Publications
Realistic Electrolyzer Temperature and Pressure Conditions Evaluation of NiFeP/Zn-coated Electrodes for Alkaline Water Splitting
Jul 2025
Publication
The current transition to renewable energies has motivated research into energy storage using various techniques. Of these electrolysis for pure hydrogen production stands out as hydrogen is a crucial energy vector molecule capable of decarbonizing multiple sectors. However the low efficiency of the electrolysis process presents a major limitation. In this work an electrochemical evaluation of catalyst materials for water splitting under elevated temperature and pressure (ETP) conditions to replicate realistic electrolyzer operating environments is proposed. The NiFeP/Zn-coated nickel foam electrodes demonstrated a brain-like compact morphology with EDS revealing a composition of 62.20 at% Ni 13.90 at% Fe 1.60 at% Zn 7.65 at% P and 15.21 at% O2. Electrochemical performance tests revealed a significant reduction in overpotential for the hydrogen evolution reaction (HER) achieving 38 mV at 8 bar and 80 ◦C while the oxygen evolution reaction (OER) exhibited 119 mV at 1 bar and 80 ◦C both at |30| mAcm− 2 . Chronopotentiometry confirmed the stability of the coating for over 24 h at high current density of |400| mAcm− 2 . The bifunctional capability of the coating was validated in a fullcell test obtaining a remarkably low overpotential of 1.47 V at 30 mAcm− 2 for overall water splitting under 80 ◦C and 8 bar conditions.
A COMSOL Framework for Predicting Hydrogen Embrittlement - Part 1: Coupled Hydrogen Transport
Mar 2025
Publication
Hydrogen threatens the structural integrity of metals and thus predicting hydrogen-material interactions is key to unlocking the role of hydrogen in the energy transition. Quantifying the interplay between material deformation and hydrogen diffusion ahead of cracks and other stress concentrators is key to the prediction and prevention of hydrogen-assisted failures. In this work a generalised theoretical and computational framework is presented that for the first time encompasses: (i) stress-assisted diffusion (ii) hydrogen trapping due to multiple trap types rigorously accounting for the rate of creation of dislocation trap sites (iii) hydrogen transport through dislocations (iv) equilibrium (Oriani) and non-equilibrium (McNabb-Foster) trapping kinetics (v) hydrogen-induced softening and (vi) hydrogen uptake considering the role of hydrostatic stresses and local electrochemistry. Particular emphasis is placed on the numerical implementation in COMSOL Multiphysics releasing the relevant models and discussing stability discretisation and solver details. Each of the elements of the framework is independently benchmarked against results from the literature and implications for the prediction of hydrogen-assisted fractures are discussed. The second part of this work (Part II) shows how these crack tip predictions can be combined with crack growth simulations.
Flame Acceleration, Detonation Limit and Heat Loss for Hydrogen-Oxygen Mixture at Cryogenic Temperature of 77 K
Sep 2023
Publication
Experiments are performed in hydrogen-oxygen mixtures at the cryogenic temperature of 77 K with the equivalence ratio of 1.5 and 2.0. The optical fibers pressure sensors and the smoked foils are used to record the flame velocity overpressure evolution curve and detonation cells respectively. The 1st and 2nd shock waves are captured and they finally merge to form a stronger precursor shock wave prior to the onset of detonation. The cryogenic temperature will cause the larger expansion ratio which results in the occurrence of strong flame acceleration. The stuttering mode the galloping mode and the deflagration mode are observed when the initial pressure decreases from 0.50 atm to 0.20 atm with the equivalence ratio of 1.5 and the detonation limit is within 0.25-0.30 atm. The heat loss effect on the detonation limit is analysed. In addition the regularity of detonation cell is investigated and the larger post-shock specific heat ratio !"" and the lower normalized activation energy # at lower initial pressure will cause the more regular detonation cell. Also the detonation cell width is predicted by a model of = ($) ⋅ Δ# and the prediction results are mainly consistent with the experimental results.
A Brief on Nano-Based Hydrogen Energy Transition
Sep 2023
Publication
Considering the clean renewable and ecologically friendly characteristics of hydrogen gas as well as its high energy density hydrogen energy is thought to be the most potent contender to locally replace fossil fuels. The creation of a sustainable energy system is currently one of the critical industrial challenges and electrocatalytic hydrogen evolution associated with appropriate safe storage techniques are key strategies to implement systems based on hydrogen technologies. The recent progress made possible through nanotechnology incorporation either in terms of innovative methods of hydrogen storage or production methods is a guarantee of future breakthroughs in energy sustainability. This manuscript addresses concisely and originally the importance of including nanotechnology in both green electroproduction of hydrogen and hydrogen storage in solid media. This work is mainly focused on these issues and eventually intends to change beliefs that hydrogen technologies are being imposed only for reasons of sustainability and not for the intrinsic value of the technology itself. Moreover nanophysics and nano-engineering have the potential to significantly change the paradigm of conventional hydrogen technologies.
Effects of Surface Modification on a Proton Exchange Membrane for Improvements in Green Hydrogen Production
Oct 2023
Publication
Proton Exchange Membrane (PEM) electrolysis an advanced technique for producing hydrogen with efficiency and environmental friendliness signifies the forefront of progress in this domain. Compared to alkaline cells these electrolytic cells offer numerous advantages such as lower operating temperatures enhanced hydrogen production efficiency and eliminating the need for an aqueous solution. However PEM electrolysis still faces limitations due to the high cost of materials used for the membrane and catalysts resulting in elevated expenses for implementing large-scale systems. The pivotal factor in improving PEM electrolysis lies in the Platinum catalyst present on the membrane surface. Enhancing catalytic efficiency through various methods and advancements holds immense significance for the progress of this technology. This study investigates the use of patterned membranes to improve the performance of PEM electrolytic cells toward green hydrogen production. By increasing the Platinum loading across the membrane surface and enhancing catalytic performance these patterned membranes overcome challenges faced by conventionally fabricated counterparts. The findings of this research indicate that membranes with modified surfaces not only exhibit higher current draw but also achieve elevated rates of hydrogen production.
Optimizing Green Hydrogen Production from Wind and Solar for Hard-to-abate Industrial Sectors Across Multiple Sites in Europe
Jul 2024
Publication
This article analyzes a power-to-hydrogen system designed to provide high-temperature heat to hard-to-abate industries. We leverage on a geospatial analysis for wind and solar availability and different industrial demand profiles with the aim to identify the ideal sizing of plant components and the resulting Levelized Cost of Hydrogen (LCOH). We assess the carbon intensity of the produced hydrogen especially when grid electricity is utilized. A methodology is developed to size and optimize the PV and wind energy capacity the electrolyzer unit and hybrid storage by combining compressed hydrogen storage with lithium-ion batteries. The hydrogen demand profile is generated synthetically thus allowing different industrial consumption profiles to be investigated. The LCOH in a baseline scenario ranges from 3.5 to 8.9 €/kg with the lowest values in wind-rich climates. Solar PV only plays a role in locations with high PV full-load hours. It was found that optimal hydrogen storage can cover the users’ demand for 2–3 days. Most of the considered scenarios comply with the emission intensity thresholds set by the EU. A sensitivity analysis reveals that a lower variability of the demand profile is associated with cost savings. An ideally constant demand profile results in a cost reduction of approximately 11 %.
An Analysis of Hybrid Renewable Energy-Based Hydrogen Production and Power Supply for Off-Grid Systems
Jun 2024
Publication
Utilizing renewable energy sources to produce hydrogen is essential for promoting cleaner production and improving power utilization especially considering the growing use of fossil fuels and their impact on the environment. Selecting the most efficient method for distributing power and capacity is a critical issue when developing hybrid systems from scratch. The main objective of this study is to determine how a backup system affects the performance of a microgrid system. The study focuses on power and hydrogen production using renewable energy resources particularly solar and wind. Based on photovoltaics (PVs) wind turbines (WTs) and their combinations including battery storage systems (BSSs) and hydrogen technologies two renewable energy systems were examined. The proposed location for this study is the northwestern coast of Saudi Arabia (KSA). To simulate the optimal size of system components and determine their cost-effective configuration the study utilized the Hybrid Optimization Model for Multiple Energy Resources (HOMER) software (Version 3.16.2). The results showed that when considering the minimum cost of energy (COE) the integration of WTs PVs a battery bank an electrolyzer and a hydrogen tank brought the cost of energy to almost 0.60 USD/kWh in the system A. However without a battery bank the COE increased to 0.72 USD/kWh in the same location because of the capital cost of system components. In addition the results showed that the operational life of the fuel cell decreased significantly in system B due to the high hours of operation which will add additional costs. These results imply that long-term energy storage in off-grid energy systems can be economically benefited by using hydrogen with a backup system.
Optimal Design of Hydrogen Delivery Infrastructure for Multi-sector End Uses at Regional Scale
Jul 2024
Publication
Hydrogen is a promising solution for the decarbonisation of several hard-to-abate end uses which are mainly in the industrial and transport sectors. The development of an extensive hydrogen delivery infrastructure is essential to effectively activate and deploy a hydrogen economy connecting production storage and demand. This work adopts a mixed-integer linear programming model to study the cost-optimal design of a future hydrogen infrastructure in presence of cross-sectoral hydrogen uses taking into account spatial and temporal variations multiple production technologies and optimised multi-mode transport and storage. The model is applied to a case study in the region of Sicily in Italy aiming to assess the infrastructural needs to supply the regional demand from transport and industrial sectors and to transfer hydrogen imported from North Africa towards Europe thus accounting for the region’s role as transit point. The analysis integrates multiple production technologies (electrolysis supplied by wind and solar energy steam reforming with carbon capture) and transport options (compressed hydrogen trucks liquid hydrogen trucks pipelines). Results show that the average cost of hydrogen delivered to demand points decreases from 3.75 €/kgH2 to 3.49 €/kgH2 when shifting from mobilityonly to cross-sectoral end uses indicating that the integrated supply chain exploits more efficiently the infrastructural investments. Although pipeline transport emerges as the dominant modality delivery via compressed hydrogen trucks and liquid hydrogen trucks remains relevant even in scenarios characterised by large hydrogen flows as resulting from cross-sectoral demand demonstrating that the system competitiveness is maximised through multi-mode integration.
Optimal Multi-layer Economical Schedule for Coordinated Multiple Mode Operation of Wind-solar Microgrids with Hybrid Energy Storage Systems
Nov 2023
Publication
The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.
The UK Hydrogen Innovation Opportunity: Techno-economic Methodology
Apr 2024
Publication
This report outlines the methods and assumptions used in the hydrogen technology market analysis. The results of the analysis are presented in The UK Hydrogen Innovation Opportunity and the supporting report Hydrogen technology roadmaps. They include forecasts for the following market data:
○ Global hydrogen economy The overall size of the global hydrogen economy in 2023 2030 and 2050.
○ Global and UK hydrogen technology market by technology family
This is the proportion of the total future hydrogen economy attributable to hydrogen-related technologies in 2023 2030 and 2050. The hydrogen economy is defined as the ‘end-to-end’ value created from hydrogen production storage & distribution and use. This includes the direct economic value associated with production and distribution of hydrogen as a fuel or chemical feedstock hydrogen infrastructure technologies products services and the indirect economic value created through products and services that indirectly support the use of hydrogen in industry transport power generation and heating. This endto-end definition of the hydrogen economy is represented in Figure 1 overleaf.
This report can also be downloaded for free on the Hydrogen Innovation Initiative website.
○ Global hydrogen economy The overall size of the global hydrogen economy in 2023 2030 and 2050.
○ Global and UK hydrogen technology market by technology family
This is the proportion of the total future hydrogen economy attributable to hydrogen-related technologies in 2023 2030 and 2050. The hydrogen economy is defined as the ‘end-to-end’ value created from hydrogen production storage & distribution and use. This includes the direct economic value associated with production and distribution of hydrogen as a fuel or chemical feedstock hydrogen infrastructure technologies products services and the indirect economic value created through products and services that indirectly support the use of hydrogen in industry transport power generation and heating. This endto-end definition of the hydrogen economy is represented in Figure 1 overleaf.
This report can also be downloaded for free on the Hydrogen Innovation Initiative website.
Enabling Safe and Sustainable Hydrogen Mobility: Circular Economy-Driven Management of Hydrogen Vehicle Safety
Sep 2023
Publication
Hydrogen vehicles encompassing fuel cell electric vehicles (FCEVs) are pivotal within the UK’s energy landscape as it pursues the goal of net-zero emissions by 2050. By markedly diminishing dependence on fossil fuels FCEVs including hydrogen vehicles wield substantial influence in shaping the circular economy (CE). Their impact extends to optimizing resource utilization enabling zero-emission mobility facilitating the integration of renewable energy sources supplying adaptable energy storage solutions and interconnecting diverse sectors. The widespread adoption of hydrogen vehicles accelerates the UK’s transformative journey towards a sustainable CE. However to fully harness the benefits of this transition a robust investigation and implementation of safety measures concerning hydrogen vehicle (HV) use are indispensable. Therefore this study takes a holistic approach integrating quantitative risk assessment (QRA) and an adaptive decision-making trial and evaluation laboratory (DEMATEL) framework as pragmatic instruments. These methodologies ensure both the secure deployment and operational excellence of HVs. The findings underscore that the root causes of HV failures encompass extreme environments material defects fuel cell damage delivery system impairment and storage system deterioration. Furthermore critical driving factors for effective safety intervention revolve around cultivating a safety culture robust education/training and sound maintenance scheduling. Addressing these factors is pivotal for creating an environment conducive to mitigating safety and risk concerns. Given the intricacies of conducting comprehensive hydrogen QRAs due to the absence of specific reliability data this study dedicates attention to rectifying this gap. A sensitivity analysis encompassing a range of values is meticulously conducted to affirm the strength and reliability of our approach. This robust analysis yields precise dependable outcomes. Consequently decision-makers are equipped to discern pivotal underlying factors precipitating potential HV failures. With this discernment they can tailor safety interventions that lay the groundwork for sustainable resilient and secure HV operations. Our study navigates the intersection of HVs safety and sustainability amplifying their importance within the CE paradigm. Using the careful amalgamation of QRA and DEMATEL methodologies we chart a course towards empowering decision-makers with the insights to steer the hydrogen vehicle domain to safer horizons while ushering in an era of transformative eco-conscious mobility.
A New Path towards Sustainable Energy Transition: Techno-Economic Feasibility of a Complete Hybrid Small Modular Reactor/Hydrogen (SMR/H2) Energy System
Oct 2023
Publication
Small modular reactors (SMRs) are nuclear reactors with a smaller capacity than traditional large-scale nuclear reactors offering advantages such as increased safety flexibility and cost-effectiveness. By producing zero carbon emissions SMRs represent an interesting alternative for the decarbonization of power grids. Additionally they present a promising solution for the production of hydrogen by providing large amounts of energy for the electrolysis of water (pink hydrogen). The above hint at the attractiveness of coupling SMRs with hydrogen production and consumption centers in order to form clusters of applications which use hydrogen as a fuel. This work showcases the techno-economic feasibility of the potential installation of an SMR system coupled with hydrogen production the case study being the island of Crete. The overall aim of this approach is the determination of the optimal technical characteristics of such a system as well as the estimation of the potential environmental benefits in terms of reduction of CO2 emissions. The aforementioned system which is also connected to the grid is designed to serve a portion of the electric load of the island while producing enough hydrogen to satisfy the needs of the nearby industries and hotels. The results of this work could provide an alternative sustainable approach on how a hydrogen economy which would interconnect and decarbonize several industrial sectors could be established on the island of Crete. The proposed systems achieve an LCOE between EUR 0.046/kWh and EUR 0.052/kWh while reducing carbon emissions by more than 5 million tons per year in certain cases.
Centralized Offshore Hydrogen Production from Wind Farms in the Baltic Sea Area—A Study Case for Poland
Aug 2023
Publication
In Poland hydrogen production should be carried out using renewable energy sources particularly wind energy (as this is the most efficient zero-emission technology available). According to hydrogen demand in Poland and to ensure stability as well as security of energy supply and also the realization of energy policy for the EU it is necessary to use offshore wind energy for direct hydrogen production. In this study a centralized offshore hydrogen production system in the Baltic Sea area was presented. The goal of our research was to explore the possibility of producing hydrogen using offshore wind energy. After analyzing wind conditions and calculating the capacity of the proposed wind farm a 600 MW offshore hydrogen platform was designed along with a pipeline to transport hydrogen to onshore storage facilities. Taking into account Poland’s Baltic Sea area wind conditions with capacity factor between 45 and 50% and having obtained results with highest monthly average output of 3508.85 t of hydrogen it should be assumed that green hydrogen production will reach profitability most quickly with electricity from offshore wind farms.
Optimal Decarbonization Strategies for an Industrial Port Area by Using Hydrogen as Energy Carrier
Jul 2023
Publication
This article discusses possible strategies for decarbonizing the energy systems of an existing port. The approach consists in creating a complete superstructure that includes the use of renewable and fossil energy sources the import or local production of hydrogen vehicles and other equipment powered by Diesel electricity or hydrogen and the associated refuelling and storage units. Two substructures are then identified one including all these options the other considering also the addition of the energy demand of an adjacent steel industry. The goal is to select from each of these two substructures the most cost-effective configurations for 2030 and 2050 that meet the emission targets for those years under different cost scenarios for the energy sources and conversion/storage units obtained from the most reliable forecasts found in the literature. To this end the minimum total cost of all the energy conversion and storage units plus the associated infrastructures is sought by setting up a Mixed Integer Linear Programming optimization problem where integer variables handle the inclusion of the different generation and storage units and their activation in the operational phases. The comprehensive picture of possible solutions set allows identifying which options can most realistically be realized in the years to come in relation to the different assumed cost scenarios. Optimization results related to the scenario projected to 2030 indicate the key role played by Diesel hybrid and electric systems while considering the most stringent or much more stringent scenarios for emissions in 2050 almost all vehicles energy demand and industry hydrogen demand is met by hydrogen imported as ammonia by ship.
Microwave-enhanced Hydrogen Production: A Review
Apr 2023
Publication
Currently the massive use of fossil fuels which still serve as the dominant global energy has led to the release of large amounts of greenhouse gases. Providing abundant clean and safe renewable energy is one of the major technical challenges for humankind. Nowadays hydrogen-based energy is widely considered a potentially ideal energy carrier that could provide clean energy in the fields of transportation heat and power generation and energy storage systems almost without any impact on the environment after consumption. However a smooth energy transition from fossil-fuel-based energy to hydrogen-based energy must overcome a number of key challenges that require scientific technological and economic support. To accelerate the hydrogen energy transition advanced efficient and cost-effective methods for producing hydrogen from hydrogen-rich materials need to be developed. Therefore in this study a new alternative method based on the use of microwave (MW) heating technology in enhanced hydrogen production pathways from plastic biomass low-carbon alcohols and methane pathways compared with conventional heating methods is discussed. Furthermore the mechanisms of MW heating MW-assisted catalysis and MW plasma are also discussed. MW-assisted technology usually has the advantages of low energy consumption easy operation and good safety practices which make it a promising solution to supporting the future hydrogen society
Green Hydrogen: Resources Consumption, Technological Maturity, and Regulatory Framework
Aug 2023
Publication
Current climate crisis makes the need for reducing carbon emissions more than evident. For this reason renewable energy sources are expected to play a fundamental role. However these sources are not controllable but depend on the weather conditions. Therefore green hydrogen (hydrogen produced from water electrolysis using renewable energies) is emerging as the key energy carrier to solve this problem. Although different properties of hydrogen have been widely studied some key aspects such as the water and energy footprint as well as the technological development and the regulatory framework of green hydrogen in different parts of the world have not been analysed in depth. This work performs a data-driven analysis of these three pillars: water and energy footprint technological maturity and regulatory framework of green hydrogen technology. Results will allow the evaluation of green hydrogen deployment both the current situation and expectations. Regarding the water footprint this is lower than that of other fossil fuels and competitive with other types of hydrogen while the energy footprint is higher than that of other fuels. Additionally results show that technological and regulatory framework for hydrogen is not fully developed and there is a great inequality in green hydrogen legislation in different regions of the world.
Analytical Model of Cryogenic Hydrogen Releases
Sep 2023
Publication
Hydrogen is one of the most promising alternative sources to relieve the energy crisis and environmental pollution. Hydrogen can be stored as cryogenic compressed hydrogen (CcH2) to achieve high volumetric energy densities. Reliable safety codes and standards are needed for hydrogen production delivery and storage to promote hydrogen commercialization. Unintended hydrogen releases from cryogenic storage systems are potential accident scenarios that are of great interest for updating safety codes and standards. This study investigated the behavior of CcH2 releases and dispersion. The extremely low-temperature CcH2 jets can cause condensation of the air components including water vapor nitrogen and oxygen. An integral model considering the condensation effects was developed to predict the CcH2 jet trajectories and concentration distributions. The thermophysical properties were obtained from the COOLPROP database. The model divides the CcH2 jet into the underexpanded initial entrainment and heating flow establishment and established flow zones. The condensation effects on the heat transfer and flow were included in the initial entrainment and heating zones. The empirical coefficients in the integral model were then modified based on measured concentration results. Finally the analytical model predictions are shown to compare well with measured data to verify the model accuracy. The present study can be used to develop quantitative risk assessment models and update safety codes and standards for cryogenic hydrogen facilities.
Renewable Energy Sources for Green Hydrogen Generation in Colombia and Applicable Case of Studies
Nov 2023
Publication
Electrification using renewable energy sources represents a clear path toward solving the current global energy crisis. In Colombia this challenge also involves the diversification of the electrical energy sources to overcome the historical dependence on hydropower. In this context green hydrogen represents a key energy carrier enabling the storage of renewable energy as well as directly powering industrial and transportation sectors. This work explores the realistic potential of the main renewable energy sources including solar photovoltaics (8172 GW) hydropower (56 GW) wind (68 GW) and biomass (14 GW). In addition a case study from abroad is presented demonstrating the feasibility of using each type of renewable energy to generate green hydrogen in the country. At the end an analysis of the most likely regions in the country and paths to deploy green hydrogen projects are presented favoring hydropower in the short term and solar in the long run. By 2050 this energy potential will enable reaching a levelized cost of hydrogen (LCOH) of 1.7 1.5 3.1 and 1.4 USD/kg-H2 for solar photovoltaic wind hydropower and biomass respectively.
Particle Swarm Optimisation for a Hybrid Freight Train Powered by Hydrogen or Ammonia Solid Oxide Fuel Cells
May 2024
Publication
All diesel-only trains in the UK will be phased out by 2040. Hydrogen and ammonia emerge as alternative zerocarbon fuel for greener railway. Solid Oxide Fuel Cells (SOFCs) provide an alternative prime mover option which efficiently convert zero-carbon fuels into electricity without emitting nitrogen oxides (NOx) unlike traditional engines. Superior to Proton Exchange Membrane Fuel Cells (PEMFCs) in efficiency SOFCs fulfil MW-scale power needs and can use ammonia directly. This study investigates innovative strategies for integrating SOFCs into hybrid rail powertrains using hydrogen or ammonia. Utilizing an optimization framework incorporating Particle Swarm Optimization (PSO) the study aims to minimize operational costs while considering capital and replacement expenditures powertrain performance and component sizing. The findings suggest that hybrid powertrains based on ammonia-fueled SOFCs may potentially reduce costs by 30% compared to their hydrogen counterparts albeit requiring additional space for engine compartments. Ammonia-fueled SOFCs trains also exhibit a 5% higher efficiency at End-of-Life (EoL) showing less performance degradation than those powered by hydrogen. The State of Charge (SoC) of the batteries in range of 30–70% for both cases is identified as most costeffective.
Numerical Study of Highly Turbulent Under-expanded Hydrogen Jet Flames Impinging Walls
Sep 2023
Publication
Heat flux on walls from under-expanded H2/AIR jet flames have been numerically investigated. The thermal behaviour of a plate close to different under-expanded jet flames has been compared with rear-face plate temperature measurements. In this study two straight nozzles with millimetric diameter were selected with H2 reservoir pressure in a range from 2 to 10 bar. The CFD study of these two quite different horizontal jet flames employs the Large Eddy Simulation (LES) formalism to capture the turbulent flame-wall interaction. The results demonstrated a good agreement with experimental wall heat fluxes computed from plate temperature measurements. The present study assesses the prediction capability of LES for flame-wall heat transfer.
Hydrogen Revolution in Europe: Bibliometric Review of Industrial Hydrogen Applications for a Sustainable Future
Jul 2024
Publication
Industrial applications of hydrogen are key to the transition towards a sustainable lowcarbon economy. Hydrogen has the potential to decarbonize industrial sectors that currently rely heavily on fossil fuels. Hydrogen with its unique and versatile properties has several in-industrial applications that are fundamental for sustainability and energy efficiency such as the following: (i) chemical industry; (ii) metallurgical sector; (iii) transport; (iv) energy sector; and (v) agrifood sector. The development of a bibliometric analysis of industrial hydrogen applications in Europe is crucial to understand and guide developments in this emerging field. Such an analysis can identify research trends collaborations between institutions and countries and the areas of greatest impact and growth. By examining the scientific literature and comparing it with final hydrogen consumption in different regions of Europe the main actors and technologies that are driving innovation in industrial hydrogen use on the continent can be identified. The results obtained allow for an assessment of the knowledge gaps and technological challenges that need to be addressed to accelerate the uptake of hydrogen in various industrial sectors. This is essential to guide future investments and public policies towards strategic areas that maximize the economic and environmental impact of industrial hydrogen applications in Europe.
From Waste to Energy: Enhancing Fuel and Hydrogen Production through Pyrolysis and In-Line Reforming of Plastic Wastes
Jun 2024
Publication
Plastics have become integral to modern life playing crucial roles in diverse industries such as agriculture electronics automotive packaging and construction. However their excessive use and inadequate management have had adverse environmental impacts posing threats to terrestrial and marine ecosystems. Consequently researchers are increasingly searching for more sustainable ways of managing plastic wastes. Pyrolysis a chemical recycling method holds promise for producing valuable fuel sustainably. This study explores the process of the pyrolysis of plastic and incorporates recent advancements. Additionally the study investigates the integration of reforming into the pyrolysis process to improve hydrogen production. Hydrogen a clean and eco-friendly fuel holds significance in transport engines power generation fuel cells and as a major commodity chemical. Key process parameters influencing the final products for pyrolysis and in-line reforming are evaluated. In light of fossil fuel depletion and climate change the pyrolysis and in-line reforming strategy for hydrogen production is anticipated to gain prominence in the future. Amongst the various strategies studied the pyrolysis and in-line steam reforming process is identified as the most effective method for optimising hydrogen production from plastic wastes.
Optimizing Underground Hydrogen Storage in Aquifers: The Impact of Cushion Gas Type
Aug 2023
Publication
This study investigated the impact of cushion gas type and presence on the performance of underground hydrogen storage (UHS) in an offshore North Sea aquifer. Using numerical simulation the relationship between cushion gas type and UHS performance was comprehensively evaluated providing valuable insights for designing an efficient UHS project delivery. Results indicated that cushion gas type can significantly impact the process's recovery efficiency and hydrogen purity. CO2 was found to have the highest storage capacity while lighter gases like N2 and CH4 exhibited better recovery efficiency. Utilising CH4 as a cushion gas can lead to a higher recovery efficiency of 80%. It was also determined that utilising either of these cushion gases was always more beneficial than hydrogen storage alone leading to an incremental hydrogen recovery up to 7%. Additionally hydrogen purity degraded as each cycle progressed but improved over time. This study contributes to a better understanding of factors affecting UHS performance and can inform the selection of cushion gas type and optimal operational strategies.
Cost of Green Hydrogen
Sep 2024
Publication
Acting in accordance with the requirements of the 2015 Paris Agreement Poland as well as other European Union countries have committed to achieving climate neutrality by 2050. One of the solutions to reduce emissions of harmful substances into the environment is the implementation of large-scale hydrogen technologies. This article presents the cost of producing green hydrogen produced using an alkaline electrolyzer with electricity supplied from a photovoltaic farm. The analysis was performed using the Monte Carlo method and for baseline assumptions including an electricity price of 0.053 EUR/kWh the cost of producing green hydrogen was 5.321 EUR/kgH2 . In addition this article presents a sensitivity analysis showing the impact of the electricity price before and after the energy crisis and other variables on the cost of green hydrogen production. The large change occurring in electricity prices (from 0.035 EUR/kWh to 0.24 EUR/kWh) significantly affected the levelized cost of green hydrogen (LCOH) which could change by up to 14 EUR/kgH2 in recent years. The results of the analysis showed that the parameters that successively have the greatest impact on the cost of green hydrogen production are the operating time of the plant and the unit capital expenditure. The development of green hydrogen production facilities along with the scaling of technology in the future can reduce the cost of its production.
Optimization of Emergency Alternatives for Hydrogen Leakage and Explosion Accidents Based on Improved VIKOR
Nov 2023
Publication
Hydrogen leakage and explosion accidents have obvious dangers ambiguity of accident information and urgency of decision-making time. These characteristics bring challenges to the optimization of emergency alternatives for such accidents. Effective emergency decision making is crucial to mitigating the consequences of accidents and minimizing losses and can provide a vital reference for emergency management in the field of hydrogen energy. An improved VIKOR emergency alternatives optimization method is proposed based on the combination of hesitant triangular fuzzy set (HTFS) and the cumulative prospect theory (CPT) termed the HTFS-CPT-VIKOR method. This method adopts the hesitant triangular fuzzy number to represent the decision information on the alternatives under the influence of multi-attributes constructs alternatives evaluation indicators and solves the indicator weights by using the deviation method. Based on CPT positive and negative ideal points were used as reference points to construct the prospect matrix which then utilized the VIKOR method to optimize the emergency alternatives for hydrogen leakage and explosion accidents. Taking an accident at a hydrogen refueling station as an example the effectiveness and rationality of the HTFS-CPT-VIKOR method were verified by comparing with the existing three methods and conducting parameter sensitivity analysis. Research results show that the HTFS-CPT-VIKOR method effectively captures the limited psychological behavior characteristics of decision makers and enhances their ability to identify filter and judge ambiguous information making the decisionmaking alternatives more in line with the actual environment which provided strong support for the optimization of emergency alternatives for hydrogen leakage and explosion accidents.
Decarbonizing Hard-to-Abate Sectors with Renewable Hydrogen: A Real Case Application to the Ceramics Industry
Jul 2024
Publication
Hydrogen produced from renewable energy sources is a valuable energy carrier for linking growing renewable electricity generation with the hard-to-abate sectors such as cement steel glass chemical and ceramics industries. In this context this paper presents a new model of hydrogen production based on solar photovoltaics and wind energy with application to a real-world ceramics factory. For this task a novel multipurpose profit-maximizing model is implemented using GAMS. The developed model explores hydrogen production with multiple value streams that enable technical and economical informed decisions under specific scenarios. Our results show that it is profitable to sell the hydrogen produced to the gas grid rather than using it for self-consumption for low-gas-price scenarios. On the other hand when the price of gas is significantly high it is more profitable to use as much hydrogen as possible for self-consumption to supply the factory and reduce the internal use of natural gas. The role of electricity self-consumption has proven to be key for the project’s profitability as without this revenue stream the project would not be profitable in any analysed scenario.
Validation of a Hydrogen Jet Fire Model in FDS
Sep 2023
Publication
Hydrogen jet fire occurs with high probability when hydrogen leaks from high-pressure equipment. The hydrogen jet fire is characterized by its high velocity and energy. Computational Fluid Dynamics (CFD) numerical analysis is a prominent way to predict the potential hazards associated with hydrogen jet fire. Validation of the CFD model is essential to ensure and quantify the accuracy of numerical results. This study focuses on the validation of the hydrogen jet fire model using Fire Dynamic Simulation (FDS). Hydrogen release is modeled using high-speed Lagrangian particles released from a virtual nozzle thus avoiding the modeling of the actual nozzle. The mesh size sensitivity analysis of the model is carried out in a container-size domain with 0.04m – 0.08m resolution of the jet. The model is validated by comparing gas temperatures and heat fluxes with test data. The promising results demonstrated that the model could predict the hazardous influence of the jet fire.
Sustainable Energy Solutions: Utilising UGS for Hydrogen Production by Electrolysis
Jul 2024
Publication
Increasing the share of renewable energy sources (RESs) in the energy mix of countries is one of the main objectives of the energy transition in national economies which must be established on circular economy principles. In the natural gas storage in geological structures (UGSs) natural gas is stored in a gas reservoir at high reservoir pressure. During a withdrawal cycle the energy of the stored pressurised gas is irreversibly lost at the reduction station chokes. At the same time there is a huge amount of produced reservoir water which is waste and requires energy for underground disposal. The manuscript explores harnessing the exergy of the conventional UGS reduction process to generate electricity and produce hydrogen via electrolysis using reservoir-produced water. Such a model which utilises sustainable energy sources within a circular economy framework is the optimal approach to achieve a clean energy transition. Using an innovative integrated mathematical model based on real UGS production data the study evaluated the application of a turboexpander (TE) for electricity generation and hydrogen production during a single gas withdrawal cycle. The simulation results showed potential to produce 70 tonnes of hydrogen per UGS withdrawal cycle utilising 700 m3 of produced field water. The analysis showed that hydrogen production was sensitive to gas flow changes through the pressure reduction station underscoring the need for process optimisation to maximise hydrogen production. Furthermore the paper considered the categorisation of this hydrogen as “green” as it was produced from the energy of pressurised gas a carbon-free process.
How do Variations in Ship Operation Impact the Techno-economic Feasibility and Environmental Performance of Fossil-free Fuels? A Life Cycle Study
Aug 2023
Publication
Identifying an obvious non-fossil fuel solution for all ship types for meeting the greenhouse gas reduction target in shipping is challenging. This paper evaluates the technical viability environmental impacts and economic feasibility of different energy carriers for three case vessels of different ship types: a RoPax ferry a tanker and a service vessel. The energy carriers examined include battery-electric and three electro-fuels (hydrogen methanol and ammonia) which are used in combination with engines and fuel cells. Three methods are used: preliminary ship design feasibility life cycle assessment and life cycle costing. The results showed that battery-electric and compressed hydrogen options are not viable for some ships due to insufficient available onboard space for energy storage needed for the vessel's operational range. The global warming reduction potential is shown to depend on the ship type. This reduction potential of assessed options changes also with changes in the carbon intensity of the electricity mix. Life cycle costing results shows that the use of ammonia and methanol in engines has the lowest life cycle cost for all studied case vessels. However the higher energy conversion losses of these systems make them more vulnerable to fluctuations in the price of electricity. Also these options have higher environmental impacts on categories like human toxicity resource use (minerals and metals) and water use. Fuel cells and batteries are not as cost-competitive for the case vessels because of their higher upfront costs and shorter lifetimes. However these alternatives are less expensive than alternatives with internal combustion engines in the case of higher utilization rates and fuel costs.
Competitive Analysis of Heavy Trucks with Five Types of Fuels under Different Scenarios—A Case Study of China
Aug 2024
Publication
As the country that emits the most carbon in the world China needs significant and urgent changes in carbon emission control in the transportation sector in order to achieve the goals of reaching peak carbon emissions before 2030 and achieving carbon neutrality by 2060. Therefore the promotion of new energy vehicles has become the key factor to achieve these two objectives. For the reason that the comprehensive transportation cost directly affects the end customer’s choice of heavy truck models this work compares the advantages disadvantages and economic feasibility of diesel liquefied natural gas (LNG) electric hydrogen and methanol heavy trucks from a total life cycle cost and end-user perspective under various scenarios. The study results show that when the prices of diesel LNG electricity and methanol fuels are at their highest and the price of hydrogen is 35 CNY/kg the total life cycle cost of the five types of heavy trucks from highest to lowest are hydrogen heavy trucks (HHT) methanol heavy trucks (MHT) diesel heavy trucks (DHT) electric heavy trucks (EHT) and LNG heavy trucks (LNGHT) ignoring the adverse effects of cold environments on car batteries. When the prices of diesel LNG electricity and methanol fuels are at average or lowest levels and the price of hydrogen is 30 CNY/kg or 25 CNY/kg the life cycle cost of the five heavy trucks from highest to lowest are HHT DHT MHT EHT and LNGHT. When considering the impact of cold environments even with lower electricity prices EHT struggle to be economical when LNG prices are low. If the electricity price is above 1 CNY/kWh regardless of the impact of cold environments the economic viability of EHT is lower than that of HHT with a purchase cost of 500000 CNY and a hydrogen price of 25 CNY/kg. Simultaneously an exhaustive competitiveness analysis of heavy trucks powered by diverse energy sources highlights the specific categories of heavy trucks that ought to be prioritized for development during various periods and the challenges they confront. Finally based on the analysis results and future development trends the corresponding policy recommendations are proposed to facilitate high decarbonization in the transportation sector.
Current and Future Role of Natural Gas Supply Chains in the Transition to a Low-Carbon Hydrogen Economy: A Comprehensive Review on Integrated Natural Gas Supply Chain Optimisation Models
Nov 2023
Publication
Natural gas is the most growing fossil fuel due to its environmental advantages. For the economical transportation of natural gas to distant markets physical (i.e. liquefaction and compression) or chemical (i.e. direct and indirect) monetisation options must be considered to reduce volume and meet the demand of different markets. Planning natural gas supply chains is a complex problem in today’s turbulent markets especially considering the uncertainties associated with final market demand and competition with emerging renewable and hydrogen energies. This review study evaluates the latest research on mathematical programming (i.e. MILP and MINLP) as a decisionmaking tool for designing and planning natural gas supply chains under different planning horizons. The first part of this study assesses the status of existing natural gas infrastructures by addressing readily available natural monetisation options quantitative tools for selecting monetisation options and single-state and multistate natural gas supply chain optimisation models. The second part investigates hydrogen as a potential energy carrier for integration with natural gas supply chains carbon capture utilisation and storage technologies. This integration is foreseen to decarbonise systems diversify the product portfolio and fill the gap between current supply chains and the future market need of cleaner energy commodities. Since natural gas markets are turbulent and hydrogen energy has the potential to replace fossil fuels in the future addressing stochastic conditions and demand uncertainty is vital to hedge against risks through designing a responsive supply chain in the project’s early design stages. Hence hydrogen supply chain optimisation studies and the latest works on hydrogen–natural gas supply chain optimisation were reviewed under deterministic and stochastic conditions. Only quantitative mathematical models for supply chain optimisation including linear and nonlinear programming models were considered in this study to evaluate the effectiveness of each proposed approach.
The Technical and Economic Aspects of Integrating Energy Sectors for Climate Neutrality
Sep 2024
Publication
With the development of an energy sector based on renewable primary sources structural changes are emerging for the entire national energy system. Initially it was estimated that energy generation based on fossil fuels would decrease until its disappearance. However the evolution of CO2 capture capacity leads to a possible coexistence for a certain period with the renewable energy sector. The paper develops this concept of the coexistence of the two systems with the positioning of green hydrogen not only within the renewable energy sector but also as a transformation vector for carbon dioxide captured in the form of synthetic fuels such as CH4 and CH3OH. The authors conducted pilot-scale research on CO2 capture with green H2 both for pure (captured) CO2 and for CO2 found in combustion gases. The positive results led to the respective recommendation. The research conducted by the authors meets the strict requirements of the current energy phase with the authors considering that wind and solar energy alone are not sufficient to meet current energy demand. The paper also analyzes the economic aspects related to price differences for energy produced in the two sectors as well as their interconnection. The technical aspect as well as the economic aspect of storage through various other solutions besides hydrogen has been highlighted. The development of the renewable energy sector and its demarcation from the fossil fuel energy sector even with the transcendent vector represented by green hydrogen leads to the deepening of dispersion aspects between the electricity sector and the thermal energy sector a less commonly mentioned aspect in current works but of great importance. The purpose of this paper is to highlight energy challenges during the current transition period towards climate neutrality along with solutions proposed by the authors to be implemented in this phase. The current stage of combustion of the CH4 − H2 mixture imposes requirements for the capture of the resulting CO2.
The Race Between Hydrogen and Heat Pumps for Space and Water Heating: A Model-based Scenario Analysis
Nov 2023
Publication
This paper analyses different levels and means of the electrification of space and hot water heating using an explorative modelling approach. The analysis provides guidance to the ongoing discussion on favourable pathways for heating buildings and the role of secondary energy carriers such as hydrogen or synthetic fuels. In total 12 different scenarios were modelled with decarbonisation pathways until 2050 which cover all 27 member states of the European Union. Two highly detailed optimisation models were combined to cover the building stock and the upstream energy supply sector. The analysis shows that decarbonisation pathways for space and water heating based on large shares of heat pumps have at least 11% lower system costs in 2050 than pathways with large shares of hydrogen or synthetic fuels. This translates into system cost savings of around €70 bn. Heat pumps are cost-efficient in decentralised systems and in centralised district heating systems. Hence heat pumps should be the favoured option to achieve a cost-optimal solution for heating buildings. Accordingly the paper makes a novel and significant contribution to understanding suitable and cost-efficient decarbonisation pathways for space and hot water heating via electrification. The results of the paper can provide robust guidance for policymakers.
Techno-Economic Feasibility of Fuel Cell Vehicle-to-Grid Fast Frequency Control in Non-Interconnected Islands
Dec 2024
Publication
This paper presents an innovative approach to fast frequency control in electric grids by leveraging parked fuel cell electric vehicles (FCEVs) especially heavy-duty vehicles such as trucks. Equipped with hydrogen storage tanks and fuel cells these vehicles can be repurposed as dynamic grid-support assets while parked in designated areas. Using an external cable and inverter system FCEVs inject power into the grid by converting DC from fuel cells into AC to be compatible with grid requirements. This functionality addresses sudden power imbalances providing a rapid and efficient solution for frequency stabilization. The system’s external inverter serves as a central control hub monitoring real-time grid frequency and directing FCEVs to supply virtual inertia and primary reserves through droop control as required. Simulation results validate that FCEVs could effectively complement thermal generators preventing unacceptable frequency drops load shedding and network blackouts. A techno-economic analysis demonstrates the economic feasibility of the concept concluding that each FCEV consumes approximately 0.3 kg of hydrogen per day incurring a daily cost of around EUR 1.5. For an island grid with a nominal power of 100 MW maintaining frequency stability requires a fleet of 100 FCEVs resulting in a total daily cost of EUR 150. Compared to a grid-scale battery system offering equivalent frequency response services the proposed solution is up to three times more cost-effective highlighting its economic and technical potential for grid stabilization in renewable-rich non-interconnected power systems.
Techno-Economic Analysis of Combined Production of Wind Energy and Green Hydrogen on the Northern Coast of Mauritania
Sep 2024
Publication
Green hydrogen is becoming increasingly popular with academics institutions and governments concentrating on its development efficiency improvement and cost reduction. The objective of the Ministry of Petroleum Mines and Energy is to achieve a 35% proportion of renewable energy in the overall energy composition by the year 2030 followed by a 50% commitment by 2050. This goal will be achieved through the implementation of feed-in tariffs and the integration of independent power generators. The present study focused on the economic feasibility of green hydrogen and its production process utilizing renewable energy resources on the northern coast of Mauritania. The current investigation also explored the wind potential along the northern coast of Mauritania spanning over 600 km between Nouakchott and Nouadhibou. Wind data from masts Lidar stations and satellites at 10 and 80 m heights from 2022 to 2023 were used to assess wind characteristics and evaluate five turbine types for local conditions. A comprehensive techno-economic analysis was carried out at five specific sites encompassing the measures of levelized cost of electricity (LCOE) and levelized cost of green hydrogen (LCOGH) as well as sensitivity analysis and economic performance indicators. The results showed an annual average wind speed of 7.6 m/s in Nouakchott to 9.8 m/s in Nouadhibou at 80 m. The GOLDWIND 3.0 MW model showed the highest capacity factor of 50.81% due to its low cut-in speed of 2.5 m/s and its rated wind speed of 10.5 to 11 m/s. The NORDEX 4 MW model forecasted an annual production of 21.97 GWh in Nouadhibou and 19.23 GWh in Boulanoir with the LCOE ranging from USD 5.69 to 6.51 cents/kWh below the local electricity tariff and an LCOGH of USD 1.85 to 2.11 US/kg H2 . Multiple economic indicators confirmed the feasibility of wind energy and green hydrogen projects in assessed sites. These results boosted the confidence of the techno-economic model highlighting the resilience of future investments in these sustainable energy infrastructures. Mauritania’s north coast has potential for wind energy aiding green hydrogen production for energy goals.
Optimizing the Operational Efficiency of the Underground Hydrogen Storage Scheme in a Deep North Sea Aquifer through Compositional Simulations
Aug 2023
Publication
In this study we evaluate the technical viability of storing hydrogen in a deep UKCS aquifer formation through a series of numerical simulations utilising the compositional simulator CMG-GEM. Effects of various operational parameters such as injection and production rates number and length of storage cycles and shut-in periods on the performance of the underground hydrogen storage (UHS) process are investigated in this study. Results indicate that higher H2 operational rates degrade both the aquifer's working capacity and H2 recovery during the withdrawal phase. This can be attributed to the dominant viscous forces at higher rates which lead to H2 viscous fingering and gas gravity override of the native aquifer water resulting in an unstable displacement of water by the H2 gas. Furthermore analysis of simulation results shows that longer and less frequent storage cycles lead to higher storage capacity and decreased H2 retrieval. We conclude that UHS in the studied aquifer is technically feasible however a thorough evaluation of the operational parameters is necessary to optimise both storage capacity and H2 recovery efficiency.
Development of a Reliable Simulation Framework for Techno-economic Analyses on Green Hydrogen Production from Wind Farms using Alkaline Electrolyzers
Mar 2024
Publication
The present study investigates the feasibility of coupling the intermittent electric power generation from a wind farm with alkaline electrolyzers to produce green hydrogen. A physically accurate model of commercial elec trolytic modules has been first developed accounting for conversion efficiency drop due to modules’ cool down effects of shutdowns due to the intermittence of wind power and voltage degradation over the working time frame. The model has been calibrated on real modules for which industrial data were available. Three com mercial module sizes have been considered i.e. 1 2 and 4 MW. As a second step the model has been coupled with historical power datasets coming from a real wind farm characterized by a nominal installed power of 13.8 MW. Finally the model was implemented within a sizing algorithm to find the best combination between the actual wind farm power output and the electrolyzer capacity to reach the lowest Levelized Cost Of Hydrogen (LCOH) possible. To this end realistic data for the capital cost of the whole system (wind farm and electrolyzers) have been considered based on industrial data and market reports as well as maintenance costs including both periodic replacements of degraded components and periodic maintenance. Simulations showed that if the right sizing of the two systems is made competitive hydrogen production costs can be achieved even with current technologies. Bigger modules are less flexible but by now considerably cheaper than smaller ones. A future economy of scale in alkaline electrolyzers is then needed to foster the diffusion of the technology.
Strategic Overview on Fuel Cell-Based Systems for Mobility and Electrolytic Cells for Hydrogen Production
Mar 2022
Publication
Given the global effort to embrace research actions and technology enhancement for the energy transition innovative sustainable systems are needed both for energy production and for those sectors that are responsible for high pollution and CO2 emissions. In this context electrolytic cells and fuel cells in their variety and flexibility are energy systems characterized by high efficiency and important performance guaranteeing a sustainable solution for future energy systems and for the circular economy. The scope of this paper is therefore to present the state of the art of such systems. An overview of the electrolyzers for hydrogen production is presented by detailing the level of applications for their different technologies from low-temperature units to high-temperature units the fuel flexibility the electrolysis and co-electrolysis mode and the potential coupling with renewable sources. Fuel cell-based systems are also presented and their application in the mobility sector is investigated by considering road transport with light-duty and heavy-duty applications and marine transport. A comparison with conventional technologies will be also presented providing some hints on the potential applications of electrolytic cells and fuel cell systems given their important contribution to the sustainable and circular economy.
Addressing Environmental Challenges: The Role of Hydrogen Technologies in a Sustainable Future
Dec 2023
Publication
Energy and environmental issues are of great importance in the present era. The transition to renewable energy sources necessitates technological political and behavioral transformations. Hydrogen is a promising solution and many countries are investing in the hydrogen economy. Global demand for hydrogen is expected to reach 120 million tonnes by 2024. The incorporation of hydrogen for efficient energy transport and storage and its integration into the transport sector are crucial measures. However to fully develop a hydrogen-based economy the sustainability and safety of hydrogen in all its applications must be ensured. This work describes and compares different technologies for hydrogen production storage and utilization (especially in fuel cell applications) with focus on the research activities under study at SaRAH group of the University of Naples Federico II. More precisely the focus is on the production of hydrogen from bio-alcohols and its storage in formate solutions produced from renewable sources such as biomass or carbon dioxide. In addition the use of materials inspired by nature including biowaste as feedstock to produce porous electrodes for fuel cell applications is presented. We hope that this review can be useful to stimulate more focused and fruitful research in this area and that it can open new avenues for the development of sustainable hydrogen technologies.
Social Life Cycle Assessment of Green Hydrogen Production: Evaluating a Projected Portuguese Industrial Production Plant
Sep 2024
Publication
The increase in industrial production and energy consumption has led to excessive exploitation of non-renewable resources resulting in serious environmental problems such as greenhouse gas emissions. In response there’s a growing investment in renewable energies such as hydroelectric wind and solar power. However these sources are unable to fully meet demand leading to imbalances between consumption and production. An emerging solution to this challenge is green hydrogen produced from clean sources reducing dependence on fossil fuels and mitigating greenhouse gas emissions. The S-LCA methodology presented in the UNEP/SETAC Guidelines for the Social Life Cycle Assessment is applied to the production of green hydrogen via the electrolytic separation of water using a proton exchange electrolyser. The process involves the extraction and processing of raw materials from the electrolyser BOP and reverse osmosis system the manufacture of the systems and the production of green hydrogen. The data from each stage is inventoried and entered into the PSILCA v.3.1 and SHDB 2022FV5 databases integrated into the SimaPro software version 9.3.0.2 enabling a complete analysis of the social im pacts associated with the production of green hydrogen. The data was evaluated considering 4 stakeholder categories: workers value chain actors society and local community. The results indicate that the extraction and processing of raw materials for the electrolyser was the primary stage responsible for the social impacts in both databases. However the electrolyser manufacturing stage was the main contributor to the indicators “weekly working hours per employee” and “union density” in the PSILCA database. Nafion® and Iridium were identified as the major contributors among components in both databases. The study highlights the significant role played by countries like China and South Africa in social impacts particularly in the extraction and processing of raw materials. Despite this Portugal emerged as the largest contributor to five out of fourteen indicators in the PSILCA database while its contributions in the SHDB database were less than 7 %. Moreover a comparison between the two databases revealed that PSILCA exhibited a greater distribution of results across various stages components and countries assessed whereas SHDB showed more centralized results. The observed discrepancies between the results obtained from different databases can be attributed to three main factors: the input-output database utilized in each S-LCA tool the assumed risk levels for each indicator and the equivalence between indicators and subcategories. This exploratory study offers valuable insights for guiding strategic decisions regarding the social component of sustainability providing a detailed understanding of the social impacts associated with the specific case of green hydrogen production in a planned hub in Portugal.
Methods for Enhancing Electrolysis for Hydrogen Production: The Benefits of Applying Magnetic Fields
Sep 2024
Publication
The electrolysis of water is one of the most promising ways of producing green hydrogen. This produces hydrogen using electricity and does not generate additional carbon dioxide like the more conventional reforming of fossil fuels. However making electrolysis competitive with conventional methods for hydrogen production is a challenge because of the cost of electricity and because of inefficiencies and costs in electrolysis systems. Initially this review looks at the basic design of water electrolysis and asks where energy is lost. Then a selection of the latest results in the area of magnetic field-enhanced water electrolysis are examined and discussed in particular focusing on the empirical results of magnetic field-assisted electrolysis with the aim of comparing findings and identifying limitations of current studies such that recommendations can be made for advanced design of hydrogen producing electrolysis systems.
Safety Risk and Strategy Analysis of On-Board Hydrogen System of Hydrogen Fuel Cell Vehicles in China
Nov 2023
Publication
Hydrogen fuel cell vehicles (HFCVs) represent an important breakthrough in the hydrogen energy industry. The safe utilization of hydrogen is critical for the sustainable and healthy development of hydrogen fuel cell vehicles. In this study risk factors and preventive measures are proposed for on-board hydrogen systems during the process of transportation storage and use of fuel cell vehicles. The relevant hydrogen safety standards in China are also analyzed and suggestions involving four safety strategies and three safety standards are proposed.
Implementation of a Decision-making Approach for a Hydrogen-based Multi-energy System Considering EVs and FCEVs Availability
Aug 2024
Publication
Innovative green vehicle concepts have become increasingly prevailing in consumer purchasing habits as technology evolves. The global transition towards sustainable transportation indicates an increase in new-generation vehicles including both fuel-cell electric vehicles (FCEVs) and plug-in electric vehicles (PEVs) that will take on roads in the future. This change requires new-generation stations to support electrification. This study introduced a prominent multi-energy system concept with a hydrogen refueling station. The proposed multi-energy system (MES) consists of green hydrogen production a hydrogen refueling station for FCEVs hydrogen injection into natural gas (NG) and a charging station for PEVs. An on-site renewable system projected at the station and a polymer electrolyte membrane electrolyzer (PEM) to produce hydrogen for two significant consumers support MES. In addition the MES offers the ability to conduct two-way trade with the grid if renewable energy systems are insufficient. This study develops a comprehensive multi-energy system with an economically optimized energy management model using a mixed-integer linear programming (MILP) approach. The determinative datasets of vehicles are generated in a Python environment using Gauss distribution. The fleet of FCEVs and PEVs are currently available on the market. The study includes fleets of the most common models from well-known brands. The results indicate that profits increase when the storage capacity of the hydrogen tank is higher and natural gas injections are limitless. Optimization results for all cases tend to choose higher-priced natural gas injections over hydrogen refueling because of the difference in costs of refueling and injection expenses. The analyses reveal the highest hydrogen sales to the natural gas (NG) grid by consuming 2214.31 kg generating a revenue of $6966 and in contrast the lowest hydrogen sales to the natural gas grid at 1045.38 kg resulting in a revenue of $3286. Regarding electricity the highest sales represent revenue of $7701 and $2375 for distribution system consumption and electric vehicles (EV) respectively. Conversely Cases 1 and 2 have achieved sales to EV of $2286 and $2349 respectively but do not have any sales to distribution system consumption regarding the constraints. Overall the optimization results show that the solution is optimal for a multi-energy system operator to achieve higher profits and that all end-user parties are satisfied.
Spillovers Between Hydrogen, Nuclear and AI Sectors: The Impact of Climate Policy Uncertainty and Geopolitical Risks
Mar 2025
Publication
This study investigates the spillover effects between hydrogen energy nuclear energy and artificial intelligence (AI) sectors in the context of the global clean energy transition with a particular focus on the impact of climate policy uncertainty (CPU) and geopolitical risks (GPR). Employing the TVP-VAR extended joint connectedness approach the findings show a high connectedness that indicates significant spillovers among these sectors. Hydrogen energy emerges as a dominant transmitter of shocks reflecting its sensitivity to regulatory changes and fluctuating demand. However nuclear energy acts as a stabilising force that offers hedging opportunities and resilience against market turbulence. The AI sector exhibits strong connectedness primarily as a net receiver of shocks driven by its dependency on clean energy sources and vulnerability to energy market volatility. Using the GARCHMIDAS framework the study identifies a temporal asymmetry in market responses to CPU and GPR. CPU triggers immediate but short-lived disruptions while GPR induces delayed yet persistent effects that intensify cross-sector spillovers over time. These results underline the vulnerabilities of sectors reliant on regulatory clarity and geopolitical stability. This study provides practical insights for investors policymakers technology and energy companies to better manage systemic risks at the crossroads of clean energy technological innovation and uncertainty.
Techno-economic Analysis of Wind-powered Green Hydrogen Production to Facilitate the Decarbonization of Hard-to-abate Sectors: A Case Study on Steelmaking
Apr 2023
Publication
Green hydrogen is among the most promising energy vectors that may enable the decarbonization of our society. The present study addresses the decarbonization of hard-to-abate sectors via the deployment of sustainable alternatives to current technologies and processes where the complete replacement of fossil fuels is deemed not nearly immediate. In particular the investigated case study tackles the emission reduction potential of steelmaking in the Italian industrial framework via the implementation of dedicated green hydrogen production systems to feed Hydrogen Direct Reduction process the main alternative to the traditional polluting routes towards emissions abatement. Green hydrogen is produced via the coupling of an onshore wind farm with lithium-ion batteries alkaline type electrolyzers and the interaction with the electricity grid. Building on a power generation dataset from a real utility-scale wind farm techno-economic analyses are carried out for a large number of system configurations varying components size and layout to assess its performance on the basis of two main key parameters the levelized cost of hydrogen (LCOH) and the Green Index (GI) the latter presented for the first time in this study. The optimal system design and operation logics are investigated accounting for the necessity of providing a constant mass flow rate of H2 and thus considering the interaction with the electricity network instead of relying solely on RES surplus. In-house-developed models that account for performances degradation over time of different technologies are adapted and used for the case study. The effect of different storage technologies is evaluated via a sensitivity analysis on different components and electricity pricing strategy to understand how to favour green hydrogen penetration in the heavy industry. Furthermore for a better comprehension and contextualization of the proposed solutions their emission-reduction potential is quantified and presented in comparison with the current scenario of EU-27 countries. In the optimal case the emission intensity related to the steel making process can be lowered to 235 kg of CO2 per ton of output steel 88 % less than the traditional route. A higher cost of the process must be accounted resulting in an LCOH of such solutions around 6.5 €/kg.
Hydrogen Refueling Stations: A Review of the Technology Involved from Key Energy Consumption Processes to Related Energy Management Strategies
Sep 2024
Publication
Over the last few years hydrogen has emerged as a promising solution for problems related to energy sources and pollution concerns. The integration of hydrogen in the transport sector is one of the possible various applications and involves the implementation of hydrogen refueling stations (HRSs). A key obstacle for HRS deployment in addition to the need for well-developed technologies is the economic factor since these infrastructures require high capital investments costs and are largely dependent on annual operating costs. In this study we review hydrogen’s application as a fuel summarizing the principal systems involved in HRS from production to the final refueling stage. In addition we also analyze the main equipment involved in the production compression and storage processes of hydrogen. The current work also highlights the main refueling processes that impact energy consumption and the methodologies presented in the literature for energy management strategies in HRSs. With the aim of reducing energy costs due to processes that require high energy consumption most energy management strategies are based on the use of renewable energy sources in addition to the use of the power grid.
Water Vapour Condensation within Hydrogen-Blended Natural Gas in Laval Nozzles
Mar 2025
Publication
Hydrogen-blended natural gas (NG) pipeline network transport is the most effective approach for solving the problem of large-scale hydrogen use. Hydrogen-blended NG that contains water vapour is prone to water vapour condensation when it passes through complex NG pipeline networks leading to pipeline network failures. To analyse the condensation behaviour of hydrogenblended NG containing water vapour in a Laval nozzle a condensation model of water vapour was established. A computational fluid dynamics approach was used to calculate the condensation process of hydrogen-blended NG containing water vapour in Laval nozzles for four countries: Iran USA Russia and Australia. Hydrogen-blended NG components affect the flow characteristics of the gas mixture in the nozzle. The gas components have the greatest effect on the Mach number. The difference between the maximum and minimum Mach numbers at the outlet was 0.02 Mach. Hydrogen-blended NG containing water vapour condenses downstream of the throat of the Laval nozzle. Hydrogen-blended NG from Russia had the largest condensation ratio (79.63%). The largest droplet radius and liquid mass fraction were observed in the hydrogen-blended NG from Australia. The condensation process can accelerate the future research and engineering application of water vapour into hydrogen-blended NG.
Artificial Intelligence-Driven Innovations in Hydrogen Safety
Jun 2024
Publication
This review explores recent advancements in hydrogen gas (H2 ) safety through the lens of artificial intelligence (AI) techniques. As hydrogen gains prominence as a clean energy source ensuring its safe handling becomes paramount. The paper critically evaluates the implementation of AI methodologies including artificial neural networks (ANN) machine learning algorithms computer vision (CV) and data fusion techniques in enhancing hydrogen safety measures. By examining the integration of wireless sensor networks and AI for real-time monitoring and leveraging CV for interpreting visual indicators related to hydrogen leakage issues this review highlights the transformative potential of AI in revolutionizing safety frameworks. Moreover it addresses key challenges such as the scarcity of standardized datasets the optimization of AI models for diverse environmental conditions etc. while also identifying opportunities for further research and development. This review foresees faster response times reduced false alarms and overall improved safety for hydrogen-related applications. This paper serves as a valuable resource for researchers engineers and practitioners seeking to leverage state-of-the-art AI technologies for enhanced hydrogen safety systems.
Hierarchical Model Predictive Control for Islanded and Grid-connected Microgrids with Wind Generation and Hydrogen Energy Storage Systems
Aug 2023
Publication
This paper presents a novel energy management strategy (EMS) to control a wind-hydrogen microgrid which includes a wind turbine paired with a hydrogen-based energy storage system (HESS) i.e. hydrogen production storage and re-electrification facilities and a local load. This complies with the mini-grid use case as per the IEA-HIA Task 24 Final Report where three different use cases and configurations of wind farms paired with HESS are proposed in order to promote the integration of wind energy into the grid. Hydrogen production surpluses by wind generation are stored and used to provide a demand-side management solution for energy supply to the local and contractual loads both in the grid-islanded and connected modes with corresponding different control objectives. The EMS is based on a hierarchical model predictive control (MPC) in which long-term and short-term operations are addressed. The long-term operations are managed by a high-level MPC in which power production by wind generation and load demand forecasts are considered in combination with day-ahead market participation. Accordingly the hydrogen production and re-electrification are scheduled so as to jointly track the load demand maximize the revenue through electricity market participation and minimize the HESS operating costs. Instead the management of the short-term operations is entrusted to a low-level MPC which compensates for any deviations of the actual conditions from the forecasts and refines the power production so as to address the real-time market participation and the short time-scale equipment dynamics and constraints. Both levels also take into account operation requirements and devices’ operating ranges through appropriate constraints. The mathematical modeling relies on the mixed-logic dynamic (MLD) framework so that the various logic states and corresponding continuous dynamics of the HESS are considered. This results in a mixed-integer linear program which is solved numerically. The effectiveness of the controller is analyzed by simulations which are carried out using wind forecasts and spot prices of a wind farm in center-south of Italy.
The Environmental Impacts of Future Global Sales of Hydrogen Fuel Cell Vehicles
Oct 2024
Publication
During the last decade developing more sustainable transportation modes has become a primary objective for car manufacturers and governments around the world to mitigate environmental issues such as climate change the continuous increase in greenhouse gas (GHG) emissions and energy depletion. The use of hydrogen fuel cell technology as a source of energy in electric vehicles is considered an emerging and promising technology that could contribute significantly to addressing these environmental issues. In this study the effects of Hydrogen Fuel Cell Battery Electric Vehicles (HFCBEVs) on global GHG emissions compared to other technologies such as BEVs were determined based on different relevant factors such as predicted sales for 2050 (the result of the developed prediction model) estimated daily traveling distance estimated future average global electricity emission factors future average Battery Electric Vehicle (BEV) emission factors future global hydrogen production emission factors and future average HFCBEV emission factors. As a result the annual GHG emissions produced by passenger cars that are expected to be sold in 2050 were determined by considering BEV sales in the first scenario and HFCBEV replacement in the second scenario. The results indicate that the environmental benefits of HFCBEVs are expected to increase over time compared to those of BEVs due to the eco-friendly methods that are expected to be used in hydrogen production in the future. For instance in 2021 HFCBEVs could produce more GHG emissions than BEVs by 54.9% per km of travel whereas in 2050 BEVs could produce more GHG emissions than HFCBEVs by 225% per km of travel.
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