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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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