China, People’s Republic

Methanol steam reforming (MSR) represents a highly promising pathway for sustainable hydrogen production due to its favorable hydrogen-to-carbon ratio and relatively low operating temperatures. The performance of the MSR process is strongly dependent on the selection and rational design of catalysts which govern methanol conversion hydrogen selectivity and the suppression of undesired side reactions such as carbon monoxide formation. Moreover advancements in reactor configuration and thermal management strategies play a vital role in minimizing heat loss and enhancing heat and mass transfer efficiency. Effective carbon monoxide removal technologies are indispensable for obtaining high-purity hydrogen particularly for applications sensitive to CO contamination. This review systematically summarizes recent progress in catalyst development reactor design and gas purification technologies for MSR. In addition the key technical challenges and potential future directions of the MSR process are critically discussed. The insights provided herein are expected to contribute to the development of more efficient stable and scalable MSR-based hydrogen production systems.

Underground hydrogen storage has gained interest in recent years due to the enormous demand for clean energy. Hydrogen is more diffusive than air with a smaller density and lower viscosity. These unique properties introduce distinctive hydrodynamic phenomena in hydrogen storage one of which is fingering. Fingering could induce the fluid trapped in small clusters of pores leading to a dramatic decrease in hydrogen saturation and a lower recovery rate. In this study numerical simulations are performed at the microscopic scale to understand the evolution of hydrogen saturation and the impacts of injection and withdrawal cycles. Two sets of micromodels with different porosity (0.362 and 0.426) and minimum sizes of pore throats (0.362 mm and 0.181 mm) are developed in the numerical model. A parameter analysis is then conducted to understand the influence of injection velocity (in the range of 10-2 m/s to 10-5 m/s) and porous structure on the fingering pattern followed by an image analysis to capture the evolution of the fingering pattern. Viscous fingering capillary fingering and crossover fingering are observed and identified under different boundary conditions. The fractal dimension specific area mean angle and entropy of fingers are proposed as geometric descriptors to characterize the shape of the fingering pattern. When porosity increases from 0.362 to 0.426 the saturation of hydrogen increases by 26.2%. Narrower pore throats elevate capillary resistance which hinders fluid invasion. These results underscore the importance of pore structures and the interaction between viscous and capillary forces for hydrogen recovery efficiency. This work illuminates the influence of the pore structures and the fluid properties on the immiscible displacement of hydrogen and can be further extended to optimize the injection strategy of hydrogen in underground hydrogen storage.

Hydrogen-powered unmanned aerial vehicles (UAVs) offer significant advantages such as environmental sustainability and extended endurance demonstrating broad application prospects. However the hydrogen fuel cells face prominent thermal management challenges during flight operations. This study established a numerical model of the fuel cell thermal management system (TMS) for a hydrogen-powered UAV. Computational fluid dynamics (CFD) simulations were subsequently performed to investigate the impact of various design parameters on cooling performance. First the cooling performance of different fan density configurations was investigated. It was found that dispersed fan placement ensures substantial airflow through the peripheral flow channels significantly enhancing temperature uniformity. Specifically the nine-fan configuration achieves an 18.5% reduction in the temperature difference compared to the four-fan layout. Additionally inlets were integrated with the fan-based cooling system. While increased external airflow lowers the minimum fuel cell temperature its impact on high-temperature zones remains limited with a temperature difference increase of more than 19% compared to configurations without inlets. Furthermore the middle inlet exhibits minimal vortex interference delivering superior thermal performance. This configuration reduces the maximum temperature and average temperature by 9.1% and 22.2% compared to the back configuration.

Photocatalytic membrane reactors (PMRs) which combine photocatalysis with membrane separation represent a pivotal technology for sustainable water treatment and resource recovery. Although extensive research has documented various configurations of photocatalytic-membrane hybrid processes and their potential in water treatment applications a comprehensive analysis of the interrelationships among reactor architectures intrinsic physicochemical mechanisms and overall process efficiency remains inadequately explored. This knowledge gap hinders the rational design of highly efficient and stable reactor systems—a shortcoming that this review seeks to remedy. Here we critically examine the connections between reactor configurations design principles and cutting-edge applications to outline future research directions. We analyze the evolution of reactor architectures relevantreaction kinetics and key operational parameters that inform rational design linking these fundamentals to recent advances in solar-driven hydrogen production CO2 conversion and industrial scaling. Our analysis reveals a significant disconnect between the mechanistic understanding of reactor operation and the system-level performance required for innovative applications. This gap between theory and practice is particularly evident in efforts to translate laboratory success into robust and economically feasible industrial-scale operations. We believe that PMRs willrealize theirtransformative potential in sustainable energy and environmental applications in future.

Environmental pollution caused by shipping has always received great attention from the international community. Currently due to the difficulty of fully electrifying medium- and large-scale ships the hybrid energy ship power system (HESPS) will be the main type in the future. Considering the economic and long-term energy efficiency of ships as well as the uncertainty of the output power of renewable energy units this paper proposes an improved design for an integrated power system for large cruise ships combining renewable energy and a hybrid energy storage system. An energy management strategy (EMS) based on time-gradient control and considering load dynamic response as well as an energy storage power allocation method that considers the characteristics of energy storage devices is designed. A bi-level power capacity optimization model grounded in comprehensive scenario planning and aiming to optimize maximum return on equity is constructed and resolved by utilizing an improved particle swarm optimization algorithm integrated with dynamic programming. Based on a large-scale cruise ship the aforementioned method was investigated and compared to the conventional planning approach. It demonstrates that the implementation of this optimization method can significantly decrease costs enhance revenue and increase the return on equity from 5.15% to 8.66%.

Thermo-chemical conversion of waste plastics offers a sustainable strategy for integrated waste management and clean energy generation. To address the challenges of low gas yield and rapid catalyst deactivation due to coking in conventional gasification processes an innovative three-stage chemical looping gasification (CLG) system specifically designed for enhanced hydrogen-rich syngas production was proposed in this work. A comparative analysis between conventional gasification and the staged CLG system were firstly conducted coupled with online gas analysis for mechanistic elucidation. The influence of Fe/Al molar ratios in oxygen carriers and their cyclic stability were systematically examined through multicycle experiments. Results showed that the three-stage CLG in the presence of Fe1Al2 demonstrated exceptional performance achieving 95.23 mmol/gplastic of H2 and 129.89 mmol/gplastic of syngas respectively representing 1.32-fold enhancement over conventional method. And the increased H2/CO ratio (2.68-2.75) reflected better syngas quality via water-gas shift. Remarkably the oxygen carrier maintained nearly 100% of its initial activity after 7 redox cycles attributed to the incorporation of Al2O3 effectively mitigating sintering and phase segregation through metal-support interactions. These findings establish a three-stage CLG configuration with Fe-Al oxygen carriers as an efficient platform for efficient hydrogen production from waste plastics contributing to sustainable waste valorisation and carbon-neutral energy systems.

Hydrogen-powered aircraft as a cutting-edge exploration of clean-energy air transportation have more stringent requirements for lightweight hydrogen storage equipment due to the limitations of aircraft weight and volume. Composite hydrogen storage cylinders have become one of the preferred solutions for hydrogen storage systems in hydrogen-powered aircraft due to their light weight and high strength. However during the automated placement of high-stiffness thermoplastic composites (T700/PEEK) fibers can buckle or fracture in the header section. As the header radius decreases the overlap of adjacent tows increases resulting in buildup in the thickness of the polar pores which contradicts the lightweight requirements. To solve this problem this paper derives the trajectory algorithm as a manufacturing process limitation when thermoplastic fiber bundles are laid without wrinkles and the effect of different ellipsoid ratios of head profile changes on the overlap of fiber bundles is investigated. The larger the ellipsoid ratio of the prolate ellipsoid is the smaller overlap of gaps generated by neighboring fiber bundles is and the overlap at the pole holes is also smaller whereas the change of the oblate ellipsoid is not significant. The prolate ellipsoid has more application and research value than the oblate ellipsoid in terms of processability which is of great exploration significance for the design and fabrication of thermoplastic composite hydrogen storage cylinders for hydrogen-powered aircraft.

To mitigate explosion hazards arising from hydrogen leakage and subsequent mixing with air the injection of inert gases can substantially diminish explosion risk. However prevailing research has predominantly characterized inert gas dilution effects on explosion behavior under quiescent conditions largely neglecting the turbulence-mediated explosion enhancement inherent to dynamic mixing scenarios. A comprehensive investigation was conducted on the combustion behavior of 30% 50% and 70% H2-air mixtures subjected to jet-induced (CO2 N2 He) turbulent flow incorporating quantitative characterization of both the evolving turbulent flow field and flame front dynamics. Research has demonstrated that both an increased H2 concentration and a higher jet medium molecular weight increase the turbulence intensity: the former reduces the mixture molecular weight to accelerate diffusion whereas the latter results in more pronounced disturbances from heavier molecules. In addition when CO2 serves as the jet medium a critical flame radius threshold emerges where the flame propagation velocity decreases below this threshold because CO2 dilution effects suppress combustion whereas exceeding it leads to enhanced propagation as initial disturbances become the dominant factor. Furthermore at reduced H2 concentrations (30–50%) flow disturbances induce flame front wrinkling while preserving the spherical geometry; conversely at 70% H2 substantial flame deformation occurs because of the inverse correlation between the laminar burning velocity and flame instability governing this transition. Through systematic quantitative analysis this study elucidates the evolutionary patterns of both turbulent fields and flame fronts offering groundbreaking perspectives on H2 combustion and explosion propagation in turbulent environments.

With the accelerating global transition to clean energy underground hydrogen storage (UHS) has gained significant attention as a flexible and renewable energy storage technology. Ontario Canada as a pioneer in energy transition offers substantial underground storage potential with its geological conditions of salt limestone and sandstone providing diverse options for hydrogen storage. However the hydrogen transport characteristics of different rock media significantly affect the feasibility and safety of energy storage projects warranting in-depth research. This study simulates the hydrogen flow and transport characteristics in typical energy storage digital rock core models (salt rock limestone and sandstone) from Ontario using the improved quartet structure generation set (I-QSGS) and the lattice Boltzmann method (LBM). The study systematically investigates the distribution of flow velocity fields directional characteristics and permeability differences covering the impact of hydraulic changes on storage capacity and the mesoscopic flow behavior of hydrogen in porous media. The results show that salt rock due to its dense structure has the lowest permeability and airtightness with extremely low hydrogen transport velocity that is minimally affected by pressure differences. The microfracture structure of limestone provides uneven transport pathways exhibiting moderate permeability and fracture-dominated transport characteristics. Sandstone with its higher porosity and good connectivity has a significantly higher transport rate compared to the other two media showing local high-velocity preferential flow paths. Directional analysis reveals that salt rock and sandstone exhibit significant anisotropy while limestone’s transport characteristics are more uniform. Based on these findings salt rock with its superior sealing ability demonstrates the best hydrogen storage performance while limestone and sandstone also exhibit potential for storage under specific conditions though further optimization and validation are required. This study provides a theoretical basis for site selection and operational parameter optimization for underground hydrogen storage in Ontario and offers valuable insights for energy storage projects in similar geological settings globally.

The maritime sector’s transition to sustainable energy is critical for achieving global carbon neutrality with container terminals representing a key focus due to their high energy consumption and emissions. This study explores the potential of hydrogen energy as a decarbonization solution for port operations using the Chuanshan Port Area of Ningbo Zhoushan Port (CPANZP) as a case study. Through a comprehensive analysis of hydrogen production storage refueling and consumption technologies we demonstrate the feasibility and benefits of integrating hydrogen systems into port infrastructure. Our findings highlight the successful deployment of a hybrid “wind-solar-hydrogen-storage” energy system at CPANZP which achieves 49.67% renewable energy contribution and an annual reduction of 22000 tons in carbon emissions. Key advancements include alkaline water electrolysis with 64.48% efficiency multi-tier hydrogen storage systems and fuel cell applications for vehicles and power generation. Despite these achievements challenges such as high production costs infrastructure scalability and data integration gaps persist. The study underscores the importance of policy support technological innovation and international collaboration to overcome these barriers and accelerate the adoption of hydrogen energy in ports worldwide. This research provides actionable insights for port operators and policymakers aiming to balance operational efficiency with sustainability goals.