Publications

Various concepts have been proposed to use hydrocarbon fuels in solid oxide fuel cell (SOFC) systems. A combination of either allothermal or adiabatic pre-reforming and water recirculation (WR) or anode off-gas recirculation (AOGR) is commonly used to convert the fuel into a hydrogen rich mixture before it is electrochemically oxidised in the SOFC. However it is unclear how these reforming concepts affect the electrochemistry and temperature gradients in the SOFC stack. In this study four reforming concepts based on either allothermal or adiabatic pre-reforming and either WR or AOGR are modelled on both stack and system level. The electrochemistry and temperature gradients in the stack are simulated with a one-dimensional SOFC model and the results are used to calculate the corresponding system efficiencies. The highest system efficiencies are obtained with allothermal pre-reforming and WR. Adiabatic pre-reforming and AOGR result in a higher degree of internal reforming which reduces the cell voltage compared to allothermal pre-reforming and WR. Although this lowers the stack efficiency higher degrees of internal reforming reduce the power consumption by the cathode air blower as well leading to higher system efficiencies in some cases. This illustrates that both stack and system operation need to be considered to design an efficient SOFC system and predict potentially deteriorating temperature gradients in the stack.

On this weeks episode the team discuss the Hydrogen Council the global stakeholder forum that has been at the forefront of efforts to advance the role of hydrogen and fuel cell technologies globally. We are excited to have as our guests Pierre-Etienne Franc Vice President for the Hydrogen Energy World Business Unit at Air Liquide and Stephan Herbst General Manager at Toyota Motor Europe. On the show we discuss why Air Liquide and Toyota decided to engage with the Council its strategy vision and perspective on the role that hydrogen can play in the energy transition and how companies can work with policymakers to enable this process. All this and more on the show!

The podcast can be found on their website

This paper discusses the performance improvement of a green building by optimization procedures and the influences of load characteristics on optimization. The green building is equipped with a self-sustained hybrid power system consisting of solar cells wind turbines batteries proton exchange membrane fuel cell (PEMFC) electrolyzer and power electronic devices. We develop a simulation model using the Matlab/SimPowerSystemTM and tune the model parameters based on experimental responses so that we can predict and analyze system responses without conducting extensive experiments. Three performance indexes are then defined to optimize the design of the hybrid system for three typical load profiles: the household the laboratory and the office loads. The results indicate that the total system cost was reduced by 38.9% 40% and 28.6% for the household laboratory and office loads respectively while the system reliability was improved by 4.89% 24.42% and 5.08%. That is the component sizes and power management strategies could greatly improve system cost and reliability while the performance improvement can be greatly influenced by the characteristics of the load profiles. A safety index is applied to evaluate the sustainability of the hybrid power system under extreme weather conditions. We further discuss two methods for improving the system safety: the use of sub-optimal settings or the additional chemical hydride. Adding 20 kg of NaBH4 can provide 63 kWh and increase system safety by 3.33 2.10 and 2.90 days for the household laboratory and office loads respectively. In future the proposed method can be applied to explore the potential benefits when constructing customized hybrid power systems.

Europe’s low-carbon energy policy favors a greater use of fuel cells and technologies based on hydrogen used as a fuel. Hydrogen delivered at the hydrogen refueling station must be compliant with requirements stated in different standards. Currently the quality control process is performed by offline analysis of the hydrogen fuel. It is however beneficial to continuously monitor at least some of the contaminants onsite using chemical sensors. For hydrogen quality control with regard to contaminants high sensitivity integration parameters and low cost are the most important requirements. In this study we have reviewed the existing sensor technologies to detect contaminants in hydrogen then discussed the implementation of sensors at a hydrogen refueling stations described the state-of-art in protocols to perform assessment of these sensor technologies and finally identified the gaps and needs in these areas. It was clear that sensors are not yet commercially available for all gaseous contaminants mentioned in ISO14687:2019. The development of standardized testing protocols is required to go hand in hand with the development of chemical sensors for this application following a similar approach to the one undertaken for air sensors.

For many a large-scale hydrogen economy is essential to a a clean energy future with three quarters of the more than 1100 senior energy professionals we surveyed saying Paris Agreement targets will not be possible without it.

DNV’s research Rising to the challenge of a hydrogen economy explores the outlook for emerging hydrogen value chains from production to consumption. It combines the wider view from the energy industry with commentary from business leaders and experts. Our research finds that the challenge is not in the ambition but in changing the timeline: from hydrogen on the horizon to hydrogen in our homes businesses and transport systems.

We see that the energy industry is rising to this challenge. By 2025 almost half (44%) of energy companies globally involved in hydrogen expect it to account for more than a tenth of their revenue rising to 73% of companies by 2030 – up significantly from just 8% of companies today. The research identifies infrastructure and cost as two of the biggest hurdles while the right regulations are deemed the most powerful enabler followed by carbon pricing. Proving the safety case will also be key to scaling the hydrogen economy.

Download your complimentary copy of DNV’s latest hydrogen research at their website link

Milford Haven: Energy Kingdom is a two-year project exploring what a decarbonised smart local energy system could look like for Milford Haven Pembroke and Pembroke Dock.

The project explores the potential of hydrogen as part of a multi-vector approach to decarbonisation. Central to the project and to achieving Net Zero is a commitment to engage with the community and local industry providing insight and opportunities for growth.

The ambition is to gather detailed insight into the whole energy system around Milford Haven to identify and design a future smart local energy system based on a truly multi-vector approach and comprehensive energy systems architecture.

The transition to Net Zero requires action across the economy. As the UK’s largest energy port Milford Haven is an industrial cluster that can handle 30% of total UK gas demand is home to Europe’s largest gas power station powering 3.5 million homes and businesses has ambitions to build 90MW of floating offshore wind supports 5000 jobs and injects £324m to the Pembrokeshire economy.

This work describes the outcomes of the effort to define designs of future energy system architectures combining; technology the interconnectivity between them and data; with markets trading platforms and policies; with business models and defined organisational governance. The aim of these designs is to provide:

• The basis for a roadmap for the next phases of development and implementation
• Confidence to innovators and investors in the future longevity of investments in hydrogen and
• A common basis of understanding for all stakeholders wishing to contribute to the Milford Haven: Energy Kingdom.

The classical approach to use hydrogen as a fuel for Internal Combustion Engines (ICEs) is premixed combustion. In order to avoid knocking and to limit NOx emissions very lean mixtures are employed thus resulting in a high boost pressure demand or low specific engine power. To overcome these limitations the possibility of a diesellike jet-guided combustion of hydrogen is explored. The approach is to ignite a directly injected hydrogen jet at its periphery by means of a conventional spark discharge followed by a diffusion-controlled combustion while injection remains active. An optically accessible Rapid Compression Expansion Machine (RCEM) is used to investigate ignition and combustion of underexpanded hydrogen jets in air by means of simultaneous Schlieren visualization and OH chemiluminescence. Different injection and ignition timing are investigated resulting in premixed partially premixed and diffusion-controlled (jet-guided) combustion conditions. The possibility of ignition and combustion of the hydrogen jets in diffusion-controlled conditions is investigated for different orientations of the incoming fuel jet with respect to spark location. The combustion tests are analyzed in terms of ignition success rate ignition delay reacting surface and heat release rate and an optimal orientation of the jet is assessed. The present study provides insights for optimizing hydrogen direct injection ignition and combustion for later application in ICEs.

From an evaluation of the GB housing stock it is clear that a mosaic of low carbon heating technologies will be needed to reach net zero. While heat pumps are an important component of this mix our analysis shows that it is likely to be impractical to heat many GB homes with heat pumps only. A combination of lack of exterior space and/or the thermal properties of the building fabric mean that a heat pump is not capable of meeting the space heating requirement of 8 to 12m homes (or 37% to 54% of the 22.7m homes assessed in this report) or can do so only through the installation of highly disruptive and intrusive measures such as solid wall insulation. Hybrid heat pumps that are designed to optimise efficiency of the system do not have the same requirements of a heat pump and may be a suitable solution for some of these homes. This is likely to mean that decarbonised gas networks are therefore critical to delivery of net zero. 3 to 4m homes1 (or 14% to 18% of homes assessed in our analysis) could be made suitable for heat pump retrofit through energy efficiency measures such as cavity wall insulation. For 7 to 10m homes there are no limiting factors and they require minimal/no upgrade requirements to be made heat pump-ready. Nevertheless given firstly the levels of disruption to the floors and interiors of homes caused by the installation of heat pumps and secondly the cost and disruption associated with the requirement to significantly upgrade the electricity distribution networks to cope with large numbers of heat pumps operating at peak demand times - combined with the availability of a decarbonised gas network which requires a simple like-for-like boiler replacement - is likely to mean that many of these ‘swing’ properties will be better served through a gas based technology such as hydrogen (particularly when consumer choice is factored in) or a hybrid system. A recent trial run in winter 2018-19 by the Energy System Catapult revealed that all participants were reluctant to make expensive investments to improve the energy efficiency of their homes just to enhance the performance of their heat pump. They were more interested in less costly upgrades and tangible benefits such as lower bills or greater comfort. This means that renewable gases including hydrogen as heating fuels are a crucial component of the journey to net zero and the UK’s hydrogen ambitions should be reflective of this. The analysis presented in this paper focuses on the external fabric of the buildings further analysis should be undertaken to consider the internal system changes that would be required for heat pumps and hydrogen boilers for example BEIS Domestic Heat Distribution Systems: Gathering Report from February 2021 which considers the suitability of radiators for the low carbon transition.

In this paper a systematic review of academic literature and policy papers since 2008 is undertaken with an aim of identifying the prevalent energy systems models and tools in the UK. A list of all referenced models is presented and the literature is analysed with regards sectoral coverage and technological inclusion as well as mathematical structure of models. The paper compares available models using an appropriate classification schema the introduction of which is aimed at making the model landscape more accessible and perspicuous thereby enhancing the diversity of models within use. The distinct classification presented in this paper comprises three sections which specify the model purpose and structure technological detail and mathematical approach. The schema is not designed to be comprehensive but rather to be a broad classification with pertinent level of information required to differentiate between models. As an example the UK model landscape is considered and 22 models are classified in three tables as per the proposed schema.

On today's show the EAH team will be joined by Brendan Norman to talk about deployment of sustainable FCEV technologies across many different segments of the transport sector and utility vehicles. Brendan is the CEO of H2X a new vehicle manufacturing company based in Sydney with a manufacturing facility in Port Kembla will deliver its first hydrogen FCEVs to market beginning in 2022 before expanding its vehicle offerings in subsequent years. Brendan joined the EAH team via SquadCast from Kuala Lumpur to talk fuel cells with us and you don't want to miss the excellent discussion that we had on this week's episode.

The podcast can be found on their website

Hydrogen can be used to reduce carbon emissions by blending into other gaseous energy carriers such as natural gas. However hydrogen blending into natural gas has important implications for safety which need to be evaluated. Hydrogen has different physical properties than natural gas and these properties affect safety evaluations concerning a leak of the blended gas. The intent of this report is to begin to investigate the safety implications of blending hydrogen into the natural gas infrastructure with respect to a leak event from a pipeline. A literature review was conducted to identify existing data that will better inform future hazard and risk assessments for hydrogen/natural gas blends. Metrics with safety implications such as heat flux and dispersion behavior may be affected by the overall blend ratio of the mixture. Of the literature reviewed there was no directly observed separation of the hydrogen from the natural gas or methane blend. No literature was identified that experimentally examined unconfined releases such as concentration fields or concentration at specific distances. Computational efforts have predicted concentration fields by modified versions of existing engineering models but the validation of these models is limited by the unavailability of literature data. There are multiple literature sources that measured flame lengths and heat flux values which are both relevant metrics to risk and hazard assessments. These data can be more directly compared to the outputs of existing engineering models for validation.

The paper can be downloaded on their website

Ammonia has been proposed as a potential energy storage medium in the transition towards a low-carbon economy. This paper details experimental results and numerical calculations obtained to progress towards optimisation of fuel injection and fluidic stabilisation in swirl burners with ammonia as the primary fuel. A generic tangential swirl burner has been employed to determine flame stability and emissions produced at different equivalence ratios using ammonia–methane blends. Experiments were performed under atmospheric and medium pressurised conditions using gas analysis and chemiluminescence to quantify emission concentrations and OH production zones respectively. Numerical calculations using GASEQ and CHEMKIN-PRO were performed to complement compare with and extend experimental findings hence improving understanding concerning the evolution of species when fuelling on ammonia blends. It is concluded that a fully premixed injection strategy is not appropriate for optimised ammonia combustion and that high flame instabilities can be produced at medium swirl numbers hence necessitating lower swirl and a different injection strategy for optimised power generation utilising ammonia fuel blends.

Hydrogen-induced cracking behavior in high-strength steel mainly composed of martensite was analyzed by acoustic emission (AE) technique and finite element method (FEM) in slow strain-rate tensile (SSRT) tests and welding tests. The crack initiation was detected by the AE signals and the time evolution of stress concentration and hydrogen diffusion were calculated by FEM. The effect of hardness and plastic strain on the hydrogen diffusion coefficientwas explicitly introduced into the governing equation in FEM. The criterion and indicator parameter for the crack initiation were derived as a function of maximum principal stress and locally accumulated hydrogen concentration. The results showed that the cracking criterion derived by AE and FEM is useful for predicting the cold cracking behavior and determining the critical preheat temperature to prevent hydrogeninduced cracking.

On this episode of EAH we are joined by Andrew Clennett Co-Founder and CEO of Hiringa Energy. Hiringa is headquartered in New Zealand where they are building clean hydrogen production projects using renewable energy to displace the use of fossil fuels for transport and industrial feedstock across New Zealand. We are delighted to have Andrew with us today to speak about how Hiringa are using hydrogen to change the energy and carbon landscape of New Zealand.

This podcast can be found on their website

On this week's episode the EAH team speaks with Prof. Armin Schnettler CEO of New Energy Business at Siemens Energy to talk about where green hydrogen solutions fit into the path to decarbonisation how companies like Siemens are looking at those solutions and working to scale them to meet future demand timelines for deployment in different markets how governments can help the private sector and much much more.

The podcast can be found on their website

Hydrogen energy attracts an amount of attention as an environmentally friendly and sustainable energy source. However hydrogen is also flammable. Hydrogen fires and explosions might occur in wet-dust-removal systems if accumulated aluminum dust reacts with water. Hydrogen inhibition is a safe method to address these issues. For this purpose we used sodium citrate a renewable and nontoxic raw material to inhibit H2 formation. Specifically hydrogen inhibition experiments with sodium citrate were carried out using custom-built equipment developed by our research group. When the concentration of sodium citrate solution was in the range of 0.4–4.0 g/L a protective coating was formed on the surface of the Al particles which prevented them from contacting with water. The inhibitory effect was achieved when the concentration of sodium citrate was in a certain range and too much or too little addition may reduce the inhibitory effect. In this paper we also discuss the economic aspects of H2 inhibition with this method because it offers excellent safety advantages and could be incorporated on a large scale. Such an intrinsic safety design of H2 inhibition to control explosions in wet-dust-removal systems could be applied to ensure the safety of other systems such as nuclear reactors.

In the present study hydrogen utilization as diesel engine fuel at low load operation was investigated. Hydrogen cannot be used directly in a diesel engine due to its auto ignition temperature higher than that of diesel fuel. One alternative method is to use hydrogen in enrichment or induction. To investigate the combustion characteristics of this dual fuel engine a single cylinder diesel research engine was converted to utilize hydrogen as fuel. Hydrogen was introduced to the intake manifold using a mixer before entering the combustion chamber. The engine was run at a constant speed of 2000 rpm and 10 Nm load. Hydrogen was introduced at the flow rate of 21.4 36.2 and 49.6 liter/minute. Specific energy consumption indicated efficiency and cylinder pressure were investigated. At this low load the hydrogen enrichment reduced the cylinder peak pressure and the engine efficiency. The reaction progress variable and combustion rate of reaction were slower as shown by the CFD calculation.

On this episode of Everything About Hydrogen the team is joined by Sam French Business Development Director at JM who spent some time speaking with us about the transition from grey hydrogen to low-carbon generation technologies and what steps the UK - and countries all over the world - to use hydrogen as part of the pathway to a sustainable energy future.

The podcast can be found on their website

The capacity of each component in an off-grid water electrolyzer hydrogen production plant integrated with solar photovoltaics and a battery energy storage system represents a significant factor affecting the viability and reliability of the system. This paper describes a novel method that optimizes simultaneously the component capacities and finite-state machine based control of the system to minimize the cost of green hydrogen production. The components and control in the system are referenced to a proton exchange membrane water electrolyzer stack with a fixed nominal power of 4.5 kW. The end results are thus scalable by changing the nominal power of the electrolyzer. Simulations are carried out based on data collected from a residential solar photovoltaic installation with 300 s time resolution. Optimization of the system is performed with particle swarm optimization algorithm. A sensitivity analysis performed over the prices of the different components reveals that the price of the water electrolyzer has the greatest impact on the green hydrogen production cost. It is found that the price of the battery has to be below 0.3 e/Wh to become a feasible solution as overnight energy storage.

The major demand of energy in today’s world is fulfilled by the fossil fuels which are not renewable in nature and can no longer be used once exhausted. In the beginning of the 21st century the limitation of the fossil fuels continually growing energy demand and growing impact of greenhouse gas emissions on the environment were identified as the major challenges with current energy infrastructure all over the world. The energy obtained from fossil fuel is cheap due to its established infrastructure; however these possess serious issues as mentioned above and cause bad environmental impact. Therefore renewable energy resources are looked to as contenders which may fulfil most energy requirements. Among them hydrogen is considered as the most environmentally friendly fuel. Hydrogen is clean sustainable fuel and it has promise as a future energy carrier. It also has the ability to substitute the present energy infrastructure which is based on fossil fuel. This is seen and projected as a solution for the above-mentioned problems including rise in global temperature and environmental degradation. Environmental and economic aspects are the important factors to be considered to establish hydrogen infrastructure. This article describes the various aspects of hydrogen including production storage and applications with a focus on fuel cell based electric vehicles. Their environmental as well as economic aspects are also discussed herein.

The aim of this study is to assess numerically the influence of terrain landscape on the distribution of probable harmful consequences to personnel of hydrogen fueling station caused by an accidentally released and exploded hydrogen. In order to extract damaging factors of the hydrogen explosion wave (maximum overpressure and impulse of pressure phase) a three-dimensional mathematical model of gas mixture dynamics with chemical interaction is used. It allows controlling current pressure in every local point of actual space taking into account complex terrain. This information is used locally in every computational cell to evaluate the conditional probability of such consequences on human beings as ear-drum rupture and lethal ones on the basis of probit analysis. In order to use this technique automatically during the computational process the tabular dependence ""probit-functionimpact probability"" is replaced by a piecewise cubic spline. To evaluate the influence of the landscape profile on the non-stationary three-dimensional overpressure distribution above the earth surface near an epicenter of accidental hydrogen explosion a series of computational experiments with different variants of the terrain is carried out. Each variant differs in the level of mutual arrangement of the explosion epicenter and the places of possible location of personnel. Two control points with different distances from the explosion epicenter are considered. Diagrams of lethal and ear-drum rupture conditional probabilities are build to compare different variants of landscape profile. It is found that the increase or decrease in the level of the location of the control points relative to the level of the epicenter of the explosion significantly changes the scale of the consequences in the actual zone around the working places and should be taken into account by the risk managing experts at the stage of deciding on the level of safety at hydrogen fueling stations.

Biogas is a renewable gas with low heat energy which makes it extremely difficult to use as fuel in conventional natural gas equipment. Nonetheless the use of hydrogen as a biogas additive has proven to have a beneficial effect on flame stability and combustion behavior. This study evaluates the biogas–hydrogen combustion in a conventional natural gas burner able to work up to 100 kW. Tests were performed for three different compositions of biogas: BG70 (30% CO₂) BG60 (40% CO₂) and BG50 (50% CO₂). To achieve better flame stability each biogas was enriched with hydrogen from 5% to 25%. The difficulty of burning biogas in conventional systems was proven as the burner does not ignite when the biogas composition contains more than 40% of CO₂. The best improvements were obtained at 5% hydrogen composition since the exhaust gas temperature and thus the enthalpy rises by 80% for BG70 and 65% for BG60. The stability map reveals that pure biogas combustion is unstable in BG70 and BG60; when the CO₂ content is 50% ignition is inhibited. The properties change slightly when the hydrogen concentrations are more than 20% in the fuel gas and do not necessarily improve.

As the use of fossil fuels becomes more and more restricted there is a need for alternative fuels also at sea. For short sea distance travel purposes batteries may be a solution. However for longer distances when there is no possibility of recharging at sea batteries do not have sufficient capacity yet. Several projects have demonstrated the use of compressed hydrogen (CH₂) as a fuel for road transport. The experience with hydrogen as a maritime fuel is very limited. In this paper the similarities and differences between liquefied hydrogen (LH₂) and liquefied natural gas (LNG) as a maritime fuel will be discussed based on literature data of their properties and our system knowledge. The advantages and disadvantages of the two fuels will be examined with respect to use as a maritime fuel. Our objective is to discuss if and how hydrogen could replace fossil fuels on long distance sea voyages. Due to the low temperature of LH₂ and wide flammability range in air these systems have more challenges related to storage and processing onboard than LNG. These factors result in higher investment costs. All this may also imply challenges for the LH₂ supply chain.

The world is facing a challenge in meeting its needs for energy. Global energy consumption in the last half-century has increased very rapidly and is expected to continue to grow over the next 50 years. However it is expected to see significant differences between the last 50 years and the next. This paper aims at introducing a good solution to replace or work with conventional marine power plants. This includes the use of fuel cell power plant operated with hydrogen produced through water electrolysis or hydrogen produced from natural gas gasoline or diesel fuels through steam reforming processes to mitigate air pollution from ships.

Fuel starvation is a major cause of anode corrosion in low temperature polymer electrolyte fuel cells. The fuel cell start-up is a critical step as hydrogen may not yet be evenly distributed in the active area leading to local starvation. The present work investigates the hydrogen distribution and risk for starvation during start-up and after nitrogen purge by extending an existing computational fluid dynamic model to capture transient behavior. The results of the numerical model are compared with detailed experimental analysis on a 25 cm2 triple serpentine flow field with good agreement in all aspects and a required time step size of 1 s. This is two to three orders of magnitude larger than the time steps used by other works resulting in reasonably quick calculation times (e.g. 3 min calculation time for 1 s of experimental testing time using a 2 million element mesh).

Growing prosperity among its population and an inherent increasing demand for energy complicate China’s target of combating climate change while maintaining its economic growth. This paper therefore describes three potential decarbonization pathways to analyze different effects for the electricity transport heating and industrial sectors until 2050. Using an enhanced version of the multi-sectoral open-source Global Energy System Model enables us to assess the impact of different CO2 budgets on the upcoming energy system transformation. A detailed provincial resolution allows for the implementation of regional characteristics and disparities within China. Conclusively we complement the model-based analysis with a quantitative assessment of current barriers for the needed transformation. Results indicate that overall energy system CO2 emissions and in particular coal usage have to be reduced drastically to meet (inter-) national climate targets. Specifically coal consumption has to decrease by around 60% in 2050 compared to 2015. The current Nationally Determined Contributions proposed by the Chinese government of peaking emissions in 2030 are therefore not sufficient to comply with a global CO2 budget in line with the Paris Agreement. Renewable energies in particular photovoltaics and onshore wind profit from decreasing costs and can provide a more sustainable and cheaper energy source. Furthermore increased stakeholder interactions and incentives are needed to mitigate the resistance of local actors against a low-carbon transformation.

This research work presents an artificial intelligence approach to predicting the hydrogen concentration in the producer gas from biomass gasification. An experimental gasification plant consisting of an air-blown downdraft fixed-bed gasifier fueled with exhausted olive pomace pellets and a producer gas conditioning unit was used to collect the whole dataset. During an extensive experimental campaign the producer gas volumetric composition was measured and recorded with a portable syngas analyzer at a constant time step of 10 seconds. The resulting dataset comprises nearly 75 hours of plant operation in total. A hybrid intelligent model was developed with the aim of performing fault detection in measuring the hydrogen concentration in the producer gas and still provide reliable values in the event of malfunction. The best performing hybrid model comprises six local internal submodels that combine artificial neural networks and support vector machines for regression. The results are remarkably satisfactory with a mean absolute prediction error of only 0.134% by volume. Accordingly the developed model could be used as a virtual sensor to support or even avoid the need for a real sensor that is specific for measuring the hydrogen concentration in the producer gas.

The experimental data on hydrogen adsorption on five nanoporous activated carbons (ACs) of various origins measured over the temperature range of 303–363 K and pressures up to 20 MPa were compared with the predictions of hydrogen density in the slit-like pores of model carbon structures calculated by the Dubinin theory of volume filling of micropores. The highest amount of adsorbed hydrogen was found for the AC sample (ACS) prepared from a polymer mixture by KOH thermochemical activation characterized by a biporous structure: 11.0 mmol/g at 16 MPa and 303 K. The greatest volumetric capacity over the entire range of temperature and pressure was demonstrated by the densest carbon adsorbent prepared from silicon carbide. The calculations of hydrogen density in the slit-like model pores revealed that the optimal hydrogen storage depended on the pore size temperature and pressure. The hydrogen adsorption capacity of the model structures exceeded the US Department of Energy (DOE) target value of 6.5 wt.% starting from 200 K and 20 MPa whereas the most efficient carbon adsorbent ACS could achieve 7.5 wt.% only at extremely low temperatures. The initial differential molar isosteric heats of hydrogen adsorption in the studied activated carbons were in the range of 2.8–14 kJ/mol and varied during adsorption in a manner specific for each adsorbent.

Transformation of road transport sector through replacing of internal combustion vehicles with zero-emission technologies is among key challenges to achievement of climate neutrality by 2050. In a constantly developing economy the demand for transport services increases to ensure continuity in the supply chain and passenger mobility. Deployment of electric technologies in the road transport sector involves both businesses and households its pace depends on the technological development of zero-emission vehicles presence of necessary infrastructure and regulations on emission standards for new vehicles entering the market. Thus this study attempts to estimate how long combustion vehicles will be in use and what the state of the fleet will be in 2050. For obtainment of results the TR3E partial equilibrium model was used. The study simulates the future fleet structure in passenger and freight transport. The results obtained for Poland for the climate neutrality (NEU) scenario show that in 2050 the share of vehicles using fossil fuels will be ca. 30% in both road passenger and freight transport. The consequence of shifts in the structure of the fleet is the reduction of CO2 emissions ca. 80% by 2050 and increase of the transport demand for electricity and hydrogen.

The price of constructing hydrogen generation units is very high and sometimes it is not possible to build them in the desired location so the transfer of hydrogen from the hydrogen generation system to the units that need it is justified. Since the storage of hydrogen gas needs a large volume and its transportation is very complex so if hydrogen is stored in liquid form this problem can be resolved. In transporting liquid hydrogen (LH2) over long distances owing to heat transfer to the environment the LH2 vaporizes forming boil-off gas (BOG). Herein in lieu of only reliquifying the BOG this study proposes and assesses a system employing the BOG partially as feed for a novel liquefaction process and also the remaining utilized in a proton exchange membrane fuel cell (PEMFC) to generate power. Using the cold energy of the onsite liquid oxygen utility of the LH2 cargo vessel the mixed refrigerant liquefaction cycle is further cooled down. In this regard by using 130 kg/h BOG as input 60.37 kg/h of liquid hydrogen is produced and the rest enters PEMFC with 552.7 kg/h oxygen to produce 1592 kW of power. The total thermal efficiency of the integrated system and electrical efficiency of the PEMFC is 83.18% and 68.76% respectively. Regarding the liquefaction cycle its specific power consumption (SPC) and coefficient of performance (COP) were achieved at 3.203 kWh/kgLH2 and 0.1876 respectively. The results of exergy analysis show that the exergy destruction of the whole system is 937.4 kW and also its exergy efficiency is calculated to be 58.38%. Exergoeconomic and Markov analyses have also been applied to the integrated system. Also by changing the important parameters of PEMFC its optimal performance has been extracted.

Hydrogen is a clean fuel for transportation and energy storage. It has several attractive features including a higher energy content by weight use in fuel cells that produces only water as a by-product storage in small and large quantities by various methods and established transportation and infrastructures. A hydrogen economy consists of three steps i.e. hydrogen production storage and applications. All three steps involved in a hydrogen economy can be divided into catalytic and non-catalytic approaches. For catalytic processes the efficiency highly depends on the type and physico-chemical characteristics of the catalysts. Therefore for the improvement of these catalytic processes the development of highly efficient and stable catalysts is highly required.

In this present investigation a packed-filter bioreactor was employed to produce hydrogen utilizing an expired soft drink as a substrate. The effects of feeding substrate concentrations ranging from 19.51 10.19 5.34 3.48 to 2.51 g total sugar/L were examined and the position of the packed filter installed in the bioreactor at dimensionless heights (h/H) of 1/4 2/4 3/4 and 4/4 was studied. The results revealed that with a substrate concentration of 20 g total sugar/L and a hydraulic retention time (HRT) of 1 h a packed filter placed at the half-height position of the bioreactor (h/H 2/4) has the optimal hydrogen production rate hydrogen yield and average biomass concentration in the bioreactor resulting in 55.70 ± 2.42 L/L/d 0.90 ± 0.06 mol H₂/mol hexose and 17.86 ± 1.09 g VSS/L. When feeding substrate concentrations varied from 20 10 to 5 g total sugar/L with the packed-filter position at h/H 2/4 Clostridium sp. Clostridium tyrobutyricum and Bifidobacterium crudilactis were the predominant bacteria community. Finally it was discovered that the packed-filter bioreactor can produce stable hydrogen in high-strength organic effluent.

Underground Hydrogen Storage (UHS) is an attractive technology for large-scale (TWh) renewable energy storage. To ensure the safety and efficiency of the UHS it is crucial to quantify the H2 interactions with the reservoir fluids and rocks across scales including the micro scale. This paper reports the experimental measurements of advancing and receding contact angles for different channel widths for a H2 /water system at P = 10 bar and T = 20 ◦C using a microfluidic chip. To analyse the characteristics of the H2 flow in straight pore throats the network is designed such that it holds several straight channels. More specifically the width of the microchannels range between 50 μm and 130 μm. For the drainage experiments H2 is injected into a fully water saturated system while for the imbibition tests water is injected into a fully H2 -saturated system. For both scenarios high-resolution images are captured starting the introduction of the new phase into the system allowing for fully-dynamic transport analyses. For better insights N2 /water and CO2 /water flows were also analysed and compared with H2 /water. Results indicate strong water-wet conditions with H2 /water advancing and receding contact angles of respectively 13◦–39◦ and 6◦–23◦ . It was found that the contact angles decrease with increasing channel widths. The receding contact angle measured in the 50 μm channel agrees well with the results presented in the literature by conducting a core-flood test for a sandstone rock. Furthermore the N2 /water and CO2 /water systems showed similar characteristics as the H2 /water system. In addition to the important characterization of the dynamic wettability the results are also crucially important for accurate construction of pore-scale simulators.

IGEM/SR/23 (“Venting of natural gas”) provides recommendations for the conceptual design operation and safety aspects of permanent temporary and emergency venting of natural gas. The document was originally developed many years ago and the current edition dates to 1995. The document is due to be reviewed and updated for application to natural gas but the aim of this study is not to review the applicability of the document for natural gas but to assess the possible impact of 100% hydrogen on specific aspects of the existing guidance.<br/>A key element of the guidance concerns the safe dispersion distances for natural gas as vents are intended to provide a means of safely dispersing gas in the atmosphere without ignition. Guidance on safe dispersion distances for venting are provided in Section 6.6 accompanied by graphs showing the relationship between the mass flow rate through the vent and the safe (horizontal) dispersion distance. Details of the model used to predict the dispersion distances are given in Appendix 1. However for dispersion the guidance in IGEM/SR/23 has been superseded by similar guidance on hazard distances for unignited releases in IGEM/SR/25 (“Hazardous area classification of natural gas installations”) [2]. A comprehensive review of the applicability of IGEM/SR/25 to hydrogen is already underway for the LTS Futures project and is not duplicated here.<br/>However IGEM/SR/23 contains guidance on other important aspects relevant to the safe design and operation of vents which are not addressed elsewhere in the IGEM suite of standards; in particular guidance on hazard ranges for thermal radiation (in the event of an unplanned ignition of the venting gas) and noise.<br/>The main aim of this report is to assess the potential impact of replacing natural gas with 100% hydrogen on the guidance in IGEM/SR/23 concerned with thermal hazards with a secondary objective of assessing the available information to comment on the possible influence of hydrogen on noise.

The climate emergency is one of the biggest challenges humanity must face in the 21st century. The global energy transition faces many challenges when it comes to ensuring a sustainable reliable and affordable energy supply. A likely outcome is decarbonizing the existing gas infrastructure. This will inevitably lead to greater penetration of hydrogen. While the introduction of hydrogen into natural gas  transmission and distribution networks creates challenges there is nothing new or inherently impossible about the concept. Indeed more than 4000 kilometers of hydrogen pipelines are currently in operation. These pipelines however were (almost) all built and operated exclusively in accordance with specific hydrogen codes which tend to be much more restrictive than their natural gas equivalents. This means that the conversion of natural gas pipelines which have often been in service for decades and have accumulated damage and been subject to cracking threats (e.g. fatigue or stress corrosion cracking (SCC)) throughout their lifetime can be challenging. This paper will investigate the impact of transporting hydrogen on the crack management of existing natural gas pipelines from an overall integrity perspective. Different cracking threats will be described including recent industry experience of those which are generic to all steel pipelines but exacerbated by hydrogen and those which are hydrogen specific. The application of a Hydrogen Framework to identify characterise and manage credible cracking threats to pipelines in order to help enable the safe economic and successful introduction of hydrogen into the natural gas network will be discussed.

The 21st century is characterized not only by large-scale transformations but also by the speed with which they occur. Transformations—political economic social technological environmental and legal-in synergy have always been a catalyst for reactions in society. The field of energy supply like many others is extremely susceptible to the external influence of such factors. To a large extent this applies to remote (especially from the position of energy supply) regions. The authors outline an approach to justifying the development of the Arctic energy infrastructure through an analysis of the demand for the amount of energy consumed and energy sources taking into account global trends. The methodology is based on scenario modeling of technological demand. It is based on a study of the specific needs of consumers available technologies and identified risks. The paper proposes development scenarios and presents a model that takes them into account. Modeling results show that in all scenarios up to 50% of the energy balance in 2035 will take gas but the role of carbon-free energy sources will increase. The mathematical model allowed forecasting the demand for energy types by certain types of consumers which makes it possible to determine the vector of development and stimulation of certain types of resources for energy production in the Arctic. The model enables considering not only the growth but also the decline in demand for certain types of consumers under different scenarios. In addition authors’ forecasts through further modernization of the energy sector in the Arctic region can contribute to the creation of prerequisites that will be stimulating and profitable for the growth of investment in sustainable energy sources to supply consumers. The scientific significance of the work lies in the application of a consistent hybrid modeling approach to forecasting demand for energy resources in the Arctic region. The results of the study are useful in drafting a scenario of regional development taking into account the Sustainable Development Goals as well as identifying areas of technology and energy infrastructure stimulation.

Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resources. However purification of syngas to remove multiple impurities such as particulates tar HCl alkali chlorides and sulfur species is required. This study investigates the feasibility of high temperature purification of syngas from MSW gasification with the focus on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises of a fluidized-bed catalytic tar reformer a filter for particulates and a fixed-bed reactor for dechlorination and then desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nano-structured nickel catalyst supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages. Experimental and thermodynamic modeling results are compared to determine the kinetic constraints in the integrated system. The hot purification system demonstrates up to 90% of tar and sulfur removal efficiency increased total syngas yield (14%) and improved cold gas efficiency (12%). The treated syngas is potentially applicable in gas engines/turbines and solid oxide fuel cells based on the dew points and concentration limits of the remaining tar compounds. Reforming of raw syngas by nickel catalyst for over 20 h on stream shows strong resistance to deactivation. Desulfurization of syngas from MSW gasification containing significantly higher proportion of carbonyl sulfide than hydrogen sulfide traces of tar and hydrogen chloride demonstrates high performance of Ni-Zn sorbents.

Hydrogen (H₂) is a promising renewable energy source that can replace fossil fuels since it can solve several environmental and economic issues. However the widespread usage of H₂ is constrained by its storage and safety issues. Many researchers consider solid materials with an excellent capacity for H₂ storage and generation as the solution for most H₂-related issues. Among solid materials ammonia borane (abbreviated hereafter as AB) is considered one of the best hydrogen storage materials due to its extraordinary H₂ content and small density. However the process must be conducted in the presence of efficient catalysts to obtain a reasonable amount of generated H₂. Electrospun nanofibrous catalysts are a new class of efficient catalysts that involves the usage of polymers. Here a comprehensive review of the ceramic-supported electrospun NF catalysts for AB hydrolysis is presented with a special focus on catalytic and photolytic performance and preparation steps. Photocatalytic AB hydrolysis was discussed in detail due to its importance and promising results. AB photocatalytic hydrolysis mechanisms under light were also explained. Electrospun catalysts show excellent activity for AB hydrolysis with good recyclability. Kinetics studies show that the AB hydrolysis reaction is independent of AB concentration and the first-order reaction of NF catalysts.

Green hydrogen for mobility represents an alternative to conventional fuel to decarbonize the transportation sector. Nevertheless the thermodynamic properties make the transport and the storage of this energy carrier at standard conditions inefficient. Therefore this study deploys a georeferenced optimal transport infrastructure for four base case scenarios in France and Germany that differs by production distribution based on wind power potential and demand capacities for the mobility sector at different penetration shares for 2030 and 2050. The restrained transport network to the road infrastructure allows focusing on the optimum combination of trucks operating at different states of aggregations and storage technologies and its impact on the annual cost and hydrogen flow using linear programming. Furthermore four other scenarios with production cost investigate the impact of upstream supply chain cost and eight scenarios with daily transport and storage optimization analyse the modeling method sensitivity. The results show that compressed hydrogen gas at a high presser level around 500 bar was on average a better option. However at an early stage of hydrogen fuel penetration substituting compressed gas at low to medium pressure levels by liquid organic hydrogen carrier minimizes the transport and storage costs. Finally in France hydrogen production matches population distribution in contrast to Germany which suffers from supply and demand disparity.

Nel Hydrogen is one of the largest electrolysis companies in the world with an array of Alkaline and PEM solutions that have been used in an array of energy and industrial applications. On the show we ask Bjørn Simonsen Vice President of Investor Relations and Corporate Communication at Nel Hydrogen to talk through how Nel has seen the green hydrogen market evolve and where Nel fits into this sector transition.

The podcast can be found on their website

As the global search for new methods to combat global warming and climate change continues renewable fuels and hydrogen have emerged as saviours for environmentally polluting industries such as aviation. Sustainable aviation is the goal of the aviation industry today. There is increasing interest in achieving carbon-neutral flight to combat global warming. Hydrogen has proven to be a suitable alternative fuel. It is abundant clean and produces no carbon emissions but only water after use which has the potential to cool the environment. This paper traces the historical growth and future of the aviation and aerospace industry. It examines how hydrogen can be used in the air and on the ground to lower the aviation industry’s impact on the environment. In addition while aircraft are an essential part of the aviation industry other support services add to the overall impact on the environment. Hydrogen can be used to fuel the energy needs of these services. However for hydrogen technology to be accepted and implemented other issues such as government policy education and employability must be addressed. Improvement in the performance and emissions of hydrogen as an alternative energy and fuel has grown in the last decade. However other issues such as the storage and cost and the entire value chain require significant work for hydrogen to be implemented. The international community’s alternative renewable energy and hydrogen roadmaps can provide a long-term blueprint for developing the alternative energy industry. This will inform the private and public sectors so that the industry can adjust its plan accordingly.

A series of experiments were performed to investigate the effect of ignition energy (Eig) and hydrogen addition on the laminar burning velocity (Su 0 ) ignition delay time (tdelay) and flame rising time (trising) of lean methane−air mixtures. The mixtures at three different equivalence ratios (φ) of 0.6 0.7 and 0.8 with varying hydrogen volume fractions from 0 to 50% were centrally ignited in a constant volume combustion chamber by a pair of pin-to-pin electrodes at a spark gap of 2.0 mm. In situ ignition energy (Eig ∼2.4 mJ ÷ 58 mJ) was calculated by integration of the product of current and voltage between positive and negative electrodes. The result revealed that the Su 0 value increases non-linearly with increasing hydrogen fraction at three equivalence ratios of 0.6 0.7 and 0.8 by which the increasing slope of Su 0 changes from gradual to drastic when the hydrogen fraction is greater than 20%. tdelay and trising decrease quickly with increasing hydrogen fraction; however trising drops faster than tdelay at φ = 0.6 and 0.7 and the reverse is true at φ = 0.8. Furthermore tdelay transition is observed when Eig > Eigcritical by which tdelay drastically drops in the pre-transition and gradually decreases in the post-transition. These results may be relevant to spark ignition engines operated under lean-burn conditions.

An eco-friendly green synthesis of mesoporous iron oxide (hematite) using pomegranate peels through a low-cost and massive product method was investigated. The mass of pomegranate peels was varied to control the morphology of the produced hematite (Fe2O3). The structures textures and optical properties of the products were investigated by FTIR XRD FE-SEM and UV–Vis spectroscopy. Three different Fe2O3 morphologies were obtained; Fe2O3(I) nanorod like shape Fe2O3(II) nanoparticles and Fe2O3(III) nanoporous structured layer. The bandgap values for Fe2O3 (I) (II) and (III) were 2.71 2.95 and 2.29 eV respectively. The newly hematite samples were used as promising photoelectrodes supported on graphite substrate for the photoelectrochemical (PEC) water splitting toward the efficient production of solar hydrogen. The number of generated hydrogen moles was calculated per active area to be 50 molh−1 cm−2 for electrode III which decreased to 15.3molh−1 cm−2 for electrode II. The effects of temperature (30–70 ◦C) on the PEC behavior of the three electrodes were addressed. Different thermodynamic parameters were calculated for the three electrodes which showed activation energies of 13.4 16.8 and 15.2 kJmol−1 respectively. The electrode stability was addressed as a function of the number of runs and exposure time in addition to electrochemical impedance study. Finally the conversion efficiency of the incident photon to-current(IPCE) was estimated under the monochromatic illumination. The optimum value was ∼11% @ 390nm for Fe2O3(III) electrode

In recent years with the development of hydrogen energy economy there is an increasing demand for hydrogen in the market and hydrogen production through biomass will provide an important way to supply clean environmentally friendly and highly efficient hydrogen. In this study cow dung was selected as the biomass source and the efficiency of the biomass to hydrogen reaction was explored by coupling high temperature pyrolysis and water vapor gasification. The experimental conditions of gasification temperature water mass fraction heating rate and feed temperature were systematically studied and optimized to determine the optimal conditions for in situ hydrogen production by gasification of cow dung. The relationship of each factor to the yield of hydrogen production by gasification of cow dung semi-coke was investigated in order to elucidate the mechanism of the hydrogen production. The experiment determined the optimal operating parameters of in situ gasification: gasification temperature 1173 K water mass fraction 80% heating rate 10 K/min and feed temperature 673 K. The semi-coke treatment separated high temperature pyrolysis and water vapor gasification and reduced the influence on gasification of volatile substances such as tar extracted from pyrolysis. The increase of semi-coke preparation temperature increases the content of coke reduces the volatile matter and improves the yield of hydrogen; the small size of semi-coke particles and large specific surface area are beneficial to the gasification reaction.

Founded in 2007 and based in Denmark Green Hydrogen Systems designs and manufactures efficient standardized and modular electrolysers for the production of green hydrogen with renewable energy. Niels-Arne Baden has led the company to the upper echelons of the electrolysis sector and he now leads the company's strategy and and public-facing initiatives as the Vice President for Strategy and Public Affairs. On this episode of the Everything About Hydrogen podcast the EAH team sits down with Niels to talk about the journey of the clean hydrogen sector over the recent decades and its rise to prominence in the transition to a decarbonized energy future and how modular electrolysis fits into that picture.

The podcast can be found on their website

Since 2014 when the firm was founded within Anglo-American AP Ventures has been at the forefront of investment in hydrogen sector technologies. At the time the firm started the concerns around climate change and investment in renewable energy tech was gearing up but interest in hydrogen as part of the path to a decarbonized future was limited. The founders of AP Ventures felt differently and saw significant potential for hydrogen to offer a means for cleaning up highly carbon intensive sectors such as heavy transport industrial manufacturing and mining operations. Today that vision for hydrogen appears rather prescient. We are delighted to have two members from the team at AP Ventures with us on the show today. The team is joined by Kevin Eggers - a founding partner at AP - and Michell Robson - associate on the firm's investment team.

The podcast can be found on their website

This research qualitatively reviews literature regarding energy system modeling in Japan specific to the future hydrogen economy leveraging quantitative model outcomes to establish the potential future deployment of hydrogen in Japan. The analysis focuses on the four key sectors of storage supplementing the gas grid power generation and transportation detailing the potential range of hydrogen technologies which are expected to penetrate Japanese energy markets up to 2050 and beyond. Alongside key model outcomes the appropriate policy settings governance and market mechanisms are described which underpin the potential hydrogen economy future for Japan. We find that transportation gas grid supplementation and storage end-uses may emerge in significant quantities due to policies which encourage ambitious implementation targets investment in technologies and research and development and the emergence of a future carbon pricing regime. On the other hand for Japan which will initially be dependent on imported hydrogen the cost of imports appears critical to the emergence of broad hydrogen usage particularly in the power generation sector. Further the consideration of demographics in Japan recognizing the aging shrinking population and peoples’ energy use preferences will likely be instrumental in realizing a smooth transition toward a hydrogen economy.

In this work a metal cobalt catalyst was synthesized and its activity in the hydrogen production process was tested. The substrates were water and ethanol. Activity tests were conducted at a temperature range of 350–600 °C water to ethanol molar ratio of 3 to 5 and a feed flow of 0.4 to 1.2 mol/h. The catalyst had a specific surface area of 1.75 m2/g. The catalyst was most active at temperatures in the range of 500–600 °C. Under the most favorable conditions the ethanol conversion was 97% the hydrogen production efficiency was 4.9 mol (H2)/mol(ethanol) and coke production was very low (16 mg/h). Apart from hydrogen and coke CO2 CH4 CO and traces of C2H2 and C2H4 were formed.

A stable energy supply will require balancing the fluctuations of renewable energy generation due to the transition to renewable energy sources. Intraday and seasonal storage systems are often limited to local geographical or infrastructural circumstances. This study experimentally verifies the application of inexpensive and abundant natural iron ores for energy storage with combined hydrogen and heat release. The incorporated iron oxides are reduced with hydrogen from electrolysis to store energy in chemically bonded form. The on–demand reoxidation releases either pure hydrogen or high-temperature heat as valuable products. Natural iron ores as storage material are beneficial as the specific costs are lower by an order of magnitude compared to synthetic iron oxide-based materials. Suitable iron ores were tested in TG analysis and in a 1 kW fixed-bed reactor. Siderite a carbonate iron ore was verified as promising candidate as it shows significantly lower reaction temperatures and twice the storage capacity over other commercial iron ores such as ilmenite. The specific storage costs are as low as 80–150 $ per MWh hydrogen stored based on the experimental in-situ tests. The experimentally determined volumetric energy storage capacity for the bulk material was 1.7 and 1.8 MWh m− 3 for hydrogen and heat release respectively. The raw siderite ore was stable for over 50 consecutive cycles at operating temperatures of 500–600 ◦C in in-situ lifetime tests. The combination of high abundance low price and reasonable capacity can thus result in very low specific energy storage costs. The study proofs that suitable natural iron ores are an interesting economic solution for large-scale and seasonal energy storage systems.

Blending hydrogen into the gas grid could be an important stepping stone during the transition to a sustainable net zero system. In particular it may: provide a significant and reliable source of demand for hydrogen producers supporting the investment case for hydrogen; provide learnings and incremental change towards what could potentially become a 100% hydrogen grid; and immediately decarbonise a portion of the gas flowing through the grid. Technical questions relating to hydrogen blending are being taken forward by the industry (e.g. through the HyDeploy project in relation to the maximum potential blend of hydrogen that can be accommodated without end user appliances needing to be altered or replaced). But if blending is to take place changes to commercial arrangements will be necessary as today these assume a relatively uniform gas quality. In particular the commercial framework will need to ensure that limits on the percentage of hydrogen that can safely be blended (currently expected to be around 20% by volume) are not exceeded. We have been commissioned by Cadent to undertake a Network Innovation Allowance (NIA) project to identify the changes required to the gas commercial framework that will enable hydrogen blending in the GB gas grid and to set out a roadmap for how these can be delivered. This report sets out our recommendations.