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Comparative Study of Battery Storage and Hydrogen Storage to Increase Photovoltaic Self-sufficiency in a Residential Building of Sweden
Dec 2016
Publication
Photovoltaic (PV) is promising to supply power for residential buildings. Battery is the most widely employed storage method to mitigate the intermittence of PV and to overcome the mismatch between production and load. Hydrogen storage is another promising method that it is suitable for long-term storage. This study focuses on the comparison of self-sufficiency ratio and cost performance between battery storage and hydrogen storage for a residential building in Sweden. The results show that battery storage is superior to the hydrogen storage in the studied case. Sensitivity study of the component cost within the hydrogen storage system is also carried out. Electrolyzer cost is the most sensitive factor for improving system performance. A hybrid battery and hydrogen storage system which can harness the advantages of both battery and hydrogen storages is proposed in the last place.
Modelling Decentralized Hydrogen Systems: Lessons Learned and Challenges from German Regions
Feb 2022
Publication
Green hydrogen produced by power‐to‐gas will play a major role in the defossilization of the energy system as it offers both carbon‐neutral chemical energy and the chance to provide flexibility. This paper provides an extensive analysis of hydrogen production in decentralized energy systems as well as possible operation modes (H2 generation or system flexibility). Modelling was realized for municipalities—the lowest administrative unit in Germany thus providing high spatial resolution—in the linear optimization framework OEMOF. The results allowed for a detailed regional analysis of the specific operating modes and were analyzed using full‐load hours share of used negative residual load installed capacity and levelized cost of hydrogen to derive the operation mode of power‐to‐gas to produce hydrogen. The results show that power‐to‐gas is mainly characterized by constant hydrogen production and rarely provides flexibility to the system. Main drivers of this dominant operation mode include future demand for hydrogen and the fact that high full‐load hours reduce hydrogen‐production costs. However changes in the regulatory market and technical framework could promote more flexibility and support possible use cases for the central technology to succeed in the energy transition.
A Review of the Latest Trends in the Use of Green Ammonia as an Energy Carrier in Maritime Industry
Feb 2022
Publication
This review paper examines the key barriers to using green ammonia as an alternative fuel in maritime industry. A literature survey is performed based on research articles and grey literature with the aim of discussing the technoeconomic problems with and benefits of ammonia and the relevant technologies. The limitations of ammonia as a maritime fuel and its supply chain the expected percentage demand by 2030 and 2050 its economic performance compared to other shipping fuels such as hydrogen and the current regulations that may impact ammonia as a maritime fuel are discussed. There are several key barriers to ammonia’s wide adoption: (1) High production costs due to the high capital costs associated with ammonia’s supply chain; (2) availability specifically the limited geographical locations available for ammonia bunkering; (3) the challenge of ramping up current ammonia production; and (4) the development of ammonia-specific regulations addressing issues such as toxicity safety and storage. The general challenges involved with blue ammonia are the large energy penalty and associated operational costs and a lack of technical expertise on its use. Regardless of the origin for ammonia to be truly zero-carbon its whole lifecycle must be considered—a key challenge that will aid in the debate about whether ammonia holds promise as a zero-carbon maritime fuel.
Toward Design of Synergistically Active Carbon-Based Catalysts for Electrocatalytic Hydrogen Evolution
Apr 2014
Publication
Replacement of precious catalyst with cost-effective alternatives would be significantly beneficial for hydrogen production via electrocatalytic hydrogen evolution reaction (HER). All candidates thus far are exclusively metallic catalysts which suffer inherent corrosion and oxidation susceptibility during acidic proton-exchange membrane electrolysis. Herein based on theoretical predictions we designed and synthesized nitrogen (N) and phosphorus (P) dual-doped graphene as a non-metallic electrocatalyst for sustainable and efficient hydrogen production. The N and Phetero-atoms could coactivate the adjacent C atom in the graphene matrix by affecting its valence orbital energy levels to induce a synergistically enhanced reactivity toward HER. As a result the dual-doped graphene showed higher electrocatalytic HER activity than single-doped ones and comparable performance to some of the traditional metallic catalysts.
Flame Acceleration and Deflagration-to-Detonation Transition in Hydrogen-Oxygen Mixture in a Channel with Triangular Obstacles
Sep 2021
Publication
Study of flame acceleration and deflagration-to-detonation transition (DDT) in obstructed channels is an important subject of research for hydrogen safety. Experiments and numerical simulations of DDT in channels equipped with triangular obstacles were conducted in this work. High-speed schlieren photography and pressure records were used to study the flame shape changes flame propagation and pressure build up in the experiments. In the simulations the fully compressible reactive Navier–Stokes equations coupled with a calibrated chemical-diffusion model for stoichiometric hydrogen-oxygen mixture were solved using a high-order numerical method. The simulations were in good agreement with the experiments. The results show that the triangular obstacles significantly promote the flame acceleration and provide conditions for the occurrence of DDT. In the early stages of flame acceleration vortices are generated in the gaps between adjacent obstacles which is the main cause for the flame roll-up and distortion. A positive feedback mechanism between the combustiongenerated flow and flame propagation results in the variations of the size and velocity of vortices. The flame-vortex interactions cause flame fragmentation and consequently rapid growth in flame surface area which further lead to flame acceleration. The initially laminar flame then develops into a turbulent flame with the creation of shocks shock-flame interactions and various flame instabilities. The continuously arranged obstacles interact with shocks and flames and help to create environments in which a detonation can develop. Both flame collision and flame-shock interaction can give rise to detonation in the channels with triangular obstacles.
Life Cycle Environmental and Cost Comparison of Current and Future Passenger Cars under Different Energy Scenarios
Apr 2020
Publication
In this analysis life cycle environmental burdens and total costs of ownership (TCO) of current (2017) and future (2040) passenger cars with different powertrain configurations are compared. For all vehicle configurations probability distributions are defined for all performance parameters. Using these a Monte Carlo based global sensitivity analysis is performed to determine the input parameters that contribute most to overall variability of results. To capture the systematic effects of the energy transition future electricity scenarios are deeply integrated into the ecoinvent life cycle assessment background database. With this integration not only the way how future electric vehicles are charged is captured but also how future vehicles and batteries are produced. If electricity has a life cycle carbon content similar to or better than a modern natural gas combined cycle powerplant full powertrain electrification makes sense from a climate point of view and in many cases also provides reductions in TCO. In general vehicles with smaller batteries and longer lifetime distances have the best cost and climate performance. If a very large driving range is required or clean electricity is not available hybrid powertrain and compressed natural gas vehicles are good options in terms of both costs and climate change impacts. Alternative powertrains containing large batteries or fuel cells are the most sensitive to changes in the future electricity system as their life cycles are more electricity intensive. The benefits of these alternative drivetrains are strongly linked to the success of the energy transition: the more the electricity sector is decarbonized the greater the benefit of electrifying passenger vehicles.
Nickel Sulfides Supported by Carbon Spheres as Efficient Catalysts for Hydrogen Evolution Reaction
Jun 2021
Publication
Ni3S2 and NiS supported on carbon spheres are successfully synthesized by a facile hydrothermal method. And then a series of physical characterizations included XRD (X-ray diffraction) EDS (energy dispersive spectroscopy) FESEM (field emission scanning electron microscopy) and XPS (X-ray photo-electron spectroscopy) were used to analyze the samples. XRD was used to confirm that NiNi3S2 S2 and NiS were successfully fabricated. FESEM indicated that Ni3S2 and NiS disperse well on carbon spheres. Electrochemical tests showed that nickel sulfides supported by carbon spheres exhibited excellent hydrogen evolution performance. The excellent catalytic activity is attributed to the synergistic effect of carbon spheres and transition metal sulfides of which the carbon spheres act to enhance the electrical conductivity and the dispersion of Ni3S2 and NiS thus providing more active sites for the hydrogen evolution reaction.
Integrating Housing Stock and Energy System Models as a Strategy to Improve Heat Decarbonisation Assessments
Aug 2014
Publication
The UK government heat strategy is partially based on decarbonisation pathways from the UK MARKAL energy system model. We review how heat provision is represented in UK MARKAL identifying a number of shortcomings and areas for improvement. We present a completely revised model with improved estimations of future heat demands and a consistent representation of all heat generation technologies. This model represents all heat delivery infrastructure for the first time and uses dynamic growth constraints to improve the modelling of transitions according to innovation theory. Our revised model incorporates a simplified housing stock model which is used produce highly-refined decarbonisation pathways for residential heat provision. We compare this disaggregated model against an aggregated equivalent which is similar to the existing approach in UK MARKAL. Disaggregating does not greatly change the total residential fuel consumption in two scenarios so the benefits of disaggregation will likely be limited if the focus of a study is elsewhere. Yet for studies of residential heat disaggregation enables us to vary consumer behaviour and government policies on different house types as well as highlighting different technology trends across the stock in comparison with previous aggregated versions of the model.
Optimal Synergy between Photovoltaic Panels and Hydrogen Fuel Cells for Green Power Supply of a Green Building—A Case Study
Jun 2021
Publication
Alternative energy resources have a significant function in the performance and decarbonization of power engendering schemes in the building application domain. Additionally “green buildings” play a special role in reducing energy consumption and minimizing CO2 emissions in the building sector. This research article analyzes the performance of alternative primary energy sources (sun and hydrogen) integrated into a hybrid photovoltaic panel/fuel cell system and their optimal synergy to provide green energy for a green building. The study addresses the future hydrogen-based economy which involves the supply of hydrogen as the fuel needed to provide fuel cell energy through a power distribution infrastructure. The objective of this research is to use fuel cells in this field and to investigate their use as a green building energy supply through a hybrid electricity generation system which also uses photovoltaic panels to convert solar energy. The fuel cell hydrogen is supplied through a distribution network in which hydrogen production is outsourced and independent of the power generation system. The case study creates virtual operating conditions for this type of hybrid energy system and simulates its operation over a one-year period. The goal is to demonstrate the role and utility of fuel cells in virtual conditions by analyzing energy and economic performance indicators as well as carbon dioxide emissions. The case study analyzes the optimal synergy between photovoltaic panels and fuel cells for the power supply of a green building. In the simulation an optimally configured hybrid system supplies 100% of the energy to the green building while generating carbon dioxide emissions equal to 11.72% of the average value calculated for a conventional energy system providing similar energy to a standard residential building. Photovoltaic panels account for 32% of the required annual electricity production and the fuel cells generate 68% of the total annual energy output of the system.
Physicochemical Properties of Proton-conducting SmNiO3 Epitaxial Films
Mar 2019
Publication
Proton conducting SmNiO3 (SNO) thin films were grown on (001) LaAlO3 substrates for systematically investigating the proton transport properties. X-ray Diffraction and Atomic Force Microscopy studies reveal that the as-grown SNO thin films have good single crystallinity and smooth surface morphology. The electrical conductivity measurements in air indicate a peak at 473 K in the temperature dependence of the resistance of the SNO films probably due to oxygen loss on heating. A Metal-Insulator-Transition occurs at 373 K for the films after annealing at 873 K in air. In a hydrogen atmosphere (3% H2/97% N2) an anomalous peak in the resistance is found at 685 K on the first heating cycle. Electrochemical Impedance Spectroscopy studies as a function of temperature indicate that the SNO films have a high ionic conductivity (0.030 S/cm at 773 K) in a hydrogen atmosphere. The activation energy for proton conductivity was determined to be 0.23 eV at 473–773 K and 0.37 eV at 773–973 K respectively. These findings demonstrate that SNO thin films have good proton conductivity and are good candidate electrolytes for low temperature proton-conducting Solid Oxide Fuel Cells.
Development of Technical Regulations for Fuel Cell Motorcycles in Japan—Hydrogen Safety
Jul 2019
Publication
Hydrogen fuel cell vehicles are expected to play an important role in the future and thus have improved significantly over the past years. Hydrogen fuel cell motorcycles with a small container for compressed hydrogen gas have been developed in Japan along with related regulations. As a result national regulations have been established in Japan after discussions with Japanese motorcycle companies stakeholders and experts. The concept of Japanese regulations was proposed internationally and a new international regulation on hydrogen-fueled motorcycles incorporating compressed hydrogen storage systems based on this concept are also established as United Nations Regulation No. 146. In this paper several technical regulations on hydrogen safety specific to fuel cell motorcycles incorporating compressed hydrogen storage systems are summarized. The unique characteristics of these motorcycles e.g. small body light weight and tendency to overturn easily are considered in these regulations.
Sustainability Indicators for the Manufacturing and Use of a Fuel Cell Prototype and Hydrogen Storage for Portable Uses
Oct 2021
Publication
A sustainability assessment regarding the manufacturing process and the use of a new proton exchange membrane fuel cell (PEMFC) specially designed for portable hydrogen applications is presented. The initial fuel cell prototype has been configured by taking into account exclusively technical issues. However a life cycle analysis considering environmental and socioeconomic impacts is crucial to improve the model to develop a more sustainable product. From the environ‐ mental perspective the durability of the system and its efficiency are key elements required to de‐ crease the potential overall impacts. High electricity consumption for manufacturing requires a commitment to the use of renewable energies due to the high current value of the projected impact of climate change (42.5 tonnes of CO2 eq). From the socioeconomic point of view the dependence of imported components required for the synthesis of some materials displaces the effects of value added and employment in Spain potentially concentrating the largest impact on countries such as Singapore Japan and the UK whereas the cell assembly would have a greater benefit for the country of fabrication. These results provide a basis for new research strategies since they can be considered standard values for improving future upgrades of the fuel cell in terms of sustainability.
Engineering a Sustainable Gas Future
Nov 2021
Publication
The Institution of Gas Engineers & Managers (IGEM) is the UK’s Professional Engineering Institution supporting individuals and businesses working in the global gas industry. IGEM was founded in 1863 with the purpose of advancing the science and relevant knowledge of gas engineering for the benefit of the public.
As a not-for-profit independent organisation IGEM acts as a trusted source of technical information guidance and services for the gas sector. In today’s net zero context IGEM is focused on engineering a sustainable gas future – we do this by:
This document outlines the current UK gas policy landscape our stance and what contribution we are making as an organisation.
As a not-for-profit independent organisation IGEM acts as a trusted source of technical information guidance and services for the gas sector. In today’s net zero context IGEM is focused on engineering a sustainable gas future – we do this by:
- Helping our members achieve and uphold the highest standards of professional competence to ensure the safety of the public
- Supporting our members in achieving their career goals by providing high quality products services and personal and professional development opportunities
- Acting as the voice of the gas industry when working with stakeholders to develop and improve gas policy.
This document outlines the current UK gas policy landscape our stance and what contribution we are making as an organisation.
Experimental Investigation of the Effects of Simultaneous Hydrogen and Nitrogen Addition on the Emissions and Combustion of a Diesel Engine
Jan 2014
Publication
Overcoming diesel engine emissions trade-off effects especially NOx and Bosch smoke number (BSN) requires investigation of novel systems which can potentially serve the automobile industry towards further emissions reduction. Enrichment of the intake charge with H2 þ N2 containing gas mixture obtained from diesel fuel reforming system can lead to new generation low polluting diesel engines. This paper investigates the effect of simultaneous H2 þ N2 intake charge enrichment on the emissions and combustion of a compression ignition engine. Bottled H2 þ N2 was simultaneously admitted into the intake pipe of the engine in 4% steps starting from 4% (2% H2 þ 2% N2) up to 16% (v/v). The results showed that under specific operating conditions H2 þ N2 enrichment can offer simultaneous NOx BSN and CO emissions reduction. Apart from regulated emissions nitrogen exhaust components were measured. Marginal N2O and zero NH3 emissions were obtained. NO/NO2 ratio increases when speed or load increases. Under low speed low load operation the oxidation of NO is enhanced by the addition of H2 þ N2 mixture. Finally admission of H2 þ N2 has a detrimental effect on fuel consumption
Molybdenum Carbide Microcrystals: Efficient and Stable Catalyst for Photocatalytic H2 Evolution From Water in The Presence Of Dye Sensitizer
Sep 2016
Publication
Rod-like molybdenum carbide (Mo2C) microcrystals were obtained from the pyrolysis of Mo-containing organic-inorganic hybrid composite. We investigated the photocatalytic H2 evolution activity of Mo2C by constructing a Mo2C-dye sensitizer photocatalyst system. A high quantum efficiency of 29.7% was obtained at 480 nm. Moreover Mo2C catalyst can be easily recycled by simple filtration.
Fuel Cell Electric Vehicle (FCEV) Energy Flow Analysis in Real Driving Conditions (RDC)
Aug 2021
Publication
The search for fossil fuels substitutes forces the use of new propulsion technologies applied to means of transportation. Already widespread hybrid vehicles are beginning to share the market with hydrogen-powered propulsion systems. These systems are fuel cells or internal combustion engines powered by hydrogen fuel. In this context road tests of a hydrogen fuel cell drive were conducted under typical traffic conditions according to the requirements of the RDE test. As a result of the carried-out work energy flow conditions were presented for three driving phases (urban rural and motorway). The different contributions to the vehicle propulsion of the hydrogen system and the electric system in each phase of the driving route are indicated. The characteristic interaction of power train components during varying driving conditions was presented. A wide variation in the contribution of the fuel cell and the battery to the vehicle’s propulsion was identified. In urban conditions the share of the fuel cell in the vehicle’s propulsion is more than three times that contributed by the battery suburban—7 times highway—28 times. In the entire test the ratio of FC/BATT use was more than seven while the energy consumption was more than 22 kWh/100 km. The amounts of battery energy used and recovered were found to be very close to each other under RDE test conditions.
Power-to-Gas Hydrogen: Techno-economic Assessment of Processes Towards a Multi-purpose Energy Carrier
Dec 2016
Publication
The present work investigates Power-to-Gas (PtG) options for variable Renewable Electricity storage into hydrogen through low temperature (alkaline and PEM) and high-temperature (SOEC) water electrolysis technologies. The study provides the assessment of the cost of the final product when hydrogen is employed for mobility (on-site refueling stations) electricity generation (by fuel cells in Power-to-Power systems) and grid injection in the natural gas network. Costs estimations are performed for 2013-2030 scenarios. A case study on the impact of variable Renewable Electricity storage by hydrogen generation on the Italian electricity and mobility sectors is presented.
Exergy and Exergoeconomic Analysis of Hydrogen and Power Cogeneration Using an HTR Plant
Mar 2021
Publication
This paper proposes using sodium-cooled fast reactor technologies for use in hydrogen vapor methane (SMR) modification. Using three independent energy rings in the Russian BN-600 fast reactor steam is generated in one of the steam-generating cycles with a pressure of 13.1 MPa and a temperature of 505 °C. The reactor's second energy cycles can increase the gas-steam mixture's temperature to the required amount for efficient correction. The 620 ton/hr 540 °C steam generated in this cycle is sufficient to supply a high-temperature synthesis current source (700 °C) which raises the steam-gas mixture's temperature in the reactor. The proposed technology provides a high rate of hydrogen production (approximately 144.5 ton/hr of standard H2) also up to 25% of the original natural gas in line with existing SMR technology for preparing and heating steam and gas mixtures will be saved. Also exergy analysis results show that the plant's efficiency reaches 78.5% using HTR heat for combined hydrogen and power generation.
Tetrahydroborates: Development and Potential as Hydrogen Storage Medium
Oct 2017
Publication
The use of fossil fuels as an energy supply becomes increasingly problematic from the point of view of both environmental emissions and energy sustainability. As an alternative hydrogen is widely regarded as a key element for a potential energy solution. However differently from fossil fuels such as oil gas and coal the production of hydrogen requires energy. Alternative and intermittent renewable energy sources such as solar power wind power etc. present multiple advantages for the production of hydrogen. On the one hand the renewable sources contribute to a remarkable reduction of pollutants released to the air and on the other hand they significantly enhance the sustainability of energy supply. In addition the storage of energy in form of hydrogen has a huge potential to balance an effective and synergetic utilization of renewable energy sources. In this regard hydrogen storage technology is a key technology towards the practical application of hydrogen as “energy carrier”. Among the methods available to store hydrogen solid-state storage is the most attractive alternative from both the safety and the volumetric energy density points of view. Because of their appealing hydrogen content complex hydrides and complex hydride-based systems have attracted considerable attention as potential energy vectors for mobile and stationary applications. In this review the progresses made over the last century on the synthesis and development of tetrahydroborates and tetrahydroborate-based systems for hydrogen storage purposes are summarized.
Enhanced Hydrogen Generation from Hydrolysis of MgLi Doped with Expanded Graphite
Apr 2021
Publication
Hydrolysis of Mg-based materials is considered as a potential means of safe and convenient real-time control of H2 release enabling efficient loading discharge and utilization of hydrogen in portable electronic devices. At present work the hydrogen generation properties of MgLi-graphite composites were evaluated for the first time. The MgLi-graphite composites with different doping amounts of expanded graphite (abbreviated as EG hereinafter) were synthesized through ball milling and the hydrogen behaviors of the composites were investigated in chloride solutions. Among the above doping systems the 10 wt% EG-doped MgLi exhibited the best hydrogen performance in MgCl2 solutions. In particular the 22 h-milled MgLi-10 wt% EG composites possessed both desirable hydrogen conversion and rapid reaction kinetics delivering a hydrogen yield of 966 mL H2 g−1 within merely 2 min and a maximum hydrogen generation rate of 1147 mL H2 min−1 g−1 as opposed to the sluggish kinetics in the EG-free composites. Moreover the EG-doped MgLi showed superior air-stable ability even under a 75 RH% ambient atmosphere. For example the 22 h-milled MgLi-10 wt% EG composites held a fuel conversion of 89% after air exposure for 72 h rendering it an advantage for Mg-based materials to safely store and transfer in practical applications. The similar favorable hydrogen performance of MgLi-EG composites in (simulate) seawater may shed light on future development of hydrogen generation technologies.
Studies on the Impact of Hydrogen on the Results of THT Measurement Devices
Dec 2021
Publication
An essential prerequisite for safe transport and use of natural gas is their appropriate odorization. This enables the detection of uncontrolled gas leaks. Proper and systematic odorization inspection ensures both safe use of gas and continuity of the process itself. In practice it is conducted through among others measuring odorant concentrations in gas. Control devices for rapid gas odorization measurements that are currently used on a large scale in the gas industry are equipped with electrochemical detectors selective for sulfur compounds like tetrahydrothiophene (THT). Because the selectivity of electrochemical detector response to one compound (e.g. THT) the available declarations of manufacturers show that detector sensitivity (indirectly also the quality of the measurement result) is influenced by the presence of increased e.g. sulfur or hydrogen compound content in the gas. Because of the lack of sufficient source literature data in this field it was necessary to experimentally verify this impact. The results of studies on experimental verification of suspected influence of increased amounts of hydrogen in gas on the response of electrochemical detector was carried out at the Oil and Gas Institute—National Research Institute (INiG—PIB). They are presented in this article. The data gathered in the course of researching the dependence between THT concentration measurement result quality and hydrogen content in gas composition enabled a preliminary assessment of the threat to the safety of end users of gaseous fuels caused by the introduction of this gas into the distribution network. Noticing the scope of necessary changes in the area of odorization is necessary to guarantee this safety.
Overview of Current Development in Electrical Energy Storage Technologies and the Application Potential in Power System Operation
Oct 2014
Publication
Electrical power generation is changing dramatically across the world because of the need to reduce greenhouse gas emissions and to introduce mixed energy sources. The power network faces great challenges in transmission and distribution to meet demand with unpredictable daily and seasonal variations. Electrical Energy Storage (EES) is recognized as underpinning technologies to have great potential in meeting these challenges whereby energy is stored in a certain state according to the technology used and is converted to electrical energy when needed. However the wide variety of options and complex characteristic matrices make it difficult to appraise a specific EES technology for a particular application. This paper intends to mitigate this problem by providing a comprehensive and clear picture of the state-of-the-art technologies available and where they would be suited for integration into a power generation and distribution system. The paper starts with an overview of the operation principles technical and economic performance features and the current research and development of important EES technologies sorted into six main categories based on the types of energy stored. Following this a comprehensive comparison and an application potential analysis of the reviewed technologies are presented.
Recent Developments in High-Performance Nafion Membranes for Hydrogen Fuel Cells Applications
Aug 2021
Publication
As a promising alternative to petroleum fossil energy polymer electrolyte membrane fuel cell has drawn considerable attention due to its low pollution emission high energy density portability and long operation times. Proton exchange membrane (PEM) like Nafion plays an essential role as the core of fuel cell. A good PEM must have satisfactory performance such as high proton conductivity excellent mechanical strength electrochemical stability and suitable for making membrane electrode assemblies (MEA). However performance degradation and high permeability remain the main shortcomings of Nafion. Therefore the development of a new PEM with better performance in some special conditions is greatly desired. In this review we aim to summarize the latest achievements in improving the Nafion performance that works well under elevated temperature or methanol-fueled systems. The methods described in this article can be divided into some categories utilizing hydrophilic inorganic material metal-organic frameworks nanocomposites and ionic liquids. In addition the mechanism of proton conduction in Nafion membranes is discussed. These composite membranes exhibit some desirable characteristics but the development is still at an early stage. In the future revolutionary approaches are needed to accelerate the application of fuel cells and promote the renewal of energy structure.
Hydrogenation Production via Chemical Looping Reforming of Coke Oven Gas
Jun 2020
Publication
Coke oven gas (COG) is one of the most important by-products in the steel industry and the conversion of COG to value-added products has attracted much attention from both economic and environmental views. In this work we apply the chemical looping reforming technology to produce pure H2 from COG. A series of La1-xSrxFeO3 (x = 0 0.2 0.3 0.4 0.5 0.6) perovskite oxides were prepared as oxygen carriers for this purpose. The reduction behaviours of La1-xSrxFeO3 perovskite by different reducing gases (H2 CO CH4 and the mixed gases) are investigated to discuss the competition effect of different components in COG for reacting with the oxygen carriers. The results show that reduction temperatures of H2 and CO are much lower than that of CH4 and high temperatures (>800 °C) are requested for selective oxidation of methane to syngas. The co-existence of CO and H2 shows weak effect on the equilibrium of methane conversion at high temperatures but the oxidation of methane to syngas can inhibit the consumption of CO and H2. The doping of suitable amounts of Sr in LaFeO3 perovskite (e.g. La0.5Sr0.5FeO3) significantly promotes the reactivity for selective oxidation of methane to syngas and inhibits the formation of carbon deposition obtaining both high methane conversion in the COG oxidation step and high hydrogen yield in the water splitting step. The La0.5Sr0.5FeO3 shows the highest methane conversion (67.82%) hydrogen yield (3.34 mmol·g-1) and hydrogen purity (99.85%). The hydrogen yield in water splitting step is treble as high as the hydrogen consumption in reduction step. These results reveal that chemical looping reforming of COG to produce pure H2 is feasible and an O2-assistant chemical looping reforming process can further improve the redox stability of oxygen carrier.
Continuum Level Simulation of the Grain Size and Misorientation Effects on Hydrogen Embrittlement in Nickel
Jul 2016
Publication
This paper addresses the size and misorientation effects on hydrogen embrittlement of a four grain nickel aggregate. The grain interior is modelled with orthotropic elasticity and the grain boundary with cohesive zone technique. The grain misorientation angle is parameterized by fixing the lower grains and rotating the upper grains about the out-of-plane axis. The hydrogen effect is accounted for via the three-step hydrogen informed cohesive zone simulation. The grain misorientation exerts an obvious weakening effect on the ultimate strength of the nickel aggregate which reaches its peak at misorientation angles around 20◦ but such effect becomes less pronounced in the case with a pre-crack. The misorientation could induce size effect in the otherwise size independent case without a pre-crack. The contribution of misorientation to the size effect is negligible compare to that caused by the existence of a pre-crack. These findings indicate that the misorientation effect in cases with a deep pre-crack is weaker than expected in shallow-pre-crack situations. Most of these conclusions hold for the hydrogen charging situation except that the ultimate strength is lowered in all the sub-cases due to hydrogen embrittlement. Interestingly it is observed that the size effect becomes less pronounced with hydrogen taken into account which is caused by the fact that hydrogen takes more time to reach the failure initiation site in larger grains.
HyDeploy Report: Trial Management
Aug 2018
Publication
The trial management philosophy of HyDeploy has been developed to enable the overall objectives of the project to be achieved; the safe demonstration of operating a Gas Distribution Network (GDN) on a blend of natural gas and hydrogen. This document provides an overview of the management and governance processes associated with the trial itself. The operational and safety related undertakings before during and after the trial are summarised within this report as well as the intrial experimental programme. The detailed operational procedures are covered in HyD-Rep09.<br/>The programme structure of HyDeploy consists of three phases: Phase 1: Enabling work for preparation of GS(M)R Exemption Phase 2: Construction and installation of process equipment and Phase 3: Safe injection of hydrogen – the trial.<br/>This report focuses on Phase 3 which has two parts; the Proving Trial and; the Trial. As Statutory Duty Holder Keele is accountable for operation of the network it owns over the course of the trial. Operation and maintenance of the network will be undertaken according to the provisions of the Exemption on the basis of agreed revised procedures (HyD-Rep09) by Keele and Cadent. A governance process is in place to manage the blending of hydrogen into the network. This isdescribed in Sections 2 and 3.<br/>Safety related undertakings will be actioned before during and after the trial to mitigate risks identified through the house-to-house testing (HyD-Rep06) procedural review (HyD-Rep09) and quantitative risk assessment (HyD-Rep02). This scope of the undertakings includes actions associated with the end appliances the network itself and the process equipment to be installed.<br/>The detail of these undertakings is given in Section 4.<br/>As part of the trial an experimental programme has been designed to provide further evidence relating to the interactions of a hydrogen blend on network materials and end appliances. The experimental programme is detailed in Section 5.<br/>Click the supplements tab to see the other documents from this report
Irreversible Hydrogen Embrittlement Study of B1500HS High Strength Boron Steel
Dec 2020
Publication
The reversible/irreversible recovery of mechanical properties and the microstructure characteristics of a typical hot-stamped steel B1500HS have been studied under different conditions of hydrogen permeation. Initially all tested specimens were permeated by hydrogen atoms through an electrochemical hydrogen charging scheme. Then the comparisons between different currents and charging time were performed. The influence of different storage time was compared as well. Additionally the effect of the plastic strain introduced by pre-stretching was also investigated. The experimental results showed that the negative impact of hydrogen embrittlement was altered from reversible to irreversible as the magnitude of the charging current increased. The hydrogen blistering and the hydrogen charging-induced cracks were both observed and inspected in the tested samples regarding the irreversible situation. Moreover the adverse influence of hydrogen embrittlement was enhanced by plastic pre-straining or extending the charging period. At the micro-level hydrogen charging-induced cracks generally were generated at defect locations such as the prior austenite grain boundaries and lath martensite interfaces. Particularly crack direction occurred perpendicular to the orientation of lath martensite and transgranular fracture occurred at the prior austenite grains.
Hydrogen Generation from Wood Chip and Biochar by Combined Continuous Pyrolysis and Hydrothermal Gasification
Jun 2021
Publication
Hydrothermal gasification (HTG) experiments were carried out to extract hydrogen from biomass. Although extensive research has been conducted on hydrogen production with HTG limited research exists on the use of biochar as a raw material. In this study woodland residues (wood chip) and biochar from wood-chip pyrolysis were used in HTG treatment to generate hydrogen. This research investigated the effect of temperature (300–425 °C) and biomass/water (0.5–10) ratio on gas composition. A higher temperature promoted hydrogen production because the water–gas shift reaction and steam-reforming reaction were promoted with an increase in temperature. The methane concentration was related positively to temperature because of the methanation and hydrogenation reactions. A lower biomass/water ratio promoted hydrogen production but suppressed carbon-monoxide production. Most reactions that produce hydrogen consume water but water also affects the water–gas shift reaction balance which decreases the carbon-monoxide concentration. By focusing on the practical application of HTG we attempted biochar treatment by pyrolysis (temperature of heating part: 700 °C) and syngas was obtained from hydrothermal treatment above 425 °C.
Hybrid Power-heat Microgrid Solution Using Hydrogen as an Energy Vector for Residential Houses in Spain. A Case Study
May 2022
Publication
In order to favor a transition to a renewable energy economy it is necessary to study the possible permeation of renewable energy sources not only in the electric grid or industrial scale but also in the small householding scale. One of the most interesting technologies available for this purpose is solar energy since it is a mature technology that can be easily installed in every rooftop. Thus a techno-economic assessment was carried out to evaluate the installation of a solar-based power-heat hybrid microgrid considering the use of hydrogen as an energy vector in a typical residential house in Spain. Lead-acid batteries plus the photovoltaic and solar thermal energy installation are complemented with a hydrogen system composed of an electrolyzer two metal hydride bottles and a fuel cell. A simulation tool has been generated using experimental models developed and validated with real equipment for each one of the electric microgrid component. Three operating modes were tested making use of this tool to better manage the energy consumed/produced and optimize the economic output of the facility. The results show that setting up a hydrogen-based microgrid in a residential house is unviable today mainly due to the high cost of hydrogen generation and consumption equipment. If only solar energy is considered the microgrid inversion (12.500 €) is recovered in ten years. On the other hand selling the electricity output has almost no repercussions considering current electrical rates in Spain. Finally while using an optimization algorithm to manage energy use battery life-spam and economic benefit slightly increase. However this profit may not be enough to justify the use of a more complex control system. The results of this research will help users renewable energy companies investigators and policymakers to better understand the different factors influencing the spread of renewable smart grids in households and propose solutions to address these.
Evaluation of Hydrogen Permeation Characteristics in Rubbery Polymers
Oct 2020
Publication
To find suitable sealing material with low permeability against hydrogen the elaborated evaluation techniques for hydrogen transport properties are necessary. We developed two techniques determining the permeability of hydrogen including software for diffusion behavior analysis. The techniques contain gas chromatography and volumetric collection of hydrogen gas. By measuring the hydrogen released from polymer samples with respect to the elapsed time after being decompressed from the high pressure total amount of adsorption and diffusivity (D) of hydrogen are evaluated with self-developed program of Fick's diffusion equation specified to a sample shape. The solubility (S) and permeability (P) of the polymers are determined through Henry's law and a relation of P=SD respectively. Developed techniques were applied to three kinds of spherical-shaped sealing rubbers NBR EPDM and FKM. The D S and P have been measured as function of pressure. The permeability obtained by both methods are discussed with Comsol simulation.
Economic Value of Flexible Hydrogen-based Polygeneration Energy Systems
Jan 2016
Publication
Polygeneration energy systems (PES) have the potential to provide a flexible high-efficiency and low-emissions alternative for power generation and chemical synthesis from fossil fuels. This study aims to assess the economic value of fossil-fuel PES which rely on hydrogen as an intermediate product. Our analysis focuses on a representative PES configuration that uses coal as the primary energy input and produces electricity and fertilizer as end-products. We derive a series of propositions that assess the cost competitiveness of the modeled PES under both static and flexible operation modes. The result is a set of metrics that quantify the levelized cost of hydrogen the unit profit-margin of PES and the real option values of ‘diversification’ and ‘flexibility’ embedded in PES. These metrics are subsequently applied to assess the economics of Hydrogen Energy California (HECA) a PES currently under development in California. Under our technical and economic assumptions HECA’s levelized cost of hydrogen is estimated at 1.373 $/kgh. The profitability of HECA as a static PES increases in the share of hydrogen converted to fertilizer rather than electricity. However when configured as a flexible PES HECA almost breaks even on a pre-tax basis. Diversification and flexibility are valuable for HECA when polygeneration is compared to static monogeneration of electricity but these two real options have no value when comparing polygeneration to static monogeneration of fertilizers.
Hazards Assessment and Technical Actions Due to the Production of Pressured Hydrogen within a Pilot Photovoltaic-electrolyser-fuel Cell Power System for Agricultural Equipment
Jun 2016
Publication
A pilot power system formed by photovoltaic panels alkaline electrolyser and fuel cell stacks was designed and set up to supply the heating system of an experimental greenhouse. The aim of this paper is to analyse the main safety aspects of this power system connected to the management of the pressured hydrogen such as the explosion limits of the mixture hydrogen-oxygen the extension of the danger zone the protection pressure vessels and the system to make unreactive the plant. The electrolyser unit is the core of this plant and from the safety point of view has been equipped with devices able to highlight the mal-functions before they cause damages. Alarm situations are highlighted and the production process is cut off in safe conditions in the event that the operational parameters have an abnormal deviation from the design values. Also the entire power system has been designed so that any failure to its components does not compromise the workers’ safety even if the risk analysis is in progress because technical operation are being carried out for enhancing the plant functionality making it more suitable to the designed task of supplying electrically the green-house heating system during cold periods. Some experimental data pertinent to the solar radiation and the corresponding hydrogen pro-duction rate are also reported. At present it does not exist a well-established safety reference protocol to design the reliability of these types of power plants and then the assumed safety measures even if related to the achieved pilot installation can represent an original base of reference to set up guidelines for designing the safety of power plants in the future available for agricultural purposes.
Enhanced Performance and Durability of Low Catalyst Loading PEM Water Electrolyser Based on a Short-side Chain Perfluorosulfonic Ionomer
Sep 2016
Publication
Water electrolysis supplied by renewable energy is the foremost technology for producing ‘‘green” hydrogen for fuel cell vehicles. In addition the ability to rapidly follow an intermittent load makes electrolysis an ideal solution for grid-balancing caused by differences in supply and demand for energy generation and consumption. Membrane-electrode assemblies (MEAs) designed for polymer electrolyte membrane (PEM) water electrolysis based on a novel short-side chain (SSC) perfluorosulfonic acid (PFSA) membrane Aquivion with various cathode and anode noble metal loadings were investigated in terms of both performance and durability. Utilizing a nanosized Ir0.7Ru0.3O solid solution anode catalyst and a supported Pt/C cathode catalyst in combination with the Aquivion membrane gave excellent electrolysis performances exceeding 3.2 A cm-2 at 1.8 V terminal cell voltage ( 80% efficiency) at 90 ºC in the presence of a total catalyst loading of 1.6 mg cm−2. A very small loss of efficiency corresponding to 30 mV voltage increase was recorded at 3 A cm 2 using a total noble metal catalyst loading of less than 0.5 mg cm−2 (compared to the industry standard of 2 mg cm−2). Steady-state durability tests carried out for 1000 h at 1 A cm -2 showed excellent stability for the MEA with total noble metal catalyst loading of 1.6 mg cm−2 (cell voltage increase 5 lV/h). Moderate degradation rate (cell voltage increase 15 lV/h) was recorded for the low loading 0.5 mg cm-2 MEA. Similar stability characteristics were observed in durability tests at 3 A cm−2. These high performance and stability characteristics were attributed to the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the the enhanced proton conductivity and good stability of the novel membrane the optimized structural properties of the Ir and Ru oxide solid solution and the enrichment of Ir species on the surface for the anodic catalyst.
Optimal Supply Chains and Power Sector Benefits of Green Hydrogen
Jul 2021
Publication
Green hydrogen can help to decarbonize parts of the transportation sector but its power sector interactions are not well understood so far. It may contribute to integrating variable renewable energy sources if production is sufficiently flexible in time. Using an open-source co-optimization model of the power sector and four options for supplying hydrogen at German filling stations we find a trade-of between energy efficiency and temporal flexibility. For lower shares of renewables and hydrogen more energy-efficient and less flexible small-scale on-site electrolysis is optimal. For higher shares of renewables and/or hydrogen more flexible but less energy-efficient large-scale hydrogen supply chains gain importance as they allow to temporally disentangle hydrogen production from demand via storage. Liquid hydrogen emerges as particularly beneficial followed by liquid organic hydrogen carriers and gaseous hydrogen. Large-scale hydrogen supply chains can deliver substantial power sector benefits mainly through reduced renewable curtailment. Energy modelers and system planners should consider the distinct flexibility characteristics of hydrogen supply chains in more detail when assessing the role of green hydrogen in future energy transition scenarios. We also propose two alternative cost and emission metrics which could be useful in future analyses.
Enhanced Hydrogen Storage of Alanates: Recent Progress and Future Perspectives
Feb 2021
Publication
The global energy crisis and environmental pollution have caused great concern. Hydrogen is a renewable and environmentally friendly source of energy and has potential to be a major alternative energy carrier in the future. Due to its high capacity and relatively low cost of raw materials alanate has been considered as one of the most promising candidates for hydrogen storage. Among them LiAlH4 and NaAlH4 as two representative metal alanates have attracted extensive attention. Unfortunately the high desorption temperature and sluggish kinetics restrict its practical application. In this paper the basic physical and chemical properties as well as the hydrogenation/dehydrogenation reaction mechanism of LiAlH4 and NaAlH4 are briefly reviewed. The recent progress on strategic optimizations toward tuning the thermodynamics and kinetics of the alanate including nanoscaling doping catalysts and compositing modification are emphatically discussed. Finally the coming challenges and the development prospects are also proposed in this review.
Consumer Perceptions of Blended Hydrogen in the Home: Learning from HyDeploy
Apr 2022
Publication
This report presents the results of research into consumer perceptions and the subsequent degree of acceptance of blended hydrogen in domestic properties. Evidence from two trial sites of the HyDeploy programme: i) a private site trial at Keele University North Staffordshire; ii) and a public site trial at Winlaton Gateshead are discussed.
Green Hydrogen: A New Flexibility Source for Security Constrained Scheduling of Power Systems with Renewable Energies
Apr 2021
Publication
Green hydrogen i.e. the hydrogen generated from renewable energy sources (RES) will significantly contribute to a successful energy transition. Besides to facilitate the integration and storage of RES this promising energy carrier is well capable to efficiently link various energy sectors. By introduction of green hydrogen as a new flexibility source to power systems it is necessary to investigate its possible impacts on the generation scheduling and power system security. In this paper a security-constrained multi-period optimal power flow (SC-MPOPF) model is developed aiming to determine the optimal hourly dispatch of generators as well as power to hydrogen (P2H) units in the presence of large-scale renewable energy sources (RES). The proposed model characterizes the P2H demand flexibility in the proposed SC-MPOPF model taking into account the electrolyzer behavior reactive power support of P2H demands and hydrogen storage capability. The developed SC-MPOPF model is applied to IEEE 39-bus system and the obtained numerical results demonstrate the role of P2H flexibility on cost as well as RES's power curtailment reduction.
Scenarios for Deployment of Hydrogen in Meeting Carbon Budgets (E4tech)
Nov 2015
Publication
This research considers the potential role of hydrogen in meeting the UK’s carbon budgets. It was written by consultancy E4tech.<br/>The CCC develops scenarios for the UK’s future energy system to assess routes to decarbonisation and to advise UK Government on policy options. Uncertainty to 2050 is considerable and so different scenarios are needed to assess different trajectories targets and technology combinations. Some of these scenarios assess specific technologies or fuels which have the potential to make a significant contribution to future decarbonisation.<br/>Hydrogen is one such fuel. It has been included in limited quantities in some CCC scenarios but not extensively examined in part due to perceived or anticipated higher costs than some other options. But as hydrogen technology is developed and deployed the cost projections and other performance indicators have become more favourable.
Experimental Study of Hot Inert Gas Jet Ignition of Hydrogen-Oxygen Mixture
Sep 2005
Publication
Experiments were performed to investigate the diffusion ignition process that occurs when hot inert gas (argon or nitrogen) is injected into the stoichiometric hydrogen-oxygen mixture at the test section. Detonation wave initiated by spark plug in the driver section in stoichiometric acetylene-oxygen mixture At P=0.5 MPa and room temperature propagates as incident shockwave in the driven section through inert gas after bursting the diaphragm separating the sections. At the end wall of driver section the inert gas is heated behind the reflected shock wave and then injected in to the test section with the stoichiometric hydrogen-oxygen mixture through the hole 8mm in diameter. An increase of the initial pressure of the combustible mixture in the test section from 0.2 to 0.6MPa resulted in decrease of the minimum temperature of injected gas causing ignition from 1650K to 850K. At the same time the induction time for ignition process has increased from 190 to 320μs when hot argon was injected. For the injection of hot nitrogen an increase of the initial pressure of the combustible mixture from 0.2 to 0.4 MPa resulted in decrease of the minimum temperature of injected inert gas giving ignition from 1150K to 850Kand an increase of the induction time from 170 to 240μs.The results of experiments indicate that ignition occurs when the static enthalpy of injected mass of inert gas exceeds some critical value. The mechanism of ignition process was also studied by schlieren photography.
UK Climate Action Following the Paris Agreement
Oct 2016
Publication
The Paris Agreement marks a significant positive step in global action to tackle climate change. This report considers the domestic actions the UK Government should take as part of a fair contribution to the aims of the Agreement.<br/>The report concludes that the Paris Agreement is a significant step forward in global efforts to tackle climate change. It is more ambitious in its aims to limit climate change than the basis of the UK’s existing climate targets. However it is not yet appropriate to set new UK targets. Existing targets are already stretching and the priority is to take action to meet them.
Next Steps for UK Heat Policy
Oct 2016
Publication
Heating and hot water for UK buildings make up 40% of our energy consumption and 20% of our greenhouse gas emissions. It will be necessary to largely eliminate these emissions by around 2050 to meet the targets in the Climate Change Act and to maintain the UK contribution to international action under the Paris Agreement.<br/>Progress to date has stalled. The Government needs a credible new strategy and a much stronger policy framework for buildings decarbonisation over the next three decades. Many of the changes that will reduce emissions will also contribute toward modern affordable comfortable homes and workplaces and can be delivered alongside a major expansion in the number of homes. This report considers that challenge and sets out possible steps to meet it.
Zero Emission HGV Infrastructure Requirements
May 2019
Publication
The Committee on Climate Change commissioned Ricardo Energy and Environment to carry out research to assess the infrastructure requirements and costs for the deployment of different zero emission heavy goods vehicle (HGV) technology options. The infrastructure considered includes hydrogen refuelling stations ultra-rapid charge points at strategic locations electric overhead recharging infrastructure on the roads and hybrid solutions combining these options.
The research concluded:
It is feasible to build refuelling infrastructure to support the deployment of zero emission HGVs so that they constitute the vast majority of vehicles on the roads by 2050.
Looking at infrastructure alone deploying hydrogen refuelling stations is the cheapest of the options costing a total of £1.7bn in capital expenditure in the time period from now until 2060. The strategic deployment of ultra-rapid charge points is the most expensive at £10.7bn. In all scenarios a significant number of smaller electric HGVs are deployed as these options are available and operating on the streets today. The cost of installing chargers at depots for these vehicles is included.
When the costs of the fuel as well as the infrastructure are included the costs of deploying electricity or hydrogen HGVs are cheaper compared to the continued use of diesel.
Moving to zero-carbon infrastructure for HDVs is a significant challenge and requires planning co-ordination supply chains resource and materials and a skilled workforce as well as strong government policy to enable the market to deliver.
The Report can be found here
The research concluded:
It is feasible to build refuelling infrastructure to support the deployment of zero emission HGVs so that they constitute the vast majority of vehicles on the roads by 2050.
Looking at infrastructure alone deploying hydrogen refuelling stations is the cheapest of the options costing a total of £1.7bn in capital expenditure in the time period from now until 2060. The strategic deployment of ultra-rapid charge points is the most expensive at £10.7bn. In all scenarios a significant number of smaller electric HGVs are deployed as these options are available and operating on the streets today. The cost of installing chargers at depots for these vehicles is included.
When the costs of the fuel as well as the infrastructure are included the costs of deploying electricity or hydrogen HGVs are cheaper compared to the continued use of diesel.
Moving to zero-carbon infrastructure for HDVs is a significant challenge and requires planning co-ordination supply chains resource and materials and a skilled workforce as well as strong government policy to enable the market to deliver.
The Report can be found here
2050 Energy Scenarios: The UK Gas Networks Role in a 2050 Whole Energy System
Jul 2016
Publication
Energy used for heat accounts (in terms of final consumption) for approximately 45% of our total energy needs and is critical for families to heat their homes on winter days. Decarbonising heat while still meeting peak winter heating demands is recognised as a big perhaps the biggest challenge for the industry. The way heat has been delivered in the UK has not fundamentally changed for decades and huge investments have been made in gas infrastructure assets ranging from import terminals to networks through to the appliances in our homes. Changing how heat is delivered whichever way is chosen will be a major economic and practical challenge affecting families and businesses everywhere. Any plan to decarbonise will need to address power and transport alongside heat. Our report has also looked at potential decarbonisation of power and transport as part of a whole energy system approach.
In this report we explore ways that the heat sector can be decarbonised by looking at four possible future scenarios set in 2050. These stylised scenarios present illustrative snapshots of alternative energy solutions. The scenarios do not present a detailed roadmap – indeed the future may include some elements from each. We have analysed the advantages disadvantages and costs of each scenario. All our scenarios meet the 2050 Carbon emissions targets. In this report we have concentrated on reductions to CO2 emissions and we have not considered other greenhouse gases.
In this report we explore ways that the heat sector can be decarbonised by looking at four possible future scenarios set in 2050. These stylised scenarios present illustrative snapshots of alternative energy solutions. The scenarios do not present a detailed roadmap – indeed the future may include some elements from each. We have analysed the advantages disadvantages and costs of each scenario. All our scenarios meet the 2050 Carbon emissions targets. In this report we have concentrated on reductions to CO2 emissions and we have not considered other greenhouse gases.
Flexible Electricity Dispatch of an Integrated Solar Combined Cycle through Thermal Energy Storage and Hydrogen Production
Jun 2021
Publication
In this work the flexible operation of an Integrated Solar Combined Cycle (ISCC) power plant has been optimized considering two different energy storage approaches. The objective of this proposal is to meet variable users’ grid demand for an extended period at the lowest cost of electricity. Medium temperature thermal energy storage (TES) and hydrogen generation configurations have been analyzed from a techno-economic point of view. Results found from annual solar plant performance indicate that molten salts storage solution is preferable based on the lower levelized cost of electricity (0.122 USD/kWh compared to 0.158 USD/kWh from the hydrogen generation case) due to the lower conversion efficiencies of hydrogen plant components. However the hydrogen plant configuration exceeded in terms of plant availability and grid demand coverage as fewer design constraints resulted in a total demand coverage of 2155 h per year. It was also found that grid demand curves from industrial countries limit the deployment of medium-temperature TES systems coupled to ISCC power plants since their typical demand curves are characterized by lower power demand around solar noon when solar radiation is higher. In such scenarios the Brayton turbine design is constrained by noon grid demand which limits the solar field and receiver thermal power design. View Full-Text
National Training Facility for Hydrogen Safety. Five year plan for HAMMER
Sep 2005
Publication
A suitably trained emergency response force is an essential component for safe implementation of any type of fuel infrastructure. Because of the relative newness of hydrogen as a fuel however appropriate emergency response procedures are not yet well understood by responder workforces across the United States and around the world. A significant near-term training effort is needed to ensure that the future hydrogen infrastructure can be developed and operated with acceptable incident risk. Efforts are presently underway at the HAMMER site in Washington State to develop curricula related to hydrogen properties and behavior identification of problems (e.g. incorrect equipment installation) and appropriate response and other relevant information intended for classroom instruction. In addition a number of hands-on training props are planned for realistic simulation of hydrogen incidents in order to convey proper response procedures in high-pressure cryogenic high leakage or other high-risk accident situations. Surveys of emergency responders fire marshals regulatory authorities manufacturers and others are being undertaken to ensure that the capabilities developed and offered at HAMMER will meet the acknowledged need. This paper describes the training curricula and props anticipated at HAMMER and is intended to provide useful information to others planning similar training programs.
Getting Net Zero Done- The Crucial Role of Decarbonised Gas and How to Support It
May 2020
Publication
The term ‘decarbonised gas’ refers to biogases hydrogen and carbon capture utilisation and storage (CCUS). This strategy paper sets out how decarbonised gas can help to get net zero done by tackling the hard-to-decarbonise sectors – industry heavy transport and domestic heating – which together account for around 40% of UK greenhouse gas emissions. It also illustrates the crucial importance of supportive public opinion and sets out in detail how decarbonised gas can help to ensure that net zero is achieved with public support. The report is based on extensive quantitative and qualitative opinion research on climate change in general net zero emissions in the UK and the specific decarbonised gas solutions in homes transport and industry. The full quantitative data is contained in the Supplements tab.<br/><a href="https://www.dgalliance.org/wp-content/uploads/2020/05/DGA-Getting-Net-Zero-Done-final-May-2020.pdf"/><a href="https://www.dgalliance.org/wp-content/uploads/2020/05/DGA-Getting-Net-Zero-Done-final-May-2020.pdf"/>
Heat Network Detailed Project Development Resource: Guidance on Strategic and Commercial Case
Jul 2016
Publication
This document provides guidance on the commercial and strategic elements of a heat network project to support completion of a project business case.
The guidance is intended for local authorities and heat network developers to support their investigations and enable progression from feasibility stage through to business case delivery. The guidance has been drafted with reference to policy legislation and regulation in England and Wales; however much of the guidance is likely also to be relevant to projects in Scotland and Northern Ireland.
The guidance specifically supports the HMT Green Book Five Cases Business Model (the Five Cases Model) and the derived DBEIS Business Case Template (DBEIS BCT) that follows this structure but will also be applicable in other instances. The Five Cases Model (and similarly the DBEIS BCT) considers the viability of the project from five perspectives:
Although all five elements are relevant this guide particularly focuses on the Strategic and Commercial cases.
Related Document Heat Networks 2020
The guidance is intended for local authorities and heat network developers to support their investigations and enable progression from feasibility stage through to business case delivery. The guidance has been drafted with reference to policy legislation and regulation in England and Wales; however much of the guidance is likely also to be relevant to projects in Scotland and Northern Ireland.
The guidance specifically supports the HMT Green Book Five Cases Business Model (the Five Cases Model) and the derived DBEIS Business Case Template (DBEIS BCT) that follows this structure but will also be applicable in other instances. The Five Cases Model (and similarly the DBEIS BCT) considers the viability of the project from five perspectives:
- Strategic
- Economic
- Commercial
- Financial
- Management
Although all five elements are relevant this guide particularly focuses on the Strategic and Commercial cases.
Related Document Heat Networks 2020
Gas Goes Green: Delivering the Pathway to Net Zero
May 2020
Publication
Gas Goes Green brings together the engineering expertise from the UK’s five gas network operators building on the foundations of our existing grid infrastructure innovation projects and the wider scientific community. This is a blueprint to meet the challenges and opportunities of climate change delivering net zero in the most cost effective and least disruptive way possible.<br/>Delivering our vision is not just an engineering challenge but will involve active participation from policy makers regulators the energy industry and consumers. Gas Goes Green will undertake extensive engagement to deliver our programme and collaborate with existing projects already being delivered across the country.<br/>Britain’s extensive gas network infrastructure provides businesses and the public with the energy they need at the times when they need it the most. The gas we deliver plays a critical role in our everyday lives generating electricity fuelling vehicles heating our homes and providing the significant amounts of energy UK heavy industry needs. The Gas Goes Green programme aims to ensure that consumers continue to realise these benefits by transitioning our infrastructure into a net zero energy system.
Experimental Study on Hydrogen Explosions in a Full-scale Hydrogen Filling Station Model
Sep 2005
Publication
In order for fuel cell vehicles to develop a widespread role in society it is essential that hydrogen refuelling stations become established. For this to happen there is a need to demonstrate the safety of the refuelling stations. The work described in this paper was carried out to provide experimental information on hydrogen outflow dispersion and explosion behaviour. In the first phase homogeneous hydrogen-air-mixtures of a known concentration were introduced into an explosion chamber and the resulting flame speed and overpressures were measured. Hydrogen concentration was the dominant factor influencing the flame speed and overpressure. Secondly high-pressure hydrogen releases were initiated in a storage room to study the accumulation of hydrogen. For a steady release with a constant driving pressure the hydrogen concentration varied as the inlet airflow changed depending on the ventilation area of the room the external wind conditions and also the buoyancy induced flows generated by the accumulating hydrogen. Having obtained this basic data the realistic dispersion and explosion experiments were executed at full-scale in the hydrogen station model. High-pressure hydrogen was released from 0.8-8.0mm nozzle at the dispenser position and inside the storage room in the full-scale model of the refuelling station. Also the hydrogen releases were ignited to study the overpressures that can be generated by such releases. The results showed that overpressures that were generated following releases at the dispenser location had a clear correlation with the time of ignition distance from ignition point.
CFD Investigation of Filling and Emptying of Hydrogen Tanks
Oct 2015
Publication
During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from −40 °C to 85 °C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the simulation results have been compared with new experimental data for different filling and emptying strategies. The comparison between experiments and simulations is shown for the temperatures of the gas inside the tank for the temperatures at the interface between the liner and the composite material and for the temperatures on the external surface of the vessel.
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