32 research outputs found
Development of a Waste Plastic-to-Fuel Conversion System for Sustainable Energy Generation in Urban Nigeria
No full textPlastic waste pollution has emerged as a critical environmental and public health concern in Nigeria’s rapidly urbanising regions, where improper disposal and inefficient waste management systems persist. In parallel, the country faces acute energy insecurity, largely driven by erratic diesel supply and rising fossil fuel costs. This study presents the design, optimisation, and techno-environmental evaluation of a decentralised pyrolysis-based conversion system for transforming plastic waste into liquid fuel. Polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polystyrene (PS) were thermally degraded at controlled temperatures between 350°C and 500°C under inert conditions. Experimental trials revealed that oil yield increased with temperature, peaking at 450°C for all polymers. PP demonstrated the highest yield (65.1%) followed by PS (63.0%), HDPE (62.5%), and LDPE (60.4%). Fuel characterisation showed calorific values of up to 42.7 MJ/kg and physicochemical properties within acceptable diesel standards. Emissions analysis using flue gas monitoring confirmed low outputs of CO, NOx, and SO₂, all within Euro VI regulatory limits. Energy efficiency was highest for PP-derived fuel at 71.4%. Techno-economic modelling, based on a 10-year operational horizon, produced a net present value of ₦11.8 million, an internal rate of return of 28.4%, and a break-even fuel price of ₦290/litre. Statistical modelling further validated temperature and polymer type as primary determinants of yield performance. The findings demonstrate that decentralised plastic pyrolysis systems can simultaneously address urban waste accumulation, reduce environmental emissions, and provide affordable alternative fuels, making them suitable for integration into Nigeria’s circular economy and energy access strategies
Design and Fabrication of a Modular Mini-Hydro Turbine for Off-Grid Electrification in Nigeria’s Riverine Communities
No full textThis research presents the design, simulation, fabrication, and performance evaluation of a modular crossflow mini-hydro turbine engineered to address persistent energy access challenges in Nigeria’s off-grid riverine communities. The system was conceived to operate efficiently under low-head, variable-flow conditions typical of inland watercourses, using a fully modular design framework that emphasises ease of deployment, maintenance, and scalability. Computational fluid dynamics (CFD) was employed during the design phase to optimise internal flow characteristics, nozzle geometry, and runner-blade profiles. The turbine achieved a hydraulic efficiency of 62% to 68% and produced a consistent power output of 300–340 W per module across a range of flow conditions. Empirical testing validated the CFD predictions with deviations remaining under 7%, confirming the design’s reliability. Environmental assessments revealed noise and vibration levels well within rural acceptability thresholds, and casing integrity was preserved under continuous operational testing. A key innovation of the system lies in its modular configuration. All primary components—including the shaft-runner assembly, generator unit, and control interface—were designed to be independently replaceable using basic tools. Scalability tests confirmed that dual-module operation retained 92% efficiency, demonstrating the viability of phased expansion in community-scale installations. The turbine aligns with national electrification objectives and offers a replicable, context-sensitive solution for rural electrification in sub-Saharan Africa. The study contributes a practical and scalable model for clean energy deployment, advancing the case for modular micro-hydro systems as critical infrastructure in remote and underserved regions
Computational Fluid Dynamics (CFD) Modeling for Bio-Inspired Aerodynamic Optimization in Autonomous Drones
No full textThis study explores the aerodynamic benefits of bio-inspired design modifications for autonomous drones using advanced Computational Fluid Dynamics (CFD) simulations. Four bio-inspired configurations—leading-edge serrations, winglets, riblet surfaces, and curved wings—were assessed and compared against a baseline drone model to evaluate their impact on aerodynamic performance. The results indicated that all bio-inspired designs significantly enhanced lift, reduced drag, and improved overall aerodynamic efficiency. The leading-edge serration configuration achieved the highest performance gains, with a 33.6% increase in maximum lift coefficient (CL) and a 29.5% improvement in lift-to-drag ratio (CL/CD), primarily due to delayed flow separation and reduced turbulence. Winglets minimized wingtip vortices, leading to an 18.3% reduction in drag coefficient (CD) and improved lift efficiency. Riblet surfaces moderately decreased drag by streamlining boundary layer flow, while the curved wing design enhanced stability and manoeuvrability at high angles of incidence. These findings demonstrate the potential of bio-inspired designs to optimize drone performance, extending their operational range and adaptability across varying flight conditions. The study provides valuable insights for development of next-generation UAVs, offering a pathway to improved energy efficiency, flight stability, and versatility in diverse operational environments
Development and Characterization of Advanced Recycled Hybrid Metal Matrix Composites via Enhanced Stir Squeeze Casting Method for Industrial Applications
No full textThis study presents the development and characterization of advanced recycled hybrid metal matrix composites (HMMCs) using an optimized stir squeeze casting technique. The hybrid composites were fabricated using recycled aluminum alloy (AA6061), ceramic particles, and carbon fibers. The optimization of critical process parameters such as stirring speed, casting temperature, and squeeze pressure resulted in composites with superior mechanical and physical properties. Comprehensive testing revealed that the HMMCs exhibited a 20% increase in tensile strength, a 30% improvement in hardness, and a 15% enhancement in impact resistance compared to conventional metal matrix composites (MMCs). Additionally, the composites demonstrated a 10% improvement in thermal conductivity, making them suitable for applications requiring efficient heat dissipation. The successful incorporation of recycled materials not only promoted sustainability but also reduced production costs. The findings underscore the potential of these hybrid composites for high-performance applications in automotive, aerospace, and thermal management industries. Future research should explore the use of other recycled materials and further optimization of casting parameters to enhance composite performance
Life Cycle Assessment of Sustainable Building Materials in the Nigerian Construction Industry
No full textThis study presented a comprehensive life cycle assessment (LCA) of sustainable building materials within the Nigerian construction industry, focusing on bamboo, recycled steel, and low-carbon concrete. The research aimed to evaluate the environmental impacts of these materials across all stages of their life cycles, from raw material extraction to end-of-life disposal. A mixed-methods approach was employed, with primary data gathered through interviews and surveys with industry professionals, while secondary data was obtained from reputable databases and literature. The results indicated that bamboo was the most environmentally friendly material, exhibiting the lowest global warming potential, ozone depletion, eutrophication, and resource depletion impacts. Low-carbon concrete also demonstrated significant environmental benefits, particularly in reducing greenhouse gas emissions compared to conventional concrete. Recycled steel, while advantageous in promoting the circular economy, incurred higher energy consumption and emissions due to the energy-intensive recycling process. The study identified several barriers to the widespread adoption of sustainable materials in Nigeria, including high initial costs, limited availability, and a lack of regulatory support. To address these challenges, the research suggested strengthening regulatory frameworks, providing financial incentives, enhancing local production capabilities, and increasing awareness through education and training programs. The findings underscored the potential of sustainable materials to reduce the environmental footprint of construction activities in Nigeria, highlighting the need for coordinated efforts to promote their adoption. This study contributed valuable insights to policymakers, industry stakeholders, and researchers focused on advancing sustainability in the built environment
Development of an abrasive material using periwinkle shells
No full textAbstractIn this study, abrasive properties of periwinkle shell grains with the binding effect of polyester resin on periwinkle shell grains at high concentration were investigated. The abrasive properties considered are hardness, compressive strength and wear resistance. Periwinkle shells were processed into FEPA grit standards by ball milling and then sieved using ASTM E11 set of sieves into grain sizes of P40, P60 and P140 grits. Further on, the grits were developed into polymer matrix composite with particles varying from 95wt.% to 87wt.% and resin 4wt.% to 12wt.% with 0.5wt.% each of cobalt naphthalene and methyl ethyl ketone peroxide hardener by mixing and mold compression in a hydraulic press. It was found that hardness and compressive strength increased, wear rate decreased with an increase in polyester resin content. The composition with most improved abrasive properties was 87wt.% periwinkle shell grains to 12wt.% polyester resin. Scanning Electron Microscope (SEM) surface morphology of the composite microstructure revealed this composition to possess good interfacial bonding between particles of PWS and polyester resin, PWS grains to retain a defined shape and grain orientation with less distortion from compressive stresses and less grain pull-out effect from wear
Evaluation of the wear and thermal properties of asbestos free brake pad using periwinkles shell particles
No full textThe use of asbestos fiber is being avoided due to its carcinogenic nature that might cause health risks. A new brake pad produced using periwinkles shell particles to replace asbestos and thermoset resin as a binder was investigated. The periwinkles shell particles were varied from 710-125 µm. The surface morphology, wear test and thermal analysis of the samples were examined. The results showed that there was good interfacial bonding as the particle size of periwinkles shell decreased from 710-125 µm. The wear rate increased as the load and periwinkles particles size increased. The co-efficient of friction obtained was within the recommended standard for automobile brake pad. The temperature of maximal decomposition of periwinkle shell was higher than asbestos and many agro-wastes currently used in the production of brake pad materials. It means that periwinkle shell can withstand higher temperature than asbestos. The results of this research indicated that periwinkles shell particles can be effectively used as a substitute for asbestos in brake pad manufacture
Performance Evaluation of Unglazed Tiles Produced from Locally Developed Tile Making Machine
No full textA tile making machine (TMM) was designed and fabricated (see Plate IV), varieties of tiles in different sizes and thickness were extruded and certain properties of the tiles were also tested. This is in order to determine and certify the functional reliability of the machine and it’s products when compared with similar machines earlier in operation. A body of ball (Bomo) clay and kaolin (kankara) clay in equal percentage of 50% was used for the tile extruded. Empirical method was employed to prepare the tile materials beginning with locating, identifying and charting of local deposits, exploration, procurement, transportation, beneficiation, compounding/mixing of ceramic materials, aging, production with the prepared recipes, drying and firing which mark the final stage. Tensile, hardness and impact resistance tests were carried out on the tiles produced with the TMM and two ready-made glazed China tiles in the market. The produced tiles results on the tensile test were (20mm = 1311.06 N/ mm2, 15mm = 951.78 N/ mm2 and 10mm = 741.47 N/ mm2); hardness test: (20mm = 40.2 HRF, 15mm = 29.7 HRF and 10mm = 18.7 HRF); and impact test: (20mm = 5.5J, 15mm = 2.13J and 10mm = 0.63J). The two results compared showed significant relationship in the parameters measured. Even though tiles produced from the TMM machine were not glazed but they met the standard parameters for unglazed tiles as obtained in literatures. From the parameters measured and the results obtained these tiles suitably match with the klinker tiles used as floor tiles and for other hard lining surfaces. Keywords: Test, Performance, Efficiency, Standard, Unglazed, Mechanica
Evaluating the influence of green building certifications on construction practices in Nigeria: a systematic review / Hyginus Unegbu ... [et al.]
No full textThis research explores the impact of green building certifications—specifically LEED, EDGE, and BREEAM—on construction practices in Nigeria. Through a detailed review of literature published between 2015 and 2023, the study examines the rate of adoption of these certifications, the resulting changes in construction practices, and the associated economic and environmental outcomes. The findings show that while the uptake of green building certifications is gradually increasing, it remains significantly lower than global standards. Certified buildings in Nigeria have demonstrated marked improvements in energy efficiency, water conservation, and waste management, contributing to both environmental sustainability and reduced operational costs. However, several barriers continue to hinder broader adoption, including the high initial investment required for green construction, a lack of adequately trained professionals, and insufficient government policies and incentives to support sustainable building practices. The study highlights the need for enhanced regulatory frameworks that mandate minimum sustainability standards, along with financial incentives such as subsidies and tax breaks to offset the initial costs. Additionally, raising public awareness through education and outreach initiatives is vital for increasing demand for certified buildings. The research further underscores the importance of fostering local industries for sustainable building materials and the critical role of professional training programs in closing the skills gap. Future research should explore the long-term economic benefits of green buildings, investigate the specific barriers impeding their adoption, and conduct comparative studies with other developing nations to provide insights into overcoming these challenges. This study offers key recommendations for policymakers, developers, and industry professionals seeking to promote green building practices in Nigeria, contributing to the global sustainability agenda
Development of an abrasive material using periwinkle shells
No full textIn this study, abrasive properties of periwinkle shell grains with the binding effect of polyester resin on periwinkle shell grains at high concentration were investigated. The abrasive properties considered are hardness, compressive strength and wear resistance. Periwinkle shells were processed into FEPA grit standards by ball milling and then sieved using ASTM E11 set of sieves into grain sizes of P40, P60 and P140 grits. Further on, the grits were developed into polymer matrix composite with particles varying from 95 wt.% to 87 wt.% and resin 4 wt.% to 12 wt.% with 0.5 wt.% each of cobalt naphthalene and methyl ethyl ketone peroxide hardener by mixing and mold compression in a hydraulic press. It was found that hardness and compressive strength increased, wear rate decreased with an increase in polyester resin content. The composition with most improved abrasive properties was 87 wt.% periwinkle shell grains to 12 wt.% polyester resin. Scanning Electron Microscope (SEM) surface morphology of the composite microstructure revealed this composition to possess good interfacial bonding between particles of PWS and polyester resin, PWS grains to retain a defined shape and grain orientation with less distortion from compressive stresses and less grain pull-out effect from wear
