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Hydrogen
Scopus
ISSN 2673-4141 · MDPI AG · 425 articles in the index
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Biohydrogen for a Circular Economy: Progress, Challenges, and Net-Zero Pathways
Hydrogen will play a key role in decarbonising hard-to-abate sectors, yet the current supply is mostly fossil-based and carbon-intensive. Biohydrogen, produced from biomass and organic residues, offers a low-carbon alternative and can achieve negative emissions when integrated with carbon capture…
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Life Cycle Assessment of a Chamotte–Nickel Oxygen Carrier: Environmental Hotspot Identification in Oxygen-Carrier Synthesis
Oxygen carriers (OCs) are essential materials in chemical looping technologies for low-carbon hydrogen production; however, the environmental implications of their synthesis remain insufficiently explored. This study presents a gate-to-gate life cycle assessment (LCA) of a chamotte–nickel OC…
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Bifunctional NiCo/rGO Bimetallic Nanocomposites for Efficient Alkaline Hydrogen and Oxygen Evolution Reaction
Recently, efficient and robust electrocatalysts for alkaline HER and OER are essential for water splitting applications. In the present work, the combination of nickel (Ni) and cobalt (Co) bimetallic nanocomposites embedded on rGO were prepared by the solid-state sintering process. X-ray…
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Exergy-Based Assessment of Green Hydrogen Production for Rational Energy Use in Brazil
The growing global demand for electrical energy and the necessity for decarbonization highlight the importance of assessing the rational use of renewable resources and energy. Thus, this study examined the energy and exergy performance of two offshore wind energy destinations and conversions in…
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Modeling the Non-Premixed Combustion of Methane Enriched by Hydrogen in a Cylindrical Combustor
The global shift toward cleaner energy has positioned hydrogen-enriched methane (CH4/H2) as a practical bridge fuel. While it burns more efficiently and produces fewer carbon emissions than traditional hydrocarbons, it introduces operational and safety challenges. Hydrogen’s high reactivity and…
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Synergistic Co-Digestion of Livestock and Crop Residues: A Techno–Economic and Environmental Comparison of Biorefinery Pathways
The global interest in utilizing waste from agro–industrial processes through the implementation of clean technologies is rapidly increasing. This study evaluates the technical, economic, and environmental feasibility of valorizing regional agro–industrial residues in Santander, Colombia…
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Integrated Spatial and Multiperiod Optimization of Morocco’s Green Hydrogen Supply Chain Using Mixed Integer Linear Programming and a FlexSim/FloWorks Based Digital Twin Simulation
The World Bank’s Lighthouse Strategy identifies Morocco as a first mover exporter of green hydrogen and its derivatives to Europe; however, the engineering feasibility of the associated transport and storage network has not been quantitatively demonstrated. This study addresses that gap through an…
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Numerical Simulation Study on Microwave-Driven Thermal Chemical Decomposition of H2O in Gd-Doped Cerium Oxide
Microwave-driven thermochemical cycles can split water for hydrogen production at temperatures far below those of conventional solar thermochemical routes, yet the responsible physical mechanisms remain unclear and numerical models for the coupled solar-microwave hybrid system are still scarce…
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Clinical Significance of Breath Hydrogen as an External Variable of the Redox Environment
Hydrogen (H2) is a common product of carbohydrate fermentation by the intestinal microbiota, transferred to the blood along the pressure gradient, and exhaled. As H2 is not produced or metabolized in human cells, alveolar H2 is distributed throughout the human body, including cellular organelles…
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Governance Misalignment and the Deployment of Hydrogen as a Marine Fuel
Hydrogen appears in almost every maritime decarbonization roadmap, yet it barely sails: 19 vessels against more than 1600 powered by liquefied natural gas. This study combines an analysis of the global alternative-fueled fleet and orderbook (3094 fuel-vessel records) with an assessment of 26…
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Heat Pumps in Green Hydrogen Production Systems: A Technical Review
Green hydrogen production through water electrolysis is a key pathway to the decarbonization of future energy systems. However, part of the electrical input is transformed into waste heat. In this study, alkaline, proton-exchange membrane, anion-exchange membrane, and solid oxide electrolysis…
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Techno-Economic Assessment of a Hybrid Offshore Wind–Tidal System for Green Hydrogen Production and Maritime Export in Morocco: A Model-Based Feasibility Study
Morocco’s National Green Hydrogen Roadmap targets large-scale hydrogen exports, yet the offshore wind and tidal resources of the Atlantic Sahara coast remain underexplored, and single-resource electrolysis plants suffer from low, variable electrolyser utilisation. This study presents a…
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Optimizing In-Cylinder Charge Preparation in H2DI IC Engines: The Impact of Nozzle Cap Azimuthal and Inclination Angles on Jet Breakup
In recent years, hydrogen-fueled internal combustion engines offer significant potential for achieving high efficiency and near-zero carbon emissions. However, stable combustion remains challenging due to the limited time available for fuel–air mixing, particularly in direct-injection concepts…
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Institutional Fragility and the Conditional Transferability of Green Hydrogen Strategy Across the Middle East and North Africa (MENA): Heterogeneous Burdens, Shared Mechanism
Green hydrogen strategies proliferate across developing economies, yet most assume the planning authority possesses the state capacity, regulatory autonomy, and investment conditions that conflict-affected and fragile economies lack. Whether a strategy logic derived in one such context transfers to…
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Machine Learning-Driven Advances in Hydrogen Embrittlement of Steels: A Comprehensive Review
Hydrogen embrittlement (HE) remains one of the key challenges limiting the safe and reliable deployment of steels in hydrogen production, storage, transportation, and utilization systems. Artificial intelligence (AI) and machine learning (ML) have emerged as powerful tools for predicting HE…
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A Multiphysics Equivalent Stiffness Model for PEMFC Stacks: Design of Experiments Screening of Assembly and Operating Factors
The performance of a Proton Exchange Membrane Fuel Cell (PEMFC) stack is largely determined during assembly, where component materials, sealant selection, and clamping force jointly influence both sealing effectiveness and interfacial losses. These factors interact through coupled mechanical…
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Propagation of Hydrogen-Subsystem Characteristics to Aircraft Level in a Liquid-Hydrogen Fuel-Cell Short-Range Aircraft
Liquid-hydrogen fuel-cell propulsion is a promising option for reducing the climate impact of short-range aviation, but its aircraft-level feasibility depends on the concurrent integration of cryogenic storage, megawatt-class propulsion systems, and thermal management. This paper presents an…
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Hydrogen-Powered Annular Combustor Design and Aerothermal Optimization for a Short-Haul Large-Bypass Turbofan Engine
Commercial aviation contributes approximately 3% of global CO2 emissions, while nitrogen oxides (NOx) remain a major environmental concern. Hydrogen is a promising carbon-free fuel for future gas turbine engines and offers a potential pathway towards net-zero aviation. This study presents the…
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Photobiological Hydrogen Production by Photosynthetic Microorganisms: Integrating Microbial Systems and Bioprocess Engineering
Hydrogen (H2) is widely regarded as a critical energy vector for achieving carbon neutrality, owing to its high energy density and CO2-free combustion. Among sustainable production methods, photobiological H2 synthesis using photosynthetic microorganisms has emerged as a promising strategy due to…
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Mechanism and Energetics of Hydrogen Sulfide Thermolysis from Reactive Molecular Dynamics: Cutoff-Radius Effects, Thermochemically Validated Energy Costs, and the Elementary Reaction Network
Hydrogen sulfide (H2S), a high-volume by-product of the hydrodesulfurization of fossil fuels, can be valorized by thermolysis to recover both molecular hydrogen and elemental sulfur, rather than being oxidized as in the conventional Claus process. The viability of this route depends on quantitative…