United Kingdom

Underground Hydrogen Storage (UHS) has gathered interest over the past decade as an efficient means of storing energy. Although a significant number of research and demonstration projects have sought to understand the associated technical challenges it is yet to be achieved on commercial scales. We highlight case studies from town gas and blended hydrogen storage focusing on leakage pathways and hydrogen reactivity. Experience from helium storage serves as an analogue for the containment security of hydrogen as the two gases share physiochemical similarities including small molecular size and high diffusivity. Natural gas storage case studies are also investigated to highlight well integrity and safety challenges. Technical parameters identified as having adverse effects on storage containment security efficiency and hydrogen reactivity were then used to develop high-level and site-specific screening criteria. Thirty-two depleted offshore hydrocarbon reservoirs in the UK Continental Shelf (UKCS) are identified as potential storage formations based on the application of our high-level criteria. The screened fields reflect large hydrogen energy capacities low cushion gas requirements and proximity to offshore wind farms thereby highlighting the widespread geographic availability and potential for efficient UHS in the UKCS. Following the initial screening we propose that analysis of existing helium concentrations and investigation of local tectonic settings are key site-specific criteria for identifying containment security of depleted fields for stored hydrogen.

The high efficiency light weight and reliability of hydrogen energy electrochemical equipment are among the future development directions. Membrane electrode assemblies (MEAs) and electrolyzers as key components have structures and strengths that determine the efficiency of their power generation and the hydrogen production efficiency of electrolyzers. This article summarizes the evolution of membrane electrode and electrolyzer structures and their power and efficiency in recent years highlighting the significant role of integrated structures in promoting proton transport and enhancing performance. Finally it proposes the development direction of integrating electrolyte and electrode manufacturing using phase-change methods.

Thermo-chemical conversion of waste plastics offers a sustainable strategy for integrated waste management and clean energy generation. To address the challenges of low gas yield and rapid catalyst deactivation due to coking in conventional gasification processes an innovative three-stage chemical looping gasification (CLG) system specifically designed for enhanced hydrogen-rich syngas production was proposed in this work. A comparative analysis between conventional gasification and the staged CLG system were firstly conducted coupled with online gas analysis for mechanistic elucidation. The influence of Fe/Al molar ratios in oxygen carriers and their cyclic stability were systematically examined through multicycle experiments. Results showed that the three-stage CLG in the presence of Fe1Al2 demonstrated exceptional performance achieving 95.23 mmol/gplastic of H2 and 129.89 mmol/gplastic of syngas respectively representing 1.32-fold enhancement over conventional method. And the increased H2/CO ratio (2.68-2.75) reflected better syngas quality via water-gas shift. Remarkably the oxygen carrier maintained nearly 100% of its initial activity after 7 redox cycles attributed to the incorporation of Al2O3 effectively mitigating sintering and phase segregation through metal-support interactions. These findings establish a three-stage CLG configuration with Fe-Al oxygen carriers as an efficient platform for efficient hydrogen production from waste plastics contributing to sustainable waste valorisation and carbon-neutral energy systems.

Minimizing carbon dioxide emissions is crucial due to the generation of energy from fossil fuels. The significance of carbon capture and storage (CCS) technology which is highly successful in mitigating carbon emissions has increased. On the other hand hydrogen is an important energy carrier for storing and transporting energy and technologies that rely on hydrogen have become increasingly promising as the world moves toward a more environmentally friendly approach. Nevertheless the integration of CCS technologies into power production processes is a significant challenge requiring the enhancement of the combined power generation–CCS process. In recent years there has been a growing interest in process intensification (PI) which aims to create smaller cleaner and more energy efficient processes. The goal of this research is to demonstrate the process intensification potential and to model and simulate a hybrid integrated–intensified adsorptive-membrane reactor process for simultaneous carbon capture and hydrogen production. A comprehensive multi-scale multi-phase dynamic computational fluid dynamics (CFD)-based process model is constructed which quantifies the various underlying complex physicochemical phenomena occurring at the pellet and reactor levels. Model simulations are then performed to investigate the impact of dimensionless variables on overall system performance and gain a better understanding of this cyclic reaction/separation process. The results indicate that the hybrid system shows a steady-state cyclic behavior to ensure flexible operating time. A sustainability evaluation was conducted to illustrate the sustainability improvement in the proposed process compared to the traditional design. The results indicate that the integrated–intensified adsorptive-membrane reactor technology enhances sustainability by 35% to 138% for the chosen 21 indicators. The average enhancement in sustainability is almost 57% signifying that the sustainability evaluation reveals significant benefits of the integrated–intensified adsorptive-membrane reactor process compared to HTSR + LTSR.

As the global demand for energy increases and the transition to renewable and clean sources accelerates microgrid (MG) has emerged as a promising solution. Hydrogen fuel cell vehicles (HFCVs) offer significant advantages over gasoline vehicles in terms of reducing carbon dioxide emissions. However the development of HFCVs is hindered by the substantial up-front costs of hydrogen refueling stations (HRSs) coupled with the high cost of hydrogen transportation and the limitations of the hydrogen supply chain. This research proposes a multimicrogrid (MMG) system that integrates hydrogen energy and utilizes it as the HRS for fuel vehicle refueling. An adaptive hydrogen energy management method is employed for fuel cell vehicles to optimize the coupling between the transportation network and the power system. An integrated transportation state assessment model is developed and a smart MMG system is deployed to receive information from the transportation network. Building on this foundation an adaptive hydrogen scheduling model is developed. HFCVs are influenced by the hydrogen price adjustments leading them to travel to different MGs for refueling which in turn regulates the unit output of the MMG system. The MMG system is then integrated with the IEEE 33 bus distribution system to analyze the daily load balance. This integrated approach results in reduced traffic congestion lower MG costs and optimized power distribution network load balance.

Large-scale H2 storage in depleted hydrocarbon reservoirs offers a practical way to use existing energy infra structure to address renewable energy intermittency. Cushion gases often constitute a large initial investment especially when expensive H2 is used. Cheaper alternatives such as CO2 or in-situ CH4 can reduce costs and in the case of CO2 integrate within carbon capture and storage systems. This study explored cushion and working gas dynamics through numerically modelling a range of storage scenarios in laterally extensive reservoirs – such as those in the Southern North Sea. In all simulations the cushion and working gases were separated laterally to limit contact surface area and therefore mixing. This work provides valuable insights into (i) capacity estima tions of CO2 storage and H2 withdrawal (ii) macro-scale fluid dynamics and (iii) the effects of gas mixing trends on H2 purity. The results underscore key trade-offs between CO2 storage volumes and H2 withdrawal and purity

To meet the new regulation for the deployment of alternative fuels infrastructure which sets targets for electric recharging and hydrogen refuelling infrastructure by 2025 or 2030 a large infrastructure comprising trucksuitable hydrogen refuelling stations will soon be required. However further standardisation is required to support the uptake of hydrogen for heavy-duty transport for Europe’s green energy future. Hydrogen-powered vehicles require pure hydrogen as some contaminants can reduce the performance of the fuel cell even at very low levels. Even if previous projects have paved the way for the development of the European quality infrastructure for hydrogen conformity assessment sampling systems and methods have yet to be developed for heavy-duty hydrogen refuelling stations (HD-HRS). This study reviews different aspects of the sampling of hydrogen at heavy-duty hydrogen refuelling stations for purity assessment with a focus on the current and future specifications and operations at HD-HRS. This study describes the state-of-the art of sampling systems currently under development for use at HD-HRS and highlights a number of aspects which must be taken into consideration to ensure safe and accurate sampling: risk assessment for the whole sampling exercise selection of cylinders methods to prepare cylinders before the sampling filling pressure and venting of the sampling systems.

In the present study pilot simulations of the phenomena of blast wave and fireball generated by the rupture of a high-pressure (35 MPa) hydrogen tank (volume 72 L) due to fire were carried out. The computational fluid dynamics (CFD) model includes the realizable k-ε model for turbulence and the eddy dissipation model coupled with the one-step chemical reaction mechanism for combustion. The simulation results were compared with experimental data on a stand-alone hydrogen tank rupture in a bonfire test. The simulations provided insights into the interaction between the blast wave propagation and combustion process. The simulated blast wave decay is approximately identical to the experimental data concerning pressure at various distances. Fireball is first ignited at the ground level which is considered to be due to stagnation flow conditions. Subsequently the flame propagates toward the interface between hydrogen and air.

Hydrogen energy is crucial for achieving net zero targets making the resilience of hydrogen supply chains (HSCs) increasingly important. Understanding current research on HSC resilience is key to enhancing it. Few studies summarise HSC resilience evaluation methods and link them to the general supply chain resilience and complex adaptive system (CAS) evaluation approaches. This study addresses this gap by systematically reviewing the literature on HSC resilience evaluations defining HSC resilience and conducting content analysis. It proposes a conceptual framework integrating technical operational and organisational perspectives. Each perspective is further subdivided based on the course of events resulting in a system-based HSC resilience evaluation frame work with three layers of analysis. By linking HSC indicators with CAS theory and supply chain performance metrics the study offers novel insights into HSC resilience evaluations identifies research gaps provides prac tical guidance for practitioners and outlines future research directions for advancing HSC resilience understanding.

Hydrogen (H2) offers a green medium for storing the excess from renewables production instead of dumping it thus being crucial to decarbonisation efforts. Hydrogen also offers a storage medium for the grid’s cheap electricity to be used during grid peak demand or grid power cutoffs. Funded by the Scottish Government’s Emerging Energy Technologies this paper presents the design and performance analysis of a hydrogen uninterruptible power supply (H2GEN) for Cygnas Solutions Ltd. which is intended to enable continuity of supply in the residential sector while eradicating the need for environmentally and health risky lead–acid batteries and diesel generator backup. This paper presents the design optimal sizing and analysis of two H2Gen architectures one powered by the grid alone and the other powered by both the grid and a renewable (PV) source. By developing a model of each architecture in the HOMER space and using residential location weather data the home yearly load–demand profile and the grid yearly power outages profile in the developed models the optimal sizing of each H2Gen design was realised by minimising the costs while ensuring the H2Gen meets the home power demand during grid outages To enable HOMER to optimise its selection the sizes technical specifications and costs of all the market-available H2GEN components were added in the HOMER search space. Moreover the developed models were also used in assessing the sensitivity of the simulation outputs to several changes in the modelled system design and settings. Using a residential home with frequent power outages in New Delhi India as a case study it was found that the optimal sizing of H2Gen Architecture 1 is comprised of a 2 kW electrolyser a 0.2 kg type-I tank and a 2 kW water-cooled fuel cell directly connected to the AC bus offering an operational lifetime of 14.3 years. It was also found that the optimal sizing of Architecture 2 is comprised of a 1 kV PV utilised with the same 2 kW electrolyser 0.2 kg type-I tank and 2 kW water-cooled fuel cell connected to the AC bus. While the second design was found to have a higher capital cost due to the added PV it offered a more cost-effective and environmentally friendly architecture which contributes to the ongoing energy transition. This paper further investigated the capacity expansion of each H2GEN architecture to meet higher load demands or increased grid power outages. From the analysis of the simulation results it has been concluded that the most feasible and cost-effective H2GEN system expansion for meeting increased power demands or increased grid outages can be realised by using the developed models for optimally sizing the expanded H2Gen on a case-by-case basis because the increase in these profiles is highly time-dependent (for example an increased load demand or increased grid outage in the morning can be met by the PV while in the evening it must be met by the H2GEN). Finally this paper investigated the impact of other environmental variables such as the temperature and relative humidity on the H2GEN’s performance and provided further insights into increasing the overall system efficiency and cost benefit through utilising the H2GEN’s exhaust heat in the home space for heating/cooling and selling the electrolyser exhaust’s O2 as a commodity.