Hydrogen

Building on the early investigation by Sidney W. Fox that dry-heated amino acids can spontaneously form microspheres, this research studies the self-organization of glycine and alanine with hydrogen in a liquid system. This study aimed to investigate the spontaneous formation of membraneless, microscale amino acid assemblies under simulated prebiotic hydrothermal conditions, such as hot mineral sources and ponds. Aqueous solutions of glycine and alanine were prepared in a hydrogen-rich mineral buffer and thermally incubated at 75 °C. Phase-contrast microscopy, transmission electron microscopy (TEM), and molecular modeling were employed to analyze the morphology and internal organization of the resulting structures. Microscopy revealed that zwitterionic glycine and alanine spontaneously self-organize into spherical microspheres (~12 µm), in which the charged –NH₃⁺ and –COO⁻ groups orient outward, while the hydrophobic methyl groups of alanine point inward, forming a stabilized internal core. The primary studies were performed with hot mineral water from Rupite, Bulgaria, at 73.4 °C. The resulting osmotic pressure difference Δπ ≈ 2490 Pa, derived from the van’t Hoff equalization. This suggests a chemically asymmetric system capable of sustaining directional water flux and passive molecular enrichment. The zwitterionic nature of glycine and alanine, which possesses both –NH₃⁺ and –COO⁻ groups, supports the formation of microspheres in our experiments. Under conditions with hot mineral water and hydrogen acting as a reducing agent in the primordial atmosphere, these amino acids self-organized into dense interfacial microspheres. These findings support the idea that thermally driven, zwitterion-mediated aggregation of simple amino acids, such as glycine and alanine, with added hydrogen, could generate membraneless, selectively organized microenvironments on the early Earth. Such microspheres may represent a plausible intermediate between dispersed organisms and microspheres. Full article

The transition to low-carbon energy systems requires efficient hydrogen production methods that minimise CO₂ emissions. This study presents a techno-economic assessment of hydrogen production via methane pyrolysis, utilising a novel liquid metal bubble column reactor (LMBCR) designed for CO₂-free hydrogen and solid carbon outputs. Operating at 20 bar and 1100 °C, the reactor employs a molten nickel-bismuth alloy as both catalyst and heat transfer medium, alongside a sodium bromide layer to enhance carbon purity and facilitate separation. Four operational scenarios were modelled, comparing various heating and recycling configurations to optimise hydrogen yield and process economics. Results indicate that the levelised cost of hydrogen (LCOH) is highly sensitive to methane and electricity prices, CO₂ taxation, and the value of carbon by-products. Two reactor configurations demonstrate competitive LCOHs of 1.29 $/kgH₂ and 1.53 $/kgH₂, highlighting methane pyrolysis as a viable low-carbon alternative to steam methane reforming (SMR) with carbon capture and storage (CCS). This analysis underscores the potential of methane pyrolysis for scalable, economically viable hydrogen production under specificmarket conditions. Full article

Effective thermal management is crucial for optimizing the performance, efficiency, and durability of fuel-cell technologies, including proton-exchange membrane fuel cells (PEMFCs) and solid-oxide fuel cells (SOFCs). The operation of fuel cells involves complex heat generation mechanisms, primarily driven by electrochemical reactions, which can lead to significant energy loss as heat. This review examines the specific heat generation sources and challenges associated with different fuel-cell types, highlighting the critical importance of effective thermal management strategies. Key techniques for thermal regulation, including active and passive cooling systems, are examined in detail. Active cooling methods like liquid cooling and air cooling are effective in dissipating excess heat, while passive methods leverage advanced materials and optimized designs to enhance natural heat dissipation. Furthermore, innovative heat recovery systems are explored, demonstrating their potential to enhance overall energy efficiency by capturing and repurposing waste heat. The integration of machine learning techniques has arisen as a promising avenue for advancing temperature control in fuel cells. Reinforcement learning, deep learning algorithms, and support vector machines, along with artificial neural networks, are discussed in the context of their application in managing temperature dynamics and optimizing thermal performance. The review also emphasizes the significance of real-time monitoring, as well as adaptive control strategies to respond effectively to the dynamic operating conditions of fuel cells. Understanding and applying these thermal management strategies is essential for the successful commercialization of fuel cells across various sectors, ranging from automotive to stationary power generation. With the growing demand for clean energy solutions, progress in thermal management techniques will be crucial in improving the dependability and practicality of fuel-cell systems. Full article

Hydrogen is gaining significant interest from researchers because of its renewable and clean nature. In this study, we explored the effects of promoters and oxygen addition on biogas reforming. The promotion of catalysts with alkaline earth metals (Ca and Mg) improved the basicity of the catalyst, leading to enhanced catalytic activity and stability. The promotion of the Ni/TiO₂ catalyst with Ca showed higher CH₄ conversion and H₂ yield compared to the bare and Mg-Ni/TiO₂ catalysts. The enhanced activity of Ca-Ni/TiO₂ could be attributed to its high dispersion, small particulate size, and strong metal–support interaction. Adding oxygen to the reactor feed improved the activity and stability of the catalyst due to the simultaneous occurrence of dry and partial oxidative reforming. The maximum CH₄ conversion and H₂ yield of 81.13 and 37.5% were obtained at 800 °C under dry reforming conditions, which increased to 96 and 57.6% under dry-oxidative reforming (O₂/CH₄ = 0.5). The CHNS analysis of the spent Ca-Ni/TiO₂ catalyst also showed carbon deposition of only 0.58% after 24 h of continuous dry-oxidative reforming compared to 25.16% under continuous dry reforming reaction. XRD analysis of the spent catalyst also confirmed the formation of carbon deposits under dry reforming. Adding oxygen to the feed resulted in the simultaneous removal of carbon species formed over the catalytic surface through gasification. These findings demonstrate that Ca promotion combined with oxygen addition significantly improves the catalyst efficiency and durability, offering a promising pathway for stable, long-term hydrogen generation. The results highlight the potential of Ca–Ni/TiO₂ catalysts for integration into biogas reforming units at an industrial scale, supporting renewable hydrogen production and carbon mitigation in future energy systems. Full article

Pipe exits into cryogenic systems, such as an exit of a venting or sensor tube inside a cryogenic storage tank, can affect spontaneously occurring acoustic oscillations, known as Taconis oscillations. The amplitude which such oscillations will reach is dependent on losses at the pipe exit that prevent resonant oscillations from growing without bound. Consequently, being able to accurately determine minor losses at a pipe exit is important in predicting the behavior of these oscillations. Current thermoacoustic modeling of such transitions typically relies on steady-flow minor loss coefficients, which are usually assumed to be constant for a pipe entrance or exit. In this study, numerical simulations are performed for acoustic flow at a pipe exit, with and without a wall adjacent to the exit. The operating fluid is cryogenic hydrogen gas, while the pipe radius (2 and 4 mm), temperature (40 and 80 K), and acoustic velocity amplitudes (varying in the range of 10 m/s to 70 m/s) are variable parameters. The simulation results are compared with one-dimensional acoustic models to determine the behavior of minor losses. Results are also analyzed to find harmonics behavior and a build-up of mean pressure differences. Minor losses decrease to an asymptotic value with increasing Reynolds number, while higher temperatures also reduce minor losses (10% reduction at 80 K versus 40 K). A baffle sharply increases minor losses as the distance to pipe exit decreases. These findings can be used to improve the accuracy of oscillation predictions by reduced-order thermoacoustic models. Full article

Social acceptability is a critical factor in the successful implementation of emerging energy technologies, particularly hydrogen, which faces both technical and perceptual challenges. This study offers the first systematic investigation of public perceptions of hydrogen technologies in Albania, addressing a key knowledge gap in the Western Balkan countries. Using a structured survey of 440 respondents, it examines awareness, perceived benefits and risks, institutional trust, and willingness to adopt hydrogen solutions. While 84.5% had heard of hydrogen, only 23.6% were familiar with its technologies and just 9.3% felt well-informed—this highlights a major knowledge gap. Public attitudes were largely positive: 73.4% acknowledged hydrogen’s role in reducing emissions and 70.7% its potential to lower energy dependence. However, 34.5% viewed hydrogen as too dangerous near residential areas, and 50% were undecided. The most cited barriers were lack of information (50.5%) and infrastructure (19.5%). Trust in institutions was moderate, and gender differences were significant, with men showing higher awareness and support. Encouragingly, 78% of respondents wanted to learn more, and 63% showed interest in future use. Educational institutions were the most trusted information source. The findings highlight the need for public awareness campaigns, transparent risk communication, and community-oriented policies to foster a socially inclusive hydrogen transition in Albania. Full article

This review presents a critical analysis of Japan’s hydrogen strategy, focusing on the broader context of its decarbonization efforts. Japan aims to achieve carbon neutrality by 2050, with intermediate targets including 3 million tons of hydrogen use by 2030 and 20 million tons by 2050. Unlike countries with abundant domestic renewables, Japan’s approach emphasizes hydrogen imports and advanced storage technologies, driven by limited local renewable capacity. This review not only synthesizes policy and project-level developments but also critically evaluates Japan’s hydrogen roadmap by examining its alignment with global trends, technology maturity, and infrastructure scalability. The review integrates recent policy updates, infrastructure developments, and pilot project results, providing insights into value chain modeling, cost reduction strategies, and demand forecasting. Three policy conclusions emerge. First, Japan’s geography justifies an import-reliant pathway, but it heightens exposure to price, standards, and supply-chain risk; diversification across LH₂ and ammonia with robust certification and offtake mechanisms is essential. Second, near-term deployment is most credible in industrial feedstocks (steel, ammonia, methanol) and the maritime sector, while refueling rollout lags materially behind plan and should be recalibrated. Third, cost competitiveness hinges less on electrolyzer CAPEX than on electricity price, liquefaction, transport; policy should prioritize bankable offtake, grid-connected renewables and transmission, and targeted CAPEX support for import terminals, bunkering, and cracking. Japan’s experience offers a pathway in the global hydrogen transition, particularly for countries facing similar geographic and energy limitations. By analyzing both the progress and the limitations of Japan’s hydrogen roadmap, this study contributes to understanding diverse national strategies in the rapidly changing state of implementation of clean energy. Full article

The paper investigates the potential of co-electrolysis as a viable pathway for hydrogen production and industrial decarbonization, expanding on previous studies on water electrolysis. The analysis adopts a general and critical perspective, aiming to assess the realistic scope of this technology with regard to current energy and environmental needs. Although co-electrolysis theoretically offers improved efficiency by simultaneously converting H₂O and CO₂ into syngas, the practical advantages are difficult to consolidate. The study highlights that the energetic margins of the process remain relatively narrow and that several key aspects, including system irreversibility and the limited availability of CO₂ in many contexts, significantly constrain its applicability. Despite the growing interest and promising technological developments, co-electrolysis still faces substantial challenges before it can be implemented on a larger scale. The findings suggest that its success will depend on targeted integration strategies, advanced thermal management, and favorable boundary conditions rather than on the intrinsic efficiency of the process alone. However, there are specific sectors where assessing the implementation potential of co-electrolysis could be of interest, a perspective this paper aims to explore. Full article

Green hydrogen is gaining global attention as a zero-carbon energy carrier with the potential to drive sustainable energy transitions, particularly in regions facing rising fossil fuel costs and resource depletion. In sub-Saharan Africa, financing mechanisms and structured off-take agreements are critical to attracting investment across the green hydrogen value chain, from advisory and pilot stages to full-scale deployment. While substantial funding is required to support a green economic transition, success will depend on the effective mobilization of capital through smart public policies and innovative financial instruments. This review evaluates financing mechanisms relevant to sub-Saharan Africa, including green bonds, public–private partnerships, foreign direct investment, venture capital, grants and loans, multilateral and bilateral funding, and government subsidies. Despite their potential, current capital flows remain insufficient and must be significantly scaled up to meet green energy transition targets. This study employs a mixed-methods approach, drawing on primary data from utility firms under the H₂Atlas-Africa project and secondary data from international organizations and the peer-reviewed literature. The analysis identifies that transitioning toward Net-Zero emissions economies through hydrogen development in sub-Saharan Africa presents both significant opportunities and measurable risks. Specifically, the results indicate an estimated investment risk factor of 35%, reflecting potential challenges such as financing, infrastructure, and policy readiness. Nevertheless, the findings underscore that green hydrogen is a viable alternative to fossil fuels in sub-Saharan Africa, particularly if supported by targeted financing strategies and robust policy frameworks. This study offers practical insights for policymakers, financial institutions, and development partners seeking to structure bankable projects and accelerate green hydrogen adoption across the region. Full article

Hydrogen energy is considered a crucial clean energy carrier for replacing fossil fuels in the future. Liquid hydrogen (LH₂), with its economic advantages and high purity, is central to the development of future hydrogen refueling stations (HRSs). However, leakage poses significant fire and explosion risks, challenging its safe industrial use. In this study, a numerical model of LH₂ leakage at an HRS in Chongqing was established using Computational Fluid Dynamics (CFD) software. The diffusion law of a flammable gas cloud (FGC) was examined under the synergistic effect of the leakage direction, rate, and wind speed of an LH₂ storage tank in an HRS. The phase transition of LH₂ presents dual risks of combustion and frostbite owing to the spatial overlap between low-temperature areas and FGCs. The findings revealed that the equivalent stoichiometric gas cloud volume (Q9) reached 685 m³ in the case of crosswind leakage, with the superimposed effect of reflected waves from the LH₂ transport vehicle resulting in a peak explosion overpressure of 0.61 bar. The low-temperature hazard area and the FGC (with a concentration of 30–75%) show significant spatial overlap. These research outcomes offer crucial theoretical underpinning for enhancing equipment layout optimization and safety protection strategies at HRSs. Full article

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. Full article

Green hydrogen derived from renewable resources is increasingly recognized as a basis for future low-carbon energy systems. This study presents a comprehensive techno-environmental comparison of two thermochemical conversion pathways utilizing biomethane: steam methane reforming (SMR) and chemical looping reforming (CLR). Through integrated process simulations, compositional analyses, energy modeling, and cost evaluation, we examine the comparative advantages of each route in terms of hydrogen yield, carbon separation efficiency, process energy intensity, and economic performance. The results demonstrate that CLR achieves a significantly higher hydrogen concentration in the raw syngas stream (62.44%) than SMR (43.14%), with reduced levels of residual methane and carbon monoxide. The energy requirements for hydrogen production are lower in the CLR system, averaging 1.2 MJ/kg, compared to 3.2 MJ/kg for SMR. Furthermore, CLR offers a lower hydrogen production cost (USD 4.3/kg) compared to SMR (USD 6.4/kg), primarily due to improved thermal integration and the absence of solvent-based CO₂ capture. These insights highlight the potential of CLR as a next-generation reforming strategy for producing green hydrogen. To advance its technology readiness, it is proposed to develop a pilot-scale CLR facility to validate system performance under operational conditions and support the pathway to commercial implementation. Full article

In the design of pressure vessels for hydrogen storage, the durability and robustness of the designs are tested by using experimental methods, numerical simulations, or both. However, in the initial design phase, it is widely known that using numerical simulation tools reduces the cost of performing experiments; therefore, models that provide accurate and reliable results must be developed. This work presents an axisymmetric finite element model to predict the mechanical response of reinforced wire pressure vessels of type II. The main contribution of the present model is the use of equivalent properties and a minor number of contact elements to simulate the behavior of the wire reinforcement, which reduces the computational effort compared to a model with a solid-based mesh. The accuracy of the proposed model is tested against solid elements with very good agreement and experimental results with reasonable agreement. A parametric study was conducted to test the influence of the number of layers of reinforcement, and it was concluded that there is a limit to increasing the number of layers, which does not increase the vessel’s strength considerably, but it does with its mass. Full article

Given the urgent need to decarbonize the global energy system, green hydrogen has emerged as a key alternative in the transition to renewables. However, its production via electrolysis demands high water quality and raises environmental concerns, particularly regarding reject water discharge. This study employs an experimental and analytical approach to define optimal water characteristics for electrolysis, focusing on conductivity as a key parameter. A pilot water treatment plant with reverse osmosis and electrodeionization (EDI) was designed to simulate industrial-scale pretreatment. Twenty water samples from diverse natural sources (surface and groundwater) were tested, selected for geographical and geological variability. A predictive algorithm was developed and validated to estimate useful versus reject water based on input quality. Three conductivity-based categories were defined: optimal (0–410 µS/cm), moderate (411–900 µS/cm), and restricted (>900 µS/cm). Results show that water quality significantly affects process efficiency, energy use, waste generation, and operating costs. This work offers a technical and regulatory framework for assessing potential sites for green hydrogen plants, recommending avoidance of high-conductivity sources. It also underscores the current regulatory gap regarding reject water treatment, stressing the need for clear environmental guidelines to ensure project sustainability. Full article

Inspired by the Toyota Mirai, this study presents a high-fidelity data-driven approach for modelling and simulation of a fuel cell hybrid electric powertrain. This study utilises technical assessment data sourced from Argonne National Laboratory’s publicly available report, faithfully modelling most of the vehicle subsystems as data-driven entities. The simulation framework is developed in the MATLAB/Simulink environment and is based on a power dynamics approach, capturing nonlinear interactions and performance intricacies between different powertrain elements. This study investigates subsystem synergies and performance boundaries under a combined driving cycle composed of the NEDC, WLTP Class 3 and US06 profiles, representing urban, extra-urban and aggressive highway conditions. To emulate the real-world load-following strategy, a state transition power management and allocation method is synthesised. The proposed method dynamically governs the power flow between the fuel cell stack and the traction battery across three operational states, allowing the battery to stay within its allocated bounds. This simulation framework offers a near-accurate and computationally efficient digital counterpart to a commercial hybrid powertrain, serving as a valuable tool for educational and research purposes. Full article

Hydrogen is a potential key component of a carbon-neutral energy carrier and an input to marine industrial processes. This study examines the consequences of coupled hydrogen release and marine environmental factors during floating photovoltaic hydrogen production (FPHP) system failures. A validated three-dimensional numerical model of FPHP comprehensively characterizes hydrogen leakage dynamics under varied rupture diameters (25, 50, 100 mm), transient release duration, dispersion patterns, and wind intensity effects (0–20 m/s sea-level velocities) on hydrogen–air vapor clouds. FLACS-generated data establish the concentration–dispersion distance relationship, with numerical validation confirming predictive accuracy for hydrogen storage tank failures. The results indicate that the wind velocity and rupture size significantly influence the explosion risk; 100 mm ruptures elevate the explosion risk, producing vapor clouds that are 40–65% larger than 25 mm and 50 mm cases. Meanwhile, increased wind velocities (>10 m/s) accelerate hydrogen dilution, reducing the high-concentration cloud volume by 70–84%. Hydrogen jet orientation governs the spatial overpressure distribution in unconfined spaces, leading to considerable shockwave consequence variability. Photovoltaic modules and inverters of FPHP demonstrate maximum vulnerability to overpressure effects; these key findings can be used in the design of offshore platform safety. This study reveals fundamental accident characteristics for FPHP reliability assessment and provides critical insights for safety reinforcement strategies in maritime hydrogen applications. Full article

This work addresses for the first time the effect of anode serpentine channel depth on Methanol Electrolysis Cells (MECs) and Direct Methanol Fuel Cells (DMFCs) for improving performance of both devices. Anode plates with serpentine flow fields of 0.5 mm, 1.0 mm and 1.5 mm depths are designed and tested in single-cells to compare their behaviour. Performance was evaluated through methanol crossover, polarization and power density curves. Results suggest shallower channels enhance mass transfer efficiency reducing MEC energy consumption for hydrogen production at 40 mA∙cm⁻² by 4.2%, but increasing methanol crossover by 30.3%. The findings of this study indicate 1.0 mm is the best depth among those studied for a MEC with 16 cm² of active area, while 0.5 mm is the best for a DMFC with the same area with an increase in peak power density of 14.2%. The difference in results for both devices is attributed to higher CO₂ production in the MEC due to its higher current density operation. This increased CO₂ production alters anode two-phase flow, partially hindering the methanol oxidation reaction with shallower channels. These findings underscore the critical role of channel depth in the efficiency of both MEC and DMFC single-cells. Full article

The promising development of hydrogen and fuel cell technologies has garnered increased attention in recent years, assuming a significant role in industrial applications and the decarbonisation of the shipping industry. Given that the shipping industry generates considerable greenhouse gas emissions, it is crucial and imperative to implement integrated solutions based on clean energy sources, thereby meeting the proposed climate objectives. This study presents the standard hydrogen production, storage, and transport methods and analysis technologies that use hydrogen fuel cells in marine and industrial applications. Technologies based on hydrogen fuel cells and hybrid systems will have an increased perspective of application in industry and maritime transport under the conditions of optimising technological models, developing the hydrogen industrial chain, and updating standards and regulations in the field. However, there are still many shortcomings. The paper’s main contribution is analysing the hydrogen industrial chain, presenting the progress and obstacles associated with the technologies used in industrial and marine applications based on hydrogen energy. Full article

This study examines the surface chemistry of platinum, palladium, rhodium, and ruthenium-substituted lanthanum strontium cobaltate perovskite catalysts in the context of the dry reforming of methane (DRM). The catalysts were synthesized by the solution combustion method and characterized by using a series of techniques. To explore the effect of noble metal ion substitution on the DRM, surface reaction was probed by CH₄/CO₂ TPSR using mass spectroscopy. It was recognized that La_1−xSr_xCo_1−yPd_yO₃ show the best activities for the reaction in terms of the temperature but became deactivated over time. CH₄/CO₂ temperature-programmed surface reactions (TPSRs) were set up to unravel the details of the surface phenomena responsible for the deactivation of the DRM activity on the LSPdCO. The CH₄/CO₂ TPSR analysis conclusively demonstrated the importance of lattice oxygen in the removal of carbon, which is responsible for the stability of the catalysts on the synthesized perovskites upon noble metal ion substitution. Full article