Publications

Climate change and energy crises push Europe to accelerate the energy-industry transition towards higher shares of renewable energy and a more efficient integrated electricity-based energy-industry system. The study examines transition scenarios ranging from carbon neutrality reached in 2050 to highest ambitions with 100% renewable electricity supply reached by 2030 and an overall carbon-neutral energy-industry system by 2035. The fastest transition coincidences with higher cost but still with an acceptable tolerance. Reaching carbon neutrality by 2040 allows for a substantial reduction in CO2 emissions and energy costs are lower compared to the fastest transition. Allowing e-fuel imports substantially reduces the energy cost in Europe compared to complete energy sovereignty with an optimal import share at only 7% of primary energy demand. Reaching an affordable energy supply requires close cooperation of European countries to exploit the best renewable resources and all sources of energy system flexibility to enable a low-cost energy supply.

This study engineered seabed sediment with microwave-assisted Ni2+ -substitution to enhance its composition and properties. The catalytic activity of microwave-assisted Ni2+ - substituted seabed sediment (Mwx%Ni-SB) was investigated in the two-stage pyrolysis of plastic waste for hydrogen production. The characterization reveals microwave irradiation synergistically modifies the physical properties (increasing functional groups reducing crystallinity) and electronic properties (modulating bandgap energy increasing electron density) of the Mwx%Ni-SB thereby improving methane reforming performance. Microwave treatment compresses and rearranges Ni2+ ions within the sediment lattice resulting in increased order and density and creating defects that enhance catalytic activity. GC-TCD analysis demonstrates that the use of catalysts in the first and second stages more than doubled hydrogen production (109.74%) compared to not using catalysts. Therefore increased Ni2+ substitution significantly reduced methane production by 49.04% while simultaneously boosting hydrogen production by 23.00%.

Discussions about the transition to hydrogen in various applications have become an important topic in recent years. A key factor for an effective transition is public acceptance of hydrogen technologies. However the increase in acceptance depends among other things on individual knowledge about the hydrogen colors and the linked hydrogen production pathways currently under discussion. In communications colors such as green grey and blue are used to distinguish hydrogen sources. With new research additional colors have become necessary. Unfortunately there is no unified definition for the colors. The aim of this perspective is to identify the most frequent hydrogen colors used by scientists and the public derive open definitions and propose a solution to a representation problem. The general use of hydrogen colors in communication and the implications on public acceptance are briefly outlined. We then identified definitions for colors associated with a specific pathway and discussed some discrepancies between science and media use. To make better use of the existing colors more open definitions were formulated. We point out the representation problem with shades of a color and provide a connection between the assigned color and a view-independent RGB color code as proposal. The derived definitions can be used to unify communication in science and public media.

A real-time on-site monitoring of the concentration of hydrogen and the heating value of a blend of hydrogen and natural gas is of key importance for its safe distribution in existing pipelines as proposed by the ‘Power-toGas’ concept. Although current gas chromatography (PGC) methods deliver this information accurately they are unsuitable for a quick and pipelineintegrated measurement. We analyse the possibility to monitor this blend with a combination of sensors of thermodynamic properties—thermal conductivity speed of sound and density—as a potential substitute for PGC. We propose a numerical method for this multi-sensor detection based on the assumption of ideal gas (i.e. low-pressure) behaviour treating natural gas as a ‘mixture of mixtures’ depending on how many geographical sources are drawn upon for its distribution. By performing a Monte-Carlo simulation with known concentrations of natural gas proceeding from different European sources we conclude that the combined measurement of thermal conductivity together with either speed of sound or density can yield a good estimation of both variables of interest (hydrogen concentration and heating value) even under variability in the composition of natural gas.

This review synthesizes recent research on alternative fuels for piston-engine aircraft and related propulsion technologies. Biofuels show substantial promise but face technological economic and regulatory barriers to widespread adoption. Among liquid options biodiesel offers a high cetane number and strong lubricity yet suffers from poor low-temperature flow and reduced combustion efficiency. Alcohol fuels (bioethanol biomethanol) provide high octane numbers suited to high-compression engines but are limited by hygroscopicity and phase-separation risks. Higher-alcohols (biobutanol biopropanol) combine favorable heating values with stable combustion and emerge as particularly promising candidates. Biokerosene closely matches conventional aviation kerosene and can function as a drop-in fuel with minimal engine modifications. Emissions outcomes are mixed across studies: certain biofuels reduce NOx or CO while others elevate CO2 and HC underscoring the need to optimize combustion and advance second- to fourth-generation biofuel production pathways. Beyond biofuels hydrogen engines and hybrid-electric systems offer compelling routes to lower emissions and improved efficiency though they require new infrastructure certification frameworks and cost reductions. Demonstrated test flights with biofuels synthetic fuels and hydrogen confirm technical feasibility. Overall no single option fully replaces aviation gasoline today; instead a combined trajectory—biofuels alongside hydrogen and hybrid-electric propulsion—defines a pragmatic medium- to long-term pathway for decarbonizing general aviation.

The growing share of renewables in power grids increases the need for backup generators able to compensate production profiles whenever needed. Hydrogen internal combustion engines (H2 ICEs) offer a promising solution in terms of flexibility reduced capital cost and looser requirements on hydrogen purity. These systems are however still not well characterized. This study introduces a zero-dimensional (0D) model for a 100 % hydrogen engine calibrated using experimental data under varying loads and air-fuel ratios. Unlike existing models it proposes validated electrical efficiency data across multiple operating points. Efficiency curves are provided in quadratic and linear forms allowing integration into diverse energy system simulations including linear programming. The model performance is evaluated in a peak-shaving case study using real data from a remote site with limited grid supply. Three engine-generators are used to match single-minute resolution load demand. Compared to typical models that lack validation and ignore part-load efficiency losses the proposed model highlights differences in hydrogen consumption estimation up to 13.4 % thus offering improved accuracy for techno-economic analyses of hydrogen-based systems.

At present transportation energy comes primarily from fossil fuels. In order to mitigate the effects of greenhouse gas emissions it is necessary to transition to low-carbon transportation technologies. These technologies can include battery electric vehicles fuel cell vehicles and biofuel vehicles. This transition includes not only the development and production of suitable vehicles but also the development of appropriate infrastructure. For example in the case of battery electric vehicles this infrastructure would include additional grid capacity for battery charging. For fuel cell vehicles infrastructure could include facilities for the production of suitable electrofuels which again would require additional grid capacity. In the present paper we look at some specific examples of infrastructure requirements for battery electric vehicles and vehicles using hydrogen and other electrofuels in either internal combustion engines or fuel cells. Analysis includes the necessary additional grid capacity energy storage requirements and land area associated with renewable energy generation by solar photovoltaics and wind. The present analysis shows that the best-case scenario corresponds to the use of battery electric vehicles powered by electricity from solar photovoltaics. This situation corresponds to a 47% increase in grid electricity generation and the utilization of 1.7% of current crop land.

In the context of energy interconnection and low-carbon power the power-to-gas (P2G) carbon trading mechanism is integrated into the integrated energy system (IES) model of multi-energy coupling units to achieve lowcarbon economic dispatch considering both the economic and environmental benefits of system operation. First the characteristics of each unit in the system are comprehensively considered and a joint dispatch structure for a regionally integrated energy system is developed including P2G equipment energy source equipment storage equipment and conversion equipment. The working mechanism of P2G is analyzed and its carbon trading model is established. Next a comprehensive energy system optimization model is formulated with the goal of maximizing system operating profit while accounting for carbon transaction costs. Finally Cplex and Yalmip software are used to perform simulation analysis in MATLAB to verify the effectiveness of the proposed model in reducing system carbon emissions through participation in the carbon trading market ensuring system economy and reducing the dependence of the integrated energy system on the external market.

Excessive reliance on traditional energy sources such as coal petroleum and gas leads to a decrease in natural resources and contributes to global warming. Consequently the adoption of renewable energy sources in power systems is experiencing swift expansion worldwide especially in offshore areas. Floating solar photovoltaic (FPV) technology is gaining recognition as an innovative renewable energy option presenting benefits like minimized land requirements improved cooling effects and possible collaborations with hydropower. This study aims to assess the levelized cost of electricity (LCOE) associated with floating solar initiatives in offshore and onshore environments. Furthermore the LCOE is assessed for initiatives that utilize floating solar PV modules within aquaculture farms as well as for the integration of various renewable energy sources including wind wave and hydropower. The LCOE for FPV technology exhibits considerable variation ranging from 28.47 EUR/MWh to 1737 EUR/MWh depending on the technologies utilized within the farm as well as its geographical setting. The implementation of FPV technology in aquaculture farms revealed a notable increase in the LCOE ranging from 138.74 EUR/MWh to 2306 EUR/MWh. Implementation involving additional renewable energy sources results in a reduction in the LCOE ranging from 3.6 EUR/MWh to 315.33 EUR/MWh. The integration of floating photovoltaic (FPV) systems into green hydrogen production represents an emerging direction that is relatively little explored but has high potential in reducing costs. The conversion of this energy into hydrogen involves high final costs with the LCOH ranging from 1.06 EUR/kg to over 26.79 EUR/kg depending on the complexity of the system.

The global need for energy has risen sharply recently. A global shift to clean energy is urgently needed to avoid catastrophic climate impacts. Hydrogen (H2) has emerged as a potential alternative energy source with near-net-zero emissions. In the African continent for sustainable access to clean energy and the transition away from fossil fuels this paper presents a new approach through which waste energy can produce green hydrogen from biomass. Bio-based hydrogen employing organic waste and biomass is recommended using biological (anaerobic digestion and fermentation) processes for scalable cheaper and low-carbon hydrogen. By reviewing all methods for producing green hydrogen dark fermentation can be applied in developed and developing countries without putting pressure on natural resources such as freshwater and rare metals the primary feedstocks used in producing green hydrogen by electrolysis. It can be expanded to produce medium- and long-term green hydrogen without relying heavily on energy sources or building expensive infrastructure. Implementing the dark fermentation process can support poor communities in producing green hydrogen as an energy source regardless of political and tribal conflicts unlike other methods that require political stability. In addition this approach does not require the approval of new legislation. Such processes can ensure the minimization of waste and greenhouse gases. To achieve cost reduction in hydrogen production by 2030 governments should develop a strategy to expand the use of dark fermentation reactors and utilize hot water from various industrial processes (waste energy recovery from hot wastewater).

Integration of polymer electrolyte membrane water electrolyzers (PEMWEs) for clean hydrogen generation requires a robust understanding of the impact cell designs and conditioning protocols have on operation and stability. Here catalyst-coated electrode and catalyst-coated membrane cells employing Pt/C cathode catalyst layer an IrO2 anode catalyst layer with a platinized titanium mesh or a carbon paper with a microporous layer as the porous transport layer were developed. The impact of cell conditioning above and below 0.25 A cm− 2 was investigated using advanced electrochemical impedance spectroscopy analyses and microscopic imaging with the electrochemical response related to physicochemical processes. Operation below 0.25 A cm− 2 prior to operation above 0.25 A cm− 2 resulted in anode corrosion and titanium cation contamination increasing the cell voltage at 1 A cm− 2 by 200 mV compared to uncontaminated cells. Conditioning above 0.25 A cm− 2 led to nonnegligible hydrogen transport resistances due to cathode flooding that resulted in a ca. 50 mV contribution at 1 A cm− 2 and convoluted with the anode impedance response. The presence of a microporous layer increased catalyst utilization but increased the cell voltage by 300 mV at 1 A cm− 2 due to increased anodic mass transport resistances. These results yield critical insights into the impact of PEMWE cell design and operation on corresponding cell performance and stability while highlighting the need for application dependent standardized operating protocols and operational windows.

To reduce hydrogen consumption by hydrogen fuel cell vehicles (HFCVs) an adaptive power-following control strategy based on gated recurrent unit (GRU) neural network operating condition recognition was proposed. The future vehicle speed was predicted based on a GRU neural network and a driving cycle condition recognition model was established based on k-means cluster analysis. By predicting the speed over a specific time horizon feature parameters were extracted and compared with those of typical operating conditions to determine the categories of the parameters thus the adjustment of the power-following control strategy was realized. The simulation results indicate that the proposed control strategy reduces hydrogen consumption by hydrogen fuel cell vehicles (HFCVs) by 16.6% with the CLTC-P driving cycle and by 4.7% with the NEDC driving cycle compared to the conventional power-following control strategy. Additionally the proposed strategy effectively stabilizes the battery’s state of charge (SOC).

This report investigates the status and trend of Renewable Fuels of Non-Biological Origin (RFNBO) except hydrogen which are needed to cover part of the EU’s demand for low carbon renewable fuels in the coming years. The report is an update of the CETO 2023 report. Most of the conversion technologies investigated have been already demonstrated at small-scale and the current EU legislative framework under the recast of the Renewable Energy Directive (EU) 2018/2001 (Directive EU 2023/2413) sets specific targets for their use. As a pre-requisite well-established solid hydrogen supply chains are needed together with carbon capture technologies to provide carbon dioxide as Carbon Capture and Use (CCU). Fuels that may be produced starting from H2 and CO2 or N2 are hydrocarbons alcohols and ammonia. RFNBO may play a crucial role in the energytransition towards decarbonisation especially in hard-to-abate sectors where direct electrification is not possible. In addition most RFNBO can use existing infrastructure. The growing interest in these fuels is witnessed by the many funding programmes which are today available. Moreover EU leads the sector in terms of patents companies and demonstration activities. Finally the report considers the major challenges and the opportunities for a rapid market uptake of such fuels.

The supplement to the standard IGEM/TD/1 gives the additional requirements and qualifications for pipelines transporting hydrogen and hydrogen/natural gas blends (NG/H blends) at pressures at MOP exceeding 7 barg.<br/>Where there is no numbered section in the supplement corresponding to a section in the main document the requirements of the main document apply in full. Where there is a corresponding numbered section in the main document the numbered section in the supplement is either in addition to or replaces the section in the main document.<br/>Repurposing in accordance with the recommendations of this supplement should only be considered for pipelines which have been operated in accordance with the recommendations of the main document for at least 5 years and which have been audited in accordance with the recommendations of clause 12.4.2.1. This requirement is specified so that compliance with the operational and maintenance requirements specified in the main standard is confirmed through records. With respect to pipelines this includes the requirements for MOP affirmation. This requirement is more onerous than the requirement is ASME B31.12 Clause GR-5.2.1[1] which requires that assessment for conversion to hydrogen service shall be assessed at the time of conversion and reassessment of integrity shall be done within 5 years of conversion.<br/>NG/H blends containing more than 10% mol hydrogen are considered to be equivalent to 100 mol.% hydrogen with respect to limits on design stresses and the potential effect on the material properties and damage and defect categories and acceptance levels unless an additional technical evaluation is carried out to qualify the materials (see clause S5.8). It is noted that there is no evidence to confirm that blends containing up to 10 mol.% hydrogen do not cause material degradation but it is considered that the risk is low.<br/>With respect to industry experience with towns gas this product contained 10-20 % carbon monoxide which has been identified as inhibiting the effect of hydrogen on fracture toughness and fatigue crack growth. Therefore the historical experience with town gas is not relevant.

The continuous increase of energy demand with the subsequent huge fossil fuel consumption is provoking dramatic environmental consequences. The main challenge of this century is to develop and promote alternative more eco-friendly energy production routes. In this framework Solid Oxide Cells (SOCs) are a quite attractive technology which could satisfy the users’ energy request working in reversible operation. Two operating modes are alternated: from “Gas to Power” when SOCs work as fuel cells fed with hydrogen-rich mixture to provide both electricity and heat to “Power to Gas” when SOCs work as electrolysers and energy is supplied to produce hydrogen. If solid oxide fuel cells are an already mature technology with several stationary and mobile applications the use of solid oxide electrolyser cells and even more reversible cells are still under investigation due to their insufficient lifetime. Aiming at providing a better understanding of this new technological approach the study presents a detailed description of cell operation in terms of electrochemical behaviour and possible degradation highlighting which are the most commonly used performance indicators. A thermodynamic analysis of system efficiency is proposed followed by a comparison with other available electrochemical devices in order to underline specific solid oxide cell advantages and limitations.

Hydrogen will play a key role in decarbonizing economies. Here we quantify the costs and environmental impacts of possible large-scale hydrogen economies using four prospective hydrogen demand scenarios for 2050 ranging from 111–614 megatonne H2 year−1 . Our findings confirm that renewable (solar photovoltaic and wind) electrolytic hydrogen production generates at least 50–90% fewer greenhouse gas emissions than fossil-fuel-based counterparts without carbon capture and storage. However electrolytic hydrogen production could still result in considerable environmental burdens which requires reassessing the concept of green hydrogen. Our global analysis highlights a few salient points: (i) a mismatch between economical hydrogen production and hydrogen demand across continents seems likely; (ii) regionspecific limitations are inevitable since possibly more than 60% of large hydrogen production potentials are concentrated in water-scarce regions; and (iii) upscaling electrolytic hydrogen production could be limited by renewable power generation and natural resource potentials.

In the introduction to this article a brief overview of the generated energy and the power produced by the photovoltaic systems with a peak power of 3 MWp and different tilt and orientation of the photovoltaic panels is given. The characteristics of the latest systems generating energy by wind turbines with a capacity of 3.45 MW are also presented. In the subsequent stages of the research the necessity of balancing the energy in power networks powered by a mix of renewable energy sources is demonstrated. Then a calculation algorithm is presented in the area of balancing the energy system powered by a photovoltaic–wind energy mix and feeding the low-emission hydrogen production process. It is analytically and graphically demonstrated that the process of balancing the entire system can be influenced by structural changes in the installation of the photovoltaic panels. It is proven that the tilt angle and orientation of the panels have a significant impact on the level of power generated by the photovoltaic system and thus on the energy mix in individual hourly intervals. Research has demonstrated that the implementation of planned design changes in the assembly of panels in a photovoltaic system allows for a reduction in the size of the energy storage system by more than 2 MWh. The authors apply actual measurement data from a specific geographical context i.e. from the Lublin region in Poland. The calculations use both traditional statistical methods and probabilistic analysis. Balancing the generated power and the energy produced for the entire month considered in hourly intervals throughout the day is the essence of the calculations made by the authors.

A pivotal ambition to aid global decarbonisation efforts is green electrolytic hydrogen produced with renewable energy. Prolonged operation of water electrolysers induces cell degradation decreasing production efficiency and gas yield over the lifespan of the electrolyser stack. Considerations for degradation modelling is seen to a varying extent in previous literature. This work shows the effects of including degradation modelling within existing system scenarios and new ones to demonstrate the impact of inclusion on key techno-economic parameters. A fundamental Anion Exchange Membrane electrolyser model is constructed validated and utilised into a broader hydrogen and oxygen co-production system powered by solar-PV. A second scenario tests the compatibility of the no-degradation trend with reference material and then investigates the effects of including degradation modelling showing only a 1.47% increase in levelised cost of hydrogen (LCOH). Subsequent scenarios include determining that byproduct oxygen utilisation becomes beneficial for a scenario with rated electrolyser power of above 35 MW and the observations related to stack replacement strategies are discussed. Under hypothetically higher degradation rates detriment to gas yield and LCOH is around 5% for average operational degradation rates of 15–20 μV/hr and around 10% for 30–40 μV/hr compared to around 2% for the model baseline average rate of 5.23–5.26 μV/hr.

Recent advancements in membrane-assisted seawater electrolysis powered by renewable energy offer a sustainable path to green hydrogen production. However its large-scale implementation faces challenges due to slow powerto-hydrogen (P2H) conversion rates. Here we report a modular forward osmosis-water splitting (FOWS) system that integrates a thin-film composite FO membrane for water extraction with alkaline water electrolysis (AWE) denoted as FOWSAWE. This system generates high-purity hydrogen directly from wastewater at a rate of 448 Nm3 day−1 m−2 of membrane area over 14 times faster than the state-of-the-art practice with specific energy consumption as low as 3.96 kWh Nm−3 . The rapid hydrogen production rate results from the utilisation of 1 M potassium hydroxide as a draw solution to extract water from wastewater and as the electrolyte of AWE to split water and produce hydrogen. The current system enables this through the use of a potassium hydroxide-tolerant and hydrophilic FO membrane. The established waterhydrogen balance model can be applied to design modular FO and AWE units to meet demands at various scales from households to cities and from different water sources. The FOWSAWE system is a sustainable and an economical approach for producing hydrogen at a record-high rate directly from wastewater marking a significant leap in P2H practice.

Low-carbon hydrogen is a promising option for energy security and decarbonization. Cooperation is needed to ensure the widespread use of low-carbon energy. Cooperation among hydrogen supply chain (HSC) agents is essential to overcome the high costs the lack of infrastructure that needs heavy financial support and the environmental failure risk. But how can cooperation be operationalized and its potential benefits be measured to evaluate the impact of different allocation schemes in low-carbon HSCs? This research works around this question and aims to analyze the potential of cooperation in a generalized low-carbon HSC with limited and critical resources using systems and cooperative game theory. This work is original in several aspects. It evaluates cooperation effects under different benefit allocation schemes while considering infrastructure agents’ dependencies (production transportation and storage) and specific traits. Additionally it provides a transparent replicable methodology adaptable to various case studies. It is highlighted that HSC coalitions form hierarchies with veto power pursuing common goals like maximizing decarbonization and demand fulfillment. A cooperative game theory toolbox is developed to evaluate display and compare the results of six allocation solutions. The toolbox does not aim to determine the best allocation scheme but rather to support smart decision-making in the bargaining process facilitating debate and agreement on a trade-off solution that ensures the viability and achievement of long-term coalition goals. It is built on three naïve and three game-theoretical allocation rules (Gately Nucleolus and Shapley value) applicable to peer group games with transferable utility. Results are presented for an 8-agent low-carbon HSC along with the total environmental benefit the allocated individual shares and numerical indicators (stability satisfaction propensity to disrupt) reflecting the acceptability of allocations. Numerical results show that the Nucleolus achieves the highest satisfaction among stable allocations while the Gately allocation minimizes disruption propensity. Naïve rules yield different outcomes: “equal distribution for producers” carries the highest risk whereas “equal shares for all agents” and “proportional to individual benefits” rules are stable but perform poorly on other criteria.

Metal-organic frameworks (MOFs) have emerged as promising candidates for solid-state hydrogen storage owing to their exceptional specific surface area high pore volume and chemically tunable structural properties. In this work a diverse set of experimentally synthesized MOFs were evaluated to model and predict hydrogen storage capacity (wt%) using 4 key descriptors which are Brunauer–Emmett–Teller (BET) surface area pore volume operating pressure and temperature. Correlation analysis revealed positive associations between BET surface area pressure and pore volume with storage capacity and a negative association with temperature consistent with physisorption mechanism. Six machine learning models were developed: support vector regression (SVR) artificial neural networks (ANN) random forest (RF) Gaussian process regression (GPR) gradient boosting (GB) and a Committee of Expert Systems (CES) integrating all base learners. While GB was the top-performing standalone model the CES delivered the highest predictive fidelity (R2 = 0.9958 MSE = 0.0094) as confirmed by parity plots and residual analysis. SHapley Additive exPlanations (SHAP) corroborated the statistical feature rankings consistently identifying BET surface area and pressure as the most influential positive contributors in alignment with adsorption thermodynamics. Paired t-tests on root-mean-square error (RMSE) values confirmed statistically significant CES improvements over all individual models. The CES framework thus offers a dataefficient accurate and interpretable approach for rapid MOF screening with straightforward adaptability to other porous materials and adsorption-based energy storage systems.

Through mathematical modeling this paper integrates economic safety and environmental assessments to evaluate alternative hydrogen supply options (on-site production and external supply) and various hydrogenbased system configurations for decarbonizing energy-intensive industries. The model is applied to a case study in the glass sector. While reliance on natural gas remains the most cost-effective and safest solution it does not align with decarbonization objectives. Assuming a complete hydrogen transition on-site production reduces emissions by 85 % compared to current levels and improves safety performance over external supply. External supply of grey hydrogen becomes counterproductive increasing emissions by 68 % compared to natural gas operations. Nevertheless hydrogen cost rises from 3.6 €/kg with external supply to 4.2 €/kg with on-site production doubling the fuel cost relative to natural gas. To address the trade-offs the paper explores how specific constraints influence system design. A sensitivity analysis on key factors affecting hydrogen-related decisions provides additional support for strategic decision-making.

The main aim of this study deals with the potential evaluation of a fluidized bed membrane reactor (FBMR) for hydrogen production as a clean fuel carrier via methanol steam reforming reaction comparing its performance with other reactors including packed bed membrane reactors (PBMR) fluidized bed reactors (FBR) and packed bed reactors (PBR). For this purpose a two-dimensional axisymmetric numerical model was developed using computational fluid dynamics (CFD) to simulate the reactor performances. Model accuracy was validated by comparing the simulation results for PBMR and PB with experimental data showing an accurate agreement within them. The model was then employed to examine the effects of key operating parameters including reaction temperature pressure steam-to-methanol molar ratio and gas volumetric space velocity on reactor performance in terms of methanol conversion hydrogen yield hydrogen recovery and selectivity. At 573 K 1 bar a feed molar ratio of 3/1 and a space velocity of 9000 h−1 the PBMR reached the best results in terms of methanol conversion hydrogen yield hydrogen recovery and hydrogen selectivity such as 67.6% 69.5% 14.9% and 97.1% respectively. On the other hand the FBMR demonstrated superior performance with respect to the latter reaching a methanol conversion of 98.3% hydrogen yield of 95.8% hydrogen recovery of 74.5% and hydrogen selectivity of 97.4%. These findings indicate that the FBMR offers significantly better performance than the other reactor types studied in this work making it a highly efficient method for hydrogen production through methanol steam reforming and a promising pathway for clean energy generation.

An important element of modern firefighting is sometimes the use of foam. After the use of extinguishing foam on vehicles or machinery operated by compressed gases it is conceivable that masses of foam were enriched by escaping fuel gas. Furthermore new foam creation enriched with a high level of fuel gas from the deposed foam solution becomes theoretically possible. The aim of this study was to carry out basic experimental investigations on the combustion of water-based H2/air foam. Ignition tests were carried out in a transparent and vertically oriented cylindrical tube (d = 0.09 m; 1.5 m length) and a rectangular thin layer channel (0.02 m × 0.2 m; 2 m length). Additionally results from larger scale tests performed inside a pool (0.30 m × 1 m × 2 m) are presented. All ducts are semi-confined and a foam generator fills the ducts from below with the defined foam. The foams vary in type and concentration of the foaming agent and hydrogen concentration. The expansion ratio of the combustible foam is in the range of 20 to 50 and the investigated H2-concentrations vary from 8 to 70% H2 in air. High-speed imaging is used to observe the combustion and determine flame velocities. The study shows that foam is flammable over a wide range of H2-concentrations from 9 to 65% H2 in air. For certain H2/air-mixtures an abrupt flame acceleration is observed. The velocity of combustion increases rapidly by an order of magnitude and reaches velocities of up to 80 m/s.

This manuscript presents a comprehensive technical review of low-temperature proton exchange membrane fuel cells (LT-PEMFCs) focusing on their performance applications and current challenges within commercial contexts. LT-PEMFCs have reached commercial deployment in light-duty vehicles buses trains heavy-duty trucks stationary combined heat and power units and early maritime platforms. This review consolidates datasheetbased specifications and reconstructed performance parameters from leading manufacturers complemented by qualitative evidence from large-scale deployments in Japan and China to provide the first cross-sectoral benchmarking of LT-PEMFC systems. The analysis is structured around the key performance indicators (KPIs) of the Clean Hydrogen Joint Undertaking and the U.S. Department of Energy which define quantitative targets for 2024 and 2030. Results show that while several light-duty and bus platforms already meet or approach KPI compliance for hydrogen consumption and efficiency other sectors such as heavy-duty stationary and maritime remain below target ranges due to integration constraints and limited transparency in datasheet reporting. The study further highlights divergences between laboratory-reported stack metrics and commercial module specifications demonstrating the need for harmonized definitions of volumetric power density efficiency at rated power and durability. By situating catalogue-only and prototype systems within the technological pipeline the review clarifies how near-term developments may close performance gaps and reduce platinum dependency while also acknowledging the economic and infrastructural dimensions that condition future adoption. This includes recent advances in PGM-free catalysts alloyed and core–shell architectures and ionomer-free electrodes which complement low-PGM approaches in reducing material cost and supply risk. The contribution lies in delivering a transparent and replicable framework that not only maps the current state of LT-PEMFC commercialization but also provides directionality for research policy and industrial innovation on the pathway to 2030 deployment objectives. This represents the first systematic cross-sectoral benchmarking of LTPEMFCs that integrates datasheet-derived and reconstructed specifications with DOE and CHJU KPI frameworks providing both quantitative visualizations and a replicable methodology that clarifies current achievements while indicating where targeted innovation is needed to reach 2030 objectives.