Italy

In this novel conceptual fuel cell vehicle (FCV) an on-board CH4 steam reforming (MSR) membrane reformer (MR) is considered to generate pure H2 for supplying a Fuel Cell (FC) system as an alternative to the conventional automobile engines. Two on-board tanks are forecast to store CH4 and water useful for feeding both a combustion chamber (designed to provide the heat required by the system) and a multi tubes Pd-Ag MR useful to generate pure H2 via methane steam reforming (MSR) reaction. The pure H2 stream is hence supplied to the FC. The flue gas stream coming out from the combustion chamber is used to preheat the MR feed stream by two heat exchangers and one evaporator. Then this theoretical work demonstrates by a 1-D model the feasibility of the MR based system in order to generate 5 kg/day of pure H2 required by the FC system for cruising a vehicle for around 500 km. The calculated CH4 and water consumptions were 50 and 70 kg respectively per 1 kg of pure H2. The on-board MR based FCV presents lower CO2 emission rates than a conventional gasoline-powered vehicle also resulting in a more environmentally friendly solution.

The H2-ICE project aims at developing through numerical simulation a new generation of hybrid powertrains featuring a hydrogen-fueled Internal Combustion Engine (ICE) suitable for 12 m urban buses in order to provide a reliable and cost-effective solution for the abatement of both CO2 and criteria pollutant emissions. The full exploitation of the potential of such a traction system requires a substantial enhancement of the state of the art since several issues have to be addressed. In particular the choice of a more suitable fuel injection system and the control of the combustion process are extremely challenging. Firstly a high-fidelity 3D-CFD model will be exploited to analyze the in-cylinder H2 fuel injection through supersonic flows. Then after the optimization of the injection and combustion process a 1D model of the whole engine system will be built and calibrated allowing the identification of a “sweet spot” in the ultra-lean combustion region characterized by extremely low NOx emissions and at the same time high combustion efficiencies. Moreover to further enhance the engine efficiency well above 40% different Waste Heat Recovery (WHR) systems will be carefully scrutinized including both Organic Rankine Cycle (ORC)-based recovery units as well as electric turbo-compounding. A Selective Catalytic Reduction (SCR) aftertreatment system will be developed to further reduce NOx emissions to near-zero levels. Finally a dedicated torque-based control strategy for the ICE coupled with the Energy Management Systems (EMSs) of the hybrid powertrain both optimized by exploiting Vehicle-To-Everything (V2X) connection allows targeting H2 consumption of 0.1 kg/km. Technologies developed in the H2-ICE project will enhance the know-how necessary to design and build engines and aftertreatment systems for the efficient exploitation of H2 as a fuel as well as for their integration into hybrid powertrains.

In recent years several approaches and pathways have been discussed to decarbonise the transport sector; however any effort to reduce emissions might be complex due to specific socio-economic and technical characteristics of different regions. In Mexico the transport sector is the highest energy consumer representing 38.9% of the national final energy demand with gasoline and diesel representing 90% of the sector´s total fuel consumption. Energy systems models are powerful tools to obtain insights into decarbonisation pathways to understand costs emissions and rate of deployment that could serve for energy policy development. This paper focuses on the modelling of the current Mexican transport system using the MUSE-MX multi-regional model with the aim to project a decarbonisation pathway through two different scenarios. The first approach being business as usual (BAU) which aims to analyse current policies implementation and the second being a goal of net zero carbon emissions by 2050. Under the considered net zero scenario results show potential deployment of hydrogen-based transport technologies especially for subsectors such as lorries (100% H2 by 2050) and freight train (25% H2 by 2050) while cars and buses tend to full electrification by 2050.

This paper presents a comparative analysis of two hydrogen station configurations during the refueling process: the conventional “directly pressurized refueling process” and the innovative “cascade refueling process.” The objective of the cascade process is to refuel vehicles without the need for booster compressors. The experiments were conducted at the Hydrogen Research and Fueling Facility located at California State University Los Angeles. In the cascade refueling process the facility buffer tanks were utilized as high-pressure storage enabling the refueling operation. Three different scenarios were tested: one involving the cascade refueling process and two involving compressor-driven refueling processes. On average each refueling event delivered 1.6 kg of hydrogen. Although the cascade refueling process using the high-pressure buffer tanks did not achieve the pressure target it resulted in a notable improvement in the nozzle outlet temperature trend reducing it by approximately 8 ◦C. Moreover the overall hydrogen chiller load for the two directly pressurized refuelings was 66 Wh/kg and 62 Wh/kg respectively whereas the cascading process only required 55 Wh/kg. This represents a 20% and 12% reduction in energy consumption compared to the scenarios involving booster compressors during fueling. The observed refueling range of 150–350 bar showed that the cascade process consistently required 12–20% less energy for hydrogen chilling. Additionally the nozzle outlet temperature demonstrated an approximate 8 ◦C improvement within this pressure range. These findings indicate that further improvements can be expected in the high-pressure region specifically above 350 bar. This research suggests the potential for significant improvements in the high-pressure range emphasizing the viability of the cascade refueling process as a promising alternative to the direct compression approach.

Electrification of the transportation sector is one of the main drivers in the decarbonization of energy and mobility systems and it is a way to ensure security of energy supply. Public bus fleets can assist in achieving fast reduction of CO2 emissions. This article provides an analysis of a unique real-world dataset to support decision makers in the decarbonization of public fleets and interlink it with the social acceptance of drivers. Data was collected from 21 fuel cell and electric buses. The tank-to-wheel efficiency results of fuel cell electric buses (FCEB) are much lower than that of battery electric buses (BEB) and there is a higher variation in consumption for BEBs compared to FCEBs. Both technologies permit a strong reduction in CO2 emissions compared to conventional buses. There is a high level of acceptance of drivers which are likely to support the transition towards zero-emission buses introduced by the management.

The valorization of integrated steelworks process off-gases as feedstock for synthesizing methane and methanol is in line with European Green Deal challenges. However this target can be generally achieved only through process off-gases enrichment with hydrogen and use of cutting-edge syntheses reactors coupled to advanced control systems. These aspects are addressed in the RFCS project i3 upgrade and the central role of hydrogen was evident from the first stages of the project. First stationary scenario analyses showed that the required hydrogen amount is significant and existing renewable hydrogen production technologies are not ready to satisfy the demand in an economic perspective. The poor availability of low-cost green hydrogen as one of the main barriers for producing methane and methanol from process off-gases is further highlighted in the application of an ad-hoc developed dispatch controller for managing hydrogen intensified syntheses in integrated steelworks. The dispatch controller considers both economic and environmental impacts in the cost function and although significant environmental benefits are obtainable by exploiting process off-gases in the syntheses the current hydrogen costs highly affect the dispatch controller decisions. This underlines the need for big scale green hydrogen production processes and dedicated green markets for hydrogen-intensive industries which would ensure easy access to this fundamental gas paving the way for a C-lean and more sustainable steel production.

Within integrated steelmaking industries significant research efforts are devoted to the efficient use of resources and the reduction of CO2 emissions. Integrated steelworks consume a considerable quantity of raw materials and produce a high amount of by-products such as off-gases currently used for the internal production of heat steam or electricity. These off-gases can be further valorized as feedstock for methane and methanol syntheses but their hydrogen content is often inadequate to reach high conversions in synthesis processes. The addition of hydrogen is fundamental and a suitable hydrogen production process must be selected to obtain advantages in process economy and sustainability. This paper presents a comparative analysis of different hydrogen production processes from renewable energy namely polymer electrolyte membrane electrolysis solid oxide electrolyze cell electrolysis and biomass gasification. Aspen Plus® V11-based models were developed and simulations were conducted for sensitivity analyses to acquire useful information related to the process behavior. Advantages and disadvantages for each considered process were highlighted. In addition the integration of the analyzed hydrogen production methods with methane and methanol syntheses is analyzed through further Aspen Plus®-based simulations. The pros and cons of the different hydrogen production options coupled with methane and methanol syntheses included in steelmaking industries are analyzed

To meet environmental goals while maintaining economic competitiveness worldwide ports have increased the amount of renewable energy production and have focused in optimizing performances and energy efficiency. However carbon-neutral operation of industrial port areas (IPA) is challenging and requires the decarbonization of industrial processes and heavy transport systems. This study proposes a comprehensive review of decarbon ization strategies for IPA with a particular focus on the role that green hydrogen could play when used as renewable energy carrier. Much information on existing and future technologies was also derived from the analysis of 74 projects (existing and planned) in 36 IPAs 80 % of which are in Europe concerning hydrogenbased decarbonization strategies. The overall review shows that engine operation of ships at berth are respon sible of more than 70 % of emissions in ports. Therefore onshore power supply (OPS) seems to be one of the main strategies to reduce port pollution. Nevertheless OPS powered by hydrogen is not today easily achievable. By overcoming the current cost-related and regulation barriers hydrogen can also be used for the import/export of green energy and the decarbonization of hard-to-abate sectors. The technical and economic data regarding hydrogen-based technologies and strategies highlighted in this paper are useful for further research in the field of definition and development of decarbonization strategies in the IPA.

Green hydrogen (GH2) is expected to play an important role in future energy systems in their fight against climate change. This study after briefly recalling how GH2 is produced and the main steps throughout its life cycle analyses its current development environmental and social impacts and a series of case studies from selected literature showing its main applications as fuel in transportation and electricity sectors as a heat producer in high energy intensive industries and residential and commercial buildings and as an industrial feedstock for the production of other chemical products. The results show that the use of GH2 in the three main areas of application has the potential of contributing to the decarbonization goals although its generation of non-negligible impacts in other environmental categories requires attention. However the integration of circular economy (CE) principles is important for the mitigation of these impacts. In social terms the complexity of the value chain of GH2 generates social impacts well beyond countries where GH2 is produced and used. This aspect makes the GH2 value chain complex and difficult to trace somewhat undermining its renewability claims as well as its expected localness that the CE model is centred around.

Hydrogen is a key energy carrier for decarbonizing multiple sectors particularly when produced via water electrolysis powered by renewable energy. Proton exchange membrane (PEM) electrolyzers are well suited for this application due to their ability to rapidly adjust to fluctuating power inputs. Despite being conventionally operated at high temperatures and pressures to reduce heating and compression needs recent studies suggest that under partial loads lower operating conditions may enhance efficiency. This study introduces a novel optimization framework for dynamically adjusting pressure and temperature in PEM electrolyzers. The model integrates an efficiency map within a Mixed-Integer Linear Programming (MILP) formulation and applies McCormick tightening to address nonlinearities. A one-week case study demonstrates operational cost reductions of up to 12.5 % through optimal control favoring lower temperatures and pressures at low current densities and higher temperatures near rated load while maintaining moderate pressures. The results show improved efficiency and reduced hydrogen crossover enhancing safety and enabling scalable application over extended time horizons. These insights are valuable for long-term planning and evaluation of hydrogen production and storage systems.