Publications

Japan and other industrialized countries rely on the import of green hydrogen (H2 ) as they lack the resources to meet their own demand. In contrast countries such as Australia have the potential to produce hydrogen and its derivatives using wind and solar energy. Solar energy can be harnessed to produce electricity using photovoltaic systems or to generate thermal energy by concentrating solar irradiation. Thus thermal and electrical energy can be used in a solid oxide electrolysis process for low-cost hydrogen production. The operation of a solid oxide electrolysis cell (SOEC) stack integrated with solar energy is experimentally investigated and further analyzed using a validated simulation model. Furthermore a techno-economic assessment is conducted to estimate the hydrogen production costs including the expenses associated with liquefaction and transportation from Australia to Japan. High conversion efficiencies and low-cost SOECs are projected to result in production costs below 4 USD/kg.

Against the backdrop of ever‑increasing energy demand and growing awareness of en‑ vironmental protection the research and optimization of hydrogen‑related multi‑energy systems have become a key and hot issue due to their zero‑carbon and clean characteristics. In the scheduling of such multi‑energy systems a typical problem is how to describe and deal with the uncertainties of multiple types of energy. Scenario‑based methods and ro‑ bust optimization methods are the two most widely used methods. The first one combines probability to describe uncertainties with typical scenarios and the second one essentially selects the worst scenario in the uncertainty set to characterize uncertainties. The selection of these scenarios is essentially a trade‑off between the economy and robustness of the so‑ lution. In this paper to achieve a better balance between economy and robustness while avoiding the complex min‑max structure in robust optimization we leverage artificial in‑ telligence (AI) technology to generate enough scenarios from which economic scenarios and feasible scenarios are screened out. While applying a simple single‑layer framework of scenario‑based methods it also achieves both economy and robustness. Specifically first a Transformer architecture is used to predict uncertainty realizations. Then a Gener‑ ative Adversarial Network (GAN) is employed to generate enough uncertainty scenarios satisfying the actual operation. Finally based on the forecast data the economic scenar‑ ios and feasible scenarios are sequentially screened out from the large number of gener‑ ated scenarios and a balance between economy and robustness is maintained. On this ba‑ sis a multi‑energy collaborative optimization method is proposed for a hydrogen‑based multi‑energy microgrid with consideration of the coupling relationships between energy sources. The effectiveness of this method has been fully verified through numerical exper‑ iments. Data show that on the premise of ensuring scheduling feasibility the economic cost of the proposed method is 0.67% higher than that of the method considering only eco‑ nomic scenarios. It not only has a certain degree of robustness but also possesses good economic performance.

Urban transportation systems particularly public buses contribute significantly to global pollution creating an urgent need for sustainable solutions. Alternative fuel buses and other disruptive technological advancements in this field are essential to resolve these problems. The absence of studies on the life cycle assessment (LCA) of hydrogen-fueled buses along with comparative analyses of alternative-fueled buses makes this research particularly timely. This study develops a comprehensive LCA framework to measure the economic and environmental impact of using different technologies (i.e. hydrogen-fueled electric and diesel buses). Different fuel production methods were examined considering operational factors such as energy consumption across various routes. This study contributes to enhancing the LCA methodology for public bus operations by using machine learning algorithms to cluster routes and identify optimal demonstration routes for analysis. The results highlight the impact of fuel production methods for hydrogen-fueled buses in the significant pollutant reductions (e.g. CO2 and NO ) despite their high life cycle costs. The proposed framework is validated with real data from Halifax Canada and expanded to assess public bus networks in cities with varying routes topology and population levels. The paper’s analyses consider future technological advances to lower costs aligning them with electric buses over time. This study helps policymakers choose the best public bus alternatives to improve the economic environmental and social sustainability of urban transportation.

A tool for parametric finite element modeling and analysis of LH2 tanks for aviation is developed. Passively insulated cryogenic composite sandwich pressure vessels are investigated as they conjugate simplicity effectiveness and lightweight design for aeronautical applications. Several parametric analyses are performed with the aim of gaining both general and case-specific understanding of how particular design choices may impact the tank mechanical and thermal performance. Differently from most of previous studies multiple design choices including tank walls thicknesses constraints for airframe integration strategies as well as the presence position and integration of refuelling cutouts and anti-sloshing bulkheads are considered. The thermo-mechanical analyses are performed considering first a simple reference configuration with the aim of evaluating possible directions for performance enhancement. Results indicate how different design features affect the gravimetric and thermal efficiency of the tank without compromising structural integrity if the walls thicknesses are suitably sized. The effects of different constraints and geometric discontinuities which reflect specific fuselage integration choices must be carefully assessed as they reduce safety margins. Ultimately a vessel model including features necessary for safe operation is presented as it serves as a baseline for further optimization.

Hydrogen is a promising energy carrier in the future which can help improve air quality and enhance energy security. Hydrogen production mainly relies on fossil fuels (natural gas and coal). Hydrogen production from fossil fuels can result in the significant emissions of carbon dioxide aggravating the global greenhouse effect. At the same time fossil fuels are non-renewable and the use of fossil fuels to produce hydrogen further exacerbates the crisis of fossil fuel shortages. Fortunately water as a carbon-free and hydrogen-rich renewable resource offers one of the best solutions to replace hydrogen production from fossil fuels through its decomposition. Furthermore hydrogen production by decomposition of water is vital for the realization of the sustainable development. In this paper we review the current mainstream technologies (electrolysis pyrolysis and photolysis) for hydrogen production by decomposing water. The principles processes advantages and disadvantages and the latest progresses of these technologies are also discussed. At last this paper provides a summary and outlook on water decomposition for hydrogen production and thinks that the yield energy efficiency and cost of hydrogen production from water decomposition are largely dependent on the development of new materials and the improvement of existing materials. Moreover utilizing renewable energy to decompose water for hydrogen production offers the possibility of achieving the hydrogen economy.

This study explores hydrogen’s potential as a sustainable energy source for Brunei given the nation’s reliance on fossil fuels and associated environmental concerns. Specifically it evaluates two hydrogen production technologies; steam methane reforming (SMR) and alkaline water electrolysis (AWE) through a techno-economic framework that assesses life cycle cost (LCC) efficiency scalability and environmental impact. SMR the most widely used technique is cost-effective but carbon-intensive producing considerable carbon dioxide emissions unless combined with carbon capture to yield “blue hydrogen”. On the other hand AWE particularly when powered by renewable energy offers a cleaner alternative despite challenges in efficiency and cost. The assessment revealed that AWE has a significantly higher LCC than SMR making AWE the more economically viable hydrogen production method in the long term. A sensitivity analysis was also conducted to determine the main cost factors affecting the LCC providing insights into the long term viability of each technology from an operational and financial standpoint. AWE’s economic viability is mostly driven by the high electricity and feedstock costs while SMR relies heavily on feedstock costs. However Environmental Impact Analysis (EIA) indicates that AWE produces significantly higher carbon dioxide emissions than SMR which emits approximately 9100 metric tons of carbon dioxide annually. Nevertheless findings suggest that AWE remains the more sustainable option due to its higher LCC costs and compatibility with renewable energy especially in regions with access to low-cost renewable electricity

An experimental study was devised to assess the technical environmental and economic impact of incorporating hydrogen into natural gas. The experimental tests were conducted on a GUNT ET 792 demonstration unit characterized by operating on a gas cycle in a twin-shaft configuration. The equipment was adapted to accommodate natural gas and mixtures of natural gas with hydrogen in volumetric fractions of 5% 10% and 20%. The tests carried out ensured the viability of using these mixtures from a safety perspective. On the other hand it was possible to evaluate the main differences in the use of these fuel gases in terms of the temperatures and pressures that characterize the main points of the gas cycle fuel injection pressures air/fuel ratios excess air power output overall cycle efficiencies NOX and CO2 emissions and operational cost.

As global energy demand increases and reliance on fossil fuels becomes unsustainable hydrogen presents a promising clean energy alternative due to its high energy density and potential for significant CO2 emission reductions. However current hydrogen production methods largely depend on fossil fuels contributing to considerable CO2 emissions and underscoring the need to transition to renewable energy sources and improved production technologies. Life Cycle Analysis (LCA) is essential for evaluating and optimizing hydrogen production by assessing environmental impacts such as Global Warming Potential (GWP) energy consumption toxicity and water usage. The key findings indicate that energy sources and feedstocks heavily influence the environmental impacts of hydrogen production. Hydrogen production from renewable energy sources particularly wind solar and hydropower demonstrates significantly lower environmental impacts than grid electricity and fossil fuel-based methods. Conversely hydrogen production from grid electricity primarily derived from fossil fuels shows a high GWP. Furthermore challenges related to data accuracy economic analysis integration and measuring mixed gases are discussed. Future research should focus on improving data accuracy assessing the impact of technological advancements and exploring new hydrogen production methods. Harmonizing assessment methodologies across different production pathways and standardizing functional units such as “1 kg of hydrogen produced “ are critical for enabling transparent and consistent sustainability evaluations. Techniques such as stochastic modelling and Monte Carlo simulations can improve uncertainty management and enhance the reliability of LCA results.

Against the backdrop of high investment costs in distributed energy storage systems this paper proposes a bi-level energy management model based on shared multi-type energy storage to enhance system economics and resource utilization efficiency. First an electricity–heat–hydrogen coupled shared storage architecture is developed incorporating hydrogen-blended gas turbines gas boilers and hydrogen loads to achieve deep coupling between the power grid and natural gas network. Then a bi-level game model is formulated with the upper-level objective of minimizing the storage operator’s cost and the lower-level objective of minimizing the cost of the integrated energy microgrid (IEM) aggregator. A cooperative game mechanism is introduced within the microgrids to support peer-to-peer energy trading. Nash bargaining theory is applied to determine benefit allocation and dynamic pricing strategies among microgrids. The model is solved using a genetic algorithm (GA) and the alternating direction method of multipliers (ADMM). Simulation results validate the proposed strategy’s effectiveness and feasibility in reducing system costs improving overall benefits and achieving fair benefit allocation.

Supplying the growing energy demand of emerging economies by utilizing available biogenic streams will be a key challenge in the coming years. Hydrogen is a promising alternative energy carrier to support the transition of the energy sector and other industries. In recent years the use of biomass as a renewable energy source for bio-based hydrogen production has gained significant attention due to its potential to reduce environmental impact. Among the various thermochemical processes biomass pyrolysis can be used to produce hydrogen though the current use of this process is limited. Reforming the volatile fraction of biomass pyrolysis products has been only marginally explored differently from gasification; the reforming of pyrogasses can then be seen as a viable method to enhance hydrogen yield. This review explores the key factors influencing hydrogen yield including operating conditions and the role of catalysts. It is noteworthy that most of the studies evaluated in this review are in the laboratory and pilot scales and the focus of this study is on the slow pyrolysis process in the first stage. Findings indicate that hydrogen production can be significantly improved with the proper choice of catalysts with metal-based and nonmetal-based catalysts among the most effective. The outcomes of this review highlight the key effect of increasing the reforming temperature and steam-to-biomass ratio to enhance hydrogen production.