South Africa

This paper reports on an experimental evaluation of the hydrogen separation performance in a proton exchange membrane system with Pt-Co/C as the anode electrocatalyst. The recovery of hydrogen from H2/CO2 H2/CH4 and H2/NH3 gas mixtures were determined in the temperature range of 100–160 ◦C. The effects of both the impurity concentration and cell temperature on the separation performance of the cell and membrane were further examined. The electrochemical properties and performance of the cell were determined by means of polarization curves limiting current density open-circuit voltage hydrogen permeability hydrogen selectivity hydrogen purity and cell efficiencies (current voltage and power efficiencies) as performance parameters. High purity hydrogen (>99.9%) was obtained from a low purity feed (20% H2 ) after hydrogen was separated from H2/CH4 mixtures. Hydrogen purities of 98–99.5% and 96–99.5% were achieved for 10% and 50% CO2 in the feed respectively. Moreover the use of proton exchange membranes for electrochemical hydrogen separation was unsuccessful in separating hydrogen-rich streams containing NH3 ; the membrane underwent irreversible damage.

This paper performs a technoeconomic comparison of two hybrid renewable energy supplies (HRES) for a specific location in Ghana and suggests the optimal solution in terms of cost energy generation capacity and emissions. (e two HRES considered in this paper were wind/hydrogen/fuel-cell and wind/battery storage respectively. (e necessity of this study was derived from the rise and expansion of hybrid renewable energy supply in a decentralised network. (e readiness to embrace these new technologies is apparently high but the best combination for a selected location that brings optimum benefits is not obvious and demands serious technical knowledge of their technical and economic models. In the methodology an analytical model of energy generation by the various RE sources was first established and data were collected about a rural-urban community in Doderkope Ghana to test the models. HOMER software was used to design the two hybrid systems based on the same load profiles and results were compared. It turns out that the HRES 1 (wind/hydrogen/fuel-cell) had the lowest net present cost (NPC) and levelized cost of electricity (COE) over the project life span of 25 years. (e energy reserve with the HRES 2 (wind/battery storage) was huge compared to that with the HRES 1 about 270% bigger. Furthermore with respect to the emissions the HRES 2 was environmentally friendlier than the HRES 1. Even though the battery storage seems to be more cost-effective than the hydrogen fuel cell technology the latter presents some merits regarding system capacity and emission that deserve greater attention as the world looks into more sustainable energy storage systems.

Hydrogen is a crucial energy carrier for the Clean Energy Sustainable Development Goals and the just transition to low/zero-carbon energy. As a top CO2-emitting country hydrogen (especially green hydrogen) production in South Africa has gained momentum due to the availability of resources such as solar energy land wind energy platinum group metals (as catalysts for electrolysers) and water. However the demand for green hydrogen in South Africa is insignificant which implies that the majority of the production must be exported. Despite the positive developments there are unclear matters such as dependence on the national electricity grid for green hydrogen production and the cost of transporting it to Asian and European markets. Hence this study aims to explore opportunities for economic expansion for sustainable production transportation storage and utilisation of green hydrogen produced in South Africa. This paper uses a thematic literature review methodology. The key findings are that the available renewable energy sources incentivizing the green economy carbon taxation and increasing the demand for green hydrogen in South Africa and Africa could decrease the cost of hydrogen from 3.54 to 1.40 €/kgH2 and thus stimulate its production usage and export. The appeal of green hydrogen lies in diversifying products to green hydrogen as an energy carrier clean electricity synthetic fuels green ammonia and methanol green fertilizers and green steel production with the principal purpose of significant energy decarbonisation and economic and foreign earnings. These findings are expected to drive the African hydrogen revolution in agreement with the AU 2063 agenda.

An equilibrium-based steady-state simulator model that predicts and optimizes hydrogen production from steam gasification ofbiomass is developed using ASPEN Plus software and artificial intelligence techniques. Corn cob’s chemical composition wascharacterized to ensure the biomass used as a gasifier and with potential for production of hydrogen. Artificial intelligence is usedto examine the effects of the significant input variables on response variables such as hydrogen mole fraction and hydrogen energycontent. Optimizing the steam-gasification process using response surface methodology (RSM) considering a variety of biomass-steam ratios was carried out to achieve the best results. Hydrogen yield and the impact of main operating parameters wereconsidered. A maximum hydrogen concentration is found in the gasifier and water-gas shift (WGS) reactor at the highest steam-to-biomass (S/B) ratio and the lowest WGS reaction temperature while the gasification temperature has an optimum value. ANFISwas used to predict hydrogen of mole fraction 0.5045 with the input parameters of S/B ratio of 2.449 and reactor pressure andtemperature of 1 bar and 848°C respectively. With the steam-gasification model operating at temperature (850°C) pressure (1 bar)and S/B ratio of 2.0 an ASPEN simulator achieved a maximum of 0.5862 mole fraction of hydrogen while RSM gave an increaseof 19.0% optimum hydrogen produced over the ANFIS prediction with the input parameters of S/B ratio of 1.053 and reactorpressure and temperature of 1 bar and 850°C respectively. Varying the gasifier temperature and S/B ratio have on the other handa crucial effect on the gasification process with artificial intelligence as a unique tool for process evaluation prediction andoptimization to increase a significant impact on the products especially hydrogen.

The depletion and overuse of fossil fuels present formidable challenge to energy supply system and environment. The human society is in great need of clean renewable and sustainable energy which can guarantee the long-term utilization without leading to escalation of greenhouse effect. Hydrogen as an extraordinary secondary energy is capable of realizing the target of environmental protection and transferring the intermittent primary energy to the application terminal while its nature of low volumetric energy density and volatility need suitable storage method and proper carrier. In this context liquid organic hydrogen carrier (LOHC) among a series of storage methods such as compressed and liquefied hydrogen provokes a considerable amount of research interest since it is proven to be a suitable carrier for hydrogen with safety and stability. However the dehydrogenation of hydrogen-rich LOHC materials is an endothermic process and needs large energy consumption which hampers the scale up of the LOHC system. The heat issue is thus essential to be addressed for fulfilling the potential of LOHC. In this work several strategies of heat intensification and management for LOHC system including the microwave irradiation circulation of exhaust heat and direct LOHC fuel cell are summarized and analyzed to provide suggestions and directions for future research.

The power and transport sectors are responsible for significant emissions of greenhouse gases. Therefore it is imperative that substantial efforts are directed towards the decarbonisation of these industries. This study establishes a combined-solar-wind system's economic and technical practicality for producing hydrogen for an onsite hydrogen refuelling station (HRS) and electricity to meet peak demand. To minimise the levelised cost of electricity and maximise the system's reliability at different commercial locations in South Africa the dual-objective optimisation sizing is carried out using Mixed Integer Quadratic Constrained Programming (MICQP) model and was executed with an Advanced Multi-dimensional Modelling System (AIMMS) [61] [62]. The levelised costs of electricity and hydrogen at Johannesburg Pretoria and Cape Town for 2 MW grid export benchmark are 74.2 $/MWh/5.85 $/kg 76.3 $/MWh/5.97 $/kg and 50 $/MWh/4.45 $/kg respectively. The CO₂ equivalent emissions (tonnes) are 54000 55800 59000 and the corresponding carbon taxes ($) avoided for the locations are 432100 446200 and 472000 for Johannesburg Pretoria and Cape Town respectively. The results of the framework show that it can be adopted as a viable and fossil-free replacement for conventional peaking generators.

The Middle East and North Africa region has not played a major role in climate action so far and several countries depend economically on fossil fuel exports. However this is a region with vast solar energy resources which can be exploited affordably for power generation and hydrogen production at scale to eventually reach carbon neutrality. In this paper we elaborate on the case of the United Arab Emirates and explore the aspirations and feasibility of its net-zero by 2050 target. While we affirm the concept per se we also highlight the technological complexity and economic dimensions that accompany such transformation. We expect the UAE’s electricity demand to triple between today and 2050 and the annual green hydrogen production is expected to reach 3.5 Mt accounting for over 40% of the electricity consumption. Green hydrogen will provide power-to-fuel solutions for aviation maritime transport and hard-to-abate industries. At the same time electrification will intensify—most importantly in road transport and low-temperature heat demands. The UAE can meet its future electricity demands primarily with solar power followed by natural gas power plants with carbon capture utilization and storage while the role of nuclear power in the long term is unclear at this stage.

Fuel cells have become a fundamental technology in the development of clean energy systems playing a vital role in the global shift toward a low-carbon future. With the growing need for sustainable hydrogen production perfluoro sulfonic acid (PFSA) ionomer membranes play a critical role in optimizing green hydrogen technologies and fuel cells. This study aims to investigate the effects of different environmental and solvent treatments on the chemical and physical properties of Nafion N−115 membranes to evaluate their suitability for both hydrogen production in proton exchange membrane (PEM) electrolyzers and hydrogen utilization in fuel cells supporting integrated applications in the local and global green hydrogen economy. To achieve this Nafion N−115 membranes were partially dissolved in various solvent mixtures including ethanol/isopropanol (EI) isopropanol/water (IW) dimethylformamide/N-methyl-2-pyrrolidone (DN) and ethanol/methanol/isopropanol (EMI) evaluated under water immersion and thermal stress and characterized for chemical stability mechanical strength water uptake and proton conductivity using advanced electrochemical and spectroscopic techniques. The results demonstrated that the EMI-treated membrane showed the highest proton conductivity and maintained its structural integrity making it the most promising for hydrogen electrolysis applications. Conversely the DN-treated membrane exhibited reduced stability and lower conductivity due to solvent-induced degradation. This study highlights the potential of EMI as an optimal solvent mixture for enhancing PFSA membranes performance in green hydrogen production contributing to the advancement of sustainable energy solutions.

The increasing global wastewater generation and reliance on fossil fuels for energy production necessitate sustainable treatment and energy recovery solutions. This study explores supercritical water gasification (SCWG) of sewage sludge from municipal wastewater as a hydrogen production pathway focusing on the role of alkali catalysts (KOH K₂CO₃ Na₂CO₃). The effects of temperature (450–550◦C) reaction time (5–30 min) and catalyst type on gas yield and efficiency were analyzed. At 550◦C the highest carbon efficiency (61 %) gas efficiency (69 %) and hydrogen yield (41 mol/kg) were observed. After 30 min the gas composition reached H₂ (58 %) CO₂ (26 %) CH₄ (11.7 %) and CO (4 %). Among catalysts Na₂CO₃ exhibited superior H₂ yield (29 mol/kg) carbon efficiency (58 %) and gas efficiency (51 %). This study highlights SCWG as a viable technology for hydrogen-rich gas production contributing to sustainable energy solutions and wastewater valorization.

The hydrogen economy stands at the forefront of the global energy transition and additive manufacturing (AM) is increasingly recognized as a critical enabler of this transformation. AM offers unique capabilities for improving the performance and durability of hydrogen energy components through rapid prototyping topology optimization functional integration of cooling channels and the fabrication of intricate hierarchical structured pores with precisely controlled connectivity. These features facilitate efficient heat and mass transfer thereby improving hydrogen production storage and utilization efficiency. Furthermore AM’s multi-material and functionally graded printing capability holds promise for producing components with tailored properties to mitigate hydrogen embrittlement significantly extending operational lifespan. Collectively these advances suggest that AM could lower manufacturing costs for hydrogen-related systems while improving performance and reliability. However the current literature provides limited evidence on the integrated techno-economic advantages of AM in hydrogen applications posing a significant barrier to large-scale industrial adoption. At present the technological readiness level (TRL) of AM-based hydrogen components is estimated to be 4–5 reflecting laboratory-scale progress but underscoring the need for further development validation and industrial-scale demonstration before commercialization can be realized.