Institution of Gas Engineers & Managers

The adoption of clean hydrogen is expected to transform the global energy landscape reducing greenhouse gas emissions bridging gaps in renewable energy integration and driving innovation across multiple sectors. In the medical and pharmaceutical industries hydrogen offers unique opportunities for transformative progress. This review critically examines recent advances in three domains: hydrogen fuel cells as reliable scalable and sustainable energy solutions for hospitals; molecular hydrogen as a therapeutic and preventive medical gas particularly for brain disorders; and hydrogenation technologies for the efficient and sustainable pharmaceutical production. Despite encouraging advancements widespread adoption remains limited by economic constraints regulatory gaps and limited clinical evidence. Addressing these barriers through technological innovation largescale studies and life-cycle sustainability assessments is essential to translate hydrogen’s full potential into clinical and industrial practice. Responsible adoption of green hydrogen is poised to reshape the clinical approach to global health and enhance the quality of life for people worldwide.

This study presents an experimental investigation of a direct injection ammonia-fuelled engine using hydrogen pre-chamber jet ignition. All tests have been conducted in an optically accessible combustion chamber that is installed in the head of a single-cylinder engine. The effect of ammonia injection timing on ignition and combustion characteristics was investigated with the timing varied from 165 CAD BTDC to 40 CAD BTDC. The experiments were conducted with a fixed spark timing of 14 CAD BTDC while ammonia injection duration was adjusted to maintain a main chamber global equivalence ratio of 0.6. Two pre-chamber nozzle configurations a single-hole and a multi-hole were tested. The results show that the later NH3 injection timing (40 CAD BTDC) significantly improved combustion with a peak in-cylinder pressure of 80 bar measured compared to a peak in-cylinder pressure of 50 bar with earlier injection (165 CAD BTDC). This study indicates the importance of optimising ammonia injection timing in order to enhance combustion stability and efficiency. The hydrogen pre-chamber jet ignition combined with a late ammonia injection is a promising approach for addressing the combustion challenges of ammonia as a zero-carbon fuel for maritime applications.

Underground hydrogen storage (UHS) is a relatively new technology that demonstrates notable potential for the efficient storage of large quantities of green hydrogen. Its large-scale implementation requires a comprehensive understanding of numerous factors including safe and effective storage methods as well as overcoming various thresholds and challenges. This article presents strategies for accelerating the implementation of this technology identifying the thresholds and challenges affecting the development and future scale-up of UHS. It characterises challenges and constraints related to geology (including the type and geological characterisation of structures hydrogen storage capacity and hydrogen interactions with underground environments) the technological aspects of hydrogen storage (such as infrastructure management and monitoring) and economic and legal considerations. The need for the rapid implementation of demonstration projects has been emphasised. The identified thresholds and challenges along with the resulting recommendations are crucial for paving the way for the large-scale implementation of UHS. Addressing these issues will significantly influence the implementation of this technology post-2030.

H2 is increasingly recognized as a cornerstone of global decarbonization strategies including in hard-toabate sectors such as aviation. Its large-scale applicability remains limited owing to the limited diversity and maturity of low-carbon production pathways. Approximately 96% of global H2 production originates from non-renewable sources primarily through steam methane reforming (SMR) which remains the most commercially established route. Another critical barrier to the substitution of conventional aviation fuels lies in hydrogen storage as the current volumetric energy density and cryogenic storage requirements render onboard integration impractical for most aircraft configurations. To address these challenges this study developed a techno-economic and environmental benchmarking framework that compares conventional thermal reforming technologies (SMR autothermal and POX) with emerging electrochemical routes (water electrolysis and alcohol electro-oxidation) highlighting their potential roles in the transition toward sustainable aviation fuels (SAF). By normalizing efficiency energy intensity CO2 emissions and cost (USD kg 1 H2 and USD GJ 1 ) this study quantifies the trade-offs that define current and emerging pathways. SMR remains the industrial baseline (70%–85% thermal efficiency 1–2 USD kg−1 H2 9–12 kg CO2 kg−1 H2) whereas ethanol-based electrochemical reforming operates 0.3–0.9 V below conventional electrolysis achieving up to 40% lower electrical energy demand (∼2.4 kW h Nm−3 H2 with near-zero direct emissions. A sensitivity analysis demonstrates that a 60% reduction in catalyst cost or electricity prices below 0.03 USD (kW h)−1 could make electrochemical reforming cost-competitive with SMR. This study consolidates fragmented knowledge into a comprehensive roadmap that links catalyst performance and technology readiness for aviation decarbonization by integrating engineering metrics with policy and infrastructure perspectives to identify realistic transition pathways toward sustainable hydrogen and hybrid aviation fuels.

Hydrogen handling equipment suffers from interaction with their operating environment which degrades the mechanical properties and compromises component integrity. Hydrogen-assisted cracking is responsible for several industrial failures with potentially severe consequences. A thorough failure analysis can determine the failure mechanism locate its origin and identify possible root causes to avoid similar events in the future. Postmortem fractographic analysis can classify the fracture mode and determine whether the hydrogen-metal interaction contributed to the component’s breakdown. Experts in fracture classification identify characteristic marks and textural features by visual inspection to determine the failure mechanism. Although widely adopted this process is time-consuming and influenced by subjective judgment and individual expertise. This study aims to automate fractographic analysis through advanced computer vision techniques. Different materials were tested in hydrogen atmospheres and inert environments and their fracture surfaces were analyzed by scanning electron microscopy to create an extensive image dataset. A pre-trained Convolutional Neural Network was finetuned to accurately classify brittle and ductile fractures. In addition Grad-CAM interpretability method was adopted to identify the image regions most influential in the model’s prediction and compare the saliency maps with expert annotations. This approach offered a reliable data-driven alternative to conventional fractographic analysis.

The recent updates to the Single Day-Ahead Coupling (SDAC) framework in the European energy market along with new rules for providing manual frequency restoration reserve (mFRR) products in the Nordic Energy Activation Market (EAM) have introduced a finer Market Time Unit (MTU) resolution. These developments underscore the growing importance of flexible assets such as power-to-hydrogen (PtH) facilities in delivering system flexibility. However to successfully participate in such markets well-designed and accurate bidding strategies are essential. To fulfill this aim this paper proposes a Mixed Integer Linear Programming (MILP) model to determine the optimal bidding strategies for a typical PtH facility accounting for both the technical characteristics of the involved technologies and the specific participation requirements of the mFRR EAM. The study also explores the economic viability of sourcing electricity from nearby wind turbines (WTs) under a Power Purchase Agreement (PPA). The simulation is conducted using a case study of a planned PtH facility at the Port of Hirtshals Denmark. Results demonstrate that participation in the mFRR EAM particularly through the provision of downward regulation can yield significant economic benefits. Moreover involvement in the mFRR market reduces power intake from the nearby WTs as capacity must be reserved for downward services. Finally the findings highlight the necessity of clearly defined business models for such facilities considering both technical and economic aspects.

For five decades photocatalysis has promised clean hydrogen from solar energy yet a persistent “efficiency ceiling” linked to fundamental challenges including the trade-off between light absorption and redox potential in single-component materials has hindered its practical application. This review illuminates three key paradigm shifts overcoming this challenge. First we examine Z-scheme and S-scheme heterojunctions which resolve the bandgap dilemma by spatially separating redox sites to achieve both broad light absorption and strong redox power. Second we discuss replacing the sluggish oxygen evolution reaction (OER) with value-added organic oxidations. This strategy bypasses kinetic bottlenecks and improves economic viability by co-producing valuable chemicals from feedstocks like biomass and plastic waste. Third we explore manipulating the reaction environment where synergistic photothermal effects and concentrated sunlight can dramatically enhance kinetics and unlock markedly enhanced solar-to-hydrogen (STH) efficiencies. Collectively these strategies chart a clear course to overcome historical limitations and realize photocatalysis as an impactful technology for a sustainable energy future.

China is developing renewable energy bases (REBs) in the desert and Gobi regions. However the intermittency of renewable energy and the temporal mismatch between peak renewable generation and peak load demand severely disrupt the power supply reliability of these REBs. Hydrogen storage technology characterized by high energy density and long-term storage capability is an effective method for enhancing the power supply reliability. Therefore this paper proposes a REB planning model in the desert and Gobi regions considering seasonal hydrogen storage introduction as well as electricity-carbon-hydrogen markets trading. Furthermore a combination scenario generation method considering extreme scenario optimization is proposed. Among which the extreme scenarios selected through an iterative selection method based on maximizing scenario divergence contain more incremental information providing data support for the proposed model. Finally the simulation was conducted in the desert and Gobi regions of Yinchuan Ningxia Province China primarily verifying that (1) the REB incorporating hydrogen storage can fully leverage hydrogen storage to achieve seasonal and long-term electricity transfer and utilization. The project has a payback period of 10 years with an internal rate of return of 13.30% and a return on investment of 16.34% thus showing significant development potential. (2) Compared to the typical battery-involved REB the hydrogen-involved energy storage facility achieved a 59.39% annual profit a 10.98% internal rate of return a 14.93% return on investment and a 1.51% improvement in power supply reliability by sacrificing a 52.49% increase in construction cost. (3) Compared to REB planning based only on typical scenarios the power supply reliability of REBs based on the proposed combination scenario generation method improved by 8.58%.

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.

In northern China the long winter heating period is accompanied by severe wind curtailment. To address this issue a joint optimization scheduling strategy of electric vehicles (EVs) and electro–olefin–hydrogen electromagnetic energy supply device (EHED) is proposed to promote deep wind–solar integration. Firstly the feasibility analysis of EVs participating in scheduling is conducted and the operation models of dispatchable EVs and thermal energy storage EHEDs within the scheduling period are established. Secondly a control strategy for the joint optimization scheduling of wind–solar farms EVs EHEDs and power grid is constructed. Then an economic dispatch model for joint optimization of EVs and EHEDs is established to minimize the system operation cost within the scheduling period and the deep wind–solar integration of the joint optimization model is studied by considering EVs under different demand responses. Finally the proposed model is solved by CPLEX solver. The simulation results show that the established joint optimization economic dispatch model of EV-EHEDs can improve the enthusiasm of dispatchable EVs to participate in deep wind–solar integration reduce wind curtailment power and decrease the overall system operation cost.