Chemical, mineralogical and morphological investigation of coal fly ash obtained from Mpumalanga Province, South Africa
- Authors: Alegbe, John , Ayanda, Olushola Sunday , Ndungu, Patrick , Alexander, Nechaev , Fatoba, Ojo Olanrewaju , Petrik, Leslie Felicia
- Date: 2018
- Subjects: Coal fly ash , Physicochemical properties , Thermal power plant
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/271555 , uj:28884 , Citation: Alegbe, J., Ayanda, O.S., Ndungu, P., Alexander, N., Fatoba, O.O. & Petrik, L.F. 2018. Chemical, mineralogical and morphological investigation of coal fly ash obtained from Mpumalanga Province, South Africa. Research Journal of Environmental Sciences, 12: 98-105. DOI: 10.3923/rjes.2018.98.105 , ISSN: 1819-3412
- Description: Abstract: Background and Objective: Coal fly ash generated from the combustion of coal by thermal power plant stations are enormous and the disposal there of is a big problem. In the present study, the chemical, mineralogical and morphological characterization of coal fly ash samples (CFAs) obtained from Mpumalanga province, South Africa were investigated. Materials and Methods: The CFAs were characterised by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), high resolution transmission electron spectroscopy (HRTEM) and the selected area electron diffraction (SAED) analytical technique. Result: Experimental results showed that the CFAs contain hematite, magnetite, calcite, lime, mullite and quartz. The CFAs are polycrystalline, could be categorized as class F fly ash and the particles are spherical in shape. Conclusion: The phase characterization suggested that CFA could be used for the synthesis of nanoparticles, as well as extraction of valuable metals, more so, the elemental composition of the CFAs suggested that the storage and disposal of CFAs could lead to the release of salts and toxic elements into the environment, thereby, contaminating surface and ground waters.
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Geospatial investigation of physico-chemical properties and thermodynamic parameters of biomass residue for energy generation
- Authors: Olatunji, Obafemi O. , Akinlabi, Stephen , Madushele, Nkosinathi , Adedeji, Paul A. , Ndolomingo, Matumuene J.
- Date: 2020
- Subjects: Corn cob , Geospatial investigation , Physicochemical properties
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/436538 , uj:37870
- Description: Abstract: , Biomass represents vast under-explored feedstock for energy generation across the globe. Among other factors, the location from where the feedstock is harvested may affect the overall properties and the efficiency of bioreactors used in the conversion process. Herein is reported some physicochemical properties, the kinetic study and thermodynamic analysis of corn cob sourced from two major economies in sub-Sahara African region. Brunauer Emmett and Teller (BET) analysis was performed to investigate the surface characteristics of corn cob while Fourier Transform Infrared Spectroscopy (FTIR) revealed the corresponding functional group present in the selected biomass residue. The proximate and CHNSO analyses were performed using the standard equipment and following the standard procedures, then the result is reported and compared based on the geographical locations under consideration. Also, the thermal decomposition study was carried out at different heating rate (10, 15, 30 Cmin-1) in inert atmosphere while the kinetic parameters were evaluated based on Flynn–Wall–Ozawa (FWO), and Kissinger–Akahira–Sunose (KAS) methods The Analysis of variance (ANOVA) showed that there is a statistically significant difference between ultimate constituents, the fixed carbon, and volatile matter obtained from the two countries at 95% confidence level. FTIR showed different spectra peak in both samples which means there are varying quantity of structural elements in each feedstock. The pore surface area (1.375 m²/g ) obtained for corncob from South Africa (SC25) was greater than the value (1.074 m²/g ) obtained for Nigeria (NC25). From the result, the highest value of activation energy, (Ea =190.1 kJmol-1 and 189.9 kJmol-1) was estimated for SC25 based on KAS and FWO methods respectively. The result showed that geographical location may somewhat affect some energetic properties of biomass and further provides useful information about thermodynamic and kinetic parameters which could be deployed in the simulation, optimization and scale-up of the bioreactors for pyrolysis process.
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