Search

[Display omitted] • The alcohol yields achieved were 41.3 wt% and 48.5 wt% from the corrugated box and A4 paper. • Cellulose exhibited the conversion rate of 100 %, with alcohol substances achieving a yield of 71.2 wt% and a selectivity of 89.4 % within 6 h. • The mechanism of cellulose hydrolysis and the catalytic effect of CuMgAlO x were explored. • Multiple techniques were utilized to analyze the alcoholysis pathways and mechanisms of cellulose in waste paper. In an effort to valorize under-exploited cellulose sources like waste paper for sustainable energy production, this study investigates a catalytic process to convert these materials into low-carbon alcohols. We explored the conversion efficiency of various cellulose materials, including corrugated box, A4 paper, and pure cellulose, under the influence of a CuMgAlO x catalyst. Our findings indicate that at 360 °C for 6 h, the conversion rates were substantial, yielding 70.1 % for corrugated box, 85.2 % for A4 paper, and 100 % for cellulose. The respective alcohol selectivities achieved were 54.7 %, 83.0 %, and 89.4 %, with alcohol yields of 41.3 wt%, 48.5 wt%, and 71.2 wt%. Notably, the absence of the catalyst led predominantly to the production of sugars and lipids, whereas the catalytic conditions facilitated the formation of alcohols. The study also examined the effects of temperature and reaction time on cellulose conversion. It was found that a complete conversion was possible at 320 °C within 1 h, with extended temperature and time improving the alcohol yield. The development of a kinetic model for the cellulose conversion process has allowed for accurate predictions of the transformations under varied conditions, which offers a strategic framework for reaction optimization. Furthermore, the role of the CuMgAlO x catalyst was elucidated through the examination of model compounds, demonstrating its capability in converting cellulose intermediates such as sugars, lipids, and ketones into alcohols. This research highlights a potent strategy for the production of high-value, eco-friendly green fuels from readily available paper products and cellulose biomass, marking a significant advancement in chemical engineering and sustainable energy resources. [ABSTRACT FROM AUTHOR]

• Surface engineering of paper electrode through simple voltametric scanning and pre-anodization techniques. • Role of functional groups and influence on hydrogen evolution reaction. • Low-potential HER in 0.5 M H 2 SO 4 with two Tafel slope, 34.2 and 49.88 mV/ dec−1. Hydrogen evolution reaction (HER) is considered the most promising way to produce clean and sustainable hydrogen energy. Carbon-based materials have been discovered to be efficient for catalyzing HER reactions in addition to conventional noble metal-based electrodes. Surface engineering of electrodes through simple methods are important to enhance the electrochemical properties and to keep the cost economical. Herein, we tried to understand the influence of simple electrochemical pre-treatment methods on Paper electrode (PPE) surface towards electrocatalytical activity. The pretreatment methods involving simple voltametric scanning and pre-anodization has been carried out under various electrolytic conditions and investigated for their role on electrochemical activities. The pretreated electrodes were thoroughly characterized with surface morphological and electrochemical techniques. The pre-anodized disposable paper electrode (PA-PPE- H 2 SO 4) modified with pyrene butyric acid (PA-PPE- H 2 SO 4 -PBA) was found to show excellent electrochemical properties and exhibited a low-potential HER (Onset potential, E onset = -0.1 V Vs. RHE) in 0.5 M H 2 SO 4 with a Tafel slopes, 34.2 and 49.88 mV/ dec−1. The obtained results are substantially better than that of reported carbon-based electrodes, where the benefit of Platinum leaching out from the counter electrodes are speculated. The formation of edge-plane sites/defects, and functional groups on electrode surfaces and modification effect by PBA are the reason behind the increased the electrochemical response. Since paper has been used as a substrate for fabrication of the electrodes, possibility to use the same in future as a flexible current collector for self-powering wearable devices/sensors are anticipated. [Display omitted] [ABSTRACT FROM AUTHOR]

Global energy security is a growing worldwide concern in the presence of high economic policy uncertainty (EPU) that can be addressed by advancing sustainable energy diversification (ED) practices. Energy security can be estimated by combining ED and EPU indices; hence, this study uses a dataset covering three continents and 26 countries from 1995 to 2023 to measure energy security employing this approach. The study employs quantile regression and panel data analysis, finding a positive relationship between EPU and ED. The results reveal that when EPU increases, the spectrum of energy sources declines, negatively impacting energy security. Other factors of globalization, Gross Domestic Product, gross capital formation, and the labor force also have an impact on the spectrum of energy sources. To obtain a sustainable level of ED, policymakers should increase investment in gross capital formation because economic growth and openness via pro-global policies have less impact on ED. This study also demonstrates that labor capital shifts have a significant effect on ED. The quantitative results reveal the importance of clear and precise economic policies for increasing investment in carbon-free energy security. [Display omitted] [ABSTRACT FROM AUTHOR]

Algae-based wastewater bioremediation offers a cost-effective method for sustainably treating wastewater while simultaneously addressing global water scarcity and pollution. This study highlights the benefits of treating primary-treated (PTW) and secondary-treated (STW) paper-pulp industrial wastewaters using the microalga Tetradesmus obliquus (Turpin) Kützing. A batch culture study revealed that 50 % secondary treated wastewater can increase the biomass yield 1.8 fold to 2.51 g L−1 in 15 days with a corresponding lipid yield of 390.2 mg L−1. Upscaling this work in 200 L open raceway ponds with 50 % STW as the growth medium showed areal biomass and lipid productivities of 26.80 and 3.90 g m−2 day−1, respectively, in 15 days at 20 cm culture depth. This translates to a projected high annual biomass productivity of approximately 85.0 tons hectare−1 year−1 based on datasets spanning two consecutive years. Bioremediation efficiencies of 80.0 %, 91.51 %, and 92.10 % were achieved for COD, TOC, and NH 4 + respectively. Biodiesel produced showed a large percentage of saturated and monounsaturated fatty acids (∼90 %) and its fuel properties complied with the global biodiesel standards. This study thus shows that using paper-pulp industrial wastewater for algal growth offers a sustainable solution for energy generation and wastewater treatment, with significant implications for environmental sustainability. [ABSTRACT FROM AUTHOR]

[Display omitted] The global municipal solid waste (MSW) generation rate is 2.01 billion metric tonnes annually with an average of 0.74 kg waste/person/day. Approximately 92 % of the MSW originates from organics composition (e.g., food waste; plastic; paper; garden waste/woods, and textile), where 33 % of overall MSW is improperly managed in an efficient and environmentally safe manner. One of the promising methods to solve MSW management issues is to convert MSW into refuse-derived fuel (RDF) that can be used for the clinker burning process in cement kiln to replace the usage of fossil-based solid fuel. Thus, the potential of local MSW composition in energy recovery; suitability of RDF production technology; as well as international-industry requirement on RDF in co-processing and environmental concerns are discussed. Due to heterogeneous composition and sizes in nature, high moisture, and substantial amount of chloride content in MSW, it needs to undergo pre-treatment processes to enhance the RDF's physio-chemical properties that comply with RDF ASTM/EN standards, where expected high heating value (HHV) is > 20 MJ/kg, ash (<10 %), Chloride (Cl) (<0.80 – 1.00 %), Sulphate (S) (<1.50 %), Nitrate (N) (<1.00 %). As the development of upgraded MSW to RDF is still new in the commercial phase, there is minimal information and data on the techno-economic analysis, as well as recent industrial-scale of thermos-chemical conversion technologies for RDF preparation. Hence, the present work provides a clear picture on overview of municipal solid waste (MSW) generation, MSW composition, MSW pretreatment, and application as co-processing in cement industry are discussed. Besides, recent thermochemical upgrading process (torrefaction, dry carbonization, and hydrothermal carbonization) of MSW from R&D to commercial scale was further highlighted. In summary, this review serves as basic criterion and strategies to explore the new path of upgrading the waste into RDF for the purpose of sustainable energy recovery that adopting in circular carbon economy framework. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional and superhydrophobic cellulose composite paper (CCP) is fabricated. • CCP shows a high EMI shielding effectiveness and electrical conductivity. • The superhydrophobic surface is used as the hydraulic triboelectric nanogenerator. • Surface temperature of CCP can reach 140 °C with a applied voltage of 6 V. Cellulose-based materials have attracted tremendous interest recently due to their fascinating merits of renewability, biodegradability, and low cost, holding great promise in electromagnetic protection, clean energy harvesting, and thermal management. However, the simple and effective integration of multiple functions into single cellulose material remains a challenge. Herein, we report the fabrication of a multifunctional and superhydrophobic cellulose composite paper (CCP) via coated MXene modified by in-situ polymerized polypyrrole and PDMS/candle soot on the opposite surface of the paper. CCP exhibits high-performance electromagnetic interference shielding effectiveness (~40 dB) while maintaining high electrical conductivity (1467 S/m). Moreover, the superhydrophobic surface of CCP can be used as the hydraulic triboelectric nanogenerator (H-TENG) to harvest water energy due to the liquid–solid contact triboelectrification and electrostatic induction. The hydraulic triboelectric energy can be captured and released when water droplets drop from a height of 2 cm and roll at a tilt angle of 20°, the output current can reach a peak of 0.8 nA. Furthermore, the surface saturation temperature of CCP can reach 140 °C with a low applied voltage of 6 V enabled by the Joule effect. Thus, CCP holds great potentials in applications of integrated smart electronics, clean energy harvesting, and thermal management. [ABSTRACT FROM AUTHOR]

[Display omitted] • GDL with excellent bulk hydrophobicity and strength based on interspersed PP network. • Novel bulk- and self- hydrophobicity GDL require no fluoride posttreatment. • Excellent water management under high current density in PEMFC operation. • Cost-effective production of high-performance GDL through paper making. In the quest for sustainable energy, proton exchange membrane fuel cells (PEMFCs) are emerging as a key technology due to their high efficiency and low pollutant emissions. However, the performance and longevity of PEMFCs rely heavily on effective water management within the gas diffusion layer (GDL). Traditional GDLs, comprised of carbon fiber paper treated with perfluorinated hydrophobic agents, suffered from environmental, economic, and performance limitations and exhibited unsatisfactory water regulation due to the surface hydrophobicity. To overcome these challenges, we have developed a fluorine-free bulk hydrophobic GDL with an interpenetrating network composed of graphene, cellulose fiber, and modified polypropylene fiber with impressive mechanical strength (22 MPa) and enhanced hydrophobicity without the use of harmful fluorinated agents through the scalable papermaking. The resulting GDL offers significantly improved PEMFC performance by enhancing water management, achieving a current density of 1.25 A cm−2 at 0.6 V and a maximum power density of 0.746 W cm−2. Furthermore, it exhibits superior water management capabilities compared to commercial GDL under high current density and demonstrates a more straightforward, less energy-intensive production process. Our findings suggest a scalable, cost-effective pathway for advanced GDL manufacturing, promoting a shift towards more sustainable and high-performing PEMFCs. [ABSTRACT FROM AUTHOR]

The transition to sustainable energy sources is a global imperative in the face of climate change and dwindling fossil fuel reserves. Hydrogen, as a clean and versatile energy carrier, has garnered significant attention as a potential solution. This paper provides a comprehensive overview of various electrolyzer types, their features, advantages, disadvantages, and future expectations in the context of sustainable energy generation. The article begins by outlining the fundamental principles of electrolysis, highlighting its potential to harness surplus renewable energy. Four main types of electrolyzers are discussed: alkaline electrolyzers, proton exchange membrane electrolyzers, anion exchange membrane electrolyzers, and solid oxide electrolyzers. Each type is explored in depth, with a focus on their unique operating principles, efficiency, scalability, and suitability for different applications. The paper further delves into recent advancements in electrolyzer technology, discussing emerging trends, improved catalysts, and innovative system designs aimed at enhancing efficiency and reducing costs. It also explores the role of policy support and research initiatives in accelerating the adoption of electrolysis for sustainable hydrogen production. • Water electrolyzer systems are one of the most promising technologies for green hydrogen production. • This review provides insights into the current state and future potential of water electrolysis technologies. • Challenges, advantages, and future directions of electrolyzer types are discussed. • Green hydrogen plays a crucial role in decarbonization efforts and offers a sustainable solution for future energy needs. [ABSTRACT FROM AUTHOR]

Many proposals are being made for cleaner, more sustainable forms of energy production. Terrestrial solar photovoltaic farms (SPFs) could potentially deliver large quantities of energy to the grid, although these are limited to daytime use. The output from these SPFs could be enhanced, particularly around dawn and dusk, by the use of orbiting solar reflectors (OSRs) in near-polar orbit. These would reflect an image of the solar disk, or solar image (SI), onto the SPFs to augment their energy output. Pointing requirements are therefore to ensure that reflected sunlight is delivered to the terrestrial SPF, avoiding the losses incurred by an offset of the SI and the SPF itself. The SI would typically be of order 10 km for a reflector in a 1000 km orbit. Given the potentially large size of the reflectors, this presents a challenge for the attitude determination and control system (ADCS) to ensure that the maximum quantity of energy can be delivered to a SPF, typically requiring large control moment gyro actuators. In addition, there exist numerous sources of error in the ADCS which can cause further degradation in the quantity of energy delivered to the SPF. These errors can manifest in the resolution of the various sensors, flexible structural modes, manufacturing inaccuracies, and misalignments due to vibration during launch. This paper will investigate the effects of pointing error sources (PES) on the reflector ADCS and so on the quantity of energy delivered to the SPF. With the application of a PD controller with feedforward compensation, and the set of noise characteristics defined in this paper, numerical simulations will show the typical losses in energy delivered to SPFs of 0.015% when the model accounts for PES in onboard sensors, actuator uncertainty and flexible structural modes. • Orbiting solar reflectors. • Sensor and actuator noise modelling. • Establishing the energy delivery losses due to noise in OSRs and finding the minimum losses using PD controllers. [ABSTRACT FROM AUTHOR]

Nowadays, hydrogen is gaining attention as one of the green energy alternatives within transition to a zero-emission economy. Increasing demand for hydrogen and its production has prompted the development of low-carbon strategies and technologies for hydrogen generation from hydrocarbons. This paper provides a thorough analysis of traditional and innovative methods for hydrogen production from fossil feedstock, reviewing the critical aspects and recent advancements in the field. The paper emphasizes the potential of in situ hydrogen generation as the most promising method, taking into account CO2 emission concerns. Additionally, this study explores the use of software packages for modeling hydrogen production, outlining their advantages and disadvantages and proposing the most favorable software for in situ hydrogen generation from hydrocarbons. Subsequent analysis sheds light on the effectiveness, economic viability, environmental impact, and future perspectives of various hydrogen production technologies. • Overview of hydrogen production technologies: conventional and innovative methods. • Key issues and best practices of the latest experimental and numerical studies. • Comparative analysis of various hydrogen production technologies and approaches. • Subsurface hydrogen generation has a great development potential. • There are methods for clean hydrogen production from hydrocarbon feedstock. [ABSTRACT FROM AUTHOR]

This paper examines the potential of solar and hydrogen (H 2) energy-based hybrid energy systems for residential applications. The growing need for energy and the demand for sustainable energy sources have led to the development of integrated energy systems that combine renewable energy resources to meet energy needs. This paper overviews recent studies on hybrid energy systems for on-grid and off-grid residential utilizations. It discusses the system configuration and components of hybrid energy systems, including solar panels, electrolyzers, fuel cells (FC), and batteries. It also covers the technical optimization of integrated energy systems, including sizing, control strategies, and economic analysis. The key findings of this review paper indicate that hybrid energy systems can offer dependable and sustainable energy for residential applications. Through numerical analyses, the optimal dimensioning of the system elements and control strategies can significantly enhance the system's performance and lower the cost of energy. This study also highlights the challenges and opportunities for integrating hybrid energy systems within residential applications. Overall, it provides in-depth perspectives on the possibilities inherent in solar and hydrogen energy-based hybrid energy systems for residential applications. The findings can guide future research and the advancement of hybrid energy systems for sustainable energy solutions. • Comprehensive review on solar and hydrogen-based residential applications. • Holistic approach to system configuration, optimization, and economics. • Detailed analysis of interconnected components enhancing system efficiency. • Unique focus on real-world residential applications and scenarios. • Broad applicability across diverse geographical regions. [ABSTRACT FROM AUTHOR]

Transitioning to a sustainable energy future necessitates innovative storage solutions for renewable energies, where hydrogen (H₂) emerges as a pivotal energy carrier for its low emission potential. This paper explores unlined rock caverns (URCs) as a promising alternative for underground hydrogen storage (UHS), overcoming the geographical and technical limitations of UHS methods like salt rock caverns and porous media. Drawing from the experiences of natural gas (NG) and compressed air energy storage (CAES) in URCs, we explore the viability of URCs for storing hydrogen at gigawatt-hour scales (>100 GWh). Despite challenges such as potential uplift failures (at a depth of approximately less than 1000 m) and hydrogen reactivity with storage materials at typical conditions (below temperatures of 100°C and pressures of 15 MPa), URCs present a flexible, scalable option closely allied with green hydrogen production from renewable sources. Our comprehensive review identifies critical design considerations, including hydraulic containment and the integrity of fracture sealing materials under UHS conditions. Addressing identified knowledge gaps, particularly around the design of hydraulic containment systems and the interaction of hydrogen with cavern materials, will be crucial for advancing URC technology. The paper underscores the need for further experimental and numerical studies to refine URC suitability for hydrogen storage, highlighting the role of URCs in enhancing the compatibility of renewable energy sources with the grid. • Detailed exploration of unlined rock cavern (URC) technology. • Analysis of URCs' potential for large-scale hydrogen storage. • Insights from historical use of URCs in compressed gas storage. • Examination of the opportunities and challenges in using URCs for hydrogen storage. [ABSTRACT FROM AUTHOR]

Promoting green hydrogen has emerged as a pivotal discourse in the contemporary energy landscape, driven by pressing environmental concerns and the quest for sustainable energy solutions. This paper delves into the multifaceted domain of C -Suite issues about green hydrogen, encompassing both technological advancements and policy considerations. The question of whether green hydrogen is poised to become the focal point of the upcoming energy race is explored through an extensive analysis of its potential as a clean and versatile energy carrier. The transition from conventional fossil fuels to green hydrogen is considered a fundamental shift in energy paradigms, with far-reaching implications for global energy markets. The paper provides a comprehensive overview of state-of-the-art green hydrogen technologies, including fuel cells, photocatalysts, photo electrocatalysts, and hydrogen panels. In tandem with technological advancements, the role of policy and strategy in fostering the development of green hydrogen energy assumes paramount significance. The paper elucidates the critical interplay between government policies, market dynamics, and corporate strategies in shaping the green hydrogen landscape. It delves into policy mechanisms such as subsidies, carbon pricing, and renewable energy mandates, shedding light on their potential to incentivize the production and adoption of green hydrogen. This paper offers a nuanced exploration of C -Suite issues surrounding green hydrogen, painting a comprehensive picture of the technological and policy considerations that underpin its emergence as a transformative energy source. As the global community grapples with the imperatives of climate change mitigation and the pursuit of sustainable energy solutions, understanding these issues becomes imperative for executives, policymakers, and stakeholders alike. [Display omitted] • The latest advancements in photo electrocatalysts and fuel cell technologies are reviewed. • The storage and transportation within the realm of green hydrogen energy were discussed. • Policy and strategy for fostering the development of green energy are proposed. [ABSTRACT FROM AUTHOR]

This review paper explores into the extensive realm of alkaline water electrolysis (AWE), a transformative technology for hydrogen production, offering profound insights and future prospects for sustainable growth. It embarks on this journey by explaining the fundamental principles, the application of Faraday's laws, electrolyzer design, and the intricate electrochemical processes transpiring at the cathode and anode. Subsequently, it investigates electrode materials, catalysts, membrane material and their recent developments, unveiling essential aspects of material selection and performance enhancement. The exploration extends to the domain of alkaline electrolyte solutions, where it provides a comprehensive overview of common electrolytes, the impact of concentration on system performance, and pioneering research on alternative electrolytes. Shifting focus towards large-scale systems and industrial applications, the paper unravels the economic feasibility, considerations regarding costs, and the transformative influence of alkaline water electrolysis on diverse industries. The final segment is dedicated to emerging trends and future directions. It casts light on recent breakthroughs and the potential for commercialization, presenting a vivid image of the evolving role of this technology in the sustainable energy landscape. The conclusive segment, this review offers a recapitulation of the key discoveries and insights presented throughout the paper, while delivering a critical evaluation of the present state of alkaline water electrolysis. It emphasizes the potential of the technology while recognizing critical research areas such as electrode materials, safety standards, scaling efficiency, flexible operation, and surface modification techniques. In the rapidly changing energy scenario, this paper stands as a testament to the dynamic nature of alkaline water electrolysis and its pivotal role in a sustainable energy future. • Identifying different alkaline water electrolysis (AWE) cell efficiencies and transport resistances. • Insights into recent development in electrodes, catalysts, and separator membranes materials. • Recognizing recently examined alkaline electrolytes. • Recent and emerging trends in AWE including the use of electromagnetic field and pulsating potential. • Perspectives of scaling up AWE and its industrial commercial applications. [ABSTRACT FROM AUTHOR]

Hydrogen is a kind of clean renewable energy with great development potential. However, traditional electrocatalytic water splitting methods often require high energy consumption and expensive catalysts, which limits their practical application. Transition metal selenides (TMSes), as a new type of hydrogen production materials from electrolytic water, have been the focus of research in recent years. The basic principle of electrochemical water cracking and the preparation of TMSes are reviewed in this paper. The electrocatalysts for hydrogen evolution, oxygen evolution and integral water cracking based on TMSes, including single metal selenides, binary metal selenides, and multinary mixed metal selenides, are discussed. Finally, the future research direction and the development prospect of TMSes electrocatalysts are prospected. • Eley-Rideal and Langmuir-Hinshelwood mechanisms were used to analyze the OER reaction mechanism. • The production and properties of transition metal selenides in recent years are introduced in detail. • In this paper, transition metal selenides are introduced from single TMSes, binary TMSes and multinary mixed TMSes. • The physical properties and electronic structures of transition metal selenides are described in detail. [ABSTRACT FROM AUTHOR]

This paper explores green hydrogen-based carbon dioxide (CO 2) hydrogenation for the production of oxygenates, presenting it as a pivotal strategy for mitigating carbon emissions and advancing sustainable energy solutions. The conversion of CO 2 into oxygenates through hydrogenation emerges as a promising avenue, particularly in the context of transportation applications where the storage of hydrogen poses challenges. The substitution of fossil diesel and gasoline fuels with green hydrogen-derived dimethyl ether, or methanol/ethanol, is advantageous from a life cycle analysis (LCA) CO 2 emission perspective even without the capture of the CO 2. However, the greatest sustainability appeal is contingent on the crucial aspect of capturing CO 2 when utilizing these fuels, which is an aspect currently absent in the literature. This narrative review comprehensively explores catalytic processes, mechanisms, sustainability perspectives, and the current state of research in this evolving area. It encompasses both the production of oxygenates through CO 2 hydrogenation and the subsequent utilization of these oxygenates in fuel cells or combustion systems, emphasizing the integration of CO 2 capture technologies. The paper contributes to the discourse surrounding the environmental and technological dimensions of energy storage ecosystems, providing a holistic view of their potential to foster sustainable energy solutions. [ABSTRACT FROM AUTHOR]

In the context of a microgrid, green hydrogen production from wind power was assessed in this paper. A Wind-Hydrogen Integrated Power Grid Model was employed to address the intermittent nature of wind energy resources. Wind power generation was analyzed and integrated with hydrogen production to contribute to sustainable energy solutions. Meticulous estimation and scenarios analysis were performed to quantify the potential of green hydrogen production capacity achievable through wind energy integration. Additionally, sensitivity analyses were conducted to enhance the understanding of the system's dynamics and potential challenges. This paper significantly contributed to the understanding of this critical aspect and paved the way for the future development of a comprehensive Energy Management System (EMS) designed to optimize energy flow between the grid, wind power generation, and the electrolyzer. [ABSTRACT FROM AUTHOR]

With the rapidly evolving geo-political landscape and unceasing advancements in technology, sustainable energy security is a very important topic. Research indicates that electrochemical energy systems are quite promising to solve many of energy conversion, storage, and conservation challenges while offering high efficiencies and low pollution. The paper provides an overview of electrochemical energy devices and the various optimization techniques used to evaluate them. The optimization techniques include linear regression, factorial design, the Taguchi method, artificial neural networks, filters, and a combination of such methods to improve these systems. To support the growing interest in research, the bulk of this study focuses on a review of the most promising and highly researched electrochemical energy devices, such as fuel cells, batteries, and supercapacitors. The paper also provides modest commentary on hydrogen production technologies, electrochemical reactors, and membrane separation technologies, amongst other technologies. Building on a previous paper by the authors of this paper on artificial intelligence in hybrid renewable energy systems with fuel cells, this work provides a comparative review of optimization techniques for supercapacitors by highlighting key findings based on model accuracy. A summary of the advantages and disadvantages of the different major optimization techniques is presented. The paper concludes that a combination of optimization techniques is used to overcome the drawbacks of individual techniques, with adaptive filters being the most widely studied. This paper presents studies on the Design of Experiments (DoE) with the goal of building a better understanding of the relationships that exist between different operating variables in various electrochemical devices. • The electrochemical systems can be optimized for better performance with high accuracy. • The optimization techniques used are either model-based or data-driven. • Linear regression and artificial neural networks are the most common techniques studied. • Hybrid models could be applied to enhance systems' accuracy and minimize errors. [ABSTRACT FROM AUTHOR]

With the growing demand for green technologies, hydrogen energy devices, such as Proton Exchange Membrane (PEM) fuel cells and water electrolysers, have received accelerated developments. However, the materials and manufacturing cost of these technologies are still relatively expensive which impedes their widespread commercialization. Additive Manufacturing (AM), commonly termed 3D Printing (3DP), with its advanced capabilities, could be a potential pathway to solve the fabrication challenges of PEM parts. Herein, in this paper, the research studies on the novel AM fabrication methods of PEM components are thoroughly reviewed and analysed. The key performance properties, such as corrosion and hydrogen embrittlement resistance, of the additively manufactured materials in the PEM working environment are discussed to emphasise their reliability for the PEM systems. Additionally, the major challenges and required future developments of AM technologies to unlock their full potential for PEM fabrication are identified. This paper provides insights from the latest research developments on the significance of advanced manufacturing technologies in developing sustainable energy systems to address the global energy challenges and climate change effects. • The AM technologies relevant to PEM fabrication are reviewed. • Corrosion performance of AM materials in the PEM working environment is presented. • The challenges and prospects of AM for PEM fabrication are discussed. • AM has the potential to revolutionize the fabrication of PEM systems. [ABSTRACT FROM AUTHOR]

A solid oxide electrolyzer cell (SOEC) is a promising clean energy technology due to with high conversion efficiency and the ability to directly produce syngas. This paper summarizes technical challenges of SOEC in terms of dynamic response, co-electrolysis and material degradation, and recent developments on the manufacturing technology, materials for each component, mathematical models, flow channel designs and reversible solid oxide fuel cells (RSOFCs). The model development and related research on SOECs are explored in this paper, encompassing sensitivity analyses, dynamic responses, structural degradation and practical applications. This paper aims to promote the future development of SOECs, including the improvement of electrolysis efficiency, lifetime and economic performance. • Technological limitations and recent developments for SOEC are reviewed. • The dynamic response, co-electrolysis and material degradation are discussed. • Component materials and their manufacturing techniques are summarized. • Multi-physics coupling models at different scales are highlighted. • Future research direction in materials and modeling are proposed. [ABSTRACT FROM AUTHOR]

Nowadays, grid power loss and power quality deterioration are causing many problems, especially for sensitive uses such as data centers, airports, healthcare, banking, insurance, and telecom. These issues must be resolved through energy continuity coverage and optimization. Dynamic voltage restorers (DVR) are generally used to mitigate network voltage disturbances and maintain a constant voltage value between load terminals for a short and limited duration due to limited energy storage facilities. However, this paper's proposed (DVR) system controlled by the adaptive-network fuzzy inference system (ANFIS) controller can compensate for prolonged power quality disturbances by integrating a hybrid renewable energy system (HRES) managed using classical Proportional Integral (PI) controller power management. This paper proposes a new (DVR) topology coupled with a hybrid renewable energy system (HRES) to exploit free and clean energy, consisting of a solar panel, a PEM fuel cell, and a battery storage device connected through DC-DC converters to a DC transmission, the obtained results from the simulation process of the proposed DVR system in the environment of MATLAB / Simulink showed the ability to eliminate sag that exceeded 0.9 pu in a period of more than 3 min and swells that exceeded 1.2 pu in a period that exceeded one minute. In comparison, the load voltage's total harmonic distortion THDv was reduced from 29% to 5%, and the source current total harmonic distortion THDi from 30.25% to 2.79%. [ABSTRACT FROM AUTHOR]

Biomass gasification technology has gained significant attention as a potential solution for circular economies by converting organic waste into valuable energy and products (Waste-to-Power-to-X). This paper comprehensively evaluates biomass gasification technology from a techno-economic-policy perspective, providing valuable insights for circular economies. It examines technical aspects such as processes, feedstocks, and syngas production, assessing advancements that would improve efficiency and environmental performance by addressing key challenges like tar removal and gas cleaning. Economic feasibility is analysed through a techno-economic assessment, considering capital costs, operational expenses, revenue streams, and potential markets. Real-world examples and case studies offer insights into economic viability of these processes. The paper emphasizes the significance of supportive policy frameworks, discussing stimulus measures like feed-in tariffs, tax incentives, and regulatory reforms to promote biomass gasification adoption. By combining technological, economic, and policy perspectives, this paper provides a holistic reality check of biomass gasification technology, identifying opportunities, challenges, and pathways for leveraging as a sustainable and economically viable solution for waste management and energy production. The findings and insights presented in this paper can assist policymakers, investors, and stakeholders in making informed decisions regarding the implementation of biomass gasification projects in the future. [Display omitted] • These findings serve as valuable insights for exploring the market potential. • Waste materials are transformed into valuable resources. • Effectively managing by-products is crucial in unlocking their economic potential. [ABSTRACT FROM AUTHOR]

This paper provides new evidence on the dynamic dependence and connectedness between investments in Financial Technology (FinTech) and green assets across different market conditions and investment horizons. The paper uses daily data and relies on wavelets coherency and quantile-based connectedness methods. First, our results indicate that the co-movement between FinTech and green bonds and clean energy stocks is mostly positive and strongest in the long-term but weak in the short-term, indicating a high probability of large joint losses for long-term investors and hedging opportunities of FinTech stocks for short-term investors in green financial assets. Second, the level of connectedness is stronger at both tails of the return distribution and similar in the short- and long-term while in the medium-term, normal market period total connectedness became stronger than the bearish market period connectedness during the COVID-19 pandemic. Lastly, results also indicate that across all market conditions and time scales, FinTech stocks dominate most of the green financial assets as demonstrated by the net pairwise directional risk spillover. This suggests that FinTech stocks may not offer good hedging opportunities for green financial indexes. The paper provides some crucial implications based on these findings. [ABSTRACT FROM AUTHOR]

It is of great significance for cleaner production to partially replace traditional coke with biomass fuel in iron ore sintering processes. However, the higher reactivity of biomass leads to an unacceptable deterioration in sintering performance, which limits its high proportion application. This paper presents the numerical simulation of the technology of combining gaseous fuels and biomass for iron ore sintering. The improvement effect and mechanism of the methane injection method on the heat pattern and performance of the coke/biochar co-sintering bed were discussed. To more accurately quantify the coupling phenomena involved, the proposed model especially considers sub-processes of biomass combustion and gaseous reactions including volatile release/char formation, burning of the volatiles, and the oxidation and gasification of char particles. The results indicated that the equivalent methane heat injection method reached its limit of improvement at a concentration of about 0.6%, and failed to obtain qualified products. The thermal indicators and yield kept increasing within the concentration simulation range of 0∼0.8% under the extra methane method. At a concentration of 0.8%, peak temperature (PT), duration time (DTMZ), and enclosed area (MQI) in the high-temperature zone are 1442.094 K, 165.6 s, and 15923.72 K s, respectively, reaching the level of all coke method. The use of local concentration segregation can significantly optimize heat distribution and increase the yield of the coke/biochar co-sintering process. • A numerical model for combining gaseous fuel and biomass in sintering is proposed. • Extra methane injection has no improvement limit within concentrations 0.1%–0.8%. • Gaseous fuel combustion zone makes the melting zone enlarge. • Coke/biochar co-combustion is helpful in attaching the secondary combustion zone. • Methane injection makes 60% biochar sintering reach the level of all coke method. [ABSTRACT FROM AUTHOR]

This paper proposes stochastic programming to optimal economic scheduling problems of a sustainable integrated energy system with renewable resources including power, natural gas, and hydrogen carriers. Hydrogen is considered a byproduct of electrical power and natural gas carriers using water electrolysis and steam methane reform process technologies. The main objective is to minimize the operation and emission costs while addressing uncertainties of electric/heating/cooling demands, electricity price, and renewable generation using scenario-based stochastic programming. To achieve a risk-hedging strategy, downside risk constraints are involved to minimize the risky scenarios portfolio. The whole problem is modeled as mixed-integer linear programming in GAMS optimization software. The analysis revealed that the expected operation cost without DRC is $ 577.52 and the expected risk-in-cost value for risky scenarios is $ 470.7. However, a conservative decision for reaching zero risk is costly and increases the expected cost up to $ 2901.1, which is not economically viable. A modest decision-making strategy compromises the cost and risk values where for decreasing the risk-in-cost to $ 288.7 (36.8%), the expected cost increased by to $1010.39 (75.95%). Moreover, the risk-averse decision-maker lowers the power sold to the grid, increases the use of water electrolyzing instead of the SMR process to reduce the environmental charges, and tries to increase flexibility with the help of hydrogen and battery storage. • The operation of a multi-carrier energy system is evaluated by stochastic programming. • The risk of different uncertainties is involved using downside risk constraints. • The risk-neutral and risk-averse strategies are developed by adjusting a risk level. • The hydrogen carrier considered as an intermediate to serve multi-energy demands. • The water electrolyze and steam methane reform technologies produce hydrogen gas. [ABSTRACT FROM AUTHOR]

Hydrogen, as a clean energy carrier, presents a significant step toward sustainable energy solutions but faces challenges in storage due to its low energy density and high volatility. This study addresses the optimization of Type V hydrogen storage tanks by investigating the burst pressure performance of spherical, cylindrical, and toroidal shapes. Using finite element analysis (FEA) and first-order shear deformation theory, we examined how these geometries impact burst pressure outcomes across a range of composite materials and layup configurations. The materials tested included carbon T700/epoxy, Kevlar/epoxy, E-glass fiber/epoxy, and basalt/epoxy. Results demonstrate that the toroidal shape significantly outperforms spherical and cylindrical designs in stress distribution and burst pressure, with basalt/epoxy composites exhibiting superior burst pressure performance (12.7 MPa) compared to Kevlar/epoxy (10.8 MPa), E-glass fiber/epoxy (11.4 MPa), and carbon T700/epoxy (8.9 MPa). Kevlar/epoxy toroidal tanks outperform other materials in weight performance, having a structural performance index of 0.0305 Mpa.m3/kg and hydrogen density per unit mass of 0.0251 kg H 2 /kg. The stacking sequence [-45/45]s optimized stress distribution for the toroidal shape across all materials. The findings highlight that toroidal designs offer significant advantages for high-pressure hydrogen storage, providing efficient stress management and improved safety. This paper underlines the potential of toroidal vessels for enhancing hydrogen storage efficiency and emphasizes the importance of material selection and stacking sequences in achieving optimal burst pressure performance for international organization for standardization (ISO) certification. • Toroidal tanks show superior burst pressure over spherical and cylindrical designs. • The [-45/45]s stacking sequence optimizes stress distribution for toroidal tanks. • Basalt/epoxy composites outperform other materials in burst pressure performance. • Kevlar/epoxy toroidal tank outperforms others in weight performance. • Toroidal tanks offer efficient stress management and enhanced safety for hydrogen storage. [ABSTRACT FROM AUTHOR]

Green hydrogen production from renewable energy sources has emerged as a promising solution towards achieving the global target of net-zero emissions by 2050. The sultanate of Oman is among the countries that have a significant green hydrogen potential, as evident by the national target of producing one million tons of green hydrogen by 2030. This paper aims to study the techno-economic viability of integrating a floating solar photovoltaic (FPV) system with hydrogen energy storage for electricity generation in Oman. The integration of this system is modelled and simulated using HOMER Pro software to determine the optimum component sizes with the minimum cost of energy (COE). While the FPV system is designed and simulated using PVsyst software. The simulated system incorporates a 26.57 MWp FPV system, 22 MW PEM electrolyser, 13 MW PEM fuel cell, 60,000 kg hydrogen tank and 12.4 MW converter and generates 65.5 GWh of clean electricity annually. The system produces 826,624 kg of green hydrogen annually, significantly contributing to Oman's green hydrogen economy. The simulation results reveal a levelized cost of energy (LCOE) of $0.97/kWh and a levelized cost of hydrogen (LCOH) of $29.7/kg. The relatively high LCOH is attributed to the utilisation of large-scale hydrogen energy storage components, which results in a higher initial cost of the system. However, the system demonstrated its ability to meet the electrical demands of 422 households near Wadi Dayqah dam area in Qurayat with minimal capacity shortage, emphasising its technical viability. The economic viability may be improved in the future with advancements in hydrogen energy storage technology and rising fossil fuel prices. • Techno-economic analysis of large-scale hydrogen storage with FPV application. • LCOE is determined to be at $0.970/kWh. • The system is capable of fulfilling 100% of the electrical demands of 422 households. [ABSTRACT FROM AUTHOR]

Hydrogen stations are an important component of urban clean energy development. In the event of an accident, they can have a serious impact on the safety and stability of the urban system. This paper identifies and analyzes the main influencing factors of hydrogen station safety resilience based on an improved HFACS model. It establishes a safety resilience evaluation index system from four dimensions: spatial resilience, engineering resilience, management resilience, and social resilience. Subjective index weights are determined through fuzzy analytic hierarchy process, objective index weights are determined through entropy method, and combined index weights are determined based on game theory. A system dynamics model of hydrogen station safety resilience is constructed, and model verification and comparative analysis are conducted. The influence of different dimensions on system safety resilience is analyzed, and quantitative evaluation and prediction research on hydrogen station safety resilience is carried out. Targeted safety resilience improvement suggestions are also proposed. The research results can provide a reference for the safety management of hydrogen stations. • Constructing a resilience evaluation index system using the modified HFACS model. • Modeling the safety resilience evaluation of hydrogen stations from four dimensions. • Simulation and prediction of safety resilience levels for hydrogen stations. [ABSTRACT FROM AUTHOR]

This paper presents a detailed techno-economic review and assessment of a hydrogen refueling station (HRS) powered by a grid-connected photovoltaic (PV) system to address the issues of carbon emissions and energy sustainability in transportation. In the study, the HRS system with 1, 3 and 5 MW PV installed capacity for Ankara, the capital city of Türkiye, is considered for different system lifetimes. In the proposed HRS, on-site hydrogen production is achieved through anion exchange membrane water electrolysis (AEMWE) using a grid-connected PV system, and the produced hydrogen is stored in a cascaded storage system and is utilized at the HRS station. In order to evaluate the cost competitiveness and economic viability of the designed HRS system, the levelized cost of hydrogen (LCOH) is determined by considering the initial investment costs, operating expenses and potential revenue streams. The results show that the HRS capacity, PV installed capacity and system lifetime significantly impact the LCOH. The technoeconomic analysis results show that the best system configuration was determined as 8.54 €/kg H 2 in the 20-year long term refueling scenario for a 5 MW installed PV capacity with a daily refueling capacity of 170 kg H 2. This study contributes to the development of sustainable energy infrastructure by providing a comprehensive framework for the design, calculation and economic evaluation of PV-integrated hydrogen refueling stations. The results provide valuable information for policymakers, industry stakeholders, and researchers to help achieve a carbon-neutral transportation sector and promote energy sustainability. • PV integrated onsite hydrogen refueling station is proposed. • Techno-economic evaluation of the HRS was conducted. • The lowest levelized cost of hydrogen (LCOH) was obtained as 8.54 €/kg H 2. • HRS infrastructure required to support hydrogen vehicles through the carbon zero transition. [ABSTRACT FROM AUTHOR]

As a promising green energy technology, low-temperature proton exchange membrane (PEM) electrolysis exhibits different reaction efficiencies and flow performances under various flow channel structures, but the specific impacts of these different layouts on performance are not well understood. To reveal the influence of the channel layouts, a two-phase PEM electrolysis model is established based on the experiment in this paper. Combing with flow characteristics, current density, and product distribution in the porous transport layers (PTLs) and catalyst layers (CLs), the results indicate that the flows from different directions have a significant impact on the electrolyzer. The vertical flow, perpendicular to the CLs, can greatly alleviate the product accumulation; meanwhile the transverse flow, parallel to the CLs, has a weaker but noticeable effect in gas ventilation. Partial gas will continue to accumulate in the region of weak vertical flow, especially at the end of the transverse flow. Except for the pin-type layout, other structures have a neat and orderly transverse flow within the porous medium, in the direction perpendicular to the flow channel's orientation. This flow pattern leads to product accumulation increasing along the exit direction, as well as product stagnation in the region of weak flow intensity. To facilitate the product discharge, a new flow channel layout, the pyramidal flow layout is proposed, which navigates the flow trend and enhances the convection near the exit. This new layout greatly evens out the current density and product concentration distribution. • Based on two-phase flow PEM electrolysis model of different flow channel layouts. • Finding a universal flow pattern within the porous medium among different layouts. • Proposed a new flow layout with better product distribution and discharge efficiency. [ABSTRACT FROM AUTHOR]

In this paper, the structure, hydrogen storage capacity, mechanical, electronic, optical and thermodynamic properties of hydride perovskites KCuH 3 and RbCuH 3 are systematically studied via using density functional theory (DFT) for the first time. The formation energies and mechanical properties of XCuH 3 (X = K, Rb) hydrides indicate that KCuH 3 and RbCuH 3 are both thermodynamically and mechanically stable. The values of Pugh's index and Cauchy pressure for KCuH 3 and RbCuH 3 indicate that they are both brittle materials. In addition, their bonding types are mainly ionic bonds. Electronic properties show that these compounds are metallic. The hydrogen storage capacities of KCuH 3 and RbCuH 3 are calculated to be 2.78 wt% and 1.95 wt%, respectively. The optical properties indicate that KCuH 3 and RbCuH 3 both have high dielectric functions in the visible range and their absorption coefficient peak in the ultraviolet range. Additionally, the thermodynamic properties, including free energy, Debye temperature, melting temperature, entropy and heat capacity are calculated. The analyzed physical properties of KCuH 3 and RbCuH 3 perovskite hydrides suggest that they have great prospect in hydrogen applications. All the above parameters are calculated for the first time, which could contribute significantly to the development of sustainable energy technologies. • XCuH 3 (X = K, Rb) perovskite have been investigated using the first principles. • XCuH 3 perovskite exhibit thermodynamic and mechanical stability. • The gravimetric hydrogen storage capacity is found to be 2.78 wt% for KCuH 3. [ABSTRACT FROM AUTHOR]

In pursuit of environmentally friendly and effective photocatalytic materials for water splitting, this research paper presents a thorough evaluation of WSi 2 N 4 , WGe 2 N 4 , and their Janus counterpart WSiGeN 4 monolayers through the application of Density Functional Theory. The study elucidates the optical, electronic, and structural characteristics of these monolayers, thereby demonstrating their potential as highly favorable contenders for applications involving photocatalytic water splitting. By means of comprehensive optimization and analysis, it is shown that these monolayers possess advantageous characteristics, such as favorable band gaps, stable work functions, and stability over a broad pH range. These attributes are of utmost importance in ensuring the effectiveness of hydrogen evolution reaction (HER). The inclusion of Janus WSiGeN 4 , which possesses an intrinsic mirror asymmetry, significantly improves the photocatalytic efficacy of the material. This is achieved by meeting the demands of optimal redox reaction levels in both the conduction and valence bands. In conjunction with machine learning force fields, ab initio molecular dynamics (AIMD) simulations validate the thermal stability of these monolayers at 300 K. In addition, our analysis of the optical properties reveals substantial absorption in the visible spectrum - vital for photocatalytic applications powered by solar energy. In summary, the research highlights the potential of Janus WSiGeN 4 , WGe 2 N 4 , and WSi 2 N 4 monolayers as multifunctional and effective substances for forthcoming photocatalytic water-splitting systems. This advancement indicates of a significant stride in the direction of sustainable energy solution development. • Analyzed WSi 2 N 4 , WGe 2 N 4 , and WSiGeN 4 for effective hydrogen production. • Proved thermal stability at 300 K, enabling real-world use. • Highlighted Janus WSiGeN 4 's superior efficiency for photocatalysis. • Confirmed stability via machine learning, promising for sustainable technology. • Noted significant visible light absorption for solar-driven applications. [ABSTRACT FROM AUTHOR]

The competitiveness of hydrogen as a sustainable energy carrier depends greatly on its transportation and storage costs. Liquefying hydrogen offers advantages such as enhanced purity, versatility, and higher density, yet current industrial liquefaction processes face efficiency and cost challenges. Although various large-scale and efficient liquefaction concepts exist in the literature, they often overlook the economic and technical viability of such plants. Here, we addresses this issue by establishing a framework for modeling a large-scale hydrogen liquefaction concept and conducting both technical and economic assessments, with a specific focus on 125 tonnes per day (TPD) high-pressure hydrogen Claude-cycle concept. The technical analysis involves preliminary designs of key process components, while the economic assessment utilizes Aspen Process Economic Analyzer. Our findings indicate that at an electricity price of €0.1/kWh, the Claude-cycle liquefier concept yields a specific liquefaction cost (SLC) of €1.55/kg LH 2 . A sensitivity analysis was performed, which shows that electricity price has a significant influence on the economics. Further investigation on the compressors design shows that incorporating high-speed centrifugal compressors could reduce the SLC by 5.42% and potentially more. Scaling up to 250 and 500 TPD reveals further cost improvements, while cost projections indicate substantial declines as the technology matures. Ultimately, this paper presents novel cost-scaling and experience curves of hydrogen liquefaction technology, demonstrating the compelling economic viability of integrating large-scale hydrogen liquefaction into sustainable energy infrastructure. [Display omitted] • A process model of a large-scale Claude-cycle hydrogen liquefaction plant has been developed for both technical assessment and economic analysis. • The technical evaluation primarily centers on the preliminary design of key process equipment, such as compressors, turbo-expanders, and heat exchangers. • The techno-economic assessment is performed based on the process simulation and equipment preliminary design. • Capital cost estimation is carried out using the Aspen Process Economics Analyzer. • These cost estimations serve as the basis for predicting cost and experience curves of hydrogen liquefaction technology. [ABSTRACT FROM AUTHOR]

To tackle the carbon emission problem, the exploitation of renewable energy resources (RESs) with zero emissions has gained much importance. In this context, hydrogen has become an important resource to involve itself in distributed energy resources (DERs) to generate electricity, energize vehicles, and heat our living areas. The utilization of hydrogen technologies is indispensable due to their procurement, environmental friendliness, and high efficiency for DERs. A challenging area in the field of hydrogen energy technologies is extracting efficient power and integration to DERs. This paper investigates how to model and operate a proton exchange membrane fuel cell (PEMFC) stack in a DER application to establish a living lab facility for educational and research purposes by covering Power-to-X (P2X). The PEMFC model of the studied system is designed in a MATLAB/Simulink environment and implemented in an experimental testbed. Thus, a fuel cell (FC) unit as a complementary source is preferred to be used near a photovoltaic (PV) array, a small-scale wind turbine (WT), and a lead acid battery energy storage system (BESS) by creating a P2X concept to form a living lab platform. Beyond the model, regarding the experimental part, a PV array, a WT, and a BESS are combined with a PEMFC module that is rated output of 1200 W. Expect for all systems, the FC part is emphasized in this study. Also, a dynamic model of the mentioned PEMFC is proposed and verified. • Importance of hydrogen energy is focused on its advantages, future role, potential, and challenges. • FC unit as a complementary source is evaluated by creating a P2X concept. • This platform is designed to meet the energy needs of research-education, diversify the supply, increase energy independence. • Energy procurement is supplied via green energy during a lesson, which is noteworthy and instructive. • Feasibility of combined PV/WT/BESS/PEMFC system is investigated. [ABSTRACT FROM AUTHOR]

Today, hydrogen fuel cells (HFCs) have become very popular in various applications because of their ability to be a clean energy source. One of the difficulties associated with HFCs is their sluggish response to variations in the load. This paper presents a nested control strategy based on a type-2 neuro-fuzzy controller (T2NFC) to improve the HFC's dynamic response in a hybrid stand-alone power network using HFC and battery. A system model is constructed using Matlab-Simulink. An interleaved converter is used to draw the maximal power from the HFC and reduce the ripple in the HFC's current. Two T2NFCs control DC voltage and battery charge/discharge current. The robustness of the T2NFC is evaluated for input disturbance, output disturbance, and both disturbances. The results show that the proposed control strategy is robust against input and output disturbances. Also, it provides improved dynamic response of the HFC, lower ripple in HFC current, and less overshoot or undershoot in DC voltage both in transient and steady-state. For step reference input, the proposed controller improves settling time of 24.06 % and overshoot of 59.55 % compared to the conventional PI controller. The results verify the effectiveness of the proposed controller under different operating conditions of hybrid stand-alone power network with fuel cell and battery. • The response of HFC is enhanced, leading to faster and more accurate power generation. • The hydrogen fuel cell's current is experienced a significant reduction in ripples. • The hydrogen fuel cell is now being operated at its maximum power point. • A Type-2 Neuro-Fuzzy Controller is developed to provide robust control of the hydrogen fuel cell's output voltage. [ABSTRACT FROM AUTHOR]

Biorenewable hydrogen is requisite to replace non-renewable hydrogen. Decarbonization is assured. Hydrogen demand is severely rising due to mitigating climate change and reducing fossil fuel dependency. Green Hydrogen from agro waste proposition makes bio-circular economy upcycling. The main objective of this study is to reinforce the hope of renewable, sustainable H 2 production from agro-waste. Initially, this paper shows the demand for green hydrogen, the sustainable availability of agro waste, and their capability to produce H 2. Insights into the gasification of agro waste about cellulose, hemicellulose, and lignin with conventional gasification. The effect of catalyst and supercritical gasification and their challenges is discussed. Most uniquely, other reviews highlight various aspirations behind agro-waste gasification to attain a strong business model, such as co-production, co-gasification, and CO 2 reforming with H2 yield. This review exhibits some main insight into various aspects of agro-waste gasification. H 2 from agrowaste gasification has high energy content (122 kJ/g) and high energy conversion efficiency in the range of 55–58 %, in addition to gaining the economic penalties of 2.2–2.5 net points for decarbonization. Agro waste is composed of lignocellulosic material that is relatively richer in hydrogen than fossil fuel resources. In SCWG, water is one of the natural solvents, which means feedstock effectively dissolves with water solvents. Intermittent density, low viscosity, and surface tension are nearly zero values due to SCW having no specific phase boundary, which enhances the gasification and substantially reduces tar formation during SCWG. Catalyst utilization enhances H 2 production. The present study comprehensively exhibits the role of catalyst and their supporter and promoter. Ni-based catalysts are mostly suggested for H2 production but fall into reusability issues. The main reason behind this is that Ni is inefficient in removing HCl, H 2 S, and total trace elements during gasification. Recently, low-cost and waste-to-wealth transformation aspects of biochar-based catalysts have gained attention. Renewable-assisted gasification significantly improves the energy and exergy of the system and suppresses the important concern of energy consumption during gasification. Renewable assisted and various aspiration incorporation into gasification is solidly recommended for future implementation based on energy, economic, and environmental benefits from them. Plastic and biomass are richer in hydrocarbon and oxygen, respectively; this synergistic effect has the potential to enhance the H 2 yield. From this study, PP plastic is mostly preferred for co-gasification with biomass. Compared to 100 wt% of biomass, the introduction of plastic slightly increased the coke formation, but the H 2 yield was improved. When the plastic mixture of 10 wt% increases coke deposition, however, significant coke deposition is not reported when 20 wt% of plastic concentration is not reported. Carbon capture via CO 2 inert gas supply enhances the H 2 yield, provides a route to carbon trade, and substantially contributes to GHG pollution mitigation. Agro-waste gasification is produced by a product that has the potential to be used in a wide range of applications due to its unique properties, such as large specific surface area, porosity, functional groups, high reliability, and minimum cost. Hopefully, this review will be an optic to the most appropriate green hydrogen production path for sustainable clean energy production and effective agro-waste management. • This review acts as an optic to the most appropriate green hydrogen production path. • Hydrogen separation, purification, and storage need more care. • Carbon dioxide reformation aids a carbon trading system and reduces environmental effect. • These research provide direction for energy nexuses that may be derived from agricultural waste. [ABSTRACT FROM AUTHOR]

The investigation of cost-effective and highly efficient electrocatalysts for alkaline water and simulative seawater oxidation is essential to the conversion and storage of renewable energy. In this paper, the Ce–NiSe 2 /CoP catalyst with multihole and ultrathin nanosheet structure is generated. The unique structural characteristics of Ce–NiSe 2 /CoP heterojunction nanosheets contribute the excellent OER performance under different alkaline 1 M KOH and simulated seawater (1 M KOH + 0.5 M NaCl) electrolytes. Specifically, this catalyst exhucture is generated. The unique structural characteristics of Ce–NiSe 2 /CoP heterojunction nanosheets conibits the low overpotentials of 287 and 304 mV at the current density of 10 mA cm−2, along with the Tafel slopes of 87.1 and 78.8 mV dec−1 in two solutions, respectively. Moreover, the Ce–NiSe 2 /CoP target product also displays good stability. The present study introduces a promising strategy for the advancement of high-performance electrocatalysts in green energy field. [Display omitted] • The Ce-doped NiSe 2 /CoP heterostructure nanosheets are triumphantly generated. • The Ce–NiSe 2 /CoP product possesses multihole and ultrathin lamella architecture. • Each nanosheet with coarse surface is composed of prolifically nanosecondary units. • This catalyst presents fine OER properties in alkaline water and simulative seawater. [ABSTRACT FROM AUTHOR]

In response to climate change and the imperative for sustainable energy solutions, this study investigates the feasibility of producing green hydrogen and associated e-fuels (methane, methanol, and ammonia) using a renewable energy hybrid system in Dakhla, Morocco. Utilizing the System Advisor Model (SAM) software for simulation-based analysis, the research evaluates a hybrid system combining concentrated solar power (CSP) and photovoltaic (PV) plants against standalone counterparts. Various simulations comparing standalone PV and CSP plants with a novel CSP/PV hybrid concept were carried out. The hybrid system demonstrates significant promise, exhibiting increased annual energy yield and capacity factors up to 90%, leading to enhanced efficiency, performance, and cost savings with a Levelized Cost of Electricity (LCOE) approximating 17 cents/kWh. Furthermore, this paper conducts an in-depth exploration into the feasible production of hydrogen and its derived synthetic fuels utilizing hybrid renewable systems. The study provides a thorough examination of the production processes, yields, and efficiencies of hydrogen and its derivative e-fuels, with a focus on green hydrogen production through water electrolysis, CO2 hydrogenation, the Sabatier process, and the Haber-Bosch process. It sheds light on the potential applications of these fuels in the transportation sector, including in electric and hydrogen vehicles and aviation. The insights garnered are indispensable for crafting future strategies and policies in sustainable energy planning. These findings not only provide valuable direction for forthcoming initiatives in renewable energy but also underscore the pivotal role of hybridization in enhancing the efficient production and utilization of hydrogen within both renewable energy and transportation sectors. • PV and CSP systems to generate electricity for the Dakhla city was investigated. • A Hybrid system optimization has been proposed. • The Electricity surplus was used to produce hydrogen and hydrogen-based products. • Various scenarios for the heavy-duty application of e-fuel were presented and discussed. [ABSTRACT FROM AUTHOR]

In this paper we study clean energy transition in a modified version of the Ramsey growth model by including nonrenewable and renewable resources as well as pollution externalities. The main difference from previous works is that we consider imperfect substitution between nonrenewable and renewable resources. We characterize the social optimum and show that the economy converges to a clean state in the long run. We then study the decentralized equilibrium and show that the economy converges to the same state even without regulation, but with higher environmental damage. Further, we investigate the properties of the taxation trajectory that drives the laissez-faire economy to follow the optimal path and show that it can be either increasing or decreasing over time. We identify different channels that influence the path of optimal taxation and show that it depends, among other things, on the level of capital, the cost of renewable energy and the degree of substitution between renewable and nonrenewable resources. • A growth model with nonrenewable and renewable resources and pollution externalities. • Nonrenewable and renewable resources are considered as imperfect substitutes. • Social optimum and decentralized equilibrium characterized. • Decentralized economy converges to the clean state even without regulation. • Optimal taxation trajectory can be increasing or decreasing over time. [ABSTRACT FROM AUTHOR]

This paper intends to give an impression of new technologies and processes that are in development for application to achieve decarbonization, and about which less or no experience on associated hazards exists in the process industry. More or less an exception is hydrogen technology because its hazards are relatively known and there is industry experience in handling it safely, but problems will arise when it is produced, stored, and distributed on a large scale. So, when its use spreads to communities and it becomes as common as natural gas now, measures to control the risks will be needed. And even with hydrogen, surprise findings have been shown lately, e.g., its BLEVE behavior when in a liquified form stored in a vessel heated externally. Substitutes for hydrogen are not without hazard concern either. The paper will further consider the hazards of energy storage in batteries and the problems to get those hazards under control. Relatively much attention will be paid to the electrification of the process industry. Many new processes are being researched, which given green energy, will be beneficial to reduce greenhouse gases and enhance sustainability, but of which hazards are rather unknown. Therefore, as last chapter the developments with respect to the concept of hazard identification and scenario definition will be considered in quite detail. Improvements in that respect are also being possible due to the digitization of the industry and the availability of data and considering the entire life cycle, all facilitated by the data model standard ISO 15926 with the scope of integration of life-cycle data for process plants including oil and gas production facilities. Conclusion is that the new technologies and processes entail new process and personal hazards, and that much effort is going into renewal but safety analyses are scarce. Right in a period of process renewal, attention should be focused on possibilities to implement inherently safer design. [ABSTRACT FROM AUTHOR]

The global problem of climate change and difficulties related to energy access, air pollution, and water pollution in India (and other developing countries) necessitate the need to look for alternative clean, local, and low-carbon energy sources for displacing fossil fuels. This paper analyses the existing waste-to-biomethane potential of the sericulture, fisheries, and agro-industrial sectors in India, which have mostly been neglected previously in India's waste-to-energy assessments. In the process, the volume of wastewaters generated from India's agro-industries are also estimated, data on which are scarce in the academic and grey literature. India's annual biomethane potentials (for 2018–19) were found to be 88 million m3, 207 million m3, and 3514 million m3 from the three sectors, respectively. To assess the energy generation potential of these wastes, a comprehensive literature review was conducted and data on residue-to-product ratios, results of proximate analyses, and specific biomethane yields were either compiled or calculated. The gross thermal energy and electricity generation potentials are 132 PJ and 22 TWh respectively; between 19 and 95 million people can benefit from such waste-to-energy production, depending on the end use of the biomethane for electricity generation or as a domestic cooking fuel. The corresponding mean removal of organic pollution from India's surface waters can be between 5.5 and 9.3 million tonnes of chemical oxygen demand. For the end uses of biomethane in electricity generation and cooking, the cumulative GHG abatements attributable to these industries are 11.4 million tonnes and 6.8 million tonnes of carbon dioxide-equivalent respectively. Besides the numeric results reported, this paper also contains a comprehensive compilation of data on waste characteristics and biomethane productions. The present status of biogas generation and related policy implementation in India are reviewed and discussed. Overall, our findings indicate that biomethane from these wastes and wastewaters can generate substantial energy for India, is in line with recent government policies, and can aid India in achieving six Sustainable Development Goals of the United Nations. • Annual estimates of wastes from India's sericulture, fisheries and agro-industries • The corresponding annual biomethane generation potential is 3810 million m3. • Clean electricity or cooking gas for 19 and 95 million people respectively • Quantitative estimates of atmospheric GHG and surface water COD removals • Biomethane data compilation and a review of present status and policies in India [ABSTRACT FROM AUTHOR]

There is a great desire to integrate multiple energy systems by forming low-carbon energy hubs. Among various energy platforms, the integration of power and gas networks via Power-to-Gas (PtG) technologies is introduced as a promising solution to enhance the flexibility of power grids and facilitate seamless adoption for high penetration levels of renewable energy resources. In addition, the production of green hydrogen from waste/inexpensive clean electricity has recently been identified as a potential means for large-scale energy storage, deployment of hydrogen mobility, and decarbonization of several processes that utilize hydrogen. As integrated hydrogen-based energy hubs (H 2 Hubs) attract more attention for widespread deployment, the security of such new platforms against various cyberattacks is also becoming a critical topic for investigation. This paper proposes a new data estimation technique, developed and integrated with H 2 Hubs scheduling models, for real-time optimal adaptive collection and organization of the system operating parameters for cybersecurity assessment. A new formulation is presented for the adaptive formation of a newly proposed concept, referred to as the system feasibility area , via real-time acquisition of the system operating information. The created feasibility areas are utilized for real-time post-occurrence detection of the bad scheduling data that is invisible to the existing cybersecurity layers. Numerical studies are conducted to demonstrate the efficacy and feasibility of the proposed model. The results demonstrate that the historical data can be adaptively collected in real time and successfully utilized to create feasibility areas to categorize the system operating points. • An optimal scheduling model is proposed for hydrogen-based energy hubs (H 2 Hubs). • A new data estimation method is developed and integrated with the scheduling model. • A new formulation is given for the adaptive creation of the feasibility area. • Simulation case studies are presented and discussed. [ABSTRACT FROM AUTHOR]

With the future of green energy relying on increases in green-energy production scale to support demand, placing importance on location selection for new energy production methods is going to be vital to secure a zero-carbon future. In this paper, a method called H2Locate is introduced to conduct a down selection sequence for identifying hydrogen production plant location within a defined region. Following the method, resource availability, energy availability, and social impact metrics are analyzed to understand which variables are most vital and what data must be obtained to achieve confidence in the selection of an implementation location. An illustrative example using Oklahoma as the region is produced to demonstrate the proposed method. The counties within Oklahoma are analyzed to identify potential subregions for implementing a hydrogen production plant. Excel-based software, The Probability of Hydrogen Implementation (PHI), using publicly available data regarding energy, resources, and social variables is utilized to carry out the proposed method. Considering the illustrative example with a 290 MW alkaline electrolysis facility, we find that Kay County, Johnston County, Caddo County, and the counties directly surrounding them are the most suitable locations in Oklahoma for the implementation given variables related to the desired energy, resource, and social metrics. • The H2Locate down selection method guides hydrogen production plant location selection. • Analyzes 7 hydrogen hub reports to identify key hydrogen industry variables. • Categorizes energy, feedstock, and social factor variables utilized in the H2Locate method. • An illustrative 290 MW alkaline electrolysis example in Oklahoma identified Kay, Johnston, and Caddo counties as prime locations. [ABSTRACT FROM AUTHOR]

This paper addresses the urgent need for efficient hydrogen storage methods in the context of combating climate change and transitioning to sustainable energy sources. Among various storage options, LiBH 4 is highlighted for its high volumetric and gravimetric energy densities, critical factors in determining its suitability for energy applications. However, challenges arise due to its high thermolysis temperature, which poses difficulties, especially in applications like automotive use where high temperatures are required. The commercial viability of LiBH 4 remains a significant obstacle due to the nascent stage of chemical hydride technology and the absence of large-scale production facilities. Environmental concerns also loom large, as the production of LiBH 4 relies on extensive mining of lithium and boron, known for their environmental impact. Furthermore, the economic feasibility of LiBH 4 as a hydrogen storage medium is questioned, given the substantial portion of total expenses attributed to hydrogen costs, affecting all methods except those based on fossil fuels or electricity. Nevertheless, there is optimism that with technological advancements and improved infrastructure, the costs associated with LiBH 4 and hydrogen storage overall may decrease over time. In conclusion, while LiBH 4 presents promising energy density characteristics, its practical implementation faces challenges such as high production costs, environmental concerns, and technological limitations. Overcoming these obstacles is crucial for realizing a sustainable and carbon-free energy landscape driven by hydrogen. • LiBH 4 shows promise for high energy density storage but faces obstacles high production costs and environmental concerns. • A comprehensive decision matrix analysis showcases the strengths and weaknesses of various hydrogen storage options. • LiBH 4 may find applications in small-scale personal storage due to its safety and energy density. [ABSTRACT FROM AUTHOR]

This paper explores the feasibility of utilizing lead-free multilayer piezo stacks, particularly focusing on Zr-doped 0.95(Bi 0. 5 Na 0.5)TiO 3 -0.05(BaTiO 3) piezoceramics, for energy harvesting. Various lead-free BNT-BT disk samples with different Zr concentrations undergo structural, microstructural, and electrical characterizations. The results illustrate that Zr-doping improves piezoelectric constitutive parameters, notably at a 2.0 mol% concentration. Electromechanical tests were conducted on multilayer piezo stacks, involving variations in electric load, mechanical load, frequency, and number of stacked disks. These tests demonstrate the ability of the multilayer transducer to produce up to 1.5 V (peak) under particular conditions: a 250 Hz frequency, a 10 N mechanical load, and an open circuit electric load, utilizing a stack comprising 5 disks. Employing an analytical mathematical model, an effective d 33 e f f of the system is determined, yielding values ranging from 588 to 625 pC/N for a stack composed of 5 disks. These findings highlight the considerable potential of lead-free multilayer piezo stacks in energy harvesting applications, offering crucial insights for the development of sustainable and eco-friendly energy solutions. [ABSTRACT FROM AUTHOR]

This paper argues that energy efficiency is a potent shield against oil price uncertainty in an increasingly interconnected world fraught with geopolitical tensions. By reducing dependence on oil, enhancing economic resilience, and improving energy security, energy efficiency measures offer multifaceted benefits for both national economies and global stability. Specifically, a wavelet coherence analysis is conducted to study the response of global energy efficiency to geopolitical oil price uncertainty. Quantile-on-quantile and quantile regressions are additionally employed to separate the impacts of various geopolitical oil price risk quantiles on the quantiles of energy efficiency. These methods are utilized in the examination of global time-series data covering the timeframe 2004:Q1–2020:Q4. The wavelet coherence outcomes indicate a positive correlation between geopolitical oil price uncertainty and energy efficiency, particularly during the energy crisis of the 2000s and the COVID-19 pandemic. The results also reveal that geopolitical oil price uncertainty leads to energy efficiency, indicating that an upsurge in geopolitical oil price uncertainty causes energy efficiency to increase. Moreover, the results from quantile-on-quantile and quantile regressions affirm the predominantly positive effects of geopolitical oil price uncertainty on global energy efficiency. Our conclusion therefore is that through strategic investments, innovative policies, and international collaborations relating to energy efficiency, nations can fortify themselves against the destabilizing effects of geopolitical conflicts on energy markets. This would ensure a more sustainable and secure energy future for all. [ABSTRACT FROM AUTHOR]

The research investigates the correlation between FinTech innovation and the index of renewable energy volatility from May 1, 2019, to October 28, 2022, by utilizing cutting-edge multiple wavelet analysis (MWA) techniques, including coherency and gain of partial wavelets. FinTech innovation and the green energy sector exhibit multiple coherencies. These coherencies suggest that three cycles, spanning from January 2020 to June 2020, December 2020 to April 2021, and January 2022 to May 2022, were focused on the high-frequency spectrum (3–68 days). Meanwhile, the other cycles were focused on low frequencies (69–130 days), which coexisted between June 2019 and January 2021 and January 2022 and October 2022. Green bonds and FinTech innovation's partial coherency indicate that modifications to the green bond markets caused shifts in FinTech innovation between June and November of 2019. FinTech innovation is in sync with green bonds pushing from December 2021 to October 2022. The partial consistency of FinTech innovation and sustainable energy demonstrates that both metrics align with the current FinTech innovation cycle, pushing from May 2019 to August 2019 and from December 2020 to July 2021, and both indicators are in sync with ARKF pushing. We also demonstrate how unexpected events like the Ukraine-Russia conflict and the COVID-19 epidemic affect these dynamic connectednesses. Hence, our paper calls for policy designs that promote the role of FinTech development in stabilizing the renewable energy market. [ABSTRACT FROM AUTHOR]

• Significant reduction (18.44%) in overall Spanish GHG emissions from 2008 to 2018, highlighting some differences depending on the considered phase of the crisis. • The total intensity effect has been noticeable negative, especially in Agriculture, Transport, and Other Services. • The total carbonization effect has contributed to increase GHG emissions by 5.86%, being particularly negative in the case of Industry. • Per capita production effect was strongly negative in Industry and slightly positive in the rest of the economic sectors. • R&D, more eco-friendly technologies, green energies, circular economy and consumer green attitudes: the best strategies to reduce GHG emissions. The reduction of GHG emissions to reverse the greenhouse effect is one of the main challenges in this century. In this paper we pursue two objectives. First, we analyze the evolution of GHG emissions in Spain in 2008–2018, at both the global and sectoral levels, with the variation in emissions decomposed into a set of determining factors. Second, we propose several actions specifically oriented to more tightly controlling the level of emissions. Our results showed a remarkable reduction (18.44%) in GHG emissions, mainly due to the intensity effect, but also to the production-per-capita effect. We detected somewhat different patterns among the various sectors analyzed. While the intensity effect was the most influential one in the agricultural, transport, and others sectors, the production-per-capita effect was predominant in the case of industry. The carbonization effect was revealed as crucial in the commerce sector. The above findings highlight the importance of the energy efficiency measures taken in recent years in the Spanish economy, also pointing to the need to deepen those strategies and to propose new measures that entail greater efficiency in emissions. Additional efforts in areas like innovation, R&D, diffusion of more eco-friendly technologies, and a greater use of greener energies all prove to be essential reduction actions to fight the greenhouse effect. [ABSTRACT FROM AUTHOR]

Solar photovoltaic systems can reduce carbon emissions by harnessing green energy from the sunlight, however, tremendous end-of-life solar panels may pose a threat to the local environment in the coming decades. What's worse, fewer regulations have been mandated to deal with the disposal of solar waste. To address this issue, this paper investigates a game-based, government-subsidized solar recycling model, and extends the model to a dynamic system. By analyzing the equilibrium outcomes, optimal decisions are revealed for all stakeholders. More importantly, we find regulatory subsidies can benefit all members of the solar recycling chain. Furthermore, when confronted with low-quality solar panels with a high degradation rate, we suggest that the government announces a low R&D subsidy rate. Even so, the level of the manufacturer's R&D efforts is still high, which leads to more R&D subsidies provided by the government. Based on an analysis of the dynamic system, it's better to be extremely careful when the government enacts the subsidy policy. Otherwise, the profits of all the chain members may be hurt due to the bifurcation and chaos phenomena. • A government-subsidized solar recycling model has been studied. • The impacts of subsidy and risk aversion on optimal strategies are revealed. • When facing low-quality panels with a high degradation rate, the governor should provide a low R&D subsidy rate. • A dynamic system is investigated to understand decision making process in long-term operations. [ABSTRACT FROM AUTHOR]