Australia

The MultHyFuel project aims to develop evidence-based guidelines for the safe implementation of Hydrogen Refueling Stations (HRS) in a multi-fuel context. As a part of the generation of good practice guidelines for HRS Hazardous Area Classification (HAC) methodologies were analyzed and applied to case studies representing example configurations of HRS. It has been anticipated that Negligible Extent (NE) classifications might be applicable for sections of the HRS for instance a hydrogen generator. A NE zone requires that an ignition of a flammable cloud would result in negligible consequences. In addition depending on the pressure of the system IEC 60079-10-1:2020 establishes specific requirements in order to classify the hazardous area as being of NE. One such requirement is that a zone of NE shall not be applied for releases from flammable gas systems at pressures above 2000 kPag (20 barg) unless a specific detailed risk assessment is documented. However there is no definition within the standard as to the requirements of the specific detailed risk assessment. In this work an example for a specific detailed risk assessment for the NE classification is presented:<br/>• Firstly the requirements of cloud volume dilution and background concentration for a zone of NE classification from IEC 60079-10-1:2020 are analyzed for hydrogen releases from equipment placed in a mechanically ventilated enclosure.<br/>• Secondly the consequences arising from the ignition of the localized cloud are estimated and compared to acceptable harm criteria in order to assess if negligible consequences are obtained from the scenario.<br/>• In addition a specific qualitative risk assessment for the ignition of the cloud in the enclosure was considered incorporating the estimated consequences and analyzing the available safeguards in the example system.<br/>Recommendations for the specific detailed risk assessment are proposed for this scenario with the intention to support improved definition of the requirement in future revisions of IEC 60079-10-1.

Environmental emissions global warming and energy-related concerns have accelerated the advancements in conventional vehicles that primarily use internal combustion engines. Among the existing technologies hydrogen fuel cell electric vehicles and fuel cell hybrid electric vehicles may have minimal contributions to greenhouse gas emissions and thus are the prime choices for environmental concerns. However energy management in fuel cell electric vehicles and fuel cell hybrid electric vehicles is a major challenge. Appropriate control strategies should be used for effective energy management in these vehicles. On the other hand there has been significant progress in artificial intelligence machine learning and designing data-driven intelligent controllers. These techniques have found much attention within the community and state-of-the-art energy management technologies have been developed based on them. This manuscript reviews the application of machine learning and intelligent controllers for prediction control energy management and vehicle to everything (V2X) in hydrogen fuel cell vehicles. The effectiveness of data-driven control and optimization systems are investigated to evolve classify and compare and future trends and directions for sustainability are discussed.

Global warming is an accepted fact of life on Earth posing grave consequences in the form of weather patterns with life-threatening outcomes for inhabitants and their cultures especially those of island countries. These wild and unpredictable weather patterns have persuaded authorities governments and industrial leaders to adapt a range of solutions to combat the temperature rise on Earth. One such solution is to abandon fossil fuels (hydrocarbons) for energy generation and employ renewable energy sources or at least use energy sources that do not generate greenhouse gases. One such energy carrier is hydrogen which is expected to slowly replace natural gas and will soon be pumped into the energy distribution pipeline network. Since the current energy distribution network was designed for hydrocarbons its use for hydrogen may pose some threat to the safety of urban society. This is the first time an overview article has examined the replacement of hydrocarbons by hydrogen from a totally different angle by incorporating material science viewpoints. This article discusses hydrogen properties and warns about the issue of hydrogen embrittlement in the current pipeline network if hydrogen is to be pumped through the current energy distribution network i.e. pipelines. It is recommended that sufficient study and research be planned and carried out to ensure the safety of using the current energy distribution network for hydrogen distribution and to set the necessary standards and procedures for future design and construction.

Hydrogen has emerged as a promising alternative to meet the growing demand for sustainable and renewable energy sources. Underground hydrogen storage (UHS) in depleted gas reservoirs holds significant potential for large-scale energy storage and the seamless integration of intermittent renewable energy sources due to its capacity to address challenges associated with the intermittent nature of renewable energy sources ensuring a steady and reliable energy supply. Leveraging the existing infrastructure and well-characterized geological formations depleted gas reservoirs offer an attractive option for large-scale hydrogen storage implementation. However significant knowledge gaps regarding storage performance hinder the commercialization of UHS operation. Hydrogen deliverability hydrogen trapping and the equation of state are key areas with limited understanding. This literature review critically analyzes and synthesizes existing research on hydrogen storage performance during underground storage in depleted gas reservoirs; it then provides a high-level risk assessment and an overview of the techno-economics of UHS. The significance of this review lies in its consolidation of current knowledge highlighting unresolved issues and proposing areas for future research. Addressing these gaps will advance hydrogen-based energy systems and support the transition to a sustainable energy landscape. Facilitating efficient and safe deployment of UHS in depleted gas reservoirs will assist in unlocking hydrogen’s full potential as a clean and renewable energy carrier. In addition this review aids policymakers and the scientific community in making informed decisions regarding hydrogen storage technologies.

The addition of small amounts of certain gases such as O2 CO and SO2 may mitigate hydrogen embrittlement in high-pressure gas transmission pipelines that transport hydrogen. To practically implement such inhibition in gas transmission pipelines a comprehensive understanding and quantification of this effect are essential. This review examines the impact of various added gases to hydrogen including typical odorants on gaseous hydrogen embrittlement of steels and evaluates their inhibition effectiveness. O2 CO and SO2 were found to be effective inhibitors of hydrogen embrittlement. Yet the results in the literature have not always been consistent partly because of the diverse range of mechanical tests and their parameters. The absence of systematic studies hinders the evaluation of the feasibility of using gas phase inhibitors for controlling gaseous hydrogen embrittlement. A method to quantify the effectiveness of gas phase inhibition is proposed using gas phase permeation studies.

The transition from fossil fuels to renewable energy sources particularly hydrogen has emerged as a central strategy for decarbonization and the pursuit of net-zero carbon emissions. Meeting the demand for large-scale hydrogen storage a crucial component of the hydrogen supply chain has led to the exploration of underground hydrogen storage as an economically viable solution to global energy needs. In contrast to other subsurface storage options such as salt caverns and aquifers which are geographically limited depleted gas reservoirs have garnered increasing attention due to their broader distribution and higher storage capacity. However the safe storage and cycling of hydrogen in depleted gas reservoirs require the preservation of high stability and integrity in the caprock reservoir and wellbore. Nevertheless there exists a significant gap in the current research concerning storage integrity in underground hydrogen storage within depleted gas reservoirs and a systematic approach is lacking. This paper aims to address this gap by reviewing the primary challenges associated with storage integrity including geochemical reactions microbial activities faults and fractures and perspectives on hydrogen cycling. The study comprehensively reviews the processes and impacts such as abiotic and biotic mineral dissolution/precipitation reactivation and propagation of faults and fractures in caprock and host-rock wellbore instability due to cement degradation and casing corrosion and stress changes during hydrogen cycling. To provide a practical solution a technical screening tool has been developed considering controlling variables risks and consequences affecting storage integrity. Finally this paper highlights knowledge gaps and suggests feasible methods and pathways to mitigate these risks facilitating the development of large-scale underground hydrogen storage in depleted gas reservoirs.

Hydrogen is the gas of the moment: an abundant element that can be created using renewable energy transported in gaseous or liquid form and offering the ability to provide energy with only water vapour as an emission. Hydrogen can also be used in a fuel blend in electricity generation gas turbines providing a low carbon option for providing the peak electricity to cover high demand and firming.<br/>While the electricity grid is itself transforming to decarbonising hard-to-abate industries such as cement and bauxite refineries are slower to reduce emissions constrained by their high temperature process requirements. Hydrogen offers a solution allowing onsite production process heat with waste heat recovery supporting blended gas turbine generation for onsite electricity supply.<br/>This article builds on decarbonisation pathway simulation results from an ANEM model of the electricity grid identifying the amount of peak demand energy required from gas turbines. The research then examines the quantity flow rate storage requirements and emissions reduction if this peak generation were supplied by open cycle hydrogen capable gas turbines.

Installing multi-renewable energy (RE) power plants at designated locations known as RE parks is a promising solution to address their intermittent power. This research focuses on optimizing RE parks for three scenarios: photovoltaic (PV)-only wind-only and hybrid PV-wind with the aim of generating green hydrogen in locations with different RE potentials. To ensure rapid response to RE fluctuations a Proton Exchange Membrane (PEM) electrolyzer is employed. Furthermore this research proposes detailed models for manufacturer-provided wind power curves electrolyzer efficiency against its operating power and electrolyzer cost towards its capacity. Two optimization cases are conducted in MATLAB evaluating the optimum sizes of the plants in minimizing levelized cost of hydrogen (LCOH) using classical discrete combinatorial method and determining the ideal PV-to-wind capacity ratio for operating PEM electrolyzer within hybrid PV-wind parks using particle swarm optimization. Numerical simulations show that wind power-based hydrogen production is more cost-effective than PV-only RE parks. The lowest LCOH $4.26/kg H2 and the highest LCOH $14.378/kg H2 are obtained from wind-only and PV-only configurations respectively. Both occurred in Adum-Kirkeby Denmark as it has highest average wind speed and lowest irradiance level. Notably LCOH is reduced with the hybrid PV-wind configuration. The results suggest the optimum PV-to-wind capacity ratio is 65:35 on average and indicate that LCOH is more sensitive to electrolyzer’s cost than to electricity tariff variation. This study highlights two important factors i.e. selecting the suitable location based on the available RE resources and determining the optimum size ratio between the plants within the RE park.

Hydrogen as a primary carbon-free energy carrier is confronted by challenges in storage and transportation. However liquid organic hydrogen carriers (LOHCs) present a promising solution for storing and transporting hydrogen at ambient temperature and atmospheric pressure. Unlike circular energy carriers such as methanol ammonia and synthetic natural gas LOHCs do not produce by-products during hydrogen recovery. LOHCs only act as hydrogen carriers and the carriers can also be recycled for reuse. Although there are considerable advantages to LOHCs there are also some drawbacks especially relative to the energy consumption during the dehydrogenation step of the LOHC recycling. This review summarizes the recent progresses in LOHC technologies focusing on catalyst developments process and reactor designs applications and techno-economic assessments (TEA). LOHC technologies can potentially offer significant benefits to Australia especially in terms of hydrogen as an export commodity. LOHCs can help avoid capital costs associated with infrastructure such as transportation vessels while reducing hydrogen loss during transportation such as in the case of liquid hydrogen (LH2). Additionally it minimises CO2 emissions as observed in methane and methanol reforming. Thus it is essential to dedicate more efforts to explore and develop LOHC technologies in the Australian context.

The shift from fossil fuels to clean energy carriers such as renewable H2 is imminent. Consequently a global H2 market is taking shape involving countries with limited or insufficient energy resources importing from renewable-rich countries. This study evaluates the techno-economics of renewable hydrogen (H2) export in a globally significant scenario in which Australia exports to Japan. To gain insight into the immediate realisable future the base year was selected as 2030 with a consequently small (in export terms) hydrogen production rate of 100 t/day landed capacity. Electricity was generated by photovoltaic arrays (PV) connected directly to proton exchange membrane (PEM) electrolyser plant allowing for flexible gaseous hydrogen (GH2) production. To enhance the fidelity of the technoeconomic model we incorporated rarely applied but impactful parameters including dynamic efficiency and the overload capacity of PEM electrolysers. The GH2 produced was assumed to be converted into condensed forms suitable for export by sea: liquid hydrogen (LH2) and the chemical carriers liquid ammonia (LNH3) methanol (MeOH) methylcyclohexane (MCH). These were assumed to be reconverted to GH2 at the destination. LNH3 and MCH emerged as promising carriers for export yielding the lowest landed levelised cost of hydrogen (LCOH). LH2 yielded the highest LCOH unless boiloff gas could be managed effectively and cheaply. A sensitivity analysis showed that a lower weighted average cost of capital (WACC) and scale-up can significantly reduce the landed LCOH. Increasing the production rate to 1000 t/day landed capacity very significantly lowered the landed LCOH providing a strong incentive to scale up and optimise the entire supply chain as fast as possible.