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All Journal International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis
Kivevele, Thomas
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Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering

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Electrical power output potential of different solar photovoltaic systems in Tanzania Warburg, Christopher Thomas; Pogrebnaya, Tatiana; Kivevele, Thomas
International Journal of Renewable Energy Development Vol 13, No 4 (2024): July 2024
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2024.58972

Abstract

This study examines the photovoltaic (PV) energy output and levelized cost of energy (LCOE) in seven regions of Tanzania across five different tilt adjustments of 1 MW PV systems. The one-diode model equations and the PVsyst 7.2 software were used in the simulation. The results reveal variations in energy output and LCOE among the regions and tilt adjustments indicating a strong correlation between PV energy output and solar irradiance incident on the PV panel. For horizontal mounting, the annual energy output ranges from 1229 MWh/year in Kilimanjaro to 1977 MWh/year in Iringa. Among the three optimal tilt adjustments, annually, monthly and seasonal, the last two are predicted to yield larger energy outputs, whereas the two axis tracking configuration consistently provides the maximal energy output in all regions, ranging from 1533 MWh/year in Kilimanjaro to 2762 MWh/year in Iringa. The LCOE analysis demonstrates the cost-effectiveness of solar PV systems compared to grid-connected and isolated mini-grid tariffs. The LCOE values across the regions and tilt adjustments range from $0.07/kWh to $0.16/kWh. In comparison, the tariff for grid-connected solar PV is $0.165/kWh, while for isolated mini-grids; it is $0.181/kWh. The monthly optimal tilt configuration proves to be the most cost-effective option for energy generation in multiple regions, as it consistently exhibits the lowest energy cost compared to the other four configurations. The results provide valuable insights into the performance and economic feasibility of various system setups. Through meticulous simulation and data analysis, we have gained a comprehensive understanding of the factors influencing energy generation and costs in the context of solar photovoltaic systems.
Textural Properties and Surface Chemistry of Rice Husk–Derived Biochar and Bio-silica Supports in Ni-Catalyzed Oleic Acid Deoxygenation Mahene, Wilson Leonidas; Machunda, Revocatus Lazaro; Buckman, Tom A.; Salifu, Ali Azeko; Kivevele, Thomas
Bulletin of Chemical Reaction Engineering & Catalysis 2026: Just Accepted Manuscript and Article In Press 2026
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20690

Abstract

Rice husk (RH), an abundant agricultural residue, is a promising precursor for the production of carbon- and silica-based catalyst supports for upgrading lipid feedstocks. Previous studies have shown that RH-derived biochar and biosilica can serve as effective catalyst supports in reactions involving relatively small molecules; however, their application in the deoxygenation of lipid-derived molecules remains largely unexplored. In this study, RH was converted into three distinct supports, desilicated biochar (RH-C), KOH-activated desilicated biochar (RH-AC), and biosilica (RH-SiO₂), which were systematically compared as supports for Ni catalysts in the solvent-free deoxygenation of oleic acid. The supports and catalysts were characterized by BET, TEM, XRD, XPS, and TGA. Ni/RH-AC exhibited the highest surface area (809.8 m2 g-1) but lower mesopore volume than Ni-RH-C, while Ni/RH-SiO2 showed moderate surface area and minimal microporosity. XPS revealed minimal electronic perturbation of Ni supported on biochar, whereas biosilica induced electron withdrawal. All catalysts predominantly followed the decarboxylation/decarbonylation (deCOx) pathway, although Ni/RH-SiO2 also exhibited noticeable hydrodeoxygenation (HDO). Ni/RH-C achieved the highest conversion (96%), while Ni/RH-AC and Ni/RH-SiO2 achieved 76% and 72%, respectively. TGA/DSC analysis showed greater carbonaceous material deposition on Ni/RH-AC than on Ni/RH-C, with Ni/RH-SiO2 exhibiting the lowest coking. These findings reveal a clear structure-property-performance relationship, revealing that desilicated rice-husk biochar provides higher catalytic activity, whereas biosilica offers greater stability and lower susceptibility to coking. Moreover, excessive chemical activation after desilication appears unnecessary and may even be detrimental.
Co-Authors Buckman, Tom A. Budi Waluyo Machunda, Revocatus Lazaro Mahene, Wilson Leonidas Muji Setiyo Pirouzfar, Vahid Pogrebnaya, Tatiana Raja, Thirunavukkarasu Salifu, Ali Azeko Warburg, Christopher Thomas