Spain

Hydrogen (H2) used as feedstock (i.e. as raw material) in chemicals refineries and steel is currently produced from fossil fuels thus leading to significant carbon dioxide (CO2) emissions. As these hard-to-abate sectors have limited electrification alternatives H2 produced by electrolysis offers a potential option for decarbonising them. Existing modelling analyses to date provide limited insights due to their predominant use of sector-specific static non-recursive and non-open models. This paper advances research by presenting a dynamic recursive open-access energy model using System Dynamics to study long-term systemic and environmental impacts of transitioning from fossil-based methods to electrolytic H2 production for industrial feedstock. The regional model adopts a bottom-up approach and is applied to the EU across five innovative decarbonisation scenarios including varying technological transition speeds and a paradigm-shift scenario (Degrowth). Our results indicate that assuming continued H2 demand trends and large-scale electrolytic H2 deployment by 2030 grid decarbonisation in the EU must accelerate to ensure green H2 for industrial feedstock emits less CO2 than fossil fuel methods doubling the current pace. Otherwise electrolytic H2 won’t offer clear CO2 reduction benefits until 2040. The most effective CO2 emission mitigation occurs in growth-oriented ambitious decarbonisation (− 91 %) and Degrowth (− 97 %) scenarios. From a sectoral perspective H2 use in steel industry achieves significantly greater decarbonisation (− 97 %). However meeting electricity demand for electrolytic H2 (700–1180 TWh in 2050 for 14–22.5 Mtons) in growth-oriented scenarios would require 25 %–42 % of the EU’s current electricity generation exceeding current renewable capacity and placing significant pressure on future power system development.

The use of hydrogen as an energy carrier represents a promising alternative for mitigating climate change. However its practical application requires achieving a high degree of purity throughout the production process. In this study the influence of the type of catalytic support on H2 production via steam glycerol reforming was evaluated with the objective of obtaining syngas with the highest possible H2 concentration. Three types of support were analyzed: two natural materials (zeolite and dolomite) and one metal oxide alumina. Alumina and dolomite were coated with Ni at different loadings while zeolite was only evaluated without Ni. Reforming experiments were carried out at a constant temperature of 850 ◦C with continuous monitoring of H2 CO2 CO and CH4 concentrations. The results showed that zeolite yielded the lowest H2 concentration (51%) mainly due to amorphization at high temperatures and the limited effectiveness of physical adsorption processes. In contrast alumina and dolomite achieved H2 purities of around 70% which increased with Ni loading. The improvement was particularly significant in dolomite owing to its higher porosity and the recarbonation processes of CaO enabling H2 purities of up to 90%.

This study employs computational thermodynamics to evaluate the feasibility of replacing methane with hydrogen as both burner fuel and reductant during blister copper deoxidation aiming to enhance deoxidation efficiency and reduce CO2 emissions. A comprehensive thermodynamic model was developed using FactSage 8.3 for dilute Cu–O and Cu–S–O melts containing trace impurities (Fe Ni Pb Zn) incorporating methane thermal decomposition and temperature-dependent variations in liquid copper density with oxygen and sulfur content. Model parameters were optimized against over 105 deoxidation simulation data points yielding temperature- and composition-dependent expressions for rapid density estimates. Benchmarking against existing literature models demonstrated improved accuracy. Key findings include: (1) increasing impurities contents from electronics waste recycling (Fe Ni Pb Zn) reduces oxygen activity deteriorating the deoxidation efficiency; (2) under global equilibrium methane provides greater reducing power per mole than hydrogen due to full thermal cracking but real-world mass transfer limitations render hydrogen more consistently effective up to 1200 C with methane gas needing to achieve at least 472 C to match hydrogen’s performance; (3) adiabatic flame equilibrium studies show that O2/H2 ratios of 0.5 to 1 yield liquid copper oxygen activities comparable to industrial O2/CH4 ratios of 2 to 3 supporting the direct substitution of methane with hydrogen in oxy-fuel anode furnace burners without compromising metal quality.

Hydrogen production from gasification of biowaste generates large volumes of CO2 due to endothermic biowaste decomposition. Alternatively the Sun can provide that energy. To evaluate the yield and performance of solarbased gasifiers at country scale a multi-scale approach is required. First the operation of a solar gasifier is analyzed by developing a two-phase model validated and scaled to industrial level. Next the performance and yield of such technology as a function of the radiation received is studied taking Spain as a case study. The results were promising obtaining a syngas rich in H2. However tar and char were not reduced due to insufficient temperature. Scale-up studies revealed energy losses to the environment in the industrial-scale gasifier which suggested the use of segmented heating. In turn diameters no larger than 0.8 m and biomass feeding rates below 0.85 kg/s highlight the deployment of a modular design due to particle size limitations. Finally the large-scale waste valorization showed that the gasifier can only operate in Spain in the summer months. It can run over 180 h/month and more than 250 days/year only in C´ adiz and Santa Cruz de Tenerife which also showed the highest yearly production capacities.

This study presents an experimental approach to modelling PEM electrolysers for green hydrogen production using solar energy. The objective is to implement a temperature steady-state electrolyser model to assess the optimal coupling configuration with a photovoltaic plant and estimate the yearly hydrogen production capacity. The research focuses on the energy consumption of ancillary systems under different load conditions developing a steady-state operational model that improves hydrogen production predictions by accounting for these consumptions. The model based on polynomial equations captures the non-linear variation in energy costs under partial load conditions. PEM electrolysers produce hydrogen above 3.0 quality (99.9% purity) and it is feasible to integrate purification processes to reach 5.0 quality (99.999% purity). While small-scale systems include purification large-scale facilities separate it enabling process optimisation. Two models are introduced to estimate hydrogen mass flow depending on purity: a base-purity model and a high-purity model that includes drying and pressure swing adsorption. Both are based on experimental data from a five-year-old small-scale electrolyser and are applicable to large-scale systems at partial load. Due to test conditions the model applied to large-scale facilities underestimates hydrogen production affected by energy losses from a non-optimised purification process and electrolyser degradation. Model validation with large-scale operational data from the literature shows the model captures plant behaviour well despite the consistent underestimation described above. The model is applied to several European locations to identify optimal photovoltaic-to-electrolyser ratios. Oversizing factors between 1.4 and 2 are needed to cover ancillary consumption. The levelised cost remains comparable for both purity levels despite higher energy demands for high-purity hydrogen due to the greater cost of the electrolyser over the photovoltaic plant.

The growing concern about the increase in European Union (EU)’s total CO2 emissions due to maritime activities and the ambitious goal of net zero emissions they are asked to fulfil by 2050 are leading the way to the adoption of new sustainable strategies. In this article a novel methodology for the classification of the sustainable actions is proposed. Moreover new indicators have been designed to compare the level of sustainable development of each port. Among them a new coefficient for the assessment of the Ports’ Potential Sustainability (PPS) have been designed. Main results showed that 56% of the actions were in the improvement and environmentally sustainable group while 19% were shift-economic actions related to the installation of technologies. As a matter of the fact all European ports under analysis have adopted cold ironing system which can reduce up to 4% of the global shipping emissions. Similarly 50% of them have already integrated renewables energies and prioritize equipment electrification in their processes. Finally the most relevant projects to optimize the energy consumption of daily operations and the main challenges that still need to be addressed have been analyzed showing the current trends maritime sector is undertaking to advance towards the sustainable development.

Hydrogen (H2) is an attractive fuel due to its high specific energy and zero direct carbon emissions. Membraneless electrolyzers (MEs) offer a lower-cost route to hydrogen production but their operation is complex and current efficiencies are modest. Although multi-objective optimization is widely used its heavy compute demands and weak integration with modern learning methods limit scalability and adaptability. We introduce a practical ML-guided way to design Tesla-valve (TV) membraneless electrolyzers by building diodicity (Di) directly into the geometry search. Using multilayer-perceptron surrogates trained on 150 high-fidelity simulations (R2 > 0.95) we link four design knobs (We Wc Wd Di) to pressure drop (Δp) and ohmic loss. A Genetic Algorithm (GA)-based multi-objective search over realistic ranges delivers 60 Pareto-optimal designs that make the Δp–ohmic trade-off explicit; TOPSIS then selects a balanced geometry (We = 1.708 mm Wc = 0.200 mm Wd = 1.012 mm Di = 1.618) with ohmic loss 4.069 V and Δp 6.169 Pa. The approach delivers faster lower-cost design maps and is supported by experimental checks pointing to an actionable route for scalable interpretable optimization of sustainable hydrogen production.

The paper studies and analyzes electric vehicle engines powered by hydrogen under the WLTP standard driving protocol. The driving range extension is estimated using a specific protocol developed for FCEV compared with the standard value for battery electric vehicles. The driving range is extended by 10 km averaging over the four protocols with a maximum of 11.6 km for the FTP-75 and a minimum of 7.7 km for the WLTP. This driving range extension represents a 1.8% driving range improvement on average. Applying the FCEV current weight the driving range is extended to 18.9 km and 20.4 km on average when using power source energy capacity standards for BEVs and FCEVs.