http://197.159.135.214/jspui/handle/123456789/10 2026-04-04T09:16:53Z 2026-04-04T09:16:53Z Woenagnon, Komlan Djiwonou http://197.159.135.214/jspui/handle/123456789/1104 2026-03-05T14:32:37Z 2025-09-29T00:00:00Z

Simulation of Biohydrogen Production by Sequential Dark-Photo Fermentation of Pineapple Waste Woenagnon, Komlan Djiwonou Biomass from agro-industrial waste represents a sustainable resource for bioenergy production. JUS DELICE, a pineapple processing factory in Togo generates large streams of waste but relies solely on composting as waste valorization pathway. As a result, the energy potential of the generated waste is still unexplored. On the other hand, Aspen Plus is a software widely used for the simulation of thermochemical processes. However, the software rooted in thermochemical processes is very limited in the simulation of biochemical processes due to the lack of built-in models for microbial kinetics, metabolic conversions, and inhibition effects. This study investigated biohydrogen production using pineapple peels collected from JUS DELICE through three valorization pathways: dark fermentation, photo fermentation and the integrated sequential process. The peels were characterized through ultimate analysis, proximate analysis and fiber content and the data from characterization was used in Aspen Plus to simulate biohydrogen production under mesophilic conditions. The results revealed a good potential of pineapple peels for biohydrogen production with very high volatile solid content of 94.99% and high carbohydrates content on dry matter basis. It was also found that the integrated sequential process significantly improved the conversion process with a cumulative biohydrogen yield of 798.7 𝑚𝑙/𝑔𝑉𝑆 and a heating value conversion efficiency of 54.36%. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use, the Université de Lomé, Togo, and the Universität Rostock in partial fulfillment of the requirements for the International Master Program in Renewable Energy and Green Hydrogen (Bioenergy/Biofuels & Green Hydrogen Technology)

2025-09-29T00:00:00Z Aviansou, Romance Gloire http://197.159.135.214/jspui/handle/123456789/1103 2026-03-05T14:25:43Z 2025-09-29T00:00:00Z

alorization of Okara (Soy pulp) and yam peels for bioenergy: effect of anaerobic co-digestion on biogas generation efficiency Aviansou, Romance Gloire In West Africa, reliance on firewood for cooking contributes to deforestation and household air pollution, while agro-industrial residues such as Okara and yam peels are often discarded, creating environmental challenges. Valorizing these wastes through anaerobic digestion (AD) offers a suitable alternative, though mono-digestion of Okara is often unstable and can lead to low biogas yield. Therefore, the objective of the present study is to evaluate the biogas potential of co-digesting Okara with local lignocellulosic wastes such as yam peels. Batch experiments were conducted under mesophilic conditions with three mixing ratios (Okara:yam peels 1:3, 1:1, and 3:1) at substrate-to-inoculum (S/I) ratios of 0.5 and 0.6. The environmental implications of the best performing ratio were then compared to landfilling using the ReCiPe 2016 Midpoint (H) method in OpenLCA software, while biogas combustion impacts were contrasted with firewood use. Credits from firewood substitution and digestate fertilizer displacement were also considered in the net assessment. Results confirmed the suitability of both substrates for AD due to their high volatile solids and organic matter content. Mono-digestion yielded 610.58 mL/g VS for Okara and 468.82 mL/g VS for yam peels. The co-digestion tests produced between 609.10 to 661.00 mL/g VS, with the highest yield performed at the 3:1 mix ratio. The findings highlight synergistic effects between nitrogen-rich Okara and carbon-rich yam peels. The environmental assessment revealed that landfilling 1 kg of Okara and yam peels generated high burdens, particularly climate change (0.55 kg/CO2-Eq) and terrestrial acidification, while AD significantly reduced impacts. Replacing firewood with biogas further reduced emissions harmful to human health and terrestrial ecosystems. Overall, AD reduces impacts and became impact-avoiding when accounting for avoided burdens. Economically, the system proved viable, with a benefit-cost ratio of 1.64 and a payback period of 3.20 years. These findings support anaerobic co-digestion as a sustainable valorization route for local bio-wastes in West Africa, offering simultaneously energy recovery, environmental improvements, and economic benefits. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use, the Université de Lomé, Togo, and the Universität Rostock in partial fulfillment of the requirements for the International Master Program in Renewable Energy and Green Hydrogen (Bioenergy/Biofuels & Green Hydrogen Technology)

2025-09-29T00:00:00Z Sarr, Ndeye Ngoné http://197.159.135.214/jspui/handle/123456789/1102 2026-03-05T14:20:31Z 2025-09-30T00:00:00Z

Agro-Forestry and Agri-Pv Technologies using Bamboo, Sunflowerand Indian Mustard to Regenerate Nature in Post-Mining Areasassociated with Aspen Plus Simulation of Hydrogen Production Sarr, Ndeye Ngoné The management of soil contaminated with heavy metals, especially that ofabandoned mining sites, represents a major challenge for environmentalprotection. Among the possible solutions, phytoremediation offers promisingprospects for post-mining restoration. However, this option is limited by the needfor long-term monitoring and the considerable potential of inedible biomass. Thisstudy aimed to combine agroforestry and Agri-PV systems to regeneratedegraded land while producing green hydrogen from solar energy andbiohydrogen from harvested biomass. To achieve this, a one-hectare copper mining site in Zambia was divided into twoplots: one for agroforestry and the other for Agri-PV. Moreover, three plants,sunflower, Indian mustard and bamboo, were theoretically evaluated for theirphytoextraction and phytostabilisation efficiency. Thereby, Aspen Plus was usedto simulate the production of green hydrogen by alkaline water electrolysis fromsurplus electricity from the Agri-PV system, after meeting irrigation needs. Inaddition, biohydrogen production was modelled with the same software frombiomass harvested at the contaminated site, using downflow gasification withenhanced tar and char cracking. The results revealed that sunflower is the most suitable for phytoextraction,thanks to its high translocation of metals to the aerial parts (TF > 1). On theother hand, mustard and bamboo showed better phytostabilisation capacity, withgreater accumulation in the roots. Bamboo stood out for its high efficiency inabsorbing and removing heavy metals. After one season, all metals were reducedto acceptable levels, except for copper and cobalt, which would require anadditional two and nine years, respectively, to be completely remediated. Energysimulations yielded 7,923.3 kg of green H2/year and 284.3 kg of bio H2/year, for atotal of 8,207.5 kg of H2/year for the two systems combined. The theoretical model designed for the restoration of abandoned mining sitesshows particular promise for the ecological rehabilitation of soils contaminatedwith heavy metals. However, experimental validation remains an essential stepin confirming its effectiveness and demonstrating its practical relevance, pavingthe way for its actual application in the field. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use, the Université de Lomé, Togo, and the Universität Rostock in partial fulfillment of the requirements for the International Master Program in Renewable Energy and Green Hydrogen (Bioenergy/Biofuels & Green Hydrogen Technology)

2025-09-30T00:00:00Z Roufaï Elhadji Mamane, Nana Tamamatou http://197.159.135.214/jspui/handle/123456789/1101 2026-03-05T13:53:51Z 2025-09-30T00:00:00Z

Economic Evaluation of Green Hydrogen Production, Storage, and Export from Niger to Europe Roufaï Elhadji Mamane, Nana Tamamatou This thesis investigates the economic viability of producing, storing, and exporting green hydrogen from Niger to Europe, addressing a notable gap in existing research. Niger has abundant solar energy potential, substantial agricultural waste, and proximity to Europe; however, it is not currently involved in any global hydrogen projects. The study uses a techno-economic evaluation approach, combining resource assessment, cost modeling, and logistics analysis. It explores three hydrogen production methods: biomass gasification, dark fermentation, and solar steam methane reforming (SSMR), which uses methane derived from slaughterhouse blood. Techno-economic modeling shows that the levelized cost of hydrogen (LCOH) from biomass pathways is between 2.5 and 5.1 USD/kg. However, solar-assisted SSMR can get lower values when the irradiation conditions are good and exceed 2,000 kWh/m²/year. Levelized cost of storage (LCOS) analysis compares various storage options, such as compressed gaseous hydrogen and liquefied hydrogen. Compressed hydrogen is a suitable choice for storage in small to medium-sized applications, while liquefied hydrogen is better suited for long-distance exports at $5.98/kg. The export route is evaluated through retrofitted oil pipelines to Europe at $ 0.85/ton/km. Findings show that Niger's solar and agricultural waste resources make hydrogen production competitive. Dark fermentation offers a decentralized option, gasification provides scalability, and SSMR proves efficient when paired with solar power. Retrofitted pipelines emerge as the most cost-effective long-term export solution. Overall, results indicate Niger could become a new hydrogen supplier, aiding Europe in achieving renewable energy goals, boosting local industry growth, increasing energy access, and strengthening the economy. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use, the Université de Lomé, Togo, and the Universität Rostock in partial fulfillment of the requirements for the International Master Program in Renewable Energy and Green Hydrogen (Bioenergy/Biofuels & Green Hydrogen Technology)

2025-09-30T00:00:00Z