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Hy4Heat Hydrogen Colourant Report
May 2021
Publication
As part of Work Package 2 (WP2) of the Hy4Heat programme DNV produced a substantive report regarding colourant within a potential hydrogen gas network within the UK. Considering the advances within the hydrogen industry over the past year this covering document provides an update to the results as presented by DNV based on current industry progress and research.
The Hydrogen Colourant report was a study to determine if there is a requirement for adding a colourant to hydrogen to ensure that safe burning and user acceptance is achieved and to investigate the optimum solution if a colourant is required. The recommendation is that adding colourant to a future hydrogen gas network for use within buildings is not necessary if engineering measures are put in place to enable safe appliance operation."
- Advancements have been made in the understanding of key topics:
- Flame visibility and supervision
- Health and safety of colourant additives
- Production of Nitrogen Oxides (NOx)
- Likelihood of ignition from domestic electrical installations
- Nature of gas escapes
The Hydrogen Colourant report was a study to determine if there is a requirement for adding a colourant to hydrogen to ensure that safe burning and user acceptance is achieved and to investigate the optimum solution if a colourant is required. The recommendation is that adding colourant to a future hydrogen gas network for use within buildings is not necessary if engineering measures are put in place to enable safe appliance operation."
Grand Canonical Monte Carlo Simulations of the Hydrogen Storage Capacities of Slit-shaped Pores, Nanotubes and Torusenes
Jan 2022
Publication
Grand Canonical Monte Carlo GCMC simulations are used to study the gravimetric and volumetric hydrogen storage capacities of different carbon nanopores shapes: Slit-shaped nanotubes and torusenes at room temperature 298.15 K and at pressures between 0.1 and 35 MPa and for pore diameter or width between 4 and 15 A. The influence of the pore shape or curvature on the storage capacities as a function of pressure temperature and pore diameter is investigated and analyzed. A large curvature of the pores means in general an increase of the storage capacities of the pores. While torusenes and nanotubes have surfaces with more curvature than the slit-shaped planar pores their capacities are lower than those of the slit-shaped pores according to the present GCMC simulations. Torusene a less studied carbon nanostructure has two radii or curvatures but their storage capacities are similar or lower than those of nanotubes which have only one radius or curvature. The goal is to obtain qualitative and quantitative relationships between the structure of porous materials and the hydrogen storage capacities in particular or especially the relationship between shape and width of the pores and the hydrogen storage capacities of carbon-based porous materials.
Hydrogen as a Long-Term Large-Scale Energy Storage Solution to Support Renewables
Oct 2018
Publication
This paper presents a case study of using hydrogen for large-scale long-term storage application to support the current electricity generation mix of South Australia state in Australia which primarily includes gas wind and solar. For this purpose two cases of battery energy storage and hybrid battery-hydrogen storage systems to support solar and wind energy inputs were compared from a techno-economical point of view. Hybrid battery-hydrogen storage system was found to be more cost competitive with unit cost of electricity at $0.626/kWh (US dollar) compared to battery-only energy storage systems with a $2.68/kWh unit cost of electricity. This research also found that the excess stored hydrogen can be further utilised to generate extra electricity. Further utilisation of generated electricity can be incorporated to meet the load demand by either decreasing the base load supply from gas in the present scenario or exporting it to neighbouring states to enhance economic viability of the system. The use of excess stored hydrogen to generate extra electricity further reduced the cost to $0.494/kWh.
Inefficient Investments as a Key to Narrowing Regional Economic Imbalances
Feb 2022
Publication
Policy led decisions aiming at decarbonizing the economy may well exacerbate existing regional economic imbalances. These effects are seldomly recognised in spatially aggregated top-down and techno-economic decarbonization strategies. Here we present a spatial economic framework that quantifies the gross value added associated with low carbon hydrogen investments while accounting for region-specific factors such as the industrial specialization of regions their relative size and their economic interdependencies. In our case study which uses low carbon hydrogen produced via autothermal reforming combined with carbon capture and storage to decarbonize the energy intensive industries in Europe and in the UK we demonstrate that interregional economic interdependencies drive the overall economic benefits of the decarbonization. Policies intended to concurrently transition to net zero and address existing regional imbalances as in the case of the UK Industrial Decarbonization Challenge should take these local factors into account.
Hydrogen Production, Storage and Transport for Renewable Energy and Chemicals: An Environmental Footprint Assessment
Dec 2022
Publication
Hydrogen applications range from an energy carrier to a feedstock producing bulk and other chemicals and as an essential reactant in various industrial applications. However the sustainability of hydrogen production storage and transport are neither unquestionable nor equal. Hydrogen is produced from natural gas biogas aluminium acid gas biomass electrolytic water splitting and others; a total of eleven sources were investigated in this work. The environmental impact of hydrogen production storage and transport is evaluated in terms of greenhouse gas and energy footprints acidification eutrophication human toxicity potential and eco-cost. Different electricity mixes and energy footprint accounting approaches supported by sensitivity analysis are conducted for a comprehensive overview. H2 produced from acid gas is identified as the production route with the highest eco-benefit (− 41188 €/t H2) while the biomass gasification method incurred the highest eco-cost (11259 €/t H2). The water electrolysis method shows a net positive energy footprint (60.32 GJ/t H2) suggesting that more energy is used than produced. Considering the operating footprint of storage and transportation gaseous hydrogen transported via a pipeline is a better alternative from an environmental point of view and with a lower energy footprint (38 %–85%) than the other options. Storage and transport (without construction) could have accounted for around 35.5% of the total GHG footprint of a hydrogen value chain (production storage transportation and losses) if liquefied and transported via road transport instead of a pipeline. The identified results propose which technologies are less burdensome to the environment.
A Review of Technical Advances, Barriers, and Solutions in the Power to Hydrogen Roadmap
Oct 2020
Publication
Power to hydrogen (P2H) provides a promising solution to the geographic mismatch between sources of renewable energy and the market due to its technological maturity flexibility and the availability of technical and economic data from a range of active demonstration projects. In this review we aim to provide an overview of the status of P2H analyze its technical barriers and solutions and propose potential opportunities for future research and industrial demonstrations. We specifically focus on the transport of hydrogen via natural gas pipeline networks and end-user purification. Strong evidence shows that an addition of about 10% hydrogen into natural gas pipelines has negligible effects on the pipelines and utilization appliances and may therefore extend the asset value of the pipelines after natural gas is depleted. To obtain pure hydrogen from hydrogen-enriched natural gas (HENG) mixtures end-user separation is inevitable and can be achieved through membranes adsorption and other promising separation technologies. However novel materials with high selectivity and capacity will be the key to the development of industrial processes and an integrated membrane-adsorption process may be considered in order to produce high-purity hydrogen from HENG. It is also worth investigating the feasibility of electrochemical separation (hydrogen pumping) at a large scale and its energy analysis. Cryogenics may only be feasible when liquefied natural gas (LNG) is one of the major products. A range of other technological and operational barriers and opportunities such as water availability byproduct (oxygen) utilization and environmental impacts are also discussed. This review will advance readers’ understanding of P2H and foster the development of the hydrogen economy.
Stationary Hybrid Renewable Energy Systems for Railway Electrification: A Review
Sep 2021
Publication
This article provides an overview of modern technologies and implemented projects in the field of renewable energy systems for the electrification of railway transport. In the first part the relevance of the use of renewable energy on the railways is discussed. Various types of power-generating systems in railway stations and platforms along the track as well as in separate areas are considered. The focus is on wind and solar energy conversion systems. The second part is devoted to the analysis of various types of energy storage devices used in projects for the electrification of railway transport since the energy storage system is one of the key elements in a hybrid renewable energy system. Systems with kinetic storage electrochemical storage batteries supercapacitors hydrogen energy storage are considered. Particular attention is paid to technologies for accumulating and converting hydrogen into electrical energy as well as hybrid systems that combine several types of storage devices with different ranges of charge/discharge rates. A comparative analysis of various hybrid electric power plant configurations depending on the functions they perform in the electrification systems of railway transport has been carried out.
Green Hydrogen Powering Sustainable Festivals: Public Perceptions of Generators, Production and Ownership
Nov 2022
Publication
This paper is the first to explore public perceptions about a particular market niche for hydrogen; mobile generators. By utilising a combined research approach including in-situ surveys and online focus groups this paper explores what festival audience members and residents who live near festival sites think about the displacement of incumbent diesel generator technology with hydrogen alternatives. We investigate if hydrogen production methods are important in informing perceptions and subsequent support including the extent to which participants are influenced by the organisation or entity that produces the fuel and stands to profit from its sale. In addition to a primary focus on hydrogen energy we reflect upon how sustainability might be better conceptualised in a festival context. Our findings reveal broad support for hydrogen generators the use of green hydrogen as a fuel to generate electricity and community-led hydrogen production.
Simulation of a Multi-Functional Energy System for Cogeneration of Steam, Power and Hydrogen in a Coke Making Plant
Mar 2013
Publication
In this paper a multifunctional energy system (MES) is proposed for recovering energy from the extra of coke oven gas (COG) which is usually flared or vented out as a waste stream in coke making plants. The proposed system consists of a pressure swing adsorption (PSA) unit for extracting some of the hydrogen from COG a gas turbine for producing heat and power from PSA offgas and a heat recovery steam generator (HRSG) for generating the steam required by the plant's processes. o assess the performance of the system practically simulations are carried out on the basis of the design and operational conditions of Zarand Coke Making Plant in Iran. The results indicate that by utilizing about 4.39 tons of COG per hour 6.5 MW of net electric power can be approximately produced by the gas turbine which can supply the coke making plant's total electrical power demand. Furthermore through recovering heat from gas turbine's exhaust close to 57% of the plant's steam demand can be supplied by the HRSG unit. It is also found that around 350 kilograms per hour of nearly pure hydrogen (99.9% purity) at 200 bar can be produced by the PSA unit. According to the sensitivity analysis results if the hydrogen content of the coke oven gas decreases by about 10% the gross power output of the gas turbine also declines by around 5.2% due to the reduction of LHV of the PSA offgas. Moreover economic evaluation of the system shows that the payback period of the investment which is estimated at 36.1 M$ is about 5.5 years. The net present value (NPV) and internal rate of return on investment (ROI) are calculated to be 17.6% and 43.3 M$ respectively.
Industrial Energy Use and Carbon Emissions Reduction in the Chemicals Sector: A UK Perspective
Aug 2017
Publication
The opportunities and challenges to reducing industrial energy demand and carbon dioxide (CO2 ) emissions in the Chemicals sector are evaluated with a focus on the situation in the United Kingdom (UK) although the lessons learned are applicable across much of the industrialised world. This sector can be characterised as being heterogeneous; embracing a diverse range of products (including advanced materials cleaning fluids composites dyes paints pharmaceuticals plastics and surfactants). It sits on the boundary between energy-intensive (EI) and non-energy-intensive (NEI) industrial sectors. The improvement potential of various technological interventions has been identified in terms of their energy use and greenhouse gas (GHG) emissions. Currently-available best practice technologies (BPTs) will lead to further short-term energy and CO2 emissions savings in chemicals processing but the prospects for the commercial exploitation of innovative technologies by mid-21st century are far more speculative. A set of industrial decarbonisation ‘technology roadmaps’ out to the mid-21st Century are also reported based on various alternative scenarios. These yield low-carbon transition pathways that represent future projections which match short-term and long-term (2050) targets with specific technological solutions to help meet the key energy saving and decarbonisation goals. The roadmaps’ contents were built up on the basis of the improvement potentials associated with various processes employed in the chemicals industry. They help identify the steps needed to be undertaken by developers policy makers and other stakeholders in order to ensure the decarbonisation of the UK chemicals industry. The attainment of significant falls in carbon emissions over this period will depends critically on the adoption of a small number of key technologies [e.g. carbon capture and storage (CCS) energy efficiency techniques and bioenergy] alongside a decarbonisation of the electricity supply.
Delivering Net-zero Carbon Heat: Technoeconomic and Whole-system Comparisons of Domestic Electricity- and Hydrogen-driven Technologies in the UK
Apr 2022
Publication
Proposed sustainable transition pathways for moving away from natural gas in domestic heating focus on two main energy vectors: electricity and hydrogen. Electrification would be implemented by using vapourcompression heat pumps which are currently experiencing market growth in many countries. On the other hand hydrogen could substitute natural gas in boilers or be used in thermally–driven absorption heat pumps. In this paper a consistent thermodynamic and economic methodology is developed to assess the competitiveness of these options. The three technologies along with the option of district heating are for the first time compared for different weather/ambient conditions and fuel-price scenarios first from a homeowner’s and then from a wholeenergy system perspective. For the former two-dimensional decision maps are generated to identify the most cost-effective technologies for different combinations of fuel prices. It is shown that in the UK hydrogen technologies are economically favourable if hydrogen is supplied to domestic end-users at a price below half of the electricity price. Otherwise electrification and the use of conventional electric heat pumps will be preferred. From a whole-energy system perspective the total system cost per household (which accounts for upstream generation and storage as well as technology investment installation and maintenance) associated with electric heat pumps varies between 790 and 880 £/year for different scenarios making it the least-cost decarbonisation pathway. If hydrogen is produced by electrolysis the total system cost associated with hydrogen technologies is notably higher varying between 1410 and 1880 £/year. However this total system cost drops to 1150 £/year with hydrogen produced cost-effectively by methane reforming and carbon capture and storage thus reducing the gap between electricity- and hydrogen-driven technologies.
Energy Management System for Hybrid PV/Wind/Battery/Fuel Cell in Microgrid-Based Hydrogen and Economical Hybrid Battery/Super Capacitor Energy Storage
Sep 2021
Publication
The present work addresses the modelling control and simulation of a microgrid integrated wind power system with Doubly Fed Induction Generator (DFIG) using a hybrid energy storage system. In order to improve the quality of the waveforms (voltages and currents) supplied to the grid instead of a two level-inverter the rotor of the DFIG is supplied using a three-level inverter. A new adaptive algorithm based on combined Direct Reactive Power Control (DRPC) and fuzzy logic controls techniques is applied to the proposed topology. In this work two topologies are proposed. In the first one the active power injected into the grid is smoothened by using an economical hybrid battery and supercapacitor energy storage system. However in the second one the excess wind energy is used to produce and store the hydrogen and then a solid oxide fuel cell system (SOFC) is utilized to regenerate electricity by using the stored hydrogen when there is not enough wind energy. To avoid overcharging deep discharging of batteries to mitigate fluctuations due to wind speed variations and to fulfil the requirement of the load profile a power management algorithm is implemented. This algorithm ensures smooth output power in the first topology and service continuity in the second. The modelling and simulation results are presented and analysed using Matlab/Simulin.
Comparison of Two Energy Management Strategies Considering Power System Durability for PEMFC-LIB Hybrid Logistics Vehicle
Jun 2021
Publication
For commercial applications the durability and economy of the fuel cell hybrid system have become obstacles to be overcome which are not only affected by the performance of core materials and components but also closely related to the energy management strategy (EMS). This paper takes the 7.9 t fuel cell logistics vehicle as the research object and designed the EMS from two levels of qualitative and quantitative analysis which are the composite fuzzy control strategy optimized by genetic algorithm and Pontryagin’s minimum principle (PMP) optimized by objective function respectively. The cost function was constructed and used as the optimization objective to prolong the life of the power system as much as possible on the premise of ensuring the fuel economy. The results indicate that the optimized PMP showed a comprehensive optimal performance the hydrogen consumption was 3.481 kg/100 km and the cost was 13.042 $/h. The major contribution lies in that this paper presents a method to evaluate the effect of different strategies on vehicle performance including fuel economy and durability of the fuel cell and battery. The comparison between the two totally different strategies helps to find a better and effective solution to reduce the lifetime cost.
Seasonal and Multi-Seasonal Energy Storage by Power-to-Methane Technology
Jun 2021
Publication
The time-range of applicability of various energy-storage technologies are limited by self-discharge and other inevitable losses. While batteries and hydrogen are useful for storage in a time-span ranging from hours to several days or even weeks for seasonal or multi-seasonal storage only some traditional and quite costly methods can be used (like pumped-storage plants Compressed Air Energy Storage or energy tower). In this paper we aim to show that while the efficiency of energy recovery of Power-to-Methane technology is lower than for several other methods due to the low self-discharge and negligible standby losses it can be a suitable and cost-effective solution for seasonal and multi-seasonal energy storage.
Potentialities of Hydrogen Enriched Natural Gas for Residential Heating Decarbonization and Impact Analysis on Premixed Boilers
Sep 2019
Publication
Nowadays decarbonization of energy economy is a topical theme and several pathways are under discussion. Gaseous fuels will play a primary role during this transition and the production of renewable or low carbon-impact gaseous fuels is necessary to deal with this challenge. Decarbonization will be sustained by an increasing share of renewables which production intermittency can be critical for the energy system. Renewable hydrogen generation is a viable solution since this energy vector can be produced from electricity with a fast response and injected in the existing natural gas infrastructures granting storage capacity and easy transport. Parallelly to the renewable-based energy production fossil-based energy can be exploited with a low carbon impact using methane from reservoirs to produce hydrogen capturing CO2. The mentioned scenarios will lead to hydrogen enrichment of natural gas which impact on the infrastructures is being actively studied. The effect on end-user devices instead is poorly analysed but is fundamental to be assessed. This paper highlights the impact on the widely used premixed condensing boilers which will be fired with hydrogen enriched natural gas in the near future and the changes required to components.
Green Synthesis of Olefin-linked Covalent Organic Frameworks for Hydrogen Fuel Cell Applications
Mar 2021
Publication
Green synthesis of crystalline porous materials for energy-related applications is of great significance but very challenging. Here we create a green strategy to fabricate a highly crystalline olefin-linked pyrazine-based covalent organic framework (COF) with high robustness and porosity under solvent-free conditions. The abundant nitrogen sites high hydrophilicity and well-defined one-dimensional nanochannels make the resulting COF an ideal platform to confine and stabilize the H3PO4 network in the pores through hydrogen-bonding interactions. The resulting material exhibits low activation energy (Ea) of 0.06 eV and ultrahigh proton conductivity across a wide relative humidity (10–90 %) and temperature range (25–80 °C). A realistic proton exchange membrane fuel cell using the olefin-linked COF as the solid electrolyte achieve a maximum power of 135 mW cm−2 and a current density of 676 mA cm−2 which exceeds all reported COF materials.
Sub-second and Ppm-level Optical Sensing of Hydrogen Using Templated Control of Nano-hydride Geometry and Composition
Apr 2021
Publication
The use of hydrogen as a clean and renewable alternative to fossil fuels requires a suite of flammability mitigating technologies particularly robust sensors for hydrogen leak detection and concentration monitoring. To this end we have developed a class of lightweight optical hydrogen sensors based on a metasurface of Pd nano-patchy particle arrays which fulfills the increasing requirements of a safe hydrogen fuel sensing system with no risk of sparking. The structure of the optical sensor is readily nano-engineered to yield extraordinarily rapid response to hydrogen gas (<3 s at 1 mbar H2) with a high degree of accuracy (<5%). By incorporating 20% Ag Au or Co the sensing performances of the Pd-alloy sensor are significantly enhanced especially for the Pd80Co20 sensor whose optical response time at 1 mbar of H2 is just ~0.85 s while preserving the excellent accuracy (<2.5%) limit of detection (2.5 ppm) and robustness against aging temperature and interfering gases. The superior performance of our sensor places it among the fastest and most sensitive optical hydrogen sensors.
Options for Producing Low-carbon Hydrogen at Scale
Feb 2018
Publication
Low-carbon hydrogen has the potential to play a significant role in tackling climate change and poor air quality. This policy briefing considers how hydrogen could be produced at a useful scale to power vehicles heat homes and supply industrial processes.
Four groups of hydrogen production technologies are examined:
Thermochemical Routes to Hydrogen
These methods typically use heat and fossil fuels. Steam methane reforming is the dominant commercial technology and currently produces hydrogen on a large scale but is not currently low carbon. Carbon capture is therefore essential with this process. Innovative technology developments may also help and research is underway. Alternative thermal methods of creating hydrogen indicate biomass gasification has potential. Other techniques at a low technology readiness level include separation of hydrogen from hydrocarbons using microwaves.
Electrolytic Routes to Hydrogen
Electrolytic hydrogen production also known as electrolysis splits water into hydrogen and oxygen using electricity in an electrolysis cell. Electrolysis produces pure hydrogen which is ideal for low temperature fuel cells for example in electric vehicles. Commercial electrolysers are on the market and have been in use for many years. Further technology developments will enable new generation electrolysers to be commercially competitive when used at scale with fluctuating renewable energy sources.
Biological Routes to Hydrogen
Biological routes usually involve the conversion of biomass to hydrogen and other valuable end products using microbial processes. Methods such as anaerobic digestion are feasible now at a laboratory and small pilot scale. This technology may prove to have additional or greater impact and value as route for the production of high value chemicals within a biorefinery concept.
Solar to Fuels Routes to Hydrogen
A number of experimental techniques have been reported the most developed of which is ‘solar to fuels’ - a suite of technologies that typically split water into hydrogen and oxygen using solar energy. These methods have close parallels with the process of photosynthesis and are often referred to as ‘artificial photosynthesis’ processes. The research is promising though views are divided on its ultimate utility. Competition for space will always limit the scale up of solar to fuels.
The briefing concludes that steam methane reforming and electrolysis are the most likely technologies to be deployed to produce low-carbon hydrogen at volume in the near to mid-term providing that the challenges of high levels of carbon capture (for steam methane reforming) and cost reduction and renewable energy sources (for electrolysis) can be overcome.
Four groups of hydrogen production technologies are examined:
Thermochemical Routes to Hydrogen
These methods typically use heat and fossil fuels. Steam methane reforming is the dominant commercial technology and currently produces hydrogen on a large scale but is not currently low carbon. Carbon capture is therefore essential with this process. Innovative technology developments may also help and research is underway. Alternative thermal methods of creating hydrogen indicate biomass gasification has potential. Other techniques at a low technology readiness level include separation of hydrogen from hydrocarbons using microwaves.
Electrolytic Routes to Hydrogen
Electrolytic hydrogen production also known as electrolysis splits water into hydrogen and oxygen using electricity in an electrolysis cell. Electrolysis produces pure hydrogen which is ideal for low temperature fuel cells for example in electric vehicles. Commercial electrolysers are on the market and have been in use for many years. Further technology developments will enable new generation electrolysers to be commercially competitive when used at scale with fluctuating renewable energy sources.
Biological Routes to Hydrogen
Biological routes usually involve the conversion of biomass to hydrogen and other valuable end products using microbial processes. Methods such as anaerobic digestion are feasible now at a laboratory and small pilot scale. This technology may prove to have additional or greater impact and value as route for the production of high value chemicals within a biorefinery concept.
Solar to Fuels Routes to Hydrogen
A number of experimental techniques have been reported the most developed of which is ‘solar to fuels’ - a suite of technologies that typically split water into hydrogen and oxygen using solar energy. These methods have close parallels with the process of photosynthesis and are often referred to as ‘artificial photosynthesis’ processes. The research is promising though views are divided on its ultimate utility. Competition for space will always limit the scale up of solar to fuels.
The briefing concludes that steam methane reforming and electrolysis are the most likely technologies to be deployed to produce low-carbon hydrogen at volume in the near to mid-term providing that the challenges of high levels of carbon capture (for steam methane reforming) and cost reduction and renewable energy sources (for electrolysis) can be overcome.
Blue Hydrogen
Apr 2021
Publication
The urgency of reaching net-zero emissions requires a rapid acceleration in the deployment of all emissions reducing technologies. Near-zero emissions hydrogen (clean hydrogen) has the potential to make a significant contribution to emissions reduction in the power generation transportation and industrial sectors.
As part of the Circular Carbon Economy: Keystone to Global Sustainability series with the Center on Global Energy Policy at Columbia University SIPA this report explores the potential contribution of blue hydrogen to climate mitigation.
The report looks at:
As part of the Circular Carbon Economy: Keystone to Global Sustainability series with the Center on Global Energy Policy at Columbia University SIPA this report explores the potential contribution of blue hydrogen to climate mitigation.
The report looks at:
- Cost drivers for renewable hydrogen and hydrogen produced with fossil fuels and CCS;
- Resource requirements and cost reduction opportunities for clean hydrogen; and
- Policy recommendations to drive investment in clean hydrogen production.
- Blue hydrogen is well placed to kickstart the rapid increase in the utilisation of clean hydrogen for climate mitigation purposes but requires strong and sustained policy to incentivise investment at the rate necessary to meet global climate goals.
Current Research Trends and Perspectives on Solid-State Nanomaterials in Hydrogen Storage
Jan 2021
Publication
Hydrogen energy with environment amicable renewable efficiency and cost-effective advantages is the future mainstream substitution of fossil-based fuel. However the extremely low volumetric density gives rise to the main challenge in hydrogen storage and therefore exploring effective storage techniques is key hurdles that need to be crossed to accomplish the sustainable hydrogen economy. Hydrogen physically or chemically stored into nanomaterials in the solid-state is a desirable prospect for effective large-scale hydrogen storage which has exhibited great potentials for applications in both reversible onboard storage and regenerable off-board storage applications. Its attractive points include safe compact light reversibility and efficiently produce sufficient pure hydrogen fuel under the mild condition. This review comprehensively gathers the state-of-art solid-state hydrogen storage technologies using nanostructured materials involving nanoporous carbon materials metal-organic frameworks covalent organic frameworks porous aromatic frameworks nanoporous organic polymers and nanoscale hydrides. It describes significant advances achieved so far and main barriers need to be surmounted to approach practical applications as well as offers a perspective for sustainable energy research.
The Path to Carbon Neutrality in China: A Paradigm Shift in Fossil Resource Utilization
Jan 2022
Publication
The Paris Agreement has set the goal of carbon neutrality to cope with global climate change. China has pledged to achieve carbon neutrality by 2060 which will strategically change everything in our society. As the main source of carbon emissions the consumption of fossil energy is the most profoundly affected by carbon neutrality. This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization. The significance of transforming fossils from energy to resource utilization in the future is addressed while the development direction and key technologies are discussed.
Editorial—Special Issue “Catalysis for Energy Production”
Jun 2021
Publication
The rapid increase in anthropogenic greenhouse gas concentrations in the last several decades means that the effects of climate change are fast becoming the familiar horsemen of a planetary apocalypse. Catalysis one of the pillars of the chemical and petrochemical industries will play a critical role in the effort to reduce the flow of greenhouse gases into the atmosphere. This Special Issue is timely as it provides a collection of high-quality manuscripts in a diverse range of topics which include the production of green hydrogen via water electrolysis the steam reforming of ethanol propane or glycerol the dry reforming of methane and the autothermal reforming of diesel surrogate fuel. The topic of the transformation of biomass waste to chemicals is also well represented as is the tackling of CO2 emissions via novel utilization technologies. The Editors are grateful to all authors for their valuable contributions and confident that this Special Issue will prove valuable to scholars university professors and students alike.
Hydrogen Addition Influence for the Efficient and Ecological Parameters of Heavy-Duty Natural Gas Si Engine
May 2017
Publication
The paper presents the experimental research results of heavy-duty vehicle (public transport bus) fuelled with natural gas and hydrogen fuel mixtures. Spark ignition six cylinder engine tested with different hydrogen additions (from 5% up to 20% according to volume) in the natural gas fuel. The tests were performed on heavy-duty vehicle’s dyno test stand in company “SG dujos Auto” research laboratory. The tests were carried out at three load points and one engine speed. Engine had originally a port fuel injection and exhaust gas recirculation system. Experiments showed that engine fuelled with hydrogen addition was able to achieve lower fuel consumption and brake specific fuel consumption. It was also possible to achieve small increase of engine efficiency. The exhaust gas measurements showed that hydrogen addition in natural gas reduced the CO CO2 and HC emissions because of the H/C atom ratio change in fuel mixture and improved combustion process. The NOx emission level was decreasing although bigger amounts of hydrogen were used in natural gas fuel.
Between Hope And Hype: A Hydrogen Vision For The UK
Mar 2021
Publication
There is a growing conversation around the role that hydrogen can play in the future of the UK and how to best harness its potential to secure jobs show climate leadership promote industrial competitiveness and drive innovation. The Government’s ‘Ten Point Plan for a Green Industrial Revolution’ included hydrogen as one of its ten actions targeting 5GW of ‘low carbon’ hydrogen production by 2030. Britain is thus joining the EU US Japan Germany and a host of other countries seeking to be part of the hydrogen economy of the future.<br/><br/>A focus on clean green hydrogen within targeted sectors and hubs can support multiple Government goals – including demonstrating climate leadership reducing regional inequalities through the ‘levelling up’ agenda and ensuring a green and cost-effective recovery from the coronavirus pandemic which prioritises jobs and skills. A strategic hydrogen vision must be honest and recognise where green hydrogen does not present the optimal pathway for decarbonisation – for instance where alternative solutions are already readily available for roll-out are more efficient and cost-effective. A clear example is hydrogen use for heating where it is estimated to require around 30 times more offshore wind farm capacity than currently available to produce enough green hydrogen to replace all gas boilers as well as adding costs for consumers.<br/><br/>This paper considers the offer of hydrogen for key Government priorities – including an inclusive and resilient economic recovery from the pandemic demonstrating climate leadership and delivering for all of society across the UK. It assesses existing evidence and considers the risks and opportunities and how they might inform a strategic vision for the UK. Ahead of the forthcoming Hydrogen Strategy it sets expectations for Government and outlines key recommendations.
Energetics of LOHC: Structure-Property Relationships from Network of Thermochemical Experiments and in Silico Methods
Feb 2021
Publication
The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC) that are involved in the hydrogen storage technologies. With this in silico tool the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically leading to the design and development of efficient materials for various niche applications.
Australian Hydrogen Hubs Study
Nov 2019
Publication
Arup have conducted interviews with targeted industry and government stakeholders to gather data and perspectives to support the development of this study. Arup have also utilised private and publicly available data sources building on recent work undertaken by Geoscience Australia and Deloitte and the comprehensive stakeholder engagement process to inform our research. This study considers the supply chain and infrastructure requirements to support the development of export and domestic hubs. The study aims to provide a succinct “Hydrogen Hubs” report for presentation to the hydrogen working group.
The hydrogen supply chain infrastructure required to produce hydrogen for export and domestic hubs was identified along with feedback from the stakeholder engagement process. These infrastructure requirements can be used to determine the factors for assessing export and domestic hub opportunities. Hydrogen production pathways transportation mechanisms and uses were also further evaluated to identify how hubs can be used to balance supply and demand of hydrogen.
A preliminary list of current or anticipated locations has been developed through desktop research Arup project knowledge and the stakeholder consultation process. Over 30 potential hydrogen export locations have been identified in Australia through desktop research and the stakeholder survey and consultation process. In addition to establishing export hubs the creation of domestic demand hubs will be essential to the development of an Australian hydrogen economy. It is for this reason that a list of criteria has been developed for stakeholders to consider in the siting and design of hydrogen hubs. The key considerations explored are based on demand supply chain infrastructure and investment and policy areas.
Based on these considerations a list of criteria were developed to assess the viability of export and domestic hydrogen hubs. Criteria relevant to assessing the suitability of export and domestic hubs include:
A framework that includes the assessment criteria has been developed to aid decision making rather than recommending specific locations that would be most appropriate for a hub. This is because there are so many dynamic factors that go into selecting a location of a hydrogen hub that it is not appropriate to be overly prescriptive or prevent stakeholders from selecting the best location themselves or from the market making decisions based on its own research and knowledge. The developed framework rather provides information and support to enable these decision-making processes.
The hydrogen supply chain infrastructure required to produce hydrogen for export and domestic hubs was identified along with feedback from the stakeholder engagement process. These infrastructure requirements can be used to determine the factors for assessing export and domestic hub opportunities. Hydrogen production pathways transportation mechanisms and uses were also further evaluated to identify how hubs can be used to balance supply and demand of hydrogen.
A preliminary list of current or anticipated locations has been developed through desktop research Arup project knowledge and the stakeholder consultation process. Over 30 potential hydrogen export locations have been identified in Australia through desktop research and the stakeholder survey and consultation process. In addition to establishing export hubs the creation of domestic demand hubs will be essential to the development of an Australian hydrogen economy. It is for this reason that a list of criteria has been developed for stakeholders to consider in the siting and design of hydrogen hubs. The key considerations explored are based on demand supply chain infrastructure and investment and policy areas.
Based on these considerations a list of criteria were developed to assess the viability of export and domestic hydrogen hubs. Criteria relevant to assessing the suitability of export and domestic hubs include:
- Health and safety provisions;
- Environmental considerations;
- Economic and social considerations;
- Land availability with appropriate zoning and buffer distances & ownership (new terminals storage solar PV industries etc.);•
- Availability of gas pipeline infrastructure;
- Availability of electricity grid connectivity backup energy supply or co-location of renewables;
- Road & rail infrastructure (site access);
- Community and environmental concerns and weather. Social licence consideration;
- Berths (berthing depth ship storage loading facilities existing LNG and/or petroleum infrastructure etc.);
- Port potential (current capacity & occupancy expandability & scalability);
- Availability of or potential for skilled workers (construction & operation);
- Availability of or potential for water (recycled & desalinated);
- Opportunity for co-location with industrial ammonia production and future industrial opportunities;
- Interest (projects priority ports state development areas politics etc.);
- Shipping distance to target market (Japan & South Korea);
- Availability of demand-based infrastructure (i.e. refuelling stations).
A framework that includes the assessment criteria has been developed to aid decision making rather than recommending specific locations that would be most appropriate for a hub. This is because there are so many dynamic factors that go into selecting a location of a hydrogen hub that it is not appropriate to be overly prescriptive or prevent stakeholders from selecting the best location themselves or from the market making decisions based on its own research and knowledge. The developed framework rather provides information and support to enable these decision-making processes.
A Solar Thermal Sorption-enhanced Steam Methane Reforming (SE-SMR) Approach and its Performance Assessment
Feb 2022
Publication
This paper proposes an integration of concentrating solar power (CSP) with a sorption-enhanced steam methane reforming (SE-SMR) process and assesses its overall solar-to-fuel conversion performance. A thermodynamic treatment of the SE-SMR process for H2 production is presented and evaluated in an innovative two reactors system configuration using CSP as a heat input. Four metal carbonate/metal oxide pairs are considered and the equilibrium thermodynamics reveals that CaCO3/CaO pair is the most suitable candidate for this process. Additionally a reactor-scale thermodynamic model is developed to determine the optimum operating conditions for the process. For the carbonation step temperatures between 700 and 900 K and steam-to-methane ratio ≥4 are found to be the most favorable. Furthermore an advanced process model which utilizes operating conditions determined from the reactor-scale model is developed to evaluate the process efficiency. The model predicts that the proposed process can achieve a solar-to-fuel efficiency ~41% for calcination temperature of 1500 K and carbonation temperature of 800 K without considering any solid heat recovery. An additional 2.5% increase in the process efficiency is feasible with the consideration of the solid heat recovery. This study shows the thermodynamic feasibility of integrating the SE-SMR process with CSP technologies.
Timmermans’ Dream: An Electricity and Hydrogen Partnership Between Europe and North Africa
Oct 2021
Publication
Because of differences in irradiation levels it could be more efficient to produce solar electricity and hydrogen in North Africa and import these energy carriers to Europe rather than generating them at higher costs domestically in Europe. From a global climate change mitigation point of view exploiting such efficiencies can be profitable since they reduce overall renewable electricity capacity requirements. Yet the construction of this capacity in North Africa would imply costs associated with the infrastructure needed to transport electricity and hydrogen. The ensuing geopolitical dependencies may also raise energy security concerns. With the integrated assessment model TIAM-ECN we quantify the trade-off between costs and benefits emanating from establishing import-export links between Europe and North Africa for electricity and hydrogen. We show that for Europe a net price may have to be paid for exploiting such interlinkages even while they reduce the domestic investments for renewable electricity capacity needed to implement the EU’s Green Deal. For North African countries the potential net benefits thanks to trade revenues may build up to 50 billion €/yr in 2050. Despite fears over costs and security Europe should seriously consider an energy partnership with North Africa because trade revenues are likely to lead to positive employment income and stability effects in North Africa. Europe can indirectly benefit from such impacts.
Electrochemical Conversion Technologies for Optimal Design of Decentralized Multi-energy Systems: Modeling Framework and Technology Assessment
Apr 2018
Publication
The design and operation of integrated multi-energy systems require models that adequately describe the behavior of conversion and storage technologies. Typically linear conversion performance or fixed data from technology manufacturers are employed especially for new or advanced technologies. This contribution provides a new modeling framework for electrochemical devices that bridges first-principles models to their simplified implementation in the optimization routine. First thermodynamic models are implemented to determine the on/off-design performance and dynamic behavior of different types of fuel cells and of electrolyzers. Then as such nonlinear models are intractable for use in the optimization of integrated systems different linear approximations are developed. The proposed strategies for the synthesis of reduced order models are compared to assess the impact of modeling approximations on the optimal design of multi-energy systems including fuel cells and electrolyzers. This allows to determine the most suitable level of detail for modeling the underlying electrochemical technologies from an integrated system perspective. It is found that the approximation methodology affects both the design and operation of the system with a significant effect on system costs and violation of the thermal energy demand. Finally the optimization and technology modeling framework is exploited to determine guidelines for the installation of the most suitable fuel cell technology in decentralized multi-energy systems. We show how the installation costs of PEMFC SOFC and MCFC their electrical and thermal efficiencies their conversion dynamics and the electricity price affect the system design and technology selection.
Influence of Synthesis Gas Components on Hydrogen Storage Properties of Sodium Aluminium Hexahydride
Feb 2021
Publication
A systematic study of different ratios of CO CO2 N2 gas components on the hydrogen storage properties of the Na3AlH6 complex hydride with 4 mol% TiCl3 8 mol% aluminum and 8 mol% activated carbon is presented in this paper. The different concentrations of CO and CO2in H2 and CO CO2 N2 in H2 mixture were investigated. Both CO and CO2gas react with the complex hydride forming Al oxy-compounds NaOH and Na2CO3 that consequently cause serious decline in hydrogen storage capacity. These reactions lead to irreversible damage of complex hydride under the current experimental condition. Thus after 10 cycles with 0.1 vol % CO + 99.9 vol %H2 and 1 vol % CO + 99 vol %H2 the dehydrogenation storage capacity of the composite material decreased by 17.2% and 57.3% respectively. In the case of investigation of 10 cycles with 1 vol % CO2 + 99 vol % H2 gas mixture the capacity degradation was 53.5%. After 2 cycles with 10 vol % CO +90 vol % H2 full degradation was observed whereas after 6 cycles with 10 vol % CO2+ 90 vol % H2 degradation of 86.8% was measured. While testing with the gas mixture of 1.5 vol % CO + 10 vol % CO2+ 27 vol % H2 + 61.5 vol % N2 the degradation of 94% after 6 cycles was shown. According to these results it must be concluded that complex aluminum hydrides cannot be used for the absorption of hydrogen from syngas mixtures without thorough purification.
100% Renewable Energy in Japan
Feb 2022
Publication
Low-cost solar photovoltaics and wind offer a reliable and affordable pathway to deep decarbonization of energy which accounts for three quarters of global emissions. However large-scale deployment of solar photovoltaics and wind requires space and may be challenging for countries with dense population and high per capita energy consumption. This study investigates the future role of renewable energy in Japan as a case study. A 40-year hourly energy balance model is presented of a hypothetical 100% renewable Japanese electricity system using representative demand data and historical meteorological data. Pumped hydro energy storage high voltage interconnection and dispatchable capacity (existing hydro and biomass and hydrogen energy produced from curtailed electricity) are included to balance variable generation and demand. Differential evolution is used to find the least-cost solution under various constraints. This study shows that Japan has 14 times more solar and offshore wind resources than needed to supply 100% renewable electricity and vast capacity for off-river pumped hydro energy storage. Assuming significant cost reductions of solar photovoltaics and offshore wind towards global norms in the coming decades driven by large-scale deployment locally and global convergence of renewable generation costs the levelized cost of electricity is found to be US$86/Megawatt-hour for a solar-dominated system and US$110/Megawatt-hour for a wind-dominated system. These costs can be compared with 2020 average system prices on the spot market in Japan of US$102/Megawatt-hour. Cost of balancing 100% renewable electricity in Japan ranges between US$20–27/Megawatt-hour for a range of scenarios. In summary Japan can be self-sufficient for electricity supply at competitive costs provided that the barriers to the mass deployment of solar photovoltaics and offshore wind in Japan are overcome.
Micro Gas Turbine Role in Distributed Generation with Renewable Energy Sources
Jan 2023
Publication
To become sustainable the production of electricity has been oriented towards the adoption of local and renewable sources. Distributed electric and thermal energy generation is more suitable to avoid any possible waste and the Micro Gas Turbine (MGT) can play a key role in this scenario. Due to the intrinsic properties and the high flexibility of operation of this energy conversion system the exploitation of alternative fuels and the integration of the MGT itself with other energy conversion systems (solar field ORC fuel cells) represent one of the most effective strategies to achieve higher conversion efficiencies and to reduce emissions from power systems. The present work aims to review the results obtained by the researchers in the last years. The different technologies are analyzed in detail both separately and under a more complete view considering two or more solutions embedded in micro-grid configurations.
A Comprehensive Overview of Hydrogen-Fueled Internal Combustion Engines: Achievements and Future Challenges
Oct 2021
Publication
This paper provides a comprehensive review and critical analysis of the latest research results in addition to an overview of the future challenges and opportunities regarding the use of hydrogen to power internal combustion engines (ICEs). The experiences and opinions of various international research centers on the technical possibilities of using hydrogen as a fuel in ICE are summarized. The advantages and disadvantages of the use of hydrogen as a solution are described. Attention is drawn to the specific physical chemical and operational properties of hydrogen for ICEs. A critical review of hydrogen combustion concepts is provided drawing on previous research results and experiences described in a number of research papers. Much space is devoted to discussing the challenges and opportunities associated with port and direct hydrogen injection technology. A comparison of different fuel injection and ignition strategies and the benefits of using the synergies of selected solutions are presented. Pointing to the previous experiences of various research centers the hazards related to incorrect hydrogen combustion such as early pre‐ignition late pre‐ignition knocking combustion and backfire are described. Attention is focused on the fundamental importance of air ratio optimization from the point of view of combustion quality NOx emissions engine efficiency and performance. Exhaust gas scrubbing to meet future emission regulations for hydrogen powered internal combustion engines is another issue that is considered. The article also discusses the modifications required to adapt existing engines to run on hydrogen. Referring to still‐unsolved problems the reliability challenges faced by fuel injection systems in particular are presented. An analysis of more than 150 articles shows that hydrogen is a suitable alternative fuel for spark‐ignition engines. It will significantly improve their performance and greatly reduce emissions to a fraction of their current level. However its use also has some drawbacks the most significant of which are its high NOx emissions and low power output and problems in terms of the durability and reliability of hydrogen‐fueled engines.
Energy Transition: Measurement Needs for Carbon Capture, Usage and Storage
Jan 2021
Publication
This latest report describes the potential for CCUS as an important technology during the UK’s energy transition and focuses on the role that metrology (the science of measurement) could play in supporting its deployment. High priority measurement needs and challenges identified within this report include:
- Measuring and comparing the efficiency of different capture techniques and configurations to provide confidence in investments into technologies;
- Improving equations of state to support the development of accurate models used for controlling operational conditions;
- Improving CO2 flow measurement to support fiscal and financial metering as well as process control and;
- Improving the understanding and validation of dispersion models for emitted CO2 including plume migration to support safety assessment.
Ex Situ Thermo-catalytic Upgrading of Biomass Pyrolysis Vapors Using a Traveling Wave Microwave Reactor
Sep 2016
Publication
Microwave heating offers a number of advantages over conventional heating methods such as rapid and volumetric heating precise temperature control energy efficiency and lower temperature gradient. In this article we demonstrate the use of 2450 MHz microwave traveling wave reactor to heat the catalyst bed for thermo-catalytic upgrading of pyrolysis vapors. HZSM-5 catalyst was tested at three different temperatures (290 330 and 370°C) at a catalyst to biomass ratio of 2. Results were compared with conventional heating and induction heating method of catalyst bed. The yields of aromatic compounds and coke deposition were dependent on temperature and method of heating. Microwave heating yielded higher aromatic compounds and lower coke deposition. Microwave heating was also energy efficient compared to conventional reactors. The rate of catalyst deterioration was lower for catalyst heated in microwave system.
Hydrogen Fuel Cell Road Vehicles: State of the Art and Perspectives
Nov 2020
Publication
Driven by a small number of niche markets and several decades of application research fuel cell systems (FCS) are gradually reaching maturity to the point where many players are questioning the interest and intensity of its deployment in the transport sector in general. This article aims to shed light on this debate from the road transport perspective. It focuses on the description of the fuel cell vehicle (FCV) in order to understand its assets limitations and current paths of progress. These vehicles are basically hybrid systems combining a fuel cell and a lithium-ion battery and different architectures are emerging among manufacturers who adopt very different levels of hybridization. The main opportunity of Fuel Cell Vehicles is clearly their design versatility based on the decoupling of the choice of the number of Fuel Cell modules and hydrogen tanks. This enables manufacturers to meet various specifications using standard products. Upcoming developments will be in line with the crucial advantage of Fuel Cell Vehicles: intensive use in terms of driving range and load capacity. Over the next few decades long-distance heavy-duty vehicles and fleets of taxis or delivery vehicles will develop based on range extender or mild hybrid architectures and enable the hydrogen sector to mature the technology from niche markets to a large-scale market.
Suspension Plasma Sprayed Coatings Using Dilute Hydrothermally Produced Titania Feedstocks for Photocatalytic Applications
May 2015
Publication
Titanium dioxide coatings have potential applications including photocatalysts for solar assisted hydrogen production solar water disinfection and self-cleaning windows. Herein we report the use of suspension plasma spraying (SPS) for the deposition of conformal titanium dioxide coatings. The process utilises a nanoparticle slurry of TiO2 (ca. 6 and 12 nm respectively) in water which is fed into a high temperature plasma jet (ca. 7000–20 000 K). This facilitated the deposition of adherent coatings of nanostructured titanium dioxide with predominantly anatase crystal structure. In this study suspensions of nano-titanium dioxide made via continuous hydrothermal flow synthesis (CHFS) were used directly as a feedstock for the SPS process. Coatings were produced by varying the feedstock crystallite size spray distance and plasma conditions. The coatings produced exhibited ca. 90–100% anatase phase content with the emainder being rutile (demonstrated by XRD). Phase distribution was homogenous throughout the coatings as determined by micro-Raman spectroscopy. The coatings had a granular surface with a high specific surface area and consisted of densely packed agglomerates interspersed with some melted material. All of the coatings were shown to be photoactive by means of a sacrificial hydrogen evolution test under UV radiation and compared favourably with reported values for CVD coatings and compressed discs of P25.
Kinetic Parameters Estimation via Dragonfly Algorithm (DA) and Comparison of Cylindrical and Spherical Reactors Performance for CO2 Hydrogenation to Hydrocarbons
Oct 2020
Publication
Climate change and global warming as well as growing global demand for hydrocarbons in industrial sectors make great incentives to investigate the utilization of CO2 for hydrocarbons production. Therefore finding an in-depth understanding of the CO2 hydrogenation reactors along with simulating reactor responses to different operating conditions are of paramount importance. However the reaction mechanisms for CO2 hydrogenation and their corresponding kinetic parameters have been disputable yet. In this regard considering the previously proposed Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanism which considered CO2 hydrogenation as a combination of reverse water gas shift (RWGS) and Fischer-Tropsch (FT) reactions and using a one-dimensional pseudo-homogeneous non-isothermal model kinetic parameters of the rate expressions are estimated via fitting experimental and modelling data through a novel swarm intelligence optimization technique called dragonfly algorithm (DA). The predicted reactants conversion using DA algorithm are closer to the experimental data (with about 4% error) comparing to those obtained by the artificial bee colony (ABC) algorithm and are in significant agreement with available literature data. The proposed model is used to assess the effect of reactor configuration on the performance and temperature fluctuations. Results show that axial flow spherical reactor (AFSR) and radial flow spherical reactor (RFSR) exhibiting the same surface area with that of the cylindrical reactor (CR) i.e. AFSR-2 and RFSR-2-i are the most efficient exhibiting hydrocarbons selectivity of 40.330% and 40.286% at CO2 conversion of 53.763% and 53.891%. In addition it is revealed that the location of the jacket has an essential role in controlling the reactor temperature.
Analysis of Hydrogen Production Potential from Waste Plastics by Pyrolysis and In Line Oxidative Steam Reforming
Oct 2021
Publication
A study was carried out on the valorization of different waste plastics (HDPE PP PS and PE) their mixtures and biomass/HDPE mixtures by means of pyrolysis and in line oxidative steam reforming. A thermodynamic equilibrium simulation was used for determining steam reforming data whereas previous experimental results were considered for setting the pyrolysis volatile stream composition. The adequacy of this simulation tool was validated using experimental results obtained in the pyrolysis and in line steam reforming of different plastics. The effect the most relevant process conditions i.e. temperature steam/plastic ratio and equivalence ratio have on H2 production and reaction enthalpy was evaluated. Moreover the most suitable conditions for the oxidative steam reforming of plastics of different nature and their mixtures were determined. The results obtained are evidence of the potential interest of this novel valorization route as H2 productions of up to 25 wt% were obtained operating under autothermal conditions.
Microwave Absorption of Aluminum/Hydrogen Treated Titanium Dioxide Nanoparticles
Dec 2018
Publication
Interactions between incident electromagnetic energy and matter are of critical importance for numerous civil and military applications such as photocatalysis solar cells optics radar detection communications information processing and transport et al. Traditional mechanisms for such interactions in the microwave frequency mainly rely on dipole rotations and magnetic domain resonance. In this study we present the first report of the microwave absorption of Al/H2 treated TiO2 nanoparticles where the Al/H2 treatment not only induces structural and optical property changes but also largely improves the microwave absorption performance of TiO2 nanoparticles. Moreover the frequency of the microwave absorption can be finely controlled with the treatment temperature and the absorption efficiency can reach optimal values with a careful temperature tuning. A large reflection loss of −58.02 dB has been demonstrated with 3.1 mm TiO2 coating when the treating temperature is 700 °C. The high efficiency of microwave absorption is most likely linked to the disordering-induced property changes in the materials. Along with the increased microwave absorption properties are largely increased visible-light and IR absorptions and enhanced electrical conductivity and reduced skin-depth which is likely related to the interfacial defects within the TiO2 nanoparticles caused by the Al/H2 treatment.
Dual Z-scheme Charge Transfer in TiO2–Ag–Cu2O Composite for Enhanced Photocatalytic Hydrogen Generation
Apr 2015
Publication
Photocatalytic hydrogen generation is one of the most promising solutions to convert solar power into green chemical energy. In this work a multi-component TiO2–Ag–Cu2O composite was obtained through simple impregnation-calcination of Cu2O and subsequent photodeposition of Ag onto electrospun TiO2 nanotubes. The resulting TiO2–Ag–Cu2O photocatalyst exhibits excellent photocatalytic H2 evolution activity due to the synergetic effect of Ag and Cu2O on electrospun TiO2nanotubes. A dual Z-scheme charge transfer pathway for photocatalytic reactions over TiO2–Ag–Cu2O composite was proposed and discussed. This work provides a prototype for designing Z-scheme photocatalyst with Ag as an electron mediator.
Raw Biomass Electroreforming Coupled to Green Hydrogen Generation
Mar 2021
Publication
Despite the tremendous progress of coupling organic electrooxidation with hydrogen generation in a hybrid electrolysis electroreforming of raw biomass coupled to green hydrogen generation has not been reported yet due to the rigid polymeric structures of raw biomass. Herein we electrooxidize the most abundant natural amino biopolymer chitin to acetate with over 90% yield in hybrid electrolysis. The overall energy consumption of electrolysis can be reduced by 15% due to the thermodynamically and kinetically more favorable chitin oxidation over water oxidation. In obvious contrast to small organics as the anodic reactant the abundance of chitin endows the new oxidation reaction excellent scalability. A solar-driven electroreforming of chitin and chitin-containing shrimp shell waste is coupled to safe green hydrogen production thanks to the liquid anodic product and suppression of oxygen evolution. Our work thus demonstrates a scalable and safe process for resource upcycling and green hydrogen production for a sustainable energy future.
Parametric Study of Pt/C-Catalysed Hydrothermal Decarboxylation of Butyric Acid as a Potential Route for Biopropane Production
Jun 2021
Publication
Sustainable fuel-range hydrocarbons can be produced via the catalytic decarboxylation of biomass-derived carboxylic acids without the need for hydrogen addition. In this present study 5 wt% platinum on carbon (Pt/C) has been found to be an effective catalyst for hydrothermally decarboxylating butyric acid in order to produce mainly propane and carbon dioxide. However optimisation of the reaction conditions is required to minimise secondary reactions and increase hydrocarbon selectivity towards propane. To do this reactions using the catalyst with varying parameters such as reaction temperatures residence times feedstock loading and bulk catalyst loading were carried out in a batch reactor. The highest yield of propane obtained was 47 wt% (close to the theoretical decarboxylation yield of 50 wt% on butyric acid basis) corresponding to a 96% hydrocarbon selectivity towards propane. The results showed that the optimum parameters to produce the highest yield of propane from the range investigated were 0.5 g butyric acid (0.57 M aqueous solution) 1.0 g Pt/C (50 mg Pt content) at 300 °C for 1 h. The reusability of the catalyst was also investigated which showed little or no loss of catalytic activity after four cycles. This work has shown that Pt/C is a suitable and potentially hydrothermally stable heterogeneous catalyst for making biopropane a major component of bioLPG from aqueous butyric acid solutions which can be sourced from bio-derived feedstocks via acetone-butanol-ethanol (ABE) fermentation.
Energy Modeling Approach to the Global Energy-mineral Nexus: Exploring Metal Requirements and the Well-below 2 °C Target with 100 Percent Renewable Energy
Jun 2018
Publication
Detailed analysis of pathways to future sustainable energy systems is important in order to identify and overcome potential constraints and negative impacts and to increase the utility and speed of this transition. A key aspect of a shift to renewable energy technologies is their relatively higher metal intensities. In this study a bottom-up cost-minimizing energy model is used to calculate aggregate metal requirements in different energy technology including hydrogen and climate policy scenarios and under a range of assumptions reflecting uncertainty in future metal intensities recycling rate and life time of energy technologies. Metal requirements are then compared to current production rates and resource estimates to identify potentially “critical” metals. Three technology pathways are investigated: 100 percent renewables coal & nuclear and gas & renewables each under the two different climate policies: net zero emissions satisfying the well-below 2 °C target and business as usual without carbon constraints resulting together in six scenarios. The results suggest that the three different technology pathways lead to an almost identical degree of warming without any climate policy while emissions peaks within a few decades with a 2 °C policy. The amount of metals required varies significantly in the different scenarios and under the various uncertainty assumptions. However some can be deemed “critical” in all outcomes including Vanadium. The originality of this study lies in the specific findings and in the employment of an energy model for the energy-mineral nexus study to provide better understanding for decision making and policy development.
The Role of Hydrocarbons in the Global Energy Agenda: The Focus on Liquefied Natural Gas
May 2020
Publication
Presently there is a paradoxical situation in the global energy market related to a gap between the image of hydrocarbon resources (HCR) and their real value for the economy. On the one hand we face an increase in expected HCR production and consumption volumes both in the short and long term. On the other hand we see the formation of the image of HCR and associated technologies as an unacceptable option without enough attention to the differences in fuels and the ways of their usage. Due to this it seems necessary to take a step back to review the vitality of such a political line. This article highlights an alternative point of view with regard to energy development prospects. The purpose of this article is to analyse the consistency of criticism towards HCR based on exploration of scientific literature analytical documents of international corporations and energy companies as well as critical assessment of technologies offered for the HCR substitution. The analysis showed that: (1) it is impossible to substitute the majority of HCR with alternative power resources in the near term (2) it is essential that the criticism of energy companies with regard to their responsibility for climate change should lead not to destruction of the industry but to the search of sustainable means for its development (3) the strategic benchmarks of oil and coal industries should shift towards chemical production but their significance should not be downgraded for the energy sector (4) liquified natural gas (LNG) is an independent industry with the highest expansion potential in global markets in the coming years as compared to alternative energy options and (5) Russia possesses a huge potential for the development of the gas industry and particularly LNG that will be unlocked if timely measures on higher efficiency of the state regulation system are implemented.
Impact Assessment of Hydrogen Transmission on TD1 Parallel Pipeline Separation Distances
Mar 2021
Publication
The recommended minimum separation distances in IGEM/TD/1 were based on a research programme that studied the different ways in which a failure of one buried natural gas transmission pipeline can affect another similar pipeline installed adjacent to the first taking account of the initial pressure wave propagating through the ground the size of the ground crater produced and the threat of escalation from fire if the second pipeline is exposed. The methodology developed from the research was first published in 2010 and is implemented in a software program (“PROPHET”). The distances in IGEM/TD/1 are generally cautious and are essentially determined by the size of the ground crater produced by pipeline ruptures as predicted by the methodology.
To assess the impact of hydrogen transmission on the recommended separation distances the possibility of one pipeline transporting natural gas and the other transporting hydrogen was considered as well as both pipelines transporting hydrogen. The following steps were carried out to assess the impact of hydrogen transmission on parallel pipeline separation distances drawing on existing knowledge only:
To assess the impact of hydrogen transmission on the recommended separation distances the possibility of one pipeline transporting natural gas and the other transporting hydrogen was considered as well as both pipelines transporting hydrogen. The following steps were carried out to assess the impact of hydrogen transmission on parallel pipeline separation distances drawing on existing knowledge only:
- Estimate the ground pressure loading predicted from a hydrogen pipeline rupture.
- Consider the ground pressure effect on a parallel natural gas or hydrogen pipeline.
- Evaluate available ground crater formation models and assess if existing natural gas model is cautious for hydrogen.
- Consider effects of thermal loading due to hydrogen fires where recommended natural gas separation distances are not met.
- Ground pressure loading: The current natural gas methodology is cautious.
- Ground pressure effects: The current natural gas methodology is applicable (no change for hydrogen).
- Ground crater formation: The current natural gas methodology is cautious for ruptures and applicable for punctures (almost no change for hydrogen).
- Thermal loading: The current natural gas methodology is cautious for the thermal loading from ruptures but not necessarily cautious for punctures. Calculations of the minimum flow velocity required to prevent failure of a natural gas pipeline are not cautious for hydrogen.
Assessing Uncertainties of Well-To-Tank Greenhouse Gas Emissions from Hydrogen Supply Chains
Jun 2017
Publication
Hydrogen is a promising energy carrier in the clean energy systems currently being developed. However its effectiveness in mitigating greenhouse gas (GHG) emissions requires conducting a lifecycle analysis of the process by which hydrogen is produced and supplied. This study focuses on the hydrogen for the transport sector in particular renewable hydrogen that is produced from wind- or solar PV-powered electrolysis. A life cycle inventory analysis is conducted to evaluate the Well-to-Tank (WtT) GHG emissions from various renewable hydrogen supply chains. The stages of the supply chains include hydrogen being produced overseas converted into a transportable hydrogen carrier (liquid hydrogen or methylcyclohexane) imported to Japan by sea distributed to hydrogen filling stations restored from the hydrogen carrier to hydrogen and filled into fuel cell vehicles. For comparison an analysis is also carried out with hydrogen produced by steam reforming of natural gas. Foreground data related to the hydrogen supply chains are collected by literature surveys and the Japanese life cycle inventory database is used as the background data. The analysis results indicate that some of renewable hydrogen supply chains using liquid hydrogen exhibited significantly lower WtT GHG emissions than those of a supply chain of hydrogen produced by reforming of natural gas. A significant piece of the work is to consider the impacts of variations in the energy and material inputs by performing a probabilistic uncertainty analysis. This suggests that the production of renewable hydrogen its liquefaction the dehydrogenation of methylcyclohexane and the compression of hydrogen at the filling station are the GHG-intensive stages in the target supply chains.
Design Challenges in Hydrogen-Fueled Rotary Engine-A Review
Jan 2023
Publication
The rotary engine (RE) is a potential power plant for unmanned aerial vehicles (UAVs) and automobiles because of its structural and design merits. However it has some serious drawbacks such as frequent maintenance requirements and excessive fuel consumption. This review paper presents the current status of hydrogen-fueled rotary engine (HRE) technology and identifies the existing research and development gaps in combustion efficiency and performance of this engine that might benefit transportation sector. Focusing primarily on the research from past ten years the crucial challenges encountered in hydrogen-powered rotary engines have been reviewed in terms of knock hydrocarbon (HC) emissions and seal leakages. The paper identifies the recent advances in design concepts and production approaches used in hydrogen-fueled rotary engines such as geometric models of trochoid profiles port configurations fuel utilization systems and currently available computational fluid dynamics (CFD) tools. This review article is an attempt to collect and organize literature on existing design methods up to date and provide recommendations for further improvements in RE technology.
Life Cycle Assessment of Improved High Pressure Alkaline Electrolysis
Aug 2015
Publication
This paper investigates environmental impacts of high pressure alkaline water electrolysis systems. An advanced system with membranes on polymer basis is compared to a state-of-the-art system with asbestos membranes using a Life Cycle Assessment (LCA) approach. For the advanced system a new improved membrane technology has been investigated within the EU research project “ELYGRID”. Results indicate that most environmental impacts are caused by the electricity supply necessary for operation. During the construction phase cell stacks are the main contributor to environmental impacts. New improved membranes have relatively small contributions to impacts caused by cell construction within the advanced systems. As main outcome the systems comparison illustrates a better ecological performance of the new developed system
Exergetic Aspects of Hydrogen Energy Systems—The Case Study of a Fuel Cell Bus
Feb 2017
Publication
Electrifying transportation is a promising approach to alleviate climate change issues arising from increased emissions. This study examines a system for the production of hydrogen using renewable energy sources as well as its use in buses. The electricity requirements for the production of hydrogen through the electrolysis of water are covered by renewable energy sources. Fuel cells are being used to utilize hydrogen to power the bus. Exergy analysis for the system is carried out. Based on a steady-state model of the processes exergy efficiencies are calculated for all subsystems. The subsystems with the highest proportion of irreversibility are identified and compared. It is shown that PV panel has exergetic efficiency of 12.74% wind turbine of 45% electrolysis of 67% and fuel cells of 40%.
Decarbonization of Australia’s Energy System: Integrated Modelling of the Transformation of Electricity, Transportation, and Industrial Sectors
Jul 2020
Publication
To achieve the Paris Agreement’s long-term temperature goal current energy systems must be transformed. Australia represents an interesting case for energy system transformation modelling: with a power system dominated by fossil fuels and specifically with a heavy coal component there is at the same time a vast potential for expansion and use of renewables. We used the multi-sectoral Australian Energy Modelling System (AUSeMOSYS) to perform an integrated analysis of implications for the electricity transport and selected industry sectors to the mid-century. The state-level resolution allows representation of regional discrepancies in renewable supply and the quantification of inter-regional grid extensions necessary for the physical integration of variable renewables. We investigated the impacts of different CO2 budgets and selected key factors on energy system transformation. Results indicate that coal-fired generation has to be phased out completely by 2030 and a fully renewable electricity supply achieved in the 2030s according to the cost-optimal pathway implied by the 1.5 °C Paris Agreement-compatible carbon budget. Wind and solar PV can play a dominant role in decarbonizing Australia’s energy system with continuous growth of demand due to the strong electrification of linked energy sectors.
How To Transport and Store Hydrogen – Facts and Figures
Apr 2021
Publication
The EU has set a goal of achieving climate neutrality by 2050 and decided to raise its 2030 climate target to 55%. For this the EU needs to transform its energy system. It is of paramount importance that it will become more efficient affordable and interconnected. Hydrogen can play a pivotal role in the EU’s decarbonisation efforts and be at the centre of the energy system integration supporting transport of renewable energy over very long distances and facilitating renewables storage from one season to another.<br/><br/>ENTSOG GIE and Hydrogen Europe have joined forces on a factsheet that answers a number of fundamental questions about gaseous and liquid hydrogen transport and storage titled “How to transport and store hydrogen? Facts and figures”. This factsheet provides an objective and informative analysis on key concepts terminology and facts and figures from different public sources.<br/><br/>The factsheet illustrates the EU’s potential to enable a global hydrogen economy and to become a global technology leader due to its extensive gas infrastructure that can be used to transport blends of hydrogen or be converted to transport pure hydrogen.
Onshore, Offshore or In-turbine Electrolysis? Techno-economic Overview of Alternative Integration Designs for Green Hydrogen Production into Offshore Wind Power Hubs
Aug 2021
Publication
Massive investments in offshore wind power generate significant challenges on how this electricity will be integrated into the incumbent energy systems. In this context green hydrogen produced by offshore wind emerges as a promising solution to remove barriers towards a carbon-free economy in Europe and beyond. Motivated by the recent developments in Denmark with the decision to construct the world’s first artificial Offshore Energy Hub this paper investigates how the lowest cost for green hydrogen can be achieved. A model proposing an integrated design of the hydrogen and offshore electric power infrastructure determining the levelised costs of both hydrogen and electricity is proposed. The economic feasibility of hydrogen production from 2 Offshore Wind Power Hubs is evaluated considering the combination of different electrolyser placements technologies and modes of operations. The results show that costs down to 2.4 €/kg can be achieved for green hydrogen production offshore competitive with the hydrogen costs currently produced by natural gas. Moreover a reduction of up to 13% of the cost of wind electricity is registered when an electrolyser is installed offshore shaving the peak loads.
Thickness-Prediction Method Involving Tow Redistribution for the Dome of Composite Hydrogen Storage Vessels
Feb 2022
Publication
Traditional thickness-prediction methods underestimate the actual dome thickness at polar openings leading to the inaccurate prediction of the load-bearing capacity of composite hydrogen storage vessels. A method of thickness prediction for the dome section of composite hydrogen storage vessels was proposed which involved fiber slippage and tow redistribution. This method considered the blocking effect of the port on sliding fiber tows and introduced the thickness correlation to predict the dome thickness at polar openings. The arc length corresponding to the parallel circle radius was calculated and then the actual radius values corresponding to the bandwidth were obtained by the interpolation method. The predicted thickness values were compared with the actual measured thickness. The maximum relative error of the predicted thickness was 4.19% and the mean absolute percentage error was 2.04%. The results show that the present method had a higher prediction accuracy. Eventually this prediction method was used to perform progressive damage analysis on vessels. By comparing with the results of the cubic spline function method the analysis results of the present method approached the actual case. This showed that the present method improved the accuracy of the design.
Material-based Hydrogen Storage Projection
Sep 2021
Publication
Massive consumption of fossil fuel leads to shortage problems as well as various global environmental issues. Due to the global climatic problem in the world techniques to supply energy demand change from conventional methods that use fossil fuel as the energy source to clean and renewable sources such as solar and wind. However these renewable energy sources are not permanent. Energy storage methods can ensure to supply the energy demand in need if the energy is stored when the renewable source is available. Hydrogen is considered a promising alternative feedstock owing to has unique properties such as clean energy high energy density absence of toxic materials and carbon-free nature. Hydrogen is used main fuel source in fuel cells and hydrogen can be produced with various methods such as wind or electrolysis of water systems that supply electricity from renewable sources. However the safe effective and economical storage of hydrogen is still a challenge that limits the spread of the usage of hydrogen energy. High pressed hydrogen gas and cryogenic hydrogen liquid are two applied storage pathways although they do not meet the above-mentioned requirement. To overcome these drawbacks materials-based hydrogen storage materials have been mostly investigated research field recently. The aim of the study is that exhibiting various material-based hydrogen storage systems and development of these techniques worldwide. Additionally past and current status of the technology are explained and future perspective is discussed.
Fuel Cells and Hydrogen Observatory Hydrogen Molecule Market Report
Sep 2021
Publication
The purpose of the hydrogen molecule market analysis is to track changes in the structure of hydrogen supply and demand in Europe. This report is mainly focused on presenting the current landscape - that will allow for future year-on-year comparisons in order to assess the progress Europe is making with regards to deployment of clean hydrogen production capacities as well as development of demand for clean hydrogen from emerging new hydrogen applications in the mobility sector or in industry. The following report summarizes the hydrogen molecule market landscape and contains data about hydrogen production and consumption in the EEA countries (EU countries together with Switzerland Norway Iceland and Liechtenstein). Hydrogen production capacity is presented by country and by technology whereas the hydrogen consumption data is presented by country and by end-use sector. The analysis undertaken for this report was completed using data available at the end of 2019. Hydrogen market (on both the demand and supply side) is dominated by ammonia and refining industries with three countries (DE NL PL) responsible for almost half hydrogen consumption. Today hydrogen is overwhelmingly produced by reforming of fossil fuels (mostly natural gas). Clean hydrogen production capacities are insignificant with blue hydrogen capacities at below 1% and green hydrogen production capacity below 0.1% of total.
Bayesian Inference and Uncertainty Quantification for Hydrogen-Enriched and Lean-Premixed Combustion Systems
May 2021
Publication
Development of probabilistic modelling tools to perform Bayesian inference and uncertainty quantification (UQ) is a challenging task for practical hydrogen-enriched and low-emission combustion systems due to the need to take into account simultaneously simulated fluid dynamics and detailed combustion chemistry. A large number of evaluations is required to calibrate models and estimate parameters using experimental data within the framework of Bayesian inference. This task is computationally prohibitive in high-fidelity and deterministic approaches such as large eddy simulation (LES) to design and optimize combustion systems. Therefore there is a need to develop methods that: (a) are suitable for Bayesian inference studies and (b) characterize a range of solutions based on the uncertainty of modelling parameters and input conditions. This paper aims to develop a computationally-efficient toolchain to address these issues for probabilistic modelling of NOx emission in hydrogen-enriched and lean-premixed combustion systems. A novel method is implemented into the toolchain using a chemical reactor network (CRN) model non-intrusive polynomial chaos expansion based on the point collocation method (NIPCE-PCM) and the Markov Chain Monte Carlo (MCMC) method. First a CRN model is generated for a combustion system burning hydrogen-enriched methane/air mixtures at high-pressure lean-premixed conditions to compute NOx emission. A set of metamodels is then developed using NIPCE-PCM as a computationally efficient alternative to the physics-based CRN model. These surrogate models and experimental data are then implemented in the MCMC method to perform a two-step Bayesian calibration to maximize the agreement between model predictions and measurements. The average standard deviations for the prediction of exit temperature and NOx emission are reduced by almost 90% using this method. The calibrated model then used with confidence for global sensitivity and reliability analysis studies which show that the volume of the main-flame zone is the most important parameter for NOx emission. The results show satisfactory performance for the developed toolchain to perform Bayesian inference and UQ studies enabling a robust and consistent process for designing and optimising low-emission combustion systems.
Enabling Low-carbon Hydrogen Supply Chains Through Use of Biomass and Carbon Capture and Storage: A Swiss Case Study
Jul 2020
Publication
This study investigates the optimal design of low-carbon hydrogen supply chains on a national scale. We consider hydrogen production based on several feedstocks and energy sources namely water with electricity natural gas and biomass. When using natural gas we couple hydrogen production with carbon capture and storage. The design of the hydrogen biomass and carbon dioxide (CO2 ) infrastructure is performed by solving an optimization problem that determines the optimal selection size and location of the hydrogen production technologies and the optimal structure of the hydrogen biomass and CO2 O2 networks. First we investigate the rationale behind the optimal design of low-carbon hydrogen supply chains by referring to an idealized system configuration and by performing a parametric analysis of the most relevant design parameters of the supply chains such as biomass availability. This allows drawing general conclusions independent of any specific geographic features about the minimum-cost and minimum-emissions system designs and network structures. Moreover we analyze the Swiss case study to derive specific guidelines concerning the design of hydrogen supply chains deploying carbon capture and storage. We assess the impact of relevant design parameters such as location of CO2 storage facilities techno-economic features of CO2 capture technologies and network losses on the optimal supply chain design and on the competition between the hydrogen and CO2 networks. Findings highlight the fundamental role of biomass (when available) and of carbon capture and storage for decarbonizing hydrogen supply chains while transitioning to a wider deployment of renewable energy sources.
Selected Aspects of Hydrogen Production via Catalytic Decomposition of Hydrocarbons
Feb 2021
Publication
Owing to the high hydrogen content hydrocarbons are considered as an alternative source for hydrogen energy purposes. Complete decomposition of hydrocarbons results in the formation of gaseous hydrogen and solid carbonaceous by-product. The process is complicated by the methane formation reaction when the released hydrogen interacts with the formed carbon deposits. The present study is focused on the effects of the reaction mixture composition. Variations in the inlet hydrogen and methane concentrations were found to influence the carbon product’s morphology and the hydrogen production efficiency. The catalyst containing NiO (82 wt%) CuO (13 wt%) and Al2O3 (5 wt%) was prepared via a mechanochemical activating procedure. Kinetics of the catalytic process of hydrocarbons decomposition was studied using a reactor equipped with McBain balances. The effects of the process parameters were explored in a tubular quartz reactor with chromatographic analysis of the outlet gaseous products. In the latter case the catalyst was loaded piecemeal. The texture and morphology of the produced carbon deposits were investigated by nitrogen adsorption and electron microscopy techniques.
Water Photo-Electrooxidation Using Mats of TiO2 Nanorods, Surface Sensitized by a Metal–Organic Framework of Nickel and 1,2-Benzene Dicarboxylic Acid
Apr 2021
Publication
Photoanodes comprising a transparent glass substrate coated with a thin conductive film of fluorine-doped tin oxide (FTO) and a thin layer of a photoactive phase have been fabricated and tested with regard to the photo-electro-oxidation of water into molecular oxygen. The photoactive layer was made of a mat of TiO2 nanorods (TDNRs) of micrometric thickness. Individual nanorods were successfully photosensitized with nanoparticles of a metal–organic framework (MOF) of nickel and 12-benzene dicarboxylic acid (BDCA). Detailed microstructural information was obtained from SEM and TEM analysis. The chemical composition of the active layer was determined by XRD XPS and FTIR analysis. Optical properties were determined by UV–Vis spectroscopy. The water photooxidation activity was evaluated by linear sweep voltammetry and the robustness was assessed by chrono-amperometry. The OER (oxygen evolution reaction) photo-activity of these photoelectrodes was found to be directly related to the amount of MOF deposited on the TiO2 nanorods and was therefore maximized by adjusting the MOF content. The microscopic reaction mechanism which controls the photoactivity of these photoelectrodes was analyzed by photo-electrochemical impedance spectroscopy. Microscopic rate parameters are reported. These results contribute to the development and characterization of MOF-sensitized OER photoanodes.
The ‘Green’ Ni-UGSO Catalyst for Hydrogen Production under Various Reforming Regimes
Jun 2021
Publication
A new spinelized Ni catalyst (Ni-UGSO) using Ni(NO3)2·6H2O as the Ni precursor was prepared according to a less material intensive protocol. The support of this catalyst is a negative-value mining residue UpGraded Slag Oxide (UGSO) produced from a TiO2 slag production unit. Applied to dry reforming of methane (DRM) at atmospheric pressure T = 810 °C space velocity of 3400 mL/(h·g) and molar CO2/CH4 = 1.2 Ni-UGSO gives a stable over 168 h time-on-stream methane conversion of 92%. In this DRM reaction optimization study: (1) the best performance is obtained with the 10–13 wt% Ni load; (2) the Ni-UGSO catalysts obtained from two different batches of UGSO demonstrated equivalent performances despite their slight differences in composition; (3) the sulfur-poisoning resistance study shows that at up to 5.5 ppm no Ni-UGSO deactivation is observed. In steam reforming of methane (SRM) Ni-UGSO was tested at 900 °C and a molar ratio of H2O/CH4 = 1.7. In this experimental range CH4 conversion rapidly reached 98% and remained stable over 168 h time-on-stream (TOS). The same stability is observed for H2 and CO yields at around 92% and 91% respectively while H2/CO was close to 3. In mixed (dry and steam) methane reforming using a ratio of H2O/CH4 = 0.15 and CO2/CH4 = 0.97 for 74 h and three reaction temperature levels (828 °C 847 °C and 896 °C) CH4 conversion remains stable; 80% at 828 °C (26 h) 85% at 847 °C (24 h) and 95% at 896 °C (24 h). All gaseous streams have been analyzed by gas chromatography. Both fresh and used catalysts are analyzed by scanning electron microscopy-electron dispersive X-ray spectroscopy (SEM-EDXS) X-ray diffraction (XRD) and thermogravimetric analysis (TGA) coupled with mass spectroscopy (MS) and BET Specific surface. In the reducing environment of reforming such catalytic activity is mainly attributed to (a) alloys such as FeNi FeNi3 and Fe3Ni2 (reduction of NiFe2O4 FeNiAlO4) and (b) to the solid solution NiO-MgO. The latter is characterized by a molecular distribution of the catalytically active Ni phase while offering an environment that prevents C deposition due to its alkalinity.
Shining the Light on Clean Hydrogen
Jun 2021
Publication
Clean hydrogen:
- What's driving the excitement?
- Will hydrogen stay on the main stage of the energy transition?
- What is the market for clean hydrogen today?
Progress and Challenges on the Thermal Management of Electrochemical Energy Conversion and Storage Technologies: Fuel Cells, Electrolysers, and Supercapacitors
Oct 2021
Publication
It is now well established that electrochemical systems can optimally perform only within a narrow range of temperature. Exposure to temperatures outside this range adversely affects the performance and lifetime of these systems. As a result thermal management is an essential consideration during the design and operation of electrochemical equipment and can heavily influence the success of electrochemical energy technologies. Recently significant attempts have been placed on the maturity of cooling technologies for electrochemical devices. Nonetheless the existing reviews on the subject have been primarily focused on battery cooling. Conversely heat transfer in other electrochemical systems commonly used for energy conversion and storage has not been subjected to critical reviews. To address this issue the current study gives an overview of the progress and challenges on the thermal management of different electrochemical energy devices including fuel cells electrolysers and supercapacitors. The physicochemical mechanisms of heat generation in these electrochemical devices are discussed in-depth. Physics of the heat transfer techniques currently employed for temperature control are then exposed and some directions for future studies are provided.
Overview of Biomass Conversion to Electricity and Hydrogen and Recent Developments in Low-Temperature Electrochemical Approaches
Nov 2020
Publication
Biomass is plant or animal material that stores both chemical and solar energies and that is widely used for heat production and various industrial processes. Biomass contains a large amount of the element hydrogen so it is an excellent source for hydrogen production. Therefore biomass is a sustainable source for electricity or hydrogen production. Although biomass power plants and reforming plants have been commercialized it remains a difficult challenge to develop more effective and economic technologies to further improve the conversion efficiency and reduce the environmental impacts in the conversion process. The use of biomass-based flow fuel cell technology to directly convert biomass to electricity and the use of electrolysis technology to convert biomass into hydrogen at a low temperature are two new research areas that have recently attracted interest. This paper first briefly introduces traditional technologies related to the conversion of biomass to electricity and hydrogen and then reviews the new developments in flow biomass fuel cells (FBFCs) and biomass electrolysis for hydrogen production (BEHP) in detail. Further challenges in these areas are discussed.
Techno-Economics Optimization of H2 and CO2 Compression for Renewable Energy Storage and Power-to-Gas Applications
Nov 2021
Publication
The decarbonization of the industrial sector is imperative to achieve a sustainable future. Carbon capture and storage technologies are the leading options but lately the use of CO2 is also being considered as a very attractive alternative that approaches a circular economy. In this regard power to gas is a promising option to take advantage of renewable H2 by converting it together with the captured CO2 into renewable gases in particular renewable methane. As renewable energy production or the mismatch between renewable production and consumption is not constant it is essential to store renewable H2 or CO2 to properly run a methanation installation and produce renewable gas. This work analyses and optimizes the system layout and storage pressure and presents an annual cost (including CAPEX and OPEX) minimization. Results show the proper compression stages need to achieve the storage pressure that minimizes the system cost. This pressure is just below the supercritical pressure for CO2 and at lower pressures for H2 around 67 bar. This last quantity is in agreement with the usual pressures to store and distribute natural gas. Moreover the H2 storage costs are higher than that of CO2 even with lower mass quantities; this is due to the lower H2 density compared with CO2 . Finally it is concluded that the compressor costs are the most relevant costs for CO2 compression but the storage tank costs are the most relevant in the case of H2.
Criticality and Life-Cycle Assessment of Materials Used in Fuel-Cell and Hydrogen Technologies
Mar 2021
Publication
The purpose of this paper is to obtain relevant data on materials that are the most commonly used in fuel-cell and hydrogen technologies. The focus is on polymer-electrolyte-membrane fuel cells solid-oxide fuel cells polymer-electrolyte-membrane water electrolysers and alkaline water electrolysers. An innovative methodological approach was developed for a preliminary material assessment of the four technologies. This methodological approach leads to a more rapid identification of the most influential or critical materials that substantially increase the environmental impact of fuel-cell and hydrogen technologies. The approach also assisted in amassing the life-cycle inventories—the emphasis here is on the solid-oxide fuel-cell technology because it is still in its early development stage and thus has a deficient materials’ database—that were used in a life-cycle assessment for an in-depth material-criticality analysis. All the listed materials—that either are or could potentially be used in these technologies—were analysed to give important information for the fuel-cell and hydrogen industries the recycling industry the hydrogen economy as well as policymakers. The main conclusion from the life-cycle assessment is that the polymer-electrolyte membrane water electrolysers have the highest environmental impacts; lower impacts are seen in polymer-electrolyte-membrane fuel cells and solid-oxide fuel cells while the lowest impacts are observed in alkaline water electrolysers. The results of the material assessment are presented together for all the considered materials but also separately for each observed technology.
Cryogenic and Ambient Gaseous Hydrogen Blowdown with Discharge Line Effects
Sep 2021
Publication
The present work performed within the PRESLHY EC-project presents a simplified 1-d transient modelling methodology to account for discharge line effects during blowdown. The current formulation includes friction extra resistance area change and heat transfer through the discharge line walls and is able to calculate the mass flow rate and distribution of all physical variables along the discharge line. Choked flow at any time during the transient is calculated using the Possible Impossible Flow (PIF) algorithm. Hydrogen single phase physical properties and vapour-liquid equilibrium are calculated using the Helmholtz Free Energy (HFE) formulation. Homogeneous Equilibrium Mixture (HEM) model is used for two-phase physical properties. Validation is performed against the new experiments with compressed gaseous hydrogen performed at the DISCHA facility in the framework of PRESLHY (200 bar ambient and cryogenic initial tank temperature 77 K and 4 nozzle diameters 0.5 1 2 and 4 mm) and an older experiment at 900 bar ambient temperature and 2 mm nozzle. Predictions are compared against measured data from the experiments and the relative importance of line heat transfer compared to flow resistance is analysed.
CFD Simulations of Large Scale LH2 Dispersion in Open Environment
Sep 2021
Publication
An inter-comparison among partners’ CFD simulations has been carried out within the EU-funded project PRESLHY to investigate the dispersion of the mixture cloud formed from large scale liquid hydrogen release. Rainout experiments performed by Health and Safety Executive (HSE) have been chosen for the work. From the HSE experimental series trial-11 was selected forsimulation due to its conditions where only liquid flow at the nozzle was achieved. During trial-11 liquid hydrogen is spilled horizontally 0.5 m above a concrete pad from a 5 barg tank pressure through a 12 mm (1/2 inch) nozzle. The dispersion takes place outdoors and thus it is imposed to variant wind conditions. Comparison of the CFD results with the measurements at several sensors is presented and useful conclusions are drawn.
Net Zero in the Heating Sector: Technological Options and Environmental Sustainability from Now to 2050
Jan 2021
Publication
Heating and hot water within buildings account for almost a quarter of global energy consumption. Approximately 90% of this heat is derived directly from the combustion of fossil fuels primarily natural gas leading to the unabated emission of carbon dioxide. This paper assesses the environmental sustainability of a range of heating technologies and scenarios on a life cycle basis. The major technologies considered are natural gas boilers air source heat pumps hydrogen boilers and direct electric heaters. The scenarios use the UK as an example due to its status as a major economy with a legally-binding net-zero carbon target for 2050; they consider plausible future electricity and natural gas mixes including the potential growth of domestic shale gas. The environmental impacts are estimated using ReCiPe 2016. Current gas boilers have a climate change impact of 220 g CO2 eq./kWh of heat which could fall to 64 g CO2 eq./kWh for boilers fuelled by hydrogen derived from natural gas with carbon capture. Heat from electric air source heat pumps or hydrogen from electrolysis can achieve net zero with a decarbonised electricity mix but electrolysis has the highest energy demand of all options which leads to the highest impacts across 17 of the 19 categories. Despite their high carbon emissions gas boilers remain the lowest impact option across 12 categories as they avoid the impacts related to electricity generation including metal depletion toxicities and eutrophication. By 2050 the best performing scenario sees the climate change impact of the heating mix fall by 95%; this is achieved by prioritising electric air source heat pumps without hydrofluorocarbon refrigerants alongside demand reduction. The results show that if infrastructure and financial challenges can be overcome there are several viable decarbonisation strategies for heating with heat pumps offering the most environmentally sustainable option of those considered here. However increased renewable electricity demand may worsen some environmental impacts compared to natural gas boilers.
Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst
Nov 2020
Publication
A novel Pd/templated carbon catalyst (Pd/TC) was developed characterized and tested in the dehydrogenation of formic acid (FA) under mild conditions with the possibility to control the H2 generation rate in the absence or presence of HCOONa (SF) by adjusting the Pd:FA and/or FA:SF ratios. The characterization results of the templated carbon obtained by the chemical vapor deposition of acetylene on NaY zeolite revealed different structural and morphological properties compared to other C-based supports. Therefore it was expected to induce a different catalytic behavior for the Pd/TC catalyst. Indeed the TC-supported Pd catalyst exhibited superior activity in the decomposition of FA even at room temperature with turnover frequencies (TOFs) of up to 143.7 and 218.8 h−1 at 60 °C. The H2 generation rate increased with an increasing temperature while the H2 yield increased with a decreasing FA concentration. Constant generation of gaseous flow (H2 + CO2) was achieved for 11 days by the complete dehydrogenation of FA at room temperature using a 2 M FA solution and Pd:FA = 1:2100. The presence of SF in the reaction medium significantly enhanced the H2 generation rate (535 h−1 for FA:SF = 3:1 and 60 °C).
The Role of Green and Blue Hydrogen in the Energy Transition—A Technological and Geopolitical Perspective
Dec 2020
Publication
Hydrogen is currently enjoying a renewed and widespread momentum in many national and international climate strategies. This review paper is focused on analysing the challenges and opportunities that are related to green and blue hydrogen which are at the basis of different perspectives of a potential hydrogen society. While many governments and private companies are putting significant resources on the development of hydrogen technologies there still remains a high number of unsolved issues including technical challenges economic and geopolitical implications. The hydrogen supply chain includes a large number of steps resulting in additional energy losses and while much focus is put on hydrogen generation costs its transport and storage should not be neglected. A low-carbon hydrogen economy offers promising opportunities not only to fight climate change but also to enhance energy security and develop local industries in many countries. However to face the huge challenges of a transition towards a zero-carbon energy system all available technologies should be allowed to contribute based on measurable indicators which require a strong international consensus based on transparent standards and targets.
A Decarbonization Roadmap for Singapore and Its Energy Policy Implications
Oct 2021
Publication
As a signatory to the Paris Agreement Singapore is committed to achieving net-zero carbon emissions in the second half of the century. In this paper we propose a decarbonization roadmap for Singapore based on an analysis of Singapore’s energy landscape and a technology mapping exercise. This roadmap consists of four major components. The first component which also underpins the other three components is using centralized post-combustion carbon capture technology to capture and compress CO2 emitted from multiple industrial sources in Jurong Island. The captured CO2 is then transported by ship or an existing natural gas pipeline to a neighboring country where it will be stored permanently in a subsurface reservoir. Important to the success of this first-of-a-kind cross-border carbon capture and storage (CCS) project is the establishment of a regional CCS corridor which makes use of economies of scale to reduce the cost of CO2 capture transport and injection. The second component of the roadmap is the production of hydrogen in a methane steam reforming plant which is integrated with the carbon capture plant. The third component is the modernizing of the refining sector by introducing biorefineries increasing output to petrochemical plants and employing post-combustion carbon capture. The fourth component is refueling the transport sector by introducing electric and hydrogen fuel cell vehicles using biofuels for aviation and hydrogen for marine vessels. The implications of this roadmap on Singapore’s energy policies are also discussed.
Asymmetric Solvation of the Zinc Dimer Cation Revealed by Infrared Multiple Photon Dissociation Spectroscopy of Zn2+(H2O)n (n = 1–20)
Jun 2021
Publication
Investigating metal-ion solvation—in particular the fundamental binding interactions—enhances the understanding of many processes including hydrogen production via catalysis at metal centers and metal corrosion. Infrared spectra of the hydrated zinc dimer (Zn2+(H2O)n; n = 1–20) were measured in the O–H stretching region using infrared multiple photon dissociation (IRMPD) spectroscopy. These spectra were then compared with those calculated by using density functional theory. For all cluster sizes calculated structures adopting asymmetric solvation to one Zn atom in the dimer were found to lie lower in energy than structures adopting symmetric solvation to both Zn atoms. Combining experiment and theory the spectra show that water molecules preferentially bind to one Zn atom adopting water binding motifs similar to the Zn+(H2O)n complexes studied previously. A lower coordination number of 2 was observed for Zn2+(H2O)3 evident from the highly red-shifted band in the hydrogen bonding region. Photodissociation leading to loss of a neutral Zn atom was observed only for n = 3 attributed to a particularly low calculated Zn binding energy for this cluster size.
Greenhouse Gas Abatement in EUROPE—A Scenario-Based, Bottom-Up Analysis Showing the Effect of Deep Emission Mitigation on the European Energy System
Feb 2022
Publication
Greenhouse gas emissions need to be drastically reduced to mitigate the environmental impacts caused by climate change and to lead to a transformation of the European energy system. A model landscape consisting of four final energy consumption sector models with high spatial (NUTS-3) and temporal (hourly) resolution and the multi-energy system model ISAaR is extended and applied to investigate the transformation pathway of the European energy sector in the deep emission mitigation scenario solidEU. The solidEU scenario describes not only the techno-economic but also the socio-political contexts and it includes the EU27 + UK Norway and Switzerland. The scenario analysis shows that volatile renewable energy sources (vRES) dominate the energy system in 2050. In addition the share of flexible sector coupling technologies increases to balance electricity generation from vRES. Seasonal differences are balanced by hydrogen storage with a seasonal storage profile. The deployment rates of vRES in solidEU show that a fast profound energy transition is necessary to achieve European climate protection goals.
Emerging Electrochemical Energy Conversion and Storage Technologies
Sep 2014
Publication
Electrochemical cells and systems play a key role in a wide range of industry sectors. These devices are critical enabling technologies for renewable energy; energy management conservation and storage; pollution control/monitoring; and greenhouse gas reduction. A large number of electrochemical energy technologies have been developed in the past. These systems continue to be optimized in terms of cost life time and performance leading to their continued expansion into existing and emerging market sectors. The more established technologies such as deep-cycle batteries and sensors are being joined by emerging technologies such as fuel cells large format lithium-ion batteries electrochemical reactors; ion transport membranes and supercapacitors. This growing demand (multi-billion dollars) for electrochemical energy systems along with the increasing maturity of a number of technologies is having a significant effect on the global research and development effort which is increasing in both in size and depth. A number of new technologies which will have substantial impact on the environment and the way we produce and utilize energy are under development. This paper presents an overview of several emerging electrochemical energy technologies along with a discussion some of the key technical challenges.
Quantifying the Potential of Renewable Natural Gas to Support a Reformed Energy Landscape: Estimates for New York State
Jun 2021
Publication
Public attention to climate change challenges our locked-in fossil fuel-dependent energy sector. Natural gas is replacing other fossil fuels in our energy mix. One way to reduce the greenhouse gas (GHG) impact of fossil natural gas is to replace it with renewable natural gas (RNG). The benefits of utilizing RNG are that it has no climate change impact when combusted and utilized in the same applications as fossil natural gas. RNG can be injected into the gas grid used as a transportation fuel or used for heating and electricity generation. Less common applications include utilizing RNG to produce chemicals such as methanol dimethyl ether and ammonia. The GHG impact should be quantified before committing to RNG. This study quantifies the potential production of biogas (i.e. the precursor to RNG) and RNG from agricultural and waste sources in New York State (NYS). It is unique because it is the first study to provide this analysis. The results showed that only about 10% of the state’s resources are used to generate biogas of which a small fraction is processed to RNG on the only two operational RNG facilities in the state. The impact of incorporating a second renewable substitute for fossil natural gas “green” hydrogen is also analyzed. It revealed that injecting RNG and “green” hydrogen gas into the pipeline system can reduce up to 20% of the state’s carbon emissions resulting from fossil natural gas usage which is a significant GHG reduction. Policy analysis for NYS shows that several state and federal policies support RNG production. However the value of RNG can be increased 10-fold by applying a similar incentive policy to California’s Low Carbon Fuel Standard (LCFS).
Synergistic Hybrid Marine Renewable Energy Harvest System
Mar 2024
Publication
This paper proposes a novel hybrid marine renewable energy-harvesting system to increase energy production reduce levelized costs of energy and promote renewable marine energy. Firstly various marine renewable energy resources and state-of-art technologies for energy exploitation and storage were reviewed. The site selection criteria for each energy-harvesting approach were identified and a scoring matrix for site selection was proposed to screen suitable locations for the hybrid system. The Triton Knoll wind farm was used to demonstrate the effectiveness of the scoring matrix. An integrated energy system was designed and FE modeling was performed to assess the effects of additional energy devices on the structural stability of the main wind turbine structure. It has been proven that the additional energy structures have a negligible influence on foundation/structure deflection.
Economic Analysis of Hydrogen Household Energy Systems Including Incentives on Energy Communities and Externalities: A Case Study in Italy
Sep 2021
Publication
The building sector is one of the key energy consumers worldwide. Fuel cell micro-Cogeneration Heat and Power systems for residential and small commercial applications are proposed as one of the most promising innovations contributing to the transition towards a sustainable energy infrastructure. For the application and the diffusion of these systems in addition to their environmental performance it is necessary however to evaluate their economic feasibility. In this paper a life cycle assessment of a fuel cell/photovoltaic hybrid micro-cogeneration heat and power system for a residential building is integrated with a detailed economic analysis. Financial indicators (net present cost and payback time are used for studying two different investments: reversible-Solid Oxide Fuel Cell and natural gas SOFC in comparison to a base scenario using a homeowner perspective approach. Moreover two alternative incentives scenarios are analysed and applied: net metering and self-consumers’ groups (or energy communities). Results show that both systems obtain annual savings but their high capital costs still would make the investments not profitable. However the natural gas Solide Oxide Fuel Cell with the net metering incentive is the best scenario among all. On the contrary the reversible-Solid Oxide Fuel Cell maximizes its economic performance only when the self-consumers’ groups incentive is applied. For a complete life cycle cost analysis environmental impacts are monetized using three different monetization methods with the aim to internalize (considering them into direct cost) the externalities (environmental costs). If externalities are considered as an effective cost the natural gas Solide Oxide Fuel Cell system increases its saving because its environmental impact is lower than in the base case one while the reversible-Solid Oxide Fuel Cell system reduces it.
Improve Hydrogen Economy for Vehicular Fuel Cell System via Investigation and Control of Optimal Operating Oxygen Excess Ratio
Apr 2022
Publication
This study investigates and controls the optimal operating oxygen excess ratio (OER) for PEMFC which effectively prevents oxygen starvation and improves the hydrogen economy of proton exchange membrane fuel cells (PEMFC). Firstly the PEMFC output characteristic model and the five-order nonlinear air supply system model are established. Moreover an adaptive algebraic observer was developed to observe the partial pressure of gas in PEMFC and further reconstruct OER. Secondly to achieve the minimum hydrogen consumption under the required power the reference OER is determined by analyzing the PEMFC system output power with its minimum current. Finally the super-twisting algorithm is adopted to track reference OER. Simulation results show that the average absolute observation errors of oxygen nitrogen and cathode pressures under the Highway Fuel Economy Test are 1351.1 Pa (5.1%) 1724.2 Pa (0.9%) and 409.9 Pa (1.6%) respectively. The OER adjust average absolute error is 0.03. Compared with the commonly used fixed OER (e.g. OER of 1.5 and 2.3) the optimal OER strategy can reduce the hydrogen consumption of the PEMFC system by 5.2% and 1.8% respectively. Besides a DSP hardware in loop test is conducted to show the real-time performance of the proposed optimal method.
Past, Present and Near Future: An Overview of Closed, Running and Planned Biomethanation Facilities in Europe
Sep 2021
Publication
The power-to-methane technology is promising for long-term high-capacity energy storage. Currently there are two different industrial-scale methanation methods: the chemical one (based on the Sabatier reaction) and the biological one (using microorganisms for the conversion). The second method can be used not only to methanize the mixture of pure hydrogen and carbon dioxide but also to methanize the hydrogen and carbon dioxide content of low-quality gases such as biogas or deponia gas enriching them to natural gas quality; therefore the applicability of biomethanation is very wide. In this paper we present an overview of the existing and planned industrial-scale biomethanation facilities in Europe as well as review the facilities closed in recent years after successful operation in the light of the scientific and socioeconomic context. To outline key directions for further developments this paper interconnects biomethanation projects with the competitiveness of the energy sector in Europe for the first time in the literature. The results show that future projects should have an integrative view of electrolysis and biomethanation as well as hydrogen storage and utilization with carbon capture and utilization (HSU&CCU) to increase sectoral competitiveness by enhanced decarbonization.
Fuel Cells and Hydrogen Observatory Technology and Market Report
Sep 2021
Publication
The information in this report covers the period January 2019 – December 2019. The technology and market module of the FCHO presents a range of statistical data as an indicator of the health of the sector and the progress in market development over time. This includes statistical information on the size of the global fuel cell market including number and capacity of fuel cell systems shipped in a calendar year. For this first edition data to the end of 2019 is presented where possible alongside analysis of key sector developments. Fuel cell system shipments for each calendar year are presented both as numbers of units and total system megawatts. The data are further divided and subdivided by: • Application: Total system shipments are divided into Transport Stationary and Portable applications • Fuel cell type: Numbers are provided for each of the different fuel cell chemistry types • Region of integration: Region where the final manufacturer – usually the system integrator – integrates the fuel cell into the final product • Region of deployment: Region where the final product was shipped to for deployment The data is sourced directly from industry players as well as other relevant sources including press releases associations and other industry bodies.
Impacts of Variation Management on Cost-optimal Investments in Wind Power and Solar Photovoltaics
Dec 2019
Publication
This work investigates the impacts of variation management on the cost-optimal electricity system compositions in four regions with different pre-requisites for wind and solar generation. Five variation management strategies involving electric boilers batteries hydrogen storage low-cost biomass and demand-side management are integrated into a regional investment model that is designed to account for variability. The variation management strategies are considered one at a time as well as combined in four different system contexts. By investigating how the variation management strategies interact with each other as well as with different electricity generation technologies in a large number of cases this work support policy-makers in identifying variation management portfolios relevant to their context. It is found that electric boilers demand-side management and hydrogen storage increase the cost-optimal variable renewable electricity (VRE) investments if the VRE share is sufficiently large to reduce its marginal system value. However low-cost biomass and hydrogen storage are found to increase cost-optimal investments in wind power in systems with a low initial wind power share. In systems with low solar PV share variation management reduce the cost-optimal solar PV investments. In two of the regions investigated a combination of variation management strategies results in a stronger increase in VRE capacity than the sum of the single variation management efforts.
Setting Thresholds to Define Indifferences and Preferences in PROMETHEE for Life Cycle Sustainability Assessment of European Hydrogen Production
Jun 2021
Publication
The Life Cycle Sustainability Assessment (LCSA) is a proven method for sustainability assessment. However the interpretation phase of an LCSA is challenging because many different single results are obtained. Additionally performing a Multi-Criteria Decision Analysis (MCDA) is one way—not only for LCSA—to gain clarity about how to interpret the results. One common form of MCDAs are outranking methods. For these type of methods it becomes of utmost importance to clarify when results become preferable. Thus thresholds are commonly used to prevent decisions based on results that are actually indifferent between the analyzed options. In this paper a new approach is presented to identify and quantify such thresholds for Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) based on uncertainty of Life Cycle Impact Assessment (LCIA) methods. Common thresholds and this new approach are discussed using a case study on finding a preferred location for sustainable industrial hydrogen production comparing three locations in European countries. The single LCSA results indicated different preferences for the environmental economic and social assessment. The application of PROMETHEE helped to find a clear solution. The comparison of the newly-specified thresholds based on LCIA uncertainty with default thresholds provided important insights of how to interpret the LCSA results regarding industrial hydrogen production.
How Green Are the National Hydrogen Strategies?
Feb 2022
Publication
Since Japan promulgated the world’s first national hydrogen strategy in 2017 28 national (or regional in the case of the EU) hydrogen strategies have been issued by major world economies. As carbon emissions vary with different types of hydrogen and only green hydrogen produced from renewable energy can be zero-emissions fuel this paper interrogates the commitment of the national hydrogen strategies to achieve decarbonization objectives focusing on the question “how green are the national hydrogen strategies?” We create a typology of regulatory stringency for green hydrogen in national hydrogen strategies analyzing the text of these strategies and their supporting policies and evaluating their regulatory stringency toward decarbonization. Our typology includes four parameters fossil fuel penalties hydrogen certifications innovation enablement and the temporal dimension of coal phasing out. Following the typology we categorize the national hydrogen strategies into three groups: zero regulatory stringency scale first and clean later and green hydrogen now. We find that most national strategies are of the type “scale first and clean later” with one or more regulatory measures in place. This article identifies further challenges to enhancing regulatory stringency for green hydrogen at both national and international levels.
Thermoacoustic Instability Considerations for High Hydrogen Combustion in Lean Premixed Gas Turbine Combustors: A Review
Jan 2021
Publication
Hydrogen is receiving increasing attention as a versatile energy vector to help accelerate the transition to a decarbonised energy future. Gas turbines will continue to play a critical role in providing grid stability and resilience in future low-carbon power systems; however it is recognised that this role is contingent upon achieving increased thermal efficiencies and the ability to operate on carbon-neutral fuels such as hydrogen. An important consideration in the development of gas turbine combustors capable of operating with pure hydrogen or hydrogen-enriched natural gas are the significant changes in thermoacoustic instability characteristics associated with burning these fuels. This article provides a review of the effects of burning hydrogen on combustion dynamics with focus on swirl-stabilised lean-premixed combustors. Experimental and numerical evidence suggests hydrogen can have either a stabilising or destabilising impact on the dynamic state of a combustor through its influence particularly on flame structure and flame position. Other operational considerations such as the effect of elevated pressure and piloting on combustion dynamics as well as recent developments in micromix burner technology for 100% hydrogen combustion have also been discussed. The insights provided in this review will aid the development of instability mitigation strategies for high hydrogen combustion.
Energy Optimization of a Sulfur-Iodine Thermochemical Nuclear Hydrogen Production Cycle
Dec 2021
Publication
The use of nuclear reactors is a large studied possible solution for thermochemical water splitting cycles. Nevertheless there are several problems that have to be solved. One of them is to increase the efficiency of the cycles. Hence in this paper a thermal energy optimization of a SulfureIodine nuclear hydrogen production cycle was performed by means a heuristic method with the aim of minimizing the energy targets of the heat exchanger network at different minimum temperature differences. With this method four different heat exchanger networks are proposed. A reduction of the energy requirements for cooling ranges between 58.9-59.8% and 52.6-53.3% heating compared to the reference design with no heat exchanger network. With this reduction the thermal efficiency of the cycle increased in about 10% in average compared to the reference efficiency. This improves the use of thermal energy of the cycle.
The Heralds of Hydrogen: The Economic Sectors that are Driving the Hydrogen Economy in Europe
Jan 2021
Publication
This paper looked at 39 hydrogen associations across Europe to understand which economic sectors support the hydrogen transition in Europe and why they do so. Several broad conclusions can be drawn from this paper. It is clear that the support for hydrogen is broad and from a very wide spectrum of economic actors that have clear interests in the success of the hydrogen transition. Motivations for support differ. Sales and market growth are important for companies pursuing professional scientific and technical activities as well as manufacturers of chemicals machinery electronic or electrical equipment and fabricated metals. The increasing cost of CO2 combines with regulatory and societal pressure to decarbonize and concerns from investors about the long-term profitability of sectors with high emissions. This makes hydrogen especially interesting for companies working in the energy transport steel and chemical industries. Another motivation is the ability to keep using existing fixed assets relevant for ports oil and gas companies and natural gas companies. More sector-specific concerns are a technological belief held by some motor vehicle manufacturers in the advantages of FCVs over BEVs for private mobility which is held more widely regarding heavy road transport. Security of supply and diversifying the current business portfolio come up specifically for natural gas companies. Broader concerns about having to shift into other energy technologies as a core business are reasons for interest from the oil and gas sector and ports.
Perhaps the most important lesson is that the hydrogen transition has already begun – but it needs continued policy support and political commitment. Carbon-intensive industries such as steel and chemicals are clearly interested and willing to invest billions but need policy support to avoid carbon leakage to high-carbon competitors before they commit. The gas grid is ready and many operators and utility companies are eager but they need clearance to experiment with blending in hydrogen. Hydrogen road vehicles still face many regulatory hurdles. There are several clusters that can serve as models and nuclei for the future European hydrogen economy in different parts of Europe. However these nuclei will need more public funding and regulatory support for them to grow.
Link to document on Oxford Institute for Energy Studies website
Perhaps the most important lesson is that the hydrogen transition has already begun – but it needs continued policy support and political commitment. Carbon-intensive industries such as steel and chemicals are clearly interested and willing to invest billions but need policy support to avoid carbon leakage to high-carbon competitors before they commit. The gas grid is ready and many operators and utility companies are eager but they need clearance to experiment with blending in hydrogen. Hydrogen road vehicles still face many regulatory hurdles. There are several clusters that can serve as models and nuclei for the future European hydrogen economy in different parts of Europe. However these nuclei will need more public funding and regulatory support for them to grow.
Link to document on Oxford Institute for Energy Studies website
The Impact of Operating Conditions on the Performance of a CH4 Dry Reforming Membrane Reactor for H2 Production
May 2020
Publication
Biogas is a promising resource for the production of H2 since it liberates energy by recycling waste along with the reduction of CO2. In this paper the biogas dry reforming membrane reactor is proposed to produce H2 for use in fuel cells. Pd/Cu alloy membrane is used to enhance the performance of the biogas dry reforming reactor. This study aims at understanding the effect of operating parameters such as feed ratio of sweep gas pressure in the reactor and reaction temperature on the performance of the biogas dry reforming membrane reactor. The effect of the molar ratio of the supplied CH4:CO2 feed ratio of the sweep gas and the valve located at the outlet of the reaction chamber on the performance of biogas dry reforming are investigated. Besides the thermal efficiency of the proposed reactor is also evaluated. The results show that the concentration of H2 in the closed valve condition is higher than that of the open valve and the optimum feed ratio of the sweep gas to produce H2 is 1 irrespective of the molar ratio of supplied CH4:CO2. Also H2 selectivity and CO selectivity increases and decreases respectively when the reaction temperature increases irrespective of the molar ratio of supplied CH4:CO2. Therefore the thermal efficiency of the closed valve is higher than that of the opened valve. Also the thermal efficiency is the maximum when the feed ratio of the sweep gas is 1 due to high H2 production performance.
Validation of GreenH2armony® as a Tool for the Computation of Harmonised Life-Cycle Indicators of Hydrogen
Apr 2020
Publication
The Life Cycle Assessment (LCA) methodology is often used to check the environmental suitability of hydrogen energy systems usually involving comparative studies. However these comparative studies are typically affected by inconsistent methodological choices between the case studies under comparison. In this regard protocols for the harmonisation of methodological choices in LCA of hydrogen are available. The step-by-step application of these protocols to a large number of case studies has already resulted in libraries of harmonised carbon energy and acidification footprints of hydrogen. In order to foster the applicability of these harmonisation protocols a web-based software for the calculation of harmonised life-cycle indicators of hydrogen has recently been developed. This work addresses—for the first time—the validation of such a tool by checking the deviation between the available libraries of harmonised carbon energy and acidification footprints of hydrogen and the corresponding tool-based harmonised results. A high correlation (R2 > 0.999) was found between the library- and tool-based harmonised life-cycle indicators of hydrogen thereby successfully validating the software. Hence this tool has the potential to effectively promote the use of harmonised life-cycle indicators for robust comparative LCA studies of hydrogen energy systems significantly mitigating misinterpretation.
A Holistic Consideration of Megawatt Electrolysis as a Key Component of Sector Coupling
May 2022
Publication
In the future hydrogen (H2) will play a significant role in the sustainable supply of energy and raw materials to various sectors. Therefore the electrolysis of water required for industrial‐ scale H2 production represents a key component in the generation of renewable electricity. Within the scope of fundamental research work on cell components for polymer electrolyte membrane (PEM) electrolyzers and application‐oriented living labs an MW electrolysis system was used to further improve industrial‐scale electrolysis technology in terms of its basic structure and systems‐ related integration. The planning of this work as well as the analytical and technical approaches taken along with the essential results of research and development are presented herein. The focus of this study is the test facility for a megawatt PEM electrolysis stack with the presentation of the design processing and assembly of the main components of the facility and stack.
Storage System of Renewable Energy Generated Hydrogen for Chemical Industry
Nov 2012
Publication
Chemical industry is the base of the value chains and has strong influence on the competitiveness of almost all branches in economics. To develop the technologies for sustainability and climate protection and at the same time to guarantee the supply of raw material is a big challenge for chemical industry. In the project CO2RRECT (CO2 - Reaction using Regenerative Energies and Catalytic Technologies) funded by the German federal ministry of Education and Research carbon dioxide is used as the source of carbon for chemical products with certain chemical processes. Hydrogen that is needed in these processes is produced by electrolyzing water with renewable energy. To store a large amount of hydrogen different storage systems are studied in this project including liquid hydrogen tanks/cryo tanks high pressure tanks pipelines and salt cavities. These systems are analyzed and compared considering their storage capacity system costs advantages and disadvantages. To analyze capital and operational expenditure of the hydrogen storage systems a calculation methodology is also developed in this work.
Life Cycle Inventory Data Generation by Process Simulation for Conventional, Feedstock Recycling and Power-to-X Technologies for Base Chemical Production
Jan 2022
Publication
The article presents the methodology and applicable data for the generation of life cycle inventory for conventional and alternative processes for base chemical production by process simulation. Addressed base chemicals include lower olefins BTX aromatics methanol ammonia and hydrogen. Assessed processes include conventional chemical production processes from naphtha LPG natural gas and heavy fuel oil; feedstock recycling technologies via gasification and pyrolysis of refuse derived fuel; and power-to-X technologies from hydrogen and CO2. Further process variations with additional hydrogen input are covered. Flowsheet simulation in Aspen Plus is applied to generate datasets with conclusive mass and energy balance under uniform modelling and assessment conditions with available validation data. Process inventory data is generated with no regard to the development stage of the respective technology but applicable process data with high technology maturity is prioritized for model validation. The generated inventory data can be applied for life cycle assessments. Further the presented modelling and balancing framework can be applied for inventory data generation of similar processes to ensure comparability in life cycle inventory data.
Flare Gas Monetization and Greener Hydrogen Production via Combination with Crypto Currency Mining and Carbon Dioxide Capture
Jan 2022
Publication
In view of the continuous debates on the environmental impact of blockchain technologies in particular crypto currency mining accompanied by severe carbon dioxide emissions a technical solution has been considered assuming direct monetization of associated petroleum gas currently being flared. The proposed approach is based on the technology of low-temperature steam reforming of hydrocarbons which allows flare gas conditioning towards the requirements for fuel for gas piston and gas turbine power plants. The generation of electricity directly at the oil field and its use for on-site crypto currency mining transforms the process of wasteful flaring of valuable hydrocarbons into an economically attractive integrated processing of natural resources. The process is not carbon neutral and is not intended to compete zero-emission technologies but its combination with technologies for carbon dioxide capture and re-injection into the oil reservoir can both enhance the oil recovery and reduce carbon dioxide emissions into the atmosphere. The produced gas can be used for local transport needs while the generated heat and electricity can be utilized for on-site food production and biological carbon dioxide capture in vertical greenhouse farms. The suggested approach allows significant decrease in the carbon dioxide emissions at oil fields and although it may seem paradoxically on-site cryptocurrency mining actually may lead to a decrease in the carbon footprint. The amount of captured CO2 could be transformed into CO2 emission quotas which can be spent for the production of virtually “blue” hydrogen by steam reforming of natural gas in locations where the CO2 capture is technically impossible and/or unprofitable.
Factors Affecting Hydrogen Adsorption in Metal–Organic Frameworks: A Short Review
Jun 2021
Publication
Metal–organic frameworks (MOFs) have significant potential for hydrogen storage. The main benefit of MOFs is their reversible and high-rate hydrogen adsorption process whereas their biggest disadvantage is related to their operation at very low temperatures. In this study we describe selected examples of MOF structures studied for hydrogen adsorption and different factors affecting hydrogen adsorption in MOFs. Approaches to improving hydrogen uptake are reviewed including surface area and pore volume in addition to the value of isosteric enthalpy of hydrogen adsorption. Nanoconfinement of metal hydrides inside MOFs is proposed as a new approach to hydrogen storage. Conclusions regarding MOFs with incorporated metal nanoparticles which may be used as nanoscaffolds and/or H2 sorbents are summarized as prospects for the near future.
Energy Transition: Measurement Needs Within the Hydrogen Industry
Dec 2017
Publication
Hydrogen in the UK is beginning to shift from hypothetical debates to practical demonstration projects. An ever-growing evidence base has showcased how the costs of hydrogen and its barriers to entry are reducing such that it now has practical potential to contribute to the decarbonisation of the UK's energy sector.
Despite this hydrogen has yet to have wide commercial uptake due in part to a number of barriers where measurement plays a critical role. To accelerate the shift towards the hydrogen economy these challenges have been identified and prioritised by NPL.
The report Energy transition: Measurement needs within the hydrogen industry outlines the challenges identified. The highest priority issues are:
This Document can be downloaded from their website
Despite this hydrogen has yet to have wide commercial uptake due in part to a number of barriers where measurement plays a critical role. To accelerate the shift towards the hydrogen economy these challenges have been identified and prioritised by NPL.
The report Energy transition: Measurement needs within the hydrogen industry outlines the challenges identified. The highest priority issues are:
- Material development for fuel cells and electrolysers to reduce costs and assess critical degradation mechanisms – extending lifetime and durability is key to the commercialisation of these technologies.
- Impact assessment of added odorant to hydrogen to aid leak detection. Measurement of its impact during pipeline transportation and on the end-use application (particularly fuel cell technology) will be important to provide assurance that it will not affect lifetime and durability.
- Determination of the blend ratio when hydrogen is mixed with natural gas in the gas grid. Accurate flow rate measurement and validated metering methods are needed to ensure accurate billing of the consumer.
- Measurement of the combustion properties of hydrogen including flame detection and propagation temperature and nitrogen oxides (NOx) emissions should it be used for heat applications to ensure existing and new appliances are suitable for hydrogen.
- Assessment of the suitability of existing gas infrastructure and materials for hydrogen transportation. Building an understanding of what adaptations might need to be made to avoid for example air permeation metal embrittlement and hydrogen leakage.
- Validated techniques for hydrogen storage which will require measurement of the efficiency and capacity of each mechanism through robust metering leakage detection and purity analysis to ensure they are optimised for the storage of hydrogen gas.
This Document can be downloaded from their website
H2 Green Hydrogen Discussion Paper: Victorian Hydrogen Investment Program
Nov 2019
Publication
This discussion paper is for stakeholders who would like to shape the development of Victoria’s emerging green hydrogen sector identifying competitive advantages and priority focus areas for industry and the Victorian Government.<br/>The Victorian Government is using this paper to focus on the economic growth and sector development opportunities emerging for a Victorian hydrogen industry powered by renewable energy also known as ‘green’ hydrogen. In addition this paper seeks input from all stakeholders on how where and when the Victorian Government can act to establish a thriving green hydrogen economy.<br/>Although green hydrogen is the only type of hydrogen production within the scope of this discussion paper the development of the VHIP aligns with the policies projects and initiatives which support these other forms of hydrogen production. The VHIP is considering the broad policy landscape and actively coordinating with related hydrogen programs policies and strategies under development including the Council of Australian Governments (COAG) Energy Council’s National Hydrogen Strategy to ensure a complementary approach. In Victoria there are several programs and strategies in development and underway that have linkages with hydrogen and the VHIP.
Photoelectrochemical Hydrogen Production by Screen-Printed Copper Oxide Electrodes
May 2021
Publication
In this work copper oxides-based photocathodes for photoelectrochemical cells (PEC) were produced for the first time by screen printing. A total 7 × 10−3 g/m2 glycerine trioleate was found as optimum deflocculant amount to assure stable and homogeneous inks based on CuO nano-powder. The inks were formulated considering different binder amounts and deposited producing films with homogenous thickness microstructure and roughness. The as-produced films were thermally treated to obtain Cu2O- and Cu2O/CuO-based electrodes. The increased porosity obtained by adding higher amounts of binder in the ink positively affected the electron transfer from the surface of the electrode to the electrolyte thus increasing the corresponding photocurrent values. Moreover the Cu2O/CuO system showed a higher charge carrier and photocurrent density than the Cu2O-based one. The mixed Cu2O/CuO films allowed the most significant hydrogen production especially in slightly acid reaction conditions.
Electrolyzer Modeling and Real-time Control for Optimized Production of Hydrogen Gas
Oct 2020
Publication
We present a method that operates an electrolyzer to meet the demand of a hydrogen refueling station in a cost-effective manner by solving a model-based optimal control problem. To formulate the underlying problem we first conduct an experimental characterization of a Siemens SILYZER 100 polymer electrolyte membrane electrolyzer with 100 kW of rated power. We run experiments to determine the electrolyzer’s conversion efficiency and thermal dynamics as well as the overload-limiting algorithm used in the electrolyzer. The resulting detailed nonlinear models are used to design a real-time optimal controller which is then implemented on the actual system. Each minute the controller solves a deterministic receding-horizon problem which seeks to minimize the cost of satisfying a given hydrogen demand while using a storage tank to take advantage of time-varying electricity prices and photovoltaic inflow. We illustrate in simulation the significant cost reduction achieved by our method compared to others in the literature and then validate our method by demonstrating it in real-time operation on the actual system.
Technology Investment Roadmap First Low Emissions Technology Statement – 2020 Global Leadership in Low Emissions Technologies
Sep 2020
Publication
Australia’s Technology Investment Roadmap is a strategy to accelerate development and commercialisation of low emissions technologies.
Annual low emissions statements are key milestones of the roadmap process. These statements prioritise low emissions technologies with potential to deliver the strongest economic and emissions reduction outcomes for Australia. They focus government investment on new and emerging technologies.
In this Statement
The first Low Emissions Technology Statement presents a vision of a prosperous Australia recognised as a global low emissions technology leader
Annual low emissions statements are key milestones of the roadmap process. These statements prioritise low emissions technologies with potential to deliver the strongest economic and emissions reduction outcomes for Australia. They focus government investment on new and emerging technologies.
In this Statement
The first Low Emissions Technology Statement presents a vision of a prosperous Australia recognised as a global low emissions technology leader
- priority technologies and economic stretch goals
- Australia’s big technology challenges and opportunities
- Technology Investment Framework
- monitoring transparency and impact evaluation
Energy System Requirements of Fossil-free Steelmaking using Hydrogen Direct Reduction
May 2021
Publication
The iron and steel industry is one of the world’s largest industrial emitters of greenhouse gases. One promising option for decarbonising the industry is hydrogen direct reduction of iron (H-DR) with electric arc furnace (EAF) steelmaking powered by zero carbon electricity. However to date little attention has been given to the energy system requirements of adopting such a highly energy-intensive process. This study integrates a newly developed long-term energy system planning tool with a thermodynamic process model of H-DR/EAF steelmaking developed by Vogl et al. (2018) to assess the optimal combination of generation and storage technologies needed to provide a reliable supply of electricity and hydrogen. The modelling tools can be applied to any country or region and their use is demonstrated here by application to the UK iron and steel industry as a case study. It is found that the optimal energy system comprises 1.3 GW of electrolysers 3 GW of wind power 2.5 GW of solar 60 MW of combined cycle gas with carbon capture 600 GWh/600 MW of hydrogen storage and 30 GWh/130 MW of compressed air energy storage. The hydrogen storage requirements of the industry can be significantly reduced by maintaining some dispatchable generation for example from 600 GWh with no restriction on dispatchable generation to 140 GWh if 20% of electricity demand is met using dispatchable generation. The marginal abatement costs of a switch to hydrogen-based steelmaking are projected to be less than carbon price forecasts within 5–10 years.
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