Publications

The cost of polymer electrolyte water electrolysis (PEWE) is dominated by the price of electricity used to power the water splitting reaction. We present a liquid water fed polymer electrolyte water electrolyzer cell operated at a cell temperature of 100 °C in comparison to a cell operated at state-of-the-art operation temperature of 60 °C over a 300 h constant current period. The hydrogen conversion efficiency increases by up to 5% at elevated temperature and makes green hydrogen cheaper. However temperature is a stress factor that accelerates degradation causes in the cell. The PEWE cell operated at a cell temperature of 100 °C shows a 5 times increased cell voltage loss rate compared to the PEWE cell at 60 °C. The initial performance gain was found to be consumed after a projected operation time of 3500 h. Elevated temperature operation is only viable if a voltage loss rate of less than 5.8 μV h−1 can be attained. The major degradation phenomena that impact performance loss at 100 °C are ohmic (49%) and anode kinetic losses (45%). Damage to components was identified by post-test electron-microscopic analysis of the catalyst coated membrane and measurement of cation content in the drag water. The chemical decomposition of the ionomer increases by a factor of 10 at 100 °C vs 60 °C. Failure by short circuit formation was estimated to be a failure mode after a projected lifetime 3700 h. At elevated temperature and differential pressure operation hydrogen gas cross-over is limiting since a content of 4% hydrogen in oxygen represents the lower explosion limit.

A range of existing and newly developed hydrogen standards certification and labelling (SCL) schemes aim to promote the role of ‘renewable’ ‘clean’ or ‘green’ hydrogen in decarbonising energy transitions. This paper analyses a sample of these SCLs to assess their role in the scaling up of renewable hydrogen and its derivatives. To analyse these hydrogen SCLs we embellish a novel conceptual framework that brings together Sustainability Systems Thinking and Governance (SSG) literatures. The results reveal noteworthy scheme differences in motivation approach criteria and governance; highlighting the complex interconnected and dynamic reality within which energy systems are embedded. We consider whether the sustainable utilisation of renewable hydrogen is well-served by the proliferation of SCLs and recommend an SSG-informed approach. An SSG approach will better promote collaboration towards an authoritative global multistakeholder compromise on hydrogen certification that balances economic considerations with social and environmental dimensions.

Endeavors have recently been concentrated on minimizing the dependency on fossil fuels in order to mitigate the ever-increasing problem of greenhouse gas (GHG) emissions. Hydrogen energy is regarded as an alternative to fossil fuels due to its cleaner emission attributes. Reforming of hydrocarbon fuels is amongst the most popular and widely used methods for hydrogen production. Hydrogen produced from reforming processes requires additional processes to separate from the reformed gases. In some cases further purification of hydrogen has to be carried out to use the hydrogen in power generation applications. Metallic membranes especially palladium (Pd)-based ones have demonstrated sustainable hydrogen separation potential with around 99.99% hydrogen purity. Comprehensive and critical research investigations must be performed to optimize membrane-assisted reforming as well as to maximize the production of hydrogen. The computational fluid dynamic (CFD) can be an excellent tool to analyze and visualize the flow/reaction/permeation mechanisms at a lower cost in contrast with the experiments. In order to provide the necessary background knowledge on membrane reactor modeling this study reviews summarizes and analyses the kinetics of different fuel reforming processes equations to determine hydrogen permeation and lastly various geometry and operating condition adopted in the literature associated with membrane-reactor modeling works. It is indicated that hydrogen permeation through Pd-membranes depends highly on the difference in hydrogen pressure. It is found that hydrogen permeation can be improved by employing different pressure configuration introducing sweep flow on the permeate side of the membrane reducing retentate side flow rate and increasing the temperature.

This article presents a 3D model of a yellow hydrogen generation system that uses the electricity produced by a photovoltaic carport. The 3D models of all key system components were collected and their characteristics were described. Based on the design of the 3D model of the photovoltaic carport the amount of energy produced monthly was determined. These quantities were then applied to determine the production of low-emission hydrogen. In order to increase the amount of low-emission hydrogen produced the usage of a stationary energy storage facility was proposed. The Metalog family of probability distributions was adopted to develop a strategic model for low-emission hydrogen production. The hydrogen economy of a company that uses small amounts of hydrogen can be based on such a model. The 3D modeling and calculations show that it is possible to design a compact low-emission hydrogen generation system using rapid prototyping tools including the photovoltaic carport with an electrolyzer placed in the container and an energy storage facility. This is an effective solution for the climate and energy transition of companies with low hydrogen demand. In the analytical part the Metalog probability distribution family was employed to determine the amount of monthly energy produced by 6.3 kWp photovoltaic systems located in two European countries: Poland and Italy. Calculating the probability of producing specific amounts of hydrogen in two European countries is an answer to a frequently asked question: In which European countries will the production of low-emission hydrogen from photovoltaic systems be the most profitable? As a result of the calculations for the analyzed year 2023 in Poland and Italy specific answers were obtained regarding the probability of monthly energy generation and monthly hydrogen production. Many companies from Poland and Italy are taking part in the European competition to create hydrogen banks. Only those that offer low-emission hydrogen at the lowest prices will receive EU funding.

Due to the increase in electric energy consumption and the significant growth in the number of electric vehicles (EV) at the level of the distribution network new networks have started using new fuels such as hydrogen to improve environmental indicators and at the same time better efficiency from the excess capacity of renewable resources. In this article the services that can be provided by hydrogen refueling stations and charging electric vehicles in the optimal performance of microgrids have been investigated. The model proposed in this paper includes a two-stage stochastic framework for scheduling resources in microgrids especially hydrogen refueling stations and electric vehicle charging. In this model two main goals of cost minimization and greenhouse gas emissions are considered. In the proposed framework and in the first stage the service range of microgrids is determined precisely according to the electrical limitations of distribution systems in emergency situations. Then in the second stage the problem of energy management in each microgrid will be solved centrally. In this situation various indicators including the output energy of renewable sources smart charging of hydrogen and electric vehicle charging stations (EV/FCV) and flexible loads (FL) are evaluated. The final mathematical model is implemented as a multivariate integer multiple linear problem (MILP) using the GUROBI solver in GAMS software. The simulation results on the modified IEEE 118-Bus network show the positive effect of the presence of flexible loads and smart charging strategies by charging stations. Also the numerical derivation shows that the operating costs of the entire system can be reduced by 4.77% and the use of smart charging strategies can reduce greenhouse gas emissions by 49.13%.

Offshore green hydrogen emerges as a guiding light in the global pursuit of environmental sustainability and net-zero objectives. The burgeoning expansion of offshore wind power faces significant challenges in grid integration. This avenue towards generating offshore green hydrogen capitalises on its ecological advantages and substantial energy potential to efficiently channel offshore wind power for onshore energy demands. However a substantial research void exists in efficiently integrating offshore wind electricity and green hydrogen. Innovative designs of offshore hydrogen platforms present a promising solution to bridge the gap between offshore wind and hydrogen integration. Surprisingly there is a lack of commercially established offshore platforms dedicated to the hydrogen industry. However the wealth of knowledge from oil and gas platforms contributes valuable insights to hydrogen platform design. Diverging from the conventional decentralised hydrogen units catering to individual turbines this study firstly introduces a pioneering centralised Offshore Green Hydrogen Platform (OGHP) which seamlessly integrates modular production storage and offloading modulars. The modular design of facilitates scalability as wind capacity increases. Through a detailed case study centred around a 100-Megawatt floating wind farm the design process of offshore green hydrogen modulars and its floating sub-structure is elucidated. Stability analysis and hydrodynamic analysis are performed to ensure the safety of the OGHP under the operation conditions. The case study will enhance our understanding OGHP and its modularised components. The conceptual design of modular OGHP offers an alternative solution to ‘‘Power-to-X’’ for offshore renewable energy sector.

This paper investigates the feasibility of hydrogen-powered hybrid electric vehicles as a solution to transportation-related pollution. It focuses on optimizing energy use to improve efficiency and reduce emissions. The study details the creation and real-time performance assessment of a hydrogen hybrid electric vehicle (HHEV)system using an STM32F407VG board. This system includes a fuel cell (FC) as the main energy source a battery (Bat) to provide energy during hydrogen supply disruptions and a supercapacitor (SC) to handle power fluctuations. A multi-agent-based artificial intelligence tool is used to model the system components and an energy management algorithm (EMA) is applied to optimize energy use and support decision-making. Real Global Positioning System (GPS) data are analyzed to estimate energy consumption based on trip and speed parameters. The EMA developed and implemented in real-time using Matlab/Simulink(2016) identifies the most energy-efficient routes. The results show that the proposed vehicle architecture and management strategy effectively select optimal routes with minimal energy use.

Conventional turboshaft engines are high power density movers suffering from low efficiency at part power operation and producing significant emissions. This paper presents a design exploration and feasibility assessment of a hybrid hydrogen-fueled powerplant for Urban Air Mobility (UAM) rotorcraft. A multi-disciplinary approach is devised comprising models for rotorcraft performance tank and subsystems sizing and engine performance. The respective trade-offs between payload-range and mission level performance are quantified for kerosene-fueled and hybrid hydrogen tilt-rotor variants. The effects of gas turbine scaling and fuel cell pressurization are evaluated for different hybridization degrees. Gas turbine scaling with hybridization (towards the fuel cell) results in up to 21% benefit in energy consumption relative to the non-scaled case with the benefits being more pronounced at high hybridization degrees. Pressurizing the fuel cell has shown significant potential as cell efficiency can increase up to 10% when pressurized to 6 bar which translates to a 6% increase in overall efficiency. The results indicate that current fuel cells (1 kW/kg) combined with current hydrogen tank technology severely limit the payload range capability of the tilt-rotor. However for advanced fuel cell technology (2.5 kW/kg) and low ranges hybrid powerplant show the potential to reduce energy consumption and reduce emissions footprint.

A new model is presented to predict hydrogen-assisted fatigue. The model combines a phase field description of fracture and fatigue stress-assisted hydrogen diffusion and a toughness degradation formulation with cyclic and hydrogen contributions. Hydrogen-assisted fatigue crack growth predictions exhibit an excellent agreement with experiments over all the scenarios considered spanning multiple load ratios H2 pressures and loading frequencies. These are obtained without any calibration with hydrogen-assisted fatigue data taking as input only mechanical and hydrogen transport material properties the material’s fatigue characteristics (from a single test in air) and the sensitivity of fracture toughness to hydrogen content. Furthermore the model is used to determine: (i) what are suitable test loading frequencies to obtain conservative data and (ii) the underestimation made when not pre-charging samples. The model can handle both laboratory specimens and large-scale engineering components enabling the Virtual Testing paradigm in infrastructure exposed to hydrogen environments and cyclic loading.

This paper presents work undertaken as part of the Hytunnel-CS project a consortium investigating safety considerations for fuel cell hydrogen (FCH) vehicles in tunnels and similar confined spaces. This test programme investigated erosive effects of an ignited high pressure hydrogen jet impinging onto tunnel structural materials specifically concrete as used for tunnel linings and asphalt road surfacing for the road itself. The chosen test conditions mimicked a high-pressure release (700 bar) from an FCH car as a result of activation of the thermal pressure relief device (TPRD) on the fuel tank. These devices typically have a release opening of 2 mm and thus a nozzle diameter of approximately 2 mm was used. The resultant releases were ignited using a propane pilot light and test samples were placed in the jet path at varying standoff distances from the release nozzle.<br/>An initial characterization test of a free unimpeded ignited jet demonstrated a rapid and intense temperature increase up to 1650 °C lasting in the order of 3 - 5 minutes for that fuel inventory (4 kg hydrogen). Five tests were carried out where the ignited jet was impinged onto five structural samples. It was found that erosion occurred in the concrete samples where no fire mitigation namely addition of polypropylene fibres was applied. The road-surface sample was found to become molten but did not progress to combustion.<br/>Post-test material analysis including compressive strength and thermal conductivity measurements was carried out on some of the concrete samples to investigate whether structural deformities had occurred within the sample microstructure. The results suggested that the erosive damage caused by the hydrogen jet was mostly superficial and as such did not present an increased fire risk to the structural integrity to that of conventional hydrocarbon fires i.e. those that would result from petrol or diesel fuel tank releases. In terms of fire resistance standards it is suggested that current fire mitigation strategies and structural testing standards would be adequate for hydrogen vehicles on the road network.

Nowadays high-pressure hydrogen storage is the most commercially used technology owing to its high hydrogen purity rapid charging/discharging of hydrogen and low-cost manufacturing. Despite numerous reviews on hydrogen storage technologies there is a relative scarcity of comprehensive examinations specifically focused on high-pressure gaseous hydrogen storage and its associated materials. This article systematically presents the manufacturing processes and materials used for a variety of high-pressure hydrogen storage containers including metal cylinders carbon fiber composite cylinders and emerging glass material-based hydrogen storage containers. Furthermore it introduces the relevant principles and theoretical studies showcasing their advantages and disadvantages compared to conventional high-pressure hydrogen storage containers. Finally this article provides an outlook on the future development of high-pressure hydrogen storage containers.

Industry is the biggest sector of energy consumption and greenhouse gas emissions whose decarbonisation is essential to achieve the Sustainable Development Goals. Carbon capture energy efficiency improvement and hydrogen are among the main strategies for industrial decarbonization. However novel approaches are needed to address the key requirements and differences between sectors to ensure they can work together to well integrate industrial decarbonisation with heat CO2 and hydrogen. The emerging Calcium Looping (CaL) is attracting interest in designing CO2-involved chemical processes for heat capture and storage. The reversibility relatively high-temperature (600 to 900 ◦C) and high energy capacity output as well as carbon capture function make CaL well-fit for CO2 capture and utilisation and waste heat recovery from industrial flue gases. Meanwhile methane dry reforming (MDR) is a promising technology to produce blue hydrogen via the consumption of two major greenhouse gases i.e. CO2 and CH4. It has great potential to combine the two technologies to achieve insitu CO2 utilization with multiple benefits. In this paper progresses on the reaction conditions and performance of CaL for CO2 capture and industrial waste heat recovery as well as MDR were screened. Secondly recent approaches to CaL-MDR synergy have been reviewed to identify the advantages. The major challenges in such a synergistic process include MDR catalyst deactivation CaL sorbents sintering and system integration. Thirdly the paper outlooks future work to explore a rational design of a multi-function system for the proposed synergistic process.

As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7) SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to stimulate advancements. Hydrogen has been proposed as a versatile energy carrier to be applied in both pillars of SDG target 7.1: electrification and clean cooking. This paper conducts a semi-systematic literature review to provide the status quo of research on the application of hydrogen in the rationale of SDG 7.1 covering the technical integration pathways as well as the key economic environmental and social aspects of its use. We identify decisive factors for the future development of hydrogen use in the rationale of SDG target 7.1 and by complementing our analysis with insights from the related literature propose future avenues of research. The literature on electrification proposes that hydrogen can serve as a backup power supply in rural off-grid communities. While common electrification efforts aim to supply appliances that use lower amounts of electricity a hydrogen-based power supply can satisfy appliances with higher power demands including electric cook stoves while simultaneously supporting clean cooking efforts. Alternatively with the exclusive aim of stimulating clean cooking hydrogen is proposed to be used as a clean cooking fuel via direct combustion in distribution and utilization infrastructures analogous to Liquid Petroleum Gas (LPG). While expected economic and technical developments are seen as likely to render hydrogen technologies economically competitive with conventional fossil fuels in the future the potential of renewably produced hydrogen usage to reduce climate-change impacts and point-of-use emissions is already evident today. Social benefits are likely when meeting essential safety standards as a hydrogen-based power supply offers service on a high tier that might overachieve SDG 7.1 ambitions while hydrogen cooking via combustion fits into the existing social habits of LPG users. However the literature lacks clear evidence on the social impact of hydrogen usage. Impact assessments of demonstration projects are required to fill this research gap.

Transition to a sustainable energy supply is essential for addressing the challenges of climate change and achieving a low-carbon future. Green hydrogen produced from solar photovoltaic (PV) systems presents a promising solution in Ghana where energy demands are increasing rapidly. The levelized cost of hydrogen (LCOH) is considered a critical metric to evaluate hydrogen production techniques cost competitiveness and economic viability. This study presents a comprehensive analysis of LCOH from solar PV systems. The study considered a 5 MW green hydrogen production plant in Ghana’s capital Accra as a proposed system. The results indicate that the LCOH is about $9.49/kg which is comparable to other findings obtained within the SubSaharan Africa region. The study also forecasted that the LCOH for solar PV-based hydrogen produced will decrease to $5–6.5/kg by 2030 and $2–2.5/kg by 2050 or lower making it competitive with fossil fuel-based hydrogen. The findings of this study highlight the potential of green hydrogen as a sustainable energy solution and its role in driving the country’s net-zero emissions agenda in relation to its energy transition targets. The study’s outcomes are relevant to policymakers researchers investors and energy stakeholders in making informed decisions regarding deploying decentralised green hydrogen technologies in Ghana and similar contexts worldwide.

The aim of this study is to investigate the long-term planning of the Italian power sector from 2021 to 2050. The key role of photovoltaic and wind technologies in combination with power-to-power systems based on hydrogen and batteries is investigated. An updated version of the OSeMOSYS tool is used which employs a clustering method for the representation of time-varying input data. First the potential of variable renewable energy sources (VRES) is assessed. A sensitivity analysis is also performed on the temporal resolution of the model to determine an adequate trade-off between the computation time and the accuracy of the results. Then a technoeconomic optimization scenario is carried out resulting in a total net present cost of about 233.7 B€. A high penetration of VRES technologies is foreseen by 2050 with a total VRES installed capacity of 272.9 GW (mainly photovoltaic and onshore wind). Batteries are found to be the preferable energy storage solution in the first part of the energy transition while the hydrogen storage starts to be convenient from about the year 2040. Indeed the role of hydrogen storage becomes fundamental as the VRES penetration increases thanks to its cost-effective long-term storage capability. By 2050 74.6 % of electricity generation will be based on VRES which will also enable a significant reduction in CO2 emissions of about 87 %.

This paper addresses the problem of the reduction in the huge energy demand of hospitals and health care facilities. The sharp increase in the natural gas price due to the Ukrainian–Russian war has significantly reduced economic savings achieved by combined heat and power (CHP) units especially for hospitals. In this framework this research proposes a novel system based on the integration of a reversible CHP solid oxide fuel cell (SOFC) and a photovoltaic field (PV). The PV power is mainly used for balancing the hospital load. The excess power production is exploited to produce renewable hydrogen. The SOFC operates in electrical tracking mode. The cogenerative heat produced by the SOFC is exploited to partially meet the thermal load of the hospital. The SOFC is driven by the renewable hydrogen produced by the plant. When this hydrogen is not available the SOFC is driven by natural gas. In fact the SOFC is coupled with an external reformer. The simulation model of the whole plant including the reversible SOFC PV and hospital is developed in the TRNSYS18 environment and MATLAB. The model of the hospital is calibrated by means of measured data. The proposed system achieves very interesting results with a primary energy-saving index of 33% and a payback period of 6.7 years. Therefore this energy measure results in a promising solution for reducing the environmental impact of hospital and health care facilities.

The present study comprehensively examines the application of hydro wave tidal undersea current and geothermal energy sources of Canada for green hydrogen fuel production. The estimated potential capacity of each province is derived from official data and acceptable assumptions and is subject to discussion and evaluation in the context of a viable hydrogen economy. According to the findings the potential for green hydrogen generation in Canada is projected to be 48.86 megatons. The economic value of the produced green hydrogen results in an equivalent of 21.30 billion US$. The top three provinces with the highest green hydrogen production potential using hydro resources including hydro wave tidal undersea current and geothermal are Alberta Quebec and British Columbia with 26.13 Mt 7.34 Mt and 4.39 Mt respectively. Quebec is ranked first by only considering the marine sources including 4.14 Mt with hydro 1.46 Mt with wave 0.27 Mt underwater current and 1.45 Mt with tidal respectively. Alberta is listed as the province with the highest capacity for hydrogen production from geothermal energy amounting up to 26.09 Mt. The primary objective is to provide comprehensive hydrogen maps for each province in Canada which will be based on the identified renewable energy potential and the utilization of electrolysers. This may further be examined within the framework of the prevailing policies implemented by local communities and officials in order to develop a sustainable energy plan for the nation.

This work is part of the MULTHYFUEL E.U. research program [1] aiming at enabling the implementation of hydrogen dispersers in refuelling stations. One important challenge is the severity of accidents due to a leakage of hydrogen from a dispenser in the forecourt. The work presented in this paper deals with the quantification of the leakage scenarios in terms of frequencies and severities. The risk analysis exercise although performed by experts showed very large discrepancies between the frequencies of leakages of the same categories and even between the consequences. A large part of the disagreement comes from the failure databases chosen as shown in the paper. The mismatch between the components on which the databases have been settled and the actual hydrogen components may be responsible for this situation. However as it stands limited confidence can be laid on the outcome of the risk analysis.<br/>A new method is being developed to calculate the frequencies of the leakage and the flowrate based on an accurate description of each component and of each hazardous situation. For instance the possibility for a fitting to become untight due to pressure cycling is modelled based on the contact mechanics. Human errors can also be introduced by describing the tasks. In addition of the description of the method the application to a disperser is proposed with some comparison to experiments. One of the outcomes is that leakage cross sections can be much larger than expected.

Low-carbon ammonia has recently received interest as alternative fuel for the maritime sector. This paper presents a techno-economic analysis of the total cost of ownership (TCO) of a Post-Panamax vessel powered by low-carbon ammonia. We also calculate the annual increase in carbon tax needed to compensate for the increment in TCO compared to a vessel powered by very low sulfur fuel oil. The increment in TCO is calculated as function of propulsion efficiency to account for uncertainties in the thermodynamics of ammonia combustion for three different cost scenarios of low-carbon ammonia. We evaluate the benefits and drawbacks of hydrogen and diesel as dual fuel for three types of propulsion systems: a compression ignition engine a spark-ignition engine and a combination of a solid oxide fuel cell (SOFC) system and a spark-ignition engine. We incorporate three different cost levels for ammonia and a variable engine efficiency ranging from 35% to 55%. If the ammonia engine has the efficiency of a conventional marine engine the increment in TCO is 25% in the most optimistic cost scenario. SOFCs can reach a better efficiency and yield no pollutant emissions but the reduction in fuel expenses in comparison to conventional combustion engines only offsets their high investment costs at either low engine efficiency or high fuel prices. The increment in TCO and reduction in GHG emissions depend on whether high combustion efficiencies small dual fuel fractions and low NOx N2O and NH3 emissions can be simultaneously achieved.

In light of growing concerns regarding greenhouse gas emissions and the increasingly severe impacts of climate change the global situation demands immediate action to transition towards sustainable energy solutions. In this sense hydrogen could play a fundamental role in the energy transition offering a potential clean and versatile energy carrier. This paper reviews the recent results of Life Cycle Assessment studies of different hydrogen production pathways which are trying to define the routes that can guarantee the least environmental burdens. Steam methane reforming was considered as the benchmark for Global Warming Potential with an average emission of 11 kgCO2eq/kgH2. Hydrogen produced from water electrolysis powered by renewable energy (green H2 ) or nuclear energy (pink H2 ) showed the average lowest impacts with mean values of 2.02 kgCO2eq/kgH2 and 0.41 kgCO2eq/kgH2 respectively. The use of grid electricity to power the electrolyzer (yellow H2 ) raised the mean carbon footprint up to 17.2 kgCO2eq/kgH2 with a peak of 41.4 kgCO2eq/kgH2 in the case of countries with low renewable energy production. Waste pyrolysis and/or gasification presented average emissions three times higher than steam methane reforming while the recourse to residual biomass and biowaste significantly lowered greenhouse gas emissions. The acidification potential presents comparable results for all the technologies studied except for biomass gasification which showed significantly higher and more scattered values. Regarding the abiotic depletion potential (mineral) the main issue is the lack of an established recycling strategy especially for electrolysis technologies that hamper the inclusion of the End of Life stage in LCA computation. Whenever data were available hotspots for each hydrogen production process were identified.

Energy transition is a key driver to combat climate change and achieve zero carbon future. Sustainable and costeffective hydrogen production will provide valuable addition to the renewable energy mix and help minimize greenhouse gas emissions. This study investigates the performance of in-situ hydrogen production (IHP) process using a full-field compositional model as a precursor to experimental validation The reservoir model was simulated as one geological unit with a single point uniform porosity value of 0.13 and a five-point connection type between cell to minimize computational cost. Twenty-one hydrogen forming reactions were modelled based on the reservoir fluid composition selected for this study. The thermodynamic and kinetic parameters for the reactions were obtained from published experiments due to the absence of experimental data specific to the reservoir. A total of fifty-four simulation runs were conducted using CMG STARS software for 5478 days and cumulative hydrogen produced for each run was recorded. Results generated were then used to build a proxy model using Box-Behnken design of experiment method and Support Vector Machine with RBF kernel. To ascertain accuracy of the proxy models analysis of variance (ANOVA) was conducted on the variables. The average absolute percentage error between the proxy model and numerical simulation was calculated to be 10.82%. Optimization of the proxy model was performed using genetic algorithm to maximize cumulative hydrogen produced. Based on this optimized model the influence of porosity permeability well location injection rate and injection pressure were studied. Key results from this study reveals that lower permeability and porosity reservoirs supports more hydrogen yield injection pressure had a negligible effect on hydrogen yield and increase in oxygen injection rate corelated strongly with hydrogen production until a threshold value beyond which hydrogen yield decreased. The framework developed in the study could be used as tool to assess candidate reservoirs for in-situ hydrogen production.

This article summarizes current research on the life cycle assessment (LCA) of fuel cell electric vehicles (FCEVs) in road transport. Increasing greenhouse gas emissions and climate change are pushing the transport sector to intensify efforts toward decarbonization. One promising solution is the adoption of hydrogen technologies whose development is supported by European Union regulations such as the “Fit for 55” package. FCEVs are characterized by zero emissions during operation but their environmental impact largely depends on the methods of hydrogen production. The use of renewable energy sources in hydrogen production can significantly reduce greenhouse gas emissions while hydrogen produced from fossil fuels can even result in higher emissions compared to internal combustion engine vehicles. This article also discusses the importance of hydrogen refueling infrastructure and the efficiency of fuel storage and transportation systems. In conclusion LCA shows that FCEVs can support the achievement of climate goals provided that the development of hydrogen production technologies based on renewable sources and the corresponding infrastructure is ensured. The authors also highlight the potential of hybrid technologies as a transitional solution in the process of transforming the transport sector.

Hydrogen has emerged as a key element in the transition to a sustainable energy model. Among hydrogen storage and transport technologies liquid organic hydrogen carriers (LOHCs) stand out as a promising alternative for large-scale long-term use. Catalysts essential in these systems are usually composed of platinum group metals (PGMs) over alumina known for their high cost and scarcity. This study analyzes the overall environmental impact of the LOHC benzyltoluene/perhydro-benzyltoluene-based hydrogen supply chain by means of the life cycle assessment (LCA) focusing on the synthesis processes of novel low-PGM catalysts which remain under explored in existing literature. The results identify dehydrogenation as the most impactful step due to significant heat consumption and highlight the substantial environmental footprint associated with the use of platinum in catalyst production. This research provides crucial insights into the environmental implications of LOHC systems particularly the role of novel low-PGM catalysts and offers guidance for their future large-scale applications.

Clean hydrogen is touted as a cornerstone of the global energy transition. It can help to decarbonize hard-to-electrify sectors ship renewable power over great distances and boost energy security. Clean hydrogen’s appeal is increasingly felt in the Global South where countries seek to benefit from production export and consumption opportunities new infrastructures and technological innovations. These geographies are however in the process of taking shape and their associated power configurations spatialities and socio-ecological consequences are yet to be more thoroughly understood and examined. Drawing on political geography perspectives this article proposes the concept of “hydrogen landscape” – or in short H2-scape – to theorize and explore hydrogen transitions as space-making processes imbued with power relations institutional orders and social meanings. In this endeavor it outlines a conceptual framework for understanding the making of H2-scapes and offers three concrete directions for advancing empirical research on hydrogen transitions in the Global South: (1) H2-scapes as resource frontiers; (2) H2-scapes as port-centered arrangements; and (3) H2-scapes as failure. As hydrogen booms in finances projects and visibility the article illuminates conceptual tools and perspectives to think about and facilitate further research on the emergent political geographies of hydrogen transitions particularly in more uneven unequal and vulnerable Global South landscapes.

Low temperature water electrolysers such as Proton Exchange Membrane Water Electrolysers (PEMWEs) Alkaline Water Electrolysers (AWEs) and Anion Exchange Membrane Water Electrolysers (AEMWEs) are known to be sensitive to water quality with a range of common impurities impacting performance hydrogen quality and device lifetime. Purification of feed water adds to cost operational complexity and design limitations while failure of purification equipment can lead to degradation of electrolyser materials and components. Increased robustness to impurities will offer a route to longer device lifetimes and reduced operating costs but understanding of the impact of impurities and associated degradation mechanisms is currently limited. This critical review offers for the first time a comprehensive overview of relevant impurities in operating electrolysers and their impact. Impurity sources degradation mechanisms characterisation techniques water purification technologies and mitigation strategies are identified and discussed. The review generalises already reported mechanisms proposes new mechanisms and provides a framework for consideration of operational implications.