Publications

The development of hydrogen production technologies as well as new uses represents an opportunity both to accelerate the ecological transition and to create an industrial sector. However the risks associated with the use of hydrogen must not be overlooked. The mitigation of a hydrogen explosion in an enclosure is partly based on prevention strategies such as detection and ventilation but also on protection strategies such as explosion venting. However in several situations such as in highly constrained urban environments the discharge of the explosion through blast walls could generate significant overpressure effects outside the containment which are unacceptable. Thus having alternative mitigation solutions can make the effects of the explosion acceptable by reducing the flame speed and the overpressure loading or suppressing the secondary explosion. The objective of this paper is to present the experimental study of the mitigation of hydrogen-air deflagration in a 4 m3 vented enclosure by injection of aqueous foam. After a description of the experimental set-up the main experimental results are presented showing the influence of aqueous foam on flame propagation (Fig. 1). Different foam expansion ratios were investigated. An interpretation of the mitigating effect of foam on the explosion effects is proposed based on the work of Kichatov [5] and Zamashchikov [2].

Driven by global targets to reduce greenhouse gas emissions energy systems are expected to undergo fundamental changes. In light of carbon neutrality policies China is expected to significantly increase the proportion of hydrogen and electricity in its energy system in the future. Nevertheless the future trajectory remains shrouded in uncertainty. To explore the potential ramifications of varying growth scenarios pertaining to hydrogen and electricity on the energy landscape this study employs a meticulously designed bottom-up model. Through comprehensive scenario calculations the research aims to unravel the implications of such expansions and provide a nuanced analysis of their effects on the energy system. Results show that with an increase in electrification rates cumulative carbon dioxide emissions over a certain planning horizon could be reduced at the price of increased unit reduction costs. By increasing the share of end-use electricity and hydrogen from 71% to 80% in 2060 the unit carbon reduction cost will rise by 17%. Increasing shares of hydrogen could shorten the carbon emission peak time by approximately five years but it also brings an increase in peak shaving demand.

This report shows how the infrastructure that exists today can evolve from one based on the supply of fossil fuels to one providing the backbone of a clean hydrogen system. The ambitious government hydrogen targets across the UK will only be met with clarity focus and partnership. The gas networks are ready to play their part in the UK’s energy future. They have a plan know what is needed to deliver it and are taking the necessary steps to do just that.

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.

Green hydrogen has recently gained importance as a key element in the transition to a low-carbon energy future sparking a boom in possible production regions. This article aims at situating incipient hydrogen production in the Argentine province of Río Negro within a global production network (GPN). The early configuration of the hydrogen-GPN includes several stakeholders and is contested in many ways. To explore the possible materialization of the hydrogen economy in Argentina this article links GPN literature to the concept of sociotechnical imaginaries. In so doing this study finds three energy imaginaries linked to hydrogen development: First advocates of green hydrogen (GH2) project a sociotechnical imaginary in which GH2 is expected to promote scientific and technological progress. Second proponents of blue hydrogen point to Vaca Muerta and the role of natural gas for energy autonomy. Third opponents of the GH2 project question the underlying growth and export model emphasizing conservation and domestic energy sovereignty. The competition between different capital fractions i.e. green and fossil currently poses the risk of pro-fossil path decisions and lock-in effects. Current power constellations have led to the replacement of green with low-emission resulting in the promotion of multi-colored hydrogen. This is particularly evident in the draft for the new national hydrogen law and the actors involved in defining the national hydrogen strategy. The conceptual combination of actors and their interests their current power relations and the sociotechnical imaginaries they deploy illustrates how Argentina's energy future is already being shaped today.

The updraft rotating bed gasifier (URBG) offers a sustainable solution for waste-to-energy conversion utilizing low-grade lignite and municipal solid waste (MSW) from metropolitan dumping sites. This study investigates the co-gasification of lignite with various MSW components demonstrating a significant enhancement in gasification efficiency due to the synergistic effects arising from their higher hydrogen-to-carbon (H/C) ratios. We find feedstock blending is key to maximizing gasification efficiency from 11% to 52% while reducing SO emissions from 739 mg/kg to 155 mg/kg. Increasing the combustion zone temperature to 1100 K resulted in a peak hydrogen yield which was 19% higher than at 800 K. However steam management is complicated as increasing it improves hydrogen fraction in produced gas but gasification efficiency is compromised. These findingsshowcase the URBG’s potential to address both energy production and waste management challenges guiding fossil-reliant regions toward a more sustainable energy future.

To improve the recovery of waste heat and avoid the problem of abandoning wind and solar energy a multi-energy complementary distributed energy system (MECDES) is proposed integrating waste heat and surplus electricity for hydrogen storage. The system comprises a combined cooling heating and power (CCHP) system with a gas engine (GE) solar and wind power generation and miniaturized natural gas hydrogen production equipment (MNGHPE). In this novel system the GE’s waste heat is recycled as water vapor for hydrogen production in the waste heat boiler while surplus electricity from renewable sources powers the MNGHPE. A mathematical model was developed to simulate hydrogen production in three building types: offices hotels and hospitals. Simulation results demonstrate the system’s ability to store waste heat and surplus electricity as hydrogen thereby providing economic benefit energy savings and carbon reduction. Compared with traditional energy supply methods the integrated system achieves maximum energy savings and carbon emission reduction in office buildings with an annual primary energy reduction rate of 49.42–85.10% and an annual carbon emission reduction rate of 34.88–47.00%. The hydrogen production’s profit rate is approximately 70%. If the produced hydrogen is supplied to building through a hydrogen fuel cell the primary energy reduction rate is further decreased by 2.86–3.04% and the carbon emission reduction rate is further decreased by 12.67–14.26%. This research solves the problem of waste heat and surplus energy in MECDESs by the method of hydrogen storage and system integration. The economic benefits energy savings and carbon reduction effects of different building types and different energy allocation scenarios were compared as well as the profitability of hydrogen production and the factors affecting it. This has a positive technical guidance role for the practical application of MECDESs.

The transition from traditional petrol-based combustion engines to hydrogen-powered systems represents a promising advancement in sustainable and clean energy solutions. This review paper explores the intricacies of converting a conventional internal combustion engine to operate on hydrogen gas. Key topics include the performance limitations of hydrogen engines the role of water injection in combustion modulation and the investigation of direct injection and port injection systems. This review also examines challenges associated with lean and rich mixtures risks of backfire and pre-ignition and the conversion’s overall impact on engine performance and longevity. Additionally this paper discusses hydrogen lubrication to prevent mechanical wear and addresses emission-related considerations.

Future liquid hydrogen-powered aircraft requires the design and optimization of a large number of systems and subsystems with cryogenic tanks being one of the largest and most critical. Considering previous space applications these tanks are usually stiffened by internal members such as stringers frames and stiffeners resulting in a complex geometry that leads to an eventual reduction in weight. Cryogenic tanks experience a variety of mechanical and thermal loading conditions and are usually constructed out of several different materials. The complexity of the geometry and the loads highlights the necessity for a computational tool in order to conduct analysis. In this direction the present work describes the development of a multi-physics finite element digital simulation conducting heat transfer and structural analysis in a fully parametric manner in order to be able to support the investigation of different design concepts materials geometries etc. The capabilities of the developed model are demonstrated by the design process of an independent-type aluminum 2219 cryogenic tank for commuter aircraft applications. The designed tank indicates a potential maximum take-off weight reduction of about 8% for the commuter category and demonstrates that aluminum alloys are serious candidate materials for future aircraft.

Hydrogen valleys are encompassed within a defined geographical region with various technologies across the entire hydrogen value chain. The scope of this study is to analyze and assess the different hydrogen technologies for their application within the hydrogen valley context. Emphasizing on the coupling of renewable energy sources with electrolyzers to produce green hydrogen this study is focused on the most prominent electrolysis technologies including alkaline proton exchange membrane and solid oxide electrolysis. Moreover challenges related to hydrogen storage are explored alongside discussions on physical and chemical storage methods such as gaseous or liquid storage methanol ammonia and liquid organic hydrogen carriers. This article also addresses the distribution of hydrogen within valley operations especially regarding the current status on pipeline and truck transportation methods. Furthermore the diverse applications of hydrogen in the mobility industrial and energy sectors are presented showcasing its potential to integrate renewable energy into hard-to-abate sectors.