http://197.159.135.214/jspui/handle/123456789/1107 Tue, 16 Jun 2026 09:43:20 GMT 2026-06-16T09:43:20Z http://197.159.135.214/jspui/handle/123456789/1210 Title: Life Cycle Assessment of Electricity Production from Anaerobic Digestion of Municipal Solid Waste in Ghana: A Case Study of Atwima Nwabiagya Municipality Authors: Baidoo, Theophilus Abstract: Ghana relies heavily on fossil fuels for energy generation. This dependence on fossil fuels not only burdens the economy but also prevents the exploitation of the country’s indigenous renewable energy resources. Anaerobic digestion (AD) is one of the promising waste-to-energy technologies that has great potential for generating clean energy while solving waste management problems in Ghana. A life cycle assessment (LCA) is needed to understand the overall environmental impact of waste-to-energy technologies and to implement future alternatives sustainably. This study applied an LCA to assess the inventory results of a hybrid waste-to-energy plant in the Atwima Nwabiagya Municipality in Ghana and its impact on the environment, including greenhouse gas emissions and energy generation. The study revealed that the anaerobic digestion plant will generate 805,574 kWh/year of electricity, equivalent to 352,589 Nm3/year of biogas, from 8,615 tons of municipal solid waste. The life cycle inventory further indicated that greenhouse gas emissions, including CH4 (3,786.8 kg), NOx (1,614.48 kg), and N2O (12.79 kg), are produced, which contribute to the overall carbon footprint. Environmental benefits were observed in 10 out of 11 impact categories in the CML-IA baseline method, except for abiotic depletion, which recorded an environmental burden. Contribution analysis revealed that the transport of waste to the plant site was the highest contributor to the environmental impact of the anaerobic digestion system. Scenario analysis suggested that replacing solar PV electricity with Ghana's electricity production mix (2018) leads to a substantial reduction in the abiotic depletion category (-99.61%) but results in increased burdens, notably in acidification (725%). The uncertainty analysis showed that data reliability and temporal correlation play significant roles in quantifying uncertainty The study concluded that anaerobic digestion is a viable waste-to-energy technology in Ghana that can reduce greenhouse gas emissions and generate renewable energy, but further improvements are needed to optimize its environmental performance and reduce its resource consumption. Description: thesis submitted to the Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi in partial fulfillment of the requirements for the degree of Master of Philosophy in Chemical Engineering Fri, 01 Sep 2023 00:00:00 GMT http://197.159.135.214/jspui/handle/123456789/1210 2023-09-01T00:00:00Z http://197.159.135.214/jspui/handle/123456789/1209 Title: Optimization of Solid Fuel Production by Co-Hydrothermal Carbonization of Polyvinyl Chloride and Pontederia Crassipes Authors: Asare, Solomon Abstract: The chlorine content of Polyvinyl chloride (PVC) in municipal waste creates a major challenge in its disposal. Water hyacinth (WH), an invasive plant, disrupts aquatic life and impedes the movement of vessels on water bodies that they colonize. These two materials, PVC and WH however have high caloric value making them suitable to be used as a source of fuel. Hydrothermal carbonization (HTC), a method for producing solid fuel has been identified as a safe medium to remove chlorine from PVC. In this work, PVC, and WH were subjected to Co-HTC using water as the solvent. Response Surface Methodology (RSM) was used to optimize the hydrochar produced by varying the temperatures, residence time, and mixing ratios. 5 g of the feedstock was subjected to Co-HTC at temperatures 200 ℃, 230 ℃, and 260 ℃; residence time of 60 minutes, 90 minutes, and 120 minutes; and mixing ratio of PVC/WH 1:1 to 1:3. The result showed that increasing the temperature and resident time increased the dechlorination efficiency (DE) of the PVC with the highest DE at 94.3%. The mixing ratio had a minimal effect on the output variables. Increasing temperatures and residence time reduced the mass yield of hydrochar but increased their corresponding High Heating Values (HHV). The highest hydrochar yield, 70.33%, occurred at 200 ℃, the highest DE of 94.39% occurred at 260 ℃, and the highest HHV, 32.34 MJ/Kg occurred at 260 ℃. FTIR microscopy, TGA analysers, and Van Krevelen diagrams were used in analysing the thermal properties of the fuel produced. The optimal conditions predicted from the data using the RSM are temperature, 230 ℃, residence time, 86 minutes, and mixing ratio of 0.33. These parameters were used for the confirmation and validation and the HHV obtained was 27.32 MJ/Kg. The HHV is close to that of coal, implying that hydrochar produced from PVC and WH feedstocks can be a good source of fuel for domestic and industrial usage. Description: A thesis submitted to The Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, Kumasi in partial fulfilment of the requirement for the degree of Master of Philosophy in Bioenegineering Sat, 01 Jul 2023 00:00:00 GMT http://197.159.135.214/jspui/handle/123456789/1209 2023-07-01T00:00:00Z http://197.159.135.214/jspui/handle/123456789/1208 Title: Synthesis and characterization of nanocrystalline Zeolite Socony Mobil-5 using some Ghanaian clays as the starting raw materials By Benjamin Kwadzo Kokloku (B. Authors: Kokloku, Benjamin Kwadzo Abstract: Zeolites are aluminosilicate crystals having a porous structure and are useful as catalysts, adsorbents, and ion exchange materials. The synthesis of zeolites using clay minerals is a promising approach because it utilizes inexpensive and widely available starting materials. However, clays originate from different sources and the parameters of synthesis vary depending on the environment and nature of the clay. Therefore, the process requires suitable pre-treatment of the raw clay and the optimization of the synthesis parameters to ensure that the synthesized zeolite has the desired properties. In this work, a protocol to be used in the synthesis of ZSM-5 zeolite using Anfoega, Mfensi, Teleku-Bokazo, and Tetebu clays was developed. These clays serve as silica and alumina sources. The raw clays were first calcined, followed by acid leaching to dealuminate the calcined samples to increase the SiO2/Al2O3 molar ratio while removing impurities, and finally hydrothermal zeolitization. From the results obtained, acquiring the ZSM-5 phase in the final product depended greatly on the pre-treatment technique applied to the raw clay. ZSM-5 zeolite was effectively synthesized from all four clay sources at a crystallization temperature and crystallization period of 190 °C and 24 h, respectively. The relative crystallinity and crystallite sizes of the ZSM-5 phase were calculated to be 41.23% and 36.08 nm, 32.02% and 35.53 nm, 35.37% and 34.75 nm, and 54.43% and 29.74 nm for Anfoega, Mfensi, Teleku-Bokazo, and Tetegu clays respectively. The synthesis conditions of the ZSM-5 zeolite using Tetegu clay were further investigated in more detail and the parameters were optimized. Hence, for the Tetegu clay, the effects of key synthesis parameters, i.e., temperature, time, aging conditions, and reactant molar ratios were investigated. The optimal production conditions of nano-crystallite ZSM-5 zeolite using the Tetegu clay were found to be a molar ratio of SiO2/Al2O3 = 51.97, NaOH/SiO2 = 0.032, TPABr/SiO2 = 0.072, H2O/SiO2 = 25; crystallization temperature = 190 °C; crystallization time = 24 h, with aging at room temperature (without stirring) for 24 h. This study has established the viability of clay samples obtained from Anfoega, Mfensi, Teleku-Bokazo, and Tetegu as starting materials for the production of ZSM-5 zeolite, and the appropriate optimal production conditions were established for Tetegu clay. Description: A thesis submitted to the Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi-Ghana, in partial fulfillment of the requirements for the award of the degree of Master of Philosophy in Chemistry Wed, 01 Nov 2023 00:00:00 GMT http://197.159.135.214/jspui/handle/123456789/1208 2023-11-01T00:00:00Z http://197.159.135.214/jspui/handle/123456789/1207 Title: Effect of Steam Explosion Pretreatment on the Pyrolysis Properties of Pineapple (Ananas Comosus) Crown Waste Authors: Sackey, Augustine Junior Abstract: The use of biomass as a substitute for fossil fuel has gained attention due to its renewability and availability. Biomass can be converted into fossil fuel equivalents through processes such as gasification, pyrolysis or hydrothermal liquefaction. However, before conversion into valuable fuel forms, several pre-treatment activities are carried out to make biomass amenable to the conversion process. One such pre-treatment approach is steam explosion where biomass components are broken down by high-pressure saturated steam. Pineapple crown waste is a typical biomass source that requires attention regarding disposal. During harvesting and processing activities, a lot of waste is generated from peels to crowns which may end up in landfills or burnt in the open. This can contribute to environmental problems and thus, exploitation of this waste's valuable uses is imperative. Therefore, this study seeks to determine the effect of steam explosion pre-treatment on thermal decomposition behaviour during the pyrolysis of pineapple crown waste. Three pre-treatment pressures of 6 bar, 8 bar and 10 bar were used for the process in a reactor. Each pre-treatment pressure had residence times varied at 5 min,10 min, and 15 min. Compositional analysis revealed the potential of pineapple crown waste biomass as a valuable resource for thermochemical applications. After the steam explosion pre-treatment, the pyrolysis study was done through thermogravimetric analysis (TGA) at a heating rate of 20 ˚C min-1. TGA curves and derivative thermogravimetry (DTG) curves showed the decomposition pattern of the pineapple crown waste biomass components. Thermal degradation of the pineapple crown waste happened in four different stages. Moisture was released in the early stage, followed by the degradation of weak cellulose and hemicelluloses in the second stage. The third stage is where cellulose mainly decomposes and pyrolysis primarily occurs to produce bio-oil and gas. The final stage decomposed the remaining biomass components which were not degraded during the previous stages, forming char. Lignin is mostly degraded at this stage. Pronounced peaks were observed for each pre-treatment pressure at 15 min residence time. Calculation of kinetic parameters according to the Coats and Redfern model depicted an increase in frequency factor and a slight significant decrease in activation energy, especially for pre-treatment pressure at 10 bar. This shows that the thermal reactivity of the pineapple crown waste was improved with steam explosion pre-treatment. Also, higher pressure and increased residence time during pre-treatment contributed to the better decomposition of pineapple crown biomass during pyrolysis, and thus yield good products for biofuel utilization. Description: The Federal Ministry of Research, Technology and Space (BMFTR) Sun, 01 Jan 2023 00:00:00 GMT http://197.159.135.214/jspui/handle/123456789/1207 2023-01-01T00:00:00Z