Search Results (2,879)

Salicornia europaea L. is a spontaneous halophytic plant, widespread in coastal environments, recognized for its high polyphenol content and bioactivities. In this study, a sustainable extraction strategy was developed by coupling natural deep eutectic solvents (NADESs) with ultrasound-assisted extraction (UAE) to recover bioactive compounds from autochthonous S. europaea collected in the Apulia region of southern Italy. Sixty-one NADES combinations were screened using COSMOtherm software, based on the predicted solubility of isorhamnetin, the major flavonol in Salicornia spp, to identify optimal hydrogen-bond donor (HBD) and acceptor (HBA) pairs. Six selected and prepared NADESs (B:CA, B:Suc, ChCl:U, ChCl:Xil, CA:Glc and Pro:MA) were used to extract S. europaea, and the resulting extracts were evaluated for total phenolic content (TPC), antioxidant capacity (DPPH, ABTS, FRAP) and antibacterial activity against four ATCC bacterial strains (Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus). Among the tested extracts, Pro:MA exhibited the highest TPC (6.79 mg GAE/g) and interesting antioxidant activity (DPPH IC₅₀ = 0.09 mg GAE/g; ABTS = 8.12 mg TE/g; FRAP = 2.41 mg TE/g). In the antibacterial assays, the Pro:MA extract demonstrated the highest activity, with minimum inhibitory concentrations (MICs) ranging from 0.1% to 0.4% v/v and minimum bactericidal concentrations (MBCs) from 0.2% to 0.8% v/v. In addition, the Pro:MA extract maintained TPC stability over a 90-day storage period. These findings support the NADES-UAE system as a green and efficient approach for the recovery of bioactive compounds and for the valorization of halophyte plants, such as S. europaea, with promising ready-to-use applications in the food, pharmaceutical and cosmeceutical sectors. Full article

The integration of renewable energy resources (RES) into microgrids (MGs) poses significant challenges due to the intermittent nature of generation and the increasing complexity of multi-energy scheduling. To enhance operational flexibility and reliability, this paper proposes an intelligent energy management system (EMS) for MGs incorporating a hybrid hydrogen-battery energy storage system (HHB-ESS). The system model jointly considers the complementary characteristics of short-term and long-term storage technologies. Three conflicting objectives are defined: economic cost (EC), system response stability, and battery life loss (BLO). To address the challenges of multi-objective trade-offs and heterogeneous storage coordination, a novel deep-reinforcement-learning (DRL) algorithm, termed MOATD3, is developed based on a dynamic reward adjustment mechanism (DRAM). Simulation results under various operational scenarios demonstrate that the proposed method significantly outperforms baseline methods, achieving a maximum improvement of 31.4% in SRS and a reduction of 46.7% in BLO. Full article

With the deepening electrification of transportation, hydrogen fuel cell electric vehicles (FCEVs) are emerging as a vital component of clean and electrified transportation systems. Nonetheless, renewable-based hydrogen production–refueling stations (HPRSs) for FCEVs still need solid models for accurate simulations and a practical capacity optimization method for cost reduction. To address this gap, this study leverages real operation data from China’s largest HPRS to establish and validate a comprehensive model integrating hydrogen production, storage, renewables, FCEVs, and the power grid. Building on this validated model, a novel capacity optimization framework is proposed, incorporating an improved Jellyfish Search Algorithm (JSA) to minimize the initial investment cost, operating cost, and levelized cost of hydrogen (LCOH). The results demonstrate the framework’s significant innovations and effectiveness: It achieves the maximum reductions of 29.31% in the initial investment, 100% in the annual operational cost, and 44.19% in LCOH while meeting FCEV demand. Simultaneously, it reduces peak grid load by up to 43.80% and enables renewable energy to cover up to 89.30% of transportation hydrogen demand. This study contributes to enhancing economic performance and optimizing the design and planning of HPRS for FCEVs, as well as promoting sustainable transportation electrification. 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

The maritime industry, while indispensable to global trade, is a significant contributor to greenhouse gas (GHG) emissions, accounting for approximately 3% of global emissions. As international regulatory bodies, particularly the International Maritime Organization (IMO), push for ambitious decarbonization targets, hydrogen-based technologies have emerged as promising alternatives to conventional fossil fuels. This review critically examines the potential of hydrogen fuels—including hydrogen fuel cells (HFCs) and hydrogen internal combustion engines (H2ICEs)—for maritime applications. It provides a comprehensive analysis of hydrogen production methods, storage technologies, onboard propulsion systems, and the associated techno-economic and regulatory challenges. A detailed life cycle assessment (LCA) compares the environmental impacts of hydrogen-powered vessels with conventional diesel engines, revealing significant benefits particularly when green or blue hydrogen sources are utilized. Despite notable hurdles—such as high production and retrofitting costs, storage limitations, and infrastructure gaps—hydrogen holds considerable promise in aligning maritime operations with global sustainability goals. The study underscores the importance of coordinated government policies, technological innovation, and international collaboration to realize hydrogen’s potential in decarbonizing the marine sector. Full article

Underground hydrogen storage (UHS) in shale and tight reservoirs offers a promising solution for large-scale energy storage, playing a critical role in the transition to a hydrogen-based economy. However, the successful deployment of UHS in these low-permeability formations depends on a thorough understanding of the geomechanical and geochemical factors that affect storage integrity, injectivity, and long-term stability. This review critically examines the geomechanical aspects, including stress distribution, rock deformation, fracture propagation, and caprock integrity, which govern hydrogen containment under subsurface conditions. Additionally, it explores key geochemical challenges such as hydrogen-induced mineral alterations, adsorption effects, microbial activity, and potential reactivity with formation fluids, to evaluate their impact on storage feasibility. A comprehensive analysis of experimental studies, numerical modeling approaches, and field applications is presented to identify knowledge gaps and future research directions. Full article

The objective of this study was to evaluate the physical, chemical, mechanical, thermal, and topological properties of polyvinyl alcohol (PVA) and gelatin (GL) films after incorporating three different fractions of blueberry extract: crude extract (EB, without purification), phenolic portion (EF), and concentrated anthocyanins (EA). Additionally, the study aimed to analyze the efficiency of these colorimetric indicator films in monitoring the freshness quality of shrimp. The experiment followed a completely randomized design with one factor—different types of films—studied at six levels: film incorporated with crude blueberry extract (FB), film incorporated with phenolic extract (FF), and film incorporated with anthocyanin extract (FA), in addition to the control films: the plasticized blend containing glycerol, PVA, and GL (FC), the pristine gelatin film (FG), and the pristine PVA film (FPVA). To evaluate the colorimetric sensitivity of the indicators applied to shrimp, storage time was studied at two levels: T0 (before storage—on the day of collection) and T7 (after 7 days of storage at 6.5 ± 1 °C) for the FB and FA films. Regarding thermal properties, the degradation profile occurred in three stages, with the FC film being the most thermally stable. In terms of mechanical behavior, the isolated anthocyanin content increased the elasticity of FA, while the crude extract and other phenolic compounds contributed to the stiffness of FB (Young’s modulus, YM = 22.52) and FF (YM = 37.33). Structurally, the FC film exhibited a smooth and well-blended polymeric surface, whereas FF, FB, and FA displayed heterogeneous and discontinuous phases. The incorporation of blueberry extracts reduced water absorption, leading to decreased swelling and solubility. FF showed the lowest solubility (S = 16.14%), likely due to hydrogen bonding between phenolic compounds and the polymer matrix. Notably, FB demonstrated superior physical, chemical, and mechanical performance, as well as the highest thermal stability among the extract-containing films. It also showed a visible color change (from purple to green/brown) after 7 days of shrimp storage, corresponding with spoilage and pH values unsuitable for consumption. Both FA and FB effectively monitored shrimp freshness, offering a sustainable approach to quality assurance and food waste reduction. Among them, FB was the most practical for visual detection. Overall, these films demonstrated strong potential as pH-sensitive indicators for evaluating the freshness of shrimp. Full article

In this study, we developed polypropylene-based nanocomposites using different (0.3, 0.5, and 1 wt%) fillers of multi-walled carbon nanotubes (MWCNTs), with a particular focus on their applicability as lining materials for Type IV hydrogen storage tanks. The aim of this research was to improve the thermal stability and rheological behavior of PP, while also evaluating the recyclability of the resulting composites in order to support sustainability goals. A realistic recycling approach was simulated by producing original and regranulated (REG) samples using a twin-screw extruder. Thermal analysis showed that the incorporation of MWCNTs promoted crystallization, increasing both the degree of crystallinity and lamellar thickness, which are beneficial factors in terms of reducing gas permeability. Rheological tests showed increased storage and loss moduli in both nanocomposites and their recycled counterparts, especially at low frequencies. It is noteworthy that in REG samples with 0.3 and 1 wt% content, the zero-shear viscosity increased by approximately 50% and 90%, respectively, compared to pure PP. In our research, we produced nanocomposites that could offer significant advances in the field of hydrogen storage and liner materials, while the results of the regranulated composites could further enhance the sustainability of our materials. Full article

With high storage capacity and zero emissions, hydrogen energy stands as a favorable replacement for fossil fuels. Therefore, earth-abundant electrocatalysts have attracted significant research interest. Particularly, a heteroatom doping strategy demonstrated exceptional capability in precisely modulating the electronic structure of transition metal-based catalysts while optimizing their local coordination environments, thereby representing a new paradigm for intrinsic catalytic activity enhancement. This review provides a systematic overview of recent advances in heteroatom doping strategies for transition metal catalysts. It is particularly focused on elucidating the fundamental mechanisms through atom dopants, which can efficiently regulate electronic configurations and catalytic behavior. By comprehensively analyzing structure–activity relationships and underlying catalytic principles, this work will establish a framework for precise doping strategies to engineer high-performance electrocatalysts. Full article

The clean energy transition has elevated renewable hydrogen as a key energy vector, yet challenges in cost-competitiveness and infrastructure planning persist. This study conducts a PRISMA-based systematic review of recent geospatial applications across the hydrogen value chain—production, storage, transport, and end-use. Bibliometric analysis reveals a strong focus on production (48%), with less attention to storage (12%) and end-uses (18%). Geographic Information Systems (GIS) dominate (80%), primarily for siting, potential assessment, and infrastructure planning, while other techniques such as geophysics and real-time monitoring are emerging. Identified research gaps include fragmented and low-resolution data, lack of harmonization, and high computational demands, which are independent from the phase in the hydrogen value chain. Promising areas for future research include hydrological resource mapping for electrolysis, offshore infrastructure clustering, and spatialized levelized cost modeling. The review concludes with a call for high-resolution, AI-enabled geospatial frameworks to support automated, location-specific decision-making and scalable renewable hydrogen deployment. Full article

The primary challenge for European society today is to strike a balance between maximizing energy efficiency and environmental care, while also ensuring an accessible and safe living environment. The research presented in this Special Issue addressed various aspects of energy storage methods and covered advances in the energy efficiency of buildings and cities in light of the climate change awareness and the need to reduce energy consumption and the carbon footprint from the built environment. Results of empirical and modelling research were compared to advanced simulations and measurements rooted in real-world case studies performed with the purpose of extending the knowledge on holistic sustainable design towards efficient energy use. Key aspects enabling improvements in the energy performance of buildings and contributing to the achievement of climate goals cover thermal comfort and overheating in buildings and cities, including district heating, hydrogen energy storage, renewable energy source integration, carbon emissions, and the economic benefits of building deep renovation. The research findings help us to understand the critical importance of transforming the built environment into renewable energy sources while supporting the energy efficiency of buildings, cities, and neighbourhoods. Full article

This article focuses on activities addressed in the European project hydrogen lightweight & innovative tank for zero-emission aircraft, H2ELIOS. The authors propose a preliminary approach oriented to the design of a structural health monitoring SHM system conceived for a cryo-tank liquid hydrogen storage for medium range vehicles. The system was ideated to be installed on board and operating during service, to provide early detection and localization of potential damage, critical both in terms of safety and maintenance. The use of optical fibers for strain measurement is justified, on one hand, by the capability of pure silica fiber to prevent hydrogen darkening effects and, on the other hand, by the absence of metal components, which eliminates the risk of embrittlement. In detail, distributed and fiber Bragg grating FBG sensors designed for this specific application have demonstrated reliable monitoring capabilities, even after exposure to hydrogen and at cryogenic temperatures. Furthermore, another key contribution of this preliminary activity is the analysis of thermoplastic material faults by correlating damage characteristics with static and dynamic response. This is due to the fact that the investigated physics strongly depend on the nature of occurring damage. Achievements lie in the demonstrated ability to assess the health status of the reference composite structure, establishing the first steps for a future qualification of the proprietary system, made of commercial and original hardware and software. Full article

This paper explores the integration of microgrids within utility networks and distinguishes selfish from collaborative microgrids. Research has shown that selfish microgrids tend to increase volatility of order updates to power generators, whereas collaborative microgrids decrease that volatility, resulting in smoother, more controllable operations of networks. This paper proposes an analytical formula linking power volatility to power quality, i.e., to issues such as voltage dips, surges, and transients. These are known risks for disrupting the operation of utility grids, causing instability and jeopardising efficiency and reliability. As collaborative microgrids reduce volatility, they improve power quality. That argument is extended to propose that collaborative microgrids can act as quality improvements agents within wider networks. Full article

In the renewable energy conversion system, water electrolysis technology is widely regarded as the core means to achieve clean hydrogen production. However, the anodic oxygen evolution reaction (OER) has become a key bottleneck limiting the overall water splitting efficiency due to its slow kinetic process and high overpotential. This study proposes a novel Co₃O₄-TiO₂/CNTs p-n heterojunction catalyst, which was synthesized by hydrothermal method and significantly improved OER activity by combining heterojunction interface regulation and light field enhancement mechanism. Under illumination conditions, the catalyst achieved an overpotential of 390 mV at a current density of 10 mA cm⁻², which is superior to the performance of the dark state (410 mV) and single component Co₃O₄-TiO₂ catalysts. The material characterization results indicate that the p-n heterojunction structure effectively promotes the separation and migration of photogenerated carriers and enhances the visible light absorption capability. This work expands the design ideas of energy catalytic materials by constructing a collaborative electric light dual field regulation system, providing a new strategy for developing efficient and low-energy water splitting electrocatalysts, which is expected to play an important role in the future clean energy production and storage field. Full article

Hydrogen offers an effective pathway for the large-scale storage of renewable energy. For a tourist city located in a plateau region rich in renewable energy, hydrogen shows great potential for reducing carbon emissions and utilizing uncertain renewable energy. Herein, the wind–solar–hydrogen stand-alone and grid-connected systems in the plateau tourist city of Lijiang City in Yunnan Province are modeled and techno-economically evaluated by using the HOMER Pro software (version 3.14.2) with the multi-criteria decision analysis models. The system is composed of 5588 kW solar photovoltaic panels, an 800 kW wind turbine, a 1600 kW electrolyzer, a 421 kWh battery, and a 50 kW fuel cell. In addition to meeting the power requirements for system operation, the system has the capacity to provide daily electricity for 200 households in a neighborhood and supply 240 kg of hydrogen per day to local hydrogen-fueled buses. The stand-alone system can produce 10.15 × 10⁶ kWh of electricity and 93.44 t of hydrogen per year, with an NPC of USD 8.15 million, an LCOE of USD 0.43/kWh, and an LCOH of USD 5.26/kg. The grid-connected system can generate 10.10 × 10⁶ kWh of electricity and 103.01 ton of hydrogen annually. Its NPC is USD 7.34 million, its LCOE is USD 0.11/kWh, and its LCOH is USD 3.42/kg. This study provides a new solution for optimizing the configuration of hybrid renewable energy systems, which will develop the hydrogen economy and create low-carbon-emission energy systems. Full article