Publications

The U.S. produces 10 million metric tons (MMT) of hydrogen annually emitting about 41 MMT of carbon dioxide equivalents (CO2-eqs). With rising hydrogen demand and new emission regulations integrating conventional and novel hydrogen production systems is crucial. This study presents an integrated optimization framework to model diversified hydrogen economies as mixed integer linear programs (MILPs). Moreover the accounting of emissions extends to the system exterior (scope 3) thus providing a comprehensive sustainability assessment. The primary focus of the presented computational example is to analyze the impact of scope 3 emissions particularly material emissions during the construction phase on process system optimization while complying with stringent environmental constraints such as carbon limits. By evaluating emission reduction scenarios the model highlights the role of power purchase agreements (PPAs) from renewable sources and the trade-offs between conventional and novel hydrogen production technologies. The key findings indicate that while electrolyzer-based systems (PEM and AWE) offer potential for emission reduction their high energy demand and significant scope 3 material emissions pose challenges for a complete transition in the near term. The study identified two optimal design configurations: one utilizing PPAs as the primary energy source coupled with the conventional SMR-CCS process and another that combines both conventional (SMR-CCS) and novel hydrogen production technologies under a hybrid purview. Ultimately the findings contribute toward the ongoing efforts to achieve true net-carbon neutrality.

Hydrogen embrittlement (HE) threatens the structural integrity of industrial components exposed to hydrogenrich environments. This review critically explores hydrogen barrier coatings (HBCs) polymeric metallic ceramic and composite their application and assessment focusing on measured effectiveness in limiting hydrogen permeation and hydrogen embrittlement. Also coating application methods and permeation assessment techniques are evaluated. Recent advances in nanostructured and hybrid coatings are emphasized highlighting the pressing need for durable scalable and environmentally sustainable hydrogen barrier coatings to ensure the reliability of emerging hydrogen-based energy solutions. This comprehensive critical review further distinguishes itself by linking coating deposition methods to defect-driven transport behaviour critically assessing permeation test approaches. It also highlights the emerging role of polymeric and hybrid multilayer coatings with direct implications for advanced and reliable hydrogen production storage and transport infrastructure.

The electrochemical modelling of proton exchange membrane electrolyzers (PEMEZs) relies on the precise determination of several unknown parameters. Achieving this accuracy requires addressing a challenging optimization problem characterized by nonlinearity multimodality and multiple interdependent variables. Thus a novel approach for determining the unknown parameters of a detailed PEMEZ electrochemical model is proposed using the weighted mean of vectors algorithm (WMVA). An objective function based on mean square deviation (MSD) is proposed to quantify the difference between experimental and estimated voltages. Practical validation was carried out on three commercial PEMEZ stacks from different manufacturers (Giner Electrochemical Systems and HGenerators™). The first two stacks were tested under two distinct pressure-temperature settings yielding five V–J data sets in total for assessing the WMVA-based model. The results demonstrate that WMVA outperforms all optimizers achieving MSDs of 1.73366e−06 1.91934e−06 1.09306e−05 6.18248e−05 and 4.41586e−06 corresponding to improvements of approximately 88% 82.9% 82.4% 54.5% and 59.5% over the poorest-performing algorithm in each case respectively. Moreover comparative analyses statistical studies and convergence curves confirm the robustness and reliability of the proposed optimizer. Additionally the effects of temperature and hydrogen pressure variations on the electrical and physical steady-state performance of the PEMEZ are carefully investigated. The findings are further reinforced by a dynamic simulation that illustrates the impact of temperature and supplied current on hydrogen production. Accordingly the article facilitates better PEMEZ modelling and optimizing hydrogen production performance across various operating conditions.

Hydrogen is the energy carrier for a sustainable future without fossil fuels. As this requires a reliable transportation infrastructure the conversion of existing natural gas (NG) grids is an essential part of the worldwide individual national hydrogen strategies in addition to newly erected pipelines. In view of the known effect of hydrogen embrittlement the compatibility of the materials already in use (typically low-alloy steels in a wide range of strengths and thicknesses) must be investigated. Initial comprehensive studies on the hydrogen compatibility of pipeline materials indicate that these materials can be used to a certain extent. Nevertheless the material compatibility for hydrogen service is currently of great importance. However pipelines require frequent maintenance and repair work. In some cases it is necessary to carry out welding work on pipelines while they are under pressure e.g. the well-known tapping of NG grids. This in-service welding brings additional challenges for hydrogen operations in terms of additional hydrogen absorption during welding and material compatibility. The challenge can be roughly divided into two parts: (1) the possible austenitization of the inner piping material exposed to hydrogen which can lead to additional hydrogen absorption and (2) the welding itself causes an increased temperature range. Both lead to a significantly increased hydrogen solubility in the respective materials compared to room temperature. In that connection the knowledge on hot tapping on hydrogen pipelines is rare so far due to the missing service experiences. Fundamental experimental investigations are required to investigate the possible transferability of the state-of-the-art concepts from NG to hydrogen pipeline grids. This is necessary to ensure that no critical material degradation occurs due to the potentially increased hydrogen uptake. For this reason the paper introduces the state of the art in pipeline hot tapping encompassing current research projects and their individual solution strategies for the problems that may arise for future hydrogen service. Methods of material testing their limitations and possible solutions will be presented and discussed.

The urgency for sustainable and efficient hydrogen production has increased interest in heterostructured nanomaterials known for their excellent photocatalytic properties. Traditional synthesis methods often rely on trial-and-error resulting in inefficiencies in material discovery and optimization. This work presents a new AI-driven framework that overcomes these challenges by integrating advanced machine-learning techniques specific to heterostructured nanomaterials. Graph Neural Networks (GNNs) enable accurate representations of atomic structures predicting material properties like bandgap energy and photocatalytic efficiency within ±0.05 eV. Reinforcement Learning optimises synthesis parameters reducing experimental iterations by 40% and boosting hydrogen yield by 15–20%. Physics-Informed Neural Networks (PINNs) successfully predict reaction pathways and intermediate states minimizing synthesis errors by 25%. Variational Autoencoders (VAEs) generate novel material configurations improving photocatalytic efficiency by up to 15%. Additionally Bayesian Optimisation enhances predictive accuracy by 30% through efficient hyperparameter tuning. This holistic framework integrates material design synthesis optimization and experimental validation fostering a synergistic data flow. Ultimately it accelerates the discovery of novel heterostructured nanomaterials enhancing efficiency scalability and yield thus moving closer to sustainable hydrogen production with improvements in photolytic efficiency setting a benchmark for AI-assisted research.

Liquid organic hydrogen carriers (LOHCs) are a promising class of hydrogen storage media in which hydrogen is reversibly bound to organic molecules. In this work we focus explicitly on cyclic LOHCs (both homocyclic and heterocyclic organic compounds) and their catalytic dehydrogenation. We clarify that other carriers (e.g. alcohols like methanol or carboxylic acids like formic acid) exist but are not the focus here; these alternatives are discussed only in comparative context. Cyclic LOHCs typically enable safe ambient-temperature hydrogen storage with hydrogen contents around 6–8 wt%. Key challenges include the high dehydrogenation temperatures (often 200–350 °C) catalyst costs and catalyst deactivation via coke formation. We introduce a comparative analysis table contrasting cyclic LOHCs with alternative carriers in terms of hydrogen density operating conditions catalyst types toxicity and cost. We also expand the catalyst discussion to highlight coke formation mechanisms and the use of mesoporous metal-oxide supports to mitigate deactivation. Finally a techno-economic analysis is provided to address system costs of LOHC storage and regeneration. Finally we underscore the viability and limitations of cyclic LOHCs including practical storage capacities catalyst life and projected costs.

This study presents the design and techno-economic optimization of a hybrid renewable energy system (HRES) for a coastal hotel in Manavgat Türkiye. The system integrates photovoltaic (PV) panels wind turbines (WT) pumped hydro storage (PHS) hydrogen storage (electrolyzer tank and fuel cell) batteries a fuel cell-based combined heat and power (CHP) unit and a boiler to meet both electrical and thermal demands. Within this broader optimization framework six optimal configurations emerged representing gridconnected and standalone operation modes. Optimization was performed in HOMER Pro to minimize net present cost (NPC) under strict reliability (0% unmet load) and renewable energy fraction (REF > 75%) constraints. The grid-connected PHS–PV–WT configuration achieved the lowest NPC ($1.33 million) and COE ($0.153/kWh) with a renewable fraction of ~96% and limited excess generation (~21%). Off-grid PHS-based and PHS–hydrogen configurations showed competitive performance with slightly higher costs. Hydrogen integration additionally provides complementary storage pathways coordinated operation waste heat utilization and redundancy under component unavailability. Battery-only systems without PHS or hydrogen storage resulted in 37–39% higher capital costs and ~53% higher COE confirming the economic advantage of long-duration PHS. Sensitivity analyses indicate that real discount rate variations notably affect NPC and COE particularly for battery-only systems. Component cost sensitivity highlights PV and WT as dominant cost drivers while PHS stabilizes system economics and the hydrogen subsystem contributes minimally due to its small scale. Overall these results confirm the techno-economic and environmental benefits of combining seawater-based PHS with optional hydrogen and battery storage for sustainable hotel-scale applications.

On the path to an emission free energy economy proton exchange membrane water electrolysis (PEMWE) is a promising technology for a sustainable production of green hydrogen at high current densities and thus high production rates. Long lifetime increasing the current density and the reduction of platinum group metal loadings are major challenges for a widespread implementation of PEMWE. In this context this work investigates the aging of a PEMWE stack operating at 4 A cm-2 which is twice the nominal current density of commercial electrolyzers. Specifically an 8-cells PEMWE stack using catalyst coated membranes (CCMs) with different platinum group metal (PGM) loading was operated for 2200 h. To understand degradation phenomena physical ex-situ analyses such as scanning electron microscopy (SEM) atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were carried out. The same aging mechanism were observed in all cells independent on their position in stack or the specific PGM loading of the membrane electrode assembly (CCM): (i) a decrease of ohmic resistance over time related to membrane thinning (ii) a significant loss of ionomer at anodes (iii) loss of noble metal from the electrodes leading to deposition of small Ir and Pt concentrations in the membrane (iv) heterogeneous enrichment of Ti on the cathode side likely originating from the cathode-side of the Ti bipolar plates (BPPs). These results are in good agreement with the electrochemical performance loss. Thus we were able to identify the degradation phenomena that dominate under high-current operation and their impact on performance.

The gas equation of state (EOS) serves as a critical tool for analyzing the thermal effects within the hydrogen storage tank during refueling processes. It quantifies the dynamic relationships among pressure temperature and volume playing a vital role in numerical simulations of hydrogen refueling the development of refueling protocols and ensuring refueling safety. This study first establishes a lumped-parameter thermodynamic model for the hydrogen refueling process which combines a zero-dimensional gas model with a one-dimensional tank wall model (0D1D). The model’s accuracy was validated against experimental data and will be used in combination with different EOSs to simulate hydrogen temperature and pressure. Subsequently parameter values are derived for the van der Waals EOS and its modified forms—Redlich–Kwong Soave and Peng–Robinson. The accuracy of the modified forms is evaluated using the Joule–Thomson inversion curve. A polynomial EOS is formulated and its parameters are numerically determined. Finally the hydrogen temperatures and pressures calculated using the van der Waals EOS Redlich– Kwong EOS polynomial EOS and the National Institute of Standards and Technology (NIST) database are compared. Within the initial and boundary conditions set in this study the results indicate that among the modified forms for van der Waals EOS the Redlich– Kwong EOS exhibits higher accuracy than the Soave and Peng–Robinson EOSs. Using the NIST-calculated hydrogen pressure as a benchmark the relative error is 0.30% for the polynomial EOS 1.83% for the Redlich–Kwong EOS and 17.90% for the van der Waals EOS. Thus the polynomial EOS exhibits higher accuracy followed by the Redlich–Kwong EOS while the van der Waals EOS demonstrates lower accuracy. This research provides a theoretical basis for selecting an appropriate EOS in numerical simulations of hydrogen refueling processes.

In this study we investigate the dual-fuel operation of compression ignition engines using biodiesel at varying concentrations in combination with biogas with and without hydrogen enrichment. A response surface methodology based on a central composite experimental design was employed to optimize energy efficiency and minimize pollutant emissions. The partial substitution of diesel with gaseous fuel substantially reduces the specific fuel consumption achieving a maximum decrease of 21% compared with conventional diesel operation. Enriching biogas with hydrogen accounting for 13.3% of the total flow rate increases the thermal efficiency by 0.8% compensating for the low calorific value and reduced volumetric efficiency of biogas. Variations in biodiesel concentration exhibits a nonlinear effect yielding an additional average efficiency gain of 0.4%. Regarding emissions the addition of hydrogen to biogas contributes to an average reduction of 5% in carbon monoxide emissions compared to the standard dual-fuel operation. However dual-fuel operation leads to higher unburned hydrocarbon emissions relative to neat diesel; hydrogen enrichment mitigates this drawback by reducing hydrocarbon emissions by 4.1%. Although NOx emissions increase by an average of 26.6% with hydrogen addition dual-fuel strategies achieve NOx reductions of 11.5% (hydrogen-enriched mode) and 33.3% (pure biogas mode) relative to diesel-only operation. Furthermore the application of response surface methodology is robust and reliable with experimental validation showing errors of 0.55–8.66% and an overall uncertainty of 4.84%.

The transport sector is a major contributor to greenhouse gas emissions largely due to its dependence on fossil fuels. Electrifying transport through Battery Electric Vehicles (BEVs) and Hydrogen Fuel Cell Electric Vehicles (FCEVs) is widely recognized as a key pathway to reducing emissions. While both BEVs and FCEVs are zero-emission during operation they still require electricity to function. Sourcing this electricity from solar energy presents a promising opportunity for sustainable operation. The novelty of this work lies in exploring how solar energy can be effectively integrated into both BEV and FCEV systems. The paper examines the potential scope and infrastructure requirements of these vehicle types as well as innovative charging and refuelling strategies. For BEVs charging options include fixed charging stations battery swapping stations and wireless charging. In the context of solar integration photovoltaic (PV) systems can be mounted directly on the vehicle body or used to power charging stations. While current PV efficiency and reliability are insufficient to meet the full energy demand of BEVs they can provide valuable auxiliary power. For FCEVs solar energy can be utilized for hydrogen production enabling the concept of solar-powered FCEVs. Refuelling options include onsite and offsite hydrogen production facilities as well as mobile refuelling units. In both cases land requirements for PV installations are significant. Alternatives to ground-mounted PV such as floating PV or agrivoltaics (agriPV) should be considered to optimize land use. While solar-powered charging or refuelling stations are technically feasible complete reliance on solar power alone is not yet practical. A hybrid approach with grid connections energy storage or backup generation remains necessary to ensure consistent energy availability. For BEVs the cost of charging particularly for long-distance travel where rapid charging is required remains a barrier. For FCEVs challenges include the high cost of hydrogen production and the limited availability of refuelling infrastructure despite their advantage of fast refuelling times. Government policies and incentives are playing a critical role in overcoming these barriers fostering investment in infrastructure and accelerating the transition toward a cleaner transport sector. In summary integrating solar energy into BEV and FCEV infrastructure can advance sustainable mobility by reducing lifecycle emissions. While current PV efficiency storage and hydrogen production limitations require hybrid energy solutions ongoing technological improvements and supportive policies can enable broader adoption. A balanced renewable energy mix with solar as a key component will be essential for realizing truly sustainable zero-emission transport.

Hydrogen propulsion technologies are emerging as a key enabler for decarbonizing the aviation sector especially for regional commercial aircraft. The evolution of aircraft propulsion technologies in recent years raises the question of the feasibility of a hydrogen propulsion system for beyond regional aircraft. This paper presents a comprehensive review of hydrogen propulsion technologies highlighting key advancements in component-level performance metrics. It further explores the technological transitions necessary to enable hydrogen-powered aircraft beyond the regional category. The feasibility assessment is based on key performance parameters including power density efficiency emissions and integration challenges aligned with the targets set for 2035 and 2050. The adoption of hydrogen-electric powertrains for the efficient transition from KW to MW powertrains depends on transitions in fuel cell type thermal management systems (TMS) lightweight electric machines and power electronics and integrated cryogenic cooling architectures. While hydrogen combustion can leverage existing gas turbine architectures with relatively fewer integration challenges it presents its technical hurdles especially related to combustion dynamics NOx emissions and contrail formation. Advanced combustor designs such as micromix staged and lean premixed systems are being explored to mitigate these challenges. Finally the integration of waste heat recovery technologies in the hydrogen propulsion system is discussed demonstrating the potential to improve specific fuel consumption by up to 13%.

The transition to low-carbon energy systems demands robust strategies that leverage existing fossil resources while integrating renewable technologies. In this work a single-cycle Gaussian-based producibility model is developed to forecast natural gas production profiles domestic consumption export potential hydrogen production and revenues adaptive for untapped natural gas discoveries. Annual natural gas production is represented by a bell curve defined by peak year and maximum capacity allowing flexible adaptation to different reserve sizes. The model integrates renewable energy adoption and steam–methane reforming to produce hydrogen while tracking revenue streams from domestic sales exports and hydrogen markets alongside carbon taxation. Applicability is demonstrated through a case study of Eastern Mediterranean gas discoveries where combined reserves of 2399 bcm generate a production peak of 100 bcm/year in 2035 and deliver 40.71 billion kg of hydrogen by 2050 leaving 411.87 bcm of reserves. A focused Cyprus scenario with 411 bcm of reserves peaks at 10 bcm/year produces 4.07 billion kg of hydrogen and retains 212.29 bcm of reserves. Cumulative revenues span from USD 84.37 billion under low hydrogen pricing to USD 247.29 billion regionally while the Cyprus-focused case yields USD 1.79 billion to USD 18.08 billion. These results validate the model’s versatility for energy transition planning enabling strategic insights into infrastructure deployment market dynamics and resource management in gas-rich regions.

The transition toward environmentally friendly steelmaking using hydrogen direct reduced iron as feed material in electric arc furnaces will eventually require process adjustments due to changes in the pellet properties when compared to e.g. blast furnace pellets. To this end the melting of hydrogen direct reduced iron pellets with 68 and 100% reduction degrees and Fe content of 67.24% was investigated in a laboratory-scale electric arc furnace. The presence of iron oxide-rich slag had a significant effect on the arc movement on the melt and an inhibiting effect on iron evaporation. The melting was monitored with video recording and optical emission spectroscopy. The videos were used to monitor the melting behavior whereas optical emissions revealed iron gangue elements and hydrogen from the pellets radiating in the plasma. Furthermore the flow of the melt is well seen in the videos as well as the movement of slag droplets on the melt surface. After the experiments the metal had silica-rich inclusions whereas slag had mostly penetrated into the crucible. The most notable differences in melting behavior can be attributed to the iron oxide-rich slag its interaction with the arc and penetration into the crucible and how it affects the arc movement and heat transfer.

Hydrogen is the key to decarbonising heavy-duty transport. Understanding the distribution of hydrogen demand is crucial for effective planning and development of infrastructure. However current data on future hydrogen demand is often coarse and aggregated limiting its utility for detailed analysis and decision-making. This study developed a spatial disaggregation approach to estimating hydrogen demand for heavy-duty trucks and mapping the spatial distribution of hydrogen demand across multiple scales in Australia. By integrating spatial datasets with economic factors market penetration rates and technical specifications of hydrogen fuel cell vehicles the approach disaggregates the projected demand into specific demand centres allowing for the mapping of regional hydrogen demand patterns and the identification of key centres of hydrogen demand based on heavy-duty truck traffic flow projections under different scenarios. This approach was applied to Australia and the findings offered valuable insights that can help policymakers and stakeholders plan and develop hydrogen infrastructure such as optimising hydrogen refuelling station locations and support the transition to a low-carbon heavy-duty transport sector.

This study presents a comparative techno-economic and environmental assessment of three leading stationary energy storage technologies: lithium-ion batteries lead-acid batteries and hydrogen systems (electrolyzer–tank–fuel cell). The analysis integrates Life Cycle Assessment (LCA) and Levelized Cost of Storage (LCOS) to provide a holistic evaluation. The LCA covers the full cradle-to-grave stages while LCOS accounts for capital and operational expenditures efficiency and cycling frequency. The results indicate that lithium-ion batteries achieve the lowest LCOS (120–180 EUR/MWh) and high round-trip efficiency (90–95%) making them optimal for short- and medium-duration storage. Lead-acid batteries though characterized by low capital expenditures (CAPEX) and high recyclability (>95%) show limited cycle life and lower efficiency (75–80%). Hydrogen systems remain costly (>250 EUR/MWh) and less efficient (30–40%) yet they demonstrate clear advantages for long-term and seasonal storage particularly under scenarios with “green” hydrogen production and reduced CAPEX. These findings provide practical guidance for policymakers investors and industry stakeholders in selecting appropriate storage solutions aligned with decarbonization and sustainability goals.

As the transport of gaseous hydrogen and its use as a low carbon-footprint energy vector become increasingly likely scenarios both the scientific literature and technical standards addressing the compatibility of pipeline steels with high-pressure hydrogen environments are rapidly expanding. This work presents a detailed review of the most relevant hydrogen embrittlement testing methodologies proposed in standards and the academic literature. The focus is placed on testing approaches that support design-oriented assessments rather than simple alloy qualification for hydrogen service. Particular attention is given to tensile tests (conducted on smooth and notched specimens) as well as to J-integral and fatigue tests performed following the fracture mechanics’ approach. The influences of hydrogen partial pressure and deformation rate are critically examined as these parameters are essential for ensuring meaningful comparisons across different studies.

Based on the global efforts to reduce fossil fuel dependence and its environmental concerns green hydrogen has been considered a promising pathway towards sustainable energy transition. Iran is considered a promising location for green hydrogen production due to its considerable solar energy potential. While global interest in green hydrogen continues to grow studies that explore the techno-economic feasibility of small-scale solar-based green hydrogen systems tailored to Iran’s diverse climatic conditions are still relatively limited. This study aims to assess the technical and economic feasibility of small-scale green hydrogen production based on solar energy (photovoltaics) in six cities of Iran including Isfahan Kerman Kermanshah Shiraz Tehran and Zahedan by examining whether such systems can be financially viable despite their relatively high unit costs. The study employs TRNSYS for dynamic simulation of the hydrogen production system and RETScreen for economic analysis. The results indicate that the system has an annual energy production capacity ranging from 831.52 to 1062.22 MWh across the studied locations. The system's hydrogen production rate was between 16800 and 21114 kg/year. Based on the results the lowest levelized cost of hydrogen (LCOH) was recorded in Shiraz at $6.43/kg H₂ while Tehran experienced the highest value ($8.81/kg H₂). Among the evaluated cities Shiraz demonstrated the most favorable financial performance with an internal rate of return (IRR) of 18.5% and a payback period of 8 years. These findings can be useful for policymakers in Iran and the MENA region in investment planning related to the clean energy transition.

As an energy-intensive sector China’s iron and steel industry is crucial for achieving “Dual Carbon” goals. This study fills the research gap in systematically comparing the synergistic effects of multiple policies by evaluating five key measures (2020–2023) in ultra-low-emission retrofits and clean energy alternatives. Using public macro-data at the national level this study quantified cumulative reductions in air pollutants (SO2 NOx PM VOCs) and CO2. A synergistic control effect coordinate system and a normalized synergistic emission reduction equivalent (APeq) model were employed. The results reveal significant differences: Sintering machine desulfurization and denitrification (SDD) showed the highest APeq but increased CO2 emissions in 2023. Dust removal equipment upgrades (DRE) and unorganized emission control (UEC) demonstrated stable co-reduction effects. While electric furnace short-process steelmaking (ES) and hydrogen metallurgy (HM) showed limited current benefits they represent crucial deep decarbonization pathways. The framework provides multi-dimensional policy insights beyond simple ranking suggesting balancing short-term pollution control with long-term transition by prioritizing clean alternatives.

Hydrogen fuel cell systems are a viable option for electrified aero engines due to their efficiency and environmental benefits. However integrating these systems presents challenges notably in terms of overall system weight and thermal management. Heat exchangers are crucial for the effective thermal management system of electric propulsion systems in commercial electrified aviation. This paper provides a comprehensive review of various heat exchanger types and evaluates their potential applications within these systems. Selection criteria are established based on the specific requirements for air and hydrogen heat exchangers in electrified aircraft. The study highlights the differences in weighting criteria for these two types of heat exchangers and applies a weighted point rating system to assess their performance. Results indicate that extended surface microchannel and printed circuit heat exchangers exhibit significant promise for aviation applications. The paper also identifies key design challenges and research needs particularly in enhancing net heat dissipation increasing compactness improving reliability and ensuring effective integration with aircraft systems.

The LCOH calculator manual explains the methodology behind the calculator in detail and demonstrates how the calculator can be used.<br/>In this second version the default prices are updated based on the latest data available in the calculator and a new use case is introduced on changing the economic lifetime and cost of capital of an electrolysis installation.

Sorption-enhanced steam reforming (SorESR) is an advanced thermochemical process integrating in-situ CO2 capture via solid sorbents to significantly enhance hydrogen production and purity. By coupling CO2 adsorption with steam reforming SorESR shifts the reaction equilibrium toward increased H₂ yield surpassing the limitations of conventional steam reforming (SR). The efficacy of SorESR critically depends on the physicochemical properties of the solid CO2 sorbents employed. This review critically evaluates widely studied sorbents including Ca-based Mg-based hydrotalcite-like and alkali ceramic sorbents focusing on their CO2 capture capacity reaction kinetics thermal stability and cyclic durability under SR conditions. Furthermore recent progress in multifunctional sorbent-catalysts that synergistically facilitate catalytic steam reforming alongside CO2 sorption is critically discussed. Moreover the review summarises recent performance achievements and proposes strategies to improve sorbent capacity and reaction kinetics thereby making the SorESR process more appealing for commercial applications. Large-scale SorESR implementation is expected to substantially increase hydrogen production efficiency while concurrently reducing CO2 emissions and advancing sustainable energy technologies. This review offers novel insights into the development of advanced sorbent-catalyst systems and provides new strategies for enhancing SorESR efficiency and scalability for commercial H2 Production.

The passive combination of fuel cells and supercapacitors possesses promising applications in the automotive industry due to its ability to decrease stack size maintain peak power capacity improve system productivity and go away with the need for additional control all without Direct current to Direct Current (DC/DC) converters. This research describes the steps to create and evaluate a fuel cell (FC) and supercapacitor (SC) passive hybrid electrical system for a 60-V lightweight vehicle. Also study offers a thorough design approach and model and experimentally to validate every passive hybrid testing station component. When both concepts are stable the voltage errors are about 2 % and 3 % respectively for fuel cells and supercapacitors. The results of the experiments provide more evidence that the passive design is effective under step loads and driving cycles. The results of the measurements match the models used to simulate the passive hybrid system if a step load voltage is used. A smaller FC stack is possible since the fuel cell controls the steady-state current. Alternatively the supercapacitors provide varying currents because of their reduced resistance. This study use a driving cycle to show that the FC stack can lower its output to 25 % of the peak power required by the load.

Hydrogen blending offers significant potential for decarbonizing natural gas-based thermal processes particularly in the steel and cement sectors. Due to its distinct combustion properties compared to natural gas – such as lower minimum air requirements and altered flame speeds – the hydrogen fraction of the fuel must be monitored for combustion control. In this study we present an ultrasonic time-of-flight measurement system for hydrogen concentrations of 0–40% in natural gas. The system is verified with test gas mixtures at laboratory scale and validated in a technical-scale setup using a real blower burner (< 60 kW). We evaluate uncertainty of the hydrogen fraction measurement and analyze the influence of varying natural gas compositions. We show that standard uncertainties below 4% can be achieved without knowledge of the specific natural gas composition. Our results provide insights for measurement system design and support the safe application of hydrogen in thermal systems for industrial processes.

In the context of mounting concerns over carbon emissions and the need to accelerate the energy transition green hydrogen has emerged as a strategic solution for decarbonizing hard-to-abate sectors. This paper introduces a methodological innovation by proposing the Green Hydrogen Efficiency Index (GHEI) a unified and quantitative framework that integrates multiple stages of the hydrogen value chain into a single comparative metric. The index encompasses six core criteria: electricity source water treatment electrolysis efficiency compression end-use conversion and associated greenhouse gas emissions. Each are normalized and weighted to reflect different performance priorities. Two weighting profiles are adopted: a first profile which assigns equal importance to all criteria referred to as the balanced profile and a second profile derived using the analytic hierarchy process (AHP) based on structured expert judgment named the AHP profile. The methodology was developed through a systematic literature review and was applied to four representative case studies sourced from the academic literature covering diverse configurations and geographies. The results demonstrate the GHEI’s capacity to distinguish the energy performance of different green hydrogen routes and support strategic decisions related to technology selection site planning and logistics optimization. The results highlight the potential of the index to contribute to more sustainable hydrogen value chains and advance decarbonization goals by identifying pathways that minimize energy losses and maximize system efficiency