Applications & Pathways

Renewable hydrogen is emerging as the key to a sustainable energy transition with multiple applications and uses. In the field of transport in addition to fuel cell vehicles it is necessary to develop an extensive network of hydrogen refueling stations (hereafter HRSs). The characteristics and properties of hydrogen make ensuring the safe operation of these facilities a crucial element for their successful deployment and implementation. This paper shows the outcomes of an analysis of hydrogen incidents and accidents considering their potential application to HRSs. For this purpose the HIAD 2.0 was reviewed and a total of 224 events that could be repeated in any of the major industrial processes related to hydrogen refueling stations were analyzed. This analysis was carried out using a mixed methodology of quantitative and qualitative techniques considering the following hydrogen value chain: production storage delivery and industrial use. The results provide general information segmented by event frequency damage classes and failure typology. The analysis shows the main processes of the value chain allow the identification of key aspects for the safety management of refueling facilities.

Hydrogen refueling stations (HRS) can cause a significant fraction of the hydrogen refueling cost. The main cost contributor is the currently used mechanical compressor. Electrochemical hydrogen compression (EHC) has recently been proposed as an alternative. However its optimal integration in an HRS has yet to be investigated. In this study we compare the performance of a gaseous HRS equipped with different compressors. First we develop dynamic models of three process configurations which differ in the compressor technology: mechanical vs. electrochemical vs. combined. Then the design and operation of the compressors are optimized by solving multi-stage dynamic optimization problems. The optimization results show that the three configurations lead to comparable hydrogen dispensing costs because the electrochemical configuration exhibits lower capital cost but higher energy demand and thus operating cost than the mechanical configuration. The combined configuration is a trade-off with intermediate capital and operating cost.

Shipping corridors act as the arteries of the global economy. The maritime shipping sector is also a major source of greenhouse gas emissions accounting for 2.9% of the global total. The international nature of the shipping sector combined with issues surrounding the use of battery technology means that these emissions are considered difficult to eliminate. This work explores the transition to renewable fuels by examining the use of electrofuels (in the form of liquid hydrogen methane methanol ammonia and Fischer-Tropsch fuel) to decarbonise large container ships from a technical economic and environmental perspective. For an equivalent range to current fossil fuel vessels the cargo capacity of vessels powered by electrofuels decreases by between 3% and 16% depending on the fuel of choice due to the lower energy density compared with conventional marine fuels. If vessel operators are willing to sacrifice range cargo space can be preserved by downsizing onboard energy storage which necessitates more frequent refuelling. For a realistic green hydrogen cost of €3.5/kg (10.5 €c/kWh) in 2030 the use of electrofuels in the shipping sector results in an increase in the total cost of ownership of between 124% and 731% with liquid hydrogen in an internal combustion engine being the most expensive and methanol in an internal combustion engine resulting in the lowest cost increase. Despite this we find that the increased transportation costs of some consumer goods to be relatively small adding for example less than €3.27 to the cost of a laptop. In general fuels which do not require cryogenic storage and can be used in internal combustion engines result in the lowest cost increases. For policymakers reducing the environmental impact of the shipping sector is a key priority. The use of liquid hydrogen which results in the largest cost increase offers a 70% reduction in GHG emissions for an electricity carbon intensity of 80 gCO2e/ kWh which is the greatest reduction of all fuels assessed in this work. A minimum carbon price of €400/tCO2 is required to allow these fuels to reach parity with conventional shipping operations. To meet European Union emissions reductions targets electricity with an emissions intensity below 40 gCO2e/kWh is required which suggests that for electrofuels to be truly sustainable direct connection with a source of renewable electricity is required.

The report addresses the environmental challenges faced by European sea ports and aims to provide guidance to smaller ports for improving their environmental performance while achieving sustainability goals through experiences gained by implementing noteworthy green initiatives in practice. Larger ports possess significant advantages in terms of financial resources risk tolerance and organisational capacity. They often have the means to invest in innovative solutions and actively participate in research and development projects leading to co-funded pilot implementation of green initiatives. They typically have more skilled personnel stronger influence and stakeholder leverage which position them better to lead the way in sustainability efforts. Finally larger ports often form robust collaborations to drive collective action towards sustainable goals. Smaller ports face unique challenges stemming from typically limited resources and risk aversion. They often prioritise mature solutions relying on tested practices to mitigate potential risks. They may lack internal expertise requiring guidance and capacity-building programmes to navigate the selection and implementation of green practices. Also they require financial and technical support particularly as they may underutilise available funding mechanisms and have limited participation in R&D programmes. They may benefit from partnerships with other ports and stakeholders to create synergies and gain experience from their lessons learned to boost their capacity to implement green practices

Hydrogen Refueling Stations (HRS) are a key infrastructure to the successful deployment of hydrogen mobility. Their cost-effectiveness will represent an increasingly crucial issue considering the foreseen growth of vehicle fleets from few captive fleets to large-scale penetration of hydrogen vehicles. In this context a detailed component-oriented cost model is important to assess HRS costs for different design concepts layout schemes and possible customizations respect to aggregate tools which are mostly available in literature. In this work an improved version of a previously developed component-oriented scale-sensitive HRS cost model is applied to 5 different European HRS developed within the 3Emotion project with different refueling capacities (kgH2/day) hydrogen supply schemes (in-situ production or delivery) storage volumes and pressures and operational strategies. The model output allows to assess the upfront investment cost (CAPEX) the annual operational cost (OPEX) and the Levelized Cost of Hydrogen (LCOH) at the dispenser and identify the most crucial cost components. The results for the five analyzed HRS sites show an LCOH at the nozzle of around 8-9 €/kg for delivery based HRSs which are mainly dominated by the H2 retail price and transport service price and around 11-12 €/kg for on-site producing HRS for which the electrolyzer CAPEX and electricity price plays a key role in the cost structure. The compression storage and dispensing sections account for between 1-3 €/kg according to the specific design & performance requirements of the HRS. The total LCOH values are comparable with literature standard market prices for similar scale HRSs and with the 3Emotion project targets.

Under the guidance of energy-saving and emission reduction goals a lowcarbon economic operation method for integrated energy systems (IES) has been proposed. This strategy aims to enhance energy utilization efficiency bolster equipment operational flexibility and significantly cut down on carbon emissions from the IES. Firstly a thorough exploration of the two-stage operational framework of Power-to-Gas (P2G) technology is conducted. Electrolyzers methane reactors and hydrogen fuel cells (HFCs) are introduced as replacements for traditional P2G equipment with the objective of harnessing the multiple benefits of hydrogen energy. Secondly a cogeneration and HFC operational strategy with adjustable heat-to-electricity ratio is introduced to further enhance the IES’s low-carbon and economic performance. Finally a step-by-step carbon trading mechanism is introduced to effectively steer the IES towards carbon emission control.

The maritime sector plays a crucial role in global trade yet its contribution to greenhouse gas emissions remains significant. The adoption of hydrogen as a clean energy solution is gaining traction to address this. This review paper delves into the opportunities and challenges of integrating hydrogen as a marine fuel. The entire hydrogen supply chain is investigated from production to end use highlighting advancements limitations and potential safety risks. Key findings reveal that while hydrogen offers promise for reducing emissions its widespread adoption requires a well-established production storage and distribution infrastructure. Challenges persist in large-scale storage transportation and bunkering particularly in addressing space limitations and ensuring safety protocols. Propulsion systems such as internal combustion engines gas turbines and fuel cells show po tential for hydrogen adoption yet further research is needed to optimize efficiency and address technical con straints. Safety considerations also appear prominently necessitating comprehensive bunkering operations and hazard management protocols. Addressing knowledge gaps is imperative for successfully integrating hydrogen as a marine fuel. Future research should focus on optimizing storage methods developing efficient propulsion systems and enhancing safety measures to enhance hydrogen utilization in the maritime sector.

The Paris Agreement aims to limit global warming and one of the most polluting sectors is heavy industry where cement production is a significant contributor. This work briefly explores some alternatives recycling reducing clinker content waste heat recovery and carbon capture discussing their advantages and drawbacks. Then it examines the economic viability and benefits of increasing oxygen concentration in the primary burning air from 21 to 27 vol.% which could improve clinker production by 7% and the production of hydrogen through PEM electrolysis to make up 5% of the fuel thermal fraction considering both in a cement plant producing 3000 tons of clinker per day. This analysis used reference values from Secil an international company for cement and building materials to determine the required scale of the oxygen and hydrogen production respectively and calculate the CAPEX of each approach. It is concluded that oxygen enrichment can provide substantial fuel savings for a relatively low cost despite a possible significant increase in NOx emissions. However hydrogen production at this scale is not currently economically viable.

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies using hydrogen (H2 ) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions making it a promising option for diesel engines. Due to the importance and novelty of this the continuation of ongoing research and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design operating conditions fuel mixing ratios and supplying techniques on the CO CO2 NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However using hydrogen with diesel reduces CO CO2 and HC emissions but increases NOx. On the other hand HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately resulting in decreased emissions of CO CO2 HC and NOx. The inclusion of hydrogen improves combustion efficiency reduces ignition delay and enhances heat release and in-cylinder pressure. Additionally operational parameters such as engine power speed load air–fuel ratio compression ratio and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

Due to the aviation energy sector's increasing contribution to climate change and the impact of climate change on the aviation sector determining key energy policy and economic research priorities for enabling an effective and equitable aviation climate action is becoming an increasingly important topic. In this perspective we address this research need using a four-pronged methodology. It includes (i) identifying topical matters highlighted in the media (news); (ii) formulating novel and feasible policy and economic research challenges that pertain to these contemporary issues; (iii) cross-referencing the proposed research challenges with academic literature to confirm their novelty and refining them as necessary; and (iv) validating the importance novelty and feasibility of these research challenges through consultation with a diverse group of aviation experts in fuel policy technology and infrastructure fields. Our results highlight twelve main themes. Among these the top emerging policy and economic research challenges as prioritized by expert input are – (i) frameworks for equitable responsibility allocation between developed and developing country airlines for future emissions; (ii) cost analysis of airlines' net-zero by 2050 commitments; (iii) effectiveness and opportunity cost of airlines investing in offsetting relative to reduction measures; (iv) EU aviation policies' historical and potential effects on airfares demand emissions EU air carriers' competitiveness passenger traffic through EU hubs regional economies and social climate funds' ability to mitigate distributional effects of EU aviation policies. These identified priorities can steer both industry and academic research toward creating practical recommendations for policymakers and industry participants. When it comes to future research the ever-changing nature of the challenges in achieving aviation climate action means that our findings might need regular updates.