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Living Carbon Free – Exploring What a Net-zero Target Means for Households
Jun 2019
Publication
The Energy Systems Catapult (ESC) explored the role of households in a net-zero emissions society to accompany the CCC’s Net Zero report looking at opportunities and challenges for households to reduce emissions from today’s levels and to support the stretch from an 80% emissions reduction to a net-zero greenhouse gas target. As well as describing a net-zero emissions world for households of different types the ESC looked at average household emissions under different decarbonisation scenarios and the options households can take to contribute to the decarbonisation effort.
This supported the Net Zero Technical report.
This supported the Net Zero Technical report.
Quantitative Evaluations of Hydrogen Diffusivity in V-X (X = Cr, Al, Pd) Alloy Membranes Based on Hydrogen Chemical Potential
Jan 2021
Publication
Vanadium (V) has higher hydrogen permeability than Pd-based alloy membranes but exhibits poor resistance to hydrogen-induced embrittlement. The alloy elements are added to reduce hydrogen solubility and prevent hydrogen-induced embrittlement. To enhance hydrogen permeability the alloy elements which improve hydrogen diffusivity in V are more suitable. In the present study hydrogen diffusivity in V-Cr V-Al and V-Pd alloy membranes was investigated in view of the hydrogen chemical potential and compared with the previously reported results of V-Fe alloy membranes. The additions of Cr and Fe to V improved the mobility of hydrogen atoms. In contrast those of Al and Pd decreased hydrogen diffusivity. The first principle calculations revealed that the hydrogen atoms cannot occupy the first-nearest neighbour T sites (T1 sites) of Al and Pd in the V crystal lattice. These blocking effects will be a dominant contributor to decreasing hydrogen diffusivity by the additions of Al and Pd. For V-based alloy membranes Fe and Cr are more suitable alloy elements compared with Al and Pd in view of hydrogen diffusivity.
Boosting Photocatalytic Hydrogen Production from Water by Photothermally Induced Biphase Systems
Feb 2021
Publication
Solar-driven hydrogen production from water using particulate photocatalysts is considered the most economical and effective approach to produce hydrogen fuel with little environmental concern. However the efficiency of hydrogen production from water in particulate photocatalysis systems is still low. Here we propose an efficient biphase photocatalytic system composed of integrated photothermal–photocatalytic materials that use charred wood substrates to convert liquid water to water steam simultaneously splitting hydrogen under light illumination without additional energy. The photothermal–photocatalytic system exhibits biphase interfaces of photothermally-generated steam/photocatalyst/hydrogen which significantly reduce the interface barrier and drastically lower the transport resistance of the hydrogen gas by nearly two orders of magnitude. In this work an impressive hydrogen production rate up to 220.74 μmol h−1 cm−2 in the particulate photocatalytic systems has been achieved based on the wood/CoO system demonstrating that the photothermal–photocatalytic biphase system is cost-effective and greatly advantageous for practical applications.
Performance Evaluation of Empirical Models for Vented Lean Hydrogen Explosions
Sep 2017
Publication
Explosion venting is a method commonly used to prevent or minimize damage to an enclosure caused by an accidental explosion. An estimate of the maximum overpressure generated though explosion is an important parameter in the design of the vents. Various engineering models (Bauwens et al. 2012 Molkov and Bragin 2015) and European (EN 14994 ) and USA standards (NFPA 68) are available to predict such overpressure. In this study their performance is evaluated using a number of published experiments. Comparison of pressure predictions from various models have also been carried out for the recent experiments conducted by GexCon using a 20 feet ISO container. The results show that the model of Bauwens et al. (2012) predicts well for hydrogen concentration between 16% and 21% and in the presence of obstacles. The model of Molkov et al. (2015) is found to work well for hydrogen concentrations between 10% and 30% without obstacles. In the presence of obstacles as no guidelines are given to set the coefficient for obstacles in the model it was necessary to tune the coefficient to match the experimental data. The predictions of the formulas in NFPA 68 show a large scatter across different tests. The current version of both EN 14994 and NFPA 68 are found to have very limited range of applicability and can hardly be used for vent sizing of hydrogen-air deflagrations. Overall the accuracy of all the engineering models was found to be limited. Some recommendations concerning their applicability will be given for vented lean-hydrogen explosion concentrations of interest to practical applications.
Hydrogen‐Rich Gas Production from Two‐Stage Catalytic Pyrolysis of Pine Sawdust with Calcined Dolomite
Jan 2022
Publication
Tao Xu,
Jue Xu and
Yongping Wu
The potential of catalytic pyrolysis of biomass for hydrogen and bio‐oil production has drawn great attention due to the concern of clean energy utilization and decarbonization. In this paper the catalytic pyrolysis of pine sawdust with calcined dolomite was carried out in a novel moving bed reactor with a two‐stage screw feeder. The effects of pyrolysis temperature (700–900 °C) and catalytic temperature (500–800 °C) on pyrolysis performance were investigated in product distribution gas composition and gas properties. The results showed that with the temperature increased pyrolysis gas yield in‐ creased but the yield of solid and liquid products decreased. With the increase in temperature the CO and H2 content increased significantly while the CO2 and CH4 decreased correspondingly. The calcined dolomite can remove the tar by 44% and increased syngas yield by 52.9%. With the increasing catalytic temperature the catalytic effect of calcined dolomite was also enhanced.
The Pathway to Net Zero Heating in the UK: A UKERC Policy Brief
Oct 2020
Publication
There is uncertainty over how heating might practically be decarbonised in the future. This briefing provides some clarity about the possible pathways forward focusing on the next 5-10 years.<br/>Meeting the UK government’s net zero emissions goal for 2050 will only be possible by complete decarbonisation of the building stock (both existing and new). There is uncertainty over the extent to which heating might practically be decarbonised in the future and what the optimal technologies may be. This paper provides some clarity about the pathways forward focusing on the next 5-10 years.
Pathways to Low-cost Clean Hydrogen Production with Gas Switching Reforming
Feb 2020
Publication
Gas switching reforming (GSR) is a promising technology for natural gas reforming with inherent CO2 capture. Like conventional steam methane reforming (SMR) GSR can be integrated with CO2 -gas shift and pressure swing adsorption units for pure hydrogen production. The resulting GSR-H2 process concept was techno-economically assessed in this study. Results showed that GSR-H2 can achieve 96% CO2 capture at a CO2 avoidance cost of 15 $/ton (including CO2 transport and storage). Most components of the GSR-H2 process are proven technologies but long-term oxygen carrier stability presents an important technical uncertainty that can adversely affect competitiveness when the material lifetime drops below one year. Relative to the SMR benchmark GSR-H2 replaces some fuel consumption with electricity consumption making it more suitable to regions with higher natural gas prices and lower electricity prices. Some minor alterations to the process configuration can adjust the balance between fuel and electricity consumption to match local market conditions. The most attractive commercialization pathway for the GSR-H2 technology is initial construction without CO2 capture followed by simple retrofitting for CO2 capture when CO2 taxes rise and CO2 transport and storage infrastructure becomes available. These features make the GSR-H2 technology robust to almost any future energy market scenario.
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.
Opportunities and Challenges of Low-Carbon Hydrogen via Metallic Membranes
Jun 2020
Publication
Today electricity & heat generation transportation and industrial sectors together produce more than 80% of energy-related CO2 emissions. Hydrogen may be used as an energy carrier and an alternative fuel in the industrial residential and transportation sectors for either heating energy production from fuel cells or direct fueling of vehicles. In particular the use of hydrogen fuel cell vehicles (HFCVs) has the potential to virtually eliminate CO2 emissions from tailpipes and considerably reduce overall emissions from the transportation sector. Although steam methane reforming (SMR) is the dominant industrial process for hydrogen production environmental concerns associated with CO2 emissions along with the process intensification and energy optimization are areas that still require improvement. Metallic membrane reactors (MRs) have the potential to address both challenges. MRs operate at significantly lower pressures and temperatures compared with the conventional reactors. Hence the capital and operating expenses could be considerably lower compared with the conventional reactors. Moreover metallic membranes specifically Pd and its alloys inherently allow for only hydrogen permeation making it possible to produce a stream of up to 99.999+% purity.
For smaller and emerging hydrogen markets such as the semiconductor and fuel cell industries Pd-based membranes may be an appropriate technology based on the scales and purity requirements. In particular at lower hydrogen production rates in small-scale plants MRs with CCUS could be competitive compared to centralized H2 production. On-site hydrogen production would also provide a self-sufficient supply and further circumvent delivery delays as well as issues with storage safety. In addition hydrogen-producing MRs are a potential avenue to alleviate carbon emissions. However material availability Pd cost and scale-up potential on the order of 1.5 million m3/day may be limiting factors preventing wider application of Pd-based membranes.
Regarding the economic production of hydrogen the benchmark by the year 2020 has been determined and set in place by the U.S. DOE at less than $2.00 per kg of produced hydrogen. While the established SMR process can easily meet the set limit by DOE other carbon-free processes such as water electrolysis electron beam radiolysis and gliding arc technologies do not presently meet this requirement. In particular it is expected that the cost of hydrogen produced from natural gas without CCUS will remain the lowest among all of the technologies while the hydrogen cost produced from an SMR plant with solvent-based carbon capture could be twice as expensive as the conventional SMR without carbon capture. Pd-based MRs have the potential to produce hydrogen at competitive prices with SMR plants equipped with carbon capture.
Despite the significant improvements in the electrolysis technologies the cost of hydrogen produced by electrolysis may remain significantly higher in most geographical locations compared with the hydrogen produced from fossil fuels. The cost of hydrogen via electrolysis may vary up to a factor of ten depending on the location and the electricity source. Nevertheless due to its modular nature the electrolysis process will likely play a significant role in the hydrogen economy when implemented in suitable geographical locations and powered by renewable electricity.
This review provides a critical overview of the opportunities and challenges associated with the use of the MRs to produce high-purity hydrogen with low carbon emissions. Moreover a technoeconomic review of the potential methods for hydrogen production is provided and the drawbacks and advantages of each method are presented and discussed.
For smaller and emerging hydrogen markets such as the semiconductor and fuel cell industries Pd-based membranes may be an appropriate technology based on the scales and purity requirements. In particular at lower hydrogen production rates in small-scale plants MRs with CCUS could be competitive compared to centralized H2 production. On-site hydrogen production would also provide a self-sufficient supply and further circumvent delivery delays as well as issues with storage safety. In addition hydrogen-producing MRs are a potential avenue to alleviate carbon emissions. However material availability Pd cost and scale-up potential on the order of 1.5 million m3/day may be limiting factors preventing wider application of Pd-based membranes.
Regarding the economic production of hydrogen the benchmark by the year 2020 has been determined and set in place by the U.S. DOE at less than $2.00 per kg of produced hydrogen. While the established SMR process can easily meet the set limit by DOE other carbon-free processes such as water electrolysis electron beam radiolysis and gliding arc technologies do not presently meet this requirement. In particular it is expected that the cost of hydrogen produced from natural gas without CCUS will remain the lowest among all of the technologies while the hydrogen cost produced from an SMR plant with solvent-based carbon capture could be twice as expensive as the conventional SMR without carbon capture. Pd-based MRs have the potential to produce hydrogen at competitive prices with SMR plants equipped with carbon capture.
Despite the significant improvements in the electrolysis technologies the cost of hydrogen produced by electrolysis may remain significantly higher in most geographical locations compared with the hydrogen produced from fossil fuels. The cost of hydrogen via electrolysis may vary up to a factor of ten depending on the location and the electricity source. Nevertheless due to its modular nature the electrolysis process will likely play a significant role in the hydrogen economy when implemented in suitable geographical locations and powered by renewable electricity.
This review provides a critical overview of the opportunities and challenges associated with the use of the MRs to produce high-purity hydrogen with low carbon emissions. Moreover a technoeconomic review of the potential methods for hydrogen production is provided and the drawbacks and advantages of each method are presented and discussed.
Adsorption-Based Hydrogen Storage in Activated Carbons and Model Carbon Structures
Jul 2021
Publication
The experimental data on hydrogen adsorption on five nanoporous activated carbons (ACs) of various origins measured over the temperature range of 303–363 K and pressures up to 20 MPa were compared with the predictions of hydrogen density in the slit-like pores of model carbon structures calculated by the Dubinin theory of volume filling of micropores. The highest amount of adsorbed hydrogen was found for the AC sample (ACS) prepared from a polymer mixture by KOH thermochemical activation characterized by a biporous structure: 11.0 mmol/g at 16 MPa and 303 K. The greatest volumetric capacity over the entire range of temperature and pressure was demonstrated by the densest carbon adsorbent prepared from silicon carbide. The calculations of hydrogen density in the slit-like model pores revealed that the optimal hydrogen storage depended on the pore size temperature and pressure. The hydrogen adsorption capacity of the model structures exceeded the US Department of Energy (DOE) target value of 6.5 wt.% starting from 200 K and 20 MPa whereas the most efficient carbon adsorbent ACS could achieve 7.5 wt.% only at extremely low temperatures. The initial differential molar isosteric heats of hydrogen adsorption in the studied activated carbons were in the range of 2.8–14 kJ/mol and varied during adsorption in a manner specific for each adsorbent.
Energy Innovation Needs Assessment: Road Transport
Nov 2019
Publication
The Energy Innovation Needs Assessment (EINA) aims to identify the key innovation needs across the UK’s energy system to inform the prioritisation of public sector investment in low-carbon innovation. Using an analytical methodology developed by the Department for Business Energy & Industrial Strategy (BEIS) the EINA takes a system level approach and values innovations in a technology in terms of the system-level benefits a technology innovation provides. This whole system modelling in line with BEIS’s EINA methodology was delivered by the Energy Systems Catapult (ESC) using the Energy System Modelling Environment (ESMETM) as the primary modelling tool.
To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.
This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.
This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.
To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.
This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.
This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.
Commercialisation of Energy Storage
Mar 2015
Publication
This report was created to ensure a deeper understanding of the role and commercial viability of energy storage in enabling increasing levels of intermittent renewable power generation. It was specifically written to inform thought leaders and decision-makers about the potential contribution of storage in order to integrate renewable energy sources (RES) and about the actions required to ensure that storage is allowed to compete with the other flexibility options on a level playing field.<br/>The share of RES in the European electric power generation mix is expected to grow considerably constituting a significant contribution to the European Commission’s challenging targets to reduce greenhouse gas emissions. The share of RES production in electricity demand should reach about 36% by 2020 45-60% by 2030 and over 80% in 2050.<br/>In some scenarios up to 65% of EU power generation will be covered by solar photovoltaics (PV) as well as on- and offshore wind (variable renewable energy (VRE) sources) whose production is subject to both seasonal as well as hourly weather variability. This is a situation the power system has not coped with before. System flexibility needs which have historically been driven by variable demand patterns will increasingly be driven by supply variability as VRE penetration increases to very high levels (50% and more).<br/>Significant amounts of excess renewable energy (on the order of TWh) will start to emerge in countries across the EU with surpluses characterized by periods of high power output (GW) far in excess of demand. These periods will alternate with times when solar PV and wind are only generating at a fraction of their capacity and non-renewable generation capacity will be required.<br/>In addition the large intermittent power flows will put strain on the transmission and distribution network and make it more challenging to ensure that the electricity supply matches demand at all times.<br/>New systems and tools are required to ensure that this renewable energy is integrated into the power system effectively. There are four main options for providing the required flexibility to the power system: dispatchable generation transmission and distribution expansion demand side management and energy storage. All of these options have limitations and costs and none of them can solve the RES integration challenge alone. This report focuses on the question to what extent current and new storage technologies can contribute to integrate renewables in the long run and play additional roles in the short term.
A Review of Techno-economic Data for Road Transportation Fuels
May 2019
Publication
Worldwide the road transport sector typically arises as one of the main sources of air pollutants due to its high energy intensity and the use of fossil fuels. Thus governments and social agents work on the development and prospective planning of decarbonisation strategies oriented towards sustainable transport. In this regard the increase in the use of alternative fuels is the recurrent approach to energy planning e.g. through the promotion of electric vehicles biofuels natural gas liquefied petroleum gas etc. However there is a lack of comprehensive information on the techno-economic performance of production pathways for alternative fuels. The acquisition of robust techno-economic data is still a challenge for energy planners modellers analysts and policy-makers when building their prospective models to support decision-making processes. Hence this article aims to fill this gap through a deep literature review including the most representative production routes for a wide range of road transportation fuels. This led to the development of datasets including investment costs operating and maintenance costs and transformation efficiencies for more than 40 production pathways. The techno-economic data presented in this work are expected to be especially useful to those energy actors interested in performing long-term studies on the transition to a sustainable transport system.
Accelerating to Net Zero with Hydrogen Blending Standards Development in the UK, Canada and the US - Part 1
Mar 2021
Publication
"Hydrogen is expected to play a critical role in the move to a net-zero economy. However large-scale deployment is still in its infancy and there is still much to be done before we can blend hydrogen in large volumes into gas networks and ramp up the production that is required to meet demands of the energy transport and industry sectors. KTN Global Alliance will host two webinars to explore these challenges and opportunities in hydrogen blending on the 2nd and 3rd March 2021.
Exciting pilot projects are being conducted and explored in the UK Canada and US states such as California to determine the technical feasibility of blending hydrogen into existing natural gas systems. Whilst the deployment of hydrogen is in its early stages there is increasing interest around permitting significant percentage blends of hydrogen into gas networks which would enable the carbon intensity of gas supplies to be reduced creating a new demand for hydrogen and with the use of separation and purification technologies downstream support the transportation of pure hydrogen to markets.
Gaps in codes and standards need to be addressed to enable adoption and there may be opportunities for international collaboration and harmonisation to ensure that best practices are shared globally and to facilitate the growth of trade and export markets. There is an opportunity for the UK Canada and US three G7 countries to work together and show market making leadership in key enabling regulation for the new hydrogen economy.
Delivered by KTN Global Alliance on behalf of the British Consulate-General in Vancouver and the UK Science and Innovation Network in Canada and the US these two webinars will showcase hydrogen blending pilot projects in the UK Canada and California highlighting challenges and opportunities with regard to standards development for hydrogen blending and supporting further transatlantic collaboration in this area. The events also form part of the UK’s international engagement to build momentum towards a successful outcome at COP26 the UN climate summit that the UK will host in Glasgow in November 2021. The webinars will bring together experts from industry academia and policy from the UK Canada and California. Attendees will have an opportunity to ask questions and interact using Mentimeter."
Part 2 Highlights and Perspectives from Canada and California can be found here.
Exciting pilot projects are being conducted and explored in the UK Canada and US states such as California to determine the technical feasibility of blending hydrogen into existing natural gas systems. Whilst the deployment of hydrogen is in its early stages there is increasing interest around permitting significant percentage blends of hydrogen into gas networks which would enable the carbon intensity of gas supplies to be reduced creating a new demand for hydrogen and with the use of separation and purification technologies downstream support the transportation of pure hydrogen to markets.
Gaps in codes and standards need to be addressed to enable adoption and there may be opportunities for international collaboration and harmonisation to ensure that best practices are shared globally and to facilitate the growth of trade and export markets. There is an opportunity for the UK Canada and US three G7 countries to work together and show market making leadership in key enabling regulation for the new hydrogen economy.
Delivered by KTN Global Alliance on behalf of the British Consulate-General in Vancouver and the UK Science and Innovation Network in Canada and the US these two webinars will showcase hydrogen blending pilot projects in the UK Canada and California highlighting challenges and opportunities with regard to standards development for hydrogen blending and supporting further transatlantic collaboration in this area. The events also form part of the UK’s international engagement to build momentum towards a successful outcome at COP26 the UN climate summit that the UK will host in Glasgow in November 2021. The webinars will bring together experts from industry academia and policy from the UK Canada and California. Attendees will have an opportunity to ask questions and interact using Mentimeter."
Part 2 Highlights and Perspectives from Canada and California can be found here.
Dispersion of Cryogenic Hydrogen Through High-aspect Ratio Nozzles
Sep 2019
Publication
Liquid hydrogen is increasingly being used as a delivery and storage medium for stations that provide compressed gaseous hydrogen for fuel cell electric vehicles. In efforts to provide scientific justification for separation distances for liquid hydrogen infrastructure in fire codes the dispersion characteristics of cryogenic hydrogen jets (50–64 K) from high aspect ratio nozzles have been measured at 3 and 5 barabs stagnation pressures. These nozzles are more characteristic of unintended leaks which would be expected to be cracks rather than conventional round nozzles. Spontaneous Raman scattering was used to measure the concentration and temperature field along the major and minor axes. Within the field of interrogation the axis-switching phenomena was not observed but rather a self-similar Gaussian-profile flow regime similar to room temperature or cryogenic hydrogen releases through round nozzles. The concentration decay rate and half-widths for the planar cryogenic jets were found to be nominally equivalent to that of round nozzle cryogenic hydrogen jets indicating a similar flammable envelope. The results from these experiments will be used to validate models for cryogenic hydrogen dispersion that will be used for simulations of alternative scenarios and quantitative risk assessment
Secure, Affordable, Low Carbon: Gas in our Future Energy System
Feb 2020
Publication
Our gas network is one of the best developed in the world providing safe secure affordable energy to homes and businesses across the UK.<br/><br/>To meet the biggest energy challenge of our generation – making deep cuts to carbon emissions by 2050 – it needs to embrace new technology which builds on these strengths and delivers the integrated flexible network of the future. This briefing sets out how it is already doing that. Take a look at our Gas Futures Messages booklet attached.
Sustainability Assessment of Fuel Cell Buses in Public Transport
May 2018
Publication
Hydrogen fuel cell (H2FC) buses operating in every day public transport services around Europe are assessed for their sustainability against environmental economic and social criteria. As part of this assessment the buses are evaluated against diesel buses both in terms of sustainability and in terms of meeting real world requirements with respect to operational performance. The study concludes that H2FC buses meet operability and performance criteria and are sustainable environmentally when ‘green’ hydrogen is used. The economic sustainability of the buses in terms of affordability achieves parity with their fossil fuel equivalent by 2030 when the indirect costs to human health and climate change are included. Societal acceptance by those who worked with and used the buses supports the positive findings of earlier studies although satisfactory operability and performance are shown to be essential to positive attitudes. Influential policy makers expressed positive sentiments only if ‘green’ hydrogen is used and the affordability issues can be addressed. No “show-stopper” is identified that would prevent future generations from using H2FC buses in public transport on a broad scale due to damage to the environment or to other factors that impinge on quality of life.
The Effect of the Temperature and Moisture to the Permeation Properties of PEO-Based Membranes for Carbon-Dioxide Separation
Jun 2021
Publication
An increased demand for energy in recent decades has caused an increase in the emissions of combustion products among which carbon-dioxide is the most harmful. As carbon-dioxide induces negative environmental effects like global warming and the greenhouse effect a decrease of the carbon-dioxide emission has emerged as one of the most urgent tasks in engineering. In this work the possibility for the application of the polymer-based dense mixed matrix membranes for flue gas treatment was tested. The task was to test a potential decrease in the permeability and selectivity of a mixed-matrix membrane in the presence of moisture and at elevated temperature. Membranes are based on two different poly(ethylene oxide)-based polymers filled with two different zeolite powders (ITR and IWS). An additive of detergent type was added to improve the contact properties between the zeolite and polymer matrix. The measurements were performed at three different temperatures (30 60 and 90 °C) under wet conditions with partial pressure of the water equal to the vapor pressure of the water at the given temperature. The permeability of carbon-dioxide hydrogen nitrogen and oxygen was measured and the selectivity of the carbon-dioxide versus other gases was determined. Obtained results have shown that an increase of temperature and partial pressure of the vapor slightly increase both the selectivity and permeability of the synthesized membranes. It was also shown that the addition of the zeolite powder increases the permeability of carbon-dioxide while maintaining the selectivity compared to hydrogen oxygen and nitrogen.
HyDeploy Report: Gas Characteristics (Leakage, Dispersion and Flammability)
Sep 2018
Publication
The Health and Safety Laboratory (HSL) has carried out an investigation into the gas characteristics that may influence the leakage dispersion and flammability hazards associated with blended natural gas-hydrogen mixtures containing up to 20 % mol/mol hydrogen. The work was carried out under contract to Cadent & Northern Gas Networks as part of the HyDeploy project which was commissioned to investigate the feasibility of using blended hydrogen-natural gas mixtures in UK mains gas distribution networks.
Under the HyDeploy project a demonstration scheme is being carried out at Keele University in which it is planned to inject up to 20 % mol/mol hydrogen. Keele is Britain’s largest campus university and an ideal test site for a demonstration scheme as its gas distribution network is largely independent of the national gas network but still subject to UK gas industry procedural controls. It is anticipated that a successful demonstration scheme will facilitate the use of blended natural gas-hydrogen mixtures throughout the UK leading to significant reductions in carbon dioxide emissions. The project is being led by Cadent & Northern Gas Networks and also involves ITM Power Progressive Energy Keele University and HSL in consortium.
Click the supplements tab to view the other documents in this report
Under the HyDeploy project a demonstration scheme is being carried out at Keele University in which it is planned to inject up to 20 % mol/mol hydrogen. Keele is Britain’s largest campus university and an ideal test site for a demonstration scheme as its gas distribution network is largely independent of the national gas network but still subject to UK gas industry procedural controls. It is anticipated that a successful demonstration scheme will facilitate the use of blended natural gas-hydrogen mixtures throughout the UK leading to significant reductions in carbon dioxide emissions. The project is being led by Cadent & Northern Gas Networks and also involves ITM Power Progressive Energy Keele University and HSL in consortium.
Click the supplements tab to view the other documents in this report
Sustainable Hydrogen Production: A Role for Fusion
Apr 2007
Publication
This Meeting Report summarises the findings of a two-day workshop in April 2007 at the Culham Science Centre and Worcester College Oxford which explored the potential for large-scale Hydrogen production through methods other than electrolysis.<br/>Operating at the cusp of research and policy-making the UK Energy Research Centre's mission is to be the UK's pre-eminent centre of research and source of authoritative information and leadership on sustainable energy systems. The Centre takes a whole systems approach to energy research incorporating economics engineering and the physical environmental and social sciences while developing and maintaining the means to enable cohesive research in energy. A key supporting function of UKERC is the Meeting Place based in Oxford which aims to bring together members of the UK energy community and overseas experts from different disciplines to learn identify problems develop solutions and further the energy debate.
Charge Carrier Mapping for Z-scheme Photocatalytic Water-splitting Sheet via Categorization of Microscopic Time-resolved Image Sequences
Jun 2021
Publication
Photocatalytic water splitting system using particulate semiconductor materials is a promising strategy for converting solar energy into hydrogen and oxygen. In particular visible-light-driven ‘Z-scheme’ printable photocatalyst sheets are cost-effective and scalable. However little is known about the fundamental photophysical processes which are key to explaining and promoting the photoactivity. Here we applied the pattern-illumination time-resolved phase microscopy for a photocatalyst sheet composed of Mo-doped BiVO4 and Rh-doped SrTiO3 with indium tin oxide as the electron mediator to investigate photo-generated charge carrier dynamics. Using this method we successfully observed the position- and structure-dependent charge carrier behavior and visualized the active/inactive sites in the sheets under the light irradiation via the time sequence images and the clustering analysis. This combination methodology could provide the material/synthesis optimization methods for the maximum performance of the photocatalyst sheets.
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.
Brittle Fracture Manifestation in Gas Pipeline Steels after Long-term Operation
Dec 2020
Publication
Gas pipelines are exposed to operational loads combined with corrosive environment action during their long-term service. Complicated service conditions lead to a worsening of steel properties a reduction of serviceability of the whole object therefore a risk of its premature failure rises. Aware of the importance of the existing problem the aim of this study is the analysis of various mechanical properties of steels after their long-term operation on gas pipelines and detecting and evaluating fractographic signs of this degradation.<br/>Mechanical properties of operated pipe steels characterizing their brittle fracture resistance were significantly decreased. Delamination areas as one of a feature of brittle fracture were identified on the fracture surfaces of specimens after SSRT of the operated steels in corrosive environment. Fracture was initiated from the outer surface of the specimens along the boundaries of ferrite and pearlite grains with significant secondary cracking.<br/>The obvious texture in the steels affects noticeably the results of the impact tests. Higher KCV values for the specimens cut in the longitudinal direction relative to the pipe axis comparing with the specimens of transversal orientation were obtained. This was explained by different length of narrow pearlite strips alternated by wide ferrite bands and interrupted by individual ferrite grains depending on the orientation of the specimen fracture surface relative to the pipe axis. Thus a proper direction of specimen cutting to achieve the maximum sensitivity of KCV parameter to operational degradation of steels is discussed. The effect of specimen orientation on the results of the Charpy testing becomes much more pronounced with steel operation. Defects accumulated in steels during their service are preferentially oriented in the pipe axial direction along the boundaries between ferrite and pearlite strips. Analyzing the fracture surfaces of the Charpy specimens after their impact testing certain signs of embrittlement were found for long term operated steels in the form of delaminations varying in size and shape and some cleavage fragments. Furthermore their percentage of total fracture surface (generally formed by dimples) correlates well with a drop in the impact toughness. The established relationship could be the basis for the introduction of fractographic criteria of the steel serviceability.
On The Kinetics of Alh3 Decomposition and the Subsequent Al Oxidation
Sep 2011
Publication
Metal hydrides are used for hydrogen storage. AlH3 shows a capacity to store about 10 wt% hydrogen. Its hydrogen is split-off in the temperature interval of 400–500 K. On dehydrogenation a nano-structured Al material emerges with specific surfaces up to 15–20 m2/g. The surface areas depend on the heating rate because of a temperature dependent crystallite growth. The resulting Al oxidizes up to 20–25% weight on air access forming an alumina passivation layer of 3–4 nm thickness on all exposed surfaces. The heat released from this Al oxidation induces a high risk to this type of hydrogen storage if the containment might be destroyed accidentally. The kinetics of the dehydrogenation and the subsequent oxidation is investigated by methods of thermal analysis. A reaction scheme is confirmed which consists of a starting Avrami-Erofeev mechanism followed by formal 1st order oxidation on unlimited air access. The kinetic parameters activation energies and pre-exponentials are evaluated and can be used to calculate the reaction progress. Together with the heat of the Al oxidation the overall heat release and the related rate can be estimated.
New Integrated Process for the Efficient Production of Methanol, Electrical Power, and Heating
Jan 2022
Publication
In this paper a novel process is developed to cogenerate 4741 kg/h of methanol 297.7 kW of electricity and 35.73 ton/h of hot water including a hydrogen purification system an absorption– compression refrigeration cycle (ACRC) a regenerative Organic Rankine Cycle (ORC) and parabolic solar troughs. The heat produced in the methanol reactor is recovered in the ORC and ACRC. Parabolic solar troughs provide thermal power to the methanol distillation tower. Thermal efficiencies of the integrated structure and the liquid methanol production cycle are 78.14% and 60.91% respectively. The process’s total exergy efficiency and irreversibility are 89.45% and 16.89 MW. The solar thermal collectors take the largest share of exergy destruction (34%) followed by heat exchangers (30%) and mixers (19%). Based on the sensitivity analysis D17 (mixture of H2 and low-pressure fuel gas before separation) was the most influential stream affecting the performance of the process. With the temperature decline of stream D17 from −139 to −149 °C the methanol production rate and the total thermal efficiency rose to 4741.2 kg/h and 61.02% respectively. Moreover the growth in the hydrogen content from 55% to 80% molar of the feed gas the flow rate of liquid methanol and the total exergy efficiency declined to 4487 kg/h and 86.05%.
What is Needed to Deliver Carbon-neutral Heat Using Hydrogen and CCS?
Sep 2020
Publication
In comparison with the power sector large scale decarbonisation of heat has received relatively little attention at the infrastructural scale despite its importance in the global CO2 emissions landscape. In this study we focus on the regional transition of a heating sector from natural gas-based infrastructure to H2 using mathematical optimisation. A discrete spatio-temporal description of the geographical region of Great Britain was used in addition to a detailed description of all network elements for illustrating the key factors in the design of nation-wide H2 and CO2 infrastructure. We have found that the synergistic deployment of H2 production technologies such as autothermal reforming of methane and biomass gasification with CO2 abatement technologies such as carbon capture and storage (CCS) are critical in achieving cost-effective decarbonisation. We show that both large scale underground H2 storage and water electrolysis provide resilience and flexibility to the heating system competing on cost and deployment rates. The optimal regions for siting H2 production infrastructure are characterised by proximity to: (1) underground H2 storage (2) high demands for H2 (3) geological storage for CO2. Furthermore cost-effective transitions based on a methane reforming pathway may necessitate regional expansions in the supply of natural gas with profound implications for security of supply in nations that are already highly reliant potentially creating an infrastructure lock-in during the near term. We found that the total system cost comprising both investment and operational elements is mostly influenced by the natural gas price followed by biomass price and CapEx of underground caverns. Under a hybrid Regulated Asset Base (RAB) commercial framework with private enterprises delivering production infrastructure the total cost of heat supply over the infrastructure lifetime is estimated as 5.2–8.6 pence per kW h. Due to the higher cost relative to natural gas a Contract for Difference payment between d20 per MW h and d53 per MW h will be necessary for H2-derived heat to be competitive in the market.
Real World Hydrogen Technology Validation
Sep 2011
Publication
The Department of Energy the Department of Defense's Defense Logistics Agency and the Department of Transportation's Federal Transit Administration have funded learning demonstrations and early market deployments to provide insight into applications of hydrogen technologies on the road in the warehouse and as stationary power. NREL's analyses validate the technology in real-world applications reveal the status of the technology and facilitate the development of hydrogen and fuel cell technologies manufacturing and operations. This paper presents the maintenance safety and operation data of fuel cells in multiple applications with the reported incidents near misses and frequencies. NREL has analyzed records of more than 225000 kilograms of hydrogen that have been dispensed through more than 108000 hydrogen fills with an excellent safety record.
A New Approach to Vented Deflagration Modeling
Sep 2017
Publication
In the present work CFD simulations of a hydrogen deflagration experiment are performed. The experiment carried out by KIT was conducted in a 1 m3 enclosure with a square vent of 0.5 m2 located in the center of one of its walls. The enclosure was filled with homogeneous hydrogen-air mixture of 18% v/v before ignition at its back-wall. As the flame propagates away from the ignition point unburned mixture is forced out through the vent. This mixture is ignited when the flame passes through the vent initiating a violent external explosion which leads to a rapid increase in pressure. The work focuses on the modeling of the external explosion phenomenon. A new approach is proposed in order to predict with accuracy the strength of external explosions using Large Eddy Simulation. The new approach introduces new relations to account for the interaction between the turbulence and the flame front. CFD predictions of the pressure inside and outside the enclosure and of the flame front shape are compared against experimental measurements. The comparison indicates a much better performance of the new approach compared to the initial model.
Safety and Risk Management in Nuclear-Based Hydrogen Production with Thermal Water Splitting
Sep 2013
Publication
The challenges and approaches of the safety and risk management for the hydrogen production with nuclear-based thermochemical water splitting have been far from sufficiently reported as the thermochemical technology is still at a fledgling stage and the linkage of a nuclear reactor with a hydrogen production plant is unprecedented. This paper focuses on the safety issues arising from the interactions between the nuclear heat source and thermochemical hydrogen production cycle as well between the proximate individual processes in the cycle. As steam is utilized in most thermochemical cycles for the water splitting reaction and heat must be transferred from the nuclear source to hydrogen production plant this paper particularly analyzes and quantifies the heat hazard for the scenarios of start-up and shutdown of the hydrogen production plant. Potential safety impacts on the nuclear reactor are discussed. It is concluded that one of the main challenges of safety and risk management is efficient rejection of heat in a shutdown accident. Several options for the measures to be taken are suggested. Copper-chlorine and sulphur-iodine thermochemical cycles are taken as two representative examples for the hazard analysis. It is expected that these newly reported challenges and approaches could help build the future safety and risk management codes and standards for the infrastructure of the thermochemical hydrogen production.
Materials Towards Carbon-free, Emission-free and Oil-free Mobility: Hydrogen Fuel-cell Vehicles—Now and in the Future
Jul 2010
Publication
In the past material innovation has changed society through new material-induced technologies adding a new value to society. In the present world engineers and scientists are expected to invent new materials to solve the global problem of climate change. For the transport sector the challenge for material engineers is to change the oil-based world into a sustainable world. After witnessing the recent high oil price and its adverse impact on the global economy it is time to accelerate our efforts towards this change.
Industries are tackling global energy issues such as oil and CO2 as well as local environmental problems such as NOx and particulate matter. Hydrogen is the most promising candidate to provide carbon-free emission-free and oil-free mobility. As such engineers are working very hard to bring this technology into the real society. This paper describes recent progress of vehicle technologies as well as hydrogen-storage technologies to extend the cruise range and ensure the easiness of refuelling and requesting material scientists to collaborate with industry to fight against global warming.
Link to document download on Royal Society Website
Industries are tackling global energy issues such as oil and CO2 as well as local environmental problems such as NOx and particulate matter. Hydrogen is the most promising candidate to provide carbon-free emission-free and oil-free mobility. As such engineers are working very hard to bring this technology into the real society. This paper describes recent progress of vehicle technologies as well as hydrogen-storage technologies to extend the cruise range and ensure the easiness of refuelling and requesting material scientists to collaborate with industry to fight against global warming.
Link to document download on Royal Society Website
Boundary Layer Effects on the Critical Nozzle of Hydrogen Sonic Jet
Oct 2015
Publication
When hydrogen flows through a small finite length constant exit area nozzle the viscous effects create a fluid throat which acts as a converging-diverging nozzle and lead to Mach number greater than one at the exit if the jet is under-expanded. This phenomenon influences the mass flow rate and the dispersion cloud size. In this study the boundary layer effect on the unsteady hydrogen sonic jet flow through a 1 mm diameter pipe from a high pressure reservoir (up to 70 MPa) is studied using computational fluid dynamics with a large eddy simulation turbulence model. This viscous flow simulation is compared with a non-viscous simulation to demonstrate that the velocity is supersonic at the exit of a small exit nozzle and that the mass flow is reduced.
Clean Hydrogen Monitor
Oct 2020
Publication
It’s the first of its kind overview showing the state of play with regards to hydrogen technologies in Europe. On an annual basis there will be an update serving as a basis for your investment or political decisions.<br/><br/>OUR MISSION IS – NO EMISSION!<br/>From day 1 Hydrogen Europe promoted clean hydrogen and clean hydrogen technologies as enablers of a decarbonised energy system. We strongly support the adoption of very ambitious climate targets for 2030 and the objective of carbon neutrality in the EU by 2050. Clean hydrogen can help to realise this transition of our energy system in multiple sectors from energy production storage and distribution to end-uses in transport industry heating and others.<br/><br/>CLEAN HYDROGEN TECHNOLOGIES CAN AND WILL REPLACE<br/>not just fossil-based hydrogen in current (industrial) uses but also other fossil-based energies such as petrol diesel and hydrocarbon fuels in the transport sector coal /coke in the steel sector natural gas in the heating sector and other polluting and emitting fuels and feedstocks. <br/><br/>WE ARE TALKING ABOUT A SYSTEMIC CHANGE.<br/>The use of clean hydrogen needs adaptations in production schemes in the infrastructure and in the deployment of hydrogen by the end users. This cannot – of course –be done in a day. Yet we should not wait for the implementation of the different hydrogen strategies on private municipal regional national or European level until other geographies worldwide race ahead.<br/><br/>
Evaluation of Hydrogen, Propane and Methane-air Detonations Instability and Detonability
Sep 2013
Publication
In this paper the detonation propensity of different compositions of mixtures of hydrogen propane and methane with air has been evaluated over a wide range of compositions. We supplement the conventional calculations of the induction delay with calculations of the characteristic acceleration parameter recently suggested by Radulescu Sharpeand Bradley(RSB) to characterize the instability of detonations. While it is well established that the ignition delay provides a good measure for detonability the RSB acceleration or its non-dimensionalform provides a further discriminant between mixtures with similar ignition delays. The present assessment of detonability reveals that while a stoichiometric mixture of hydrogen-air has an ignition delay one and two orders of magnitude shorter than respectively propane and methane hydrogen also has a parameter smaller by respectively one and two orders of magnitude. Its smaller propensity for instability is reflected by an RSB acceleration parameter similar to the two hydrocarbons. The predictions however indicate that lean hydrogen mixtures are likely to be much more unstable than stoichiometric ones. The relation between the parameter and potential to amplify an unstable transverse wave structure has been further determined through numerical simulation of decaying reactive Taylor-Sedov blast waves. Using a simplified two-step model calibrated for these fuels we show that methane mixtures develop cellular structures more readily than propane and hydrogen when observed on similar induction time scales. Future work should be devoted towards a quantitative inclusion of the RSB parameter in assessing the detonability of a given mixture.
Hydrogen: The Future Energy Carrier
Jul 2010
Publication
Since the beginning of the twenty-first century the limitations of the fossil age with regard to the continuing growth of energy demand the peaking mining rate of oil the growing impact of CO2 emissions on the environment and the dependency of the economy in the industrialized world on the availability of fossil fuels became very obvious. A major change in the energy economy from fossil energy carriers to renewable energy fluxes is necessary. The main challenge is to efficiently convert renewable energy into electricity and the storage of electricity or the production of a synthetic fuel. Hydrogen is produced from water by electricity through an electrolyser. The storage of hydrogen in its molecular or atomic form is a materials challenge. Some hydrides are known to exhibit a hydrogen density comparable to oil; however these hydrides require a sophisticated storage system. The system energy density is significantly smaller than the energy density of fossil fuels. An interesting alternative to the direct storage of hydrogen are synthetic hydrocarbons produced from hydrogen and CO2 extracted from the atmosphere. They are CO2 neutral and stored like fossil fuels. Conventional combustion engines and turbines can be used in order to convert the stored energy into work and heat.
Link to document download on Royal Society Website
Link to document download on Royal Society Website
Polymer Electrolyte Membrane Fuel Cell and Hydrogen Station Networks for Automobiles: Status, Technology, and Perspectives
Feb 2021
Publication
The U.S. transportation sector accounts for 37% of total energy consumption. Automobiles are a primary application of polymer electrolyte membrane (PEM) fuel cells which operate under low temperature and high efficiency to reduce fossil fuel consumption and CO2 emissions. Using hydrogen fuel PEM fuel cells can reach a practical efficiency as high as 65% with water as the only byproduct. Almost all the major automakers are involved in fuel cell electric vehicle (FCEV) development. Toyota and Hyundai introduced FCEVs (the Mirai and NEXO respectively) to consumers in recent years with a driving range between 312 and 402 miles and cold-start capacity from -30 °C. About 50 fuel cell electric buses (FCEB) are operating in California and most of them have achieved the durability target i.e. 25000 h in real-world driving conditions. As of September 2020 over 8573 FCEVs have been sold or leased in the U.S. More than 3521 FCEVs and 22 FCEBs have been sold or leased in Japan as of September 2019. An extensive hydrogen station network is required for the successful deployment of FCEVs and FCEBs. The U.S. currently has over 44 hydrogen fuelling stations (HFSs) nearly all located in California. Europe has over 139 HFSs with ~1500 more stations planned by 2025. This review has three primary objectives: 1) to present the current status of FCEV/FCEB commercialization and HFS development; 2) to describe the PEM fuel cell research/development in automobile applications and the significance of HFS networks; and 3) to outline major challenges and opportunities.
Hydrogen Production from Natural Gas and Biomethane with Carbon Capture and Storage – A Techno-environmental Analysis
Mar 2020
Publication
This study presents an integrated techno-environmental assessment of hydrogen production from natural gas and biomethane combined with CO2 capture and storage (CCS). We have included steam methane reforming (SMR) and autothermal reforming (ATR) for syngas production. CO2 is captured from the syngas with a novel vacuum pressure swing adsorption (VPSA) process that combines hydrogen purification and CO2 separation in one cycle. As comparison we have included cases with conventional amine-based technology. We have extended standard attributional Life Cycle Assessment (LCA) following ISO standards with a detailed carbon balance of the biogas production process (via digestion) and its by-products. The results show that the life-cycle greenhouse gas (GHG) performance of the VPSA and amine-based CO2 capture technologies is very similar as a result of comparable energy consumption. The configuration with the highest plant-wide CO2 capture rate (almost 100% of produced CO2 captured) is autothermal reforming with a two-stage water-gas shift and VPSA CO2 capture – because the latter has an inherently high CO2 capture rate of 98% or more for the investigated syngas. Depending on the configuration the addition of CCS to natural gas reforming-based hydrogen production reduces its life-cycle Global Warming Potential by 45–85 percent while the other environmental life-cycle impacts slightly increase. This brings natural gas-based hydrogen on par with renewable electricity-based hydrogen regarding impacts on climate change. When biomethane is used instead of natural gas our study shows potential for net negative greenhouse gas emissions i.e. the net removal of CO2 over the life cycle of biowaste-based hydrogen production. In the special case where the biogas digestate is used as agricultural fertiliser and where a substantial amount of the carbon in the digestate remains in the soil the biowaste-based hydrogen reaches net-negative life cycle greenhouse gas emissions even without the application of CCS. Addition of CCS to biomethane-based hydrogen production leads to net-negative emissions in all investigated cases.
Sizing and Operation of a Pure Renewable Energy Based Electric System through Hydrogen
Nov 2021
Publication
Today in order to reduce the increase of the carbon dioxide emissions a large number of renewable energy resources (RES) are already implemented. Considering both the intermittency and uncertainty of the RES the energy storage system (ESS) is still needed for balancing and stabilizing the power system. Among different existing categories of ESS the hydrogen storage systems (HSS) have the highest energy density and are crucial for the RES integration. In addition RES are located in faraway regions and are often transmitted to the terminal consumption center through HVDC (high voltage direct current) due to its lower power loss. In this paper we present a power supply system that achieves low-carbon emissions through combined HSS and HVDC technology. First the combined HSS and the HVDC model are established. Secondly the rule-based strategy for operating the HSS microgrid is presented. Then an operating strategy for a typical network i.e. the pure RES generation station-HVDC transmission-microgrids is demonstrated. Finally the best sizing capacities for all components are found by the genetic algorithm. The results prove the efficiency of the presented sizing approach for a pure RES electric system.
Simulation of the Combustion Process for a CI Hydrogen Engine in an Argon-oxygen Atmosphere
May 2018
Publication
Hydrogen combustion in a noble gas atmosphere increases the combustion chamber temperature and the high specific heat ratio of the gas increases the thermal efficiency. In this study nitrogen was replaced by argon as the intake air along with pure oxygen to supply the engine. The objectives of this study are to determine the effects of different engine parameters on combustion and to analyse the emissions from hydrogen combustion in an argon-oxygen atmosphere. This research was conducted through simulations using CONVERGE 2.2.0 software and the YANMAR engine NF19SK model was used to determine the basic parameters. Changing the injector location affects the pressure and temperature in the combustion chamber. With increasing compression ratio the pressure increases more rapidly than the temperature. However combustion at high compression ratios decreases the maximum heat release rate and increases the combustion duration. Hydrogen combustion at ambient temperatures below 1200 K follows the Arrhenius equation.
The Ten Point Plan for a Green Industrial Revolution: Building Back Better, Supporting Green Jobs, and Accelerating Our Path to Net Zero
Nov 2020
Publication
As the world looks to recover from the impact of coronavirus on our lives livelihoods and economies we have the chance to build back better: to invest in making the UK a global leader in green technologies.
The plan focuses on increasing ambition in the following areas:
The plan focuses on increasing ambition in the following areas:
- advancing offshore wind
- driving the growth of low carbon hydrogen
- delivering new and advanced nuclear power
- accelerating the shift to zero emission vehicles
- green public transport cycling and walking
- ‘jet zero’ and green ships
- greener buildings
- investing in carbon capture usage and storage
- protecting our natural environment
- green finance and innovation
Rock Mass Response for Lined Rock Caverns Subjected to High Internal Gas Pressure
Mar 2022
Publication
The storage of hydrogen gas in underground lined rock caverns (LRCs) enables the implementation of the first fossil-free steelmaking process to meet the large demand for crude steel. Predicting the response of rock mass is important to ensure that gas leakage due to rupture of the steel lining does not occur. Analytical and numerical models can be used to estimate the rock mass response to high internal pressure; however the fitness of these models under different in situ stress conditions and cavern shapes has not been studied. In this paper the suitability of analytical and numerical models to estimate the maximum cavern wall tangential strain under high internal pressure is studied. The analytical model is derived in detail and finite element (FE) models considering both two-dimensional (2D) and three-dimensional (3D) geometries are presented. These models are verified with field measurements from the LRC in Skallen southwestern Sweden. The analytical model is inexpensive to implement and gives good results for isotropic in situ stress conditions and large cavern heights. For the case of anisotropic horizontal in situ stresses as the conditions in Skallen the 3D FE model is the best approach
Investigation of Hydrogen Embrittlement Susceptibility and Fracture Toughness Drop after in situ Hydrogen Cathodic Charging for an X65 Pipeline Steel
Apr 2020
Publication
The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader category of High Strength Low Alloy Steels (HSLA) and its microstructure consists of equiaxed ferritic and bainitic grains with a low volume fraction of degenerated pearlite islands. The studied X65 steel specimens were extracted from pipes with 19.15 mm wall thickness. The fracture toughness parameters were determined after imposing the fatigue pre-cracked specimens on air on a specific electrolytic cell under a slow strain rate bending loading (according to ASTM G147-98 BS7448 and ISO12135 standards). Concerning the results of this study in the first phase the hydrogen cations’ penetration depth the diffusion coefficient of molecular and atomic hydrogen and the surficial density of blisters were determined. Next the characteristic parameters related to fracture toughness (such as J KQ CTODel CTODpl) were calculated by the aid of the Force-Crack Mouth Open Displacement curves and the relevant analytical equations.
Hydrogen Storage: Recent Improvements and Industrial Perspectives
Sep 2017
Publication
Efficient storage of hydrogen is crucial for the success of hydrogen energy markets (early markets as well as transportation market). Hydrogen can be stored either as a compressed gas a refrigerated liquefied gas a cryo-compressed gas or in hydrides. This paper gives an overview of hydrogen storage technologies and details the specific issues and constraints related to the materials behaviour in hydrogen and conditions representative of hydrogen energy uses. It is indeed essential for the development of applications requiring long-term performance to have good understanding of long-term behaviour of the materials of the storage device and its components under operational loads.
World Energy Issues Monitor 2021: Humanising Energy
Mar 2021
Publication
Based on data collection carried out between October and December 2020 and the testing of emerging findings with the Council’s regional communities during a series of digital workshops held during February 2021 the report has shown
- Energy leaders’ perceptions of areas of risk opportunity and priorities for action have radically changed over the last 12 months. While economic turbulence stemming from the ongoing reverberations of COVID-19 is the biggest area of uncertainty with uncertainty around economic trends increasing by a third over the previous year there is also a growing focus on the social agenda associated with a faster paced energy transition.
- There is an increased awareness of the societal and human impact of both recovery and the wider energy transition. The issue of energy affordability has rapidly risen up the industry’s priority list with its impact and uncertainty perceived 20% larger than a year ago. Energy affordability affects society across all geographies ranging from city dwellers in developed countries to the rural poor in developing ones.
- The emergence of a new generation of digital energy services and energy entrepreneurs. Increasingly agile disruptive technologies have taken advantage of the social upheaval to gain market share at the expense of supply-centric energy solutions. There is a growing focus on customer-centric demand-driven solutions and fast changing patterns of global and local demand.
Pd Catalysts Supported on Bamboo-Like Nitrogen-Doped Carbon Nanotubes for Hydrogen Production
Mar 2021
Publication
Bamboo-like nitrogen-doped carbon nanotubes (N-CNTs) were used to synthesize supported palladium catalysts (0.2–2 wt.%) for hydrogen production via gas phase formic acid decomposition. The beneficial role of nitrogen centers of N-CNTs in the formation of active isolated palladium ions and dispersed palladium nanoparticles was demonstrated. It was shown that although the surface layers of N-CNTs are enriched with graphitic nitrogen palladium first interacts with accessible pyridinic centers of N-CNTs to form stable isolated palladium ions. The activity of Pd/N-CNTs catalysts is determined by the ionic capacity of N-CNTs and dispersion of metallic nanoparticles stabilized on the nitrogen centers. The maximum activity was observed for the 0.2% Pd/N-CNTs catalyst consisting of isolated palladium ions. A ten-fold increase in the concentration of supported palladium increased the contribution of metallic nanoparticles with a mean size of 1.3 nm and decreased the reaction rate by only a factor of 1.4.
Design of Experiment to Predict the Time Between Hydrogen Purges for an Air-breathing PEM Fuel Cell in Dead-end Mode in a Closed Environment
Feb 2021
Publication
Fuel cells are promising technologies for zero-emission energy conversion. They are used in several applications such as power plants cars and even submarines. Hydrogen supply is crucial for such systems and using Proton Exchange Membrane Fuel Cell in dead-end mode is a solution to save hydrogen. Since water and impurities accumulate inside the stack purging is necessary. However the importance of operating parameters is not well known for fuel cells working in closed environments. A Design of Experiment approach studying time between two purges and cell performance was conducted on an air-breathing stack in a closed environment. The most influential parameters on the time between two purges are the relative humidity and the current load. Convection in the closed environment can decrease the stability of the fuel cell. A linear model with interactions between these last three parameters was found to accurately describe the studied responses.
Global Energy Transformation: A Roadmap to 2050
Apr 2019
Publication
Dolf Gielen,
Ricardo Gorini,
Nicholas Wagner,
Rodrigo Leme,
Laura Gutierrez,
Gayathri Prakash,
Elisa Asmelash,
Luis Janeiro,
Giacomo Gallina,
Guilia Vale,
Lorenzo Sani,
Xavier Garcia Casals,
Rabia Ferroukhi,
Bishal Parajuli,
Jinlei Feng,
Eva Alexandri,
Unnada Chewpreecha,
Mary Goldman,
Sophie Heald,
Jon Stenning,
Hector Pollitt,
Celia García-Baños and
Michael Renner
Increased use of renewable energy combined with intensified electrification could prove decisive for the world to meet key climate goals by 2050. This study from the International Renewable Energy Agency (IRENA) highlights immediately deployable cost-effective options for countries to fulfil climate commitments and limit the rise of global temperatures. The envisaged energy transformation would also reduce net costs and bring significant socio-economic benefits such as increased economic growth job creation and overall welfare gains.<br/>The report – the second under the Global Energy Transformation banner – expands IRENA’s comprehensive roadmap which examines technology pathways and policy implications to ensure a sustainable energy future. Ramping up electricity to over half of the global energy mix (up from one-fifth currently) in combination with renewables would reduce the use of fossil fuels responsible for most greenhouse-gas emissions.
The Influence of Refractory Metals on the Hydrogen Storage Characteristics of FeTi-based Alloys Prepared by Suspended Droplet Alloying
Jun 2020
Publication
The influence of the addition of refractory metals (molybdenum and tantalum) on the hydrogenation properties of FeTi intermetallic phase-based alloys was investigated. The suspended droplet alloying technique was applied to fabricate FeTiTa-based and FeTiMo-based alloys. The phase composition and hydrogen storage properties of the samples were investigated. The samples modified with the refractory metals exhibited lower plateau pressures and lower hydrogen storage capacities than those of the FeTi reference sample due to solid solution formation. It was observed that the equilibrium pressures decreased with the amount of molybdenum which is in good agreement with the increase in the cell parameters of the TiFe phase. Suspended droplet alloying was found to be a practical method to fabricate alloys with refractory metal additions; however it is appropriate for screening samples with desired chemical and phase compositions rather than for manufacturing purposes.
Study on Hydrogen from Renewable Resources in the EU
Feb 2016
Publication
Hydrogen can be produced from a broad range of renewable energy sources acting as a unique energy hub providing low or zero emission energy to all energy consuming sectors. Technically and efficiently producing hydrogen from renewable sources is a key enabler for these developments.<br/>Traditionally hydrogen has been produced from fossil sources by steam methane reforming of natural gas. At present the technology of choice to produce renewable ‘green’ hydrogen is water electrolysis using renewable electricity. The FCH JU has been supporting research and development of electrolyser technology and application projects aiming to increase the energy efficiency of electrolytic hydrogen production from renewable sources and to reduce costs.<br/>This study complements these activities by focusing on renewable hydrogen generation other than electrolysis. In this report these alternative hydrogen generation technologies are described characterized by their technical capabilities maturity and economic performance and assessed for their future potential.<br/>A methodology has been devised to first identify and structure a set of relevant green hydrogen pathways (eleven pathways depicted in the figure below) analyse them at a level of detail allowing a selection of those technologies which fit into and promise early commercialization in the framework of FCH 2 JU’s funding program.<br/>These originally proposed eleven pathways use solar thermal energy sunlight or biomass as major energy input.
Potential for Hydrogen Production from Sustainable Biomass with Carbon Capture and Storage
Jan 2022
Publication
Low-carbon hydrogen is an essential element in the transition to net-zero emissions by 2050. Hydrogen production from biomass is a promising bio-energy with carbon capture and storage (BECCS) scheme that could produce low-carbon hydrogen and generate the carbon dioxide removal (CDR) envisioned to be required to offset hard-to-abate emissions. Here we design a BECCS supply chain for hydrogen production from biomass with carbon capture and storage and quantify at high spatial resolution the technical potential for hydrogen production and CDR in Europe. We consider sustainable biomass feedstocks that have minimal impacts on food security and biodiversity namely agricultural residues and waste. We find that this BECCS supply chain can produce up to 12.5 Mtons of H2 per year (currently ~10 Mtons of H2 per year are used in Europe) and remove up to 133 Mtons CO2 per year from the atmosphere (or 3% of European total greenhouse gas emissions). We then perform a geospatial analysis to quantify transportation distances between where biomass feedstocks are located and potential hydrogen users and find that 20% of hydrogen potential is located within 25 km from hard-toelectrify industries. We conclude that BECCS supply chains for hydrogen production from biomass represent an overlooked near-term opportunity to generate carbon dioxide removal and low-carbon hydrogen.
Hydrogen-air Vented Explosions- New Experimental Data
Sep 2013
Publication
The use of hydrogen as an energy carrier is a real perspective in Europe since a number of breakthroughs obtained in the last decades open the possibility to envision a deployment at the industrial scale if safety issues are duly accounted. However on this particular aspects experimental data are still lacking especially about the explosion dynamics in realistic dimensions. The purpose of this paper is to provide a set of totally new and well instrumented hydrogen - air vented explosions. Experiments were performed in a large explosion chamber within the scope of the DIMITRHY project (sponsored by the National French Agency for Research). The 4 m3 rectangular experimental chamber (2 m height 2 m width and 1 m depth) is equipped with transparent walls and is vented (0.25 and 0.5 m2 square vents).. Six pressure gauges were used to measure the overpressure evolution inside and outside the chamber. Six concentration gauges were used to control the hydrogen repartition in the vessel. The hydrogen-air cloud was seeded with micro particles of ammonium chloride to see the propagation of the flame the movement of the cloud inside and outside the chamber. The incidence of reactivity vent size ignition position and non homogenous repartition of hydrogen received a particular attention.
Durability of Anion Exchange Membrane Water Electrolyzers
Apr 2021
Publication
Interest in the low-cost production of clean hydrogen is growing. Anion exchange membrane water electrolyzers (AEMWEs) are considered one of the most promising sustainable hydrogen production technologies because of their ability to split water using platinum group metal-free catalysts less expensive anode flow fields and bipolar plates. Critical to the realization of AEMWEs is understanding the durability-limiting factors that restrict the long-term use of these devices. This article presents both durability-limiting factors and mitigation strategies for AEMWEs under three operation modes i.e. pure water-fed (no liquid electrolyte) concentrated KOH-fed and 1 wt% K2CO3-fed operating at a differential pressure of 100 psi. We examine extended-term behaviors of AEMWEs at the single-cell level and connect their behavior with the electrochemical chemical and mechanical instability of single-cell components. Finally we discuss the pros and cons of AEMWEs under these operation modes and provide direction for long-lasting AEMWEs with highly efficient hydrogen production capabilities.
Seasonal and Multi-Seasonal Energy Storage by Power-to-Methane Technology
Jun 2021
Publication
The time-range of applicability of various energy-storage technologies are limited by self-discharge and other inevitable losses. While batteries and hydrogen are useful for storage in a time-span ranging from hours to several days or even weeks for seasonal or multi-seasonal storage only some traditional and quite costly methods can be used (like pumped-storage plants Compressed Air Energy Storage or energy tower). In this paper we aim to show that while the efficiency of energy recovery of Power-to-Methane technology is lower than for several other methods due to the low self-discharge and negligible standby losses it can be a suitable and cost-effective solution for seasonal and multi-seasonal energy storage.
Hydrogen Explosion Hazards Limitation in Battery Rooms with Different Ventilation Systems
Sep 2019
Publication
When charging most types of industrial lead-acid batteries hydrogen gas is emitted. A large number of batteries especially in relatively small areas/enclosures and in the absence of an adequate ventilation system may create an explosion hazard. This paper describes full scale tests in confined space which demonstrate conditions that can occur in a battery room in the event of a ventilation system breakdown. Over the course of the tests full scale hydrogen emission experiments were performed to study emission time and flammable cloud formation according to the assumed emission velocity. On this basis the characteristics of dispersion of hydrogen in the battery room were obtained. The CFD model Fire Dynamic Simulator (NIST) was used for confirmation that the lack of ventilation in a battery room can be the cause of an explosive atmosphere developing and leading to a potential huge explosive hazard. It was demonstrated that different ventilation systems provide battery rooms with varying efficiencies of hydrogen removal. The most effective type appeared to be natural ventilation which proved more effective than mechanical means.
Future Cost and Performance of Water Electrolysis: An Expert Elicitation Study
Nov 2017
Publication
The need for energy storage to balance intermittent and inflexible electricity supply with demand is driving interest in conversion of renewable electricity via electrolysis into a storable gas. But high capital cost and uncertainty regarding future cost and performance improvements are barriers to investment in water electrolysis. Expert elicitations can support decision-making when data are sparse and their future development uncertain. Therefore this study presents expert views on future capital cost lifetime and efficiency for three electrolysis technologies: alkaline (AEC) proton exchange membrane (PEMEC) and solid oxide electrolysis cell (SOEC). Experts estimate that increased R&D funding can reduce capital costs by 0–24% while production scale-up alone has an impact of 17–30%. System lifetimes may converge at around 60000–90000 h and efficiency improvements will be negligible. In addition to innovations on the cell-level experts highlight improved production methods to automate manufacturing and produce higher quality components. Research into SOECs with lower electrode polarisation resistance or zero-gap AECs could undermine the projected dominance of PEMEC systems. This study thereby reduces barriers to investment in water electrolysis and shows how expert elicitations can help guide near-term investment policy and research efforts to support the development of electrolysis for low-carbon energy systems.
Role of Hydrogen in a Low-Carbon Electric Power System: A Case Study
Jan 2021
Publication
The European Union set a 2050 decarbonization target in the Paris Agreement to reduce carbon emissions by 90–95% relative to 1990 emission levels. The path toward achieving those deep decarbonization targets can take various shapes but will surely include a portfolio of economy-wide low-carbon energy technologies/options. The growth of the intermittent renewable power sources in the grid mix has helped reduce the carbon footprint of the electric power sector. Under the need for decarbonizing the electric power sector we simulated a low-carbon power system. We investigated the role of hydrogen for future electric power systems under current cost projections. The model optimizes the power generation mix economically for a given carbon constraint. The generation mix consists of intermittent renewable power sources (solar and wind) and dispatchable gas turbine and combined cycle units fuelled by natural gas with carbon capture and sequestration as well as hydrogen. We created several scenarios with battery storage options pumped hydro hydrogen storage and demand-side response (DSR). The results show that energy storage replaces power generation and pumped hydro entirely replaces battery storage under given conditions. The availability of pumped hydro storage and demand-side response reduced the total cost as well as the combination of solar photovoltaic and pumped hydro storage. Demand-side response reduces relatively costly dispatchable power generation reduces annual power generation halves the shadow carbon price and is a viable alternative to energy storage. The carbon constrain defines the generation mix and initializes the integration of hydrogen (H2). Although the model rates power to gas with hydrogen as not economically viable in this power system under the given conditions and assumptions hydrogen is important for hard-to-abate sectors and enables sector coupling in a real energy system. This study discusses the potential for hydrogen beyond this model approach and shows the differences between cost optimization models and real-world feasibility.
Transport Energy Air Pollution Model
May 2019
Publication
The transport sector remains at the centre of any debates around energy conservation exaggerated by the stubborn and overwhelming reliance on fossil fuels by its motorised forms whether passenger and freight road rail sea and air.<br/>The very slow transition to alternative fuel sources to date has resulted in this sector being increasingly and convincingly held responsible for the likely failure of individual countries including the UK to meet their obligations under consecutive international climate change agreements.<br/>Electrification of transport is largely expected to take us down the path to a ‘zero carbon future’ (CCC 2019; DfT 2018). But there are serious concerns about future technology performance availability costs and uptake by consumers and businesses. There are also concerns about the increasing gap between lab and ‘real world’ performance of energy use carbon and air pollution emissions. Recently the role of consumer ‘lifestyles’ has increased in prominence (e.g. IPCC 2018) but as yet has not been taken seriously by the DfT BEIS or even the CCC (2019).
The Effect of Graphite Size on Hydrogen Absorption and Tensile Properties of Ferritic Ductile Cast Iron
Jun 2019
Publication
Ductile cast iron (DCI) is one of prospective materials used for the hydrogen equipment because of low-cost good workability and formability. The wide range of mechanical properties of DCI is obtained by controlling microstructural factors such as graphite size volume fraction of graphite matrix structure and so on. Therefore it is important to find out an optimal microstructural condition that is less susceptible to hydrogen embrittlement. In this study the effects of graphite size on the hydrogen absorption capability and the hydrogen-induced ductility loss of ferritic DCI were investigated.<br/>Several kinds of ferritic DCIs with a different graphite diameter of about 10 µm - 30 µm were used for the tensile test and the hydrogen content measurement. Hydrogen charging was performed prior to the tensile test by exposing a specimen to high-pressure hydrogen gas. Then the tensile test was performed in air at room temperature. The hydrogen content of a specimen was measured by a thermal desorption analyzer.<br/>It was found that the amount of hydrogen stored in DCI was dependent on the graphite size. As the graphite diameter increased the hydrogen content sharply increased at a certain graphite diameter and then it became nearly constant irrespective of increase in graphite diameter. In other words there was the critical graphite diameter that significantly changed the hydrogen absorption capability. The ductility was decreased by hydrogen and the hydrogen-induced ductility loss was dependent on the hydrogen content. Therefore the hydrogen embrittlement of DCI became remarkable when the graphite size was larger than the critical value.
Fuel Cell Codes and Standards Resource
Jan 2021
Publication
Although hydrogen has been used in industry for decades its use as a fuel for vehicles or stationary power generation in consumer environments is relatively new. As such hydrogen and fuel cell codes and standards are in various stages of development. Industry manufacturers the government and other safety experts are working with codes and standards development organizations to prepare review and promulgate technically-sound codes and standards for hydrogen and fuel cell technologies and systems.
Codes and standards are being adopted revised or developed for vehicles; fuel delivery and storage; fueling service and parking facilities; and vehicle fueling interfaces. Codes and standards are also being adopted revised or developed for stationary and portable fuel cells and interfaces as well as hydrogen generators. A list of current of international codes and standards is available on the Fuel Cells Codes and Standards Resource.
Link to website
Codes and standards are being adopted revised or developed for vehicles; fuel delivery and storage; fueling service and parking facilities; and vehicle fueling interfaces. Codes and standards are also being adopted revised or developed for stationary and portable fuel cells and interfaces as well as hydrogen generators. A list of current of international codes and standards is available on the Fuel Cells Codes and Standards Resource.
Link to website
Potential Economic Impacts of the HyNet North West Project
Jan 2018
Publication
The objective of the analysis is to provide a robust assessment of the economic impact of HyNet NW over the period to 2050 across both the North West of England and the UK as a whole. Impact is assessed through modelling of direct indirect and induced effect frameworks:
Consideration is also given to the potential impacts of inward investment attracted to the North West/UK in the wake of the Project.
- Direct effects – activities that directly accrue due to the construction and operation of the facilities;
- Indirect effects – the purchase of goods and services to facilitate construction/operation; and
- Induced effects – spending of wages and salaries generated directly and indirectly through construction and operation.
Consideration is also given to the potential impacts of inward investment attracted to the North West/UK in the wake of the Project.
Synthesis and Characterisation of Platinum-cobalt-manganese Ternary Alloy Catalysts Supported on Carbon Nanofibers: An Alternative Catalyst for Hydrogen Evolution Reaction
Mar 2020
Publication
A systematic method for obtaining a novel electrode structure based on PtCoMn ternary alloy catalyst supported on graphitic carbon nanofibers (CNF) for hydrogen evolution reaction (HER) in acidic media is proposed. Ternary alloy nanoparticles (Co0.6Mn0.4 Pt) with a mean crystallite diameter under 10 nm were electrodeposited onto a graphitic support material using a two-step pulsed deposition technique. Initially a surface functionalisation of the carbon nanofibers is performed with the aid of oxygen plasma. Subsequently a short galvanostatic pulse electrodeposition technique is applied. It has been demonstrated that if pulsing current is employed compositionally controlled PtCoMn catalysts can be achieved. Variations of metal concentration ratios in the electrolyte and main deposition parameters such as current density and pulse shape led to electrodes with relevant catalytic activity towards HER. The samples were further characterised using several physico-chemical methods to reveal their morphology structure chemical and electrochemical properties. X-ray diffraction confirms the PtCoMn alloy formation on the graphitic support and energy dispersive X-ray spectroscopy highlights the presence of the three metallic components from the alloy structure. The preliminary tests regarding the electrocatalytic activity of the developed electrodes display promising results compared to commercial Pt/C catalysts. The PtCoMn/CNF electrode exhibits a decrease in hydrogen evolution overpotential of about 250 mV at 40 mA cm−2 in acidic solution (0.5 M H2SO4) when compared to similar platinum based electrodes (Pt/CNF) and a Tafel slope of around 120 mV dec−1 indicating that HER takes place under the Volmer-Heyrovsky mechanismm
Cryogenic Hydrogen Jets: Flammable Envelope Size and Hazard Distances for Jet Fire
Sep 2019
Publication
Engineering tools for calculation of hazard distances for cryogenic hydrogen jets are currently missing. This study aims at the development of validated correlations for calculation of hazard distances for cryogenic unignited releases and jet fires. The experiments performed by Sandia National Laboratories (SNL) on jets from storage temperature in the range 46-295 K and pressure up to 6 bar abs are used to expand the validation domain of the correlations. The Ulster’s under-expanded jet theory is applied to calculate parameters at the real nozzle exit. The similarity law for concentration decay in momentum-dominated jets is shown to be capable to reproduce experimental data of SNL on 9 unignited cryogenic releases. The accuracy of the similarity law to predict experimentally measured axial concentration decay improves with the increase of the release diameter. This is thought due to decrease of the effect of friction and minor losses for large release orifices. The dimensionless flame length correlation is applied to analyse 30 cryogenic jet fire tests. The deviation of calculated flame length from measured in experiments is mostly within acceptable accuracy for engineering correlations 20% similarly to releases from storage and equipment at atmospheric temperatures. It is concluded that the similarity law and the dimensionless flame correlation can be used as universal engineering tools for calculation of hazard distances for hydrogen releases at any storage temperature including cryogenic.
Fuel Cells and Hydrogen: Joint Undertaking Programme Review 2019 Final Report
Nov 2020
Publication
The 2019 Programme Review Report presents the findings of a review into activities supported by the FCH 2 JU under the EU’s Seventh Framework Programme and Horizon 2020 by the European Commission’s Joint Research Centre (JRC ). It pays particular attention to the added value effectiveness and techno-economic efficiency of FCH 2 JU projects assigned to six review panels under two main pillars:<br/>Transport and Energy (TRANSPORT: a.trials and deployment of fuel cell applications and b.the next generation of products) (ENERGY: a.trials and deployment of fuel cell applications b.next generation of products and c.hydrogen for sectoral integration)<br/>Support for market uptake (cross-cutting activities such as standards and consumer awareness)<br/>This report covers all 81 projects that were ongoing for any time between April and October 2018 and assesses the strengths and accomplishments of each panel and areas that would benefit from further attention.
Modeling and Economic Operation of Energy Hub Considering Energy Market Price and Demand
Feb 2022
Publication
This paper discusses the economic operation strategy of the energy hub which is being established in South Korea. The energy hub has five energy conversion devices: a turbo expander generator a normal fuel cell a fuel cell with a hydrogen outlet a small-scale combined heat and power device and a photovoltaic device. We are developing the most economically beneficial operation strategy for the operators who own the hub without making any systematic improvements to the energy market. First sixteen conversion efficiency matrices can be achieved by turning each device (except the PV) on or off. Next even the same energy must be divided into different energy flows according to price. The energy flow is controlled to obtain the maximum profit considering the internal load of the energy hub and the price fluctuations of the energy market. Using our operating strategy the return on investment period is approximately 9.9 years which is three years shorter than that without the operating strategy.
Complex Methods of Estimation Technological Strength of Welded Joints in Welding at Low Temperatures
Feb 2021
Publication
A comprehensive methodology for estimating the technological strength of welded joints are developed based on parameters reflecting the welding technology weldability hydrogen force and deformation conditions for welding and other informative parameters that correlate with the characteristics of the welded joint as well as improving existing methods for estimating the technological strength of welded joints connections through the introduction of modern equipment and non-destructive testing systems. It has been established that the proposed comprehensive estimation methodology will allow reaching a new qualitative level in assessing the technological strength of a welded joint using modern equipment and measuring instruments. According to the results of the experimental work it was found that when welding at low temperatures the increase in the probability of the formation and development of cold cracks is mainly determined by the critical content of diffusible hydrogen in the weld metal depending on the structural and force parameters of the welded joints.
Integration of Water Electrolysis for Fossil-free Steel Production
Sep 2020
Publication
This study investigates the integration of water electrolysis technologies in fossil-free steelmaking via the direct reduction of iron ore followed by processing in an electric arc furnace (EAF). Hydrogen (H2) production via low or high temperature electrolysis (LTE and HTE) is considered for the production of carbon-free direct reduced iron (DRI). The introduction of carbon into the DRI reduces the electricity demand of the EAF. Such carburization can be achieved by introducing carbon monoxide (CO) into the direct reduction process. Therefore the production of mixtures of H2 and CO using either a combination of LTE coupled with a reverse water-gas shift reactor (rWGS-LTE) or high-temperature co-electrolysis (HTCE) was also investigated. The results show that HTE has the potential to reduce the specific electricity consumption (SEC) of liquid steel (LS) production by 21% compared to the LTE case. Nevertheless due to the high investment cost of HTE units both routes reach similar LS production costs of approximately 400 €/tonne LS. However if future investment cost targets for HTE units are reached a production cost of 301 €/tonne LS is attainable under the conditions given in this study. For the production of DRI containing carbon a higher SEC is calculated for the LTE-rWGS system compared to HTCE (4.80 vs. 3.07 MWh/tonne LS). Although the use of HTCE or LTE-rWGS leads to similar LS production costs future cost reduction of HTCE could result in a 10% reduction in LS production cost (418 vs. 375 €/tonne LS). We show that the use of HTE either for the production of pure H2 or H2 and CO mixtures may be advantageous compared to the use of LTE in H2 -based steelmaking although results are sensitive to electrolyzer investment costs efficiencies and electricity prices.
People’s Attitude to Energy from Hydrogen—From the Point of View of Modern Energy Technologies and Social Responsibility
Dec 2020
Publication
Energy from hydrogen is an appropriate technological choice in the context of sustainable development. The opportunities offered by the use of energy from hydrogen also represent a significant challenge for mobile technologies and daily life. Nevertheless despite a significant amount of research and information regarding the benefits of hydrogen energy it creates considerable controversy in many countries. Globally there is a lack of understanding about the production process of hydrogen energy and the benefits it provides which leads to concerns regarding the consistency of its use. In this study an original questionnaire was used as a research tool to determine the opinions of inhabitants of countries in which hydrogen energy is underutilized and where the infrastructure for hydrogen energy is underdeveloped. Respondents presented their attitude to ecology and indicated their knowledge regarding the operation of hydrogen energy and the use of hydrogen fuel. The results indicate that society is not convinced that the safety levels for energy derived from hydrogen are adequate. It can be concluded that knowledge about hydrogen as an energy source and the production safety and storage methods of hydrogen is very low. Negative attitudes to hydrogen energy can be an important barrier in the development of this energy in many countries.
Methodology for Efficient Parametrisation of Electrochemical PEMFC Model for Virtual Observers: Model Based Optimal Design of Experiments Supported by Parameter Sensitivity Analysis
Nov 2020
Publication
Determination of the optimal design of experiments that enables efficient parametrisation of fuel cell (FC) model with a minimum parametrisation data-set is one of the key prerequisites for minimizing costs and effort of the parametrisation procedure. To efficiently tackle this challenge the paper present an innovative methodology based on the electrochemical FC model parameter sensitivity analysis and application of D-optimal design plan. Relying on this consistent methodological basis the paper answers fundamental questions: a) on a minimum required data-set to optimally parametrise the FC model and b) on the impact of reduced space of operational points on identifiability of individual calibration parameters. Results reveal that application of D-optimal DoE enables enhancement of calibration parameters information resulting in up to order of magnitude lower relative standard errors on smaller data-sets. In addition it was shown that increased information and thus identifiability inherently leads to improved robustness of the FC electrochemical model.
Dual Z-scheme Charge Transfer in TiO2–Ag–Cu2O Composite for Enhanced Photocatalytic Hydrogen Generation
Apr 2015
Publication
Photocatalytic hydrogen generation is one of the most promising solutions to convert solar power into green chemical energy. In this work a multi-component TiO2–Ag–Cu2O composite was obtained through simple impregnation-calcination of Cu2O and subsequent photodeposition of Ag onto electrospun TiO2 nanotubes. The resulting TiO2–Ag–Cu2O photocatalyst exhibits excellent photocatalytic H2 evolution activity due to the synergetic effect of Ag and Cu2O on electrospun TiO2nanotubes. A dual Z-scheme charge transfer pathway for photocatalytic reactions over TiO2–Ag–Cu2O composite was proposed and discussed. This work provides a prototype for designing Z-scheme photocatalyst with Ag as an electron mediator.
Renewable Energy Market Analysis: Africa and its Regions
Jan 2022
Publication
An energy system centred on renewable energy can help resolve many of Africa’s social economic health and environmental challenges. A profound energy transition is not only feasible it is essential for a climate-safe future in which sustainable development prerogatives are met. Renewables are key to overcoming energy poverty providing needed energy services without damaging human health or ecosystems and enabling a transformation of economies in support of development and industrialisation.
Africa is extraordinarily diverse and no single approach will advance its energy future. But efforts must be made to build modern resilient and sustainable energy systems across the continent to avoid trapping economies and societies in increasingly obsolete energy systems that burden them with stranded assets and limited economic prospects.
This report from the International Renewable Energy Agency (IRENA) sets out the opportunities at hand while also acknowledging the challenges Africa faces. It lays out a pathway to a renewables-based energy system and shows that the transition promises substantial gains in GDP employment and human welfare in each region of the continent.
Among the findings:
A large part of Africa has so far been left out of the energy transition:
Africa is extraordinarily diverse and no single approach will advance its energy future. But efforts must be made to build modern resilient and sustainable energy systems across the continent to avoid trapping economies and societies in increasingly obsolete energy systems that burden them with stranded assets and limited economic prospects.
This report from the International Renewable Energy Agency (IRENA) sets out the opportunities at hand while also acknowledging the challenges Africa faces. It lays out a pathway to a renewables-based energy system and shows that the transition promises substantial gains in GDP employment and human welfare in each region of the continent.
Among the findings:
A large part of Africa has so far been left out of the energy transition:
- Only 2% of global investments in renewable energy in the last two decades were made in Africa with significant regional disparities
- Less than 3% of global renewables jobs are in Africa
- In Sub-Saharan Africa electrification rate was static at 46% in 2019 with 906 million people still lacking access to clean cooking fuels and technologies
- Africa has vast resource potential in wind solar hydro and geothermal energy and falling costs are increasingly bringing renewables within reach
- Central and Southern Africa have abundant mineral resources essential to the production of electric batteries wind turbines and other low-carbon technologies
- Renewable energy deployment has grown in the last decade with more than 26 GW of renewables-based generation capacity added. The largest additions were in solar energy
- Average annual investments in renewable energy grew ten-fold from less than USD 0.5 billion in the 2000-2009 period to USD 5 billion in 2010-2020
- Distributed renewable energy solutions including stand-alone systems and mini-grids are playing a steadily growing role in expanding electricity access in off-grid areas and strengthening supply in already connected areas
- The energy transition under IRENA’s 1.5°C Scenario pathway predicts 6.4% higher GDP 3.5% higher economy-wide jobs and a 25.4% higher welfare index than that realised under current plans on average up to 2050
- Jobs created in the renewable energy transition will outweigh those lost by moving away from traditional energy. Every million U.S. dollars invested in renewables between 2020 – 2050 would create at least 26 job-years; for every million invested in energy efficiency at least 22 job-years would be created annually; for energy flexibility the figure is 18
- A comprehensive policy package that combines the pursuit of climate and environmental goals; economic development and jobs creation; and social equity and welfare for society as a whole
- Strong institutions international co-operation (including South- South co-operation) and considerable co-ordination at the regional level
Accumulation of Hydrogen Released into a Vented Enclosure - Experimental Results
Sep 2013
Publication
This paper reports experimental results from a series of experiments in which gaseous hydrogen was released into a 31 m3 enclosure and the hydrogen concentrations at a number of points within the enclosure were monitored to assess whether hydrogen accumulation occurred and whether a homogeneous or stratified mixture was formed. The enclosure was located in the open air and therefore subject to realistic and therefore variable wind conditions. The hydrogen release rate and the passive vent arrangements were varied. The experiments were carried out as part of the EU Hyindoor Project.
The Pressure Peaking Phenomenon: Validation for Unignited Releases in Laboratory-scale Enclosure
Oct 2015
Publication
This study is aimed at the validation of the pressure peaking phenomenon against laboratory-scale experiments. The phenomenon was discovered recently as a result of analytical and numerical studies performed at Ulster University. The phenomenon is characterized by the existence of a peak on the overpressure transient in an enclosure with vent(s) at some conditions. The peak overpressure can significantly exceed the steady-state pressure and jeopardise a civil structure integrity causing serious life safety and property protection problems. However the experimental validation of the phenomenon was absent until recently. The validation experiments were performed at Karlsruhe Institute of Technology within the framework of the HyIndoor project. Tests were carried out with release of three different gases (air helium and hydrogen) within a laboratory-scale enclosure of about 1 m3 volume with a vent of comparatively small size. The model of pressure peaking phenomenon reproduced closely the experimental pressure dynamics within the enclosure for all three used gases. The prediction of pressure peaking phenomenon consists of two steps which are explained in detail. Examples of calculation for typical hydrogen applications are presented.
Emissions control and performance evaluation of spark ignition engine with oxy-hydrogen blending
Mar 2018
Publication
Fast depletion of fossil fuels and their detrimental effect to the environment is demanding an urgent need of alternative fuels for meeting sustainable energy demand with minimum environmental impact. Expert studies indicate hydrogen is one of the most promising energy carriers for the future due to its superior combustion qualities and availability. The use of hydrogen in spark ignition internal combustion engine may be part of an integrated solution to the problem of depletion of fossil fuels and pollution of the environment. The broader flammability limits and fast flame propagation velocity of hydrogen ensures complete combustion of fuel and allows engine to be operated at lean ranges. Lean burn operation comparatively maintains NOx CO and HC emissions at a very low level. In the present work oxyhydrogen (HHO) gas is produced in leak proof plexiglass reactor by electrolysis of water using potassium hydroxide as electrolyte. The HHO gas generator is attached to a spark ignition engine currently operating on the road without any modifications of the engine. The HHO gas produced is then added to the air which is being drawn into the engine. Experiments were conducted on a 4-stroke single cylinder natural air cooled spark ignition engine to determine total fuel consumption specific fuel consumption air fuel ratio brake power and brake thermal efficiency and emissions CO CO2 O2 NOx HC at different loads with and without addition of HHO gas to gasoline for lower speeds ranging from 700 rpm to 1500 rpm. Also mileage tests were conducted to find the speed at which the fuel consumption is optimum.
Hydrogen Station Technology Development Review Through Patent Analysis
May 2018
Publication
This study is a review of hydrogen station patents using the Derwent Innovation system and also a secondary screening. This was undertaken by the researchers to better understand and identify hydrogen station trends. The review focuses on analyzing the developing trends of patent technologies associated with a hydrogen station. The results of the review indicated that the countries with the major distribution of patents were Japan China the USA and Europe. Japan is leading the developmental trajectory of hydrogen stations. The results of the analysis found the leading developers of these patented technologies are Kobe Steel Nippon Oil Toyota and Honda. Other active patent developers analyzed include Linde Hyundai and Texaco. The review concludes with a suggestion that using a patent analysis methodology is a good starting point to identify evaluate and measure the trend in hydrogen station commercial development.
3D Risk Management for Hydrogen Installations (HY3DRM)
Oct 2015
Publication
This paper introduces the 3D risk management (3DRM) concept with particular emphasis on hydrogen installations (Hy3DRM). The 3DRM framework entails an integrated solution for risk management that combines a detailed site-specific 3D geometry model a computational fluid dynamics (CFD) tool for simulating flow-related accident scenarios methodology for frequency analysis and quantitative risk assessment (QRA) and state-of-the-art visualization techniques for risk communication and decision support. In order to reduce calculation time and to cover escalating accident scenarios involving structural collapse and projectiles the CFD-based consequence analysis can be complemented with empirical engineering models reduced order models or finite element analysis (FEA). The paper outlines the background for 3DRM and presents a proof-of-concept risk assessment for a hypothetical hydrogen filling station. The prototype focuses on dispersion fire and explosion scenarios resulting from loss of containment of gaseous hydrogen. The approach adopted here combines consequence assessments obtained with the CFD tool FLACS-Hydrogen from Gexcon and event frequencies estimated with the Hydrogen Risk Assessment Models (HyRAM) tool from Sandia to generate 3D risk contours for explosion pressure and radiation loads. For a given population density and set of harm criteria it is straightforward to extend the analysis to include personnel risk as well as risk-based design such as detector optimization. The discussion outlines main challenges and inherent limitations of the 3DRM concept as well as prospects for further development towards a fully integrated framework for risk management in organizations.
Oxford Energy Podcast – The Role of Ammonia and Hydrogen in Meeting International Maritime Organisation Targets for Decarbonising Shipping
Jul 2021
Publication
The world’s shipping fleet is responsible for approximately 0.9 Gt of CO2 emissions annually around 2.9 per cent of the world’s man-made emissions. Under an IEA ‘business as usual’ scenario this is forecast to rise to almost 1.7 Gt per year by 2050. The industry’s principal regulatory body the International Maritime Organization (IMO) aims to reduce world shipping’s greenhouse gas emissions in line with the 2015 Paris Agreement targeting a 50 per cent reduction compared with 2008 levels by 2050. The cost of achieving these emission targets however is about $1 trillion and will require focus from regulators operators and end consumers who in the end will have to pay. In this podcast David Ledesma talks to Bruce Moore Howe Robinson Partners to discuss these issues and ask in such a fragmented industry what the immediate priorities for the marine sector must be and how can it bring about a mix of commercial incentives and regulatory change that result in tangible emissions reductions.
The podcast can be found on their website
The podcast can be found on their website
Application of Natural Ventilation Engineering Models to Hydrogen Build Up in Confined Zones
Sep 2013
Publication
Correlative engineering models (Linden 1994) are compared to recent published (Cariteau et al. (2009) Pitts et al. (2009) Barley and Gawlick (2009) Swain et al. (1999) Merilo et al. (2010)) and unpublished (CEA experiments in a 1 m3 with two openings) experimental hydrogen or helium distribution in enclosures (with one and two openings). The modelling-experiments comparison is carried out in transient and in steady state conditions. On this basis recommendations and limits of use of these models are proposed.
FCH Programme Review Report 2014
Apr 2015
Publication
The 2014 Review is the fourth review of the FCH JU project portfolio. The reviews began in 2011 following a recommendation arising from the interim evaluation of the FCH JU which identified the need to ensure that the FCH JU project portfolio as a whole fulfilled the objectives of the Multi-Annual Implementation or Work Plan.<br/><br/>An international team of leading experts in the FCH field undertakes each review based on (1) The achievements of the portfolio against the strategic objectives and content of the FCH JU’s MAIP/MAWP and the AIP/AWPs as set out for the transportation and energy innovation pillars and the cross-cutting category; (2) The extent to which the portfolio meets the FCH JU’s remit for promoting the horizontal activities of RCS PNR safety life-cycle and socio-economic analysis education and training and public awareness; (3) The portfolio’s effectiveness in promoting linkages and co-operation between projects and between FCH JU-supported projects and those supported by other European instruments the Member States and internationally. Review panels The 2014 review comprised six panels covering a total of 114 projects. Each panel covered between 10 and 24 projects as shown in Table 1 below. The objective was to assess projects within each panel as a sub-portfolio (within the FCH JU portfolio) and not as individual projects although examples of individual projects representing good practice were highlighted.
Analysis of Hydrogen Filling of 175 Liter Tank for Large-Sized Hydrogen Vehicle
May 2022
Publication
Due to the low density of hydrogen gas under ambient temperature and atmospheric pressure conditions the high-pressure gaseous hydrogen storage method is widely employed. With high-pressure characteristics of hydrogen storage rigorous safety precautions are required such as filling of compressed gas in a hydrogen tank to achieve reliable operational solutions. Especially for the large-sized tanks (above 150 L) safety operation of hydrogen storage should be considered. In the present study the compressed hydrogen gas behavior in a large hydrogen tank of 175 L is investigated for its filling. To validate the numerical approach used in this study numerical models for the adaptation of the gas and turbulence models are examined. Numerical parametric studies on hydrogen filling for the large hydrogen tank of 175 L are conducted to estimate the hydrogen gas behavior in the hydrogen tank under various conditions of state of charge of pressure and ambient temperature. From the parametric studies the relationship between the initial SOC pressure condition and the maximum temperature rise of hydrogen gas was shown. That is the maximum temperature rise increases as the ambient temperature decreases and the rise increases as the SOC decreases.
Unusual Hydrogen Implanted Gold with Lattice Contraction at Increased Hydrogen Content
Mar 2021
Publication
The experimental evidence for the contraction of volume of gold implanted with hydrogen at low doses is presented. The contraction of lattice upon the addition of other elements is very rare and extraordinary in the solid-state not only for gold but also for many other solids. To explain the underlying physics the pure kinetic theory of absorption is not adequate and the detailed interaction of hydrogen in the lattice needs to be clarified. Our analysis points to the importance of the formation of hydride bonds in a dynamic manner and explains why these bonds become weak at higher doses leading to the inverse process of volume expansion frequently seen in metallic hydrogen containers.
Effect of Anion Exchange Ionomer Content on Electrode Performance in AEM Water Electrolysis
Aug 2020
Publication
Anion exchange membrane water electrolysis (AEMWE) has acquired substantial consideration as a cost-effective hydrogen production technology. The anion ionomer content in the catalyst layers during hydrogen and oxygen evolution reaction (HER and OER) is of ultimate significance. Herein an in-situ half-cell analysis with reference electrodes was carried out for simultaneous potential measurements and identification of the influence of the anion exchange ionomer (AEI) content on anode and cathode performance. The measured half-cell potentials proved the influence of AEI content on the catalytic activity of HER and OER which was supported by the rotating disk electrode (RDE) measurements. Cathode overpotential of Ni/C was not negligible and more affected by the AEI content than anode with the optimized AEI content of 10 wt% while NiO anode OER overpotential was independent of the AEI content. For the same AEI content PGM catalysts showed higher electroactivity than Ni-based catalysts for HER and OER and the cathode catalyst's intrinsic activity is of high importance in the AEM electrolysis operation. Post-mortem analysis by SEM mapping of both AEI and catalyst distributions on the electrode surface showed the effect of AEI loading on the catalyst morphology which could be related to the electrode performance.
Hydrogen Strategy for Canada: Seizing the Opportunities for Hydrogen - A Call to Action
Dec 2020
Publication
For more than a century our nation’s brightest minds have been working on the technology to turn the invisible promise of hydrogen into tangible solutions. Canadian ingenuity and innovation has once again brought us to a pivotal moment. As we rebuild our economy from the impacts of COVID-19 and fight the existential threat of climate change the development of low-carbon hydrogen is a strategic priority for Canada. The time to act is now.<br/>The Hydrogen Strategy for Canada lays out an ambitious framework for actions that will cement hydrogen as a tool to achieve our goal of net-zero emissions by 2050 and position Canada as a global industrial leader of clean renewable fuels. This strategy shows us that by 2050 clean hydrogen can help us achieve our net-zero goal—all while creating jobs growing our economy and protecting our environment. This will involve switching from conventional gasoline diesel and natural gas to zero-emissions fuel sources taking advantage of new regulatory environments and embracing new technologies to give Canadians more choice of zero emission alternatives.<br/>As one of the top 10 hydrogen producers in the world today we are rich in the feedstocks that produce hydrogen. We are blessed with a strong energy sector and the geographic assets that will propel Canada to be a major exporter of hydrogen and hydrogen technologies. Hydrogen might be nature’s smallest molecule but its potential is enormous. It provides new markets for our conventional energy resources and holds the potential to decarbonize many sectors of our economy including resource extraction freight transportation power generation manufacturing and the production of steel and cement. This Strategy is a call to action. It will spur investments and strategic partnerships across the country and beyond our borders. It will position Canada to seize economic and environmental opportunities that exist coast to coast. Expanding our exports. Creating as many as 350000 good green jobs over the next three decades. All while dramatically reducing our greenhouse gas emissions. And putting a net-zero future within our reach.<br/>The importance of Canada’s resource industries and our clean technology sectors has been magnified during the pandemic. We must harness our combined will expertise and financial resources to fully seize the opportunities that hydrogen presents. This strategy is the product of three years of study and analysis including extensive engagement sessions where we heard from more than 1500 of our country’s leading experts and stakeholders. But its release is not the end of a process. This is only the beginning. Together we will use this Strategy to guide our actions and investments. By working with provinces and territories Indigenous partners and the private-sector and by leveraging our many advantages we will create the prosperity we all want protect the planet we all cherish and we will ensure we leave no one behind.
Hydrogen Embrittlement of Steel Pipelines During Transients
May 2021
Publication
Blending hydrogen into natural gas pipelines is a recent alternative adopted for hydrogen transportation as a mixture with natural gas. In this paper hydrogen embrittlement of steel pipelines originally designed for natural gas transportation is investigated. Solubility permeation and diffusion phenomena of hydrogen molecules into the crystalline lattice structure of the pipeline material are followed up based on transient evolution of internal pressure applied on the pipeline wall. The transient regime is created through changes of gas demand depending on daily consumptions. As a result the pressure may reach excessive values that lead to the acceleration of hydrogen solubility and its diffusion through the pipeline wall. Furthermore permeation is an important parameter to determine the diffusion amount of hydrogen inside the pipeline wall resulting in the embrittlement of the material. The numerical obtained results have shown that using pipelines designed for natural gas conduction to transport hydrogen is a risky choice. Actually added to overpressure and great fluctuations during transients that may cause fatigue and damage the structure also the latter pressure evolution is likely to induce the diffusion phenomena of hydrogen molecules into the lattice of the structure leading to brittle the pipe material. The numerical simulation reposes on solving partial differential equations describing transient gas flow in pipelines coupled with the diffusion equation for mass transfer. The model is built using the finite elements based software COMSOL Multiphysics considering different cases of pipe material; API X52 (base metal and nutrided) and API X80 steels. Obtained results allowed tracking the evolution with time of hydrogen concentration through the pipeline internal wall based on the pressure variation due to transient gas flow. Such observation permits to estimate the amount of hydrogen diffused in the metal to avoid leakage of this flammable gas. Thus precautions may be taken to prevent explosive risks due to hydrogen embrittlement of steel pipelines among other effects that can lead to alter safe conditions of gas conduction.
Mind the Gap—A Socio-Economic Analysis on Price Developments of Green Hydrogen, Synthetic Fuels, and Conventional Energy Carriers in Germany
May 2022
Publication
In recent years the development of energy prices in Germany has been frequently accompanied by criticism and warnings of socio-economic disruptions. Especially with respect to the electricity sector the debate on increasing energy bills was strongly correlated with the energy system transition. However whereas fossil fuels have rapidly increased in price recently renewable substitutes such as green hydrogen and synthetic fuels also enter the markets at comparatively high prices. On the other hand the present fossil fuel supply is still considered too low-priced by experts because societal greenhouse gas-induced environmental impact costs are not yet compensated. In this study we investigate the development of the price gap between conventional energy carriers and their renewable substitutes until 2050 as well as a suitable benchmark price incorporating the societal costs of specific energy carriers. The calculated benchmark prices for natural gas (6.3 ct kWh−1 ) petrol (9.9 ct kWh−1 ) and grey hydrogen from steam methane reformation (12 ct kWh−1 ) are nearly 300% above the actual prices for industry customers in 2020 but below the price peaks of early 2022. In addition the price gap between conventional fuels and green hydrogen will be completely closed before 2050 for all investigated energy carriers. Furthermore prognosed future price developments can be considered rather moderate compared to historic and especially to the recent price dynamics in real terms. A gradual implementation of green hydrogen and synthetic fuels next to increasing CO2 prices however may temporarily lead to further increasing expenses for energy but can achieve lower price levels comparable to those of 2020 in the long term.
A Review of Recent Advances on the Effects of Microstructural Refinement and Nano-Catalytic Additives on the Hydrogen Storage Properties of Metal and Complex Hydrides
Dec 2010
Publication
The recent advances on the effects of microstructural refinement and various nano-catalytic additives on the hydrogen storage properties of metal and complex hydrides obtained in the last few years in the allied laboratories at the University of Waterloo (Canada) and Military University of Technology (Warsaw Poland) are critically reviewed in this paper. The research results indicate that microstructural refinement (particle and grain size) induced by ball milling influences quite modestly the hydrogen storage properties of simple metal and complex metal hydrides. On the other hand the addition of nanometric elemental metals acting as potent catalysts and/or metal halide catalytic precursors brings about profound improvements in the hydrogen absorption/desorption kinetics for simple metal and complex metal hydrides alike. In general catalytic precursors react with the hydride matrix forming a metal salt and free nanometric or amorphous elemental metals/intermetallics which in turn act catalytically. However these catalysts change only kinetic properties i.e. the hydrogen absorption/desorption rate but they do not change thermodynamics (e.g. enthalpy change of hydrogen sorption reactions). It is shown that a complex metal hydride LiAlH4 after high energy ball milling with a nanometric Ni metal catalyst and/or MnCl2 catalytic precursor is able to desorb relatively large quantities of hydrogen at RT 40 and 80 °C. This kind of behavior is very encouraging for the future development of solid state hydrogen systems.
The Study on Permissible Value of Hydrogen Gas Concentration in Purge Gas of Fuel Cell Vehicles
Sep 2019
Publication
Ignition conditions and risks of ignition on a permissible value of hydrogen concentration in purge gas prescribed by HFCV-GTR were reevaluated. Experiments were conducted to investigate burning behavior and thermal influence of continuous evacuation of hydrogen under continuous purge of air / hydrogen premixed gas which is close to an actual purge condition of FCV and thermal evacuation of hydrogen. As a result of the re-evaluation it was shown from the viewpoint of safety that the permissible value of hydrogen concentration in purge gas prescribed by the current HFCV GTR is appropriate.
Utilization and Recycling of End of Life Plastics for Sustainable and Clean Industrial Processes Including the Iron and Steel Industry
Aug 2019
Publication
About 400 million tonnes of plastics are produced per annum worldwide. End-of-life of plastics disposal contaminates the waterways aquifers and limits the landfill areas. Options for recycling plastic wastes include feedstock recycling mechanical /material recycling industrial energy recovery municipal solid waste incineration. Incineration of plastics containing E-Wastes releases noxious odours harmful gases dioxins HBr polybrominated diphenylethers and other hydrocarbons. This study focusses on recycling options in particular feedstock recycling of plastics in high-temperature materials processing for a sustainable solution to the plastic wastes not suitable for recycling. Of the 7% CO2 emissions attributed to the iron and steel industry worldwide ∼30% of the carbon footprint is reduced using the waste plastics compared to other carbon sources in addition to energy savings. Plastics have higher H2 content than the coal. Hydrogen evolved from the plastics acts as the reductant alongside the carbon monoxide. Hydrogen reduction of iron ore in presence of plastics increases the reaction rates due to higher diffusion of H2 compared to CO. Plastic replacement reduces the process temperature by at least 100–200 °C due to the reducing gases (hydrogen) which enhance the energy efficiency of the process. Similarly plastics greatly reduce the emissions in other high carbon footprint process such as magnesia production while contributing to energy.
Charpy Impact Properties of Hydrogen-Exposed 316L Stainless Steel at Ambient and Cryogenic Temperatures
May 2019
Publication
316L stainless steel is a promising material candidate for a hydrogen containment system. However when in contact with hydrogen the material could be degraded by hydrogen embrittlement (HE). Moreover the mechanism and the effect of HE on 316L stainless steel have not been clearly studied. This study investigated the effect of hydrogen exposure on the impact toughness of 316L stainless steel to understand the relation between hydrogen charging time and fracture toughness at ambient and cryogenic temperatures. In this study 316L stainless steel specimens were exposed to hydrogen in different durations. Charpy V-notch (CVN) impact tests were conducted at ambient and low temperatures to study the effect of HE on the impact properties and fracture toughness of 316L stainless steel under the tested temperatures. Hydrogen analysis and scanning electron microscopy (SEM) were conducted to find the effect of charging time on the hydrogen concentration and surface morphology respectively. The result indicated that exposure to hydrogen decreased the absorbed energy and ductility of 316L stainless steel at all tested temperatures but not much difference was found among the pre-charging times. Another academic insight is that low temperatures diminished the absorbed energy by lowering the ductility of 316L stainless steel
Large-scale Storage of Hydrogen
Mar 2019
Publication
The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale the approach is not applicable in all regions due to varying geological conditions. Therefore other storage methods are necessary. In this article options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies such as liquid hydrogen methanol ammonia and dibenzyltoluene is found to be advantageous in terms of storage density cost of storage and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting these variable costs may be tolerable.
Modifications in the Composition of CuO/ZnO/Al2O3 Catalyst for the Synthesis of Methanol by CO2 Hydrogenation
Jun 2021
Publication
Renewable methanol obtained from CO2 and hydrogen provided from renewable energy was proposed to close the CO2 loop. In industry methanol synthesis using the catalyst CuO/ZnO/Al2O3 occurs at a high pressure. We intend to make certain modification on the traditional catalyst to work at lower pressure maintaining high selectivity. Therefore three heterogeneous catalysts were synthesized by coprecipitation to improve the activity and the selectivity to methanol under mild conditions of temperature and pressure. Certain modifications on the traditional catalyst Cu/Zn/Al2O3 were employed such as the modification of the synthesis time and the addition of Pd as a dopant agent. The most efficient catalyst among those tested was a palladium-doped catalyst 5% Pd/Cu/Zn/Al2O3. This had a selectivity of 64% at 210 °C and 5 bar.
A Comprehensive Review of Microbial Electrolysis Cells (MEC) Reactor Designs and Configurations for Sustainable Hydrogen Gas Production
Nov 2015
Publication
Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles. A cutting edge technology called a microbial electrolysis cell (MEC) can achieve sustainable and clean hydrogen production from a wide range of renewable biomass and wastewaters. Enhancing the hydrogen production rate and lowering the energy input are the main challenges of MEC technology. MEC reactor design is one of the crucial factors which directly influence on hydrogen and current production rate in MECs. The rector design is also a key factor to upscaling. Traditional MEC designs incorporated membranes but it was recently shown that membrane-free designs can lead to both high hydrogen recoveries and production rates. Since then multiple studies have developed reactors that operate without membranes. This review provides a brief overview of recent advances in research on scalable MEC reactor design and configurations.
Five Minute Guide to Hydrogen
Feb 2016
Publication
Hydrogen is an emerging energy vector many components of which are mature technologies. Current hydrogen technology is already able to provide advantages over other energy vectors and many of its challenges are being actively addressed by research and development.<br/><br/>Hydrogen can be derived stored and converted through various processes each of which represents different levels of carbon intensity efficiency and end use functionality. Our latest five minute guide looks at this energy vector in brief including public perception transportation and storage as well as using hydrogen as a solution.
Choked Two-phase Flow with Account of Discharge Line Effects
Jan 2019
Publication
An engineering tool is presented to predict steady state two-phase choked flow through a discharge line with variable cross section with account of friction and without wall heat transfer. The tool is able to predict the distribution of all relevant physical quantities along the discharge line. Choked flow is calculated using the possible-impossible flow algorithm implemented in a way to account for possible density discontinuities along the line. Physical properties are calculated using the Helmholtz Free Energy formulation. The tool is verified against previous experiments with water and evaluated against previous experiments with cryogenic two-phase hydrogen.
Research Progress of Cryogenic Materials for Storage and Transportation of Liquid Hydrogen
Jul 2021
Publication
Liquid hydrogen is the main fuel of large-scale low-temperature heavy-duty rockets and has become the key direction of energy development in China in recent years. As an important application carrier in the large-scale storage and transportation of liquid hydrogen liquid hydrogen cryogenic storage and transportation containers are the key equipment related to the national defense security of China’s aerospace and energy fields. Due to the low temperature of liquid hydrogen (20 K) special requirements have been put forward for the selection of materials for storage and transportation containers including the adaptability of materials in a liquid hydrogen environment hydrogen embrittlement characteristics mechanical properties and thermophysical properties of liquid hydrogen temperature which can all affect the safe and reliable design of storage and transportation containers. Therefore it is of great practical significance to systematically master the types and properties of cryogenic materials for the development of liquid hydrogen storage and transportation containers. With the wide application of liquid hydrogen in different occasions the requirements for storage and transportation container materials are not the same. In this paper the types and applications of cryogenic materials commonly used in liquid hydrogen storage and transportation containers are reviewed. The effects of low-temperature on the mechanical properties of different materials are introduced. The research progress of cryogenic materials and low-temperature performance data of materials is introduced. The shortcomings in the research and application of cryogenic materials for liquid hydrogen storage and transportation containers are summarized to provide guidance for the future development of container materials. Among them stainless steel is the most widely used cryogenic material for liquid hydrogen storage and transportation vessel but different grades of stainless steel also have different applications which usually need to be comprehensively considered in combination with its low temperature performance corrosion resistance welding performance and other aspects. However with the increasing demand for space liquid hydrogen storage and transportation the research on high specific strength cryogenic materials such as aluminum alloy titanium alloy or composite materials is also developing. Aluminum alloy liquid hydrogen storage and transportation containers are widely used in the space field while composite materials have significant advantages in being lightweight. Hydrogen permeation is the key bottleneck of composite storage and transportation containers. At present there are still many technical problems that have not been solved.
Multi-Period Planning of Hydrogen Supply Network for Refuelling Hydrogen Fuel Cell Vehicles in Urban Areas
May 2020
Publication
The hydrogen economy refers to an economic and industrial structure that uses hydrogen as its main energy source replacing traditional fossil-fuel-based energy systems. In particular the widespread adoption of hydrogen fuel cell vehicles (HFCVs) is one of the key factors enabling a hydrogen economy and aggressive investment in hydrogen refuelling infrastructure is essential to make large-scale adoption of HFCVs possible. In this study we address the problem of effectively designing a hydrogen supply network for refuelling HFCVs in urban areas relatively far from a large hydrogen production site such as a petrochemical complex. In these urban areas where mass supply of hydrogen is not possible hydrogen can be supplied by reforming city gas. In this case building distributed hydrogen production bases that extract large amounts of hydrogen from liquefied petroleum gas (LPG) or compressed natural gas (CNG) and then supply hydrogen to nearby hydrogen stations may be a cost-effective option for establishing a hydrogen refuelling infrastructure in the early stage of the hydrogen economy. Therefore an optimization model is proposed for effectively deciding when and where to build hydrogen production bases and hydrogen refuelling stations in an urban area. Then a case study of the southeastern area of Seoul known as a commercial and residential center is discussed. A variety of scenarios for the design parameters of the hydrogen supply network are analyzed based on the target of the adoption of HFCVs in Seoul by 2030. The proposed optimization model can be effectively used for determining the time and sites for building hydrogen production bases and hydrogen refuelling stations.
Modelling and Simulation of a Zero-emission Hybrid Power Plant for a Domestic Ferry
Jan 2021
Publication
This paper presents a simulation tool for marine hybrid power-plants equipped with polymer exchange membrane fuel cells and batteries. The virtual model through the combination of operational data and dynamically modelled subsystems can simulate power-plants of different sizes and configurations in order to analyze the response of different energy management strategies. The model aims to replicate the realistic behavior of the components included in the vessel's grid to asses if the hardware selected by the user is capable of delivering the power set-point requested by the energy management system. The model can then be used to optimize key factors such as hydrogen consumption. The case study presented in the paper demonstrates how the model can be used for the evaluation of a retrofitting operation replacing a diesel electric power-plant with fuel cells and batteries. The vessel taken into consideration is a domestic ferry operating car and passenger transport in Denmark. The vessel is outfitted with a diesel electric plant and an alternative hybrid power-plant is proposed. The hybrid configuration is tested using the model in a discrete time-domain.
Hy4Heat Safety Assessment: Precis - Work Package 7
May 2021
Publication
The Hy4Heat Safety Assessment has focused on assessing the safe use of hydrogen gas in certain types of domestic properties and buildings. The summary reports (the Precis and the Safety Assessment Conclusions Report) bring together all the findings of the work and should be looked to for context by all readers. The technical reports should be read in conjunction with the summary reports. While the summary reports are made as accessible as possible for general readers the technical reports may be most accessible for readers with a degree of technical subject matter understanding. All of the safety assessment reports have now been reviewed by the HSE.<br/><br/>This document is an overview of the Safety Assessment work undertaken as part of the Hy4Heat programme
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.
Hydrogen as a Maritime Fuel–Can Experiences with LNG Be Transferred to Hydrogen Systems?
Jul 2021
Publication
As the use of fossil fuels becomes more and more restricted there is a need for alternative fuels also at sea. For short sea distance travel purposes batteries may be a solution. However for longer distances when there is no possibility of recharging at sea batteries do not have sufficient capacity yet. Several projects have demonstrated the use of compressed hydrogen (CH2) as a fuel for road transport. The experience with hydrogen as a maritime fuel is very limited. In this paper the similarities and differences between liquefied hydrogen (LH2) and liquefied natural gas (LNG) as a maritime fuel will be discussed based on literature data of their properties and our system knowledge. The advantages and disadvantages of the two fuels will be examined with respect to use as a maritime fuel. Our objective is to discuss if and how hydrogen could replace fossil fuels on long distance sea voyages. Due to the low temperature of LH2 and wide flammability range in air these systems have more challenges related to storage and processing onboard than LNG. These factors result in higher investment costs. All this may also imply challenges for the LH2 supply chain.
Micro and Macro Mechanical Analysis of Gas Pipeline Steels
Sep 2017
Publication
The actual safety margins of gas pipelines depend on a number of factors that include the mechanical characteristics of the material. The evolution with time of the metal properties can be evaluated by mechanical tests performed at different scales seeking for the best compromise between the simplicity of the experimental setup to be potentially employed in situ and the reliability of the results. Possible alternatives are comparatively assessed on pipeline steels of different compositions and in different states.
Power to Hydrogen and Power to Water Using Wind Energy
May 2022
Publication
The need for energy and water security on islands has led to an increase in the use of wind power. However the intermittent nature of wind generation means it needs to be coupled with a storage system. Motivated by this two different models of surplus energy storage systems are investigated in this paper. In both models renewable wind energy is provided by a wind farm. In the first model a pumped hydro storage system (PHS) is used for surplus energy storage while in the second scenario a hybrid pumped hydrogen storage system (HPHS) is applied consisting of a PHS and a hydrogen storage system. The goal of this study is to compare the single and the hybrid storage system to fulfill the energy requirements of the island’s electricity load and desalination demands for domestic and irrigation water. The cost of energy (COE) is 0.287 EUR/kWh for PHS and 0.360 EUR/kWh for HPHS while the loss of load probability (LOLP) is 22.65% for PHS and 19.47% for HPHS. Sensitivity analysis shows that wind speed is the key parameter that most affects COE cost of water (COW) and LOLP indices while temperature affects the results the least.
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