Publications

The proton exchange membrane fuel cell (PEMFC) is a promising device in the fields of power generation energy storage aerospace and public transportation. The hydrogen recirculation ejector with the advantages of low cost high durability and no parasitic power is the key component of PEMFC systems. However it is challenging to design a hydrogen recirculation ejector to cover the wide operating conditions of PEMFC systems. In order to design an ejector for fuel cell systems a comprehensive understanding of ejector research is required. Consequently the state-of-the-art research work on the hydrogen recirculation ejector is analyzed including characteristics of the ejector in PEM fuel cell systems geometry design and optimization different types of ejectors and a comparison between them and system integration and control. Through a comprehensive analysis of ejectors further research suggestions on designing high-performance ejectors are presented.

Hydrogen is emerging as a new energy vector outside of its traditional role and gaining more recognition internationally as a viable fuel route. This review paper offers a crisp analysis of the most recent developments in hydrogen production techniques using conventional and renewable energy sources in addition to key challenges in the production of Hydrogen. Among the most potential renewable energy sources for hydrogen production are solar and wind. The production of H2 from renewable sources derived from agricultural or other waste streams increases the flexibility and improves the economics of distributed and semi-centralized reforming with little or no net greenhouse gas emissions. Water electrolysis equipment driven by off-grid solar or wind energy can also be employed in remote areas that are away from the grid. Each H2 manufacturing technique has technological challenges. These challenges include feedstock type conversion efficiency and the need for the safe integration of H2 production systems with H2 purification and storage technologies.

Industry is frequently framed as hard-to-decarbonize given its diversity of requirements technologies and supply chains many of which are unique to particular sectors. Net zero commitments since 2019 have begun to challenge the carbon intensity of these various industries but progress has been slow globally. Against this backdrop the United Kingdom has emerged as a leader in industrial decarbonization efforts. Their approach is based on industrial clusters which cut across engineering spatial and socio-political dimensions. Two of the largest of these clusters in England in terms of industrial emissions are the Humber and Merseyside. In this paper drawn from a rich mixed methods original dataset involving expert interviews (N = 46 respondents) site visits (N = 20) a review of project documents and the academic literature we explore ongoing efforts to decarbonize both the Humber and Merseyside through the lens of spatially expansive and technically complex megaprojects. Both have aggressive implementation plans in place for the deployment of net-zero infrastructure with Zero Carbon Humber seeking billions in investment to build the country’s first large-scale bioenergy with carbon capture and storage (BECCS) plant alongside a carbon transport network and hydrogen production infrastructure and HyNet seeking billions in investment to build green and blue hydrogen facilities along with a carbon storage network near Manchester and Liverpool. We draw from the social construction of technology (SCOT) literature to examine the relevant social groups interpretive flexibility and patterns of closure associated with Zero Carbon Humber and HyNet. We connect our findings to eight interpretive frames surrounding the collective projects and make connections to problems contestation and closure.

Green hydrogen production i.e. produced on a CO2 -neutral basis through the electrolysis of water employing renewable electricity has attracted increasing attention. The electricity required is generated from Renewable Energy Sources (RES) for example wind energy hydropower or solar energy. Since neither the process of production nor the end products of H2 and O2 are harmful to the environment green hydrogen is climate neutral. Developing electrolysis technology is therefore a research topic to follow. Anion Exchange Membrane (AEM) Water Electrolysis (WE) is an innovative technology that couples the advantages of the more mature technologies of Proton Exchange Membrane (PEM) and conventional alkaline electrolysis with the potential to eliminate the drawbacks of both. AEMWE technology is in an evolutionary stage and involves more investigation on several research topics such as membrane and catalyst development and stability as well as alternative feeding solutions that do not compromise the availability of fresh water. These topics are addressed in this paper mentioning the state-of-the-art materials new promising ones and providing future research directions to improve AEMWE towards a most mature technology.

Non-energy use of natural gas is gaining importance. Gas used for 183 million tons annual ammonia production represents 4% of total global gas supply. 1.5-degree pathways estimate an ammonia demand growth of 3–4-fold until 2050 as new markets in hydrogen transport shipping and power generation emerge. Ammonia production from hydrogen produced via water electrolysis with renewable power (green ammonia) and from natural gas with CO2 storage (blue ammonia) is gaining attention due to the potential role of ammonia in decarbonizing energy value chains and aiding nations in achieving their net-zero targets. This study assesses the technical and economic viability of different routes of ammonia production with an emphasis on a systems level perspective and related process integration. Additional cost reductions may be driven by optimum sizing of renewable power capacity reducing losses in the value chain technology learning and scale-up reducing risk and a lower cost of capital. Developing certification and standards will be necessary to ascertain the extent of greenhouse gas emissions throughout the supply chain as well as improving the enabling conditions including innovative finance and de-risking for facilitating international trade market creation and large-scale project development.

Hydrogen fuel cell vehicle (HFCV) technology poses great promise as an alternative to significantly reduce the environmental impact of the transport sector’s emissions. However hydrogen fuel cell technology is relatively new therefore confirmation of the reliability and safety analysis is still required particularly for fire scenarios within confined spaces such as tunnels. This study applied the computational fluid dynamics (CFD) simulations in conjunction with probabilistic calculation methods to determine the associated thermal risk of a hydrogen jet fire in a tunnel and its dependency on scenarios with different tunnel slopes longitudinal and transverse ventilation velocities and fire positions. A large-scale model of 102 m in which the effects of outlined parameter variations on the severity of the fire incident were analysed. It is found that both tunnel ventilation techniques and slope were critical for the effective ejection of accumulated heat. With ventilation playing a primary role in the ejection of heat and gas and slope ensuring the stability of the ejected heat probabilities of thermal burns were found to be reduced by up to approximately 35% with a strong suggestion of critical combinations to further reduce the dangers of hydrogen tunnel fires.

This study investigates the production of green hydrogen for use in oil refining as specified in the draft of European union delegated act published in May 2022. The European union plans to set strict requirements of additionality and reporting regarding the criteria of renewable electricity used in hydrogen production. Alkaline electrolyzer proton exchange membrane electrolyzer and solid oxide electrolyzer are evaluated in various scenarios supplied by wind power: power purchase agreement-based scenarios and wind power investment-based scenarios. In power purchase agreement-based scenarios baseload and pay as produced power purchase agreements (with and without electricity storage) are assessed. According to results the use of 600 MW compressed air energy storage could reduce the dependency on the grid by 7% but increase the cost of green hydrogen significantly. Investment-based scenarios produce green hydrogen with a lower operation cost but higher break-even price compared to power purchase agreement-based scenarios. The cheapest green hydrogen can be achieved by alkaline electrolyzer with baseload power purchase agreement. Direct ownership of wind power is outside the operation of oil refining industry thus power purchase agreements contracting is more likely to realize.

This paper reviews recent optimization models for hydrogen supply chains and production. Optimization is a central component of systematic methodologies to support hydrogen expansion. Hydrogen production is expected to evolve in the coming years to help replace fossil fuels; these high expectations arise from the potential to produce low-carbon hydrogen via electrolysis using electricity generated by renewable sources. However hydrogen is currently mainly used in refinery and industrial operations; therefore physical infrastructures for transmission distribution integration with other energy systems and efficient hydrogen production processes are lacking. Given the potential of hydrogen the greenfield state of infrastructures and the variability of renewable sources systematic methodologies are needed to reach competitive hydrogen prices and design hydrogen supply chains. Future research topics are identified: 1) improved hydrogen demand projections 2) integrated sector modeling 3) improving temporal and spatial resolutions 4) accounting for climate change 5) new methods to address sophisticated models.

In recent years hydrogen is rapidly developing because it is environmentally friendly and sustainable. In this case hydrogen energy storage systems (HESSs) can be widely used in the distribution network. The application of hybrid electric-hydrogen energy storage systems can solve the adverse effects caused by renewable energy access to the distribution network. In order to ensure the rationality and effectiveness of energy storage systems (ESSs) configuration economic indicators of battery energy storage systems (BESSs) and hydrogen energy storage systems power loss and voltage fluctuation are chosen as the fitness function in this paper. Meanwhile multi-objective particle swarm optimization (MOPSO) is used to solve Pareto non-dominated set of energy storage systems’ optimal configuration scheme in which the technique for order preference by similarity to ideal solution (TOPSIS) based on information entropy weight (IEW) is used select the optimal solution in Pareto non-dominated solution set. Based on the extended IEEE-33 system and IEEE-69 system the rationality of energy storage systems configuration scheme under 20% and 35% renewable energy penetration rate is analyzed. The simulation results show that the power loss can be reduced by 7.9%–22.8% and the voltage fluctuation can be reduced by 40.0%–71% when the renewable energy penetration rate is 20% and 35% respectively in IEEE-33 and 69 nodes systems. Therefore it can be concluded that the locations and capacities of energy storage systems obtained by multi-objective particle swarm optimization can improve the distribution network stability and economy after accessing renewable generation.

To accelerate clean energy transition China has explored the potential of hydrogen as an energy carrier since 2001. Until 2020 49 national hydrogen policies were enacted. This paper explores the relevance of these policies to the development of the hydrogen industry and energy transition in China. We examine the reasons impacts and challenges of Chinese national hydrogen policies through the conceptual framework of Thomas Dye’s policy analysis method and the European Training Foundation’s policy analysis guide. This research provides an ex‐post analysis for previous policies and an ex‐ante analysis for future options. We argue that the energy supply revolution and energy technology revolution highlight the importance of hydrogen development in China. Particularly the pressure of the automobile industry transition leads to experimentation concerning the application of hydrogen in the transportation sector. This paper also reveals that hydro‐ gen policy development coincides with an increase in resource input and has positive spill over effects. Furthermore we note that two challenges have impeded progress: a lack of regulations for the industry threshold and holistic planning. To address these challenges the Chinese government can design a national hydrogen roadmap and work closely with other countries through the Belt and Road Initiative.