Publications

The increasing demand for renewable energy sources (RES) to address environmental concerns and reduce fossil fuel dependency highlights the need for efficient energy storage and balancing mechanisms to manage RES output uncertainty. However providing dedicated storage units to RES owners is often infeasible. Additionally the growing interest in hydrogen utilization complicates optimal decision-making for multi-energy systems. To tackle these challenges this paper presents a novel bidding strategy enabling wind farms to participate in dayahead balancing and hydrogen markets through shared multi-energy storage (SMES) systems. These SMES which include both battery and hydrogen storage offer a cost-effective solution by allowing RES owners to rent storage capacity. By optimizing SMES utilization and wind farm management we propose an integrated strategy for day-ahead electrical and real-time balancing markets and also hydrogen markets. The approach incorporates with uncertainties of wind generation bidding by using conditional value at risk (CVaR) to account for different risk-aversion levels. The Dantzig–Wolfe Decomposition (DWD) method is applied to decentralize the problem reduce the calculation burden and enhance the data privacy. The framework is modeled as a mixed-integer linear program (MILP) and solved using CPLEX solver via GAMS software. The results demonstrate the effectiveness of this strategy offering insights into the risk-oriented market participation of wind power plants with the aid of SMES system supporting a more sustainable and resilient energy system. The numerical results show that by utilizing a SMES with only batteries the revenue can be increased by 17.3% and equipping the SMES with hydrogen storage and participating in both markets leads to 36.9% increment in the revenue of the wind power plant.

The design of an efficient techno-economic autonomous fuel cell hybrid electric vehicle(FCHEV) is a crucial challenge. This paper investigates the design of a near optimal PI controller for an automated FCHEV where autonomy is expressed as efficient and robust tracking of a given reference speed trajectory without driver’s intervention. An impartial comparison is introduced to illustrate the effectiveness of the proposed metaheuristic-based optimal controllers in enhancing the system dynamic performance. The comprehensive optimization performance indicator is considered as a function of the vehicle dynamic characteristics while determining the optimal controller gains. In this paper the proposed effective up-to-date metaheuristic techniques are the grey wolf optimization (GWO) as well as the artificial bee colony (ABC). Using MATLAB TM /Simulink numerical simulations clearly illustrate the efficiency of near-optimal gains in the optimized tuning methodologies and the fixed manual one in realizing adequate velocity tracking. The simulation results demonstrate the superiority of both ABC and GWO rather than the manual controller for driving cycles of high acceleration and deceleration levels. In absence of these latter the manual defined gain controller is considered sufficient. Through a comprehensive sensitivity analysis the robustness of both metaheuristic-based controllers is verified under diverse driving cycles of different operation features and nature. Despite GWO results in better dynamic characteristics the ABC provides more economical feature with about 1.5% compared to manual system in extra urban driving cycle. However manual-controller has the minimum fuel cost under the United States driving cycle developed by the environmental protection agency as a New York city cycle(US EPA NYCC) and urban driving cycle (ECE). Ecologically electric vehicles have an environmentally friendly effect especially when driven with green hydrogen. Autonomous vehicles involving velocity control systems would raise car share and provide more comfort.

Hydrogen and ammonia are primary carbon-free fuels that have massive production potential. In regard to their flame properties these two fuels largely represent the two extremes among all fuels. The extremely fast flame speed of hydrogen can lead to an easy deflagration-to-detonation transition and cause detonation-type engine knock that limits the global equivalence ratio and consequently the engine power. The very low flame speed and reactivity of ammonia can lead to a low heat release rate and cause difficulty in ignition and ammonia slip. Adding ammonia into hydrogen can effectively modulate flame speed and hence the heat release rate which in turn mitigates engine knock and retains the zero-carbon nature of the system. However a key issue that remains unclear is the blending ratio of NH3 that provides the desired heat release rate emission level and engine power. In the present work a 3D computational combustion study is conducted to search for the optimal hydrogen/ammonia mixture that is knock-free and meanwhile allows sufficient power in a typical spark-ignition engine configuration. Parametric studies with varying global equivalence ratios and hydrogen/ammonia blends are conducted. The results show that with added ammonia engine knock can be avoided even under stoichiometric operating conditions. Due to the increased global equivalence ratio and added ammonia the energy content of trapped charge as well as work output per cycle is increased. About 90% of the work output of a pure gasoline engine under the same conditions can be reached by hydrogen/ammonia blends. The work shows great potential of blended fuel or hydrogen/ammonia dual fuel in high-speed SI engines.

In this paper a computational fluid dynamics (CFD) model was established and verified on the basis of experimental results and then the effect of hydrogenation addition on combustion and emission characteristics of a diesel–hydrogen dual-fuel engine fueled with hydrogenation addition (0% 5% and 10%) under different hydrogenation energy shares (HESs) and compression ratios (CRs) were investigated using CONVERGE3.0 software. And this work assumed that the hydrogen and air were premixed uniformly. The correctness of the simulation model was verified by experimental data. The values of HES are in the range of 0% 5% 10% and 15%. And the values of CR are in the range of 14 16 18 and 20. The results of this study showed that the addition of hydrogen to diesel fuel has a significant effect on the combustion characteristics and the emission characteristics of diesel engines. When the HES was 15% the in-cylinder pressure increased by 10.54%. The in-cylinder temperature increased by 15.11%. When the CR was 20 the in-cylinder pressure and the in-cylinder temperature increased by 66.10% and 13.09% respectively. In all cases HC CO CO2 and soot emissions decreased as the HES increased. But NOx emission increased.

The growing awareness about climate change and environmental pollution is pushing the industrial and academic world to investigate more sustainable solutions to reduce the impact of anthropic activities. As a consequence a process of electrification is involving all kind of vehicles with a view to gradually substitute traditional powertrains that emit several pollutants in the exhaust due to the combustion process. In this context fuel cell powertrains are a more promising strategy with respect to battery electric alternatives where productivity and endurance are crucial. It is important to replace internal combustion engines in those vehicles such as the those in the sector of NonRoad Mobile Machinery. In the present paper a preliminary analysis of a fuel cell powertrain for a telehandler is proposed. The analysis focused on performance fuel economy durability applicability and environmental impact of the vehicle. Numerical models were built in MATLAB/Simulink and a simple power follower strategy was developed with the aim of reducing components degradation and to guarantee a charge sustaining operation. Simulations were carried out regarding both peak power conditions and a typical real work scenario. The simulations’ results showed that the fuel cell powertrain was able to achieve almost the same performances without excessive stress on its components. Indeed a degradation analysis was conducted showing that the fuel cell system can achieve satisfactory durability. Moreover a Well-to-Wheel approach was adopted to evaluate the benefits in terms of greenhouse gases of adopting the fuel cell system. The results of the analysis demonstrated that even if considering grey hydrogen to feed the fuel cell system the proposed powertrain can reduce the equivalent CO2 emissions of 69%. This reduction can be further enhanced using hydrogen from cleaner production processes. The proposed preliminary analysis demonstrated that fuel cell powertrains can be a feasible solution to substitute traditional systems on off-road vehicles even if a higher investment cost might be required.

The global shift toward sustainable energy solutions emphasises the urgent need to harness renewable sources for green hydrogen production presenting a critical opportunity in the transition to a low-carbon economy. Despite its potential integrating renewable energy with electrolysis to produce green hydrogen faces significant technological and economic challenges particularly in achieving high efficiency and cost-effectiveness at scale. This review systematically examines the latest advancements in electrolysis technologies—alkaline proton exchange membrane electrolysis cell (PEMEC) and solid oxide—and explores innovative grid integration and energy storage solutions that enhance the viability of green hydrogen. The study reveals enhanced performance metrics in electrolysis processes and identifies critical factors that influence the operational efficiency and sustainability of green hydrogen production. Key findings demonstrate the potential for substantial reductions in the cost and energy requirements of hydrogen production by optimising electrolyser design and operation. The insights from this research provide a foundational strategy for scaling up green hydrogen as a sustainable energy carrier contributing to global efforts to reduce greenhouse gas emissions and advance toward carbon neutrality. The integration of these technologies could revolutionise energy systems worldwide aligning with policy frameworks and market dynamics to foster broader adoption of green hydrogen.

Hydrogen is gaining prominence in global efforts to combat greenhouse gas emissions and climate change. While steam methane reforming remains the predominant method of hydrogen production alternative approaches such as water electrolysis and methane cracking are gaining attention. The bridging technology – methane cracking – has piqued scientific interest with its lower energy requirement (74.8 kJ/mol compared to steam methane reforming 206.278 kJ/mol) and valuable by-product of filamentous carbon. Nevertheless challenges including coke formation and catalyst deactivation persist. This review focuses on two main reactor types for catalytic methane decomposition – fixed-bed and fluidised bed. Fixed-bed reactors excel in experimental studies due to their operational simplicity and catalyst characterisation capabilities. In contrast fluidised-bed reactors are more suited for industrial applications where efforts are focused on optimising the temperature gas flow rate and particle characterisation. Furthermore investigations into various fluidised bed regimes aim to identify the most suitable for potential industrial deployment providing insights into the sustainable future of hydrogen production. While the bubbling regime shows promise for upscaling fluidised bed reactors experimental studies on turbulent fluidised-bed reactors especially in achieving high hydrogen yield from methane cracking are limited highlighting the technology’s current status not yet reaching commercialisation.

This review comprehensively evaluates the integration of solar-powered electrolytic hydrogen (H2) production and captured carbon dioxide (CO2) management for clean fuel production considering all potential steps from H2 production methods to CO2 capture and separation processes. It is expected that the near future will cover CO2-capturing technologies integrated with solar-based H2 production at a commercially viable level and over 5 billion tons of CO2 are expected to be utilized potentially for clean fuel production worldwide in 2050 to achieve carbon-neutral levels. The H2 production out of hydrocarbon-based processes using fossil fuels emits greenhouse gas emissions of 17-38 kg CO2/kg H2. On the other hand . renewable energy based green hydrogen production emits less than 2 kg CO2/kg H2 which makes it really clean and appealing for implementation. In addition capturing CO2 and using for synthesizing alternative fuels with green hydrogen will help generate clean fuels for smart cities. In this regard the most sustainable and promising CO2 capturing method is post-combustion with an adsorption-separation-desorption processes using monoethanolamine adsorbent with high CO2 removal efficiencies from flue gases. Consequently this review article provides perspectives on the potential of integrating CO2-capturing technologies and renewable energy-based H2 production systems for clean production to create sustainable cities and communities.

Hydrogen Fuel Cell Electric Vehicles (HFC EVs) represent an alternative to replace current internal combustion engine vehicles. The use of these vehicles with storage of compressed gaseous hydrogen (CGH2) or cryogenic liquid hydrogen (LH2) in confined spaces such as tunnels underground car parks etc. creates new challenges to ensure the protection of people and property and to keep the risk at an acceptable level. Several studies have shown that confinement or congestion can lead to severe accidental consequences compared to accidents in an open atmosphere. It is therefore necessary to develop validated hazard and risk assessment tools for the behaviour of hydrogen in tunnels. The HYTUNNEL-CS project sponsored by the FCH-JU pursues this objective. Among the experiments carried out in support of the validation of the hydrogen safety tools the CEA conducted tests on large-scale jet fires in a full-scale tunnel geometry.<br/>The tests were performed in a decommissioned road tunnel in two campaigns. The first one with 50 liters type II tanks under a pressure of 20 MPa and the second one with 78 liters type IV tanks under 70 MPa. In both cases a flate plate was used to simulate the vehicle. Downward and upward gas discharges to simulate a rollover have been investigated with various release diameters. For the downward discharge the orientation varied from normal to the road to a 45° rearward inclination. The first campaign took place under a concrete vault while the second under a rocky vault. Additional tests with the presence of a propane fire simulating a hydrocarbon powered vehicle fire were performed to study the interaction between the two reactive zones.<br/>In the paper all the results obtained during the second campaign for the evolution of the hydrogen jet-fire size the radiated heat fluxes and the temperature of the hot gases released in the tunnel are reported. Comparisons with the classical correlations from open field tests used in engineering models are also presented and conclusions are given as to their applicability.

This paper focuses on the battle for a dominant design for renewable hydrogen electrolysis in which the designs alkaline and proton exchange membrane compete for dominance. First a literature review is performed to determine the most relevant factors that influence technology dominance. Following that a Best Worst Method analysis is conducted by interviewing multiple industry experts. The most important factors appear to be: Price Safety Energy consumption Flexibility Lifetime Stack size and Materials used. The opinion of experts on Proton Exchange Membrane and alkaline electrolyser technologies is slightly skewed in favour of alkaline technologies. However the margin is too small to identify a winner in this technology battle. The following paper contributes to the ongoing research on modelling the process of technology selection in the energy sector.