Publications

As an important piece of equipment for hydrogen energy application the hydrogen internal combustion engine is helpful for the realization of zero carbon emissions where the aluminum connecting rod is one of the key core components. A semi-solid forging forming process for the 7075 aluminum alloy connecting rod is proposed in this work. The influence of process parameters such as the forging ratio sustaining temperature and duration time on the microstructures of the semi-solid blank is experimentally investigated. The macroscopic morphology metallographic structure and physical properties of the connecting-rod parts are analyzed. Reasonable process parameters for preparing the semi-solid blank are obtained from the experimental results. Under the reasonable parameters the average grain size is 41.48~42.57 µm and the average shape factor is 0.80~0.81. The yield strength and tensile strength improvement ratio of the connecting rod produced by the proposed process are 47.07% and 20.89% respectively.

Green hydrogen promises to be critical in achieving a sustainable and renewable energy transition. As green hydrogen is produced with renewables green hydrogen could become an energy storage medium of the future and even substitute the current unsustainable grey or blue hydrogen used in the industry. Bringing this transition into reality for instance in Germany there are visions to rapidly build hydrogen facilities in Africa and export the produced green hydrogen to Europe. One problem however is that these visions presumably conflict with the visions of actors within Africa. Therefore this study aims to provide an initial assessment of African stakeholders’ visions for future energy exports and renewable energy expectations. By comparing visions from Germany and Africa this assessment was conducted to identify differences in green energy and hydrogen visions that could lead to conflict and similarities that could be the basis for cooperation. The National Hydrogen Strategy outlines the German visions which clarifies that Germany will have to import green hydrogen to meet its green transition target. In this context of future energy export demand a partnership between German and African researchers on assessing green hydrogen potentials in Africa started. The African visions were explored by surveying the partners from different African countries working on the project. The results revealed that while both sides see the need for an immediate transition to renewable energy the African side is not envisioning the immediate export of green hydrogen. Based on the responses the partners are primarily concerned with improving the continent’s still deficient energy access for both the population and industry. Nevertheless this African perspective greatly emphasises cross-border cooperation where both sides can realise their visions. In the case of Germany that German investment could build infrastructure which would benefit the receiving African country or countries and open up the possibility for the envisioned green hydrogen export to Europe.

Chile abundant in solar and wind energy resources presents significant potential for the production of green hydrogen a promising renewable energy vector. However realizing this potential requires an understanding of the most suitable locations for the installation of green hydrogen industries. This study proposes a quantitative methodology that identifies and ranks potential public lands for industrial use based on a range of technical parameters (such as solar and wind availability) and socio-environmental considerations (including land use restrictions and population density). The results reveal optimal locations that can facilitate informed sustainable decision-making for large-scale green hydrogen implementation in Chile. While this methodology does not replace project-specific technical or environmental impact studies it provides a flexible general classification to guide initial site selection. Notably this approach can be applied to other regions worldwide with abundant solar and wind resources such as Australia and Northern Africa promoting more effective and sustainable global decision-making for green hydrogen production.

Canada’s commitment to be net-zero by 2050 combined with ATCO’s own Environmental Social and Governance goals has led ATCO to pursue hydrogen blending within the existing natural gas system to reduce CO2 emissions while continuing to provide safe reliable energy service to customers. Utilization of hydrogen in the distribution system is the least-cost alternative for decarbonizing the heating loads in jurisdictions like Alberta where harsh winter climates are encountered and low-carbon hydrogen production can be abundant. ATCO’s own Fort Saskatchewan Hydrogen Blending Project began blending 5% hydrogen by volume to over 2100 customers in the Fall of 2022 and plans to increase the blend rates to 20% hydrogen in 2023. Prior to blending ATCO worked together with DNV to examine the impact of hydrogen blended natural gas to twelve Canadian appliances: range/stove oven garage heater high and medium efficiency furnaces conventional and on demand hot water heaters barbeque clothes dryer radiant heater and two gas fireplaces. The tests were performed not only within the planned blend rates of 0-20% hydrogen but also to higher percentages to determine how much hydrogen can be blended into a system before appliance retrofits would be required. The testing was designed to get insights on safety-related combustion issues such as flash-back burner overheating flame detection and other performance parameters such as emissions and burner power. The experimental results indicate that the radiant heater is the most sensitive appliance for flashback observed at 30 vol% hydrogen in natural gas. At 50% hydrogen the range and the radiant burner of the barbeque tested were found to be sensitive to flashback. All other 9 appliances were found to be robust for flashback with no other short-term issues observed. This paper will detail the findings of ATCO and DNV’s appliance testing program including results on failure mechanisms and sensitivities for each appliance.

This comprehensive review explores the transformative role of nanomaterials in advancing the frontier of hydrogen energy specifcally in the realms of storage production and transport. Focusing on key nanomaterials like metallic nanoparticles metal–organic frameworks carbon nanotubes and graphene the article delves into their unique properties. It scrutinizes the application of nanomaterials in hydrogen storage elucidating both challenges and advantages. The review meticulously evaluates diverse strategies employed to overcome limitations in traditional storage methods and highlights recent breakthroughs in nanomaterial-centric hydrogen storage. Additionally the article investigates the utilization of nanomaterials to enhance hydrogen production emphasizing their role as efcient nanocatalysts in boosting hydrogen fuel cell efciency. It provides a comprehensive overview of various nanocatalysts and their potential applications in fuel cells. The exploration extends to the realm of hydrogen transport and delivery specifcally in storage tanks and pipelines ofering insights into the nanomaterials investigated for this purpose and recent advancements in the feld. In conclusion the review underscores the immense potential of nanomaterials in propelling the hydrogen energy frontier. It emphasizes the imperative for continued research aimed at optimizing the properties and performance of existing nanomaterials while advocating for the development of novel nanomaterials with superior attributes for hydrogen storage production and transport. This article serves as a roadmap shedding light on the pivotal role nanomaterials can play in advancing the development of clean and sustainable hydrogen energy technologies.

The role of hydrogen as a clean energy source is a promising but also a contentious issue. The global energy production is currently characterized by an unprecedented shift to renewable energy sources (RES) and their technologies. However the local and environmental benefits of such RES-based technologies show a wide variety of technological maturity with a common mismatch to local RES stocks and actual utilization levels of RES exploitation. In this literature review the collected documents taken from the Scopus database using relevant keywords have been organized in homogeneous clusters and are accompanied by the registration of the relevant studies in the form of one figure and one table. In the second part of this review selected representations of typical hydrogen energy system (HES) installations in realistic in-field applications have been developed. Finally the main concerns challenges and future prospects of HES against a multi-parametric level of contributing determinants have been critically approached and creatively discussed. In addition key aspects and considerations of the HES-RES convergence are concluded.

This report aims to summarise the status of the European hydrogen policies and standards landscape. It is based on the information available at the European Hydrogen Observatory (EHO) platform the leading source of data and information on hydrogen in Europe (EU27 EFTA and the UK) providing an overview of the European and national policies legislations strategies and codes and standards which impact the deployment of hydrogen technologies and infrastructures. The EHO database covers a total of 29 EU policies and legislations that directly or indirectly affect the development and deployment of hydrogen technologies. To achieve its net zero ambitions the EU started with cross-cutting strategies such as the EU Green Deal and the EU Hydrogen Strategy setting forward roadmaps and targets that are to be achieved in the near future. As a next step the EU has developed legislations such as those bundled in the Fit for 55 package to meet the targets they have put forward. The implemented legislations including funding vehicles and initiatives have an impact on the whole value chain of hydrogen including production transport storage and distribution and end-uses. At national level as of July 2023 63% of the European countries have successfully published their national strategies in the hydrogen sector while 6% of the countries are currently in the draft stage. Several European countries have strategically incorporated quantitative indicators within their national strategies outlining their targets and estimates across the hydrogen value chain. This deliberate approach reflects a commitment to providing clear and measurable goals within their hydrogen strategies. A target often used in the national strategies is on electrolyser capacity as an effort to enhance the domestic renewable hydrogen production. Germany took the lead with an ambitious goal of achieving 10 GW by 2030 followed by France (6.5 GW) and Denmark (4 - 6 GW). Other targets that some of the countries use in their strategies are on the number of hydrogen refuelling stations fuel cell electric vehicles and total (renewable) hydrogen demand. A few countries also have targets on renewable hydrogen uptake in industry and hydrogen injection limit in the transmission grid. To monitor the policies and legislation that are adopted on a national level across the hydrogen value chain a survey was launched with national experts which was validated by Hydrogen Europe. In total 28 European countries have participated to the survey. On production the survey revealed that 61% of country specialists report that their country provides support for capital expenditure (CAPEX) in the development of renewable or low-carbon hydrogen production plants. Moreover 7 countries also provide support for operational expenditure (OPEX). Furthermore 8 countries have instituted official 6 permitting guidelines for hydrogen production projects while 5 countries have enacted a legal act or established an agency serving as a single point of contact for hydrogen project developers. For transmission only two countries reported to provide support schemes for hydrogen injection. Several countries have policies in place that clearly define the hydrogen limit in their transmission grid for now and in the future ranging from 0.02% up to 15% while a few countries define within their policies the operation of hydrogen storage facilities. On end-use the majority of countries totalling 71% reported to have implemented support schemes aimed at promoting the adoption of hydrogen in the mobility sector. Purchase subsidies stand out as the predominant form of support for fuel cell electric vehicles (FCEVs) with implementation observed in 17 countries. In the context of support schemes for stationary fuel applications for heating or power generation only two countries have adopted such measures. A slightly larger group of four countries do provide support for the deployment of residential and commercial heating systems utilizing hydrogen. For hydrogen end-use in industry a total of 9 countries reported to provide support schemes with a major focus on ammonia production (8) and the chemicals industry (7). On the topic of technology manufacturing 7 countries have reported to have support schemes of which grants emerge as the mainly used method (4). Exploring the latest advancements into European codes and standards relevant to the deployment of hydrogen technologies and infrastructures a total of 11 standards have been revised and developed between January 2022 and September 2023. This includes standards covering the following areas: 6 for fuel cell technologies 2 for gas cylinders 2 for road vehicles and 1 for hydrogen refuelling. Moreover 5 standards were published since September 2023 which will be added to the EHO database in its next update. This includes ISO/TS 19870:2023 which sets a methodology for determining the greenhouse gas emissions associated with the production conditioning and transport of hydrogen to consumption gate. This landmark standard which was unveiled at COP28 aims to act as a foundation for harmonization safety interoperability and sustainability across the hydrogen value chain.

A global energy shift to a carbon‐neutral society requires clean energy. Hydrogen can accelerate the process of expanding clean and renewable energy sources. However conventional hydrogen compression and storage technology still suffers from inefficiencies high costs and safety concerns. An electrochemical hydrogen compressor (EHC) is a device similar in structure to a water electrolyzer. Its most significant advantage is that it can accomplish hydrogen separation and compression at the same time. With no mechanical motion and low energy consumption the EHC is the key to future hydrogen compression and purification technology breakthroughs. In this study the compression performance efficiency and other related parameters of EHC are investigated through experiments and simulation calculations. The experimental results show that under the same experimental conditions increasing the supply voltage and the pressure in the anode chamber can improve the reaction rate of EHC and balance the pressure difference between the cathode and anode. The presence of residual air in the anode can impede the interaction between hydrogen and the catalyst as well as the proton exchange membrane (PEM) resulting in a decrease in performance. In addition it was found that a single EHC has a better compression ratio and reaction rate than a double EHC. The experimental results were compatible with the theoretical calculations within less than a 7% deviation. Finally the conditions required to reach commercialization were evaluated using the theoretical model.

The depletion of fossil fuel reserves has resulted from their application in the industrial and energy sectors. As a result substantial efforts have been dedicated to fostering the shift from fossil fuels to renewable energy sources via technological advancements in industrial processes. Microalgae can be used to produce biofuels such as biodiesel hydrogen and bioethanol. Microalgae are particularly suitable for hydrogen production due to their rapid growth rate ability to thrive in diverse habitats ability to resolve conflicts between fuel and food pro duction and capacity to capture and utilize atmospheric carbon dioxide. Therefore microalgae-based bio hydrogen production has attracted significant attention as a clean and sustainable fuel to achieve carbon neutrality and sustainability in nature. To this end the review paper emphasizes recent information related to microalgae-based biohydrogen production mechanisms of sustainable hydrogen production factors affecting biohydrogen production by microalgae bioreactor design and hydrogen production advanced strategies to improve efficiency of biohydrogen production by microalgae along with bottlenecks and perspectives to over come the challenges. This review aims to collate advances and new knowledge emerged in recent years for microalgae-based biohydrogen production and promote the adoption of biohydrogen as an alternative to con ventional hydrocarbon biofuels thereby expediting the carbon neutrality target that is most advantageous to the environment.

Proton-Exchange Membrane-Fuel Cells (PEM-FC) are regarded as one of the prime candidates to provide emissions-free electricity for propulsion systems of aircraft. Here a turbocharged Fuel Cell Power System (FCPS) powered with liquid H2 (LH2) is designed and modelled to provide a primary power source in retrofitted Cessna 208 Caravan aircraft. The proposed FCPS comprises multiple PEM-FCs assembled in stacks two single-stage turbochargers to mitigate the variation of the ambient pressure with altitude two preheaters two humidifiers and two combustors. Interlinked component sub-models are constructed in MATLAB and referenced to commercially available equipment. The FCPS model is used to simulate steady-state responses in a proposed 1.5 h (∼350 km) mission flight determining the overall efficiency of the FCPS at 43% and hydrogen consumption of ∼28 kg/h. The multi-stack FCPS is modelled applying parallel fluidic and electrical architectures analysing two power-sharing methods: equally distributed and daisy-chaining. The designed LH2-FCPS is then proposed as a power system to a retrofitted Cessna 208 Caravan and with this example analysed for the probability of failure occurrence. The results demonstrate that the proposed “dual redundant” FCPS can reach failure rates comparable to commercial jet engines with a rate below 1.6 failures per million hours.

Hydrogen and electricity derived from renewable sources present feasible alternative energy options for the decarbonisation of the transportation and power sectors. This study presents the utilisation of hydrogen generated from solar and wind energy resources as a clean fuel for mobility and backup storage for stationary applications under economic and environmental uncertainties. This is achieved by developing a detailed technoeconomic model of an integrated system consisting of a hydrogen refuelling station and an electric power generation system using Mixed Integer Quadratic Constrained Programming (MIQCP) which is further relaxed to Mixed Integer Linear Programming (MILP). The model is implemented in the Advanced Interactive Multidi mensional Modelling Software (AIMMS) and considering the inherent uncertainties in the wind resource solar resource costs and discount rate the total cost of the three configurations (Hybrid PV-Wind Standalone PV and Standalone wind energy system) was minimised using robust optimisation technique and the corresponding optimal sizes of the components levelised cost of energy (LCOE) excess energy greenhouse emission avoided and carbon tax were evaluated. The levelised cost of the deterministic optimisation solution for all the config uration ranges between 0.0702 $/kWh to 0.0786 $/kWh while the levelised cost of the robust optimisation solution ranges between 0.07188 $/kWh to 0.1125 $/kWh. The proposed integration has the advantages of affordable hydrogen and electricity prices minimisation of carbon emissions and grid export of excess energy.

Apart from many limitations the usage of hydrogen in different day-to-day applications have been increasing drastically in recent years. However numerous techniques available to produce hydrogen electrolysis of water is one of the simplest and cost-effective hydrogen production techniques. In this method water is split into hydrogen and oxygen by using external electric current. In this research a novel hydrogen production system incorporated with Photovoltaic – Thermal (PVT) solar collector is developed. The influence of different parameters like solar collector tilt angle thermal collector design and type of heat transfer fluid on the performance of PVT system and hydrogen production system are also discussed. Finally thermal efficiency electrical efficiency and hydrogen production rate have been predicted by using the Adaptive Neuro-Fuzzy Inference System (ANFIS) technique. Based on this study results it can be inferred that the solar collector tilt angle plays a significant role to improve the performance of the electrical and thermal performance of PVT solar system and Hydrogen yield rate. On the other side the spiral-shaped thermal collector with water exhibited better end result than the other hydrogen production systems. The predicted results ANFIS techniques represent an excellent agreement with the experimental results. In consequence it is suggested that the developed ANFIS model can be adopted for further studies to predict the performance of the hydrogen production system.

Future Energy Scenarios (FES) represent a range of different credible ways to decarbonise our energy system as we strive towards the 2050 target.<br/>We’re less than 30 years away from the Net Zero deadline which isn’t long when you consider investment cycles for gas networks electricity transmission lines and domestic heating systems.<br/>FES has an important role to play in stimulating debate and helping to shape the energy system of the future.

The present paper reports a techno-economic analysis of two solar assisted hydrogen production technologies: a photoelectrochemical (PEC) system and its major competitor a photovoltaic system connected to a conventional water electrolyzer (PV-E system). A comparison between these two types was performed to identify the more promising technology based on the levelized cost of hydrogen (LCOH). The technical evaluation was carried out by considering proven designs and materials for the PV-E system and a conceptually design for the PEC system extrapolated to future commercial scale. The LCOH for the off-grid PV-E system was found to be 6.22 $/kgH2 with a solar to hydrogen efficiency of 10.9%. For the PEC system with a similar efficiency of 10% the LCOH was calculated to be much higher namely 8.43 $/kgH2. A sensitivity analysis reveals a great uncertainty in the LCOH of the prospective PEC system. This implies that much effort would be needed for this technology to become competitive on the market. Therefore we conclude that the potential techno-economic benefits that PEC systems offer over PV-E are uncertain and even in the best case limited. While research into photoelectrochemical cells remains of interest it presents a poor case for dedicated investment in the technology’s development and scale-up.

Hydrogen–gasoline hybrid refueling stations can minimize construction and management costs and save land resources and are gradually becoming one of the primary modes for hydrogen refueling stations. However catastrophic consequences may be caused as both hydrogen and gasoline are flammable and explosive. It is crucial to perform an effective risk assessment to prevent fire and explosion accidents at hybrid refueling stations. This study conducted a risk assessment of the refueling area of a hydrogen–gasoline hybrid refueling station based on the improved Accident Risk Assessment Method for Industrial Systems (ARAMIS). An improved probabilistic failure model was used to make ARAMIS more applicable to hydrogen infrastructure. Additionally the accident consequences i.e. jet fires and explosions were simulated using Computational Fluid Dynamics (CFD) methods replacing the traditional empirical model. The results showed that the risk levels at the station house and the road near the refueling area were 5.80 × 10−5 and 3.37 × 10−4 respectively and both were within the acceptable range. Furthermore the hydrogen dispenser leaked and caused a jet fire and the flame ignited the exposed gasoline causing a secondary accident considered the most hazardous accident scenario. A case study was conducted to demonstrate the practicability of the methodology. This method is believed to provide trustworthy decisions for establishing safe distances from dispensers and optimizing the arrangement of the refueling area.

This report aims to summarise the status of the European hydrogen market landscape. It is based on the information available at the European Hydrogen Observatory (EHO) platform the leading source of data and information on hydrogen in Europe (EU27 EFTA and the UK) providing a full overview of the hydrogen market and the deployment of clean hydrogen technologies. As of the end of 2022 a total of 476 operational hydrogen production facilities across Europe boasting a cumulative hydrogen production capacity of approximately 11.30 Mt were identified. Notably the largest share of this capacity is contributed by key European countries including Germany the Netherlands Poland Italy and France which collectively account for 56% of the total hydrogen capacity. The hydrogen consumption in Europe has been estimated at approximately 8.23 Mt reflecting an average capacity utilisation rate of 73%. It's worth highlighting that conventional hydrogen production methods encompassing reforming by-product production from ethylene and styrene and by-product electrolysis collectively yield 11.28 Mt of hydrogen capacity. These conventional processes are distributed across 376 production facilities constituting 99.9% of the total production capacity in 2022. Throughout the year 2022 there were no newly commissioned hydrogen production facilities that integrated carbon capture technology into their operations. Additionally a notable presence of water electrolysis-based hydrogen production projects in Europe was identified. There was a total of 97 water electrolysis projects with 67 of them having a minimum capacity of 0.5 MW resulting in a cumulative production capacity of 174.28 MW. Furthermore 46 such projects were found to be under construction and are anticipated to contribute an additional 1199.07 MW of water electrolysis capacity upon becoming operational with the estimated timeframe ranging from January 2023 to 2025. A significant 87% of the total hydrogen production capacity in Europe is dedicated to onsite captive consumption indicating that it is primarily produced and used within the facility. The remaining 13% of capacity is specifically allocated for external distribution and sale characterizing what's known as merchant consumption. Despite the prevailing dominance of captive hydrogen production within Europe it's noteworthy that thousands of metric tonnes of hydrogen are already being traded and distributed across the continent. These transfers often occur through dedicated hydrogen pipelines or transportation via trucks. In 2022 an example of this growing trend was the hydrogen export from Belgium to the Netherlands which emerged as the single most significant hydrogen flow between European countries constituting a substantial 75% of all hydrogen traded in Europe. Belgium earned distinction as Europe's leading hydrogen exporter with 78% of the hydrogen that flowed between European countries originating 6 from its facilities. Conversely the Netherlands played a pivotal role as Europe's primary hydrogen importer accounting for an impressive 76% of the hydrogen imported into the continent. The rise of the clean hydrogen market in Europe coupled with the European Union's ambition to import 10 Mt of renewable hydrogen from non-EU sources by 2030 is expected to drive an increase in hydrogen flows both exports and imports among European countries. In 2022 the total demand for hydrogen in Europe was estimated to be 8.19 Mt. The biggest share of hydrogen demand comes from refineries which were responsible for 57% of total hydrogen use (4.6 Mt) followed by the ammonia industry with 24% (2.0 Mt). Together these two sectors consumed 81% of the total hydrogen consumption in Europe. Clean hydrogen demand while currently making up less than 0.1% of the overall hydrogen demand is notably driven by the mobility sector. Forecasts project an impressive growth trajectory in total hydrogen demand for Europe over the coming decades. Projections show a remarkable 127% surge from 2030 to 2040 followed by a substantial 63% increase from 2040 to 2050. Considering the current hydrogen demand there is a projected 51% increase until 2030. Throughout the three decades under examination the industrial sector is anticipated to maintain its predominant position consistently demonstrating the highest demand for hydrogen. However this conclusion refers to average values and variations that may exist. The total number of Hydrogen Fuel Cell Electric Vehicles (FCEV) registrations in Europe in 2022 was estimated at 1537 units. In comparison to the previous year the number of registrations increased by 31%. This surge in registrations has had a pronounced impact on the overall FCEV fleet's evolution in Europe which increased from 4050 units to 5570 (+38%). Notably passenger cars dominated the landscape constituting 86% of the total FCEV fleet. Exploring the latest advancements in hydrogen infrastructure across Europe in 2022 the hydrogen distribution network comprised spanning a total length of 1569 km. Within Europe the largest networks are situated in Belgium and Germany at 600 km and 400 km respectively. Of particular importance is the cross-border network of France Belgium and the Netherlands spanning a total of 964 km. To keep pace with the rising number of Fuel Cell Electric Vehicles (FCEVs) on European roads and promote their wider integration it is key to ensure sufficient accessibility to refuelling infrastructure. Consequently many countries are endorsing the establishment of hydrogen refuelling stations (HRS) so that they are publicly accessible on a nationwide scale. More recharging and refuelling stations for alternative fuels will be deployed in the coming years across Europe enabling the transport sector to significantly reduce its carbon footprint following the adoption of the alternative fuel infrastructure regulation (AFIR). Part of the regulation's main target is that hydrogen refuelling stations serving both cars and lorries must be deployed from 7 2030 onwards in all urban nodes and every 200 km along the TEN-T core network. Since 2015 the total number of operational and publicly accessible HRS in Europe has grown at an accelerated pace from 38 to 178 by the summer of 2023. Germany takes the lead having the largest share at approximately 54% of the total number of HRS with 96 stations currently operational. The majority of the HRS (89%) are equipped with 700 bar car dispensers. In 2022 the levelized production costs of hydrogen generated through Steam Methane Reforming (SMR) in Europe averaged approximately 6.23 €/kg H2. When incorporating a carbon capture system the average cost of hydrogen production via SMR in Europe increased to 6.38 €/kg H2. Additionally the production costs of hydrogen in Europe for 2022 utilizing grid electricity averaged 9.85 €/kg H2. Hydrogen production costs through electrolysis with a direct connection to a renewable energy source had an average estimated cost of 6.86 €/kg. As of May 2023 Europe's operational water electrolyser manufacturing capacity stands at 3.11 GW/year with an additional 2.64 GW planned by the end of 2023. Alkaline technologies make up 53% of the total capacity. Looking ahead to 2025 ongoing projects are expected to raise the total capacity to 7.65 GW/year. Fuel cell deployment in Europe has showed an increasing trend over the past decade. The total number of shipped fuel cells were forecasted on around 11200 units in 2021 and a total capacity of 190 MW. The most significant increase in capacity occurred between 2018 and the forecast of 2021 (+148.8 MW).

Renewable energy technologies and resources particularly solar photovoltaic systems provide cost-effective and environmentally friendly solutions for meeting the demand for electricity. The design of such systems is a critical task as it has a significant impact on the overall cost of the system. In this paper a mixed-integer linear programming-based model is proposed for designing an integrated photovoltaic-hydrogen renewable energy system to minimize total life costs for one of Saudi Arabia’s most important fields a greenhouse farm. The aim of the proposed system is to determine the number of photovoltaic (PV) modules the amount of hydrogen accumulated over time and the number of hydrogen tanks. In addition binary decision variables are used to describe either-or decisions on hydrogen tank charging and discharging. To solve the developed model an exact approach embedded in the general algebraic modeling System (GAMS) software was utilized. The model was validated using a farm consisting of 20 greenhouses a worker-housing area and a water desalination station with hourly energy demand. The findings revealed that 1094 PV panels and 1554 hydrogen storage tanks are required to meet the farm’s load demand. In addition the results indicated that the annual energy cost is $228234 with a levelized cost of energy (LCOE) of 0.12 $/kWh. On the other hand the proposed model reduced the carbon dioxide emissions to 882 tons per year. These findings demonstrated the viability of integrating an electrolyzer fuel cell and hydrogen tank storage with a renewable energy system; nevertheless the cost of energy produced remains high due to the high capital cost. Moreover the findings indicated that hydrogen technology can be used as an energy storage solution when the production of renewable energy systems is variable as well as in other applications such as the industrial residential and transportation sectors. Furthermore the results revealed the feasibility of employing renewable energy as a source of energy for agricultural operations.

This paper proposes an energy management strategy for a fuel cell (FC) hybrid power system based on dynamic programming and state machine strategy which takes into account the durability of the FC and the hydrogen consumption of the system. The strategy first uses the principle of dynamic programming to solve the optimal power distribution between the FC and supercapacitor (SC) and then uses the optimization results of dynamic programming to update the threshold values in each state of the finite state machine to realize real-time management of the output power of the FC and SC. An FC/SC hybrid tramway simulation platform is established based on RTLAB real-time simulator. The compared results verify that the proposed EMS can improve the durability of the FC increase its working time in the high-efficiency range effectively reduce the hydrogen consumption and keep the state of charge in an ideal range.

This paper explores the opportunities for and progress in establishing a social licence to operate (SLO) for CCS in industrial clusters in the UK focusing on the perspectives of key stakeholders. The evolution of narratives and networks relating to geographical clusters as niches for CCS in industrial decarbonisation is evaluated in relation to seven pillars supporting SLO. Evidence is drawn from a combination of cluster mapping documentary analysis and stakeholder interviews to identify the wider contexts underpinning industrial decarbonisation stakeholder networks interaction and communication critical narratives the conditions for establishing trust and confidence different scales of social licence and maintaining a SLO. The delivery of a sustainable industrial decarbonisation strategy will depend on multiple layers of social licence involving discourses at different scales and potentially for different systems (heat transport different industrial processes). Despite setbacks as a result of funding cancellations and changes to government policy the UK is positioned to be at the forefront of CCS deployment. While there is a high ambition and a strong narrative from government of the urgency to accelerate projects involving CCS clear coordinated strategy and funding frameworks are necessary to build confidence that UK policy is both compatible with net zero and economically viable.

To contribute to a more diverse and efficient energy infrastructure large quantities of hydrogen are requested for industries (e.g. mining refining fertilizers…). These applications need large scale facilities such as dozens of electrolyzer stacks from atmospheric pressure to 30 bar with a total capacity ranging from 100 up to 400 MW and associated hydrogen storage from a few to 50 tons.

Local use can be fed by electrolyzer in 20 feet container and stored in bundles with small volumes. Nevertheless industrial applications can request much bigger capacity of production which are generally located in buildings. The different technologies available for the production of hydrogen at large scale are alkaline or PEM electrolyzer with for example 100 MW capacity in a building of 20000 m3 and hydrogen stored in tube trailers or other fixed hydrogen storage solution with large volumes.

These applications led to the use of hydrogen inside large but confined spaces with the risk of fire and explosion in case of loss of containment followed by ignition. This can lead to severe consequences on asset workers and public due to the large inventories of hydrogen handled.

This article aims to provide an overview of the strategy to safely design large scale hydrogen production facilities in buildings through benchmarks based on projects and literature reviews best practices & standards regulations. It is completed by a risk assessment taking into consideration hydrogen behavior and influence of different parameters in dispersion and explosion in large buildings.

This article provides recommendations for hydrogen project stakeholders to perform informed-based decisions for designing large scale production buildings. It includes safety measures as reducing hydrogen inventories inside building allocating clearance around electrolyzer stacks implementing early detection and isolation devices and building geometry to avoid hydrogen accumulation.

The design of future energy systems requires the efficient use of all available renewable resources. Biomass can complement variable renewable energy sources by ensuring energy system flexibility and providing a reliable feedstock to produce renewable fuels. We identify biomass gasification suitable to utilise the limited biomass resources efficiently. In this study we inquire about its role in a 100% renewable energy system for Denmark and a net-zero energy system for Europe in the year 2050 using hourly energy system analysis. The results indicate bio-electrofuels produced from biomass gasification and electricity to enhance the utilisation of wind and electrolysis and reduce the energy system costs and fuels costs compared to CO2-electrofuels from carbon capture and utilisation. Despite the extensive biomass use overall biomass consumption would be higher without biomass gasification. The production of electromethanol shows low biomass consumption and costs while Fischer-Tropsch electrofuels may be an alternative for aviation. Syngas from biomass gasification can supplement biogas in stationary applications as power plants district heat or industry but future energy systems must meet a balance between producing transport fuels and syngas for stationary units. CO2-electrofuels are found complementary to bio-electrofuels depending on biomass availability and remaining non-fossil CO2 emitters

Our Future Energy Scenarios (FES) draw on hundreds of experts’ views to model four credible energy pathways for Britain over coming decades. Matthew Wright our head of strategy and regulation outlines what the 2021 outlook means for consumers society and the energy system itself.<br/>This year’s Future Energy Scenarios insight reveals a glimpse of a Britain that is powered with net zero carbon emissions.<br/>Our analysis shows that our country can achieve its legally-binding carbon reduction targets: in three out of four scenarios in the analysis the country reaches net zero carbon emissions by 2050 with Leading the Way – our most ambitious scenario – achieving it in 2047 and becoming net negative by 2050.

The maritime industry is a major source of greenhouse gas (GHG) emissions largely due to ships running on fossil fuels. Transitioning to hydrogen-powered marine transportation in the Mediterranean Sea requires the development of a network of hydrogen refueling stations across the region to ensure a steady supply of green hydrogen. This paper explores the technoeconomic viability of harnessing wave energy from the Mediterranean Sea to produce green hydrogen for hydrogenpowered ships. Four promising island locations—near Sardegna Galite Western Crete and Eastern Crete—were selected based on their favorable wave potential for green hydrogen production. A thorough analysis of the costs associated with wave power facilities and hydrogen production was conducted to accurately model economic viability. The techno-economic results suggest that with anticipated cost reductions in wave energy converters the levelized cost of hydrogen could decrease to as low as 3.6 €/kg 4.3 €/kg 5.5 €/kg and 3.9 €/kg for Sardegna Galite Western Crete and Eastern Crete respectively. Furthermore the study estimates that in order for the hydrogen-fueled ships to compete effectively with their oil-fueled counterparts the levelized cost of hydrogen must drop below 3.5 €/kg. Thus despite the competitive costs further measures are necessary to make hydrogen-fueled ships a viable alternative to conventional diesel-fueled ships.

As global energy shifts toward sustainable solutions switching to sustainable energy particularly those involving energy storage from hydrogen relies on effective storage technologies. This is necessary for harnessing the potential of hydrogen as a clean energy carrier. This review discussed the latest advancements in materials designed to improve hydrogen storage efficiency safety and scalability. The articles reported different storage materials such as metal hydrides chemical hydrides advanced adsorbents and their challenges and prospects. Developing innovations like nanostructured and hybrid materials are explained showing how these cutting-edge approaches improve hydrogen kinetics. However despite the advancements challenges like feasibility and sustainability remain. Hence this study discusses these barriers through life cycle assessments and recycling. Moreover the study offers an understanding of the applications of these materials illustrating their prospects to simplify a hydrogen economy. Through examining current research and identifying important trends the article aims to illuminate the way forward for materials science in hydrogen storage applications. The findings highlight the importance of material development and emphasise the collaborative efforts researchers require to realise the potential of hydrogen as a keystone of sustainable energy systems.

The technique of producing hydrogen by utilizing green and renewable energy sources is called green hydrogen production. Therefore by implementing this technique hydrogen will become a sustainable and clean energy source by lowering greenhouse gas emissions and reducing our reliance on fossil fuels. The key beneft of producing green hydrogen by utilizing green energy is that no harmful pollutants or greenhouse gases are directly released throughout the process. Hence to guarantee all of the environmental advantages it is crucial to consider the entire hydrogen supply chain involving storage transportation and end users. Hydrogen is a promising clean energy source and targets plan pathways towards decarbonization and net-zero emissions by 2050. This paper has highlighted the techniques for generating green hydrogen that are needed for a clean environment and sustainable energy solutions. Moreover it summarizes an overview outlook and energy transient of green hydrogen production. Consequently its perspective provides new insights and research directions in order to accelerate the development and identify the potential of green hydrogen production.

With rapidly depleting fossil fuels and growing environmental alarms due to their usage hydrogen as an energy vector provides a clean and sustainable solution. However the challenge lies in replacing mature fossil fuel technology with efficient and economical hydrogen production. This paper provides a technoeconomic and environmental overview of H2 production technologies. Reforming of fossil fuels is still considered as the backbone of large-scale H2 production. Whereas renewable hydrogen has technically advanced and improved its cost remains an area of concern. Finding alternative catalytic materials would reduce such costs for renewable hydrogen production. Taking a mid-term timeframe a viable scenario is replacing fossil fuels with solar hydrogen production integrated with water splitting methods or from biomass gasification. Gasification of biomass is the preferred option as it is carbon neutral and costeffective producing hydrogen at 1.77 – 2.77 $/kg of H2. Among other uses of hydrogen in industrial applications the most viable approach is to use it in hydrogen fuel cells for generating electricity. Commercialization of fuel cell technology is hindered by a lack of hydrogen infrastructure. Fuel cells and hydrogen production units should be integrated to achieve desired results. Case studies of different fuel cells and hydrogen production technologies are presented at the end of this paper depicting a viable and environmentally acceptable approach compared with fossil fuels.

Hydrogen refueling stations (HRS) can cause a significant fraction of the hydrogen refueling cost. The main cost contributor is the currently used mechanical compressor. Electrochemical hydrogen compression (EHC) has recently been proposed as an alternative. However its optimal integration in an HRS has yet to be investigated. In this study we compare the performance of a gaseous HRS equipped with different compressors. First we develop dynamic models of three process configurations which differ in the compressor technology: mechanical vs. electrochemical vs. combined. Then the design and operation of the compressors are optimized by solving multi-stage dynamic optimization problems. The optimization results show that the three configurations lead to comparable hydrogen dispensing costs because the electrochemical configuration exhibits lower capital cost but higher energy demand and thus operating cost than the mechanical configuration. The combined configuration is a trade-off with intermediate capital and operating cost.

Hydrogen-based Power Systems (H2PSs) are gaining accelerating momentum globally to reduce energy costs and dependency on fossil fuels. A H2PS typically comprises three main parts: hydrogen production storage and power generation called packages. A review of the literature and Original Equipment Manufacturers (OEM) datasheets reveals that no single manufacturer supplies all H2PS components posing significant challenges in system design parts integration and safety assurance. Additionally both the literature and H2PS projects’ database highlight a gap in a systematic hydrogen equipment and auxiliary sub-systems technology selection process and how this selection affects the overall H2PS Balance of Plant (BoP). This study addresses that gap by providing a guideline for available technology options and their impact on the H2PS-BoP. The analysis compares packages and auxiliary sub-system technologies to support informed engineering decisions regarding technology and equipment selection. The study finds that each package’s technology influences the selection criteria of the other packages and the associated BoP requirements. Furthermore the choice of technologies across packages significantly affects overall system integrity and BoP. These interdependencies are illustrated using a cause-and-effect matrix. The study’s significance lies in establishing a structured guideline for engineering design and operations enhancing the accuracy of feasibility studies and accelerating the global implementation of H2PS.

The production of synthetic fuels and chemicals from solar energy and abundant reagents offers a promising pathway to a sustainable fuel economy and chemical industry. For the production of hydrogen photoelectrochemical or integrated photovoltaic and electrolysis devices have demonstrated outstanding performance at the lab scale but there remains a lack of larger-scale on-sun demonstrations (>100 W). Here we present the successful scaling of a thermally integrated photoelectrochemical device—utilizing concentrated solar irradiation— to a kW-scale pilot plant capable of co-generation of hydrogen and heat. A solar-to-hydrogen device-level efficiency of greater than 20% at an H2 production rate of >2.0 kW (>0.8 g min−1) is achieved. A validated model-based optimization highlights the dominant energetic losses and predicts straightforward strategies to improve the system-level efficiency of >5.5% towards the device-level efficiency. We identify solutions to the key technological challenges control and operation strategies and discuss the future outlook of this emerging technology.

Billions of litres of wastewater are produced daily from domestic and industrial areas and whilst wastewater is often perceived as a problem it has the potential to be viewed as a rich source for resources and energy. Wastewater contains between four and five times more energy than is required to treat it and is a potential source of bio-hydrogen—a clean energy vector a feedstock chemical and a fuel widely recognised to have a role in the decarbonisation of the future energy system. This paper investigates sustainable low-energy intensive routes for hydrogen production from wastewater critically analysing five technologies namely photo-fermentation dark fermentation photocatalysis microbial photo electrochemical processes and microbial electrolysis cells (MECs). The paper compares key parameters influencing H2 production yield such as pH temperature and reactor design summarises the state of the art in each area and highlights the scale-up technical challenges. In addition to H2 production these processes can be used for partial wastewater remediation providing at least 45% reduction in chemical oxygen demand (COD) and are suitable for integration into existing wastewater treatment plants. Key advancements in lab-based research are included highlighting the potential for each technology to contribute to the development of clean energy. Whilst there have been efforts to scale dark fermentation electro and photo chemical technologies are still at the early stages of development (Technology Readiness Levels below 4); therefore pilot plants and demonstrators sited at wastewater treatment facilities are needed to assess commercial viability. As such a multidisciplinary approach is needed to overcome the current barriers to implementation integrating expertise in engineering chemistry and microbiology with the commercial experience of both water and energy sectors. The review concludes by highlighting MECs as a promising technology due to excellent system modularity good hydrogen yield (3.6–7.9 L/L/d from synthetic wastewater) and the potential to remove up to 80% COD from influent streams.

Sustainable aviation fuels (SAFs) represent the short-term solution to reduce fossil carbon emissions from aviation. The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was globally adopted to foster and make SAFs production economically competitive. Fischer-Tropsch synthetic paraffinic kerosene (FTSPK) produced from forest residue is a promising CORSIA-eligible fuel. FT conversion pathway permits the integration of carbon capture and storage (CCS) technology which provides additional carbon offsetting ca pacities. The FT-SPK with CCS process was modelled to conduct a comprehensive analysis of the conversion pathway. Life-cycle assessment (LCA) with a well-to-wake approach was performed to quantify the SAF’s carbon footprint considering both biogenic and fossil carbon dynamics. Results showed that 0.09 kg FT-SPK per kg of dry biomass could be produced together with other hydrocarbon products. Well-to-wake fossil emissions scored 21.6 gCO2e per MJ of FT-SPK utilised. When considering fossil and biogenic carbon dynamics a negative carbon flux (-20.0 gCO2eMJ− 1 ) from the atmosphere to permanent storage was generated. However FT-SPK is limited to a 50 %mass blend with conventional Jet A/A1 fuel. Using the certified blend reduced Jet A/A1 fossil emissions in a 37 % and the net carbon flux resulted positive (30.9 gCO2eMJ− 1 ). Sensitivity to variations in process as sumptions was investigated. The lifecycle fossil-emissions reported in this study resulted 49 % higher than the CORSIA default value for FT-SPK. In a UK framework only 0.7 % of aviation fuel demand could be covered using national resources but the emission reduction goal in aviation targeted for 2037 could be satisfied when considering CCS.

Hydrogen is gaining traction as a key energy carrier due to its clean combustion high energy content and versatility. As the world shifts towards sustainable energy hydrogen demand is rapidly increasing. This paper introduces a novel hybrid time series modeling approach designed and developed to accurately predict hydrogen demand by mixing linear and nonlinear models and accounting for the impact of non-recurring events and dynamic energy market changes over time. The model incorporates key economic variables like hydrogen price oil price natural gas price and gross domestic product (GDP) per capita. To address these challenges we propose a four-part framework comprising the Hodrick–Prescott (HP) filter the autoregressive fractionally integrated moving average (ARFIMA) model the enhanced empirical wavelet transform (EEWT) and high-order fuzzy cognitive maps (HFCM). The HP filter extracts recurring structural patterns around specific data points and resolves challenges in hybridizing linear and nonlinear models. The ARFIMA model equipped with statistical memory captures linear trends in the data. Meanwhile the EEWT handles non-stationary time series by adaptively decomposing data. HFCM integrates the outputs from these components with ridge regression fine-tuning the HFCM to handle complex time series dynamics. Validation using stochastic non-Gaussian synthetic data demonstrates that this model significantly enhances prediction performance. The methodology offers notable improvements in prediction accuracy and stability compared to existing models with implications for optimizing hydrogen production and storage systems. The proposed approach is also a valuable tool for policy formulation in renewable energy and smart energy transitions offering a robust solution for forecasting hydrogen demand

Cement industry due to the decomposition of CaCO3 and the production of clinker emits large amounts of CO2 into the atmosphere. This anthropogenic gas can be captured and through its synthesis with green hydrogen methanol and finally synthetic fuels are achieved. By using e-fuel Europe’s climate neutrality objectives could be achieved. However the energy transition still lacks a clear roadmap and decisions are strongly affected by the geopolitical situation the energy demand and the economy. Therefore different scenarios are analysed to assess the influence of key factors on the overall economic viability of the process: 1) A business-as-usual scenario EU perspectives 2) allowing e-fuels and 3) improving H2 production processes. The technical feasibility of the production of synthetic fuels is verified. The most optimistic projections indicate future production costs of synthetic fuels will be lower than those of fossil fuels. This is directly related to the cost of green hydrogen production.

The flow rate strategies of deionized water have a significant impact on the mass transfer process of proton exchange membrane (PEM) electrolyzers which are critical for the efficient and safe operation of hydrogen production systems. Electrochemical impedance spectroscopy is an effective tool for distinguishing different kinetic processes within the electrolyzer. In this study three different Ti-felt porous transport layers (PTLs) are tested with two flow rate modes constant flow (50 mL/min) and periodic cycling flow (10 mL/min–50 mL/min–10 mL/min) to investigate the influence of flow rate strategies on the mass transfer impedance of the electrolyzer. The following observations were made: (1) For PTL with better performance the flow rate of the periodic cycling flow has little effect on its mass transfer impedance and the mass transfer impedance of the periodic circulation flow mode is not much different from that of the constant flow. (2) For PTL with poorer performance in the periodic cycling mode the mass transfer impedance at 10 mL/min is smaller than that at 50 mL/min but both are higher than the impedance under constant flow. The conclusions of this study provide a theoretical basis for the flow management of PEM electrolytic hydrogen production systems.

Hydrogen-powered aviation is gaining momentum as a sustainable alternative to fossil-fueled flight yet the field faces complex technological and operational challenges. To better understand commercial innovation pathways this study analyzes the claims sections of 166 hydrogen aviation patents issued between 2018 and 2024. Unlike prior studies that focused on patent titles or abstracts this approach reveals the protected technical content driving commercialization. The study classifies innovations into seven domains: fuel storage fuel delivery fuel management turbine enhancement fuel cell integration hybrid propulsion and safety enhancement. Thematic word clouds and term co-occurrence networks based on natural language processing techniques validate these classifications and highlight core technical themes. Scientometric analyses uncover rapid patent growth rising international participation and strong engagement from both established aerospace firms and young companies. The findings provide stakeholders with a structured view of the innovation landscape helping to identify technological gaps emerging trends and areas for strategic investment and policymaking. This claims-based method offers a scalable framework to track progress in hydrogen aviation and is adaptable to other emerging technologies.

The present study investigates the design and scale-up of a pure hydrogen oxy-fuel combustion burner for industrial applications. In recent years this technology has garnered attention as an effective approach to the decarbonisation of high-temperature industrial processes. Replacing air with oxygen in combustion processes significantly reduces nitrogen oxides emissions and leads to sustainable energy use. A laboratory-scale burner was designed with inlet nozzle dimensions adapted to the specific properties of hydrogen and oxygen as fuel and oxidant respectively. Implementing oxy-fuel combustion requires addressing several technical issues to prevent the burner wall from overheating and to ensure a stable flame. An infrared camera was used to characterise the performance and operating conditions of the laboratory-scale burner in the range of 2.5–30 kW. The 10 kW baseline case was analysed numerically and validated experimentally using thermocouples. This revealed stable lifted flames with maximum temperatures of 2800 K and a flame length of 0.15 m. A key challenge in engineering is transferring results from laboratory-scale to large-scale industrial applications. Once validated the prototype design was scaled up numerically from 10 kW to 1 MW investigating the feasibility of different scaling criteria. The impact of these criteria on flame characteristics mixing patterns and the volumetric distribution of the reaction zone was then assessed. The constant velocity criterion yielded the lowest pressure drops although it also resulted in longer flame lengths. In contrast the constant residence time criterion generated the highest pressure drops. The increased velocities associated with this criterion enhanced mixing leading to shorter flame lengths as noted in the cases of 200 kW decreasing from 0.98 m under constant velocity criterion to 0.46 m. The intermediate criteria demonstrated a feasible alternative for scaling up the burner by effectively balancing flame length mixing rate and pressure losses. Nevertheless all criteria enabled the burner to sustain high combustion efficiency. Overall this investigation provides valuable insight into the potential of hydrogen oxy-fuel combustion technology to reduce carbon emissions in high-temperature processes.

The urgent need for low carbon emissions in hydrogen production has become increasingly critical as global energy demands rise highlighting the inefficiencies in traditional methods and the industry’s challenges in meeting evolving environmental standards. This review aims to provide a comprehensive overview of these challenges and opportunities. The current review discusses the use of artificial intelligence (AI) technologies especially machine learning (ML) and deep learning (DL) algorithms for process optimization in hydrogen production and associated power systems. The current study analyzes data from several important industry case studies and recently published studied evidence by using a review methodology in order to critically evaluate the effectiveness of AI applications. Key findings show how AI greatly improves operational efficiency through optimized production conditions and forecasted energy use. The review indicates that real-time data processing by AI helps to quickly detect anomalies for timely correction minimizing downtimes and maximizing reliability. Integrating AI with energy management solutions not only optimizes hydrogen production but also supports a transition to sustainable energy systems. Thus the current review recommends strategic investments in AI technologies and comprehensive training programs to harness their full potential ultimately contributing to a more sustainable energy future.

Hydrogen is one of the energy vectors that are called to play a key role in a decarbonised energy future. On the other hand offshore energy is one of the options to increase renewable energy generation either electricity or other vectors as hydrogen. At this respect the OCEANH2 project aims to design a plant for the generation storage and distribution of modular flexible and intelligent offshore green hydrogen hybridizing floating wind and photovoltaic technology produced in locations at Gran Canarias and Carboneras (Spain) 1250 and 700 m to the coast. The intake of hydrogen to land is one of the bottlenecks of such project impacting in the whole economy of the levelized cost of hydrogen that is produced. From the analysis that is presented it is concluded that the practical alternatives in the framework of the OCEANH2 project are mainly by dedicated carbon steel pipelines due to the existing uncertainties on the utilization of non-metallic pipes and the low distance to the intake facilities at the port in the project. We have evaluated as well the implementation of hydrogen refuelling stations and truck loading stations for short-distance hydrogen delivery based on compressed hydrogen with a capital cost of 1.7 and 7 M€ for a hydrogen management of 100 kg/day. Hydrogen transport by vessel when produced hydrogen offshore has been discarded for the particular case of OCEANH2.

Significant shortfalls in meeting the climate mitigation targets and volatile energy markets make evident the need for an urgent transition from fossil fuels to sustainable alternatives. However the integration of zero-carbon fuels like green hydrogen and ammonia is an immense project and will take time and the construction of new infrastructure. It is during this transitional period that lower-carbon natural gas alternatives are essential. In this study the industrial sectors of Lithuania are analysed based on their energy consumption. The industrial sectors that are the most energy-intensive are food chemical and wood-product manufacturing. Synthetic natural gas (SNG) has become a viable substitute and biomethane has also become viable given a feedstock price of 21 EUR/MWh in the twelfth year of operation and 24 EUR/MWh in the eighth year assuming an electricity price of 140 EUR/MWh and a natural gas price of 50 EUR/MWh. Nevertheless the scale of investment in hydrogen production is comparable to the scale of investment in the production of other chemical elements; however hydrogen production is constrained by its high electricity demand—about 3.8 to 4.4 kWh/Nm3—which makes it economically viable only at negative electricity prices. This analysis shows the techno-economic viability of biomethane and the SNG as transition pathways towards a low-carbon energy future.

Hydrogen is a promising energy carrier for decarbonizing maritime and stationary applications. However using 100% hydrogen in large-bore engines introduces combustion challenges such as pre-ignition and backfire. These statistically occurring combustion anomalies particularly their spatial and temporal behavior cannot be fully understood through thermodynamic data alone. This study applies optical diagnostics to a medium-speed single-cylinder research engine (bore: 350 mm stroke: 440 mm displacement: 42.3 dm3 ) operated with 100% hydrogen exceeding 20 bar IMEP. By varying the air–fuel equivalence ratio between 2.3 and 4.0 and comparing active pre-chamber and open combustion chamber ignition systems backfire-induced operating limits are identified. High-speed flame imaging through two endoscopic accesses and up to three cameras captures both visible and UV (308 nm) flame chemiluminescence. An implemented visual vibration compensation method using fiber optics enables tracking of flame origins and propagation. The recordings show that 65% of ignition events initiate near one intake valve suggesting local hydrogen enrichment confirmed via 3D-CFD simulations. This is linked to intake manifold geometry which leads to mixture inhomogeneity up to −260◦ CA BTDC. At loads above 15 bar IMEP the localized enrichment reduces or shifts attributed to increased turbulence and intake mass flow. CFD simulations also reveal that gas temperatures under the intake valves exceeding the ignition temperature of hydrogen as early as 300◦ CA BTDC create the risk of backfire in the early gas phase. Additionally glowing oil droplets and ignition zones near the piston were observed indicating that lube oil ignition may be a cause of later (after −290◦ CA BTDC) backfire events. These findings contribute to the understanding of hydrogen combustion anomalies and support future experimental and modeling-based optimization of large-bore hydrogen engines.

High-temperature proton exchange membranes (HT-PEMs) for fuel cells are considered transformative technologies for efficient energy conversion particularly in hydrogen-based transportation owing to their ability to deliver high power density and operational efficiency in harsh environments. However several critical challenges limit their broader adoption notably the limited durability and high costs associated with core components such as membranes and electrocatalysts under elevated temperature conditions. This review systematically addresses these challenges by examining the role of engineered nanomaterials in overcoming performance and stability limitations. The potential of nanomaterials to improve catalytic activity proton conductivity and thermal stability is discussed in detail emphasizing their impact on the optimization of catalyst layer composition including catalysts binders phosphoric acid electrolytes and additives. Recent advancements in nanostructured assemblies and 3D morphologies are explored to enhance fuel cell efficiency through synergistic interactions of these components. Additionally ongoing issues such as catalyst degradation long-term stability and resistance to high-temperature operation are critically analyzed. This manuscript offers a comprehensive overview of current HT-PEMs research and proposes future material design strategies that could bridge the gap between laboratory prototypes and large-scale industrial applications.

Hydrogen is a key energy carrier for decarbonizing multiple sectors particularly when produced via water electrolysis powered by renewable energy. Proton exchange membrane (PEM) electrolyzers are well suited for this application due to their ability to rapidly adjust to fluctuating power inputs. Despite being conventionally operated at high temperatures and pressures to reduce heating and compression needs recent studies suggest that under partial loads lower operating conditions may enhance efficiency. This study introduces a novel optimization framework for dynamically adjusting pressure and temperature in PEM electrolyzers. The model integrates an efficiency map within a Mixed-Integer Linear Programming (MILP) formulation and applies McCormick tightening to address nonlinearities. A one-week case study demonstrates operational cost reductions of up to 12.5 % through optimal control favoring lower temperatures and pressures at low current densities and higher temperatures near rated load while maintaining moderate pressures. The results show improved efficiency and reduced hydrogen crossover enhancing safety and enabling scalable application over extended time horizons. These insights are valuable for long-term planning and evaluation of hydrogen production and storage systems.

This comprehensive review explores silica aerogels and their application in environmental remediation. Due to rapid growth in the consumption of energy and water resources the purification of contaminated resources for use by humankind should be considered important. The primary objectives of this review are to assess the evolving landscape of silica aerogels their preparation and drying techniques and to discuss the main findings from a wide range of empirical studies and theoretical perspectives. Based on a significant amount of research this review provides information about aerogels’ capabilities as an adsorbent and catalyst. The analysis spans a variety of contexts for the generation of hydrogen and the degradation of the dyes employed in industry showing better performance in environmental remediation. The implications of this review point to the need for well-informed policies innovative synthesis strategies and ongoing research to harness the full potential for environmental management.

This work included preparing and characterizing new platinum complexes with the ligand 345 -trimethoxybenzoic acid (TMB). The reactions were carried out using a n autoclave in microwave within 3 minutes only in an alkali medium of triethylamine where two moles of TMB reacted with one mole of platinum ion and two moles of PPh 3 or with one mole of diphosphines (Bis(diphenylphosphino)x; x=methane (dppm) ethane (dppe) propane (dppp) ferrocene (dppf)). The prepared complexes were characterized by measuring melting points and by the techniques of (C.H.N) molar electrical conductivity FT -IR and 1 H -NMR. The characterization results demonstrated that the TMB ligand behaves as a bidentate ligand through the oxygen atom of the carboxylic groups and its geometric shape is a square planar around the platinum ion. The complex formed with high yield ([Pt(TMB) 2(dppf)]) was used in hydrogen storage application. The storage isotherm showed that the complex has a high storage capacity of about 4.2 wt% at 61 bar under low temperature (77 K). The study showed that the thermodynamic functions were -0.67KJ/mol and -3.6 J/mol H 2 for enthalpy and entropy indicating the occurrence of physical hydrogen storage.

To mitigate the risk of hydrogen leakage in ship fuel systems powered by internal combustion engines a Bayesian network model was developed to evaluate the risk of hydrogen fuel leakage. In conjunction with the Bow-tie model fuzzy set theory and the Noisy-OR Gate model an in-depth analysis was also conducted to examine both the causal factors and potential consequences of such incidents. The Bayesian network model estimates the likelihood of hydrogen leakage at approximately 4.73 × 10−4 and identifies key risk factors contributing to such events including improper maintenance procedures inadequate operational protocols and insufficient operator training. The Bowtie model is employed to visualize the causal relationships between risk factors and their potential consequences providing a clear structure for understanding the events leading to hydrogen leakage. Fuzzy set theory is used to address the uncertainties in expert judgments regarding system parameters enhancing the robustness of the risk analysis. To mitigate the subjectivity inherent in root node probabilities and conditional probability tables the NoisyOR Gate model is introduced simplifying the determination of conditional probabilities and improving the accuracy of the evaluation. The probabilities of flash or pool fires jet fires and vapor cloud explosions following a leakage are calculated as 4.84 × 10−5 5.15 × 10−5 and 4.89 × 10−7 respectively. These findings highlight the importance of strengthening operator training and enforcing stringent maintenance protocols to mitigate the risks of hydrogen leakage. The model provides a valuable framework for safety evaluation and leakage risk management in hydrogen-powered ship fuel systems.

Multi-energy systems (MESs) can address issues such as low renewable energy utilization and power imbalances by optimizing the integration of various energy sources. This paper proposes an optimization operation strategy for MES to regulate the hydrogen and battery storage system (HBRS) based on carbon emission factors (CEFs). Insufficient renewable energy utilization caused by reverse peak regulation can be addressed by guiding the optimal output of HBRS through this model thereby achieving multi-energy complementarity. The CEF is used to balance the output of the HBRS to achieve a low-carbon economic operating system. First the fluctuation of renewable energy is decomposed and reconstructed. Subsequently The HBRS system is utilized to smooth out the fluctuations caused by different frequencies of new energy and then the CEF is used to promote the output of the low-carbon subsystem. Finally comparative verification is conducted across validation cases to demonstrate the effectiveness of the proposed model and the optimization strategy.

This study evaluates the feasibility of repurposing produced water—an abundant byproduct of hydrocarbon extraction—for green hydrogen production in Wyoming USA. Analysis of geospatial distribution and production volumes reveals that there are over 1 billion barrels of produced water annually from key basins with a general total of dissolved solids (TDS) ranging from 35000 to 150000 ppm though Wyoming’s sources are often at the lower end of this spectrum. Optimal locations for hydrogen production hubs have been identified particularly in high-yield areas like the Powder River Basin where the top 2% of fields contribute over 80% of the state’s produced water. Detailed water-quality analysis indicates that virtually all of the examined sources exceed direct electrolyzer feed requirements (e.g. 10% LCOH) are notable electricity pricing (50–70% LCOH) and electrolyzer CAPEX (20–40% LCOH) are dominant cost factors. While leveraging produced water could reduce freshwater consumption and enhance hydrogen production sustainability further research is required to optimize treatment processes and assess economic viability under real-world conditions. This study emphasizes the need for integrated approaches combining water treatment renewable energy and policy incentives to advance a circular economy model for hydrogen production.

Considering economic and environmental aspects this study explored the potential of replacing urea imports in Jordan with local production utilizing green hydrogen considering agricultural land distribution fertilizer need and hydrogen demand. The analysis estimated the 2023 urea imports at approximately 13991.37 tons and evaluated the corresponding costs under various market scenarios. The cost of urea imports was projected to range between USD 6.30 million and USD 8.39 million; domestic production using green hydrogen would cost significantly more ranging from USD 30.37 million to USD 70.85 million. Despite the economic challenges transitioning to green hydrogen would achieve a 100% reduction in CO2 emissions eliminating 48739.87 tons of CO2 annually. Considering the Jordanian case an SWOT analysis was conducted to highlight the potential transition strengths such as environmental benefits and energy independence alongside weaknesses such as high initial costs and infrastructure gaps. A competitive analysis was conducted to determine the competition of green hydrogen-based ammonia compared to conventional methods. Further the analysis identified opportunities advancements in green hydrogen technology and potential policy support. Threats were assessed considering global competition and market dynamics.

The growing demand for clean energy and sustainable industrial processes has driven interest in integrated energy systems that optimize resource utilization while minimizing environmental impacts. This study presents the simulation and environmental sustainability assessment of an integrated process combining liquefied natural gas (LNG) Allam–Fetvedt cycle solid oxide electrolysis’ system and methanol synthesis to produce clean energy. The proposed system enhances overall efficiency and sustainability by utilizing the Allam–Fetvedt cycle to generate power while capturing CO2 which is then used in the manufacture of syngas and hydrogen by the electrolysis of water and CO2. Syngas is subsequently transformed into methanol a viable alternative fuel characterized by lowcarbon emissions. A comprehensive process simulation is conducted to evaluate energy efficiency material flows and system performance. The sustainability assessment focuses on environmental impact indicators including carbon footprint reduction energy efficiency improvements and resource optimization. The results demonstrate that the integrated system significantly reduces CO2 emissions while maximizing energy recovery making it a promising approach for decarbonized energy production. In this study the integrated process including the ASU power cycle electrolyzers methanol production units and LNG unit results in carbon emissions of 0.29 kg CO2 per kg of LNG produced which is very close to the literature-reported lower limit even though it also has methanol production. On the other hand when the identical process is assessed solely for methanol production (without the LNG unit) it attains net-zero carbon emissions. Despite the incorporation of high-energy electrolyzer systems the overall energy demand of the proposed integrated process remains comparable to that of existing conventional technologies with high emission outputs.

This study explores the integration and optimization of a hydrogen-based energy system emphasizing the use of metal hydride (MH) storage coupled with Proton Exchange Membrane Fuel Cell Micro Combined Heat and Power (PEMFC MCHP) system for residential applications. MH storage coupled to a heat pump operates at charging and discharging pressures of 10 bar. COMSOL model in 6.1 version using heat transfer in solids and fluids in brinkman equations modules is validated by experimental data and uses machine learning (Feedforward Neural Networks) for predictive modeling of MH dynamics. Smaller 500 NL tanks were found to have high mass-specific heat demand but faster hydrogen gas kinetics reaching (~77 % capacity in one hour) whereas larger 6500 NL (~57 %/hour) absorb hydrogen gas more gradually but reduce thermal management intensities. Using 13 × 500 NL tanks reach ~25 % discharge in 1 h but require ~2170 Wh heating whereas one 6500 NL tank only attains ~48.5 % discharge yet uses ~1750 Wh illustrating a trade-off between faster kinetics and lower thermal load. A genetic algorithm identified an optimal configuration of two 6500 NL tanks that covered ~68 % of total hydrogen gas consumption and 65 % of production at a maximum of 2.4 kW heating and 2.45 kW cooling. Additional comparisons with 170 bar compressed storage revealed lower instantaneous thermal requirements for high-pressure gas tanks. Adding a 170 bar compressed H2 alongside the 10 bar MH system hydrogen gas coverage rose from ~70 % to ~97 % when storage expanded to 200 Nm3 but at the cost of higher compression energy. The proposed MH-based approach especially at moderate pressures with carefully planned tank geometries achieves enhanced operational flexibility for a residential 120 m2 building’s space heating and hot water while machine learning optimizations further refine charge–discharge performance.