Netherlands
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.
Quantitative Risk Analysis of a Hazardous Jet Fire Event for Hydrogen Transport in Natural Gas Transmission Pipelines
Jan 2021
Publication
With the advent of large-scale application of hydrogen transportation becomes crucial. Reusing the existing natural gas transmission system could serve as catalyst for the future hydrogen economy. However a risk analysis of hydrogen transmission in existing pipelines is essential for the deployment of the new energy carrier. This paper focuses on the individual risk (IR) associated with a hazardous hydrogen jet fire and compares it with the natural gas case. The risk analysis adopts a detailed flame model and state of the art computational software to provide an enhanced physical description of flame characteristics.<br/>This analysis concludes that hydrogen jet fires yield lower lethality levels that decrease faster with distance than natural gas jet fires. Consequently for large pipelines hydrogen transmission is accompanied by significant lower IR. Howbeit ignition effects increasingly dominate the IR for decreasing pipeline diameters and cause hydrogen transmission to yield increased IR in the vicinity of the pipeline when compared to natural gas.
Achievements of European Projects on Membrane Reactor for Hydrogen Production
May 2017
Publication
Membrane reactors for hydrogen production can increase both the hydrogen production efficiency at small scale and the electric efficiency in micro-cogeneration systems when coupled with Polymeric Electrolyte Membrane fuel cells. This paper discusses the achievements of three European projects (FERRET FluidCELL BIONICO) which investigate the application of the membrane reactor concept to hydrogen production and micro-cogeneration systems using both natural gas and biofuels (biogas and bio-ethanol) as feedstock. The membranes used to selectively separate hydrogen from the other reaction products (CH4 CO2 H2O etc.) are of asymmetric type with a thin layer of Pd alloy (<5 μm) and supported on a ceramic porous material to increase their mechanical stability. In FERRET the flexibility of the membrane reactor under diverse natural gas quality is validated. The reactor is integrated in a micro-CHP system and achieves a net electric efficiency of about 42% (8% points higher than the reference case). In FluidCELL the use of bio-ethanol as feedstock for micro-cogeneration Polymeric Electrolyte Membrane based system is investigated in off-grid applications and a net electric efficiency around 40% is obtained (6% higher than the reference case). Finally BIONICO investigates the hydrogen production from biogas. While BIONICO has just started FERRET and FluidCELL are in their third year and the two prototypes are close to be tested confirming the potentiality of membrane reactor technology at small scale.
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.
Methane Pyrolysis in a Molten Gallium Bubble Column Reactor for Sustainable Hydrogen Production: Proof of Concept & Techno-economic Assessment
Dec 2020
Publication
Nowadays nearly 50% of the hydrogen produced worldwide comes from Steam Methane Reforming (SMR) at an environmental burden of 10.5 tCO2 eq/tH2 accelerating the consequences of global warming. One way to produce clean hydrogen is via methane pyrolysis using melts of metals and salts. Compared to SMR significant less CO2 is produced due to conversion of methane into hydrogen and carbon making this route more sustainable to generate hydrogen. Hydrogen is produced with high purity and solid carbon is segregated and deposited on the molten bath. Carbon may be sold as valuable co-product making industrial scale promising. In this work methane pyrolysis was performed in a quartz bubble column using molten gallium as heat transfer agent and catalyst. A maximum conversion of 91% was achieved at 1119 °C and ambient pressure with a residence time of the bubbles in the liquid of 0.5 s. Based on in-depth analysis of the carbon it can be characterized as carbon black. Techno-economic and sensitivity analyses of the industrial concept were done for different scenarios. The results showed that if co-product carbon is saleable and a CO2 tax of 50 euro per tonne is imposed to the processes the molten metal technology can be competitive with SMR.
Hydrogen Permeation Studies of Composite Supported Alumina-carbon Molecular Sieves Membranes: Separation of Diluted Hydrogen from Mixtures with Methane
Jun 2020
Publication
One alternative for the storage and transport of hydrogen is blending a low amount of hydrogen (up to 15 or 20%) into existing natural gas grids. When demanded hydrogen can be then separated close to the end users using membranes. In this work composite alumina carbon molecular sieves membranes (Al-CMSM) supported on tubular porous alumina have been prepared and characterized. Single gas permeation studies showed that the H2/CH4 separation properties at 30 °C are well above the Robeson limit of polymeric membranes. H2 permeation studies of the H2–CH4 mixture gases containing 5–20% of H2 show that the H2 purity depends on the H2 content in the feed and the operating temperature. In the best scenario investigated in this work for samples containing 10% of H2 with an inlet pressure of 7.5 bar and permeated pressure of 0.01 bar at 30 °C the H2 purity obtained was 99.4%.
Analysis of Photon-driven Solar-to-hydrogen Production Methods in the Netherlands
Oct 2021
Publication
Hydrogen is deemed necessary for the realization of a sustainable society especially when renewable energy is used to generate hydrogen. As most of the photon-driven hydrogen production methods are not commercially available yet this study has investigated the techno economic and overall performance of four different solar-to hydrogen methods and photovoltaics-based electrolysis methods in the Netherlands. It was found that the photovoltaics-based electrolysis is the cheapest option with production cost of 9.31 $/kgH2. Production cost based on photo-catalytic water splitting direct bio-photolysis and photoelectrochemical water splitting are found to be 18.32 $/kgH2 18.45 $/kgH2 and 18.98 $/kgH2 respectively. These costs are expected to drop significantly in the future. Direct bio-photolysis (potential cost of 3.10 $/kgH2) and photo-catalytic water splitting (3.12 $/kgH2) may become cheaper than photovoltaics-based electrolysis. Based on preferences of three fictional technology investors i.e. a short-term a green and a visionary investor the overall performance of these methods are determined. Photovoltaics-based electrolysis is the most ideal option with photoelectrochemical water splitting a complementary option. While photovoltaics-based electrolysis has an advantage on the short-term because it is a non-integrated energy system on the long-term this might lead to relatively higher cost and performance limitations. Photochemical water splitting are integrated energy systems and have an advantage on the long-term because they need a relatively low theoretical overpotential and benefit from increasing temperatures. Both methods show performance improvements by the use of quantum dots. Bio-photolysis can be self-sustaining and can use wastewater to produce hydrogen but sudden temperature changes could lead to performance decrease.
Agent-Based as an Alternative to Prognostic Modelling of Safety Risks in Hydrogen Energy Scenarios
Sep 2005
Publication
Interest in the future is not new. Economic constraints and acceptability considerations of today compel decision-makers from industry and authorities to speculate on possible safety risks originating from a hydrogen economy developed in the future. Tools that support thinking about the long-term consequences of today's actions and resulting technical systems are usually prognostic based on data from past performance of past or current systems. It has become convention to assume that the performance of future systems in future environments can be accommodated in the uncertainties of such prognostic models resulting from sensitivity studies. This paper presents an alternative approach to modelling future systems based on narratives about the future. Such narratives based on the actions and interactions of individual "agents" are powerful means for addressing anxiety about engaging the imagination in order to prepare for events that are likely to occur detect critical conditions and to thus achieve desirable outcomes. This is the methodological base of Agent-Based Models (ABM) and this paper will present the approach discuss its strengths and weaknesses and present a preliminary application to modelling safety risks related to energy scenarios in a possible future hydrogen economy.
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.
Sensitivity to Detonation and Detonation Cellular Structure of H2-O2-AIr-H2O2 Gas Mixtures
Sep 2005
Publication
Today it is not known – neither qualitatively not quantitatively - how large the impact can be of the promoters on sensitivity to hydrogen-air detonation in hypothetical accidents at hydrogen-containing installations transport or storage facilities. Report goal is to estimate theoretically an effect of hydrogen-peroxide (as representative promoter) on sensitivity to detonation of the stoichiometric hydrogen-oxygen gas mixtures. The classical H2-O2-Ar (2:1:7) gas mixture was chosen as reference system with the well established and unambiguously interpreted experimental data. In kinetic simulations it was found that the ignition delay time is sensitive to H2O2addition for small initial H2O2concentrations and is nearly constant for the large ones. Parametric reactive CFD studies of two dimensional cellular structure of 2H2-O2-7Ar-H2O2 detonations with variable hydrogen peroxide concentration (up to 10 vol.%) were also performed. Two un-expected results were obtained. First result: detonation cell size is practically independent upon variation of initial hydrogen peroxide concentration. For practical applications it means that presence of hydrogen-peroxide did not change drastically sensitivity of the stoichiometric hydrogen-oxygen gas mixtures. These theoretical speculations require an experimental verification. Second result: for large enough initial H2O2concentrations (> 1 vol.% at least) a new element of cellular structure of steady detonation wave was revealed. It is a system of multiple secondary longitudinal shock waves (SLSW) which propagates in the direction opposite to that of the leading shock wave. Detailed mechanism of SLSW formation is proposed.
Testing of Hydrogen Safety Sensors in Service Simulated Conditions
Sep 2005
Publication
Reliable and effective sensors for the accurate detection of hydrogen concentrations in air are essential for the safe operation of fuel cells hydrogen fuelled systems (e.g. vehicles) and hydrogen production distribution and storage facilities. The present paper describes the activity on-going at JRC for the establishment of a facility that can be used for testing and validating the performance of hydrogen sensors under a range of conditions representative of those to be encountered in service. Potential aspects to be investigated in relation to the sensors performances are the influence of temperature humidity and pressure (simulating variations in altitude) the sensitivity to target gas and the cross sensitivity to other gases/vapours the reaction and recovery time and the sensors’ lifetime. The facility set up at JRC for the execution of these tests is described including the program for its commissioning. The results of a preliminary test are presented and discussed as an example.
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.
Assessing the Durability and Integrity of Natural Gas Infrastructures for Transporting and Distributing Mixtures of Hydrogen and Natural Gas
Sep 2005
Publication
Extensive infrastructure exists for the transport of natural gas and it is an obvious step to assess its use for the movement of hydrogen. The Naturalhy project’s objective is to prepare the European natural gas industry for the introduction of hydrogen by assessing the capability of the natural gas infrastructure to accept mixtures of hydrogen and natural gas. This paper presents the ongoing work within both Durability and Integrity Work Packages of the Naturalhy project. This work covers a gap in knowledge on risk assessment required for delivering H2+natural gas blends by means of the existing natural gas grids in safe operation.<br/>Experiments involving several parts of the existing infrastructure will be described that are being carried out to re-examine the major risks previously studied for natural gas including: effect of H2 on failure behaviour and corrosion of transmission pipes and their burst resistance (link to the Work Package Safety) on permeability and ageing of distribution pipes on reliability and ageing of domestic gas meters tightness to H2 of domestic appliances and their connexions. The information will be integrated into existing Durability assessment methodologies originally developed for natural gas.<br/>An Integrity Management Tool will be developed taking account of the effect of hydrogen on the materials properties. The tool should enable a cost effective selection of appropriate measures to control the structural integrity and maintaining equipment. The main measures considered are monitoring non destructive examination (pigging and non pigging) and repair strategies. The tool will cover a number of parameters e.g.: percentage of hydrogen in the gas mixture material of construction operating conditions and condition of cathodic protection. Thus the Integrity Management Tool will yield an inspection and maintenance plan based on the specific circumstances.
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.
A Review of Fuel Cell Powertrains for Long-Haul Heavy-Duty Vehicles: Technology, Hydrogen, Energy and Thermal Management Solutions
Dec 2022
Publication
Long-haul heavy-duty vehicles including trucks and coaches contribute to a substantial portion of the modern-day European carbon footprint and pose a major challenge in emissions reduction due to their energy-intensive usage. Depending on the hydrogen fuel source the use of fuel cell electric vehicles (FCEV) for long-haul applications has shown significant potential in reducing road freight CO2 emissions until the possible maturity of future long-distance battery-electric mobility. Fuel cell heavy-duty (HD) propulsion presents some specific characteristics advantages and operating constraints along with the notable possibility of gains in powertrain efficiency and usability through improved system design and intelligent onboard energy and thermal management. This paper provides an overview of the FCEV powertrain topology suited for long-haul HD applications their operating limitations cooling requirements waste heat recovery techniques state-of-the-art in powertrain control energy and thermal management strategies and over-the-air route data based predictive powertrain management including V2X connectivity. A case study simulation analysis of an HD 40-tonne FCEV truck is also presented focusing on the comparison of powertrain losses and energy expenditures in different subsystems while running on VECTO Regional delivery and Long-haul cycles. The importance of hydrogen fuel production pathways onboard storage approaches refuelling and safety standards and fleet management is also discussed. Through a comprehensive review of the H2 fuel cell powertrain technology intelligent energy management thermal management requirements and strategies and challenges in hydrogen production storage and refuelling this article aims at helping stakeholders in the promotion and integration of H2 FCEV technology towards road freight decarbonisation.
Fuel Cell Cars in a Microgrid for Synergies Between Hydrogen and Electricity Networks
Nov 2016
Publication
Fuel cell electric vehicles convert chemical energy of hydrogen into electricity to power their motor. Since cars are used for transport only during a small part of the time energy stored in the on-board hydrogen tanks of fuel cell vehicles can be used to provide power when cars are parked. In this paper we present a community microgrid with photovoltaic systems wind turbines and fuel cell electric vehicles that are used to provide vehicle-to-grid power when renewable power generation is scarce. Excess renewable power generation is used to produce hydrogen which is stored in a refilling station. A central control system is designed to operate the system in such a way that the operational costs are minimized. To this end a hybrid model for the system is derived in which both the characteristics of the fuel cell vehicles and their traveling schedules are considered. The operational costs of the system are formulated considering the presence of uncertainty in the prediction of the load and renewable energy generation. A robust minmax model predictive control scheme is developed and finally a case study illustrates the performance of the designed system.
The NederDrone: A Hybrid Lift, Hybrid Energy Hydrogen UAV
Mar 2021
Publication
Many Unmanned Air Vehicle (UAV) applications require vertical take-off and landing and very long-range capabilities. Fixed-wing aircraft need long runways to land and electric energy is still a bottleneck for helicopters which are not range efficient. In this paper we introduce the NederDrone a hybrid lift hybrid energy hydrogen-powered UAV that can perform vertical take-off and landings using its 12 propellers while flying efficiently in forward flight thanks to its fixed wings. The energy is supplied from a combination of hydrogen-driven Polymer Electrolyte Membrane fuel-cells for endurance and lithium batteries for high-power situations. The hydrogen is stored in a pressurized cylinder around which the UAV is optimized. This work analyses the selection of the concept the implemented safety elements the electronics and flight control and shows flight data including a 3h38 flight at sea while starting and landing from a small moving ship.
Optimal Hydrogen Production in a Wind-dominated Zero-emission Energy System
May 2021
Publication
The role of hydrogen in future energy systems is widely acknowledged: from fuel for difficult-to-decarbonize applications to feedstock for chemicals synthesis to energy storage for high penetration of undispatchable renewable electricity. While several literature studies investigate such energy systems the details of how electrolysers and renewable technologies optimally behave and interact remain an open question. With this work we study the interplay between (i) renewable electricity generation through wind and solar (ii) electricity storage in batteries (iii) electricity storage via Power-to-H2 and (iv) hydrogen commodity demand. We do so by designing a cost-optimal zero-emission energy system and use the Netherlands as a case study in a mixed integer linear model with hourly resolution for a time horizon of one year. To account for the significant role of wind we also provide an elaborate approach to model broad portfolios of wind turbines. The results show that if electrolyzers can operate flexibly batteries and power-to-H2-to-power are complementary with the latter using renewable power peaks and the former using lower renewable power outputs. If the operating modes of the power-to-H2-to-power system are limited - artificially or technically - the competitive advantage over batteries decreases. The preference of electrolyzers for power peaks also leads to an increase in renewable energy utilization for increased levels of operation flexibility highlighting the importance of capturing this feature both from a technical and a modeling perspective. When adding a commodity hydrogen demand the amount of hydrogen converted to electricity decreases hence decreasing its role as electricity storage medium.
Hydrogen-based Integrated Energy and Mobility System for a Real-life Office Environment
Mar 2020
Publication
The current focus on the massive CO2 reduction highlights the need for the rapid development of technology for the production storage transportation and distribution of renewable energy. In addition to electricity we need other forms of energy carriers that are more suitable for energy storage and transportation. Hydrogen is one of the main candidates for this purpose since it can be produced from solar or wind energy and then stored; once needed it can be converted back to electricity using fuel cells. Another important aspect of future energy systems is sector coupling where different sectors e.g. mobility and energy work together to provide better services. In such an integrated system electric vehicles – both battery and hydrogen-based fuel cell – can provide when parked electricity services such as backup power and balancing; when driving they produce no emissions. In this paper we present the concept design and energy management of such an integrated energy and mobility system in a real-life environment at the Shell Technology Centre in Amsterdam. Our results show that storage using hydrogen and salt caverns is much cheaper than using large battery storage systems. We also show that the integration of electric vehicles into the electricity network is technically and economically feasible and that they can provide a flexible energy buffer. Ultimately the results of this study show that using both electricity and hydrogen as energy carriers can create a more flexible reliable and cheaper energy system at an office building.
Control of Electrons’ Spin Eliminates Hydrogen Peroxide Formation During Water Splitting
Jul 2017
Publication
The production of hydrogen through water splitting in a photoelectrochemical cell suffers from an overpotential that limits the efficiencies. In addition hydrogen-peroxide formation is identified as a competing process affecting the oxidative stability of photoelectrodes. We impose spin-selectivity by coating the anode with chiral organic semiconductors from helically aggregated dyes as sensitizers; Zn-porphyrins and triarylamines. Hydrogen peroxide formation is dramatically suppressed while the overall current through the cell correlating with the water splitting process is enhanced. Evidence for a strong spin-selection in the chiral semiconductors is presented by magnetic conducting (mc-)AFM measurements in which chiral and achiral Zn-porphyrins are compared. These findings contribute to our understanding of the underlying mechanism of spin selectivity in multiple electron-transfer reactions and pave the way toward better chiral dye-sensitized photoelectrochemical cells.
An Innovative Approach for Energy Transition in China? Chinese National Hydrogen Policies from 2001 to 2020
Jan 2023
Publication
To accelerate clean energy transition China has explored the potential of hydrogen as an energy carrier since 2001. Until 2020 49 national hydrogen policies were enacted. This paper explores the relevance of these policies to the development of the hydrogen industry and energy transition in China. We examine the reasons impacts and challenges of Chinese national hydrogen policies through the conceptual framework of Thomas Dye’s policy analysis method and the European Training Foundation’s policy analysis guide. This research provides an ex‐post analysis for previous policies and an ex‐ante analysis for future options. We argue that the energy supply revolution and energy technology revolution highlight the importance of hydrogen development in China. Particularly the pressure of the automobile industry transition leads to experimentation concerning the application of hydrogen in the transportation sector. This paper also reveals that hydro‐ gen policy development coincides with an increase in resource input and has positive spill over effects. Furthermore we note that two challenges have impeded progress: a lack of regulations for the industry threshold and holistic planning. To address these challenges the Chinese government can design a national hydrogen roadmap and work closely with other countries through the Belt and Road Initiative.
Timmermans’ Dream: An Electricity and Hydrogen Partnership Between Europe and North Africa
Oct 2021
Publication
Because of differences in irradiation levels it could be more efficient to produce solar electricity and hydrogen in North Africa and import these energy carriers to Europe rather than generating them at higher costs domestically in Europe. From a global climate change mitigation point of view exploiting such efficiencies can be profitable since they reduce overall renewable electricity capacity requirements. Yet the construction of this capacity in North Africa would imply costs associated with the infrastructure needed to transport electricity and hydrogen. The ensuing geopolitical dependencies may also raise energy security concerns. With the integrated assessment model TIAM-ECN we quantify the trade-off between costs and benefits emanating from establishing import-export links between Europe and North Africa for electricity and hydrogen. We show that for Europe a net price may have to be paid for exploiting such interlinkages even while they reduce the domestic investments for renewable electricity capacity needed to implement the EU’s Green Deal. For North African countries the potential net benefits thanks to trade revenues may build up to 50 billion €/yr in 2050. Despite fears over costs and security Europe should seriously consider an energy partnership with North Africa because trade revenues are likely to lead to positive employment income and stability effects in North Africa. Europe can indirectly benefit from such impacts.
Towards a CO2-neutral Steel Industry: Justice Aspects of CO2 Capture and Storage, Biomass- and Green Hydrogen-based Emission Reductions
Apr 2022
Publication
A rapid transition towards a CO2-neutral steel industry is required to limit climate change. Such a transition raises questions of justice as it entails positive and negative impacts unevenly distributed across societal stakeholders. To enable stakeholders to address such concerns this paper assesses the justice implications of three options that reduce emissions: CO2 capture and storage (CCS) on steel (up to 70%) bio-based steelmaking (up to 50%) and green hydrogen-based steel production (up to 100%). We select justice indicators from the energy climate labour and environmental justice literature and assess these indicators qualitatively for each of the technological routes based on literature and desk research. We find context-dependent differences in justness between the different technological routes. The impact on stakeholders varies across regions. There are justice concerns for local communities because of economic dependence on and environmental impact of the industry. Communities elsewhere are impacted through the siting of infrastructure and feedstock production. CCS and bio-based steelmaking routes can help retain industry and associated economic benefits on location while hydrogen-based steelmaking may deal better with environmental concerns. We conclude that besides techno-economic and environmental information transparency on sector-specific justice implications of transforming steel industries is essential for decision-making on technological routes
CFD Simulations of Filling and Emptying of Hydrogen Tanks
Jun 2016
Publication
During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from −40 °C to 85 °C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the simulation results have been compared with new experimental data for different filling and emptying strategies. The comparison between experiments and simulations is shown for the temperatures of the gas inside the tank for the temperatures at the interface between the liner and the composite material and for the temperatures on the external surface of the vessel.
Direct Route from Ethanol to Pure Hydrogen through Autothermal Reforming in a Membrane Reactor: Experimental Demonstration, Reactor Modelling and Design
Nov 2020
Publication
This work reports the integration of thin (~3e4 mm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept in particular the capacity to reach a hydrogen recovery factor up to 70% while the operation at different fluidization regimes oxygen-to-ethanol and steam-to-ethanol ratios feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.
Influence of the Gas Injector Configuration on the Temperature Evolution During Refueling of On-board Hydrogen Tanks
Jul 2016
Publication
In this article we show a refuelling strategy analysis using different injector configurations to refuel a 70 MPa composite reinforced type 4 tank. The gas has been injected through single openings of different diameters (3 mm 6 mm and 10 mm) and alternatively through multiple small holes (4 × 3 mm). For each injector configuration slow (12 min) and faster (3 min) fillings have been performed. The gas temperature has been measured at different positions inside the tank as well as the temperatures of the wall materials at various locations: on the external surface and at the interface between the liner and the fiber reinforced composite. In general the larger the injector diameter and the slower the filling the higher the chance that the gas develops vertical temperature gradients (a so-called gas temperature stratification) resulting in higher than average temperatures near the top of the tank and lower than average at its bottom. While the single 3 mm opening injector causes homogeneous gas temperatures for both filling speeds both the 6 mm and 10 mm opening injectors induce gas temperature stratification during the 12 min fillings. The injector with multiple holes has an area comparable to the 6 mm single opening injector: in general this more complex geometry tends to limit the inhomogeneity of gas temperatures during slow fillings. When gas temperature stratification develops the wall materials temperature is also locally affected. This results in a higher than average temperature at the top of the tank and higher the slower the filling.
Fuel Cell Electric Vehicles and Hydrogen Balancing 100 Percent Renewable and Integrated National Transportation and Energy Systems
Feb 2021
Publication
Future national electricity heating cooling and transport systems need to reach zero emissions. Significant numbers of back-up power plants as well as large-scale energy storage capacity are required to guarantee the reliability of energy supply in 100 percent renewable energy systems. Electricity can be partially converted into hydrogen which can be transported via pipelines stored in large quantities in underground salt caverns to overcome seasonal effects and used as electricity storage or as a clean fuel for transport. The question addressed in this paper is how parked and grid-connected hydrogen-fuelled Fuel Cell Electric Vehicles might balance 100 per cent renewable electricity heating cooling and transport systems at the national level in Denmark Germany Great Britain France and Spain? Five national electricity heating cooling and transport systems are modeled for the year 2050 for the five countries assuming only 50 percent of the passenger cars to be grid-connected Fuel Cell Electric Vehicles the remaining Battery Electric Vehicles. The grid-connected Fuel Cell Electric Vehicle fleet can always balance the energy systems and their usage is low having load factors of 2.1–5.5 percent corresponding to an average use of 190–480 h per car per year. At peak times occurring only a few hours per year 26 to 43 percent of the grid-connected Fuel Cell Electric Vehicle are required and in particular for energy systems with high shares of solar energy such as Spain balancing by grid-connected Fuel Cell Electric Vehicles is mainly required during the night which matches favorably with driving usage.
Fatigue Behavior of AA2198 in Liquid Hydrogen
Aug 2019
Publication
Tensile and fatigue tests were performed on an AA2198 aluminum alloy in the T851 condition in ambient air and liquid hydrogen (LH2). All fatigue tests were performed under load control at a frequency of 20 Hz and a stress ratio of R=0.1. The Gecks-Och-Function [1] was fitted on the measured cyclic lifetimes.<br/><br/>The tensile strength in LH2 was measured to be 46 % higher compared to the value determined at ambient conditions and the fatigue limit was increased by approximately 60 %. Both S-N curves show a distinct S-shape but also significant differences. Under LH2 environment the transition from LCF- to HCF-region as well as the transition to the fatigue limit is shifted to higher cyclic lifetimes compared to ambient test results. The investigation of the crack surfaces showed distinct differences between ambient and LH2 conditions. These observed differences are important factors in the fatigue behavior change.
Test Methodologies for Hydrogen Sensor Performance Assessment: Chamber vs. Flow-through Test Apparatus
Sep 2017
Publication
Certification of hydrogen sensors to meet standards often prescribes using large-volume test chambers. However feedback from stakeholders such as sensor manufacturers and end-users indicates that chamber test methods are often viewed as too slow and expensive for routine assessment. Flow-through test methods are potentially an efficient and cost-effective alternative for sensor performance assessment. A large number of sensors can be simultaneously tested in series or in parallel with an appropriate flow-through test fixture. The recent development of sensors with response times of less than 1s mandates improvements in equipment and methodology to properly capture the performance of this new generation of fast sensors; flow methods are a viable approach for accurate response and recovery time determinations but there are potential drawbacks. According to ISO 26142 flow-through test methods may not properly simulate ambient applications. In chamber test methods gas transport to the sensor is dominated by diffusion which is viewed by some users as mimicking deployment in rooms and other confined spaces. Conversely in flow-through methods forced flow transports the gas to the sensing element. The advective flow dynamics may induce changes in the sensor behaviour relative to the quasi-quiescent condition that may prevail in chamber test methods. The aim of the current activity in the JRC and NREL sensor laboratories is to develop a validated flow-through apparatus and methods for hydrogen sensor performance testing. In addition to minimizing the impact on sensor behaviour induced by differences in flow dynamics challenges associated with flow-through methods include the ability to control environmental parameters (humidity pressure and temperature) during the test and changes in the test gas composition induced by chemical reactions with upstream sensors. Guidelines on flow-through test apparatus design and protocols for the evaluation of hydrogen sensor performance have been developed. Various commercial sensor platforms (e.g. thermal conductivity catalytic and metal semiconductor) were used to demonstrate the advantages and issues with the flow-through methodology.
Internal and Surface Damage after Electrochemical Hydrogen Charging for Ultra Low Carbon Steel with Various Degrees of Recrystallization
Jul 2016
Publication
An ultra low carbon (ULC) steel was subjected to electrochemical hydrogen charging to provoke hydrogen induced damage in the material. The damage characteristics were analyzed for recrystallized partially recrystallized and cold deformed material. The goal of the study is to understand the effect of cold deformation on the hydrogen induced cracking behavior of a material which is subjected to cathodic hydrogen charging. Additionally charging conditions i.e. charging time and current density were varied in order to identify correlations between on the one hand crack initiation and propagation and on the other hand the charging conditions. The obtained hydrogen induced cracks were studied by optical microscopy scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Hydrogen induced cracks were observed to propagate transgranularly independently of the state of the material. Deformed samples were considerably more sensitive to hydrogen induced cracking which implies the important role of dislocations in hydrogen induced damage mechanisms.
Efficient Hydrogen Storage in Defective Graphene and its Mechanical Stability: A Combined Density Functional Theory and Molecular Dynamics Simulation Study
Dec 2020
Publication
A combined density functional theory and molecular dynamics approach is employed to study modifications of graphene at atomistic level for better H2 storage. The study reveals H2 desorption from hydrogenated defective graphene structure V222 to be exothermic. H2 adsorption and desorption processes are found to be more reversible for V222 as compared to pristine graphene. Our study shows that V222 undergoes brittle fracture under tensile loading similar to the case of pristine graphene. The tensile strength of V222 shows slight reduction with respect to their pristine counterpart which is attributed to the transition of sp2 to sp3-like hybridization. The study also shows that the V222 structure is mechanically more stable than the defective graphene structure without chemically adsorbed hydrogen atoms. The current fundamental study thus reveals the efficient recovery mechanism of adsorbed hydrogen from V222 and paves the way for the engineering of structural defects in graphene for H2 storage.
Assessing the Environmental Impacts of Wind-based Hydrogen Production in the Netherlands Using Ex-ante LCA and Scenarios Analysis
Mar 2021
Publication
Two electrolysis technologies fed with renewable energy sources are promising for the production of CO2-free hydrogen and enabling the transition to a hydrogen society: Alkaline Electrolyte (AE) and Polymer Electrolyte Membrane (PEM). However limited information exists on the potential environmental impacts of these promising sustainable innovations when operating on a large-scale. To fill this gap the performance of AE and PEM systems is compared using ex-ante Life Cycle Assessment (LCA) technology analysis and exploratory scenarios for which a refined methodology has been developed to study the effects of implementing large-scale sustainable hydrogen production systems. Ex-ante LCA allows modelling the environmental impacts of hydrogen production exploratory scenario analysis allows modelling possible upscaling effects at potential future states of hydrogen production and use in vehicles in the Netherlands in 2050. A bridging tool for mapping the technological field has been created enabling the combination of quantitative LCAs with qualitative scenarios. This tool also enables diversity for exploring multiple sets of visions. The main results from the paper show with an exception for the “ozone depletion” impact category (1) that large-scale AE and PEM systems have similar environmental impacts with variations lower than 7% in all impact categories (2) that the contribution of the electrolyser is limited to 10% of all impact categories results and (3) that the origin of the electricity is the largest contributor to the environmental impact contributing to more than 90% in all impact categories even when renewable energy sources are used. It is concluded that the methodology was applied successfully and provides a solid basis for an ex-ante assessment framework that can be applied to emerging technological systems.
Development of a Model Evaluation Protocol for CFD Analysis of Hydrogen Safety Issues – The SUSANA Project
Oct 2015
Publication
The “SUpport to SAfety aNAlysis of Hydrogen and Fuel Cell Technologies (SUSANA)” project aims to support stakeholders using Computational Fluid Dynamics (CFD) for safety engineering design and assessment of FCH systems and infrastructure through the development of a model evaluation protocol. The protocol covers all aspects of safety assessment modelling using CFD from release through dispersion to combustion (self-ignition fires deflagrations detonations and Deflagration to Detonation Transition - DDT) and not only aims to enable users to evaluate models but to inform them of the state of the art and best practices in numerical modelling. The paper gives an overview of the SUSANA project including the main stages of the model evaluation protocol and some results from the on-going benchmarking activities.
Hydrogen Refuelling Stations in the Netherlands: An Intercomparison of Quantitative Risk Assessments Used for Permitting
May 2018
Publication
As of 2003 15 hydrogen refuelling stations (HRSs) have been deployed in the Netherlands. To become established the HRS has to go through a permitting procedure. An important document of the permitting dossier is the quantitative risk assessment (QRA) as it assesses the risks of the HRS associated to people and buildings in the vicinity of the HRS. In the Netherlands a generic prescribed approach exists on how to perform a QRA however specific guidelines for HRSs do not exist. An intercomparison among the QRAs of permitted HRSs has revealed significant inconsistencies on various aspects of the QRA: namely the inclusion of HRS sub-systems and components the HRS sub-system and component considerations as predefined components the application of failure scenarios the determination of failure frequencies the application of input parameters the consideration of preventive and mitigation measures as well as information provided regarding the HRS surroundings and the societal risk. It is therefore recommended to develop specific QRA guidelines for HRSs.
Workshop Report: Summary & Outcomes, Putting Science into Standards Power-to-Hydrogen and HCNG
Oct 2014
Publication
The Joint Research Centre (JRC) of the European Commission together with the European Association of Research and Technology Organisations (EARTO) the European Standards Organisations (ESO) CEN and CENELEC and the European Commission Directorate-General Enterprise and Industry (ENTR) have launched an initiative within the context of the European Forum on Science and Industry to bring the scientific and standardization communities closer together. The second and very successful workshop in a series entitled “Putting Science into Standards" was held in at the Institute for Energy and Transport of the JRC in Petten on 21-22 October 2014.<br/>The workshop focused on Power to Hydrogen (P2H) and Hydrogen Compressed Natural Gas (HCNG) which represent a promising and major contribution to the challenging management of increased integration of renewable energy sources in the overall energy system. The workshop offered a platform to exchange ideas on technologies policy and standardization issues. The participation of major stakeholders from both industry and research to this event proved fruitful in moving towards consensus on the relevant technical issues involved and at identifying a common way forward to increase the maturity and market visibility of P2H components and systems. Other outcomes include a clarification of expectations of industry of where and how policy and standardization can contribute to a competitive development of P2H and related issues. The workshop results will be used to devise a roadmap on "Opportunities for Power to Hydrogen and HCNG" by CEN/CENELEC outlining the next steps of standardization activities.
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.
Uncertainties in Explosion Risk Assessment for a Hydrogen Refuelling Station
Sep 2011
Publication
The project “Towards a Hydrogen Refuelling Infrastructure for Vehicles” (THRIVE) aimed at the determination of conditions to stimulate the building of a sustainable infrastructure for hydrogen as a car fuel in The Netherlands. Economic scenarios were constructed for the development of such an infrastructure for the next one to four decades. The eventual horizon will require the erection of a few hundred to more than a thousand hydrogen refuelling stations (HRS) in The Netherlands. The risk acceptability policy in The Netherlands implemented in the External Safety Establishments decree requires the assessment and management of safety risks imposed on the public by car fuelling stations. In the past a risk-informed policy has been developed for the large scale introduction of liquefied petroleum gas (LPG) as a car fuel and a similar policy will also be required if hydrogen is introduced in the public domain. A risk assessment methodology dedicated to cope with accident scenarios relevant for hydrogen applications is to be developed. Within the THRIVE project a demo risk assessment was conducted for the possible implementation of an HRS within an existing station for conventional fuels. The studied station is located in an urban area occupied with housing and commercial activities. The HRS is based on delivery and on-site storage of liquid hydrogen and dispensing of high pressure gaseous hydrogen into vehicles. The main challenges in the risk assessment were in the modelling of release and dispersion of liquid hydrogen. Definition of initial conditions for computational fluid dynamics (CFD) modelling to evaluate dispersion of a cold hydrogen air mixture appears rather complex and is not always fully understood. The modelling assumptions in the initial conditions determine to a large extent the likelihood and severity of potential explosion effects. The paper shows the results of the investigation and the sensitivity to the basic assumptions in the model input.
The Role of the Substrate on the Mechanical and Thermal Stability of Pd Thin Films During Hydrogen (De)sorption
Nov 2020
Publication
In this work we studied the mechanical and thermal stability of ~100 nm Pd thin films magnetron sputter deposited on a bare oxidized Si(100) wafer a sputtered Titanium (Ti) intermediate layer and a spin-coated Polyimide (PI) intermediate layer. The dependence of the film stability on the film morphology and the film-substrate interaction was investigated. It was shown that a columnar morphology with elongated voids at part of the grain boundaries is resistant to embrittlement induced by the hydride formation (α↔β phase transitions). For compact film morphology depending on the rigidity of the intermediate layer and the adherence to the substrate complete transformation (Pd-PI-SiO2/Si) or partly suppression (Pd-Ti-SiO2/Si) of the α to β-phase was observed. In the case of Pd without intermediate layer (Pd-SiO2/Si) buckling delamination occurred. The damage and deformation mechanisms could be understood by the analysis of the stresses and dislocation (defects) behavior near grain boundaries and the film-substrate interface. From diffraction line-broadening combined with microscopy analysis we showed that in Pd thin films stresses relax at critical stress values via different relaxation pathways depending on film-microstructure and film-substrate interaction. On the basis of the in-situ hydriding experiments it was concluded that a Pd film on a flexible PI intermediate layer exhibits free-standing film-like behavior besides being strongly clamped on a stiff SiO2/Si substrate.
Measuring Accuracy and Computational Capacity Trade-offs in an Hourly Integrated Energy System Model
Feb 2021
Publication
Improving energy system modelling capabilities can directly affect the quality of applied studies. However some modelling trade-offs are necessary as the computational capacity and data availability are constrained. In this paper we demonstrate modelling trade-offs resulting from the modification in the resolution of four modelling capabilities namely transitional scope European electricity interconnection hourly demand-side flexibility description and infrastructure representation. We measure the cost of increasing resolution in each capability in terms of computational time and several energy system modelling indicators notably system costs emission prices and electricity import and export levels. The analyses are performed in a national-level integrated energy system model with a linear programming approach that includes the hourly electricity dispatch with European nodes. We determined that reducing the transitional scope from seven to two periods can reduce the computational time by 75% while underestimating the objective function by only 4.6%. Modelers can assume a single European Union node that dispatches electricity at an aggregated level which underestimates the objective function by 1% while halving the computational time. Furthermore the absence of shedding and storage flexibility options can increase the curtailed electricity by 25% and 8% respectively. Although neglecting flexibility options can drastically decrease the computational time it can increase the sub-optimality by 31%. We conclude that an increased resolution in modelling flexibility options can significantly improve the results. While reducing the computational time by half the lack of electricity and gas infrastructure representation can underestimate the objective function by 4% and 6% respectively.
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.
The Role of Initial Tank Temperature on Refuelling of On-board Hydrogen Tanks
Jun 2016
Publication
The influence of the initial tank temperature on the evolution of the internal gas temperature during the refuelling of on-board hydrogen tanks is investigated in this paper. Two different types of tanks four different fuel delivery temperatures (from ambient temperature refuelling to a pre-cooled hydrogen at −40 °C) several filling rates and initial pressures are considered. It has been found that the final gas temperature increases linearly with the increase of the initial tank temperature while the temperature increase (ΔT) and the final state of charge (SOC) decrease linearly with increasing the initial temperature. This dependency has been found to be larger on type III than on type IV tank and larger the larger the initial pressure. Additionally CFD simulations are performed to better understand the role of the relevant phenomena on the gas temperature histories e.g. gas compression gas mixing and heat transfer. By comparing the results of calculations with adiabatic and diathermal tank walls the effect of the initial gas temperature has been separated from the effect of the initial wall temperature on the process.
The Curious Case of the Conflicting Roles of Hydrogen in Global Energy Scenarios
Oct 2019
Publication
As energy systems transition from fossil-based to low-carbon they face many challenges particularly concerning energy security and flexibility. Hydrogen may help to overcome these challenges with potential as a transport fuel for heating energy storage conversion to electricity and in industry. Despite these opportunities hydrogen has historically had a limited role in influential global energy scenarios. Whilst more recent studies are beginning to include hydrogen the role it plays in different scenarios is extremely inconsistent. In this perspective paper reasons for this inconsistency are explored considering the modelling approach behind the scenario scenario design and data assumptions. We argue that energy systems are becoming increasingly complex and it is within these complexities that new technologies such as hydrogen emerge. Developing a global energy scenario that represents these complexities is challenging and in this paper we provide recommendations to help ensure that emerging technologies such as hydrogen are appropriately represented. These recommendations include: using the right modelling tools whilst knowing the limits of the model; including the right sectors and technologies; having an appropriate level of ambition; and making realistic data assumptions. Above all transparency is essential and global scenarios must do more to make available the modelling methods and data assumptions used.
The Battle between Battery and Fuel Cell Powered Electric Vehicles: A BWM Approach
Oct 2017
Publication
The transition to a more sustainable personal transportation sector requires the widespread adoption of electric vehicles. However a dominant design has not yet emerged and a standards battle is being fought between battery and hydrogen fuel cell powered electric vehicles. The aim of this paper is to analyze which factors are most likely to influence the outcome of this battle thereby reducing the uncertainty in the industry regarding investment decisions in either of these technologies. We examine the relevant factors for standard dominance and apply a multi-criteria decision-making method best worst method to determine the relative importance of these factors. The results indicate that the key factors include technological superiority compatibility and brand reputation and credibility. Our findings show that battery powered electric vehicles have a greater chance of winning the standards battle. This study contributes to theory by providing further empirical evidence that the outcome of standards battles can be explained and predicted by applying factors for standard success. We conclude that technology dominance in the automotive industry is mostly driven by technological characteristics and characteristics of the format supporter.
Direct Conversion of CO2 to Dimethyl Ether in a Fixed Bed Membrane Reactor: Influence of Membrane Properties and Process Conditions
Jun 2021
Publication
The direct hydrogenation of CO2 to dimethyl ether (DME) is a promising technology for CO2 valorisation. In this work a 1D phenomenological reactor model is developed to evaluate and optimize the performance of a membrane reactor for this conversion otherwise limited by thermodynamic equilibrium and temperature gradients. The co-current circulation of a sweep gas stream through the permeation zone promotes both water and heat removal from the reaction zone thus increasing overall DME yield (from 44% to 64%). The membrane properties in terms of water permeability (i.e. 4·10−7 mol·Pa−1m−2s−1) and selectivity (i.e. 50 towards H2 30 towards CO2 and CO 10 towards methanol) for optimal reactor performance have been determined considering for the first time non-ideal separation and non-isothermal operation. Thus this work sheds light into suitable membrane materials for this applications. Then the non-isothermal performance of the membrane reactor was analysed as a function of the process parameters (i.e. the sweep gas to feed flow ratio the gradient of total pressure across the membrane the inlet temperature to the reaction and permeation zone and the feed composition). Owing to its ability to remove 96% of the water produced in this reaction the proposed membrane reactor outperforms a conventional packed bed for the same application (i.e. with 36% and 46% improvement in CO2 conversion and DME yield respectively). The results of this work demonstrate the potential of the membrane reactor to make the CO2 conversion to DME a feasible process.
The Potential of Green Ammonia Production to Reduce Renewable Power Curtailment and Encourage the Energy Transition in China
Apr 2022
Publication
The pursuing of inter-regional power transmission to address renewable power curtailment in China has resulted in disappointing gains. This paper evaluates the case of local green ammonia production to address this issue. An improved optimization-based simulation model is applied to simulate lifetime green manufacturing and the impacts of main institutional incentives and oxygen synergy on investment are analysed. Levelized cost of ammonia is estimated at around 820 USD/t which is about twice the present price. The operating rate ammonia price the electrical efficiency of electrolysers and the electricity price are found to be the key factors in green ammonia investment. Carbon pricing and value-added tax exemption exert obvious influences on the energy transition in China. A subsidy of approximately 450 USD/t will be required according to the present price; however this can be reduced by 100 USD/t through oxygen synergy. Compared to inter-regional power transmission green ammonia production shows both economic and environmental advantages. Therefore we propose an appropriate combination of both options to address renewable power curtailment and the integration of oxygen manufacturing into hydrogen production. We consider the findings and policy implications will contribute to addressing renewable power curtailment and boosting the hydrogen economy in China.
Development of a Flashback Correlation for Burner-stabilized Hydrogen-air Premixed Flames
Feb 2022
Publication
With a growing need for replacing fossil fuels with cleaner alternatives hydrogen has emerged as a viable candidate for providing heat and power. However stable and safe combustion of hydrogen is not simple and as such a number of key issues have been identified that need to be understood for a safe design of combustion chambers. One such issue is the higher propensity of hydrogen flames to flashback compared to that for methane flames. The flashback problem is coupled with higher burner temperatures that could cause strong thermal stresses in burners and could hinder their performance. In order to systematically investigate flashback in premixed hydrogen-air flames for finding a global flashback criteria in this study we use numerical simulations as a basic tool to study flashback limits of slit burners. Flashback limits are found for varying geometrical parameters and equivalence ratios and the sensitivity of each parameter on the flashback limit and burner temperatures are identified and analyzed. It is shown that the conventional flashback correlation with critical velocity gradient does not collapse the flashback data as it does not take into account stretch induced preferential diffusion effects. A new Karlovitz number definition is introduced with physical insights that collapses the flashback data at all tested conditions in an excellent manner.
Measurement Challenges for Hydrogen Vehicles
Apr 2019
Publication
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.
Guidelines and Recommendations for Indoor Use of Fuel Cells and Hydrogen Systems
Oct 2015
Publication
Deborah Houssin-Agbomson,
Simon Jallais,
Elena Vyazmina,
Guy Dang-Nhu,
Gilles Bernard-Michel,
Mike Kuznetsov,
Vladimir V. Molkov,
Boris Chernyavsky,
Volodymyr V. Shentsov,
Dmitry Makarov,
Randy Dey,
Philip Hooker,
Daniele Baraldi,
Evelyn Weidner,
Daniele Melideo,
Valerio Palmisano,
Alexandros G. Venetsanos,
Jan Der Kinderen and
Béatrice L’Hostis
Hydrogen energy applications often require that systems are used indoors (e.g. industrial trucks for materials handling in a warehouse facility fuel cells located in a room or hydrogen stored and distributed from a gas cabinet). It may also be necessary or desirable to locate some hydrogen system components/equipment inside indoor or outdoor enclosures for security or safety reasons to isolate them from the end-user and the public or from weather conditions.<br/>Using of hydrogen in confined environments requires detailed assessments of hazards and associated risks including potential risk prevention and mitigation features. The release of hydrogen can potentially lead to the accumulation of hydrogen and the formation of a flammable hydrogen-air mixture or can result in jet-fires. Within Hyindoor European Project carried out for the EU Fuel Cells and Hydrogen Joint Undertaking safety design guidelines and engineering tools have been developed to prevent and mitigate hazardous consequences of hydrogen release in confined environments. Three main areas are considered: Hydrogen release conditions and accumulation vented deflagrations jet fires and including under-ventilated flame regimes (e.g. extinguishment or oscillating flames and steady burns). Potential RCS recommendations are also identified.
CFD Benchmark Based on Experiments of Helium Dispersion in a 1m3 Enclosure–intercomparisons for Plumes
Sep 2013
Publication
In the context of the French DIMITRHY project ANR-08-PANH006 experiments have been carried out to measure helium injections in a cubic 1 m3 box - GAMELAN in a reproducible and quantitative manner. For the present work we limit ourselves to the unique configuration of a closed box with a small hole at its base to prevent overpressure. This case leads to enough difficulties of modelisations to deserve our attention. The box is initially filled with air and injections of helium through a tube of diameter 20 mm is operated. The box is instrumented with catharometres to measure the helium volume concentration within an accuracy better than 0.1%. We present the CFD (Fluent and CASTEM ANSYS-CFX and ADREA-HF) calculations results obtained by 5 different teams participating to the benchmark in the following situation: the case of a plume release of helium in a closed box (4NL/min). Parts of the CFD simulations were performed in the European co-funded project HyIndoor others were performed in the French ANR-08-PANH006 DimitrHy project.
Material Testing and Design Recommendations for Components Exposed to Hydrogen Enhanced Fatigue – the Mathryce Project
Sep 2013
Publication
The three years European MATHRYCE project dedicated to material testing and design recommendations for components exposed to hydrogen enhanced fatigue started in October 2012. Its main goal is to provide an “easy” to implement methodology based on lab-scale experimental tests under hydrogen gas to assess the service life of a real scale component taking into account fatigue loading under hydrogen gas. Dedicated experimental tests will be developed for this purpose. In the present paper the proposed approach is presented and compared to the methodologies currently developed elsewhere in the world.
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