Publications

Understanding water evolved gas and ionic transport in membrane-electrode-assemblies (MEAs) is essential for the development of high performance and durable anion exchange membrane water electrolyzers (AEMWEs). This study evaluates the MEA conditioning process operating conditions and short-term stability in a 1 M potassium hydroxide (KOH) electrolyte focusing on the underlying transport phenomena. We observe a significant initial voltage loss in continuous cell operation which could be associated with gas bubble accumulation transport layer or flow field passivation and changes in the catalyst oxidation state. Further we investigate the effects of materials and operational configurations including the membrane type and thickness and the electrolyte flow rate including KOH being fed to both electrodes as well as to the anode only. Furthermore the effect of membrane drying temperature on ex situ as well as in situ electrochemical performance is evaluated. Finally we discuss 700 h of AEMWE operation at 1 A/cm2 highlighting the underlying degradation phenomena.

Hydrogen leakage is a critical safety concern for high-pressure storage systems where orifice geometry significantly influences dispersion and risk. Previous studies on leakage and diffusion have mostly focused on closed or semi-closed environments while thorough exploration has been conducted on open and unshielded environments. This work compares three typical orifice types—circular slit and Y-type—through controlled experiments. Results show that circular orifices generate directional jets with steep gradients but relatively low concentrations with a 1 mm case reaching only 0.725% at the jet core. Slit orifices exhibit more uniform diffusion; at 1 mm concentrations ranged from 2.125% to 2.625%. Y-type orifices presented the highest hazard with 0.5 mm leaks producing 2.9% and 1 mm cases approaching the 4% lower flammability limit within 375 s. Equilibrium times increased with orifice size from 400–800 s for circular and slit leaks to up to 900 s for Y-type leaks some of which failed to stabilize. Response behavior also varied: Y-type leaks achieved rapid multi-point responses (as short as 10 s) while circular and slit leaks responded more slowly away from the jet core. Overall risk ranking was circular < slit < Y-type underscoring the urgent need for geometry-specific monitoring strategies sensor layouts and emergency thresholds to ensure safe hydrogen storage.

Hydrogen-rich gas (HRG) injection is a promising low-carbon solution for blast furnace ironmaking. This study conducted numerical simulations in the lower part of a blast furnace to analyze the combustion behavior of coinjected coke oven gas (COG) and pulverized coal (PC) within the raceway and the associated thermal load on the tuyere. A three-dimensional computational fluid dynamics model incorporating fluid–thermal–solid coupling and the GRI-Mech 3.0 chemical kinetic mechanism (validated for 300–2500 K) was established to simulate the lance–blowpipe–tuyere–raceway region. The simulation results revealed that moderate COG injection accelerated volatile release from PC and enlarged the high-temperature zone (>2000 K). However excessive COG injection intensified oxygen competition and shortened the residence time of PC ultimately decreasing the burnout rate. Notably although COG has high reactivity its injection did not cause an increase in tuyere temperature. By contrast the presence of an unburned gas layer near the upper wall of the tuyere and the existence of a strong convective cooling effect contributed to a reduction in tuyere temperature. An optimized cooling water channel was designed to enhance flow distribution and effectively suppress localized overheating. The findings of this study offer valuable technical insights for ensuring safe COG injection and advancing low-carbon steelmaking practices.

The transition to carbon-neutral energy has renewed interest in hydrogen as a gas turbine fuel in the form of fuel blends with hydrocarbons. However the distinct fluid properties and chemical kinetics of hydrogen and hydrocarbon blends necessitate redeveloped combustor designs. While conventional combustor design and emissions estimation through computational fluid dynamics (CFD) is preferred it is computationally intensive and impractical for system-level simulations. To alleviate this a thermofluid network model was developed to predict the performance of a MGT combustor operating on pure and fuel blends of propane and hydrogen. It incorporates sub-component pressure losses and heat transfer and presents the first implementation of well-stirred and plug-flow reactors into Flownex SE. A 3-D CFD study of the combustor revealed that hydrogen addition improved combustion efficiency and reduced wall temperatures. However although it produces less CO2 it leads to 70 % more CO and 80 % more NO than for propane-only operation. Validated against the 3-D CFD data the network model predicted the combustor outlet total temperature and pressure within 0.55 % and 0.26 % respectively. The change in total pressure across subcomponents (<6 %) and the mass flow distribution showed similarly strong agreement. Major species mass fractions CO₂ and H₂O were predicted accurately. However by assuming that the temperature and composition are uniform within combustion zones zone and wall temperatures and pollutant predictions deviated considerably. NO was overpredicted by a factor of 8.2–10.7 and CO was overpredicted for propane-only but underpredicted for blended cases. The network model achieved this performance 420 times faster than CFD making it suitable for rapid design exploration.

Liquid hydrogen (LH2) is a promising candidate for zero emission aviation but its cryogenic properties make the refuelling process fundamentally different from that of conventional jet fuels. Although previous studies have addressed LH2 storage and system integration detailed modelling of the refuelling process remains limited. This paper presents the first part of a two-part study focused on simulation of the refuelling process for an LH2-powered commercial aircraft. An existing tank model is substantially modified to more accurately capture relevant physical phenomena including heat transfer and droplet dynamics during top-fill spray injection. Newly available experimental data on LH2 no-vent filling enables direct validation of the model under conditions that match the experimental setup. A sensitivity analysis identifies the most influential parameters that affect model precision including loss coefficient droplet diameter radiative heat ingress and vent-closing pressure. The validated model forms the basis for Part 2 of this study in which it is applied to a representative LH2-powered commercial aircraft to simulate refuelling times quantify venting losses and assess the impact of key operational settings. These results support the design of efficient LH2 refuelling systems for future aircraft and airport infrastructure.

In this work a plasma fluidized bed reactor has been studied as an electrified methane decomposition reactor for sustainable hydrogen production. A combined 3D rotating gliding arc/fluidized bed reactor assembly demonstrates a stable operation with a CH4/Ar mixture containing up to 8 vol% of CH4. The reactor provides a 97.2 % H2 selectivity at a methane conversion of 16.6 % and energy costs of 10.6 kJ L− 1 . This performance provides a new benchmark for electrified H2 production with a potential to utilise renewable electricity. In addition carbon materials are produced. The characterizations show difference in the morphology of the materials collected in different reactor zones.

Hydrogen’s increasing potential as an alternative fuel for heavy-duty transport has led to the conversion of conventional diesel compression-ignition engines to spark-ignition hydrogen operation. Hydrogen’s broad flammability range enables leaner operation achieving both higher engine efficiency and near-zero emissions. In particular direct injection hydrogen combustion improves volumetric efficiency and reduces problems including pre-ignition and knock related to hydrogen port-fuel injection. In the present work we performed an optical investigation of direct injection (DI) hydrogen combustion under leaner mixture conditions. The study was conducted using a heavy-duty optical diesel engine modified for spark-ignition operation. Bottom-view natural flame luminosity and OH-PLIF imaging were conducted along with in-cylinder pressure measurements. Experiments were conducted at three air-excess ratios (3 3.4 and 3.8) with spark timings (ST) varied from − 15 ◦CA aTDC to − 30 ◦CA aTDC. Hydrogen injection ended at − 30 ◦CA aTDC with the start of injection adjusted accordingly to achieve the desired lambda conditions. The maximum IMEPg corresponded to the lowest COV of the IMEPg indicating optimal spark timing for lean DI hydrogen combustion. The optimized spark timing for λ = 3 λ = 3.4 and λ = 3.8 were occurred at − 25 ◦CA aTDC − 25 ◦CA aTDC and − 30 ◦CA aTDC respectively. The corresponding COV of IMEPg values were below 5 % indicating stable combustion. The flame kernel first initiates at the spark plug and then propagates toward the piston’s outer boundary however the flame propagation does not remain as a continuous front unlike port-fuel injected hydrogen combustion. The effect of fuel stratification is evident in combustion luminosity and OH-PLIF images showing pockets of varying intensity within the combustion chamber. Natural flame luminosity images reveal incomplete flame coverage and asymmetric combustion emphasizing the need for metal engine experiments to further quantify the unburned hydrogen and associated combustion losses.

This study evaluates the techno-economic performance of hybrid renewable microgrids integrating hydrogen storage and fuel cells in two Moroccan pilot farms: a grid-connected site (BLFARM) and an off-grid site (RIMSAR). Real meteorological and load data were analyzed in HOMER Pro to assess feasibility. In 2024 BLFARM achieved a Levelized Cost of Energy (LCOE) of e1.63/kWh and a Renewable Fraction (Ren Frac) of 83.9% while RIMSAR reached e4.32/kWh with 100% renewable contribution. Hydrogen use remained limited due to low demand and high costs. Assuming 2050 hydrogen-technology reductions LCOE decreased to e0.160/kWh (BLFARM) and e0.425/kWh (RIMSAR) while hydrogen components were still underutilized. Aggregating demand from 5-80 farms reduced LCOE by over 50% from e0.093 to e0.045/kWh (BLFARM) and from e0.142 to e0.074/kWh (RIMSAR) while increasing electrolyzer and fuelcell operation. Community-networked hydrogen microgrids thus enhance component utilization energy resilience and cost effectiveness in rural Moroccan agriculture.

Hydrogen blending in natural gas systems is a key transitional strategy for reducing carbon emissions. This study explores the influence of hydrogen on combustion properties including flame flashback risk quenching distance and energy efficiency. Experimental and computational analyses demonstrate that hydrogen addition increases flame speed but reduces calorific value and quenching distance thereby impacting combustion stability and safety. Findings suggest that optimizing burner design and combustion control strategies is essential for safely and efficiently using hydrogen-enriched natural gas. Experimental validation confirmed that a 1.50 mm channel dimension effectively prevented flame flashback for hydrogen concentrations up to 40% in natural gas. As energy systems evolve toward decarbonization this research provides critical insights into the feasibility and challenges of hydrogen integration in residential or industrial applications. The study investigated the combustion behavior of natural gas enriched with various concentrations of hydrogen (up to 25%). Dynamic or fluctuating mixing conditions were excluded as the implementation of such a system in energy sector applications would necessitate a stable and well-defined gas composition.

To address the economic and reliability challenges of high-penetration renewable energy integration in electricity-heat-hydrogen integrated energy systems and support the dualcarbon strategy this paper proposes an optimal dispatch method integrating Information Gap Decision Theory (IGDT) and Fuzzy Chance-Constrained Programming (FCCP). An IES model coupling multiple energy components was constructed to exploit multi-energy complementarity. A stepped carbon trading mechanism was introduced to quantify emission costs. For interval uncertainties in renewable generation IGDT-based robust and opportunistic dispatch models were established; for fuzzy load uncertainties FCCP transformed them into deterministic equivalents forming a dual-layer “IGDT-FCCP” uncertainty handling framework. Simulation using CPLEX demonstrated that the proposed model dynamically adjusts uncertainty tolerance and confidence levels effectively balancing economy robustness and low-carbon performance under complex uncertainties: reducing total costs by 12.7% cutting carbon emissions by 28.1% and lowering renewable curtailment to 1.8%. This study provides an advanced decision-making paradigm for low-carbon resilient IES.