Search Results (2,540)

Hoop-wrapped vessels with metal liners (Type II vessels) are susceptible to the risks of brittle fracture and fatigue failure in high-pressure hydrogen environments. However, there is limited research concerning fitness-for-service (FFS) assessments of Type II vessels. An FFS assessment was conducted on a specific Type II vessel designed for high-pressure hydrogen storage. The mechanical properties of the liner material 4130X were obtained through in situ mechanical testing in a hydrogen environment. Based on the measured data, the stress distribution within the Type II vessel under different working conditions was determined using a finite element analysis by ANSYS Workbench 2019 R2 software. A leak-before-burst (LBB) analysis and a brittle fracture assessment of the Type II vessel were performed using the failure assessment diagram (FAD) methodology. The results indicate that the measured fracture toughness of 4130X under high-pressure hydrogen is 46 MPa·m^0.5, which is significantly lower than the 178 MPa·m^0.5 required for LBB failure for the studied vessel. However, the vessel remains in a safe state when the crack depth is under 3.03 mm. Furthermore, the remaining fatigue life of a Type II vessel containing a crack was calculated. The relationship between the non-destructive testing (NDT) capability requirement and the inspection interval for this type of vessel was explored, providing references for establishing inspection schedules for Type II vessels. Full article

A form of long-term hydrogen storage with high volume efficiency is hydrogen absorption into the host lattice of a metal or an alloy. Unlike high-pressure hydrogen storage, this form of storage is characterised by a low operating pressure. By employing metal hydride (MH) materials in a low-pressure refuelling station, it is possible to significantly increase the safety of hydrogen storage and, at the same time, to facilitate the refuelling of external devices that use MH storage tanks without the necessity of using a compressor. In this article, a methodology for the identification of the mathematical correlations among the hydrogen pressure in the storage tank, the hydrogen concentration in the alloy and the volumetric flow rate of hydrogen is described. This methodology may be used to identify the kinetics of the process and to create simplified simulations of the hydrogen release from an absorption-based storage tank by applying a finite difference method. The mathematical correlations are based on measurements of hydrogen desorption, during which hydrogen was released from the storage tank at stabilised pressure levels. The resulting mathematical description facilitates the identification of the approximate hydrogen pressure, depending on its flow rate, for a particular MH storage tank, while respecting the complexity of its internal structure, heat transfer and the hydrogen’s passage through a porous powder MH material. The identified mathematical dependence applies to the certified MNTZV-159 storage tank at pressures ranging from 7 to 29.82 bar, with hydrogen concentrations ranging from 0.223 to 1.342%, an input temperature of 59.5 °C and a cooling water flow rate of 4.36 L·min⁻¹. This methodology for the identification of a correlation between the flow rate, pressure and hydrogen concentration applies to this particular type of storage tank, and it depends not only on the alloy used and the quantity of this alloy but also on the internal structure of the heat exchanger. Full article

The aim of this study is to compare the performance of the multi-layer and the single-layer CO₂ injection methods used in offshore carbon capture and storage (CCS) through TOUGH-FLAC numerical simulations. Four key indicators, namely CO₂ saturation, pore pressure, vertical displacement, and Coulomb Failure Stress (CFS), are employed as indices to assess the storage capacity of reservoirs and the mechanical stability of caprocks. Numerical simulation results show that the multi-layer injection method increases the CO₂ migration distance and reduces CFS values compared with the single-layer injection method. After 1 year of injection, the combined CO₂ migration distance across two aquifers in Case 3 is 610 m, which is greater than that obtained using single-layer injection in Cases 1 and 2 (350 m and 380 m, respectively). Additionally, deep saline aquifers demonstrate superior CO₂ storage capacity due to higher overburden pressure, which also reduces the risk of caprock failures. After 30 years of injection, in Cases 1 and 2, the maximum CFS values are 0.591 and 0.567, respectively, and the CO₂ migration distances are 2400 m and 2650 m, respectively. Overall, the findings of this study indicate that the multi-layer injection method, particularly in deep saline aquifers, provides a safer and more efficient CO₂ injection approach for offshore CCS projects. Full article

This study investigates the energy consumption characteristics of individual and clustered thermal storage electric heating systems, focusing on their sustainability implications for regional load distribution and user energy consumption patterns. Simulation results show that thermal storage electric heating shifts peak energy demand from daytime to nighttime low-price hours, reducing electricity costs and optimizing grid load balancing. As the proportion of thermal storage electric heating increases from 10% to 30%, the daytime minimum load reduction rate rises from 7% to 22%, while the nighttime maximum load increase rate increases from 16% to 63%. This operational mode supports sustainable energy usage by alleviating daytime grid peak pressure and leveraging low-cost, off-peak electricity for heat storage. The findings highlight the potential of thermal storage electric heating to enhance energy efficiency, integrate renewable energy, and promote grid stability, contributing to a more sustainable energy system. Full article

To reduce CO₂ emissions, CO₂ geological storage is recognized as an effective approach to decrease atmospheric carbon concentration. Sequestration in deep saline aquifers has become a research focus. However, the physicochemical property changes in saline formations induced by CO₂ injection remain unclear, making it difficult to assess their CO₂ storage potential. This study focuses on saline aquifers within the Jurassic Badaowan formation (J₁b), Sangonghe formation (J₁s), and Cretaceous Tugulu Group (K₁tg) of the Baijiahai Uplift in the Junggar Basin. An integrated methodology combining laboratory experiments—including CO₂ static immersion tests, dynamic displacement tests, X-ray diffraction (XRD), mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR) measurements, and mechanical testing—with CMG-based numerical modeling was employed to analyze CO₂ storage mechanisms and evaluate storage potential. The results show that after CO₂ immersion, extensive dissolution of calcite in J₁s, clay swelling/cementation in J₁b, and extensive dissolution of calcite in K₁tg all lead to increased porosity and permeability, with the J₁b formation exhibiting superior CO₂ storage capacity, the highest MICP-derived porosity, and the greatest NMR-measured porosity among the three formations. Numerical simulations further confirmed J₁b’s leading sequestration volume. Based on integrated experimental and simulation results, the J₁b formation is identified as the optimal reservoir for CO₂ storage. However, to manage potential mechanical instability during real-world injection scenarios, injection pressures and rates should be carefully controlled and continuously monitored to avoid formation fracturing and ensure long-term storage security. This study provides a reference for implementing saline aquifer CCUS projects. Full article

The global energy transition is accelerating, yet new and underestimated challenges have emerged since 2024. Rising electricity demand—driven by artificial intelligence data centres, extreme heatwaves, and the electrification of transport—has exceeded earlier projections and shifted the system’s pressure point from generation to flexibility. At the same time, an oversupply of solar PV panels and lithium-ion batteries is lowering costs but increasing the risk of trade conflicts and supply chain concentration. This article presents a meta-analysis of 12 energy scenarios from 2024 to 2025, based on institutional outlooks (IEA, BNEF, and WEF) and peer-reviewed publications selected using transparent quality criteria (TRL thresholds, JRC guidance, and data transparency). A difference-in-differences method is applied to identify changes between editions. Results show a demand increase of over 2200 TWh by 2035, a decline in the “Net-Zero premium” from 19% to 15%, and a pressing need to redirect investment from gas infrastructure to grids, storage, and hydrogen. A case study for Central and Eastern Europe reveals that Poland will require USD 5–6 billion annually, primarily for transmission networks. These findings support a capital shift toward resilient and socially acceptable decarbonisation pathways. Full article

Hydrogen is emerging as a key energy vector for the transition toward renewable and sustainable energy sources. However, its safe and efficient storage remains a significant technical challenge in terms of cost, safety, and performance. In this study, we aimed to address the kinetic limitations of Mg by synthesizing catalyzed Mg@Ni systems using commercially available micrometric magnesium particles (~26 µm), which were decorated via electroless nickel plating under both aqueous and anhydrous conditions. Morphological and compositional characterization was carried out using SEM, EDS, and XRD. The resulting materials were evaluated through Temperature-Programmed Desorption (TPD), DSC, and isothermal hydrogen absorption/desorption kinetics. Reversibility over multiple absorption–desorption cycles was also investigated. The synthesized Mg@NiB system shows a reduction of 37 °C in the hydrogen release activation temperature at atmospheric pressure and a decrease of 167.3 °C under high vacuum conditions (4.5 × 10⁻⁷ MPa), in addition to a reversible hydrogen absorption/desorption capacity of 3.5 ± 0.09 wt.%. Additionally, the apparent activation energy for hydrogen desorption was lower (161.7 ± 21.7 kJ/mol) than that of hydrogenated commercial pure magnesium and was comparable to that of milling MgH₂ systems. This research is expected to contribute to the development of efficient and low-cost processing routes for large-scale Mg catalysis. Full article

Chronic skin wounds are difficult to heal or nonhealing. These wounds may become infected and progress to tissue necrosis, potentially leading to limb amputation, sepsis, reduced quality of life, depression, economic burden on the healthcare system, and social isolation. Several clinical strategies, including negative pressure wound therapy, antibiotic-based infection control, and wound debridement, have been developed to treat skin wounds. However, these approaches primarily target local wound conditions and offer only short-term relief, not achieving sustained functional regeneration. Stem cell-based therapy has emerged as an alternative therapeutic method for skin wound treatment owing to its ability to suppress inflammation, stimulate angiogenesis, and promote cellular proliferation. However, the low post-transplantation survival rate of stem cells remains a major limitation. Exosomes, nanosized extracellular vesicles, transport proteins, lipids, mRNAs, and miRNAs and mediate regenerative functions, including anti-inflammatory effects, angiogenesis promotion, and extracellular matrix remodeling. Stem cell-derived exosomes (SC-Exos) offer several advantages over their parent cells, including greater stability, lower immunogenicity, absence of tumorigenic risks, and ease of storage and distribution. These attributes render SC-Exos particularly attractive for cell-free regenerative therapies. In this review, we introduce exosomes derived from various types of stem cells and explore their therapeutic applications in skin wound regeneration. Full article

Air separation units (ASUs) are power-intensive devices on the electricity demand side with significant potential for large-scale energy storage. Liquid air energy storage (LAES) is currently a highly promising large-scale energy storage technology. Coupling ASU with LAES equipment can not only reduce the initial investment for LAES, but also significantly lower the operating electricity costs of the ASU. This study proposes a novel modular-integrated process for coupling an externally compressed ASU (ECAS) with LAES. The core advantages of this integrated process are as follows: the liquefaction unit’s storage capacity is not constrained by the ASU surplus load capacity and it integrates cold, heat, electricity, and material utilization. Taking an integrated system with 40,000 Nm³/h oxygen production capacity as an example, under liquefaction pressure of 90 bar and discharge expansion pressure of 110 bar, the system achieves its highest electrical round trip efficiency of 55.3%. Its energy storage capacity reaches 31.32 MWh/10⁴ Nm³ O₂, exceeding the maximum capacity of existing energy storage systems of the ECAS by 1.7 times. Based on a peak-flat-valley electricity price ratio of 3.4:2:1, an optimal economic performance is attained at 100 bar liquefaction pressure, delivering a 7.21% in cost saving rate compared to conventional ASUs. The liquefaction unit’s payback period is 6.39 years—68.1% shorter than conventional LAES. This study aims to enhance both the energy storage capacity and economic performance of integrated systems combining ECAS with LAES. Full article

Liquid Organic Hydrogen Carriers (LOHCs) represent a promising technology for the safe storage and transport of hydrogen. Its technical development largely depends on the catalysts used in the hydrogenation and dehydrogenation processes. Typically, noble metal-based monometallic catalysts are employed, although they present limitations in terms of cost and availability. This study uses the DBT system to explore the potential of nickel (Ni) as a catalytic alternative. In dehydrogenation, its role as an additive in low-loaded Pt-based catalysts (0.25 wt%) was evaluated, showing a significant increase in activity, with dehydrogenation levels exceeding 95%, compared to 82% obtained with monometallic Pt catalysts. This improvement is attributed to the formation of Pt-Ni alloys. On the other hand, although the bimetallic systems were not effective in hydrogenation, a commercial Ni/Al₂O₃-SiO₂ catalyst was tested, achieving hydrogenation degrees of 80% in just 40 min, after pressure and catalyst loading optimization. These results position Ni as a key component in LOHC catalysis, either as an effective additive in Pt-based systems or as an active metal itself, due to its excellent performance and low cost. This paves the way for economically viable and efficient catalytic solutions for hydrogen storage applications, bridging the gap between performance and practicality. Full article

The storage conditions of multi-floor grain warehouses change frequently during grain circulation. This paper investigates the effects of various storage conditions on the seismic performance of multi-floor grain warehouses. The numerical results indicate that the higher the storage material distribution position, the greater the damping ratio of the structural model and the more obvious the contribution of storage material movement to the damping of the structure. The intensity of earthquake action and the spatial height of the floor where the storage material is located are negatively correlated with the acceleration response of the structure. Under full-silo conditions, when the peak ground acceleration (PGA) is 0.4 g, the acceleration amplification factor at the top of the structure is 69.7% of the corresponding parameter at 0.1 g. The discontinuity in the storage space of the structure results in a torsional effect on the structure. When PGA = 0.22 g, the peak inter-story displacement angle of the first floor differs by nearly 1.7 times under different operating conditions, and the peak inter-story displacement angle of the second floor during an earthquake with PGA = 0.40 g differs by about 1.5 times under different operating conditions. The lateral pressure of the silo wall at different burial depths under earthquake action shows a highly nonlinear distribution trend, and the overpressure coefficient at the same burial depth of the warehouse wall is proportional to the PGA of the earthquake action. During 0.1 g, 0.22 g, and 0.40 g earthquakes, the maximum overpressure coefficients at the bottom of the warehouse wall on different floors are 1.13, 1.21, and 1.66, respectively. Full article

To alleviate the pressure on grid regulation and ensure grid safety, pumped storage power stations need to frequently start and stop and change operating conditions, leading to the pump-turbine easily entering the hump characteristic zone, causing flow oscillation within the unit and significant changes in its input power, resulting in increased vibration and grid connection failure. The spatial distribution of energy losses and the hydrodynamic flow features within the hump zone of a pump-turbine under pumped storage operation are the focus of the study. The SST k-ω turbulence model is applied in CFD simulations of the pump-turbine within this work, focusing on the unstable operating range of the positive slope, with model testing providing experimental support. The model test method combines numerical simulation with experimental verification. The LEPR method is used to quantitatively investigate the unstable phenomenon in the hump zone, and the distribution law of energy loss is discussed. The results show that, at operating points in the hump zone, up to 72–86% of the energy dissipation is attributed to the runner, the guide vane passage, and the double vane row assembly within the guide vane system. The flow separation in the runner’s bladeless area evolves into a vortex group, leading to an increase in runner energy loss. With decreasing flow rate, the impact and separation of the water flow intensify the energy dissipation. The high-speed gradient change and dynamic–static interference in the bladeless area cause high energy loss in the double vane row area, and energy loss mainly occurs near the bottom ring. In the hump operation zone, the interaction between adverse flows such as vortices and recirculation and the passage walls directly drive the sharp rise in energy dissipation. Full article

Seismic waves induce pore pressure changes in aquifers, leading to water level oscillations in wells. These oscillations are often used to estimate the poroelastic properties of aquifers, but their interpretation is influenced by factors such as aquifer properties, seismic wave characteristics, and wellbore storage. The aim of this study is to evaluate the effect of wellbore storage on seismically induced water level oscillations. We analyze water level responses to similar seismic forcing in two adjacent deep wells (~1000 m) tapping the same confined aquifer: one open (artesian) and one closed (flowing artesian). Seismic forcing was characterized using ground motion velocity data from a nearby seismic station. The results show that the wells differ by three orders of magnitude in their wellbore storage. In the open well, pore pressure oscillations are reliably detected only for teleseismic events, while in the closed well, they are also reliably recorded for regional earthquakes. Under these conditions, it is possible to estimate the first-order approximation of the aquifer’s poroelastic coefficients. These findings emphasize the importance of accounting for wellbore storage when interpreting seismically induced water level fluctuations. Full article

Hydrogen energy is valued for its diverse sources and clean, low-carbon nature and is a promising secondary energy source with wide-ranging applications and a significant role in the global energy transition. Nonetheless, hydrogen’s low energy density makes its large-scale storage and transport challenging. Liquid hydrogen, with its high energy density and easier transport, offers a practical solution. This study examines the global hydrogen liquefaction methods, with a particular emphasis on the liquid nitrogen pre-cooling Claude cycle process. It also examines the factors in the helium refrigeration cycle—such as the helium compressor inlet temperature, outlet pressure, and mass—that affect energy consumption in this process. Using HYSYS software, the hydrogen liquefaction process is simulated, and a complete process system is developed. Based on theoretical principles, this study explores the pre-cooling, refrigeration, and normal-to-secondary hydrogen conversion processes. By calculating and analyzing the process’s energy consumption, an optimized flow scheme for hydrogen liquefaction is proposed to reduce the total power used by energy equipment. The study shows that the hydrogen mass flow rate and key helium cycle parameters—like the compressor inlet temperature, outlet pressure, and flow rate—mainly affect energy consumption. By optimizing these parameters, notable decreases in both the total and specific energy consumption were attained. The total energy consumption dropped by 7.266% from the initial 714.3 kW, and the specific energy consumption was reduced by 11.94% from 11.338 kWh/kg. Full article

As an important part of global carbon neutrality strategies, carbon dioxide (CO₂) capture, utilization, and storage technologies have emerged as critical solutions for reducing carbon emissions. However, conventional CO₂ applications, including food preservation, industrial synthesis, and enhanced oil recovery, face inherent limitations such as suboptimal gas–liquid mass transfer efficiency and inadequate long-term stability. Recent advancements in CO₂ micro-nanobubbles (CO₂ MNBs) have demonstrated remarkable potential across multidisciplinary domains, owing to their distinctive physicochemical characteristics encompassing elevated internal pressure, augmented specific surface area, exceptional stability, etc. In this review, we try to comprehensively explore the unique physicochemical properties of CO₂ MNBs and their emerging applications, including industrial, agricultural, environmental, and energy fields. Furthermore, we provide a prospective analysis of how these minuscule bubbles can emerge as pivotal in future technological innovations. We also offer novel insights and directions for research and applications across related fields. Finally, we engage in predicting their future development trends as a promising technological pathway for advancing carbon neutrality objectives. Full article