Publications

Presented is an evaluation of the carbon footprint and costs associated with hydrogen production via the aluminum-water reaction (AWR) identifying an optimized scenario that achieves 1.45 kgCO2 equiv per kg of hydrogen produced. U.S.-based data are used to compare results with conventional production methods and to assess hydrogen use in fuel-cell passenger vehicles. In the optimized scenario major contributors include the use of recycled aluminum (0.38 kgCO2 equiv) aluminum processing (0.45 kgCO2 equiv) and alloy activator recovery (0.57 kgCO2 equiv). A cost analysis estimates hydrogen production at $9.2/kg when using scrap aluminum alloy recovery and recycling thermal energy aligning with current green hydrogen prices. Reselling reaction byproducts such as boehmite could generate revenue 5.6 times greater than input costs enhancing economic feasibility. The cradle-to-grave assessment suggests that aluminum fuel as an energy carrier for hydrogen distribution and fuel cell vehicle applications offers a low-emission and economically viable pathway for clean energy deployment.

Clean hydrogen is expected to play a crucial role in the future decarbonized energy mix. This places the gasification of biomass as a critical conversion pathway for hydrogen production owing to its carbon neutrality. However there is limited research on the direction of the body of literature on this subject matter. Utilising the Bibliometrix package R this paper conducts a systematic review and bibliometric analysis of the literature on gasification-derived hydrogen production over the previous three decades. The results show a decade-wise spike in hydrogen research mostly contributed by China the United States and Europe whereas the scientific contribution of Africa on the topic is limited with less than 6% of the continent’s research output on the subject matter sponsored by African institutions. The current trend of the research is geared towards alignment with the Paris Agreement through feedstock diversification to include renewable sources such as biomass and municipal solid waste and decarbonising the gasification process through carbon-capture technologies. This review reveals a gap in the experimental evaluation of heterogenous organic municipal solid waste for hydrogen production through gasification within the African context. The study provides an incentive for policy actors and researchers to advance the green hydrogen economy in Africa.

This work studies the feasibility of integrating a hydrogen-powered propulsion system in a regional aircraft at the conceptual design level. The developed system consists of fuel cells which will be studied at three technological levels and batteries also studied for four hybridization factors (X = 0 0.05 0.10 0.20). Hydrogen can absorb great thermal loads since it is stored in the tank at cryogenic temperatures and is used as fuel in the fuel cells at around 80 ◦C. Taking advantage of this characteristic two thermal management system (TMS) architectures were developed to ensure the proper functioning of the aircraft during the designated mission: A1 which includes a vapor compression system (VCS) and A2 which omits it for a simpler design. The models were developed in MATLAB® and consist of different components and technologies commonly used in such systems. The analysis reveals that A2 due to the exclusion of the VCS outperformed A1 in weight (10–23% reduction) energy consumption and drag. A1’s TMS required significantly more energy due to the VCS compressor. Hybridization with batteries increased system weight substantially (up to 37% in A2) and had a greater impact on energy consumption in A2 due to additional fan work. Hydrogen’s heat sink capacity remained underutilized and the hydrogen tank was deemed suitable for a non-integral fuselage design. A2 had the lowest emissions (10–20% lower than A1 for X = 0) but hybridization negated these benefits significantly increasing emissions in pessimistic scenarios.

Water electrolysis for hydrogen production has garnered significant attention in the context of increasing global energy demands and the “dual-carbon” strategy. However practical implementation is hindered by challenges such as high overpotentials high catalysts costs and insufficient catalytic activity. In this study three mono and bimetallic metal−organic framework (MOFs)-derived electrocatalysts Fe-MOFs Fe/Co-MOFs and Fe/Mn-MOFs were synthesized via a one-step hydrothermal method using nitroterephthalic acid (NO2-BDC) as the ligand and NN-dimethylacetamide (DMA) as the solvent. Electrochemical tests demonstrated that the Fe/Mn-MOFs catalyst exhibited superior performance achieving an overpotential of 232.8 mV and a Tafel slope of 59.6 mV·dec−1 alongside the largest electrochemical active surface area (ECSA). In contrast Fe/Co-MOFs displayed moderate catalytic activity while Fe-MOFs exhibited the lowest efficiency. Stability tests revealed that Fe/Mn-MOFs retained 92.3% of its initial current density after 50 h of continuous operation highlighting its excellent durability for the oxygen evolution reaction (OER). These findings emphasize the enhanced catalytic performance of bimetallic MOFs compared to monometallic counterparts and provide valuable insights for the development of high-efficiency MOF-based electrocatalysts for sustainable hydrogen production.

Underground Hydrogen Storage (UHS) in depleted oil and gas reservoirs could provide a cost-effective solution to balance seasonal fluctuations in renewable energy generation. However data and knowledge on UHS at subsurface conditions are limited so it is difficult to estimate how effective this type of storage could be. In this study we perform high pressure experiment to measure the effectiveness of cyclic hydrogen (H2) storage in a specimen of Temblor sandstone retrieved from the San Joaquin Basin of California. Our experiment mimics reservoir pressure conditions to measure H2-brine relative permeability and fluid-rock interactions over the course of ten charging and discharging cycles. Initial gas breakthrough occurred at 15 % to 25 % H2 saturation in the specimen with 3 % NaCl brine as the resident fluid. Continuing injecting to 4 pore volumes (PV) of H2 yielded an asymptotic H2 saturation of 38 % to 41 % a level often referred to as the irreducible gas saturation based on two-phase flow. The boundary condition in this study mimics the near wellbore region which experiences bidirectional H2 flow. This bi-directional flow led to evaporative drying of the specimen resulting in 94 % H2 saturation at the end of 10th cycle. This indicates that cyclic flow and evaporative drying can lead to more efficient reservoir storage where a larger fraction of the reservoir porosity is usable to store H2. The produced gas stream consisted of H2 mixed with 8 % to 22 % H2O indicating formation dry-out by evaporation. Meanwhile produced water chemistry indicated calcite and silicate dissolution with calcite sourced from fossil fragments. This led to a loss of cementation and weakened the rock sample. Combined our results indicate dry-out compaction increased H2 saturation rock weakening and permeability loss during cyclic UHS. Overall we anticipate that the combined effects should lead to higher than anticipated UHS storage efficiency per volume of sandstone reservoir rock.

Sweden with its abundant access to low-cost fossil-free electricity is well-positioned to become a significant hydrogen exporter. This study presents a techno-economic analysis of different hydrogen carriers—compressed hydrogen methanol ammonia and liquid organic hydrogen carriers (LOHC)—for export applications. Using the Northern Green Crane Project as a reference for scale the analysis focuses on cost optimization for hydrogen production storage and transportation. A linear programming model is developed to optimize capacities and operational strategies for each carrier ensuring a fair basis for comparison. Results indicate that LOHC and ammonia are competitive with compressed hydrogen showing particular promise for larger-scale long-distance deliveries. These findings offer valuable insights for policymakers and industry stakeholders developing Sweden’s hydrogen export strategies.

This study focuses on arguably the most contentious choice of energy supply option available for decarbonizing general-purpose long-haul road freight: hydrogen. For operators infrastructure providers energy providers and vehicle manufacturers to make the investments necessary to enable this transition it is essential to evaluate the feasibility of individual energy supply choices. A literature review is conducted identifying ten requirements for an energy supply choice to be feasible which are then translated into “what would need to be true” conditions for hydrogen to meet these requirements. Considering these evidence from literature is used to assess the likelihood of each condition becoming true within the lifespan of a vehicle bought today. It is concluded that it is unlikely that hydrogen will become feasible in this time frame meaning it can be disregarded as a current vehicle purchase consideration as it will not undermine the competitiveness or resale value of a vehicle using a different energy source bought today. There are two principal innovations in the study approach: the consideration of socio-technical and political as well as techno-economic factors; and the application of realist retroductive option assessment. While not necessary to address the research question regarding hydrogen a realist retroductive assessment is also presented for other prominent low carbon energy source options: battery electric electric road systems (ERS) and biofuels; and the conditions under which these options could be feasible are considered.

Hydrogen is widely considered advantageous for long-duration storage applications however the conditions under which hydrogen outperforms batteries remain unclear. This study employs a novel load parameterisation approach to systematically examine the conditions under which integrating hydrogen significantly reduces the levelised cost of energy (LCOE). The study analyses a broad spectrum of 210 synthetic load profiles varying independently in duration frequency and timing at two Australian locations. This reveals that batteries dominate short frequent or wellaligned solar loads and that hydrogen becomes economically beneficial during prolonged infrequent or poorly aligned loads—achieving up to 122 % (Gladstone) and 97 % (Geelong) LCOE improvements under current fuel cell costs and even higher savings under reduced costs. This systematic method clarifies the load characteristics thresholds that define hydrogen’s advantage providing generalisable insights beyond individual case studies.

Green hydrogen is critical for achieving net-zero emissions with water electrolysis offering a CO2-free solution. This study provides a comprehensive comparative financial and economic assessment of a hybrid PV/wind hydrogen production system using three types of electrolysers including Alkaline Electrolyser (AEL) Proton Exchange Membrane Electrolyser (PEMEL) and Solid Oxide Electrolyser (SOEL). Key performance metrics such as net present value (NPV) Internal Rate of Return (IRR) revenues Earnings Before Interest Tax Depreciation and Amortization (EBITDA) Earning Before Taxes (EBT) Debt Service Coverage Ratio (DSCR) and levelized cost of Hydrogen (LCOH) are evaluated to identify the most cost-effective option. The findings reveal that AEL is the most economical solution achieving a higher NPV (503374 k€) and IRR (16.94 % for project IRR) though PEMEL and SOEL remain competitive. Other metrics such as DSCR show that the hydrogen project generates 30 % more cash flow than is required to cover its debt service. Additionally the results of the LCOH analysis demonstrate that a hybrid plant consisting of 10 % PV and 90 % wind is more cost-effective in the studied region than both solar-based or wind-based hydrogen production plants. AEL and PEMEL are approximately 7–6 €/kg less expensive than SOEL but this gap is expected to be narrowed by 2030. The hybrid renewable energy project reduces CO2 emissions by 6786.6 Mt over its lifetime. These findings guide policymakers and investors toward scalable cost-effective green hydrogen deployment emphasizing the synergy of hybrid renewables and mature electrolysis technologies.

This study examines the economic and regulatory implications of the development of Germany’s hydrogen core network. Using a mathematical-economic model of the amortization account and a reproduction of the network topology based on the German transmission system operators’ draft proposals the analysis evaluates the impact of delaying the network expansion with completion postponed from 2032 to 2037. The proposed phased approach prioritizes geographically clustered regions and ensures sufficient demand alignment during each expansion stage. The results demonstrate that strategic adjustments to the network size and timing significantly enhance cost-efficiency. In the initially reduced and delayed scenario uncapped network tariffs remain below €15/ kWh/h/a suggesting that under specific conditions the amortization account may become redundant while maintaining supply security and supporting the market ramp-up of hydrogen. These findings highlight the potential for demand-driven phased hydrogen infrastructure development to reduce financial burdens and foster a sustainable transition to a hydrogen-based energy system.