Browsing by Author "Mukelabai, Mulako Dean"
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Item Open Access Hydrogen technology adoption analysis in Africa using a Doughnut-PESTLE hydrogen model (DPHM)(Elsevier, 2022-09-14) Mukelabai, Mulako Dean; Wijayantha, Upul K. G.; Blanchard, Richard E.The hydrogen economy requires the right conditions to produce hydrogen by sustainable routes and provide it to local and international markets for suitable applications. This study evaluated the political, economic, social, technological, legal, and environmental (PESTLE) conditions that can be instrumental in adopting hydrogen technologies most effectively by encapsulating aspects relevant to key stakeholders from hydrogen technology developers through to end-users. For instance, the analysis has shown that countries within a government effectiveness index of 0.5 and −0.5 are leading the planning of hydrogen economies through strategic cooperation with hydrogen technology developers. Furthermore, the combination of a Doughnut and PESTLE analysis created a novel approach to assessing the adoption of hydrogen technologies while evaluating the impact of the hydrogen economy. For instance, the estimated ammonia demand in 2050 and subsequent anthropogenic nitrogen extraction rate will be about two and a half times more than the 2009 extraction rate.Item Open Access A novel integration of a green power-to-ammonia to power system: reversible solid oxide fuel cell for hydrogen and power production coupled with an ammonia synthesis unit(Elsevier, 2021-03-31) Mukelabai, Mulako Dean; Gillard, Jonathon M.; Patchigolla, KumarRenewable energy is a key solution in maintaining global warming below 2 °C. However, its intermittency necessitates the need for energy conversion technologies to meet demand when there are insufficient renewable energy resources. This study aims to tackle these challenges by thermo-electrochemical modelling and simulation of a reversible solid oxide fuel cell (RSOFC) and integration with the Haber Bosch process. The novelty of the proposed system is usage of nitrogen-rich fuel electrode exhaust gas for ammonia synthesis during fuel cell mode, which is usually combusted to prevent release of highly flammable hydrogen into the environment. RSOFC round-trip efficiencies of 41–53% have been attained when producing excess ammonia (144 kg NH3/hr) for the market and in-house consumption respectively. The designed system has the lowest reported ammonia electricity consumption of 6.4–8.21 kWh/kg NH3, power-to-hydrogen, power-to-ammonia, and power-generation efficiencies of 80%, 55–71% and, 64–66%.Item Open Access Renewable hydrogen economy outlook in Africa(Elsevier, 2022-06-28) Mukelabai, Mulako Dean; Wijayantha, Upul K. G.; Blanchard, Richard E.Hydrogen presents an opportunity for Africa to not only decarbonise its own energy use and enable clean energy access for all, but also to export renewable energy. This paper developed a framework for assessing renewable resources for hydrogen production and provides a new critical analysis as to how and what role hydrogen can play in the complex African energy landscape. The regional solar, wind, CSP, and bio hydrogen potential ranges from 366 to 1311 Gt/year, 162 to 1782 Gt/year, 463 to 2738 Gt/year, and 0.03 to 0.06 Gt/year respectively. The water availability and sensitivity results showed that the water shortages in some countries can be abated by importing water from regions with high renewable water resources. A techno-economic comparative analysis indicated that a high voltage direct current (HVDC) system presents the most cost-effective transportation system with overall costs per kg hydrogen of 0.038 $/kg, followed by water pipeline with 0.084 $/kg, seawater desalination 0.1 $/kg, liquified hydrogen tank truck 0.12 $/kg, compressed hydrogen pipeline 0.16 $/kg, liquefied ammonia pipeline 0.38 $/kg, liquefied ammonia tank truck 0.60 $/kg, and compressed hydrogen tank truck with 0.77 $/kg. The results quantified the significance of economies of scale due to cost effectiveness of systems such as compressed hydrogen pipeline and liquefied hydrogen tank truck systems when hydrogen production is scaled up. Decentralization is favorable under some constraints, e.g., compressed hydrogen and liquefied ammonia tank truck systems will be more cost effective below 800 km and 1400 km due to lower investment and operation costs.