Publications

This study presents a novel web-based decision support system (DSS) that optimizes the locations of hydrogen refueling stations (HRSs) and hydrogen supply chains (HSCs). The system is developed with a design science approach that identifies key design requirements and features through interviews and literature reviews. Based on the findings a system architecture and data model were designed incorporating scenario management optimization model visualization and data management components. The DSS provides a two-stage solution model that links demand to HRSs and production facilities to HRSs. A prototype is demonstrated with a plan for 2025 and 2030 in the Republic of Korea where 450 to 660 stations were deployed nationwide and linked to production facilities. User evaluation confirmed the effectiveness of the DSS in solving optimization problems and its potential to assist the government and municipalities in planning hydrogen infrastructure.

Alkaline electrolyzers are the most widespread technology due to their maturity low cost and large capacity in generating hydrogen. However compared to proton exchange membrane (PEM) electrolyzers they request the use of potassium hydroxide (KOH) or sodium hydroxide (NaOH) since the electrolyte relies on a liquid solution. For this reason the performances of alkaline electrolyzers are governed by the electrolyte concentration and operating temperature. Due to the growing development of the water electrolysis process based on alkaline electrolyzers to generate green hydrogen from renewable energy sources the main purpose of this paper is to carry out a comprehensive survey on alkaline electrolyzers and more specifically about their electrical domain and specific electrolytic conductivity. Besides this survey will allow emphasizing the remaining key issues from the modeling point of view.

The negative environmental impact of carbon emissions from fossil fuels has promoted hydrogen utilization and storage in underground structures. Hydrogen leakage from storage structures through wells is a major concern due to the small hydrogen molecules that diffuse fast in the porous well cement sheath. The second-order parabolic partial differential equation describing the hydrogen diffusion in well cement was solved numerically using the finite difference method (FDM). The numerical model was verified with an analytical solution for an ideal case where the matrix and fluid have invariant properties. Sensitivity analyses with the model revealed several possibilities. Based on simulation studies and underlying assumptions such as non-dissolvable hydrogen gas in water present in the cement pore spaces constant hydrogen diffusion coefficient cement properties such as porosity and saturation etc. hydrogen should take about 7.5 days to fully penetrate a 35 cm cement sheath under expected well conditions. The relatively short duration for hydrogen breakthrough in the cement sheath is mainly due to the small molecule size and high hydrogen diffusivity. If the hydrogen reaches a vertical channel behind the casing a hydrogen leak from the well is soon expected. Also the simulation result reveals that hydrogen migration along the axial direction of the cement column from a storage reservoir to the top of a 50 m caprock is likely to occur in 500 years. Hydrogen diffusion into cement sheaths increases with increased cement porosity and diffusion coefficient and decreases with water saturation (and increases with hydrogen saturation). Hence cement with a low water-to-cement ratio to reduce water content and low cement porosity is desirable for completing hydrogen storage wells.

The supply storage and (international) transport of green hydrogen (H2) are essential for the decarbonization of the energy sector. The goal of this study was to assess the final cost-price and carbon footprint of imported green H2 in the market via maritime shipping of liquid organic hydrogen carriers (LOHCs) including dibenzyl toluene-perhydro-dibenzyltoluene (DBTPDBT) and toluene-methylcyclohexane (TOL-MCH) systems. The study focused on logistic steps in intra-European supply chains in different scenarios of future production in Portugal and demand in the Netherlands and carbon tariffs between 2030 and 2050. The case study is based on a formally accepted agreement between Portugal and the Netherlands within the Strategic Forum on Important Projects of Common European Interest (IPCEI). Under the following assumptions the results show that LOHCs are a viable technical-economic solution with logistics costs from 2030 to 2050 varying between 0.30-0.37 €/kg-H2 for DBT-PDBT and 0.28-0.34 €/kg-H2 for TOL-MCH. The associated CO2 emissions of these international H2 supply chains are between 0.46 and 2.46 kg-CO2/GJ (LHV) and 0.55-2.95 kg-CO2/GJ (LHV) for DBT-PDBT and TOL-MCH respectively.

As the world moves to clean renewable energy questions arise as to how best to produce and use hydrogen. Here we propose using hydrogen produced only by electrolysis with clean renewable electricity (green hydrogen). We then test the impact of producing such hydrogen intermittently versus continuously for steel and ammonia manufacturing and long-distance transport via fuel cells on the cost of matching electricity heat cold and hydrogen demand with supply and storage on grids worldwide. An estimated 79 32 and 91 Tg-H2/y of green hydrogen are needed in 2050 among 145 countries for steel ammonia and long-distance transport respectively. Producing and compressing such hydrogen for these processes may consume ~12.1% of the energy needed for end-use sectors in these countries after they transition to 100% wind-water-solar (WWS) in all such sectors. This is less than the energy needed for fossil fuels to power the same processes. Due to the variability of WWS electricity producing green hydrogen intermittently rather than continuously thus with electrolyzer use factors significantly below unity (0.2–0.65) may reduce overall energy costs with 100% WWS. This result is subject to model uncertainties but appears robust. In sum grid operators should incorporate intermittent green hydrogen production and use in planning.

Modernising Australia’s old truck fleet and adopting a more stringent standard to reduce emissions and air pollutants is a primary objective for the Australian truck sector. Various strategies worldwide have been introduced to cut emissions and pollutants in the truck sector such as a low-emission strategy supported by strict diesel standards and a zero-emission strategy to shift to battery-electric or hydrogen trucks. The paper focuses on emissions and local air pollutants of trucks under various transition scenarios at both the tailpipe and the wider supply chain including domestic power generation and hydrogen production. In contrast for diesel we focus on tailpipe outputs following fuel standards in Australia given diesel is imported other than in some limited refineries. We compare and recommend actions that government and truck operators may take in the near to longer term in transitioning to cleaner energy. We tested a number of scenarios using a decision support system incorporating all the latest information on costs and emissions for all truck classes using diesel electric or hydrogen. A key finding from our scenario tests is that the current electricity mix has high carbon emissions and air pollutants due to fossil fuel-fired sources for power generation. Without improvement in using renewable energy sources in the future transitioning to electric trucks implies more carbon emissions and air pollutants in the atmosphere from power plants even though electric trucks generate zero tailpipe emissions. The main motivation for switching to zero-emission trucks is energy cost savings. We urge the government to decide on a clear roadmap for the truck sector before the sector is in a position to take action to shift to low or zero-emission trucks without totally relying on the likely reduction of emission intensity in electricity and renewable energy production.

Green hydrogen is gaining increasing attention as a key component of the global energy transition towards a more sustainable industry. Chile with its vast renewable energy potential is well positioned to become a major producer and exporter of green hydrogen. In this context this paper explores the prospects for green hydrogen production and use in Chile. The perspectives presented in this study are primarily based on a compilation of government reports and data from the scientific literature which primarily offer a theoretical perspective on the efficiency and cost of hydrogen production. To address the need for experimental data an ongoing experimental project was initiated in March 2023. This project aims to assess the efficiency of hydrogen production and consumption in the Atacama Desert through the deployment of a mobile on-site laboratory for hydrogen generation. The facility is mainly composed by solar panels electrolyzers fuel cells and a battery bank and it moves through the Atacama Desert in Chile at different altitudes from the sea level to measure the efficiency of hydrogen generation through the energy approach. The challenges and opportunities in Chile for developing a robust green hydrogen economy are also analyzed. According to the results Chile has remarkable renewable energy resources particularly in solar and wind power that could be harnessed to produce green hydrogen. Chile has also established a supportive policy framework that promotes the development of renewable energy and the adoption of green hydrogen technologies. However there are challenges that need to be addressed such as the high capital costs of green hydrogen production and the need for supportive infrastructure. Despite these challenges we argue that Chile has the potential to become a leading producer and exporter of green hydrogen or derivatives such as ammonia or methanol. The country’s strategic location political stability and strong commitment to renewable energy provide a favorable environment for the development of a green hydrogen industry. The growing demand for clean energy and the increasing interest in decarbonization present significant opportunities for Chile to capitalize on its renewable energy resources and become a major player in the global green hydrogen market.

The investment in hydrogen-refueling stations (HRS) is key to the development of a hydrogen economy. This paper focuses on the decision-making for potential investors faced with the thought-provoking question of when the optimal timing to invest in HRS is. To fill the gap that exists due to the fact that few studies explain why HRS investment timing is critical we expound that earlier investment in HRS could induce the first mover advantages of the technology diffusion theory. Additionally differently from the previous research that only considered that HRS investment is just made by one individual firm we innovatively examine the HRS co-investment made by two different firms. Accordingly we compare these two optional investment modes and determine which is better considering either independent investment or co-operative investment. We then explore how the optimal HRS investment timing could be figured out under conditions of uncertainty with the real options approach. Given the Chinese HRS case under the condition of demand uncertainty the hydrogen demand required for triggering investment is viewed as the proxy for investment timing. Based on analytical and numerical results we conclude that one-firm independent investment is better than two-firm cooperative investment to develop HRS not only in terms of the earlier investment timing but also in terms of the attribute for dealing with the uncertainty. Finally we offer recommendations including stabilizing the hydrogen demand for decreasing uncertainty and accelerating firms’ innovation from both technological and strategic perspectives in order to ensure firms can make HRS investments on their own.

The green hydrogen industry highly efficient and safe is endowed with flexible production and low carbon emissions. It is conducive to building a low-carbon efficient and clean energy structure optimizing the energy industry system and promoting the strategic transformation of energy development and enhancing energy security. In order to achieve carbon emission peaking by 2030 and neutrality by 2060 (dual carbon goals) China is vigorously promoting the green hydrogen industry. Based on an analysis of the green hydrogen industry policies of the U.S. the EU and Japan this paper explores supporting policies issued by Chinese central and local authorities and examines the inherent advantages of China’s green hydrogen industry. After investigating and analyzing the basis for the development of the green hydrogen industry in China we conclude that China has enormous potential including abundant renewable energy resources as well as commercialization experience with renewable energy robust infrastructure and technological innovation capacity demand for large-scale applications of green hydrogen in traditional industries etc. Despite this China’s green hydrogen industry is still in its early stage and has encountered bottlenecks in its development including a lack of clarity on the strategic role and position of the green hydrogen industry low competitiveness of green hydrogen production heavy reliance on imports of PEMs perfluorosulfonic acid resins (PFSR) and other core components the development dilemma of the industry chain lack of installed capacity for green hydrogen production and complicated administrative permission etc. This article therefore proposes that an appropriate development road-map and integrated administration supervision systems including safety supervision will systematically promote the green hydrogen industry. Enhancing the core technology and equipment of green hydrogen and improving the green hydrogen industry chain will be an adequate way to reduce dependence on foreign technologies lowering the price of green hydrogen products through the scale effect and thus expanding the scope of application of green hydrogen. Financial support mechanisms such as providing tax breaks and project subsidies will encourage enterprises to carry out innovative technological research on and invest in the green hydrogen industry.

Hydrogen (H2) usage was 90 metric tonnes (Mt) in 2020 almost entirely for industrial and refining uses and generated almost completely from fossil fuels leading to nearly 900 Mt of carbon dioxide emissions. However there has been significant growth of H2 in recent years. Electrolysers' total capacity which are required to generate H2 from electricity has multiplied in the past years reaching more than 300 MW through 2021. Approximately 350 projects reportedly under construction could push total capacity to 54 GW by the year 2030. Some other 40 projects totalling output of more than 35 GW are in the planning phase. If each of these projects is completed global H2 production from electrolysers could exceed 8 Mt by 2030. It's an opportunity to take advantage of H2S prospects to be a crucial component of a clean safe and cost-effective sustainable future. This paper assesses the situation regarding H2 at the moment and provides recommendations for its potential future advancement. The study reveals that clean H2 is experiencing significant unparalleled commercial and political force with the amount of laws and projects all over the globe growing quickly. The paper concludes that in order to make H2 more widely employed it is crucial to significantly increase innovations and reduce costs. The practical and implementable suggestions provided to industries and governments will allow them to fully capitalise on this growing momentum.

Although hydrogen leakage at hydrogen refueling stations has been a concern less effort has been devoted to hydrogen leakage during the refueling of hydrogen-powered vehicles. In this study hydrogen leakage and dilution from the hydrogen dispenser during the refueling of hydrogen-powered vehicles were numerically investigated under different wind configurations. The shape size and distribution of flammable gas clouds (FGC) during the leakage and dilution processes were analyzed. The results showed that the presence of hydrogen-powered vehicles resulted in irregular FGC shapes. Greater wind speeds (vwv) were associated with longer FGC propagation distances. At vwv =2 m/s and 10 m/s the FGC lengths at the end of the leakage were 7.9 m and 20.4 m respectively. Under downwind conditions higher wind speeds corresponded to lower FGC heights. The FGC height was larger under upwind conditions and was slightly affected by the magnitude of the wind speed. In the dilution process the existence of a region with a high hydrogen concentration led to the FGC volume first increasing and then gradually decreasing. Wind promoted the mixing of hydrogen and air accelerated FGC dilution inhibited hydrogen uplifting and augmented the horizontal movement of the FGC. At higher wind speeds the low-altitude FGC movements could induce potential safety hazards.

Many factors to be appropriately addressed in moving towards energy sustainability are examined. These include harnessing sustainable energy sources utilizing sustainable energy carriers increasing efficiency reducing environmental impact and improving socioeconomic acceptability. The latter factor includes community involvement and social acceptability economic affordability and equity lifestyles land use and aesthetics. Numerous illustrations demonstrate measures consistent with the approach put forward and options for energy sustainability and the broader objective of sustainability. Energy sustainability is of great importance to overall sustainability given the pervasiveness of energy use its importance in economic development and living standards and its impact on the environment.

In this paper by using a large eddy simulation we study the combustion process in the HyShot II scramjet combustor. By conducting a detailed analysis of the mass-fraction distributions of the main species such as H2 H2O and the radicals OH and HO2 of the mass source terms of these main species and of the chemical source term of the energy equation we detect the regions where chemical reactions occur through a diffusion process and the regions where auto-ignition and premixed combustion may develop. The analysis indicates that the combustion process is mainly of diffusive type along a thin shear layer enveloping the hydrogen plume whereas there could be some auto-ignition and/or premixed combustion cores inside the plume.

The topic of energy islands is currently a focal point in the push for the energy transition. An ambitious project in the North Sea aims to build an offshore wind-powered electrolyser for green hydrogen production. Power-to-X (PtX) is a process of converting renewable electricity into hydrogen-based energy carriers such as natural gas liquid fuels and chemicals. PtH2 represents a subset of PtX wherein hydrogen is the resultant green energy from the conversion process. Many uncertainties surround PtH2 plants affecting the economic success of the investment and making the price of hydrogen and the levelized cost of hydrogen (LCOH) of this technology uncompetitive. Several studies have analysed PtH2 layouts to identify the hydrogen price without considering how component capacities and external inputs affect the breakeven price. Unlike previous works this paper investigates component capacity dependencies under variables such as wind and hydrogen demand shape for dedicated/non-dedicated system layouts. To this end the techno-economic analysis finds the breakeven price optimising the components to reach the lowest selling price. Results show that the hydrogen price can reach 2.2 €/kg for a non-dedicated system for certain combinations of maximum demand and electrolyser capacity. Furthermore the LCOH analysis revealed that the offshore wind electrolyser system is currently uncompetitive with hydrogen production from carbon-based technologies but is competitive with renewable technologies. The sensitivity analysis reveals the green electricity price in the non-dedicated case for which a dedicated system has a lower optimum hydrogen price. The price limit for the dedicated case is 116 €/MWh.

The UK government’s plans to decarbonise residential heating will mean major changes to the energy system whatever the specific technology pathway chosen driving a range of impacts on users and suppliers. We use an energy system model (UK TIMES) to identify the potential energy system impacts of alternative pathways to low or zero carbon heating. We find that the speed of transitioning can affect the network investment requirements the overall energy use and emissions generated while the primary heating fuel shift will determine which sectors and networks require most investment. Crucially we identify that retail price differences between heating fuels in the UK particularly gas and electricity could erode or eliminate bill savings from switching to more efficient heating systems.

Hydrogen is emerging as one of the most promising energy carriers for a decarbonised global energy system. Transportation and storage of hydrogen are critical to its large-scale adoption and to these ends liquid hydrogen is being widely considered. The liquefaction and storage processes must however be both safe and efficient for liquid hydrogen to be viable as an energy carrier. Identifying the most promising liquefaction processes and associated transport and storage technologies is therefore crucial; these need to be considered in terms of a range of interconnected parameters ranging from energy consumption and appropriate materials usage to considerations of unique liquid-hydrogen physics (in the form of ortho–para hydrogen conversion) and boil-off gas handling. This study presents the current state of liquid hydrogen technology across the entire value chain whilst detailing both the relevant underpinning science (e.g. the quantum behaviour of hydrogen at cryogenic temperatures) and current liquefaction process routes including relevant unit operation design and efficiency. Cognisant of the challenges associated with a projected hydrogen liquefaction plant capacity scale-up from the current 32 tonnes per day to greater than 100 tonnes per day to meet projected hydrogen demand this study also reflects on the next-generation of liquid-hydrogen technologies and the scientific research and development priorities needed to enable them.

Green hydrogen produced by water electrolysis is one of the most promising technologies to realize the efficient utilization of intermittent renewable energy and the decarbonizing future. Among various electrolysis technologies the emerging anion-exchange membrane water electrolysis (AEMWE) shows the most potential for producing green hydrogen at a competitive price. In this review we demonstrate a comprehensive introduction to AEMWE including the advanced electrode design the lab-scaled testing system establishment and the electrochemical performance evaluation. Specifically recent progress in developing high activity transition metal-based powder electrocatalysts and self-supporting electrodes for AEMWE is summarized. To improve the synergistic transfer behaviors between electron charge water and gas inside the gas diffusion electrode (GDE) two optimizing strategies are concluded by regulating the pore structure and interfacial chemistry. Moreover we provide a detailed guideline for establishing the AEMWE testing system and selecting the electrolyzer components. The influences of the membrane electrode assembly (MEA) technologies and operation conditions on cell performance are also discussed. Besides diverse electrochemical methods to evaluate the activity and stability implement the failure analyses and realize the in-situ characterizations are elaborated. In end some perspectives about the optimization of interfacial environment and cost assessments have been proposed for the development of advanced and durable AEMWE.

In recent years sustainable development has become a challenge for many societies due to natural or other disruptive events which have disrupted economic environmental and energy infrastructure growth. Developing hydrogen energy infrastructure is crucial for sustainable development because of its numerous benefits over conventional energy sources. However the complexity of hydrogen energy infrastructure including production utilization and storage stages requires accounting for potential vulnerabilities. Therefore resilience needs to be considered along with sustainable development. This paper proposes a decision-making framework to evaluate the resilience of hydrogen energy infrastructure by integrating resilience indicators and sustainability contributing factors. A holistic taxonomy of resilience performance is first developed followed by a qualitative resilience assessment framework using a novel Intuitionistic fuzzy Weighted Influence Nonlinear Gauge System (IFWINGS). The results highlighted that Regulation and legislation Government preparation and Crisis response budget are the most critical resilience indicators in the understudy hydrogen energy infrastructure. A comparative case study demonstrates the practicality capability and effectiveness of the proposed approach. The results suggest that the proposed model can be used for resilience assessment in other areas.

With the development of hydrogen energy containerized hydrogen fuel cell systems are being used in distributed energy-supply systems. Hydrogen pipelines and electronic equipment of fuel cell containers can trigger hydrogen-explosion accidents. In the present study Computational Fluid Dynamics (CFD) software was used to calculate the affected areas of hydrogen fuel cell container-explosion accidents with and without protective walls. The protective effects were studied for protective walls at various distances and heights. The results show that strategically placing protective walls can effectively block the propagation of shock waves and flames. However the protective wall has a limited effect on the reduction of overpressure and temperature behind the wall when the protective wall is insufficiently high. Reflected explosion shock waves and flames will cause damage to the area inside the wall when the protective wall is too close to the container. In this study a protective wall that is 5 m away from the container and 3 m high can effectively protect the area behind the wall and prevent damage to the container due to the reflection of shock waves and flame. This paper presents a suitable protective wall setting scheme for hydrogen fuel cell containers.

A global energy shift to a carbon‐neutral society requires clean energy. Hydrogen can accelerate the process of expanding clean and renewable energy sources. However conventional hydrogen compression and storage technology still suffers from inefficiencies high costs and safety concerns. An electrochemical hydrogen compressor (EHC) is a device similar in structure to a water electrolyzer. Its most significant advantage is that it can accomplish hydrogen separation and compression at the same time. With no mechanical motion and low energy consumption the EHC is the key to future hydrogen compression and purification technology breakthroughs. In this study the compression performance efficiency and other related parameters of EHC are investigated through experiments and simulation calculations. The experimental results show that under the same experimental conditions increasing the supply voltage and the pressure in the anode chamber can improve the reaction rate of EHC and balance the pressure difference between the cathode and anode. The presence of residual air in the anode can impede the interaction between hydrogen and the catalyst as well as the proton exchange membrane (PEM) resulting in a decrease in performance. In addition it was found that a single EHC has a better compression ratio and reaction rate than a double EHC. The experimental results were compatible with the theoretical calculations within less than a 7% deviation. Finally the conditions required to reach commercialization were evaluated using the theoretical model.

Bangladesh focuses on green energy sources to be a lesser dependent on imported fossil fuels and to reduce the GHG emission to decarbonize the energy sector. The integration of renewable energy technologies for green hydrogen production is promising for Bangladesh. Hybrid renewable plants at the coastline along the Bay of Bengal Kuakata Sandwip St. Martin Cox’sbazer and Chattogram for green hydrogen production is very promising to solve the power demand scarcity of Bangladesh. Hydrogen gas turbine and hydrogen fuel cell configured power plant performances are studied to observe the feasibility/prospect to the green energy transition. The Plant’s performances investigated based on specification of the plant’s units and verified by MATLAB SIMULINK software. Fuels blending (different percent of hydrogen with fossil fuel/NG) technique makes the hydrogen more feasible as turbine fuel. The net efficiency of the fuel cell-based combined cycle configuration (74%) is higher than that of the hydrogen gas turbine-based configuration (51.9%). Moreover analyses show that the increment of combined cycle gas turbine efficiency (+18.5%) is more than the combined cycle PEMFC configuration (+14%). Long-term storage of renewable energy in the salt cavern as green hydrogen can be a source of energy for emergency. A significant share of power can be generated by a numbers of green power plants at specified places in Bangladesh.

The increasing demand for sustainable air mobility has led to the development of innovative aircraft designs necessitating a balance between environmental responsibility and profitability. However despite technological advancements there is still limited understanding of the maintenance implications for hydrogen systems in aviation. The aim of this study is to estimate the maintenance costs of replacing the hydrogen storage system in an aircraft as part of its life cycle costs. To achieve this we compared conventional and hydrogenpowered aircraft. As there is insufficient data for new aircraft concepts typical probabilistic methods are not applicable. However by combining global sensitivity analysis with Dempster–Shafer Theory of Evidence and discrete event simulation it is possible to identify key uncertainties that impact maintenance costs and economic efficiency. This innovative framework offers an early estimate of maintenance costs under uncertainty enhancing understanding and assisting in decision-making when integrating hydrogen storage systems and new aviation technologies.

The need to reduce the dependency of chemicals on fossil fuels has recently motivated the adoption of renewable energies in those sectors. In addition due to a growing population the treatment and disposition of residual biomass from agricultural processes such as sugar cane and orange bagasse or even from human waste such as sewage sludge will be a challenge for the next generation. These residual biomasses can be an attractive alternative for the production of environmentally friendly fuels and make the economy more circular and efficient. However these raw materials have been hitherto widely used as fuel for boilers or disposed of in sanitary landfills losing their capacity to generate other by-products in addition to contributing to the emissions of gases that promote global warming. For this reason this work analyzes and optimizes the biomass-based routes of biochemical production (namely hydrogen and ammonia) using the gasification of residual biomasses. Moreover the capture of biogenic CO2 aims to reduce the environmental burden leading to negative emissions in the overall energy system. In this context the chemical plants were designed modeled and simulated using Aspen plus™ software. The energy integration and optimization were performed using the OSMOSE Lua Platform. The exergy destruction exergy efficiency and general balance of the CO2 emissions were evaluated. As a result the irreversibility generated by the gasification unit has a relevant influence on the exergy efficiency of the entire plant. On the other hand an overall negative emission balance of −5.95 kgCO2/kgH2 in the hydrogen production route and −1.615 kgCO2/kgNH3 in the ammonia production route can be achieved thus removing from the atmosphere 0.901 tCO2/tbiomass and 1.096 tCO2/tbiomass respectively.

Facing global warming and recent bans on the use of diesel in vehicles there is a growing need to develop vehicles powered by renewable energy sources to mitigate greenhouse gas and pollutant emissions. Among the various forms of non-fossil energy for vehicles hydrogen fuel is emerging as a promising way to combat global warming. To date most studies on vehicle carbon emissions have focused on diesel and electric vehicles (EVs). Emission assessment methodologies are usually developed for fast-moving consumer goods (FMCG) which are non-durable household goods such as packaged foods beverages and toiletries instead of vehicle products. There is an increase in the number of articles addressing the product carbon footprint (PCF) of hydrogen fuel cell vehicles in the recent years while relatively little research focuses on both vehicle PCF and fuel cycle. Zero-emission vehicles initiative has also brought the importance of investigating the emission throughout the fuel cycle of hydrogen fuel cell and its environmental impact. To address these gaps this study uses the life-cycle assessment (LCA) process of GREET (greenhouse gases regulated emissions and energy use in transportation) to compare the PCF of an EV (Tesla Model 3) and a hydrogen fuel cell car (Toyota MIRAI). According to the GREET results the fuel cycle contributes significantly to the PCF of both vehicles. The findings also reveal the need for greater transparency in the disclosure of relevant information on the PCF methodology adopted by vehicle manufacturers to enable comparison of their vehicles’ emissions. Future work will include examining the best practices of PCF reporting for vehicles powered by renewable energy sources as well as examining the carbon footprints of hydrogen production technologies based on different methodologies.

This review focuses on the energy structure of iron and steel production and a feasible development path for carbon reduction. The process path and feasible development direction of carbon emission reduction in the iron and steel industry have been analyzed from the perspective of the carbon–electricity–hydrogen ternary relationship. Frontier technologies such as “hydrogen replacing carbon” are being developed worldwide. Combining the high efficiency of microwave electric-thermal conversion with the high efficiency and pollution-free advantages of hydrogen-reducing agents may drive future developments. In this review a process path for “microwave + hydrogen” synergistic metallurgy is proposed. The reduction of magnetite powder by H2 (CO) in a microwave field versus in a conventional field is compared. The driving effect of the microwave field is found to be significant and the synergistic reduction effect of microwaves with H2 is far greater than that of CO.