Applications & Pathways

There is a large literature exploring possible hydrogen futures using various modelling and scenario approaches. This paper compares the rates of transition depicted in that literature with a set of historical analogies. These analogies are cases in which alternative-fuelled vehicles have penetrated vehicle markets. The paper suggests that the literature has tended to be optimistic about the possible rate at which hydrogen vehicles might replace oil-based transportation. The paper compares 11 historical adoptions of alternative fuel vehicles with 24 scenarios from 20 studies that depict possible hydrogen futures. All but one of the hydrogen scenarios show vehicle adoption faster than has occurred for hybrid electric vehicles in Japan the most successful market for hybrids. Several scenarios depict hydrogen transitions occurring at a rate faster than has occurred in any of the historic examples. The paper concludes that scenarios of alternative vehicle adoption should include more pessimistic scenarios alongside optimistic ones.

Integrated steelworks off-gases are generally exploited to produce heat and electricity. However further valorization can be achieved by using them as feedstock for the synthesis of valuable products such as methane and methanol with the addition of renewable hydrogen. This was the aim of the recently concluded project entitled “Intelligent and integrated upgrade of carbon sources in steel industries through hydrogen intensified synthesis processes (i3 upgrade)”. Within this project several activities were carried out: from laboratory analyses to simulation investigations from design development and tests of innovative reactor concepts and of advanced process control to detailed economic analyses business models and investigation of implementation cases. The final developed methane production reactors arerespectively an additively manufactured structured fixedbed reactor and a reactor setup using wash-coated honeycomb monoliths as catalyst; both reactors reached almost full COx conversion under slightly over-stoichiometric conditions. A new multi-stage concept of methanol reactor was designed commissioned and extensively tested at pilot-scale; it shows very effective conversion rates near to 100% for CO and slightly lower for CO2 at one-through operation for the methanol synthesis. Online tests proved that developed dispatch controller implements a smooth control strategy in real time with a temporal resolution of 1 min and a forecasting horizon of 2 h. Furthermore both offline simulations and cost analyses highlighted the fundamental role of hydrogen availability and costs for the feasibility of i 3 upgrade solutions and showed that the industrial implementation of the i 3 upgrade solutions can lead to significant environmental and economic benefits for steelworks especially in case green electricity is available at an affordable price.

Hydrogenation technology is an indispensable chemical upgrading process for converting the heavy feedstock into favorable lighter products. In this work a new kinetic model containing four hydrocarbon lumps (feedstock diesel gasoline cracking gas) was developed to describe the coal tar hydrogenation process the Levenberg–Marquardt’s optimization algorithm was used to determine the kinetic parameters by minimizing the sum of square errors between experimental and calculated data the predictions from model validation showed a good agreement with experimental values. Subsequently an adiabatic reactor model based on proposed lumped kinetic model was constructed to further investigate the performance of hydrogenation fixed-bed units the mass balance and energy balance within the phases in the reactor were taken into accounts in the form of ordinary differential equation. An application of the reactor model was performed for simulating the actual bench-scale plant of coal tar hydrogenation the simulated results on the products yields and temperatures distribution along with the reactor are shown to be good consistent with the experimental data.

As the world prepares to exit from the COVID-19 crisis the pace of the global power revolution is expected to accelerate. A new publication from the World Energy Council in collaboration with PwC underscores the imperative for electricity grid owners and operators to fundamentally transform themselves to secure a role in a more integrated flexible and smarter electricity system in the energy transition to a low carbon future.

“Performing While Transforming: The Role of Transmission Companies in the Energy Transition” is based on in-depth interviews with CEOs and senior leaders from 37 transmission companies representing 35 countries and over 4 million kilometres – near global coverage - of the transmission network. While their roles will evolve transmission companies will remain at the heart of the electricity grid and need to balance the challenges of keeping the lights on while transforming themselves for the future.

The publication explores the various challenges affecting how transmission companies prepare and re-think their operations and business models and leverages the insights from interviewees to highlight four recommendations for transmission companies to consider in their journey:

• Focus on the future through enhanced forecasting and scenario planning  
• Shape the ecosystem by collaborating with new actors and enhancing interconnectivity
• Embrace automation and technology to optimise processes and ensure digital delivery
• Transform organisation to attract new talent and maintain social licence with consumers

In conjunction with John Zink Co. LLC the Chevron Energy Technology Company conducted a three part study evaluating potential issues with switching refinery process heaters from fuel gas to hydrogen fuel for the purpose of greenhouse gas emissions reduction via CO2 capture and storage.

The focus was on the following areas:

• Heater performance
• Burner performance and robustness
• Fuel gas system retrofit requirements

This paper will summarize the findings of the study.

The influence of the previous electrolytic hydrogenation on the micromechanical properties and tribological behavior of the surface layers of iron and carbon steels has been studied. The concentrations of diffusion-moving and residual hydrogen in steels are determined depending on the carbon content. It is shown that the amount of sorbed hydrogen is determined by the density of dislocations and the relative volume of cementite. After desorption of diffusion-moving hydrogen the microhardness increases and materials plasticity decreases. The change of these characteristics decreases with the increase of carbon content in the steels. Internal stresses increase and redistribute under hydrogen desorption. Fragmentation of ferrite and perlite occurs as a result of electrolytic hydrogenation. Ferrite is characterized by the structure fragmentation and change of the crystallographic orientation of planes. The perlite structure shows the crushing of cementite plates and their destruction. The influence of hydrogen desorption on the microhardness of structural components of ferrite-perlite steels is shown. Large scattering of microhardness is found in perlite due to different diffusion rates of hydrogen because of the unequally oriented cementite plates. It was found that the tendency of materials to blister formation is reduced with the increase of carbon content. The influence of hydrogen on the tribological behaviour of steels under dry and boundary friction has been studied. It is shown that hydrogen desorption intensifies the materials wear. After hydrogen desorption tribological behaviour is determined by the adhesion interaction between the contacting pairs.

The use of RES in buildings is difficult for their random nature; therefore the plants using photovoltaic solar collectors must be connected to a power supply or interconnected with Energy accumulators if the building is isolated. The conversion of electricity into hydrogen technology is best suited to solve the problem and allows you to transfer the solar energy captured from day to night from summer to winter. This paper presents the feasibility study for a house powered by PV cogeneration solar collectors that reverse the electricity on the control unit that you command by a PC to power the household using a heat pump an electrolytic cell for the production of hydrogen to accumulate; control units sorting to the utilities the electricity produced by the fuel cell. The following are presented: The Energy analysis of the building the plant design economic analysis.

As the transport sector is ought to be decarbonized fuel-cell-powered trains are a viable zero-tailpipe technology alternative to the widely employed diesel multiple units in regional railway service on non-electrified tracks. Carbon-free hydrogen can be provided by water-electrolysis from renewable energies. In this study we introduce an approach to assess the potential of wind-based hydrogen for use in adjacent regional rail transport by applying a GIS approach in conjunction with a site-level cost model. In Brandenburg about 10.1 million train-km annually could be switched to fuel cell electric train operation. This relates to a diesel consumption of appr. 9.5 million liters today. If fuel cell trains would be employed that translated to 2198 annual tons hydrogen annually. At favorable sites hydrogen costs of approx. 6.40 €/kg - including costs of hydrogen refueling stations - could be achieved. Making excess hydrogen available for other consumers would further decrease hydrogen production costs.

Electric trains (ET) and hydrogen trains (HT) are considered zero emission at the point of use. True emissions are dependent upon non-tailpipe sources primarily in energy production. We present UK carbon dioxide (CO₂) operating emission model outputs for conventionally fuelled trains (CFT) ETs and HTs between 2017 and 2050 under four National Grid electricity generation scenarios.



Comparing four service categories (urban regional intercity and high speed) to private conventionally fuelled vehicles (CFV) and electric vehicles considering average distance travelled per trip under different passenger capacity levels (125% 100% 75% 50% and 25%).



Results indicate by 2050 at 100% capacity CFTs produce a fifth of the emissions of CFVs per kilometre per person. Under two degree generation scenario by 2050 ETs produced 14 times and HTs produced five times less emissions than CFTs. Policymakers should encourage shifts away from private vehicles to public transport powered by low carbon electricity.

Transitioning German road transport partially to hydrogen energy is among the possibilities being discussed to help meet national climate targets. This study investigates impacts of a hypothetical complete transition from conventionally-fuelled to hydrogen-powered German transport through representative scenarios. Our results show that German emissions change between −179 and +95 MtCO₂eq annually depending on the scenario with renewable-powered electrolysis leading to the greatest emissions reduction while electrolysis using the fossil-intense current electricity mix leads to the greatest increase. German energy emissions of regulated pollutants decrease significantly indicating the potential for simultaneous air quality improvements. Vehicular hydrogen demand is 1000 PJ annually requiring 446–525 TWh for electrolysis hydrogen transport and storage which could be supplied by future German renewable generation supporting the potential for CO₂-free hydrogen traffic and increased energy security. Thus hydrogen-powered transport could contribute significantly to climate and air quality goals warranting further research and political discussion about this possibility.

During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from −40 °C to 85 °C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the simulation results have been compared with new experimental data for different filling and emptying strategies. The comparison between experiments and simulations is shown for the temperatures of the gas inside the tank for the temperatures at the interface between the liner and the composite material and for the temperatures on the external surface of the vessel.

There are several alternatives for how to phase out diesel in heavy-duty transports thereby reducing the sector’s climate change impact. This paper assesses the well-to-wheel (WTW) greenhouse gas (GHG) emissions of energy carriers for heavy-duty vehicles analyzing the effect of the carbon intensity of the electricity used in production. The results show that energy carriers with high electricity dependence are not necessarily better than diesel from a WTW perspective. In particular fuels produced through electrolysis are not well suited in carbon-intense electricity systems. Conversely waste-based biofuels have low GHG emissions regardless of the electricity system. Battery-electric buses show a large reduction of GHG emissions compared to diesel buses and many other alternatives while battery-electric trucks have higher GHG emissions than diesel in carbon intense electricity systems. Thus electrifying transports or switching to renewable fuels will not suffice if the electricity system is not made renewable first.

This report provides an outlook for jointly achieving a commercialisation pathway.<br/>Building on the findings of the 2012 FCH JU technology study on alternative powertrains for urban buses this report provides an assessment of the commercialisation pathway from an operational perspective. It reflects the actual situation in which operators deploy large scale demonstration projects in the next years from a rather conservative angle and argues why it makes sense to deploy FC buses now. The insights are based on first-hand data and assessments of the coalition members from the hydrogen and fuel cell industry as well as local governments and public transport operators in Europe.

Power-to-X is one of the most attention-grabbing topics in the energy sector. Researchers are exploring the potential of harnessing power from renewable technologies and converting it into fuels used in various industries and the transportation sector. With the current market and research emphasis on Power-to-X and the accompanying substantial investments a review of Power-to-X is becoming essential. Optimization will be a crucial aspect of managing an energy portfolio that includes Power-to-X and electrolysis systems as the electrolyzer can participate in multiple markets. Based on the current literature and published reviews none of them adequately showcase the state-of-the-art optimization algorithms for energy portfolios focusing on Power-to-X. Therefore this paper provides an in-depth review of the optimization algorithms applied to energy portfolios with a specific emphasis on Power-to-X aiming to uncover the current state-of-the-art in the field.

This article presents an analysis of the permeation tests established in the current regulations for the type-approval of on board tanks in hydrogen vehicles. The analysis is done from the point of view of a test maker regarding the preparation for the execution of a permeation test. The article contains a description of the required instrumentation and set-up to carry out a permeation test according to the applicable standards and regulations. Tank conditions at the beginning of the test configuration of permeation chamber duration of the test or permeation rate to be reported are aspects that are not well-defined in regulations. In this paper we examine the challenges when carrying out a permeation test and propose possible solutions to overcome them with the intention of supporting test makers and helping the development of permeation test guidelines.

China has pledged that it will strive to achieve peak carbon emission by 2030 and realize carbon neutrality by 2060 which has spurred renewed interest in hydrogen for widespread decarbonization of the economy. Hydrogen energy is an important secondary clean energy with the advantage of high density high calorific value rich reserves extensive sources and high conversion efficiency that can be widely used in power generation transportation fuel and other fields. In recent years with the guidance of policies and the progress of technology China’s hydrogen energy industry has developed rapidly. About 42% of China’s carbon emissions comes from the power system and Shenzhen has the largest urban power grid in China. Bringing the utilization of hydrogen energy into Shenzhen’s power system is an important method to achieve industry transformation achieve the “double carbon” goal and promote sustainable development. This paper outlines the domestic and international development status of hydrogen energy introduces the characteristics of Shenzhen new power system the industrial utilization of hydrogen energy and the challenges of further integrating hydrogen energy into Shenzhen new power system and finally suggests on the integration of hydrogen energy into Shenzhen new power system in different dimensions.

Wind curtailment and weak inertia characteristics are two factors that shackle the permeability of wind power. An electric hydrogen production device consumes electricity to produce hydrogen under normal working conditions to solve the problem of abandoning wind. When participating in frequency regulation it serves as a load reduction method to assist the system to rebuild a power balance and improve the wind power permeability. However due to its own working characteristics an electric hydrogen production device cannot undertake the high-frequency component of the frequency regulation power command; therefore an energy storage device was selected to undertake a high-frequency power command to assist the electric hydrogen production device to complete the system frequency regulation. This paper first proposes and analyzes the architecture of a wind storage hydrogen-generating station for centralized hydrogen production with a distributed energy storage and proposes the virtual inertia and droop characteristic mechanism of the wind storage hydrogen-generating station to simulate a synchronous unit. Secondly an alkaline electrolysis cell suitable for large-scale engineering applications is selected as the research object and its mathematical model is established the matching between different energy storage devices and their cooperation in power grid frequency regulation is analyzed and a super capacitor is selected. A control strategy for the wind storage hydrogen-generating power station to participate in power grid frequency regulation with a wide time scale is then proposed. Using the first-order low-pass filter the low-frequency component of the frequency regulation power command is realized by an electric hydrogen production device load reduction and a high-frequency component is realized by the energy storage device. Finally the effectiveness and rationality of the proposed control strategy are verified by establishing the simulation model of the wind storage hydrogen-generating power station with different initial wind speed states comparing the system frequency dip values under the proposed multi-energy cooperative control strategy and a single energy device control strategy.

The free-piston engine is a type of none-crank engine that could be operated under variable compression ratio and this provides it flexible fuel applicability and low engine emission potential. In this work several 1-D engine models including conventional gasoline engines free-piston gasoline engines and free-piston hydrogen engines have been established. Both engine performance and emission performance under engine speeds between 5–11 Hz and with different equivalent ratios have been simulated and compared. Results indicated that the free-piston engine has remarkable potential for NOx reduction and the largest reduction is 57.37% at 6 Hz compared with a conventional gasoline engine. However the figure of NOx from the hydrogen free-piston engine is slightly higher than that of the gasoline free-piston engine and the difference increases with the increase of engine speed. In addition several factors and their relationships related to hydrogen combustion in the free-piston engine have been investigated and results show that the equivalent ratio ϕ = 0.88 is a vital point that affects NOx production and the ignition advance timing could also affect combustion duration the highest in-cylinder temperature and NOx production to a large extent.

Fuel cell electric vehicles (FCEV) are developing quickly from passenger vehicles to trucks or fork-lifts. Policymakers are supporting an ambitious strategy to deploy fuel cell electrical vehicles with infrastructure as hydrogen refueling stations (HRS) as the European Green deal for Europe. The hydrogen fuel quality according to international standard as ISO 14687 is critical to ensure the FCEV performance and that poor hydrogen quality may not cause FCEV loss of performance. However the sampling system is only available for nozzle sampling at HRS. If a FCEV may show a lack of performance there is currently no methodology to sample hydrogen fuel from a FCEV itself. It would support the investigation to determine if hydrogen fuel may have caused any performance loss. This article presents the first FCEV sampling system and its comparison with the hydrogen fuel sampling from the HRS nozzle (as requested by international standard ISO 14687). The results showed good agreement with the hydrogen fuel sample. The results demonstrate that the prototype developed provides representative samples from the FCEV and can be an alternative to determine hydrogen fuel quality. The prototype will require improvements and a larger sampling campaign.

Increasing sales of conventional fuel-based vehicles are leading to an increase in carbon emissions which are dangerous to the environment. To reduce these conventional fuel-based vehicles must be replaced with alternative fuel vehicles such as hydrogen-fueled. Hydrogen can fuel vehicles with near-zero greenhouse gas emissions. However to increase the penetration of such alternative fuel vehicles there needs to be adequate infrastructure specifically refueling infrastructure in place. This paper presents a comprehensive review of the different optimization strategies and methods used in the location of hydrogen refueling stations. The findings of the review in this paper show that there are various methods which can be used to optimally locate refueling stations the most popular being the p-median and flow-capture location models. It is also evident from the review that there are limited studies that consider location strategies of hydrogen refueling stations within a rural setting; most studies are focused on urban locations due to the high probability of penetration into these areas. Furthermore it is apparent that there is still a need to incorporate factors such as the safety elements of hydrogen refueling station construction and for risk assessments to provide more robust realistic solutions for the optimal location of hydrogen refueling stations. Hence the methods reviewed in this paper can be used and expanded upon to create useful and accurate models for a hydrogen refueling network. Furthermore this paper will assist future studies to achieve an understanding of the extant studies on hydrogen refueling station and their optimal location strategies.

Extensive decarbonisation efforts result in major changes in energy demand for the extractive industry. In 2021 the extraction and primary processing of metals and minerals accounted for 4.5 Gt of CO2 eq. per year. The aluminium industry was responsible for 1.1 Gt CO2 eq. direct and indirect emissions. To reach the European milestone of zero emissions by 2050 a reduction of 3% annually is essential. To this end the industry needs to take a turn towards less impactful production practices coupling secondary production with green energy sources. The present work aims to comprehensively compare the lifecycle energy consumption and environmental performance of a secondary aluminium smelter employing alternative thermal and electricity sources. In this frame a comparative analysis of the environmental impact of different thermal energy sources namely natural gas light fuel oil liquified petroleum gas hydrogen and electricity for a secondary aluminium smelter is presented. The results show that H2 produced by renewables (green H2 ) is the most environmentally beneficial option accounting for −84.156 kg CO2 eq. By producing thermal energy as well as electricity on site H2 technologies also serve as a decentralized power station for green energy production. These technologies account for a reduction of 118% compared to conventionally used natural gas. The results offer a comprehensive overview to aid decision-makers in comparing environmental impacts caused by different energy sources.

This report sets out progress against our strategic framework for decarbonising aviation as well as the latest aviation emissions data and updated Jet Zero analysis.<br/>Among the significant milestones achieved since the Jet Zero strategy launch are the:<br/>- agreement at the International Civil Aviation Organization for a long-term aspirational goal for aviation of net zero 2050 carbon dioxide (CO2) emissions for international aviation<br/>- publication of the 2040 zero emissions airport target call for evidence<br/>significant progress on sustainable aviation fuels (SAF) including:<br/>- publishing the second SAF mandate consultation<br/>- launching a second round of the Advanced Fuels Fund<br/>- publishing the Philip New report and the government response on how to develop a UK SAF industry<br/>- publication of the government response to the UK ETS consultation setting out a range of commitments that will enhance the effectiveness of the UK Emissions Trading Scheme (ETS) for aviation<br/>- launch of the expressions of interest for 2 DfT- funded research projects into aviation’s non-CO2 impacts<br/>The report also acknowledges that big challenges remain and we need to continue to work across the aviation sector and with experts across the economy to ensure we continue to make progress on our path to decarbonise aviation.

Gaseous hydrogen for fuel cell electric vehicles must meet quality standards such as ISO 14687:2019 which contains maximal control thresholds for several impurities which could damage the fuel cells or the infrastructure. A review of analytical techniques for impurities analysis has already been carried out by Murugan et al. in 2014. Similarly this document intends to review the sampling of hydrogen and the available analytical methods together with a survey of laboratories performing the analysis of hydrogen about the techniques being used. Most impurities are addressed however some of them are challenging especially the halogenated compounds since only some halogenated compounds are covered not all of them. The analysis of impurities following ISO 14687:2019 remains expensive and complex enhancing the need for further research in this area. Novel and promising analyzers have been developed which need to be validated according to ISO 21087:2019 requirements.

The decreasing abundance of conventional energy resources of nature such as crude oil natural gas and coal is putting forward the issues of energy shortcoming for the future. With a sentiment of this most researchers are now directing either on non-conventional resources that already prevail or invent it. The most promising non-conventional energy resource is the hydrogen energy which can be used in fuel cell to get electricity. Therefore a number of researchers are putting a light on developing the most efficient and affordable fuel cell. This review is mainly focused on the developments of proton exchange membranes (PEMs) in two parts as low and high temperature PEMs for proton exchange membrane fuel cell (PEMFC) and based on that some outperformed PEMs are mentioned in the respective tables. Most of the energy and automobile industries are concentrating to apply PEMFCs for power generation and to apply in vehicles. The cost of PEMFCs is higher due to the manufacturing cost of PEM. Therefore research works in PEMs are now in trend to reduce the cost to improve efficiency and to withstand particular operating conditions. In this review article recent developments in PEM by number of researchers and the importance of it in near future have been elicited.

Currently renewable energy-based generators are considered worldwide to achieve net zero targets. However the stochastic nature of renewable energy systems leads to regulation and control challenges for power system operators especially in remote and regional grids with smaller footprints. A hybrid system (i.e. solar wind biomass energy storage) could minimise this issue. Nevertheless the hybrid system is not possible to develop in many islands due to the limited land area geographical conditions and others. Hydrogen as a carrier of clean energy can be used in locations where the installation of extensive or medium-scale renewable energy facilities is not permissible due to population density geographical constraints government policies and regulatory issues. This paper presents a techno-economic assessment of designing a green hydrogen-based microgrid for a remote island in North-east Australia. This research work determines the optimal sizing of microgrid components using green hydrogen technology. Due to the abovementioned constraints the green hydrogen production system and the microgrid proposed in this paper are located on two separate islands. The paper demonstrates three cost-effective scenarios for green hydrogen production transportation and electricity generation. This work has been done using Hybrid Optimisation Model for Multiple Energy Resources or HOMER Pro simulation platform. Simulation results show that the Levelized Cost of Energy using hydrogen technology can vary from AU$0.37/kWh to AU$1.08/kWh depending on the scenarios and the variation of key parameters. This offers the potential to provide lower-cost electricity to the remote community. Furthermore the CO2 emission could be reduced by 1760777 kg/year if the renewable energy system meets 100% of the electricity demand. Additionally the sensitivity analysis in this paper shows that the size of solar PV and wind used for green hydrogen production can further be reduced by 50%. The sensitivity analysis shows that the system could experience AU$0.03/kWh lower levelized cost if the undersea cable is used to transfer the generated electricity between islands instead of hydrogen transportation. However it would require environmental approval and policy changes as the islands are located in the Great Barrier Reef.