be utilized as an energy carrier and can provide a source of clean and sustainable energy with no emissions. This paper aims to review the prospects and challenges for the potential use of green hydrogen in several production and utilization pathways in the Philippines. The study identified green hydrogen production routes from available renewable energy sources in the country including geothermal hydropower wind solar biomass and ocean. Opportunities for several utilization pathways include transportation industry utility and energy storage. From the analysis this study proposes a roadmap for a green hydrogen economy in the country by 2050 divided into three phases: green hydrogen as industrial feedstock green hydrogen as fuel cell technology and commercialization of green hydrogen. On the other hand the analysis identified several challenges including technical economic and social aspects as well as the corresponding policy implications for the realization of a green hydrogen economy that can be applied in the Philippines and other developing countries.
Renewable Power and Heat for the Decarbonisation of Energy-Intensive Industries
Dec 2022
Publication
The present review provides a catalogue of relevant renewable energy (RE) technologies currently available (regarding the 2030 scope) and to be available in the transition towards 2050 for the decarbonisation of Energy Intensive Industries (EIIs). RE solutions have been classified into technologies based on the use of renewable electricity and those used to produce heat for multiple industrial processes. Electrification will be key thanks to the gradual decrease in renewable power prices and the conversion of natural-gas-dependent processes. Industrial processes that are not eligible for electrification will still need a form of renewable heat. Among them the following have been identified: concentrating solar power heat pumps and geothermal energy. These can supply a broad range of needed temperatures. Biomass will be a key element not only in the decarbonisation of conventional combustion systems but also as a biofuel feedstock. Biomethane and green hydrogen are considered essential. Biomethane can allow a straightforward transition from fossil-based natural gas to renewable gas. Green hydrogen production technologies will be required to increase their maturity and availability in Europe (EU). EIIs’ decarbonisation will occur through the progressive use of an energy mix that allows EU industrial sectors to remain competitive on a global scale. Each industrial sector will require specific renewable energy solutions especially the top greenhouse gas-emitting industries. This analysis has also been conceived as a starting point for discussions with potential decision makers to facilitate a more rapid transition of EIIs to full decarbonisation.
Comparison Between Carbon Molecular Sieve and Pd-Ag Membranes in H2-CH4 Separation at High Pressure
Aug 2020
Publication
From a permeability and selectivity perspective supported thin-film Pd–Ag membranes are the best candidates for high-purity hydrogen recovery for methane-hydrogen mixtures from the natural gas grid. However the high hydrogen flux also results in induced bulk-to-membrane mass transfer limitations (concentration polarization) especially when working at low hydrogen concentration and high pressure which further reduces the hydrogen permeance in the presence of mixtures. Additionally Pd is a precious metal and its price is lately increasing dramatically. The use of inexpensive CMSM could become a promising alternative. In this manuscript a detailed comparison between these two membrane technologies operating under the same working pressure and mixtures is presented.<br/>First the permeation properties of CMSM and Pd–Ag membranes are compared in terms of permeance and purity and subsequently making use of this experimental investigation an economic evaluation including capital and variable costs has been performed for a separation system to recover 25 kg/day of hydrogen from a methane-hydrogen mixture. To widen the perspective also a sensitivity analysis by changing the pressure difference membrane lifetime membrane support cost and cost of Pd/Ag membrane recovery has been considered. The results show that at high pressure the use of CMSM is to more economic than the Pd-based membranes at the same recovery and similar purity.
Expert Opinion Analysis on Renewable Hydrogen Storage Systems Potential in Europe
Nov 2016
Publication
Among the several typologies of storage technologies mainly on different physical principles (mechanical electrical and chemical) hydrogen produced by power to gas (P2G) from renewable energy sources complies with chemical storage principle and is based on the conversion of electrical energy into chemical energy by means of the electrolysis of water which does not produce any toxic or climate-relevant emission. This paper aims to pinpoint the potential uses of renewable hydrogen storage systems in Europe analysing current and potential locations regulatory framework governments’ outlooks economic issues and available renewable energy amounts. The expert opinion survey already used in many research articles on different topics including energy has been selected as an effective method to produce realistic results. The obtained results highlight strategies and actions to optimize the storage of hydrogen produced by renewables to face varying electricity demand and generation-driven fluctuations reducing the negative effects of the increasing share of renewables in the energy mix of European Countries.
A Review at the Role of Storage in Energy Systems with a Focus on Power to Gas and Long-term Storage
Aug 2017
Publication
A review of more than 60 studies (plus m4ore than 65 studies on P2G) on power and energy models based on simulation and optimization was done. Based on these for power systems with up to 95% renewables the electricity storage size is found to be below 1.5% of the annual demand (in energy terms). While for 100% renewables energy systems (power heat mobility) it can remain below 6% of the annual energy demand. Combination of sectors and diverting the electricity to another sector can play a large role in reducing the storage size. From the potential alternatives to satisfy this demand pumped hydro storage (PHS) global potential is not enough and new technologies with a higher energy density are needed. Hydrogen with more than 250 times the energy density of PHS is a potential option to satisfy the storage need. However changes needed in infrastructure to deal with high hydrogen content and the suitability of salt caverns for its storage can pose limitations for this technology. Power to Gas (P2G) arises as possible alternative overcoming both the facilities and the energy density issues. The global storage requirement would represent only 2% of the global annual natural gas production or 10% of the gas storage facilities (in energy equivalent). The more options considered to deal with intermittent sources the lower the storage requirement will be. Therefore future studies aiming to quantify storage needs should focus on the entire energy system including technology vectors (e.g. Power to Heat Liquid Gas Chemicals) to avoid overestimating the amount of storage needed.
Use of Hydrogen Safety Sensors Under Anaerobic Conditions – Impact of Oxygen Content on Sensor Performance
Sep 2011
Publication
In any application involving the production storage or use of hydrogen sensors are important devices for alerting to the presence of leaked hydrogen. Hydrogen sensors should be accurate sensitive and specific as well as resistant to long term drift and varying environmental conditions. Furthermore as an integral element in a safety system sensor performance should not be compromised by operational parameters. For example safety sensors may be required to operate at reduced oxygen levels relative to air. In this work we evaluate and compare a number of sensor technologies in terms of their ability to detect hydrogen under conditions of varying oxygen concentration.
Hysafe SBEP-V20: Numerical Predictions of Release Experiments Inside a Residential Garage With Passive Ventilation
Sep 2009
Publication
This work presents the results of the Standard Benchmark Exercise Problem (SBEP) V20 of Work Package 6 (WP6) of HySafe Network of Excellence (NoE) co-funded by the European Commission in the frame of evaluating the quality and suitability of codes models and user practices by comparative assessments of code results. The benchmark problem SBEP-V20 covers release scenarios that were experimentally investigated in the past using helium as a substitute to hydrogen. The aim of the experimental investigations was to determine the ventilation requirements for parking hydrogen fuelled vehicles in residential garages. Helium was released under the vehicle for 2 h with 7.200 l/h flow rate. The leak rate corresponded to a 20% drop of the peak power of a 50 kW fuel cell vehicle. Three double vent garage door geometries are considered in this numerical investigation. In each case the vents are located at the top and bottom of the garage door. The vents vary only in height. In the first case the height of the vents is 0.063 m in the second 0.241 m and in the third 0.495 m. Four HySafe partners participated in this benchmark. The following CFD packages with the respective models were applied to simulate the experiments: ADREA-HF using k–ɛ model by partner NCSRD FLACS using k–ɛ model by partner DNV FLUENT using k–ɛ model by partner UPM and CFX using laminar and the low-Re number SST model by partner JRC. This study compares the results predicted by the partners to the experimental measurements at four sensor locations inside the garage with an attempt to assess and validate the performance of the different numerical approaches.
Beyond Haber-Bosch: The Renaissance of the Claude Process
Apr 2021
Publication
Ammonia may be one of the energy carriers in the hydrogen economy. Although research has mostly focused on electrochemical ammonia synthesis this however remains a scientific challenge. In the current article we discuss the feasibility of single-pass thermochemical ammonia synthesis as an alternative to the high-temperature high-pressure Haber-Bosch synthesis loop. We provide an overview of recently developed low temperature ammonia synthesis catalysts as well as an overview of solid ammonia sorbents. We show that the low temperature low pressure single-pass ammonia synthesis process can produce ammonia at a lower cost than the Haber-Bosch synthesis loop for small-scale ammonia synthesis (<40 t-NH3 d−1).
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