Publications

In response to growing environmental concerns hydrogen production has emerged as a critical element in the transition to a sustainable global economy. We evaluate the impact of hydrogen production on both the financial performance and market value of energy sector companies using balanced panel data from 288 European-listed firms over the period of 2018 to 2022. The findings reveal a paradox. While hydrogen production imposes significant financial constraints it is positively recognized by market participants. Despite short-term financial challenges companies engaged in hydrogen production experience higher market value as investors view these activities as a long-term growth opportunity aligned with global sustainability goals. We contribute to the literature by offering empirical evidence on the financial outcomes and market valuation of hydrogen engagement distinguishing between production and storage activities and further categorizing production into green blue and gray hydrogen. By examining these nuances we highlight the complex relationship between financial market results. While hydrogen production may negatively impact short-term financial performance its potential for long-term value creation driven by decarbonization efforts and sustainability targets makes it attractive to investors. Ultimately this study provides valuable insights into how hydrogen engagement shapes corporate strategies within the evolving European energy landscape.

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.

The integration of renewable energy into industrial processes is crucial for reducing the carbon footprint of conventional hydrogen production. This work presents detailed design optical–thermal simulation and performance analysis of a solar parabolic dish (SPD) system for supplying high-temperature steam to a Steam Methane Reforming (SMR) plant. A 5 m diameter dish with a focal length of 3 m was designed and optimized using COMSOL Multiphysics (version 6.2) and MATLAB (version R2023a). Optical ray tracing confirmed a geometric concentration ratio of 896× effectively focusing solar irradiation onto a helical cavity receiver. Thermal–fluid simulations demonstrated the system’s capability to superheat steam to 551 ◦C at a mass flow rate of 0.0051 kg/s effectively meeting the stringent thermal requirements for SMR. The optimized SPD system with a 5 m dish diameter and 3 m focal length was designed to supply 10% of the total process heat (≈180 GJ/day). This contribution reduces natural gas consumption and leads to annual fuel savings of approximately 141000 SAR (Saudi Riyal) along with a substantial reduction in CO2 emissions. These quantitative results confirm the SPD as both a technically reliable and economically attractive solution for sustainable blue hydrogen production.

The spark-ignited (SI) hydrogen combustion engine has the potential to noticeably reduce greenhouse gas emissions from passenger cars. To prevent nitrogen oxide emissions and to increase fuel efficiency and power output complex air paths and operating strategies are utilized. This makes the engine control problem more complex challenging the conventional engine calibration process. This work combines and extends the state-of-the-art in real-time combustion engine modeling and optimal control presenting a novel control concept for the efficient operation of a hydrogen combustion engine. The extensive experimental validation with a 1.5 l three-cylinder hydrogen SI engine and a dynamically operated engine test bench with emission and in-cylinder pressure measurements provides a comprehensible comparison to conventional engine control. The results demonstrate that the proposed optimal control decreased the load tracking errors by a factor of up to 2.8 and increased the engine efficiency during lean operation by up to 10 percent while decreasing the calibration effort compared to conventional engine control.

This study employs first principles calculations and thermodynamic analyses to investigate the dissociative adsorption of hydrogen on the Fe(110) surface. The results show that the adsorption energies of hydrogen at different sites on the iron surface are −1.98 eV (top site) −2.63 eV (bridge site) and −2.98 eV (hollow site) with the hollow site being the most stable adsorption position. Thermodynamic analysis further reveals that under operational conditions of 25 ◦C and 12 MPa the Gibbs free energy change (∆G) for hydrogen dissociation is −1.53 eV indicating that the process is spontaneous under pipeline conditions. Moreover as temperature and pressure increase the spontaneity of the adsorption process improves thus enhancing hydrogen transport efficiency in pipelines. These findings provide a theoretical basis for optimizing hydrogen transport technology in natural gas pipelines and offer scientific support for mitigating hydrogen embrittlement improving pipeline material performance and developing future hydrogen transportation strategies and safety measures.

Under the UK’s carbon neutrality goals for 2050 the Liverpool City Region’s (LCR) strategic positioning with its rich industrial heritage and infrastructure assets such as extensive port facilities and proximity to vast renewable energy resources positions it as a potential leader in the UK’s shift towards a hydrogen economy. Given this the regional hydrogen industry and stakeholders in decarbonisation initiatives intend to undertake a critical review of the opportunities challenges and uncertainties to local hydrogen supply and demand systems to assist in their decision-making. To achieve this goal this study reviews the readiness of the hydrogen supply chain infrastructure within the LCR which highlights four sectors in the hydrogen economy i.e. production storage transportation and utilisation. Subsequently to offer the first-hand data in practice a multi-faceted approach that incorporates a broad array of stakeholders through the Triple Helix (TH) model is adopted. Special attention is given to hydrogen’s role in transforming heavy industry transportation and heating sectors supported by significant local projects like HyNet North West. During a roundtable discussion industry-academia-government stakeholders identify challenges in scaling up infrastructure and assess the economic and technological landscape for hydrogen adoption. To the best of our knowledge this will be the first regional academic endeavour to comprehensively examine the alignment between hydrogen supply and demand theory and practice. Based on a detailed SWOT analysis this study outlines the region’s strengths including established industrial clusters and technological capabilities in manufacturing. It also highlights weaknesses such as the high costs associated with emerging hydrogen technologies technological immaturity and gaps in necessary infrastructure. The opportunities presented by national policy incentives and growing global demand for sustainable energy solutions are considered alongside threats including regulatory complexities and the slow pace of public acceptance. This comprehensive examination not only maps the current landscape but also sets the stage for strategic interventions needed to realise hydrogen’s full potential within the LCR aiming to guide policymakers industry leaders and researchers in their efforts to foster a viable hydrogen economy. Moreover the findings offer valuable insights that can inform the development of hydrogen strategies in other regions and cities.

The paper approaches a computational evaluation of the 100% hydrogen fueled DLR micro-Gas Turbine (mGT) burner F400S.3 through high-fidelity Large Eddy Simulations (LES). Sensitivity analyses on the thermal boundary conditions of the burner walls and the turbulent combustion model were conducted. The experimental OH*-Chemiluminescence distribution was compared with numerical results obtained using the Partially Stirred Reactor (PaSR) and the Extended Flamelet Generated Manifold (ExtFGM) combustion models. The results showed good agreement regarding the flame shape and reactivity prediction when non-adiabatic thermal boundary conditions were applied at the burner walls and the PaSR model was implemented. On the contrary the ExtFGM model exhibited underprediction in flame length and flame lift-off overestimating flame reactivity. Finally after selecting the combustion model that best retrieved the experimental data a pressurized LES was performed on the combustor domain to evaluate its performance under real operating conditions for mGT.

Blue hydrogen production typically achieved by combining steam methane reforming with amine-based CO2 capture is widely considered an economical route towards clean hydrogen. However it suffers from high energy demands associated with solvent regeneration. To overcome this limitation we propose a novel hybrid approach integrating steam methane reforming with membrane-based CO2 capture and O2-enriched combustion. Using process simulations we conducted comprehensive techno-economic and environmental analyses to assess critical parameters affecting the levelised cost of hydrogen (LCOH) and CO2 emissions. Optimal results were obtained at an enriched oxygen level of 30% using vacuum pumping and CO2 capture via feed compression at 11 bar. This configuration achieved an LCOH of ~$1.8/kg H2 and total specific CO2 emissions of ~4.9 kg CO2/kg H2. This aligns closely with conventional blue hydrogen benchmarks with direct emissions significantly reduced to around 1 kg CO2/kg H2. Additionally sensitivity analysis showed robust economic performance despite variations in energy prices. Anticipated advancements in membrane technology could reduce the LCOH further to approximately $1.5/kg H2. Thus this hybrid membrane-based process presents a competitive and sustainable strategy supporting the achievement of the 2050 net-zero emissions goals in hydrogen production.

Methane pyrolysis offers a compelling pathway for low-carbon hydrogen production by avoiding CO2 emissions and enabling distributed deployment in locations with natural gas supply thereby eliminating the need for costly hydrogen transport. While promising the commercial deployment is constrained by the lack of detailed reactor modeling and technoeconomic assessment at small production scales. This study addresses these gaps by designing and modeling a small-scale (1–10 t-H2/day) bubble column reactor employing molten Ni–Bi alloy catalyst for methane pyrolysis. A coupled kinetic–hydrodynamic model was developed to simulate gas holdup bubble behavior and conversion under different operating conditions. The reactor design was integrated into an Aspen Plus simulation of the full process including heat recovery and hydrogen purification. Optimization of pressure temperature and single-pass conversion revealed that operation at 1100 ◦C 15 bar and 70–75 % conversion minimized reactor volume and cost. The lowest levelized cost of hydrogen (LCOH) achieved was $3.06/kg-H2 without sale of carbon significantly lower than green H2 produced from water electrolysis and competitive with blue H2 produced via centralized reforming when transportation costs are included. Sensitivity analysis reveals that carbon byproduct is a key economic lever; carbon sale at $250/t-C reduces LCOH by 25 % while a price of $700/t-C would meet U.S. DOE $1/kg-H₂ target. These results demonstrate the technoeconomic viability of molten metal methane pyrolysis and highlight future opportunities.

The transition to hydrogen as an aviation fuel as outlined in current decarbonization roadmaps is expected to result in the entry into service of hydrogen-powered aircraft in 2035. To achieve this evolution certification regulations are key enablers. Due to the disruptive nature of hydrogen aircraft technologies and their associated hazards it is essential to assess the maturity of the existing regulatory framework for certification to ensure its availability when manufacturers apply for aircraft certification. This paper presents the work conducted under the Clean Aviation CONCERTO project to advance certification readiness by comprehensively identifying gaps in the current European regulations. Generic methodologies were developed for regulatory gap and risk analyses and applied to a hydrogen turbine aircraft with non-propulsive fuel cells as the APU. The gap analysis conducted on certification specifications for large and normal-category airplanes as well as engines confirmed the overall adequacy of many existing requirements. However important gaps exist to appropriately address hydrogen hazards particularly concerning fire and explosion hydrogen storage and fuel systems crashworthiness and occupant survivability. The paper concludes by identifying critical areas for certification and highlighting the need for complementary hydrogen phenomenology data which are key to guiding future research and regulatory efforts for certification readiness maturation.