Italy

In this paper we propose an alternative strategy to produce green hydrogen in a more sustainable way than standard water electrolysis where a substantial amount of the electrical energy is wasted in the oxygen evolution quite often simply released in the atmosphere. The HER (hydrogen evolution reaction) is effectively coupled with the oxidation of guaiacol at the anode leading to the simultaneous production of H2 and valuable guaiacol oligomers. Significative points i) a substantial decrease of the potential difference for the HER 0.85 V with guaiacol ii) HER is accompanied by the production of industrially appealing and sustainable guaiacol based oligomers iii) guaiacol oxidation runs efficiently on carbon-based surfaces like graphite and glassy carbon which are cheap and not-strategic materials. Then the electrochemical oxidation mechanism of guaiacol is studied in detail with in-situ EPR measurements and post-electrolysis product characterization: LC-DAD LC-MS and NMR. Experimental results and theoretical calculations suggest that guaiacol polymerization follows a Kane-Maguire mechanism.

A comprehensive literature review highlights how the nature of active metals support materials promoters and synthesis methods influences catalytic performance with particular attention to ruthenium-based catalysts as the current benchmark. Kinetic models are presented to describe the reaction pathway and predict catalyst behavior. Various reactor configurations including fixed-bed membrane catalytic membrane perovskitebased and microreactors are evaluated in terms of their suitability for ammonia decomposition. While ruthenium remains the benchmark catalyst alternative transition metals such as iron nickel and cobalt have also been investigated although they typically require higher operating temperatures (≥500 °C) to achieve comparable conversion levels. At the industrial scale catalyst development must balance performance with cost. Inexpensive and scalable materials (e.g. MgO Al2O3 CaO K Na) and simple preparation techniques (e.g. wet impregnation incipient wetness) may offer lower performance than more advanced systems but are often favored for practical implementation. From a reactor engineering standpoint membrane reactors emerge as the most promising technology for combining catalytic reaction and product separation in a single unit operation. This review provides a critical overview of current advances in ammonia decomposition for hydrogen production offering insights into both catalytic materials and reactor design strategies for sustainable energy applications.

As the need to reduce Greenhouse Gas (GHG) emissions and dependence on fossil fuels grows new vehicle concepts are emerging as sustainable solutions for urban mobility. Beyond evaluating tailpipe emissions indirect emissions associated with energy and hydrogen production as vehicle manufacturing must be accounted offering a holistic Lifecycle Assessment (LCA) perspective. This study compares Battery Electric Vehicles (BEVs) Fuel Cell Vehicles (FCVs) Hydrogen Internal Combustion Engine Vehicles (H2ICEVs) and hybrid H2ICEVs analyzing energy efficiency and GHG emissions in urban environment across the European Union. Future scenarios (2030 2050) are examined as well with evolving energy mixes and manufacturing impacts. Findings show BEVs as the most efficient configuration with the lowest GHG emissions in 2024 while FCVs become the best option in future scenarios due to greener hydrogen production and improved manufacturing. This study emphasizes the need for tailored strategies to achieve sustainable urban mobility providing insights for policymakers and stakeholders.

A tool for parametric finite element modeling and analysis of LH2 tanks for aviation is developed. Passively insulated cryogenic composite sandwich pressure vessels are investigated as they conjugate simplicity effectiveness and lightweight design for aeronautical applications. Several parametric analyses are performed with the aim of gaining both general and case-specific understanding of how particular design choices may impact the tank mechanical and thermal performance. Differently from most of previous studies multiple design choices including tank walls thicknesses constraints for airframe integration strategies as well as the presence position and integration of refuelling cutouts and anti-sloshing bulkheads are considered. The thermo-mechanical analyses are performed considering first a simple reference configuration with the aim of evaluating possible directions for performance enhancement. Results indicate how different design features affect the gravimetric and thermal efficiency of the tank without compromising structural integrity if the walls thicknesses are suitably sized. The effects of different constraints and geometric discontinuities which reflect specific fuselage integration choices must be carefully assessed as they reduce safety margins. Ultimately a vessel model including features necessary for safe operation is presented as it serves as a baseline for further optimization.

Hydrogen is commonly perceived as the key player in the transition towards a low-carbon future. Nevertheless H2 low energy density hinders its easy storage and transportation. To address this issue different alternatives (liquefied hydrogen ammonia and liquid organic hydrogen carriers) are explored as hydrogen vectors. The techno-economic assessment of H2 transport through these carriers is strongly dependent on the basis of design adopted such that it is difficult to draw general conclusions. In this respect this work is aimed at performing a sensitivity analysis on the hypotheses introduced in the layout of H2 value chains. Different scenarios are discussed depending on harbour-to-harbour distances cost of utilities and raw materials and H2 application to the industrial or mobility sector. The most cost-effective carrier is selected for each case-study: NH3 is the most advantageous for industrial sector while LH2 holds promises for mobility. Critical issues are pointed out for future large-scale applications.

Solid oxide electrolysis cells (SOEC) system has potential to offer an efficient green hydrogen production technology. However the significant cost of this technology is related to the high operating temperatures materials and thermal management including the waste heat. Recovering the waste heat can be conducted through techniques to reduce the overall energy consumption. This approach aims to improve accuracy and efficiency by recovering and reusing the heat that would otherwise be lost. In this paper thermal energy models are proposed based on waste heat recovery methodologies to utilize the heat from outlet fluids within the SOEC system. The mathematical methods for calculating thermal energy and energy transfer in SOEC systems have involved the principles of heat transfer. To address this different simplified thermal models are developed in Simulink Matlab R2025b. The obtained results for estimating proper thermal energy for heating incoming fluids and recycled heat are discussed and compared to determine the efficient and potential thermal model for improvement the waste heat recovery.

As highlighted by the recent roadmaps from the European Union and the United States water electrolysis is the most valuable high-intensity technology for producing green hydrogen. Currently two commercial low-temperature water electrolyzer technologies exist: alkaline water electrolyzer (A-WE) and proton-exchange membrane water electrolyzer (PEM-WE). However both have major drawbacks. A-WE shows low productivity and efficiency while PEM-WE uses a significant amount of critical raw materials. Lately the use of anion-exchange membrane water electrolyzers (AEM-WE) has been proposed to overcome the limitations of the current commercial systems. AEM-WE could become the cornerstone to achieve an intense safe and resilient green hydrogen production to fulfill the hydrogen targets to achieve the 2050 decarbonization goals. Here the status of AEM-WE development is discussed with a focus on the most critical aspects for research and highlighting the potential routes for overcoming the remaining issues. The Review closes with the future perspective on the AEM-WE research indicating the targets to be achieved.

The development of hydrogen refueling infrastructure plays a strategic role in enabling the decarbonization of the transport sector especially along major freight and passenger corridors such as the Trans-European Transport Network (TEN-T). Despite the growing interest in hydrogen mobility existing methodologies for the optimal location of hydrogen refueling stations (HRS) remain fragmented and often overlook operational dynamics. Following a review of the existing literature on HRS location models and approaches this study highlights key methodological gaps that hinder effective infrastructure planning. In response a two-stage framework is proposed combining a flow-based location model with a stochastic queueing approach to determine both the optimal placement of HRS and the number of dispensers required at each site. The method is applied to a real segment of the TEN-T network in Northern Italy. The results demonstrate the flexibility of the model in accommodating different hydrogen vehicle penetration scenarios and its utility as a decision-support tool for public authorities and infrastructure planners.

Direct electrification and hydrogen utilization represent two key pathways for decarbonizing the glass industry with their effectiveness subject to adequate furnace design and renewable energy availability. This study presents a techno-economic assessment for optimal solar energy integration in a representative 300 t/d oxyfuel container glass furnace with a specific energy consumption of 4.35 GJ/t. A mixed-integer linear programming formulation is developed to evaluate specific melting costs carbon emissions and renewable energy self-consumption and self-production rates across three scenarios: direct solar coupling battery storage and a hydrogen-based infrastructure. Battery storage achieves the greatest reductions in specific melting costs and emissions whereas hydrogen integration minimizes electricity export to the grid. By incorporating capital investment considerations the study quantifies the cost premiums and capacity requirements under varying decarbonization targets. A combination of 30 MW of solar plant and 9 MW of electric boosting enables the realization of around 30% carbon reduction while increasing total costs by 25%. Deeper decarbonization targets require more advanced systems with batteries emerging as a cost-effective solution. These findings offer critical insights into the economic and environmental trade-offs as well as the technical constraints associated with renewable energy adoption in the glass industry providing a foundation for strategic energy and decarbonization planning.

In this work we present the simulation of a plant for the exploitation of renewable hydrogen (e.g. from biomass gasification) with production of renewable ammonia as hydrogen vector and energy storage medium. The simulation and sizing of all unit operations were performed with Aspen Plus® as software. Vegetable waste biomass is used as raw material for hydrogen production more specifically pine sawdust.<br/>The hydrogen production process is based on a gasification reactor operating at high temperature (700–800 °C) in the presence of a gasifying agent such as air or steam. At the outlet a solid residue (ash) and a certain amount of gas which mainly contains H2 CH4 CO and some impurities (e.g. sulphur or chlorine compounds) are obtained. Subsequently this gas stream is purified and treated in a series of reactors in order to maximize the hydrogen yield. In fact after the removal of the sulphur compounds through an absorption column with MEA (to avoid poisoning of the catalytic processes) 3 reactors are arranged in series: Methane Steam Reforming (MSR) High temperature Water-Gas Shift (HT-WGS) Low temperature Water-Gas Shift (LT-WGS).<br/>In the first MSR reactor methane reacts at 1000 °C in presence of steam and a nickel-based catalyst in order to obtain mainly H2 CO and CO2. Subsequently two steps of WGS are present to convert most of the CO into H2 and CO2. Also these reactions are carried out in the presence of a catalyst and with an excess of water.<br/>All the oxygenated compounds must be carefully eliminated: the remaining traces of CO are methanated while CO2 is removed by a basic scrubbing with MEA (35 wt%) inside an absorption column. The Haber-Bosch synthesis of ammonia was carried out at 200 bar and in a temperature range between 300 and 400 °C using two catalysts: Fe (wustite) and Ru/C.<br/>As overall balance from an hourly flow rate of 1000 kg of dry biomass and 600 kg of nitrogen 550 kg of NH3 at 98.8 wt% were obtained demonstrating the proof of concept of this newly designed process for the production of hydrogen from renewable waste biomass and its transformation into a liquid hydrogen vector to be easily transported and stored.