Publications

The present work demonstrates a comparative study of hydrogen fuel cells and combustion aircraft to investigate the potential of fuel cells as a visionary propulsion system for radically more sustainable medium- to long-range commercial aircraft. The study which considered future airframe and propulsion technologies under the Se2A project was conducted to quantify potential emissions and costs associated with such aircraft and to determine the benefits and drawbacks of each energy system option for different market segments. Future technologies considered in the present work include laminar flow control active load alleviation new materials and structures ultra-high bypass ratio turbofan engines more efficient thermal management systems and superconducting electric motors. A multi-fidelity initial sizing framework with coupled constraint and mission analysis blocks was used for parametric airplane sizing and calculations of all necessary characteristics. Analyses performed for three reference aircraft of different sizes and ranges concluded that fuel-cell aircraft could have operating cost increases in the order of 30% compared to hydrogen combustion configurations and were caused by substantial weight and fuel burn increases. In-flight changes in emissions of fuel cell configurations at high altitudes were progressively reduced from medium-range to long-range segments from being similar to hydrogen combustion for medium-range to 24% for large long-range aircraft although fuel cell aircraft consume 22–30% more fuel than combustion aircraft. Results demonstrate a positive environmental impact of fuel cell propulsion for longrange applications the possibilities of being a more emission-universal solution if desired optimistic technology performance metrics are satisfied. The study also demonstrates progressively increasing technology requirements for larger aircraft making the long-range application’s feasibility more challenging. Therefore substantial development of fuel cell technologies for long-range aircraft is imperative. The article also emphasizes the importance of airframe and propulsion technologies and the necessity of green hydrogen production to achieve desired emissions.

The EU Horizon2020 RISE project 778307 “Hydrogen fuelled utility and their support systems utilising metal hydrides” (HYDRIDE4MOBILITY) worked on the commercialization of hydrogen powered forklifts using metal hydride (MH) based hydrogen stores. The project consortium joined forces of 9 academic and industrial partners from 4 countries. The work program included a) Development of the materials for hydrogen storage and compression; b) Theoretical modelling and optimisation of the materials performance and system integration; c) Advanced fibre reinforced composite cylinder systems for H2 storage and compression; d) System validation. Materials development was focused on i) Zr/Ti-based Laves type high entropy alloys; ii) Mg-rich composite materials; iii) REMNiSn intermetallics; iv) Mg based materials for the hydrolysis process; v) Cost-efficient alloys. For the optimized AB2±x alloys the Zr/Ti content was optimized at A = Zr78-88Ti12–22 while B=Ni10Mn5.83VFe. These alloys provided a) Low hysteresis of hydrogen absorption-desorption; b) Excellent kinetics of charge and discharge; c) Tailored thermodynamics; d) Long cycle life. Zr0.85Ti0.15TM2 alloy provided a reversible H storage and electrochemical capacity of 1.6 wt% H and 450 mAh/g. The tanks development targeted: i) High efficiency of heat and hydrogen exchange; ii) Reduction of the weight and increasing the working H2 pressure; iii) Modelling testing and optimizing the H2 stores with fast performance. The system for power generation was validated at the Implats plant in a fuel cell powered forklift with on-board MH hydrogen storage and on-site H2 refuelling. The outcome on the HYDRIDE4MOBILITY project (2017–2024) (http://hydride4mobility.fesb.unist. hr) was presented in 58 publications.

Integrating coal-to-hydrogen production with Carbon Capture Utilization and Storage (CCUS) is essential for reducing greenhouse gas emissions and facilitating a shift towards a more sustainable energy paradigm. This paper explores the diffusion of CCUS technology within the coal-to-hydrogen sector against the dynamic backdrop of the carbon trading market. An evolutionary game-theoretic approach is utilized within a smallworld network framework to analyze the spread of CCUS technology among coal-tohydrogen enterprises. The simulation reveals that current market dynamics along with technological market and policy-related uncertainties do not robustly encourage the adoption of CCUS. As the carbon trading market continues to mature carbon prices become a significant factor influencing the diffusion of CCUS technology in coal-to-hydrogen processes. Furthermore investment costs hydrogen market prices and governmental policies are identified as pivotal elements in the propagation of CCUS technology. This study contributes valuable insights into the sustainable development of the hydrogen industry and the broader implications for low-carbon energy transition strategies.

The transition to hydrogen as a clean energy source is critical for addressing climate change and supporting environmental sustainability. This review provides an accessible summary of general research trends in hydrogen risk assessment methodologies enabling diverse stakeholders including researchers policymakers and industry professionals to gain insights into this field. By examining representative studies across theoretical experimental and simulation-based approaches the review highlights prominent trends and applications within academia and industry. The key focus is on evaluating risks in stationary and transportation applications paying particular attention to hydrogen storage systems transportation infrastructures and energy systems. By offering a concise yet informative summary of hydrogen risk assessment trends this paper aims to serve as a foundational resource for fostering safer and more sustainable hydrogen systems.

Hydrogen is emerging as a critical component in the global energy transition providing a low-carbon alternative for sectors such as industry and transportation. This paper aims to comprehensively address water usage in hydrogen production by exploring the water demands of different production methods and their implications for water management particularly in Texas. Key variables influencing water consumption are identified and potential water demands under different hydrogen market scenarios are estimated. Using spatial analysis regions where hydrogen production may stress local water resources are identified alongside policy recommendations for sustainable water use.

Proton exchange membrane electrolyzers are an attractive technology for hydrogen production due to their high efficiency low maintenance cost and scalability. To receive these benefits however electrolyzers require high power reliability and have relatively high demand. Due to their intermittent nature integrating renewable energy sources like solar and wind has traditionally resulted in a supply too sporadic to consistently power a proton exchange membrane electrolyzer. This study develops an electrolyzer model operating with renewable energy sources at a highly instrumented university site. The simulation uses dynamic models of photovoltaic solar and wind systems to develop models capable of responding to changing climatic and seasonal conditions. The aim therefore is to observe the feasibility of operating a proton exchange membrane system fuel cell yearround at optimal efficiency. To address the problem of feasibility with dynamic renewable generation a case study demonstrates the proposed energy management system. A site with a river onsite is chosen to ensure sufficient wind resources. Aside from assessing the feasibility of pairing renewable generation with proton exchange membrane systems this project shows a reduction in the intermittency plaguing previous designs. Finally the study quantifies the performance and effectiveness of the PEM energy management system design. Overall this study highlights the potential of proton exchange membrane electrolysis as a critical technology for sustainable hydrogen production and the importance of modeling and simulation techniques in achieving its full potential.

The use of hydrogen as fuel presents many safety challenges due to its flammability and explosive nature combined with its lack of color taste and odor. The purpose of this paper is to present an electrochemical sensor that can achieve rapid and accurate detection of hydrogen leakage. This paper presents both the component elements of the sensor like sensing material sensing element and signal conditioning as well as the electronic protection and signaling module of the critical concentrations of H2. The sensing material consists of a catalyst type Vulcan XC72 40% Pt from FuelCellStore (Bryan TX USA). The sensing element is based on a membrane electrode assembly (MEA) system that includes a cathode electrode an ion-conducting membrane type Nafion 117 from FuelCellStore (Bryan TX USA). and an anode electrode mounted in a coin cell type CR2016 from Xiamen Tob New Energy Technology Co. Ltd (Xiamen City Fujian Province China). The electronic block for electrical signal conditioning which is delivered by the sensing element uses an INA111 from Burr-Brown by Texas Instruments Corporation (Dallas TX USA). instrumentation operational amplifier. The main characteristics of the electrochemical sensor for hydrogen leakage detection are operation at room temperature so it does not require a heater maximum amperometric response time of 1 s fast recovery time of maximum 1 s and extended range of hydrogen concentrations detection in a range of up to 20%.

This study examines the effects of transitioning to hydrogen production in the National Capital Region (NCR) and Palawan Province Philippines focusing on technology environment and stakeholder impact. This research conducted through a July 2022 survey aimed to assess public awareness knowledge risk perception and acceptance of hydrogen and its environmentally friendly variant green hydrogen infrastructure. Disparities were found between urban NCR and rural Palawan with lower awareness in Palawan. Safety concerns were highlighted with NCR respondents generally considering hydrogen production safe while Palawan respondents had mixed feelings particularly regarding nuclear-based hydrogen generation. This report emphasizes the potential ecological advantages of hydrogen technology but highlights potential issues concerning water usage and land impacts. It suggests targeted public awareness campaigns robust safety assurance programs regional pilot projects and integrated environmental plans to facilitate the seamless integration of hydrogen technology into the Philippines’ energy portfolio. This collective effort aims to help the country meet climate action obligations foster sustainable development and enhance energy resilience.

Offshore wind power construction has seen significant development due to the high density of offshore wind energy and the minimal terrain restrictions for offshore wind farms. However integrating this energy into the grid remains a challenge. The scientific community is increasingly focusing on hydrogen as a means to enhance the integration of these fluctuating renewable energy sources. This paper reviews the research on renewable energy power generation water electrolysis for hydrogen production and large-scale hydrogen storage. By integrating the latest advancements we propose a system that couples offshore wind power generation seawater electrolysis (SWE) for hydrogen production and salt cavern hydrogen storage. This coupling system aims to address practical issues such as the grid integration of offshore wind power and large-scale hydrogen storage. Regarding the application potential of this coupling system this paper details the advantages of developing renewable energy and hydrogen energy in Jiangsu using this system. While there are still some challenges in the application of this system it undeniably offers a new pathway for coastal cities to advance renewable energy development and sets a new direction for hydrogen energy progress.

This paper establishes a framework of boundary conditions for implementing hydrogen energy systems in ships identifying what is feasible within maritime constraints. To support a comprehensive understanding of hydrogen systems onboard vessels an extensive technical review of hydrogen storage and power systems is provided covering the entire power value chain. Key aspects include equipment arrangement integration of fuel cell powertrain and presentation of the complete storage system in compliance with regulations. Engineering considerations such as material selection and insulation equipment specifications (e.g. pressure relief valves and hydrogen purity) and system configurations are analysed. Key findings reveal that fuel cells must achieve operational lifespans exceeding 46000 h to be viable for maritime applications. Additionally reliance solely on volumetric energy density underestimates storage needs necessitating provisions for cofferdams ullage space tank heels and hydrogen conditioning areas. Regulatory gaps are identified including inadequate safety provisions and inappropriate material guidelines.