Publications

The Fischer-Tropsch synthesis (FTS) is considered as a power-to-X (PtX) storage concept for converting temporally available excess energy to fuels or chemical compounds without the need of fossil resources. Fluctuating energy supplies demand a load-flexible energy system and a dynamically operating FTS reactor might be beneficial compared to traditional steady-state operations which rely on expensive upstream buffer capacities. This review provides an overview of recent experimental and simulation studies dealing with dynamic FTS operation and summarizes the main findings. The results are presented the two categories process intensification and PtX application. The review further discusses the experimentally difficult task of wide-ranging product characterization with a high temporal resolution. While dynamic reactor operation is often related to a complicated process control which challenges a save and efficient reactor performance the literature findings indicate that for dynamic FTS operation such concerns might not be as critical as assumed at least within well-known boundaries. Researchers further agree that dynamic operation might be a tool for process intensification. Especially hydrogen pulsing seems to be a potentially beneficial operating technique to remove accumulated liquid products restore initial catalyst activity and increase diesel-range productivity. The main challenge in this context is the prevention of high methane selectivity. A lucid future engineering goal seems to be the combination of the two applications: a robust and reliable FTS reactor in a PtX scenario that not only handles a fluctuating feed but uses such variations for process enhancement.

Hydrogen leakage is a key safety issue for hydrogen energy application. For hydrogen leakage hydrogen releases with low momentum hence the development of the leakage jet is dominated by both initial momentum and buoyancy. It is important for a computational code to capture the flow characteristics transiting from momentum-dominated jet to buoyancy dominated plume during leakage. GASFLOW-MPI is a parallel computational fluid dynamics (CFD) code which is well validated and widely used for hydrogen safety analysis. In this paper its capability for small scale hydrogen leakage is validated with unintended hydrogen release experiment. In the experiment pure hydrogen is released into surrounding stagnant air through a jet tube on a honeycomb plate with various Froude numbers (Fr). The flow can be fully momentum-dominated at the beginning while the influence of buoyancy increases with the Fr decreases along the streamline. Several quantities of interest including velocity along the centerline radial profiles of the time-averaged H2 mass fraction are obtained to compare with experimental data. The good agreement between the numerical results and the experimental data indicates that GASFLOW-MPI can successfully simulate hydrogen turbulent dispersion driven by both momentum and buoyant force. Different turbulent models i.e. k-ε LES and DES model are analyzed for code performance the result shows that all these three models are adequate for hydrogen leakage simulation k-ε simulation is sufficient for industrial applications while LES model can be adopted for detail analysis for a jet/plume study like entrainment. The DES model possesses both characters of the former two model only the performance of its result depends on the grid refinement.

In our factsheet where we debunk 3 myths around hydrogen production and water consumption: electrolysis uses vast amounts of water; electrolysis uses freshwater resources only and electrolysis is bound to create water stress in water-scarce regions.

This study compares the cost of several low-greenhouse gas (GHG) or GHG-neutral residential heating technologies in the year 2050: (1) hydrogen boilers (2) hydrogen fuel cells with an auxiliary hydrogen boiler for cold spells (3) air-source heat pumps using renewable electricity and (4) heat pumps with an auxiliary hydrogen boiler for cold spells. The assessment includes low-carbon hydrogen from steam-methane reforming (SMR) using natural gas combined with carbon capture and storage (CCS) or SMR + CCS and zero-carbon hydrogen produced from renewable electricity using electrolysis.

The analysis finds that air-source heat pumps are the most cost-effective residential heating technology in 2050 and are at least 50% lower cost than the hydrogen-only technologies. In a sensitivity analysis we find that even if natural gas costs were 50% lower or renewable electricity prices were 50% higher in 2050 compared to our central assumptions heat pumps would still be more cost-effective than hydrogen boilers or fuel cells. Renewable electrolysis hydrogen can be cost-competitive with SMR + CCS hydrogen in 2050 although electrolysis hydrogen is not produced at scale today. At the same time energy efficiency measures to reduce heat demand would be a more cost-effective strategy for achieving GHG reductions than any of the low-GHG heating pathways we assess in this study.

The analysis shows that all pathways using renewable electricity have a near-zero GHG intensity while SMR + CCS hydrogen could reduce GHG emissions by 69%–93% compared to natural gas if improvements are made in the future to reduce the GHG intensity of this pathway. Quantifying the GHG impact and cost effectiveness of various heating pathways is relevant for European policymakers facing decisions on how to both decarbonize buildings and alleviate energy poverty in line with commitments made in the Renovation Wave Initiative.

The document can be downloaded from the ICCT website

We investigate the influence of microstructural traps in hydrogen-assisted fatigue crack growth. To this end a new formulation combining multi-trap stress-assisted diffusion mechanism-based strain gradient plasticity and a hydrogen- and fatigue-dependent cohesive zone model is presented and numerically implemented. The results show that the ratio of loading frequency to effective diffusivity governs fatigue crack growth behaviour. Increasing the density of beneficial traps not involved in the fracture process results in lower fatigue crack growth rates. The combinations of loading frequency and carbide trap densities that minimise embrittlement susceptibility are identified providing the foundation for a rational design of hydrogen-resistant alloys.

The H21 Leeds City Gate project is a study with the aim of determining the feasibility from both a technical and economic viewpoint of converting the existing natural gas network in Leeds one of the largest UK cities to 100% hydrogen. The project has been designed to minimise disruption for existing customers and to deliver heat at the same cost as current natural gas to customers. The project has shown that:

• The gas network has the correct capacity for such a conversion
• It can be converted incrementally with minimal disruption to customers
• Minimal new energy infrastructure will be required compared to alternatives
• The existing heat demand for Leeds can be met via steam methane reforming and salt cavern storage using technology in use around the world today

The project has provided costs for the scheme and has modelled these costs in a regulatory finance model. In addition the availability of low-cost bulk hydrogen in a gas network could revolutionise the potential for hydrogen vehicles and via fuel cells support a decentralised model of combined heat and power and localised power generation.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

The main objectives were to identify materials issues relating to the widespread use of hydrogen as a fuel.

MAIN FINDINGS

• Hydrogen is seen by many as the answer to the environmental problems of reliance on fossil fuels for energy needs. A great deal of effort is currently being invested in research into all areas of the hydrogen economy such as fuel cells hydrogen generation transportation and storage.
• Fuel cells have the potential to provide power for a very wide range of applications ranging from small portable electronics devices to large stationary electricity production and vehicles covering the whole range of road vehicles and possibly extending to rail marine and even aviation.
• The main obstacles to achieving a viable hydrogen economy are costs of producing hydrogen from renewable sources issues relating to transportation and storage due to the low energy density of hydrogen gas and the cost and reliability of fuel cells.
• The main material considerations relating to the use of hydrogen are hydrogen embrittlement material properties at cryogenic temperatures (due to use of liquid hydrogen) and permeability.
• A number of new materials are likely to come to prominence in a hydrogen economy; high performance composites are likely to be used extensively for high pressure hydrogen cylinders new materials or combinations of materials may be used for hydrogen pipelines and a range of new materials are currently being considered for hydrogen storage such as metal hydrides and carbon nanotubes.
• Due to the effect of hydrogen on materials it is important to test any materials in the environment in which they would be used. Depending on the type of test this could require the use of very specialist expensive equipment. 

As part of FCH-JU funded HyCoRA project running from 2014 to 2017 28 gaseous and 13 particulate samples were collected from hydrogen refuelling stations in Europe. Samples were collected with commercial sampling instruments and analysis performed in compliance with prevailing fuel quality standards. Sampling was conducted with focus on diversity in feedstock as well as commissioning date of the HRS. Results indicate that the strategy for sampling was good. No evidence of impurity cross-over was observed. Parallel samples collected indicate some variation in analytical results. It was however found that fuel quality was generally good. Fourteen analytical results were in violation with the fuel tolerance limits. Therefore eight or 29% of the samples were in violation with the fuel quality requirements. Nitrogen oxygen and organics were the predominant impurities quantified. Particulate impurities were found to be within fuel quality specifications. No correlation between fuel quality and hydrogen feedstock or HRS commissioning date was found. Nitrogen to oxygen ratios gave no indication of samples being contaminated by air. A comparison of analytical results between two different laboratories were conducted. Some difference in analytical results were observed.

Improving efficiency of hydrogen cooling in cryogenic conditions is important for the wider applications of hydrogen energy systems. The approach investigated in this study is based on a Ranque-Hilsch vortex tube (RHVT) that generates temperature separation in a working fluid. The simplicity of RHVT is also a valuable characteristic for cryogenic systems. In the present work novel shapes of RHVT are computationally investigated with the goal to raise efficiency of the cooling process. Specifically a smooth transition is arranged between a vortex chamber where compressed gas is injected and the main tube with two exit ports at the tube ends. Flow simulations have been carried out using STAR-CCM+ software with the real-gas Redlich-Kwong model for hydrogen at temperatures near 70 K. It is determined that a vortex tube with a smooth transition of moderate size manifests about 7% improvement of the cooling efficiency when compared vortex tubes that use traditional vortex chambers with stepped transitions and a no-chamber setup with direct gas injection.

Explosion venting is a widely used mitigation solution in the process industry to protect indoor equipment or buildings from excessive internal pressure caused by accidental explosions. However vented explosions are very complicated to model using computational fluid dynamics (CFD). In the framework of a French working group the main target of this investigation is to assess the predictive capabilities of five CFD codes used by five different organizations by means of comparison with recent experimental data. On this basis several recommendations for the CFD modelling of vented explosions are suggested.

Reliable predictive tools for hydrogen safety engineering are needed to meet increased and more widespread use of hydrogen in the society. Industrial models and methods used to establish thermal radiation hazard safety distances from hydrogen jet fires are often based on models previously developed for hydrocarbon jet fires. Their capability of predicting radiative heat fluxes from hydrogen jet fires has often only been validated against small-scale or medium-scale jet flame experiments. However large-scale hydrogen jet fire experiments have shown that thermal radiation levels can be significantly higher than one might expect from extrapolation of experience on smaller hydrogen flames. Here two large-scale horizontal hydrogen jet fires (from a 20.9 mm and a 52.5 mm diameter release respectively) have been modelled and simulated with the advanced industrial CFD code KAMELEON FIREEX KFX® based on the Eddy Dissipation Concept by Magnussen for turbulent combustion modelling. The modelling of the high-pressure hydrogen gas releases is based on a pseudo-source concept using real-gas thermodynamic data for hydrogen. The discrete transport method of Lockwood and Shah is used to calculate the radiative heat transfer and radiative properties of water vapour are modelled according to Leckner. The predicted thermal radiation is compared to data from large-scale hydrogen jet fire experiments and discussed. This work was conducted as part of a KFX-H2 R&D project supported by the Research Council of Norway.

As hydrogen-air mixtures are flammable in a wide range of concentrations and the minimum ignition energy is low compared to hydrocarbon fuels the safe handling of hydrogen is of utmost importance. Additional hazards may arise with the accidental spill of liquid hydrogen. Such a release of LH2 leads to a formation of a cryogenic pool a dynamic vaporization process and consequently a dispersion of gaseous hydrogen into the environment. Several LH2 release experiments as well as modelling approaches address this phenomenology. In contrast to existing approaches a new CFD model capable of simulating liquid and gaseous distribution was developed at Forschungszentrum Jülich. It is validated against existing experiments and yields no substantial lacks in the physical model and reveals a qualitatively consistent prediction. Nevertheless the deviation between experiment and simulation raises questions on the completeness of the database in particular with regard to the boundary conditions and available measurements.

It’s the first of its kind overview showing the state of play with regards to hydrogen technologies in Europe. On an annual basis there will be an update serving as a basis for your investment or political decisions.<br/><br/>OUR MISSION IS – NO EMISSION!<br/>From day 1 Hydrogen Europe promoted clean hydrogen and clean hydrogen technologies as enablers of a decarbonised energy system. We strongly support the adoption of very ambitious climate targets for 2030 and the objective of carbon neutrality in the EU by 2050. Clean hydrogen can help to realise this transition of our energy system in multiple sectors from energy production storage and distribution to end-uses in transport industry heating and others.<br/><br/>CLEAN HYDROGEN TECHNOLOGIES CAN AND WILL REPLACE<br/>not just fossil-based hydrogen in current (industrial) uses but also other fossil-based energies such as petrol diesel and hydrocarbon fuels in the transport sector coal /coke in the steel sector natural gas in the heating sector and other polluting and emitting fuels and feedstocks. <br/><br/>WE ARE TALKING ABOUT A SYSTEMIC CHANGE.<br/>The use of clean hydrogen needs adaptations in production schemes in the infrastructure and in the deployment of hydrogen by the end users. This cannot – of course –be done in a day. Yet we should not wait for the implementation of the different hydrogen strategies on private municipal regional national or European level until other geographies worldwide race ahead.<br/><br/>

According to European Directive 2014/94/EU hydrogen providers have the responsibility to prove that their hydrogen is of suitable quality for fuel cell vehicles. Contaminants may originate from hydrogen production transportation refuelling station or maintenance operation. This study investigated the probability of presence of the 13 gaseous contaminants (ISO 14687-2) in hydrogen on 3 production processes: steam methane reforming (SMR) process with pressure swing adsorption (PSA) chlor-alkali membrane electrolysis process and water proton exchange membrane electrolysis process with temperature swing adsorption. The rationale behind the probability of contaminant presence according to process knowledge and existing barriers is highlighted. No contaminant was identified as possible or frequent for the three production processes except oxygen (frequent for chlor-alkali membrane process) carbon monoxide (frequent) and nitrogen (possible) for SMR with PSA. Based on it a hydrogen quality assurance plan following ISO 19880-8 can be devised to support hydrogen providers in monitoring the relevant contaminants.

Following the unprecedented Covid-19 outbreak currently unfolding Hydrogen Europe is publishing its latest paper: "Post COVID-19 and the Hydrogen Sector - A Hydrogen Europe Analysis"<br/><br/>On the long-term climate and environmental challenges remain the major threat to our planet and to humanity as a whole.  The economic crisis following the Covid-19 pandemic may cause a significant delay to the adoption and commercial roll-out of clean hydrogen. It may even permanently endanger the capacity of the clean hydrogen sector to take-up its role as the missing link in the energy transition.<br/><br/>A swift decisive and coordinated action is necessary to address the risks and at least dampen the negative impact that they may have on the deployment of clean hydrogen technologies and on our transition to a net carbon yet powerful and wealthy economy.<br/><br/>Our document outlines the need for and rationale behind rapid action as a result of the Covid-19 impact. Please find here below a short summary of what you will find in it:<br/><br/>Is there a need to take action? – describing why the current pandemic will result in significantly jeopardising the hydrogen sector if no action is taken.<br/><br/>Why should action be taken? – underlining the importance of the hydrogen sector to EU’s decarbonisation efforts as well as its long-term potential to support sustainable economic growth of the EU.  <br/><br/>What can be done? – outlining several potential options for supporting the industry starting from most obvious monetary support but including also no less important policy actions that can be taken to restore investors’ confidence.<br/><br/>How much will it cost? – containing an estimation of the value of the monetary support needed in order to retain the high skilled workforce and the sector’s investment portfolio followed by an estimation of what will be the impact of the action.

In this study the effect of precipitates on the surface mechanical properties in the presence of hydrogen (H) is investigated by in situ electrochemical nanoindentation. The nickel superalloy 718 is subjected to three different heat treatments leading to different sizes of the precipitates: (i) solution annealing (SA) to eliminate all precipitates (ii) the as-received (AR) sample with fine dispersed precipitates and (iii) the over-aged (OA) specimen with coarser precipitates. The nanoindentation is performed using a conical tip and a new method of reverse imaging is employed to calculate the nano-hardness. The results show that the hardness of the SA sample is significantly affected by H diffusion. However it could be recovered by removing the H from its matrix by applying an anodic potential. Since the precipitates in the OA and AR samples are different they are influenced by H differently. The hardness increase for the OA sample is more significant in −1200mV while for the AR specimen the H is more effective in −1500mV. In addition the pop-in load is reduced when the samples are exposed to cathodic charging and it cannot be fully recovered by switching to an anodic potential.

In the present work methane carbon monoxide hydrogen and the binary mixtures 20 % CH4–80 % H2 80 % CH4–20 % H2 25 % CO–75 % H2 (by volume) were considered as fuels of a naturally aspirated port-fuel injection four-cylinder Volkswagen 1.4 L spark-ignition (SI) engine. The interest in these fuels lies in the fact that they can be obtained from renewable resources such as the fermentation or gasification of residual biomasses as well as the electrolysis of water with electricity of renewable origin in the case of hydrogen. In addition they can be used upon relatively easy modifications of the engines including the retrofitting of existing internal combustion engines. It has been found that the engine gives similar performance regardless the gaseous fuel nature if the air–fuel equivalence ratio (λ) is the same. Maximum brake torque and mean effective pressure values within 45–89 N⋅m and 4.0–8.0 bar respectively have been obtained at values of λ between 1 and 2 at full load engine speed of 2000 rpm and optimum spark-advance. In contrast the nature of the gaseous fuel had great influence upon the range of λ values at which a fuel (either pure or blend) could be used. Methane and methane-rich mixtures with hydrogen or carbon monoxide allowed operating the engine at close to stoichiometric conditions (i.e. 1 < λ < 1.5) yielding the highest brake torque and mean effective pressure values. On the contrary hydrogen and hydrogen-rich mixtures with methane or carbon monoxide could be employed only in the very fuel-lean region (i.e. 1.5 < λ < 2). The behavior of carbon monoxide was intermediate between that of methane and hydrogen. The present study extends and complements previous works in which the aforementioned fuels were compared only under stoichiometric conditions in air (λ = 1). In addition a simple zero-dimensional thermodynamic combustion model has been developed that allows describing qualitatively the trends set by the several fuels. Although the model is useful to understand the influence of the fuels properties on the engine performance its predictive capability is limited by the simplifications made.

Hydrogen is a highly efficient and clean renewable energy source and water splitting through electrocatalytic hydrogen evolution is a most promising approach for hydrogen generation. Layered transition metal dichalcogenides-based nano-structures have recently attracted significant interest as robust and durable catalysts for hydrogen evolution. We systematically investigated the platinum (Pt) based dichalcogenides (PtS₂ PtSe₂ and PtTe₂) as highly energetic and robust hydrogen evolution electrocatalysts. PtTe₂ catalyst unveiled the rapid hydrogen evolution process with the low overpotentials of 75 and 92 mV (vs. RHE) at a current density of 10 mA cm⁻² and the small Tafel slopes of 64 and 59 mV/dec in acidic and alkaline medium respectively. The fabricated PtTe₂ electrocatalyst explored a better catalytic activity than PtS₂ and PtSe₂. The density functional theory estimations explored that the observed small Gibbs free energy for H-adsorption of PtTe₂ was given the prominent role to achieve the superior electrocatalytic and excellent stability activity towards hydrogen evolution due to a smaller bandgap and the metallic nature. We believe that this work will offer a key path to use Pt based dichalcogenides for hydrogen evolution electrocatalysts.

The current greatest challenge that all gas turbine manufactures and users have in front of them for the years to come is the energy transition while reducing CO2 footprint and to contrast climate change. To this aim the introduction of hydrogen as fuel gas (or its blend) is playing a very important role. The benefit from an environmental point of view is undisputed but the presence of hydrogen introduces a series of safety related aspects to be considered for the design of all systems of a gas turbine package. Most of the design standards developed and adopted in the past are based on conventional natural gas however physical properties of hydrogen require to analyze additional aspects or revise the current ones. In this context the design for safety is paramount as it is strongly impacted by the low energy ignition of hydrogen blend fuels. Baker Hughes has built its experience on several sites different Customers and applications currently installed. These gas turbines run with a variety of hydrogen blends with concentration as high as 100% hydrogen. Baker Hughes has achieved several milestones moving from design to experimental set up leveraging the internal infrastructures consolidating design assumptions. In this work the critical aspects such as material selection instrumentation electrical devices and components are discussed in the framework of package safety with the aim to evolve conventional design minimizing the impacts on package configurations.

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.

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.

Condensation of hydrogen Rydberg atoms (highly electronically excited) into the lowest energy state of condensed hydrogen i.e. the ultra-dense hydrogen phase H(0) has gained increased attention not only from the fundamental aspects but also from the applied point of view. The physical properties of ultra-dense hydrogen H(0) were recently reviewed summarizing the results reported in 50 publications during the last ten years. The main application of H(0) so far is as the fuel and working medium in nuclear particle generators and nuclear fusion reactors which are under commercial development. The first fusion process showing sustained operation above break-even was published in 2015 (AIP Advances) and used ultra-dense deuterium D(0) as fuel. The first generator giving a high-intensity muon flux intended for muon-catalyzed fusion reactors was patented in 2017 using H(0) as the working medium. Here we first focus on the different nuclear processes using hydrogen isotopes for energy generation and then on the detailed processes of formation of H(0). The production of H(0) employs heterogeneous catalysts which are active in hydrogen transfer reactions. Iron oxide-based alkali promoted catalysts function well but also platinum group metals and carbon surfaces are active in this process. The clusters of highly excited Rydberg hydrogen atoms H(l) are formed upon interaction with alkali Rydberg matter. The final conversion step from ordinary hydrogen Rydberg matter H(l) to H(0) is spontaneous and does not require a solid surface. It is concluded that the exact choice of catalyst is not very important. It is also concluded that the crucial feature of the catalyst is to provide excited alkali atoms at a sufficiently high surface density and in this way enabling formation and desorption of H(0) clusters. Finally the relation to industrial catalytic processes which use H(0) formation catalysts is described and some important consequences like the muon and neutron radiation from H(0) are discussed.

Hydrogen is the cleanest fuel available because its combustion product is water. The internal combustion engine can in principle and without significant modifications run on hydrogen to produce mechanical energy. Regarding the technological solution leading to compact engines a question to ask is the following: Can combustion engine systems be lubricated with hydrogen? In general since many applications such as in turbomachines is it possible to use the surrounding gas as a lubricant? In this paper journal bearings global parameters are calculated and compared for steady state and dynamic conditions for different gas constituents such as air pentafluoropropane helium and hydrogen. Such a bearing may be promising as an ecological alternative to liquid lubrication.

Whereas noise generated by road traffic is an important factor in urban pollution little attention has been paid to this issue in the field of hydrogen-fueled vehicles. The objective of this study is to analyze the influence of the type of fuel (gasoline or hydrogen) on the sound levels produced by a vehicle with an internal combustion engine. A Volkswagen Polo 1.4 vehicle adapted for its bi-fuel hydrogen-gasoline operation has been used. Tests were carried out with the vehicle when stationary to eliminate rolling and aerodynamic noise. Acoustics and psychoacoustics levels were measured both inside and outside the vehicle. A slight increase in the noise level has only been found outside when using hydrogen as fuel compared to gasoline. The increase is statistically significant can be quantified between 1.1 and 1.7 dBA and is mainly due to an intensification of the 500 Hz band. Loudness is also higher outside the vehicle (between 2 and 4 sones) when the fuel is hydrogen. Differences in sharpness and roughness values are lower than the just-noticeable difference (JND) values of the parameters. Higher noise levels produced by hydrogen can be attributed to its higher reactivity compared to gasoline.

Residues and by-products from vegetables and fruit wholesale markets are suitable for recovery in the form of energy through anaerobic digestion allowing waste recovery and introducing them into the circular economy. This suitability is due to their composition structural characteristics and to the biogas generation process which is stable and without inhibition. However it has been observed that the proportion of methane and the level of degradation of the substrate is low. It is decided to study whether the effect of pretreatments on the substrate is beneficial. Freezing ultrafreezing and lyophilization pretreatments are studied. A characterization of the substrates has been performed the route of action of pretreatment determined and the digestion process studied to calculate the generation of biogas methane hydrogen and the proportions among these. Also a complete analysis of the process has been performed by processing the data with mathematical and statistical methods to obtain disintegration constants and levels of degradation. It has been observed that the three pretreatments have positive effects when increasing the solubility of the substrate increasing porosity and improving the accessibility of microorganisms to the substrate. Generation of gases are greatly increased reaching a methane enrichment of 59.751%. Freezing seems to be the best pretreatment as it increases the biodegradation level the speed of the process and the disintegration constant by 306%.

Preliminary research suggests domestic carbon monoxide detectors with an electrochemical sensor are approximately 10 -20% sensitive to hydrogen atmospheres in their factory configuration. That is the display on a carbon monoxide detector would give a carbon monoxide reading of approximately 10-20% of the concentration of hydrogen it is exposed to. Current British standards require detectors to sound an alarm within three minutes when subjected to a continuous concentration of ≥ 300 ppm CO. This would equate to a concentration of 1500-3000 ppm hydrogen in air or approximately 3.75 – 7% %LEL. The current evacuation criteria for a natural gas leak in a domestic property is 20 %LEL indicating that standard carbon monoxide detectors could be used as cheap and reliable early warning systems for hydrogen leaks. Given the wide use of carbon monoxide detectors and the affordability of the devices the use of carbon monoxide detectors for hydrogen detection is of particular interest as the UK drives towards energy decarbonisation. Experiments to determine the exact sensitivity of a range of the most common domestic carbon monoxide detectors have been completed by DNV Spadeadam Research & Testing. Determining the effects of repeated exposure to varying concentrations of hydrogen in air on the sensitivity of electrochemical sensors allows recommendations to be made on their adoption as hydrogen detectors. Changing the catalysts used within the electrochemical cell would improve the sensitivity to hydrogen however simply calibrating the sensor to report a concentration of hydrogen rather than carbon monoxide would represent no additional costs to manufacturers. Having determined the suitability of such sensors at an early stage; the technology can then be linked with other technological developments required for the change to hydrogen for domestic heating (e.g. change in metering equipment and appliances). This report finds that from five simple and widely available carbon monoxide detectors the lowest sensitivity to hydrogen measured at the concentration required to sound an alarm within three minutes was approximately 10%. It was also discovered that as the hydrogen concentration was increased over the range tested the sensitivity to hydrogen also increased. It is proposed that coupling these devices with other elements of the domestic gas system would allow actions such as remote meter isolation or automatic warning signals sent to response services would provide a reliable and inherently safe system for protecting occupants as gas networks transition to net-zero greenhouse gas emissions. In this respect it is noted that wireless linking of smoke and heat detectors for domestic application is already widely available in low-cost devices. This could be extended to CO detectors adapted for hydrogen use.

Hydrogen sourced from energy recovery processes and conversion of waste materials is a method of providing both a clean fuel and a sustainable waste management alternative to landfill and incineration. The question is whether waste-to–hydrogen can become part of the zero-carbon future energy mix and serve as one of the cleaner hydrogen sources which is economically viable and environmentally friendly. This work critically assessed the potential of waste as a source of hydrogen production via various thermochemical (gasification and pyrolysis) and biochemical (fermentation and photolysis) processes. Research has shown hydrogen production yields of 33.6 mol/kg and hydrogen concentrations of 82% from mixed waste feedstock gasification. Biochemical methods such as fermentation can produce hydrogen up to 418.6 mL/g. Factors including feedstock quality process requirements and technology availability were reviewed to guide technology selection and system design. Current technology status and bottlenecks were discussed to shape future development priorities. These bottlenecks include expensive production and operation processes heterogeneous feedstock low process efficiencies inadequate management and logistics and lack of policy support. Improvements to hydrogen yields and production rates are related to feedstock processing and advanced energy efficiency processes such as torrefaction of feedstock which has shown thermal efficiency of gasification up to 4 MJ/kg. This will affect the economic feasibility and concerns around required improvements to bring the costs down to allow waste to viewed as a serious competitor for hydrogen production. Recommendations were also made for financially competitive waste-to-hydrogen development to be part of a combined solution for future energy needs.

Methanol can be obtained through CO₂ hydrogenation in a membrane reactor with higher yield or lower pressure than in a conventional packed bed reactor. In this study we explore a new kind of membrane with the potential suitability for such membrane reactors. Silicone–ceramic composite membranes are synthetized and characterized for their capability to selectively remove water from a mixture containing hydrogen CO₂ and water at temperatures typical for methanol synthesis. We show that this membrane can achieve selective permeation of water under such harsh conditions and thus is an alternative candidate for use in membrane reactors for processes where water is one of the products and the yield is limited by thermodynamic equilibrium.

Despite their high thermal efficiency (>50%) large two-stroke (2 T) diesel engines burning very cheap heavy fuel oil (HFO) produce a high level of carbon dioxide (CO₂). To achieve the low emission levels of greenhouse gases (GHG) that will be imposed by future legislation the use of hydrogen (H₂) as fuel in 2 T diesel engines is a viable option for reducing or almost eliminate CO₂ emissions. In this work from experimental data and system modelling an analysis of dual combustion is carried out considering different strategies to supply H₂ to the engine and for different H2 fractions in energy basis. Previously a complete thermodynamic model of a 2 T diesel engine with an innovative scavenging model is developed and validated. The most important drawbacks of this type of engines are controlled in this work using dual combustion and water injection reducing nitrogen oxides emissions (NOx) self-ignition and combustion knocking. The results show that the developed model matches engine performance data in diesel mode achieving a higher efficiency and mean effective pressure (MEP) in hydrogen mode of 53% and 14.62 bar respectively.

The 30 integrated steel plants operating in the European Union (EU) are among the largest single-point CO₂ emitters in the region. The deployment of bioenergy with carbon capture and storage (bio-CCS) could significantly reduce their emission intensities. In detail the results demonstrate that CO₂ emission reduction targets of up to 20% can be met entirely by biomass deployment. A slow CCS technology introduction on top of biomass deployment is expected as the requirement for emission reduction increases further. Bio-CCS could then be a key technology particularly in terms of meeting targets above 50% with CO₂ avoidance costs ranging between €60 and €100 tCO2−1 at full-scale deployment. The future of bio-CCS and its utilisation on a larger scale would therefore only be viable if such CO₂ avoidance cost were to become economically appealing. Small and medium plants in particular would economically benefit from sharing CO₂ pipeline networks. CO₂ transport however makes a relatively small contribution to the total CO₂ avoidance cost. In the future the role of bio-CCS in the European iron and steelmaking industry will also be influenced by non-economic conditions such as regulations public acceptance realistic CO₂ storage capacity and the progress of other mitigation technologies.

A feasible path to limit planetary warming to 1.5°C requires certain countries and sectors to go below net zero and to do so well before the middle of the century according to new analysis from the authors of the Energy Transition Outlook. DNV’s pathway to net zero says North America and Europe must be carbon neutral by 2042 whereas Indian Subcontinent is set to be a net emitter by 2050 Net zero report says carbon capture storage and use is required as energy production will not be carbon neutral by 2050 Aim to halve emissions by 2030 is out of reach but massive early action is needed if we are to have any chance of reaching a 1.5°C future DNV’s new report “Pathway to Net Zero Emissions” describes a feasible way to limit global warming to 1.5°C Policy makers are set to meet in Glasgow for the COP 26 summit with an eye on achieving zero emissions by 2050. For this to happen North America and Europe must be carbon neutral by 2042 and then carbon negative thereafter according to DNV’s pathway to net zero. The pathway also finds that Greater China must reduce emissions by 98% from 2019 levels by 2050. There are regions that cannot realistically transition completely away from fossil fuels in the same timeframe such as the Indian Subcontinent which will reduce emissions by 64%. Pathway to Net Zero Emissions also lays out the pace at which different industry sectors need to decarbonize. The so-called hard-to-abate sectors will take longer to decarbonize and even if sectors like maritime (-90% CO2 emissions in 2050) and iron and steel production (-82%) scale up the introduction of greener technologies they will still be net emitters by 2050.

Hydrogen is often touted as the fuel of the future but hydrogen is already an important feedstock for the chemical industry. This review highlights current means for hydrogen production and use and the importance of progressing R&D along key technologies and policies to drive a cost reduction in renewable hydrogen production and enable the transition of chemical manufacturing toward green hydrogen as a feedstock and fuel. The chemical industry is at the core of what is considered a modern economy. It provides commodities and important materials e.g. fertilizers synthetic textiles and drug precursors supporting economies and more broadly our needs. The chemical sector is to become the major driver for oil production by 2030 as it entirely relies on sufficient oil supply. In this respect renewable hydrogen has an important role to play beyond its use in the transport sector. Hydrogen not only has three times the energy density of natural gas and using hydrogen as a fuel could help decarbonize the entire chemical manufacturing but also the use of green hydrogen as an essential reactant at the basis of many chemical products could facilitate the convergence toward virtuous circles. Enabling the production of green hydrogen at cost could not only enable new opportunities but also strengthen economies through a localized production and use of hydrogen. Herein existing technologies for the production of renewable hydrogen including biomass and water electrolysis and methods for the effective storage of hydrogen are reviewed with an emphasis on the need for mitigation strategies to enable such a transition.

It is well-documented experimentally that the influence of hydrogen on the mechanical properties of structural alloys like austenitic stainless steels nickel superalloys and carbon steels strongly depends on temperature. A typical curve plotting any hydrogen-affected mechanical property as a function of temperature gives a temperature THEmax where the degradation of this mechanical property reaches a maximum. Above and below this temperature the degradation is less. Unfortunately the underlying physico-mechanical mechanisms are not currently understood to the level of detail required to explain such temperature effects. Though this temperature effect is important to understand in the context of engineering applications studies to explain or even predict the effect of temperature upon the mechanical properties of structural alloys could not be identified. The available experimental data are scattered significantly and clear trends as a function of chemistry or microstructure are difficult to see. Reported values for THEmax are in the range of about 200–340 K which covers the typical temperature range for the design of structural components of about 230–310 K (from −40 to +40 °C). That is the value of THEmax itself as well as the slope of the gradient might affect the materials selection for a dedicated application. Given the current lack of scientific understanding a statistical approach appears to be a suitable way to account for the temperature effect in engineering applications. This study reviews the effect of temperature upon hydrogen effects in structural alloys and proposes recommendations for test temperatures for gaseous hydrogen applications

The growing rate of electricity generation from renewables is leading to new operational and management issues on the power grid because the electricity generated exceeds local requirements and the transportation or storage capacities are inadequate. An interesting option that is under investigation by several years is the opportunity to use the renewable electricity surplus to power electrolyzers that split water into its component parts with the hydrogen being directly injected into natural gas pipelines for both storage and transportation. This innovative approach merges together the concepts of (i) renewable power-to-hydrogen (P2H) and of (ii) hydrogen blending into natural gas networks. The combination of renewable P2H and hydrogen blending into natural gas networks has a huge potential in terms of environmental and social benefits but it is still facing several barriers that are technological economic legislative. In the framework of the new hydrogen strategy for a climate-neutral Europe Member States should design a roadmap moving towards a hydrogen ecosystem by 2050. The blending of “green hydrogen” that is hydrogen produced by renewable sources in the natural gas network at a limited percentage is a key element to enable hydrogen production in a preliminary and transitional phase. Therefore it is urgent to evaluate at the same time (i) the potential of green hydrogen blending at low percentage (up to 10%) and (ii) the maximum P2H capacity compatible with low percentage blending. The paper aims to preliminary assess the green hydrogen blending potential into the Italian natural gas network as a tool for policy makers grid and networks managers and energy planners.

Following up on our report Uncomfortable Home Truths: why Britain urgently needs a low carbon heat strategy Pipeline to 2050 sets out recommendations for BEIS’ forthcoming Heat and Buildings Strategy. Based on the findings of five roundtables held between January and July 2020 with cross-party parliamentarians policy-makers and experts from industry academia and non-governmental organisations the publication calls for a joined-up approach that simultaneously addresses all aspects of heat decarbonisation.<br/>The report highlights that today there is a patchwork of heat policy initiatives. Although they might incentivise positive development in themselves are nevertheless too dispersed and not enough to drive the level of coordinated action that is needed given the complexity of heat decarbonisation. Setting out propositions to tackle challenges associated with the transition to low carbon heat in the areas of governance funding innovation and public engagement; the publication calls for a Heat and Buildings Strategy that shows a step change in terms of ambition for heat decarbonisation.<br/>The report recommends that the Heat and Buildings Strategy needs to put forward a systematic approach that joins up all policy aspects and principles needed for the transition to low carbon heat. Moreover given the cross-sectoral engagement needed between consumers industry research and various levels of the government it argues that the Strategy has to be constructed in a way that simultaneously catalyses action from all stakeholders that are needed to take part in the process for effective heat decarbonisation.

This paper presents two different scenarios for the energy system of the Netherlands that achieve the Dutch government’s national target of near net-zero greenhouse gas emissions in 2050. Using the system optimisation model OPERA the authors have analysed the technology sector and cost implications of the assumptions underlying these scenarios. While the roles of a number of key energy technology and emission mitigation options are strongly dependent on the scenario and cost assumptions the analysis yields several common elements that appear in both scenarios and that consistently appear under differing cost assumptions. For example one of the main options for the decarbonisation of the Dutch energy system is electrification of energy use in end-use sectors and for the production of renewable hydrogen with electrolysers. As a result the level of electricity generation in 2050 will be three to four times higher than present generation levels. Ultimately renewable energy – particularly from wind turbines and solar panels – is projected to account for the vast majority of electricity generation around 99% in 2050. Imbalances between supply and demand resulting from this variable renewable electricity production can be managed via flexibility options including demand response and energy storage. Hydrogen also becomes an important energy carrier notably for transportation and in industry. If import prices are lower than costs of domestic production from natural gas with CCS or through electrolysis from renewable electricity (2.4–2.7 €/kgH2) the use of hydrogen increases especially in the built environment.

The Small Punch test has been recently used to estimate mechanical properties of steels in aggressive environments. This technique very interesting when there is shortage of material consists in using a small plane specimen and punch it until it fails. The type of tests normally used are under a constant load in an aggressive environment with the target to determine the threshold stress. However this is an inaccurate technique which takes time as the tests are quite slow. In this paper the Small Punch tests are combined with the step loading technique collected in the standard ASTM F1624 [1] to obtain the value of threshold stress of an S420 steel in a total time of approximately one week. The ASTM F1624 indicates how to apply constant load steps in hydrogen embrittlement environments increasing them subsequently and adapting their duration until the specimen fails. The environment is created by means of cathodic polarization of cylindrical tensile specimens in an acid electrolyte. A batch of standard tests are performed to validate the methodology.

Palladium-based membranes for hydrogen separation have been studied by several research groups during the last 40 years. Much effort has been dedicated to improving the hydrogen flux of these membranes employing different alloys supports deposition/production techniques etc. High flux and cheap membranes yet stable at different operating conditions are required for their exploitation at industrial scale. The integration of membranes in multifunctional reactors (membrane reactors) poses additional demands on the membranes as interactions at different levels between the catalyst and the membrane surface can occur. Particularly when employing the membranes in fluidized bed reactors the selective layer should be resistant to or protected against erosion. In this review we will also describe a novel kind of membranes the pore-filled type membranes prepared by Pacheco Tanaka and coworkers that represent a possible solution to integrate thin selective membranes into membrane reactors while protecting the selective layer. This work is focused on recent advances on metallic supports materials used as an intermetallic diffusion layer when metallic supports are used and the most recent advances on Pd-based composite membranes. Particular attention is paid to improvements on sulfur resistance of Pd based membranes resistance to hydrogen embrittlement and stability at high temperature.

A detailed thermodynamic analysis of the sorption enhanced chemical looping reforming of methane (SE-CL-SMR) using CaO and NiO as CO2 sorbent and oxygen transfer material (OTM) respectively was conducted. Conventional reforming (SMR) and sorption enhanced reforming (SE-SMR) were also investigated for comparison reasons. The results of the thermodynamic analysis show that there are significant advantages of both sorption enhanced processes compared to conventional reforming. The presence of CaO leads to higher methane conversion and hydrogen purity at low temperatures. Addition of the OTM in the SECL-SMR process concept minimizes the thermal requirements and results in superior performance compared to SE-SMR and SMR in a two-reactor concept with use of pure oxygen as oxidant/sweep gas.

This Insight continues the OIES series considering the future of gas. The clear message from previous papers is that on the (increasingly certain) assumption that governments in major European gas markets remain committed to decarbonisation targets the existing natural gas industry is under threat.   It is therefore important to develop a decarbonisation narrative leading to a low- or zero-carbon gas implementation plan.



Previous papers have considered potential pathways for gas to decarbonise specifically considering biogas and biomethane and power-to-gas (electrolysis) . This paper goes on to consider the potential for production transport and use of hydrogen in the decarbonising energy system. Previous papers predominately focused on Europe which has been leading the way in decarbonisation. Hydrogen is now being considered more widely in various countries around the world so this paper reflects that wider geographical coverage.



Since the term ‘hydrogen economy’ was first used in 1970 there have been a number of ‘false dawns’ with bold claims for the speed of transition to hydrogen.  This Insight argues that this time for some applications at least there are grounds for optimism about a future role for decarbonised hydrogen but the lesson from history is that bold claims need to be examined carefully and treated with some caution. There are no easy or low-cost solutions to decarbonisation of the energy system and this is certainly the case for possible deployment of low-carbon hydrogen. A key challenge is to demonstrate the technical commercial economic and social acceptability of various possibilities at scale. Hydrogen will certainly play a role in decarbonisation of the energy system although the size of the role may be more limited than envisaged in some more optimistic projections.



Open document on OIES website

The Fuel Cell Industry Review 2020 offers data analysis and commentary on key events in the industry in 2020. Now in its seventh year the Review has been compiled by a team led by E4tech - a specialist energy strategy consultancy with deep expertise in the hydrogen and fuel cell sector (see www.e4tech.com).



Despite the title of this publication we’ve said before that the fuel cell ‘industry’ is not a single industry at all. As those inside it know it is divided by different materials stages of maturity applications and regions – all contributors to the fact it has taken time to get going. But it does seem to be getting traction. Part of that is down to decades of hard work and investment in R&D technology improvement and demonstrations. Thankfully part of it is also down to changes in external conditions. Improving air quality is increasingly non-negotiable. Reducing greenhouse gas emissions likewise. And all while maintaining economic development and opportunity.



The growth spurt of the battery industry allied with some of the drivers above has catalysed thinking in where and how fuel cells can fit. Countries and regions which did not support batteries early on are scrambling to catch up and wish not to risk a repeat of their errors with fuel cells. So support is being targeted at industrial development and competitiveness as well as solving societal problems. Which in turn is helping industry to decide on and take investment steps: Weichai’s 20000 unit per annum PEM factory in China; Daimler and Volvo setting up their fuel cell truck JV; CHEM Energy building a factory for remote systems in S Africa."

Green hydrogen has been known in the UK since Robert Boyle described flammable air in 1671. This paper describes how green hydrogen has become a new priority for the UK in 2021 beginning to replace fossil hydrogen production exceeding 1 Mte in 2021 when the British Government started to inject significant funding into green hydrogen sources though much less than the USA Germany Japan and China. Recent progress in the UK was initiated in 2008 when the first UK green hydrogen station opened in Birmingham University refuelling 5 hydrogen fuel cell battery electric vehicles (HFCBEVs) for the 50 PhD chemical engineering students that arrived in 2009. Only 10 kg/day were required in contrast to the first large green ITM power station delivering almost 600 kg/day of green hydrogen that opened in the UK in Tyseley in July 2021. The first question asked in this paper is: ‘What do you mean Green?’. Then the Clean Air Zone (CAZ) in Birmingham is described with the key innovations defined. Progress in UK green hydrogen and fuel cell introduction is then recounted. The remarks of Elon Musk about this ‘Fool Cell; Mind bogglingly stupid’ technology are analysed to show that he is incorrect. The immediate deployment of green hydrogen stations around the UK has been planned. Another century may be needed to make green hydrogen dominant across the country yet we will be on the correct path once a profitable supply chain is established in 2022.

The falling cost of making hydrogen from wind and solar power offers a promising route to cutting emissions in some of the most fossil fuel dependent sectors of the economy such as steel heavy-duty vehicles shipping and cement.



Hydrogen Economy Outlook a new and independent global study from research firm BloombergNEF (BNEF) finds that clean hydrogen could be deployed in the decades to come to cut up to 34% of global greenhouse gas emissions from fossil fuels and industry – at a manageable cost. However this will only be possible if policies are put in place to help scale up technology and drive down costs.



The report’s findings suggest that renewable hydrogen could be produced for $0.8 to $1.6/kg in most parts of the world before 2050. This is equivalent to gas priced at $6-12/MMBtu making it competitive with current natural gas prices in Brazil China India Germany and Scandinavia on an energy-equivalent basis. When including the cost of storage and pipeline infrastructure the delivered cost of renewable hydrogen in China India and Western Europe could fall to around $2/kg ($15/MMBtu) in 2030 and $1/kg ($7.4/MMBtu) in 2050.



Kobad Bhavnagri head of industrial decarbonization for BNEF and lead author of the report said: “Hydrogen has potential to become the fuel that powers a clean economy. In the years ahead it will be possible to produce it at low cost using wind and solar power to store it underground for months and then to pipe it on-demand to power everything from ships to steel mills.”



Hydrogen is a clean-burning molecule that can be used as a substitute for coal oil and gas in a large variety of applications. But for its use to have net environmental benefits it must be produced from clean sources rather than from unabated fossil fuel processes – the usual method at present.



Renewable hydrogen can be made by splitting water into hydrogen and oxygen using electricity generated by cheap wind or solar power. The cost of the electrolyzer technology to do this has fallen by 40% in the last five years and can continue to slide if deployment increases. Clean hydrogen can also be made using fossil fuels if the carbon is captured and stored but this is likely to be more expensive the report finds.



Read the full report on the BloombergNEF website here

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 

Climate change is one of the most serious threats to the human habitat. The required structural change to limit anthropogenic forcing is expected to fundamentally change daily social and economic life. The production of iron and steel is a special case of economic activities since it is not only associated with combustion but particularly with process emissions of greenhouse gases which have to be dealt with likewise. Traditional mitigation options of the sector like efficiency measures substitution with less emission-intensive materials or scrap-based production are bounded and thus insufficient for rapid decarbonization necessary for complying with long-term climate policy targets. Iron and steel products are basic materials at the core of modern socio-economic systems additionally being essential also for other mitigation options like hydro and wind power. Therefore a system-wide assessment of recent technological developments enabling almost complete decarbonization of the sector is substantially relevant. Deploying a recursive-dynamic multi-region multi-sector computable general equilibrium approach we investigate switches from coke-to hydrogen-based iron and steel technologies in a scenario framework where industry decisions (technological choice and timing) and climate policies are mis-aligned. Overall we find that the costs of industry transition are moderate but still ones that may represent a barrier for implementation because the generation deciding on low-carbon technologies and bearing (macro)economic costs might not be the generation benefitting from it. Our macroeconomic assessment further indicates that anticipated bottom-up estimates of required additional domestic renewable electricity tend to be overestimated. Relative price changes in the economy induce electricity substitution effects and trigger increased electricity imports. Sectoral carbon leakage is an imminent risk and calls for aligned course of action of private and public actors.

The increasing ambition of climate targets creates a major role for hydrogen especially in achieving carbon-neutrality in sectors presently difficult to decarbonise. This work examines to what extent the currently carbon-intensive hydrogen production in Europe could be replaced by water electrolysis using electricity from renewable energy resources (RES) such as solar photovoltaic onshore/offshore wind and hydropower (green hydrogen). The study assesses the technical potential of RES at regional and national levels considering environmental constraints land use limitations and various techno-economic parameters. It estimates localised clean hydrogen production and examines the capacity to replace carbon-intensive hydrogen hubs with ones that use RES-based water electrolysis. Findings reveal that -at national level- the available RES electricity potential exceeds the total electricity demand and the part for hydrogen production from electrolysis in all analysed countries. At regional level from the 109 regions associated with hydrogen production (EU27 and UK) 88 regions (81%) show an excess of potential RES generation after covering the annual electricity demand across all sectors and hydrogen production. Notably 84 regions have over 50% excess RES electricity potential after covering the total electricity demand and that for water electrolysis. The study provides evidence on the option to decarbonize hydrogen production at regional level. It shows that such transformation is possible and compatible with the ongoing transition towards carbon–neutral power systems in the EU. Overall this work aims to serve as a tool for designing hydrogen strategies in harmony with renewable energy policies.

Hydrogen sulfide (H₂S) is an important mediator of inflammatory processes. However controversial findings also exist and its underlying molecular mechanisms are largely unknown. Recently the byproducts of H₂S per-/polysulfides emerged as biological mediators themselves highlighting the complex chemistry of H₂S. In this study we characterized the biological effects of P* a slow-releasing H₂S and persulfide donor. To differentiate between H₂S and polysulfide-derived effects we decomposed P* into polysulfides. P* was further compared to the commonly used fast-releasing H₂S donor sodium hydrogen sulfide (NaHS). The effects on oxidative stress and interleukin-6 (IL-6) expression were assessed in ATDC5 cells using superoxide measurement qPCR ELISA and Western blotting. The findings on IL-6 expression were corroborated in primary chondrocytes from osteoarthritis patients. In ATDC5 cells P* not only induced the expression of the antioxidant enzyme heme oxygenase-1 via per-/polysulfides but also induced activation of Akt and p38 MAPK. NaHS and P* significantly impaired menadione-induced superoxide production. P* reduced IL-6 levels in both ATDC5 cells and primary chondrocytes dependent on H₂Srelease. Taken together P* provides a valuable research tool for the investigation of H₂S and per-/polysulfide signalling. These data demonstrate the importance of not only H₂S but also per-/polysulfides as bioactive signaling molecules with potent anti-inflammatory and in particular antioxidant properties.

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.

Copper cobalt oxide nanoparticles (CCO NPs) were synthesized as an oxygen evolution electrocatalyst via a simple co-precipitation method with the composition being controlled by altering the precursor ratio to 1:1 1:2 and 1:3 (Cu:Co) to investigate the effects of composition changes. The effect of the ratio of Cu2+/Co3+ and the degree of oxidation during the co-precipitation and annealing steps on the crystal structure morphology and electrocatalytic properties of the produced CCO NPs were studied. The CCO1:2 electrode exhibited an outstanding performance and high stability owing to the suitable electrochemical kinetics which was provided by the presence of sufficient Co3+ as active sites for oxygen evolution and the uniform sizes of the NPs in the half cell. Furthermore single cell tests were performed to confirm the possibility of using the synthesized electrocatalyst in a practical water splitting system. The CCO1:2 electrocatalyst was used as an anode to develop an anion exchange membrane water electrolyzer (AEMWE) cell. The full cell showed stable hydrogen production for 100 h with an energetic efficiency of >71%. In addition it was possible tomass produce the uniform highly active electrocatalyst for such applications through the co-precipitation method.

The current status of a project is described which aims to demonstrate the technical and economic feasibility of converting the vast wind energy available over the globe’s oceans and lakes into storable energy. To this end autonomous high-performance sailing ships are equipped with hydrokinetic turbines whose output is stored either in electric batteries or is fed into electrolysers to produce hydrogen which then is compressed and stored in tanks. In the present paper the previous analytical studies which showed the potential of this “energy ship concept” are summarized and progress on its hardware demonstration is reported involving the conversion of a model sailboat to autonomous operation. The paper concludes with a discussion of the potential of this concept to achieve the IPCC-mandated requirement of reducing the global CO₂ emissions by about 45% by 2030 reaching net zero by 2050.