Australia
A Theoretical Study on Reversible Solid Oxide Cells as Key Enablers of Cyclic Conversion between Electrical Energy and Fuel
Jul 2021
Publication
Reversible solid oxide cells (rSOC) enable the efficient cyclic conversion between electrical and chemical energy in the form of fuels and chemicals thereby providing a pathway for longterm and high-capacity energy storage. Amongst the different fuels under investigation hydrogen methane and ammonia have gained immense attention as carbon-neutral energy vectors. Here we have compared the energy efficiency and the energy demand of rSOC based on these three fuels. In the fuel cell mode of operation (energy generation) two different routes have been considered for both methane and ammonia; Routes 1 and 2 involve internal reforming (in the case of methane) or cracking (in the case of ammonia) and external reforming or cracking respectively. The use of hydrogen as fuel provides the highest round-trip efficiency (62.1%) followed by methane by Route 1 (43.4%) ammonia by Route 2 (41.1%) methane by Route 2 (40.4%) and ammonia by Route 1 (39.2%). The lower efficiency of internal ammonia cracking as opposed to its external counterpart can be attributed to the insufficient catalytic activity and stability of the state-of-the-art fuel electrode materials which is a major hindrance to the scale-up of this technology. A preliminary cost estimate showed that the price of hydrogen methane and ammonia produced in SOEC mode would be ~1.91 3.63 and 0.48 $/kg respectively. In SOFC mode the cost of electricity generation using hydrogen internally reformed methane and internally cracked ammonia would be ~52.34 46.30 and 47.11 $/MWh respectively.
Evaluation and Outlook for Australian Renewable Energy Export via Circular Liquid Hydrogen Carriers
Oct 2023
Publication
To combat global temperature rise we need affordable clean and renewable energy that does not add carbon to the atmosphere. Hydrogen is a promising option because it can be used as a carbon-free energy source. However storing and transporting pure hydrogen in liquid or gaseous forms is challenging. To overcome the limitations associated with conventional compressed and liquefied hydrogen or physio-chemical adsorbents for bulk storage and transport hydrogen can be attached to other molecules known as hydrogen carriers. Circular carriers which involve the production of CO2 or nitrogen during the hydrogen recovery process include substances such as methanol ammonia or synthetic natural gas. These carriers possess higher gravimetric and volumetric hydrogen densities (i.e. 12.5 wt% and 11.88 MJ/L for methanol) than cyclic carriers (i.e. 6.1 wt% and 5.66 MJ/L for methylcyclohexane (MCH)) which produce cyclic organic chemicals during dehydrogenation. This makes circular carriers particularly appealing for the Australian energy export market. Furthermore the production-decomposition cycle of circular carriers can be made carbon-neutral if they are derived from renewable H2 sources and combined with atmospheric or biomass-based CO2 or nitrogen. The key parameters are investigated in this study focusing on circular hydrogen carriers relevant to Australia. The parameters are ranked from 0 (worst) to 10 (best) depending on the bandwidth of the parameter in this review. Methanol shows great potential as a cost-effective solution for long-distance transport of renewable energy being a liquid at standard conditions with a boiling point of 64.7 °C. Methane is also an important hydrogen carrier due to the availability of natural gas infrastructure and its role as a significant export product for Australia.
Modulating Selectivity and Stability of the Direct Seawater Electrolysis for Sustainable Green Hydrogen Production
Feb 2025
Publication
Direct seawater electrolysis (DSE) has emerged as a compelling route to sustainable hydrogen production leveraging the vast global reserves of seawater. However the inherently complex composition of seawater—laden with halide ions multivalent cations (Mg2+ Ca2+) and organic/biological impurities—presents formidable challenges in maintaining both selectivity and durability. Chief among these obstacles is mitigating chloride corrosion and suppressing chlorine evolution reaction (ClER) at the anode while also preventing the precipitation of magnesium and calcium hydroxides at the cathode. This review consolidates recent advances in material engineering and cell design strategies aimed at controlling undesired side reactions enhancing electrode stability and maximizing energy efficiency in DSE. We first outline the fundamental thermodynamic and kinetic hurdles introduced by Cl⁻ and other impurities. This discussion highlights how these factors accelerate catalyst degradation and drive suboptimal reaction pathways. We then delve into innovative approaches to improve selectivity and durability of DSE—such as engineering protective barrier layers tuning electrolyte interfaces developing corrosion-resistant materials and techniques to minimize Mg/Ca-related precipitations. Finally we explore emerging reactor configurations including asymmetric and membrane-free electrolyzers which address some barriers for DSE commercialization. Collectively these insights provide a framework for designing next-generation DSE systems which can achieve large-scale cost-effective and environmentally benign hydrogen production.
Transient-state Behaviours of Blast Furnace Ironmaking: The Role of Shaft-injected Hydrogen
Aug 2025
Publication
Hydrogen shaft injection into blast furnaces (BFs) has a large potential to eliminate carbon dioxide emissions yet the temporal evolution of thermal and chemical states following shaft-injected hydrogen utilisation has not been reported in the open literature. In this research a recently developed transient-state multifluid BF model is applied to elucidate the temporal evolution of in-furnace phenomena. Besides a domain-average method is adopted to analyse the extensive simulation data to determine the time required to attain the next steady-like state. The results show that the evolution of thermal and chemical conditions varies across different regions with distinct characteristics near the furnace wall. The shifts in iron oxide reduction behaviour are completed within 10 to 20 h after the new operation and the transition time points to the next steady-like states of thermal and chemical conditions are different. As the hydrogen flow rate increases the average transition time decreases. However 2 to 4 days are required for the studied BF to reach a new steady-like state in the considered scenarios. The model offers a cost-effective approach to investigating the transient smelting characteristics of an ironmaking BF with hydrogen injection.
Sustainable Aviation Fuels: Addressing Barriers to Global Adoption
Oct 2025
Publication
The aviation industry is responsible for approximately 2–3% of worldwide CO2 emissions and is increasingly subjected to demands for the attainment of net-zero emissions targets by the year 2050. Traditional fossil jet fuels which exhibit lifecycle emissions of approximately 89 kg CO2-eq/GJ play a substantial role in exacerbating climate change contributing to local air pollution and fostering energy insecurity. In contrast Sustainable Aviation Fuels (SAFs) derived from renewable feedstocks including biomass municipal solid waste algae or through CO2- and H2-based power-to-liquid (PtL) represent a pivotal solution for the immediate future. SAFs generally accomplish lifecycle greenhouse gas (GHG) reductions of 50–80% (≈20–30 kg CO2-eq/GJ) possess reduced sulfur and aromatic content and markedly diminish particulate emissions thus alleviating both climatic and health-related repercussions. In addition to their environmental advantages SAFs promote energy diversification lessen reliance on unstable fossil fuel markets and invigorate regional economies with projections indicating the creation of up to one million green jobs by 2030. This comprehensive review synthesizes current knowledge on SAF sustainability advantages compared to conventional aviation fuels identifying critical barriers to large-scale deployment and proposing integrated solutions that combine technological innovation supportive policy frameworks and international collaboration to accelerate the aviation industry’s sustainable transformation.
Quantifying Natural Hydrogen Generation Rates and Volumetric Potential in Onshore Serpentinization
Mar 2025
Publication
This study explores the generation of natural hydrogen through the serpentinization of onshore ultramafic rocks highlighting its potential as a clean energy resource. By investigating critical factors such as mineral composition temperature and pressure the research develops an empirical model using multiple regression analysis to predict hydrogen generation rates under varying geological conditions. A novel five-stage volumetric calculation methodology is introduced to estimate hydrogen production from ultramafic rock bodies. The application of this framework to the Giles Complex an ultramafic-mafic intrusion in Australia suggests a hydrogen generation potential of approximately 2.24 × 1013 kg of hydrogen through partial serpentinization. This estimate is based on the assumed mineral composition depth and temperature conditions within the intrusion which influence the extent of serpentinization reactions. The findings demonstrate the significant potential of ultramafic complexes for natural hydrogen production and provide a foundation for advancing natural hydrogen exploration refining predictive models and supporting sustainable energy development.
Hydrogen Storage Potential of Unlined Granite Rock Caverns: Experimental and Numerical Investigations on Geochemical Interactions
Jun 2025
Publication
Underground Hydrogen Storage (UHS) offers a promising solution for large-scale energy storage yet suitable geological formations are often scarce. Unlined rock caverns (URCs) constructed in crystalline rocks like granite present a novel alternative particularly in regions where salt caverns or porous media are unsuitable. Despite their potential URCs remain largely unexplored for hydrogen storage. This study addresses this gap by providing one of the first comprehensive investigations into the geochemical interactions between hydrogen and granite host rock using a combined experimental and numerical approach. Granite powder samples were exposed to hydrogen and inert gas (N₂) in brine at room temperature and 5 MPa pressure for 14 weeks. Results showed minimal reactivity of silicate minerals with hydrogen indicated by negligible differences in elemental concentrations between H₂ and N₂ atmospheres. A validated geochemical model demonstrated that existing thermodynamic databases can accurately predict silicate‑hydrogen interactions. Additionally a kinetic batch model was developed to simulate long-term hydrogen storage under commercial URC conditions at Haje. The model predicts a modest 0.65 % increase in mineral volume over 100 years due to mineral precipitation which decreases net porosity and potentially enhances hydrogen containment by limiting leakage pathways. These findings support the feasibility of granite URCs for UHS providing a stable long-term storage option in regions lacking traditional geological formations. By filling a critical knowledge gap this study advances scalable hydrogen storage solutions contributing to the development of resilient renewable energy infrastructure.
Feasibility Assessment and Response Surface Optimisation of a Fuel Cell-integrated Sustainable Wind Farm in Italy
Sep 2025
Publication
This study explores the design and feasibility of a novel fuel cell-powered wind farm for residential electricity hydrogen/oxygen production and cooling/heating via a compression chiller. Wind turbine energy powers Proton Exchange Membrane (PEM) electrolyzers and a compression chiller unit. The proposed system was modeled using EES thermodynamic software and its economic viability was assessed. A case study across seven Italian regions with varying wind potentials evaluated the system’s feasibility in diverse weather conditions. Multi-objective optimization using Response Surface Methodology (RSM) determined the number of wind turbines as optimum number of electrolyzers & fuel cell units. Optimization results indicated that 37 wind turbines 1 fuel cell unit and 2 electrolyzer units yielded an exergy efficiency of 27.98 % and a cost rate of 619.9 $/h. TOPSIS analysis suggested 32 wind turbines 2 electrolyzers and 2 reverse osmosis units as an alternative configuration. Further twelve different scenarios were examined to enhance the distribution of wind farmgenerated electricity among the grid electrolyzers and reverse osmosis systems. revealing that directing 25 % to reverse osmosis 20 % to electrolyzers and 55 % to grid sales was optimal. Performance analysis across seven Italian cities (Turin Bologna Florence Palermo Genoa Milan and Rome) identified Genoa Palermo and Bologna as the most suitable locations due to favorable wind conditions. Implementing the system in Genoa the optimal site could produce 28435 MWh of electricity annually prevent 5801 tons of CO2 emissions (equivalent to 139218 $). Moreover selling this clean electricity to the grid could meet the annual clean electricity needs of approximately 5770 people in Italy
Towards Decarbonizing Gas: A Generic Optimal Gas Flow Model with Linepack Constraints for Assessing the Feasibility of Hydrogen Blending in Existing Gas Networks
Aug 2025
Publication
Hydrogen blending into natural gas networks is a promising pathway to decarbonize the gas sector but requires bespoke fluid-dynamic models to accurately capture the properties of hydrogen and assess its feasibility. This paper introduces a generalizable optimal transient gas flow model for transporting homogeneous natural gashydrogen mixtures in large-scale networks. Designed for preliminary planning the model assesses whether a network can operate under a given hydrogen blending ratio without violating existing constraints such as pressure limits pipeline and compressor capacity. A distinguishing feature of the model is a multi-day linepack management strategy that engenders realistic linepack profiles by precluding mathematically feasible but operationally unrealistic solutions thereby accurately reflecting the flexibility of the gas system. The model is demonstrated on Western Australia’s 7560 km transmission network using real system topology and demand data from several representative days in 2022. Findings reveal that the system can accommodate up to 20 % mol hydrogen potentially decarbonizing 7.80 % of gas demand.
Sustainable Aviation Fuels: A Review of Current Techno Economic Viability and Life Cycle Impacts
Oct 2025
Publication
Australia has set a new climate target of reducing emissions by 62–70% below 2005 levels by 2035 with sustainable aviation fuel (SAF) central to achieving this goal. This review critically examines techno-economic analysis (TEA) and life cycle assessment (LCA) of Powerto-Liquid (PtL) electrofuels (e-fuels) which synthesize atmospheric CO2 and renewable hydrogen (H2) via Fischer-Tropsch (FT) synthesis. Present PtL pathways require ~0.8 kg of H2 and 3.1 kg of CO2 per kg SAF with ~75% kerosene yield. While third-generation feedstocks could cut greenhouse gas emissions by up to 93% (as low as 8 gCO2e/MJ) real world reductions have been limited (~1.5%) due to variability in technology rollout and feedstock variability. Integrated TEA–LCA studies demonstrate up to 20% energy efficiency improvements and 40% cost reductions but economic viability demands costs below $3/kg. In Australia abundant solar resources vast transport networks and supportive policy frameworks present both opportunities and challenges. This review provides the first comprehensive assessment of PtL-FT SAF for Australian conditions highlighting that large-scale development will require technological advancement feedstock development infrastructure investment and coordinated policy support.
Influence of Hydrogen-Based Direct Reduction Shaft Furnace Interior Structure on Shaft Furnace Performance
Oct 2025
Publication
Hydrogen-based direct reduction of iron ore is a promising route to reduce CO2 emissions in steelmaking where uniform particle flow inside shaft furnaces is essential for efficient operation. In this study a full-scale three-dimensional Discrete Element Method (DEM) model of a shaft furnace was developed to investigate the effects of a diverter device on granular flow. By systematically varying the radial width and top/bottom diameters of the diverter particle descent velocity residence time compressive force distribution and collision energy dissipation were analyzed. The results demonstrate that introducing a diverter effectively suppresses funnel flow prolongs residence time and improves radial flow uniformity. Among the tested configurations the smaller central diameter diverter showed the most favorable performance achieving a faster and more uniform descent reduced compressive force concentration and lower collision energy dissipation. These findings highlight the critical role of diverter design in regulating particle dynamics and provide theoretical guidance for optimizing shaft furnace structures to enhance the efficiency of hydrogen-based direct reduction processes.
Zero-emission Traction for Rail
Jul 2025
Publication
Replacing the energy density and convenience of diesel fuel for all forms of fossil fuel-powered trains presents significant challenges. Unlike the traditional evolutions of rail which has largely self-optimised to different fuels and cost structures over 150 years the challenges now present with a timeline of just a few decades. Fortunately unlike the mid-1800s simulation and modelling tools are now quite advanced and a full range of scenarios of operations and train trips can be simulated before new traction systems are designed. Full trip simulations of large heavy haul trains or high speed passenger trains are routinely completed controlled by emulations of human drivers or automated control systems providing controls of the “virtual train”. Recent developments in digital twins can be used to develop flexible and dynamic models of passenger and freight rail systems to support the new complexities of decarbonisation efforts. Interactions between many different traction components and the train multibody system can be considered as a system of systems. Adopting this multi-modelling paradigm enables the secure and integrated interfacing of diverse models. This paper demonstrates the application of the multi-modelling approach to develop digital twins for rail decarbonisation traction and it presents physics-based multi-models that include key components required for studying rail decarbonisation problems. Specifically the challenge of evaluating zero-emission options is addressed by adding further layers of modelling to the existing fully detailed multibody dynamics simulations. The additional layers detail control options energy storage the alternate traction system components and energy management systems. These traction system components may include both electrical system and inertia dynamics models to accurately represent the driveline and control systems. This paper presents case study examples of full trip scenarios of both long haul freight trains and higher speed passenger trains. These results demonstrate the many complex scenarios that are difficult to anticipate. Flowing on from this risks can be assessed and practical designs of zero-emission systems can be proposed along with the required recharging or refuelling systems.
Techno-economic and Environmental Optimization of Hydrogen-based Hybrid Energy Systems for Remote Off-grid Australian Communities
Jun 2025
Publication
This study presents a techno-economic and environmental optimization of hydrogen-based hybrid energy systems (HESs) for Broken Hill City Council in New South Wales Australia. Two configurations are evaluated: Configuration 1 includes solar PV battery fuel cell electrolyzer and hydrogen storage while Configuration 2 includes solar PV fuel cell electrolyzer and hydrogen storage but excludes the battery. The system is optimized using advanced metaheuristic algorithms such as Harris Hawks Algorithm (HHA) Red-Tailed Hawk Algorithm and Non-Dominated Sorting Genetic Algorithm-II while ensuring real-time supply–demand balance and system stability through a robust energy management strategy. This integrated approach simultaneously determines the optimal sizes of PV arrays battery storage (where applicable) fuel cells electrolyzers and hydrogen storage units and maintains reliable energy supply. Results show that HHA Configuration 1 achieves the lowest net present cost of $338111 a levelized cost of electricity of $0.185/kWh and a levelized cost of hydrogen of $4.60/kg. Sensitivity analysis reveals that PV module and hydrogen storage costs significantly impact system economics while improving fuel cell efficiency from 40% to 60% can reduce costs by up to 40%. Beyond cost-effectiveness life cycle analysis demonstrates annual CO2 emission reductions exceeding 500000 kg compared to an equivalent diesel generator system meeting the same load demand. Socio-economic assessments further indicate that the HES can support improvements in the Human Development Index by enhancing access to healthcare education and economic opportunities while also creating local jobs in PV installation battery maintenance and hydrogen infrastructure. These findings establish hydrogen-based HES as a scalable cost-effective and environmentally sustainable solution for energy access in remote areas.
Catalytic Hydrogen Combustion as Heat Source for the Dehydrogenation of Liquid Organic Hydrogen Carriers using a Novel Compact Autothermal Reactor
Sep 2025
Publication
The experimental performance of an autothermal hydrogen release unit comprising a perhydro benzyltoluene (H12-BT) dehydrogenation chamber and a catalytic hydrogen combustion (CHC) chamber in thermal contact is discussed. In detail the applied set-up comprised a multi-tubular CHC heating based on seven parallel tubes with the reactor shell containing a commercial dehydrogenation catalyst. In this way the CHC heated the endothermal LOHC dehydrogenation using a part of the hydrogen generated in the dehydrogenation. The proposed heating concept for autothermal LOHC dehydrogenation offers several advantages over state-of-the-art heating concepts including minimized space consumption high efficiency and zero NOx emissions. During performance tests the process reached a minimum hydrogen combustion fraction of 37 % while the minimum heat requirement for the dehydrogenation reaction for industrial scale plants is 33 %. The reactor orientation (vertical vs horizontal) and the flow configuration (counter-current vs. co-current) showed very little influence on the performance demonstrating the robustness of the proposed reactor design.
Artificial Intelligence-based Multi-objective Optimization of a Solar-driven System for Hydrogen Production with Integrated Oxygen and Power Co-generation Across Different Climates
Oct 2025
Publication
This study develops and optimizes a solar-powered system for hydrogen generation with oxygen and power coproducts addressing the need for efficient scalable carbon-free energy solutions. The system combines a linear parabolic collector a Steam Rankine cycle and a Proton Exchange Membrane Electrolyzer (PEME) to produce electricity for electrolysis. Thermodynamic modeling was accomplished in Engineering Equation Solver while a hybrid Artificial Intelligence (AI) framework combining Artificial Neural Networks and Genetic Algorithms in Statistica coupled with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) decision support optimized technical and economic performance. Optimization considered seven key decision variables covering collector design thermodynamic inputs and component efficiencies. The optimization achieved energy and exergy efficiencies of 30.83 % and 26.32 % costing 47.02 USD/h and avoiding CO2 emissions equivalent to 190 USD/ton. Economic and exergy analyses showed the solar and hydrogen units had the highest costs (38.17 USD/h and 9.61 USD/h) with 4503 kWh of exergy destruction to generate 575 kWh of electricity. A case study across six cities suggested that Perth Bunbury and Adelaide with higher solar irradiance delivered the highest annual power and hydrogen outputs consistent with irradiance–electrolyzer correlation. Unlike conventional single-site studies this work delivers a climate-responsive multi-city analysis integrating solar thermal and PEME within an AI-driven framework. By linking techno-economic performance with quantified environmental value and co-production synergies of hydrogen oxygen and electricity the study highlights a novel pathway for scalable clean hydrogen measurable CO2 reductions and global decarbonization with future work focused on digital twins and dynamic uncertainty-aware optimization.
Overcoming Hurdles and Harnessing the Potential of the Hydrogen Transition in Germany
Jun 2025
Publication
Green hydrogen has become a core element of Europe’s energy transition to assist in lowering carbon emissions. However the transition to green hydrogen faces challenges including the cost of production availability of renewable energy sources public opposition and the need for supportive government policies and financial initiatives. While there are other alternatives for producing low-carbon hydrogen for example blue hydrogen German funding favours projects that involve hydrogen production via electrolysis. Beyond climate goals it is anticipated that a green hydrogen industry will create economic benefits and a wide-range of collaborative opportunities with key international partnerships increasing energy security if done appropriately. Germany a leader in green hydrogen technology will need to rely on imports to meet long-term demand due to limited renewable energy capacity. Despite the current obstacles to transitioning to green hydrogen it is felt that ultimately the benefits of this industry and reducing emissions will outweigh the associated costs of production. This study analyses the hydrogen transition in Germany by interviewing 37 European experts guided by the research question: What are the key perceived barriers and opportunities influencing the successful adoption and integration of hydrogen technologies in Germany’s hydrogen transition?
Effect of Injection Timing on Gas Jet Developments in a Hydrogen Low-pressure Direct-injection Spark-ignition Engine
Sep 2025
Publication
Injection timing in low-pressure hydrogen direct injection (H2LPDI) engines plays a critical role in optimising gas jet structure and mixture formation due to the complex and transient nature of ambient air flow and density inside the cylinder. This study systematically investigates the macroscopic characteristics of gas jet development at five distinct injection timings from 210 to 120 ◦CA bTDC with the intake valve closure (IVC) as a reference point in a motored inline four-cylinder spark-ignition engine at 2000 rpm and 160 Nm load using low-pressure injection of 3.5 MPa. Optical access was made with two endoscopes: one for high-speed imaging and the other for laser insertion to realise laser shadowgraph imaging of the gas jet delivered using a side-mounted outwardopening pintle nozzle injector. The experimental results reveal spatial and temporal variations in jet morphology penetration spreading angle and mixture dispersion as a function of injection timing. Pre-IVC injection (210 ◦CA bTDC) produced a narrow mean cone angle of ~40◦ and the highest penetration-rate proxy (0.49) whereas postIVC injection (120 ◦CA bTDC) retained a wider ~53◦ cone yet reduced the penetration rate to 0.28 while increasing the sheet-based mixing index from − 0.084 to − 0.106. Pre-IVC injection occurring under low ambient pressure and with active intake airflow was found to produce elongated jets with enhanced penetration and mixing rates though accompanied by substantial cyclic variations. Conversely post-IVC injection was strongly influenced by a fully developed tumble flow which redirected the jet trajectory towards the pent-roof and facilitated mixing through increased turbulence. However the elevated air density constrained the jet penetration. At-IVC injection resulted in a more uniform and stable jet structure. However the lack of convective flow constrained the overall mixing effectiveness. Quantitative analysis of jet spreading angle pixel intensity gradient and centroid movement using 100 consecutive cycles confirms the critical role of injection timing in shaping the gas jet development as suggested by the images.
Mitigating Microbial Artifacts in Laboratory Research on Underground Hydrogen Storage
Jul 2025
Publication
The global energy sector is aiming to substantially reduce CO2 emissions to meet the UN climate goals. Among the proposed strategies underground storage solutions such as radioactive disposal CO2 NH3 and underground H2 storage (UHS) have emerged as promising options for mitigating anthropogenic emissions. These approaches require rigorous research and development (R&D) often involving laboratory-scale experiments to establish their feasibility before being scaled up to pilot plant operations. Microorganisms which are ubiquitous in laboratory environments can significantly influence geochemical reactions under variable experimental conditions of porous media and a salt cavern. We have selected a consortium composed of Bacillus sp. Enterobacter sp. and Cronobacter sp. bacteria which are typically present in the laboratory environment. These microorganisms can contaminate the rock sample and develop experimental artifacts in UHS experiments. Hence it is pivotal to sterilize the rock prior to conduct experimental research related to effects of microorganisms in the porous media and the salt cavern for the investigation of UHS. This study investigated the efficacy of various disinfection and sterilization methods including ultraviolet irradiation autoclaving oven heating ethanol treatments and gamma irradiation in removing the microorganisms from silica sand. Additionally the consideration of their effects on mineral properties are reviewed. A total of 567 vials each filled with 9 mL of acid-producing bacteria (APB) media were used to test killing efficacy of the cleaning methods. We conducted serial dilutions up to 10−8 and repeated them three times to determine whether any deviation occurred. Our findings revealed that gamma irradiation and autoclaving were the most effective techniques for eradicating microbial contaminants achieving sterilization without significantly altering the mineral characteristics. These findings underscore the necessity of robust cleaning protocols in hydrogeochemical research to ensure reliable reproducible data particularly in future studies where microbial contamination could induce artifacts in laboratory research.
Modeling Porosity Distribution Strategies in PEM Water Electrolyzers: A Comparative Analytical and Numerical Study
Jun 2025
Publication
Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology for green hydrogen production. However the adoption of PEMWE-based hydrogen production systems remains limited due to several challenges including high material costs limited performance and durability and difficulties in scaling the technology. Computational modeling serves as a powerful tool to address these challenges by optimizing system design improving material performance and reducing overall costs thereby accelerating the commercial rollout of PEMWE technology. Despite this conventional models often oversimplify key components such as porous transport and catalyst layers by assuming constant porosity and neglecting the spatial heterogeneity found in real electrodes. This simplification can significantly impact the accuracy of performance predictions and the overall efficiency of electrolyzers. This study develops a mathematical framework for modeling variable porosity distributions—including constant linearly graded and stepwise profiles—and derives analytical expressions for permeability effective diffusivity and electrical conductivity. These functions are integrated into a three-dimensional multi-domain COMSOL simulation to assess their impact on electrochemical performance and transport behavior. The results reveal that although porosity variations have minimal effect on polarization at low voltages they significantly influence internal pressure species distribution and gas evacuation at higher loads. A notable finding is that reversing stepwise porosity—placing high porosity near the membrane rather than the channel—can alleviate oxygen accumulation and improve current density. A multi-factor comparison highlights this reversed configuration as the most favorable among the tested strategies. The proposed modeling approach effectively connects porous media theory and systemlevel electrochemical analysis offering a flexible platform for the future design of porous electrodes in PEMWE and other energy conversion systems.
Machine Learning-driven Stochastic Bidding for Hydrogen Refueling Station-integrated Virtual Power Plants in Energy Market
Aug 2025
Publication
Virtual power plants (VPPs) are gaining significance in the energy sector due to their capacity to aggregate distributed energy resources (DERs) and optimize energy trading. However their effectiveness largely depends on accurately modeling the uncertain parameters influencing optimal bidding strategies. This paper proposes a deep learning-based forecasting method to predict these uncertain parameters including solar irradiation temperature wind speed market prices and load demand. A stochastic programming approach is introduced to mitigate forecasting errors and enhance accuracy. Additionally this research assesses the flexibility of VPPs by mapping the flexible regions to determine their operational capabilities in response to market dynamics. The study also incorporates power-to‑hydrogen (P2H) and hydrogen-to-power (H2P) conversion processes to facilitate the integration of hydrogen fuel cell vehicles (HFCVs) into VPPs enhancing both technical and economic aspects. A network-aware VPP connected to generation resources storage facilities demand response programming (DRP) vehicle-to-grid technology (V2G) P2H and H2P is used to evaluate the proposed method. The problem is formulated as a convex model and solved using the GUROBI optimizer. Results indicate that a hydrogen refueling station can increase profits by approximately 49 % compared to the base case of directly selling surplus generation from renewable energy sources (RESs) to the market and profits can further increase to roughly 86 % when other DERs are incorporated alongside the hydrogen refueling station.
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