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Hydrogen as an Energy Vector to Optimize the Energy Exploitation of a Self-consumption Solar Photovoltaic Facility in a Dwelling House
Nov 2019
Publication
Solar photovoltaic (PV) plants coupled with storage for domestic self-consumption purposes seem to be a promising technology in the next years as PV costs have decreased significantly and national regulations in many countries promote their installation in order to relax the energy requirements of power distribution grids. However electrochemical storage systems are still unaffordable for many domestic users and thus the advantages of self-consumption PV systems are reduced. Thus in this work the adoption of hydrogen systems as energy vectors between a PV plant and the energy user is proposed. As a preliminary study in this work the design of a PV and hydrogen-production self-consumption plant for a single dwelling is described. Then a technical and economic feasibility study conducted by modeling the facility within the Homer Energy Pro energy systems analysis tool is reported. The proposed system will be able to provide back not only electrical energy but also thermal energy through a fuel cell or refined water covering the fundamental needs of the householders (electricity heat or cooling and water). Results show that although the proposed system effectively increases the energy local use of the PV production and reduces significantly the energy injections or demands into/from the power grid avoiding power grid congestions and increasing the nano-grid resilience operation and maintenance costs may reduce its economic attractiveness for a single dwelling.
Synergies between Renewable Energy and Flexibility Investments: A Case of a Medium-Sized Industry
Nov 2021
Publication
Climate and energy policies are tools used to steer the development of a sustainable economy supplied by equally sustainable energy systems. End-users should plan their investments accounting for future policies such as incentives for system-oriented consumption emission prices and hydrogen economy to ensure long-term competitiveness. In this work the utilization of variable renewable energy and flexibility potentials in a case study of an an aggregate industry is investigated. An energy concept considering PV and battery expansion flexible production fuel cell electric trucks (FCEV) and hydrogen production is proposed and analysed under expected techno-economic conditions and policies of 2030 using an energy system optimization model. Under this concept total costs and emissions are reduced by 14% and 70% respectively compared to the business-as-usual system. The main benefit of PV investment is the lowered electricity procurement. Flexibility from schedule manufacturing and hydrogen production increases not only the self-consumption of PV generation from 51% to 80% but also the optimal PV capacity by 41%. Despite the expected cost reduction and efficiency improvement FCEV is still not competitive to diesel trucks due to higher investment and fuel prices i.e. its adoption increases the costs by 8%. However this is resolved when hydrogen can be produced from own surplus electricity generation. Our findings reveal synergistic effects between different potentials and the importance of enabling local business models e.g. regional hydrogen production and storage services. The SWOT analysis of the proposed concept shows that the pursuit of sustainability via new technologies entails new opportunities and risks. Lastly end-users and policymakers are advised to plan their investments and supports towards integration of multiple application consumption sectors and infrastructure.
Industrial Decarbonization Pathways: The Example of the German Glass Industry
Nov 2022
Publication
Mitigating anthropogenic climate change and achieving the Paris climate goals is one of the greatest challenges of the twenty-first century. To meet the Paris climate goals sector-specific transformation pathways need to be defined. The different transformation pathways are used to hypothetically quantify whether a defined climate target is achievable or not. For this reason a bottom-up model was developed to assess the extent of selected industrial decarbonization options compared to conventionally used technologies from an emissions perspective. Thereby the bottom-up model is used to analyze the German container and flat glass industries as an example. The results show that no transformation pathway can be compatible with the 1.5 °C based strict carbon dioxide budget target. Even the best case scenario exceeds the 1.5 °C based target by approximately +200%. The 2 °C based loose carbon dioxide budget target is only achievable via fuel switching the complete phase-out from natural gas to renewable energy carriers. Furthermore the results of hydrogen for flat glass production demonstrate that missing investments in renewable energy carriers may lead to the non-compliance with actually achievable 2 °C based carbon dioxide budget targets. In conclusion the phase-out from natural gas to renewable energies should be executed at the end of the life of any existing furnace and process emissions should be avoided in the long term to contribute to 1.5 °C based strict carbon dioxide budget target.
Current Research Progress in Magnesium Borohydride for Hydrogen Storage (A review)
Nov 2021
Publication
Hydrogen storage in solid-state materials is believed to be a most promising hydrogen-storage technology for high efficiency low risk and low cost. Mg(BH4)2 is regarded as one of most potential materials in hydrogen storage areas in view of its high hydrogen capacities (14.9 wt% and 145–147 kg cm3 ). However the drawbacks of Mg(BH4)2 including high desorption temperatures (about 250 C–580 C) sluggish kinetics and poor reversibility make it difficult to be used for onboard hydrogen storage of fuel cell vehicles. A lot of researches on improving the dehydrogenation reaction thermodynamics and kinetics have been done mainly including: additives or catalysts doping nanoconfining Mg(BH4)2 in nanoporous hosts forming reactive hydrides systems multi-cation/anion composites or other derivatives of Mg(BH4)2. Some favorable results have been obtained. This review provides an overview of current research progress in magnesium borohydride including: synthesis methods crystal structures decomposition behaviors as well as emphasized performance improvements for hydrogen storage.
An Innovative and Comprehensive Approach for the Consequence Analysis of Liquid Hydrogen Vessel Explosions
Oct 2020
Publication
Hydrogen is one of the most suitable solutions to replace hydrocarbons in the future. Hydrogen consumption is expected to grow in the next years. Hydrogen liquefaction is one of the processes that allows for increase of hydrogen density and it is suggested when a large amount of substance must be stored or transported. Despite being a clean fuel its chemical and physical properties often arise concerns about the safety of the hydrogen technologies. A potentially critical scenario for the liquid hydrogen (LH2) tanks is the catastrophic rupture causing a consequent boiling liquid expanding vapour explosion (BLEVE) with consequent overpressure fragments projection and eventually a fireball. In this work all the BLEVE consequence typologies are evaluated through theoretical and analytical models. These models are validated with the experimental results provided by the BMW care manufacturer safety tests conducted during the 1990’s. After the validation the most suitable methods are selected to perform a blind prediction study of the forthcoming LH2 BLEVE experiments of the Safe Hydrogen fuel handling and Use for Efficient Implementation (SH2IFT) project. The models drawbacks together with the uncertainties and the knowledge gap in LH2 physical explosions are highlighted. Finally future works on the modelling activity of the LH2 BLEVE are suggested.
Recent Application of Nanomaterials to Overcome Technological Challenges of Microbial Electrolysis Cells
Apr 2022
Publication
Microbial electrolysis cells (MECs) have attracted significant interest as sustainable green hydrogen production devices because they utilize the environmentally friendly biocatalytic oxidation of organic wastes and electrochemical proton reduction with the support of relatively lower external power compared to that used by water electrolysis. However the commercialization of MEC technology has stagnated owing to several critical technological challenges. Recently many attempts have been made to utilize nanomaterials in MECs owing to the unique physicochemical properties of nanomaterials originating from their extremely small size (at least <100 nm in one dimension). The extraordinary properties of nanomaterials have provided great clues to overcome the technological hurdles in MECs. Nanomaterials are believed to play a crucial role in the commercialization of MECs. Thus understanding the technological challenges of MECs the characteristics of nanomaterials and the employment of nanomaterials in MECs could be helpful in realizing commercial MEC technologies. Herein the critical challenges that need to be addressed for MECs are highlighted and then previous studies that used nanomaterials to overcome the technological difficulties of MECs are reviewed.
Geological Hydrogen Storage: Geochemical Reactivity of Hydrogen with Sandstone Reservoirs
Jun 2022
Publication
The geological storage of hydrogen is necessary to enable the successful transition to a hydrogen economy and achieve net-zero emissions targets. Comprehensive investigations must be undertaken for each storage site to ensure their long-term suitability and functionality. As such the systematic infrastructure and potential risks of large-scale hydrogen storage must be established. Herein we conducted over 250 batch reaction experiments with different types of reservoir sandstones under conditions representative of the subsurface reflecting expected time scales for geological hydrogen storage to investigate potential reactions involving hydrogen. Each hydrogen experiment was paired with a hydrogen-free control under otherwise identical conditions to ensure that any observed reactions were due to the presence of hydrogen. The results conclusively reveal that there is no risk of hydrogen loss or reservoir integrity degradation due to abiotic geochemical reactions in sandstone reservoirs.
Everything About Hydrogen Podcast: Building Hydrogen Infrastructure with Black & Veatch
Feb 2020
Publication
On this weeks episode the team are talking all things hydrogen with Maryline Daviaud Lewett Director of Business Development for Transformative Technologies at Black & Veatch (B&V). On the show we discuss the role that Engineering Procurement and Construction (EPC) firms are playing in developing hydrogen and fuel cell infrastructure as well as discussing the unique aspects of developing projects in North America. As the leading EPC for hydrogen refuelling stations in North America and a wealth of experience across electric vehicle charging and hydrogen Maryline brings a uniquely well rounded perspective to the discussion and shares a wealth of insights for how the market may evolve. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Carbon Capture from Biogas by Deep Eutectic Solvents A COSMO Study to Evaluate the Effect of Impurities on Solubility and Selectivity
Jun 2021
Publication
Deep eutectic solvents (DES) are compounds of a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) that contain a depressed melting point compared to their individual constituents. DES have been studied for their use as carbon capture media and biogas upgrading. However contaminants’ presence in biogas might affect the carbon capture by DES. In this study conductor-like screening model for real solvents (COSMO-RS) was used to determine the effect of temperature pressure and selective contaminants on five DES’ namely choline chloride-urea choline chloride-ethylene glycol tetra butyl ammonium chloride-ethylene glycol tetra butyl ammonium bromide-decanoic acid and tetra octyl ammonium chloride-decanoic acid. Impurities studied in this paper are hydrogen sulfide ammonia water nitrogen octamethyltrisiloxane and decamethylcyclopentasiloxane. At infinite dilution CO2 solubility dependence upon temperature in each DES was examined by means of Henry’s Law constants. Next the systems were modeled from infinite dilution to equilibrium using the modified Raoults’ Law where CO2 solubility dependence upon pressure was examined. Finally solubility of CO2 and CH4 in the various DES were explored with the presence of varying mole percent of selective contaminants. Among the parameters studied it was found that the HBD of the solvent is the most determinant factor for the effectiveness of CO2 solubility. Other factors affecting the solubility are alkyl chain length of the HBA the associated halogen and the resulting polarity of the DES. It was also found that choline chloride-urea is the most selective to CO2 but has the lowest CO2 solubility and is the most polar among other solvents. On the other hand tetraoctylammonium chloride-decanoic acid is the least selective has the highest maximum CO2 solubility is the least polar and is the least affected by its environment.
Development of a Tangential Neutron Radiography System for Monitoring the Fatigue Cracks in Hydrogen Fuel Tanks
Jun 2016
Publication
Purpose- To present an overview of the research and development carried out in a European funded framework 7 (FP7) project called SafeHPower for the implementation of neutron radiography to inspect fatigue cracks in vehicle and storage hydrogen fuel tanks. Project background– Hydrogen (H2) is the most promising replacement fuel for road transport due to its abundance efficiency low carbon footprint and the absence of harmful emissions. For the mass market of hydrogen to take off the safety issue surrounding the vehicle and storage hydrogen tanks needs to be addressed. The problem is the residual and additional stresses experienced by the tanks during the continuous cyclic loading between ambient and storage pressure which can result in the development of fatigue cracks. Steel tanks used as storage containers at service stations and depots and/or the composite tanks lined with steel are known to suffer from hydrogen embrittlement (HE). Another issue is the explosive nature of hydrogen (when it is present in the 18-59% range) where it is mixed with oxygen which can lead to catastrophic consequences including loss of life. Monitoring systems that currently exist in the market impose visual examination tests pressure tests and hydrostatic tests after the tank installation [1] [2]. Three inspection systems have been developed under this project to provide continuous monitoring solutions. Approach and scope- One of the inspection systems based on the neutron radiography (NR) technology that was developed in different phases with the application of varied strategies has been presented here. Monte Carlo (MCNP) simulation results to design and develop a bespoke collimator have been presented. A limitation of using an inertial electrostatic Deuterium-Tritium (D-T) pulsed neutron generator for fast neutron radiography has been discussed. Radiographs from the hydrogen tank samples obtained using thermal neutrons from a spallation neutron source at ISIS Rutherford laboratory UK have been presented. Furthermore radiograph obtained using thermal neutrons from a portable D-T neutron generator has been presented. In conclusion a proof in principle has been made to show that the defects in the hydrogen fuel tank can be detected using thermal neutron radiography.
A Hot Syngas Purification System Integrated with Downdraft Gasification of Municipal Solid Waste
Jan 2019
Publication
Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resources. However purification of syngas to remove multiple impurities such as particulates tar HCl alkali chlorides and sulfur species is required. This study investigates the feasibility of high temperature purification of syngas from MSW gasification with the focus on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises of a fluidized-bed catalytic tar reformer a filter for particulates and a fixed-bed reactor for dechlorination and then desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nano-structured nickel catalyst supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages. Experimental and thermodynamic modeling results are compared to determine the kinetic constraints in the integrated system. The hot purification system demonstrates up to 90% of tar and sulfur removal efficiency increased total syngas yield (14%) and improved cold gas efficiency (12%). The treated syngas is potentially applicable in gas engines/turbines and solid oxide fuel cells based on the dew points and concentration limits of the remaining tar compounds. Reforming of raw syngas by nickel catalyst for over 20 h on stream shows strong resistance to deactivation. Desulfurization of syngas from MSW gasification containing significantly higher proportion of carbonyl sulfide than hydrogen sulfide traces of tar and hydrogen chloride demonstrates high performance of Ni-Zn sorbents.
Wind Resource Assessment and Techno-economic Analysis of Wind Energy and Green Hydrogen Production in the Republic of Djibouti
Jul 2022
Publication
The ever increasing energy demand of the Republic of Djibouti leads to the diversification of energy sources. While a few studies have explored the prospects of green hydrogen production from wind energy in developing countries and particularly in Africa the economic risk analysis of wind power production for electricity generation and green hydrogen production has not been assessed for African countries. This study evaluates for the first time the potential of wind energy for electricity and green hydrogen production in the Republic of Djibouti. In this study wind speed characteristics were analyzed using wind data measured at five meteorological stations from 2015 to 2019. The technoeconomic analysis of five wind farms with a total capacity of 450 MW is performed. Levelized cost of energy production (LCOE) levelized cost of green hydrogen production (LCOH) sensitivity analysis Monte Carlo simulation and economic performance indicators are presented. Results reveal that the annual wind speed varies between 5.52 m/s and 9.01 m/s for the five sites. ERA5 wind reanalysis indicates that the seasonal variability of wind is stable between different years. The proposed wind farms estimate 1739 GWh per year of electrical energy with LCOE ranging from 6.94 to 13.30 US cents/kWh which is less than the locale electricity tariff. The production cost of green hydrogen was competitive with LCOH ranging from 1.79 to 3.38 US $/kg H2. The sensitivity analysis shows that the most relevant parameters in the economic analysis are the initial investment cost the interest rate and the factor capacity.
Neutron Scattering and Hydrogen Storage
Nov 2009
Publication
Hydrogen has been identified as a fuel of choice for providing clean energy for transport and other applications across the world and the development of materials to store hydrogen efficiently and safely is crucial to this endeavour. Hydrogen has the largest scattering interaction with neutrons of all the elements in the periodic table making neutron scattering ideal for studying hydrogen storage materials. Simultaneous characterisation of the structure and dynamics of these materials during hydrogen uptake is straightforward using neutron scattering techniques. These studies will help us to understand the fundamental properties of hydrogen storage in realistic conditions and hence design new hydrogen storage materials.
Co-gasification of Refuse-derived Fuels and Bituminous Coal with Oxygen/steam Blend to Hydrogen Rich Gas
May 2022
Publication
The gasification technology of refuse-derived fuels (RDF) can represent a future alternative to the global hydrogen production and a pathway for the development of the circular economy. The paper presents an innovative way of utilizing RDF through their oxygen/steam co-gasification with bituminous coal to hydrogen rich gas. Five different RDF samples (RDF1÷RDF5) were investigated. The in-depth analyses of the co-gasification of bituminous coal blends with different amounts of RDF (10 15 and 20%w/w) under various temperature conditions were conducted with the application of Hierarchical Clustering Analysis (HCA). The results of the research study revealed a decrease in the total gas yield as well as in the hydrogen yield observed with the increase in the RDF fraction in the fuel blend. The lowest hydrogen yield and the highest carbon conversion were noted for the co-gasification tests of coal blends with 20%w/w for all the studied RDFs. The SEM-EDS (Scanning Electron Microscopy with Energy Dispersive Spectroscopy) and WDXRF (Wavelength Dispersive X-ray Fluorescence) results showed a significantly higher H2 yield in RDF2 co-gasification with coal in comparison with all the remaining RDFs due to the higher concentration of calcium in the sample. The molecular structure analysis of polymers using Fourier transform infrared spectroscopy (FTIR) demonstrated that the most prevalent synthetic polymers in RDF2 are polyethylene terephthalate and polyvinyl chloride characterized by the lowest thermal stability compared to polyethylene and polypropylene.
Fuel Cells and Hydrogen Observatory 2019 EU and National Policies Report
Sep 2021
Publication
The policy module of the FCHO presents an overview of EU and national policies across various hydrogen and fuel cell related sectors. It provides a snapshot of the current state of hydrogen legislation and policy. Scope: While FCHO covers 38 entities around the world due to the completeness of the data at the moment of writing this report covers 29 entities. The report reflects data collected January 2019 – December 2019. Key Findings: Hydrogen policies are relatively commonplace among European countries but with large differences between member states. EU hydrogen leaders do not lag behind global outliers such as South Korea or Japan.
Vision for a European Metrology Network for Energy Gases
Mar 2022
Publication
As Europe moves towards decarbonising its energy infrastructure new measurement needs will arise that require collaborative efforts between European National Metrology Institutes and Designated Institutes to tackle. Such measurement needs include flow metering of hydrogen or hydrogen enriched natural gas in the gas grid for billing quality assurance of hydrogen at refuelling stations and equations of state for carbon dioxide in carbon capture and storage facilities. The European metrology network for energy gases for the first time provides a platform where metrology institutes can work together to develop a harmonised strategy prioritise new challenges and share expertise and capabilities to support the European energy gas industry to meet stringent EU targets for climate change and emissions reductions
THyGA - Intermediate Report on the Test of Technologies by Segment – Impact of the Different H2 Concentrations on Safety, Efficiency, Emissions and Correct Operation
Jan 2022
Publication
This report is the very first version of the document that will present the THyGA short-term test. These tests are carried out to observe how appliances react in the short term (few minutes to few hours) on different H2NG mixtures and long-term test are observing behaviour over several weeks. The analysis is based on the test of about 20 appliances only and is not yet covering extensively all the segments of the project. However most of the aspects of the testing are included in the present version that shall be considered as a draft working document to prepare the final report. We have tried to incorporate all aspects that are important to us but there may be more aspects and more analyses that could be added and will be added in the light of the comments and corrections we will gather after the dissemination of the document.
Towards Electrochemical Hydrogen Storage in Liquid Organic Hydrogen Carriers via Proton-coupled Electron Transfers
Jun 2022
Publication
Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO2. A possible solution for the transport of H2 in a safe and low-cost way is in the form of liquid organic hydrogen carriers (LOHCs). As an alternative to loading LOHC with H2 via a two-step procedure involving preliminary electrolytic production of H2 and subsequent chemical hydrogenation of the LOHC we explore here the possibility of electrochemical hydrogen storage (EHS) via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC (R) via a proton-coupled electron transfer (PCET) reaction: . 2 + +2 ― + ox↔ 0 2red We chose 9-fluorenone/fluorenol (Fnone/Fnol) conversion as such a model PCET reaction. The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity which enabled us to both quantify and get the mechanistic insight on PCET. The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.
Review of the Liquid Hydrogen Storage Tank and Insulation System for the High-Power Locomotive
Jun 2022
Publication
Hydrogen has been attracting attention as a fuel in the transportation sector to achieve carbon neutrality. Hydrogen storage in liquid form is preferred in locomotives ships drones and aircraft because these require high power but have limited space. However liquid hydrogen must be in a cryogenic state wherein thermal insulation is a core problem. Inner materials including glass bubbles multi-layer insulation (MLI) high vacuum and vapor-cooled shields are used for thermal insulation. An analytic study is preferred and proceeds liquid hydrogen tanks due to safety regulations in each country. This study reviewed the relevant literature for thermodynamic modeling. The literature was divided into static dynamic and systematic studies. In summary the authors summarized the following future research needs: The optimal design of the structure including suspension baffle and insulation system can be studied to minimize the boil-off gas (BOG). A dynamic study of the pressure mass flow and vaporizer can be completed. The change of the components arrangement from the conventional diesel–electric locomotive is necessary.
State-of-the-art Expansion Planning of Integrated Power, Natural Gas, and Hydrogen Systems
Apr 2022
Publication
Renewable hydrogen is considered key in the transition towards a carbon-neutral future. This is due to its spatio-temporal storage and sector coupling potential which has seen it referred to as energy vector. However many unresolved issues remain regarding hydrogen's large-scale deployment e.g. least-cost production optimal facility siting and overall implications on power and energy systems. Expansion planning provides an option to study these issues in the holistic context of energy systems. To this end this article presents a comprehensive review on state-of-the-art expansion planning models that consider integrated power natural gas and hydrogen systems. We cluster the existing literature in terms of modelling themes and scope study the applied systematic modelling characteristics and conduct an in-depth analysis of the technical model features regarding hydrogen technologies and natural gas infrastructure. Finally we identify and discuss research gaps in the existing literature.
A Quantitative Assessment of the Hydrogen Storage Capacity of the UK Continental Shelf
Nov 2020
Publication
Increased penetration of renewable energy sources and decarbonisation of the UK's gas supply will require large-scale energy storage. Using hydrogen as an energy storage vector we estimate that 150 TWh of seasonal storage is required to replace seasonal variations in natural gas production. Large-scale storage is best suited to porous rock reservoirs. We present a method to quantify the hydrogen storage capacity of gas fields and saline aquifers using data previously used to assess CO2 storage potential. We calculate a P50 value of 6900 TWh of working gas capacity in gas fields and 2200 TWh in saline aquifers on the UK continental shelf assuming a cushion gas requirement of 50%. Sensitivity analysis reveals low temperature storage sites with sealing rocks that can withstand high pressures are ideal sites. Gas fields in the Southern North Sea could utilise existing infrastructure and large offshore wind developments to develop large-scale offshore hydrogen production.
The Role of Hydrogen in Heavy Transport to Operate within Planetary Boundaries
Jul 2021
Publication
Green hydrogen i.e. produced from renewable resources is attracting attention as an alternative fuel for the future of heavy road transport and long-distance driving. However the benefits linked to zero pollution at the usage stage can be overturned when considering the upstream processes linked to the raw materials and energy requirements. To better understand the global environmental implications of fuelling heavy transport with hydrogen we quantified the environmental impacts over the full life cycle of hydrogen use in the context of the Planetary Boundaries (PBs). The scenarios assessed cover hydrogen from biomass gasification (with and without carbon capture and storage [CCS]) and electrolysis powered by wind solar bioenergy with CCS nuclear and grid electricity. Our results show that the current diesel-based-heavy transport sector is unsustainable due to the transgression of the climate change-related PBs (exceeding standalone by two times the global climate-change budget). Hydrogen-fuelled heavy transport would reduce the global pressure on the climate change-related PBs helping the transport sector to stay within the safe operating space (i.e. below one-third of the global ecological budget in all the scenarios analysed). However the best scenarios in terms of climate change which are biomass-based would shift burdens to the biosphere integrity and nitrogen flow PBs. In contrast burden shifting in the electrolytic scenarios would be negligible with hydrogen from wind electricity emerging as an appealing technology despite attaining higher carbon emissions than the biomass routes
An Investigation into the Change Leakage when Switching from Natural Gas to Hydrogen in the UK Gas Distribution Network
Sep 2021
Publication
The H21 National Innovation Competition project is examining the feasibility of repurposing the existing GB natural gas distribution network for transporting 100% hydrogen. It aims to undertake an experimental testing programme that will provide the necessary data to quantify the comparative risk between a 100% hydrogen network and the natural gas network. The first phase of the project focuses on leakage testing of a strategic set of assets that have been removed from service which provide a representative sample of assets across the network. This paper presents the work undertaken for Phase 1A (background testing) where HSE and industry partners have tested a range of natural gas pipework assets of varying size material age and pressure-rating in a new bespoke open-air testing facility at the HSE Science and Research Centre Buxton. The assets have been pressurised with hydrogen and then methane and the leakage rate from the assets measured in both cases. The main finding of this work is that the assets tested which leak hydrogen also leak methane. None of the assets were found to leak hydrogen but not methane. In addition repair techniques that were effective at stopping methane leaks were also effective at stopping hydrogen leaks. The data from the experiments have been interpreted to obtain a range of leakage ratios between the two gases for releases under different conditions. This has been compared to the predicted ratio of hydrogen to methane volumetric leak rates for laminar (1.2:1) and turbulent (2.9:1) releases and good agreement was observed.
Assessing the Prospective Environmental Performance of Hydrogen from High Temperature Electrolysis Coupled with Concentrated Solar Power
Jul 2022
Publication
Hydrogen is currently being promoted because of its advantages as an energy vector its potential 12 to decarbonise the economy and strategical implications in terms of energy security. Hydrogen 13 from high-temperature electrolysis coupled with concentrated solar power (CSP) is especially 14 interesting since it enhances the last two aspects and could benefit from significant technological 15 progress in the coming years. However there is a lack of studies assessing its future 16 environmental performance. This work fills this gap by carrying out a prospective life cycle 17 assessment based on the expected values of key performance parameters in 2030. The results 18 show that parabolic trough CSP coupled with a solid oxide electrolyser is a promising solution 19 under environmental aspects. It leads to a prospective hydrogen carbon footprint (1.85 kg CO2 20 eq/kg H2) which could be classified as low-carbon according to current standards. The 21 benchmarking study for the year 2030 shows that the assessed system significantly decreases the 22 hydrogen carbon footprint compared to future hydrogen from steam methane reforming (81% 23 reduction) and grid electrolysis (51%) even under a considerable penetration of renewable energy 24 sources.
A 1000 MWth Boiler for Chemical-looping Combustion of Solid Fuels – Discussion of Design and Costs
May 2015
Publication
More than 2000 h of solid-fuel CLC operation in a number of smaller pilot units clearly indicate that the concept works. A scale-up of the technology to 1000 MWth is investigated in terms of mass and heat balances flows solids inventories boiler dimensions and the major differences between a full-scale Circulating Fluidized-Bed (CFB) boiler and a Chemical-Looping Combustion CFB (CLC–CFB). Furthermore the additional cost of CLC–CFB relative to CFB technology is analysed and found to be 20 €/tonne CO2. The largest cost is made up of compression of CO2 which is common to all capture technologies. Although the need for oxygen to manage incomplete conversion is estimated to be only a tenth of that of oxy-fuel combustion oxygen production is nonetheless the second largest cost. Other significant costs include oxygen-carrier material increased boiler cost and steam for fluidization of the fuel reactor.
Simulation-Assisted Determination of the Start-Up Time of a Polymer Electrolyte Fuel Cell
Nov 2021
Publication
Fuel starvation is a major cause of anode corrosion in low temperature polymer electrolyte fuel cells. The fuel cell start-up is a critical step as hydrogen may not yet be evenly distributed in the active area leading to local starvation. The present work investigates the hydrogen distribution and risk for starvation during start-up and after nitrogen purge by extending an existing computational fluid dynamic model to capture transient behavior. The results of the numerical model are compared with detailed experimental analysis on a 25 cm2 triple serpentine flow field with good agreement in all aspects and a required time step size of 1 s. This is two to three orders of magnitude larger than the time steps used by other works resulting in reasonably quick calculation times (e.g. 3 min calculation time for 1 s of experimental testing time using a 2 million element mesh).
Conceptual Study and Development of an Autonomously Operating, Sailing Renewable Energy Conversion System
Jun 2022
Publication
With little time left for humanity to reduce climate change to a tolerable level a highly scalable and rapidly deployable solution is needed that can be implemented by any country. Offshore wind energy in international waters is an underused resource and could even be harnessed by landlocked countries. In this paper the use of sailing wind turbines operating autonomously in high seas to harvest energy is proposed. The electrical energy that is generated by the wind turbine is converted to a renewable fuel and stored onboard. Later the fuel will be transferred to shore or to other destinations of use. The presented idea is explored at the system level where the basic subsystems necessary are identified and defined such as energy conversion and storage as well as propulsion subsystems. Moreover various operating possibilities are investigated including a comparison of different sailing strategies and fuels for storage. Existing ideas are also briefly addressed and an example concept is suggested as well. In this paper the proposed sailing renewable energy conversion system is explored at a higher level of abstraction. Following up on this conceptual study more detailed investigations are necessary to determine whether the development of such a sailing renewable energy conversion system is viable from an engineering economic and environmental point of view.
Safety Design and Engineering Solution of Fuel Cell Powered Ship in Inland Waterway of China
Oct 2021
Publication
From the perspective of risk control when hydrogen fuel and fuel cells are used on ships there is a possibility of low-flash fuel leakage leading to the risk of explosion. Since the fuel cell space (cabin for fuel cell installations) is an enclosed space any small amount of leakage must be handled properly. In ship design area classification is a method of analyzing and classifying the areas where explosive gas atmospheres may occur. If the fuel cell space is regarded as a hazardous area all the electrical devices inside it must be explosion-proof type which will make the ship’s design very difficult. This paper takes a Chinese fuel cell powered ship as an example to analyze its safety. Firstly the leakage rates of fuel cell modules valves and connectors are calculated. Secondly the IEC60079-10-1 algorithm is used to calculate the risk level of the fuel cell space. Finally the ship and fuel cells are optimized and redesigned and the risk level of the fuel cell space is recalculated and compared. The result shows that the optimized fuel space risk level could be reduced to the level of the non-hazardous zone.
Effect of Mechanical Ventilation on Accidental Hydrogen Releases - Large Scale Experiments
Sep 2021
Publication
This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces like underground garages. The purpose was to find the mass flow rate limit hence the TPRD diameter limit that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard outlet 315 mm diameter. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzle from different hydrogen reservoir pressures. Both types of mass flow: constant and blowdown were included in the experimental matrix. The analysis of hydrogen concentration of created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step.
Everything About Hydrogen Podcast: Hydrogen 101
Aug 2019
Publication
A 10-minute tour of hydrogen industry technology and terminology for those who are new to the sector or who would simply like a quick review of the basics behind this burgeoning energy source.
Podcast can be found on their website
Podcast can be found on their website
Everything About Hydrogen Podcast: Ending on a Hy Note
Jul 2021
Publication
This week's show is the last episode of Season 2! To celebrate we invited our friend and colleague Markus Wilthaner partner at McKinsey & Company to come speak with us. Markus has been a leader in the hydrogen space for the past ten years and has drafted a number of the Hydrogen Council's reports since its founding including the newly released - and highly anticipated - Hydrogen Insights 2021 (link below). In this episode we speak with Markus about the state of the market and the innovation he has seen in the last couple of years that make hydrogen a critical part of the energy transition. We had a lot of fun recording this interview and it was the perfect way to end a fantastic EAH season!
The podcast can be found on their website
The podcast can be found on their website
Life Cycle Assessments on Battery Electric Vehicles and Electrolytic Hydrogen: The Need for Calculation Rules and Better Databases on Electricity
May 2021
Publication
LCAs of electric cars and electrolytic hydrogen production are governed by the consumption of electricity. Therefore LCA benchmarking is prone to choices on electricity data. There are four issues: (1) leading Life Cycle Impact (LCI) databases suffer from inconvenient uncertainties and inaccuracies (2) electricity mix in countries is rapidly changing year after year (3) the electricity mix is strongly fluctuating on an hourly and daily basis which requires time-based allocation approaches and (4) how to deal with nuclear power in benchmarking. This analysis shows that: (a) the differences of the GHG emissions of the country production mix in leading databases are rather high (30%) (b) in LCA a distinction must be made between bundled and unbundled registered electricity certificates (RECs) and guarantees of origin (GOs); the residual mix should not be applied in LCA because of its huge inaccuracy (c) time-based allocation rules for renewables are required to cope with periods of overproduction (d) benchmarking of electricity is highly affected by the choice of midpoints and/or endpoint systems and (e) there is an urgent need for a new LCI database based on measured emission data continuously kept up-to-date transparent and open access.
CFD Simulation of Pressure Reduction Inside Large-scale Liquefied Hydrogen Tank
Sep 2021
Publication
Building the international hydrogen supply chain requires the large-scale liquefied hydrogen(LH2) carrier. During shipping LH2 with LH2 Carrier the tank is pressurized by LH2 evaporation due to heat ingress from outside. Before unloading LH2 at the receiving terminal reducing the tank pressure is essential for the safe tank operation. However pressure reduction might cause flashing leading to rapid vaporization of liquefied hydrogen liquid leakage. Moreover it was considered that pressure recovery phenomenon which was not preferred in terms of tank pressure management occurred at the beginning of pressure reduction. Hence the purpose of our research is to clarify the phenomenon inside the cargo tank during pressure reduction. The CFD analysis of the pressure reduction phenomenon was conducted with the VOF based in-house CFD code utilizing the C-CUP scheme combined with the hybrid Level Set and MARS method. In our previous research the pressure reduction experiments with the 30 m³ LH2 tank were simulated and the results showed that the pressure recovery was caused by the boiling delay and the tank pressure followed the saturation pressure after the liquid was fully stirred. In this paper the results were re-evaluated in terms of temperature. While pressure reduction was dominant the temperature of vapor-liquid interface decreased. Once the boiling bubble stirred the interface its temperature reached the saturation temperature after pressure recovery occurred. Moreover it was found that the liquid temperature during pressure reduction could not be measured because of the boiling from the wall of the thermometer. The CFD analysis on pressure reduction of 1250 m³ tank for the LH2 Carrier was also very could occur in the case of the 1250 m³ tank in a certain condition. These results provide new insight into the development of the LH2 carrier.
Everything About Hydrogen Podcast: Masters of Scale: How to Build the Hydrogen Infrastructure of the Future
Oct 2020
Publication
On this week's episode the EAH team speaks with Prof. Armin Schnettler CEO of New Energy Business at Siemens Energy to talk about where green hydrogen solutions fit into the path to decarbonisation how companies like Siemens are looking at those solutions and working to scale them to meet future demand timelines for deployment in different markets how governments can help the private sector and much much more.
The podcast can be found on their website
The podcast can be found on their website
Time‐Decoupling Layered Optimization for Energy and Transportation Systems under Dynamic Hydrogen Pricing
Jul 2022
Publication
The growing popularity of renewable energy and hydrogen‐powered vehicles (HVs) will facilitate the coordinated optimization of energy and transportation systems for economic and en‐ vironmental benefits. However little research attention has been paid to dynamic hydrogen pricing and its impact on the optimal performance of energy and transportation systems. To reduce the dependency on centralized controllers and protect information privacy a time‐decoupling layered optimization strategy is put forward to realize the low‐carbon and economic operation of energy and transportation systems under dynamic hydrogen pricing. First a dynamic hydrogen pricing mechanism was formulated on the basis of the share of renewable power in the energy supply and introduced into the optimization of distributed energy stations (DESs) which will promote hydro‐ gen production using renewable power and minimize the DES construction and operation cost. On the basis of the dynamic hydrogen price optimized by DESs and the traffic conditions on roads the raised user‐centric routing optimization method can select a minimum cost route for HVs to purchase fuels from a DES with low‐cost and/or low‐carbon hydrogen. Finally the effectiveness of the proposed optimization strategy was verified by simulations.
Optimal Integration of Hydrogen-Based Energy Storage Systems in Photovoltaic Microgrids: A Techno-Economic Assessment
Aug 2020
Publication
The feasibility and cost-effectiveness of hydrogen-based microgrids in facilities such as public buildings and small- and medium-sized enterprises provided by photovoltaic (PV) plants and characterized by low electric demand during weekends were investigated in this paper. Starting from the experience of the microgrid being built at the Renewable Energy Facility of Sardegna Ricerche (Italy) which among various energy production and storage systems includes a hydrogen storage system a modeling of the hydrogen-based microgrid was developed. The model was used to analyze the expected performance of the microgrid considering different load profiles and equipment sizes. Finally the microgrid cost-effectiveness was evaluated using a preliminary economic analysis. The results demonstrate that an effective design can be achieved with a PV system sized for an annual energy production 20% higher than the annual energy requested by the user and a hydrogen generator size 60% of the PV nominal power size. This configuration leads to a self-sufficiency rate of about 80% and without public grants a levelized cost of energy comparable with the cost of electricity in Italy can be achieved with a reduction of at least 25–40% of the current initial costs charged for the whole plant depending on the load profile shape.
Experimental Study of Hydrogen Production Using Electrolyte Nanofluids with a Simulated Light Source
Dec 2021
Publication
In this research we conducted water electrolysis experiments of a carbon black (CB) based sodium sulfate electrolyte using a Hoffman voltameter. The main objective was to investigate hydrogen production in such systems as well as analyse the electrical properties and thermal properties of nanofluids. A halogen lamp mimicking solar energy was used as a radiation source and a group of comparative tests were also conducted with different irradiation areas. The results showed that by using CB and light it was possible to increase the hydrogen production rate. The optimal CB concentration was 0.1 wt %. At this concentration the hydrogen production rate increased by 30.37% after 20 min of electrolysis. Hence we show that using CB in electrolytes irradiated by solar energy could save the electrical energy necessary for electrolysis processes.
Modeling the Effects of Implementation of Alternative Ways of Vehicle Powering
Nov 2021
Publication
The trend to replace traditional fossil fuel vehicles is becoming increasingly apparent. The replacement concerns the use of pure biofuels or in blends with traditional fuels the use of hydrogen as an alternative fuel and above all the introduction of electric propulsion. The introduction of new types of vehicle propulsion affects the demand for specific fuels the needs for new infrastructure or the nature of the emissions to the environment generated by fuel production and vehicle operation. The article presents a mathematical model using the difference of two logistic functions the first of which describes the development of the production of a specific type of vehicle and the second the withdrawal of this type of vehicle from traffic after its use. The model makes it possible to forecast both the number of vehicles of each generation as a function of time as well as changes in energy demand from various sources and changes in exhaust emissions. The results of the numerical simulation show replacing classic vehicles with alternative vehicles increases the total energy demand if the generation of the next generation occurs earlier than the decay of the previous generation of vehicles and may decrease in the case of overlapping or delays in the creation of new vehicles compared to the course of the decay function of the previous generation. For electric vehicles carbon dioxide emissions are largely dependent on the emissions from electricity generation. The proposed model can be used to forecast technology development variants as well as analyze the current situation based on the approximation of real data from Vehicle Registration Offices.
Global Hydrogen Review 2021
Oct 2021
Publication
The Global Hydrogen Review is a new annual publication by the International Energy Agency to track progress in hydrogen production and demand as well as in other critical areas such as policy regulation investments innovation and infrastructure development.
The report is an output of the Clean Energy Ministerial Hydrogen Initiative (CEM H2I) and is intended to inform energy sector stakeholders on the status and future prospects of hydrogen while serving as an input to the discussions at the Hydrogen Energy Ministerial Meeting (HEM) organised by Japan. It examines what international progress on hydrogen is needed to help address climate change – and compares real-world developments with the stated ambitions of government and industry and with key actions under the Global Action Agenda launched at the HEM in 2019.
Focusing on hydrogen’s usefulness for meeting climate goals this Review aims to help decision makers fine-tune strategies to attract investment and facilitate deployment of hydrogen technologies while also creating demand for hydrogen and hydrogen-based fuels.
Link to International Energy Agency website
The report is an output of the Clean Energy Ministerial Hydrogen Initiative (CEM H2I) and is intended to inform energy sector stakeholders on the status and future prospects of hydrogen while serving as an input to the discussions at the Hydrogen Energy Ministerial Meeting (HEM) organised by Japan. It examines what international progress on hydrogen is needed to help address climate change – and compares real-world developments with the stated ambitions of government and industry and with key actions under the Global Action Agenda launched at the HEM in 2019.
Focusing on hydrogen’s usefulness for meeting climate goals this Review aims to help decision makers fine-tune strategies to attract investment and facilitate deployment of hydrogen technologies while also creating demand for hydrogen and hydrogen-based fuels.
Link to International Energy Agency website
On Board 70 MPA Hydrogen Composite Pressure Vessel Safety Factor
Sep 2021
Publication
The safety factor of a composite structure in relation to its mechanical rupture is an important criterion for the safety of a 70 MPa composite pressure vessel for hydrogen storage particularly for on-board applications (car bus truck train…). After an introduction of Type IV technology the contribution of carbon fibre composite material structure manufacturing process of pressure vessels and environmental effects on the safety factor are commented. Thanks to an experimental-based evaluation on composite material and H2 composite pressure vessel the safety margins are addressed.
Techno-economic Modelling of Water Electrolysers in the Range of Several MW to Provide Grid Services While Generating Hydrogen for Different Applications: A Case Study in Spain Applied to Mobility with FCEVs
Jun 2019
Publication
The use of hydrogen as energy carrier is a promising option to decarbonize both energy and transport sectors. This paper presents an advanced techno-economic model for calculation of optimal dispatch of large-scale multi MW electrolysis plants in order to obtain a more accurate evaluation of the feasibility of business cases related to the supply of this fuel for different end uses combined with grid services' provision. The model is applied to the Spanish case using different scenarios to determine the minimum demand required from the FCEV market so that electrolysis facilities featuring several MW result in profitable business cases. The results show that grid services contribute to the profitability of hydrogen production for mobility given a minimum but considerable demand from FCEV fleets.
ZnO@ZIF-8 Core-Shell Structure Gas Sensors with Excellent Selectivity to H2
Jun 2021
Publication
As the energy crisis becomes worse hydrogen as a clean energy source is more and more widely used in industrial production and people’s daily life. However there are hidden dangers in hydrogen storage and transportation because of its flammable and explosive features. Gas detection is the key to solving this problem. High quality sensors with more practical and commercial value must be able to accurately detect target gases in the environment. Emerging porous metal-organic framework (MOF) materials can effectively improve the selectivity of sensors as a result of high surface area and coordinated pore structure. The application of MOFs for surface modification to improve the selectivity and sensitivity of metal oxides sensors to hydrogen has been widely investigated. However the influence of MOF modified film thickness on the selectivity of hydrogen sensors is seldom studied. Moreover the mechanism of the selectivity improvement of the sensors with MOF modified film is still unclear. In this paper we prepared nano-sized ZnO particles by a homogeneous precipitation method. ZnO nanoparticle (NP) gas sensors were prepared by screen printing technology. Then a dense ZIF-8 film was grown on the surface of the gas sensor by hydrothermal synthesis. The morphology the composition of the elements and the characters of the product were analyzed by X-ray diffraction analysis (XRD) transmission electron microscope (TEM) scanning electron microscope (SEM) energy dispersive spectrometer (EDS) Brunauer-Emmett-Teller (BET) and differential scanning calorimetry (DSC). It is found that the ZIF-8 film grown for 4 h cannot form a dense core-shell structure. The thickness of ZIF-8 reaches 130 nm at 20 h. Through the detection and analysis of hydrogen (1000 ppm) ethanol (100 ppm) and acetone (50 ppm) from 150 °C to 290 °C it is found that the response of the ZnO@ZIF-8 sensors to hydrogen has been significantly improved while the response to ethanol and acetone was decreased. By comparing the change of the response coefficient when the thickness of ZIF-8 is 130 nm the gas sensor has a significantly improved selectivity to hydrogen at 230 °C. The continuous increase of the thickness tends to inhibit selectivity. The mechanism of selectivity improvement of the sensors with different thickness of the ZIF-8 films is discussed.
THyGA - Tightness Testing of Gas Distribution Components in 40%H2+60%CH4
Aug 2022
Publication
The present work is concerned with the evaluation of the tightness of the components located on domestic and commercial gas lines from the gas meter to the end user appliance in presence of a mixture 40%H2+60%CH4 at 35 mbar. The components were taken from installations being used currently in Germany Denmark Belgium and France. The current standard methods to evaluate natural gas distribution tightness propose testing duration of several minutes. In this work the components tightness was first evaluated using such standard methods before carrying out tests on longer period of time and evaluate the potential influence of time and the results were compared to admissible leakage rates for natural gas in distribution network and in appliances.
Combustion of Hydrogen Enriched Methane and Biogases Containing Hydrogen in a Controlled Auto-Ignition Engine
Dec 2018
Publication
The paper describes a numerical study of the combustion of hydrogen enriched methane and biogases containing hydrogen in a Controlled Auto Ignition engine (CAI). A single cylinder CAI engine is modelled with Chemkin to predict engine performance comparing the fuels in terms of indicated mean effective pressure engine efficiency and pollutant emissions. The effects of hydrogen and carbon dioxide on the combustion process are evaluated using the GRI-Mech 3.0 detailed radical chain reactions mechanism. A parametric study performed by varying the temperature at the start of compression and the equivalence ratio allows evaluating the temperature requirements for all fuels; moreover the effect of hydrogen enrichment on the auto-ignition process is investigated. The results show that at constant initial temperature hydrogen promotes the ignition which then occurs earlier as a consequence of higher chemical reactivity. At a fixed indicated mean effective pressure hydrogen presence shifts the operating range towards lower initial gas temperature and lower equivalence ratio and reduces NOx emissions. Such reduction somewhat counter-intuitive if compared with similar studies on spark-ignition engines is the result of operating the engine at lower initial gas temperatures.
Numerical Simulation on the Thermal Dynamic Behavior of Liquid Hydrogen in a Storage Tank for Trailers
Oct 2022
Publication
In the present study a numerical model was established to investigate the thermal dynamic behavior of liquid hydrogen in a 40-foot ISO tank. The volume of fluids (VOF) method was applied to capture the liquid surface and a phase change model was used to describe the evaporation phenomenon of hydrogen. The mesh independence analysis and the experimental validation have been made. Under different filling levels motion statuses and heat leakage conditions the variations in pressure and temperature of the tank were investigated. The pressure of 90% filling level case was reduced by 12.09% compared to the 50% case. Besides the pressure of the sloshing condition has increased twofold contrasted with the stationary one and thermal stratification disappeared. Additionally 16.67 minutes were taken for the ullage pressure to reach around 1MPa in emergencies of being extremely heated. Some valuable conclusions and suggestions for the transportation of liquid hydrogen arrived. Those could be the references to predict the release time of boil-off hydrogen and primarily support for gas-releasing control strategies.
Renewable Hydrogen Economy Outlook in Africa
Jun 2022
Publication
Hydrogen presents an opportunity for Africa to not only decarbonise its own energy use and enable clean energy access for all but also to export renewable energy. This paper developed a framework for assessing renewable resources for hydrogen production and provides a new critical analysis as to how and what role hydrogen can play in the complex African energy landscape. The regional solar wind CSP and bio hydrogen potential ranges from 366 to 1311 Gt/year 162 to 1782 Gt/year 463 to 2738 Gt/year and 0.03 to 0.06 Gt/year respectively. The water availability and sensitivity results showed that the water shortages in some countries can be abated by importing water from regions with high renewable water resources. A techno-economic comparative analysis indicated that a high voltage direct current (HVDC) system presents the most cost-effective transportation system with overall costs per kg hydrogen of 0.038 $/kg followed by water pipeline with 0.084 $/kg seawater desalination 0.1 $/kg liquified hydrogen tank truck 0.12 $/kg compressed hydrogen pipeline 0.16 $/kg liquefied ammonia pipeline 0.38 $/kg liquefied ammonia tank truck 0.60 $/kg and compressed hydrogen tank truck with 0.77 $/kg. The results quantified the significance of economies of scale due to cost effectiveness of systems such as compressed hydrogen pipeline and liquefied hydrogen tank truck systems when hydrogen production is scaled up. Decentralization is favorable under some constraints e.g. compressed hydrogen and liquefied ammonia tank truck systems will be more cost effective below 800 km and 1400 km due to lower investment and operation costs.
Optimized Design of a H2-Powered Moped for Urban Mobility
Mar 2024
Publication
Micro-mobility plays an increasingly important role in the current energy transition thanks to its low energy consumption and reduced contribution to urban congestion. In this scenario fuel cell hybrid electric vehicles have several advantages over state-of-the-art battery electric vehicles such as increased driving ranges and reduced recharge times. In this paper we study the conversion of a commercial electric moped (Askoll eS3 ®) into a fuel cell hybrid electric vehicle by finding the optimal design of the components through an optimization methodology based on backward dynamic programming. This optimal design and operation strategy can also be implemented with a rulesbased approach. The results show that a system composed of a 1 kW proton exchange membrane fuel cell a 2000 Sl metal hydride hydrogen tank and a 240 Wh buffer battery can cover the same driving range as the batteries in an electric moped (119 km). Such a hybrid system occupies considerably less volume (almost 40 L) and has a negligibly higher mass. The free volume can be used to extend the driving range up to almost three times the nominal value. Moreover by using a high-pressure composite tank it is possible to increase the mass energy density of the onboard energy storage (although compression can require up to 10% of the hydrogen’s chemical energy). The fuel cell hybrid electric vehicle can be recharged with green hydrogen that is locally produced. In detail we analyze a residential scenario and a shared mobility scenario in the small Italian city of Viterbo.
Review of Hydrogen-Gasoline SI Dual Fuel Engines: Engine Performance and Emission
Mar 2023
Publication
Rapid depletion of conventional fossil fuels and increasing environmental concern are demanding an urgent carry out for research to find an alternate fuel which meets the fuel demand with minimum environmental impacts. Hydrogen is considered as one of the important fuel in the near future which meets the above alarming problems. Hydrogen–gasoline dual fuel engines use hydrogen as primary fuel and gasoline as secondary fuel. In this review paper the combustion performance emission and cyclic variation characteristics of a hydrogen–gasoline dual fuel engine have been critically analyzed. According to scientific literature hydrogen–gasoline dual fuel engines have a good thermal efficiency at low and partial loads but the performance deteriorates at high loads. Hydrogen direct injection with gasoline port fuel injection is the optimum configuration for dual fuel engine operating on hydrogen and gasoline. This configuration shows superior result in mitigating the abnormal combustion but experiences high NOx emission. Employing EGR showed a maximum reduction of 77.8% of NOx emission with a EGR flowrate of 18% further increment in flowrate leads to combustion instability. An overview on hydrogen production and carbon footprint related with hydrogen production is also included. This review paper aims to provide comprehensive findings from past works associated with hydrogen–gasoline dual fuel approach in a spark ignition engine
Agreement for the Low Carbon Hydrogen Production Business Model
Dec 2022
Publication
The Heads of Terms for the Low Carbon Hydrogen Agreement sets out the government’s proposal for the final hydrogen production business model design. It will form the basis of the Low Carbon Hydrogen Agreement the business model contract between the government appointed counterparty and a low carbon hydrogen producer.<br/>The business model will provide revenue support to hydrogen producers to overcome the operating cost gap between low carbon hydrogen and high carbon fuels. It has been designed to incentivise investment in low carbon hydrogen production and use and in doing so deliver the government’s ambition of up to 10GW of low carbon hydrogen production capacity by 2030.
Interchangeability of Hydrogen Injection in Zhejiang Natural Gas Pipelines as a Means to Achieve Carbon Neutrality
Sep 2022
Publication
The blending of hydrogen gas into natural gas pipelines is an effective way of achieving the goal of carbon neutrality. Due to the large differences in the calorific values of natural gas from different sources the calorific value of natural gas after mixing with hydrogen may not meet the quality requirements of natural gas and the quality of natural gas entering long-distance natural gas and urban gas pipelines also has different requirements. Therefore it is necessary to study the effect of multiple gas sources and different pipe network types on the differences in the calorific values of natural gas following hydrogen admixing. In this regard this study aimed to determine the quality requirements and proportions of hydrogen-mixed gas in natural gas pipelines at home and abroad and systematically determined the quality requirements for natural gas entering both long-distance natural gas and urban gas pipelines in combination with national standards. Taking the real calorific values of the gas supply cycle of seven atmospheric sources as an example the calorific and Wobbe Index values for different hydrogen admixture ratios in a one-year cycle were calculated. The results showed that under the requirement of natural gas interchangeability there were great differences in the proportions of natural gas mixed with hydrogen from different gas sources. When determining the proportion of hydrogen mixed with natural gas both the factors of different gas sources and the factors of the gas supply cycle should be considered.
The Influence of the First Filling Period Length and Reservoir Level Depth on the Operation of Underground Hydrogen Storage in a Deep Aquifer
Sep 2022
Publication
Underground storage is a method of storing large amounts of renewable energy that can be converted into hydrogen. One of the fundamental problems associated with this process concerns determining the timing and amount of injected gas in the first filling period for the operation of an underground storage facility. Ascertaining the hydrogen flow rate is essential to ensure that the capillary and fracturing pressures are not exceeded. The value of the flow rate was assessed by modelling the injection of hydrogen into a deep aquifer. The best initial H2 injection period was found to be five months. The volume of the cushion gas and the total storage capacity expanded with the extension of the first filling period length. The working capacity grew as the depth increased reaching maximum values at depths of approximately 1200e1400 m. This depth was considered optimal for storing hydrogen in the analysed structure.
Self-Sustaining Control Strategy for Proton-Exchange Membrane Electrolysis Devices Based on Gradient-Disturbance Observation Method
Mar 2023
Publication
This paper proposes a self-sustaining control model for proton-exchange membrane (PEM) electrolysis devices aiming to maintain the temperature of their internal operating environment and thus improve the electrolysis efficiency and hydrogen production rate. Based on the analysis of energy–substance balance and electrochemical reaction characteristics an electrothermal-coupling dynamic model for PEM electrolysis devices was constructed. Considering the influence of the input energy–substance and the output hydrogen and oxygen of PEM electrolysis devices on the whole dynamic equilibrium process the required electrical energy and water molar flow rate are dynamically adjusted so that the temperature of the cathode and the anode is maintained near 338.15 K. The analytical results show that the hydrogen production rate and electrolysis efficiency are increased by 0.275 mol/min and 3.9% respectively by linearly stacking 100 PEM electrolysis devices to form a hydrogen production system with constant cathode and anode operating temperatures around 338.15 K in the self-sustaining controlled mode
Alkaline Electrolysis for Hydrogen Production at Sea: Perspectives on Economic Performance
May 2023
Publication
Alkaline electrolysis is already a proven technology on land with a high maturity level and good economic performance. However at sea little is known about its economic performance toward hydrogen production. Alkaline electrolysis units operate with purified water to split its molecules into hydrogen and oxygen. Purified water and especially that sourced from the sea has a variable cost that ultimately depends on its quality. However the impurities present in that purified water have a deleterious effect on the electrolyte of alkaline electrolysis units that cause them to drop their energy efficiency. This in turn implies a source of economic losses resulting from the cost of electricity. In addition at sea there are various options regarding the electrolyte management of which the cost depends on various factors. All these factors ultimately impact on the levelized cost of the produced hydrogen. This article aims to shed some light on the economic performance of alkaline electrolysis units operating under sea conditions highlighting the knowledge gaps in the literature and initiating a debate in the field.
Supporting Hydrogen Technologies Deployment in EU Regions and Member States: The Smart Specialisation Platform on Energy (S3PEnergy)
May 2018
Publication
In order to maximise European national and regional research and innovation potential the European Union is investing in these fields through different funding mechanisms such as the ESIF or H2020 programme. This investment plan is part of the European 2020 strategy where the concept of Smart Specialisation is also included.<br/>Smart Specialisation is an innovation policy concept designed to promote the efficient and effective use of public investment in regional innovation in order to achieve economic growth. The Smart Specialisation Platform was created to support this concept by assisting regions and Member States in developing implementing and reviewing their research and innovation Smart Specialisation strategies.<br/>The Smart Specialisation Platform comprises several thematic platforms. The thematic Smart Specialisation Platform on energy (S3PEnergy) is a joint initiative of three European Commission services: DG REGIO DG ENER and the Joint Research Centre (JRC). The main objective of the S3PEnergy is to support the optimal and effective uptake of the Cohesion Policy funds for energy and to better align energy innovation activities at national local and regional level through the identification of the technologies and innovative solutions that support in the most cost-effective way the EU energy policy priorities.<br/>In the particular case of hydrogen technologies the activities of the platform are mainly focused on supporting the new Fuel Cells and Hydrogen Joint Undertaking (FCH JU) initiative involving regions and cities. To date more than 80 European cities and regions have committed to participate in this initiative through the signature of a Memorandum of Understanding and more participants are expected to join. S3PEnergy is helping in the identification of potential combination of H2020 funding (provided through FCH JU) and ESIF.<br/>To identify potential synergies among these two funding sources a mapping of the different ESIF opportunities has been performed. In order to map these opportunities Operational Programmes (OPs) and research and innovation strategies for Smart Specialisation (RIS3) of the different European regions and Member States were analysed. The results of this mapping and analysis are presented in this paper."
Dynamic Electric Simulation Model of a Proton Exchange Membrane Electrolyzer System for Hydrogen Production
Sep 2022
Publication
An energy storage system based on a Proton Exchange Membrane (PEM) electrolyzer system which could be managed by a nanoGrid for Home Applications (nGfHA) is able to convert the surplus of electric energy produced by renewable sources into hydrogen which can be stored in pressurized tanks. The PEM electrolyzer system must be able to operate at variable feeding power for converting all the surplus of renewable electric energy into hydrogen in reasonable time. In this article the dynamic electric simulation model of a PEM electrolyzer system with its pressurized hydrogen tanks is developed in a proper calculation environment. Through the calculation code the stack voltage and current peaks to a supply power variation from the minimum value (about 56 W) to the maximum value (about 440 W) are controlled and zeroed to preserve the stack the best range of the operating stack current is evaluated and hydrogen production is monitored.
The Role of Direct Air Capture in EU’s Decarbonisation and Associated Carbon Intensity for Synthetic Fuels Production
May 2023
Publication
Direct air capture (DAC) is considered one of the mitigation strategies in most of the future scenarios trying to limit global temperature to 1.5 ◦C. Given the high expectations placed on DAC for future decarbonisation this study presents an extensive review of DAC technologies exploring a number of techno-economic aspects including an updated collection of the current and planned DAC projects around the world. A dedicated analysis focused on the production of synthetic methane methanol and diesel from DAC and electrolytic hydrogen in the European Union (EU) is also performed where the carbon footprint is analysed for different scenarios and energy sources. The results show that the maximum grid carbon intensity to obtain negative emissions with DAC is estimated at 468 gCO2e/kWh which is compliant with most of the EU countries’ current grid mix. Using only photovoltaics (PV) and wind negative emissions of at least −0.81 tCO2e/tCO2 captured can be achieved. The maximum grid intensities allowing a reduction of the synthetic fuels carbon footprint compared with their fossil-fuels counterparts range between 96 and 151 gCO2e/kWh. However to comply with the Renewable Energy Directive II (REDII) sustainability criteria to produce renewable fuels of non-biological origin the maximum stays between 30.2 to 38.8 gCO2e/kWh. Only when using PV and wind is the EU average able to comply with the REDII threshold for all scenarios and fuels with fuel emissions ranging from 19.3 to 25.8 gCO2e/MJ. These results highlight the importance of using renewable energies for the production of synthetic fuels compliant with the EU regulations that can help reduce emissions from difficult-to-decarbonise sectors.
US-UK Scientific Forum on Sustainable Energy: Electrical Storage in Support of the Grid, Forum Report
Sep 2022
Publication
The effort to meet the ambitious targets of the Paris agreement is challenging many governments. The US and UK governments might have different approaches to achieving the targets but both will rely heavily on renewable energy sources such as wind and solar to power their economies. However these sources of power are unpredictable and ways will have to be developed to store renewable energy for hours days weeks seasons and maybe even years before it is used. As the disruptive and increasingly deadly impacts of climate change are being felt across the world the need to move to more sustainable sources of energy and to identify viable ways to store that energy has never been more important.<br/>This was the subject of the US–UK Science Forum on electrical storage in support of the grid which was held online from 17 – 18 March 2021. Co-organised by the Royal Society and the National Academy of Sciences it brought together a diverse group of 60 scientists policy makers industry leaders regulators and other key stakeholders for a wide-ranging discussion on all aspects of energy storage from the latest research in the field to the current status of deployment. It also considered the current national and international economic and policy contexts in which these developments are taking place. A number of key points emerged from the discussion. First it is clear that renewable energy will play an increasingly important role in the US and UK energy systems of the future and energy storage at a multi-terawatt hour scale has a vital role to play. Of course this will evolve differently to some extent in both countries and elsewhere according to the various geographical technological economic political social and regulatory environments. Second international collaboration is critical – no single nation will solve this problem alone. As two of the world’s leading scientific nations largest economies and per capita CO2 emitters with a long track record of collaboration the US and UK are well placed to play a vital role in addressing this critical challenge. As the discussion highlighted a wide range of energy storage technologies are now emerging and becoming increasingly available many of which have the potential to be critical components of a future net-zero energy system. A crucial next phase is in ensuring that these are technically developed as well as economically and political viable. This will require the support of a wide range of these potential solutions to ensure that their benefits remain widely available and to avoid costly ‘lock-in’. Scientists and science academies have a critical role to play in analysing technology options their combinations and their potential roles in future sustainable energy systems and in working with policymakers to incentivise investment and deployment.
Hydrogen Production by Methane Pyrolysis in Molten Binary Copper Alloys
Sep 2023
Publication
The utilization of hydrogen as an energy carrier and reduction agent in important industrial sectors is considered a key parameter on the way to a sustainable future. Steam reforming of methane is currently the most industrially used process to produce hydrogen. One major drawback of this method is the simultaneous generation of carbon dioxide. Methane pyrolysis represents a viable alternative as the basic reaction produces no CO2 but solid carbon besides hydrogen. The aim of this study is the investigation of different molten copper alloys regarding their efficiency as catalytic media for the pyrolysis of methane in an inductively heated bubble column reactor. The conducted experiments demonstrate a strong influence of the catalyst in use on the one hand on the conversion rate of methane and on the other hand on the properties of the produced carbon. Optimization of these parameters is of crucial importance to achieve the economic competitiveness of the process.
Technical Evaluation of the Flexibility of Water Electrolysis Systems to Increase Energy Flexibility: A Review
Jan 2023
Publication
The goal of achieving water electrolysis on a gigawatt scale faces numerous challenges regarding technological feasibility and market application. Here the flexibility of operation scenarios such as load changes and capacity of electrolysis plays a key role. This raises the question of how flexible electrolysis systems currently are and what possibilities there are to increase flexibility. In order to be able to answer this question in the following a systematic literature research was carried out with the aim to show the current technical possibilities to adapt load and capacity of electrolysis technologies and to determine limits. The result of the systematic literature research is an overview matrix of the electrolysis types AEL PEMEL HTEL and AEMEL already applied in the market. Technical data on the operation of the respective electrolysis stacks as well as details and materials for the respective stack structure (cathode anode electrolyte) were summarized. The flexibility of the individual technologies is addressed by expressing it in values such as load flexibility and startup-times. The overview matrix contains values from various sour1ces in order to make electrolysis comparable at the stack level and to be able to make statements about flexibility. The result of the overview article shows the still open need for research and development to make electrolysis more flexible.
Everything About Hydrogen Podcast: Improving PEM Efficiency
Jan 2023
Publication
On this episode of EAH we sat down with Alejandro Oyarce Barnett Chief Technology Officer and Co-Founder at Hystar. Hystar is a technology-focused company specializing in PEM electrolysers for hydrogen production using renewable energy. The company got its start as a spin-off from SINTEF one of Europe’s largest independent research organizations and has raised private funding so the company can focus on production of its high-efficiency PEM units and keep pace with demand for hydrogen generation capacity. Hystar announced on January 11 2023 that the company has closed a Series B funding round of USD 26mn to rapidly scale-up to full commercial operations with an automated GW-capacity production line by 2025. Alejandro joined us to discuss in more detail the origins of Hystar its technology and the mission at the core of the company.
The podcast can be found on their website.
The podcast can be found on their website.
Increasing the Energy Efficiency of Gas Boosters for Hydrogen Storage and for Refueling Stations
Feb 2023
Publication
A new electrically driven gas booster is described as an alternative to the classical air-driven gas boosters known for their poor energetic efficiency. These boosters are used in small scale Hydrogen storage facilities and in refueling stations for Hydrogen vehicles. In such applications the overall energy count is of significance and must include the efficiency of the compression stage. The proposed system uses an electric motor instead of the pneumatic actuator and increases the total efficiency of the compression process. Two mechanical principles are studied for the transformation of the rotational motion of the motor to the linear displacement of the compressor pistons. The strongly fluctuating power of the compressor is smoothed by an active capacitive auxiliary storage device connected to the DC circuit of the power converter. The proposed system has been verified by numeric simulation including the thermodynamic phenomena the kinetics of the new compressor drive and the the operation of the circuits of the power smoothing system.
Feasibility Study on the Provision of Electricity and Hydrogen for Domestic Purposes in the South of Iran using Grid-connected Renewable Energy Plants
Dec 2018
Publication
This work presents a feasibility study on the provision of electricity and hydrogen with renewable grid connected and off-the-grid systems for Bandar Abbas City in the south of Iran. The software HOMER Pro® has been used to perform the analysis. A techno-enviro-economic study comparing a hybrid system consisting of the grid/wind turbine and solar cell is done. The wind turbine is analyzed using four types of commercially available vertical axis wind turbines (VAWTs). According to the literature review no similar study has been performed so far on the feasibility of using VAWTs and also no work exists on the use of a hybrid system in the studied area. The results indicated that the lowest price of providing the required hydrogen was $0.496 which was achieved using the main grid. Also the lowest price of the electricity generated was $1.55 which was obtained through using EOLO VAWT in the main grid/wind turbine/solar cell scenario. Also the results suggested that the highest rate of preventing CO2 emission which was also the lowest rate of using the national grid with 3484 kg/year was associated with EOLO wind turbines where only 4% of the required electricity was generated by the national grid.
Decarbonizing Primary Steel Production : Techno-economic Assessment of a Hydrogen Based Green Steel Production Plant in Norway
Mar 2022
Publication
High electricity cost is the biggest challenge faced by the steel industry in transitioning to hydrogen based steelmaking. A steel plant in Norway could have access to cheap emission free electricity high-quality iron ore skilled manpower and the European market. An open-source model for conducting techno-economic assessment of a hydrogen based steel manufacturing plant operating in Norway has been developed in this work. Levelized cost of production (LCOP) for two plant configurations; one procuring electricity at a fixed price and the other procuring electricity from the day-ahead electricity markets with different electrolyzer capacity were analyzed. LCOP varied from $622/tls to $722/tls for the different plant configurations. Procuring electricity from the day-ahead electricity markets could reduce the LCOP by 15%. Increasing the electrolyzer capacity reduced the operational costs but increased the capital investments reducing the overall advantage. Sensitivity analysis revealed that electricity price and iron ore price are the major contributors to uncertainty for configurations with fixed electricity prices. For configurations with higher electrolyzer capacity changes in the iron ore price and parameters related to capital investment were found to affect the LCOP significantly.
Molten Carbonate Fuel Cells for Simultaneous CO2 Capture, Power Generation, and H2 Generation
Mar 2022
Publication
This article presents a new technology for the generation of power and steam or other process heat with very low CO2 emissions. It is well known that cogeneration of electricity and steam is highly efficient and that amine units can be used to remove CO2 from combustion flue gas but that the amine unit consumes a significant amount of steam and power reducing the overall system efficiency. In this report the use of molten carbonate fuel cells (MCFCs) to capture CO2 from cogen units is investigated and shown to be highly efficient due to the additional power that they produce while capturing the CO2. Furthermore the MCFCs are capable of reforming methane to hydrogen simultaneous to the power production and CO2 capture. This hydrogen can either be recycled as fuel for consumption by the cogen or MCFCs or exported to an independent combustion unit as low carbon fuel thereby decarbonizing that unit as well. The efficiency of MCFCs for CO2 capture is higher than use of amines in all cases studied often by a substantial margin while at the same time the MCFCs avoid more CO2 than the amine technology. As one example the use of amines on a cogeneration unit can avoid 87.6% of CO2 but requires 4.91 MJ/kg of additional primary energy to do so. In contrast the MCFCs avoid 89.4% of CO2 but require only 1.37 MJ/kg of additional primary energy. The high thermal efficiency and hydrogen export option demonstrate the potential of this technology for widespread deployment in a low carbon energy economy.
Influence of Longitudinal Wind on Hydrogen Leakage and Hydrogen Concentration Sensor Layout of Fuel Cell Vehicles
Jul 2023
Publication
Hydrogen has the physical and chemical characteristics of being flammable explosive and prone to leakage and its safety is the main issue faced by the promotion of hydrogen as an energy source. The most common scene in vehicle application is the longitudinal wind generated by driving and the original position of hydrogen concentration sensors (HCSs) did not consider the influence of longitudinal wind on the hydrogen leakage trajectory. In this paper the computational fluid dynamics (CFD) software STAR CCM 2021.1 is used to simulate the hydrogen leakage and diffusion trajectories of fuel cell vehicles (FCVs) at five different leakage locations the longitudinal wind speeds of 0 km/h 37.18 km/h and 114 km/h and it is concluded that longitudinal wind prolongs the diffusion time of hydrogen to the headspace and reduces the coverage area of hydrogen in the headspace with a decrease of 81.35%. In order to achieve a good detection effect of fuel cell vehicles within the longitudinal wind scene based on the simulated hydrogen concentration–time matrix the scene clustering method based on vector similarity evaluation was used to reduce the leakage scene set by 33%. Then the layout position of HCSs was optimized according to the proposed multi-scene full coverage response time minimization model and the response time was reduced from 5 s to 1 s.
A Review on the Kinetics of Iron Ore Reduction by Hydrogen
Dec 2021
Publication
A clean energy revolution is occurring across the world. As iron and steelmaking have a tremendous impact on the amount of CO2 emissions there is an increasing attraction towards improving the green footprint of iron and steel production. Among reducing agents hydrogen has shown a great potential to be replaced with fossil fuels and to decarbonize the steelmaking processes. Although hydrogen is in great supply on earth extracting pure H2 from its compound is costly. Therefore it is crucial to calculate the partial pressure of H2 with the aid of reduction reaction kinetics to limit the costs. This review summarizes the studies of critical parameters to determine the kinetics of reduction. The variables considered were temperature iron ore type (magnetite hematite goethite) H2/CO ratio porosity flow rate the concentration of diluent (He Ar N2 ) gas utility annealing before reduction and pressure. In fact increasing temperature H2/CO ratio hydrogen flow rate and hematite percentage in feed leads to a higher reduction rate. In addition the controlling kinetics models and the impact of the mentioned parameters on them investigated and compared concluding chemical reaction at the interfaces and diffusion of hydrogen through the iron oxide particle are the most common kinetics controlling models.
Refurbishment of Natural Gas Pipelines towards 100% Hydrogen—A Thermodynamic-Based Analysis
Dec 2022
Publication
Hydrogen is a key enabler of a sustainable society. Refurbishment of the existing natural gas infrastructure for up to 100% H2 is considered one of the most energy- and resource-efficient energy transportation methods. The question remains whether the transportation of 100% H2 with reasonable adaptions of the infrastructure and comparable energy amounts to natural gas is possible. The well-known critical components for refurbishment such as increased compressor power reduced linepack as well as pipeline transport efficiencies and their influencing factors were considered based on thermodynamic calculations with a step-by-step overview. A H2 content of 20–30% results in comparable operation parameters to pure natural gas. In addition to transport in pipelines decentralized H2 production will also play an important role in addressing future demands.
Carbon Footprint Assessment of Hydrogen and Steel
Dec 2022
Publication
Hydrogen has the potential to decarbonize a variety of energy-intensive sectors including steel production. Using the life cycle assessment (LCA) methodology the state of the art is given for current hydrogen production with a focus on the hydrogen carbon footprint. Beside the state of the art the outlook on different European scenarios up to the year 2040 is presented. A case study of the transformation of steel production from coal-based towards hydrogen- and electricity-based metallurgy is presented. Direct reduction plants with integrated electric arc furnaces enable steel production which is almost exclusively based on hydrogen and electricity or rather on electricity alone if hydrogen stems from electrolysis. Thus an integrated steel site has a demand of 4.9 kWh of electric energy per kilogram of steel. The carbon footprint of steel considering a European sustainable development scenario concerning the electricity mix is 0.75 kg CO2eq/kg steel in 2040. From a novel perspective a break-even analysis is given comparing the use of natural gas and hydrogen using different electricity mixes. The results concerning hydrogen production presented in this paper can also be transferred to application fields other than steel.
Chile and its Potential Role Among the Most Affordable Green Hydrogen Producers in the World
Jul 2022
Publication
As result of the adverse effects caused by climate change the nations have decided to accelerate the transition of the energy matrix through the use of non-conventional sources free of polluting emissions. One of these alternatives is green hydrogen. In this context Chile stands out for the exceptional climate that makes it a country with a lot of renewable resources. Such availability of resources gives the nation clear advantages for hydrogen production strong gusts of wind throughout the country the most increased solar radiation in the world lower cost of production of electrical supplies among others. Due to this the nation would be between the lowest estimated cost for hydrogen production i.e. 1.5 USD/kg H2 approximately scenario that would place it as one of the cheapest green hydrogen producer in the world.
Advances in Hydrogen, Carbon Dioxide, and Hydrocarbon Gas Sensor Technology Using GaN and ZnO-Based Devices
Jun 2009
Publication
In this paper we review our recent results in developing gas sensors for hydrogen using various device structures including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs). ZnO nanowires are particularly interesting because they have a large surface area to volume ratio which will improve sensitivity and because they operate at low current levels will have low power requirements in a sensor module. GaN-based devices offer the advantage of the HEMT structure high temperature operation and simple integration with existing fabrication technology and sensing systems. Improvements in sensitivity recoverability and reliability are presented. Also reported are demonstrations of detection of other gases including CO2 and C2H4 using functionalized GaN HEMTs. This is critical for the development of lab-on-a-chip type systems and can provide a significant advance towards a market-ready sensor application.
A Prompt Decarbonization Pathway for Shipping: Green Hydrogen, Ammonia, and Methanol Production and Utilization in Marine Engines
Mar 2023
Publication
The shipping industry has reached a higher level of maturity in terms of its knowledge and awareness of decarbonization challenges. Carbon-free or carbon-neutralized green fuel such as green hydrogen green ammonia and green methanol are being widely discussed. However little attention has paid to the green fuel pathway from renewable energy to shipping. This paper therefore provides a review of the production methods for green power (green hydrogen green ammonia and green methanol) and analyzes the potential of green fuel for application to shipping. The review shows that the potential production methods for green hydrogen green ammonia and green methanol for the shipping industry are (1) hydrogen production from seawater electrolysis using green power; (2) ammonia production from green hydrogen + Haber–Bosch process; and (3) methanol production from CO2 using green power. While the future of green fuel is bright in the short term the costs are expected to be higher than conventional fuel. Our recommendations are therefore as follows: improve green power production technology to reduce the production cost; develop electrochemical fuel production technology to increase the efficiency of green fuel production; and explore new technology. Strengthening the research and development of renewable energy and green fuel production technology and expanding fuel production capacity to ensure an adequate supply of low- and zero-emission marine fuel are important factors to achieve carbon reduction in shipping.
Optimal Dispatch Model for PV-electrolysis Plants in Self-consumption Regime to Produce Green Hydrogen: A Spanish Case Study
May 2022
Publication
The production of green hydrogen from renewable energy by means of water electrolysis is a promising approach to support energy sector decarbonization. This paper presents a techno-economic model of plants with PV sources connected to electrolysis in self-consumption regime that considers the dynamics of electrolysis systems. The model calculates the optimal hourly dispatch of the electrolysis system including the operational states (production standby and idle) the load factor in production and the energy imports and exports to the electricity grid. Results indicate that the model is a useful decision support tool to operate electrolysis plants connected to PV plants in self-consumption regimes with the target of reducing hydrogen production costs.
On the Cost of Zero Carbon Hydrogen: A Techno-economic Analysis of Steam Methane Reforming with Carbon Capture and Storage
May 2023
Publication
This article challenges the view that zero carbon hydrogen from steam methane reforming (SMR) is prohibitively expensive and that the cost of CO2 capture increases exponentially as residual emissions approach zero; a flawed narrative often eliminating SMR produced hydrogen as a route to net zero. We show that the capture and geological storage of 100% of the fossil CO2 produced in a SMR is achievable with commercially available post-combustion capture technology and an open art solvent. The Levelised Cost of Hydrogen (LCOH) of 69£/MWhth HHV (2.7£/kg) for UK production remains competitive to other forms of low carbon hydrogen but retains a hydrogen lifecycle carbon intensity of 5 gCO2e/MJ (LHV) due to natural gas supply chain and embodied greenhouse gas (GHG) emissions. Compensating for the remaining lifecycle GHG emissions via Direct Air Capture with geological CO2 Storage (DACCS) increases the LCOH to 71–86 £/MWhth HHV (+3–25%) for a cost estimate of 100–1000 £/tCO2 for DACCS and the 2022 UK natural gas supply chain methane emission rates. Finally we put in perspective the cost of CO2 avoidance of fuel switching from natural gas to hydrogen with long term price estimates for natural gas use and DACCS and hydrogen produced from electrolysis.
Optimal Capacity Planning of Power to Hydrogen in Integrated Electricity–Hydrogen–Gas Energy Systems Considering Flexibility and Hydrogen Injection
Apr 2022
Publication
With increasing penetration of renewable energy it is important to source adequate system flexibility to maintain security of supply and minimize renewable generation curtailment. Power to hydrogen (P2H) plays an important role in the low-carbon renewable dominated energy systems. By blending green hydrogen produced from renewable power into the natural gas pipelines it is possible to help integrate large-scale intermittent generation and smooth the variability of renewable power output through the interconnection of the natural gas network hydrogen energy network and electric network. A two-stage stochastic mixed-integer nonlinear planning framework for P2H sizing and siting is proposed in this paper considering system flexibility requirements. The problem is then reduced to a mixed-integer second-order cone (MISOC) model through convex transformation techniques in order to reduce the computation burden. Then a distributed algorithm based on Bender’s decomposition is applied to obtain the optimal solution. A modified hybrid IEEE 33-node and Gas 20-node system is then used for simulation tests. The results showed that investment of P2H can significantly reduce the total capital and operational costs with lower renewable generation curtailment and electricity demand shedding. Numerical tests demonstrated to demonstrate the validity of the proposed MISOC model.
Combined Effects of Stress and Temperature on Hydrogen Diffusion in Non-hydride Forming Alloys Applied in Gas Turbines
Jul 2022
Publication
Hydrogen plays a vital role in the utilisation of renewable energy but ingress and diffusion of hydrogen in a gas turbine can induce hydrogen embrittlement on its metallic components. This paper aims to investigate the hydrogen transport in a non-hydride forming alloy such as Alloy 690 used in gas turbines inspired by service conditions of turbine blades i.e. under the combined effects of stress and temperature. An appropriate hydrogen transport equation is formulated accounting for both stress and temperature distributions of the domain in the non-hydride forming alloy. Finite element (FE) analyses are performed to predict steady-state hydrogen distribution in lattice sites and dislocation traps of a double notched specimen under constant tensile load and various temperature fields. Results demonstrate that the lattice hydrogen concentration is very sensitive to the temperature gradients whilst the stress concentration only slightly increases local lattice hydrogen concentration. The combined effects of stress and temperature result in the highest concentration of the dislocation trapped hydrogen in low-temperature regions although the plastic strain is only at a moderate level. Our results suggest that temperature gradients and stress concentrations in turbine blades due to cooling channels and holes make the relatively low-temperature regions susceptible to hydrogen embrittlement.
Risk Analysis of Fire and Explosion of Hydrogen-Gasoline Hybrid Refueling Station Based on Accident Risk Assessment Method for Industrial System
Apr 2023
Publication
Hydrogen–gasoline hybrid refueling stations can minimize construction and management costs and save land resources and are gradually becoming one of the primary modes for hydrogen refueling stations. However catastrophic consequences may be caused as both hydrogen and gasoline are flammable and explosive. It is crucial to perform an effective risk assessment to prevent fire and explosion accidents at hybrid refueling stations. This study conducted a risk assessment of the refueling area of a hydrogen–gasoline hybrid refueling station based on the improved Accident Risk Assessment Method for Industrial Systems (ARAMIS). An improved probabilistic failure model was used to make ARAMIS more applicable to hydrogen infrastructure. Additionally the accident consequences i.e. jet fires and explosions were simulated using Computational Fluid Dynamics (CFD) methods replacing the traditional empirical model. The results showed that the risk levels at the station house and the road near the refueling area were 5.80 × 10−5 and 3.37 × 10−4 respectively and both were within the acceptable range. Furthermore the hydrogen dispenser leaked and caused a jet fire and the flame ignited the exposed gasoline causing a secondary accident considered the most hazardous accident scenario. A case study was conducted to demonstrate the practicability of the methodology. This method is believed to provide trustworthy decisions for establishing safe distances from dispensers and optimizing the arrangement of the refueling area.
Impact of Hydrogen Liquefaction on Hydrogen Fuel Quality for Transport Applications (ISO-14687:2019)
Aug 2022
Publication
Decarbonisation of the energy sector is becoming increasingly more important to the reduction in climate change. Renewable energy is an effective means of reducing CO2 emissions but the fluctuation in demand and production of energy is a limiting factor. Liquid hydrogen allows for long-term storage of energy. Hydrogen quality is important for the safety and efficiency of the end user. Furthermore the quality of the hydrogen gas after liquefaction has not yet been reported. The purity of hydrogen after liquefaction was assessed against the specification of Hydrogen grade D in the ISO-14687:2019 by analysing samples taken at different locations throughout production. Sampling was carried out directly in gas cylinders and purity was assessed using multiple analytical methods. The results indicate that the hydrogen gas produced from liquefaction is of a higher purity than the starting gas with all impurities below the threshold values set in ISO-14687:2019. The amount fraction of water measured in the hydrogen sample increased with repeated sampling from the liquid hydrogen tank suggesting that the sampling system used was affected by low temperatures (−253 ◦C). These data demonstrate for the first time the impact of liquefaction on hydrogen purity assessed against ISO-14687:2019 showing that liquified hydrogen is a viable option for long-term energy storage whilst also improving quality.
Building the Green Hydrogen Market - Current State and Outlook on Green Hydrogen Demand and Electrolyzer Manufacturing
Jul 2022
Publication
Over the past two years requirements to meet climate targets have been intensified. In addition to the tightening of the climate targets and the demand for net-zero achievement by as early as 2045 there have been discussions on implementing and realizing these goals. Hydrogen has emerged as a promising climate-neutral energy carrier. Thus over the last 1.5 years more than 25 countries have published hydrogen roadmaps. Furthermore various studies by different authorities have been released to support the development of a hydrogen economy. This paper examines published studies and hydrogen country roadmaps as part of a meta-analysis. Furthermore a market analysis of electrolyzer manufacturers is conducted. The prospected demand for green hydrogen from various studies is compared to electrolyzer manufacturing capacities and selected green hydrogen projects to identify potential market ramp-up scenarios and to evaluate if green hydrogen demand forecasts can be filled.
Feasibility Study of Vacuum Pressure Swing Adsorption for CO2 Capture From an SMR Hydrogen Plant: Comparison Between Synthesis Gas Capture and Tail Gas Capture
Dec 2021
Publication
In this paper a feasibility study was carried out to evaluate cyclic adsorption processes for capturing CO2 from either shifted synthesis gas or H2 PSA tail gas of an industrial-scale SMR-based hydrogen plant. It is expected that hydrogen is to be widely used in place of natural gas in various industrial sectors where electrification would be rather challenging. A SMR-based hydrogen plant is currently dominant in the market as it can produce hydrogen at scale in the most economical way. Its CO2 emission must be curtailed significantly by its integration with CCUS. Two Vacuum Pressure Swing Adsorption (VPSA) systems including a rinse step were designed to capture CO2 from an industrial-scale SMR-based hydrogen plant: one for the shifted synthesis gas and the other for the H2 PSA tail gas. Given the shapes of adsorption isotherms zeolite 13X and activated carbon were selected for tail gas and syngas capture options respectively. A simple Equilibrium Theory model developed for the limiting case of complete regeneration was taken to analyse the VPSA systems in this feasibility study. The process performances were compared to each other with respect to product recovery bed productivity and power consumption. It was found that CO2 could be captured more cost-effectively from the syngas than the tail gas unless the desorption pressure was too low. The energy consumption of the VPSA was comparable to those of the conventional MDEA processes.
Hydrogen-Enriched Compressed Natural Gas Network Simulation for Consuming Green Hydrogen Considering the Hydrogen Diffusion Process
Sep 2022
Publication
Transporting green hydrogen by existing natural gas networks has become a practical means to accommodate curtailed wind and solar power. Restricted by pipe materials and pressure levels there is an upper limit on the hydrogen blending ratio of hydrogen-enriched compressed natural gas (HCNG) that can be transported by natural gas pipelines which affects whether the natural gas network can supply energy safely and reliably. To this end this paper investigates the effects of the intermittent and fluctuating green hydrogen produced by different types of renewable energy on the dynamic distribution of hydrogen concentration after it is blended into natural gas pipelines. Based on the isothermal steady-state simulation results of the natural gas network two convection–diffusion models for the dynamic simulation of hydrogen injections are proposed. Finally the dynamic changes of hydrogen concentration in the pipelines under scenarios of multiple green hydrogen types and multiple injection nodes are simulated on a seven-node natural gas network. The simulation results indicate that compared with the solar-power-dominated hydrogen productionblending scenario the hydrogen concentrations in the natural gas pipelines are more uniformly distributed in the wind-power-dominated scenario and the solar–wind power balance scenario. To be specific in the solar-power-dominated scenario the hydrogen concentration exceeds the limit for more time whilst the overall hydrogen production is low and the local hydrogen concentration in the natural gas network exceeds the limit for nearly 50% of the time in a day. By comparison in the wind-power-dominated scenario all pipelines can work under safe conditions. The hydrogen concentration overrun time in the solar–wind power balance scenario is also improved compared with the solar-power-dominated scenario and the limit-exceeding time of the hydrogen concentration in Pipe 5 and Pipe 6 is reduced to 91.24% and 91.99% of the solar-power-dominated scenario. This work can help verify the day-ahead scheduling strategy of the electricity-HCNG integrated energy system (IES) and provide a reference for the design of local hydrogen production-blending systems.
Reducing the Cost of Low-carbon Hydrogen Production via Emerging Chemical Looping Process
Jan 2023
Publication
A thorough techno-economic analysis where inherent carbon capture is examined against state-of-the-art blue hydrogen production configurations for large (100000 Nm3 /h) and very large (333000 Nm3 /h) capacities. Advanced solvent-based technologies based on post-combustion capture and auto-thermal reformer combined with a gas heated reformer are simulated with process flowsheet software and compared with the emerging chemical looping process. A network of dynamically operated packed bed reactors has been designed and modelled using an in-house code and key parameters generating uncertainties in the results have been examined in a sensitivity analysis. The chemical looping reforming process presents a higher net reforming efficiency than the benchmark cases (8.2 % higher at large scale and 1.5 % higher at very large scale) ranged 75.4–75.7 % while the specific energy for CO2 avoidance is negative in the range of − 0.78 to − 0.85 MJ/kgCO2. In the carbon capture cases the chemical looping reforming in packed beds technology generated a levelised cost of hydrogen of 168.9 £/kNm3 H2 for the large scale and 159.1 £/kNm3 H2 for the very large scale with the values for the benchmark cases being higher at 196.4 and 166.6 £/kNm3 H2 respectively while the levelised cost of hydrogen values are 1 % higher in the benchmark cases where carbon emission price is accounted for. The carbon capture ratio is 99.9 % for the chemical looping reforming cases compared to 90–91 % for the benchmark ones thus providing a significant foreground for the scale-up and implementation of chemical looping reforming technologies for hydrogen production.
Global Potential of Green Ammonia Based on Hybrid PV-wind Power Plants
Apr 2021
Publication
Ammonia is one of the most commonly used feedstock chemicals globally. Therefore decarbonisation of ammonia production is of high relevance towards achieving a carbon neutral energy system. This study investigates the global potential of green ammonia production from semi-flexible ammonia plants utilising a cost-optimised configuration of hybrid PV-wind power plants as well as conversion and balancing technologies. The global weather data used is on an hourly time scale and 0.45◦ × 0.45◦ spatial resolution. The results show that by 2030 solar PV would be the dominating electricity generation technology in most parts of the world and the role of batteries would be limited while no significant role is found for hydrogen-fuelled gas turbines. Green ammonia could be generated at the best sites in the world for a cost range of 440–630 345–420 300–330 and 260–290 €/tNH3 in 2020 2030 2040 and 2050 respectively for a weighted average capital cost of 7%. Comparing this to the decade-average fossil-based ammonia cost of 300–350 €/t green ammonia could become cost-competitive in niche markets by 2030 and substitute fossil-based ammonia globally at current cost levels. A possible cost decline of natural gas and consequently fossil-based ammonia could be fully neutralised by greenhouse gas emissions cost of about 75 €/tCO2 by 2040. By 2040 green ammonia in China would be lower in cost than ammonia from new coal-based plants even at the lowest coal prices and no greenhouse gas emissions cost. The difference in green ammonia production at the least-cost sites in the world’s nine major regions is less than 50 €/tNH3 by 2040. Thus ammonia shipping cost could limit intercontinental trading and favour local or regional production beyond 2040.
Corrosion of Structural Components of Proton Exchange Membrane Water Electrolyzer Anodes: A Review
Dec 2022
Publication
Proton exchange membrane (PEM) water electrolysis is one of the low temperature processes for producing green hydrogen when coupled with renewable energy sources. Although this technology has already reached a certain level of maturity and is being implemented at industrial scale its high capital expenditures deriving from the utilization of expensive corrosion-resistant materials limit its economic competitiveness compared to the widespread fossil fuel-based hydrogen production such as steam reforming. In particular the structural elements like bipolar plates (BPP) and porous transports layers (PTL) are essentially made of titanium protected by precious metal layers in order to withstand the harsh oxidizing conditions in the anode compartment. This review provides an analysis of literature on structural element degradation on the oxygen side of PEM water electrolyzers from the early investigations to the recent developments involving novel anti-corrosion coatings that protect more cost-effective BPP and PTL materials like stainless steels.
Process Reconfiguration and Intensification: An Emerging Opportunity Enabling Efficient Carbon Capture and Low-cost Blue Hydrogen Production
Mar 2023
Publication
Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources requiring additional CO2 capture to decarbonize which energy intense and costly. In a recent Green Energy & Environment paper Cheng and Di et al. proposed a novel integration process referred to as SECLRHC to generate high-purity H2 by in-situ separation of H2 and CO without using any additional separation unit. Theoretically the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process and thus attaining high-purity hydrogen of ∼99% as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive as long as a suitable CCS measure can be integrated into the industrial manufacturing process.
The Effects of Fuel Type and Cathode Off-gas Recirculation on Combined Heat and Power Generation of Marine SOFC Systems
Dec 2022
Publication
An increasing demand in the marine industry to reduce emissions led to investigations into more efficient power conversion using fuels with sustainable production pathways. Solid Oxide Fuel Cells (SOFCs) are under consideration for long-range shipping because of its high efficiency low pollutant emissions and fuel flexibility. SOFC systems also have great potential to cater for the heat demand in ships but the heat integration is not often considered when assessing its feasibility. This study evaluates the electrical and heat efficiency of a 100 kW SOFC system for marine applications fuelled with methane methanol diesel ammonia or hydrogen. In addition cathode off-gas recirculation (COGR) is investigated to tackle low oxygen utilisation and thus improve heat regeneration. The software Cycle Tempo is used to simulate the power plant which uses a 1D model for the SOFCs. At nominal conditions the highest net electrical efficiency (LHV) was found for methane (58.1%) followed by diesel (57.6%) and ammonia (55.1%). The highest heat efficiency was found for ammonia (27.4%) followed by hydrogen (25.6%). COGR resulted in similar electrical efficiencies but increased the heat efficiency by 11.9% to 105.0% for the different fuels. The model was verified with a sensitivity analysis and validated by comparison with similar studies. It is concluded that COGR is a promising method to increase the heat efficiency of marine SOFC systems.
Design and Performance Assessment of a Solar-to-hydrogen System Thermally Assisted by Recovered Heat from a Molten Carbonate Fuel Cell
Mar 2022
Publication
Solar-to-hydrogen plants are predominantly based on steam electrolysis. Steam electrolysis requires water electricity and heat. The excess electric energy is generally converted into hydrogen via an electrolyser. The use of waste heat in hydrogen generation process promises energy efficiency improvement and production fluctuation reductions. This work investigates the techno-economic performance of the proposed system which recovers the waste heat from molten carbonate fuel cell and uses solar energy to produce steam. Comparison of thermally assisted solar system with corresponding solar system is done. The fuel cell provides 80% of the required thermal energy. The solar PV array provides the required electricity. The thermally assisted solar-to-hydrogen system annual energy efficiency (38.5 %) is higher than that of solar- to- hydrogen system. The investment cost of the proposed system is 2.4 % higher than that using only solar parabolic trough collector for the same required amount of heat. The advantage is that the fuel cell simultaneously produces electricity and heat. The recovery of waste heat allows getting an annual overall efficiency of 63.2 % for the molten carbonate fuel cell. It yields 2152 MWh of electricity per year. The 1 MW electrolysers annually generates 74 tonnes of hydrogen.
Techno-economic Assessment of Green Ammonia Production with Different Wind and Solar Potentials
Nov 2022
Publication
This paper focuses on developing a fast-solving open-source model for dynamic power-to-X plant techno-economic analysis and analysing the method bias that occurs when using other state-of-the-art power-to-X cost calculation methods. The model is a least-cost optimisation of investments and operation-costs taking as input techno-economic data varying power profiles and hourly grid prices. The fuel analysed is ammonia synthesised from electrolytic hydrogen produced with electricity from photovoltaics wind turbines or the grid. Various weather profiles and electrolyser technologies are compared. The calculated costs are compared with those derived using methods and assumptions prevailing in most literature. Optimisation results show that a semi-islanded set-up is the cheapest option and can reduce the costs up to 23% compared to off-grid systems but leads to e-fuels GHG emissions similar to fossil fuels with today’s electricity blend. For off-grid systems estimating costs using solar or wind levelized cost of electricity and capacity factors to derive operating hours leads to costs overestimation up to 30%. The cheapest off-grid configuration reaches production costs of 842 e/t3 . For comparison the "grey" ammonia price was 250 e/t3 in January 2021 and 1500 e/t3 in April 2022 (Western Europe). The optimal power mix is found to always include photovoltaic with 1-axis tracking and sometimes different types of onshore wind turbines at the same site. For systems fully grid connected approximating a highly fluctuating electricity price by a yearly average and assuming a constant operation leads to a small cost.
The Significance of Formal & Legal Factors in Selecting a Location for a Hydrogen Buffer to Stabilize the Operation of Power Distribution Networks
Oct 2022
Publication
This article presents the conceptual assumptions for the process of identifying and evaluating the formal & legal factors that impact the choice of a hydrogen buffer location to stabilize the operation of power distribution networks. The assumption for the research process was establishing a methodological framework for an in-depth analysis of legislative acts (the EU legislation and the national law) to enable identification of synthetic groups of formal & legal factors to be further analyzed using the DEMATEL method. As a result the cause-and-effect relations between the variables were examined and an in-depth analysis was carried out to investigate the level of impact of the formal & legal factors on the functioning and location of a hydrogen energy buffer.
Everything About Hydrogen Podcast: 'Having Hydrogen for Breakfast, Lunch and Dinner'
Apr 2023
Publication
On today’s show Chris Patrick and Alicia speak with Petra Schwager from UNIDO about her work promoting global green hydrogen development with particular emphasis on the Global South.
The podcast can be found on their website.
The podcast can be found on their website.
Energy-Economic Assessment of Islanded Microgrid with Wind Turbine, Photovoltaic Field, Wood Gasifier, Battery, and Hydrogen Energy Storage
Sep 2022
Publication
Island energy systems are becoming an important part of energy transformation due to the growing needs for the penetration of renewable energy. Among the possible systems a combination of different energy generation technologies is a viable option for local users as long as energy storage is implemented. The presented paper describes an energy-economic assessment of an island system with a photovoltaic field small wind turbine wood chip gasifier battery and hydrogen circuit with electrolyzer and fuel cell. The system is designed to satisfy the electrical energy demand of a tourist facility in two European localizations. The operation of the system is developed and dynamically simulated in the Transient System Simulation (TRNSYS) environment taking into account realistic user demand. The results show that in Gdansk Poland it is possible to satisfy 99% of user demand with renewable energy sources with excess energy equal to 31% while in Agkistro Greece a similar result is possible with 43% of excess energy. Despite the high initial costs it is possible to obtain Simple Pay Back periods of 12.5 and 22.5 years for Gdansk and Agkistro respectively. This result points out that under a high share of renewables in the energy demand of the user the profitability of the system is highly affected by the local cost of energy vectors. The achieved results show that the system is robust in providing energy to the users and that future development may lead to an operation based fully on renewables.
What Can Accelerate Technological Convergence of Hydrogen Energy: A Regional Perspective
Jun 2023
Publication
Focusing on technological innovation and convergence is crucial for utilizing hydrogen energy an emerging infrastructure area. This research paper analyzes the extent of technological capabilities in a region that could accelerate the occurrence of technological convergence in the fields related to hydrogen energy through the use of triadic patents their citation information and their regional information. The results of the Bayesian spatial model indicate that the active exchange of diverse original technologies could facilitate technological convergence in the region. On the other hand it is difficult to achieve regional convergence with regard to radical technology. The findings could shed light on the establishment of an R&D strategy for hydrogen technologies. This study could contribute to the dissemination and utilization of hydrogen technologies for sustainable industrial development.
Numerical Investigation of a Fuel Cell-Powered Agricultural Tractor
Nov 2022
Publication
In recent years growing awareness about environmental issues is pushing humankind to explore innovative technologies to reduce the anthropogenic sources of pollutants. Among these sources internal combustion engines in non-road mobile machinery (NRMM) such as agricultural tractors are one of the most important. The aim of this work is to explore the possibility of replacing the conventional diesel engine with an electric powertrain powered by a hybrid storage system consisting of a small battery pack and a fuel-cell system. The battery pack (BP) is necessary to help the fuel cell manage sudden peaks in power demands. Numerical models of the conventional powertrain and a fuel-cell tractor were carried out. To compare the two powertrains work cycles derived from data collected during real operative conditions were exploited and simulated. For the fuel-cell tractor a control strategy to split the electric power between the battery pack and the fuel cell was explored. The powertrains were compared in terms of greenhouse gas emissions (GHG) according to well-to-wheel (WTW) equivalent CO2 emission factors available in the literature. Considering the actual state-of-the-art hydrogen production methods the simulation results showed that the fuel-cell/battery powertrain was able to accomplish the tasks with a reduction of about 50% of the equivalent CO2 emissions compared to traditional diesel-powered vehicles.
Assessing the Feasibility of Hydrogen and Electric Buses for Urban Public Transportation using Rooftop Integrated Photovoltaic Energy in Cuenca Ecuador
Jul 2023
Publication
A main restriction of renewables from intermittent sources is the mismatch between energy resource availability and energy requirements especially when extensive power plants are producing at their highest potential causing huge energy surpluses. In these cases excess power must be stored or curtailed. One alternative is increasing urban solar potential which could be integrated to feed electric buses directly or alternatively through hydrogen (H2 ) as an energy vector. H2 from renewable electricity can be stored and used directly or through fuel cells. This study aims to determine the H2 capability that could be achieved when integrating large-scale photovoltaic (PV) generation in urban areas. This analysis was carried out by determining the PV energy potentially generated by installing PV in Cuenca City downtown (Ecuador). Cuenca is in the process of adopting renewal of the public transport vehicle fleet introducing a new model with an electric tram main network combined with “clean type buses”. The conventional diesel urban transport could be replaced establishing a required vehicle fleet of 475 buses spread over 29 routes emitting 112 tons of CO2 and burning 11175 gallons of diesel daily. Between the main findings we concluded that the electricity that could be produced in the total roof area exceeds the actual demand in the study area by 5.5 times. Taking into account the energy surplus it was determined that the available PV power will cover from 97% to 127% of the total demand necessary to mobilize the city bus fleet. The novelty of this work is the proposal of a combined methodology to find the potential to feed urban transport with urban solar power in cities close to the equatorial line.
Inspection of Coated Hydrogen Transportation Pipelines
Sep 2023
Publication
The growing need for hydrogen indicates that there is likely to be a demand for transporting hydrogen. Hydrogen pipelines are an economical option but the issue of hydrogen damage to pipeline steels needs to be studied and investigated. So far limited research has been dedicated to determining how the choice of inspection method for pipeline integrity management changes depending on the presence of a coating. Thus this review aims to evaluate the effectiveness of inspection methods specifically for detecting the defects formed uniquely in coated hydrogen pipelines. The discussion will begin with a background of hydrogen pipelines and the common defects seen in these pipelines. This will also include topics such as blended hydrogen-natural gas pipelines. After which the focus will shift to pipeline integrity management methods and the effectiveness of current inspection methods in the context of standards such as ASME B31.12 and BS 7910. The discussion will conclude with a summary of newly available inspection methods and future research directions.
A Green Hydrogen Energy System: Optimal Control Strategies for Integrated Hydrogen Storage and Power Generation with Wind Energy
Jul 2022
Publication
The intermittent nature of renewable energy resources such as wind and solar causes the energy supply to be less predictable leading to possible mismatches in the power network. To this end hydrogen production and storage can provide a solution by increasing flexibility within the system. Stored hydrogen as compressed gas can either be converted back to electricity or it can be used as feed-stock for industry heating for built environment and as fuel for vehicles. This research is the first to examine optimal strategies for operating integrated energy systems consisting of renewable energy production and hydrogen storage with direct gas-based use-cases for hydrogen. Using Markov decision process theory we construct optimal policies for day-to-day decisions on how much energy to store as hydrogen or buy from or sell to the electricity market and on how much hydrogen to sell for use as gas. We pay special emphasis to practical settings such as contractually binding power purchase agreements varying electricity prices different distribution channels green hydrogen offtake agreements and hydrogen market price uncertainties. Extensive experiments and analysis are performed in the context of Northern Netherlands where Europe’s first Hydrogen Valley is being formed. Results show that gains in operational revenues of up to 51% are possible by introducing hydrogen storage units and competitive hydrogen market-prices. This amounts to a e126000 increase in revenues per turbine per year for a 4.5 MW wind turbine. Moreover our results indicate that hydrogen offtake agreements will be crucial in keeping the energy transition on track.
Industrial Status, Technological Progress, Challenges, and Prospects of Hydrogen Energy
Apr 2022
Publication
Under the requirements of China's strategic goal of "carbon peaking and carbon neutrality" as a renewable clean and efficient secondary energy source hydrogen benefits from abundant resources a wide variety of sources a high combustion calorific value clean and non-polluting various forms of utilization energy storage mediums and good security etc. It will become a realistic way to help energy transportation petrochemical and other fields to achieve deep decarbonization and will turn into an important replacement energy source for China to build a modern clean energy system. It is clear that accelerating the development of hydrogen energy has become a global consensus. In order to provide a theoretical support for the accelerated transformation of hydrogen-related industries and energy companies and provide a basis and reference for the construction of "Hydrogen Energy China" this paper describes main key technological progresses in the hydrogen industry chain such as hydrogen production storage transportation and application. The status and development trends of hydrogen industrialization are analyzed and then the challenges faced by the development of the hydrogen industry are discussed. At last the development and future of the hydrogen industry are prospected. The following conclusions are achieved. (1) Hydrogen technologies of our country will become mature and enter the road of industrialization. The whole industry chain system of the hydrogen industry is gradually being formed and will realize the leap-forward development from gray hydrogen blue hydrogen to green hydrogen. (2) The overall development of the entire hydrogen industry chain such as hydrogen production storage and transportation fuel cells hydrogen refueling stations and other scenarios should be accelerated. Besides in-depth integration and coordination with the oil and gas industry needs more attention which will rapidly promote the high-quality development of the hydrogen industry system. (3) The promotion and implementation of major projects such as "north-east hydrogen transmission" "west-east hydrogen transmission" "sea hydrogen landing" and utilization of infrastructures such as gas filling stations can give full play to the innate advantages of oil and gas companies in industrial chain nodes such as hydrogen production and refueling etc. which can help to achieve the application of "oil gas hydrogen and electricity" four-station joint construction form a nationwide hydrogen resource guarantee system and accelerate the planning and promotion of the "Hydrogen Energy China" strategy.
Energy and Exergy Analysis of a Geothermal Sourced Multigeneration System for Sustainable City
Feb 2023
Publication
The issue of depleting fossil fuels has emphasized the use of renewable energy. Multigeneration systems fueled by renewables such as geothermal biomass solar etc. have proven to be cutting-edge technologies for the production of different valuable by-products. This study proposes a multigeneration system using a geothermal source of energy. The main outputs include power space heating cooling fresh and hot water dry air and hydrogen. The system includes a regenerative Rankine cycle a double effect absorption cycle and a double flash desalination cycle. A significant amount of electrical power hydrogen and fresh water is generated which can be used for commercial or domestic purposes. The power output is 103 MW. The thermal efficiency is 24.42% while energetic and exergetic efficiencies are 54.22% and 38.96% respectively. The COPen is found to be 1.836 and the COPex is found to be 1.678. The hydrogen and fresh water are produced at a rate of 0.1266 kg/s and 37.6 kg/s respectively.
Risk Management of Energy Communities with Hydrogen Production and Storage Technologies
Jul 2023
Publication
The distributed integration of renewable energy sources plays a central role in the decarbonization of economies. In this regard energy communities arise as a promising entity to coordinate groups of proactive consumers (prosumers) and incentivize investment on clean technologies. However the uncertain nature of renewable energy generation residential loads and trading tariffs pose important challenges both at the operational and economic levels. We study how this management can be directly undertaken by an arbitrageur that making use of an adequate price-based demand response (real-time pricing) system serves as an intermediary with the central electricity market to coordinate different types of prosumers under risk aversion. In particular we consider a sequential futures and spot market where the aggregated shortage or excess of energy within the community can be traded. We aim to study the impact of new hydrogen production and storage technologies on community operation and risk management. These interactions are modeled as a game theoretical setting in the form of a stochastic two-stage bilevel optimization problem which is later reformulated without approximation as a single-level mixed-integer linear problem (MILP). An extensive set of numerical experiments based on real data is performed to study the operation of the energy community under different technical and economical conditions. Results indicate that the optimal involvement in futures and spot markets is highly conditioned by the community’s risk aversion and self-sufficiency levels. Moreover the external hydrogen market has a direct effect on the community’s internal price-tariff system and depending on the market conditions may worsen the utility of individual prosumers.
Stochastic Low-order Modelling of Hydrogen Autoignition in a Turbulent Non-premixed Flow
Jul 2022
Publication
Autoignition risk in initially non-premixed flowing systems such as premixing ducts must be assessed to help the development of low-NOx systems and hydrogen combustors. Such situations may involve randomly fluctuating inlet conditions that are challenging to model in conventional mixture-fraction-based approaches. A Computational Fluid Dynamics (CFD)-based surrogate modelling strategy is presented here for fast and accurate predictions of the stochastic autoignition behaviour of a hydrogen flow in a hot air turbulent co-flow. The variability of three input parameters i.e. inlet fuel and air temperatures and average wall temperature is first sampled via a space-filling design. For each sampled set of conditions the CFD modelling of the flame is performed via the Incompletely Stirred Reactor Network (ISRN) approach which solves the reacting flow governing equations in post-processing on top of a Large Eddy Simulation (LES) of the inert hydrogen plume. An accurate surrogate model namely a Gaussian Process is then trained on the ISRN simulations of the burner and the final quantification of the variability of autoignition locations is achieved by querying the surrogate model via Monte Carlo sampling of the random input quantities. The results are in agreement with the observed statistics of the autoignition locations. The methodology adopted in this work can be used effectively to quantify the impact of fluctuations and assist the design of practical combustion systems. © 2022 The Authors. Published by Elsevier Inc. on behalf of The Combustion Institute.
Anion Exchange Membrane Water Electrolysis from Catalyst Design to the Membrane Electrode Assembly
Jul 2022
Publication
Anion exchange membrane (AEM) electrolysis aims to combine the benefits of alkaline electrolysis such as stability of the cheap catalyst and advantages of proton-exchange membrane systems like the ability to operate at differential pressure fast dynamic response low energy losses and higher current density. However as of today AEM electrolysis is limited by AEMs exhibiting insufficient ionic conductivity as well as lower catalyst activity and stability. Herein recent developments and outlook of AEM electrolysis such as cost-efficient transition metal catalysts for hydrogen evolution reaction and oxygen evolution reaction AEMs ionomer electrolytes ionomer catalyst–electrolyte interaction and membrane-electrode assembly performance and stability are described.
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