Australia

This study presents a technoeconomic analysis of renewables-based hydrogen production in Queensland Australia under Optimistic Reference and Pessimistic scenarios to address uncertainty in cost predictions. The goal of the work was to ascertain if the target fam-gate cost of AUD 3/kg (approx. USD 2/kg) could be reached. Economies of scale and the learning rate concept were factored into the economic model to account for the effect of scale-up and cost reductions as electrolyser manufacturing capacity grows. The model assumes that small-scale to large-scale wind turbine (WT)-based and photovoltaic (PV)-based power generation plants are directly coupled with an electrolyser array and utilises hourly generation data for the Gladstone hydrogen-hub region. Employing first a commonly used simplified approach the electrolyser array was sized based on the maximum hourly power available for hydrogen production. The initial results indicated that scale-up is very beneficial: the levelised cost of green hydrogen (LCOH) could decrease by 49% from $6.1/kg to $3.1/kg when scaling PV-based plant from 10 MW to 1 GW and for WT-based plant by 36% from $5.8/kg to $3.7/kg. Then impacts on the LCOH of incorporating curtailment of ineffective peak power and electrolyser overload capacity were investigated and shown to be significant. Also significant was the beneficial effect of recognising that electrolyser efficiency depends on input power. The latter two factors have mostly been overlooked in the literature. Incorporating in the model the influence on the LCOH of real-world electrolyser operational characteristics overcomes a shortcoming of the simplified sizing method namely that a large portion of electrolyser capacity is under-utilised leading to unnecessarily high values of the LCOH. It was found that AUD 3/kg is achievable if the electrolyser array is properly sized which should help to incentivise large-scale renewable hydrogen projects in Australia and elsewhere.

The abundant plastic wastes become an imperative global issue and how to handle these organic wastes gains growing scientific and industrial interest. Recently converting plastic wastes into hydrogen fuel has been investigated and the “waste-to-value” practice accelerates the circular economy. To accelerate the development of plastic-to-hydrogen conversion in this review recent advances in plastic-to-hydrogen conversion via thermochemical photocatalytic and electrocatalytic routes are analyzed. All of the thermo- photo- and electrochemical processes can transform different plastic wastes into hydrogen and the hydrogen production efficiency depends heavily on the selected techniques operating parameters and applied catalysts. The application of rational-designed catalysts can promote the selective production of hydrogen from plastic feedstocks. Further studies on process optimization cost-effective catalyst design and mechanism investigation are needed.

This paper investigated the opportunities and challenges of integrating ports into hydrogen (H2 ) supply chains in the context of Australia and Japan because they are leading countries in the field and are potential leaders in the upcoming large-scale H2 trade. Qualitative interviews were conducted in the two countries to identify opportunities for H2 ports necessary infrastructure and facilities key factors for operations and challenges associated with the ports’ development followed by an online survey investigating the readiness levels of H2 export and import ports. The findings reveal that there are significant opportunities for both countries’ H2 ports and their respective regions which encompass business transition processes and decarbonisation. However the ports face challenges in areas including infrastructure training standards and social licence and the sufficiency and readiness levels of port infrastructure and other critical factors are low. Recommendations were proposed to address the challenges and barriers encountered by H2 ports. To optimise logistics operations within H2 ports and facilitate effective integration of H2 applications this paper developed a user-oriented working process framework to provide guidance to ports seeking to engage in the H2 economy. Its findings and recommendations contribute to filling the existing knowledge gap pertaining to H2 ports.

Hydrogen is viewed as a potential energy solution for the 21st century with capabilities to tackle issues relating to environmental emissions sustainability energy shortages and security. Even though there are potential benefits of renewable hydrogen towards transitioning to net-zero emissions there is a limited study on the current use ongoing development and future directions of renewable hydrogen in Australia. Thus this study conducts a systematic review of studies for exploring Australia’s renewable hydrogen energy transition current trends strategies developments and future directions. By using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines earlier studies from 2005 to 2024 from two major databases such as ProQuest and Web of Science are gathered and analyzed. The study highlights significant issues relating to hydrogen energy technologies and opportunities/challenges in production storage distribution utilization and environmental impacts. The study found that Australia’s ambition for a strong hydrogen economy is made apparent with its clear strategic actions to develop a clean technology-based hydrogen production storage and distribution system. This study provides several practical insights on Australia’s hydrogen energy transition hydrogen energy technologies investments and innovation as well as strategies/recommendations for achieving a more environment friendly secure affordable and sustainable energy future.

An integrated renewable system that utilizes solid waste-based biogas is important steps towards the sustainable energy solutions to rural off-grid communities in Bangladesh. In this study a hybrid energy system consisting of photovoltaic modules wind turbines biogas generators fuel cells and electrolyzer-hydrogen tank-based energy storage is optimized using non-dominated sorting genetic algorithm (NSGA-II). The hybrid system is optimized based on the cost of energy and human health damage as objective functions and a fuzzy decision-making technique is employed to determine the optimal solution to the multi-objective approach. Additionally several economic ecological and social indicators are also investigated while meeting a certain load reliability. An energy management strategy has been developed in the MATALB environment to satisfy the community load and the battery-driven electric vehicle load. Results from this comprehensive analysis suggest that the optimal configuration of PV/WT/FC/BG has an energy cost of 0.1634 $/kWh and an ecosystem damage of 0.00098 species.year. The human health damage and the human development index of the optimized system are 0.1732 DALYs and 0.696 DALYs respectively. Additionally the proposed system has a lifecycle emission of 123730 kg CO2-eq/year carbon emission penalties of $1856/year a job creation potential of 30 jobs/MW over the 25 years of project lifetime. The hybrid system oversees solid waste management solutions and provides the community with sustainable energy and vehicle recharge.

Hydrogen embrittlement (HE) is a major concern when steel pipelines are used for hydrogen transportation and storage. The weldments of steel pipelines are of particular concern because they are reported to have higher HE susceptibility compare to the base metal. In this work targeted heat treatments were used to manipulate the microstructure in a pipeline steel weldment to examine the effects of different microstructural features on HE susceptibility. Complementary analyses of the microstructure mechanical testing and fracture surface identified inclusions and ferrite morphology as the most dominant microstructural features that affect the susceptibility to HE. Specimens with different microstructures but sharing similar Ti-rich inclusions exhibited significant re ductions in elongation to failure after hydrogen charging and showed brittle fracture surfaces decorated with multiple ‘fish-eye’ features. In addition co-existence of bainitic microstructure with Ti-rich inclusions resulted in the highest susceptibility to HE.

The transition to a sustainable future with hydrogen as a key energy carrier necessitates a comprehensive understanding of the safety aspects of hydrogen including liquid hydrogen (LH₂). Hence this study presents a detailed computational fluid mechanics analysis to explore accidental LH₂ leakage and dispersion in a hydrogen refuelling station under varied conditions which is essential to prevent fire and explosion. The correlated impact of influential parameters including wind direction wind velocity leak direction and leak rate were analysed. The study shows that hydrogen dispersion is significantly impacted by the combined effect of wind direction and surrounding structures. Additionally the leak rate and leak direction have a significant effect on the development of the flammable cloud volume (FCV) which is critical for estimating the explosion hazards. Increasing wind velocity from 2 to 4 m/s at a constant leak rate of 0.06 kg/s results in an 82% reduction in FCV. The minimum FCV occurs when leak and wind directions oppose at 4 m/s. The most critical situation concerning FCV arises when the leak and wind directions are perpendicular with a leak rate of 0.06 kg/s and a wind velocity of 2 m/s. These findings can aid in the development of optimised sensing and monitoring systems and operational strategies to reduce the risk of catastrophic fire and explosion consequences.

Renewable or green hydrogen will play a critical role in the decarbonisation of hard-to-abate sectors and will therefore be important in limiting global warming. However renewable hydrogen is not cost-competitive with fossil fuels due to the moderate energy efficiency and high capital costs of traditional water electrolysers. Here a unique concept of water electrolysis is introduced wherein water is supplied to hydrogen- and oxygen-evolving electrodes via capillary-induced transport along a porous inter-electrode separator leading to inherently bubble-free operation at the electrodes. An alkaline capillary-fed electrolysis cell of this type demonstrates water electrolysis performance exceeding commercial electrolysis cells with a cell voltage at 0.5 A cm−2 and 85 °C of only 1.51 V equating to 98% energy efficiency with an energy consumption of 40.4 kWh/kg hydrogen (vs. ~47.5 kWh/kg in commercial electrolysis cells). High energy efficiency combined with the promise of a simplified balance-ofplant brings cost-competitive renewable hydrogen closer to reality.

The use of alternative fuels is a primary means for decarbonising the maritime industry. Liquefied natural gas (LNG) liquid hydrogen (LH2) and liquid ammonia (LNH3) are liquified gases among the alternative fuels. The safety risks associated with these fuels differ from traditional fuels. In addition to their low-temperature hazards the flammability of LNG and LH2 and the high toxicity of LNH3 present challenges in fuel handlings due to their high likelihood of fuel release during bunkering. This study aims at drawing extensive comparisons of the evaporation and vapour dispersion behaviours for the three fuels after release accidents during bunkering and discuss their safety issues. The study involved the release event of the three fuels on the main deck area of a reference bulk carrier with a deadweight of 208000 tonnes. Two release scenarios were considered: Scenario 1 involved a release of 0.3 m3 of fuel and Scenario 2 involved a release of 100 kg of fuel. An empirical equation was used to calculate the fuel evaporation process and the Computational Fluid Dynamic (CFD) code FDS was employed to simulate the dispersion of vapour clouds. The obtained results reveal that LH2 has the highest evaporation rate followed by LNG and LNH3. The vapour clouds of LNG and LNH3 spread along the main deck surface while the LH2 vapour cloud exhibits upward dispersion. The flammable vapour clouds of LNG and LH2 remain within the main deck area whereas the toxic gas cloud of LNH3 disperses towards the shore and spreads near the ground on the shore side. Based on the dispersion behaviours the hazards of LNG and LH2 are com parable while LNH3 poses significantly higher hazards. In terms of hazard mitigations effective water curtain systems can suppress the vapour dispersion.

Ammonia is a promising hydrogen carrier for enabling the efficient transport of hydrogen as observed by the many hydrogen transport projects using ammonia. For the clean energy future understanding environmental impacts of the transport system is important. This study conducts life cycle assessment (LCA) for the marine transport of renewable hydrogen using ammonia as the hydrogen carrier. The LCA considered renewable hydrogen produced from four systems; wind-powered electrolysis gasification of forest residue anaerobic digestion of food waste and landfill gas reforming; followed by Haber-Bosch ammonia synthesis using the renewable hydrogen and nitrogen produced from air separation. The ammonia was then transported 11000 km by sea to a destination facility where it was decomposed using either Ru or Ni catalysts to obtain hydrogen. Among the four hydrogen transport systems operated with renewable energy electrolysis-hydrogen system presented the highest global warming impact of 3.31 kg CO2 eq/kg H2 due to electricity use for the electrolysis whereas simpler processes based on a landfill gas system led to the lowest impact of 2.27 kg CO2 eq/kg H2. Process energy consumption was the major contributor to global warming impact with 27%–49.2% of contri bution. The consumption of metals and energy during wind turbine construction resulted in the most significant impact in six out of 12 midpoint impact categories for the electrolysis-hydrogen system which also led to the highest endpoint impacts. The endpoint impacts of the four systems were in the order of electrolysis > food waste > forest residue > landfill gas (from high to low) for both endpoint human health and ecosystems impacts. Ammonia decomposition using Ru catalysts exhibited slightly lower global warming impact than Ni catalysts while final purification of hydrogen by vanadium membrane presented 4.8% lower impacts than the purification by pressure swing adsorption. Large-scale hydrogen supply chains can be achieved by technological improve ment and support of policies and financial schemes.